[Federal Register Volume 91, Number 105 (Tuesday, June 2, 2026)]
[Notices]
[Pages 33003-33004]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2026-10978]
[[Page 33003]]
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NUCLEAR REGULATORY COMMISSION
[NRC-2026-0826]
Draft Regulatory Guide: Application and Testing of Onsite
Emergency Alternating Current Power Sources in Production and
Utilization Facilities
AGENCY: Nuclear Regulatory Commission.
ACTION: Draft guide; request for comment.
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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is issuing for
public comment draft regulatory guide (DG), DG-1477, ``Application and
Testing of Onsite Emergency Alternating Current Power Sources in
Production and Utilization Facilities.'' This DG is proposed Revision 5
of Regulatory Guide (RG) 1.9 with a new title. The proposed revision to
the RG provides guidance that the staff of the NRC considers acceptable
to comply with the NRC regulations for onsite emergency alternating
current (AC) power sources in production and utilization facilities.
These power sources include emergency diesel generators (EDGs),
combustion turbine generators (CTGs) and other types of onsite
emergency AC power sources.
DATES: Submit comments by July 2, 2026. Comments received after this
date will be considered if it is practical to do so, but the NRC 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-2026-0826. Address
questions about Docket IDs in Regulations.gov to Bridget Curran;
telephone: 301-415-1003; email: [email protected]. For technical
questions, contact the individual(s) listed in the For Further
Information Contact section of this document.
Mail comments to: Office of Administration, Mail Stop:
TWFN-5-A85, 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: Sheila Ray, Office of Nuclear Reactor
Regulation; telephone: 301-415-3653; email: [email protected] and
Stanley Gardocki, Office of Nuclear Regulatory Research, telephone:
301-415-1067; email: [email protected]. Both are staff of the
U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001.
SUPPLEMENTARY INFORMATION:
I. Obtaining Information and Submitting Comments
A. Obtaining Information
Please refer to Docket ID NRC-2026-0826 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-2026-0826.
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 ADAMS Public 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.
B. Submitting Comments
The NRC encourages electronic comment submission through the
Federal rulemaking website (https://www.regulations.gov). Please
include Docket ID NRC-2026-0826 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 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. Additional Information
The NRC is issuing for public comment a DG 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 DG, entitled ``Application and Testing of Onsite Emergency
Alternating Current Power Sources in Production and Utilization
Facilities,'' is temporarily identified by its task number, DG-1477
(ADAMS Accession No. ML26007A205).
The staff is also issuing for public comment a draft regulatory
analysis (ADAMS Accession No. ML26007A215). The staff developed a
regulatory analysis to assess the value of issuing or revising a
regulatory guide as well as alternative courses of action.
The NRC previously published a DG to update RG 1.9, Revision 4. On
January 19, 2021, the NRC issued DG-1303 for public comment by Federal
Register notice (86 FR 5267). Public comments were received from
members of the public, the Nuclear Energy Institute, and Institute of
Electrical and Electronics Engineers (IEEE) (ADAMS Accession Nos.
ML21050A427, ML21050A428, and ML21050A429), and the Advisory Committee
on Reactor Safeguards (ACRS) provided feedback in a letter dated July
26, 2021 (ADAMS Accession No. ML21202A149). The staff responded to the
ACRS letter on October 13, 2021 (ADAMS Accession No. ML21277A254). The
staff considered the public comments and ACRS feedback, to the extent
possible, in the development of DG-1477. The staff issued DG-1477 to
supersede DG-1303 because International Electrotechnical Commission
(IEC) and IEEE have released new standards regarding emergency AC
standby power
[[Page 33004]]
supplies that supersede the existing standards endorsed in RG 1.9,
Revision 4. This revision of the guide (Revision 5) is updated to
endorse and provide guidance for these new standards. Revision 5
applies to production and utilization facilities licensed under part 50
of title 10 of the Code of Federal Regulations (10 CFR) and 10 CFR part
52 within the scope of this RG. Revision 5 is the result of lessons
learned from license amendment review activities and inspections,
industry operating experience, design certification reviews, combined
license application reviews, and NRC staff analysis. Furthermore,
Revision 5 includes specific guidance on CTGs and onsite emergency AC
power sources other than EDGs and CTGs. If finalized, the NRC will
issue Revision 5 of this RG to provide current guidance, based on the
generally accepted methods and procedures for EDGs, CTGs, and any other
onsite power sources.
This proposed Revision 5 of RG 1.9 endorses, with supplements and
clarifications, IEC/IEEE Std 63332 387:2024, ``Nuclear facilities-
Electrical power systems-Diesel generator units applied as standby
power sources,'' and IEEE Std 2420-2019, ``IEEE Standard Criteria for
Combustion Turbine-Generator Units Applied as Standby Power Supplies
for Nuclear Power Generating Stations.'' These standards delineate
principal design criteria and qualification and testing guidelines to
help ensure that EDGs and CTGs meet performance requirements.
III. Backfitting, Forward Fitting, and Issue Finality
The issuance of DG-1477, proposed Revision 5 to RG 1.9, provides
guidance that the staff of the NRC considers acceptable to comply with
the NRC regulations for onsite emergency AC power sources in production
and utilization facilities. Revision 5 to RG 1.9 would 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''; affect issue finality of any approval issued under 10 CFR
part 52, ``Licenses, Certificates, and Approvals for Nuclear Power
Plants''; or constitute forward fitting as defined in MD 8.4. As
explained in DG-1477, applicants or licensees generally would not be
required to comply with the positions in DG-1477.
IV. 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.
V. Executive Order (E.O.) 12866
The Office of Information and Regulatory Affairs determined that
this DG is not a significant regulatory action under E.O. 12866.
Authority:
42 U.S.C. 2011 et seq.
Dated: May 29, 2026.
For the Nuclear Regulatory Commission.
Stanley Gardocki,
Acting Chief, Regulatory Guide and Programs Management Branch, Division
of Engineering, Office of Nuclear Regulatory Research.
[FR Doc. 2026-10978 Filed 6-1-26; 8:45 am]
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