Nuclear Waste: Impediments to Completing the Yucca Mountain Repository
Project (Letter Report, 01/17/97, GAO/RCED-97-30).

Pursuant to a legislative requirement, GAO reviewed the Department of
Energy's (DOE) Yucca Mountain Project, focusing on: (1) adjustments DOE
made to the disposal program due to reduced appropriations; and (2)
potential impediments to achieving DOE's objectives and schedule for the
repository project.

GAO found that: (1) because DOE did not receive the amount of
appropriations requested for fiscal year 1996, it revised the scope and
objectives of the repository project with the goal of applying for a
construction license in March 2002, about 5 months later than had been
planned; (2) specifically, DOE: (a) curtailed most investigative
activities at Yucca Mountain in favor of analyzing the information
already collected to focus the remaining investigative activities on key
uncertainties; (b) decided to revise its guidelines for determining if
the Yucca Mountain site is suitable for a repository by deleting those
criteria that require compliance with specific technical conditions,
such as those concerning the travel time for groundwater; and (c) will
issue, in September 1998, an assessment of the expected design,
performance, and cost of a repository at Yucca Mountain. This report is
intended to support decisions on continuing the repository project and
authorizing a waste storage facility near Yucca Mountain that may be
made before DOE has determined if the site is suitable for a repository;
(3) several impediments must be resolved in DOE's favor if it is to
achieve the project's revised objectives and schedule; (4) it is
uncertain when the Environmental Protection Agency and Nuclear
Regulatory Commission (NRC) will issue the health standards and
licensing regulations, respectively, that DOE needs to determine if
Yucca Mountain is a suitable repository site; (5) the absence of
applicable standards and regulations creates uncertainty about whether
the scope of DOE's site investigation is adequate; and (6) limitations
on information that DOE is collecting in key areas, such as hydrology
and the effects of the heat generated by waste on the performance of the
repository and NRC's preparations to review a license application, add
more uncertainty to the repository project.

--------------------------- Indexing Terms -----------------------------

 REPORTNUM:  RCED-97-30
     TITLE:  Nuclear Waste: Impediments to Completing the Yucca Mountain 
             Repository Project
      DATE:  01/17/97
   SUBJECT:  Nuclear waste management
             Nuclear waste storage
             Radioactive waste disposal
             Licenses
             Safety standards
             Pollution control
             Site selection
             Research and development
             Government facility construction
             Budget cuts
IDENTIFIER:  DOE Yucca Mountain Project (NV)
             Nuclear Waste Fund
             DOE High Level Nuclear Waste Disposal Program
             Yucca Mountain (NV)
             
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Cover
================================================================ COVER


Report to Congressional Committees

January 1997

NUCLEAR WASTE - IMPEDIMENTS TO
COMPLETING THE YUCCA MOUNTAIN
REPOSITORY PROJECT

GAO/RCED-97-30

Impediments to the Yucca Mountain Repository

(302186)


Abbreviations
=============================================================== ABBREV

  DOE - Department of Energy
  EPA - Environmental Protection Agency
  NRC - Nuclear Regulatory Commission

Letter
=============================================================== LETTER


B-275449

January 17, 1997

The Honorable Frank Murkowski
Chairman
The Honorable Dale Bumpers
Ranking Minority Member
Committee on Energy and Natural Resources
United States Senate

The Honorable Thomas J.  Bliley, Jr.
Chairman
The Honorable John D.  Dingell
Ranking Minority Member
Committee on Commerce
House of Representatives

The Congress is expressing growing concern about the pace, direction,
and cost of the Department of Energy's (DOE) program to permanently
dispose of the highly radioactive waste produced by civilian nuclear
power plants and DOE's nuclear weapons activities.  The centerpiece
of the disposal program is the scientific investigation of Yucca
Mountain, Nevada, as a candidate site for disposing of the waste in a
geologic repository.  The Nuclear Waste Policy Act of 1982, as
amended, requires the Secretary of Energy to determine, on the basis
of the investigation, if the site is suitable for a repository and,
if this determination is positive, recommend to the President that
the site be selected for that purpose.  If the site is formally
selected, DOE must apply to the Nuclear Regulatory Commission (NRC)
for authorization (a license) to construct a repository there.  DOE's
current objective is to begin disposing of waste in the repository in
2010, or 12 years later than had been originally expected. 

The perceived lack of progress on the repository project has led to
renewed debate on the need for a federal facility to store waste
until the repository has been constructed and a reduced allotment of
appropriations for the project in fiscal year 1996.  The
administration had requested $472 million for the project, or almost
$100 million more than the project's previous appropriation
allotment.  However, the project was allocated $250 million of the
appropriations for the entire disposal program, or 53 percent of the
amount originally requested.\1 Because of congressional concern about
DOE's capability to maintain its schedule for the repository with
reduced appropriations, we identified the (1) adjustments DOE made to
the disposal program due to the reduced appropriations and (2)
potential impediments to achieving DOE's objectives and schedule for
the repository project.  We addressed these issues under our
responsibility, contained in the Nuclear Waste Policy Act of 1982, as
amended, to audit the disposal program and to report the results of
such audits to the Congress. 


--------------------
\1 The Energy and Water Development Appropriations Act of 1996
provided $400 million for the disposal program.  This included $152
million from the civilian Nuclear Waste Fund appropriation account
and $248 million from the defense nuclear waste disposal account. 
The act reserved $85 million of the appropriation from the latter
account for the development of a facility for the interim storage of
waste upon the enactment of statutory authority for such a facility. 
This effectively left DOE with $315 million of available
appropriations. 


   RESULTS IN BRIEF
------------------------------------------------------------ Letter :1

Because DOE did not receive the amount of appropriations requested
for fiscal year 1996, it revised the scope and objectives of the
repository project with the goal of applying for a construction
license in March 2002, about 5 months later than had been planned. 
Specifically, DOE

  -- curtailed most investigative activities at Yucca Mountain in
     favor of analyzing the information already collected to focus
     the remaining investigative activities on key uncertainties;

  -- decided to revise its guidelines for determining if the Yucca
     Mountain site is suitable for a repository by deleting those
     criteria that require compliance with specific technical
     conditions, such as those concerning the travel time for
     groundwater; and

  -- will issue, in September 1998, an assessment of the expected
     design, performance, and cost of a repository at Yucca Mountain. 
     This report, called a viability assessment, is intended to
     support decisions on continuing the repository project and
     authorizing a waste storage facility near Yucca Mountain that
     may be made before the Department has determined if the site is
     suitable for a repository. 

Several impediments must be resolved in DOE's favor if the Department
is to achieve the project's revised objectives and schedule.  First,
it is uncertain when the Environmental Protection Agency (EPA) and
NRC will issue the health standards and licensing regulations,
respectively, that DOE needs to determine if Yucca Mountain is a
suitable repository site.  Also, the absence of applicable standards
and regulations creates uncertainty about whether the scope of the
Department's site investigation is adequate.  Finally, limitations on
(1) the information that DOE is collecting in key areas, such as
hydrology and the effects of heat generated by waste on the
performance of the repository, and (2) NRC's preparations to review a
license application add more uncertainty to the repository project. 


   BACKGROUND
------------------------------------------------------------ Letter :2

No country has yet developed a geologic repository for the permanent
disposal of highly radioactive waste.  Because this type of nuclear
waste produces relatively intense levels of radiation for thousands
of years, developing an acceptably safe repository is a complex task
involving diverse scientific and technical challenges.  For example,
DOE must design a repository that is compatible with the site and
will be safe to operate for several decades.  In addition, the
Department must demonstrate how the combination of geologic (natural)
and engineered (man-made) barriers to the migration of waste from the
repository will operate effectively.  Inherent in this demonstration
are numerous uncertainties related to understanding and predicting
how a repository will perform over a very long period of time. 
Finally, safety standards for evaluating a proposed repository that
recognize the inherent uncertainty in the repository's performance
must be established. 

In the Nuclear Waste Policy Act of 1982, the Congress found that
federal efforts during the previous 30 years to devise a permanent
solution to the problems of disposing of radioactive waste had not
been adequate.  The act established, among other things, federal
policy and responsibility for the safe management and disposal of
highly radioactive waste from civilian nuclear power plants.\2 The
act charged DOE with selecting and investigating candidate sites for
two repositories, recommending the selection of two sites for
development, and constructing and operating one repository.  DOE was
required to establish guidelines for selecting and recommending
repository sites that made specified geologic considerations the
primary criteria.  To ensure the safe management and disposal of
waste for current and future generations, the act also required EPA
to set environmental standards for the disposal of waste in
repositories and NRC to establish regulations containing technical
requirements and criteria for approving or disapproving of DOE's
applications to construct and operate repositories. 

Amendments to the act in 1987 directed DOE to investigate only the
Yucca Mountain site.  And the Energy Policy Act of 1992 required EPA
to adopt specific public health and safety standards for that site on
the basis of, and consistent with, a study of the scientific basis
for such standards to be issued by the National Academy of Sciences,
at EPA's request, by the end of 1993.  The 1992 act also required
that, within 1 year after EPA adopted its standards for Yucca
Mountain, NRC had to make its licensing regulations consistent with
the standards. 

When the Congress passed the nuclear waste act, it expected that a
repository could be operable by 1998.  Subsequently, however, DOE
extended the estimated date for a repository to 2003 and then to
2010.  In the meantime, nuclear waste is accumulating and being
stored at civilian nuclear power plants.  The growing concern about
the delay in beginning to remove nuclear waste from nuclear plant
sites is reflected by a recent lawsuit and congressional
consideration of legislation.  In July 1996, the U.S.  Court of
Appeals for the District of Columbia Circuit ruled that the nuclear
waste act creates an obligation for DOE to start disposing of
utilities' waste no later than January 31, 1998, and remanded the
case for further proceedings.\3

That same month, the Senate passed a bill (S.  1936) that, among
other things, would have directed DOE to develop a facility for the
interim storage of utilities' waste on DOE's Nevada Test Site.\4 (A
portion of Yucca Mountain lies within the western boundary of the
Nevada Test Site.) Similar legislation was under consideration in the
House of Representatives when the 104th Congress adjourned. 


--------------------
\2 As permitted by the act, the President also decided in 1985 that
highly radioactive waste from DOE's nuclear weapons activities would
also be disposed of in one or more civilian repositories. 

\3 Indiana Michigan Power Co.  v.  Department of Energy, 88 F.3d 1272
(D.C.  Cir., 1996).  The administration has decided not to appeal the
decision. 

\4 The site would be used for a storage facility unless the
President, after determining that Yucca Mountain is not a suitable
site for a repository, designated another site for the facility. 


   FISCAL YEAR 1996 ADJUSTMENTS TO
   THE DISPOSAL PROGRAM
------------------------------------------------------------ Letter :3

Following the appropriation for fiscal year 1996, DOE (1) curtailed
most investigative activities at Yucca Mountain, (2) decided to
revise its guidelines for determining if the site is suitable for a
repository, and (3) announced that it would assess, in 1998, the
"viability" of a repository at Yucca Mountain.  DOE anticipates that
these changes could enable it to submit a license application to NRC
in March 2002 at an affordable cost.  (See fig.  1.)

   Figure 1:  DOE's Schedule
   Leading to License Application

   (See figure in printed
   edition.)


      DOE CURTAILED THE
      INVESTIGATION OF YUCCA
      MOUNTAIN
---------------------------------------------------------- Letter :3.1

During fiscal year 1996, DOE curtailed, for the second consecutive
year, the scope of its investigation of Yucca Mountain.  In January
1992, DOE had estimated that it would cost $6.3 billion through 2001
to investigate the site and prepare a license application.  As we
reported in 1993, however, the budget requests and allotments of
appropriations for the repository project from fiscal years 1991
through 1993 were less than the estimated funding requirements.\5
(See table 1.) Therefore, in December 1994, DOE announced a plan to
reorganize the investigation around tests to determine if the site is
suitable for a repository, tests to support a license application,
and tests that could be deferred until after the application had been
submitted to NRC. 



                                Table 1
                
                 Estimated Funding Required, Requested,
                  and Appropriated for the Repository
                                Project

                         (Dollars in millions)

                                     Funds         Funds         Funds
Fiscal year                       required     requested  appropriated
----------------------------  ------------  ------------  ------------
1991                                 $ 194          $193          $155
1992                                   340           172           166
1993                                   625           248           259
======================================================================
Total                               $1,159          $613          $580
----------------------------------------------------------------------
According to DOE, the plan identified an aggressive field program,
including drilling about 25 to 30 deep boreholes, and tests to be
conducted from the surface of the site, in laboratories, and in the
underground exploratory studies facility.  This facility, which DOE
expects to complete in 1997, is a U-shaped, 5-mile underground tunnel
through Yucca Mountain.  (See fig.  2.) DOE estimated that the
reorganized investigation would cost about $2.9 billion for the 6
fiscal years from 1995 through 2000. 

   Figure 2:  Artist's Conception
   of a Repository at Yucca
   Mountain

   (See figure in printed
   edition.)

Source:  DOE. 

Shortly after DOE received its appropriations for fiscal year 1996,
it further reduced the scope of the investigation and eliminated
about 875 positions for contract employees in the repository project. 
In addition, DOE reduced funding for waste storage, transportation,
and program management activities by $82 million and eliminated more
than 200 related positions for contract employees.  The revised
investigation is now focused on completing the viability assessment
and, according to DOE, was developed using the following priorities,
in descending order of importance:  (1) synthesis and modeling of
available information to focus testing programs on key uncertainties,
(2) testing in the exploratory studies facility, and (3) surface
testing, such as using existing and new wells from holes drilled into
the groundwater underneath the site to test the characteristics of
the groundwater.  DOE estimated the cost of the revised investigation
at about $2.1 billion for the 7 fiscal years from 1996 through 2002. 


--------------------
\5 Nuclear Waste:  Yucca Mountain Project Behind Schedule and Facing
Major Scientific Uncertainties (GAO/RCED-93-124, May 21, 1993). 


      DOE DECIDED TO REVISE ITS
      SUITABILITY GUIDELINES
---------------------------------------------------------- Letter :3.2

Fundamental to the success of DOE's revised approach for the
repository project is its decision to revise its guidelines for
determining if Yucca Mountain is a suitable site for a repository.\6
DOE's existing siting guidelines address the operation of a
repository before it is permanently closed (preclosure guidelines)
and the long-term behavior of the repository after it is closed
(postclosure guidelines).  For both areas, the guidelines are divided
into "system" and "technical" guidelines.  For example, the
postclosure system guideline requires a demonstration that a proposed
repository site and design would likely comply with EPA's disposal
standards and NRC's licensing regulations.  The technical guidelines
establish specific conditions that are important to meeting the
system guidelines.  For example, the postclosure technical guidelines
contain nine conditions that must be present at a site (qualifying
conditions) and six conditions that must be absent from a site
(disqualifying conditions) for DOE to find that the site is suitable
for permanent waste disposal. 

Instead of comparing the Yucca Mountain site's features to the
technical conditions in DOE's existing guidelines, the Department now
plans to compare how a repository at Yucca Mountain would be expected
to perform to EPA's disposal standards and NRC's licensing
regulations.  This approach, DOE says, will lead to a more efficient
process for determining the site's suitability by enabling the
Department to focus investigative activities on issues that are most
important to the performance of a repository at the site.  The
Department's proposed changes to the guidelines were published for
public comment on December 16, 1996 (61 Federal Register 66157). 


--------------------
\6 The nuclear waste act gave the Secretary of Energy the authority
to amend the siting guidelines. 


      DOE WILL ASSESS THE
      VIABILITY OF A REPOSITORY AT
      YUCCA MOUNTAIN
---------------------------------------------------------- Letter :3.3

The principal objective of DOE's new approach for the repository
project is to issue a "viability assessment" in September 1998.  The
assessment will be a statement of the (1) tentative design and
expected performance of the repository system, (2) necessary
investigation activities and associated costs to submit a license
application, and (3) estimated cost to construct and operate the
repository.  The assessment, in DOE's view, will represent an
improved appraisal of the prospects for disposing of nuclear waste at
Yucca Mountain. 

According to the director of the disposal program, the assessment is
intended to guide the completion of the work required for a site
recommendation and to provide policymakers with a better estimate of
the "viability" of a repository in the time frame required for
decision-making. 

If the repository appears to be "viable," then DOE intends to
complete the work necessary to determine the suitability of the site,
recommend that the site be selected for a repository, and, if the
site is formally selected, apply for a construction license.  The
Department has not defined what constitutes a "viable" repository
project; however, the assessment is not intended to demonstrate
either that the Yucca Mountain site is suitable for or can be
licensed as a repository. 

DOE also intends that the assessment be used to "inform" a possible
decision in 1999 by the administration and the Congress to develop a
facility near Yucca Mountain for storing nuclear waste until a
repository is operational.  An affirmative decision would trigger the
beginning of the construction and operation of the storage facility
and the transport of waste from nuclear power plants to the facility. 
As shown in figure 1, however, DOE does not expect to make a
determination of the site's suitability until July 1999 or to
recommend a site until July 2001.  Therefore, an earlier decision to
develop a storage facility near Yucca Mountain could be viewed as a
firm commitment to disposing of waste at Yucca Mountain. 

For example, the administration opposed S.  1936 because the bill
would have designated a location on DOE's Nevada Test Site as a site
for a storage facility before DOE had completed the viability
assessment.  Such a designation, in the administration's view, would
have destroyed the credibility of the disposal program by prejudicing
a future decision on a permanent repository at Yucca Mountain. 
According to the disposal program's director, making a decision to
develop a storage facility near Yucca Mountain after the viability
assessment, although before DOE determines if the Yucca Mountain site
is suitable for a repository, would provide for a more informed
decision. 


   POTENTIAL IMPEDIMENTS TO
   ACHIEVING THE OBJECTIVES AND
   SCHEDULE FOR DOE'S REPOSITORY
   PROJECT
------------------------------------------------------------ Letter :4

Several uncertainties must be resolved in DOE's favor if the
Department is to achieve the project's revised objectives and
schedule.  First, it is uncertain when EPA and NRC will issue the
health standards and licensing regulations, respectively, that DOE
will use to determine if Yucca Mountain is a suitable repository
site.  Also, the lack of applicable standards and regulations creates
uncertainty about whether the scope of the Department's site
investigation has been adequate.  Finally, limitations on the
information that DOE is collecting in key areas and on NRC's
preparations to review a license application add more uncertainty to
the repository project. 


      TIMING OF STANDARDS AND
      REGULATIONS COULD AFFECT
      DOE'S OBJECTIVES AND
      SCHEDULE
---------------------------------------------------------- Letter :4.1

The time it will take for EPA to issue its new disposal standards for
Yucca Mountain and for NRC to conform its licensing regulations to
those standards could affect DOE's ability to make a decision on the
site's suitability and a recommendation on its current schedule. 
When EPA and NRC will issue their respective standards and licensing
regulations is uncertain, but it could take 2 years or longer. 

Because NRC is required to conform its licensing regulations to EPA's
disposal standards, the standards must be issued first.  In February
1993, EPA contracted with the National Academy of Sciences for the
study, mandated by the Energy Policy Act of 1992, of the scientific
basis for standards applicable to the Yucca Mountain site.  In August
1995, the Academy issued its report.  As of January 15, 1997,
however, EPA had not issued proposed standards for public comment. 
EPA anticipates that it may be able to issue final standards within 1
year of proposing the standards for comment.  According to officials
of NRC's waste management division, NRC expects to begin the process
of revising its licensing regulations after EPA proposes its
standards.  For example, when NRC's staff provides the Commission
with comments on EPA's proposed standards for the Commission's
consideration, the staff also plans to provide the Commission with a
strategy for revising NRC's licensing regulations. 

The two regulatory agencies' previous experiences with earlier
standards and licensing regulations have shown that it could take 2
years or longer to issue the new standards and revised licensing
regulations.  For example, EPA took almost 3 years from December
1982, when it proposed its original standards for nuclear waste
repositories, to issue the final standards.\7 After the standards
were successfully challenged in court in 1987, EPA issued revised
standards for public comment in February 1993 and final standards in
December 1993.  In June 1981, NRC proposed technical regulations for
repositories.  Subsequently, it took about 2 years for NRC to adopt
the final technical regulations. 

Thus, it is unlikely that EPA's standards and NRC's revised licensing
regulations will be in place by September 1998, when DOE expects to
issue its viability assessment of the Yucca Mountain project. 
According to DOE, however, it is not important to have the standards
and licensing regulations in place for the viability assessment
because the Department does not intend to compare, in the assessment,
the expected performance of the repository to the standards and
regulations.\8

The timing of EPA's standards and NRC's revised licensing regulations
could, however, affect DOE's schedule for completing a report that
would provide the technical basis for determining if the Yucca
Mountain site complies with the Department's siting guidelines and
for making the site selection recommendation.  As discussed earlier,
the Department intends to make compliance with the standards and
licensing regulations its criteria for determining if Yucca Mountain
is a suitable site for a repository.  According to DOE, it needs to
have the standards and licensing regulations in place at least 1 year
before it makes the determination.  In July 1999, DOE plans to
complete an "interim evaluation" of the site's suitability (see fig. 
1) by issuing a technical report addressing the site's compliance
with the siting guidelines.  To adhere to the Department's schedule
for completing the report, DOE needs to have the standards and
licensing regulations in place by July 1998. 

Moreover, a recommendation by the Secretary to the President that the
Yucca Mountain site be selected for a repository must, according to
the nuclear waste act, be based on a comprehensive statement of the
basis for the recommendation.  Among other things, the comprehensive
statement must contain NRC's preliminary comments on the sufficiency
of DOE's investigation of Yucca Mountain for inclusion in a license
application and the proposed form of the waste.  In April 1999, DOE
plans to issue a report to NRC documenting the investigation's
results.  This report, DOE says, will provide information describing
and modeling the site's characteristics, the designs of the
repository and waste packages, and the expected performance of the
overall repository system.  DOE intends to use this integrated
discussion of its case for a safe repository at Yucca Mountain as the
basis for NRC to provide its preliminary comments to DOE by January
2000.  The Department will not be able to issue a meaningful report
and NRC will not be in a position to provide the Department with its
formal comments on the sufficiency of DOE's site investigation until
the standards and regulations have been issued. 


--------------------
\7 At that time, these standards would have applied at the Yucca
Mountain site; however, the Energy Policy Act of 1992 required EPA to
develop specific standards for a repository at that site. 

\8 The Department's fiscal year 1997 appropriations act directed DOE
to issue the viability assessment to the President and the Congress. 
The act also instructed DOE to include in the assessment a comparison
of the probable behavior of the repository to the "overall system
performance standards." This language is essentially identical to
language in S.1936, which would have established an overall system
performance standard of 100 millirems of radiation exposure to the
affected population per year. 


      SUBSTANCE OF STANDARDS AND
      REGULATIONS COULD AFFECT
      DOE'S OBJECTIVES AND
      SCHEDULE
---------------------------------------------------------- Letter :4.2

Until the substantive requirements of EPA's disposal standards and
NRC's revised licensing regulations are known, DOE will not know if
its scientific investigation of Yucca Mountain has adequately
addressed all of the technical issues that are important to a
credible determination of the site's suitability and an acceptable
license application. 

Although EPA has not yet proposed its standards, the National Academy
of Sciences' report to EPA on the technical basis for Yucca Mountain
standards and DOE's comments on that report show that there are
significant differences of opinion about what the substantive
requirements of the standards should be.  The Academy recommended,
among other things, standards that (1) limit the health risk, rather
than the radiation dose, to individuals from the radioactive
materials released from the repository; (2) require the measurement
of compliance out to the time of peak risk, which is expected to
occur tens or hundreds of thousands of years after the repository has
been closed; and (3) define a critical group that would be at risk. 

Subsequently, DOE expressed three key concerns with the Academy's
recommendations and made recommendations to EPA on how the standards
should be written.  First, DOE recommended limiting compliance
calculations to a 10,000-year period on the basis that the
uncertainties in calculations over a longer period of time would
limit the usefulness and validity of the calculations in a licensing
proceeding.  Second, DOE recommended using a less conservative level
of risk than the Academy had recommended as a starting point for
rulemaking.  Third, DOE recommended a less complex and conservative
approach to calculating risk to the critical group than the two
options discussed in the Academy's report.  (See app.  I for a more
detailed discussion of the Academy's report, DOE's comments, and
other issues related to the development of EPA's standards and NRC's
licensing regulations.)

The extent to which NRC revises its licensing regulations in making
the regulations consistent with EPA's standards could also affect the
adequacy of DOE's scientific investigation.  Currently, NRC's
regulations require DOE to demonstrate compliance with EPA's
"generally applicable environmental standards." However, these
standards have been revised to pertain to repositories at sites other
than Yucca Mountain.  In addition, to provide sufficient confidence
that a repository would perform as predicted, NRC's regulations
require DOE to demonstrate that the repository would comply with
three more specific requirements.  These requirements, called
subsystem performance requirements, establish a minimum lifetime for
packages containing waste, limits on the rate at which radioactive
materials can be released from engineered (man-made) barriers within
the repository, and the minimum time that water might take to travel
from the repository to the accessible environment.  NRC included
these additional requirements because of the inherent uncertainty in
an assessment of the performance of a repository over a long period
of time. 

In its August 1995 report, the Academy concluded that NRC's subsystem
performance requirements could adversely affect the performance of a
repository at Yucca Mountain by limiting DOE's design flexibility. 
DOE agreed and recommended that NRC reconsider the use of these
requirements.  There are, however, arguments favoring these
requirements.  As recognized by NRC in the early 1980s, the subsystem
performance requirements provide "defense in depth" by increasing
confidence in assessments of compliance with EPA's standards.  Also,
NRC pointed out that its regulations provide considerable design
flexibility by permitting NRC to change the subsystem performance
requirements, if warranted, during a licensing proceeding. 

According to the deputy director of NRC's Division of Waste
Management, NRC's staff is considering whether or not the regulatory
agency should retain these subsystem performance requirements in its
licensing regulations and will address this issue when it provides
the Commission with a proposed strategy for revising the agency's
licensing regulations.  The outcome of this issue, as well as other
issues that may arise as NRC revises its licensing regulations, could
affect the scope and depth of the scientific investigation that DOE
must perform to determine if Yucca Mountain is a suitable site for a
repository. 


      DOE MAY NOT HAVE ADEQUATELY
      INVESTIGATED KEY AREAS
---------------------------------------------------------- Letter :4.3

Regardless of the timing and substance of the final repository
regulations, limitations on the information that DOE is collecting
and on NRC's preparations to review a license application increase
uncertainty about the sufficiency of the Department's investigation
of Yucca Mountain. 

According to DOE, among the most important attributes of a repository
at Yucca Mountain are the rate at which water seeps into the
repository, the period of time that the packages containing waste
will prevent the release of radioactive materials from them, and the
manner in which radioactive materials that eventually reach the water
table beneath the repository will be diluted by groundwater.  Also,
heat generated by the waste in the repository will affect the
movement of water through the repository and the durability of the
waste packages.  There are indications of shortcomings in DOE's
investigation of all of these areas. 

For example, DOE may not have done enough to investigate the
groundwater beneath and beyond Yucca Mountain, including where and
how fast water moves and the rate at which water contaminated with
waste materials would be diluted and dispersed as it enters the
groundwater.  According to the U.S.  Geological Survey, which
performs groundwater research for DOE, new questions about the
importance of groundwater to the scientific investigation are
beginning to arise; in the last decade, however, no new boreholes to
address these uncertainties have been drilled, and only limited
testing of the groundwater has occurred.  One such issue is the
unexplained cause of the large drop in the elevation of the water
table at the northern end of Yucca Mountain.  Geological Survey
scientists say that this feature, which was discovered in 1981, is
the most striking hydrologic feature in the area.  According to the
scientists, until they can explain the cause of the drop in the water
table, they would find it difficult to claim that they understand the
hydrology of the site. 

DOE agrees that the drop in the water table has not been fully
evaluated.  According to the Department, however, preliminary
observations of a recently completed pumping test in an existing well
indicate that this feature of the site has no effect on the flow of
groundwater in the aquifer beneath Yucca Mountain. 

According to a 1996 report by DOE on the quality of the Geological
Survey's hydrologic investigations, major uncertainties, such as the
unexplained drop in the groundwater level, at this stage of the
scientific investigation limit understanding of how radioactive
materials would move in groundwater.  In the opinion of the report's
authors, the Geological Survey's research has been severely
handicapped by, among other things, the elimination of most borehole
drilling from the investigation.  (App.  II discusses this limitation
and others on DOE's investigations of the hydrology at Yucca
Mountain, as well as limitations on its investigations of the effects
of heat on the repository's performance and the testing of candidate
materials for waste packages.)

Under the existing legislative framework, NRC, not DOE, will
ultimately decide if the Department's investigation of Yucca Mountain
has been adequate.  Over the years, NRC has reviewed DOE's repository
project to identify and resolve technical issues, to prepare to
review a license application, and to develop criteria for an
acceptable license application.  The criteria would provide guidance
to DOE on NRC's expectations for a license application that would
adequately address the requirements of NRC's licensing regulations. 

In 1995, NRC modified its approach to reviewing DOE's repository
project.  Instead of trying to review all aspects of the project, NRC
decided to identify and emphasize the 10 most important technical
issues.  According to NRC, however, in fiscal years 1996 and 1997 it
eliminated its contractor support for independently evaluating 3 of
these 10 issues because its nuclear waste appropriations for each
year were only half of its $22 million appropriation for 1995.  In
the absence of funding, NRC will not conduct any more independent
studies of the three issues.  Instead, NRC's staff will monitor DOE's
related activities and will bound related regulatory issues using
conservative assumptions.  Moreover, NRC said, if the recent budget
trend continues, the agency would have to discontinue its
contractor's work on two more key technical issues and would not be
able to complete its review of a DOE license application in the
3-year period required by the nuclear waste act. 

Thus, an additional uncertainty confronting DOE's repository project
is NRC's position on the contents of an acceptable license
application.  NRC's review of and comments on DOE's 1998 viability
assessment will provide the first insights into NRC's formal
position.  (DOE does not intend to request comments on its viability
assessment; however, NRC believes that its evaluation of the
assessment would provide vital input to future decisions on the
repository project.) For those key technical issues that NRC has
reviewed, it intends to identify potential licensing weaknesses and
major concerns with DOE's designs or testing plans that could affect
DOE's estimate of the cost of the repository.  For technical issues
for which NRC has eliminated technical work by its contractor, the
agency's reviews of DOE's designs and technical basis for performance
assessments and cost estimates in the viability assessment will be
limited and based on conservative assumptions and available
knowledge. 

The viability assessment, however, is not a step required by the
nuclear waste act.  The first formal opportunity that the act
provides NRC to comment on the sufficiency for a license application
of DOE's investigation of Yucca Mountain will occur when DOE seeks
NRC's preliminary comments on the sufficiency of the investigation. 
DOE expects to seek NRC's comments in April 1999 and to receive the
comments in January 2000.  NRC's next formal opportunity will be its
initial review of DOE's license application in 2002 to determine if
the application is acceptable to begin the licensing proceeding.  To
the extent that NRC is unable to review important issues to gain
confidence in DOE's investigation and develop acceptance criteria,
the agency intends to adopt conservative regulatory positions. 
Conservative positions could have the consequence of either requiring
DOE to obtain and provide NRC with more information or,
alternatively, to make modifications to the design of the repository
system that could increase the system's cost. 


   OBSERVATIONS
------------------------------------------------------------ Letter :5

DOE's viability assessment may provide important insights into the
expected design, performance, and cost of a repository at the Yucca
Mountain site.  However, the assessment's utility as the basis for a
decision in 1999 to develop a waste storage facility near the site is
limited because the assessment will not demonstrate compliance with
applicable siting guidelines, standards, and licensing regulations. 
Therefore, making such a decision on the basis of the viability
assessment could be perceived as a firm commitment to eventually
disposing of nuclear waste at the site.  For essentially this reason,
the administration opposed the provisions of S.  1936 that would have
designated a site near Yucca Mountain for a storage facility before
DOE had completed its viability assessment.  The administration
argued that such a designation would have destroyed the credibility
of the disposal program by prejudicing a future decision on a
permanent repository at Yucca Mountain.  In our view, the logic of
the administration's position would also apply to such a designation
made after the assessment has been completed but in advance of the
decision on the site's suitability, a recommendation that the site be
selected for a repository, and the decision on licensing that must be
made on the basis of compliance with the guidelines, standards, and
regulations. 


   AGENCY COMMENTS AND OUR
   EVALUATION
------------------------------------------------------------ Letter :6

We provided a draft of our report to DOE, EPA, and NRC for their
review and comment.  DOE and NRC provided written comments on this
report, which appear in appendixes III and IV, respectively.  EPA
declined to comment on the report. 

DOE said that our report recommends that decisions involving the
construction of a repository be suspended until the Secretary has
recommended to the President that Yucca Mountain be selected for a
repository.  We did not propose such a recommendation.  We merely
observed that deciding to develop a waste storage facility near Yucca
Mountain before the Department has determined that the proposed
repository site complies with applicable siting guidelines,
standards, and licensing regulations could be perceived as a firm
commitment to eventually disposing of nuclear waste at the site.  We
revised our observation section to make clear that we were not
proposing any recommendation. 

DOE also said that we appear to be misinformed about its plans to
continue addressing the uncertainties related to hydrology, the
effects of heat from waste on the performance of the repository, and
waste package materials.  The Department intends to make every
reasonable effort to reduce uncertainties and, in a license
application, will identify and discuss any remaining major
uncertainties and the steps planned to reduce them.  It is important
to note, DOE added, that it is not required to demonstrate the
performance of the repository system or components of this system
until it submits a license application.  We disagree that we are
misinformed about DOE's plans for addressing key technical issues. 
Our report states that, on the basis of the limited information that
DOE has collected and concerns raised by technical experts, resolving
existing uncertainties about these issues could affect the
Department's ability to achieve its objectives and schedule for the
repository project.  Whether or not DOE's current plans to address
key uncertainties are adequate can be definitively answered only
after the Department has submitted an application to construct a
repository. 

DOE provided other specific clarifying comments that we incorporated
as appropriate. 

NRC pointed out that its previous and ongoing reviews of DOE's site
investigation project and interactions with the Department have
documented feedback to DOE on what is needed for licensing. 
Therefore, NRC's comments on the viability assessment's discussion of
DOE's plans for the license application will reflect whatever
significant differences remain between NRC's staff and the
Department.  Moreover, NRC said, interactions between the two
agencies focused on resolving licensing issues will continue, and
should differences of opinion persist, they will be documented in the
Commission's preliminary sufficiency comments to be included in DOE's
site recommendation report.  NRC provided other specific clarifying
comments that we incorporated as appropriate. 


---------------------------------------------------------- Letter :6.1

We performed our review at DOE's headquarters in Washington, D.C.,
and at DOE's Yucca Mountain Site Characterization Project Office in
Las Vegas, Nevada.  We also performed our review at the headquarters
of NRC in Rockville, Maryland, and EPA in Washington, D.C.  We
visited the Yucca Mountain site in southern Nevada and met with
representatives of the state of Nevada and Clark County, Nevada.  We
conducted our review from February 1996 through January 1997 in
accordance with generally accepted government auditing standards. 
(See app.  V for details of our scope and methodology.) A list of
related GAO products appears at the end of this report. 

We are sending copies of this report to the Secretary of Energy; the
Chairman, NRC; the Administrator of EPA; and the Director, Office of
Management and Budget.  We will also make copies available to others
on request. 

Please call me at (202) 512-3841 if you or your staff have any
questions.  Major contributors to this report are listed in appendix
VI. 

Victor S.  Rezendes
Director, Energy, Resources, and
 Science Issues


UNCERTAINTIES ABOUT REGULATORY
REQUIREMENTS COULD AFFECT THE
OBJECTIVES AND SCHEDULE FOR DOE'S
REPOSITORY PROJECT
=========================================================== Appendix I

The Department of Energy's (DOE) efforts to determine if a safe
repository can be developed at Yucca Mountain are made more difficult
because the site investigation is proceeding in parallel with
fundamental changes to the regulations governing the project.  If the
site is eventually selected for a repository, DOE must demonstrate,
in a licensing proceeding conducted by the Nuclear Regulatory
Commission (NRC), that the proposed repository would comply with
health standards issued by the Environmental Protection Agency (EPA)
and NRC's licensing regulations.  However, EPA is just beginning the
process of issuing health standards for the Yucca Mountain site that
must be consistent with the findings and recommendations of a study
by the National Academy of Sciences.  And after EPA issues its
standards, NRC must, if necessary, revise its licensing regulations
to make the regulations consistent with the standards. 

The Academy has recommended that EPA take a different approach to
setting standards for Yucca Mountain than the agency took a decade
ago in setting its original standards for all nuclear waste
repositories, including Yucca Mountain.  DOE, however, has disagreed
with several of the Academy's findings and recommendations because,
in part, of the perceived difficulty in implementing the recommended
standards in a licensing proceeding on a repository at Yucca
Mountain. 

Moreover, whether DOE's scientific investigation of Yucca Mountain
will be adequate to support a determination of the site's
suitability, a recommendation to select the site, and an acceptable
license application on the Department's current schedule will, to
some extent, depend on when the final standards and licensing
regulations are issued and their substantive requirements.  Finally,
DOE is in the process of basing its guidelines for determining the
suitability of Yucca Mountain for a repository on EPA's standards and
NRC's licensing regulations.  Thus, the timing and content of the
standards, licensing regulations, and siting guidelines that will be
used for determining if the site is suitable for a repository,
recommending that the site be selected for a repository, and applying
for a license are currently unknown. 


   BACKGROUND
--------------------------------------------------------- Appendix I:1

The Nuclear Waste Policy Act of 1982 charged EPA with setting
generally applicable environmental standards for the disposal of
nuclear waste in repositories and NRC with setting criteria and
technical requirements for licensing and regulating repositories.  In
December 1982, EPA proposed, and in September 1985 issued, its
original disposal standards (40 C.F.R.  part 191).  The primary
standard was based on containing waste materials within a
repository.\9 Specifically, the standard limited the cumulative
releases of radioactive materials from the boundary of the repository
to the accessible environment (the biosphere) for 10,000 years after
closing a repository.  In issuing this standard, EPA expected that
the assessments of the long-term performance of a repository would be
based on mathematical predictions of the anticipated behavior of both
the natural and engineered (man-made) barriers making up the
repository system and the likelihood of unanticipated events and
processes, such as earthquakes and human intrusion, that could
disrupt the repository.\10

Subsequently, the Energy Policy Act of 1992 directed EPA to set
specific disposal standards for the Yucca Mountain site that would
prescribe the maximum annual effective dose to individual members of
the public from the release of radioactive materials (disposed of in
the repository) to the accessible environment.  The act also required
EPA to (1) arrange for an analysis by the National Academy of
Sciences of the scientific basis for a standard to be applied at
Yucca Mountain and (2) adopt health and safety standards on the basis
of, and consistent with, the Academy's findings and recommendations. 
Finally, the act required NRC to make its licensing regulations for a
repository at Yucca Mountain consistent with EPA's standards. 

In February 1993, EPA contracted with the Academy to study the
technical basis for disposal standards for a repository at Yucca
Mountain.  The Academy issued its report to EPA in August 1995.\11
Among other things, the Academy recommended that EPA

  -- limit the risk to individuals of adverse health effects from
     releases of radioactive materials from the repository rather
     than limiting the radiation dose to individuals or the
     cumulative releases of radioactive materials from the
     repository;\12

  -- measure compliance with the standard out to the point of peak
     risk to individuals, which is expected to occur tens or hundreds
     of thousands of years in the future, rather than the 10,000-year
     period in EPA's original standards;

  -- define the "critical group" that would be at risk, rather than
     basing compliance on exposures of collective or worldwide
     populations to radiation;\13 and

  -- separately evaluate the risk and consequences of intrusion into
     the repository by future humans and focus this evaluation on the
     repository's capability to withstand such intrusion. 

As of January 15, 1997, EPA had not proposed standards for a
repository at Yucca Mountain; however, according to the agency's
director of the Radiation Protection Division, Office of Radiation
and Indoor Air, the agency may be able to issue final standards
within 1 year of proposing the standards. 


--------------------
\9 EPA also established standards for protecting (1) individuals in
areas surrounding a repository from receiving harmful radiation doses
and (2) groundwater from radioactive contamination for 1,000 years. 
The standards also contained qualitative assurance requirements to
increase confidence that the long-term containment requirements would
be met. 

\10 The exception to the release standards includes expected or
accidental events that, while conceivable, are expected to have less
than 1 chance in 10,000 of occurring over 10,000 years. 

\11 Technical Bases for Yucca Mountain Standards, National Research
Council, National Academy of Sciences, Aug.  1995. 

\12 The Academy recognized that the dose-based and risk-based
standards are closely related.  The risk-based standard would be
based on a statistical distribution of health effects (i.e.,
premature fatal cancers), which are derived from a distribution of
dose and the expected consequences (i.e., health effects) per unit
dose. 

\13 The critical group has been defined by the International
Commission on Radiological Protection as a relatively homogeneous
group of people whose location and habits are such that they are
representative of those individuals expected to receive the highest
doses as a result of the discharges of radioactive materials. 


   EPA'S STANDARDS COULD AFFECT
   DOE'S REPOSITORY PROJECT
--------------------------------------------------------- Appendix I:2

EPA's disposal standards for Yucca Mountain must be based on and
consistent with the Academy's findings and recommendations.  DOE,
however, expressed several concerns about the Academy's
recommendations.  Depending on the substantive requirements of the
standards that EPA eventually adopts, DOE may have to modify its
scientific investigation of Yucca Mountain. 

In a November 2, 1995, letter to EPA, DOE expressed three key
concerns about the Academy's recommendations for a Yucca Mountain
standard.  First, the Department is concerned that uncertainties in
the results of quantitative calculations made for a period that is
greater than 10,000 years would limit the usefulness and validity of
the calculations in a licensing proceeding.  Therefore, DOE
recommended that compliance calculations be limited to a period of
10,000 years.  In DOE's view, reasonably reliable calculations of a
repository's expected performance can be made for the shorter period
of time. 

Second, DOE is concerned that the level of permissible risk to the
designated critical population group that the Academy recommended as
a starting point for developing the standards is unnecessarily
conservative.  The recommended level of risk would limit annual fatal
cancers from the operation and closure of the repository to an
increase of from 1 in 1 million to 1 in 100,000 in the affected
population.  According to DOE, none of the other federal and
international regulations the Academy examined in its study require
such a stringent limit over a period of hundreds of thousands of
years.  Moreover, DOE said, because of the overwhelming conservatism
in the Academy's study related to the calculations of risk levels,
EPA should relax the starting point by a factor of 10; that is, the
permissible level of risk should be a range of 1 in 100,000 to 1 in
10,000 increased fatal cancers per year.\14

Third, DOE is concerned that the two options the Academy presented
for calculating risk to the critical group and establishing a future
reference biosphere are either too complex or too conservative.  The
majority of the Academy's panel had recommended that EPA use
theoretical statistical and analytical techniques to identify the
observed characteristics of people currently living in the vicinity
of the repository and to calculate the risk to this group.  One panel
member had recommended that EPA derive the average risk calculation
from the radiation dose likely to be received by a "subsistence
farmer." This farmer was defined as the person likely to become the
most contaminated because of his use of water extracted from a well
near the repository to drink and to grow all of his food.  DOE
commented that the first of these two options is unprecedented and,
among other things, would be very complicated to implement.  The
second option, according to DOE, appears to be simpler and easier to
implement but would result in a very conservative level of risk.  DOE
suggested that a better option for calculating risk would be to base
the calculations on the characteristics of a current population group
perceived to be most at risk to radiation exposure from drinking
contaminated groundwater and using it to irrigate the crops they
would consume.  In this option, DOE said, specific factors, such as
the diversity of occupations and lifestyles and the relative
consumption of local and imported foods, would be considered. 

The eventual content of EPA's standard for Yucca Mountain is likely
to influence the extent of the work that DOE must complete to
determine if Yucca Mountain is a suitable site for a repository,
recommend that the site be selected for that purpose, and submit an
acceptable license application to NRC.  For example, the substantive
requirements of the standards could affect the scope of the
investigation of groundwater around Yucca Mountain that is necessary
to demonstrate compliance with the standards.  According to DOE's
current strategy for containing and isolating waste in a repository
at Yucca Mountain, the use of a dose-based or risk-based
standard--instead of the release-based standard in EPA's original
standards for all repositories--would place additional emphasis on
how radioactive materials would move through the rock layers in the
saturated zone (the area containing groundwater) beneath and around
Yucca Mountain.  A goal of DOE's containment strategy is to prove
that the radioactive materials escaping into the saturated zone will
be dispersed and diluted before they reach the accessible environment
and therefore will result in acceptably low doses to humans over
thousands of years. 

Hydrologists at the U.S.  Geological Survey, who are investigating
the hydrology of Yucca Mountain for DOE, told us that they are
measuring the movement of injected tracer materials among three wells
developed in close proximity to one another to model the flow of
groundwater.  In conjunction, DOE's Los Alamos National Laboratory is
modeling how the groundwater would transport radioactive materials. 
A limitation of the tests, however, is that they measure the
transport of radioactive materials at only one point in time and
space.  For this reason, the tests are not likely to answer questions
about the total flow of the groundwater system.  A Geological Survey
official stated that the project's study plans provide for drilling
another series of holes at a different location in 1998 and 1999, but
the specifics of the study plans are uncertain.  Thus, DOE may need
to undertake additional work to help explain the flow of groundwater
in the saturated zone and transport characteristics to verify
theories that dispersion and dilution of radioactive materials will
keep radiation doses low for thousands of years. 

Similarly, the period of regulatory compliance that EPA adopts in the
final standard could affect the relative importance of hydrologic
studies to a compliance determination.  Geological Survey scientists
told us that a period of compliance that is much longer than 10,000
years would place more emphasis on the behavior of the saturated
zone.  Currently, these scientists believe that very little water
would move from Yucca Mountain down into the saturated zone in 10,000
years.  Over a much longer time period, however, more water may reach
the saturated zone.  This possibility raises questions about how
radioactive materials escaping the repository over the longer time
period would be diluted in the groundwater to limit potential human
exposure.  As discussed above and in appendix II, however,
groundwater flow and transport properties in the saturated zone are
not well understood. 


--------------------
\14 One example DOE mentioned was the Academy's assumption that
future humans can and will use groundwater contaminated as a result
of a repository losing its integrity over time and that they will not
test and treat their water supply. 


   NRC'S REVISED LICENSING
   REGULATIONS COULD AFFECT DOE'S
   REPOSITORY PROJECT
--------------------------------------------------------- Appendix I:3

The revisions that NRC may make to its licensing regulations could
affect DOE's ability to meet the objectives and schedule for its
repository project.  As required by the 1992 energy act, NRC is to
make its licensing regulations consistent with EPA's disposal
standards for Yucca Mountain.  Because EPA has not yet issued its
standards, there are outstanding questions about how DOE will
implement both the standards and NRC's revised licensing regulations. 
One key unanswered question, for example, is whether NRC will retain
certain requirements for repository performance that are contained in
its existing licensing regulations. 

NRC's existing licensing regulations require DOE to demonstrate
compliance with EPA's disposal standards.  However, when NRC
developed its regulations in the early 1980s, it recognized that the
assessment of the performance of a repository over a long period of
time entails considerable uncertainty.  Therefore, to provide
sufficient confidence that a proposed repository would perform as
predicted, NRC's regulations also require DOE to demonstrate that a
repository would comply with three more specific requirements.  These
requirements, called subsystem performance requirements, establish
(1) a minimum lifetime for packages containing waste, (2) limits on
the rate at which radioactive materials may be released from
engineered barriers within the repository, and (3) a minimum period
of time that groundwater may take to travel from the repository to
the accessible environment. 

In its report to EPA, the National Academy of Sciences concluded that
the retention of the subsystem performance requirements in NRC's
licensing regulations could result in a less than optimal design and
level of performance for the repository.  For example, according to
the Academy, DOE might find it necessary to move the repository site
within Yucca Mountain to meet the subsystem performance requirement
for groundwater travel time.  In doing so, the Academy suggested, DOE
might also increase the risk of human exposure to radioactive gases
moving from the repository to the surface.  Accordingly, the panel
recommended precluding the subsystem performance requirements from
foreclosing design options that ensure the best long-term performance
of the repository.  DOE, in commenting on the Academy's report,
agreed and recommended that NRC reconsider the use of subsystem
performance requirements.  In a previous report on seven foreign
countries' programs for disposing of nuclear waste, we noted that
regulators in most of these countries are concerned only that
proposed repositories meet overall safety goals (standards).  These
regulators said they expect to leave the design details to the
repository developers.\15

On the other hand, there are arguments in favor of retaining
subsystem performance requirements.  For example, in response to
public comments on NRC's proposed technical regulations for
repositories, issued in June 1981, NRC stated that there is
significant uncertainty in making assessments of the overall
performance of a repository for a period covering thousands of years. 
NRC added that subsystem performance requirements provide
"defense-in-depth" by increasing confidence in the assessments of
compliance with EPA's standards.  NRC also pointed out that the
subsystem performance requirements are not absolute--the final
regulations, issued in June 1983, permit NRC to change them, if
warranted, during a repository licensing proceeding.  Thus, in NRC's
view at that time, its licensing regulations provided DOE with
considerable flexibility to design an optimal repository system at a
specific site.  Furthermore, NRC noted, the subsystem performance
requirements may be necessary to ensure that a repository will meet
the numerical criteria in EPA's (original) containment standard for
unanticipated processes and events (such as earthquakes, flooding, or
disruption of the repository by humans).  Finally, NRC noted that its
task is not only one of mathematically modeling a system and
assigning values for particular barriers represented in the model to
arrive at a "bottom line" for overall system performance.  NRC is
also concerned, it said, that its final judgments be made with a high
degree of confidence.  Accordingly, NRC stated, it can and will
expect the performance of barriers to be enhanced so as to provide
greater confidence in its licensing judgments, wherever practicable
to do so. 

According to the deputy director of NRC's Division of Waste
Management, NRC's staff expects to review its technical requirements
for repositories and its licensing criteria and will re-evaluate, as
part of this review, the need for subsystem performance requirements. 
However, NRC is waiting for EPA to issue its proposed standards for
Yucca Mountain before proposing any changes to its licensing
regulations. 


--------------------
\15 Nuclear Waste:  Foreign Countries' Approaches to High-Level Waste
Storage and Disposal (GAO/RCED-94-172, Aug.  4, 1994). 


   DOE'S SITING GUIDELINES ARE TO
   BE BASED ON EPA'S STANDARDS AND
   NRC'S LICENSING REGULATIONS
--------------------------------------------------------- Appendix I:4

Fundamental to the success of DOE's revised approach to completing
the repository project is its decision to revise its criteria for
determining if Yucca Mountain is a suitable site for a repository. 
The Nuclear Waste Policy Act required DOE to establish general
guidelines for the recommendation of sites for nuclear waste
repositories.  These siting guidelines must specify detailed geologic
considerations that shall be the primary criteria for the selection
of sites in various geologic media.  After obtaining public comment,
including NRC's concurrence with the guidelines, DOE issued them as a
regulation in December 1984.  The siting guidelines require that DOE
evaluate individual sites and compare them on the basis of criteria
that address (1) the operation of a repository before it is
permanently closed (preclosure guidelines) and (2) the long-term
behavior of the repository after it is closed (postclosure
guidelines). 

Both the preclosure and postclosure guidelines are divided into
system and technical guidelines.  Three preclosure system guidelines
establish performance objectives that must be taken into account
during a repository's operations in the areas of radiation safety;
environment, socioeconomics and transportation; and ease and cost of
siting, construction, operation, and closure.  The postclosure system
guideline establishes broad performance objectives for protecting
public health and safety that are based on compliance with EPA's
disposal standards and NRC's licensing regulations.  These
requirements must be met by the repository system, which must contain
both natural and engineered barriers.  The engineered barriers are to
be designed to complement the natural barriers, which are to provide
the primary means for waste isolation. 

The preclosure and postclosure guidelines also contain technical
guidelines which establish specific conditions that are important to
meeting the system guidelines.\16 For example, the postclosure
technical guidelines contain nine conditions that must be present at
(qualifying conditions) and six conditions that must be absent from
(disqualifying conditions) a site for DOE to find that the site is
suitable for permanent waste disposal.  For each such technical
guideline, DOE is to make an evaluation of qualification or
disqualification. 

Until recently, DOE had intended to use these siting guidelines as
the basis for determining if Yucca Mountain is a suitable site for a
repository.  To this end, DOE had planned to complete, at an
estimated cost of $634 million, sufficient scientific investigations
and related technical reports to make preliminary technical findings
in 1998 on whether Yucca Mountain meets the criteria contained in the
guidelines.  DOE has now decided, however, to amend the siting
guidelines by adding new guidelines that would pertain only to the
Yucca Mountain site. 

The proposed guidelines, which were published for public comment on
December 16, 1996, would base the determination of the suitability of
Yucca Mountain as a site for a repository on a comparison of the
overall performance of a repository system at that site to EPA's new
disposal standards and NRC's revised licensing regulations.  DOE does
not, as required by the original guidelines, intend to determine the
presence or absence of each qualifying and disqualifying condition
contained in the technical guidelines.  An overall system performance
approach, DOE says, will lead to a more efficient process for
evaluating the suitability of the Yucca Mountain site. 

DOE believes that the overall approach to a repository system's
performance is the appropriate method to consider all relevant site
features because the approach identifies, in an integrated manner,
those attributes of the site and engineered components that are most
important to the protection of health and safety.  According to DOE,
the information gained from the site investigations and the
preliminary assessments of how a repository would perform at the site
show that the significance of selected site characteristics should
not be judged in isolation from one another or from a specific design
concept for the repository.\17 For example, a geological structural
feature may seem to be a detriment because it provides a fast pathway
for groundwater flow through the mountain when considered alone, but
in consideration with a specific repository design, the feature may
act beneficially by channeling groundwater flow away from the waste,
thereby reducing the chances that the groundwater will contact the
waste packages and cause them to fail. 

According to DOE, its amendments to the siting guidelines will be
developed concurrently with the development of a site-specific
radiological protection standard for Yucca Mountain by EPA and
conformance of the licensing regulations to this new standard by NRC. 
Moreover, as DOE agreed when it issued the original guidelines, the
Department intends to obtain NRC's concurrence with the amended
guidelines. 

After the completion of a public comment period, DOE expects to issue
the revised guidelines in 1997.  A key uncertainty, however, is the
timing of the issuance of EPA's standards and NRC's revised licensing
regulations.  According to DOE's manager for site suitability and
licensing, DOE needs NRC to complete revisions to its licensing
regulations 1 year before DOE makes its determination of site
suitability (now scheduled for July 1999) and 2 years beforehand if
NRC makes major changes to the regulations.  He added that DOE's
determination of the suitability of Yucca Mountain will be based on
comparing an up-to-date assessment of the repository's performance to
EPA's standard and NRC's licensing regulations. 


--------------------
\16 For the postclosure guidelines, the conditions address site
characteristics, processes, and events that may influence the
performance of a repository system after closure of the repository. 
They include hydrological and chemical characteristics of the site;
changes in climate, erosion, rock quality, movement of tectonic
plates comprising the earth's crust; and human interference with the
repository system. 

\17 Consistent with the provisions in the original EPA standards, DOE
is using an analytical method known as "performance assessment,"
which uses computer models to simulate and predict the behavior of
the Yucca Mountain site and repository over thousands of years. 


LIMITATIONS OF DOE'S ACTIVITIES
COULD AFFECT THE OBJECTIVES AND
SCHEDULE FOR DOE'S REPOSITORY
PROJECT
========================================================== Appendix II

To preserve the repository project at Yucca Mountain following the
unexpectedly low appropriations for fiscal year 1996, DOE redirected
the project to address the major unresolved technical issues so that,
in 1998, the Department can assess the viability of a repository at
the site.  DOE is developing a strategy for containing and isolating
waste in the repository to guide the preparation of this assessment. 
The draft strategy specifies the natural and engineered (man-made)
barriers that DOE will rely on to isolate waste from the accessible
environment and provide the technical basis for setting priorities
for designing the repository and completing the scientific
investigation of Yucca Mountain.  Following the viability assessment,
DOE would complete the work it believes is necessary to (1) determine
if Yucca Mountain is a suitable site for a repository, (2) recommend
selection of the site for that purpose, and (3) submit a license
application to NRC. 

However, the limited information that DOE will have in several areas
that are important to its strategy for containing and isolating waste
could affect its ability to achieve its objectives for the repository
project on its current schedule.  These key areas include the
hydrology of Yucca Mountain and the surrounding area, the effects of
heat on the repository's performance, and the testing of candidate
materials for waste packages. 


   WASTE CONTAINMENT AND ISOLATION
   STRATEGY
-------------------------------------------------------- Appendix II:1

In 1994, the Nuclear Waste Technical Review Board concluded that DOE
had not established exploration and testing priorities for
determining if Yucca Mountain is a suitable site for a repository.\18
To that end, the Board recommended that DOE articulate a clear waste
isolation strategy that provides an understandable technical
rationale for assigning priorities to studies of the site.  DOE
agreed and began developing the elements of such a strategy. 

In July 1996, DOE published a draft of its evolving strategy for
containing and isolating waste in a repository at Yucca Mountain. 
The strategy, which represents DOE's approach to addressing and
resolving issues related to the long-term performance of the
repository, is based on the observation that there is very little
water in the rocks in and around the repository area to dissolve and
transport radioactive materials to the environment.  The goals of the
strategy are to contain nearly all radioactive materials within waste
packages for several thousands of years and ensure that doses to the
public living near the site will be acceptably low. 

The strategy relies primarily on emplacing waste packages in an area
in Yucca Mountain above the water table to delay and minimize
releases of radioactive materials to the environment when the waste
packages finally begin to fail.  Secondary lines of defense to
enhance containment and isolation lie in potential engineered
(man-made) barriers adjacent to the waste packages and in the natural
system that are expected to delay the movement of radioactive
materials released from waste packages.\19 The strategy defines the
following key attributes for predicting the performance of engineered
and natural barriers: 

  -- The rate at which water seeps into the repository.  Assessments
     of the repository's performance have shown that water seeping
     into the emplacement areas is the most important attribute of
     the ability of the site to contain and isolate waste.  This
     process affects all aspects of performance, from the life of the
     waste packages to the movement of radioactive materials. 

  -- The integrity of waste packages (containment).  As long as waste
     packages remain intact, the waste will be completely contained
     and prevented from any contact with the surrounding rock or the
     groundwater.  According to DOE, containment times exceeding
     1,000 years are feasible. 

  -- The rate of release of radioactive materials from failed waste
     packages.  Performance assessments have shown that the release
     rate is one of the key factors in determining the peak doses of
     radiation that the affected public would be exposed to each
     year. 

  -- The transport of radioactive materials through barriers.  The
     potential radiation dose depends directly on the concentration
     of radioactive materials in water.  These concentrations change
     as the materials move in water through engineered and natural
     barriers to points where people can use the water. 

  -- The dilution in the groundwater.  Dilution is an important
     factor that can reduce concentrations of radioactive materials
     and limit doses of radiation to humans.  If the amount of water
     seeping into the repository and contacting the waste is small,
     the concentration of radioactive materials will be reduced when
     the contaminated water is added to the groundwater. 

The strategy also hypothesizes that some cross-cutting issues, such
as the effects on the repository's performance of the heat generated
by the waste, can be dealt with successfully as the repository is
designed and that other issues, such as the potential effects of
climate changes, human interference, and volcanoes, will not
significantly reduce the repository's performance.  The strategy
outlines tests and analyses to be pursued to try to substantiate the
five key attributes and to address cross-cutting issues. 

According to DOE, the waste containment and isolation strategy will
guide its plans for a viability assessment in 1998.  DOE would use
the strategy to guide the scientific and engineering studies
necessary to confirm or revise the models that are used to predict
the performance of the repository and to provide the technical basis
for a license application. 

In a report on its activities for 1995, the Nuclear Waste Technical
Review Board concluded that DOE was making considerable progress in
developing its waste strategy and made several recommendations for
improving it.  First, the Board said the strategy relies heavily on
the presumed dryness of the Yucca Mountain site and recommended that
the strategy identify ways to compensate for an unexpectedly high
movement of water between the repository and the water table. 
Second, the Board criticized the qualitative descriptions of the
waste attributes and recommended that DOE designate a numeric limit
for radiation doses to individuals and specify conditions under which
exposures to releases of radioactive materials would be assumed to
occur. 

Also, the Board said, DOE's strategy does not contain criteria for
validating or rejecting the five attributes; therefore, a clearer
understanding is needed of the degree of proof that is being sought
for each attribute.  Finally, after pointing out that all five
attributes address favorable conditions, the Board said the strategy
would be strengthened if DOE placed more emphasis on identifying
potential mechanisms for the repository system to fail and on
formulating testable hypotheses about the importance of these
mechanisms. 


--------------------
\18 The Nuclear Waste Policy Amendments Act of 1987 created the
Nuclear Waste Technical Review Board as a source of independent
review of the scientific and technical activities undertaken by DOE
in managing highly radioactive wastes. 

\19 DOE is evaluating whether a backfill of crushed rock around the
waste packages will be used to limit water contact with the packages
to delay corrosion and, following corrosion, to limit the dissolution
and transport of radioactive materials. 


   LIMITATIONS IN DOE'S HYDROLOGY
   PROGRAM
-------------------------------------------------------- Appendix II:2

Knowing how water moves through and under Yucca Mountain is critical
to the repository project.  DOE is studying the hydrology of both the
groundwater beneath the site and the area above the water table
because the movement of water through the mountain to the groundwater
is considered the primary means by which radioactive materials could
move from the repository to the environment.  Recently, the U.S. 
Geological Survey identified a number of issues concerning studies of
the saturated (groundwater) and unsaturated (above the water table)
zones at Yucca Mountain. 

In April 1996, Geological Survey scientists wrote a memorandum that
updated their understanding of the key inputs for the models of the
flow of water in the saturated zone.  They noted that as new issues
about the importance of uncertainties about the saturated zone have
been raised, the level of understanding of many issues has not
increased.  They attributed this situation to the lack of new
boreholes drilled to the saturated zone since the mid-1980s and the
limited testing of the saturated zone since then.  One key issue the
scientists raised is the resolution of a large drop in the elevation
of the groundwater (hydraulic gradient) at the northern end of Yucca
Mountain that was discovered in 1981.\20 Estimates of the direction
and rate that water moves beneath the site and how radioactive
materials would be diluted in the groundwater may differ
considerably, depending on different explanations of the cause of the
gradient.  The gradient remains a concern because the scientists
cannot account for its origin.  It would be difficult, they said, to
claim that they understood the hydrology of the site if they could
not explain the cause of the most striking feature in the area. 
Earlier, in 1992, the technical project officer for the Geological
Survey wrote that the large hydraulic gradient must be understood to
understand the hydrology of the saturated zone and that it would be
"folly" to determine the suitability of the site without a reasonable
understanding of this feature and its durability. 

In commenting on a draft of our report, DOE pointed out that one
existing well is being used to test hypotheses about the origin of
the large hydraulic gradient and that the Geological Survey is
currently interpreting the test information.  The test information,
DOE said, may either tell it what it needs to know or indicate how to
approach the problem by, for example, drilling another hole or
identifying another type of necessary test.  Also, NRC commented that
studies to date have not shown a significant negative effect on
performance as the result of the gradient. 

The Geological Survey also identified what it considers important\21
hydrological issues concerning the (1) scarcity of transport data and
(2) flow of water directly from the Amargosa Desert near Yucca
Mountain to Death Valley to the west.  The first issue reflects a
severe lack of information to support transport models, which in turn
support performance assessment models.  According to the Geological
Survey scientists, transport data are scarce because measurements are
being made at only one site and may be made at only one additional
site in the future.  The second issue reflects a potential change in
the conceptual model of the flow of groundwater in the region. 
Little information is available to choose among competing models, and
what information is available is subject to different
interpretations.  Acquiring additional, unambiguous information,
however, would be very expensive and may not be warranted. 

In June 1996, DOE issued a report on the Geological Survey's program
to ensure the quality of its research on the repository project. 
Although the report's authors concluded that the quality assurance
program was adequate, they also expressed concern about persistent,
major, unquantified uncertainties at this stage in the project.  The
report's authors also concluded that the project was severely
handicapped by the absence of high-quality hydrochemical data from
the site and the elimination of most borehole drilling from DOE's
site investigation plans.  Specifically, they noted that (1)
boreholes to resolve the cause of the large hydraulic gradient north
of the site and to test an aquifer at a second location have not been
drilled, (2) existing boreholes in the Amargosa Desert have not been
sampled or instrumented and drilling in the Southern Funeral
Mountains (southwest of Yucca Mountain, in the direction of Death
Valley) has not occurred, and (3) instrumentation to measure water
levels in numerous boreholes has been removed and mothballed.  These
actions are inconsistent, they continued, with what is expected of a
useful model for the flow of water in the saturated zone,
particularly insofar as such a model would be used to support
evaluations of the transport of radioactive materials.  The issues
appear to have been caused by unrealistic expectations for "bounding"
system performance in the absence of data that would allow
uncertainties to be quantified. 

According to the Geological Survey scientists, an important aspect of
understanding how water would flow through the unsaturated zone at
Yucca Mountain is to study the rate at which water infiltrates the
mountain from the surface.  Using a network of shallow boreholes
across the site, scientists are monitoring changes in moisture
content in the upper 50 feet of ground where these changes occur each
year.  This monitoring program is necessary to develop an adequate
record of moisture changes in what is one of the driest areas of the
country.  The Geological Survey has developed a model of soil
moisture and produced a preliminary map of the rates at which water
infiltrates the unsaturated zone across the mountain.  According to
the scientists, the model is fairly rigorous, but certain assumptions
must be made while using it.  However, the infiltration program has
ended sooner than had been planned and no new work is planned to
study uncertainties in the model.  The scientists are concerned about
whether there is a sufficient level of confidence in the supporting
assumptions used in its model of soil moisture and whether the data
and assumptions supporting the model can withstand external scrutiny. 
They stated that drilling and instrumenting more boreholes would
provide more information, but project officials are considering an
alternative approach of compensating for uncertainty in this area by
backfilling the repository with a material that would keep water away
from waste longer. 

Geological Survey scientists are also concerned about the adequacy of
the studies of water moving through the repository horizon (i.e.,
percolation).  According to these scientists, such studies have been
reduced substantially from original plans.  The project had planned
to drill 17 boreholes to the water table at various locations around
the site.  Monitoring of pneumatic pressure, temperature, and water
potential was to be performed in each borehole for a minimum of 3 to
5 years.  According to the Geological Survey, however, while 15
boreholes have been drilled, 4 of them were drilled in different
locations than planned.  Of the 15 boreholes, 8 do not reach the
repository horizon, and no borehole has been drilled deep enough to
characterize the Ghost Dance Fault in the Calico Hills Formation.  In
addition, only seven of the boreholes have been instrumented to
monitor pneumatic pressure, temperature, and water potential. 
Finally, other tests have been reduced or deleted from the testing
program altogether. 

In commenting on a draft of our report, DOE recognized that more
information on the saturated zone is needed and stated that its
long-range site investigation plan includes additional tests in the
saturated zone.  DOE added, however, that its primary focus remains
on the unsaturated zone because of the importance of this area to its
strategy for containing and isolating waste.  After DOE has acquired
a better understanding of the overall performance of the proposed
repository system, the Department said, it may decide that it can get
better performance from the repository system by changing waste
package materials rather than by more precisely defining some aspect
of water flow.  Finally, DOE stated that the concept of backfilling
waste storage rooms in the repository with a selected material is one
option for improving the repository's performance but that this
concept is unrelated to the potential need to reduce hydrological
uncertainties. 

One other issue has recently emerged that affects DOE's understanding
of the hydrology of the unsaturated zone at Yucca Mountain.  DOE has
detected the presence of the isotope chlorine-36, produced from
atmospheric tests of nuclear weapons about 50 years ago, at the level
of the proposed repository.  DOE has been testing for the presence of
this and other elements to provide information on the age of the
water at various locations in the mountain and on the travel time of
water through preferential paths, such as faults and fractures, in
the rock.  DOE found elevated levels of chlorine-36 in samples from
five locations within the exploratory studies facility.  According to
the disposal program's director, the findings need not be, but could
be, a critical problem.  In DOE's current view, the findings appear
to indicate rapid flow of water along preferential pathways.  DOE is
collecting and analyzing additional samples to confirm results and to
provide new information on new areas of the exploratory tunnel.  In
addition, DOE will perform more modeling studies to evaluate the
chlorine-36 data as they relate to the understanding of the
hydrologic processes of Yucca Mountain and DOE's conclusions about
the repository's performance. 


--------------------
\20 A key issue is one that is central to having sufficient
understanding of the saturated zone's flow system to make a
meaningful evaluation of the contributions that the saturated zone
can make in meeting regulatory requirements. 

\21 An important issue is one that warrants careful consideration but
may not be resolvable or may be so difficult or costly to resolve
that the Yucca Mountain Project may choose not to resolve it. 


   LIMITED INFORMATION WILL BE
   AVAILABLE ON THE EFFECTS OF
   HEAT FROM WASTE
-------------------------------------------------------- Appendix II:3

According to DOE, a key issue that it must address in its
investigation of Yucca Mountain is the uncertainty about the
interaction of the heat generated by waste in the repository with the
surrounding rock, the water contained in Yucca Mountain, and the
packages containing waste.  To provide information on this issue, DOE
planned a series of experiments in the exploratory studies facility
and at the surface near Yucca Mountain that began in 1996 and will
continue until about 2000.  DOE's general testing strategy is to
perform simpler, smaller-scale tests first and then move to a more
complex, larger test.  However, a peer review team, the Nuclear Waste
Technical Review Board, and DOE's Lawrence Livermore National
Laboratory have raised concerns about the testing program.  In
general, these concerns are that DOE is not doing large enough tests
for long enough periods of time. 

Because of the decay of radioactive materials in nuclear waste, it
will continue to produce heat for thousands of years after its
disposal in a repository.  The Nuclear Waste Technical Review Board
described this issue--called thermal loading--as one that would
largely determine the level of uncertainty about the repository's
long-term performance.  As early as 1990, the Board stated that the
strategy selected to control the temperatures in a repository is a
fundamental decision because the selected strategy will affect most
components of the waste management system, including methods for
storing and transporting waste, the design of waste packages, and the
design, size, performance, and cost of the repository. 

The thermal load of the repository has the potential to significantly
redistribute moisture within Yucca Mountain, resulting in extended
periods of dryness in the repository or channeling of moisture toward
waste packages.  Therefore, it is necessary to understand the effects
of the thermal load on the temperature of the surrounding rock as
well as the movement of water and gases in the vicinity of the
repository to have confidence in predictions of containment and
long-term waste isolation.  The distribution of temperature, liquid
saturation, and humidity within the repository will influence the
corrosion of metals, alteration of minerals, and geochemistry.  These
factors are important in predicting the containment time within the
waste package and transport times through both the engineered and
natural barrier systems. 

DOE's thermal test strategy described several sequential tests, in
general order of scale and complexity, in the exploratory studies
facility.  Early tests would be relatively small in scale and limited
in complexity.  Information gained from these early tests would help
in understanding and interpreting results from larger, more complex
tests of longer duration.  In the first underground test, a long
heating rod would be inserted in a horizontal hole to heat the
surrounding rock.  The next test that DOE intends to perform is
intended to heat a larger volume of rock with rows of heating rods
emplaced in the walls of an excavated room and in heaters, shaped
like waste containers, placed on the floor of the room.  DOE
considers this test, called a drift-scale test, to be a smaller, less
complex, and less costly surrogate to a large-scale, long-duration
test that would address information needs that could only be answered
by tests that approach the scale of several waste storage rooms
(drifts) in the repository. 

In addition to its planned underground thermal tests, DOE initiated a
test on the surface near Yucca Mountain in a large isolated block of
rock.  This test was intended to develop and evaluate techniques and
data for monitoring the changes in thermal and hydrological
properties in a heated rock mass with controlled boundary conditions
and provide data to understand the larger and more complex tests in
Yucca Mountain.  DOE stopped this large-block test in fiscal year
1996 due to budget reductions but restarted it in fiscal year 1997. 

In 1995, DOE established a team of six experts to conduct an external
peer review of its thermal testing program.  The objective of the
review was to evaluate the program's approach to understanding the
thermohydrologic conditions at Yucca Mountain that would be generated
by the heating of the repository.  In its review of the thermal
testing program, the review team's primary recommendation was that a
large-scale, long-duration test and the large-block test be carried
out.  The review team concluded that the smaller, less complex tests
with single and multiple heating rods are not needed because these
tests would be insufficient in scope to fully develop relevant
processes.  Only the large-scale, long-duration test, the review team
said, would give results over a cross-sectional area large enough to
be meaningful.  The review team noted that DOE is in a major
undertaking involving the thermohydrologic behavior of a fractured
rock mass for which there is no precedent.  By setting up a long-term
experiment, DOE could acquire a substantial database, and analysis of
the data could begin almost immediately after the experiment has
begun.  In addition, the review team said, critical design decisions
cannot be made using smaller tests because the volume of rock being
affected is too small to develop the effects that reveal the "global"
picture.  The team cautioned that the cost and time to perform the
large-scale, long-duration test would be substantial but also stated
that scientific defensibility must overrule mandated scheduling and
cost constraints.  If DOE is forced to choose from among all the
tests, the review team said, the large-scale, long-duration test
should be done. 

DOE disagreed with the review team's recommendation on the
large-scale, long-duration test.  According to DOE, its planned
approach to conducting the large-block test, the test with a single
heating rod, and the drift-scale test is consistent with DOE's
strategy of progressing from simple to complex and small to large
thermal tests and will likely provide the necessary data to defend a
thermal loading strategy for the site.  Consequently, DOE's current
plans do not include performing the large-scale, long-duration test;
however, the Department will consider implementing the large-scale,
long-duration test if it determines that the planned tests of smaller
scale and duration do not provide sufficient data and confidence in
related models. 

In 1995, the Nuclear Waste Technical Review Board wrote that there is
considerable uncertainty associated with the thermohydrologic
processes at Yucca Mountain.  According to the Board, there is
agreement that some heater tests have to be done, but there is no
clear enunciation of what types of data are to be collected, how they
will be obtained, or the ultimate use to which the data will be put. 
Furthermore, the relatively limited experience of the scientific
community in modeling complex thermohydrologic problems in areas like
the unsaturated zone at Yucca Mountain will make it especially
difficult for DOE to establish the validity of predictions through
short-term thermal testing.  The Board supported the initiation of a
long-term, tunnel-scale thermal test, recommended that DOE give more
thought to how more information can be obtained from all heater
tests, and concluded that little data will be available for use in
DOE's 1998 viability assessment. 

Finally, as early as 1992, DOE's Lawrence Livermore National
Laboratory had raised concerns about the length of heater tests at
Yucca Mountain.  DOE had established a task force to consider this
issue.\22 A draft report by the task force recommended that in order
to meet the schedule for submitting a license application in 2001, a
heater test to be performed by the laboratory should be completed in
6 years.  At that time, scientists at the laboratory argued that a
6-year test period would barely be long enough for geochemical
reactions to take place that could be sampled.  Therefore, the
scientists said, the 6-year test duration was the minimum time that
they could support from a technical standpoint.  As currently
planned, the drift-scale test would run for 4 years with options for
a longer test period if evaluation of the test data warrants the
longer duration. 

In commenting on a draft of our report, NRC stated that its principal
concern is that the thermal testing be representative of the range of
repository conditions, rather than the scale or duration of the
tests.  It added that the testing information that will be available
at DOE's current planned date of license application will be limited
and will need to be confirmed by additional data collected during
performance confirmation or, if the additional data differ
significantly from the original design bases and assumptions in the
license application, the design may be modified through the license
amendment process. 


--------------------
\22 The Yucca Mountain Project Office established the Heater Test
Duration Task Force to consider required test durations for the
project.  The task force consisted of representatives of the
organizations responsible for testing on the Yucca Mountain Project
as well as management and operating contractor representatives. 


   LIMITATIONS ON WASTE PACKAGE
   RESEARCH
-------------------------------------------------------- Appendix II:4

NRC has questioned whether DOE is allowing enough time to test
potential materials for waste packages before it submits a license
application to NRC.  The waste package refers to the waste form and
any containers, shielding, packing, and other absorbent materials
surrounding an individual waste container.  According to DOE, waste
packages will consist of multiple metal barriers designed to contain
the wastes by resisting corrosion for thousands of years.  In July
1995, NRC's representatives observed DOE's audit of the effectiveness
of the waste package design processes used by the Department's
primary contractor for the repository project.  Following the audit,
NRC's representatives reported to their managers at NRC's
headquarters that DOE is following a strategy of continuing
development and analytical work on a selected set of candidate waste
package materials.  According to this report, the final choice of
materials for waste packages will not be made until a prototype waste
package is made or by the time DOE submits its license application to
NRC.  Also, DOE's primary contractor for the repository project
indicated that none of the currently available data on the
performance of materials, such as corrosion, will be used for
licensing.  NRC's report stated that the contractor plans to obtain
test data over only 5 years to analyze long-term failures of waste
packages in the license application.  Validating waste package
performance is expected to continue during the operation of the
repository.  In their report, NRC's representatives concluded that
predicting the long-term performance of waste packages will be
difficult using only the relatively short-term test results that will
be available when the license application is submitted in 2002. 

DOE does not agree with the comments in NRC's report.  The Department
expects that available data on mechanical and corrosion performance
of materials will be used to support a license application.  Also,
DOE said it is not clear that NRC's conclusion about predicting
long-term performance of waste packages from short-term test results
is accurate.  NRC said it may still be possible to show, with
reasonable assurance, that the overall system performance standard is
met at the time of license application.  NRC added that its licensing
regulations anticipate that additional research may be required to
determine the adequacy of the design and provide that a license to
construct a repository may have conditions related to the
satisfactory resolution of safety questions for which research is
being conducted. 




(See figure in printed edition.)Appendix III
COMMENTS FROM THE DEPARTMENT OF
ENERGY
========================================================== Appendix II



(See figure in printed edition.)



(See figure in printed edition.)



(See figure in printed edition.)



(See figure in printed edition.)



(See figure in printed edition.)



(See figure in printed edition.)




(See figure in printed edition.)Appendix IV
COMMENTS FROM THE NUCLEAR
REGULATORY COMMISSION
========================================================== Appendix II



(See figure in printed edition.)



(See figure in printed edition.)



(See figure in printed edition.)



(See figure in printed edition.)


SCOPE AND METHODOLOGY
=========================================================== Appendix V

To identify the adjustments the Department of Energy made to its
disposal program and the potential impediments to achieving the
Department's current objectives and schedule for the repository
project, we performed our work primarily at DOE's headquarters in
Washington, D.C., and its Yucca Mountain Site Characterization
Project Office in Las Vegas, Nevada.  At these locations, we obtained
and reviewed information from officials of DOE's Office of Civilian
Radioactive Waste Management, including officials assigned to the
site investigation project; officials of DOE's management and
operating contractor for the project; and officials of the U.S. 
Geological Survey, which is a participant on the project.  We also
visited the candidate repository site at Yucca Mountain, Nevada,
including observing activities under way in the exploratory studies
facility tunnel in the mountain. 

We also obtained and reviewed information from officials of the (1)
Division of Waste Management, Nuclear Regulatory Commission; (2)
Office of Radiation and Indoor Air, Environmental Protection Agency,
Washington, D.C.; (3) Agency for Nuclear Projects, state of Nevada,
Carson City, Nevada; (4) comprehensive planning office of Clark
County, Nevada; and (5) Nuclear Waste Technical Review Board,
Arlington, Virginia. 


MAJOR CONTRIBUTORS TO THIS REPORT
========================================================== Appendix VI

RESOURCES, COMMUNITY, AND ECONOMIC
DEVELOPMENT DIVISION, WASHINGTON,
D.C. 

Dwayne E.  Weigel, Assistant Director
John J.  Bagnulo, Senior Evaluator
Victor J.  Sgobba, Senior Evaluator
Cassandra Joseph, Reports Analyst
Susan W.  Irwin, Senior Attorney


RELATED GAO PRODUCTS
============================================================ Chapter 0

Department of Energy:  Unethical Conduct at DOE's Yucca Mountain
Project (GAO/OSI-96-2, Sept.  30, 1996). 

Nuclear Waste:  DOE's Management and Organization of the Nevada
Repository Project (GAO/RCED-95-27, Dec.  23, 1994). 

Nuclear Waste:  Comprehensive Review of the Disposal Program Is
Needed (GAO/RCED-94-299, Sept.  27, 1994). 

Nuclear Waste:  Foreign Countries' Approaches to High-Level Waste
Storage and Disposal (GAO/RCED-94-172, Aug.  4, 1994). 

Independent Evaluation (GAO/RCED-94-258R, July 27, 1994). 

Nuclear Waste:  Yucca Mountain Project Management and Funding Issues
(GAO/T-RCED-93-58, July 1, 1993). 

Nuclear Waste:  Yucca Mountain Project Behind Schedule and Facing
Major Scientific Uncertainties (GAO/RCED-93-124, May 21, 1993). 

Energy Issues:  Transition Series (GAO/OGC-093-13TR, Dec.  1992). 

Nuclear Waste:  Status of Actions to Improve DOE User-Fee Assessments
(GAO/RCED-92-165, June 10, 1992). 

Nuclear Waste:  DOE's Repository Site Investigations, a Long and
Difficult Task (GAO/RCED-92-73, May 27, 1992). 

Nuclear Waste:  Development of Casks for Transporting Spent Fuel
Needs Modification (GAO/RCED-92-56, Mar.  13, 1992). 

Nuclear Waste:  Operation of Monitored Retrievable Storage Facility
Is Unlikely by 1998 (GAO/RCED-91-194, Sept.  24, 1991). 

Nuclear Waste:  Changes Needed in DOE User-Fee Assessments
(GAO/T-RCED-91-52, May 8, 1991). 

Nuclear Waste:  DOE Expenditures on the Yucca Mountain Project
(GAO/T-RCED-91-37, Apr.  18, 1991). 

Nuclear Waste:  Changes Needed in DOE User-Fee Assessments to Avoid
Funding Shortfall (GAO/RCED-90-65, June 7, 1990). 

Nuclear Waste:  Quarterly Report as of March 31, 1989
(GAO/RCED-89-178, Aug.  14, 1989). 


*** End of document. ***