[Federal Register Volume 90, Number 123 (Monday, June 30, 2025)]
[Notices]
[Pages 27880-27881]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-12017]
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NUCLEAR REGULATORY COMMISSION
[NRC-2025-0088]
Level 3 Probabilistic Risk Assessment Project Documentation
(Volume 6)
AGENCY: Nuclear Regulatory Commission.
ACTION: Draft report; request for comment.
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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is issuing for
public comment two draft reports on the Level 3 Probabilistic Risk
Assessment (PRA) project; specifically, ``Volume 6a: Spent Fuel Pool
Level 1 and Level 2 PRA'' and ``Volume 6b: Spent Fuel Pool Level 3
PRA.''
DATES: Submit comments by August 29, 2025. Comments received after this
date will be considered if it is practical to do so, but the Commission
is able to ensure consideration only for comments received on or before
this date.
ADDRESSES: You may submit comments by any of the following methods;
however, the NRC encourages electronic comment submission through the
Federal rulemaking website:
Federal rulemaking website: Go to https://www.regulations.gov and search for Docket ID NRC-2025-0088. Address
questions about Docket IDs in Regulations.gov to Bridget Curran;
telephone: 301-415-1003; email: [email protected]. For technical
questions, contact the individual listed in the For Further Information
Contact section of this document.
Mail comments to: Office of Administration, Mail Stop:
TWFN-7-A60M, U.S. Nuclear Regulatory Commission, Washington, DC 20555-
0001, ATTN: Program Management, Announcements and Editing Staff.
For additional direction on obtaining information and submitting
comments, see ``Obtaining Information and Submitting Comments'' in the
SUPPLEMENTARY INFORMATION section of this document.
FOR FURTHER INFORMATION CONTACT: Alan Kuritzky, Office of Nuclear
Regulatory Research, U.S. Nuclear Regulatory Commission, Washington, DC
20555-0001; telephone: 301-415-1552; email: [email protected].
SUPPLEMENTARY INFORMATION:
I. Obtaining Information and Submitting Comments
A. Obtaining Information
Please refer to Docket ID NRC-2025-0088 when contacting the NRC
about the availability of information for this action. You may obtain
publicly available information related to this action by any of the
following methods:
Federal Rulemaking website: Go to https://www.regulations.gov and search for Docket ID NRC-2025-0088.
NRC's Agencywide Documents Access and Management System
(ADAMS): You may obtain publicly available documents online in the
ADAMS Public Documents collection at https://www.nrc.gov/reading-rm/adams.html. To begin the search, select ``Begin Web-based ADAMS
Search.'' For problems with ADAMS, please contact the NRC's Public
Document Room (PDR) reference staff at 1-800-397-4209, at 301-415-4737,
or by email to [email protected]. For the convenience of the reader,
instructions about obtaining materials referenced in this document are
provided in the ``Availability of Documents'' section.
NRC's PDR: The PDR, where you may examine and order copies
of publicly available documents, is open by appointment. To make an
appointment to visit the PDR, please send an email to
[email protected] or call 1-800-397-4209 or 301-415-4737, between 8
a.m. and 4 p.m. eastern time (ET), Monday through Friday, except
Federal holidays.
B. Submitting Comments
The NRC encourages electronic comment submission through the
Federal rulemaking website (https://www.regulations.gov). Please
include Docket ID NRC-2025-0088 in your comment submission.
The NRC cautions you not to include identifying or contact
information that you do not want to be publicly disclosed in your
comment submission. The NRC will post all comment submissions at
https://www.regulations.gov as well as enter the comment submissions
into ADAMS. The NRC does not routinely edit comment submissions to
remove identifying or contact information.
If you are requesting or aggregating comments from other persons
for submission to the NRC, then you should inform those persons not to
include identifying or contact information that they do not want to be
publicly disclosed in their comment submission. Your request should
state that the NRC
[[Page 27881]]
does not routinely edit comment submissions to remove such information
before making the comment submissions available to the public or
entering the comment into ADAMS.
II. Discussion
As directed in SRM-SECY-11-0089, ``Options for Proceeding with
Future Level 3 Probabilistic Risk Assessment (PRA) Activities,'' the
staff is conducting a full-scope multi-unit site Level 3 PRA (Level 3
PRA project) that addresses all internal and external hazards, all
plant operating modes, and all reactor units, spent fuel pools (SFPs),
and dry cask storage. The reference site for this study contains 2
four-loop Westinghouse pressurized water reactors with large dry
containments. The objectives of the Level 3 PRA project are to (1)
develop a Level 3 PRA, generally based on current state-of-practice
methods, tools, and data, that (a) reflects technical advances since
the last NRC-sponsored Level 3 PRAs (NUREG-1150), which were completed
over 30 years ago, and (b) addresses scope considerations that were not
previously considered (e.g., low-power and shutdown risk, multi-unit
risk, other radiological sources); (2) extract new insights to enhance
regulatory decision making and to help focus limited NRC resources on
issues most directly related to the agency's mission to protect public
health and safety; (3) enhance PRA staff capability and expertise and
improve documentation practices to make PRA information more
accessible, retrievable, and understandable; and (4) demonstrate
technical feasibility and evaluate the realistic cost of developing new
Level 3 PRAs.
The work performed under this project is being documented as a
multi-volume report. The current Level 3 PRA project reports describe
the analyses and results for the SFP combined Level 1 and Level 2 PRA
for all hazards (Volume 6a) and the SFP Level 3 PRA for all hazards
(Volume 6b). Consistent with previous SFP studies, seismic events were
found to be the dominant contributors (particularly, the higher seismic
bins). However, effectively no populations were projected to receive
the high doses needed to result in early health effects. The bulk of
the radiological exposure (which is in the low to very low dose range)
arises from reoccupation of land after decontamination and natural
decay and weathering reduce exposures to levels below the habitability
criteria assumed in the analysis. The study also found that the risk
(which considers both frequency and consequences) of latent fatality
for the SFPs is less than that for the reactors.
While these results can vary for other plants due to variations in
their design and siting, the estimates derived for the reference plant,
when adjusted for siting and design variations, would provide useful
qualitative risk insights for other U.S. operating plants.
III. Availability of Documents
The documents identified in the following table are available to
interested persons through ADAMS, as indicated.
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Document description ADAMS Accession No.
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SRM-SECY-11-0089, ``Options for Proceeding ML112640419
with Future Level 3 Probabilistic Risk
Assessment (PRA) Activities,'' dated
September 21, 2011.
Level 3 PRA Project, Volume 6a: Spent Fuel ML25134A014
Pool Level 1 and Level 2 PRA (draft for
public comment), published June 2025.
Level 3 PRA Project, Volume 6b: Spent Fuel ML25134A015
Pool Level 3 PRA (draft for public comment),
published June 2025.
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Dated: June 25, 2025.
For the Nuclear Regulatory Commission.
Michelle Gonzalez,
Acting Chief, Probability Risk Assessment Branch, Division of Risk
Analysis, Office of Nuclear Regulatory Research.
[FR Doc. 2025-12017 Filed 6-27-25; 8:45 am]
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