[Federal Register Volume 68, Number 179 (Tuesday, September 16, 2003)]
[Rules and Regulations]
[Pages 54143-54160]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-23553]


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NUCLEAR REGULATORY COMMISSION

10 CFR Part 72

RIN 3150-AG93


Geological and Seismological Characteristics for Siting and 
Design of Dry Cask Independent Spent Fuel Storage Installations and 
Monitored Retrievable Storage Installations

AGENCY: Nuclear Regulatory Commission.

ACTION: Final rule.

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SUMMARY: The Nuclear Regulatory Commission (NRC) is amending its 
licensing requirements for dry cask modes of storage of spent nuclear 
fuel, high-level radioactive waste, and power reactor-related Greater 
than Class C (GTCC) waste in an independent spent fuel storage 
installation (ISFSI) or in a U.S. Department of Energy (DOE) monitored 
retrievable storage installation (MRS). These amendments update the 
seismic siting and design criteria, including geologic, seismic, and 
earthquake engineering considerations. The final rule allows the NRC 
and its licensees to benefit from experience gained in the licensing of 
existing facilities and to incorporate rapid advancements in the earth 
sciences and earthquake engineering. The amendments make the NRC 
regulations that govern certain ISFSIs and MRSs more compatible with 
the 1996 amendments that addressed uncertainties in seismic hazard 
analysis for nuclear power plants. The amendments allow certain ISFSI 
or MRS applicants to use a design earthquake level commensurate with 
the risk associated with an ISFSI or MRS.

EFFECTIVE DATE: This final rule is effective on October 16, 2003.

FOR FURTHER INFORMATION CONTACT: Keith K. McDaniel, Office of Nuclear 
Material Safety and Safeguards, U.S. Nuclear Regulatory Commission, 
Washington, DC 20555-0001, telephone: (301) 415-5252, e-mail: 
[email protected].


SUPPLEMENTARY INFORMATION: 
I. Background
II. Objectives
III. Applicability
IV. Discussion
V. Related Regulatory Guide and Standard Review Plans
VI. Summary of Public Comments on the Proposed Rule
VII. Summary of Final Revisions
VIII. Criminal Penalties
IX. Agreement State Compatibility
X. Voluntary Consensus Standards
XI. Finding of No Significant Environmental Impact: Availability
XII. Paperwork Reduction Act Statement
XIII. Regulatory Analysis
XIV. Regulatory Flexibility Certification
XV. Backfit Analysis
XVI. Small Business Regulatory Enforcement Fairness Act

I. Background

    In 1980, the NRC added 10 CFR part 72 to its regulations to 
establish licensing requirements for the independent storage of spent 
nuclear fuel and high-level radioactive waste (HLW) (45 FR 74693; 
November 12, 1980). In 1988, the NRC amended part 72 to provide for 
licensing the storage of spent nuclear fuel and HLW in an MRS (53 FR 
31651; August 19, 1988). Subpart E of Part 72 contains siting 
evaluation factors that must be investigated and assessed with respect 
to the siting of an ISFSI or MRS, including a requirement for 
evaluation of geological and seismological characteristics. ISFSI and 
MRS facilities are designed and constructed for the interim storage of 
spent nuclear fuel that has aged for at least one year, other 
solidified radioactive materials associated with spent fuel storage, 
and power reactor-related GTCC waste, that are pending shipment to a 
high-level radioactive waste repository or other disposal site.
    The original regulations envisioned ISFSI and MRS facilities as 
spent fuel pools or single, massive dry storage structures. The 
regulations required seismic evaluations equivalent to those for a 
nuclear power plant (NPP) when the ISFSI or MRS is located west of the 
Rocky Mountain Front (west of approximately 104[deg] west longitude), 
referred to hereafter as the western U.S., or in areas of known seismic 
activity east of the Rocky Mountain Front (east of approximately 
104[deg] west longitude), referred to hereafter as the eastern U.S. A 
seismic design requirement, equivalent to the requirements for an NPP 
(appendix A to 10 CFR part 100) seemed appropriate for these types of 
facilities, given the potential accident scenarios. For those sites 
located in the eastern U.S., and not in areas of known seismic 
activity, the regulations allowed for less stringent alternatives.
    For other types of ISFSI or MRS designs, the regulation required a 
site-specific investigation to establish site suitability commensurate 
with the specific requirements of the proposed ISFSI or MRS. The NRC 
explained that for ISFSIs which do not involve massive structures, such 
as dry storage casks and canisters, the required design earthquake will 
be determined on a case-by-case basis until more experience is gained 
with the licensing of these types of units (45 FR 74697).
    For sites located in either the western U.S. or in areas of known 
seismic activity in the eastern U.S., the regulations in 10 CFR part 72 
currently require the use of the procedures in appendix A to part 100 
for determining the design basis vibratory ground motion at a site. 
appendix A requires the use of ``deterministic'' approaches in the 
development of a single set of earthquake sources. The applicant 
develops for each source a postulated earthquake to be used to 
determine the ground motion that can affect the site, locates the 
postulated earthquake according to prescribed rules, and then 
calculates ground motions at the site.
    Advances in the sciences of seismology and geology, along with the 
occurrence of some licensing issues not foreseen in the development of 
appendix A to part 100, have caused a number of difficulties in the 
application of this regulation. Specific problematic areas include the 
following:
    1. Because the deterministic approach does not explicitly recognize 
uncertainties in geoscience parameters, probabilistic seismic hazard 
analysis (PSHA) methods were developed that allow explicit expressions 
for the uncertainty in ground motion estimates and provide a means for 
assessing sensitivity to various parameters. Appendix A to part 100 
does not allow this application.
    2. The limitations in data and geologic/seismic analyses, and the 
rapid evolution in geosciences have required considerable latitude in 
technical judgment. The inclusion of detailed geoscience assessments in 
Appendix A has inhibited the use of needed judgment and flexibility in 
applying basic principles to new situations; and
    3. Various sections of Appendix A are subject to different 
interpretations. For example, there have been differences of opinion 
and differing interpretations among experts as to the largest 
earthquakes to be considered and ground motion models to be used, thus 
often making the licensing process less predictable.
    In 1996, the NRC amended 10 CFR parts 50 and 100 to update the 
criteria

[[Page 54144]]

used in decisions regarding NPP siting, including geologic and seismic 
engineering considerations for future NPPs (61 FR 65157; December 11, 
1996). The amendments added a new Sec.  100.23 requiring that the 
uncertainties associated with the determination of the Safe Shutdown 
Earthquake Ground Motion (SSE) be addressed through an appropriate 
analysis, such as a PSHA or suitable sensitivity analyses in lieu of 
appendix A to part 100. This approach takes into account the 
problematic areas identified above in the earlier siting requirements 
and is based on developments in the technical field over the past two 
decades. Further, regulatory guides have been used to address 
implementation issues. For example, the NRC provided guidance for NPP 
license applicants in Regulatory Guide 1.165, ``Identification and 
Characterization of Seismic Sources and Determination of Safe Shutdown 
Earthquake Ground Motion,'' and Standard Review Plan NUREG-0800, 
``Standard Review Plan for the Review of Safety Analysis Reports for 
Nuclear Power Reactors,'' Section 2.5.2, ``Vibratory Ground Motion,'' 
Revision 3. However, the NRC left appendix A to part 100 in place to 
preserve the licensing basis for existing plants and confined the 
applicability of Sec.  100.23 to new NPPs.
    The NRC is now amending 10 CFR part 72 to require applicants at 
some locations to address uncertainties in seismic hazard analysis by 
using appropriate analyses, such as a PSHA or suitable sensitivity 
analyses, for determining the design earthquake ground motion (DE). The 
use of a probabilistic approach or suitable sensitivity analyses to 
siting parallels the change made to 10 CFR part 100.
    In comparison with an NPP, an operating dry cask ISFSI or MRS 
facility storing spent nuclear fuel is a passive facility in which the 
primary activities are waste receipt, handling, and storage. An ISFSI 
or MRS facility does not have the variety and complexity of active 
systems necessary to support safe operations at an NPP. Further, the 
robust cask design required for non-seismic considerations (e.g., drop 
event, shielding), assure low probabilities of failure from seismic 
events. In the unlikely occurrence of a radiological release as a 
result of a seismic event, the radiological consequences to workers and 
the public are significantly lower than those that could arise at an 
NPP. The conditions required for release and dispersal of significant 
quantities of radioactive material, such as high temperatures or 
pressures, are not present in an ISFSI or MRS. This is primarily due to 
the low heat-generation rate of spent fuel that has undergone more than 
one year of decay before storage in an ISFSI or MRS, and to the low 
inventory of volatile radioactive materials readily available for 
release to the environment. The long-lived nuclides present in spent 
fuel are tightly bound in the fuel materials and are not readily 
dispersible. Short-lived volatile nuclides, such as I-131, are no 
longer present in aged spent fuel. Furthermore, even if the short-lived 
nuclides were present during a fuel assembly rupture, the canister 
surrounding the fuel assemblies is designed to confine these nuclides.
    The standards in part 72 Subparts E, ``Siting Evaluation Factors,'' 
and F, ``General Design Criteria,'' ensure that the dry cask storage 
designs are very rugged and robust. The casks must maintain structural 
integrity during a variety of postulated non-seismic events, including 
cask drops, tip-over, and wind driven missile impacts. These non-
seismic events challenge cask integrity significantly more than seismic 
events. Therefore, the casks have substantial design margins to 
withstand forces from a seismic event greater than the design 
earthquake.
    Hence, the seismically induced risk from the operation of an ISFSI 
or MRS is less than at an operating NPP. As a result, the NRC is 
revising the DE requirements for ISFSI and MRS facilities from the 
current part 72 requirements, which are equivalent to the SSE for an 
NPP.
    As an additional minor change, the NRC is modifying Sec.  
72.212(b)(2)(i)(B) to require general licensees to evaluate dynamic 
loads, in addition to static loads, in the design of cask storage pads 
and areas for ISFSIs, to ensure that casks are not placed in unanalyzed 
conditions. Accounting for dynamic loads in the analysis of ISFSI pads 
and areas will ensure that pads continue to support the casks during 
seismic events. General licensees currently evaluate dynamic loads for 
evaluating the casks, pads and areas, to meet the cask design bases in 
the Certificate of Compliance, as required by Sec.  72.212(b)(2)(i)(A). 
Therefore, the rule will not actually require any general licensees 
operating an ISFSI to re-perform any written evaluations previously 
undertaken. Specific licensees are currently required, under Sec.  
72.122(b)(2), to design ISFSIs to withstand the effects of dynamic 
loads, such as earthquakes and tornados.
    The NRC published the proposed rule, ``Geological and Seismological 
Characteristics for Siting and Design of Dry Cask Independent Spent 
Fuel Storage Installations and Monitored Retrievable Storage 
Installations'' in the Federal Register on July 22, 2002 (67 FR 47745) 
for public comment. The NRC stated on September 5, 2002 (67 FR 56876) 
that it intended to extend the comment period for an additional 15 days 
to allow interested persons additional time to provide meaningful 
comments. The public comment period expired on October 22, 2002.
    The NRC received nine comment letters on the proposed rule. These 
comments and the NRC responses are discussed in Section VI of this 
document, ``Summary of Public Comments on the Proposed Rule.''

II. Objectives

    An ISFSI is designed, constructed, and operated under a part 72 
specific or general license. A part 72 specific license for an ISFSI is 
issued to a named person upon application filed under part 72 
regulations. A part 72 general license for an ISFSI is issued under 10 
CFR 72.210 to persons authorized to possess an NPP license under part 
50, without filing a part 72 license application. A general licensee is 
required to meet the conditions specified in subpart K of part 72. An 
MRS may be designed, constructed, and operated by DOE under a part 72 
specific license.
    The final rule reflects changes that are intended to (1) provide 
benefit from the experience gained in applying the existing regulation 
and from research; (2) provide needed regulatory flexibility to 
incorporate into licensing state-of-the-art improvements in the 
geosciences and earthquake engineering; and (3) make the regulations 
more risk informed, consistent with the Commission's recent policy.
    The objectives of this final rule are to:
    1. Require a new specific-license applicant for a dry cask storage 
facility located in either the western U.S. or in areas of known 
seismic activity in the eastern U.S., and not co-located with an NPP, 
to address uncertainties in seismic hazard analysis by using 
appropriate analyses, such as a PSHA or suitable sensitivity analyses, 
for determining the DE. All other new specific-license applicants for 
dry cask storage facilities will have the option of complying with the 
requirement to use a PSHA or suitable sensitivity analyses to address 
uncertainties in seismic hazard analysis, or other options compatible 
with the existing regulation. (Sec.  72.103)
    2. Allow new ISFSI or MRS specific-license applicants using a PSHA 
to select a DE appropriate for and commensurate with the risk 
associated with an ISFSI or MRS; and

[[Page 54145]]

    3. Require general licensees to design cask storage pads and areas 
to adequately account for dynamic loads, in addition to static loads. 
(Sec.  72.212)

III. Applicability

    This section clarifies the applicability of the new Sec.  72.103 
for Part 72 specific licensees, and modified Sec.  72.212(b)(2)(i)(B) 
for Part 72 general licensees.

Applicability of New Sec.  72.103

    (1) Applicants who apply on or after the effective date of the 
final rule, for a part 72 specific license for a dry cask storage ISFSI 
or MRS, located in either the western U.S. or in areas of known seismic 
activity in the eastern U.S., and not co-located with an NPP, will be 
required to address uncertainties in seismic hazard analysis by using 
appropriate analyses, such as a PSHA or suitable sensitivity analyses, 
for determining the DE.
    (2) Applicants who apply on or after the effective date of the 
final rule, for a part 72 specific license for a dry cask storage ISFSI 
or MRS, located in either the western U.S. or in areas of known seismic 
activity in the eastern U.S., and co-located with an NPP, will have the 
option of addressing uncertainties in seismic hazard analysis by using 
appropriate analyses, such as a PSHA or suitable sensitivity analyses, 
or using the existing design criteria for the NPP, for determining the 
DE. When the existing design criteria for the NPP are used for an ISFSI 
at a site with multiple NPPs, the criteria for the most recent NPP must 
be used.
    (3) Applicants who apply on or after the effective date of the 
final rule, for a part 72 specific license for a dry cask storage ISFSI 
or MRS, located in the eastern U.S., except in areas of known seismic 
activity, will have the option of addressing uncertainties in seismic 
hazard analysis by using appropriate analyses, such as a PSHA or 
suitable sensitivity analyses, or using a standardized DE described by 
an appropriate response spectrum anchored at 0.25 g (subject to the 
conditions in new Sec.  72.103(a)(1)), or using the existing design 
criteria for the most recent NPP (if applicable), for determining the 
DE.
    (4) The new Sec.  72.103 is not applicable to a general licensee at 
an existing NPP operating an ISFSI under a part 72 general license 
anywhere in the U.S.
    The changes apply to the design basis of both a dry cask storage 
type ISFSI and MRS, because these facilities are similar in design. The 
NRC does not intend to revise the 10 CFR part 72 geological and 
seismological criteria as they apply to wet modes of storage because 
applications for this means of storage are not expected and it is not 
cost-effective to allocate resources to develop the technical bases for 
such an expansion of the rulemaking. The NRC also does not intend to 
revise the 10 CFR part 72 geological and seismological criteria as they 
apply to dry modes of storage that do not use casks because of the lack 
of experience in licensing these types of facilities.
    The applicability of Sec.  72.103 is summarized in the table below.

Applicability of Amended Sec.  72.212(b)(2)(i)(B)

    The changes in Sec.  72.212(b)(2)(i)(B), regarding the evaluation 
of dynamic loads for the design of cask storage pads and areas, will 
apply to all general licensees for an ISFSI.
    The applicability of the modified Sec.  72.212(b)(2)(i)(B) is 
summarized in the table below.

                        Summary of Applicability
   [Design Earthquake Ground Motion for ISFSI or MRS Specific-License
 Applicants for Dry Cask Modes of Storage on or after the Effective Date
                           of the Final Rule]
------------------------------------------------------------------------
             Site condition               Specific-license applicant \1\
------------------------------------------------------------------------
Western U.S., or areas of known seismic  Must use PSHA or suitable
 activity in the eastern U.S., not co-    sensitivity analyses to
 located with NPP.                        account for uncertainties in
                                          seismic hazards inevaluations
                                          \2\.
Western U.S., or areas of known seismic  PSHA or suitable sensitivity
 activity in the eastern U.S., and co-    analyses to account for
 located with NPP.                        uncertainties in seismic
                                          hazards evaluations \2\,
                                         or
                                         existing NPP design criteria
                                          (multi-unit sites--use and co-
                                          located withthe most recent
                                          criteria). NPP
Eastern U.S., and not in areas of known  PSHA or suitable sensitivity
 seismic activity.                        analyses to account for
                                          uncertainties in seismic
                                          hazards evaluations,\2\
                                         or
                                         existing NPP design criteria,
                                          if applicable (multi-unit
                                          sites--use the most recent
                                          criteria),
                                         or
                                         an appropriate response
                                          spectrum anchored at 0.25g
                                          (subject to the conditions in
                                          new Sec.   72.103(a)(1)).
------------------------------------------------------------------------
\1\ New Sec.   72.103 does not apply to general licensees. General
  licensees must satisfy the conditions specified in 10 CFR 72.212.
\2\ Regardless of the results of the investigations anywhere in the
  continental U.S., the DE must have a value for the horizontal ground
  motion of no less than 0.10 g with the appropriate response spectrum.

IV. Discussion

    The NRC is amending certain sections of part 72 dealing with 
seismic siting and design criteria for a dry cask ISFSI or MRS. The NRC 
intends to leave the present Sec.  72.102 in place to preserve the 
ISFSI licensing bases for applications before the effective date of the 
rule, and continue the present ISFSI or MRS licensing bases for 
applications for other than dry cask modes of storage. The NRC is 
changing the heading of Sec.  72.102, adding a new Sec.  72.103, and 
modifying Sec.  72.212(b)(2)(i)(B).

A. Change to 10 CFR 72.102

    The heading of Sec.  72.102 will be changed to clarify that the 
present requirements are applicable to ISFSI or MRS specific licensees 
or specific-license applicants before the effective date of the rule. 
The requirements of Sec.  72.102 that applied to ISFSI or MRS 
licensees, or license applicants for other than dry cask modes of 
storage will continue to apply.

B. New 10 CFR 72.103

    New Sec.  72.103 describes the seismic requirements for new 
specific-license applicants for dry cask storage at an ISFSI or MRS.

[[Page 54146]]

1. Remove Detailed Guidance From the Regulation
    Part 72 currently requires license applicants for an ISFSI or MRS, 
in the western U.S. or in other areas of known seismicity, to comply 
with appendix A to part 100. Appendix A contains both requirements and 
guidance on how to satisfy those requirements. For example, Section IV, 
``Required Investigations,'' of Appendix A states that investigations 
are required for vibratory ground motion, surface faulting, and 
seismically induced floods and water waves. Appendix A then provides 
detailed guidance on what constitutes an acceptable investigation. A 
similar situation exists in Section V, ``Seismic and Geologic Design 
Bases,'' of appendix A to part 100.
    Geoscience assessments require considerable latitude in judgment 
because of (a) limitations in data; (b) changing state-of-the-art of 
geologic and seismic analyses; (c) rapid accumulation of knowledge; and 
(d) evolution in geoscience concepts. The NRC recognized the need for 
latitude in judgment when it amended part 100 in 1996.
    However, specifying geoscience assessments in detail in a 
regulation has created difficulty for applicants and the NRC by 
inhibiting needed latitude in judgment. It has inhibited the 
flexibility needed in applying basic principles to new situations and 
the use of evolving methods of analyses (for instance, probabilistic) 
in the licensing process.
    The NRC is adding a new section in part 72 that will provide 
specific siting requirements for an ISFSI or MRS instead of referencing 
another part of the regulations. The amended regulation will also 
reduce the level of detail by placing only basic requirements in the 
rule and providing the details on methods acceptable for meeting the 
requirements in an accompanying guidance document. Thus, the revised 
regulation contains requirements to:
    (i) Evaluate the geological, seismological, and engineering 
characteristics of the proposed site;
    (ii) Establish a DE; and
    (iii) Identify the uncertainties associated with these 
requirements.
    Detailed guidance on the procedures acceptable to the NRC for 
meeting the requirements are provided in Regulatory Guide 3.73, ``Site 
Evaluations and Design Earthquake Ground Motion for Dry Cask 
Independent Spent Fuel Storage and Monitored Retrievable Storage 
Installations.''
2. Address Uncertainties and Use Probabilistic Methods
    The existing approach for determining a DE for an ISFSI or MRS, 
embodied in Appendix A to Part 100, relies on a ``deterministic'' 
approach. Using this deterministic approach, an applicant develops a 
single set of earthquake sources, develops for each source a postulated 
earthquake to be used as the source of ground motion that can affect 
the site, locates the postulated earthquake according to prescribed 
rules, and then calculates ground motions at the site.
    Although this approach has worked reasonably well for the past 
several decades in the sense that the SSE for NPPs sited with this 
approach are judged to be suitably conservative, the approach has not 
explicitly recognized uncertainties in geosciences parameters. Because 
so little is known about earthquake phenomena (especially in the 
eastern U.S.), there have been differences of opinion and differing 
interpretations among experts as to the largest earthquakes to be 
considered and ground-motion models to be used, often making the 
licensing process less predictable.
    Probabilistic methods that have been developed in the past 15 to 20 
years for evaluation of seismic safety of nuclear facilities allow 
explicit incorporation of different models for zonation, earthquake 
size, ground motion, and other parameters. The advantage of using these 
probabilistic methods is their ability to incorporate different models 
and data sets, thereby providing an explicit expression for the 
uncertainty in the ground motion estimates and a means of assessing 
sensitivity to various input parameters. The western and eastern U.S. 
have fundamentally different tectonic environments and histories of 
tectonic deformation. Consequently, application of these probabilistic 
methodologies has revealed the need to vary the fundamental PSHA 
methodology depending on the tectonic environment of the site.
    In 1996, when the NRC accepted the use of a PSHA methodology or 
suitable sensitivity analyses in Sec.  100.23, it recognized that the 
uncertainties in seismological and geological information must be 
formally evaluated and appropriately accommodated in the determination 
of the SSE for seismic design of NPPs. The NRC further recognized that 
the nature of uncertainty and the appropriate approach to account for 
it depends on the tectonic environment of the site and on properly 
characterizing parameters input to the PSHA. Methods other than 
probabilistic methods (PSHA), such as sensitivity analyses, may be 
adequate for some sites to account for uncertainties. The NRC believes 
that certain new applicants for ISFSI or MRS specific licenses, as 
described in Section III, ``Applicability,'' of this document, must use 
probabilistic methods or other sensitivity analyses to account for 
uncertainties instead of using Appendix A to Part 100. The NRC does not 
intend to require new ISFSI or MRS specific-license applicants that are 
co-located with an NPP to address uncertainties because the criteria 
used to evaluate existing NPPs are considered to be adequate for 
ISFSIs, in that the criteria have been determined to be safe for NPP 
licensing, and the seismically induced risk of an ISFSI or MRS is 
considerably lower than that of an NPP, as described in Section IV of 
this document.
    The key elements of the NRC's approach for seismic and geologic 
siting for ISFSI or MRS license review and approval consists of:
    a. Conducting site-specific and regional geoscience investigations;
    b. Setting the target exceedance probability commensurate with the 
level of risk associated with an ISFSI or MRS;
    c. Conducting PSHA and determining ground motion level 
corresponding to the target exceedance probability;
    d. Determining if other sources of information change the available 
probabilistic results or data for the site; and
    e. Determining site-specific spectral shape, and scaling this shape 
to the ground motion level determined above.
    In addition, the NRC will review the application using all 
available data including insights and information from previous 
licensing experience. Thus, the revised approach requires thorough 
regional and site-specific geoscience investigations. Results of the 
regional and site-specific investigations must be considered in 
applying the probabilistic method. Two current probabilistic methods 
are the NRC-sponsored study conducted by Lawrence Livermore National 
Laboratory and the Electric Power Research Institute's seismic hazard 
study. These are essentially regional studies. The regional and site-
specific investigations provide detailed information to update the 
database of the hazard methodology to make the probabilistic analysis 
site-specific.
    Applicants must also incorporate local site geological factors, 
such as stratigraphy and topography, and account for site-specific 
geotechnical properties in establishing the DE. Guidelines to 
incorporate local site factors and advances in ground motion

[[Page 54147]]

attenuation models, and to determine ground motion estimates, are 
outlined in NUREG-0800, Section 2.5.2.
    Methods acceptable to the NRC for implementing the revised 
regulation related to the PSHA or suitable sensitivity analyses are 
described in RG 3.73.
3. Revise the Design Earthquake Ground Motion
    The present DE in part 72 is based on the deterministic 
requirements contained in Appendix A to 10 CFR Part 100 for NPPs. In 
the Statement of Considerations accompanying the initial part 72 
rulemaking, the NRC recognized that the required design earthquake need 
not be as high as for an NPP and should be determined on a ``case-by-
case'' basis until ``more experience is gained with licensing of these 
types of units'' (45 FR 74697; November 12, 1980). With the advances in 
probabilistic seismic hazard evaluation techniques, over 10 years of 
experience in licensing dry cask storage (10 specific licenses have 
been issued and 9 locations use the general license provisions), and 
analyses demonstrating robust behavior of dry cask storage systems 
(DCSSs) in accident scenarios, the NRC now has a reasonable basis to 
consider more appropriate DE parameters for a dry cask ISFSI or MRS. 
Therefore, in those instances when an ISFSI or MRS specific-license 
applicant uses PSHA methods, the NRC will allow a DE commensurate with 
the lower risk associated with these facilities.
    I. Factors that result in the lower radiological risk at an ISFSI 
or MRS compared to an NPP include the following:
    a. In comparison with an NPP, an operating ISFSI or MRS is a 
passive facility in which the primary activities are waste receipt, 
handling, and storage. An ISFSI or MRS does not have the variety and 
complexity of active systems necessary to support an operating NPP. 
After the spent fuel is in place, an ISFSI or MRS is essentially a 
static operation.
    b. During normal operations, the conditions required for the 
release and dispersal of significant quantities of radioactive 
materials are not present. There are no components carrying fluids at 
high temperatures or pressures during normal operations or under design 
basis accident conditions to cause the release and dispersal of 
radioactive materials. This is primarily due to the low heat-generation 
rate of spent fuel that has undergone more than one year of decay 
before storage in an ISFSI or MRS, and to the low inventory of volatile 
radioactive materials readily available for release to the environment.
    c. The long-lived nuclides present in spent fuel are tightly bound 
in the fuel materials and are not readily dispersible. Short-lived 
volatile nuclides, such as I-131, are no longer present in aged spent 
fuel. Furthermore, even if the short-lived nuclides were present during 
a fuel assembly rupture, the canister surrounding the fuel assemblies 
would confine these nuclides. Therefore, the NRC believes that the 
seismically induced radiological risk associated with an ISFSI or MRS 
is significantly less than the risk associated with an NPP.
    II. Additional rationale for allowing the use of a DE level 
commensurate with the risk associated with an ISFSI or MRS includes the 
following:
    a. Because the DE is defined as a smooth broad-band spectrum, which 
envelops the controlling earthquake responses, the vibratory ground 
motion specified is conservative.
    b. To evaluate dry cask storage systems' behavior during an 
earthquake, typical storage systems (one a cylindrical cask, HI-STORM 
100, the other a concrete module type, NUHOMS) were analyzed for a 
range of earthquakes. Based on the results of the analyses, the NRC has 
concluded that a free-standing dry storage cask remains stable and will 
not tip-over, or would not slide and impact the adjacent casks during 
an earthquake approximately equal to the magnitude of a SSE for an NPP. 
Additionally, parametric studies indicated that dry cask storage 
systems have significant margins against tip-over and sliding, to 
withstand an earthquake significantly higher in magnitude than the SSE 
for an NPP, without releasing radioactivity. Further, a cask is 
analyzed for a non-mechanistic tip-over event during an earthquake, to 
verify that it would maintain its structural integrity, and 
radioactivity from spent fuel would not be released to the environment. 
Therefore, based on drop accident analyses and non-mechanistic tip-over 
event evaluations, and on the results of the generic studies for the 
cask behavior during an earthquake, it can be concluded that there 
would be no radiological consequences at a dry cask ISFSI or MRS 
facility due to an earthquake.
    c. The rational for allowing a DE for an ISFSI or MRS to be lower 
than a DE for an NPP is consistent with the approach used in DOE 
Standard DOE-STD-1020, ``Natural Phenomena Hazards Design Evaluation 
Criteria for Department of Energy Facilities.''
    Regulatory Guide 3.73 (formerly DG-3021) recommends an acceptable 
mean annual probability of exceedance (MAPE) for the DE that is 
commensurate with the lower risk associated with an ISFSI or MRS as 
compared to an NPP. The basis for the recommendation is provided in a 
report entitled, ``Selection of the Design Earthquake Ground Motion 
Reference Probability''. This report may be accessed through the NRC's 
Public Electronic Reading Room on the Internet at http://www.nrc.gov/reading-rm/adams.html. If you do not have access to ADAMS or if there 
are problems in accessing the documents located in ADAMS, contact the 
NRC's PDR reference staff at 1-800-397-4209, 301-415-4737, or by email 
to [email protected]. Discussion on the recommended mean annual probability 
of exceedance is also in Section VI of this FRN, ``Summary of Public 
Comments on the Proposed Rule.''

C. Change to 10 CFR 72.212(b)(2)(i)(B)

    The NRC is modifying Sec.  72.212(b)(2)(i)(B) to require that 
general licensees evaluate dynamic loads, in addition to static loads, 
in the design of cask storage pads and areas for ISFSIs to ensure that 
casks are not placed in unanalyzed conditions. During a seismic event, 
the cask storage pads and areas experience dynamic loads in addition to 
static loads. The dynamic loads depend on the interaction of the casks, 
cask storage pads, and areas. Consideration of the dynamic loads of the 
stored casks, in addition to the static loads, for the design of the 
cask storage pads and areas, will ensure that the cask storage pads and 
areas will perform satisfactorily during a seismic event.
    The revision will also require consideration of potential 
amplification of earthquakes through soil-structure interaction, and 
soil liquefaction potential or other soil instability due to vibratory 
ground motions. Depending on the properties of soil and structures, the 
free-field earthquake acceleration input loads may be amplified at the 
top of the storage pad. These amplified acceleration input values must 
be bound by the design bases seismic acceleration values for the cask, 
specified in the Certificate of Compliance. Liquefaction of the soil 
and instability during vibratory motion due to an earthquake may affect 
the cask stability.
    The changes to Sec.  72.212 will not actually impose a new burden 
on the general licensees because they currently need to consider 
dynamic loads to meet the requirements in Sec.  72.212(b)(2)(i)(A). 
Section 72.212(b)(2)(i)(A) requires that general licensees perform 
written evaluations to meet conditions set forth in the cask 
Certificate of Compliance. These Certificates of Compliance require 
that dynamic loads, such as seismic and

[[Page 54148]]

tornado loads, be evaluated to meet the cask design bases. Specific 
licensees are currently required, under Sec.  72.122(b)(2), to design 
ISFSIs to withstand the effects of dynamic loads, such as earthquakes 
and tornados.

V. Related Regulatory Guide and Standard Review Plans

    On July 22, 2002, the NRC published DG-3021, ``Site Evaluations and 
Determination of Design Earthquake Ground Motion for Seismic Design of 
Independent Spent Fuel Storage Installations and Monitored Retrievable 
Storage Installations'' for public comment (67 FR 48956; July 26, 
2002). Regulatory Guide 3.73, Site Evaluations and Design Earthquake 
Ground Motion for Dry Cask Independent Spent Fuel Storage and Monitored 
Retrievable Storage Installations (formerly DG-3021), provides guidance 
to licensees for procedures acceptable to the NRC staff for:
    (1) Conducting a detailed evaluation of site area geology and 
foundation stability;
    (2) Conducting investigations to identify and characterize 
uncertainty in seismic sources in the site region important for the 
probabilistic seismic hazard analysis (PSHA);
    (3) Evaluating and characterizing uncertainty in the parameters of 
seismic sources;
    (4) Conducting PSHA for the site; and
    (5) Determining the DE to satisfy the requirements of 10 CFR Part 
72.
    This guide describes acceptable procedures and provides a list of 
references that present acceptable methodologies to identify and 
characterize capable tectonic sources and seismogenic sources. Section 
IV.B of this SUPPLEMENTARY INFORMATION describes the key elements of 
the regulatory guide. A document announcing the availability of 
Regulatory Guide 3.73 will be published in the Federal Register in the 
near future.
    Requests for single copies of active regulatory guides (which may 
be reproduced) or for placement on an automatic distribution list for 
single copies of future guides should be made in writing to the U.S. 
Nuclear Regulatory Commission, Washington, DC 20555, Attention: 
Reproduction and Distribution Services Section, or by fax to (301) 415-
2289; email [email protected]. Copies are available for inspection 
or copying for a fee from the NRC Public Document Room at 11555 
Rockville Pike (first floor), Rockville, MD; the PDR's mailing address 
is U.S. NRC PDR, Washington, DC 20555; telephone (301) 415-4737 or 1-
(800) 397-4209; fax (301) 415-3548; e-mail [email protected].
    In the future, editorial changes to NUREG-1536, ``Standard Review 
Plan for Dry Cask Storage Systems,'' and NUREG-1567, ``Standard Review 
Plan for Spent Fuel Dry Storage Facilities,'' will be made. For 
example, the standard review plans will be updated to reference the new 
Sec.  72.103 and Regulatory Guide 3.73.

VI. Summary of Public Comments on the Proposed Rule

    This section presents a summary of the public comments received on 
the proposed rule and supporting documents, the NRC's response to the 
comments, and changes made in the final rule and supporting documents 
as a result of these comments.
    The NRC received nine comment letters on the proposed rule from 
eight commenters. The commenters were the Nuclear Energy Institute 
(NEI), the U.S. Department of Energy (DOE), two nuclear power 
utilities, three State agencies, and one license applicant for an 
independent spent fuel storage installation. All the commenters agreed 
with the proposal to address uncertainty by requiring the use of a PSHA 
or suitable sensitivity analyses for an ISFSI or MRS in the western 
U.S., not co-located with an NPP, and in areas of known seismic 
activity in the eastern U.S. However, commenters were divided on the 
specific question for public comment related to the appropriate value 
for the MAPE posed by the Commission in the proposed rule. These 
comments are summarized in this section under the heading ``Related 
Regulatory Guide.'' All commenters supported the concept of requiring 
general licensees to evaluate both dynamic loads and static loads for 
ISFSI and MRS cask storage pads and areas.
    Copies of the public comments are available for review in the NRC 
Public Document Room, 11555 Rockville Pike, Rockville, MD. A review of 
the comments and the NRC responses follow:

General Comments

    Comment 1: A commenter stated that proposed 10 CFR 72.103(f)(1) 
does not comply with the notice and comment requirements of Section 553 
of the Administrative Procedure Act (APA) because of the way the rule 
is structured. The commenter believes that the proposed rule ``is in 
the guise of a substantive rule,'' but that the substantive 
requirements are found in the draft guidance, a document which is not a 
rule. In the commenter's view, ``the Commission attempts to give 
concrete form to its proposed rule through an interpretative document, 
DG-3021, and the Commission thereby circumvents [APA] Sec.  553 notice 
and comment rulemaking procedures,'' citing Paralyzed Veterans of 
America v. D.C. Arena L.P., 117 F.3d 579 (D.C. Cir. 1997). According to 
the commenter, a significant defect of this structure is that the rule 
gives no standards against which a licensing board or intervenors may 
evaluate whether an applicant has complied with the rule and, instead, 
gives ``unbridled and unchecked discretion to the staff in determining 
the seismic design standard for ISFSIs sited in seismic areas.'' The 
proposed rule, in the commenter's view, has no force of law because it 
has no binding standards and thus is unenforceable. Another commenter 
disagreed and supported the NRC's view that the rule is substantive and 
in compliance with the APA.
    Response: First, the NRC rejects the claim that the rule is not 
being promulgated in compliance with Sec.  553 of the APA. Section 553 
requires that notice of a proposed rulemaking be published in the 
Federal Register, including the terms or substance of the proposed 
rule, and that interested persons be given an opportunity to comment. 
The APA also provides an exception for interpretative rules and general 
statements of policy enabling those documents to be issued as final 
rules without prior notice and comment. In this case, the NRC has not 
availed itself of the exception but rather has issued both the draft 
guidance and the proposed rule for public comment. Thus, there has been 
no violation of the notice and comment requirements of Section 553 of 
the APA even if the guidance were to be considered part of the rule. 
The Paralyzed Veterans case, cited by the petitioner, concerned a 
guidance document issued by the Department of Justice which had been 
issued without prior notice and comment and raised the issue whether 
the Government could rely upon the guidance in an enforcement action. 
The court ultimately found that there was no need for the Government to 
rely on the guidance to enforce the regulation. Here, the guidance has 
been issued for comment and the NRC does not contend, as explained 
below, that the guidance is legally enforceable.
    Second, the NRC does not agree that ``substantive requirements'' 
have been placed in the guidance document. Regulatory Guide 3.73 
(formerly DG-3021) provides information on methods acceptable to the 
NRC for implementing specific parts of the rule, but it does not place 
any particular requirements on

[[Page 54149]]

applicants. As the commenter points out, ``staff regulatory guides are 
not regulations, do not have the force of regulations, and when 
challenged, are considered only one way in which an applicant may meet 
the regulations.''
    Finally, the commenter really appears to be objecting to the NRC's 
risk-informed, performance-based approach in this rulemaking in lieu of 
the deterministic approach for determining a design earthquake embodied 
in Appendix A to 10 CFR Part 100. The overall performance criteria for 
protection against environmental conditions and natural phenomena in 
the design of Part 72 facilities are contained in 10 CFR 72.122(b) of 
the NRC's regulations. In particular, Sec.  72.122(b)(2)(i) provides:

    Structures, systems, and components important to safety must be 
designed to withstand the effects of natural phenomena such as 
earthquakes * * * without impairing their capability to perform 
their intended design functions. The design bases for these 
structures, systems, and components must reflect:
    (A) Appropriate consideration of the most severe of the natural 
phenomena reported for the site and surrounding area, with 
appropriate margins to take into account the limitations of the data 
and the period of time in which the data have accumulated; and
    (B) Appropriate combinations of the effects of normal and 
accident conditions and the effects of natural phenomena.

    These performance criteria are supplemented by the requirements of 
10 CFR 72.103 governing selection of a site and determination of a DE. 
This new regulation provides specific siting requirements for an ISFSI 
or MRS instead of referencing another part of the regulations (Appendix 
A to Part 100). This new regulation also reduces the level of detail by 
placing only basic requirements in the rule and providing the details 
on methods acceptable for meeting the requirements in an accompanying 
guidance document. Thus, the new 10 CFR 72.103(f) establishes basic 
requirements for determining a DE for use in the design of structures, 
systems, and components of the ISFSI or MRS. These regulations include 
a requirement that the geological, seismological, and engineering 
characteristics of a proposed site and its environs be investigated in 
sufficient scope and detail to provide sufficient information to 
support evaluations performed to arrive at estimates of the DE (Sec.  
72.103(f)(1)); a requirement that a DE be determined for the site 
(Sec.  72.103(f)(2)); and a requirement that uncertainties be addressed 
through an appropriate analysis, such as a probabilistic seismic hazard 
analysis or suitable sensitivity analyses (Sec.  72.103(f)(2)(i)). The 
regulation further requires determinations of the potential for surface 
tectonic and nontectonic deformations (Sec.  72.103(f)(2)(ii)); the 
design bases for seismically induced floods and water waves (Sec.  
72.103(f)(2)(iii)); and the siting factors for other design conditions, 
such as liquefaction potential (Sec.  72.103(f)(2)(iv)), as well as a 
requirement that the DE must have a value for the horizontal ground 
motion of no less than 0.10 g with the appropriate response spectrum 
(Sec.  72.103(f)(3)). More specific guidance for meeting these 
standards, including guidance on an acceptable reference probability, 
is provided in Regulatory Guide 3.73 (formerly DG-3021).
    Determining whether an applicant has complied with these 
performance standards may be more difficult than would be the case with 
a prescriptive regulation; however, that does not mean that the NRC has 
``unbridled discretion'' in deciding whether the standards are met nor 
that the standards (as opposed to the guidance) are not binding. The 
NRC uses informed technical judgment to determine if an application has 
satisfactorily met the standards. The NRC's rationale and judgment are 
expressed in a safety evaluation report (SER) subject to evaluation and 
potential challenge by members of the public. In the event of a 
hearing, a licensing board would have the technical skills necessary to 
evaluate any conflicting claims.
    Comment 2: A commenter noted that, although the NRC's approach is 
similar to that used in the amendments issued for seismic evaluation 
for the siting of NPPs, the NRC has no compelling reason to follow that 
approach. First, the commenter argued, if the approach violates the 
APA, it should be rejected. Second, the commenter stated that because 
no new applications for siting NPPs have been submitted using the new 
requirements, the rule has not been put to the test. Finally, the 
commenter indicated that there are no data for ISFSIs that establish 
design basis ground motions, unlike the SSE for a nuclear power plant, 
which has at least some data to provide guidance to the NRC and the 
public.
    Response: First, the NRC disagrees that either the amendments 
issued for the seismic evaluation of siting of NPPs or these Part 72 
amendments have been issued in violation of the APA. See comment 1. 
Second, although no new license applications for siting of NPPs have 
been received to test the new requirements in 10 CFR Sec.  100.23, the 
guidance associated with the use of probabilistic methods for siting of 
NPPs (Regulatory Guide 1.165) has been used in the PSHA prepared for a 
proposed ISFSI site. It is also being followed by applicants for an 
early site permit under 10 CFR Part 52. Finally, the NRC agrees that 
there are limited data for ISFSIs that establish design basis ground 
motions because the current Part 72 regulations for seismic design of 
ISFSIs are conservatively based on the nuclear power plant seismic 
design criteria, and thus, are not risk-informed. However, experience 
has been gained in the design and construction of numerous facilities 
using the philosophy of a graded, risk-informed approach described in 
the standard building codes, similar to the approach proposed in the 
rule for ISFSIs. The graded risk-informed approach is also used by the 
Department of Energy in designing its facilities for seismic loads with 
risks varying from conventional facilities to NPPs.
    Comment 3: A commenter noted that if clear seismic standards are 
not established in the rule, the opportunity for interested persons to 
participate in a licensing proceeding involving the seismic design of 
an ISFSI will become essentially prohibited. This is because a panoply 
of specific expertise is needed to evaluate the seismic design and 
there is only a small universe of seismic experts. Utilizing these 
experts is often not feasible because of the financial burden on 
intervenors in obtaining highly specialized expertise to analyze 
probabilistic seismic risks and design of nuclear facilities.
    Response: The NRC believes the standards for ISFSI or MRS facility 
earthquake designs are clear. See the response to Comment 1. However, 
the NRC recognizes that the proposed use of the probabilistic methods 
in seismic design of ISFSIs is more complex than the current 
deterministic methods of 10 CFR Part 100 Appendix A, and would require 
specific expertise to participate in the licensing proceedings. The NRC 
staff's safety evaluation report (SER) that independently assesses the 
applicant's method of compliance with regulations is available to 
assist the public in evaluating the risk of the facility and could help 
intervenors to focus their resources. The NRC does not intend to limit 
public participation in the licensing process; however, the Congress 
has barred the use of appropriated funds to pay the expenses of, or 
otherwise compensate, parties who intervene in NRC regulatory or 
adjudicatory proceedings.
    Comment 4: A commenter stated that the proposed rule placed too 
much stock on the integrity of the dry storage cask. The commenter 
indicated that of

[[Page 54150]]

the 19 ISFSI licenses issued in the past decade, none were in seismic 
areas. The NRC has not licensed unanchored cylindrical casks in any 
seismic areas. The commenter noted that there are no performance data, 
test data, or earthquake experience data for dry casks or for ISFSIs. 
The commenter further stated that the rule is based on principles that 
are antithetical to earthquake engineering principles because, for 
unanchored casks, the NRC relies solely on the predictions of non-
linear computer models. The commenter also stated that, up to this 
point, the non-linear computer model predictions of the seismic 
behavior of casks have not been validated with shake table data or 
actual performance data. The commenter also stated that without 
adequate and reliable performance and test data, it cannot be 
determined if the casks will actually provide the critical barrier 
described and relied upon in the rule. Another commenter stated that 
non-linear dynamic analyses are inherently reliable. Further, the 
commenter noted that proper input parameters for cask stability 
analyses are not elusive unknowns but can be determined from basic 
physical principles, and that these analyses have been shown not to be 
highly sensitive to changes in input parameters. Therefore, the 
commenter argued, shake table testing is unnecessary.
    Response: The integrity of the dry storage cask during an 
earthquake is a key to protecting the health and safety of the public 
because it confines the radioactivity during a potential accident 
event, such as an earthquake, and prevents it from being dispersed into 
the environment. Contrary to traditional building designs, the cask 
design is not governed by stresses resulting from an earthquake, but is 
governed by requirements resulting from shielding, thermal, 
criticality, and postulated handling accidents. Therefore, the critical 
performance requirement for a cask is that it would remain stable and 
not displace excessively to impact adjacent casks. The cask stability 
can be determined by nonlinear dynamic analyses, considering 
uncertainties in engineering parameters, and using multiple computer 
codes. The NRC has also performed structural analyses of casks tipping 
and sliding. In neither case did the canister fail.
    It is a common engineering practice to design and build structures, 
including new design concepts, based on detailed structural analyses 
using sound engineering principles and laws of physics, without 
performing confirmatory experiments. For example, new concepts in 
structural designs and construction of landmark structures, such as the 
Sears Tower, Hancock Tower, Eiffel Tower, and space vehicles were based 
solely on analyses.
    The advent of computers has helped in the development of analytical 
tools, including the non-linear dynamic analyses. Results of these 
analyses are being used to design structures more complex than a dry 
storage cask. The concept of free-standing casks is not new. The 
buildings the NRC uses every day are free-standing on a foundation, and 
thus would move during an earthquake. The analytical tools for non-
linear structural analyses are verified and validated using multiple 
computer codes and available experimental data. Therefore, shake table 
tests or actual performance data are not necessary.
    Comment 5: A commenter requested a rule to establish a definitive 
design basis earthquake at a return period level [the return period of 
an earthquake is an inverse of the mean annual probability of 
exceedance (MAPE) of the earthquake] greater than 2,000 years that is 
tied to defined risk and performance goals.
    Response: The NRC does not agree that we must establish a 
definitive design basis earthquake by rule. The current regulations in 
Sec.  72.122(b)(2)(i), require that the structures, systems, and 
components of an ISFSI or MRS must be designed to withstand the effects 
of natural phenomena, such as earthquakes, without impairing their 
capability to perform their intended design functions. For earthquakes, 
these requirements are then supplemented by the requirements at 
Sec. Sec.  72.102, 72.103, and 72.122 for detailed site investigations 
and appropriate consideration of the most severe of the natural 
phenomena and associated probability of occurrence, including 
consideration of uncertainties, in the prediction of earthquakes. This 
approach is consistent with the NRC's philosophy of using risk-
informed, performance-based regulations. In a risk-informed, 
performance-based approach, the design of the ISFSI or MRS facility is 
based on an assessment of the radiological risk (potential for adverse 
consequences) due to an earthquake. Thus, specifying a value for the 
reference probability in the rule would preclude applicants from 
considering structures, systems, and components with risks other than 
the risk associated with the specified reference probability.
    Comment 6: A commenter stated that the supplementary information in 
the final rule should state that the NRC's policy for promulgating 
risk-informed regulations was a primary motivation for the rule 
changes.
    Response: The NRC agrees that the supplementary information for the 
final rule should more clearly state that the rule was amended, in 
part, to conform to the Commission's recent policy to increase the use 
of risk insights and information in its regulatory applications. An 
additional statement has been added to Section II, Objectives, of the 
Supplementary Information portion of this document, that states the 
intent to revise the regulation in accordance with this policy.

Applicability of Proposed Sec.  72.103

    Comment 7: A commenter requested clarification of the proposed rule 
so that applicants for an ISFSI co-located with an NPP have the option 
of using the existing DE of the NPP without any further evaluations and 
that this applies to all sections of the rule. The commenter pointed 
out that the proposed amendments at Sec. Sec.  72.103(a)(2) and 
72.103(b), as well as explanatory statements made in the proposed rule 
indicate that applicants for an ISFSI that are co-located with an NPP 
have the option of using the existing NPP design criteria without 
additional evaluations, but that this option is not identified in Sec.  
72.103(f).
    Response: To further clarify the NRC's intent that an applicant for 
an ISFSI that is co-located with an NPP has the option of using the 
existing DE of the NPP without the need to undertake any additional 
evaluations of the sort described in Sec.  72.103(f), the introductory 
phrase of that section has been modified so that it now reads: ``Except 
as provided in paragraphs (a)(2) and (b) of this section, the DE for 
use in the design of structures, systems, and components must be 
determined as follows.''
    Comment 8: Two commenters stated that the criteria presented for 
establishing the DE for ISFSI and MRS sites at existing NPPs allows for 
the use of the existing NPP SSE as one alternative. This alternative is 
key to ensuring that significant new probabilistic ground motion 
studies are not required at existing NPP sites.
    Response: The commenters are correct. The regulatory changes 
allowing the licensee flexibility to use the existing SSE for an NPP at 
co-located ISFSIs or MRSs means that new studies are not required at 
ISFSIs or MRSs co-located with NPPs.

Alternative of Adopting 10 CFR 100.23

    Comment 9: One commenter recommended withdrawing the proposed rule 
and adopting the option

[[Page 54151]]

of directing new applicants for specific licenses to comply with 10 CFR 
100.23 in its entirety, including conforming the DE to the SSE 
criteria. The commenter noted that by adopting Sec.  100.23 in its 
entirety, there would be no need to make distinctions among locations 
of facilities and the rule would incorporate state-of-the-art 
improvements in the geosciences and earthquake engineering and would 
allow uncertainty to be addressed. The commenter further noted that NRC 
had cited its 10 years of experience in reviewing dry cask storage 
installation applications as a reasonable basis for allowing an 
exceedance probability greater than that applied to a nuclear power 
plant, but pointed out that this was 10 years of analytical, not 
practical experience. In the commenter's view, this lack of practical 
experience, and the fact that a probabilistic analysis is, by its very 
nature, risk-informed with respect to uncertainty, means that there 
does not seem to be a quantifiable safety basis for any exceedance 
margin other than that now applied to seismic analysis for nuclear 
power plant proposals. The commenter stated that, absent any definitive 
experience, the seismic design criteria for an ISFSI should be no less 
protective than that of a nuclear power plant.
    Response: The NRC disagrees that new applicants for specific 
licenses should comply with Sec.  100.23 in its entirety, including 
conforming the DE to the SSE criteria. Adopting the recommendation 
would fail to recognize the differences in risk between an NPP and an 
ISFSI or MRS facility in seismic design requirements. This is counter 
to the Commission policy encouraging development of risk-informed, 
performance-based regulations, and the Commission's Performance Goals.
    The NRC acknowledges that actual earthquake performance data for 
ISFSI facilities are not available and thus that NRC's decision to 
allow an exceedance probability greater than that applied to a nuclear 
power plant is not based on practical experience. However, NRC has 
gained sufficient analytical experience to understand the performance 
of these facilities, by reviewing the analyses of these facilities 
performed by the licensees, and by performance of independent analyses. 
Additionally, experience has been gained in the design and construction 
of numerous facilities using the philosophy of a risk-informed approach 
described in the standard building codes, similar to the one proposed 
in the rule for ISFSIs. The risk-informed approach is also used by the 
Department of Energy in designing its facilities for seismic loads with 
risks varying from conventional facilities to NPPs. NRC staff's 
analyses show that ISFSI storage casks are sufficiently robust, due to 
design requirements other than for earthquakes, that there is no 
release of radioactivity at an ISFSI site with a DE at a magnitude 
equal to the SSE for a NPP. This analytical experience provides a basis 
for allowing an exceedance probability greater than that applied to a 
nuclear power plant.

Proposed Change to 10 CFR 72.103

    Comment 10: With respect to the provision in Sec.  72.103(b) that 
sites ``that lie within the range of strong near-field ground motion 
from historical earthquakes on large capable faults should be 
avoided,'' a commenter stated that the definition of ``range of strong 
near-field ground motion'' is not well defined but is often believed to 
be about 15 km. The commenter noted that this is a very large set-back 
from faults. The commenter argued that the key issue is that the design 
ground motion should represent the conditions at the site. If a site is 
located close to a large capable fault, then near-fault effects should 
be incorporated into the design ground motions rather than excluding 
these site locations.
    Response: The NRC agrees with the comment. The sentence: ``Sites 
that lie within the range of strong near-field ground motion from 
historical earthquakes on large capable faults should be avoided.'' has 
been removed from Sec.  72.103(b). Section 72.103(f)(2)(iv) requires an 
evaluation of the effects of vibratory ground motion that may affect 
the design and operation of the proposed ISFSI or MRS. Therefore, near-
fault effects must be included in the development of the ground motion 
used in design.
    Comment 11: One commenter suggested removing the distinction in 
Sec.  72.103 between western U.S. and eastern U.S. The commenter stated 
that the characterization of areas of known seismicity east of the 
Rocky Mountain Front as including three specific areas is misleading. 
The commenter argued that the entire region of the U.S. east of the 
Rocky Mountain Front is subject to earthquake occurrence and that one 
area should not be treated differently from another for the purpose of 
assessing seismic sources. Further, the commenter stated that 10 CFR 
part 100, appendix A, does not allow for less stringent alternatives 
for any area. Rather, the commenter noted, the fundamental requirements 
of that regulation apply uniformly to all regions of the U.S., 
independent of variations in the local rate of seismicity.
    Response: In specifying the criteria for determining the DE, the 
current part 72 regulations distinguish between the western U.S. and 
the eastern U.S. Although the entire eastern U.S. is subject to 
earthquake occurrence, the areas east of the Rocky Mountain Front, 
except in specific areas of known seismic activity, do not experience 
significant seismic activity. Therefore, the use of an appropriate 
seismic response anchored at 0.25 g is considered as bounding for the 
design. However, for the western U.S. there is significant seismic 
activity varying from region to region. Therefore, it is not practical 
to use a bounding approach in specifying the DE for those sites.
    However, if the applicant chooses the option of performing the PSHA 
for a site located in the eastern U.S., as allowed in Sec.  
72.103(a)(2), the seismic sources are assessed with the same rigor as 
the seismic sources for the PSHA performed for a site located in the 
western U.S. (Sec.  72.103(f)). In this case, the regulatory 
requirements of assessing the seismic sources for the PSHA method would 
apply uniformly to all regions of the U.S., independent of variations 
in the local rate of seismicity.
    Comment 12: One commenter suggested inserting the word ``sites'' 
after ``NY'' in the first sentence of Sec.  72.103(a)(1) to be 
consistent with language in Sec.  72.102.
    Response: The NRC agrees with the commenter's suggestion. The word 
``sites'' will be inserted after ``NY'' in the first sentence of Sec.  
72.103(a)(1) to be consistent with language in Sec.  72.102. In 
addition, other minor editorial changes have been made to this 
sentence.

Remove Detailed Guidance From the Regulation

    Comment 13: One commenter stated that removing detailed guidance 
from the regulation that is related to analyzing non-seismic factors 
affecting geologic stability of the site would allow excessive 
discretion for the applicant and would result in too much uncertainty 
for a safety evaluation. This commenter noted that removing 
requirements for specific types of evaluation also removes the 
certainty for both the license applicant and the public as to what is 
expected during a review. The commenter requested retaining appendix A 
of part 100 as requirements for licensing.
    Response: See the response to Comment 1.
    Comment 14: A commenter questioned NRC's statement explaining that 
NRC proposed to remove detailed guidance from the regulation, in part, 
because ``specifying geoscience assessments in detail in a regulation 
has created difficulties for applicants and

[[Page 54152]]

the NRC by inhibiting needed latitude in judgment [and] [i]t has 
inhibited the flexibility needed in applying basic principles to new 
situations.'' This commenter asked for an explanation as to how and 
when latitude and flexibility in judgment and in applying basic 
principles to new situations because geoscience assessments were 
specified in detail in a regulation, were inhibited.
    Response: The current regulation (Sec.  72.102) requires that for 
areas of known potential seismic activity, seismicity will be evaluated 
by the techniques of appendix A to part 100. appendix A contains both 
requirements and guidance on how to satisfy the requirements. For 
example, Section IV, ``Required Investigations,'' of appendix A, states 
that investigations are required for vibratory ground motion, surface 
faulting, and seismically induced floods and water waves. Appendix A 
then provides detailed guidance on what constitutes an acceptable 
investigation. Such investigations require considerable latitude in 
judgment. This latitude in judgment is needed because of limitations in 
data and rapidly evolving state-of-the-art geologic and seismic 
analyses.
    However, having geoscience assessments detailed and cast in a 
regulation has created difficulty for applicants and the NRC in terms 
of inhibiting the use of needed latitude in judgment. Also, it has 
inhibited flexibility in applying basic principles to new situations 
and the use of evolving methods of analyses (for instance, 
probabilistic) in the licensing process.
    As an example, a prescriptive requirement of applying the capable 
fault criteria (see part 100, appendix A, Sec.  III(g)) to sites in 
California meant conducting investigations and analyses for surface 
rupture potential. If a fault does not cause a surface rupture (blind 
fault), the fault would not be considered a capable fault under the 
appendix A criteria, and thus would not be considered in determining 
the DE. This would lead to seismic hazard at a facility which would be 
not conservative. This has been demonstrated by the occurrences of the 
1989 Loma Prieta, 1992 Petrolia, and 1994 Northridge earthquakes during 
which the causative faults did not rupture ground surface. On the other 
hand, the young faults, the last movements of which may satisfy the 
appendix A criteria for classifying them as capable faults, may not be 
capable faults in the true meaning of the criteria because the most 
recent displacements on them may be related to non-tectonic natural 
phenomena. In this case, use of the appendix A criteria would lead to a 
finding of seismic hazard at a facility which would be overly 
conservative. Inclusion of detailed criteria or specific numbers in the 
regulation prevents a scientific evaluation of methodologies and 
approaches that advance with the state of the art, and the rule 
eventually becomes a hindrance to the exercise of rational judgement.

Address Uncertainties and Use Probabilistic Methods

    Comment 15: A commenter urged revision of Sec.  72.103 to continue 
to allow an applicant located in the western U.S. or in areas of known 
seismic activity in the eastern U.S., and not co-located with an NPP, 
to use a deterministic analysis similar to the analysis specified in 
appendix A to 10 CFR part 100, for developing design earthquake ground 
motions because a utility may decide to perform seismic hazards 
analysis on deterministic bases that are more conservative than the 
proposed rule.
    Response: In using the deterministic approach for determining a SSE 
for a nuclear reactor site embodied in appendix A to 10 CFR part 100, 
there have often been differences of opinion and differing 
interpretations among experts as to the largest earthquakes to be 
considered and ground-motion models to be used. This often makes the 
licensing process relatively unstable. Over the past decade, analysis 
methods for incorporating these different interpretations have been 
developed and used. These ``probabilistic'' methods have been designed 
to allow explicit incorporation of different models for zonation, 
earthquake size, ground motion, and other parameters. The advantage of 
using these probabilistic methods is the ability to incorporate 
different models and different data sets and weight them using 
judgments as to the validity of the different models and data sets. 
This process provides an explicit expression for the uncertainty in the 
ground motion estimates and a means of assessing sensitivity to various 
input parameters.
    Section 72.103 explicitly recognizes that there are inherent 
uncertainties in establishing the seismic and geologic design 
parameters and requires the use of a probabilistic seismic hazard 
methodology capable of propagating uncertainties to address these 
uncertainties. The rule further recognizes that the nature of 
uncertainty and the appropriate approach to account for it depend 
greatly on the tectonic regime and parameters, such as the knowledge of 
seismic sources, the existence of historical and recorded data, and the 
understanding of tectonics. Therefore, methods other than the 
probabilistic methods, such as sensitivity analyses, may be adequate 
for some sites to account for uncertainties.
    Consistent with Sec.  100.23 for an NPP, Sec.  72.103 does not 
allow the use of the deterministic methods in appendix A to 10 CFR part 
100, to determine the DE because the deterministic methods do not 
account for the uncertainties in the seismic hazard analysis. However, 
Sec.  72.103 allows the applicant to use methods other than the 
probabilistic methods, such as sensitivity analyses, to account for 
uncertainties. Additionally, Sec.  72.103 allows a utility applying for 
a specific license for an ISFSI co-located at an NPP, the option of 
using the seismic design criteria of the NPP, which may be based on the 
deterministic methods of appendix A to 10 CFR part 100.
    For these reasons, the NRC declines to amend Sec.  72.103 as 
suggested by the commenter. However, a utility applying for a specific 
license for an ISFSI co-located at an NPP has the option of using the 
seismic design criteria of the NPP.
    Comment 16: A commenter stated that the use of the term 
``uncertainty'' in the Background section of the proposed rule (67 FR 
47746) is ambiguous, and suggested that the term be revised to 
``aleatory uncertainty''. The commenter stated that the report 
``Recommendations for Probabilistic Seismic Hazard Analysis: Guidance 
on Uncertainty and Use of Experts,'' NUREG/CR-6372 (SSHAC), 
distinguishes between ``aleatory'' and ``epistemic'' uncertainties. The 
deterministic approach can explicitly recognize epistemic uncertainty 
just as in the probabilistic approach. The deterministic approach does 
not explicitly include all components of aleatory variability. The 
commenter noted that sensitivity analyses are generally intended for 
addressing epistemic uncertainty, not aleatory variability.
    Response: Despite extensive advances in seismic knowledge in recent 
years by a large and active community of researchers around the world, 
there are still major gaps in the understanding of the mechanisms that 
cause earthquakes. These gaps in understanding mean that in any seismic 
hazard analysis, either deterministic or probabilistic, there are 
inevitably significant uncertainties in the numerical results. These 
uncertainties can be classified into two different categories: (1) 
epistemic uncertainty which is due to lack of knowledge because the 
scientific understanding is imperfect for the

[[Page 54153]]

present, but is of a character that in principle is reducible through 
further research; and (2) aleatory uncertainty which is due to the 
randomness of seismic events and, in principle, cannot be reduced. As 
stated in the SSHAC report, ``The division between the two different 
types of uncertainty, epistemic and aleatory, is somewhat arbitrary, 
especially at the border between the two. This is because, 
conceptually, some of the processes and parameters whose uncertainties 
the NRC will characterize here as aleatory (``random'') may be 
partially reducible through more elaborate models and/or further 
study''. As stated further in the SSHAC report, ``the PSHA that does 
not deal appropriately with both the epistemic and the aleatory 
uncertainties must be considered inadequate.'' Based on this, the term 
``uncertainty'' included in the proposed rule is appropriate.

Revise the Design Earthquake Ground Motion

    Comment 17: A commenter stated that performance standards are not 
clearly articulated in the proposed rule. The commenter also stated 
that before the design standard is lowered, the performance standards 
or goals by which the proposed changes were evaluated should first be 
identified.
    Response: The current regulations in Sec.  72.122(b)(2)(i) require 
that the structures, systems, and components of an ISFSI or MRS must be 
designed to withstand the effects of natural phenomena, such as 
earthquakes, without impairing their capability to perform their 
intended design functions. For earthquakes, these requirements are then 
supplemented by the Sec. Sec.  72.102 and 72.103 requirements for the 
detailed site investigations and consideration of uncertainties in the 
prediction of earthquakes. This approach is consistent with the 
Commission's philosophy of using risk-informed, performance-based 
regulations. In a risk-informed, performance-based approach, the design 
of the facility is based on considering the risk (potential for adverse 
consequences) due to an earthquake.
    Comment 18: One commenter is concerned that lowering the existing 
DE may result in a concomitant lowering of the design basis for 
locally-sourced tsunamis. The commenter is concerned because the most 
likely scenario for release of radiation in a coastal setting would be 
damage to an ISFSI or MRS during a major earthquake, followed by 
inundation of the facility by a tsunami.
    Response: Section 72.103(f)(1) requires consideration of actual or 
potential geologic and seismic effects at the proposed site, including 
locally-sourced tsunamis. Potential inundation of the facility by a 
tsunami is required to be addressed in the design of the facility under 
Sec.  72.122(b)(2). Under the amended rule, the tsunami magnitudes 
corresponding to the DE would be lower than for a nuclear power plant. 
However, an earthquake similar in magnitude to the SSE for an NPP would 
not damage an ISFSI or MRS facility, thus no release of radioactivity 
would occur even if the facility were inundated by a resulting locally-
sourced tsunami.
    Comment 19: A commenter stated that in order to issue a coastal 
development permit in California the State or a local government must 
make a finding that the proposed ISFSI will minimize risks to life and 
property in areas of high geologic hazard, and assure stability and 
structural integrity of the proposed coastal development. The commenter 
noted that, for the San Onofre Nuclear Generating Station (SONGS) 
ISFSI, the required finding was able to be made by the State only 
because the applicant proposed a seismic design standard far in excess 
of the SSE for the co-located NPP. The commenter indicated that such a 
finding may not be possible at future ISFSI sites if the applicant 
submits a design standard lower than those required for an NPP. The 
commenter stated that the proposed rule change makes approval of 
coastal development permits in California for future ISFSIs difficult 
at best.
    Response: The NRC sees no reason why the rule would make this 
finding difficult. The rule ensures adequate protection of public 
health and safety in all environs. The close proximity of faults or 
populations are considered in the regulations (for example, the dose 
requirements contained in Sec. Sec.  72.104(a) and 72.106(b)). Applying 
a risk-informed approach to seismic design of ISFSIs takes these 
factors into account and the analyses indicate that protection of 
public health and safety are adequately addressed.

Proposed Change to 10 CFR 72.212(b)(2)(i)(B)

    Comment 20: Two commenters noted that although the proposed change 
to 10 CFR 72.212(b)(2)(i)(B) to require that the cask storage pads and 
areas be designed to adequately support dynamic loads, as well as 
static loads, of the stored casks, may require more analytical effort 
than the static load evaluations that some licensees had attempted to 
utilize in the past, they find the new requirements to be technically 
correct and support the concept that the seismic evaluation should be 
conducted using state-of-the-art structural dynamics principles, 
including consideration of dynamic loads. One commenter had no 
objection to the portion of the proposed rule that would require design 
of cask storage pads and areas to adequately account for dynamic loads. 
Another commenter stated that requiring this evaluation for storage 
pads and areas clearly improves the assurance of safety.
    Response: The commenters support the NRC's decision to require 
evaluation of dynamic loads for storage cask pads and areas. Further, 
general licensees currently consider dynamic loads for evaluating the 
casks, pads and areas to meet the cask design bases in the Certificate 
of Compliance, as required by 10 CFR 72.212(b)(2)(i)(A); therefore, the 
rule change will not actually impose a new burden on the general 
licensees.

Related Regulatory Guide

    Comment 21: A commenter stated that Draft Regulatory Guide DG-3021 
``is short on firm standards'' because, although it recommends a DE at 
a MAPE of 5E-4, it also allows an applicant to demonstrate that the use 
of a higher probability of exceedance value would not impose any undue 
radiological risk to public health and safety. Thus, the draft 
guidance, in the commenter's view, ``leaves open the possibility of an 
even lower standard for seismic sites.'' Another commenter defends the 
guidance that an applicant could propose a higher probability of 
exceedance value as being an exemption to what the commenter sees as 
the norm being established in DG-3021.
    Response: Section 72.103(f)(2)(i) of the rule requires that an 
applicant include a determination of the DE for the site, considering 
the results of the investigations required by paragraph (f)(1) and 
addressing uncertainties through an appropriate analysis, such as a 
PSHA or suitable sensitivity analyses. Regulatory Guide 3.73 (formerly 
DG-3021) states that a mean annual probability of exceeding the DE of 
5E-4 is recommended to be used in conjunction with the PSHA for 
determining the DE. As the commenter notes, the draft guidance also 
indicated that ``[t]he use of a higher reference probability will be 
reviewed and accepted on a case-by-case basis.'' This statement was 
made in recognition of the fact that a regulatory guide does not 
establish legally-binding requirements. An alternative reference 
probability would not be an exemption from a requirement, but would be 
an alternative proposal which would need to be demonstrated to be 
acceptable. Thus, it is conceivable that an applicant could propose a 
higher MAPE value that the NRC staff would then have to consider. 
Although this is necessarily

[[Page 54154]]

the case for recommendations suggested in guidance documents, the NRC 
did not mean to imply that it viewed an applicant's ability to make the 
necessary safety case for a higher MAPE as being a likely prospect. To 
avoid any such implication, that sentence has been removed from the 
final guidance.
    Comment 22: One commenter stated that a DE at a MAPE of 5E-4 (2,000 
year return period) is not defensible. The commenter said that there 
are numerous standards that already use a DE at a MAPE of 4E-4 (2,500 
year return period), including DOE Standard 1020-2000. The commenter 
noted that DOE's standard is inextricably tied to meeting performance 
and risk goals. Further, the commenter indicated that certain 
buildings, such as hospitals, must meet a DE at a MAPE of 4E-4 (2,500 
year return period), as must interstate bridges in the State of Utah. 
The commenter stated that, at a minimum, a standard lower than these 
cannot be adopted.
    Response: The NRC disagrees with the commenter that the proposed 
standard for the DE at a MAPE of 5E-4 (2,000 year return period) is 
lower than the DOE Standard DOE-STD-1020-2002, or the other standards, 
such as the International Building Code (IBC-2000 Code).
    According to the DOE Standard DOE-STD-1020-2002, ISFSIs can be 
classified as Performance Category 3 (PC-3) facilities. For PC-3 
facilities, the seismic design forces for the DE are initially 
determined at 90 percent of the DE at a MAPE of 4E-4 (2,500 years 
return period). This brings the DE levels to approximately a MAPE of 
5E-4 (2,000 year return period), specified in the earlier DOE 1020 
standard, DOE-STD-1020-94. The Foreword of the DOE-STD-1020-2002 
explains the change in the return period as follows:
    ``It is not the intent of this revision to alter the methodology 
for evaluating PC-3 facilities, nor to increase the performance goal of 
PC-3 facilities, by increasing return period for the PC-3 from a 2,000-
year earthquake to a 2,500-year earthquake. Rather, the intention is 
more for convenience to provide a linkage from the NEHRP maps and DOE 
Standards.''
    Therefore, use of the reference probability of 5E-4/yr (2,000 year 
return period), for the ISFSI or MRS facility DE, would be consistent 
with that used in the DOE Standard DOE-STD-1020, for similar type 
facilities.
    For the IBC-2000 Code, the commenter is incorrectly comparing the 
ISFSI or MRS DE at a MAPE of 5E-4 (2,000 year return period), with the 
Maximum Considered Earthquake (MCE) at a MAPE of 4E-4 (2,500 year 
return period). The DE, according to the IBC-2000 Code, is two-thirds 
of the MCE, which is equivalent to a DE at a MAPE of 1.1E-3 (909 year 
return period) earthquake in the western United States, and a DE at a 
MAPE of 7E-4 (1,430 year return period) in the eastern United States. 
Thus, the DE for the ISFSI or MRS facility included in DG-3021 at a 
MAPE of 5E-4 is greater than the IBC Code DE design level.
    The NRC agrees that hospital building structures and bridges having 
critical national defense functions are designed for the DE at a MAPE 
of 4E-4 (2,500 year return period). These structures are generally 
occupied by a significant number of people. Therefore, these structures 
are designed for loads greater than those for traditional buildings to 
limit building deformations, and to minimize human losses due to an 
earthquake. The ISFSI or MRS facility, on the other hand, has a 
relatively small number of people occupying the Canister Transfer 
Building at any one time.
    Comment 23: A commenter requested that the regulatory guide specify 
a DE at a MAPE of 1E-4 (10,000 year return period), consistent with the 
requirement for NPPs. This commenter believes that meeting NPP 
standards would be easier at an ISFSI or MRS due to the relative 
simplicity of construction and robust character of the structures as 
compared to an NPP.
    Response: The NRC disagrees with the commenter and believes that 
the proposed DE at a MAPE of 5E-4 (2,000 year return period) for an 
ISFSI or MRS facility is adequate for protecting public health and 
safety. The seismically induced risk from the operation of an ISFSI or 
MRS is less than from the operation of an NPP, and based on the review 
of the current seismic design practice, the proposed DE design level is 
reasonable and consistent with the NRC's policy of risk-informed, 
performance-based regulations. Details of the NRC's review for the 
proposed DE level are provided in the report, ``Selection of Design 
Earthquake Ground Motion Reference Probability''. This report may be 
accessed through the NRC's Public Electronic Reading Room on the 
Internet at http://www.nrc.gov/reading-rm/adams.html. If you do not 
have access to ADAMS or if there are problems in accessing the 
documents located in ADAMS, contact the NRC's PDR reference staff at 1-
800-397-4209, 301-415-4737, or by email to [email protected].
    The NRC agrees with the commenter that the cask structure is simple 
in construction and robust in character resulting from the design 
considerations other than earthquake effects. Earthquake loads and the 
DE level would not govern the cask design. However, this is not the 
case in the design and stability evaluation of other ISFSI or MRS 
facility structures, systems, and components, such as the concrete pad, 
foundation, and the canister transfer building. Designs of these 
structures, systems, and components depend on the DE level. Further, 
because of the inherent safety margins in the design criteria in NUREG-
1536 and NUREG-1567, the structures, systems, and components designed 
for a DE at a MAPE of 5E-4 (2,000 year return period) would be able to 
withstand a DE at a MAPE of 1E-4 (10,000 year return period consistent 
with the NPP requirements) without impairing the ability to meet the 
Part 72 dose limits for protecting public health and safety. Therefore, 
it is an unnecessary burden on the applicant to require the ISFSI or 
MRS facility to design for a DE at a level consistent with NPP 
requirements.
    Comment 24: Two commenters stated that the seismic design standard 
(MAPE of 5E-4 (2,000 year return period)) is less protective than the 
seismic standard for municipal solid waste landfills in California 
(maximum credible earthquake (MCE) of 4E-4 (2,500 year return period)), 
and the International Building Code (MCE of 4E-4 (2,500 year return 
period)), both of which are more stringent than the proposed rule. One 
commenter is concerned that a DE at a MAPE of 5E-4 (2,000 year return 
period) may not provide an adequate margin of safety to protect the 
public.
    However, two other commenters stated that the rigor of the seismic 
evaluation criteria and the conservatism of the seismic design 
requirements significantly exceed those in modern conventional building 
codes. One of the commenters stated that the annual probability of 
unacceptable seismic performance for a dry cask ISFSI designed to a DE 
at a MAPE of 5E-4 (2,000 year return period) will be substantially less 
than that of an essential or hazardous facility designed to the modern 
conventional building code for which the DE was established at 67 
percent of the MCE of 4E-4. Another commenter stated that the level of 
safety for a dry cask storage facility designed to a DE at a MAPE of 
5E-4 (2,000 year return period) provides at least twice the level of 
safety attained by facilities designed under the International Building 
Code.
    Response: The NRC disagrees with the commenters that the seismic 
design standard (MAPE of 5E-4) is less protective than the seismic 
standard for

[[Page 54155]]

municipal solid waste landfills in California (Code of Regulations 
Section 66264.25(b), and the International Building Code--2000 (IBC-
2000). The California standard requires the municipal waste landfills 
to be designed to withstand the maximum credible earthquake (MAPE of 
4E-4) of the IBC-2000 without decreasing the level of public health and 
environmental protection. The cask and the cask transfer building at an 
ISFSI or MRS facility, designed to a DE at a MAPE of 5E-4, has the 
capacity to withstand earthquakes of greater magnitude than the one 
associated with the MAPE of 4E-4. This is because of the conservatism 
in the seismic evaluation criteria and of NRC's NUREG-1536 and NUREG-
1567, which significantly exceed those in modern conventional building 
codes. Additionally, the risk of the ISFSI or MRS facility to public 
health and safety is lower than the risk for hazardous waste and 
municipal solid waste landfills because the spent nuclear fuel is 
contained within a sealed steel cask in an isolated facility away from 
the public, with a controlled boundary at a minimum distance of 100 m. 
Landfills, on the other hand, may be open and in close proximity to 
public areas.
    Comment 25: Three commenters stated that the proposed rule provided 
no basis or quantitative analysis to justify lowering the DE to any 
particular value. One of these commenters indicated that absent any 
quantitative evidence justifying a particular value, the conservative, 
precautionary approach of requiring ISFSIs and MRSs to meet the same 
design standard as a nuclear power plant is most appropriate. One of 
these commenters noted that the adequacy of the MAPE should be 
addressed with respect to the change in the DE. The commenter stated 
that this could be addressed by using the higher proposed MAPE versus 
what is currently required and then determining if the change in the 
level of risk of a release is significant or not.
    Response: The DE level proposed in the draft regulatory guide was 
selected based on the fact that the ISFSI or MRS risk is lower than 
that of an NPP and on the fact that this level is consistent with the 
hazard levels used in the nuclear industry for similar facilities. 
Details of the NRC's analyses for establishing the DE level are 
provided in the report, ``Selection of Design Earthquake Ground Motion 
Reference Probability''. This report may be accessed through the NRC's 
Public Electronic Reading Room on the Internet at http://www.nrc.gov/reading-rm/adams.html. If you do not have access to ADAMS or if there 
are problems in accessing the documents located in ADAMS, contact the 
NRC's PDR reference staff at 1-800-397-4209, 301-415-4737, or by email 
to [email protected].
    Comment 26: Two commenters strongly endorsed the proposal to lower 
the DE. The commenters stated that the DE provided in the draft 
regulatory guide at a MAPE of 5E-4 (2,000 year return period) provides 
a level of relief in establishing the DE that is completely consistent 
with the risk-informed regulation policy and is an excellent example of 
the application of the policy. One commenter stated that the philosophy 
of applying a graded approach to seismic design requirements for 
facilities of differing risks has been in existence for more than 30 
years. The commenter described DOE's approach for seismic design 
requirements for DOE facilities, which span a range of potential risks. 
The commenter went on to state that based on the amount of radioactive 
material stored in a large dry cask ISFSI, the resulting classification 
using the DOE approach would result in a design standard with a MAPE of 
5E-4. The commenter stated that considering the minor radiological 
consequences from a single canister failure and a lack of a credible 
mechanism to cause such a failure from a seismic event would suggest 
that this design criteria level is more than adequately conservative 
for a dry cask ISFSI.
    Response: The commenters support the NRC's recommendation of the 
seismic design earthquake level to a MAPE of 5E-4 (2,000 year return 
period).

Finding of No Significant Environmental Impact: Availability

    Comment 27: Three commenters challenged the assertion that the NRC 
has considerable experience in licensing dry cask storage systems and 
analyzing cask behavior. One commenter noted that the NRC has licensed 
only four ISFSIs in the western U.S., the most seismically active part 
of the country, and none as close to major plate-boundary faults as the 
three planned for coastal California. The commenters also said that 
analytical experience in licensing does not equate with practical 
experience. One commenter stated that this will only be achieved when 
an ISFSI experiences strong ground motions as a result of a major 
earthquake. As a result, the commenter believes that neither the 
specific nor general licenses issued have been tested.
    Response: As discussed in the NRC response to Comment 4, cask 
stability can be evaluated with adequate reliability by using non-
linear dynamic analyses because the concept of free-standing structures 
is not a new one. One does not need to test all structures prior to 
using them, provided structures are simple and can be reliably 
analyzed.

Regulatory Analysis

    Comment 28: A commenter noted that the proposed changes impose no 
new burdens on establishing the DE for an ISFSI over the current 
requirements in 10 CFR part 72.
    Response: The NRC's analysis actually indicates that there would be 
an overall reduction in the total burden placed on licensees from these 
changes. The estimate of values and impacts to a specific-license 
applicant indicates additional costs of $100,000 for addressing 
uncertainties in seismic hazard analysis. In some cases, ISFSI 
specific-license applicants have sought exemptions from the design 
requirements contained in Sec.  72.102, considering site 
characteristics and other factors. The rule would reduce or eliminate 
the need for these exemption requests by reducing the DE level for 
certain structures, systems, and components, resulting in a savings of 
$150,000 per license applicant. Further, no structures, systems, and 
components would be required to be designed to withstand a DE at a MAPE 
of 1E-4 (equivalent to the SSE of an NPP), resulting in lower 
analytical and certain capital costs. The overall effect of the rule 
would be a cost savings to new specific-license applicants. However, 
the amount of these savings is highly site-specific, depending on site 
characteristics and the specified DE level.
    Finally, the rule will change Sec.  72.212(b)(2)(i)(B) to require 
written evaluations, prior to use, establishing that cask storage pads 
and areas have been evaluated for the static and dynamic loads of the 
stored casks. There are no additional costs associated with evaluating 
cask pads and areas for dynamic loads because general licensees are 
already required to consider dynamic loads to meet the cask design 
basis of the Certificate of Compliance under Sec.  72.212(b)(i)(A).

VII. Summary of Final Revisions

    This final rule will make the following changes to 10 CFR part 72:

Section 72.9 Information collection requirements: OMB approval

    In Sec.  72.9, the list of sections where approved information 
collection requirements appear is amended to add Sec.  72.103.

[[Page 54156]]

Section 72.102 Geological and seismological characteristics (Current 
Heading)

Section 72.102 Geological and seismological characteristics for 
applications before October 16, 2003 and applications for other than 
dry cask modes of storage (New Heading)

    The heading of Sec.  72.102 is revised because Sec.  72.103 is 
added for ISFSI or MRS applications after the effective date of the 
rule. Section 72.103 will only apply to dry cask modes of storage. 
Therefore, the heading of Sec.  72.102 is being modified to show the 
revised applicability of this section. The requirements of Sec.  72.102 
will continue to apply for an ISFSI or MRS using wet modes of storage 
or dry modes of storage that do not use casks.
    The NRC does not intend for existing part 72 licensees to re-
evaluate the geological and seismological characteristics for siting 
and design using the revised criteria in the changes to the 
regulations. These existing facilities are considered safe because the 
criteria used in their evaluation have been determined to be safe for 
NPP licensing, and the seismically induced risk of an ISFSI or MRS is 
significantly lower than that of an NPP. The change leaves the current 
Sec.  72.102 in place to preserve the licensing bases of present 
ISFSIs.

Section 72.103 Geological and seismological characteristics for 
applications for dry cask modes of storage on or after October 16, 2003

    The trend towards dry cask storage has resulted in the need for 
applicants for new licenses to request exemptions from Sec.  
72.102(f)(1), which requires that for sites evaluated under the 
criteria of Appendix A to Part 100, the DE must be equivalent to the 
SSE for an NPP. By making Sec.  72.102 applicable only to existing 
ISFSIs and by providing a new Sec.  72.103, the revised rule is 
intended to preclude the need for exemption requests from new specific-
license applicants.
    The new requirements in Sec.  72.103 parallel the requirements in 
Sec.  72.102. However, new specific-license applicants for sites 
located in either the western U.S. or in the eastern U.S. in areas of 
known seismic activity, and not co-located with an NPP, for dry cask 
storage applications, on or after the effective date of this rule, will 
be required to address the uncertainties in seismic hazard analysis by 
using a PSHA or sensitivity analyses instead of using the deterministic 
methods of Appendix A to Part 100 without sensitivity analyses. 
Applicants located in either the western U.S. or in areas of known 
seismic activity in the eastern U.S., and co-located with an NPP, have 
the option of using the PSHA methodology or suitable sensitivity 
analyses for determining the DE, or using the existing design criteria 
for the NPP. This change to require an understanding of the 
uncertainties in the determination of the DE will make the regulations 
compatible with 10 CFR 100.23 for NPPs and will allow the geological 
and seismological criteria for ISFSI or MRS dry cask storage facilities 
to be risk-informed.
    New Sec.  72.103(a)(1) provides that sites located in eastern U.S. 
and not in areas of known seismic activity, will be acceptable if the 
results from onsite foundation and geological investigation, literature 
review, and regional geological reconnaissance show no unstable 
geological characteristics, soil stability problems, or potential for 
vibratory ground motion at the site in excess of an appropriate 
response spectrum anchored at 0.2 g. Section 72.103(a)(1) will parallel 
the requirements currently included in Sec.  72.102(a)(1).
    New Sec.  72.103(a)(2) provides that applicants conducting 
evaluations in accordance with Sec.  72.103(a)(1) may use a 
standardized DE described by an appropriate response spectrum anchored 
at 0.25 g. These requirements parallel the requirements currently 
included in Sec.  72.102(a)(2). Section 72.102(a)(2) provides an 
alternative to determine a site-specific DE using the criteria and 
level of investigations required by Appendix A to Part 100. New Sec.  
72.103(a)(2) also provides, as an alternative, that a site-specific DE 
may be determined by using the criteria and level of investigations in 
new Sec.  72.103(f). Section 72.103(f) is a new provision that requires 
certain new ISFSI or MRS license applicants to address uncertainties in 
seismic hazard analysis by using appropriate analyses, such as a PSHA 
or suitable sensitivity analyses, in determining the DE instead of the 
current deterministic approach in Appendix A to Part 100.
    New Sec.  72.103(a)(2) also provides that if an ISFSI or MRS is 
located at an NPP site, the existing geological and seismological 
design criteria for the NPP may be used instead of PSHA techniques or 
suitable sensitivity analyses because the risk due to a seismic event 
at an ISFSI or MRS is less than that of an NPP. If the existing design 
criteria for the NPP is used and the site has multiple NPPs, then the 
criteria for the most recent NPP must be used to ensure that the 
seismic design criteria used is based on the latest seismic hazard 
information at the site.
    New Sec.  72.103(b) provides that applicants for licenses for sites 
located in either the western U.S. or in the eastern U.S. in areas of 
known seismic activity, must investigate the geological, seismological, 
and engineering characteristics of the site using the PSHA techniques 
or suitable sensitivity analyses of new Sec.  72.103(f). If an ISFSI or 
MRS is located at an NPP site, the existing geological and 
seismological design criteria for the NPP may be used instead of PSHA 
techniques or suitable sensitivity analyses because the risk due to a 
seismic event at an ISFSI or MRS is less than that of an NPP. If the 
existing design criteria for the NPP is used and the site has multiple 
NPPs, then the criteria for the most recent NPP must be used to ensure 
that the seismic design criteria used is based on the latest seismic 
hazard information at the site.
    New Sec.  72.103(c) is identical to Sec.  72.102(c). Section 
72.103(c) requires that sites, other than bedrock sites, must be 
evaluated for the liquefaction potential or other soil instability due 
to vibratory ground motion. This is to ensure that an ISFSI or MRS will 
be adequately supported on a stable foundation during a seismic event.
    New Sec.  72.103(d) is identical to Sec.  72.102(d). Section 
72.103(d) requires that site specific investigation and laboratory 
analysis must show that soil conditions are adequate for the proposed 
foundation loading. This is to ensure that an ISFSI or MRS will be 
adequately supported on a stable foundation during a seismic event.
    New Sec.  72.103(e) is identical to Sec.  72.102(e). Section 
72.103(e) requires that in an evaluation of alternative sites, those 
which require a minimum of engineered provisions to correct site 
deficiencies are preferred, and that sites with unstable geologic 
characteristics should be avoided. This is to ensure that sites with 
minimum deficiencies are selected and that an ISFSI or MRS will be 
adequately supported on a stable foundation during a seismic event.
    New Sec.  72.103(f) describes the steps required for seismic hazard 
analysis to determine the DE for use in the design of structures, 
systems, and components of an ISFSI or MRS. The scope of site 
investigations to determine the geological, seismological, and 
engineering characteristics of a site and its environs is similar to 
Sec.  100.23 requirements. Unlike Sec.  72.102(f), which requires the 
use of the deterministic method of Appendix A to Part 100, new Sec.  
72.103(f) requires evaluating uncertainty in seismic hazard analysis

[[Page 54157]]

by using a probabilistic method, such as the PSHA, or suitable 
sensitivity analyses, similar to Sec.  100.23 requirements for an NPP.
    New Sec.  72.103(f)(1) requires that the geological, seismological, 
and engineering characteristics of a site and its environs must be 
investigated in sufficient scope and detail to permit an adequate 
evaluation of the proposed site and to determine the DE. These 
requirements track existing requirements in Sec.  100.23(c).
    New Sec. Sec.  72.103(f)(2)(i) through (iv) specify criteria for 
determining the DE for the site, the potential for surface tectonic and 
nontectonic deformations, the design basis for seismically induced 
floods and water waves, and other design conditions. In particular, 
Sec.  72.103(f)(2)(i) provides that a specific-license applicant must 
address uncertainties in seismic hazard analysis by using appropriate 
analyses, such as a PSHA or suitable sensitivity analyses, for 
determining the DE. Sections 72.103(f)(2)(ii) through (iv) track the 
corresponding requirements in Sec.  100.23(d).
    Finally, the new Sec.  72.103(f)(3) provides that regardless of the 
results of the investigations anywhere in the continental U.S., the DE 
must have a value for the horizontal ground motion of no less than 0.10 
g with the appropriate response spectrum. This provision is identical 
to the requirement currently included in Sec.  72.102(f)(2).

Section 72.212 Conditions of general license issued under Sec.  72.210

    Section 72.212(b)(2)(i)(B) is revised to require general licensees 
to address the dynamic loads of the stored casks in addition to the 
static loads. The requirements are changed because during a seismic 
event the cask experiences dynamic inertia loads in addition to the 
static loads, which are supported by the concrete pad. The dynamic 
loads depend on the interaction of the casks, the pad, and the 
foundation. Consideration of the dynamic loads, in addition to the 
static loads, of the stored casks will ensure that the pad would 
perform satisfactorily during a seismic event.
    The new paragraph also requires consideration of potential 
amplification of earthquakes through soil-structure interaction, and 
soil liquefaction potential or other soil instability due to vibratory 
ground motion. Depending on the properties of soil and structures, the 
free-field earthquake acceleration input loads may be amplified at the 
top of the storage pad. These amplified acceleration input values must 
be bound by the design bases seismic acceleration values for the cask, 
specified in the Certificate of Compliance. Liquefaction of the soil 
and instability during a vibratory motion due to an earthquake may 
affect the cask stability, and thus must be addressed.
    The changes to Sec.  72.212 are intended to require that general 
licensees perform appropriate load evaluations of cask storage pads and 
areas to ensure that casks are not placed in an unanalyzed condition. 
Similar requirements currently exist in Sec.  72.102(c) for an ISFSI 
specific license and are now in Sec.  72.103(c).

VIII. Criminal Penalties

    For the purpose of Section 223 of the Atomic Energy Act (AEA), the 
Commission is issuing this final rule to amend 10 CFR Part 72 under one 
or more of sections 161b, 161i, or 161o of the AEA. Willful violations 
of the rule will be subject to criminal enforcement.

IX. Agreement State Compatibility

    Under the ``Policy Statement on Adequacy and Compatibility of 
Agreement State Programs'' approved by the Commission on June 30, 1997, 
and published in the Federal Register on September 3, 1997 (62 FR 
46517), this rule is classified as Compatibility Category ``NRC.'' 
Compatibility is not required for Category ``NRC'' regulations. The NRC 
program elements in this category are those that relate directly to 
areas of regulation reserved to the NRC by the AEA of 1954, as amended 
(AEA), or the provisions of Title 10 of the Code of Federal 
Regulations. Although an Agreement State may not adopt program elements 
reserved to the NRC, it may wish to inform its licensees of certain 
requirements via a mechanism that is consistent with the particular 
State's administrative procedure laws, but does not confer regulatory 
authority on the State.

X. Voluntary Consensus Standards

    The National Technology Transfer Act of 1995 (Pub. L. 104-113) 
requires that Federal agencies use technical standards that are 
developed or adopted by voluntary consensus standards bodies unless the 
use of such a standard is inconsistent with applicable law or otherwise 
impractical. In this final rule, the NRC is presenting amendments to 
its regulations in 10 CFR part 72 for the geological and seismological 
criteria of a dry cask independent spent fuel storage facility to make 
them commensurate with the risk of the facility. This action does not 
constitute the establishment of a standard that establishes generally 
applicable requirements.

XI. Finding of No Significant Environmental Impact: Availability

    The Commission has determined under the National Environmental 
Policy Act of 1969, as amended, and the Commission's regulations in 
Subpart A of 10 CFR part 51, that this rule is not a major Federal 
action significantly affecting the quality of the human environment and 
therefore an environmental impact statement is not required.
    The Commission concluded, based on an environmental assessment, 
that no significant environmental impact would result from this 
rulemaking. In comparison with an NPP, an operating ISFSI or MRS is a 
passive facility in which the primary activities are waste receipt, 
handling, and storage. An ISFSI or MRS does not have the variety and 
complexity of active systems necessary to support an operating NPP. 
After the spent fuel is in place, an ISFSI or MRS is essentially a 
static operation and, during normal operations, the conditions required 
for the release and dispersal of significant quantities of radioactive 
materials are not present. There are no high temperatures or pressures 
present during normal operations or under design basis accident 
conditions to cause the release and dispersal of radioactive materials. 
This is primarily due to the low heat generation rate of spent fuel 
after it has decayed for more than one year before storage in an ISFSI 
or MRS and the low inventory of volatile radioactive materials readily 
available for release to the environs. The long-lived nuclides present 
in spent fuel are tightly bound in the fuel materials and are not 
readily dispersible. The short-lived volatile nuclides, such as I-131, 
are no longer present in aged spent fuel stored at an ISFSI or MRS. 
Furthermore, even if the short-lived nuclides were present during an 
event of a fuel assembly rupture, the canister surrounding the fuel 
assemblies would confine these nuclides.
    The standards in part 72 Subparts E ``Siting Evaluation Factors,'' 
and F ``General Design Criteria,'' ensure that the dry cask storage 
designs are very rugged and robust. The casks must maintain structural 
integrity during a variety of postulated non-seismic events, including 
cask drops, tip-over, and wind driven missile impacts. These non-
seismic events challenge cask integrity significantly more than seismic 
events. Therefore, the casks have substantial design margins to 
withstand

[[Page 54158]]

forces from a seismic event greater than the design earthquake.
    Hence, the seismically induced radiological risk associated with an 
ISFSI or MRS is less than the risk associated with an NPP.
    The determination of the environmental assessment is that there 
will be no significant environmental impact due to the rule changes 
because the same level of safety would be maintained by the new 
requirements, taking into account the lesser risk from an ISFSI or MRS. 
The NRC requested public comments on the environmental assessment for 
this rule.

XII. Paperwork Reduction Act Statement

    This final rule amends information collection requirements that are 
subject to the Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq). 
These requirements were approved by the Office of Management and 
Budget, approval number 3150-0132.
    Because the rule will reduce existing information collection 
requirements, the public burden for these information collections is 
expected to be decreased by 55 hours per licensee. This reduction 
includes the time required for reviewing instructions, searching 
existing data sources, gathering and maintaining the data needed and 
completing and reviewing the information collection. Send comments on 
any aspect of these information collections, including suggestions for 
further reducing the burden, to the Records Management Branch (T-6 E6), 
U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by 
Internet electronic mail at [email protected]; and to the Desk 
Officer, Office of Information and Regulatory Affairs, NEOB-10202, 
(3150-0132), Office of Management and Budget, Washington, DC 20503.

Public Protection Notification

    The NRC may not conduct or sponsor, and a person is not required to 
respond to a request for information or an information collection 
requirement unless the requesting document displays a currently valid 
OMB control number.

XIII. Regulatory Analysis

    The Commission has prepared a Regulatory Analysis (RA) entitled: 
``Regulatory Analysis of Geological and Seismological Characteristics 
for Design of Dry Cask Independent Spent Fuel Storage Installations.'' 
The RA examines the costs and benefits of the alternatives considered 
by the Commission. The RA may be accessed through the NRC's Public 
Electronic Reading Room on the Internet at http://www.nrc.gov/reading-rm/adams.html. If you do not have access to ADAMS or if there are 
problems in accessing the documents located in ADAMS, contact the NRC's 
PDR reference staff at 1-800-397-4209, 301-415-4737, or by email to 
[email protected].

XIV. Regulatory Flexibility Certification

    In accordance with the Regulatory Flexibility Act of 1980 (5 U.S.C. 
605(b)), the Commission certifies that this rule does not have a 
significant economic impact on a substantial number of small entities. 
This rule affects applicants for a Part 72 specific license, and 
general licensees on or after the effective date of the rule for an 
ISFSI or MRS. These companies do not generally fall within the scope of 
the definition of ``small entities'' set forth in the Regulatory 
Flexibility Act or the Small Business Size Standards set out in 
regulations issued by the Small Business Administration at 13 CFR Part 
121.

XV. Backfit Analysis

    The NRC has determined that the backfit rule, 72.62, does not apply 
to the changes in Sec. Sec.  72.9, 72.102, and 72.103 because they do 
not involve any provisions that would impose backfits as defined in the 
backfit rule. Therefore, a backfit analysis is not required for these 
provisions.
    Section 72.212(b)(2)(i)(B) currently requires evaluations of static 
loads of the stored casks for design of the cask storage pads and areas 
(foundation). The revision to this section will require general 
licensees also to address the dynamic loads of the stored casks. During 
a seismic event, the cask storage pads and areas experience dynamic 
loads in addition to static loads. The dynamic loads depend on the 
interaction of the casks, cask storage pads, and areas. Consideration 
of the dynamic loads of the stored casks, in addition to the static 
loads, for the design of the cask storage pads and areas will ensure 
that the cask storage pads and areas will perform satisfactorily in the 
event of an earthquake.
    The revision will also require consideration of potential 
amplification of earthquakes through soil-structure interaction, and 
soil liquefaction potential or other soil instability due to vibratory 
ground motion. Depending on the properties of soil and structures, the 
free-field earthquake acceleration input loads may be amplified at the 
top of the storage pad. These amplified acceleration input values must 
be bound by the design bases seismic acceleration values for the cask 
specified in the Certificate of Compliance. The soil liquefaction and 
instability during a vibratory motion due to an earthquake may affect 
the cask stability.
    The changes to Sec.  72.212(b)(2)(i)(B) will impact procedures 
required to operate an ISFSI and, therefore, implicate the backfit 
rule. The changes will require that general licensees perform 
appropriate analyses to assure that the cask seismic design bases bound 
the specific site seismic conditions, and that casks are not placed in 
an unanalyzed condition. Therefore, these changes are necessary to 
assure adequate protection to occupational or public health and safety. 
Although the Commission is imposing this backfit because it is 
necessary to assure adequate protection to occupational or public 
health and safety, the changes to Sec.  72.212 will not actually impose 
new burden on the general licensees because they currently need to 
consider dynamic loads to meet the requirements in Sec.  
72.212(b)(2)(i)(A). Section 72.212(b)(2)(i)(A) requires general 
licensees to perform written evaluations to meet conditions set forth 
in the cask Certificate of Compliance. These Certificates of Compliance 
require that dynamic loads, such as seismic and tornado loads, be 
evaluated to meet the cask design bases. Because the general licensees 
currently evaluate dynamic loads for evaluating the casks, pads and 
areas, the changes to Sec.  72.212(b)(2)(i)(B) will not actually 
require any general licensees presently operating an ISFSI to re-
perform any written evaluations previously undertaken.

XVI. Small Business Regulatory Enforcement Fairness Act

    In accordance with the Small Business Regulatory Enforcement 
Fairness Act of 1996, the NRC has determined that this action is not a 
major rule and has verified this determination with the Office of 
Information and Regulatory Affairs of OMB.

List of Subjects In 10 CFR Part 72

    Administrative practice and procedure, Criminal penalties, Manpower 
training programs, Nuclear materials, Occupational safety and health, 
Penalties, Radiation protection, Reporting and recordkeeping 
requirements, Security measures, Spent fuel, Whistleblowing.

0
For the reasons set out in the preamble and under the authority of the 
Atomic Energy Act of 1954, as amended; the Energy Reorganization Act of 
1974, as amended; and 5 U.S.C. 552 and 553; the

[[Page 54159]]

NRC is adopting the following amendments to 10 CFR part 72.

PART 72--LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF 
SPENT NUCLEAR FUEL, HIGH-LEVEL RADIOACTIVE WASTE, AND REACTOR-
RELATED GREATER THAN CLASS C WASTE

0
1. The authority citation for Part 72 continues to read as follows:

    Authority: Secs. 51, 53, 57, 62, 63, 65, 69, 81, 161, 182, 183, 
184, 186, 187, 189, 68 Stat. 929, 930, 932, 933, 934, 935, 948, 953, 
954, 955, as amended, sec. 234, 83 Stat. 444, as amended (42 U.S.C. 
2071, 2073, 2077, 2092, 2093, 2095, 2099, 2111, 2201, 2232, 2233, 
2234, 2236, 2237, 2238, 2282); sec. 274, Pub. L. 86-373, 73 Stat. 
688, as amended (42 U.S.C. 2021); sec. 201, as amended, 202, 206, 88 
Stat. 1242, as amended, 1244, 1246 (42 U.S.C. 5841, 5842, 5846); 
Pub. L. 95-601, sec. 10, 92 Stat. 2951 as amended by Pub. L. 102-
486, sec. 7902, 106 Stat. 3123 (42 U.S.C. 5851); sec. 102, Pub. L. 
91-190, 83 Stat. 853 (42 U.S.C. 4332); secs. 131, 132, 133, 135, 
137, 141, Pub. L. 97-425, 96 Stat. 2229, 2230, 2232, 2241, sec. 148, 
Pub. L. 100-203, 101 Stat. 1330-235 (42 U.S.C. 10151, 10152, 10153, 
10155, 10157, 10161, 10168).
    Section 72.44(g) also issued under secs. 142(b) and 148(c), (d), 
Pub. L. 100-203, 101 Stat. 1330-232, 1330-236 (42 U.S.C. 10162(b), 
10168(c), (d)). Section 72.46 also issued under sec. 189, 68 Stat. 
955 (42 U.S.C. 2239); sec. 134, Pub. L. 97-425, 96 Stat. 2230 (42 
U.S.C. 10154). Section 72.96(d) also issued under sec. 145(g), Pub. 
L. 100-203, 101 Stat. 1330-235 (42 U.S.C. 10165(g)). Subpart J also 
issued under secs. 2(2), 2(15), 2(19), 117(a), 141(h), Pub. L. 97-
425, 96 Stat. 2202, 2203, 2204, 2222, 2224, (42 U.S.C. 10101, 
10137(a), 10161(h)). Subparts K and L are also issued under sec. 
133, 98 Stat. 2230 (42 U.S.C. 10153) and sec. 218(a), 96 Stat. 2252 
(42 U.S.C. 10198).


0
2. In Sec.  72.9, paragraph (b) is revised to read as follows:


Sec.  72.9  Information collection requirements: OMB approval.

* * * * *
    (b) The approved information collection requirements contained in 
this part appear in Sec. Sec.  72.7, 72.11, 72.16, 72.22 through 72.34, 
72.42, 72.44, 72.48 through 72.56, 72.62, 72.70, through 72.82, 72.90, 
72.92, 72.94, 72.98, 72.100, 72.102, 72.103, 72.104, 72.108, 72.120, 
72.126, 72.140 through 72.176, 72.180 through 72.186, 72.192, 72.206, 
72.212, 72.216, 72.218, 72.230, 72.232, 72.234, 72.236, 72.240, 72.242, 
72.244, 72.248.

0
3. The heading of Sec.  72.102 is revised to read as follows:


Sec.  72.102  Geological and seismological characteristics for 
applications before October 16, 2003 and applications for other than 
dry cask modes of storage.

* * * * *

0
4. A new Sec.  72.103 is added to read as follows:


Sec.  72.103  Geological and seismological characteristics for 
applications for dry cask modes of storage on or after October 16, 
2003.

    (a)(1) East of the Rocky Mountain Front (east of approximately 
104[deg] west longitude), except in areas of known seismic activity 
including but not limited to the regions around New Madrid, MO; 
Charleston, SC; and Attica, NY; sites will be acceptable if the results 
from onsite foundation and geological investigation, literature review, 
and regional geological reconnaissance show no unstable geological 
characteristics, soil stability problems, or potential for vibratory 
ground motion at the site in excess of an appropriate response spectrum 
anchored at 0.2 g.
    (2) For those sites that have been evaluated under paragraph (a)(1) 
of this section that are east of the Rocky Mountain Front, and that are 
not in areas of known seismic activity, a standardized design 
earthquake ground motion (DE) described by an appropriate response 
spectrum anchored at 0.25 g may be used. Alternatively, a site-specific 
DE may be determined by using the criteria and level of investigations 
required by paragraph (f) of this section. For a site with a co-located 
nuclear power plant (NPP), the existing geological and seismological 
design criteria for the NPP may be used. If the existing design 
criteria for the NPP is used and the site has multiple NPPs, then the 
criteria for the most recent NPP must be used.
    (b) West of the Rocky Mountain Front (west of approximately 
104[deg] west longitude), and in other areas of known potential seismic 
activity east of the Rocky Mountain Front, seismicity must be evaluated 
by the techniques presented in paragraph (f) of this section. If an 
ISFSI or MRS is located on an NPP site, the existing geological and 
seismological design criteria for the NPP may be used. If the existing 
design criteria for the NPP is used and the site has multiple NPPs, 
then the criteria for the most recent NPP must be used.
    (c) Sites other than bedrock sites must be evaluated for their 
liquefaction potential or other soil instability due to vibratory 
ground motion.
    (d) Site-specific investigations and laboratory analyses must show 
that soil conditions are adequate for the proposed foundation loading.
    (e) In an evaluation of alternative sites, those which require a 
minimum of engineered provisions to correct site deficiencies are 
preferred. Sites with unstable geologic characteristics should be 
avoided.
    (f) Except as provided in paragraphs (a)(2) and (b) of this 
section, the DE for use in the design of structures, systems, and 
components must be determined as follows:
    (1) Geological, seismological, and engineering characteristics. The 
geological, seismological, and engineering characteristics of a site 
and its environs must be investigated in sufficient scope and detail to 
permit an adequate evaluation of the proposed site, to provide 
sufficient information to support evaluations performed to arrive at 
estimates of the DE, and to permit adequate engineering solutions to 
actual or potential geologic and seismic effects at the proposed site. 
The size of the region to be investigated and the type of data 
pertinent to the investigations must be determined based on the nature 
of the region surrounding the proposed site. Data on the vibratory 
ground motion, tectonic surface deformation, nontectonic deformation, 
earthquake recurrence rates, fault geometry and slip rates, site 
foundation material, and seismically induced floods and water waves 
must be obtained by reviewing pertinent literature and carrying out 
field investigations. However, each applicant shall investigate all 
geologic and seismic factors (for example, volcanic activity) that may 
affect the design and operation of the proposed ISFSI or MRS facility 
irrespective of whether these factors are explicitly included in this 
section.
    (2) Geologic and seismic siting factors. The geologic and seismic 
siting factors considered for design must include a determination of 
the DE for the site, the potential for surface tectonic and nontectonic 
deformations, the design bases for seismically induced floods and water 
waves, and other design conditions as stated in paragraph (f)(2)(iv) of 
this section.
    (i) Determination of the Design Earthquake Ground Motion (DE). The 
DE for the site is characterized by both horizontal and vertical free-
field ground motion response spectra at the free ground surface. In 
view of the limited data available on vibratory ground motions for 
strong earthquakes, it usually will be appropriate that the design 
response spectra be smoothed spectra. The DE for the site is determined 
considering the results of the investigations required by paragraph 
(f)(1) of this section. Uncertainties are inherent in these estimates 
and must be addressed through an appropriate analysis, such as a 
probabilistic seismic hazard analysis (PSHA) or suitable sensitivity 
analyses.

[[Page 54160]]

    (ii) Determination of the potential for surface tectonic and 
nontectonic deformations. Sufficient geological, seismological, and 
geophysical data must be provided to clearly establish if there is a 
potential for surface deformation.
    (iii) Determination of design bases for seismically induced floods 
and water waves. The size of seismically induced floods and water waves 
that could affect a site from either locally or distantly generated 
seismic activity must be determined.
    (iv) Determination of siting factors for other design conditions. 
Siting factors for other design conditions that must be evaluated 
include soil and rock stability, liquefaction potential, and natural 
and artificial slope stability. Each applicant shall evaluate all 
siting factors and potential causes of failure, such as, the physical 
properties of the materials underlying the site, ground disruption, and 
the effects of vibratory ground motion that may affect the design and 
operation of the proposed ISFSI or MRS.
    (3) Regardless of the results of the investigations anywhere in the 
continental U.S., the DE must have a value for the horizontal ground 
motion of no less than 0.10 g with the appropriate response spectrum.

0
5. In Sec.  72.212, paragraph (b)(2)(i)(B) is revised to read as 
follows:


Sec.  72.212  Conditions of general license issued under Sec.  72.210.

* * * * *
    (b) * * *
    (2) * * *
    (i) * * *
    (B) Cask storage pads and areas have been designed to adequately 
support the static and dynamic loads of the stored casks, considering 
potential amplification of earthquakes through soil-structure 
interaction, and soil liquefaction potential or other soil instability 
due to vibratory ground motion; and
* * * * *

    Dated at Rockville, Maryland, this 10th day of September, 2003.

    For the Nuclear Regulatory Commission.
Annette L. Vietti-Cook,
Secretary for the Commission.
[FR Doc. 03-23553 Filed 9-15-03; 8:45 am]
BILLING CODE 7590-01-P