[Federal Register Volume 66, Number 220 (Wednesday, November 14, 2001)]
[Rules and Regulations]
[Pages 57298-57340]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-28506]



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Part V





Department of Energy





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10 CFR Parts 960 and 963



Office of Civilian Radioactive Waste Management; General Guidelines for 
the Recommnedation of Sites for Nuclear Waste Repositories; Yucca 
Mountain Site Suitability Guidelines; Final Rule

  Federal Register / Vol. 66, No. 220 / Wednesday, November 14, 2001 / 
Rules and Regulations  

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DEPARTMENT OF ENERGY

10 CFR Parts 960 and 963

[Docket No. RW-RM-99-963]
RIN 1901-AA72


Office of Civilian Radioactive Waste Management; General 
Guidelines for the Recommendation of Sites for Nuclear Waste 
Repositories; Yucca Mountain Site Suitability Guidelines

AGENCY: Office of Civilian Radioactive Waste Management, Department of 
Energy (DOE).

ACTION: Final rule.

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SUMMARY: DOE hereby amends the policies under the Nuclear Waste Policy 
Act of 1982 for evaluating the suitability of Yucca Mountain, Nevada, 
as a site for development of a nuclear waste repository. Today's final 
rule focuses on the criteria and methodology to be used for evaluating 
relevant geological and other related aspects of the Yucca Mountain 
site. Consistent with longstanding policy to conform DOE suitability 
guidelines for its nuclear waste repository program to corresponding 
regulations of the Nuclear Regulatory Commission, DOE's criteria and 
methodology are based on the Nuclear Regulatory Commission's recently 
final regulations for licensing a nuclear waste repository at Yucca 
Mountain.

EFFECTIVE DATE: December 14, 2001.

FOR FURTHER INFORMATION CONTACT: Dr. William J. Boyle, U.S. Department 
of Energy, Office of Civilian Radioactive Waste Management, Yucca 
Mountain Site Characterization Office, P.O. Box 364629, North Las 
Vegas, Nevada 89036-8629.

SUPPLEMENTARY INFORMATION:

I. Introduction
II. Background
    A. Enactment of the Nuclear Waste Policy Act of 1982
    1. Development of the Nuclear Waste Policy Act
    2. Overview of the Nuclear Waste Policy Act
    B. DOE Promulgation of the General Guidelines at 10 CFR Part 960
    1. Overview of the General Guidelines
    2. Structure of the General Guidelines
    3. Bases for the Structure of the General Guidelines
    4. Consistency with NRC Technical and Procedural Conditions
    C. DOE Application of the Guidelines
    D. 1987 Amendments to NWPA
    E. Yucca Mountain Site Characterization Plan
    1. Statutory Requirements
    2. Structure of the Site Characterization Plan
    F. Energy Policy Act of 1992
    G. Evolution of the Site Characterization Program
    H. The 1993-1995 Public Dialogue on the Guidelines
    I. The 1996 Notice of Proposed Rulemaking
    J. Proposed NRC Regulation, 10 CFR Part 63
    1. Background
    2. Structure of Proposed Part 63
    K. Proposed EPA Regulation, 40 CFR Part 197
    1. Background
    2. Structure of Proposed Part 197
    L. DOE's 1999 Notice of Proposed Rulemaking
    M. Final EPA and NRC Regulations
    N. NRC Concurrence
III. Basis for Final Rule
    A. Legal Authority and Necessity to Amend the Guidelines and 
Criteria
    1. Overview
    2. Section 112
    3. Section 113
    B. Events Necessitating Amendment of the Guidelines and Criteria
    1. Congressional Redirection of the Program
    2. Consistency Between DOE and NRC Regulations
    3. Improvements in Analytical Methods
IV. Response to Public Comments on the 1999 Proposal
    V. Description of Final Rule--10 CFR Part 960
    A. Subpart A--General Provisions
    B. Subpart B--Implementation Guidelines
    C. Appendix III
VI. Description of Final Rule--10 CFR Part 963
    A. Subpart A--General Provisions
    B. Subpart B--Site Suitability Determination, Methods and 
Criteria
VII. Regulatory Review
    A. Review for Compliance with the National Environmental Policy 
Act (NEPA)
    B. Review under the Regulatory Flexibility Act
    C. Review under the Paperwork Reduction Act
    D. Review under the Unfunded Mandates Reform Act
    E. Review under the Treasury and General Government 
Appropriations Act, 1999
    F. Review under Executive Order 12866
    G. Review under Executive Order 12875
    H. Review under Executive Order 12898
    I. Review under Executive Order 12988
    J. Review under Executive Order 13084
    K. Review under Executive Order 13132
    L. Review under Executive Order 13211
    M. Congressional Notification

I. Introduction

    Pursuant to the Nuclear Waste Policy Act of 1982, as amended, 
(NWPA), (42 U.S.C. 10101, et seq.), DOE today concludes a rulemaking 
which accomplishes two major purposes: (1) Revision of 10 CFR part 960 
(``General Guidelines for the Recommendation of Sites for Nuclear Waste 
Repositories''); and (2) promulgation of new part 963 (``Yucca Mountain 
Site Suitability Guidelines''). The NWPA provides for a multi-stage 
siting process including preliminary site screening, site 
characterization, DOE site recommendation to the President, and 
Presidential approval of a site for the location of nuclear waste 
repositories. As originally promulgated in 1984, part 960 governed DOE 
activities for comparing and selecting sites from preliminary site 
screening to site recommendation. As revised, part 960 is now limited 
to preliminary site screening to identify candidates for site 
characterization activities (i.e., physical site investigation 
activities). Consistent with 1987 amendments to the NWPA, part 963 
deals with the criteria for evaluating the suitability of the potential 
site at Yucca Mountain, Nevada, based on site characterization 
activities, as part of the material that will be considered by the 
Secretary in any site recommendation to the President. This rulemaking, 
by identifying the types of sound scientific information and methods 
that will be used in assessing the likely performance of a repository 
at the Yucca Mountain site, sets forth guidance to assist the Secretary 
in reaching a judgment on the suitability of that site for a geologic 
repository.
    DOE began this rulemaking by publishing a notice of proposed 
rulemaking on December 16, 1996 (61 FR 66158). That notice attracted 
critical comments from members of the public, State and local officials 
of Nevada, the U.S. Environmental Protection Agency (EPA), and the U.S. 
Nuclear Waste Technical Review Board (NWTRB). In substance, some 
comments criticized the omission from the proposed regulations of 
essential details of the criteria for determining site suitability. 
Other comments questioned the legal basis for the proposal, disputing 
DOE's interpretation of sections 112 and 113 of the NWPA. They also 
disputed the scientific and technical basis for the proposed 
regulations.
    On November 30, 1999, DOE published a supplemental notice of 
proposed rulemaking that revised the terms of, and its explanation of 
the legal and technical basis for, amending its site suitability 
criteria to tailor them, as required by law, to the conditions at Yucca 
Mountain (64 FR 67054). In explaining its reasons for reproposing, DOE 
acknowledged there was enough merit in the comments on its 1996 
proposal to warrant issuance of a revised and more detailed proposal 
with an expanded explanation of the legal and technical basis for the 
proposal. DOE also relied on the implications of its December, 1998, 
``Viability

[[Page 57299]]

Assessment of a Repository at Yucca Mountain'' (DOE/RW-0508) (Viability 
Assessment), on the EPA's 1999 notice of proposed rulemaking to 
establish public health and safety standards for a repository at Yucca 
Mountain at new 40 CFR part 197, and on the U.S. Nuclear Regulatory 
Commission's (NRC's) 1999 notice of proposed regulatory amendments to 
limit its general licensing regulations in 10 CFR part 60 by excluding 
the Yucca Mountain site and to promulgate a new part 63 to establish 
licensing regulations exclusively for the Yucca Mountain site. On June 
13, 2001, the EPA finalized its rulemaking on Yucca Mountain public 
health and safety standards (66 FR 32074-32135), followed by the NRC 
final rulemaking on November 2, 2001 (66 FR 55732-55816). Neither the 
EPA or NRC changed their respective rules from proposed to final form 
in any way that materially affects this rulemaking.
    In the introductory section of the Supplementary Information 
portion of the November 30, 1999, supplemental notice of proposed 
rulemaking, DOE stated that it was seeking to improve its policies for 
determining site suitability based on site characterization activities 
by enhancing their transparency, validity, and verifiability. By 
enhancing transparency, DOE means providing informative and readable 
regulations, an explanation of the legal and technical basis for the 
regulatory amendments, and explanations of complex calculations and 
computer modeling that are suitable for non-technical audiences. By 
enhancing validity, DOE means providing an explanation of basis and 
purpose that clearly shows how the regulatory conclusions followed from 
DOE's legal and technical premises. By enhancing verifiability, DOE 
means being forthcoming about documented empirical results of 
experiments and computer analyses of relevant data so as to allow 
verification of conclusions that DOE may eventually draw from known 
facts in a supporting statement for a site recommendation to the 
President under section 114 of the NWPA.
    In response to the supplemental notice of proposed rulemaking, DOE 
received a variety of written and oral comments from State and local 
officials of Nevada, other Federal agencies, industry sources, 
regulatory and oversight organizations, Native American organizations, 
and assorted private citizens and citizen groups. While supportive of 
much of the content of the proposed regulations, industry sources 
argued that the NWPA did not require this rulemaking. Although some 
Nevada local officials supported some features of the supplemental 
proposal, Nevada State and other local officials continued to take 
issue with proposed regulatory provisions and the legal and technical 
bases for them. Especially useful were comments about appropriate 
arguments to help assess the validity of computer-generated performance 
assessment calculations, comments which provided the opportunity for 
DOE to underscore provisions in part 963 requiring multiple lines of 
argument in backup documentation (eventually to be made available for 
public comment) on subjects such as uncertainty, variability of 
parameter values, the technical basis for including or excluding 
certain features, events, and processes, and the capability of natural 
and engineered barriers to isolate radioactive waste.
    In DOE's view, this rulemaking is necessary in order to correct the 
nonconformity of DOE's prior suitability guidelines to the EPA's and 
NRC's current regulatory framework for the licensing of the Yucca 
Mountain repository, modified from the prior framework by reason of a 
Congressional direction. It has also provided opportunities for State 
and local officials and other members of the public to have an impact 
on DOE's policymaking process. DOE has provided responses below to the 
relevant major issues that emerged from the comments. These responses 
appear after sections that substantially repeat portions of the 
supplemental notice of proposed rulemaking stating the background, 
basis, and purpose of the supplemental proposal. (These sections are 
repeated to assist readers who otherwise would have to look back at a 
copy of the supplemental notice of proposed rulemaking.) DOE has also 
made conforming changes to the rule consistent with final regulations 
of the NRC and EPA, and NRC concurrence comments on part 963.

II. Background

    This section provides an overview of the developments which have 
led DOE to propose to revise certain sections of the existing General 
Guidelines for the Recommendation of Sites for Nuclear Waste 
Repositories and to adopt a new rule setting out the site suitability 
criteria for the Yucca Mountain site.

A. Enactment of the Nuclear Waste Policy Act of 1982

1. Development of the Nuclear Waste Policy Act
    The NWPA was enacted to provide for the siting, construction, and 
operation of repositories for which there is a reasonable assurance 
that the public and the environment will be adequately protected from 
the hazards posed by spent nuclear fuel and high-level radioactive 
waste (hereinafter referred to as ``spent fuel'' or ``high-level 
waste'' or both). The NWPA established the Federal responsibility and 
defined Federal policy for the disposal of spent fuel and high-level 
waste. Because this waste remains radioactive for many thousands of 
years, Congress recognized that disposal involved many complex and 
novel technical and societal issues. To develop an appropriate 
framework for the resolution of these issues, several years of intense 
legislative effort were required before a political consensus emerged 
to support enactment of the NWPA.
    To meet the well-recognized reluctance of communities to host such 
facilities, the NWPA included a national site selection process that 
was designed to ensure fairness and objectivity in the identification 
of potential candidate sites for a repository. To ensure that the DOE 
would consider only candidate sites that had good potential for being 
licensed by the NRC, the NWPA required the DOE to obtain NRC 
concurrence on the DOE's General Siting Guidelines. And to ensure that 
the regulatory requirements for a repository would be set independently 
of any responsibility assigned to the DOE to develop that repository, 
the EPA was authorized to promulgate generally applicable standards for 
the protection of the environment. The NRC was authorized to establish 
repository licensing requirements and criteria, although these 
requirements and criteria could not be inconsistent with any relevant 
public health standards promulgated by the EPA.
2. Overview of the Nuclear Waste Policy Act
    As originally enacted in 1982, the NWPA set forth requirements for 
selecting sites for the disposal of spent fuel and high-level waste in 
a geological repository (42 U.S.C. 10101, et seq.). Several stages were 
established for the evaluation of potential sites, and these stages 
were defined in section 112, Recommendation of Candidate Sites for Site 
Characterization; section 113, Site Characterization; and section 114, 
Site Approval and Construction Authorization.
    Section 112 of the NWPA addresses the initial stage of the site 
selection process, and includes four distinct steps: (1) DOE 
preliminary site screening (42 U.S.C. 10132(a)); (2) DOE nomination of 
at least five sites as suitable for characterization (42 U.S.C. 
10132(b)(1)(A)); (3) DOE

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recommendation to the President of three of the five nominated sites as 
candidates for characterization (42 U.S.C. 10132(b)(1)(B)); and (4) 
Presidential approval of nominated sites for characterization (42 
U.S.C. 10132(c)). Specifically, section 112(a) directed the DOE to 
issue General Guidelines for the recommendation of candidate sites for 
repositories, and to use the Guidelines in considering sites for site 
characterization. Section 112 also directed DOE to consult with several 
federal agencies and obtain NRC concurrence on these Guidelines.
    Under section 112(a), DOE was required to specify in the 
Guidelines: (1) Detailed geologic considerations that were to be the 
primary criteria for the selection of sites for characterization in 
various geologic media; (2) certain factors (e.g., hydrology, 
geophysics, seismic activity) that would either qualify or disqualify a 
site from characterization; and (3) population density and distribution 
factors that would disqualify any site for characterization (42 U.S.C. 
10132(a)). Section 112(a) also required DOE to include certain factors 
related to the comparative advantages among candidate sites. DOE was 
directed to use the Guidelines to consider candidate sites for 
recommendation as candidates for characterization. Section 112(a) 
explicitly authorized DOE to modify the Guidelines consistent with the 
provisions of section 112(a).
    Furthermore, section 112(a) directed DOE to develop certain 
qualifying or disqualifying factors for the preliminary site screening 
stage of the site selection process. Except for population density, the 
specific content of the qualifying or disqualifying factors was left to 
DOE's discretion. Because these factors are part of the Guidelines, 
their specific content could be modified in accordance with the 
authority in section 112(a).
    Section 112(b) of the NWPA addressed DOE's recommendation to the 
President of sites for site characterization, that is, for intensive 
investigation of geologically related characteristics through surface 
and subsurface testing, among other investigative techniques. DOE was 
to nominate at least five sites as suitable for characterization. Each 
nominated site was to be accompanied by an environmental assessment. Of 
the five sites, DOE was to recommend three to the President for 
characterization. Section 112(c) of the NWPA addressed the President's 
review and approval of candidate sites for characterization.
    Section 113 of the NWPA addresses site characterization, which 
involves activities that could proceed only after the section 112 
actions had been completed. Section 113(a) authorizes DOE to conduct 
site characterization activities at the sites that had been approved by 
the President for characterization. Section 113(b) establishes the 
scope of DOE's site characterization activities, and directs the 
publication of a general plan for these activities (42 U.S.C. 
10133(b)(1)(A)). DOE is to report semiannually on its ongoing and 
planned site characterization activities and the information derived 
therefrom (42 U.S.C. 10133(b)(3)). Section 113(b) also directs DOE to 
include in the site characterization plan criteria to be used to 
determine the suitability of a site for the location of a repository, 
developed pursuant to section 112(a) (42 U.S.C. 10133(b)(1)(A)(iv)). 
Section 113(c) limits DOE's site characterization activities to those 
the Secretary considers necessary to provide the data required to 
evaluate a site's suitability for an application for a construction 
authorization as a repository and to comply with NEPA. It also provides 
direction on how DOE is to proceed if at any time it determines that a 
site would be unsuitable for development as a repository.
    Section 114 addresses site approval and construction authorization. 
Four distinct steps are defined in this section: (1) DOE recommendation 
of a site to the President for approval to develop as a repository (42 
U.S.C. 10134(a)); (2) recommendation of a site by the President to 
Congress (42 U.S.C. 10134(a)(2)); (3) Congressional designation of the 
site (42 U.S.C. 10135(b)); and (4) conduct of a licensing proceeding by 
the NRC (42 U.S.C. 10134(c)). Further, under section 115, after the 
President recommends a site to Congress, the Governor and the 
legislature of the host State may submit a notice of disapproval. If 
the State disapproves, Congress must enact a resolution of siting 
approval in order to designate the site (42 U.S.C. 10135(b)). If the 
designation takes effect, DOE is to submit an application to the NRC 
for a construction authorization within 90 days of the designation's 
taking effect. (42 U.S.C. 10134(b)).
    Section 114(a) provides for DOE activities preceding the 
Secretary's preparation of a recommendation to the President for 
Presidential approval of a site for development as a repository. These 
activities include public hearings in the vicinity of the site to 
inform residents of the area and receive their comments, and the 
completion of site characterization. Upon completion of these hearings 
and site characterization, the Secretary may decide to recommend the 
site to the President. A comprehensive statement of the basis for this 
recommendation is to accompany the recommendation, and be made 
available to the public (42 U.S.C. 10134(a)(1)). If the President 
recommends a site to the Congress and that recommendation is permitted 
to take effect, section 114(b) then directs DOE to apply to the NRC for 
construction authorization. Sections 114(c)-(e) direct the NRC and DOE 
on certain aspects of the construction authorization process. Section 
114(f) requires that a final Environmental Impact Statement (EIS) 
accompany the Secretary's recommendation of a site to the President.

B. DOE Promulgation of General Guidelines at 10 CFR Part 960

1. Overview of the General Guidelines
    Section 112(a) of the NWPA directed DOE to issue General Guidelines 
for use in considering and recommending sites for site 
characterization, in consultation with certain Federal agencies and 
interested Governors, and with the concurrence of the NRC. These 
General Guidelines were to be comparative in nature, as DOE was 
required to consider various geologic media and such considerations as 
proximity to where spent fuel and high-level waste were stored. The 
General Guidelines were also to consider non-geologic factors, such as 
population density and distribution, that would not be examined in site 
characterization. No other requirements were imposed on the issuance of 
these Guidelines.
    DOE promulgated the section 112(a) Guidelines by notice and comment 
rulemaking, in addition to the consultation and concurrence process 
specified in the NWPA. The DOE also conducted several public meetings 
on the Guidelines. These additional activities, although not required 
by the NWPA, enabled DOE to receive comments from interested members of 
the public. The General Guidelines were promulgated on December 6, 
1984, and codified in the Code of Federal Regulations at 10 CFR part 
960, General Guidelines for the Recommendation of Sites for the Nuclear 
Waste Repositories. 49 FR 47714.
2. Structure of the General Guidelines
    The Guidelines promulgated by DOE defined the basic technical 
requirements that candidate sites would be expected to meet, and 
specified how DOE would implement its site-selection process. The 
Guidelines were structured according to three categories: 
Implementation guidelines, preclosure guidelines and postclosure 
guidelines.

[[Page 57301]]

The implementation guidelines addressed general application of all the 
Guidelines, and established the methodology for applying the Guidelines 
during the various stages of the siting process: Site screening and 
nomination, recommendation for characterization, and recommendation for 
repository development. The preclosure guidelines governed the siting 
considerations that dealt with the operation of a geologic repository 
before it is closed. The postclosure guidelines governed the siting 
considerations that dealt with the long-term behavior of a geologic 
repository after waste emplacement and closure.
    Both the preclosure and postclosure guidelines were organized under 
general categories of interest, for example, geohydrology and 
geochemistry. Each category was further divided into system guidelines 
and corresponding technical guidelines. The system guidelines addressed 
broad requirements for a geologic repository under preclosure and 
postclosure conditions; the corresponding technical guidelines 
specified conditions that would qualify or disqualify a site, and 
conditions that would be considered favorable or potentially adverse. 
49 FR 47724. In effect, the technical guidelines and the associated 
qualifying and disqualifying conditions imposed specific ``subsystem'' 
performance requirements; each subsystem requirement would be used to 
evaluate the merits of a site, independent of the other requirements.
    Section 112 of the NWPA described the minimum steps that DOE was to 
take during site screening and prior to site characterization. When 
promulgating the Guidelines in 1984, DOE determined that application of 
the Guidelines should extend beyond preliminary site screening to 
encompass site characterization activities and site recommendation to 
the President. Appendix III to the Guidelines explained how certain of 
the Guidelines would be applied at the principal decision points of the 
siting process: (1) Identification of a site as being potentially 
acceptable under section 112(b); (2) nomination and recommendation of 
sites as suitable for characterization under sections 112(b) and (c); 
and (3) recommendation of a site for development as a repository 
(sections 113 and 114). 49 FR 47729-47730. With respect to the third 
decision point, which would be reached only after completion of site 
characterization activities and non-geologic data gathering activities, 
DOE did not promulgate separate guidelines. Instead, DOE indicated that 
the preclosure and postclosure guidelines would be applied to this 
decision, and appropriate findings issued, in the manner prescribed in 
Appendix III. Appendix III specified the types of findings that were to 
be issued from the application of the disqualifying and the qualifying 
conditions at each of the three decision points. The types of findings 
corresponded with the level of confidence required to make a finding; 
that is, a lower level finding required one degree of confidence in the 
finding, and a higher level finding required an increased level of 
confidence in the finding over the lower level. 49 FR 47728-47729. 
Appendix III included a table summarizing the level of the finding 
required at each of the three decision points.
    Appendix III represented the analytical process DOE would follow to 
issue findings relative to the disqualifying and qualifying conditions 
of a site, and use in its decision-making on site selection. This 
analytical process specified a higher-level of confidence in the 
findings of qualifying or disqualifying conditions at the last stage of 
the siting process, site selection for repository development, compared 
to the initial stage of the siting process, site nomination for site 
characterization. DOE anticipated that the higher-level of confidence 
in its technical findings would be obtained through the site 
characterization process undertaken at the later stages of the 
selection process.
3. Bases for the Structure of the General Guidelines
    The structure and development of the Guidelines were based on four 
primary sources of information and considerations: (1) The direction in 
the NWPA, as originally enacted; (2) the extant understanding of 
geologic disposal in the scientific and technical community; (3) 
applicable regulations proposed by the NRC and the EPA governing the 
disposal of spent nuclear fuel and high-level radioactive waste in 
geologic repositories; and (4) public comments.
    DOE initiated the rulemaking process by assembling a task force of 
program experts. 49 FR 47718. The task force developed draft Guidelines 
based on criteria used earlier in the National Waste Terminal Storage 
Program, including program objectives, system performance criteria, and 
site performance criteria. At the time, the task force reviewed other 
criteria defined for geologic repositories by the National Academy of 
Sciences and the International Atomic Energy Agency.
    The task force also sought consistency with NRC regulations and 
proposed EPA regulations related to geologic repositories. 49 FR 47718. 
NRC is the statutory agency responsible for licensing the construction 
and operation of a geologic repository; EPA is the statutory agency 
responsible for setting public health and safety standards for a 
geologic repository. Consistency of the DOE Guidelines with these 
regulatory standards was essential, since any potential site would be 
evaluated based on its ability to meet applicable regulatory 
requirements. 49 FR 47721.
    In sum, the structure and content of the Guidelines was based on 
the state of knowledge in the late-1970s and early-1980s in the 
regulatory community, as well as the national and international 
scientific community, regarding the development of geologic 
repositories and the regulations promulgated by NRC and EPA to govern 
the licensing of a repository.
    DOE sought and received extensive public comments on a draft of the 
Guidelines before submitting them to the NRC for concurrence. On 
February 7, 1983, the proposed Guidelines were published in the Federal 
Register (48 FR 5670) for public review and comment. In addition, DOE 
published a separate notice soliciting comment from the Governors of 
the six States with potentially acceptable sites, and then met 
individually with officials from each of these States. DOE also held a 
series of regional public hearings. After considering the comments 
received, DOE drafted a set of revised guidelines to address the 
comments. The revised guidelines and public comments were made 
available in a second notice on June 7, 1983 (48 FR 26441), followed by 
a second public comment period. Further regional meetings and 
consultations with Federal agencies were held before DOE submitted the 
final version of the Guidelines to NRC for concurrence on November 22, 
1983. 49 FR 47718-47719.
4. Consistency With NRC Technical and Procedural Conditions
    Of particular importance to DOE's formulation of the Guidelines was 
consistency with NRC licensing regulations for the disposal of waste in 
a geologic repository. 49 FR 47718. In June 1983, NRC amended its 
licensing regulations at 10 CFR part 60 with respect to subpart E, 
technical criteria addressing siting, design and performance objectives 
of a geologic repository. 48 FR 28194. NRC concurred in the Guidelines 
subject to conditions that would satisfy the overall need to maintain 
consistency between NRC regulations and the DOE Guidelines. Among the 
NRC conditions were: (1)

[[Page 57302]]

DOE clarifications and deletions of certain limiting terms such as 
``permanent'' and ``significant'; (2) DOE modifications for consistency 
with NRC criteria regarding anticipated processes and events, 
potentially adverse conditions, and the role of engineered barriers 
during the process for screening candidate sites for characterization; 
and (3) DOE revisions and additions to disqualifying conditions to 
ensure that unacceptable sites would be eliminated as early as 
practicable. 49 FR 47719-47722.
    NRC concurrence conditions also addressed general, procedural 
aspects of how the DOE was to apply the Guidelines. For example, NRC 
concurrence was conditioned on a lack of conflict between NRC 
regulations at 10 CFR part 60 and the Guidelines, recognition by DOE 
that NRC regulations were controlling in the event of any differences, 
and a commitment that DOE would obtain NRC concurrence on any future 
revisions to the Guidelines. 49 FR 47719-47720. NRC also requested DOE 
to specify in greater detail how the Guidelines would be applied at 
each siting stage. This specificity was provided by the addition of 
Appendix III to the Guidelines. Appendix III indicated how the 
Guidelines would be applied at all of the site selection stages, 
including the recommendations to the President for site 
characterization and for the development of a site as a repository.
    The NRC required additional changes after it met publicly with 
representatives of several interested states, Indian tribes, and DOE. 
After DOE committed to making those changes, the NRC voted to concur in 
the Guidelines. 49 FR 47720. Thus, the part 960 Guidelines took account 
of the substantial input provided by the NRC in 1984 through the 
statutory concurrence process.

C. DOE Application of the Guidelines

    Consistent with section 112(b) of the NWPA, DOE applied the 
Guidelines to: (1) nominate five sites as suitable for 
characterization; and (2) recommend to the President three of those 
five nominated sites for characterization as candidate sites for the 
first repository. On May 27, 1986, the President approved each of the 
sites that had been recommended for characterization. Yucca Mountain 
was one of the three sites that DOE recommended. The recommendation to 
the President was documented in a DOE report, Recommendation by the 
Secretary of Energy for Site Characterization for the First 
Radioactive-Waste Repository (May 1986; DOE/S-0048). In addition, a 
draft environmental assessment was prepared for each of the five sites 
and final environmental assessments were prepared for each of the three 
sites that were recommended.
    This action concluded the process that had been established by the 
NWPA for identifying sites for characterization. The Guidelines' role 
of structuring DOE's process for identifying sites for characterization 
was completed in accordance with the Congressional directives to DOE. 
Under DOE's formulation of the Guidelines at that time, however, the 
Guidelines would remain relevant and applicable through the third 
principal siting decision point, the selection of a site to be 
recommended for the development of a repository.

D. 1987 Amendments to NWPA

    In 1987, Congress amended the NWPA to mandate Yucca Mountain as the 
sole site to be characterized (42 U.S.C. 10172 (Supp. V 1987)). The 
processes for site characterization under section 113 and site approval 
under section 114 were made applicable to only Yucca Mountain. Under 
sections 113(a) and (b), Yucca Mountain was designated as the site for 
which site characterization activities would take place, and a site 
characterization plan would be issued, respectively. Under section 
113(c), Congress amended the statute to name Yucca Mountain as the site 
for which the restrictions on site characterization activities would be 
applicable. That is, DOE was directed to conduct only such activities 
at Yucca Mountain that are necessary to evaluate the suitability of the 
site for an application to the NRC for a construction authorization, 
and to comply with requirements under the National Environmental Policy 
Act (NEPA). Section 114 was amended to excuse DOE from analysis of 
alternative sites in any environmental impact statement (EIS) that may 
be prepared for the Yucca Mountain site under NEPA. Any such EIS would 
analyze the Yucca Mountain site, and no other sites, for potential 
development of a geologic repository. Further, section 160(b) directed 
DOE to ``terminate all site specific activities (other than reclamation 
activities) at all candidate sites, other than the Yucca Mountain 
site.'' (42 U.S.C. 10172(a)(2)).
    In sum, Congress made clear its intent for DOE to focus its 
resources on investigating only Yucca Mountain as a potential site for 
a high-level radioactive waste repository.

E. Yucca Mountain Site Characterization Plan

1. Statutory Requirements
    Under sections 113 and 160 of the NWPA, as amended, DOE was 
directed to conduct site characterization activities at the Yucca 
Mountain site. Prior to initiating site characterization under section 
113, DOE was required to prepare a general plan for site 
characterization activities at the Yucca Mountain site. DOE was 
required to submit the plan to the NRC and the State of Nevada for 
their review and comment (42 U.S.C. 10133(b)(1)), as well as to members 
of the public in the vicinity of Yucca Mountain (42 U.S.C. 
10133(b)(2)). Certain contents of the plan were mandated by section 
113(b), including, among other things, a description of planned 
excavation and other testing activities, a description of the possible 
form or packaging of the high-level waste, and the criteria to be used 
to determine the suitability of the site for the location of a 
repository, developed pursuant to section 112(a). Section 113(b)(3) 
also required DOE to report every six months on the progress of site 
characterization activities at Yucca Mountain, and to provide the 
reports to the NRC, and the Governor and the legislature of the State 
of Nevada.
    DOE prepared the site characterization plan in draft form in 
January 1988. In preparing the plan, DOE generally followed NRC 
guidance, as specified in the document, Standard Format and Content of 
Site Characterization Plans for High Level Waste Geologic Repositories, 
Regulatory Guide 4.17 (NRC 1987). After review and comment by NRC, the 
State of Nevada, and interested members of the public, DOE finalized 
the Site Characterization Plan: Yucca Mountain Site, Nevada Research 
and Development Area, Nevada (December 1988; DOE/RW-0198) (hereinafter 
also the SCP), in December 1988.
2. Structure of the Site Characterization Plan
    ``Site characterization'' is defined in the NWPA to include 
research activities undertaken to establish the geologic condition of a 
site, for example, borings and surface excavations, and in situ testing 
necessary to evaluate the suitability of a candidate site for the 
location of a repository (42 U.S.C. 10101(21)). In the SCP, DOE 
described the purpose of its site characterization program at Yucca 
Mountain as to obtain the information necessary to determine whether or 
not the site is suitable for a repository, and could satisfy NRC

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licensing requirements (which must be consistent with EPA public health 
and safety standards). DOE also explained there that the information 
obtained from site characterization, such as the geologic, 
geoengineering, hydrologic, and climatological conditions at a site, 
would be used to develop and optimize repository design and to evaluate 
the performance of the site and the engineered barriers as an 
integrated system.
    The purpose of the SCP was threefold: (1) To describe the site, and 
the preliminary designs for the repository and the waste packages in 
sufficient detail to form the basis for the site characterization 
program; (2) to identify issues to be resolved during site 
characterization and present the strategy for resolving the issues; and 
(3) to describe the plans for the work needed to obtain the information 
deemed necessary and to resolve outstanding issues. The SCP was 
organized along two lines: (1) An issues hierarchy, which embodied the 
DOE, NRC and EPA regulations governing the repository system; and (2) 
an issue-resolution strategy.
    The issues hierarchy was a three-tiered framework laying out what 
must be known before the Yucca Mountain site could be selected and 
licensed. ``Issues'' were defined as questions related to performance 
of the repository that must be resolved to demonstrate compliance with 
applicable regulations of DOE, NRC and EPA. DOE identified four key 
issues to be addressed, based on regulatory requirements and the four 
system guidelines in part 960: (1) Postclosure performance; (2) 
preclosure performance; (3) environment, socioeconomic, and 
transportation impacts of a repository; and (4) ease and cost of 
repository siting, construction, operation and closure. DOE also 
explained that only the first, second, and part of the fourth key issue 
would be addressed in the site characterization program, since 
resolution of these other key issues (that is, key issue 3 and part of 
key issue 4) were not dependent on information from site 
characterization activities. The issue-resolution strategy consisted of 
four parts: issue identification, performance allocation, data 
collection and analysis, and documentation of issue resolution. This 
framework was used to develop test programs and explain why the test 
programs were adequate and necessary. The object was to collect 
information to be used in a concluding set of analyses to resolve the 
issues, and to document resolution of the issues.
    As required by section 113(b)(1)(A)(iv), the SCP included criteria 
to determine the suitability of the site for development of a 
repository. Those ``criteria'' were the provisions within the 
Guidelines pertinent to site characterization activities, namely, the 
postclosure guidelines, and the preclosure guidelines related to 
radiological safety and technical feasibility of repository siting, 
construction and operation, to be applied in the manner described in 
Appendix III. Appendix III set out the level of findings DOE would make 
relative to the system and technical requirements found in the 
postclosure guidelines (subpart C) and preclosure guidelines (subpart 
D) at the final decision point of recommending a site for development 
as a repository. DOE believed that the information gained through site 
characterization and the issue resolution process would form the basis 
for these findings.
    DOE also explained in the SCP that not all of the Guidelines would 
be addressed as part of site characterization activities. The SCP would 
not address the environmental, socioeconomic and transportation 
guidelines, or certain guidelines related to ease and cost of 
repository siting, construction, operation, and closure, since DOE 
would not develop information related to those guidelines through site 
characterization activities. Those Guidelines would be addressed in 
other investigations and plans to be conducted concurrently with the 
site characterization program. Also, in light of the 1987 amendments to 
the NWPA permitting site characterization to proceed only at Yucca 
Mountain, DOE stated in the SCP that the comparative portions of the 
Guidelines would not be applied in the site suitability determination 
to be made under section 113(b).
    In accordance with section 113(b)(3), approximately every six 
months DOE has issued a report updating information on the conduct of 
site characterization activities at the Yucca Mountain site. Those 
reports briefly summarize the characterization activities undertaken at 
the site, the technical and scientific issues of key interest and their 
resolution, and issues that remain for further characterization and 
resolution. In addition, the semiannual reports provide references and 
a bibliography of other reports and documents containing more detailed 
information regarding site characterization activities. DOE has been 
providing the reports to the NRC, the Governor of Nevada, and the 
legislature of the State of Nevada.
    The progress reports also reflect DOE's ongoing interaction with 
the NRC. In July 1986, the NRC amended its regulations at 10 CFR part 
60 (51 FR 27158) to establish the method of interaction between DOE and 
the NRC on the development and implementation of the site 
characterization plan. NRC established a system for DOE to report on 
the results of site characterization, identify issues, plan for 
additional studies, eliminate planned studies no longer necessary, and 
identify decision points reached. In this manner, the NRC established a 
clear pathway to interact with DOE in the management and direction of 
the site characterization program.
    Site characterization activities have continued up to and including 
the present, and are described in greater detail below in section II.G.

F. Energy Policy Act of 1992

    In 1992, Congress enacted certain provisions in the Energy Policy 
Act of 1992 (Pub. L. No. 102-486) affecting the nation's nuclear waste 
repository program. In section 801(a) of the Energy Policy Act of 1992 
(EPACT), Congress directed EPA to promulgate a new, health-based 
standard to ensure protection of the public health from high-level 
radioactive waste that may be disposed in a geologic repository located 
at Yucca Mountain. The new standard could depart from the generic EPA 
standards promulgated at 40 CFR part 191, and would be specific to 
Yucca Mountain. In section 801(b), Congress also directed the NRC, 
within one year of EPA's adopting a new standard, to modify its 
technical requirements and criteria under section 121(b) of the NWPA 
(42 U.S.C. 10141(b)) (i.e., 10 CFR part 60), as necessary, to be 
consistent with the new EPA standard.
    Before setting the new standard, however, EPA was required to 
contract with the National Academy of Sciences (NAS) to conduct a study 
to provide findings and recommendations on reasonable standards for 
protection of the public health and safety. Under section 801(a) of the 
EPACT, EPA was required to promulgate its new standards based on, and 
consistent with, the NAS findings and recommendations. Under the EPACT 
and accompanying congressional instruction, NAS's charge was to answer 
three specific questions embodied in section 801(a)(2), and to advise 
EPA on the technical basis for the health-based standards it was 
mandated to prepare. The three questions posed in section 801(a)(2) 
addressed: (1) Whether or not a health-based standard based on doses to 
individual members of the public would provide a reasonable basis for

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protecting public health and safety; (2) whether or not it is 
reasonable to assume that a system for postclosure oversight of the 
repository, using active institutional controls, will prevent an 
unreasonable risk of breaching the repository's engineered or natural 
barriers, or of increasing the exposure of individual members of the 
public to radiation beyond allowable limits; and (3) whether or not it 
is possible to make scientifically supportable predictions of the 
probability that the repository's engineered or natural barriers will 
be breached as a result of human intrusion over a period of 10,000 
years.
    In August 1995, NAS published the statutorily mandated report, 
entitled Technical Bases for Yucca Mountain Standards. In sum, NAS 
issued findings that: (1) A health standard for Yucca Mountain based on 
risk to individuals of adverse health effects from releases from the 
repository (rather than EPA's generic standards which contain both 
individual dose and release limits) was an appropriate standard that 
would adequately protect the health and safety of the general public; 
(2) it is not reasonable to assume that a system for postclosure 
oversight can be developed, based on active institutional controls, 
which will itself prevent an unreasonable risk of breaching the 
repository's engineered barriers or of increasing the exposure of 
individual members of the public to radiation beyond allowable limits; 
and (3) it is not possible to make scientifically supportable 
predictions of the probability that a repository's engineered or 
geologic barriers will be breached as a result of human intrusion over 
a period of 10,000 years. Notwithstanding the latter two findings, the 
NAS recommended EPA include in its standards a stylized human intrusion 
event. The NAS reasoned that such an analysis may provide useful 
insight into the degree to which the ability of a repository to protect 
the public health and safety would be degraded by an intrusion.
    In reaching its findings and recommendations, the NAS consulted 
with numerous entities, including local, state and federal government 
agencies, private organizations, and scientists and engineers, both 
national and international, familiar with the technical issues under 
study, and held five open technical meetings to ensure a thorough 
review of the scientific literature on the subject. In the Technical 
Bases for Yucca Mountain Standards, the NAS provided a detailed 
explanation of the assumptions and analyses underlying the study, and 
the reasons for NAS's findings and recommendations. Among the more 
important of these is the NAS assumption, confirmed by its technical 
review, that it is possible to conduct scientifically justifiable 
analyses of repository behavior over thousands of years in order to 
assess whether or not a repository can comply with the applicable 
public health standard. In addition, based on its analyses, the NAS 
concluded that the proper way to evaluate the risks of adverse health 
effects, and to compare those risks to the proposed standard, is to 
assess the estimated potential future behavior of the entire repository 
system and its potential effect on humans. The procedure used to 
perform this analysis is called total system performance assessment 
(alternately called performance assessment).
    In discussing the possible implications of its conclusions, the NAS 
noted that, if EPA issued standards based on individual risk (as 
recommended by the NAS), then the NRC would be required to revise its 
regulations embodied in 10 CFR part 60 to be consistent with EPA. This 
is because NRC's 10 CFR part 60 is directed in part to subsystem 
technical requirements, whereas the NAS concluded that it is the 
performance of the total system, rather than that of its individual 
elements in isolation, that is crucial in the context of a risk-based 
standard. Under a risk-based standard, imposing subsystem performance 
requirements might result in a deficient repository design even if each 
subsystem element meets or exceeds a certain performance standard. The 
NAS also observed that its recommendations, if adopted, implied the 
development by EPA of different regulatory and analytical approaches 
from those employed in the past, and that the process of establishing 
the new standards would require significant time and opportunity for 
public comment and review. Nevertheless, NAS noted that these potential 
changes should not impede site characterization work by DOE at Yucca 
Mountain.

G. Evolution of the Site Characterization Program

    Since publication of the SCP in 1988, DOE's site characterization 
program at Yucca Mountain has made substantial progress in developing 
information and data about the site and resolving outstanding technical 
issues. Over time, the site characterization program has evolved and 
been driven by advances in science and technology, as well as 
legislative and managerial changes. The following summarizes the 
evolution and status of the site characterization program.
    Technical Components of the Site Characterization Program. The 
three main technical components of the site characterization program 
are testing, design, and performance assessment. Testing encompasses 
the investigation of natural features and processes at the site through 
field testing, conducted above and below ground, and laboratory testing 
of rock and water samples. Design refers to work on development of the 
description of a repository and waste packages tailored to the site 
features, supported by laboratory testing of candidate materials for 
waste packages and design-related testing in underground tunnels 
similar to those in which waste would be emplaced. Performance 
assessment refers to the quantitative estimates of the performance of 
the total repository system, over a range of possible conditions and 
for different repository configurations, by means of computer modeling 
techniques that are based on site and materials testing data and 
accepted principles of physics and chemistry.
    Through the testing program, DOE has learned a great deal about the 
geologic conditions of the site. The single largest effort undertaken 
in this regard has been construction of the Exploratory Studies 
Facility (ESF). Construction of this facility began in 1992 and was 
completed in 1998. The ESF, a 4.9 mile long underground tunnel, has 
enabled DOE to conduct testing and exploration activities in Yucca 
Mountain at the depth of the proposed repository. Utilization of this 
facility has formed the basis for increased knowledge and understanding 
of the mechanical and hydrologic characteristics of the geologic 
formation in which the repository would be constructed. Ongoing work at 
this facility will focus primarily on thermal and hydrologic testing in 
the cross drift to extend and, where necessary, modify this 
understanding of the properties of the host rock.
    The design component of the site characterization program comprises 
those activities aimed at developing concepts for the engineered 
components of the geologic repository. Design activities use 
information about the site gained through the testing program, and 
information about the engineered barrier system gained through other 
scientific investigations, to generate and develop design concepts that 
can meet the requirements placed on the engineered components of the 
repository. Site characterization activities are structured to acquire 
data needed to support the

[[Page 57305]]

design. For example, a number of the site characterization program 
tests focus on the hydrological, geomechanical and thermal properties 
of Yucca Mountain. These tests are significant because they provide the 
fundamental information needed to specify the approach to be used in 
developing the geologic repository thermal loading and underground 
support schemes. Also, under the design program, DOE examines various 
approaches to meeting engineered facility requirements, and conducts 
comparative evaluations of the costs and benefits of different 
approaches to developing design concepts.
    The performance assessment component of site characterization 
represents the analytical method (i.e., computer modeling) DOE uses to 
forecast the performance of the repository within the Yucca Mountain 
setting and assess that performance against regulatory standards. Put 
in simplified terms, performance assessment uses the information and 
data collected under the testing and design programs to feed computer 
models that describe how the site would behave in the presence of a 
repository and how the engineered system would behave within the 
environmental setting of the mountain. Each model, called a process 
model, is designed to describe the behavior of individual and coupled 
physical and chemical processes. A total system performance assessment 
(TSPA) links the results of individual process models to construct a 
computer model of the repository system and surrounding environment 
that are important to assessment of overall repository performance. 
With the TSPA model, DOE can estimate releases of radionuclides from a 
repository under a range of conditions, over thousands of years, and 
forecast the consequent probable doses to persons.
    Performance assessment (or TSPA), as described above, is an 
accepted method to assess the performance of a repository at Yucca 
Mountain. DOE's use of performance assessment models began even before 
issuance of the SCP in 1988. Since that time, however, significant 
advancements have been made in the technical capability, acceptance, 
and use of this analytical tool. In 1991, the Nuclear Energy Agency 
Radioactive Waste Management Committee and the International Atomic 
Energy Agency International Radioactive Waste Management Advisory 
Committee confirmed that TSPA provides an adequate means to evaluate 
long-term radiological impacts of a waste disposal system. On a 
national level, the NRC, the NAS and the Nuclear Waste Technical Review 
Board (``NWTRB'') (a Congressionally mandated committee of experts 
chartered to evaluate the technical and scientific validity of 
activities undertaken by DOE to characterize Yucca Mountain to 
determine its suitability as a location for a repository) have 
acknowledged the value of this method for evaluating postclosure 
performance for a repository at Yucca Mountain.
    A significant portion of the DOE site characterization program has 
been aimed at developing the scientific bases that serve as the 
foundation for the process models used in performance assessment. DOE 
developed performance assessment models and conducted benchmark 
performance assessments of the total repository system in 1991, 1993 
and 1995. Between these benchmark assessments, DOE conducted many 
performance assessments to evaluate selected features of the site and 
the evolving design. DOE used these total system and subsystem 
performance assessments to evaluate design options and to determine 
further data needed from site investigations. Another TSPA was 
conducted in 1998, the results of which are contained in the Viability 
Assessment.
    Redirection of the Site Characterization Program. In 1994, DOE 
conducted extensive internal and external reviews of the program. As a 
result of those reviews, documented in the Civilian Radioactive Waste 
Management Program Plan (December 1994; DOE/RW-0458) (Program Plan), 
DOE identified cost-cutting measures to reduce the cost of completing 
site characterization. In response to Congressional concern about the 
1994 Program Plan, DOE submitted a revised Program Plan to Congress 
that was designed to maintain scientific investigations at the site and 
retain target dates for determining site suitability and recommendation 
for construction authorization. Civilian Radioactive Waste Management 
Program Plan, Revision 1 (May 1996; DOE/RW-0458). As part of the 
revised strategy, DOE redirected project efforts to address the major 
unresolved technical questions and to complete an assessment of the 
viability of licensing and constructing a repository at Yucca Mountain. 
Congress indicated its approval of the revised Program Plan in the 
Conference Report on the Energy and Water Development Appropriations 
Act, 1997, H.R. Rep. No. 782, 104th Cong., 2d Sess. 82 (1996), by 
directing that the appropriated funds be used in accordance with the 
revised Program Plan issued by DOE in May 1996.
    In the Fiscal Year 1997 Energy and Water Development Appropriations 
Act (Pub. L. No. 104-206) (referenced above), Congress directed DOE to 
provide the viability assessment of the Yucca Mountain site, referenced 
in DOE's revised Program Plan, to Congress and the President as a basis 
for making future decisions on program funding and direction. DOE 
issued the Viability Assessment in December 1998. Drawing on 15 years 
of scientific investigation and design work, the Viability Assessment 
summarized a large technical basis of field investigations, laboratory 
tests, models, analyses and engineering. The Viability Assessment also 
identified major uncertainties relevant to the technical defensibility 
of DOE's analyses and designs, the approach to managing these 
uncertainties, and the status of work relative to the target dates of 
2001 for a determination on recommendation of Yucca Mountain and 2002 
for submittal of a license application to NRC. The Viability Assessment 
also included an iteration of the TSPA conducted in 1998, and the 
results of that process.
    Coordination with NRC. DOE's implementation of its site 
characterization program and the issue resolution strategy embodied in 
the SCP has been conducted in close coordination with the NRC. In 1995, 
the NRC revised its prelicensing repository program as a result of 
changes in the DOE civilian radioactive waste management program, the 
findings of the NAS committee recommending changes to the public health 
standard for a potential Yucca Mountain repository, and budgetary 
constraints imposed by Congress. The NRC adjusted the scope of its 
program to focus only on those topics most critical to repository 
performance, termed ``key technical issues.'' These issues were 
intended to be a vehicle to communicate to DOE those technical matters 
for which the NRC had remaining unanswered questions regarding the 
performance of the Yucca Mountain site, or the data needed to assess 
that performance. DOE's management of the site characterization program 
has included activities to obtain information to address the NRC key 
technical issues. DOE has structured the site characterization program 
in such a manner that one of its goals is for DOE and NRC to reach 
consensus that the remaining key technical issues have been addressed 
adequately, or that adequate plans are in place to address the issues.

[[Page 57306]]

H. The 1993-1995 Public Dialogue on the Guidelines

    In the SCP, issued in December 1988, DOE described how it would 
apply the part 960 Guidelines as part of the site characterization 
program to evaluate the suitability of the site. DOE indicated in the 
SCP that the Guidelines related to site characterization activities 
would be applied as the suitability criteria. DOE also indicated there 
that the comparative provisions of those requirements would not be 
applied in light of the 1987 amendments to the NWPA limiting site 
characterization activities to Yucca Mountain. Notwithstanding this 
explanation, a number of interested parties suggested it remained 
unclear how DOE would apply the Guidelines in the future. Because of 
this continuing stated uncertainty, the DOE instituted an ongoing 
dialogue with external parties on the Guidelines.
    In October 1993, DOE briefed the representatives of the affected 
units of local government and the State of Nevada on its plans for 
activities related to site suitability evaluation. DOE followed this 
briefing with a Notice of Inquiry in the Federal Register (59 FR 
19680), dated April 25, 1994, eliciting the views of the public on the 
appropriate role of the Guidelines. A public meeting was held on May 
21, 1994 in Las Vegas, Nevada. The purposes of the meeting were to 
follow-up on a previous public meeting held in August 1993; to update 
the public on site characterization activities; and to provide an 
opportunity to discuss the development of a process to evaluate site 
suitability. DOE then published a second Federal Register notice (59 FR 
39766) on August 4, 1994, announcing that it intended to use the 
Guidelines as currently written, subject to the programmatic 
reconfiguration directed in the 1987 NWPA amendments. Through that 
notice, DOE also announced the availability of a draft description of 
the proposed process and its intention to hold two additional public 
meetings to discuss the matter. Although several options were 
discussed, DOE discerned no clearly preferred option from this public 
comment process. In response to public comments at the meetings, DOE 
committed to provide background information and its rationale for 
maintaining the use of the Guidelines as originally promulgated, with 
modification to eliminate application of the comparative portions of 
the Guidelines. In September 1995, DOE published in the Federal 
Register the background information and its rationale, as committed to 
in previous public meetings. 60 FR 47737.
    In the September 1995 public notice, DOE explained that amending 
the Guidelines, either to remove those portions that are primarily used 
for comparative purposes or to develop Guidelines tailored to 
evaluation of the suitability of the Yucca Mountain site, was not 
required at that time. DOE recognized then that the Guidelines might 
have to be amended at some future date to be consistent with any 
changes to EPA or NRC requirements. 60 FR 47740. Among the options 
considered in the 1993-1995 public dialogue was abandonment of the 
Guidelines and adoption of the NRC siting criteria in 10 CFR 60.122. 
DOE noted that the Guidelines were expressly derived from, and tied to, 
the part 60 siting criteria. In addition, DOE noted that, should any 
differences between 10 CFR part 960 and 10 CFR part 60 be identified, 
10 CFR part 60 would prevail in the licensing process. While 
recognizing that much of 10 CFR part 960 subpart B, the implementation 
guidelines, was no longer applicable, DOE concluded that the Guidelines 
could be selectively interpreted to avoid the comparative aspects while 
applying the relevant provisions of subparts C and D, the postclosure 
and preclosure guidelines.

I. The 1996 Notice of Proposed Rulemaking

    For many of the reasons described earlier in this notice, including 
changes in congressional direction of the repository program and 
advancements in site characterization, on December 16, 1996, DOE 
published in the Federal Register a notice of proposed rulemaking for 
10 CFR 960.61 FR 66158. In that notice, DOE proposed to clarify and 
focus the Guidelines and to add a new, site-specific subpart E to the 
Guidelines. Subpart E would apply only to the Yucca Mountain site, and 
would contain preclosure and postclosure system guidelines, each with a 
single qualifying condition. 61 FR 66163. In each of the periods, the 
qualifying condition would be that a repository at Yucca Mountain be 
capable of limiting radiological releases within applicable standards 
to be set by EPA and implemented by the NRC through the repository 
licensing process. DOE would demonstrate this capability through 
performance assessments. 61 FR 66164. These performance assessments 
would forecast the performance of a proposed geologic repository at 
Yucca Mountain and compare the results of the assessments to the 
applicable regulatory standards to determine whether or not the site 
would be suitable for development as a repository.
    The 1996 proposal was consistent with the system-level evaluation 
originally envisioned for the conclusion of site characterization. DOE 
recognized in 1984 in the Guidelines that, only after the entire 
process of narrowing the number of potentially acceptable sites to one 
and after site characterization, would it be possible to conduct 
complete performance assessments. Such assessments require detailed 
information that can be obtained only during site characterization. 49 
FR 47717. In addition, the 1996 proposal was consistent with DOE's 
longstanding position that the Guidelines must complement and not 
conflict with EPA and NRC regulations, since the ability to meet 
applicable public health and safety standards and develop information 
adequate to support a license application has always been central to 
the site suitability determination.
    The 1996 proposal attracted a wide variety of comments from members 
of the public, the NRC, the EPA, and the Nuclear Waste Technical Review 
Board. The major issues that emerged from the public comment process 
were discussed in detail in the Supplementary Information to the 
supplemental notice of proposed rulemaking, issued on November 30, 1999 
(discussed below at section L).

J. Proposed NRC Regulation, 10 CFR Part 63

1. Background
    On February 22, 1999, the NRC published in the Federal Register a 
proposed new rule, 10 CFR part 63, containing licensing criteria for 
disposal of spent nuclear fuel and high-level radioactive waste in the 
proposed geologic repository at Yucca Mountain, along with proposed 
revisions to 10 CFR part 60 and other related regulations. 64 FR 8640. 
The proposed licensing criteria at part 63 apply exclusively to Yucca 
Mountain; part 60 is revised to limit its applicability to geologic 
repositories other than one at Yucca Mountain. NRC's proposal seeks to 
establish a new system of risk-informed, performance-based regulation. 
Under this approach, risk insights, engineering analysis and judgment, 
and performance history are used to: (1) Focus attention on the most 
important activities; (2) establish objective criteria based upon risk 
insights for evaluating performance; (3) develop measurable or 
calculable parameters for monitoring system and licensee performance; 
(4) provide flexibility to determine how

[[Page 57307]]

performance criteria are met; and (5) focus on results as the primary 
basis for regulatory decision-making. 64 FR 8643.
    The NRC's rationale for proposing part 63 stemmed from the 
requirements of the EPACT. 64 FR 8641-8643. Section 801(b) of EPACT 
required that, within one year after EPA promulgates its new standards 
for protection of public health and safety, the NRC modify its 
technical requirements and criteria for repository licensing (i.e., 
part 60) to be consistent with the new EPA standards. In addition, the 
EPACT requires NRC to include in its modifications, consistent with the 
NAS findings and recommendations, certain assumptions that are 
specified in the EPACT with regard to the effectiveness of DOE's 
postclosure oversight of the repository.
    As noted above, the NAS issued its findings and recommendations in 
the report, Technical Bases for Yucca Mountain Standards, August 1995. 
The NAS findings and recommendations reported there, along with 
consultation NRC had with EPA, provided the basis for NRC's proposed 
modifications. 64 FR 8641, 8643. The NAS' recommended approach to 
setting a public health and safety standard has a different objective 
from the NRC approach reflected in the pre-existing part 60 
requirements and criteria. 64 FR 8643. Accordingly, the modifications 
proposed by the NRC, based on the NAS report, and the subsequently 
proposed EPA rule marked a change in methodology and licensing 
philosophy.
    The NRC has now promulgated part 63 in final form. The final 
version closely resembles the proposed rule, however the final rule and 
changes made by the NRC to the proposed rule are discussed below at 
section II. M. Accordingly, we retain the discussion of the proposed 
version here, in order to facilitate an understanding of the 
development of part 963 by adhering to the chronological narrative of 
relevant events.
2. Structure of Proposed Part 63
    Preclosure Requirements. In order to obtain a license to construct, 
operate and close a repository at Yucca Mountain, proposed part 63 
would require DOE to demonstrate compliance with the applicable 
preclosure regulatory standards by the use of an integrated safety 
analysis. 64 FR 8652. An integrated safety analysis is a systematic 
examination of the geologic repository operations area's hazards and 
their potential for initiating events (for example, accidents), the 
potential consequences of the events, and the site, structures, 
systems, components, equipment and activities of personnel. The 
analysis would be conducted to ensure that all relevant hazards that 
could result in unacceptable consequences have been adequately 
evaluated and appropriate protective measures have been identified. 
``Integrated'' means joint consideration of safety measures that 
otherwise might conflict, including such measures as fire protection, 
radiation safety, criticality safety, and chemical safety. The results 
of the analysis would be used to support a finding of compliance with a 
performance objective for the preclosure period of limiting radiation 
exposures and releases within a dose limit of 25 millirem (mrem) to any 
member of the public beyond the site boundary.
    Postclosure Requirements. In order to obtain a license to 
construct, operate and close a repository at Yucca Mountain, proposed 
part 63 would require DOE to demonstrate compliance with the applicable 
postclosure regulatory standards by the use of a performance assessment 
of the potential repository. It should be noted that, in this regard, 
while certain parts of proposed part 63 are similar to part 60, in 
particular with respect to many procedural and administrative 
regulations, this part of the proposed rule, that is, the regulations 
governing postclosure performance objectives, is fundamentally 
different. The part 60 technical criteria for postclosure relied on 
several quantitative, subsystem performance objectives. In 1983-4, NRC 
believed this approach was best suited to meet its statutory 
requirement under section 121(b)(1)(B) of the NWPA to prescribe 
criteria that would involve use of a system of multiple barriers in the 
design of the repository. 64 FR 8648. At the time part 60 was written, 
NRC's technical opinion was that compliance with this requirement could 
be best demonstrated by specifying subsystem technical requirements, 
thereby assuring multiple, independent and redundant systems and 
barriers. Given advancements in technical understanding and analytical 
capability, and information acquired through site-characterization at 
Yucca Mountain, the NRC no longer believes this approach is an optimal 
and reliable approach to assure compliance with public health and 
safety standards. 64 FR 8648-8649.
    Accordingly, in its criteria for postclosure system performance and 
method for evaluating compliance with those criteria, part 63 does not 
contain subsystem performance requirements, or analogs for those 
requirements, as found in part 60. The part 63 requirements are based 
on only one quantitative standard--demonstrating compliance with an 
individual dose limit. The part 63 technical criteria are compatible 
with the NRC's current philosophy of risk-informed, performance-based 
regulation. This approach is consistent with NAS recommendations that 
would require compliance with a health-based standard as the only 
quantitative standard for postclosure repository performance. 64 FR 
8643. NRC's final rule conforms its approach on this question to EPA's, 
and DOE's final guidelines accordingly do likewise.
    This approach is also consistent with the NWPA's directive to NRC 
in section 121(b)(1)(B) to provide use of a multiple barrier system 
(i.e., consisting of both natural and engineered barriers) in the 
design of the repository. This objective is attained by requiring DOE 
to demonstrate that the natural barriers and the engineered barriers 
will work in combination to enhance overall performance of the 
repository.
    Proposed part 63 would require DOE to demonstrate compliance with 
the applicable postclosure regulatory standard by the use of 
performance assessment. 64 FR 8650. Performance assessment is a 
systematic analysis that identifies the features, events, and processes 
that might affect performance of the geologic repository, examines 
their effects on performance, and estimates the resulting expected 
annual dose. Demonstrating compliance with the postclosure performance 
of 10 CFR part 63 would require a performance assessment to 
quantitatively estimate the expected annual dose, over the compliance 
period, to the average member of a critical group. The critical group 
would be a hypothetical group of individuals reasonably expected to 
receive the greatest exposure to radioactive materials released from 
the geologic repository. Consistent with the EPACT and the 1995 NAS 
report, the NRC proposed that the results of the performance assessment 
be the sole quantitative measure used to demonstrate compliance with 
the individual dose limit. 64 FR 8650.
    Because of the importance of the performance assessment, proposed 
part 63 was structured to establish certain minimum requirements 
governing the content and validation methods for the performance 
assessment. 64 FR 8650-8651. For example, DOE would be required to 
include in the performance assessment data related to the geology, 
hydrology and geochemistry of Yucca Mountain, as well as data related 
to the design of the engineered barrier system; to account for 
uncertainties and variabilities in the data used to model performance 
of the repository; to provide the technical basis for either

[[Page 57308]]

inclusion or exclusion of specific features, events, and processes of 
the geologic setting; and to provide the technical basis for the models 
used in the overall performance assessment by providing, for example, 
comparisons of the output of detailed process-level models and 
empirical observations. In addition, proposed part 63 would prescribe 
the characteristics of the reference biosphere and receptor to be used 
in the performance assessment. DOE also would be required to conduct a 
separate performance assessment based on a limited human intrusion 
scenario prescribed by the NRC.

K. Proposed EPA Regulation, 40 CFR Part 197

1. Background
    On August 27, 1999, the EPA published in the Federal Register a 
proposed new rule, 40 CFR part 197, to establish public health and 
safety standards governing the storage and disposal of spent nuclear 
fuel and high level waste in a potential repository at Yucca Mountain, 
Nevada. 64 FR 46975. EPA promulgated this rulemaking pursuant to 
section 801(a) of the EPACT. As explained earlier in this preamble 
(section I.F.), in section 801(a)(1) of the EPACT Congress directed EPA 
to promulgate a health-based standard for the protection of the public 
from releases from radioactive materials stored or disposed of in a 
repository at the Yucca Mountain site. Also under EPACT, Congress 
directed that the EPA standard was to be the only standard applicable 
to the Yucca Mountain site, and that the EPA standard must be based 
upon and consistent with NAS'' findings and recommendations. 64 FR 
46977.
    As directed by Congress in the EPACT, it is EPA's role to establish 
the public health and safety standard, and NRC's role to implement that 
standard in any licensing process NRC may conduct for a repository at 
Yucca Mountain. It was therefore anticipated that NRC would conform its 
proposed licensing regulation at 10 CFR part 63 to the final EPA 
radiation protection standards, as necessary and appropriate. EPA has 
now promulgated its final standards as is discussed below in section 
II. M. 66 FR 32074. NRC's final part 63 contains modifications from its 
proposal necessary to make conforming changes. The NRC final rule and 
EPA's final standards closely resemble the standards as proposed. 
Changes are discussed at section II. M. below, but as in the case of 
the NRC rule, we likewise retain our discussion of the proposed EPA 
rule here on the ground that this chronological approach best advances 
understanding of the development of DOE's guidelines.
2. Structure of Proposed part 197
    The proposed EPA part 197 was structured in two subparts. Subpart A 
of the rule would establish the public health and safety standards for 
storage of spent nuclear fuel and high level waste at Yucca Mountain; 
subpart B would establish the public health and safety standards for 
disposal of spent nuclear fuel and high level waste at Yucca Mountain. 
64 FR 47013-47016. The following is an overview of the main components 
of EPA's proposed rule; in many areas of the rule EPA proposed 
alternative language and requirements for public review and 
consideration. For simplicity, not all of those alternative 
possibilities are presented here.
    For storage of spent nuclear fuel and high level waste, EPA 
proposed a standard limiting the annual committed effective dose 
equivalent (CEDE) to no more than 150 microsieverts (15 millirems 
(mrem)) to any member of the public in the general environment. 64 FR 
47013. This limit would apply to releases from the combination of 
management and storage of spent nuclear fuel and high level waste that 
is within the Yucca Mountain repository (below ground) and outside the 
Yucca Mountain repository but within the Yucca Mountain site 
(aboveground). EPA proposed this standard to be consistent with the 
risk level set in its generic standards for management and storage of 
spent nuclear fuel, high level waste, and transuranic waste, codified 
at subpart A of 40 CFR 191 and with its interpretation of section 801 
of EPACT requiring it to set site-specific standards for storage of 
waste at Yucca Mountain. 64 FR 46983-46984. In EPA's view, storage of 
waste, whether inside the Yucca Mountain repository or outside the 
Yucca Mountain repository but within the Yucca Mountain site, presents 
the same technical situation and is analogous to the storage of 
radioactive waste at other facilities covered by 40 CFR part 191. 
Accordingly, EPA proposed the storage standard for Yucca Mountain be 
essentially the same as the standard applicable to other facilities 
subject to subpart A of 40 CFR part 191.
    For disposal of spent nuclear fuel and high level waste, EPA 
proposed three standards--an individual protection standard, a human 
intrusion standard, and a ground water standard--compliance with which 
DOE would need to demonstrate to the satisfaction of the NRC to ensure 
protection of public health and safety. 64 FR 47013-47016. Under the 
individual protection standard, DOE would be required to demonstrate 
that there is a reasonable expectation that for 10,000 years following 
disposal a hypothetical reasonably maximally exposed individual (RMEI) 
receives no more than an annual committed effective dose equivalent 
(CEDE) of 150 microsieverts (15 millirems (mrem)) from releases from 
the undisturbed Yucca Mountain disposal system. All potential pathways 
must be included in this analysis. In proposing this individual 
protection standard, EPA concluded that radiation containment 
requirements, such as those embodied in 40 CFR part 191, were not 
necessary in order to protect members of the general public from 
releases from a repository at Yucca Mountain.
    For the proposed human intrusion standard, EPA proposed two 
alternative rules, one of which would impose an annual CEDE limit of 
150 microsieverts (15 mrem) to a RMEI based on an assumed human 
intrusion event, while the alternative rule would impose the dose limit 
if complete waste package penetration can be shown to occur before 
10,000 years after disposal. EPA also proposed a rule outlining the 
elements of the human intrusion scenario to be used in the analysis. 64 
FR 47015.
    Under the proposed ground water protection standard, EPA would 
require DOE to provide in its license application a reasonable 
expectation that for 10,000 years of undisturbed performance after 
disposal, releases of radionuclides from radioactive material in the 
Yucca Mountain disposal system will not cause the level of 
radioactivity in the representative volume of ground water at the point 
of compliance to exceed certain limits (e.g., combined beta and photon 
emitting radionuclides cannot exceed a limit of 40 microsieverts (4 
millirems) per year to the whole body or any organ). EPA presented for 
public review and comment several alternatives for the selection of the 
representative volume of water and for the location of the point of 
compliance. 64 FR 47015-47016.
    EPA's proposed approach to setting public health and safety 
standards for a repository at Yucca Mountain followed the NAS 
recommendations and findings. Although EPA proposed some requirements 
in its rulemaking that differ from certain NAS findings and 
recommendations (for example, EPA proposed use of a dose standard 
instead of a risk standard, and use of the RMEI concept instead of 
critical group), EPA's proposed rule is consistent with the

[[Page 57309]]

primary NAS findings and recommendations that a public health standard 
based on risk or dose to an individual member of the public can be 
protective of general public health and safety, and that the Yucca 
Mountain-related physical and geologic processes are sufficiently 
quantifiable and the related uncertainties sufficiently boundable that 
the performance can be assessed over certain time frames. 64 FR 46980-
46983.
    In the case of the individual protection standard, EPA would 
expressly require DOE to use performance assessment to calculate the 
dose limits established in its proposed radiation protection standards 
for disposal. 64 FR 47014. Although EPA generally would not prescribe 
requirements on how the performance assessments would be conducted, it 
would impose certain limitations. For example, proposed section 197.40 
would not require consideration by DOE in its performance assessments 
of events that are estimated to have less than one chance in 10,000 of 
occurring within 10,000 years of disposal. 64 FR 47016. In addition, 
EPA acknowledged certain inherent limitations in DOE's ability to 
demonstrate compliance with the public health and safety standard 
through use of performance assessment, but nevertheless mandated the 
use of that method of assessment. EPA's proposed rule recognized, 
through the concept of reasonable expectation, that, among other 
things, there are inherent uncertainties in making long-term 
projections of the performance of the Yucca Mountain disposal system, 
that performance assessments and analyses should be focused upon the 
full range of defensible and reasonable parameter distributions, and 
that assessments should not exclude important parameters simply because 
they are difficult to quantify precisely to a high degree of 
confidence. 64 FR 46997-46998; 64 FR 47014.

L. DOE's 1999 Notice of Proposed Rulemaking

    On November 30, 1999, DOE published a revised notice of proposed 
rulemaking (64 FR 67054) in order to revise its December 16, 1996, 
proposal (61 FR 66158) to amend 10 CFR part 960, the ``General 
Guidelines for the Recommendation of Sites for Nuclear Waste 
Repositories'' and to issue proposed Yucca Mountain Site Suitability 
Guidelines under a new part 963.
    In its December 16, 1996, proposal, DOE had published proposed 
regulatory amendments to the Guidelines to reflect the prevailing 
scientific view on how to evaluate the suitability of the Yucca 
Mountain site for the development of a nuclear waste repository. 
Because the preliminary site screening stage was complete and Congress 
had required DOE to focus on Yucca Mountain, Nevada, DOE's proposed 
regulatory amendments dealt with provisions of the Guidelines 
applicable to the site recommendation stage. In its November 30, 1999, 
revised proposal, DOE revised the terms of its proposal for three 
reasons.
    First, during the comment period on the December 16, 1996, 
proposal, DOE received comments from members of the public, State and 
local officials of Nevada, the EPA, and the NWTRB, that in substance 
criticized the omission from the proposed regulatory amendments of 
essential details of the criteria and methodology for evaluating the 
suitability of the Yucca Mountain site for the location of a nuclear 
waste repository. Some of the comments made pointed recommendations for 
Guidelines at a more definitive level of specificity than the proposed 
regulatory text provided. Also, there were comments critical of the 
legal basis for DOE's proposal and its consistency with what those 
commenters viewed as DOE's past position on the meaning of sections 
112(a) and 113(b) of the Act. As explained in detail later in this 
notice, DOE concluded that there was enough merit in these comments to 
warrant revision of the proposed regulatory amendments and expansion of 
the explanation of the factual and legal bases for them.
    Second, in December, 1998, DOE issued, pursuant to Congressional 
direction, the Viability Assessment. This document, which is available 
through the Internet on the web site (www.ymp.gov) or in hard copy upon 
request (see FOR FURTHER INFORMATION CONTACT) set forth the bases for 
the site suitability criteria DOE is proposing to use and the 
methodology for applying the criteria to a design for a proposed 
repository at the Yucca Mountain site. DOE can now assist commenters in 
responding to DOE's proposal with appropriate descriptions of, and 
references to, key portions of the Viability Assessment in the 
Supplementary Information.
    Third, after the close of the comment period, as noted above, the 
NRC, consistent with Congressional direction to the EPA to develop a 
site-specific radiation protection standard for the Yucca Mountain 
site, proposed site-specific licensing requirements for that site in a 
new 10 CFR part 63 and to eliminate the site from coverage under 10 CFR 
part 60. Thereafter, EPA issued the Congressionally-mandated proposal 
for site-specific public health and safety standards for a repository 
at Yucca Mountain, to be codified at 40 CFR part 197. Section 113(c) of 
the NWPA provides that a determination of site suitability for 
development as a repository is largely an estimate that an application 
to the NRC for a construction authorization would be successful (42 
U.S.C. 10133(c)). Thus, the details of the EPA and NRC proposals, which 
were not available when DOE formulated its December 16, 1996, proposal, 
affected the likely continuing usefulness of existing 10 CFR part 960, 
the text of DOE's proposed regulatory amendments, and the bases for 
those proposed amendments in performing the analysis required by 
section 113. For reasons explained in detail in its 1999 revised 
proposal, DOE presented the view that the proposed part 63, if 
finalized without significant change, would make it illogical to apply 
the existing provisions of 10 CFR part 960, which are explicitly linked 
to provisions of the NRC's part 60. Moreover, the details of the NRC's 
proposal suggested the need for making conforming changes to the 
December 16, 1996, proposal to set forth the requirements for carrying 
out a total system performance assessment as the method for applying 
the site suitability criteria to the data developed during site 
characterization of the Yucca Mountain site.
    Consistent with EPA's proposal for site-specific public health 
standards and NRC's proposal to limit part 60 and to establish a new 
part 63 for the Yucca Mountain site, DOE proposed regulations to: (1) 
Limit 10 CFR part 960 to preliminary site screening for repositories 
located elsewhere than Yucca Mountain; and (2) establish a new part 963 
to set out the site suitability criteria and the methods for 
considering the potential of the Yucca Mountain site for a nuclear 
waste repository under those criteria. Although closely linked to the 
NRC's proposed part 63 licensing criteria and requirements, as is 
necessary and appropriate, DOE's proposed regulations in part 963 in no 
way determined that the site necessarily will or will not meet all 
requirements to obtain a license from the NRC, or to be recommended by 
the Secretary for development as a geologic repository. Rather, DOE 
issued the proposed rule to better define policies and criteria to 
guide the determination of the suitability of the Yucca Mountain site 
in terms of, and based on, the information and data developed through 
the program of site characterization

[[Page 57310]]

activities DOE has conducted over the years at Yucca Mountain under 
section 113(b) of the NWPA.
    In issuing the revised notice, DOE sought to improve its policies 
for determining site suitability by enhancing their transparency, 
validity, and verifiability. In terms of enhancing transparency, DOE 
aimed at regulations that are easier to read and understand. In terms 
of enhancing validity, DOE aimed at an explanation of the legal and 
scientific basis for the regulations that shows how DOE's policies 
logically follow from scientifically supportable and legally sound 
premises. In terms of enhancing verifiability, DOE aimed at showing 
that the scientific conclusions underlying its policies are based on 
documented empirical results of experiments, and computer analyses of 
relevant data so as to allow verification of the conclusions DOE might 
eventually draw from known facts in evaluating the suitability of Yucca 
Mountain as a potential repository site.
    DOE followed the consultation procedures set forth in section 
112(a) of the NWPA for promulgation of the Guidelines in seeking review 
and comment on this revised proposal.

M. Final EPA and NRC Regulations

    On June 13, 2001, EPA issued 40 CFR part 197 (66 FR 32074-32135), 
establishing public health and environmental radiation protection 
standards for a geologic repository at the Yucca Mountain site. The 
final standards are consistent with the proposed standards, and reflect 
changes largely associated with the selection, from among proposed 
alternatives, of certain implementing assumptions and conditions. 
Consistent with the EPA proposed rule, final 40 CFR part 197 subpart A 
prescribes a standard for storage limiting the annual committed 
effective dose equivalent to no more than 15 millirems (mrem) to any 
member of the public in the general environment from the management and 
storage of spent nuclear fuel and high-level waste that is within the 
Yucca Mountain repository (below ground) and outside the Yucca Mountain 
repository but within the Yucca Mountain site (above ground). 
Similarly, consistent with the EPA proposed rule, final 40 CFR part 197 
subpart B prescribes three public health and environmental standards 
for disposal--an individual protection standard, a groundwater 
standard, and a human intrusion standard--governing the disposal of 
spent nuclear fuel and high level waste at a Yucca Mountain repository. 
The numerical radiation limits associated with each of the three 
standards are the same as in EPA's proposal. For the individual 
protection standard, the dose limit is 15 mrem annual committed 
effective dose to the reasonably maximally exposed individual. 40 CFR 
part 197.20. For the human intrusion standard, the dose limit is 15 
mrem in the case where a stylized human intrusion event is projected to 
occur before 10,000 years without recognition by the driller. 40 CFR 
part 197.25. For the ground water protection standard, the limit for 
radionuclide concentrations in the representative volume of water is 4 
mrem per year to the whole body or any organ, and radionuclide 
concentration limits of 5 and 15 picocuries per liter, respectively, 
for radium-226 and radium-228, and gross alpha activity. 40 CFR part 
197.30. Consistent with the EPA proposed rule, the final rule requires 
that DOE demonstrate compliance with the individual protection standard 
by means of performance assessment. 40 CFR part 197.20.
    In finalizing the rule, EPA selected and refined the requirements 
for certain implementing assumptions and conditions for which EPA 
sought public comment on the draft rule. For example, the location of 
the reasonably maximally exposed individual was selected to be the 
point above the highest concentration of radionuclides in the plume of 
contamination (40 CFR part 197.21), but not further from the repository 
than the southernmost boundary of the Nevada Test Site, that is, line 
of latitude 36 deg. 40' 13.6661" North. 66 FR 32093. With respect to 
the ground water standard, EPA defined the size of the representative 
volume of water to be used in the compliance calculation to be 3,000 
acre-feet based on a cautious but reasonable estimate of the size of 
the ground water resources in the area of compliance and the current 
and projected uses of that resource. 66 FR 32113. In determining 
compliance with the human intrusion standard, EPA selected a standard 
that requires DOE to determine the earliest time after disposal that a 
waste package would degrade to such an extent that a driller would not 
recognize the waste package. 40 CFR part 197.25. If this could occur at 
or before 10,000 years after disposal, then DOE must demonstrate the 
dose to the RMEI does not exceed 15 millirem; otherwise, the results of 
the analysis must be included in the Yucca Mountain environmental 
impact statement as an indicator of long-term performance. 40 CFR part 
197.25.
    Following promulgation of 40 CFR part 197, the NRC promulgated 10 
CFR part 63 on November 2, 2001. In finalizing part 63, the NRC made 
changes to its technical requirements and criteria necessary to be 
consistent with the final environmental standards for Yucca Mountain 
promulgated by EPA. The NRC identified three categories of changes to 
incorporate the EPA standards into its rule: (1) the addition of two 
subparts--Subpart K for storage and Subpart L for disposal--
corresponding to Subparts A and B of part 197, respectively; (2) the 
adoption of provisions (e.g., EPA definitions) precisely as they appear 
in part 197 and nonsubstantive changes to conform to the regulatory 
style of the NRC; and (3) the adoption of additional specifications and 
requirements where necessary to carry out the NRC's responsibilities as 
the implementing agency for the standards. 66 FR 55733.
    Accordingly, in final form, 10 CFR part 63 incorporates the public 
health and environmental standards for the preclosure (management and 
storage) and postclosure (disposal) periods as defined in 40 CFR part 
197, along with many of the assumptions and requirements to be met in 
demonstrating compliance with those standards. With respect to 
demonstrating compliance with preclosure management and storage 
requirements, the NRC adopted the standard set forth in 40 CFR 197.4, 
and made clarifying changes to the titles and descriptions of the 
requirements for the analysis of preclosure operations and safety. With 
respect to demonstrating compliance with postclosure requirements, NRC 
adopted the standards in 40 CFR part 197, Subpart B, added some 
implementing provisions, and clarified language in the rule. For 
example, NRC adopted the reasonably maximally exposed individual, 
instead of the average member of the critical group, as the 
hypothetical person for whom radiation dose limits are to be calculated 
to demonstrate compliance with the individual protection and human 
intrusion standards. 10 CFR 63.311, 63.312. In addition, the NRC added 
standards for ground water protection, and the associated requirements 
for calculating radionuclide releases to the ground water, which were 
not addressed in proposed part 63. 10 CFR 63.331. NRC also revised its 
human intrusion standard to conform to 40 CFR part 197 requirements 
that require DOE to estimate when a waste package will be fully 
breached within 10,000 years after disposal to such an extent that the 
driller would not recognize the package, and, based on this analysis, 
determine whether the 15 millirem dose limits

[[Page 57311]]

would apply or whether the analysis need only be incorporated into the 
Yucca Mountain environmental impact statement. 10 CFR 63.321. Other 
prescribed assumptions, such as the characteristics of the RMEI and the 
reference biosphere (10 CFR 63.312 and 63.305, respectively), and the 
definition of representative volume of water for calculating the 
radionuclide releases to the ground water (10 CFR 63.332), were adopted 
by the NRC as promulgated by the EPA.
    As explained in section VI of this SUPPLEMENTARY INFORMATION, DOE 
has modified part 963 as necessary to conform to the changes made in 
final part 63. These changes to part 963 do not require a reopening of 
the public comment period on part 963, as they consist of minor 
clarifications and non-discretionary, conforming changes to make part 
963 consistent with final part 63, as it implements final part 197.

N. NRC Concurrence

    DOE provided a draft final version of the part 963 rule to the NRC 
for its concurrence. NRC's concurrence on this rule was obtained by DOE 
on October 19, 2001; a notice of this decision was published in the 
Federal Register on October 26, 2001. 66 FR 54303. NRC concurrence was 
contingent on a final part 963 rule that was not substantively 
different from the draft final version reviewed by the NRC for 
concurrence. As explained above and in section VI of this SUPPLEMENTARY 
INFORMATION, DOE has made only minor clarifications and non-
discretionary, conforming changes to part 963 to make it consistent 
with final NRC and EPA regulations.

III. Basis for Final Rule

A. Legal Authority and Necessity to Amend the Guidelines and Criteria

1. Overview
    Section 112(a) of the NWPA explicitly establishes DOE authority to 
``issue general guidelines for the recommendation of sites for 
repositories'' and to ``use [the] guidelines established under this 
subsection in considering candidate sites for recommendation under 
subsection (b).'' Subsection (b) of section 112 provides for a process, 
to be conducted following promulgation of the Guidelines that would 
result in: (1) The nomination of 5 potential sites for 
characterization; and (2) the selection of 3 of those 5 sites for 
recommendation to the President as suitable for site characterization 
activities. Section 112(a) also includes explicit authority to revise 
the Guidelines, from time to time, consistent with the provisions of 
112(a).
    Shortly after the enactment of the NWPA, DOE promulgated Guidelines 
(codified at 10 CFR part 960) to implement section 112. The approach 
taken at that time was to structure the Guidelines to provide a 
framework not only for the section 112 decisions (for which it was 
statutorily required) but also for subsequent steps in the site 
selection process. Consistent with this approach, the Guidelines as 
originally promulgated also addressed actions to be taken under 
sections 113 and 114. Section 113(b) provided that DOE should include 
in its site characterization plan ``criteria to be used to determine 
the suitability of [a] site for the location of a repository, developed 
pursuant to section 112(a).'' 49 FR 47730. DOE did not need to decide 
whether this meant that it had to use the same Guidelines it had 
previously developed under section 112(a) or whether it was free to use 
other criteria provided it developed them pursuant to the procedures 
set out in 112(a). It rejected the alternative suggested, that it use 
the NRC licensing standards, because (1) the Guidelines had been 
written to be consistent with the licensing standards, and (2) the 
Guidelines were more relevant than the licensing standards to the 
particular decision at issue, that is, they were ``intended to be used 
in deciding which among the characterized sites is to be recommended to 
the President, the Congress, and finally to the NRC for appropriate 
approvals.'' 49 FR 47730. (emphasis added) That approach was 
understandable in 1984 when DOE anticipated the need to evaluate by 
comparison multiple characterized sites, a comparison similar to the 
choosing of sites for characterization for which the Guidelines were 
required by section 112(a) of the NWPA. After the 1987 amendments to 
the NWPA designated Yucca Mountain as the only site to be 
characterized, DOE indicated that it nevertheless need not revise the 
Guidelines because it could apply some, but not all, of the Guideline 
provisions in the Site Characterization Plan prepared under section 
113(b) of the NWPA as criteria to determine site suitability. DOE/RW-
0199 (1988). DOE reiterated that conclusion in 1995 when it 
reconsidered the Guidelines in the context of evaluating the 
suitability of the Yucca Mountain site under the Site Characterization 
Plan. DOE decided then that ``[b]ecause DOE need apply only the 
relevant provisions'' of the Guidelines, amending or supplanting them 
with ``Guidelines specifically tailored'' to evaluating the suitability 
of the Yucca Mountain site was ``not required at this time.'' 60 FR 
47737, 47740 (1995).
    As discussed in greater detail below, DOE has now determined that a 
new approach is called for in light of the cumulative effect of the 
intervening legislative, regulatory, and technical developments that 
have occurred since 1984. As a result of these developments, neither 
explanation that DOE gave in 1984 for using the part 960 Guidelines--
that they were consistent with the NRC's licensing criteria and that 
they were an appropriate tool because they were developed to assist in 
making comparative judgements about sites--remains valid in today's 
circumstances. Congress and the regulatory agencies acting pursuant to 
Congressional directive have changed the regulatory landscape in such a 
way that the part 960 Guidelines no longer fit comfortably within that 
framework. And the 1987 amendments to the NWPA have eliminated any 
obligation on DOE's part to make comparative judgements about sites in 
the course of making the suitability determination. Accordingly, DOE 
has now developed criteria, using section 112(a) procedures in the 
development of these criteria, but not adopting the particular section 
112(a) Guidelines as these criteria, to form the basis for a 
determination of the suitability of the Yucca Mountain site for the 
location of a repository. The rationale for this approach stems from 
the combination of the 1987 amendments' directive to DOE to focus on 
Yucca Mountain alone, the basic analysis for assessing repository 
performance recommended by the National Academy of Sciences, which 
differs from that embedded in the 1984 Guidelines, and the adoption by 
the NRC of new regulations for licensing repositories which, under the 
NWPA's structure, must define the areas and methodology of DOE's 
inquiries into Yucca Mountain's suitability.
    Accordingly, DOE today issues final revisions to the existing 
Guidelines at 10 CFR part 960 to limit their application to only the 
initial site selection process set forth in section 112. DOE may make 
additional revisions to these Guidelines if, in the future, 
circumstances were to change and DOE were to reinitiate a preliminary 
site screening process under section 112. Further, DOE today 
promulgates a new rule, consistent with section 113(b)(1)(A)(iv), to 
establish criteria to be used in determining the suitability of Yucca 
Mountain for the location of a geologic repository. The criteria 
identified in this new rule allow for consideration of the impact of 
the geologic factors and considerations

[[Page 57312]]

referenced in section 112(a), as they relate to DOE's current 
scientific understanding and methodology for assessing the suitability 
of the Yucca Mountain site as a location for a repository.
2. Section 112
    DOE's approach in today's final rule is consistent with the text of 
section 112(a) and the basic structure of the NWPA, as originally 
enacted and as amended. As originally enacted, the NWPA set up a 
sequential process for selecting, comparing, and evaluating potential 
sites for the development of a geologic repository for high-level 
waste. The 1987 amendments eliminated any continued comparison of 
sites; only Yucca Mountain is authorized for site characterization 
activities leading to possible recommendation as a repository site. 
Beyond the first step in the process, recommendation of multiple sites 
for site characterization (section 112), there is no explicit direction 
in the Act (in its original enactment or amendment) whether or how to 
utilize the Section 112(a) Guidelines in the succeeding site selection 
processes (sections 113 and 114). Instead, section 112(a) specifies the 
intended use of the Guidelines: ``[t]he Secretary shall use guidelines 
established under this subsection in considering sites to be 
recommended for site characterization under section 112(b).'' Likewise, 
the environmental assessment of the various sites nominated for 
characterization pursuant to section 112 is to include ``evaluation'' 
of each nominated site under each Guideline not requiring 
characterization for its application and all the Guidelines pertinent 
to whether or not a site is ``suitable for site characterization'' (42 
U.S.C. 10132(b)(1)(D)(I)&(ii)). Nowhere in its text does section 112 
require any additional use of the Guidelines.
    In sum, the text of section 112 and its relation to other 
provisions in the NWPA indicate that the Guidelines are to govern the 
process of selecting and comparing among potential sites to determine 
which sites are appropriate to proceed to the next, more detailed 
evaluation stage, site characterization. In contrast, nothing in the 
text of section 112 specifies that the Guidelines it requires are also 
to govern the process for determining site suitability and site 
recommendation under sections 113 and 114.
3. Section 113
    Section 113 of the NWPA requires DOE to prepare a site 
characterization plan for a candidate site selected under section 112 
for site characterization activities. A required element of a site 
characterization plan is ``criteria to be used to determine the 
suitability of such candidate site for the location of a repository, 
developed pursuant to section 112(a)'' (42 U.S.C. 10133(b)(1)(A)(iv) 
(emphasis added)). The NWPA does not define the term ``criteria,'' 
thereby suggesting the Secretary has broad discretion to determine the 
scope and content of the criteria in question.
    Section 113(b) requires that the ``criteria'' to be included in the 
Site Characterization Plan be ``developed pursuant to section 112(a)'' 
of the NWPA. Because section 112(a) of the NWPA is devoted to the 
``Guidelines'' for selecting candidate sites while section 113(b) is 
devoted to the ``criteria'' under which selected candidate sites 
subsequently are to be characterized, it is necessary to consider what 
section 113's requirement that the criteria be ``developed pursuant to 
section 112(a)'' means in terms of any required correspondence or other 
relationship between the Guidelines and the 113(b) criteria.
    It is unlikely that the Congress intended to require the 
``criteria'' to be the Guidelines themselves. It would have been simple 
enough for Congress to have legislated that policy in section 113(b) by 
a straightforward requirement that the Site Characterization Plan 
specify that the ``Guidelines developed pursuant to section 112(a)'' 
would be used ``to determine the suitability of each candidate site'' 
(Compare 42 U.S.C. 10133(b)(1)(A)(iv)). Had Congress intended this 
policy result it is unlikely that it would have chosen such an 
elliptical and opaque way of expressing it as the actual statutory text 
that does not use the term ``Guidelines'' at all. And a construction of 
section 113(b) requiring the suitability ``criteria'' to be the same as 
the section 112 Guidelines would risk tension with section 113(c)'s 
restriction that limits DOE to conducting ``only'' characterization 
activities ``necessary to provide the data required'' to prepare an NRC 
license application. The NRC, of course, is not required to base its 
licensing standards on the Guidelines adopted by DOE under section 
112(a) of the NWPA (although it was required to concur in them), nor 
does section 112 afford the NRC the ability to compel DOE to 
reformulate the Guidelines should the NRC determine to amend or 
supplant its licensing standards.
    On the other hand, section 112(a) contains specific procedural 
mandates required to be employed by DOE in issuing or revising the 
Guidelines. Before DOE may promulgate the Guidelines, DOE must consult 
with several specified federal agencies and with ``interested 
Governors'' (42 U.S.C. 10132(a)). In addition, the NRC must 
``concur[]'' in the issuance of the Guidelines. Id. These distinctive 
procedural requirements obviously are tailored to the particular 
circumstances of site decision-making under the NWPA and specify 
procedural requirements that would not otherwise obtain under the 
rulemaking provisions of the Administrative Procedure Act or the 
rulemaking provisions of the Department of Energy Organization Act that 
were in force when the NWPA was adopted. It would therefore make sense 
that Congress would want these procedures used for developing the 
section 113 ``criteria'' as well as the section 112 ``guidelines.''
    The requirement of section 113(b) that the SCP's ``criteria'' for 
characterizing sites be ``developed pursuant to section 112(a)'' 
therefore is best understood as mandating observance of the special 
procedural requirements of section 112(a) in formulating or altering 
the section 113(b) ``criteria.'' This understanding of the statutory 
text seems the most faithful to its explicit terms and the larger 
statutory context in which it occurs. Moreover, it seems the only 
understanding of section 113(b) that is consistent with the 1987 
changes to the NWPA (which mandated exclusive characterization work for 
the Yucca Mountain site without amending section 113(b) despite 
amending the statute elsewhere to remove the element of comparing 
sites, to which the Guidelines of section 112(a) were devoted). This 
understanding of the requirements of section 113(b) also comports with 
DOE's prior understanding, as was described in the 1995 notice, that 
not all the original Guideline elements need be applied in site 
characterization under section 113 of the NWPA. To the extent the 
statutory provisions are ambiguous, this interpretation seems best 
designed to result in the establishment of ``criteria'' that comport 
with what DOE believes to be the better policy approach to determining 
site suitability.

B. Events Necessitating Amendment of the Guidelines and Criteria

1. Congressional Redirection of the Program
    Since the NWPA was enacted in 1982 and the Guidelines promulgated 
in 1984, Congress has made major changes to the framework for 
developing a geologic repository. These changes are described below 
and, in part, form the basis for the revisions to 10 CFR part

[[Page 57313]]

960 and the promulgation of a new 10 CFR part 963 as presented in this 
notice of final rulemaking.
    1987 Amendments to the NWPA. Congress amended the NWPA in 1987 to 
select Yucca Mountain as the only site to be characterized. Congress, 
accordingly, directed DOE to terminate site-specific activities at the 
two other sites that had been recommended for site characterization in 
1986 (42 U.S.C. 10172). Further, Congress restricted DOE's 
characterization activities at Yucca Mountain to only those the 
Secretary considers necessary to provide the data required for 
evaluation of the suitability of the site for NRC construction 
authorization (i.e., license application), and for compliance with the 
National Environmental Policy Act of 1969, as modified to excuse DOE 
from conducting analyses of alternatives that NEPA would otherwise 
require. A provision was added to the NWPA to provide for termination 
of site characterization activities at Yucca Mountain if at any time 
the Secretary determines that Yucca Mountain is unsuitable for 
development as a repository.
    Although the 1987 amendments to the Act were decisive in focusing 
the repository program and DOE's efforts on one specific site, for many 
years DOE maintained that these changes were not so significant as to 
warrant amendment of the Guidelines. Instead, DOE believed the 
Guidelines, for the most part, could be applied to Yucca Mountain for 
purposes of determining the suitability of the site (because Yucca 
Mountain already had been found suitable for characterization under 
other provisions of the Guidelines) in support of a possible site 
recommendation by the Secretary. DOE believed that the only changes to 
the Guidelines necessitated by the 1987 amendments were to eliminate 
consideration of those parts of the Guidelines related to comparative 
analysis. Similarly, the NRC had not made significant modifications to 
its technical requirements and criteria in 10 CFR part 60 as a result 
of the 1987 amendments to the Act.
    1992 Energy Policy Act. In the 1992 Energy Policy Act, Congress 
reinforced its directive that Yucca Mountain was to be the exclusive 
focus of the nation's repository program, by explicitly extending that 
directive not only to DOE activities, but also to activities of EPA and 
NRC, the other federal agencies with authority and responsibility over 
the repository program. Section 801 of the EPACT directed the EPA to 
promulgate, by rule, new public health and safety standards for the 
protection of the public from releases from radioactive materials 
stored or disposed of in a repository at the Yucca Mountain site. 
Unlike EPA's previous standard, which applied generally to geologic 
repositories and included limits on radioactive releases to the 
environment, the new standards were required to prescribe the maximum 
annual effective dose equivalent to individual members of the public 
from releases to the accessible environment from radioactive materials 
stored or disposed of at Yucca Mountain. To aid EPA in this process, 
Congress directed a National Academy of Sciences (NAS) study to provide 
findings and recommendations on reasonable standards for protection of 
the public health and safety. EPA was required to base its new 
standards on the findings and recommendations of the NAS. For Yucca 
Mountain, these standards would replace the generally applicable 
standards for the protection of the general environment that the EPA 
had promulgated at 40 CFR part 191 pursuant to section 121 of the NWPA.
    The EPACT also directed the NRC to modify its technical 
requirements and criteria, as necessary, to be consistent with the 
EPA's new standards. In addition, NRC was directed to ensure that, 
consistent with the NAS findings and recommendations, its requirements 
and criteria for postclosure oversight of a Yucca Mountain repository 
would be sufficient to prevent any activities at the site from posing 
an unreasonable risk of breaching the engineered and natural barriers 
of the site, and to prevent any increase in exposure of individual 
members of the public beyond allowable limits.
    These changes were significant because they set the stage for 
future regulatory changes governing the standards a Yucca Mountain 
repository must meet to ensure public health and safety, and to obtain 
a license for construction. The ability to meet regulatory standards 
has always been a dominant factor in the site selection process. This 
requirement is reflected in the structure of the Guidelines, is 
reinforced by the 1987 amendments to the Act, and is a prime focus of 
DOE's site characterization program. Thus, the Congressional mandate in 
the EPACT directing new and revised regulations governing geologic 
disposal at Yucca Mountain necessarily affected DOE's formulation of 
the criteria that will be used to determine the suitability of Yucca 
Mountain as a site for development of a repository. Until recently, 
however, the full extent and nature of those impacts had not been 
defined. The NRC's proposal to amend 10 CFR part 60, its technical 
requirements and criteria for licensing a repository to exclude Yucca 
Mountain from their scope, to add a new part 63 specific to Yucca 
Mountain, provided DOE with an outline of anticipated regulatory 
changes, and signaled for DOE how and why it must conform its 
Guidelines and criteria for determining the suitability of the Yucca 
Mountain site for the location of a repository.
    Fiscal Years 1996 and 1997 Appropriations Acts and the Viability 
Assessment. Finally, in response to budgetary concerns, the Conference 
Report on the Energy and Water Development Appropriations Act, 1996 
(Pub. L. No. 104-46) (H.R. Rep. No. 293, 104th Cong., 1st Sess. 68 
(1995)) directed the DOE to focus on only those activities necessary to 
assess the performance of a repository at the Yucca Mountain site and 
to collect the scientific information needed to determine the site's 
suitability. DOE responded by revising its Program Plan for 1996 in 
which it indicated that, among other changes, DOE would complete a 
viability assessment of the Yucca Mountain site in 1998, and would 
develop a proposal to amend the Guidelines and develop new regulations 
specific to the Yucca Mountain site. Congress indicated its approval of 
the changes by directing that appropriated funds be used in accordance 
with the revised program plan. Congress reinforced this direction in 
the Fiscal Year 1997 Energy and Water Appropriations Act, where it 
mandated that DOE provide to the Congress and the President a viability 
assessment of the Yucca Mountain site in 1998.
    These changes in budget for DOE's civilian radioactive waste 
management program indicate congressional intent for DOE to focus site 
characterization activities on assessing the viability and suitability 
of Yucca Mountain, and to complete those activities in the near term. 
In light of this congressional direction, it is reasonable for DOE to 
amend the Guidelines in a manner that acknowledges Yucca Mountain as 
the only site at which site characterization has occurred and for which 
DOE would need to conduct a suitability evaluation under section 
113(b).
2. Consistency Between DOE and NRC Regulations
    Procedural Consistency. The DOE's site characterization suitability 
criteria must be consistent with the NRC's licensing criteria if the 
DOE is to present a potentially successful license application to the 
NRC. Such consistency originally was attained in the Guidelines through 
the NRC's concurrence process, as required by section 112(a) of the 
NWPA. DOE stated

[[Page 57314]]

in proposed part 963 that it would preserve this consistency in the 
final suitability criteria by ensuring that they reflect the changes to 
the licensing criteria in NRC's new rule 10 CFR part 63, and by 
soliciting NRC concurrence on DOE's final amendments to the guidelines 
and the promulgation of a new regulation at 10 CFR part 963.
    Substantive Consistency. NRC's proposed new rule establishing the 
technical requirements and criteria for repository licensing at Yucca 
Mountain, proposed 10 CFR part 63, was different from its prior general 
rule on repository licensing, 10 CFR part 60. DOE accordingly had 
little choice but to propose site suitability criteria that would be 
consistent with the NRC's proposed licensing requirements. The 
suitability of a site for the location of a repository is a function of 
the DOE's ability to demonstrate the site can meet applicable 
regulatory requirements. Section 113 makes clear that the evaluation of 
``suitability'' is an evaluation of the ``suitability of [the Yucca 
Mountain] site for an application to be submitted to the [NRC] for a 
construction authorization for a repository at such site'' and that the 
function of site characterization is to generate the data to evaluate 
whether a site can meet that standard. DOE has conducted the site 
characterization program at Yucca Mountain with that statutory 
objective of evaluating its ability to obtain construction 
authorization from the NRC for a repository at that site (i.e., to meet 
NRC licensing requirements and EPA health and safety standards, as 
implemented by NRC through the license). DOE could not scientifically 
and technically arrive at a suitability determination, without 
conforming its criteria for suitability to the proposed NRC technical 
requirements and criteria for a repository license. Such conforming 
criteria are finalized in this notice.
    The NRC proposed rule part 63 was a departure from the philosophy 
and technical requirements of 10 CFR part 60. It was based on the 1995 
NAS report recommending a risk-limit standard for a repository at Yucca 
Mountain. The NRC timed publication of its proposal to ensure NRC would 
have sufficient time, once EPA issued its new standard, to put the new 
licensing standards in effect. The proposed rule embodied a new 
approach of risk-informed, performance-based regulation, and was 
specific to Yucca Mountain. The old rule relied on subsystem 
performance objectives and a release limit standard. Under the proposed 
rule, the performance of a Yucca Mountain repository would be evaluated 
against a health-based standard in consideration of risk to a 
hypothetical critical group and this standard would be the only 
quantitative standard for the postclosure performance of the 
repository. The new rule would require DOE to demonstrate compliance 
with postclosure technical criteria through performance assessments, 
and preclosure criteria through an integrated safety analysis. The new 
approach embodied in the proposed rule would eliminate current part 60 
design and siting criteria, as well as quantitative subsystem 
requirements, but would add specific requirements for the content of 
performance assessments to ensure their sufficiency and adequacy. In 
other words, a proposed Yucca Mountain repository would be evaluated as 
an entire system, not by assessing its individual parts in isolation, 
in order to determine whether or not it meets applicable standards to 
protect public health and safety.
    It was clear that if this proposal was finalized in substantially 
the same form as proposed the current structure of DOE's part 960 
guidelines, which is premised on a demonstration of system and 
subsystem technical requirements, would no longer be consistent with, 
and in some cases might conflict with, the NRC technical requirements 
to support a license application. For example, several of DOE's part 
960 guidelines require compliance with the siting and design 
requirements set forth in 10 CFR 60.113, 60.122 and 60.133. Those 
requirements did not exist in proposed part 63 and would not be 
applicable to Yucca Mountain under proposed amendments to part 60. 
Those requirements are subsystem performance requirements that are 
inconsistent with the NRC's new approach of evaluating the technical 
merits of a potential site based on the performance of the repository 
system as an integrated whole, and not on the performance of each part 
independent of the other parts.
    A good example of this is the geohydrology guideline at part 960.4-
2-1. Under this guideline, DOE set qualifying and disqualifying 
conditions for the geohydrology of a site. The qualifying condition for 
geohydrology requires that a site be capable of compliance with 
radionuclide release limits set by EPA in 40 CFR part 191, and by NRC 
in 10 CFR 60.112, as well as compliance with DOE subsystem performance 
requirements that mirror NRC requirements in 60.113. The Yucca Mountain 
site has been exempted by the EPACT from compliance with the 
containment limits set by EPA under 40 CFR part 191, and the NRC's 
proposed amendments to 10 CFR part 60 nullified the applicability of 
60.113 to Yucca Mountain and create a new part 63 for which there is no 
analogous release limit or subsystem performance objective for 
geohydrology. Accordingly, it was clear that it would be illogical for 
DOE to reach a finding relative to this qualifying condition, as 
required by Appendix III, based on regulatory requirements that no 
longer would be applicable to the Yucca Mountain site and therefore 
could not support a determination regarding site suitability for the 
Yucca Mountain site.
    The DOE Guideline 960.4-2-1 also contains a disqualifying 
condition. Under this condition, DOE would disqualify a site if the 
pre-waste emplacement ground water travel time from the disturbed zone 
to the accessible environment is expected to be less than 1,000 years 
along any pathway of likely and significant radionuclide travel. Under 
the analogous NRC provision, 60.113, there is a performance objective 
directing that the pre-waste emplacement ground water travel time along 
the fastest path of likely radionuclide travel from the disturbed zone 
to the accessible environment must be at least 1,000 years or such 
other travel time as approved by the NRC. Under NRC's proposed 
revisions to its regulations, this subsystem performance requirement 
would no longer apply to a repository at Yucca Mountain under part 60, 
and it would not exist, nor would there be any requirement similar to 
it, under new part 63. Accordingly, it would be illogical for DOE to 
reach a finding relative to this disqualifying condition, as required 
by Appendix III, based on regulatory requirements that no longer would 
be applicable to the Yucca Mountain site and therefore could not 
support a determination regarding the site suitability of the Yucca 
Mountain site.
    Below is a table further illustrating the inconsistencies between 
the current Guidelines and the proposed part 63. Table 1 provides a 
cross walk between the technical guidelines to be applied as the 
criteria under section 113(b), their analog in existing part 60, and 
their analog, if any, in proposed part 63.

[[Page 57315]]



 
                                                     Table 1
----------------------------------------------------------------------------------------------------------------
                                                                                                New 10 CFR part
            Section                    Guideline             Condition        10 CFR part 60           63
----------------------------------------------------------------------------------------------------------------
4-1(a)........................  System................  Qualifying........  60.112...........  63.113
4-2-1(a)......................  Geohydrology..........  Qualifying........  60.112/113.......  63.113/None
4-2-1(d)......................  ......do..............  Disqualifying.....  60.113(a)(2).....  None
4-2-2(a)......................  Geochemistry..........  Qualifying........  60.112/113.......  63.113/None
4-2-3(a)......................  Rock Characteristics..  Qualifying........  60.112/113.......  63.113/None
4-2-4(a)......................  Climatic Changes......  Qualifying........  60.112...........  None
4-2-5(a)......................  Erosion...............  Qualifying........  60.112...........  None
4-2-5(d)......................  ......do..............  Disqualifying.....  60.122(b)(5).....  None
4-2-6(a)......................  Dissolution...........  Qualifying........  60.112...........  None
4-2-6(d)......................  ......do..............  Disqualifying.....  60.112...........  None
4-2-7(a)......................  Tectonics.............  Qualifying........  60.112...........  None
4-2-7(d)......................  ......do..............  Disqualifying.....  60.112...........  None
4-2-8(a)......................  Natural Resources.....  Qualifying........  60.122(c)(1).....  None
4-2-8(d)(1)...................  ......do..............  Disqualifying.....  60.122(c)(1).....  None
4-2-8(d)(2)...................  ......do..............  Disqualifying.....  60.122(c)(1).....  None
4-2-9 (a).....................  Site Ownership and      Qualifying........  60.121...........  63.121
                                 Control.
5-1(a)(1).....................  System................  Qualifying........  60.111...........  63.111
5-1(a)(3).....................  System................  Qualifying........  None.............  None
5-2-1(a)......................  Population Density and  Qualifying........  60.111...........  63.111
                                 Distribution.
5-2-1(a)(1)...................  ......do..............  Disqualifying.....  60.122(6)........  None
5-2-1(a)(2)...................  ......do..............  Disqualifying.....  60.122(6)........  None
5-2-1(a)(3)...................  ......do..............  Disqualifying.....  None.............  None
5-2-2(a)......................  Site Ownership and      Qualifying........  60.121...........  63.121
                                 Control.
5-2-3(a)......................  Meteorology...........  Qualifying........  60.111...........  63.111
5-2-4(a)......................  Offsite Installations   Qualifying........  None.............  None
                                 and Operations.
5-2-4(d)......................  ......do..............  Disqualifying.....  None.............  None
5-2-8(a)......................  Surface                 Qualifying........  60.122(c)(1).....  None
                                 Characteristics.
5-2-9(a)......................  Rock Characteristics..  Qualifying........  60.133(a)(1).....  None
5-2-9(d)......................  ......do..............  Disqualifying.....  None.............  None
5-2-10(a).....................  Hydrology.............  Qualifying........  60.111...........  None
5-2-10(d).....................  ......do..............  Disqualifying.....  None.............  None
5-2-11(a).....................  Tectonics.............  Qualifying........  60.122(b)(1).....  None
5-2-11(d).....................  ......do..............  Disqualifying.....  None.............  None
----------------------------------------------------------------------------------------------------------------

    As demonstrated in the above table, in most cases there is no 
analog between the DOE Guidelines and NRC's proposed part 63. In 
addition, the Guidelines could not continue to reference and rely on 
revised part 60, since NRC's proposed revisions to part 60 would make 
them inapplicable to a repository at Yucca Mountain. Under the 
circumstances, it would be irrational and difficult, if not impossible, 
for DOE to apply the Guidelines in their current form.
    Under these changed circumstances, DOE felt it had to act to amend 
its outdated Guidelines and conform its site suitability criteria to 
the NRC rule for licensing a Yucca Mountain repository.

3. Improvements in Analytical Methods

    DOE's final changes will also serve to conform the rules for 
assessing the suitability of a site with the current scientific and 
technical methods developed and utilized by DOE in its site 
characterization program. The final changes in the regulatory scheme 
reflect the advances in the scientific and technological understanding 
of the processes relevant to assessing the long-term performance of a 
geologic repository. The regulatory revisions issued by EPA, NRC and 
DOE, mark a change from generic regulations based on limited 
information about geologic disposal developed early in the Nation's 
quest for sites for geologic disposal, to regulations promulgated 
specifically for the Yucca Mountain site that reflect over 20 years of 
data collection and intensive site characterization activities at the 
Yucca Mountain site. It would be irrational for DOE to ignore these 
changes, and continue to rely on technical requirements that are not 
aligned with, and are not supported by, the prevailing scientific 
knowledge and understanding.
    As recognized by the NRC in its proposed part 63, during the more 
than 15 years since the NRC promulgated its initial technical criteria 
at 10 CFR part 60 (and DOE promulgated matching technical requirements 
in 10 CFR part 960), there has been considerable evolution in the 
capability of technical methods for assessing the performance of a 
geologic repository at Yucca Mountain. 64 FR 8640-8641. These advances 
result from both improved computer capability and better analytical 
methods. Indeed, these changes for the first time enable the vast 
quantities of data that have been collected through site 
characterization to all be used in models that more accurately model 
site performance. NRC stated that these new methods were not envisioned 
when the part 60 criteria were established, and that their 
implementation allows for the use of more effective and efficient 
methods of analysis for evaluating conditions at Yucca Mountain than 
the NRC generic criteria in part 60. 64 FR 8641. Moreover, NRC believes 
that implementation of these new analytical methods for evaluating 
Yucca Mountain will avoid the imposition of unnecessary, ambiguous, or 
potentially conflicting criteria that could result from the application 
of some of the generic requirements of 10 CFR part 60. 64 FR 8641.
    The evolution in performance assessment methodology formed the

[[Page 57316]]

basis for DOE's 1996 proposal to amend the Guidelines. In that 
proposal, DOE explained that only by assessing how specific design 
concepts will work within the natural system at Yucca Mountain and 
comparing the results of these assessments to the applicable regulatory 
standards, can DOE reach a meaningful conclusion regarding the site's 
suitability for development as a repository. The 1996 proposed 
amendments to the Guidelines would have required a comprehensive 
evaluation focused on whether or not a geologic repository at Yucca 
Mountain would adequately protect the public and the environment from 
the hazards posed by high-level radioactive waste and spent nuclear 
fuel (61 FR 66160). DOE explained that recent results in four major 
areas have advanced the ability to evaluate the Yucca Mountain site, 
and geologic disposal, to the point that a system approach is now 
appropriate. These four areas are: (1) Analysis and integration of data 
collected from surface-based testing and regional studies; (2) 
examination of the potential repository horizon made possible by the 
excavation of the Exploratory Studies Facility; (3) the site-specific 
conceptual design of the engineered facilities; and (4) performance 
assessment analyses (61 FR 66161).
    Like the NRC, DOE recognized that this improved understanding 
counseled in favor of reexamining General Guidelines that may be 
unnecessary or ambiguous, or that may present conflicting requirements 
for Yucca Mountain. Based on the DOE's accumulated knowledge, and 
significantly enhanced understanding, DOE has determined that a system 
performance approach provides the most meaningful method for evaluating 
whether or not the Yucca Mountain site is suitable for development as a 
repository. In today's final rule, DOE expands on its 1996 and 1999 
proposals to modify the Guidelines and incorporates performance 
assessment as the appropriate approach to assess the forecasted 
performance of a repository. This final rule provides greater detail, 
comprehension and transparency of information describing the 
performance assessment methodology, and how it serves as a foundation 
for site characterization suitability criteria.

IV. Response to Public Comments on the 1999 Proposal

    DOE published the supplemental notice of proposed rulemaking on 
November 30, 1999, in the Federal Register (64 FR 67054), and posted it 
on the Internet that same day. The public comment period on the 
supplemental notice extended from the date of publication until 
February 28, 2000. Public hearings were held on the supplemental 
notice: two sessions in Pahrump, Nevada and two sessions in Las Vegas, 
Nevada.
    DOE received numerous comments on the supplemental notice, both 
oral and written, from members of the public, State and local 
officials, Native Americans, regulatory and oversight organizations, 
and representatives of various non-governmental organizations, and the 
nuclear power industry. Opinions about the supplemental notice were 
divided. Some comments were critical of DOE's conduct of this 
rulemaking. In particular, several commenters expressed a desire for 
greater dialogue on the rulemaking, additional time to review the 
proposed rulemaking, and frustration regarding the overlapping public 
comment periods on this rulemaking and DOE's draft Environmental Impact 
Statement for a Geologic Repository for the Disposal of Spent Nuclear 
Fuel and High-Level Radioactive Waste at Yucca Mountain, Nye County, 
Nevada (hereafter ``Yucca Mountain EIS''). DOE acknowledges the 
comments, questions, and concerns raised by members of the public 
during this rulemaking, and has considered them in preparing this 
notice of final rulemaking. However, DOE believes that the comment 
period on this rulemaking, lasting 89 days, and the comprehensive 
background and description of the proposed rulemaking contained in the 
supplemental notice, provided the public with sufficient time and 
information to review the supplemental notice and provide meaningful 
comments. In addition, the public hearings on this rulemaking, although 
they coincided with some other public hearings on the Yucca Mountain 
EIS outside the State of Nevada, did not deprive the public of a full 
and fair opportunity to comment on both proceedings. The public comment 
period on the Yucca Mountain EIS was initiated in July of 1999, lasted 
for 199 days, and included 21 public hearings, 10 of which were held 
within Nevada.
    Several comments received by DOE did not directly address this 
notice of proposed rulemaking, but dealt with other aspects of DOE's 
civilian radioactive waste program. For example, several commenters 
expressed dissatisfaction with the disposal of spent fuel and high-
level waste in a geologic repository, raised claims of limited federal 
authority over Yucca Mountain, criticized the nation's dependence on 
nuclear power, and raised concerns about the transportation of high-
level waste and spent nuclear fuel to a repository. Many of these 
comments were similar to those raised during the public comment period 
on the 1996 proposal to amend the guidelines. As explained in response 
to public comments on that, many of these comments are outside the 
scope of this rulemaking. DOE recognizes that there are strong 
differences of opinion on these matters of public policy. But DOE's 
responsibility in this proceeding is to determine how best to carry out 
Congress' directive in section 113(b) of the NWPA to develop criteria 
for evaluating the suitability of Yucca Mountain as a potential site 
for a repository for nuclear waste, not to reexamine disputes whose 
resolution Congress has specified--as would be required were DOE to 
respond to the broader public policy comments. Accordingly, presented 
below is DOE's response to the major issues emerging from the public 
comments and questions directly related to the supplemental notice.

A. The Statutory Basis and Regulatory Need for Part 963

    Several commenters, including representatives of the State of 
Nevada, asserted that DOE's legal rationale for revising the guidelines 
was flawed and in violation of the NWPA, and that there is no statutory 
or legal basis for the proposed amendments. In support of this 
position, many commenters noted, among other things, that section 
112(a) of the NWPA directs DOE to promulgate guidelines for the 
recommendation of sites for a repository, not merely for site 
characterization; that the substantive requirements of section 112(a), 
such as the use of qualifying and disqualifying factors and 
consideration of transportation impacts, must be part of any site 
suitability criteria proposed by DOE; that Congress' failure to direct 
DOE to revise its guidelines in the 1987 Amendments Act and the 1992 
Energy Policy Act is an indication that Congress did not believe the 
guidelines required modification; and that the intent of section 112(a) 
was to require DOE to evaluate sites based on geology (e.g., natural 
barriers), and not engineered barriers (e.g., waste package design). 
Several commenters also noted that it was premature to revise the 
guidelines since the EPA and NRC have not yet finalized their 
regulations regarding a repository at Yucca Mountain and that, in any 
event, there is no requirement that the guidelines closely conform to 
the EPA and NRC regulations.
    DOE also received comments in support of the statutory and 
regulatory need for the revisions to part 960 and

[[Page 57317]]

the establishment of Yucca Mountain-specific-suitability criteria. 
Those comments noted that the proposed revisions to the guidelines are 
legally appropriate and timely under the NWPA; that there is no 
statutory connection between the content of the section 112(a) 
guideline requirements and the content of the section 113(b) 
suitability criteria; that there is no need to establish site 
suitability criteria in a rulemaking proceeding; and that DOE 
appropriately is updating its site suitability criteria to comport with 
current scientific understanding and regulatory revisions proposed by 
the EPA and NRC.
    As explained in detail in the SUPPLEMENTARY INFORMATION under the 
section III. A, entitled, ``Legal Authority and Necessity to Amend the 
Guidelines and Criteria,'' and in section III. B, above, DOE believes 
that there is a sound statutory and regulatory basis upon which to 
revise part 960 and promulgate part 963. DOE believes that this 
rulemaking effectively harmonizes the statutory language and purposes 
of relevant sections of the NWPA and the 1992 Energy Policy Act with 
the current state of scientific and technical understanding of how best 
to evaluate the performance of a geologic repository, as well as with 
the revised regulatory framework governing the public health and safety 
and licensing of a repository at Yucca Mountain. While DOE does not 
believe there was any misrepresentation of the statutory language of 
section 112(a) of the NWPA, as some commenters asserted, minor 
modifications were made in the background section and section III above 
of the Supplemental Information to avoid any confusion.
    As previously stated, the approach DOE elected to take in 1984 to 
implement section 112(a) and formulate the 960 guidelines was 
understandable at that time, when DOE anticipated the need to evaluate, 
by comparison, multiple characterized sites under section 113 leading 
to the selection of one site under section 114, and the NRC licensing 
regulations were premised on a demonstration of both system and 
subsystem performance requirements. In the supplemental notice of 
proposed rulemaking and in this notice, DOE has discussed in detail the 
numerous intervening events, of a regulatory, technical and legislative 
nature, that necessitated DOE's revisions to the 960 guidelines and the 
need to add a new part 963 to establish the site suitability criteria 
and methodology to be used in assessing the suitability of the Yucca 
Mountain site.
    Several commenters correctly note that Congress has not changed the 
language of the NWPA in section 112(a), despite opportunities for such 
change in the 1987 Amendments and the 1992 Energy Policy Act. 
Congressional silence on this point is hardly dispositive, however. As 
previously noted, there is no explicit language or direction in section 
112 that requires or directs DOE to use the 112(a) guidelines as the 
criteria to assess the suitability of a characterized site under 
section 113(b). Therefore, the failure of Congress to revise section 
112 has no particular bearing here.
    Other commenters stated that it seems specious to argue that 
Congress meant the 112(a) guidelines, including the requirement of 
qualifying and disqualifying factors, to be abandoned once a site was 
designated for site characterization, and that any suitability 
guidelines must include qualifying and disqualifying factors. But that 
is not the argument DOE has advanced. Rather, DOE's view is that 
Congress did not legislate at all regarding whether DOE should or 
should not use the section 112(a) guidelines for site suitability, but 
did require DOE's suitability evaluation to revolve around the 
potential licensability of the site. Hence, when the NRC modified its 
licensing criteria in such a way as to focus on system rather than 
subsystem performance, DOE could no longer use guidelines that were 
inconsistent with that approach.
    We also note that in this final rule, DOE is not abandoning the 
concept embodied in section 112(a) that a site should be evaluated 
based on such criteria as the geology, hydrology and geophysics of the 
site. Nor is DOE inappropriately accounting for engineered barriers in 
setting site suitability criteria under the NWPA. Table 2, VI. B of 
this SUPPLEMENTARY INFORMATION provides a crosswalk between the section 
112(a) geologic considerations and the criteria for evaluating site 
suitability in part 963. In addition, section 113 directs DOE to engage 
in activities related to developing waste form and packaging designs 
and describing the relationship between the waste form and the geologic 
medium. Thus, those barriers are also appropriately included in the 
criteria for assessing the suitability of a repository at Yucca 
Mountain. As is necessary, DOE has articulated the site suitability 
criteria in a manner that is consistent with the technical and 
analytical approach in the applicable EPA and NRC regulations for a 
geologic repository at Yucca Mountain.
    Moreover, as explained above, DOE interprets the language in 
section 113(b)(1)(A)(iv), referring to section 112(a), to mean that 
only the procedural requirements of section 112(a) should be followed 
in setting the criteria for site suitability under section 113(b). The 
inclusion of qualifying and disqualifying factors is in the nature of a 
substantive requirement of the guidelines promulgated under section 
112(a); it is not a statutory requirement for the establishment of 
suitability criteria under section 113(b)(1)(A)(iv). In addition, DOE 
does not believe that it is reasonable or necessary to retain explicit 
qualifying and disqualifying conditions in the present site suitability 
guidelines. Such conditions do not comport with either the revised 
regulatory framework established for a repository at Yucca Mountain, 
nor the current state of scientific and technical understanding of how 
best to evaluate the performance of a repository. Accordingly, DOE has 
established site suitability guidelines that are reasonable and fully 
consistent with the mandates of the NWPA.
    In response to other comments regarding the allegedly premature 
nature of this rulemaking, DOE believes that the rulemaking is timely 
and not premature. Although the NRC and EPA regulations were in 
proposed and not final form at the issuance of the proposed rulemaking 
on part 963, DOE deemed it necessary and appropriate to initiate the 
process for promulgating this rule in advance of the finalization of 
the EPA and NRC regulations. It was necessary to initiate the 
rulemaking process in order to allow sufficient time to obtain public 
review and comment, and NRC concurrence on the rule, prior to the time 
of a possible DOE site recommendation then planned for mid-2001. In 
addition, it was appropriate to initiate the process since the EPA and 
NRC proposed regulations provided sufficient substance to enable DOE to 
formulate its proposed rulemaking and solicit public comment on that 
rulemaking. By initiating the process in this manner, DOE did not 
intend, nor did it preclude, the option that DOE might reopen the 
comment period for this rulemaking as necessary to accommodate changes 
from the proposed to final rules of the EPA and NRC. DOE has reviewed 
the final rules of EPA and NRC, and determined that reopening the 
comment period on part 963 is not necessary. As explained in the 
description of the final rule (section VI of this SUPPLEMENTARY 
INFORMATION), the changes made to 963 from the draft to final stage 
have been made for purposes of clarity and conformance with final 63; 
the changes are not

[[Page 57318]]

substantive and do not change the basic structure, intent or analyses 
performed pursuant to the rule.
    Furthermore, DOE has fully explained in the supplemental notice and 
this notice the reasons why it is necessary and reasonable for DOE to 
conform its suitability criteria and methodology with the NRC licensing 
criteria and EPA standard, in accordance with the NWPA. As illustrated 
in Table 1 of this notice of final rulemaking, DOE does not believe 
that the 960 guidelines are substantively consistent with the newly 
developed EPA and NRC rules, thereby necessitating the amendments 
promulgated today.

B. The Proposed Rules Use (or Allow the Use of) Engineered Barriers To 
Compensate for the Inadequacies of the Site

    Several commenters stated that the proposed rule inappropriately 
allows the use of engineered barriers to compensate for inadequacies in 
the performance of the natural system. Certain of these commenters 
suggested that the NWPA, in particular section 112(a), prohibits 
reliance on the performance of engineered barriers in evaluating the 
suitability of a site for a repository system, reasoning that the 
performance of the repository must rely solely on the performance of 
the natural barriers.
    As explained above, DOE does not believe that the provisions of the 
NWPA limit or prohibit DOE's investigation and use of engineered 
barriers to assess the suitability of siting a geologic repository at 
Yucca Mountain. Section 113(b)(1)(B) of the NWPA directs DOE to 
describe the waste packages and waste forms to be used and their 
relation to the geology of the site; section 113(c) restricts DOE 
activities conducted under section 113 to those necessary to provide 
data required for a repository construction authorization application 
to the NRC (and to comply with NEPA). In turn, section 121(b)(1)(B) 
requires the NRC, in setting licensing criteria for a repository, to 
provide for the use of a system of multiple barriers in the design of 
the repository. In this context, multiple barriers means engineered and 
natural barriers. Thus, DOE believes that the NWPA, as originally 
enacted and as amended, contemplates that any site undergoing 
characterization for possible development as a repository would include 
investigation of, and reliance on, multiple barriers--natural and 
engineered barriers.
    Indeed, the NRC's original repository licensing requirements, 10 
CFR part 60, made clear that the use of both natural and engineered 
barriers would be required for repository licensing. Nevertheless, the 
NRC was also concerned, at the time of the promulgation of part 960 in 
1984, that DOE not use engineering barriers to compensate for 
deficiencies in any comparison of candidate sites. The NRC, through its 
concurrence process on the original part 960 guidelines, required DOE 
to make clear that engineered barriers would not constitute a 
compensating measure for deficiencies in the geologic media during site 
screening. This was accommodated by provisions at 10 CFR 960.3-1-5 that 
address comparisons of the sites in the basis for site evaluations. 
That provision states that comparisons of sites shall be structured so 
that engineered barriers are not relied upon to compensate for 
deficiencies in the geologic media. Furthermore, it states that 
engineered barriers shall not be used to compensate for an inadequate 
site; mask the innate deficiencies of a site; disguise the strengths 
and weaknesses of a site and the overall system; and mask differences 
between sites when they are compared. (emphasis added). In its final 
decision to concur in 10 CFR part 960, the NRC noted that the revisions 
made to 960.3-1-5 showed that DOE would not select sites where 
engineered barriers must be used to compensate for deficiencies in the 
geologic media (49 FR 28136).
    At present, DOE is not in a situation of comparing multiple sites 
for possible development as a repository. Part 963 applies only to a 
determination of the suitability of the Yucca Mountain site for 
possible development as a repository. Importantly, absent in NRC's 
current requirements for licensing, 10 CFR part 63, and in NRC's 
concurrence on this rule, are any requirements that DOE demonstrate 
repository performance based solely on natural barriers.
    The NRC expects that, in any licensing proceeding for a repository 
at Yucca Mountain, DOE will demonstrate that the natural barriers and 
the engineered barrier system will work in combination to enhance the 
overall performance of the geologic repository. NRC regulations require 
an engineered barrier system in addition to the natural barriers 
provided by the geologic setting, and that natural barriers and the 
engineered barrier system work in combination to enhance the resiliency 
of the geologic repository and increase confidence that the postclosure 
performance objective at 10 CFR 63.113(b) will be achieved.
    NRC's expectation is shared by the EPA, and other oversight 
entities. In 40 CFR part 197, EPA defines the Yucca Mountain disposal 
system as the combination of underground engineered and natural 
barriers at the Yucca Mountain site that prevents or substantially 
reduces releases from the disposed radioactive material, and emphasizes 
the importance of engineered barriers as a method, within human 
control, to delay the release of radionuclides from the repository. 
Oversight entities, such as the NWTRB and the NRC's Advisory Committee 
on Nuclear Waste, have been consistent in their recommendations to 
pursue robust, long lived waste packages to protect the health and 
safety of the public.
    In consideration of this information, DOE incorporated in its 
proposal specific criteria to address the performance of the engineered 
components of the repository system. The Department believes that the 
criteria are consistent with the Congressional intent in the NWPA, and 
the regulatory expectations of the EPA and the NRC, that there be 
performance contributions from both the natural and engineered 
barriers. DOE does not believe that reliance on such barriers would 
mask or compensate for inadequacies in the natural system, but rather, 
such barriers enhance and prolong the ability of the natural system to 
contain, and mitigate the rate of release of, individual radionuclides.

C. The Rules Should Not Be Changed To Fit the Site

1. The Site Would Be Disqualified Under Existing Guidelines
    Several commenters stated their belief that Yucca Mountain would be 
disqualified under the existing guidelines and, on that basis, DOE is 
attempting to change the rules to fit the site. This same comment was 
made in response to DOE's 1996 proposal to amend part 960. The primary 
reason for this comment, then as now, is the argument that the site 
cannot meet the disqualifying condition in 960.4-2-1(d) pertaining to 
groundwater travel time. Many commenters also questioned what condition 
would disqualify the site under part 963, and how far contaminated 
groundwater may travel under part 963.
    As stated in the preamble to the supplemental notice of proposed 
rulemaking (64 FR 67071), DOE's reasons for amending the guidelines are 
not based on a belief or finding that the Yucca Mountain site would be 
disqualified if the 960 guidelines were applied without amendment. With 
respect to groundwater travel time, the Department continues to 
evaluate

[[Page 57319]]

groundwater movement and other hydrological properties of the site to 
assess the performance of a repository at Yucca Mountain. Based on the 
results of the 1998 Viability Assessment and ongoing evaluations, the 
Department believes there is no basis at this time to find that 
conditions that would disqualify the site if 10 CFR part 960 were 
applied, exist at Yucca Mountain.
    With regard to the question of what condition would disqualify the 
Yucca Mountain site, part 963 requires the Secretary of Energy to 
evaluate the suitability of the site based on the likelihood that a 
repository at the site could meet the applicable radiation protection 
standard. Accordingly, if the Secretary determines this requirement 
cannot be met, the site may not be determined suitable by the Secretary 
and thus would be ``disqualified'' for consideration for further 
development. With regard to the question of how groundwater travel time 
will be assessed under part 963, groundwater flow and transport will be 
analyzed as suitability criteria, section 963.17(a)(7), unsaturated 
zone flow and transport, and section 963.17(a)(8), saturated zone flow 
and transport. Accordingly, groundwater flow and transport will 
continue to be studied for their role in repository performance and the 
ability of the site to meet applicable radiation protection standards.
2. DOE Is Changing the Rules in the Middle of the Game
    Several commenters claimed that DOE is inappropriately establishing 
suitability guidelines as a result of ongoing site characterization 
work, instead of setting the guidelines in advance of that work. In 
that regard, one commenter questioned whether the guidelines would 
affect the design of the repository. Stated otherwise, DOE understands 
the concern to be that it is perceived as setting guidelines to meet a 
specific repository design or other site characteristic, rather than 
setting guidelines based on predetermined criteria for repository 
design or other site characteristics.
    DOE has explained previously, however, that the reason it is 
issuing these guidelines now is based on events beyond its control that 
have made its prior guidelines an inappropriate tool for evaluating 
suitability. Under the NWPA, suitability is linked to licensability. 
Congress's decisions to change the NWPA to focus on Yucca Mountain and 
to direct the EPA and NRC to revise their standards bearing on 
licensability set in motion a chain of regulatory changes to the 
licensing rules that in turn necessitated this rulemaking.
    DOE also notes that the fact that the final site suitability 
guidelines are being issued now, instead of earlier in the site 
characterization process, is to the public's advantage, since they 
reflect the most recent developments in regulatory requirements and 
standards and technical understanding. For example, the guidelines are 
structured to evaluate repository performance against a set of criteria 
potentially important to waste isolation. The repository design, 
although not directly affected by the guidelines, will be structured to 
take advantage of the features of the natural and engineered barriers 
that are important to waste isolation.
    Moreover, DOE's current approach is consistent with earlier 
opinions expressed by the National Academy of Sciences, Board on 
Radioactive Waste Management (Board). In its report, Rethinking High-
Level Radioactive Waste Disposal (1990), the Board addressed this issue 
and discussed the relative merits of an approach that presets technical 
criteria for evaluation of a repository site versus an approach that 
remains flexible and responsive to data and information as it is 
developed. In that report, the Board criticized the U.S. high-level 
waste program for its approach, at that time, of defining in advance 
the technical requirements for every part of the multi-barrier system, 
and in its emphasis on the geologic component of the barrier. The Board 
opined that the better approach, consistent with geologic and mining 
practice, is to remain flexible instead of setting rigid predefined 
goals. The Board observed that, instead of trying to anticipate all the 
complexities of a natural geologic environment, the better approach 
would be to define the goal broadly in ultimate performance terms, 
rather than anticipatory requirements, so that increased knowledge can 
be incorporated in the design at a specific site.

D. The Part 963 Guidelines Would (a) Mask the Degree of Safety, Which 
Can Lower or Eliminate Public Confidence, and (b) Lower, or Eliminate 
the Degree of Safety

    (a) Some commenters believed that the proposed revisions, that is, 
the use of a total system performance assessment instead of individual, 
subsystem requirements, mask the degree of safety of the site. These 
commenters felt that the TSPA method, with its heavy reliance on 
computer modeling, is too uncertain and subject to mishandling to form 
the basis for assessing the safety of the site and ensuring public 
confidence in the resulting assessment. Other commenters expressed the 
view that use of the TSPA method is appropriate. One commenter, Nye 
County, Nevada, commented that the criteria provide for greater 
transparency and verifiability than DOE's initial proposed amendments 
to part 960 in 1996, and that the TSPA approach is preferred to DOE's 
previous consideration of site-specific revisions to the 960 
guidelines.
    As explained in other sections of this notice of final rulemaking, 
the prevailing view in the relevant scientific community supports use 
of the TSPA method to assess and evaluate expected performance of a 
geologic repository over thousands of years. This is the evaluation 
method required by the NRC and the EPA in assessing repository 
performance for licensing purposes. It would be unreasonable for DOE to 
establish criteria to determine the suitability of the Yucca Mountain 
site that are not based on the prevailing scientific and regulatory 
view of performance assessment.
    Over the past several years, DOE and other entities involved in 
oversight and regulation of high level waste programs have undertaken 
significant efforts to make the results of total system performance 
assessment calculations more transparent to non-technical audiences. 
This is in response to the type of concerns expressed by the commenters 
here, that the complex calculations are difficult to visualize and 
verify, and, hence, may mask the degree of safety provided. While DOE 
acknowledges the difficulty in comprehending TSPA for the lay person, 
DOE has attempted, through this rulemaking and in other public forums, 
to enhance transparency in presenting the results of TSPA and 
associated complex technical calculations and modeling. For example, in 
the Viability Assessment, DOE provided a detailed explanation of the 
TSPA method and the computer models and technical data and information 
supporting those modes. This explanation has been augmented by 
presentations and other briefings provided by DOE to oversight agencies 
and other members of the public.
    One of DOE's primary considerations in drafting and finalizing this 
rulemaking was to make the TSPA process and method more transparent and 
verifiable. As explained in the Viability Assessment, transparency is 
manifested through the ease of a reader in understanding the process by 
which a study was carried out, which assumptions are driving the 
results, how they were arrived at, and the rigor of the

[[Page 57320]]

analyses leading to the results. Transparency is achieved when a reader 
can understand what was done in the analyses, what the outcome was, and 
why. Part 963, at sections 963.16(b)(1), (5), (6), (7), and (9), 
provides a framework for the listed system performance assessment that 
should assist in accomplishing this end.
    Additionally, confidence in the results of the performance 
assessment calculations can be enhanced if the presentation 
illustrates: (1) The system's expected evolution, as defined by the 
spatial and temporal response of the system to waste emplacement; and 
(2) the uncertainty in the system's expected evolution and the 
significance of that uncertainty to the system performance goals. Part 
963 incorporates these kind of considerations under 963.16(b)(2), (3), 
(8), (9), (10), and (12).
    Further, section 963.17 lists criteria that reflect both the 
processes and the models that are important to the total system 
performance. Those criteria are expressly identifiable and traceable 
components of the TSPA, thereby increasing transparency and 
traceability of the results. In addition, DOE intends to make available 
to the public the documentation underlying any TSPA analyses and 
results. With this material, the public will have an opportunity to 
review the technical information and data underlying the analyses 
supporting the postclosure performance assessment.
    (b) Some commenters expressed the view that the use of TSPA, and 
the lack of qualifying or disqualifying subsystem requirements, would 
lower or eliminate the degree of safety.
    Part 963 is structured to align DOE's site suitability 
determination with the EPA public health and safety standard, as 
implemented by the NRC regulations, and to base a suitability 
determination on the likelihood that the site could meet applicable 
radiation protection standards. Through Congressional direction, EPA 
modified the basis for a public health and safety standard from a 
release-based standard to a health-effects standard. In turn, Congress 
directed the NRC to conform its licensing regulations to the EPA 
standard and implement that standard. Both regulators predicate a 
demonstration that the standard can be met on the use of performance 
assessment.
    DOE is in agreement with the Congress, the National Academy of 
Sciences, the EPA and the NRC that a dose-based standard, that 
explicitly limits the risk of adverse health effects and considers 
health effects to the potentially affected public, is an appropriate 
basis upon which to assess public health and safety. Further, DOE 
believes that the risk or dose approach provides additional and better 
protection to the health and safety of the public in the vicinity of 
Yucca Mountain than the release based approach reflected in the 960 
guidelines. The part 963 guidelines explicitly require DOE to consider 
health effects to the public in the vicinity of the Yucca Mountain 
site. Under the part 960 guidelines, the DOE would only have been 
required to calculate releases from the repository, not the potential 
health effects. Hence, the part 963 guidelines enhance the degree of 
safety provided to the public in the vicinity of the Yucca Mountain 
site, rather than lowering it.

E. The Appropriateness of the Proposed Criteria

    One commenter questioned the postclosure criteria proposed by DOE 
stating that the criteria were simply a list of physical 
characteristics with no bases for the discrimination that would be 
necessary for a suitability determination, while other commenters 
supported the Department's proposal indicating that the proposed 
postclosure criteria were appropriate for decisionmaking.
    As DOE noted in its supplemental notice of proposed rulemaking, we 
believe we may properly opt to use one dictionary definition of 
criteria as ``characterizing traits'' rather than the other possible 
definition ``benchmarks'' or ``pass-fail standards.'' This is because, 
among other reasons, section 112(a) of the NWPA uses the term ``primary 
criteria'' synonymously with the term ``detailed geologic 
considerations,'' a term that is more naturally understood as 
``characterizing traits'' than ``benchmarks.'' Although the specific 
section 113 criteria addressed herein are different from the specific 
``primary criteria'' referred to in section 112(a), it seems likely 
that Congress used the word ``criteria'' in both places to have the 
same general meaning, i.e., ``considerations'' rather than 
``benchmarks.'' In addition, we believe the ``characterizing traits'' 
definition is more plausible where what is at issue are criteria that 
are part of a site characterization effort, as 113(b) specifies.
    In discussing this definition of criteria in the proposed rule, DOE 
noted that criteria are not necessarily quantitative. To illustrate 
this point, DOE pointed to NRC's Quality Assurance criteria, found then 
in Appendix B of 10 CFR part 50 (now incorporated into final part 63, 
subpart G). NRC was concerned that this may have mischaracterized the 
importance and nature of the NRC requirements by noting that they are 
not expressed as quantitative, pass-fail standards. We agree that our 
discussion on this point was confused at best. This is partly because 
the two definitions of criteria, ``benchmark'' versus ``characterizing 
trait,'' represent a continuum as well as a dichotomy. NRC's Appendix B 
QA criteria and the suitability criteria of sections 963.14 and 963.17 
resemble each other in that they are non-quantitative. But NRC's QA 
criteria are also benchmarks, in that a QA plan must have them and 
describe how they will be satisfied to pass muster. In that respect 
they differ from the part 963 criteria.
    Accordingly, the sentence in the Supplementary Information 
describing the suitability criteria should have read as follows: ``For 
example, in 10 CFR part 63, Subpart G, the NRC sets forth quality 
assurance ``criteria'' that are factors that must be present, including 
a description of how they will be satisfied, for DOE's QA program to be 
judged adequate. However, although these QA criteria are required 
factors, they are not, nor do they contain, quantitative, pass-fail, 
benchmark standards.''

F. DOE Should Consider Preclosure Issues, Including Environmental, 
Socioeconomic, and Transportation Issues

    Several commenters objected to DOE's exclusion in part 963 of 
certain 960 preclosure guidelines such as environmental quality, 
socioeconomics and transportation, on the basis that section 112(a) of 
the NWPA requires consideration of those factors, along with qualifying 
or disqualifying conditions for those factors. Additionally, several 
commenters questioned where such topics would be addressed, and 
expressed their belief that the draft Yucca Mountain EIS did not fully 
or adequately address those topics.
    As previously explained, DOE does not agree that the site 
suitability criteria established under section 113(b) must be the same 
as the guidelines promulgated under section 112(a). Part 963 
establishes the criteria and methodology for determining the 
suitability of the site under section 113(b)(1)(A)(iv) as part of DOE's 
site characterization activities and site characterization plan. Since 
1988 and the publication of the Site Characterization Plan, DOE has 
indicated that information relative to socioeconomics, transportation 
and environmental quality guidelines referred to in part 960 would be

[[Page 57321]]

obtained through means other than site characterization activities. 
Accordingly, DOE does not agree that socioeconomics, transportation and 
environmental quality must be included in part 963 as criteria to 
determine the suitability of the site under section 113(b).
    DOE agrees that socioeconomics, environmental quality and 
transportation are appropriate factors for the Secretary to consider in 
determining whether to recommend the Yucca Mountain site for 
development. As stated in the rule and in this notice, those factors 
and other relevant information that will be considered in any 
Secretarial recommendation under section 114 of the NWPA will be 
addressed by DOE through other mechanisms in which the public will also 
have the opportunity to participate, such as the Yucca Mountain EIS 
process. While some commenters may be critical of the adequacy of the 
Yucca Mountain EIS analysis, or the extent of coverage, DOE believes 
that the 960 guidelines on socioeconomics, transportation and 
environmental quality are appropriately addressed in the Yucca Mountain 
EIS. DOE is in the process of evaluating public comments on the draft 
Yucca Mountain EIS, including those comments submitted under this 
rulemaking. Upon completion of the EIS, DOE believes that coverage of 
these factors will be fully adequate for consideration in any 
Secretarial site recommendation.

G. DOE Should Define the Margin by Which it Will Meet the Radiation 
Protection Standard, or the Way in Which it Will Meet the Standard

    At least one commenter suggested that DOE should be more definitive 
or restrictive for the determinations to be made in section 963.12, 
preclosure suitability, and section 963.15, postclosure suitability. 
Specifically, it was suggested that DOE be more definitive or clarify 
what is meant by the phrase ``likely to meet'' in those sections, such 
as specifying the mean result of the TSPA calculation as the basis for 
a determination of postclosure suitability.
    DOE does not believe it is useful to be more definitive or 
restrictive regarding the phrase ``likely to meet.'' By this phrase DOE 
is indicating, as it must, that site suitability is largely a DOE 
judgment call as to the likelihood that the site will qualify for a 
license from the NRC for repository construction. This determination is 
not the equivalent of a license application by DOE, nor is it the 
equivalent of an NRC determination that a license application will be 
successful. Under the circumstances, DOE believes this phrase 
accurately captures the level of information and confidence required by 
the Secretary to make a suitability determination. With regard to the 
comment that DOE should use only the mean result of the TSPA to judge 
the likelihood of meeting the standard, DOE believes more than the mean 
result would be appropriate in estimating the ability to meet licensing 
regulations. Under NRC regulations, 10 CFR subpart 63.101, DOE must 
demonstrate, at the time of licensing, reasonable assurance (for the 
preclosure period) and reasonable expectation (for the postclosure 
period) that the performance objectives can be met. This requirement 
necessitates that DOE develop and provide more than just the mean 
result in demonstrating compliance with the standard. Therefore, the 
use of ``results'' is appropriate for the suitability assessment under 
sections 963.12 and 963.15, instead of something more singular, such as 
a mean or expected result only.
    In addition, some commenters noted that the rule should require 
performance in excess of the standard; stated otherwise, that DOE 
should specify a margin or level of confidence regarding performance 
results. This same comment was made in response to the 1996 proposed 
rulemaking. DOE has reconsidered this comment here, but nevertheless 
maintains the same response as provided in response to comments on the 
1996 proposal. That is, DOE does not believe it is appropriate or most 
effective to specify or quantify a level of confidence or margin of 
safety as part of the rule. The public, as well as the Secretary of 
Energy, will have access to data and information underlying the TSPA 
analyses and supporting analyses. This information will include the 
probabilistic distribution of values around the expected value, in 
order to assess the level of confidence in the performance calculation.

H. Whether DOE Should Revoke the Guidelines in 10 CFR Part 960 in 
Making the Site Suitability Determination for the Yucca Mountain Site 
or Continue To Use Them in Addition to Part 963

    DOE proposed amendments to modify part 960 so that it would apply 
only to competitive site selection for the purpose of nominating sites 
for site characterization activities. Opinion about this part of the 
November 30, 1999, proposal was divided. Some commenters argued for 
complete revocation of part 960 because it embodies a methodology for 
site comparisons that is: (1) obsolete; (2) inconsistent with 
internationally accepted practice; and (3) inconsistent with currently 
proposed NRC and EPA rules for the Yucca Mountain site. Other 
commenters disagreed, arguing that the sub-system approach in part 960 
can and should be applied in addition to the rules for total system 
performance assessments in part 963. They viewed the provisions of part 
960 as a viable and better method than proposed part 963 for assessing 
the suitability of the Yucca Mountain site for the location of a 
nuclear waste repository.
    With regard to the comments favoring complete revocation of part 
960, DOE does not think that reaching final conclusions on their 
continued utility for competitive selection of sites for site 
characterization is appropriate for two reasons. First, the 1987 
amendments to the Nuclear Waste Policy Act of 1982 require DOE to focus 
its efforts exclusively on evaluation of Yucca Mountain. Second, if 
there is ever a need to return to competitive selection of sites for 
site characterization, that would be the time to replace part 960 with 
a methodology that reflects scientific advances since part 960 became 
effective in 1984, as well as then applicable statutory and regulatory 
requirements.
    With regard to commenters who favored application of the subsystem 
requirements of part 960 in addition to part 963, DOE thinks that this 
approach is scientifically unsound and impossible to carry out. As 
explained at length above, the subsystem methodology of part 960 is 
scientifically unsound because it largely ignores the crucial 
interactions of various features, events, and processes that should be 
determinative. In DOE's view, reliance on the methodology of part 960 
would result in conclusions that are too likely to be erroneous. Even 
if the subsystem methodology of part 960 were a scientifically sound 
basis for evaluating site suitability, DOE could not use it in 
evaluating suitability for licensing because of the NRC's revisions to 
its licensing regulations. In the notice of supplemental proposed 
rulemaking, DOE included a table, reproduced above (Table 1), which 
sets forth the cross references in part 960 to the NRC's part 60 and 
demonstrates the lack of any substitutable cross reference to the NRC's 
part 63. The table was accompanied by a narrative exploring the 
groundwater guidelines in particular to show the impossibility of 
applying them after the NRC substituted part 63 for part 60. None of 
the commenters

[[Page 57322]]

disputed this table, and in DOE's view, it shows continued use of part 
960 in the evaluation of the Yucca Mountain site is not a viable 
option.

I. Response to NRC Comments

a. Coordination With NRC
    NRC made the comment that proposed part 963 did not address the 
potential matter of a conflict between the proposed DOE regulation and 
the applicable NRC regulations. NRC recommended that DOE explain how it 
would address this matter in this statement of consideration.
    NRC correctly noted that proposed part 963 did not contain a 
provision expressly requiring NRC regulations to take precedence in the 
event of a conflict or inconsistency between the DOE regulations and 
NRC regulations. DOE does not believe such a provision is necessary, 
given the nature and structure of part 963. Moreover, DOE believes this 
provision could create confusion in the implementation of the DOE 
regulation, since it suggests that in certain circumstances not 
presently identified DOE would need to substitute an NRC regulation for 
its own.
    DOE recognizes that its site suitability guidelines must assist the 
Secretary in judging the ability of the Yucca Mountain site to meet 
licensing requirements, pursuant to section 113(c) of the NWPA, but 
that the license application process, over which NRC has jurisdiction, 
is distinct and separate from the Secretary's judgment regarding site 
suitability. Accordingly, part 963, which is specific to the Yucca 
Mountain site, is carefully crafted to conform to pertinent parts of 
the NRC's part 63, the NRC's licensing requirements specific to the 
Yucca Mountain site, that serve DOE's need for assessing the 
suitability of the site as a basis for a possible site recommendation. 
Under this structure, the necessary consistency between the DOE and NRC 
regulations is obtained during the drafting of the DOE regulation. Any 
conflicts between the DOE and NRC regulations have been resolved 
through the NRC concurrence process on the regulation.
b. Quality Assurance
    The NRC also commented that DOE should recognize in the preamble to 
part 963 the importance and role of quality assurance in DOE site 
characterization activities, and the expected pedigree of the technical 
information and data underlying the suitability determination.
    As the NRC acknowledges in its comments, the Department expects to 
use essentially the same data for both its site suitability 
determination and any potential license application, even though the 
site suitability determination is not the equivalent of a determination 
that the site will meet all the requirements needed to obtain a 
construction authorization under NRC regulations. DOE acknowledges that 
the site suitability determination must be based on credible and 
verifiable data and information, and that assurance of the quality of 
that data and information is a factor in that determination. Therefore, 
due consideration will be given by the Department to any outstanding 
quality assurance issues that may affect the pedigree of technical 
information underlying the part 963 suitability determination.
c. Definition of Cladding
    In response to a comment from the NRC that the proposed definition 
of cladding found at 10 CFR subpart 963.2 conveyed an inaccurate notion 
that all cladding is corrosion resistant, the Department has modified 
the proposed definition as follows: cladding is the metallic outer 
sheath of a fuel rod element; it is generally made of a corrosion 
resistant zirconium alloy or stainless steel, and is intended to 
isolate the fuel from the external environment. Also, the Department 
has clarified the use of the term cladding in section VI(B)(h)(2) of 
this SUPPLEMENTARY INFORMATION, and in the rule at section 
963.17(a)(5)(i).

J. Response to Nuclear Waste Technical Review Board Comments

    The NWTRB provided comments on the 963 rulemaking, noting several 
considerations for DOE to address in its suitability guidelines. The 
NWTRB endorsed the use of performance assessment in support of a site 
suitability determination, but also noted that additional lines of 
argument and evidence should be used. In particular, the NWTRB 
supported use of other lines of evidence such as safety margins, 
defense-in-depth, performance confirmation, consideration of disruptive 
process and events, and reference to insights from natural and man-made 
analogs noting that such topics were addressed in revision 3 of the 
report, ``Repository Safety Strategy: Plan to Prepare the Postclosure 
Safety Case to Support Yucca Mountain site Recommendation and Licensing 
Considerations'' (``Repository Safety Strategy'') (TRW-WIS-RL-000001, 
January 2000). The NWTRB emphasized that understanding uncertainties in 
the performance assessment analysis is a critical component to attain 
technical credibility and sound decisionmaking. In that regard, the 
NWTRB recommended that DOE include in its representation of performance 
uncertainty: (a) A description of critical assumptions; (b) an 
explanation of why particular parameter ranges were chosen; (c) a 
discussion of possible data limitations; (d) an explanation of the 
basis and justification for using expert judgments; (e) an assessment 
of confidence in the conceptual models used; and (f) identification and 
quantification of uncertainties associated with the performance 
estimates.
    DOE agrees with much of the NWTRB's comments and recommendations. 
In fact, part 963, in its proposed and final form, is addressed to 
eliciting much of the information and analysis the NWTRB recommends and 
that was identified in revision 3 of the Repository Safety Strategy. 
Under section 963.16(b), DOE will conduct TSPAs in a manner to satisfy 
twelve enumerated conditions. Those conditions correspond to a large 
degree with the specific recommendations of the NWTRB repeated above, 
and provide the additional lines of evidence and argument beyond the 
performance assessment calculations. DOE structured this section of the 
rule to correspond to NRC's licensing regulation, particularly sections 
63.114 and 63.115. To clarify this point, DOE added language to the 
description of this rule, in section VI of this SUPPLEMENTARY 
INFORMATION, to better articulate how the additional lines of evidence 
and other recommendations will be accounted for in the suitability 
determination. Presented below is additional explanation of how the 
NWTRB's comments are addressed in part 963.
    The additional lines of evidence and argument recommended by the 
NWTRB are addressed in section 963.16(b), except for performance 
confirmation. DOE believes that performance confirmation is important, 
and will develop a performance confirmation plan in conjunction with 
the licensing process. DOE will provide in the underlying documentation 
of the TSPA calculation, performed in accordance with section 
963.16(b), the ``margin'' by which the expected performance of the 
repository exceeds the applicable radiation protection standards. 
Although DOE does not agree that it is necessary to quantify or specify 
the margin of safety as part of the rule, information and data about 
the margin will be available to decision-makers for review and 
consideration in reaching a suitability determination. Under sections 
963.16(b)(8), (9), and (10), DOE

[[Page 57323]]

will identify and evaluate multiple and independent barriers to waste 
isolation, thereby providing information on defense-in-depth. 
Disruptive processes and events are analyzed and included in the TSPA 
under sections 963.16(b)(4) and (5), and are express criteria of 
suitability in section 963.17(b). Insights from natural and man-made 
analogs are also analyzed and included in the TSPA under section 
963.16(b)(7), which requires DOE to provide the technical basis for the 
TSPA models, including comparisons made with empirical observations, 
such as natural analogs.
    The other specific NWTRB recommendations, described above, are also 
addressed in part 963. NWTRB recommendation (a), describe critical 
assumptions, is addressed by section 963.16(b)(2), regarding accounting 
for uncertainties and variabilities in parameter values; section 
963.16(b)(3), regarding consideration of alternative models of features 
and processes and evaluation of the effects of the alternative models; 
and section 963.16(b)(12), regarding conduct of appropriate sensitivity 
analyses. In addition, the analyses and documentation underlying the 
TSPA will contain an explanation of assumptions to assure the quality 
of the information.
    NWTRB recommendation (b), explain why particular parameter ranges 
are chosen, is addressed by section 963.16(b)(1), regarding data 
related to the postclosure suitability criteria, and section 
963.16(b)(2), regarding an accounting of uncertainties and 
variabilities in parameter values and identification of the technical 
basis for parameter ranges, probability distributions, and bounding 
values.
    NWTRB recommendation (c), include a discussion of possible data 
limitations, is addressed by section 963.16(b), regarding explanation 
of the technical bases of the data and models (e.g., sections 
963.16(b)(2), (3), (5), (6), (7), and (10)). For example, section 
963.16(b)(6) states that DOE will provide the technical basis for 
either inclusion or exclusion of degradation, deterioration, or 
alteration processes of engineered barriers. This will entail a 
discussion of possible data limitations.
    NWTRB recommendation (d), provide an explanation of the basis and 
justification for using expert judgment, is included in the portions of 
section 963.16(b) regarding explanations of technical bases (e.g., 
sections 963.16(b)(2), (5), (6), (7), and (10)). In those explanations, 
DOE will explain where expert judgment has been used.
    NWTRB recommendation (e), provide an assessment of confidence in 
the conceptual models used, is addressed by sections 963.16(b)(3) and 
(5). Under those sections of the rule, DOE will consider alternative 
models of features and processes and their effects on performance, and 
provide the technical basis for either inclusion or exclusion of 
specific features, events and processes (FEPs) of the geologic setting. 
In essence, these analyses will help DOE and others to assess the 
validity of the conceptual models and estimates of the significance of 
those models to repository performance.
    NWTRB recommendation (f), identify and quantify the uncertainties 
associated with the performance estimates, is addressed by sections 
963.16(b)(2), (3), (5), (6), (7), (9) and (10). Under these provisions, 
DOE will identify and quantify uncertainties associated with the 
performance estimates.

V. Description of Final Rule--10 CFR Part 960

A. Subpart A--General Provisions

    This section of the Guidelines contains the statement of 
applicability and definitions. The final revisions to section 960.1, 
Applicability, limit the application of the Guidelines to evaluations 
of the suitability of sites for site characterization under section 
112(b) of the NWPA. The revisions eliminate the applicability of the 
Guidelines to determinations of suitability of a site at the site 
characterization stage under section 113, or the site recommendation 
stage under section 114. These revisions clarify that the applicability 
of the Guidelines is limited to the preliminary site screening stage, 
which entails a comparative analysis process. The final revisions to 
the third and fourth sentences update the reference to other regulatory 
requirements of the NRC and EPA, in light of the current status of 
applicable NRC and EPA regulations relative to high-level waste 
geologic repositories. The fifth through seventh sentences remain 
unchanged.
    The final revisions to the definitions section make the terms 
consistent with the NWPA and with the other revisions to the Guidelines 
limiting applicability of subparts B, C, and D of the Guidelines to 
determinations of site suitability for site characterization under 
section 112 of the NWPA.

B. Subpart B--Implementation Guidelines

    The final revisions to the implementation guidelines limit the 
procedures and basis for application of the postclosure and preclosure 
guidelines of subparts C and D, respectively, to evaluations of the 
suitability of sites for site characterization.
    Section 960.3, entitled implementation guidelines, is revised to 
eliminate the sentences in that section setting forth the procedures 
and basis for application of subparts C and D in evaluations and 
determinations of the suitability of a site under section 113 and 
section 114 of the NWPA. These revisions remove section 960.3-1-4-4, 
Site Recommendation for Repository Development, in its entirety. That 
section pertained to procedure and evidence for making a site 
recommendation decision under section 113 and 114. The part 960 
guidelines are no longer relevant to those decisions and therefore 
reference to them is removed. Section 960.3-1-5, entitled Basis for 
Site Evaluation, is revised to eliminate all references to Appendix III 
in making suitability determinations at the site characterization or 
site recommendation stages. Only the last sentence of section 960.3-2, 
Siting Process, is revised. This revision limits the applicability of 
the siting process to the recommendation of sites for site 
characterization. Section 960.3-2-4, Recommendation of Sites For the 
Development of Repositories, is removed in its entirety. These 
paragraphs pertain to the comparison of characterized sites, leading to 
a recommendation by the Secretary to the President of a site for 
development as a repository. The final revisions eliminate that 
decision process from evaluation under the Guidelines, and the section 
in its entirety is removed.

C. Appendix III

    The final revisions to Appendix III remove and eliminate the 
applicability of this Appendix to decisions for repository site 
selection and siting decisions. The qualifying and disqualifying 
conditions of the technical guidelines in subparts C and D now apply 
only to the decision point for selecting sites for site 
characterization. All references to the site selection and site 
recommendation decisions under sections 113 and 114 are removed, 
including the tabular column in Appendix III referencing the repository 
site selection siting decision.
    With respect to the Guidelines listed in Appendix III that apply to 
environmental quality, socioeconomics and transportation 
considerations, DOE considered whether to continue to require their 
applicability to a Yucca Mountain site recommendation under section 114 
of the NWPA. DOE decided not to do so because the issues

[[Page 57324]]

addressed by these Guidelines will be substantially covered in the 
environmental impact statement for the Yucca Mountain site, and section 
114(a)(1)(D) requires that the final environmental impact statement be 
part of the comprehensive statement of the basis for a site 
recommendation to the President (42 U.S.C. 10134(a)(1)(D)). 
Opportunities for public comment on the analysis of environmental 
quality, socioeconomics and transportation issues have been provided as 
part of the public review and comment process on the draft 
environmental impact statement. In sum, DOE believes that the 
environmental quality, socioeconomics and transportation guideline 
requirements are substantially and unnecessarily duplicative of 
requirements under the procedures for developing an environmental 
impact statement and for formulating and informing a site 
recommendation under section 114.

VI. Description of Final Rule--10 CFR Part 963

    The purpose of this part of the Supplementary Information is to 
explain the meaning and basis for those provisions of the final part 
963 that are not self-explanatory and to identify and explain the main 
changes in the rule from proposed to final. The following is a section 
by section analysis of the final rule.

A. Subpart A--General Provisions

    Subpart A comprises two parts, the statement of Purpose, section 
963.1, and Definitions, section 963.2.
    (a) Purpose--section 963.1. The purpose of the final rule is as 
stated in this section: to establish the methods and criteria to help 
guide DOE's determination regarding the suitability of the Yucca 
Mountain site for the location of a geologic repository. The 
suitability evaluation methods in question are consistent with the 
methods the NRC has promulgated for assessing whether a geologic 
repository at the Yucca Mountain site meets licensing criteria and 
requirements. The suitability criteria allow for evaluation of the 
geologic considerations derived from section 112(a) and reflect the 
current scientific understanding and regulatory expectations (both NRC 
and EPA) regarding the performance and safety of a geologic repository 
during the preclosure and postclosure periods of operation. Because the 
suitability criteria are part of the site characterization program, 
these criteria relate to site characterization activities. Site 
characterization activities relate to scientific and technical 
investigations of the site to determine its natural properties and 
features, for example, studying the geohydrology and geochemistry of 
the site, as distinct from consideration of other factors, such as 
cost, socioeconomics and transportation of waste to the repository. An 
explanation of how the suitability criteria were derived is provided 
below.
    It should be noted that the final rule does not address the site 
recommendation process in its entirety. Suitability is only one aspect 
of the Secretary's recommendation. Section 114(a)(1) of the NWPA sets 
out other information not addressed by this rule that the Secretary 
must consider, some of which the Secretary must submit to the President 
and make available to the public if the Secretary recommends the site 
for development as a geologic repository. Section 114(a)(1)(G) also 
indicates that the Secretary has discretion to base his recommendation 
on ``such other information as the Secretary considers appropriate.''
    Finally, we note that the guidelines established by this rule are 
just that: guidelines. Their function is to assist the Secretary in 
reaching a conclusion concerning a question that is quintessentially 
predictive and requires the exercise of judgment: how a repository that 
has not yet been built will function thousands of year in the future. 
The purpose of these guidelines is to make tools and information 
available to the Secretary to assist him in reaching this judgment, not 
to cabin his discretion in doing so.
    (b) Definitions--section 963.2. The final rule includes definitions 
of certain words and terms. The definitions clarify DOE's intent and 
meaning in the context of this rule. The definitions are also intended 
to make the terms consistent with the NRC regulations governing the 
construction and licensing of a repository at the Yucca Mountain site. 
Several of the terms are important to understanding the suitability 
evaluation process, and are addressed here.
    Applicable radiation protection standard has been added to the 
definitions section to clarify use of the phrase in the rule. By 
applicable radiation protection standard, DOE means the numerical 
radiation dose or concentration limits contained within 10 CFR part 63, 
specifically identified in our definition. Those NRC-regulatory 
provisions in turn incorporate the public health and environmental 
standards promulgated by the EPA in 40 CFR part 197. These are the same 
standards compliance with which DOE will have to demonstrate during 
licensing.
    The numeric radiation dose limits applicable in the preclosure 
period refer to the numerical dose limits in 10 CFR 63.111(a) and (b) 
and 63.204. Subpart K of 10 CFR part 63 contains the preclosure public 
health and environmental standards, adopted from 40 CFR part 197. The 
preclosure standard will require DOE to demonstrate at licensing that 
there is reasonable assurance no member of the public in the general 
environment (i.e., outside the Yucca Mountain site, the Nellis Air 
Force Range and the Nevada Test Site) will receive more than an annual 
dose of 15 mrem from the management and storage of radioactive material 
inside the Yucca Mountain repository and outside the repository but 
within the site (10 CFR part 63.204).
    In addition, the preclosure performance objectives contained in 
part 63.111(a)(2) will require DOE to demonstrate at licensing that 
there is a reasonable assurance that during normal operations any 
radiation exposures and releases of radioactive materials to any real 
member of the public outside the Yucca Mountain site are within the 
numerical radiation dose limits contained in part 63.204 and a related 
NRC regulation, 10 CFR part 20, specifying radiation protection 
standards for workers and the public involving NRC licensees. The 
performance objectives also include numerical guides for design of the 
geologic operations area (10 CFR part 63.111(b). The numerical guides 
will require DOE to demonstrate at licensing that it has designed the 
geologic repository operations area in such a manner that there is 
reasonable assurance that aggregate radiation exposures and aggregate 
releases of radioactive material will be within prescribed dose limits 
during Category 1 event sequences and that any single Category 2 event 
sequence will be within prescribed limits.
    The numeric radiation limits applicable in the postclosure period 
refer to the numerical dose limits in 10 CFR 63.311 and 63.321, and the 
numeric radionuclide concentration limits in 10 CFR 63.331. The 
postclosure public health and environment standards are contained in 
Subpart L of 10 CFR 63, and are comprised of three separate standards. 
First, the individual protection standard, at 10 CFR 63.311, requires 
DOE to demonstrate at licensing, using performance assessment, that 
there is a reasonable expectation that for 10,000 years following 
disposal, the reasonably maximally exposed individual receives no more 
than an annual dose (total effective dose equivalent) of 15 mrem

[[Page 57325]]

from releases from the undisturbed Yucca Mountain disposal system. 
Second, the human intrusion standard, at 10 CFR 63.321, requires DOE to 
determine the earliest time that the waste package would degrade 
sufficiently that a human intrusion could occur without recognition by 
the drillers. If DOE determines that complete waste package penetration 
will occur at or before 10,000 years, then DOE will have to demonstrate 
at licensing, using performance assessment, that there is a reasonable 
expectation that the repository will meet the individual protection 
standard of no more than an annual dose of 15 mrem to the reasonably 
maximally exposed individual 10,000 years following disposal. If 
complete waste package failure occurs after 10,000 years, then DOE must 
include the results of the analysis indicating the exposures to the 
reasonably maximally exposed individual at the time it occurs in the 
environmental impact statement for Yucca Mountain as an indicator of 
long-term disposal system performance. Third, the ground water 
standard, at 10 CFR 63.331, requires DOE to demonstrate at licensing 
that there is a reasonable expectation that for 10,000 years of 
undisturbed performance after disposal, releases of specified 
radionuclides from waste in the Yucca Mountain disposal system into the 
accessible environment will not cause the level of radioactivity in the 
representative volume of ground water to exceed certain limits. The 
limits for radionuclide concentrations in the representative volume of 
ground water are provided in Table 1 of part 63.331, and specify a 
limit of 4 mrem per year to the whole body or any organ from combined 
beta and photon emitting radionuclides, and limits of 5 picocuries per 
liter for combined radium-226 and radium-228 (including natural 
background) and 15 picocuries per liter of gross alpha activity 
(excluding radon and uranium).
    Barriers are defined as any material, structure or feature that 
prevents or substantially reduces the rate of movement of water or 
radionuclides from the Yucca Mountain repository to the accessible 
environment, or prevents the release or substantially reduces the 
release rate of radionuclides from the waste. Several examples of a 
barrier are provided, e.g., a geologic feature and engineered 
structure, or a waste form with physical and chemical characteristics 
that significantly decrease the mobility of radionuclides. This 
definition of barrier is slightly different from the definition in 
proposed part 963, which was based on the definition in proposed part 
63. The NRC modified its definition in final part 63.2 to be consistent 
with EPA's definition of barrier in 40 CFR 197.12. DOE is now modifying 
its definition of barrier to be consistent with the final NRC 
definition at part 63.2.
    The definition adopted here differs from the NRC definition only in 
regard to the phrase ``for a period to be determined by the NRC.'' This 
phrase is in the final NRC definition, but has not been included in 
part 963. The NRC clarified this aspect of the definition stating the 
description of each barrier includes the information on the time period 
over which each barrier will perform its intended function including 
any changes during the compliance period. Under part 963.16(b), DOE's 
performance assessment analyses will include descriptions of barriers, 
both natural and engineered, that are important to isolating 
radioactive waste. Those descriptions will include information on the 
time period over which the barriers will perform their intended 
functions, including any changes during the compliance period. 
Therefore, DOE believes it is not necessary to adopt this phrase in its 
definition of barrier for purposes of DOE's assessment of the 
suitability of the Yucca Mountain site.
    Criteria are defined as those characterizing traits that are 
relevant to assessing the performance of a geologic repository at the 
Yucca Mountain site. The criteria will allow for evaluation of the 
impact of those geologic considerations identified in section 112(a) of 
the NWPA that are relevant to the assessment of the performance of a 
geologic repository at the Yucca Mountain site. The geologic repository 
includes the natural barriers of the geologic setting and the 
engineered barriers of the repository design. The suitability criteria 
of the final rule are specific characterizing traits of the Yucca 
Mountain site that, through the site characterization process, DOE has 
identified as important indicators of the performance of the total 
repository system (that is, the integrated natural and engineered 
barrier systems).
    Consistent with varying definitions in standard dictionaries, DOE 
considered defining the term ``criteria'' as benchmark, pass-fail 
standards rather than as ``characterizing traits.'' DOE decided not to 
adopt the ``pass-fail'' definition for two reasons. First, in section 
112(a) of the NWPA, the term ``primary criteria'' is used synonymously 
with the term ``detailed geologic considerations,'' which are more 
naturally understood as ``characterizing traits'' than as 
``benchmarks.'' Although, as explained above, the section 113 criteria 
are not the same as the section 112 criteria, it seems likely Congress 
used the same words in a similar general sense to mean ``characterizing 
traits'' in both places (rather than ``characterizing traits'' in 
section 112 and ``benchmarks'' in section 113). Second, under section 
113(b), the suitability criteria are to be included in the site 
characterization plan. This further suggests they are better understood 
as ``characterizing traits.'' If a point be made of it, however, the 
proposed and final part 963 rule also contain a benchmark for the 
site's suitability. Section 963.11 states that the Secretary may find 
the site suitable if he concludes, using the evaluation methods set out 
in other portions of the rule, that it is likely to meet the applicable 
radiation protection standards set by the EPA and contained in the 
NRC's licensing rules. Hence even if section 113(b) is read to require 
the Secretary to establish benchmarks that the site must meet to be 
found suitable, he has done that as well.
    DOE's proposed rule contained a somewhat confused discussion of the 
relationship of NRC's use of the word ``criteria'' in its QA program to 
the interpretation we give it here. That discussion was confused 
because it conflated ``benchmark'' and ``quantitative,'' thereby 
suggesting that NRC's non-quantitative criteria were therefore also not 
benchmarks. We clarify that confusion in our response to comments in 
section IV of this SUPPLEMENTARY INFORMATION, and reiterate here that 
our prior statement should have read as we state it there.
    During the postclosure period, DOE will evaluate the performance of 
the total system using a computer modeling tool called total system 
performance assessment. For clarity and consistency with the NRC's 
final rules, the definition of total system performance assessment has 
been changed to match the definition of performance assessment in 10 
CFR 63.2. DOE views the change in definition as a clarifying, 
nonsubstantive change, as the series of analyses that are encompassed 
within DOE's definition of total system performance assessment, or 
performance assessment as defined by the NRC, are the same. Total 
system performance assessment identifies the features, events and 
processes that might affect the performance of the Yucca Mountain 
disposal system, as well as their probabilities and significance. Total 
system performance assessment examines the effects of those features, 
events and processes on that

[[Page 57326]]

performance by estimating the mean annual dose to the reasonably 
maximally exposed individual, including associated uncertainties, as a 
result of releases from the Yucca Mountain disposal system.
    DOE has added or modified other definitions associated with 
analyses conducted for the postclosure period either to conform 963 to 
10 CFR 63 or to make nonsubstantive clarifications. The definitions of 
engineered barrier system and reference biosphere have been modified to 
be consistent with the NRC's definitions in part 63.2. Some new 
definitions have been also added to conform to part 63. For example, 
the terms Yucca Mountain disposal system, reasonably maximally exposed 
individual, and human intrusion have been added to the definition 
section of part 963 and are the same definitions as provided in 10 CFR 
63.2. Other parts of the 963 rule which reference these terms, e.g., 
the definition of total system performance assessment (963.2) and the 
postclosure suitability evaluation method (963.16), have been updated 
to reflect these new terms.
    For the preclosure period, DOE will evaluate suitability using a 
preclosure safety evaluation method. The preclosure safety evaluation 
will consider site characteristics and preliminary engineering 
specifications to assess the adequacy of the repository facilities to 
perform their intended functions and to mitigate the effects of 
initiating events and event sequences that could affect the ability of 
the geologic repository operations area to operate safely.
    In part 63, the NRC clarified certain titles and descriptions of 
the analyses to be performed for the preclosure period. The preclosure 
objectives and performance analysis requirements in parts 63.111(a) and 
(b) and 63.112 are stated in terms of analyzing ``initiating events and 
event sequences,'' rather than ``design basis events,'' to determine 
radiation exposures and releases in the preclosure time period within 
the geologic repository operations area. Accordingly, DOE has deleted 
the definition of design basis event in part 963.2 and added 
definitions of design bases, event sequence, initiating event, and 
geologic repository operations area. These definitions track those used 
by the NRC in its final rule, and therefore, DOE considers these 
changes to be conforming, nonsubstantive changes to part 963 that leave 
the analytical requirements for the preclosure safety evaluation the 
same in substance.
    Under these new definitions, the geologic repository operations 
area refers to the high-level radioactive waste facility that is part 
of a geologic repository, including both surface and subsurface areas, 
where waste handling activities are conducted. To add clarity to the 
rule, DOE has deleted the term repository support facilities and 
incorporated it into the term surface facilities, to match the usage of 
the term surface facilities within part 963.13, the preclosure 
suitability evaluation method.
    Event sequence is defined as a series of actions and/or occurrences 
within the natural and engineered components of a geologic operations 
area that could potentially lead to exposure of individuals to 
radiation. Event sequences include one or more initiating events, and 
are categorized in two ways: (1) Those events, both natural and human-
induced, that are expected to occur one or more times before permanent 
closure (i.e., Category 1 event sequences); or (2) those events, both 
natural and human-induced, that have at least one chance in 10,000 of 
occurring before permanent closure (i.e., Category 2 event sequences). 
The preclosure safety evaluation will assess the ability of the 
geologic repository operations area to meet the applicable radiation 
protection standard for the preclosure period under both categories of 
event sequences.
    DOE's evaluation of the suitability of a geologic repository at the 
Yucca Mountain site will be based on consideration of a preliminary 
design for the geologic repository. The design is the description of 
the potential geologic repository, which includes multiple barriers to 
the release and transport of radionuclides. These multiple barriers 
consist of both the natural barriers and an engineered barrier system. 
The geologic repository includes not only the facilities and areas 
where radioactive wastes are handled, but also that portion of the 
geologic setting that provides isolation of the radioactive wastes. As 
used in the final rule, and in NRC's part 63, isolation means 
inhibiting the movement of radioactive material from the repository to 
the location where the reasonably maximally exposed individual resides, 
so that postclosure radiation doses and radiation concentrations will 
not exceed the limits prescribed in NRC's regulation.

B. Subpart B--Site Suitability Determination, Methods and Criteria

    (a) Scope--section 963.10. Subpart B describes, for both the 
preclosure and postclosure periods, various facets of DOE's suitability 
determination for the Yucca Mountain site. There are separate sections 
of the final rule for the preclosure and postclosure time periods. 
These sections also describe the site suitability criteria DOE will 
apply in accordance with section 113(b) of the NWPA, the methods it 
will use in applying the criteria and evaluating suitability, and the 
way it will reach the resulting suitability determination.
    The final rule is divided into two sections corresponding to the 
preclosure and postclosure periods, and within each period, three 
subsections. The subsections present for each period: (1) The 
suitability determination; (2) the suitability evaluation method; and 
(3) the criteria to be used for the evaluation. The preclosure and the 
postclosure periods are addressed separately because DOE will use 
different approaches to each arising out of the different 
considerations relevant to the suitability of a geologic repository 
during these two periods. This separation is consistent with the 
structure of DOE's prior Guidelines, and the structure of the original 
and revised NRC licensing regulations, which also have separate 
performance objectives for the preclosure and the postclosure periods. 
The preclosure method and criteria will guide DOE's evaluation of the 
suitability considerations that deal with the operation of the 
repository before it is closed, while waste is being received, stored 
and emplaced. They also allow for the possibility of retrieval. These 
are the considerations important in protecting the public and 
repository workers from exposures to radiation during repository 
operations, especially if an accident should occur. The postclosure 
method and criteria will guide DOE's evaluation of the suitability 
considerations that deal with the long-term behavior of the repository. 
The behavior of interest here is after waste emplacement and repository 
closure.
    (b) Suitability determination--section 963.11. This section 
describes how DOE will determine the suitability of the site based on 
the information and data developed through the program of site 
characterization activities at Yucca Mountain. DOE may find the Yucca 
Mountain site suitable for the location of a repository based on its 
determinations relative to the preclosure and postclosure suitability 
evaluations under sections 963.12 and 963.15. Those determinations, in 
turn, entail assessment of preclosure and postclosure suitability using 
the designated evaluation method and criteria for each time period. The 
overall suitability determination, if affirmative, will be one part of 
the Secretary's decision, under section 114 of the NWPA, whether or not 
to recommend the Yucca Mountain site to the

[[Page 57327]]

President for development of a repository.
    (c) Preclosure suitability determination--section 963.12. The 
suitability evaluation of the Yucca Mountain site will consider the 
safety of the geologic repository during the operational or preclosure 
time period. The preclosure criteria to evaluate the suitability of a 
geologic repository operations area at Yucca Mountain will be 
considerations that are important to determining safety during 
construction and active operation and to demonstrating compliance with 
the applicable radiation protection standard.
    (d) Preclosure suitability evaluation method--section 963.13. The 
preclosure suitability criteria will be applied through a preclosure 
safety evaluation method. The preclosure safety evaluation will guide 
the evaluation of the suitability of the site with respect to 
preclosure operations. The NRC provides a framework indicating how to 
conduct this type of evaluation in 10 CFR part 63.112. DOE designed the 
preclosure safety evaluation method in this final rule based on this 
NRC framework and a DOE assessment of what information would be useful 
to determine, at the site suitability stage, whether or not a proposed 
geologic repository at Yucca Mountain is likely to meet the applicable 
radiation protection standards for the preclosure period.
    The preclosure safety evaluation method, using preliminary 
engineering specifications, will assess the adequacy of the repository 
facilities to perform their intended functions and prevent or mitigate 
the effects of postulated event sequences. The preclosure safety 
evaluation will consider: a preliminary description of the site 
characteristics, the surface facilities, and the underground 
facilities; a preliminary description of the design for the operating 
facilities and a preliminary description of any associated limits on 
operation; a preliminary description of potential hazards (for example, 
seismic activity, flooding and severe winds), event sequences, and 
their consequences; and a preliminary description of the structures, 
systems, components, equipment, and operator actions intended to 
mitigate or prevent accidents. The purpose of the preclosure safety 
evaluation is to help assess whether relevant hazards that could result 
in unacceptable consequences have been adequately evaluated and 
appropriate protective measures have been identified, so as to help 
determine whether the geologic repository operations area is likely to 
comply with the preclosure requirements for protection against 
radiation exposures and releases of radioactive material.
    The preclosure safety evaluation will emphasize performance 
requirements, analytical bases and technical justifications, and 
evaluations that show how safety functions will be accomplished. The 
adequacy of the facility design will be evaluated by consideration of 
postulated event sequences viewed as sufficiently credible that the 
facility should be designed to prevent or mitigate their effects. Event 
sequences are those natural and human-induced events that are either 
expected to occur before closure, or have one chance in 10,000 of 
occurring before permanent closure.
    (e) Preclosure suitability criteria--section 963.14. DOE will 
evaluate the suitability of the Yucca Mountain site during the 
preclosure period using the following criteria: (a) Ability to contain 
and limit releases of radioactive materials; (b) ability to implement 
control and emergency systems to limit exposures to radiation; (c) 
ability to maintain a system and components that perform their intended 
safety functions; and (d) ability to preserve the option to retrieve 
wastes during the preclosure period. These criteria are considerations 
important to determining the performance of a potential repository at 
Yucca Mountain during this preclosure period. For example, the first 
criterion will help assess whether repository facilities are capable of 
keeping the radioactive materials confined in order to limit releases 
of radioactive material. The second and third criteria help assess 
whether emergency controls and procedures have been developed that are 
adequate to limit releases should an accident occur, and whether the 
system and its components will perform their safety function as 
intended. The fourth criterion, the capability to retrieve or recover 
the wastes from the repository should conditions warrant, is also 
plainly relevant to the safe functioning of a repository.
    These criteria will allow for evaluation of the impact of those 
geologic considerations derived from section 112(a) of the NWPA that 
are relevant to the preclosure period. These considerations are 
hydrology, geophysics, seismic activity, atomic energy defense 
activities, proximity to water supplies and proximity to populations. 
These considerations are relevant to the evaluation of preclosure 
suitability because they bear on the evaluation of repository system 
safety during the preclosure period. The hydrology and geophysics of 
the site are important to preclosure safety because they are indicators 
of possible initiating events for accidents. Seismic activity is also 
important in this regard, as it is an indication of the potential for 
earthquake activity to disrupt normal functioning of a repository 
surface facility. The location of atomic energy defense activities in 
relation to the Yucca Mountain site is important to preclosure safety 
and would be considered to the extent these activities exist and may 
impact operations of the repository facility. Proximity to water 
supplies and proximity to populations are important to preclosure 
safety because they relate to potential locations where people could 
eventually be exposed to radionuclides either through airborne 
transport or through a water pathway.
    (f) Postclosure suitability determination--section 963.15. The 
postclosure suitability evaluation of the Yucca Mountain site will 
consider the safety of the geologic repository during the time after 
operations cease, the postclosure period. DOE will determine the 
suitability of the Yucca Mountain site for the postclosure period by 
examining the results of a TSPA conducted under section 963.16. If the 
results indicate a repository at Yucca Mountain is likely to meet the 
applicable radiation protection standard, then DOE may determine, on 
the basis of site characterization activities, that the site is 
suitable for the postclosure period.
    (g) Postclosure suitability evaluation method--section 963.16. DOE 
will evaluate the suitability of a potential repository at the Yucca 
Mountain site using the TSPA method (described in greater detail 
below). Using the TSPA method, DOE will estimate quantitatively the 
mean annual dose to the reasonably maximally exposed individual and the 
level of radioactivity in the representative volume of ground water 
over the compliance period (10,000 years). With these estimates, DOE 
will evaluate the performance of the repository and its ability to 
limit radiological exposures within the applicable radiation protection 
standard.
    (1) Section 963.16(a). Section 963.16(a) describes how DOE will 
conduct separate performance assessments in order to evaluate the 
postclosure performance of a geologic repository at Yucca Mountain. One 
TSPA will be conducted in accordance with the method described in 
963.16(b), using the criteria identified in section 963.17, and 
assuming no human intrusion into the repository (i.e., an undisturbed 
Yucca Mountain disposal system). A separate TSPA will be

[[Page 57328]]

conducted in accordance with the method described in part 963.16(b) 
(except not all engineered and natural barriers will be considered), 
using the criteria in section 963.17, and assuming a human intrusion 
into the repository in accordance with the scenario specified in 10 CFR 
63.322 and the conditions of the human intrusion standard specified in 
10 CFR part 63.321. This section of 963.16(a) has been modified from 
its proposed form to add clarity to the evaluation process in light of 
changes in the NRC regulations governing the human intrusion standard 
and associated analyses. The results of each performance assessment 
will be examined by DOE to determine the suitability of the site for 
the postclosure period.
    The conduct of separate assessments is consistent with 40 CFR part 
197 and 10 CFR part 63. The EPA and NRC regulations, in turn, are based 
on NAS recommendations in the report, Technical Bases for Yucca 
Mountain Standards, on how best to assess the performance and 
resilience of a potential repository. Because the manner and likelihood 
of human intrusion occurring many hundreds or thousands of years into 
the future cannot be estimated reliably by examining either the 
historic or geologic record, the NAS recommended an approach that will 
assess how resilient the geologic repository would be against a 
postulated intrusion. The consequences of the assumed human intrusion 
event will be addressed in a ``stylized'' manner, that is, by assuming 
a particular human intrusion event occurs in a certain way. DOE will 
conduct the human intrusion analysis, and use the results of the 
performance assessment, in the manner set out in the NRC regulations 
(e.g., parts 63.321 and 63.322).
    (2) Section 963.16(b). Section 963.16(b) provides an outline of the 
contents and manner in which DOE will conduct its performance 
assessments. As described previously in this notice, and briefly 
summarized here, performance assessment in this context is a method of 
forecasting how a system or parts of a system designed to contain 
radioactive waste will behave over time. Its goal is to aid in 
determining whether or not the system can meet established performance 
requirements. A TSPA is a type of performance assessment analysis in 
which the components of a system are integrated or linked into a single 
analysis.
    The TSPA addresses both the engineered and natural system 
components. The engineered system is to some extent controllable, but 
the natural system generally is not. The responses of the total system 
extend over periods beyond those for which data have been or can be 
obtained. The relationship of the components of a TSPA is often 
described as a pyramid. The lowest level of the pyramid represents the 
complete suite of process and design data and information (that is, 
field and laboratory studies that are the first step in understanding 
the system). The next higher level indicates how the data feed into 
conceptual models that portray the operation of the individual system 
components. The next higher level represents the synthesis of 
information from the lower levels of the pyramid into computer models. 
The term abstraction often is used to indicate the extraction of 
essential information from large quantities of data. The TSPA models 
are usually referred to as abstracted models. At this point, the 
subsystem behavior may be described by linking models together into 
representations; this is the point at which performance assessment 
modeling is usually thought to begin. This is also the basis for the 
identification of the Yucca Mountain specific suitability criteria 
contained in the final rule.
    The upper level is the final level of distillation of information 
into the most significant aspects to represent the total system. At 
this point, the models are linked together. These are the models used 
to forecast system performance and estimate the likelihood that the 
performance will comply with regulations and ensure long-term safety.
    As information flows up the pyramid, it generally is distilled into 
progressively more simplified or essential forms, or becomes more 
abstracted. However, abstraction is not synonymous with simplification. 
If a particular component model cannot be simplified without losing 
essential aspects of the model, then the model becomes part of the TSPA 
calculation tool. Thus, an abstracted model in a TSPA may take the form 
of something as simple as a table of values that were calculated using 
a complex computer model, or the abstraction may take the form of a 
fully three dimensional computer simulation.
    The TSPA method described in section 963.16(b) is a systematic 
analysis that identifies the features, events, and processes (i.e., 
specific conditions or attributes of the geologic setting, degradation, 
deterioration, or alteration processes of engineered barriers, and 
interactions between the natural and engineered barriers) that might 
affect performance of the Yucca Mountain disposal system; examines 
their effects on performance; and estimates the mean annual dose to the 
reasonably maximally exposed individual and the radionuclide 
concentrations in the representative volume of water. The features, 
events, and processes considered in the TSPA will represent a wide 
range of effects on system performance. According to EPA and NRC 
regulations, those features, events, and processes expected to affect 
compliance significantly or be potentially adverse to performance are 
included, while events of very low probability (less than one chance in 
10,000 of occurring within 10,000 years of disposal) should be excluded 
from the analysis. The annual dose to the reasonably maximally exposed 
individual is estimated using the selected features, events, and 
processes, and incorporating the probability that the estimated dose 
will occur.
    The TSPA that will be used to assess the postclosure performance of 
the Yucca Mountain repository will be conducted in the manner described 
in section 963.16(b). It will synthesize data and information into a 
set of models that simulate the behavior of the individual system 
components. DOE will abstract essential information from its initial 
models and refine them into linked models, including computer models, 
that represent important aspects of system performance. DOE will use 
these models to forecast system behavior and the likelihood of system 
compliance with the applicable radiation protection standard.
    The TSPA method described in section 963.16(b) contains twelve 
enumerated conditions DOE will satisfy in conducting the TSPA for the 
postclosure suitability determination. Those conditions will provide 
DOE with multiple lines of argument and evidence in support of the 
resultant TSPA calculation. For example, as part of the TSPA 
calculation, DOE will consider disruptive processes and events, 
identify and evaluate multiple barriers to waste isolation, produce 
information relative to the margin by which the site will meet the 
applicable radiation protection standard, and include analysis of 
insights from man-made analogs. Development of this information will 
build confidence in the TSPA result and aid decision-makers in reaching 
a suitability determination. Through documentation of the technical 
basis for much of the analysis, DOE will identify and quantify 
uncertainties associated with the performance estimates, explain and 
describe the critical assumptions used and possible data limitations, 
and identify the areas

[[Page 57329]]

where expert judgment and natural analogs were used in the analyses.
    The TSPA calculations will be used to address conditions in the 
natural and engineered components of a Yucca Mountain disposal system 
over the time that the standards apply. The TSPA calculations will also 
be used to consider disruptive events that are improbable, but that are 
important to understanding the repository behavior in the future. To 
prepare the TSPA, DOE will identify those natural features of the 
geologic setting and the design features of the engineered barrier 
system that are considered barriers important to waste isolation. TSPA 
will be used to assess the capability of the barriers identified as 
important to waste isolation to isolate waste, taking into account 
uncertainties in characterizing and modeling the barriers. By 
conducting these analyses and documenting the technical basis for them, 
DOE will account for multiple and independent barriers to waste 
isolation. DOE notes that in final 10 CFR part 63, the NRC reorganized 
its requirements pertaining to analysis of multiple barriers by 
creating a new section, part 63.115, to reflect these requirements. 
These requirements, although presented in a new section, are not 
substantively different from proposed part 63 and do not require a 
change to part 963. The TSPA will also include and consider information 
derived from the performance of various sensitivity studies. 
Sensitivity studies and the regulatory definition of very unlikely 
events will provide the technical basis for inclusion or exclusion of 
specific features, events, and processes of the geologic setting in the 
TSPA.
    Specific features, events, and processes of the geologic setting 
will be evaluated through sensitivity analyses to determine if the 
magnitude and time of the resulting annual dose would be significantly 
changed by their omission. Sensitivity analysis is a technique that is 
used to examine how a system responds if one of its components is 
changed. Systems are said to be sensitive to such a component if the 
results of the calculation are changed significantly in response to 
changes in that component's values. The sensitivity calculations will 
also provide the technical basis for either inclusion or exclusion of 
degradation or alteration processes of engineered barriers in the TSPA. 
Degradation or alteration processes will be evaluated further if the 
magnitude and timing of the resulting expected annual dose would be 
significantly changed by their omission.
    Using the TSPA results, DOE can examine the sensitivity of one or 
more components of the calculations in the assessment. DOE can examine 
the response of the geologic repository system with regard to 
sensitivities of the system to the suitability criteria, in order to 
evaluate whether or not the geologic repository meets the applicable 
radiation protection standard.
    As part of the TSPA, DOE will account for uncertainties and 
variabilities in both calculations and data, and provide the technical 
bases for parameter ranges, probability distributions, and bounding 
values. This accounting will enable DOE to identify critical 
assumptions, address uncertainties in those assumptions, and understand 
possible data limitations. The reason for this accounting is that it is 
recognized, by the NRC and others, that there are inherent 
uncertainties in the understanding of the evolution of the geologic 
setting, biosphere, and engineered barrier system. DOE will evaluate 
compliance and the performance of the potential repository using 
sophisticated, complex predictive models that are supported by data 
from field and laboratory tests, site-specific monitoring, and natural 
analog studies that may be supplemented with expert judgment.
    Another aspect of DOE's conduct of the TSPA is the analysis of 
alternative models of features and processes. Under part 963.16(b)(3), 
DOE will consider alternative models of features and processes that are 
consistent with available data and current scientific understanding, 
and evaluate the effects that alternative models would have on the 
estimated performance of the geologic repository. These analyses will 
help DOE and others assess the validity of the conceptual models and 
estimates of the significance of those models to repository 
performance. In this regard, if other interested persons suggest and 
present to DOE alternative models that are consistent with available 
data and current scientific understanding, DOE will evaluate those 
other models. DOE does not believe, however, that it would be 
scientifically or technically useful, and may be administratively 
burdensome, to require that, in every case, DOE provide the bases for 
not using an alternative model suggested by another party. However, DOE 
may decide, on a case-by-case basis, to document consideration of 
alternative models that were suggested by other interested persons, but 
not used because, among other things, the model is not consistent with 
available data and current scientific understanding.
    (h) Postclosure suitability criteria--section 963.17. The 
postclosure criteria to evaluate the suitability of a geologic 
repository at Yucca Mountain will be considerations that reflect both 
the processes that are important to the total system performance of the 
geologic repository and the models used to simulate those processes. 
These criteria are characterizing traits that are relevant and 
important in the processes to be modeled in the TSPA that DOE will use 
in evaluating the suitability of the Yucca Mountain site for the 
postclosure period. These criteria also allow for evaluation of the 
impact of those geologic considerations derived from section 112(a) of 
the NWPA that are relevant to the postclosure period. Following is a 
description of how the section 112(a) geologic considerations relate to 
the postclosure suitability criteria, as well as a discussion of the 
criteria as they relate to the processes and computer models to be used 
in evaluating the performance of a geologic repository in the 
postclosure period.
    (1) Section 112(a) geologic considerations. The geologic 
considerations derived from section 112(a) of the NWPA that are 
relevant to the postclosure performance of a repository at Yucca 
Mountain are: hydrology, geophysics, seismic activity, proximity to 
water supplies, and proximity to populations. These considerations are 
relevant to postclosure performance because they affect components and 
processes of the repository system related to potential transport of 
radionuclides via ground water to members of the public.
    Hydrology- and geophysics-related conditions are relevant because 
they describe some of the geologic features of the site that are 
related to safety and the physical characteristics that are related to 
potential transport of radionuclides to the biosphere. Seismic activity 
is relevant to postclosure performance because it is related to the 
potential for changes in geologic structures that could lead to 
enhanced transport of radionuclides. Proximity to water supplies and 
populations are relevant to postclosure performance because they are 
related to potential locations where people could eventually be exposed 
to radionuclides in their water.
    Table 2 provides a cross-reference between the geologic 
considerations derived from section 112(a), and the postclosure 
suitability criteria. As previously stated, the postclosure suitability 
criteria largely represent the process model components of the total 
system performance assessment that DOE will use to evaluate the 
performance of the repository during the

[[Page 57330]]

postclosure period. DOE has identified these processes as pertinent to 
assessing the performance of a repository at Yucca Mountain through 
information and data developed under its site characterization program.
    One of the considerations found in section 112(a), location of 
natural resources, is no longer addressed through a site suitability 
criterion, and instead is addressed through the separate performance 
assessment provision, part 963.16(a)(2). Proposed part 963 included a 
criterion for inadvertent human intrusion, which was related to the 
consideration under section 112(a) of the location of valuable natural 
resources, because that is a factor that could lead to human intrusion 
through exploratory drilling or excavation and a consequent breach of 
the repository's safety barriers. Because this factor will be addressed 
through a separate performance assessment provision, part 963.16(a)(2), 
which requires assessment of potential human intrusion events in a 
manner consistent with NRC regulations governing a human intrusion 
standard and event scenario, DOE does not believe it is necessary to 
retain this suitability criterion in final part 963.

                                 Table 2
                              [Postclosure]
------------------------------------------------------------------------
NWPA Sec.  112(a) geologic considerations       Suitability criteria
------------------------------------------------------------------------
           (a) Processes pertinent to total system performance
------------------------------------------------------------------------
Hydrology, geophysics, seismic activity..  (1) Site characteristics
Hydrology, geophysics, seismic activity..  (2) Unsaturated-zone flow
                                            characteristics
Hydrology, geophysics, seismic activity..  (3) Near-field environment
                                            characteristics
Hydrology, geophysics seismic activity...  (4) Engineered barrier system
                                            degradation ,
                                            characteristics
Hydrology, geophysics, seismic activity..  (5) Waste form degradation
                                            characteristics
Hydrology, geophysics, seismic activity..  (6) Engineered barrier system
                                            degradation, flow, and
                                            transport characteristics
Hydrology, geophysics, seismic activity..  (7) Unsaturated-zone flow and
                                            transport characteristics
Hydrology, geophysics, seismic activity..  (8) Saturated-zone flow and
                                            transport characteristics
Hydrology, proximity to water supplies,    (9) Biosphere characteristics
 proximity to populations.
------------------------------------------------------------------------
                   (b) Disruptive processes and events
------------------------------------------------------------------------
Hydrology, geophysics....................  (1) Volcanism
Seismic activity, geophysics.............  (2) Seismic events
Hydrology, geophysics, seismic activity..  (3) Nuclear criticality
------------------------------------------------------------------------

    (2) Suitability criteria. DOE has developed its site 
characterization program to address those processes of the repository 
system that are pertinent to understanding how a repository at Yucca 
Mountain would be evaluated for suitability using the applicable 
radiation protection standard. The program also has been developed to 
better understand these processes, and resolve or put in place methods 
to resolve issues related to those processes. DOE has described these 
processes, and the methods to resolve issues related to the processes, 
in the SCP, in semi-annual progress reports on site characterization 
program activities, and in several TSPAs conducted over the years, 
including the Viability Assessment. These processes are simulated 
through performance assessment models; those models are integrated and 
refined to a point resulting in a representation of the performance of 
the system in total.
    Put in simple terms, the processes that are pertinent to 
understanding the performance of a repository at Yucca Mountain, and 
that form the basis for the numerical models in the TSPA and the 
suitability criteria in section 963.17, are those physical processes of 
water falling on Yucca Mountain as rain and snow, moving into the 
mountain, down through the unsaturated zone to the potential repository 
level, from the repository level to the saturated zone, and from there 
to the accessible environment. At the repository level, the water would 
be affected by the physical processes associated with the repository 
and with the waste packages and the waste forms. Eventually, the water 
could move out of the repository horizon and further downward through 
the unsaturated zone. Subsequently, it could move into the saturated 
zone where it could be transported to a point where humans could be 
exposed to any radionuclides carried in the water. Disruptive events 
could potentially affect these processes and, therefore, will be 
considered. This set of physical processes is simulated in the 
numerical modeling method of the TSPA that will be used to assess 
quantitatively the radionuclide releases to the public and, 
consequently, the safety and suitability of the Yucca mountain site.
    The suitability criteria presented in this final rule are derived 
from these pertinent physical processes. These criteria represent the 
characteristic traits pertinent to assessing the performance of a 
geologic repository at the Yucca Mountain site. They also allow for 
evaluation of the impact of geologic considerations derived from 
section 112(a) of the NWPA such as hydrology, geophysics, seismic 
activity, and proximity to water supplies and populations.
    The sequence in which the suitability criteria are presented in the 
final rule generally corresponds to the process of water flow presented 
above. In general, the criteria can be thought of as building blocks; 
each criterion in the sequence is evaluated on its own, with the 
results of that evaluation incorporated into the evaluation of the 
succeeding criteria, and so on until the final analysis. DOE may refine 
these process models to better reflect and assess the processes 
pertinent to performance of a geologic repository at the Yucca Mountain 
site. It is possible that the processes, as well as the design 
selected, could dictate other ways to arrange the information included 
under the individual criteria. While the individual components of the 
process models may vary according to improvements in data and 
information, DOE's suitability determination will be based on an 
evaluation of each of the postclosure suitability criteria.
    The criteria are separated into two categories. The first category, 
presented in section 963.17(a), represents those criteria important to 
the total system performance assessment without accounting for 
disruptive processes and events that could impact that performance. The 
second category, presented in section 963.17(b), are those criteria 
representing disruptive processes and events that could adversely 
affect the characteristics of the repository system, and consequently 
release radionuclides to the human environment. Each criterion in the 
first category is linked to a specific TSPA model component that will 
be used to evaluate the performance of that criterion. Each criterion 
in the second category is generally treated as an effect imposed on the 
system at a time that reflects the probability of occurrence of the 
disruptive event.
    Under section 963.17(a), the first and a fundamental criterion that 
will be modeled to assess performance of a repository at the Yucca 
Mountain site is the representation of pertinent site

[[Page 57331]]

characteristics. The criterion of site characteristics includes: (a) 
The geologic properties of the site--for example, stratigraphy, rock 
type and physical properties, and structural characteristics; (b) the 
hydrologic properties of the site--for example, porosity, permeability, 
moisture content, saturation, and potentiometric characteristics; (c) 
the geophysical properties of the site--for example, thermal 
properties, densities, velocities and water contents, as measured or 
deduced from geophysical logs, and (d) the geochemical properties of 
the site--for example, precipitation, dissolution characteristics, and 
sorption properties of mineral and rock surfaces. Together, as 
reflected in the performance assessment, these characteristics enable a 
representative simulation of the behavior of a geologic repository at 
the Yucca Mountain site.
    The second criterion, unsaturated zone flow characteristics, 
relates to the processes affecting the limitations and amount of water 
entering the unsaturated zone above the repository and contacting 
wastes in the repository. The unsaturated zone flow characteristics 
include: (a) Climate--for example, precipitation and postulated future 
climatic conditions; (b) infiltration--for example, precipitation 
entering the mountain in excess of water returned to the atmosphere by 
evaporation and plant transpiration; (c) unsaturated-zone flux--for 
example, water movement through the pore spaces, or flowing along 
fractures or through perched water zones above the repository; and (d) 
seepage--for example, water dripping into the underground repository 
openings from the surrounding rock. Together, the first and second 
criteria will be used to define the temporal and spatial distribution 
of water flow through the unsaturated zone above the water table at 
Yucca Mountain, and the temporal and spatial distribution of water 
seepages into the underground openings of the repository.
    The third criterion, near field environment characteristics, also 
relates to processes important to limiting the amount of water that 
could contact wastes. This criterion includes: (a) Thermal hydrology--
for example, effects of heat from the waste on water flow through the 
site, and the temperature and humidity at the engineered barriers; and 
(b) near-field geochemical environment--for example, the chemical 
reactions and products resulting from water contacting the waste and 
the engineered barriers materials. The thermal regime generated by the 
decay of the radioactive wastes can mobilize water over the first 
hundreds to thousands of years. For these reasons, the amount of water 
flowing in the rock and seeping into drifts is expected to vary with 
time.
    The fourth criterion, engineered barrier system degradation 
characteristics, relates to the processes important to long waste 
package lifetimes. This criterion includes: (a) Engineered barrier 
system component performance--for example, drip shields, backfill, 
coatings, or chemical modifications; and (b) waste package 
degradation--for example, the corrosion of the waste package materials 
within the near-field repository environment. This criterion and the 
first criterion, site characteristics, define the spatial and temporal 
distribution of the time periods when waste packages are expected to 
breach. The thermal, hydrologic, and geochemical processes acting on 
the waste package surface are the most important environmental factors 
affecting the waste package lifetime. In addition, the degradation 
characteristics of the waste package materials significantly affect the 
timing of waste package breaches.
    The fifth criterion, waste form degradation characteristics, 
addresses the initial aspects of low rate of release of radionuclides. 
This criterion includes: (a) Cladding degradation--for example, 
corrosion or break-down of the cladding on the spent fuel pellets; and, 
(b) waste form dissolution--for example, the ability of individual 
radionuclides to dissolve in water that penetrates breached waste 
packages. This criterion is important to understanding how and in what 
manner the waste forms could break down, permitting the release of 
radionuclides to the immediately surrounding environment.
    The sixth criterion, engineered barrier system degradation, flow, 
and transport characteristics, addresses the processes important to the 
manner in which radionuclides can begin to move outward once the 
engineered barrier system has been degraded. This criterion includes : 
(a) colloid formation and stability--for example, the formation of 
colloidal particles and the ability of radionuclides to adhere to these 
particles as they may be washed through the remaining barriers; and (b) 
engineered barrier transport--for example, the movement of 
radionuclides dissolved in water or adhering to colloidal particles to 
be transported through the remaining engineered barriers and in the 
underlying unsaturated zone. This criterion and the first criterion, 
site characteristics, lead to a determination of the spatial and 
temporal distribution of the mass of radioactive wastes released from 
the waste packages. Each characteristic depends on the thermal, 
hydrologic, and geochemical conditions inside the waste package, which 
change with time.
    The next two criteria--unsaturated zone flow and transport 
characteristics (criterion seven), and saturated zone flow and 
transport characteristics (criterion eight)--relate to processes 
important to radionuclide concentration reduction during transport. To 
assess the movement of radionuclides away from the degraded engineered 
barrier system, the first important process to understand is the 
unsaturated zone flow characteristics in combination with the 
unsaturated zone transport characteristics. The unsaturated zone flow 
and transport characteristics criterion includes: (a) unsaturated-zone 
transport--for example, the movement of water with dissolved 
radionuclides or colloidal particles through the unsaturated zone 
underlying the repository, including retardation mechanisms such as 
sorption on rock or mineral surfaces; and (b) thermal hydrology--for 
example, effects of heat from the waste on water flow through the site. 
The next criterion, saturated zone flow and transport characteristics, 
addresses similar radionuclide transport processes, only in the 
saturated zone. This criterion includes: (a) saturated zone transport--
for example, the movement of water with dissolved radionuclides or 
colloidal particles through the saturated zone underlying and beyond 
the repository, including retardation mechanisms such as sorption on 
rock or mineral surfaces; and (b) dilution--for example, diffusion of 
radionuclides into pore spaces, dispersion of radionuclides along flow 
paths, and mixing with non-contaminated ground water.
    The ninth criterion, biosphere characteristics, addresses the 
characteristics that describe the lifestyle and habits of individuals 
who potentially could be exposed to radioactive material at a future 
time. Because of the difficulty in predicting the lifestyles and habits 
of future generations, such assessments are to be based on 
representative current conditions. Both the EPA and the NRC's final 
rules require DOE to apply current conditions (with consideration of 
climate evolution) in assessments of the reference biosphere. This 
criterion includes: (a) A reference biosphere and reasonably maximally 
exposed individual defined, for example, by considering pathways, 
location and behavior ; and (b) biosphere transport

[[Page 57332]]

and uptake--for example, the consumption of ground or surface waters 
through direct extraction or agriculture, including mixing with non-
contaminated waters and exposure to contaminated agricultural products.
    Together, the criteria of unsaturated zone flow and transport 
characteristics, saturated zone flow and transport characteristics, and 
biosphere characteristics, address the spatial and temporal variations 
of radionuclide concentrations in ground water. The ground water 
concentration ultimately yields the mass of radionuclides that may be 
ingested or inhaled by individuals exposed to that ground water, which 
in turn leads to a level of radiological dose or risk associated with 
that potential exposure. The concentration depends on both the mass 
release rate of the radionuclides as well as the volumetric flux of 
water along the different pathways in the different components.
    We note that the NRC modified its definition of groundwater in its 
final rule to be consistent with the EPA's definition of groundwater. 
This new definition limits groundwater to water that is in the 
saturated zone, for purposes of demonstrating compliance with 
radionuclide concentration limits in groundwater that is within the 
representative volume of water, i.e., water that is located within the 
accessible environment. DOE did not have a definition of groundwater in 
its proposed rule and has decided not to add one now. DOE's historical 
groundwater evaluations include a comprehensive evaluation of water 
characteristics above the drift in the unsaturated zone, below the 
drift in the unsaturated and the saturated zones, to the repository 
site boundary and into the accessible environment beyond the controlled 
area of the site. Hence, these evaluations include, as they should, 
evaluation of groundwater in both unsaturated and saturated zones. DOE 
does not believe a conforming definition is necessary for purposes of 
estimating likely compliance with NRC's groundwater standard. In 
estimating likely compliance with the NRC groundwater protection 
standard, DOE will evaluate radionuclide concentration limits in 
groundwater in the saturated zone (in the representative volume of 
water), in accordance with NRC's rule.
    Section 963.17(b) presents three final criteria (separately 
enumerated from section 963.17(a)) under the category of disruptive 
processes and events. These criteria relate to disruptive processes and 
events that could potentially release radionuclides directly to the 
human environment, or otherwise adversely affect the characteristics of 
the system. The criteria pertinent to assessing repository performance 
that fall in this category include: (1) Volcanism--for example, the 
probability and potential consequences of a volcanic eruption 
intersecting the repository; (2) seismic events--for example, the 
probability and potential consequences of an earthquake on the 
underground facilities or hydrologic system; and (3) nuclear 
criticality--for example, the probability and potential consequences of 
a self-sustaining nuclear reaction as a result of chemical or physical 
processes affecting the waste either in or after release from breached 
waste packages.
    In proposed part 963, DOE included a fourth disruptive process and 
event criterion of inadvertent human intrusion. This criterion was not 
included in final 963 because the treatment of a possible human 
intrusion event for the postclosure period is dealt with through a 
prescribed human intrusion standard, part 63.321, and a prescribed set 
of assumptions for the human intrusion scenario, part 63.322. A 
separate performance assessment analysis is required to assess the 
impacts of the postulated human intrusion event to determine whether 
the individual protection standard in the case of human intrusion is 
applicable (i.e., if the human intrusion is determined by DOE to occur 
at or before 10,000 years), or whether the information and analyses 
relative to the exposures from the human intrusion event should be 
included in the environmental impact statement for the Yucca Mountain 
site as an indication of long-term performance. To make consistent the 
NRC requirements for human intrusion analyses and the structure of 
performance analyses required under part 963, DOE believes it 
preferable not to retain an inadvertent human intrusion event as a 
separate criterion. This change does not change the substance or 
requirements for the human intrusion analysis, and therefore DOE views 
this as a clarification of its rule.

VII. Regulatory Review

A. Review for Compliance With the National Environmental Policy Act 
(NEPA)

    One commenter questioned whether or not this rulemaking would 
require compliance with NEPA. The issuance of these amendments to the 
Guidelines is a preliminary decision-making activity pursuant to 
subsections 112 (d) and 113(d) of the Act and therefore does not 
require the preparation of an environmental impact statement pursuant 
to subsection 102(2)(C) of the NEPA or any other environmental review 
under subsection 102(2)(E) or (F) of the NEPA.

B. Review Under the Regulatory Flexibility Act

    The Regulatory Flexibility Act (5 U.S.C. 601 et seq.) was enacted 
by Congress to ensure that a substantial number of small entities do 
not unnecessarily face significant negative economic impact as a result 
of Government regulations. The DOE certifies that the rule amending the 
Guidelines will not have a significant impact on a substantial number 
of small entities. The final rule will not regulate or otherwise 
economically burden anyone outside of the DOE. It merely articulates 
considerations for the Secretary of Energy to use in determining 
whether or not the Yucca Mountain site is suitable for development as a 
repository. Moreover, in response to the revised notice of proposed 
rulemaking, a few entities who commented were small entities, and none 
of them identified economic burdens that the regulations would impose. 
Accordingly, no regulatory flexibility analysis is required under the 
Regulatory Flexibility Act.

C. Review Under the Paperwork Reduction Act

    The DOE has determined that this final rule contains no new or 
amended record keeping, reporting, or application requirements, or any 
other type of information collection requirements subject to the 
Paperwork Reduction Act (Pub. L. No. 96-511).

D. Review Under Unfunded Mandates Reform Act

    The Unfunded Mandates Reform Act of 1995 (Pub. L. No. 104-4) 
generally requires Federal agencies to closely examine the impacts of 
regulatory actions on State, local, and tribal governments. Subsection 
101(5) of Title I of that law defines a Federal intergovernmental 
mandate to include any regulation that would impose an enforceable duty 
upon State, local, or tribal governments, except, among other things, a 
condition of Federal assistance or a duty arising from participating in 
a voluntary federal program. Title II of that law requires each Federal 
agency to assess the effects of Federal regulatory actions on State, 
local, and tribal governments, in the aggregate, or to the private 
sector, other than to the extent such actions merely incorporate 
requirements specifically set forth in a statute. Section 202 of that 
title requires

[[Page 57333]]

a Federal agency to perform a detailed assessment of the anticipated 
costs and benefits of any rule that includes a Federal mandate which 
may result in costs to State, local, or tribal governments, or to the 
private sector, of $100 million or more. Section 204 of that title 
requires each agency that proposes a rule containing a significant 
Federal intergovernmental mandate to develop an effective process for 
obtaining meaningful and timely input from elected officers of State, 
local, and tribal governments.
    This final rule is not likely to result in any Federal mandate that 
may result in the expenditure by State, local, and tribal governments 
in the aggregate, or by the private sector, of $100 million or more in 
any one year. Further, the Guidelines in 10 CFR part 960, the final 
amendments to part 960 and the final part 963 largely incorporate 
requirements specifically provided in sections 112 and 113 of the Act. 
Moreover, sections 112, 113 and 114 of the Act provide for meaningful 
and timely input from elected officials of State, local and tribal 
governments. Accordingly, no assessment or analysis is required under 
the Unfunded Mandates Reform Act of 1995.

E. Review Under the Treasury and General Government Appropriations Act, 
1999

    Section 654 of the Treasury and General Government Appropriations 
Act, 1999 (Public Law 105-277) requires Federal agencies to issue a 
Family Policymaking Assessment for any final rule or policy that may 
affect family well-being. Today's final rulemaking would not have any 
impact on the autonomy or integrity of the family as an institution. 
Accordingly, DOE has concluded that it is not necessary to prepare a 
Family Policymaking Assessment.

F. Review Under Executive Order 12866

    Section 1 of Executive Order 12866 (``Regulatory Planning and 
Review''), 58 FR 51735, establishes a philosophy and principles for 
Federal agencies to follow in promulgating regulations. Section 1(b)(9) 
of that Order provides: ``Wherever feasible, agencies shall seek views 
of appropriate State, local, and tribal officials before imposing 
regulatory requirements that might significantly or uniquely affect 
those governmental entities. Each agency shall assess the effects of 
Federal regulations on State, local, and tribal governments, including 
specifically the availability of resources to carry out those mandates, 
and seek to minimize those burdens that uniquely or significantly 
affect such governmental entities, consistent with achieving regulatory 
objectives. In addition, agencies shall seek to harmonize Federal 
regulatory actions with regulated State, local and tribal regulatory 
and other governmental functions.''
    Section 6 of Executive Order 12866 provides for a review by the 
Office of Information and Regulatory Affairs (OIRA) of a ``significant 
regulatory action,'' which is defined to include an action that may 
have an effect on the economy of $100 million or more, or adversely 
affect, in a material way, the economy, competition, jobs, 
productivity, the environment, public health or safety, or State, 
local, or tribal governments. The Department has concluded that this 
final rule is a significant regulatory action that requires a review by 
the OIRA. DOE submitted this rule for OIRA clearance, and OIRA has 
completed its review.
    One commenter suggested that, under Executive Order 12866, DOE 
should assess the effects of this rulemaking on State, local, and 
tribal governments including reasonable efforts to minimize any burdens 
that uniquely or significantly affect such governmental entities. The 
commenter argued that ongoing characterization and development of the 
Yucca Mountain site affected the economy, jobs, the environment, and 
public health and safety. While certain determinations in DOE's nuclear 
waste repository program may have such effects that can be analyzed, 
the decision to promulgate today's rule is not one of them. It will not 
regulate anyone other than DOE officials. It will affect preliminary 
decision-making in a way that does not have specific identifiable 
economic, environmental, or health effects.

G. Review Under Executive Order 12875

    Executive Order 12875 (Enhancing Intergovernmental Partnership), 
provides for reduction or mitigation, to the extent allowed by law, of 
the burden on State, local and tribal governments of unfunded Federal 
mandates not required by statute. The analysis under the Unfunded 
Mandates Reform Act of 1995, above, satisfies the requirements of 
Executive Order 12875. Accordingly, no further analysis is required 
under Executive Order 12875.

H. Review Under Executive Order 12898

    Executive Order 12898 (Federal Actions to Address Environmental 
Justice in Minority Populations and Low-Income Populations) requires 
Federal agencies to achieve environmental justice by identifying and 
addressing, as appropriate, disproportionately high and adverse human 
health and environmental effects of its programs, policies, and 
activities on minority and low-income populations. One commenter on the 
proposed rule said that DOE should fully apply this Executive Order to 
this rulemaking, but did not provide any supporting reasons. In DOE's 
view, the requirements of Executive Order 12898 are not implicated by 
this rulemaking. This rulemaking has direct effects or regulates only 
DOE, and therefore will not have disproportionate and adverse human 
health effects on minority and low-income populations.

I. Review Under Executive Order 12988

    With respect to the review of existing regulations and the 
promulgation of new regulations, section 3(a) of Executive Order 12988, 
``Civil Justice Reform,'' 61 FR 4729 (February 7, 1996), imposes on 
Executive agencies the general duty to adhere to the following 
requirements: (1) Eliminate drafting errors and ambiguity; (2) write 
regulations to minimize litigation; and (3) provide a clear legal 
standard for affected conduct rather than a general standard and 
promote simplification and burden reduction. With regard to the review 
required by section 3(a), section 3(b) of Executive Order 12988 
specifically requires that Executive agencies make every reasonable 
effort to ensure that the regulation: (1) Clearly specifies the 
preemptive effect, if any; (2) clearly specifies any effect on existing 
Federal law or regulation; (3) provides a clear legal standard for 
affected conduct while promoting simplification and burden reduction; 
(4) specifies the retroactive effect, if any; (5) adequately defines 
key terms; and (6) addresses other important issues affecting clarity 
and general draftsmanship under any Guidelines issued by the Attorney 
General. Section 3(c) of Executive Order 12988 requires Executive 
agencies to review regulations in light of applicable standards in 
section 3(a) and section 3(b) to determine whether they are met or it 
is unreasonable to meet one or more of them. The DOE has completed the 
required review and determined that, to the extent permitted by law, 
the final rule meets the relevant standards of Executive Order 12988.

J. Review Under Executive Order 13084

    Under Executive Order 13084, ``Consultation and Coordination with 
Indian Tribal Governments,'' DOE may not issue a discretionary rule 
that significantly or uniquely affects Indian tribal governments and 
imposes substantial direct compliance costs.

[[Page 57334]]

This final rulemaking would not have such effects. Accordingly, 
Executive Order 13084 does not apply to this rulemaking.

K. Review Under Executive Order 13132

    Executive Order 13132 creates special requirements for preemption 
and inter-governmental consultation with regard to rules that have 
federalism implications. According to the Executive Order, a policy has 
federalism implications if it has ``substantial direct effect on 
States, on the relationship between the national government and the 
States, or on the distribution of power and responsibilities among the 
various levels of government.''
    One of the county governments in Nevada asserted that DOE should be 
demonstrating consideration of the effects of the rule on State and 
local governments, the relationship between the Federal government and 
the States, or the distribution of power and responsibility among 
various levels of government. The comment was conclusory and did not 
identify any ``substantial direct'' effects that would warrant 
consideration under the executive order. For a variety of reasons, DOE 
is of the view that the special requirements of the Executive Order 
13132 do not apply to this rule. First, the rule does not preempt State 
law. Second, the rule applies directly only to DOE and deals with a 
preliminary stage in a decision-making process about the Yucca Mountain 
site that calls for additional inter-governmental consultation and 
public hearings. Third, the rule does not regulate or alter the 
relationship between the United States and State, local, and tribal 
governments because the terms of that relationship are set forth in the 
NWPA. Fourth, the rule has no impact on the distribution of power and 
responsibilities among various levels of government.

L. Review Under Executive Order 13211

    Executive Order 13211, ``Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use,'' 66 FR 28355 
(May 22, 2001) requires Federal agencies to prepare and submit to the 
Office of Information and Regulatory Affairs (OIRA), Office of 
Management and Budget, a Statement of Energy Effects for any proposed 
significant energy action. A ``significant energy action'' is defined 
as any action by an agency that promulgates or is expected to lead to 
the promulgation of a final rule, and that: (1) Is a significant 
regulatory action under Executive Order 12866, or any successor order; 
and (2) is likely to have a significant adverse effect on the supply, 
distribution, or use of energy; or (3) is designated by the 
Administrator of OIRA, as a significant energy action. For any proposed 
significant energy action, the agency must give a detailed statement of 
any adverse effects on energy supply, distribution, or use should the 
proposal be implemented, and of reasonable alternatives to the action 
and their expected benefits to energy supply, distribution, and use.
    Today's rule is not likely to have a significant adverse effect on 
the supply, distribution, or use of energy, and has not been designated 
by OIRA as a significant energy action. Accordingly, DOE has not 
prepared a Statement of Energy Effects.

M. Congressional Notification

    As required by 5 U.S.C. 801, DOE will submit to Congress a report 
regarding the issuance of today's final rule prior to the effective 
date set forth at the outset of this notice of final rulemaking. The 
report will state that it has been determined that the rule is not a 
``major rule'' as defined by 5 U.S.C. 801(2).

List of Subjects in 10 CFR Parts 960 and 963

    Criteria, Environmental protection, Geologic repositories, Nuclear 
energy, Nuclear materials, Radiation protection, Suitability, Waste 
disposal.

    Issued in Washington, DC, on November 8, 2001.
Lake H. Barrett,
Acting Director, Office of Civilian Radioactive Waste Management.

    For the reasons stated in the preamble, DOE hereby amends part 960, 
and adds a new part 963 to Chapter II of Title 10 of the Code of 
Federal Regulations as follows:

PART 960--GENERAL GUIDELINES FOR THE PRELIMINARY SCREENING OF 
POTENTIAL SITES FOR A NUCLEAR WASTE REPOSITORY

    1. The authority citation for 10 CFR part 960 is revised to read as 
follows:

    Authority: 42 U.S.C. 2011 et seq., 42 U.S.C. 7101 et seq., 42 
U.S.C. 10101 et seq.

    2. The part heading for Part 960 is revised to read as set forth 
above.


Sec. 960.1  [AMENDED]

    3. Section 960.1 is amended by removing the phrase ``for the 
development of repositories'' from the first sentence and removing the 
phrase ``and any preliminary suitability determinations required by 
Section 114(f)'' from the second sentence.

    4. Section 960.2 is amended by revising the definitions of ``Act,'' 
``Application'' and ``Determination'' to read as follows:


Sec. 960.2  Definitions.

* * * * *
    Act means the Nuclear Waste Policy Act of 1982, as amended.
* * * * *
    Application means the act of making a finding of compliance or 
noncompliance with the qualifying or disqualifying conditions specified 
in the guidelines of subparts C and D of this part.
* * * * *
    Determination means a decision by the Secretary that a site is 
suitable for site characterization for the selection of a repository, 
consistent with applications of the guidelines of subparts C and D of 
this part in accordance with the provisions set forth in subpart B of 
this part.
* * * * *

Subpart B--Implementation Guidelines


Sec. 960.3  [Amended]

    5. Section 960.3 is amended by removing the phrase ``for the 
development of repositories'' from the first sentence.


Sec. 960.3-1-4-4  [Removed]

    6. Section 960.3-1-4-4 is removed.

    7. Section 960.3-1-5 is revised to read as follows:


Sec. 960.3-1-5  Basis for site evaluations.

    (a) Evaluations of individual sites and comparisons between and 
among sites shall be based on the postclosure and preclosure guidelines 
specified in subparts C and D of this part, respectively. Except for 
screening for potentially acceptable sites as specified in Sec. 960.3-
2-1, such evaluations shall place primary significance on the 
postclosure guidelines and secondary significance on the preclosure 
guidelines, with each set of guidelines considered collectively for 
such purposes. Both the postclosure and the preclosure guidelines 
consist of a system guideline or guidelines and corresponding groups of 
technical guidelines.
    (b) The postclosure guidelines of subpart C of this part contain 
eight technical guidelines in one group. The preclosure guidelines of 
subpart D of this part contain eleven technical guidelines separated 
into three groups that represent, in decreasing order of importance, 
preclosure radiological safety; environment, socioeconomics, and 
transportation; and ease and cost of siting, construction, operation, 
and closure.

[[Page 57335]]

    (c) The relative significance of any technical guideline to its 
corresponding system guideline is site specific. Therefore, for each 
technical guideline, an evaluation of compliance with the qualifying 
condition shall be made in the context of the collection of system 
elements and the evidence related to that guideline, considering on 
balance the favorable conditions and the potentially adverse conditions 
identified at a site. Similarly, for each system guideline, such 
evaluation shall be made in the context of the group of technical 
guidelines and the evidence related to that system guideline.
    (d) For purposes of recommending sites for development as 
repositories, such evidence shall include analyses of expected 
repository performance to assess the likelihood of demonstrating 
compliance with 40 CFR part 191 and 10 CFR part 60, in accordance with 
Sec. 960.4-1. A site shall be disqualified at any time during the 
siting process if the evidence supports a finding by the DOE that a 
disqualifying condition exists or the qualifying condition of any 
system or technical guideline cannot be met.
    (e) Comparisons between and among sites shall be based on the 
system guidelines, to the extent practicable and in accordance with the 
levels of relative significance specified above for the postclosure and 
the preclosure guidelines. Such comparisons are intended to allow 
comparative evaluations of sites in terms of the capabilities of the 
natural barriers for waste isolation and to identify innate 
deficiencies that could jeopardize compliance with such requirements. 
If the evidence for the sites is not adequate to substantiate such 
comparisons, then the comparisons shall be based on the groups of 
technical guidelines under the postclosure and the preclosure 
guidelines, considering the levels of relative significance appropriate 
to the postclosure and the preclosure guidelines and the order of 
importance appropriate to the subordinate groups within the preclosure 
guidelines. Comparative site evaluations shall place primary importance 
on the natural barriers of the site. In such evaluations for the 
postclosure guidelines of subpart C of this part, engineered barriers 
shall be considered only to the extent necessary to obtain realistic 
source terms for comparative site evaluations based on the sensitivity 
of the natural barriers to such realistic engineered barriers. For a 
better understanding of the potential effects of engineered barriers on 
the overall performance of the repository system, these comparative 
evaluations shall consider a range of levels in the performance of the 
engineered barriers. That range of performance levels shall vary by at 
least a factor of 10 above and below the engineered-barrier performance 
requirements set forth in 10 CFR 60.113, and the range considered shall 
be identical for all sites compared. The comparisons shall assume 
equivalent engineered barrier performance for all sites compared and 
shall be structured so that engineered barriers are not relied upon to 
compensate for deficiencies in the geologic media. Furthermore, 
engineered barriers shall not be used to compensate for an inadequate 
site; mask the innate deficiencies of a site; disguise the strengths 
and weaknesses of a site and the overall system; and mask differences 
between sites when they are compared. Releases of different 
radionuclides shall be combined by the methods specified in appendix A 
of 40 CFR part 191.
    (f) The comparisons specified in paragraph (e) of this section 
shall consist of two comparative evaluations that predict radionuclide 
releases for 100,000 years after repository closure and shall be 
conducted as follows. First, the sites shall be compared by means of 
evaluations that emphasize the performance of the natural barriers at 
the site. Second, the sites shall be compared by means of evaluations 
that emphasize the performance of the total repository system. These 
second evaluations shall consider the expected performance of the 
repository system; be based on the expected performance of waste 
packages and waste forms, in compliance with the requirements of 10 CFR 
60.113, and on the expected hydrological and geochemical conditions at 
each site; and take credit for the expected performance of all other 
engineered components of the repository system. The comparison of 
isolation capability shall be one of the significant considerations in 
the recommendation of sites for the development of repositories. The 
first of the two comparative evaluations specified in the paragraph (e) 
of this section shall take precedence unless the second comparative 
evaluation would lead to substantially different recommendations. In 
the latter case, the two comparative evaluations shall receive 
comparable consideration. Sites with predicted isolation capabilities 
that differ by less than a factor of 10, with similar uncertainties, 
may be assumed to provide equivalent isolation.

    8. In Sec. 960.3-2, the last sentence is revised to read as 
follows:


Sec. 960.3-2  Siting process.

    * * * The recommendation of sites as candidate sites for 
characterization shall be accomplished in accordance with the 
requirements specified in Sec. 960.3-2-3.


Sec. 960.3-2-4  [Removed]

    9. Section 960.3-2-4 is removed.

Appendix III to Part 960--[Amended]

    10. Appendix III to Part 960 is amended as follows:
    a. In paragraph 1, introductory text, first sentence, revise the 
phrase ``the principal'' to read ``certain''.
    b. In paragraph 1, remove the definition for ``Repository site 
selection''.
    c. In paragraph 3, remove the definition for the numeral ``4'' and 
paragraphs ``(a)'' and ``(b)'' which follow.
    d. The table to Appendix III is revised to read as follows:

     Findings Resulting From the Application of the Qualifying and Disqualifying Conditions of the Technical
                                      Guidelines at Major Siting Decisions
----------------------------------------------------------------------------------------------------------------
                                                                                          Siting decision
                                                                                 -------------------------------
            Section 960                   Guideline              Condition          Potentially   Nomination and
                                                                                    acceptable    recommendation
----------------------------------------------------------------------------------------------------------------
4-1(a)............................  System...............  Qualifying...........  ..............               3
4-2-1(a)..........................  Geohydrology.........  ......do.............  ..............               3
4-2-1(d)..........................  ......do.............  Disqualifying........  ..............               1
4-2-2(a)..........................  Geochemistry.........  Qualifying...........  ..............               3
4-2-3(a)..........................  Rock Characteristics.  ......do.............  ..............               3
4-2-4(a)..........................  Climatic Changes.....  ......do.............  ..............               3
4-2-5(a)..........................  Erosion..............  ......do.............  ..............               3

[[Page 57336]]

 
4-2-5(d)..........................  ......do.............  Disqualifying........               1               1
4-2-6(a)..........................  Dissolution..........  Qualifying...........  ..............               3
4-2-6(d)..........................  ......do.............  Disqualifying........               1               1
4-2-7(a)..........................  Tectonics............  Qualifying...........  ..............               3
4-2-7(d)..........................  ......do.............  Disqualifying........               1               1
4-2-8-1(a)........................  Natural Resources....  Qualifying...........  ..............               3
4-2-8-1(d)(1).....................  ......do.............  Disqualifying........               1               1
4-2-8-1(d)(2).....................  ......do.............  ......do.............  ..............               1
4-2-8-2(a)........................  Site Ownership and     Qualifying...........  ..............               3
                                     Control.
5-1(a)(1).........................  System...............  ......do.............  ..............               3
5-1(a)(2).........................  ......do.............  ......do.............  ..............               3
5-1(a)(3).........................  ......do.............  ......do.............  ..............               3
5-2-1(a)..........................  Population Density     ......do.............  ..............               3
                                     and Distribution.
5-2-1(d)(1).......................  ......do.............  Disqualifying........               1               1
5-2-1(d)(2).......................  ......do.............  ......do.............               1               1
5-2-1(d)(3).......................  ......do.............  ......do.............  ..............               1
5-2-2(a)..........................  Site Ownership and     Qualifying...........  ..............               3
                                     Control.
5-2-3(a)..........................  Meteorology..........  ......do.............  ..............               3
5-2-4(a)..........................  Offsite Installations  ......do.............  ..............               3
                                     and Operations.
5-2-4(d)..........................  ......do.............  Disqualifying........               1               1
5-2-5(a)..........................  Environmental Quality  Qualifying...........  ..............               3
5-2-5(d)(1).......................  ......do.............  Disqualifying........  ..............               1
5-2-5(d)(2).......................  ......do.............  ......do.............               1               1
5-2-5(d)(3).......................  ......do.............  ......do.............               1               1
5-2-6(a)..........................  Socioeconomic Impacts  Qualifying...........  ..............               3
5-2-6(d)..........................  ......do.............  Disqualifying........  ..............               1
5-2-7(a)..........................  Transportation.......  Qualifying...........  ..............               3
5-2-8(a)..........................  Surface                ......do.............  ..............               3
                                     Characteristics.
5-2-9(a)..........................  Rock Characteristics.  ......do.............  ..............               3
5-2-9(d)..........................  ......do.............  Disqualifying........  ..............               1
5-2-10(a).........................  Hydrology............  Qualifying...........  ..............               3
5-2-10(d).........................  ......do.............  Disqualifying........  ..............               1
5-2-11(a).........................  Tectonics............  Qualifying...........  ..............               3
5-2-11(d).........................  ......do.............  Disqualifying........               1               1
----------------------------------------------------------------------------------------------------------------


    11. New part 963 is added to read as follows:

PART 963--YUCCA MOUNTAIN SITE SUITABILITY GUIDELINES

Subpart A--General Provisions
963.1   Purpose.
963.2   Definitions.
Subpart B--Site Suitability Determination, Methods and Criteria
963.10   Scope.
963.11   Suitability determination.
963.12   Preclosure suitability determination.
963.13   Preclosure suitability evaluation method.
963.14   Preclosure suitability criteria.
963.15   Postclosure suitability determination.
963.16   Postclosure suitability evaluation method.
963.17--Postclosure   suitability criteria.

    Authority: 42 U.S.C. 2011 et seq.; 42 U.S.C. 7101 et seq.; 42 
U.S.C. 10101, et seq.

Subpart A--General Provisions


Sec. 963.1  Purpose.

    (a) The purpose of this part is to establish DOE methods and 
criteria for determining the suitability of the Yucca Mountain site for 
the location of a geologic repository. DOE will use these methods and 
criteria in analyzing the data from the site characterization 
activities required under section 113 of the Nuclear Waste Policy Act.
    (b) This part does not address other information that must be 
considered and submitted to the President, and made available to the 
public, by the Secretary under section 114 of the Nuclear Waste Policy 
Act if the Yucca Mountain site is recommended for development as a 
geologic repository.


Sec. 963.2  Definitions.

    For purposes of this part:
    Applicable radiation protection standard means (1) For the 
preclosure period, the preclosure numerical radiation dose limits in 10 
CFR 63.111(a) and (b) and 63.204; and
    (2) For the postclosure period, the postclosure numerical radiation 
dose limits in 10 CFR 63.311 and 63.321 and radionuclide concentration 
limits in 10 CFR 63.331.
    Barrier means any material, structure or feature that prevents or 
substantially reduces the rate of movement of water or radionuclides 
from the Yucca Mountain repository to the accessible environment, or 
prevents the release or substantially reduces the release rate of 
radionuclides from the waste. For example, a barrier may be a geologic 
feature, an engineered structure, a canister, a waste form with 
physical and chemical characteristics that significantly decrease the 
mobility of radionuclides, or a material placed over and around the 
waste, provided that the material substantially delays movement of 
water or radionuclides.
    Cladding is the metallic outer sheath of a fuel rod element; it is 
generally made of a corrosion resistant zirconium alloy or stainless 
steel, and is intended

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to isolate the fuel from the external environment.
    Closure means the final closing of the remaining open operational 
areas of the underground facility and boreholes after termination of 
waste emplacement, culminating in the sealing of shafts and ramps, 
except those openings that may be designed for ventilation or 
monitoring.
    Colloid means any fine-grained material in suspension, or any such 
material that can be easily suspended.
    Criteria means the characterizing traits relevant to assessing the 
performance of a geologic repository, as defined by this section, at 
the Yucca Mountain site.
    Design means a description of the engineered structures, systems, 
components and equipment of a geologic repository at Yucca Mountain 
that includes the engineered barrier system.
    Design bases means that information that identifies the specific 
functions to be performed by a structure, system, or component of a 
facility and the specific values or ranges of values chosen for 
controlling parameters as reference bounds for design. These values may 
be constraints derived from generally accepted ``state-of-the-art'' 
practices for achieving functional goals or requirements derived from 
analysis (based on calculation or experiments) of the effects of a 
postulated event under which a structure, system, or component must 
meet its functional goals. The values for controlling parameters for 
external events include:
    (1) Estimates of severe natural events to be used for deriving 
design bases that will be based on consideration of historical data on 
the associated parameters, physical data, or analysis of upper limits 
of the physical processes involved; and
    (2) Estimates of severe external human-induced events to be used 
for deriving design bases, that will be based on analysis of human 
activity in the region, taking into account the site characteristics 
and the risks associated with the event.
    DOE means the U.S. Department of Energy, or its duly authorized 
representatives.
    Engineered barrier system means the waste packages, including 
engineered components and systems other than the waste package (e.g., 
drip shields), and the underground facility.
    Event sequence means a series of actions and/or occurrences within 
the natural and engineered components of a geologic repository 
operations area that could potentially lead to exposure of individuals 
to radiation. An event sequence includes one or more initiating events 
and associated combinations of repository system component failures, 
including those produced by the action or inaction of operating 
personnel. Those event sequences that are expected to occur one or more 
times before permanent closure of the geologic repository operations 
area are referred to as Category 1 event sequences. Other event 
sequences that have at least one chance in 10,000 of occurring before 
permanent closure are referred to as Category 2 event sequences.
    Geologic repository means a system that is intended to be used for, 
or may be used for, the disposal of radioactive wastes in excavated 
geologic media. A geologic repository includes the engineered barrier 
system and the portion of the geologic setting that provides isolation 
of the radioactive waste.
    Geologic repository operations area means a high-level radioactive 
waste facility that is part of a geologic repository, including both 
surface and subsurface areas, where waste handling activities are 
conducted.
    Geologic setting means geologic, hydrologic, and geochemical system 
of the region in which a geologic repository is or may be located.
    High-level radioactive waste means
    (1) The highly radioactive material resulting from the reprocessing 
of spent nuclear fuel, including liquid waste produced directly in 
reprocessing and any solid material derived from such liquid waste that 
contains fission products in sufficient concentration; and
    (2) Other highly radioactive material that the Commission, 
consistent with existing law, determines by rule requires permanent 
isolation.
    Human intrusion means breaching of any portion of the Yucca 
Mountain disposal system within the repository footprint by any human 
activity.
    Infiltration means the flow of a fluid into a solid substance 
through pores or small openings; specifically, the movement of water 
into soil and fractured or porous rock.
    Initiating event means a natural or human induced event that causes 
an event sequence.
    Near-field means the region where the adjacent natural 
geohydrologic system has been significantly impacted by the excavation 
of the repository and the emplacement of the waste.
    NRC means the U.S. Nuclear Regulatory Commission or its duly 
authorized representatives.
    Perched water means ground water of limited lateral extent 
separated from an underlying body of ground water by an unsaturated 
zone.
    Preclosure means the period of time before and during closure of 
the geologic repository.
    Preclosure safety evaluation means a preliminary assessment of the 
adequacy of repository support facilities to prevent or mitigate the 
effects of postulated initiating events and event sequences and their 
consequences (including fire, radiation, criticality, and chemical 
hazards), and the site, structures, systems, components, equipment, and 
operator actions that would be relied on for safety.
    Postclosure means the period of time after the closure of the 
geologic repository.
    Radioactive waste or waste means high-level radioactive waste and 
other radioactive materials, including spent nuclear fuel, that are 
received for emplacement in the geologic repository.
    Reasonably maximally exposed individual means the hypothetical 
person meeting the criteria specified at 10 CFR 63.312.
    Reference biosphere means the description of the environment, 
inhabited by the reasonably maximally exposed individual. The reference 
biosphere comprises the set of specific biotic and abiotic 
characteristics of the environment, including, but not limited to, 
climate, topography, soils, flora, fauna, and human activities.
    Seepage means the inflow of ground water moving in fractures or 
pore spaces of permeable rock to an open space in the rock such as an 
excavated drift.
    Sensitivity study means an analytic or numerical technique for 
examining the effects on model outcomes, such as radionuclide releases, 
of varying specified parameters, such as the infiltration rate due to 
precipitation.
    Site characterization means activities, whether in the laboratory 
or in the field, undertaken to establish the geologic conditions and 
the ranges of the parameters of a candidate site relevant to the 
location of a repository, including borings, surface excavations, 
excavations of exploratory shafts, limited subsurface lateral 
excavations and borings, and in situ testing needed to evaluate the 
suitability of a candidate site for the location of a repository, but 
not including preliminary borings and geophysical testing needed to 
assess whether site characterization should be undertaken.
    Surface facilities means all permanent facilities within the 
restricted area constructed in support of site characterization 
activities and repository construction, operation, and closure 
activities, including surface

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structures, utility lines, roads, railroads, and similar facilities, 
but excluding the underground facility.
    System performance means the complete behavior of a geologic 
repository system at Yucca Mountain in response to the features, 
events, and processes that may affect it.
    Total system performance assessment means a probabilistic analysis 
that is used to:
    (1) Identify the features, events and processes (except human 
intrusion) that might affect the Yucca Mountain disposal system and 
their probabilities of occurring during 10,000 years after disposal;
    (2) Examine the effects of those features, events, processes, and 
sequences of events and processes (except human intrusion) on the 
performance of the Yucca Mountain disposal system; and
    (3) Estimate the dose incurred by the reasonably maximally exposed 
individual, including associated uncertainties, as a result of releases 
caused by all significant features, events, processes, and sequences of 
events and processes, weighted by their probability of occurrence.
    Underground facility means the underground structure, backfill 
materials, if any, and openings that penetrate the underground 
structure (e.g., ramps, shafts and boreholes, including their seals).
    Waste form means the radioactive waste materials and any 
encapsulating or stabilizing matrix.
    Waste package means the waste form and any containers, shielding, 
packing, and other absorbent materials immediately surrounding an 
individual waste container.
    Yucca Mountain disposal system means the combination of underground 
engineered and natural barriers within the controlled area that 
prevents or substantially reduces releases from the waste.
    Yucca Mountain site means the candidate site in the State of Nevada 
recommended by the Secretary to the President under section 
112(b)(1)(B) of the Nuclear Waste Policy Act of 1982 (NWPA) (42 U.S.C. 
1032(b)(1)(B)) on May 27, 1986.

Subpart B--Site Suitability Determination, Methods, and Criteria


Sec. 963.10  Scope.

    (a) The scope of this subpart includes the following for both the 
preclosure and postclosure periods:
    (1) The bases for the suitability determination for the Yucca 
Mountain site as a location for a geologic repository;
    (2) The suitability evaluation methods for applying the site 
suitability criteria to a geologic repository at the Yucca Mountain 
site; and
    (3) The site suitability criteria that DOE will apply in accordance 
with section 113(b)(1)(A)(iv) of the NWPA.
    (b) DOE will seek NRC concurrence on any future revisions to this 
subpart.


Sec. 963.11  Suitability determination.

    DOE will evaluate whether the Yucca Mountain site is suitable for 
the location of a geologic repository on the basis of the preclosure 
and postclosure determinations described in Secs. 963.12 and 963.15. If 
DOE's evaluation of the Yucca Mountain site for the location of a 
geologic repository under Secs. 963.12 and 963.15 shows that the 
geologic repository is likely to meet the applicable radiation 
protection standards for the preclosure and postclosure periods, then 
DOE may determine that the site is a suitable location for the 
development of such a repository.


Sec. 963.12  Preclosure suitability determination.

    DOE will apply the method and criteria described in Secs. 963.13 
and 963.14 to evaluate the suitability of the Yucca Mountain site for 
the preclosure period. If DOE finds that the results of the preclosure 
safety evaluation conducted under Sec. 963.13 show that the Yucca 
Mountain site is likely to meet the applicable radiation protection 
standard, DOE may determine the site suitable for the preclosure 
period.


Sec. 963.13  Preclosure suitability evaluation method.

    (a) DOE will evaluate preclosure suitability using a preclosure 
safety evaluation method. DOE will evaluate the performance of the 
geologic repository at the Yucca Mountain site using the method 
described in paragraph (b) of this section and the criteria in 
Sec. 963.14. DOE will consider the performance of the system in terms 
of the criteria to evaluate whether the geologic repository is likely 
to comply with the applicable radiation protection standard.
    (b) The preclosure safety evaluation method, using preliminary 
engineering specifications, will assess the adequacy of the repository 
facilities to perform their intended functions and prevent or mitigate 
the effects of postulated Category 1 and 2 event sequences. The 
preclosure safety evaluation will consider:
    (1) A preliminary description of the site characteristics, the 
surface facilities and the underground operating facilities;
    (2) A preliminary description of the design bases for the operating 
facilities and a preliminary description of any associated limits on 
operation;
    (3) A preliminary description of potential hazards, event 
sequences, and their consequences; and
    (4) A preliminary description of the structures, systems, 
components, equipment, and operator actions intended to mitigate or 
prevent accidents.


Sec. 963.14  Preclosure suitability criteria.

    DOE will evaluate preclosure suitability using the following 
criteria:
    (a) Ability to contain radioactive material and to limit releases 
of radioactive materials;
    (b) Ability to implement control and emergency systems to limit 
exposure to radiation;
    (c) Ability to maintain a system and components that perform their 
intended safety functions; and
    (d) Ability to preserve the option to retrieve wastes during the 
preclosure period.


Sec. 963.15  Postclosure suitability determination.

    DOE will apply the method and criteria described in Secs. 963.16 
and 963.17 to evaluate the suitability of the Yucca Mountain site for 
the postclosure period. If DOE finds that the results of the total 
system performance assessments conducted under Sec. 963.16 show that 
the Yucca Mountain site is likely to meet the applicable radiation 
protection standard, DOE may determine the site suitable for the 
postclosure period.


Sec. 963.16  Postclosure suitability evaluation method.

    (a) DOE will evaluate postclosure suitability using the total 
system performance assessment method. DOE will conduct a total system 
performance assessment to evaluate the ability of the geologic 
repository to meet the applicable radiation protection standard under 
the following circumstances:
    (1) DOE will conduct a total system performance assessment to 
evaluate the ability of the Yucca Mountain disposal system to limit 
radiological doses and radionuclide concentrations in the case where 
there is no human intrusion into the repository. DOE will model the 
performance of the Yucca Mountain disposal system using the method 
described in paragraph (b) of this section and the criteria in 
Sec. 963.17. DOE will consider the performance of the system in terms 
of the criteria to evaluate whether the Yucca Mountain disposal system 
is likely to comply with

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the applicable radiation protection standard.
    (2) DOE will conduct a separate total system performance assessment 
to evaluate the ability of the Yucca Mountain disposal system to limit 
radiological doses in the case where there is a human intrusion as 
specified by 10 CFR 63.322. DOE will model the performance of the Yucca 
Mountain disposal system using the method described in paragraph (b) of 
this section and the criteria in Sec. 963.17. If required by applicable 
NRC regulations regarding a human intrusion standard, Sec. 63.321, DOE 
will consider the performance of the system in terms of the criteria to 
evaluate whether the Yucca Mountain disposal system is likely to comply 
with the applicable radiation protection standard.
    (b) In conducting a total system performance assessment under this 
section, DOE will:
    (1) Include data related to the suitability criteria in 
Sec. 963.17;
    (2) Account for uncertainties and variabilities in parameter values 
and provide the technical basis for parameter ranges, probability 
distributions, and bounding values;
    (3) Consider alternative models of features and processes that are 
consistent with available data and current scientific understanding, 
and evaluate the effects that alternative models would have on the 
estimated performance of the Yucca Mountain disposal system ;
    (4) Consider only events that have at least one chance in 10,000 of 
occurring over 10,000 years;
    (5) Provide the technical basis for either inclusion or exclusion 
of specific features, events, and processes of the geologic setting, 
including appropriate details as to magnitude and timing regarding any 
exclusions that would significantly change the dose to the reasonably 
maximally exposed individual;
    (6) Provide the technical basis for either inclusion or exclusion 
of degradation, deterioration, or alteration processes of engineered 
barriers, including those processes that would adversely affect natural 
barriers, (such as degradation of concrete liners affecting the pH of 
ground water or precipitation of minerals due to heat changing 
hydrologic processes), including appropriate details as to magnitude 
and timing regarding any exclusions that would significantly change the 
dose to the reasonably maximally exposed individual;
    (7) Provide the technical basis for models used in the total system 
performance assessment such as comparisons made with outputs of 
detailed process-level models and/or empirical observations (for 
example, laboratory testing, field investigations, and natural 
analogs);
    (8) Identify natural features of the geologic setting and design 
features of the engineered barrier system important to isolating 
radioactive waste;
    (9) Describe the capability of the natural and engineered barriers 
important to isolating radioactive waste, taking into account 
uncertainties in characterizing and modeling such barriers;
    (10) Provide the technical basis for the description of the 
capability of the natural and engineered barriers important to 
isolating radioactive waste;
    (11) Use the reference biosphere and reasonably maximally exposed 
individual assumptions specified in applicable NRC regulations; and
    (12) Conduct appropriate sensitivity studies.


Sec. 963.17  Postclosure suitability criteria.

    (a) DOE will evaluate the postclosure suitability of a geologic 
repository at the Yucca Mountain site through suitability criteria that 
reflect both the processes and the models used to simulate those 
processes that are important to the total system performance of the 
geologic repository. The applicable criteria are:
    (1) Site characteristics, which include:
    (i) Geologic properties of the site--for example, stratigraphy, 
rock type and physical properties, and structural characteristics;
    (ii) Hydrologic properties of the site--for example, porosity, 
permeability,moisture content, saturation, and potentiometric 
characteristics;
    (iii) Geophysical properties of the site--for example, densities, 
velocities and water contents, as measured or deduced from geophysical 
logs; and
    (iv) Geochemical properties of the site--for example, 
precipitation, dissolution characteristics, and sorption properties of 
mineral and rock surfaces.
    (2) Unsaturated zone flow characteristics, which include:
    (i) Climate--for example, precipitation and postulated future 
climatic conditions;
    (ii) Infiltration--for example, precipitation entering the mountain 
in excess of water returned to the atmosphere by evaporation and plant 
transpiration;
    (iii) Unsaturated zone flux--for example, water movement through 
the pore spaces, or flowing along fractures or through perched water 
zones above the repository;
    (iv) Seepage--for example, water dripping into the underground 
repository openings from the surrounding rock.
    (3) Near field environment characteristics, which include:
    (i) Thermal hydrology--for example, effects of heat from the waste 
on water flow through the site, and the temperature and humidity at the 
engineered barriers.
    (ii) Near field geochemical environment--for example, the chemical 
reactions and products resulting from water contacting the waste and 
the engineered barrier materials.
    (4) Engineered barrier system degradation characteristics, which 
include:
    (i) Engineered barrier system component performance--for example, 
drip shields, backfill, coatings, or chemical modifications, and
    (ii) Waste package degradation--for example, the corrosion of the 
waste package materials within the near-field environment.
    (5) Waste form degradation characteristics, which include:
    (i) Cladding degradation--for example, corrosion or break-down of 
the cladding on the spent fuel pellets;
    (ii) Waste form dissolution--for example, the ability of individual 
radionuclides to dissolve in water penetrating breached waste packages.
    (6) Engineered barrier system degradation, flow, and transport 
characteristics, which include:
    (i) Colloid formation and stability--for example, the formation of 
colloidal particles and the ability of radionuclides to adhere to these 
particles as they may migrate through the remaining barriers; and
    (ii) Engineered barrier transport--for example, the movement of 
radionuclides dissolved in water or adhering to colloidal particles to 
be transported through the remaining engineered barriers and in the 
underlying unsaturated zone.
    (7) Unsaturated zone flow and transport characteristics, which 
include:
    (i) Unsaturated zone transport--for example, the movement of water 
with dissolved radionuclides or colloidal particles through the 
unsaturated zone underlying the repository, including retardation 
mechanisms such as sorption on rock or mineral surfaces;
    (ii) Thermal hydrology--for example, effects of heat from the waste 
on water flow through the site.
    (8) Saturated zone flow and transport characteristics, which 
include:
    (i) Saturated zone transport--for example, the movement of water 
with dissolved radionuclides or colloidal particles through the 
saturated zone

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underlying and beyond the repository, including retardation mechanisms 
such as sorption on rock or mineral surfaces; and
    (ii) Dilution--for example, diffusion of radionuclides into pore 
spaces, dispersion of radionuclides along flow paths, and mixing with 
non-contaminated ground water.
    (9) Biosphere characteristics, which include:
    (i) Reference biosphere and reasonably maximally exposed 
individual--for example, biosphere water pathways, location and 
behavior of reasonably maximally exposed individual; and
    (ii) Biosphere transport and uptake--for example, the consumption 
of ground or surface waters through direct extraction or agriculture, 
including mixing with non-contaminated waters and exposure to 
contaminated agricultural products.
    (b) DOE will evaluate the postclosure suitability of the Yucca 
Mountain disposal system using criteria that consider disruptive 
processes and events important to the total system performance of the 
geologic repository. The applicable criteria related to disruptive 
processes and events include:
    (1) Volcanism--for example, the probability and potential 
consequences of a volcanic eruption intersecting the repository;
    (2) Seismic events--for example, the probability and potential 
consequences of an earthquake on the underground facilities or 
hydrologic system; and
    (3) Nuclear criticality--for example, the probability and potential 
consequences of a self-sustaining nuclear reaction as a result of 
chemical or physical processes affecting the waste either in or after 
release from breached waste packages.
[FR Doc. 01-28506 Filed 11-13-01; 8:45 am]
BILLING CODE 6450-01-P