[Federal Register Volume 88, Number 198 (Monday, October 16, 2023)]
[Rules and Regulations]
[Pages 71277-71278]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-22789]
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NUCLEAR REGULATORY COMMISSION
10 CFR Parts 50 and 52
[NRC-2021-0179]
Regulatory Guide: Alternative Radiological Source Terms for
Evaluating Design Basis Accidents at Nuclear Power Reactors
AGENCY: Nuclear Regulatory Commission.
ACTION: Final guide; issuance.
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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is issuing
Revision 1 to Regulatory Guide (RG), 1.183, ``Alternative Radiological
Source Terms for Evaluating Design Basis Accidents at Nuclear Power
Reactors.'' This RG describes a method that the NRC staff considers
acceptable in complying with regulations for design basis accident dose
consequence analysis using an alternative source term. This guidance
for light-water reactor (LWR) designs includes the scope, nature, and
documentation of associated analyses and evaluations; consideration of
impacts on analyzed risk; and content of submittals.
DATES: Revision 1 to RG 1.183 is available on October 16, 2023.
ADDRESSES: Please refer to Docket ID NRC-2021-0179 when contacting the
NRC about the availability of information regarding this document. You
may obtain publicly available information related to this document
using any of the following methods:
Federal Rulemaking Website: Go to https://www.regulations.gov and search for Docket ID NRC-2021-0179. Address
questions about Docket IDs in Regulations.gov to Stacy Schumann;
telephone: 301-415-0624; email: [email protected]. For technical
questions, contact the individuals listed in the For Further
Information Contact section of this document.
[[Page 71278]]
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]. The ADAMS accession number for
each document referenced (if it is available in ADAMS) is provided the
first time that it is mentioned in this document.
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.
Revision 1 to RG 1.183 and the regulatory analysis may be found in
ADAMS under Accession Nos. ML23082A305 and ML21204A066, respectively.
Regulatory guides are not copyrighted, and NRC approval is not
required to reproduce them.
FOR FURTHER INFORMATION CONTACT: Michael Eudy, Office of Nuclear
Regulatory Research, telephone: 301-415-3104, email:
[email protected], Mark Blumberg, Office of Nuclear Reactor
Regulation, telephone: 301-415-1083, email: [email protected], and
Joseph Messina, Office of Nuclear Reactor Regulation, telephone: 301-
415-4226, email: [email protected]. All are staff of the U.S.
Nuclear Regulatory Commission, Washington, DC 20555-0001.
SUPPLEMENTARY INFORMATION:
I. Discussion
The NRC is issuing a revision in the NRC's ``Regulatory Guide''
series. This series was developed to describe methods that are
acceptable to the NRC staff for implementing specific parts of the
agency's regulations, to explain techniques that the staff uses in
evaluating specific issues or postulated events, and to describe
information that the staff needs in its review of applications for
permits and licenses.
The proposed Revision 1 to RG 1.183 was issued with a temporary
identification of Draft Regulatory Guide, DG-1389. (ADAMS Accession No.
ML21204A065).
This revision of the guide (Revision 1) addresses new issues
identified since the guide was originally issued. These include (1)
using the term maximum hypothetical accident loss-of-coolant accident
(LOCA) to clarify the accident that the staff finds acceptable to use
to meet the description in the applicable regulations, identified in
Section A of RG 1.183, Revision 1, with a clear delineation between
source term assumptions and plant response; (2) adding transient
release fractions from empirical data from in-pile, prompt power pulse
test programs and analyses from several international publications of
fuel rod performance under prompt power excursion conditions; (3)
revising steady-state release fractions for accidents other than the
LOCA based on a revision to the American National Standards Institute/
American Nuclear Society Standard 5.4, ``Method for Calculating the
Fractional Release of Volatile Fission Products from Oxide Fuel''; (4)
adding information to acknowledge that the RG may provide useful
information for satisfying the radiological dose analysis requirements
in parts 50 and 52 of title 10 of the Code of Federal Regulations (10
CFR), for new LWR applicants, including advanced evolutionary and
passive LWR design and siting; (5) providing additional guidance for
modeling boiling-water reactor main steam isolation valve leakage; (6)
adding guidance for accident tolerant fuel, high-burnup fuel, and
increased enrichment source term analyses; (7) revising transport and
decontamination models for the fuel handling design basis accident; (8)
adding guidance for crediting hold-up and retention of main steam
isolation valve leakage within the main steamlines and condenser for
boiling-water reactors; and (9) providing additional guidance on
meteorological assumptions.
II. Additional Information
The NRC published a notice of the availability of DG-1389 in the
Federal Register on April 21, 2022 (87 FR 23891) for a 60-day public
comment period. The public comment period closed on June 21, 2022.
Public comments on DG-1389 and the staff responses to the public
comments are available under ADAMS under Accession No. ML23082A309.
In the notice of availability for DG-1389, Section IV, ``Specific
Request for Comment,'' the NRC sought specific comments on the draft
staff technical assessment titled, ``Technical Assessment of Hold-up
and Retention of Main Steam Isolation Valve Leakage within the Main
Steam Lines and Main Condenser'' (ADAMS Accession No. ML20085J042); the
NRC staff did not receive any public comments on the draft staff
technical assessment. At this time, the staff has determined to
incorporate the supporting technical basis information from that draft
staff technical assessment into RG 1.183, Revision 1, Appendix A,
Section A-5.5, rather than finalizing the draft staff technical
assessment separately for inclusion in this RG. Accordingly, the
reference to the draft staff technical assessment was deleted from the
final RG.
As noted in the Federal Register on December 9, 2022 (87 FR 75671),
this document is being published in the ``Rules'' section of the
Federal Register to comply with publication requirements under 1 CFR
chapter I.
III. Congressional Review Act
This RG is a rule as defined in the Congressional Review Act (5
U.S.C. 801-808). However, the Office of Management and Budget has not
found it to be a major rule as defined in the Congressional Review Act.
IV. Backfitting, Forward Fitting, and Issue Finality
Issuance of RG 1.183, Revision 1, does not constitute backfitting
as defined in 10 CFR 50.109, ``Backfitting,'' and as described in NRC
Management Directive (MD) 8.4, ``Management of Backfitting, Forward
Fitting, Issue Finality, and Information Requests'' (ADAMS Accession
No. ML18093B087); affect the issue finality of an approval under 10 CFR
part 52; or constitute forward fitting as defined and described in MD
8.4 because, as explained in RG 1.183, Revision 1, applicants and
licensees are not required to comply with the positions set forth in
this RG.
V. Submitting Suggestions for Improvement of Regulatory Guides
A member of the public may, at any time, submit suggestions to the
NRC for improvement of existing RGs or for the development of new RGs.
Suggestions can be submitted on the NRC's public website at https://www.nrc.gov/reading-rm/doc-collections/reg-guides/contactus.html.
Suggestions will be considered in future updates and enhancements to
the ``Regulatory Guide'' series.
Dated: October 11, 2023.
For the Nuclear Regulatory Commission.
Stephen M. Wyman,
Acting Chief, Regulatory Guide and Programs Management Branch, Division
of Engineering, Office of Nuclear Regulatory Research.
[FR Doc. 2023-22789 Filed 10-13-23; 8:45 am]
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