[Federal Register Volume 91, Number 39 (Friday, February 27, 2026)]
[Proposed Rules]
[Pages 9733-9760]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2026-03993]
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NUCLEAR REGULATORY COMMISSION
10 CFR Part 50
[NRC-2020-0029]
RIN 3150-AK42
Approval of the 2023 Edition of the American Society of
Mechanical Engineers Boiler and Pressure Vessel Code and Code Cases,
Revision 41
AGENCY: Nuclear Regulatory Commission.
ACTION: Proposed rule.
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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is proposing to
amend its regulations to incorporate by reference the 2023 Edition of
the American Society of Mechanical Engineers (ASME) Boiler and Pressure
Vessel Code. This action is in accordance with the NRC's policy to
periodically update the regulations to incorporate by reference new
editions of the ASME Codes and is intended to maintain the safety of
nuclear power plants and to make NRC activities more effective and
efficient. The NRC also is proposing to amend its regulations to
incorporate by reference proposed revisions of three regulatory guides,
which would approve new, revised, and reaffirmed code cases published
by the ASME. This proposed action would allow nuclear power plant
licensees and applicants to use the code cases listed in these draft
regulatory guides as voluntary alternatives to engineering standards
for the construction, inservice inspection, and inservice testing of
nuclear power plant components. This proposed rule also incorporates
minor editorial corrections. The NRC is requesting comments on this
proposed rule, on the draft versions of three regulatory guides, and
the draft version of an additional regulatory guide which will not be
incorporated by reference.
DATES: Submit comments by April 28, 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 before this
date.
ADDRESSES: You may submit comments, identified by Docket ID NRC-2020-
0029, at https://www.regulations.gov. If your material cannot be
submitted using https://www.regulations.gov, call or email the
individuals listed in the FOR FURTHER INFORMATION CONTACT section of
this document for alternate instructions.
You can read a plain language description of this proposed rule at
https://www.regulations.gov/docket/NRC-2020-0029. 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: Aaron Kwok, Office of Nuclear Material
Safety and Safeguards, telephone: 301-415-1371, email:
[email protected]; and Jay Collins, Office of Nuclear Reactor
Regulation, telephone: 301-415-4038, email: [email protected]. Both
are staff of the U.S. Nuclear Regulatory Commission, Washington, DC
20555-0001.
SUPPLEMENTARY INFORMATION: This rulemaking is separate from NRC's
comprehensive review and reform of its regulations in accordance with
Executive Order (E.O.) 14300, ``Ordering the Reform of the Nuclear
Regulatory Commission'' (90 FR 22587; May 29, 2025). The rulemakings
associated with that effort will comprehensively reexamine NRC
requirements, including those in 10 CFR part 50. While there could be
additional revisions to 10 CFR part 50 as a result of these future
rulemakings, the NRC is moving forward with publication of this
proposed rule at this time because it is a deregulatory action of high
interest for stakeholders that was in progress before the issuance of
E.O. 14300.
Executive Summary
A. Need for the Regulatory Action
The NRC is proposing to amend its regulations to incorporate by
reference the 2023 Edition of the American Society of Mechanical
Engineers (ASME) Boiler and Pressure Vessel Code (BPV Code). The ASME
periodically revises and updates its Codes for nuclear power plants by
issuing new editions; this proposed rule is in accordance with the
NRC's practice to incorporate those new editions into the NRC's
regulations. This proposed rule maintains the safety of nuclear power
plants, makes NRC activities more effective and efficient, and allows
nuclear power plant licensees and
[[Page 9734]]
applicants to take advantage of the latest ASME BPV Code. The ASME is a
voluntary consensus standards organization, and the ASME BPV Code is a
voluntary consensus standard. The NRC's use of the ASME BPV Code is
consistent with applicable requirements of the National Technology
Transfer and Advancement Act (NTTAA). See Section XIV, ``Voluntary
Consensus Standards,'' of this document for more information.
In addition, the NRC is proposing to incorporate by reference into
its regulations the latest revisions of three regulatory guides (RGs)
(currently in draft form for comment). The three draft RGs identify
new, revised, and reaffirmed code cases published by the ASME that the
NRC has determined are acceptable for use as voluntary alternatives to
compliance with certain provisions of the ASME BPV Code and the ASME
Operation and Maintenance (OM) of Nuclear Power Plants, Division 1, OM
Code: Section IST (OM Code) currently incorporated by reference into
the NRC's regulations. The NRC is also proposing to revise an
additional RG listing code cases that the NRC has not approved for use.
B. Major Provisions
Major provisions of this proposed rule include the incorporation by
reference with conditions of the 2023 Edition of the ASME BPV Code into
NRC regulations and delineation of NRC requirements for the use of this
code. In addition, the NRC proposes to incorporate by reference into
the NRC's regulations the following regulatory guides: RG 1.84,
``Design, Fabrication, and Materials Code Case Acceptability, ASME
Section III,'' Revision 41 (Draft Regulatory Guide (DG)-1446); RG
1.147, ``Inservice Inspection Code Case Acceptability, ASME Section XI,
Division 1,'' Revision 22 (DG-1447); and RG 1.192, ``Operation and
Maintenance [OM] Code Case Acceptability, ASME OM Code,'' Revision 6
(DG-1448). This proposed action would allow nuclear power plant
licensees and applicants for construction permits, operating licenses,
combined licenses, standard design certifications, standard design
approvals, and manufacturing licenses to use the code cases newly
listed in these revised RGs as voluntary alternatives to ASME
engineering standards for the construction, inservice inspections, and
inservice testing of nuclear power plant components. The NRC also notes
the availability of a proposed version of RG 1.193, ``ASME Code Cases
Not Approved for Use,'' Revision 9 (DG-1449). This document lists code
cases that the NRC has not approved for generic use and would not be
incorporated by reference into the NRC's regulations.
C. Costs and Benefit
The NRC prepared a draft regulatory analysis to determine the
expected quantitative costs and benefits of this proposed rule, as well
as qualitative factors to be considered in the NRC's rulemaking
decision. The analysis concluded that this proposed rule would result
in net savings to the industry and the NRC. As shown in Table I, the
estimated total net benefit relative to the regulatory baseline and the
quantitative benefits would outweigh the costs by a range from
approximately $9.52 million (7-percent net present value) to $11.7
million (3-percent net present value).
Table I--Cost Benefit Summary
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Total averted costs (costs)
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Attribute 7% Net present 3% Net present
Undiscounted value value
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Industry Implementation............................ $0 $0 $0
Industry Operation................................. 9,580,000 6,650,000 8,150,000
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Total Industry Costs........................... 9,580,000 6,650,000 8,150,000
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NRC Implementation................................. (260,000) (230,000) (240,000)
NRC Operation...................................... 4,470,000 3,100,000 3,810,000
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Total NRC Costs................................ 4,210,000 2,870,000 3,570,000
Net........................................ 13,790,000 9,520,000 11,720,000
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The draft regulatory analysis also considered the following
qualitative considerations: (1) protection of public health and safety
and the environment; (2) consistency with the provisions of the
National Technology Transfer and Advancement Act of 1995, which
encourages Federal regulatory agencies to consider adopting voluntary
consensus standards as an alternative to de novo agency development of
standards affecting an industry; (3) consistency with the NRC's policy
of evaluating the latest versions of consensus standards in terms of
their suitability for endorsement by regulations and regulatory guides;
and (4) consistency with the NRC's goal to harmonize with international
standards to improve regulatory efficiency for both the NRC and
international standards groups.
The NRC has had a decades-long practice of approving and/or
mandating the use of certain parts of editions and addenda of ASME
Codes and certain ASME Code Cases in Sec. 50.55a through the
rulemaking process of ``incorporation by reference.'' Continuing this
practice in this proposed rule ensures regulatory stability and
predictability. This practice also provides consistency across the
industry and provides assurance to the industry and the public that the
NRC will continue to support the use of the most updated and
technically sound techniques developed by the ASME to provide adequate
protection to the public. The ASME Codes are voluntary consensus
standards developed by technical committees composed of mechanical
engineers and others who represent the broad and varied interests of
their industries, from manufacturers and installers to insurers,
inspectors, distributors, regulatory agencies, and end users. The
standards undergo extensive external review before the NRC considers
whether to incorporate them by reference. Finally, the NRC's use of the
ASME Codes is consistent with the NTTAA, which directs Federal agencies
to adopt voluntary consensus standards instead of developing
``government-unique'' (i.e., Federal
[[Page 9735]]
agency-developed) standards, unless inconsistent with applicable law or
otherwise impractical.
The draft regulatory analysis concludes that this proposed rule
should be adopted because it is justified when integrating the cost-
beneficial quantitative results and the positive and supporting
nonquantitative considerations in the decision. For more information,
please see the draft regulatory analysis as indicated in Section XVII,
``Availability of Documents,'' of this document.
Table of Contents
I. Obtaining Information and Submitting Comments
A. Obtaining Information
B. Submitting Comments
II. Background
A. Proposed Incorporation by Reference of the 2023 BPV Code
Edition
B. Proposed Incorporation by Reference of Three Regulatory
Guides
C. Direct Final Rule for Noncontroversial Code Cases
III. Discussion
A. Proposed Incorporation by Reference of the 2023 BPV Code
Edition
B. Proposed Incorporation by Reference of Three Regulatory
Guides
C. Editorial Corrections
IV. Specific Requests for Comments
V. Section-by-Section Analysis
VI. Generic Aging Lessons Learned Report
VII. Regulatory Flexibility Certification
VIII. Regulatory Analysis
IX. Backfitting and Issue Finality
A. Proposed Incorporation by Reference of the 2023 BPV Code
Edition
B. Proposed Incorporation by Reference of Three Regulatory
Guides
X. Plain Writing
XI. Environmental Assessment and Proposed Finding of No Significant
Environmental Impact
A. Proposed Incorporation by Reference of the 2023 BPV Code
Edition
B. Proposed Incorporation by Reference of Three Regulatory
Guides
XII. Paperwork Reduction Act
XIII. Executive Orders
A. Executive Order 12866: Regulatory Planning and Review (as
Amended by Executive Order 14215: Ensuring Accountability for All
Agencies)
B. Executive Order 14154: Unleashing American Energy
C. Executive Order 14192: Unleashing Prosperity Through
Deregulation
D. Executive Order 14270: Zero-Based Regulatory Budgeting To
Unleash American Energy
XIV. Voluntary Consensus Standards
XV. Incorporation By Reference--Reasonable Availability to
Interested Parties
XVI. Availability of Guidance
XVII. Availability of Documents
I. Obtaining Information and Submitting Comments
A. Obtaining Information
Please refer to Docket ID NRC-2020-0029 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-2020-0029.
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]. 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, Monday through Friday, except Federal
holidays.
Technical Library: The Technical Library, which is located
at Two White Flint North, 11545 Rockville Pike, Rockville, Maryland
20852, is open by appointment only. Interested parties may make
appointments to examine documents by contacting the NRC Technical
Library by email at [email protected] between 8 a.m. and 4 p.m.
eastern time, 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-2020-0029 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. Background
A. Proposed Incorporation by Reference of the 2023 BPV Code Edition
The American Society of Mechanical Engineers (ASME) develops and
publishes the ASME Boiler and Pressure Vessel (BPV) Code, which
contains requirements for the design, construction, and inservice
inspection (ISI) of nuclear power plant components. Until 2012, the
ASME issued new editions of the ASME BPV Code every 3 years and addenda
to the editions annually, except in years when a new edition was
issued. Starting in 2012, the ASME decided to issue editions of its BPV
Code (no addenda) every 2 years on the odd years (e.g., 2013, 2015,
etc.). The new editions typically revise provisions of the ASME BPV
Code to broaden their applicability, add specific elements to current
provisions, delete specific provisions, and/or clarify them to narrow
the applicability of the provision. The revisions to the editions of
the ASME BPV Code do not significantly change code philosophy or
approach.
The ASME also develops and publishes the ASME Operation and
Maintenance (OM) Code, which contains requirements for inservice
testing (IST) of nuclear power plant components. The ASME periodically
publishes new editions and addenda of the ASME OM Code. Starting in
2012, the ASME decided to issue editions of its OM Code (no addenda)
every 2 years on the even years (e.g., 2012, 2014, etc.). However, the
ASME did not publish a 2024 edition of the OM Code.
The NRC's practice is to establish requirements for the design,
construction, operation, ISI (examination), and IST of nuclear power
plants by approving the use of editions of the ASME BPV and OM Codes
(ASME Codes) in Sec. 50.55a of title 10 of the Code of Federal
Regulations (10 CFR). The NRC approves or mandates the use of certain
parts of editions of these ASME Codes in Sec. 50.55a through
[[Page 9736]]
the rulemaking process of incorporation by reference. Upon
incorporation by reference of the ASME Codes into Sec. 50.55a, the
provisions of the ASME Codes are legally-binding NRC requirements as
delineated in Sec. 50.55a, and subject to the conditions on certain
specific ASME Codes' provisions that are set forth in Sec. 50.55a. The
most recent editions of the ASME Codes were last incorporated by
reference into the NRC's regulations in a final rule dated August 30,
2024 (89 FR 70449).
The ASME Codes are voluntary consensus standards developed by
participants, including the NRC and licensees of nuclear power plants,
who have broad and varied interests. The ASME's adoption of new
editions of the ASME Codes does not mean that there is unanimity on
every provision in the ASME Codes. There may be disagreement among the
technical experts, including the NRC's representatives on the ASME Code
committees and subcommittees, regarding the acceptability or
desirability of a particular code provision included in an ASME-
approved Code edition. If the NRC believes that there is a significant
technical or regulatory concern with a provision in an ASME-approved
Code edition being considered for incorporation by reference, then the
NRC conditions the use of that provision when it incorporates by
reference that ASME Code edition into its regulations. In some
instances, the condition increases the level of safety afforded by the
ASME Code provision, or addresses a regulatory issue not considered by
the ASME. In other instances, where research data or experience has
shown that certain code provisions are unnecessarily conservative, the
condition may provide that the code provision need not be complied with
in some or all respects. The NRC's conditions are included in Sec.
50.55a, typically in paragraph (b) of that section. In a Staff
Requirements Memorandum (SRM) dated September 10, 1999, the Commission
indicated that NRC rulemakings adopting (incorporating by reference) a
voluntary consensus standard must identify and justify each part of the
standard that is not adopted. For this proposed rule, the provisions of
the 2023 Edition of Section III, Division 1, and the 2023 Edition of
Section XI, Division 1, of the ASME BPV Code that the NRC is not
adopting, or is only partially adopting, are identified in the
``Discussion,'' ``Regulatory Analysis,'' and ``Backfitting and Issue
Finality'' sections of this document. The provisions of those specific
editions and code cases that are the subject of this proposed rule that
the NRC finds to be conditionally acceptable, together with the
applicable conditions, are also identified in the ``Discussion,''
``Regulatory Analysis,'' and ``Backfitting and Issue Finality''
sections of this document.
The ASME Codes are voluntary consensus standards, and the NRC's
incorporation by reference of these Codes is consistent with applicable
requirements of the National Technology Transfer and Advancement Act
(NTTAA). Additional discussion on the NRC's compliance with the NTTAA
is set forth in Section XIV of this document, ``Voluntary Consensus
Standards.''
B. Proposed Incorporation by Reference of Three Regulatory Guides
The ASME develops and publishes the ASME BPV Code, which contains
requirements for the design, construction, and inservice inspection of
nuclear power plant components, and the ASME OM Code, which contains
requirements for preservice and inservice testing of nuclear power
plant components. In response to BPV and OM Code user requests, the
ASME develops code cases that provide voluntary alternatives to BPV and
OM Code requirements.
The NRC approves the ASME Codes in Sec. 50.55a, ``Codes and
standards,'' through the process of incorporation by reference. As
such, each provision of the ASME Codes incorporated by reference into
and mandated by Sec. 50.55a constitutes a legally-binding NRC
requirement imposed by rule. As noted previously, the ASME Code cases,
for the most part, represent alternative approaches for complying with
provisions of the ASME BPV and OM Codes. Accordingly, the NRC
periodically amends Sec. 50.55a to incorporate by reference the NRC's
regulatory guides (RGs) listing approved ASME Code cases that may be
used as voluntary alternatives to the BPV and OM Codes.
This proposed rule is the latest in a series of rules that
incorporate by reference new versions of several RGs that identify new,
revised, and reaffirmed ASME Code cases that the NRC unconditionally or
conditionally approves for use. In developing these RGs, the NRC
reviews the ASME BPV and OM Code Cases, determines the acceptability of
each code case, and publishes its findings in the RGs. The RGs are
revised periodically as new code cases are published by the ASME. The
NRC incorporates by reference the RGs listing acceptable and
conditionally acceptable ASME Code Cases into Sec. 50.55a. The NRC
published a final rule dated July 17, 2024 (89 FR 58039), that
incorporated by reference into Sec. 50.55a the most recent versions of
the RGs, which are RG 1.84, ``Design, Fabrication, and Materials Code
Case Acceptability, ASME Section III,'' Revision 40; RG 1.147,
``Inservice Inspection Code Case Acceptability, ASME Section XI,
Division 1,'' Revision 21; and RG 1.192, ``Operation and Maintenance
Code Case Acceptability, ASME OM Code,'' Revision 5.
C. Direct Final Rule for Noncontroversial Code Cases
In a direct final rule (DFR) (90 FR 46319; [published September 26,
2025, effective January 26, 2026]), the NRC incorporated by reference
RG1.262, ``ASME Code Cases Approved for Use Without Conditions.'' This
new approach to ASME Code Case rulemaking implements Commission
direction in SRM-SECY-21-0029 regarding streamlining Sec. 50.55a
rulemaking activities. The NRC considers the code cases approved in RG
1.262 to be noncontroversial in nature without the need for regulatory
conditions, such that issuing a DFR is an appropriate rulemaking
process. This approach allows the NRC to approve such code cases in a
more efficient manner than was possible under the former process (see
final rule, ``American Society of Mechanical Engineers Code Cases and
Update Frequency,'' issued July17,2024 (89 FR 58039)). In developing
RG1.262, the NRC reviewed the ASME BPV and OM Code Cases, determined
the acceptability of each code case, and published its findings in the
RG. This RG will be revised periodically as the NRC determines that new
code cases published by the ASME are acceptable without NRC regulatory
conditions and are noncontroversial. Using this new approach, the NRC
approved these ASME Code Cases for use by incorporating RG 1.262 by
reference into Sec. 50.55a. This rule supplements that DFR by
addressing code cases that need additional NRC regulatory conditions or
are otherwise potentially controversial.
III. Discussion
A. Proposed Incorporation by Reference of the 2023 BPV Code Edition
The NRC regulations incorporate by reference ASME Codes for nuclear
power plants. This proposed rule is the latest in a series of
rulemakings to amend the NRC's regulations to incorporate by reference
revised and updated ASME Codes for nuclear power
[[Page 9737]]
plants. This proposed rule is intended to maintain the safety of
nuclear power plants and make NRC activities more effective and
efficient.
The NRC follows a three-step process to determine acceptability of
new provisions in new editions of the ASME Codes and the need for
conditions on the uses of these ASME Codes. This process was employed
in the review of the ASME BPV Code that is the subject of this proposed
rule. First, the NRC actively participates with other ASME committee
members with full involvement in discussions and technical debates in
the development of new and revised Code provisions. This includes
technical justification of each new or revised Code provision. Second,
the NRC's committee representatives discuss the Code provisions and
technical justifications with other cognizant staff to ensure an
adequate technical review. Third, the NRC position on each Code
provision is reviewed and approved by NRC management as part of this
proposed rule amending Sec. 50.55a to incorporate by reference new
editions of the ASME Codes and conditions on their use. This regulatory
process, when considered together with the ASME's own process for
developing and approving the ASME Codes, assures that the NRC approves
for use only those new and revised code editions, with conditions as
necessary, that provide reasonable assurance of adequate protection to
the public health and safety, and that do not have significant adverse
impacts on the environment.
The NRC reviewed changes to the ASME BPV Code identified in this
proposed rule. The NRC concluded, in accordance with the process for
review of changes to the Codes, that this edition of the Code is
technically adequate, consistent with current NRC regulations, and
approved for use with the specified conditions upon the conclusion of
the rulemaking process.
The NRC is proposing to amend its regulations to incorporate by
reference the 2023 Editions of the ASME BPV Code, Section III, Division
1 and Section XI, Division 1, with conditions on their use.
The current regulations in Sec. 50.55a(a)(1)(i) incorporate by
reference ASME BPV Code, Section III, 1963 Edition through the 1970
Winter Addenda; and the 1971 Edition (Division 1) through the 2021
Edition (Division 1), subject to the conditions identified in current
Sec. 50.55a(b)(1)(i) through (xiv). This proposed rule would revise
Sec. 50.55a(a)(1)(i) to incorporate by reference the 2023 Edition
(Division 1) of the ASME BPV Code, Section III with Errata 23-2471,
``NB-5332(a)(2) (from R/N 22-1562),'' dated April 4, 2024. It also
would clarify the wording and add or revise some of the conditions as
explained in this proposed rule.
The current regulations in Sec. 50.55a(a)(1)(ii) incorporate by
reference ASME BPV Code, Section XI, 1974 Edition through the 1975
Summer Addenda, the 1995 Edition (Division 1) through the 1997 Addenda
(Division 1), and the 2001 Edition (Division 1) through the 2021
Edition (Division 1), subject to the conditions identified in current
Sec. 50.55a(b)(2)(i) through (l). This proposed rule would revise
Sec. 50.55a(a)(1)(ii) to incorporate by reference the 2023 Edition
(Division 1) of the ASME BPV Code, Section XI. It also would clarify
the wording and add, remove, or revise some of the conditions as
explained in this proposed rule.
In the introductory discussion of its Codes, ASME specifies that
errata to those Codes may be posted on the ASME website under the
Committee Pages to provide corrections to incorrectly published items,
or to correct typographical or grammatical errors in those Codes. Users
of the ASME Codes should be aware of errata when implementing the
specific provisions of those Codes. Applicants and licensees should
monitor errata to determine when they might need to submit a request
for an alternative under Sec. 50.55a(z) to implement provisions
specified in an errata to their ASME Code of Record. Each of the
proposed NRC conditions and the reasons for each are discussed in the
following sections of this document. The discussions are organized
under the applicable ASME Code and Section.
The NRC prepared an unofficial redline strikeout version of the
proposed changes to regulatory text that is intended to help the reader
identify the proposed changes. The unofficial redline strikeout version
of the proposed rule is publicly available and provided in the
``Availability of Documents'' section.
i. ASME BPV Code, Section III
Section 50.55a(a)(1)(i)(E) Rules for Construction of Nuclear Facility
Components--Division 1
The NRC proposes to revise Sec. 50.55a(a)(1)(i)(E) to incorporate
by reference the 2023 Edition of the ASME BPV Code, Section III,
including Subsection NCA and Division 1 Subsections NB through NG and
Appendices, with Errata 23-2471, ``NB-5332(a)(2) (from R/N 22-1562),''
dated April 4, 2024. As stated in Sec. 50.55a(a)(1)(i), the
Nonmandatory Appendices are excluded and not incorporated by reference.
The Mandatory Appendices are incorporated by reference because they
include information necessary for Division 1. However, the Mandatory
Appendices also include material that pertains to other Divisions that
have not been reviewed and approved by the NRC. Although this
information is included in the sections and appendices being
incorporated by reference, the NRC notes that the use of Divisions
other than Division 1 has not been approved, nor are they required by
NRC regulations and, therefore, such information is not relevant to NRC
applicants and licensees. The NRC is not taking a position on the non-
Division 1 information in the appendices and is including it in the
incorporation by reference only for convenience. Therefore, this
proposed rule revises the introductory text to Sec. 50.55a(a)(1)(i)(E)
to reference the 2023 Edition of the ASME BPV Code, Section III,
including Subsection NCA and Division 1 Subsections NB through NG and
Appendices, with Errata 23-2471, ``NB-5332(a)(2) (from R/N 22-1562),''
dated April 4, 2024.
Section 50.55a(a)(1)(v)(B) ASME NQA-1, ``Quality Assurance Requirements
for Nuclear Facility Applications''
The NRC proposes to revise Sec. 50.55a(a)(1)(v)(B) to include the
2017, 2019, and 2022 editions of NQA-1. The 2017, 2019, and 2022
editions of NQA-1 were endorsed, with conditions, by the NRC in
Revision 6 of RG 1.28.
Section 50.55a(b)(1)(xiv) Section III Condition: Repairs to Stamped
Components
The NRC proposes to revise Sec. 50.55a(b)(1)(xiv) to extend the
applicability of the condition through the latest edition of the ASME
BPV Code, Section III incorporated by reference in paragraph (a)(1)(i).
The 2023 Edition of Section III was not updated to include the
provisions of this condition. Therefore, the NRC is proposing to revise
this condition to apply to the latest edition incorporated by
reference.
Section 50.55a(b)(1)(xv) Section III Condition: Protection From
Deterioration of Radiographic Film and Lifetime Record Retention
The NRC proposes to add condition Sec. 50.55a(b)(1)(xv) to require
that reasonable protection from deterioration of radiographic film
specified in Note (3) to Table NCA-4134.17-1 and Note (1) to Table NCA-
4134.17-2 of the 2023 Edition of the ASME BPV Code, Section
[[Page 9738]]
III, must include the provisions in NCA-4134.17(c), and the
reproduction must be retained as a record in accordance with Table NCA-
4134.17-1 or NCA-4134.17-2, as applicable, of the 2023 Edition of
Section III. A similar condition, Sec. 50.55a(b)(2)(liii), is proposed
in this rule for IWA-6310(b) of the 2023 ASME BPV Code, Section XI. The
condition is in two provisions as follows:
Section 50.55a(b)(1)(xv)(A) Protection From Deterioration of
Radiographic Film and Lifetime Record Retention, First Provision
NCA-4134.17(d) requires records listed in Table NCA-4134.17-1 to be
classified as lifetime records and shall be retained and maintained for
the life of the plant. In the 2023 Edition of the ASME BPV Code,
Section III, Note (3) to Table NCA-4134.17-1 specifies that
deterioration of radiographic film is expected and radiographic film
that has deteriorated to the point where it no longer has value does
not need to be maintained as a record by the owner.
However, the NRC notes that there are existing provisions in NCA-
4134.17(c) that allow reproduction of radiographic film, including by
electronic processes (e.g., digitize) before the original film's
deterioration. Therefore, the NRC is proposing to add Sec.
50.55a(b)(1)(xv)(A) to condition Note (3) of Table NCA-4134.17-1 of the
2023 Edition of Section III to require that the reasonable protection
from deterioration of radiographic film shall include the provisions
specified in NCA-4134.17(c) of the 2023 Edition of Section III, and the
reproduction must be retained as a lifetime record in accordance with
Table NCA-4134.17-1 of the ASME BPV Code, Section III. This would
maintain the current requirements in the 2021 Edition of the ASME BPV
Code, Section III.
Section 50.55a(b)(1)(xv)(B) Protection From Deterioration of
Radiographic Film and Nonpermanent Record Retention, Second Provision
NCA-4134.17(e) requires records listed in Table NCA-4134.17-2 to be
classified as nonpermanent records and shall be retained for the period
specified in Table NCA-4134.17-2 (10 years for radiographic film). In
the 2023 Edition of the ASME BPV Code, Section III, Note (1) to Table
NCA-4134.17-2 specifies that deterioration of radiographic film is
expected and radiographic film that has deteriorated to the point where
it no longer has value does not need to be maintained as a record by
the owner.
However, the NRC notes that there are existing provisions in NCA-
4134.17(c) that allow reproduction of radiographic film, including by
electronic processes (e.g., digitize) before the original film's
deterioration. Therefore, the NRC is proposing to add Sec.
50.55a(b)(1)(xv)(B) to condition Note (1) of Table NCA-4134.17-2 of the
2023 Edition of Section III to require that the reasonable protection
from deterioration of radiographic film shall include the provisions
specified in NCA-4134.17(c) of the 2023 Edition of Section III, and the
reproduction must be retained as a nonpermanent record in accordance
with NCA-4134.17-2 of the ASME BPV Code, Section III. This would
maintain the current requirements in the 2021 Edition of the ASME BPV
Code, Section III.
ii. ASME BPV Code, Section XI
Section 50.55a(a)(1)(ii)(C) ASME Boiler and Pressure Vessel Code,
Section XI
The NRC proposes to amend the regulations in Sec.
50.55a(a)(1)(ii)(C) to incorporate by reference the 2023 Edition
(Division 1) of the ASME BPV Code, Section XI. The current regulations
in Sec. 50.55a(a)(1)(ii)(C) incorporate by reference ASME BPV Code,
Section XI, the 1974 Edition through the 1975 Summer Addenda, the 1995
Edition (Division 1) through the 1997 Edition (Division 1), and the
2001 Edition (Division 1) through the 2021 Edition (Division 1),
subject to the conditions identified in current Sec. 50.55a(b)(2)(i)
through (l).
Section 50.55a(a)(1)(iii)(A) ASME BPV Code Case N-513-3 Mandatory
Appendix I
The NRC proposes to remove and reserve Sec. 50.55a(a)(1)(iii)(A)
to delete the incorporation by reference of ASME BPV Code Case N-513-3,
Mandatory Appendix I. This mandatory appendix was previously
incorporated by reference as a reference for Sec. 50.55a(b)(2)(xxxiv),
Section XI Condition: Nonmandatory Appendix U. The reference to
Mandatory Appendix I was removed from this condition in a previous
rulemaking, and Mandatory Appendix I is no longer referenced in this
section. Therefore, this proposed rule would remove and reserve Sec.
50.55a(a)(1)(iii)(A).
Section 50.55a(b)(2)(xii) Section XI Condition: Underwater Welding
The NRC proposes to revise Sec. 50.55a(b)(2)(xii) to limit the
applicability of the condition to the 2001 Edition through the 2021
Edition of ASME BPV Code, Section XI. The current regulations in Sec.
50.55a(b)(2)(xii) state that the condition applies to the latest
edition and addenda incorporated by reference in Sec.
50.55a(a)(1)(ii). In the 2023 Edition of ASME BPV Code, Section XI,
ASME modified subparagraph IWA-4661(f) to add provisions that satisfy
the conditions in Sec. 50.55a(b)(2)(xii). Therefore, these conditions
do not apply to the 2023 Edition.
Section 50.55a(b)(2)(xviii) Section XI Condition: NDE Personnel
Certification
The NRC proposes to remove and reserve the first provision of this
condition in Sec. 50.55a(b)(2)(xviii)(A). The current regulations in
Sec. 50.55a(b)(2)(xviii) provide four provisions related to
qualification rules for nondestructive evaluation (NDE) personnel. The
condition was added in 2002 (67 FR 60520) when the 1997 Addenda, and
1998 and later Editions of ASME Code, Section XI revised the
requirement for recertification of Level I and Level II NDE personnel
from 3 years to 5 years. This was before the widespread implementation
of ASME BPV Code, Section XI, Appendix VIII rules for the performance
demonstration requirements for personnel performing ultrasonic testing
(UT). At that time the NRC had lower confidence in the quality of the
qualifications for the NDE personnel, equipment, and procedures.
ASME provided the NRC a letter dated August 23, 2024, describing
the basis for removing the provision. The basis can be summarized as
saying that changes and improvements to the 8-hour, hands-on practice
work done by NDE personnel mandated by Sec. 50.55a(b)(2)(xiv) have
been shown to maintain the proficiency of NDE personnel. Experience
with 5-year recertifications in non-nuclear fields and internationally
with ISO 9712, ``Non-destructive testing--Qualification and
certification of NDT personnel,'' supports their contention that a 5-
year recertification rate does not adversely impact the skill levels of
the NDE personnel. The NRC agrees that the improvements in NDE rigor
and experience with the 8-hour, hands-on training have shown that a 5-
year recertification rate is acceptable and will provide adequate
proficiency for NDE personnel.
Additionally, the NRC proposes to revise Sec.
50.55a(b)(2)(xviii)(D) to clarify that the alternatives listed in
paragraphs (b)(2)(xviii)(D)(1) and (2) are applicable to ASME BPV Code,
Section XI, editions and addenda later than the 2010 Edition. When
using these editions and addenda, the current provision to this
condition requires licensees and applicants to use the prerequisites
for
[[Page 9739]]
ultrasonic examination personnel certifications in Appendix VII, Table
VII-4110-1 and Appendix VIII, Subarticle VIII-2200 in the 2010 Edition.
Although alternatives to these prerequisites currently exist in
Sec. Sec. 50.55a(b)(2)(xviii)(D)(1) and 50.55a(b)(2)(xviii)(D)(2), the
current provision paragraph does not make it clear that these
alternatives are acceptable because it does not refer to them as
options. Therefore, the NRC is proposing to clarify that the
alternatives are acceptable to meet the requirement.
Section 50.55a(b)(2)(xxv) Section XV Condition: Mitigation of Defects
by Modification
The NRC proposes to revise Sec. 50.55a(b)(2)(xxv) to correct an
error in the title. The current title of Sec. 50.55a(b)(2)(xxv)
incorrectly states ``Section XV Condition.'' This proposed change would
correct the title to state ``Section XI Condition.''
Section 50.55a(b)(2)(xxviii) Section XI Condition: Analysis of Flaws
The NRC proposes to revise Sec. 50.55a(b)(2)(xxviii) to clarify
that the condition applies to A-4300(b)(1) for the ASME BPV Code,
Section XI, 2021 Edition and earlier. For the 2023 Edition, this
proposed change would clarify that the condition applies to Y-3100(c).
In the 2023 Edition, ASME moved the fatigue crack growth law for
ferritic steels in air from A-4300 to Y-3100. The existing condition in
Sec. 50.55a(b)(2)(xxviii) still applies to Y-3100.
Section 50.55a(b)(2)(xxxi) Section XI Condition: Mechanical Clamping
Devices
The NRC proposes to revise Sec. 50.55a(b)(2)(xxxi) to add several
provisions related to the use of mechanical clamping devices. In the
2023 Edition of the ASME BPV Code, Section XI, Appendix W was revised
to remove the prohibition on the use of mechanical clamps for Class 1
piping, portions of piping that form the containment boundary, piping
larger than nominal pipe size (NPS) 2 with nominal operating
temperature of 200 [deg]F (95 [deg]C) and nominal pressure of 275
pounds per square Inch gauge (psig) (1,900 kilopascal (kPa)), and
piping larger than NPS 6 (DN 150). Note that Nonmandatory Appendix W
was previously Code Case N-523 in the early 2000s, and was later
incorporated into a mandatory appendix, and finally in the 2013 Edition
of Section XI, was made into Nonmandatory Appendix W.
The existing Sec. 50.55a(b)(2)(xxxi) condition specifies that when
installing a mechanical clamping device on an ASME BPV Code class
piping system, Appendix W of Section XI shall be treated as a mandatory
appendix and all of the provisions of Appendix W shall be met for the
mechanical clamping device being installed. Additionally, the second
part of the condition specifies that use of IWA-4131.1(c) of the 2010
Edition of Section XI and IWA-4131.1(d) of the 2011 Addenda of the 2010
Edition and later versions of Section XI is prohibited on small item
Class 1 piping and portions of a piping system that form the
containment boundary. The change to Appendix W was not modified in a
way that would make it possible for the NRC to remove this condition.
Additionally, the NRC proposes four new provisions to be added to
the condition as follows:
The prohibition in Appendix W for use on Class 1 piping
was removed by ASME because it is not specified in the title of the
Nonmandatory Appendix W. However, the NRC notes that this condition is
to ensure that Class 1 is not applicable to this Appendix and will not
be an oversight in future revisions. Further discussion of this
included interpretations in other sections of ASME Code, that could
allow use of mechanical clamps on Class 1 piping which was discussed in
a final rule titled ``Incorporation be Reference of American Society of
Mechanical Engineers Codes and Code Cases'' (82 FR 32934; July 18,
2017) that incorporated by reference the 2013 Edition of the ASME Code.
Therefore, the NRC is proposing to include a condition that prohibits
the use of Appendix W on Class 1 piping to provide clarity that the
change in the ASME Code does not reflect a change in applicability of
Appendix W to Class 1 piping.
The prohibition in Appendix W for use on piping that forms
part of the containment boundary was removed by the ASME based on NRC
approval of alternative requests submitted using Sec. 50.55a(z)(2).
Although the NRC approved the use of Appendix W on a case-by-case basis
on certain systems, the NRC has not allowed Appendix W to be used
generically on an unlimited basis on numerous joints and systems that
collectively could affect the function of the system. Requesting NRC
approval through the Sec. 50.55a(z) processes allows specific
applications and limits the frequency on its use within each system as
to ensure that the structural margin is maintained, thereby reducing
the potential for challenging the structural integrity of the joints
and system. Therefore, the NRC is proposing to include a condition that
prohibits the use of Appendix W on piping that forms part of the
containment boundary.
The prohibition in Appendix W for use on piping larger
than NPS 2 (DN 50) when the nominal operating temperature or pressure
exceeds 200 [deg]F (95 [deg]C) or 275 psig (1,900 kPa) was removed. The
NRC notes that the potential consequence of failure of a high-energy
line piping limits the use of the mechanical clamps. High-energy lines
can produce consequences that are severe and challenge the function of
components and systems to safely shut down the reactor. Therefore, the
NRC is proposing to include a condition that prohibits the use of
Appendix W on piping larger than NPS 2 (DN 50) when the nominal
operating temperature or pressure exceeds 200 [deg]F (95 [deg]C) or 275
psig (1,900 kPa), which maintains the previous prohibition in earlier
editions of Appendix W.
The prohibition in Appendix W for use on piping greater
than NPS 6 (DN 150) was removed by the ASME based on NRC approval of
one alternative request submitted using Sec. 50.55a(z)(2). However,
this approval was for a discharge line that did not affect the system's
ability to perform its safety function of removing heat. Approving the
use of Appendix W on a case-by-case basis on certain locations in
systems does not allow it to be used generically on an unlimited basis
on numerous joints and systems that collectively could affect the
function of the system. The limitations on the frequency on its use
within each system is to ensure that the structural margin is
maintained, thereby reducing the potential for challenging the
structural integrity of the joints. Therefore, the NRC is proposing to
include a condition that prohibits the use of Appendix W on piping
greater than NPS 6 (DN 150), which maintains the prohibition from
earlier editions of Appendix W.
Section 50.55a(b)(2)(xxxiv) Section XI Condition: Nonmandatory Appendix
U
The NRC proposes to revise Sec. 50.55a(b)(2)(xxxiv)(B) to extend
the applicability of the condition to the 2023 Edition of ASME BPV
Code, Section XI. This condition prohibits the use of Nonmandatory
Appendix U, Supplement U-S1. The provisions of U-S1 are redundant to
those in Code Case N-513. The purpose of Sec. 50.55a(b)(2)(xxxiv)(B)
is to clarify that the more up-to-date approach of Code Case N-513 is
the appropriate method for temporary acceptance of flaws in moderate
energy piping. This condition remains applicable to the 2023 Edition of
the ASME BPV Code, Section XI.
[[Page 9740]]
Section 50.55a(b)(2)(xliv) Section XI Condition: Nonmandatory Appendix
Y
The NRC proposes to revise Sec. 50.55a(b)(2)(xliv) to correct
errors, extend its applicability to the 2023 Edition of the ASME BPV
Code, Section XI, and add one provision.
The current regulations in Sec. 50.55a(b)(2)(xliv) incorrectly
reference Subarticle Y-2440, when the correct reference is Subarticle
Y-2400. The current regulations in Sec. 50.55a(b)(2)(xliv) also
incorrectly reference Articles Y-2200 and Y-3200, when the correct
reference is Subarticles Y-2200 and Y-3200. This proposed revision
would correct those errors.
The NRC imposed Sec. 50.55a(b)(2)(xliv) on the 2021 Edition of the
ASME BPV Code, Section XI, because the crack growth laws in Subarticles
Y-2200, Y-2400, and Y-3200 are duplicated in Code Cases N-809, N-889,
and N-643, respectively. The purpose of Sec. 50.55a(b)(2)(xliv) is to
eliminate duplication and clarify that the code cases should govern.
Sec. 50.55a(b)(2)(xliv) remains applicable to the 2023 Edition of the
ASME BPV Code, Section XI.
ASME added crack growth laws for nickel alloys to Article Y-4000 in
the 2023 Edition of the ASME BPV Code, Section XI. In particular, ASME
added factors of improvement for Alloys 690, 52, 152, and variant welds
in paragraph Y-4322. The rules added to paragraph Y-4322 are duplicated
in Code Case N-909. The NRC's position is that the relevant code case
should govern whenever there are overlapping requirements between the
ASME BPV Code and a code case. Therefore, the NRC is proposing to add
Sec. 50.55a(b)(2)(xliv)(D) to prohibit use of paragraph Y-4322.
Section 50.55a(b)(2)(xlv) Section XI Condition: Pressure Testing of
Containment Penetration Piping After Repair/Replacement Activities
The NRC proposes to revise Sec. 50.55a(b)(2)(xlv) to extend the
applicability of the condition through the latest edition of the ASME
BPV Code, Section XI incorporated by reference in paragraph (a)(1)(ii).
The 2023 Edition of Section XI was not updated to include the
provisions of this condition. Therefore, the NRC is proposing to revise
this condition to apply to the latest edition incorporated by
reference.
Section 50.55a(b)(2)(xlvi) Section XI Condition: Contracted Repair/
Replacement Organization Fabricating Items Offsite of the Owner's
Facility
The NRC proposes to revise Sec. 50.55a(b)(2)(xlvi) to extend the
applicability of the condition through the latest edition of the ASME
BPV Code, Section XI incorporated by reference in paragraph (a)(1)(ii).
The 2023 Edition of Section XI was not updated to include the
provisions of this condition. Therefore, the NRC is proposing to revise
this condition to apply to the latest edition incorporated by
reference.
Section 50.55a(b)(2)(xlviii) Section XI Condition: Analytical
Evaluations of Degradation
The NRC proposes to revise Sec. 50.55a(b)(2)(xlviii) to extend the
applicability of the condition through the latest edition of the ASME
BPV Code, Section XI, incorporated by reference in paragraph
(a)(1)(ii), and make an editorial correction. This condition requires
that licensees submit to the NRC analytical evaluations performed under
ASME BPV Code, Section XI, IWB-3132.3 and IWC-3122.3. The original
requirements to submit these evaluations previously resided in ASME BPV
Code, Section XI, IWB-3134 and IWC-3125. ASME removed these
requirements in the 2019 Edition of ASME BPV Code, Section XI. The
current reference for ASME Class 2 analytical evaluation is incorrectly
referenced as IWC-3132.3 versus the correct reference of IWC-3122.3. As
an editorial change, the reference has been updated. This condition
remains applicable to the 2023 Edition of ASME BPV Code, Section XI.
Section 50.55a(b)(2)(li) Section XI Condition: Pressure Testing
Following Repair/Replacement Activity
The NRC proposes to add condition Sec. 50.55a(b)(2)(li) to
prohibit the use of IWA-4540(d)(7) in the 2023 Edition of the ASME BPV
Code, Section XI, for exempting pressure testing of Class 2 and 3 welds
that have a surface or volumetric examination performed. Current ASME
Code requirements specify a pressure test of most welds regardless of
the non-destructive examination performed. The current exemptions for
pressure testing are for welds in components or connections NPS 1 (DN
25) or smaller and other miscellaneous welds such as
tube[hyphen]to[hyphen]tubesheet welds and seal welds. ASME added IWA-
4540(d)(7) in the 2023 Edition of ASME BPV Code, Section XI, exempting
pressure testing of Class 2 and 3 welds that are examined by a
volumetric or surface examination following repair/replacement.
An ASME Code pressure test, with or without NDE, after a repair/
replacement activity is needed to ensure the ASME Class 2 and 3 system,
including emergency core cooling systems, would be able to perform its
intended function to safely shut down and maintain the reactor in a
safe condition. In addition, a pressure test is a defense-in-depth
measure, supplementing any surface or volumetric NDE conducted, even as
required by the Construction Code. The purpose of the pressure test, in
this role, is to address the possible uncertainty associated with
various NDE techniques. In addition, operational experience has shown
pressure tests identify flaws that were not revealed by volumetric and
surface examinations. Leakage from a component immediately after being
repaired indicates a quality issue that must be addressed. The NRC
position is that a pressure test should be conducted in addition to any
surface or volumetric NDE required on a repaired or replaced ASME Class
2 or 3 component. Therefore, the NRC is proposing to add Sec.
50.55a(b)(2)(li) to condition provisions IWA-4540(d)(7) of the 2023
Edition of the ASME Code, Section XI, to prohibit the exemption of
performing a pressure testing for Class 2 and 3 welds that have had a
surface or volumetric examination performed.
Section 50.55a(b)(2)(lii) Section XI Condition: Preservice and
Inservice Volumetric Examination of Nozzles Fabricated From Weld
Buildups
The NRC proposes to add condition Sec. 50.55a(b)(2)(lii) to
require preservice and inservice volumetric examination of nozzles
fabricated from weld buildups specified in Figure IWB-2500-7(d) of the
2023 Edition of the ASME BPV Code, Section XI. ASME changed Figure IWB-
2500-7(d) in the 2023 Edition to allow nozzles fabricated by weld
buildups to be installed without preservice or inservice examinations
throughout the life of the component. Nozzles fabricated by weld
buildup have multiple weld passes, which each provide an opportunity
for flaws to be located within the weld buildup. These flaws could
propagate during service and could cause component failure.
Currently, nozzles fabricated from weld buildups, such as in the
AP1000 design, are required to have a preservice and inservice
volumetric examination performed. This condition would be consistent
with current requirement for AP1000 design which consists of a
volumetric examination (ultrasonic) of weld buildups and are performed
with procedures and personnel to the ASME BPV Code, Section XI,
Appendix VIII using acceptance criteria of IWB-3514 for Category B-F
welds in the ASME BPV Code, Section XI. Therefore, the NRC is proposing
to add
[[Page 9741]]
Sec. 50.55a(b)(2)(lii) to condition provisions in Figure IWB-2500-7(d)
of the 2023 Edition of the ASME BPV Code, Section XI, to require
preservice and inservice volumetric examination of nozzles fabricated
from weld buildups. This maintains the requirements from previous
editions of the Code. The volumetric examination (ultrasonic) of weld
buildups shall be performed with procedures and personnel to the ASME
BPV Code, Section XI, Mandatory Appendix VIII using acceptance criteria
of IWB-3514 for Category B-F welds in the ASME BPV Code, Section XI.
Section 50.55a(b)(2)(liii) Section XI Condition: Protection From
Deterioration of Radiographic Film and Lifetime Record Retention
The NRC proposes to add condition Sec. 50.55a(b)(2)(liii) to
require that reasonable protection from deterioration of radiographic
film specified in IWA-6310(b) of the 2023 Edition of the ASME BPV Code,
Section XI, shall include the provisions in IWA-6320 and the
reproduction must be retained as a lifetime record in accordance with
IWA-6330, IWA-6340, and IWA-6350 of the ASME BPV Code, Section XI.
IWA-6300 requires final radiographic film to be maintained as a
lifetime record in accordance with IWA-6330, IWA-6340, and IWA-6350 of
the ASME BPV Code, Section XI. In the 2023 Edition, ASME added IWA-
6310(b), which specifies that film deteriorates and therefore need not
be maintained. While IWB-6310(b) specifies that reasonable protection
from deterioration for radiographic film shall be provided, it also
states that deterioration of radiographic film is to be expected and is
not a violation of the requirement to provide suitable protection. The
new provision further states that if radiographic film has
deteriorated, it need no longer be maintained as a lifetime record, as
determined by the owner.
However, the NRC notes that there are existing provisions in IWA-
6320 that allow reproduction of radiographic film, including by
electronic processes (e.g., digitize) before the original film's
deterioration. Therefore, the NRC is proposing to add Sec.
50.55a(b)(2)(liii) to condition provision IWA-6310(b) of the 2023
Edition of the ASME BPV Code, Section XI, to require that the
reasonable protection from deterioration of radiographic film shall
include the provisions specified in IWA-6320, and the reproduction must
be retained as a lifetime record in accordance with IWA-6330, IWA-6340,
and IWA-6350. This would maintain the current requirements in the 2021
Edition of the ASME BPV Code, Section XI.
A similar condition, Sec. 50.55a(b)(1)(xv), is proposed in this
rule for Table NCA-4134.17 of the ASME BPV Code, Section III.
Section 50.55a(g)(6)(ii)(D)(9) Volumetric Qualifications
The NRC proposes to revise Sec. 50.55a(g)(6)(ii)(D)(9) to allow
for qualification of volumetric evaluation in accordance with Section
XI, Division 1, Mandatory Appendix VIII, Supplement 15, in the 2021
Edition through the latest edition and addenda incorporated by
reference in paragraph (a)(1)(i) of this section. Licensees have the
option to use the latest version of Supplement 15 in lieu of the
requirements of Code Case N-729-6. The proposed change would allow
licensees to utilize the 2023 Edition of Supplement 15 as an option to
the volumetric qualification requirements of Code Case N-729-6.
Section 50.55a(g)(6)(ii)(F)(2)(iv) Categorization
The NRC proposes to revise Sec. 50.55a(g)(6)(ii)(F)(2)(iv) to
include inspection item B-3 in the list of categorization options for
identification of cold leg temperature welds. Inspection item B-3
(auxiliary head adapter butt welds) was previously part of inspection
item B-1. This proposed revision maintains the same requirements and
only clarifies the expansion of categorization options for licensees
for auxiliary head adapter butt welds.
Section 50.55a(g)(6)(ii)(F)(13) Encoded Ultrasonic Examination
The NRC proposes to revise Sec. 50.55a(g)(6)(ii)(F)(13) to include
inspection item B-3 in the list of encoded volumetric exams. Inspection
item B-3, auxiliary head adapter butt welds, was previously part of
inspection item B-1. This proposed revision maintains the same
requirements for encoded volumetric exams.
B. Proposed Incorporation by Reference of Three Regulatory Guides
This proposed rule would incorporate by reference the latest
revisions of the NRC's RGs that list the ASME BPV and OM Code Cases
that the NRC finds to be acceptable, or acceptable with NRC-specified
conditions (``conditionally acceptable''). RG 1.84, Revision 41 (DG-
1446) would supersede the incorporation by reference of Revision 40; RG
1.147, Revision 22 (DG-1447) would supersede the incorporation by
reference of Revision 21; and RG 1.192, Revision 6 (DG-1448) would
supersede the incorporation by reference of Revision 5.
The ASME BPV Code Cases that are the subject of this proposed rule
are the new and revised Section III and Section XI Code Cases as listed
in Supplements 3 through 6 to the 2021 Edition of the ASME BPV Code and
Supplements 0 through 3 to the 2023 Edition of the ASME BPV Code. By
letter dated October 18, 2024, ASME requested that the NRC consider
including, in part, Code Cases N-752-2, N-926 and N-934 in this
proposed rulemaking. In response, the NRC included these three code
cases within the scope of this proposed rule. The NRC also is proposing
to include OMN-32, Revision 1, ``Alternative Requirements for Range and
Accuracy of Pressure, Flow, and Differential Pressure Instruments Used
in Pump Tests,'' and OMN-34, ``Use of Pump Curve Testing,'' within the
scope of this proposed rule.
The ASME publishes code cases that provide alternatives to existing
code requirements that the ASME developed and approved. This proposed
rule would incorporate by reference the most recent revisions of RGs
1.84, 1.147, and 1.192, which allow nuclear power plant licensees, and
applicants for combined licenses, standard design certifications,
standard design approvals, and manufacturing licenses under the
regulations that govern license certifications, to use the code cases
listed in these RGs as suitable alternatives to the ASME BPV and OM
Codes for the construction, inservice inspections, and inservice
testing of nuclear power plant components. The ASME makes the issued OM
Code Cases available on the OM Code website and provides an index
listing the issued OM Code Cases and their applicability in each ASME
OM Code edition. The ASME publishes BPV Code Cases in a separate
document and at a different time than the ASME BPV Code Editions. This
proposed rule identifies the ASME BPV Code Cases by the edition of the
ASME BPV Code under which they were published by the ASME and the OM
Code Cases by the most recent edition of the ASME OM Code to which they
apply.
The following general guidance applies to the use of the ASME Code
Cases approved in the latest versions of the RGs that are incorporated
by reference into Sec. 50.55a as part of this proposed rule.
Specifically, the use of the code cases listed in the latest versions
of RGs 1.84, 1.147, and 1.192 are acceptable with the specified
conditions when implementing the editions and addenda of the ASME BPV
[[Page 9742]]
and OM Codes incorporated by reference in Sec. 50.55a.
The approval of a code case in these RGs constitutes acceptance of
its technical position for applications that are not precluded by other
requirements. The applicant or licensee is responsible for ensuring
that use of the code case does not conflict with regulatory
requirements or licensee commitments. The code cases listed in the RGs
are acceptable for use within the limits specified in the code cases.
If the RG states an NRC condition on the use of a code case, then the
NRC condition supplements and does not supersede any limitation(s)
specified in the code case, unless otherwise stated in the NRC
condition.
The ASME Code Cases may be revised for many reasons (e.g., to
incorporate operational examination and testing experience or to update
material requirements based on research results). On occasion, an
inaccuracy in an equation is discovered or an examination, as
practiced, is found not to be adequate to detect a newly discovered
degradation mechanism. Therefore, when an applicant or a licensee
initially implements a code case, Sec. 50.55a requires that the
applicant or the licensee implement the most recent version of that
code case, as listed in the RGs incorporated by reference. Code cases
superseded by revision are no longer acceptable for new applications
unless otherwise indicated.
Section III of the ASME BPV Code applies to new construction (e.g.,
the edition and addenda to be used in the construction of a plant are
selected based on the date of the construction permit and are not
changed thereafter, except voluntarily by the applicant or the
licensee). Section III also may be used for repair and replacement
activities under the provisions of Section XI of the ASME BPV Code.
Whether used for construction or later repair or replacement, when a
code case is first implemented by a licensee, the applicant implements
the latest edition incorporated by reference into Sec. 50.55a.
Thereafter, the applicant or licensee may continue to apply the
previously implemented version of the code case or may apply the later
version of the code case, including any NRC-specified conditions placed
on its use.
Code cases apply to specific editions and addenda, and code cases
may be revised for various reasons. Licensees that were using a code
case before the effective date of a final rule incorporating by
reference a regulatory guide in Sec. 50.55a(a)(3) may continue to use
the previous version until the next update to the code of record for
the ISI or IST program, as applicable. This relieves licensees of the
burden of having to update their ISI or IST program each time a code
case is revised by the ASME and approved for use by the NRC. The rules
for applying code cases are described in Sec. Sec. 50.55a(b)(4),
50.55a(f)(4), and 50.55a(g)(4).
The ASME may annul code cases that are no longer required, are
determined to be inaccurate or inadequate, or have been incorporated
into the ASME BPV or OM Codes. A code case may be revised, for example,
to incorporate user experience. The older or superseded version of the
code case cannot be applied by the licensee or applicant if it is the
first use of that code case. If an applicant or a licensee applied a
code case before it was listed as superseded or annulled, the applicant
or the licensee may continue to use the code case until the applicant
or the licensee updates its Construction Code of record (or updates its
application, in the case of an applicant) or until the licensee's code
of record interval for the ISI or IST program expires, after which the
continued use of the code case is prohibited unless NRC authorization
is given under Sec. 50.55a(z). If a code case is incorporated by
reference into Sec. 50.55a and later a revised version is issued by
the ASME because experience has shown that the design analysis,
construction method, examination method, or testing method is
inadequate, the NRC will amend Sec. 50.55a and the relevant RG to
remove the approval of the superseded code case. Applicants and
licensees should not begin to implement such superseded code cases in
advance of the rulemaking.
i. Code Cases Proposed To Be Approved for Unconditional Use
The code cases discussed in Table 2 are new, revised, or reaffirmed
code cases in which the NRC is not proposing any conditions. The table
identifies the draft regulatory guide listing the applicable code case
that the NRC proposes to approve for use.
Table II--Acceptable Code Cases
----------------------------------------------------------------------------------------------------------------
Operation and maintenance code (addressed in DG-1448, Table 1)
-----------------------------------------------------------------------------------------------------------------
Code case No. Edition Title
----------------------------------------------------------------------------------------------------------------
OMN-32 (Revision 1)........................... 2022 Alternative Requirements for Range and Accuracy
of Pressure, Flow, and Differential Pressure
Instruments Used in Pump Tests.
OMN-34........................................ 2022 Use of a Pump Curve for Testing.
----------------------------------------------------------------------------------------------------------------
ii. Code Cases Proposed To Be Approved for Use With Conditions
The NRC has determined that certain code cases, as issued by the
ASME, are generally acceptable for use, but that the alternative
requirements specified in those code cases must be supplemented in
order to provide an acceptable level of quality and safety.
Accordingly, the NRC proposes to impose conditions on the use of these
code cases to modify, limit, or clarify their requirements. The
conditions would specify, for each applicable code case, the additional
activities that must be performed, the limits on the activities
specified in the code case, and/or the supplemental information needed
to provide clarity. These ASME Code Cases, listed in Table III, are
included in Table 2 of DG-1447 (RG 1.147) and DG-1448 (RG 1.192). This
section provides the NRC's evaluation of the code cases and the reasons
for the NRC's proposed conditions. Notations indicate the conditions
duplicated from previous versions of the RG.
The NRC requests public comment on these code cases and the
proposed conditions. It also should be noted that this section only
addresses those code cases for which the NRC proposes to impose
condition(s), which are listed in the RG for the first time.
[[Page 9743]]
Table III--Conditionally Acceptable Code Cases
------------------------------------------------------------------------
Boiler and pressure vessel code, Section XI (addressed in DG-1447, Table
2)
-------------------------------------------------------------------------
Published with
Code case No. supplement Title
------------------------------------------------------------------------
N-508-5.............. 6 (2021 Edition) Rotation of Snubbers and
Pressure Retaining Items for
the Purpose of Testing or
Preventive Maintenance.
N-666-3.............. 0 (2023 Edition) Weld Overlay of Class 1, 2, and
3 Socket Welded Connections.
N-716-4.............. 1 (2023 Edition) Alternative Classification and
Examination Requirements.
N-752-2.............. 6 (2023 Edition) Risk-Informed Categorization
and Treatment for Repair/
Replacement Activities in
Class 2 and 3 Systems.
N-778-1.............. 0 (2023 Edition) Alternative Requirements for
Preparation and Submittal of
Inservice Inspection Plans,
Schedules, and Preservice and
Inservice Inspection Summary
Reports.
N-806-2.............. 3 (2023 Edition) Analytical Evaluation of Metal
Loss in Class 2 and 3 Metallic
Piping Buried in a Back-Filled
Trench.
N-830-1.............. 3 (2021 Edition) Direct Use of Fracture
Toughness for Flaw Evaluations
of Pressure Boundary Materials
in Class 1 Ferritic Steel
Components.
N-926................ 6 (2021 Edition) Alternative Examination
Requirements for Unbonded Post-
Tensioning Systems of Class CC
Components.
N-930................ 0 (2023 Edition) Alternative Experience
Requirements for
Nondestructive Examination
Personnel for Ultrasonic
Examination.
------------------------------------------------------------------------
ASME BPV Code, Section XI Code Cases (DG-1447/RG 1.147)
Code Case N-508-5 [Supplement 6, 2021 Edition]
Type: Revised.
Title: Rotation of Snubbers and Pressure Retaining Items for the
Purpose of Testing or Preventive Maintenance.
Code Case N-508 describes the circumstances under which items may
be rotated from stock for routine maintenance and testing without
following all the repair/replacement rules of IWA-4000. In Revision 5
of the code case, ASME removed a prescriptive list of items and
replaced it with ``pressure retaining items'' This change allows the
code case to be applied to a broader range of components, such as
valves and heat exchangers, that may be similarly rotated from stock.
While the NRC has no objection to the broader application of this code
case as allowed in Revision 5, the existing condition on Code Case N-
508-4 remains applicable. Therefore, the NRC proposes to approve Code
Case N-508-5 and retain the existing condition.
Code Case N-666-3 [Supplement 0, 2023 Edition]
Type: Revised.
Title: Weld Overlay of Class 1, 2, and 3 Socket Welded Connections.
Code Case N-666 provides an alternative to the defect removal
provisions of IWA-4420 by installation of weld overlay for restoring
structural integrity of a cracked or leaking socket weld if a failure
is a result of vibration fatigue. N-666-1 is currently listed in Table
2 of RG 1.147 as conditionally acceptable for use. Revision 2 extended
the applicability of the code case to dissimilar metal socket welds,
addressed the NRC condition regarding surface examination after
installation of the weld overlay on Class 1 and Class 2 piping socket
welds, deleted the prohibition on welding on water backed P-No. 1 Group
2 materials with a carbon content greater than 0.30 percent, and
removed filler metal requirements. Revision 3 of the code case
superseded revision 2 and specified applicability to tubing socket
welds and removes NIS-2 Form documentation requirements.
In revision 2 of the code case, ASME added P-43 base materials and
dissimilar welds between P-No. 1 and P-No. 8, between P-No. 8 and P-No.
43, and between P-No. 1 and P-No. 43. P-No. 43 base materials are Ni-
Cr-Fe materials such as Alloys 600 and 690. The NRC finds the addition
of P-No. 43 material and dissimilar metal welds is acceptable because
the mechanical fatigue characteristics of nickel-based alloys and their
associated filler materials are expected to be similar to that of
stainless steel, which was listed as approved in Code Case N-666-1.
In revision 3 of the code case, ASME added the terms ``tube'' and
``tubing'' in relevant sections to explicitly allow for weld overlay
repair of tubing socket welds. Moreover, the revision included the
deletion of the section requiring documenting the code case on an NIS-2
Form. This section was deemed redundant and unnecessary, as IWA-6211(d)
already mandates the documentation of all repair/replacement activities
on this form. The NRC finds these revisions to be acceptable.
The current condition on N-666-1 in Regulatory Guide 1.147,
Revision 21, states that the licensee must perform a surface
examination and disposition the results according to the construction
code. ASME modified the provisions of 5(a)(1) of the code case to
require such examination and disposition of results. The NRC finds this
change to be acceptable and proposes to remove the existing condition
for Code Case N-666-3.
ASME modified the provisions of 1(b) of the code case to remove the
limitation against water backed welding of P-No. 1 Group 2 materials
with a carbon content greater than 0.30 percent. The NRC has approved
alternative requests for welding P-No. 1 Group 2 materials with a
carbon content up to 0.35 percent (ML20111A337). However, the use of
low hydrogen electrodes when applying the shielded metal arc welding
(SMAW) process and the use of stringer beads were part of the basis for
approval, since this welding approach limits the potential for hydrogen
induced cracking. Therefore, the NRC proposes to add a condition to
Code Case N-666-3 requiring that only stringer beads (no weaving) be
used, and that when using the SMAW process, low hydrogen electrodes are
used when welding P-No. 1 Group 2 materials with carbon content greater
than 0.30 percent.
ASME deleted the listing of American Welding Society filler metal
classifications to be used. The NRC finds this change acceptable
because the code case requires that welding procedure specifications
must be qualified in accordance with the ASME BPV Code Section XI, IWA-
4440, which in turn references ASME BPV Code, Section IX. This ensures
that welding filler materials used are compatible with the base
materials and weld materials over which the weld overlay is applied.
However, as noted above, when the
[[Page 9744]]
SMAW process is used, the NRC proposes to require low hydrogen
electrodes when welding materials with a carbon content greater than
0.30 percent carbon.
Code Case N-716-4 [Supplement 1, 2023 Edition]
Type: Revised.
Title: Alternative Classification and Examination Requirements.
Code Case N-716 provides requirements for risk-informed
classification and examination for Class 1 piping welds, Class 2
components, Class 3 components, or non-class components. Code Case N-
716-3 is listed in Regulatory Guide 1.147, Revision 21, as acceptable
for use with the condition that it is not approved for use by plants
issued an operating license or combined license after January 1, 2012.
In revision 4 of the code case, the ASME modifies the successive
examination requirements for items with multiple degradation mechanisms
in cases where an initial examination has revealed flaws or relevant
conditions exceeding the acceptance standards of Section XI Article
IWB-3000, Article IWC-3000, or Article IWD-3000, as applicable. In Code
Case N-716-3, all welds were assigned different possible degradation
mechanisms, such as fatigue cracking, stress corrosion cracking, or no
degradation mechanism. If an item was subject to multiple degradation
mechanisms, all applicable degradation mechanisms were listed for the
item. If a flaw was found during examination activities, the owner
determined the damage mechanism. In Code Case N-716-3, the expanded
scope for additional examinations included inspection items with the
same postulated degradation mechanism and the combination of
degradation mechanisms. In revision 4 of the code case, the ASME
limited the scope of the additional examinations to include only those
items with the same combination of degradation mechanisms.
The NRC proposes to maintain the condition imposed on Code Case N-
716-3, as the code case was not modified to address the condition. The
NRC position is that there are enough variables possible in the design
of new reactors that the NRC should review the proposed degradation
mechanisms and risk related information for new plants before
application of the code case. Regarding the revision to the scope
expansion rules, the NRC objects to the option of limiting the scope
expansion to only those locations classified according to the same
degradation combination, because an insufficient technical basis was
provided to show that this method would be effective in assessing the
true extent of condition. The proposed Condition 2 would preserve the
wording on Section 6, ``Successive Inspections and Additional
Examinations,'' sub-paragraphs (b)(1)(-b) and (b)(1)(-c), from Code
Case N-716-3.
Code Case N-752-2 [Supplement 6, 2023 Edition]
Type: Revised, no current NRC position.
Title: Risk-Informed Categorization and Treatment for Repair/
Replacement Activities in Class 2 and 3 Systems.
Code Case N-752 provides a process for determining the risk-
informed categorization and treatment for repair/replacement activities
on Class 2 and 3 items that are categorized as low safety significant.
Revision 1 of the code case provided clarification on the scope of the
code case. Revision 2 of the code case focused categorization and
safety evaluation on items versus systems, clarified requirements for
supports, removed requirements for probabilistic risk assessment (PRA)
updates, allowed a piping segment to be a single item, provided an
additional option to verify technical adequacy of the PRA, removed the
requirements to consider external events such as seismic, and added a
new footnote to clarify no optionally Class 1 or Class 1 exempt item
can be categorized by this case before reclassification as non-Class 1
in accordance with the applicable change control process. The NRC has
not previously issued a position on Code Cases N-752 or N-752-1. The
NRC has reviewed Code Case N-752-2 and determined it to be acceptable
for use, with conditions as specified in RG 1.147.
The NRC proposes to add a condition that the owner shall review
changes to the plant, operational practices, applicable plant and
industry operational experience, and, as appropriate, update the PRA
and categorization and treatment processes, and that the owner shall
perform this review in a timely manner but no longer than once every
two refueling outages. Consistent with plant-specific Code Case N-752
relief request approvals, a review of the plant PRA must be completed
in a timely manner because the periodic update of the plant PRA may
affect the results of the categorization process. The validity of the
categorization process relies on ensuring that the performance and
conditions of structures, systems, and components (SSCs) continue to be
maintained consistent with applicable assumptions. Changes in the level
of treatment applied to an SSC might result in changes in the
reliability of SSCs credited in the categorization process. These
changes along with modifications to the plant, operational practices
and experiences should be reflected in the PRA on a consistent basis to
ensure accuracy and credibility of categorization results.
In approving the use of Code Case N-752-2, the NRC specifies that
Subparagraph-1420 from IWA-1400(o) does not relieve licensees of
obligations to document quality assurance programs or otherwise affect
NRC requirements for quality assurance outside of Sec. 50.55a (e.g.,
Appendix B to 10 CFR part 50 and Sec. 50.54(a)). Footnote 1 in Code
Case N-752-2 states that if compliance with 10 CFR part 50, Appendix B,
``Quality Assurance Criteria for Nuclear Power Plants and Fuel
Reprocessing Plants,'' or ASME Standard NQA-1, ``Quality Assurance
Requirements for Nuclear Facility Applications,'' is required at the
owner's facility, then IWA-1400(o) in ASME BPV Code, Section XI,
Division 1, is not exempt. This language in Code Case N-752-2 and
earlier versions caused confusion among nuclear power plant licensees
regarding the applicability of 10 CFR part 50, Appendix B, when
implementing Code Case N-752. The NRC resolved this confusion in NRC
Information Notice 2025-01, ``Lessons Learned When Implementing ASME
Code Case N-752,'' by stating that licensees are required to comply
with the quality assurance requirements in 10 CFR part 50, Appendix B,
for safety-related Class 2 and Class 3 low safety significant items.
Information Notice 2025-01 notes that the NRC has approved specific
changes to the Quality Assurance Program Descriptions related to the
implementation of Code Case N-752. For early uses of Code Case N-752,
licensees followed Sec. 50.54(a)(4) to establish risk-informed
supplemental processes and procedures that the NRC accepted as
satisfying the requirements of 10 CFR part 50, Appendix B, given the
low safety significance of the components within the scope of Code Case
N-752. For later adoptions of Code Case N-752, licensees followed Sec.
50.54(a)(3) to apply risk-informed quality assurance treatment of
components within the scope of Code Case N-752. The NRC regulations in
Sec. 50.54(a)(3) allow licensees to adjust their quality assurance
activities as accepted by the NRC in response to prior licensee
requests under Sec. 50.54(a)(4). Therefore, licensees are encouraged
to review prior licensee requests under Sec. 50.54(a)(4) to
[[Page 9745]]
determine the extent of the risk-informed quality assurance treatment
for components within the scope of Code Case N-752 allowed under Sec.
50.54(a)(3).
In approving the use of Code Case N-752-2, the NRC also specifies
that for a supporting requirement to be met, all relevant peer review
and other independent findings shall have been addressed and necessary
changes made to PRA models, methods, and documentation. In addition,
all relevant peer review facts and observations (F&Os) findings for the
internal events and internal flooding PRA shall have been dispositioned
and closed out using an acceptable process. Examples of NRC-endorsed
processes for these activities include NEI 17-07 Revision 2 and
Appendix X to NEI 05-04/7-12/12-06. A peer review of the PRA is
performed to determine whether the requirements established in national
consensus PRA standards, as endorsed by the NRC with exceptions and
clarifications, have been met. To remove the need for NRC review of
plant-specific PRAs in support of Code Case N-752-2, all relevant peer
review findings must be closed using an acceptable close-out process.
An acceptable close-out process includes NEI 17-07 Revision 2, as
endorsed by the NRC in RG 1.200, ``Acceptability of Probabilistic Risk
Assessment Results for Risk-Informed Activities,'' Revision 3,
Regulatory Position C.2.2. Another acceptable close-out process
includes NEI 05-04/07-12/12-06, Appendix X: ``Close-Out of Facts and
Observations (F&Os),'' dated February 21, 2017, as accepted by NRC by
letter dated May 3, 2017. The implementation of an acceptable closure
process is intended to provide the needed confidence in the resolution
of peer review F&Os against the requirements in the national consensus
PRA standard such that, when used in support of Code Case N-752-2, it
will remove the need for an in-depth review of the licensee's F&O
resolutions by NRC reviewers.
The NRC issued a policy statement on the use of PRA methods in NRC
activities in the Federal Register on August 16, 1995. The NRC's 1995
Policy Statement on the use of PRA states that the use of PRA
technology should be increased to the extent supported by the state-of-
the-art in PRA methods and data and in a manner that complements the
NRC's deterministic approach. Since the NRC issued its PRA policy
statement, a number of risk-informed regulatory activities have been
implemented and necessary technical documents developed to provide
guidance on the use of PRA information. This guidance includes RG
1.200, which describes one acceptable approach for determining the
requisite technical adequacy of the PRA is sufficient to provide
confidence in the results. The RG revisions reference successive
consensus PRA standards developed by the ASME and the American Nuclear
Society (ANS). RG 1.200, Revision 1, references ASME RA-S-2002-2002,
ASME RA-Sa-2003 and ASME RA-Sb-2005 standards; and RG 1.200, Revisions
2 and 3, references ASME/ANS RA-Sa-2008 and ASME/ANS RA-Sa-2009
standards. Furthermore, in March 2007, the NRC issued Regulatory Issue
Summary (RIS) 2007-06, ``Regulatory Guide 1.200 Implementation'' which
states ``the NRC would expect licensees to fully address all scope
elements consistent with Revision 2 of RG 1.200 by the end of 2009.''
Because of regulatory and industry initiatives, the majority of the
U.S. nuclear fleet currently have peer reviewed PRAs that show
conformance to RG 1.200, Revision 2. The NRC finds the technical
adequacy of the base PRA, as determined by RG 1.200, Revision 1, to be
sufficient with regard to use of Code Case N-752-2 to provide the
needed confidence in the results. In alignment with the NRC's policy
statement on the use of PRA, RIS 2007-06 and the status of PRAs for the
U.S. nuclear fleet, the licensee also may elect to use RG 1.200,
Revision 2, or RG 1.200, Revision 3, to ensure the technical adequacy
of the PRA by meeting supporting requirements that correspond to
supporting requirements in RG 1.200, Revision 1. This can include full-
scope peer review of internal events and internal flooding PRA against
RG 1.200, Revision 2, as well as a gap assessment of earlier peer
reviews of the internal events and internal flooding PRA against RG
1.200, Revision 2. The NRC reviewed the requirements of Table I-7 and
concluded that the corresponding supporting requirements endorsed in RG
1.200, Revision 2 and Revision 3, are adequate to meet the requirements
of Table I-7 for technical adequacy of the PRA. Therefore, the NRC
determined that licensee PRA programs that conform to RG 1.200,
Revision 2 or Revision 3, would meet the requirements of N-752-2 as
incorporated by reference in RG 1.147.
The NRC considered internal flooding supporting requirements for
inclusion in Table I-7 of Code Case N-752-2, consistent with
requirements for Code Case N-716-1, ``Alternative Classification and
Examination Requirements Section XI, Division 1,'' Mandatory Appendix
2, as endorsed in RG 1.147. The NRC evaluated the difference in
supporting requirements and concluded the methodology as outlined in
Section I-3.3.1, ``Modes and Effects Analysis,'' part (c), ``Indirect
Effects,'' adequately addresses spatial effects, as defined in the
glossary, to include flooding as part of the consequence evaluation.
The NRC considered whether a qualitative assessment should be
performed to adjust the consequence rank to reflect the pressure
boundary's failure impact on the mitigation of external events. The NRC
determined that the baseline risk from external events would have a
minimal influence on the categorization results, which already assume
complete loss of the pressure retaining item and which are primarily
driven by the availability and reliability of mitigating systems
responding to direct and indirect effects of the item's failure. This
NRC evaluation is consistent with feedback from industry stakeholders,
licensees in public meetings, and audit discussions related to passive
categorization.
Code Case N-778-1 [Supplement 0, 2023 Edition]
Type: Revised.
Title: Alternative Requirements for Preparation and Submittal of
Plans, Schedules, and Preservice and Inservice Inspection Summary
Reports.
Code Case N-778 offers alternatives to the requirements of IWA-
1400(c) and IWA-6240 for the preparation and submission of various
inspection reports and plans. In revision 1 of the code case, the ASME
modified the submission period for the inservice inspection summary
report to the NRC from 90 days to 120 days. The NRC does not object to
allowing licensees more time to prepare and submit the report.
Code Case N-778-1, paragraph (d), states that ``Plans, schedules,
and preservice and inservice inspection summary reports shall be
submitted to the enforcement and regulatory authorities having
jurisdiction at the plant site, if required by these authorities.'' The
existing conditions on Code Case N-778 specify that the preservice
inspection and inservice inspection summary reports shall be submitted
to the NRC and the timing of such submissions. Since the code case
still qualifies the requirement with ``if required by these
authorities,'' the NRC proposes to retain the existing condition.
Code Case N-806-2 [Supplement 3, 2023 Edition]
Type: Revised.
[[Page 9746]]
Title: Analytical Evaluation of Metal Loss in Class 2 and 3
Metallic Piping Buried in a Back-Filled Trench.
Code Case N-806 provides guidelines for assessing metal loss in
ASME Code Class 2 and 3 buried piping items, using data obtained from
inspection results. ASME revised this code case from N-806-1 based on
the NRC's comments. Revision 2 of the code case enhances methods for
flaw evaluation utilizing internal pressures, soil and surcharge loads,
and seismic loads. The main revision expands the analytical evaluation
framework to include Level 3 evaluations for seismic impacts on buried
piping as specified in the code case. Code Case N-806-2 is not
applicable to cast iron, leakage through a piping item or joint,
cracked piping items, non-metallic piping with or without a metallic
liner, and piping items with a minimum wall thickness of less than 0.1
inch (.25 cm).
Equation 16 of Section 6.2.2.2(c) is related to the buckling of the
buried pipe under external pressure. The existing Equation 16 requires
that Pss' <= Pcr/2, where Pss' is the
total external pressure plus negative internal pressure, Pcr
is the critical buckling pressure of the buried pipe, and ``2'' is the
structural factor. The NRC notes that Equation 16 for buckling due to
external pressure is similar to the buckling equation used in American
Lifelines Alliance, ``Guidelines for the Design of Buried Steel Pipe,''
July 2001 with Addenda through February 2005; NUREG/CR-6876, ``Risk-
Informed Assessment of Degraded Buried Piping System in Nuclear Power
Plants''; and A.P. Moser, Buried Pipe Design, Second Edition, McGraw-
Hill. However, the code case uses a structural factor of 2 in Equation
16 while these three references recommend a higher structural factor of
2.5 (when C/D = 2) or 3.0 (when C/D < 2), where C/D is soil depth to
pipe diameter ratio. Therefore, the NRC proposes to approve Code Case
N-806-2, with one condition to require the higher structural factors.
Code Case N-830-1 [Supplement 3, 2021 Edition]
Type: Revised.
Title: Direct Use of Fracture Toughness for Flaw Evaluations of
Pressure Boundary Materials in Class 1 Ferritic Steel Components.
Code Case N-830 defines fracture toughness models based on the
Master Curve Method in accordance with ASTM E1921, ``Standard Test
Method for Determination of Reference Temperature, T0, for
Ferritic Steels in the Transition Range,'' that may be used in lieu of
those specified in the ASME BPV Code, Section XI, Nonmandatory
Appendices A, G, and K.
The current condition on N-830 in Regulatory Guide 1.147, Revision
21, states that the use of Paragraph (f) in N-830 is prohibited. In
revision 1, ASME significantly revised and restructured this code case,
including a different transition temperature toughness curve. Since the
condition on the use of Paragraph (f) in N-830 applies to the
transition temperature toughness curve defined in N-830, this existing
condition is no longer applicable to the transition temperature
toughness curve defined in revision 1. Therefore, the NRC proposes to
remove the existing condition for Code Case N-830-1.
The NRC extensively reviewed Code Case N-830-1 while it was under
development. During the review, the NRC evaluated relevant aspects of
the fracture toughness models, including assumptions, datasets,
uncertainties and biases, limitations, and applicability. The NRC
generated over 40 comments to which the ASME Working Groups provided
responses. The NRC reviewed all responses and determined that they
adequately addressed the NRC's comments on the fracture toughness
models. During its review, the NRC also performed an independent
analysis of the fracture toughness models in the code case to confirm
the validity of the models for materials with low upper shelf energy.
The NRC confirmed that, where appropriate, the code case and technical
basis document were updated as a result of the NRC's review.
Code Case N-830-1 specifies that the transition reference
temperature be adjusted to account for effects of irradiation and notes
that the methods in ASTM Standard E900-15, ``Standard Guide for
Predicting Radiation-Induced Transition Temperature Shift in Reactor
Vessel Materials,'' may be used for this adjustment. The NRC noted that
while the methodology in ASTM E900-15 for calculating the transition
reference temperature shift is currently not in the regulations nor
endorsed by the NRC through a regulatory guide, it has been used in a
recent NRC final report titled ``Impacts of Embrittlement on Reactor
Pressure Vessel Integrity from a Risk-Informed Perspective,'' and in
SECY-22-0019, ``Rulemaking Plan for the Revision of Embrittlement and
Surveillance Requirements for High-Fluence Nuclear Power Plants in
Long-Term Operation.'' Accordingly, the NRC proposes to condition Code
Case N-830-1 to limit the methodology for determining the transition
reference temperature shift due to irradiation effects to a methodology
acceptable to the NRC, specifically Regulatory Guide 1.99, Revision 2,
``Radiation Embrittlement of Reactor Vessel Materials,'' including
appropriate conversion factors and margins.
Code Case N-926 [Supplement 6, 2021 Edition]
Type: New.
Title: Alternative Examination Requirements for Unbonded Post-
Tensioning Systems of Class CC Components, Section XI, Division 1.
Code Case N-926 provides an alternative examination schedule for
unbonded post-tensioning systems in Class CC containment structures.
The alternative applies to tendon groups that have completed the
required examinations at 20 years following the Structural Integrity
Test and have met additional criteria demonstrating long-term
structural integrity. Use of the alternative must be discontinued if
the specified criteria are not satisfied.
The NRC has reviewed Code Case N-926 and determined that it
provides an acceptable level of quality and safety for unbonded post-
tensioning systems of Class CC components in containment structures,
consistent with the provisions of Sec. 50.55a(z)(1). The code case
allows for a reduced testing frequency for tendon groups with a
demonstrated history of satisfactory performance. Continued use of the
alternative requires that test results remain within acceptable limits
and that tendon force predictions show adequate margins through the
next scheduled examination. In addition, the code case retains the
existing requirement for five-year visual inspections of tendon
assemblies. If these visual inspections identify degradation that may
impact tendon performance, corrective actions, including tendon
testing, may be necessary. The NRC's evaluation is further supported by
operating experience from several previously approved relief requests
that authorized similar reductions in tendon testing frequency. These
approvals were based on demonstrated long-term performance and
structural integrity of the tendon systems. This consistent operating
experience reinforces the conclusion that the alternative examination
schedule proposed in Code Case N-926 maintains an acceptable level of
quality and safety.
However, Code Case N-926 does not explicitly address tendons that
have undergone repair or replacement. To ensure consistent safety
standards, the NRC is proposing that the alternative requirements of
Code Case N-926 shall be applied to tendons affected by repair/
replacement activities only if examinations of those affected tendons
[[Page 9747]]
required by IWL-2521.2 at 20 years following tendon repair/replacement
activities have been completed and all requirements specified in the
``Scope'' paragraph of Code Case N-926 have been met.
Code Case N-930 [Supplement 0, 2023 Edition]
Type: New.
Title: Alternative Experience Requirements for Nondestructive
Examination Personnel for Ultrasonic Examination.
Code Case N-930 provides qualification requirements related to
ultrasonic examination personnel as part of the broader set of criteria
and standards outlined in the ASME BPV Code, Section XI. The code case
introduces alternative experience requirements for the qualification of
ultrasonic examination personnel, specifically for Levels II and III.
This code case presents an alternative to ASME BPV Code, Section XI,
Mandatory Appendix VII, Table VII-4100, accommodating the challenges of
reduced refueling outage durations and the application of risk-informed
inservice inspection programs.
While Table VII-4100 has minimum experience requirements for
personnel to be certified as ASME Levels I and II Ultrasonic (UT)
personnel, notes (c) and (d) of the table allow for substitution of
laboratory practice for all of the Level I experience hours and reduces
the experience hours for Level II from 800 experience hours to 400
total hours, 320 of which can be laboratory practice. Notes (c) and (d)
were added in the 2011 Addenda to the 2010 Edition of ASME BPV Code,
Section XI. As there was not a sufficient technical basis for the
reduction of hours and the substitution of laboratory practice, the NRC
held the requirements of the 2010 Edition via the condition in Sec.
50.55a(b)(2)(xviii)(D).
The NRC conducted research into the substitution of laboratory
practice hours for experience hours. This work was published in the
technical letter report ``Nondestructive Examination (NDE) Training and
Qualifications: Implications of Research on Human Learning and Memory,
Instruction and Expertise.'' This research showed that it can be
beneficial to substitute some experience hours with laboratory
practice, as while on-the-job experience helps to acclimate personnel
to the field environment, structured laboratory practice may provide
more experience with finding and sizing cracks and other flaws, as
there are relatively few in the power plants. Based on this research,
the NRC added Sec. 50.55a(b)(2)(xviii)(D)(1) and (2), which allow for
partial substitution of laboratory practice for experience hours for
Level I and II UT personnel.
In parallel with the NRC's research in this area, the Electric
Power Research Institute (EPRI) conducted a detailed evaluation of the
number of experience hours and the structure of the laboratory practice
that would be needed for personnel to obtain the needed skills to be
effective examiners. The results of the EPRI work were published in a
technical report titled ``Technical Basis for Nondestructive
Examination Experience Requirements for ASME Section XI, Appendix
VII.'' The NRC finds that the report provides a sufficient technical
basis to support the use of reduced hours and partial substitution of
laboratory hours for field experience for Personnel to obtain Levels I,
II, and III UT examiner certifications. These revised requirements are
described in ASME Code Case N-930. The requirements for Level I and II
personnel are similar to and consistent with the NRC conditions in
Sec. 50.55a(b)(2)(xviii)(D)(1) and (2). The reduced hours for UT Level
III certification are supported by the EPRI report, as well.
During a final revision to the code case, the total number of hours
was revised from 600 total hours to 630 to be consistent with the ASME
BPV Code, Section III UT Level II personnel experience requirements. As
an oversight, this change was not reflected in the allowed laboratory
practice hours in Note (d) in Table -4110-1 in the code case. The
revised ASME Code Case N-930-1 has been approved by ASME Code with NRC
support. Therefore, the NRC is proposing a condition to align Code Case
N-930 with Code Case N-930-1 and allow the use of the code case without
the error until Code Case N-930-1 is accepted into RG 1.147.
Other OM Code Cases in Proposed Revision 6 to RG 1.192
No changes were made to the OM Code Cases listed in proposed
Revision 6 to RG 1.192 (with the exception of new Code Cases OMN-32 and
OMN-34, discussed previously) from the versions that were listed in OM
Code Cases listed in Revision 5 to RG 1.192.
iii. Code Cases Not Approved for Use (DG-1449/RG-1.193)
The ASME Code Cases that are currently issued by the ASME but not
approved for generic use by the NRC are listed in RG 1.193, ``ASME Code
Cases not Approved for Use.'' In addition to the ASME Code Cases that
the NRC has found to be technically or programmatically unacceptable,
RG 1.193 includes code cases on reactor designs for high-temperature
gas-cooled reactors and liquid metal reactors, reactor designs not
currently licensed by the NRC, and certain requirements in Section III,
Division 2, for submerged spent fuel waste casks, that are not endorsed
by the NRC. RG 1.193 complements RGs 1.84, 1.147, and 1.192. It should
be noted that the NRC is not proposing to adopt any of the code cases
listed in RG 1.193. The NRC has included Revision 0 to OM Code Case
OMN-32 in RG 1.193, because Revision 1 to Code Case OMN-32 has resolved
the issues with Revision 0 of the code case.
C. Editorial Corrections
The NRC is proposing editorial corrections to Sec. Sec.
50.55a(a)(1), 50.55a(b)(2)(xliii), 50.55a(g)(4)(iv),
50.55a(g)(6)(ii)(F)(2)(v), 50.55a(g)(6)(ii)(F)(4), and
50.55a(g)(6)(ii)(F)(10). This proposed rule would correct a broken
hyperlink in Sec. 50.55a(a)(1), a typo to replace ``Licenses shall''
to ``Licensees shall,'' and the reference in Sec. 50.55a(g)(4)(iv)
from ``(a)(1)(iv) of this section'' to ``(a)(1)(iii) of this section''
and also correct references to the appropriate version of the ASME BPV
Code Case in Sec. 50.55a(g)(6)(ii)(F)(2)(v), (g)(6)(ii)(F)(4), and
(g)(6)(ii)(F)(10).
The references to ASME BPV Code Case N-770-5 would be replaced with
ASME BPV Code Case N-770-7 in Sec. 50.55a(g)(6)(ii)(F)(2)(v),
(g)(6)(ii)(F)(4), and (g)(6)(ii)(F)(10). ASME BPV Code Cases N-770-5
and N-770-7 versions are identical. All references in Sec.
50.55a(g)(6)(ii)(F)(2)(v), (g)(6)(ii)(F)(4), and (g)(6)(ii)(F)(10) to
ASME BPV Code Case N-770-5 should be replaced with N-770-7, with the
exception of Sec. 50.55a(g)(6)(ii)(F)(1), which discusses the
replacement to implement the requirements of ASME BPV Code Case N-770-7
instead of ASME BPV Code Case N-770-5.
Note that the content of the paragraphs and notes within the code
case specific to these conditions (1100(e), 2500(a), 2500(c), 2500(d),
Note 14(b) of Table 1, and Note (b) of Figure 5(a)) that are referenced
in the regulations contain no differences between the N-770-5 and N-
770-7 versions. Therefore, this correction would not cause any changes
in what is being referenced.
IV. Specific Requests for Comments
The NRC is seeking advice and recommendations from the public on
the proposed rule. The NRC is particularly interested in comments and
[[Page 9748]]
supporting rationale from the public on the following:
The NRC is proposing to remove and reserve Sec.
50.55a(a)(1)(iii)(A). This paragraph currently incorporates by
reference Mandatory Appendix I of Code Case N-513-3 and was previously
referenced in Sec. 50.55a(b)(2)(xxxiv)(B). However, this paragraph has
since been updated so that it no longer references the mandatory
appendix. Should the NRC instead retain Mandatory Appendix I of Code
Case N-513-3 in the list of documents approved for incorporation by
reference? Please provide the basis for your response.
V. Section-by-Section Analysis
The following paragraphs describe the specific changes to Sec.
50.55a proposed by this rulemaking.
Paragraph (a)(1)
This proposed rule would revise paragraph (a)(1) to correct the
broken hyperlink to https://www.asme.org/codes-standards.
Paragraph (a)(1)(i)(E)
This proposed rule would revise paragraphs (a)(1)(i)(E)(20) and
(21) and add new paragraph (a)(1)(i)(E)(22) to include the 2023
Edition.
Paragraph (a)(1)(ii)(C)
This proposed rule would revise paragraphs (a)(1)(ii)(C)(56) and
(57) and add new paragraph (a)(1)(ii)(C)(58) to include the 2023
Edition.
Paragraph (a)(1)(iii)(A)
This proposed rule would remove and reserve paragraph
(a)(1)(iii)(A). Mandatory Appendix I to ASME BPV Code Case N-513-3 is
no longer referenced in this section.
Paragraph (a)(1)(v)(B)
This proposed rule would revise paragraphs (a)(1)(v)(B)(5) and (6)
and add new paragraphs (a)(1)(v)(B)(7), (8), and (9) to include the
2017, 2019, and 2022 editions of NQA-1.
Paragraph (a)(3)(i)
This proposed rule would revise the reference to ``NRC Regulatory
Guide 1.84, Revision 40,'' by removing ``Revision 40'' and adding in
its place ``Revision 41'' and changing the month and year for the
document's revision date.
Paragraph (a)(3)(ii)
This proposed rule would revise the reference to ``NRC Regulatory
Guide 1.147, Revision 21,'' by removing ``Revision 21'' and adding in
its place ``Revision 22'' and changing the month and year for the
document's revision date.
Paragraph (a)(3)(iii)
This proposed rule would revise the reference to ``NRC Regulatory
Guide 1.192, Revision 5,'' by removing ``Revision 5'' and adding in its
place ``Revision 6'' and changing the month and year for the document's
revision date.
Paragraph (a)(3)(iv)
This proposed rule would revise the reference to ``NRC Regulatory
Guide 1.147, Revision 22,'' by removing ``Revision 21'' and adding in
its place ``Revision 22.''
Paragraph (b)(1)(xiv)
This proposed rule would revise paragraph (b)(1)(xiv) to update the
applicability of this paragraph through the latest edition incorporated
by reference in paragraph (a)(1)(i) of this section.
Paragraph (b)(1)(xv)
This proposed rule would add new paragraph (b)(1)(xv) to require
that protection from deterioration of radiographic film shall include
the provisions specified in NCA-4134.17(c) of the 2023 Edition of ASME
Code, Section III, and the copy must be retained as a record in
accordance with Table NCA-4134.17-1 or NCA-4134.17-2, as applicable, of
the 2023 Edition of Section III. The two provisions would be added in
new paragraphs (b)(1)(xv)(A) and (B).
Paragraph (b)(2)(xii)
This proposed rule would revise paragraph (b)(2)(xii) to update the
applicability of this paragraph through the 2021 Edition.
Paragraph (b)(2)(xviii)
This proposed rule would remove and reserve the provision in
paragraph (b)(2)(xviii)(A) because this provision is no longer
necessary. In addition, this proposed rule would revise paragraph
(b)(2)(xviii)(D) to clarify that the alternatives listed in paragraphs
(b)(2)(xviii)(D)(1) and (2) are applicable to editions and addenda
later than the 2010 Edition.
Paragraph (b)(2)(xxv)
This proposed rule would revise the title of paragraph (b)(2)(xxv)
from ``Section XV Condition'' to ``Section XI Condition.'' This is an
editorial correction.
Paragraph (b)(2)(xxviii)
This proposed rule would revise paragraph (b)(2)(xxviii) to add
paragraphs (A) and (B). Paragraph (A) would be the existing condition
applicable to the 2021 Edition and earlier. Paragraph (B) would be the
existing condition applicable to the 2023 Edition and replacing
reference to A-4300(b)(1) with reference to Y-3100(c).
Paragraph (b)(2)(xxxi)
This proposed rule would revise the current paragraph (b)(2)(xxxi)
to reformat the current condition to two separate provisions,
designated as new paragraphs (b)(2)(xxxi)(A) and (B). In addition, this
proposed rule would add four additional provisions, designated as new
paragraphs (b)(2)(xxxi)(C), (D), (E), and (F). The new provisions would
maintain current NRC position on the use of Nonmandatory Appendix W
concerning prohibiting use of mechanical clamps on piping for Class 1,
piping that forms the containment boundary, piping larger than NPS 2
(DN 50) when nominal operating temperature or pressure exceeds 200
[deg]F (95[deg]C) or 275 psig (1,900 kPa), and piping larger than NPS 6
(DN 150).
Paragraph (b)(2)(xxxiv)
This proposed rule would revise paragraph (b)(2)(xxxiv)(B) to
update the applicability of this paragraph through the 2023 Edition.
Paragraph (b)(2)(xliv)
This proposed rule would revise paragraph (b)(2)(xliv) to extend
its applicability to the 2023 Edition, correct errors, and add
paragraph (D). Paragraph (A) would be revised to ``Subarticle Y-2200''
instead of ``Article Y-2200.'' Paragraph (B) would be revised to
``Subarticle Y-2400'' instead of ``Subarticle Y-2440.'' Paragraph (C)
would be revised to ``Subarticle Y-3200'' instead of ``Article Y-
3200.'' New paragraph (D) would be added to prohibit the use of
Nonmandatory Appendix Y, Paragraph Y-4322.
Paragraph (b)(2)(xliii)
This proposed rule would revise paragraph 50.55a((b)(2)(xliii) to
correct a typo, revising ``Licenses shall'' to ``Licensees shall.''
Paragraph (b)(2)(xlv)
This proposed rule would revise paragraph (b)(2)(xlv) to extend its
applicability to the latest edition incorporated by reference in
paragraph (a)(1)(ii) of this section.
Paragraph (b)(2)(xlvi)
This proposed rule would revise paragraph (b)(2)(xlvi) to extend
its applicability to the latest edition
[[Page 9749]]
incorporated by reference in paragraph (a)(1)(ii) of this section.
Paragraph (b)(2)(xlviii)
This proposed rule would revise paragraph (b)(2)(xlviii) to extend
its applicability to the latest edition incorporated by reference in
paragraph (a)(1)(ii) of this section.
Paragraph (b)(2)(li)
This proposed rule would add new paragraph (b)(2)(li) to prohibit
the use of IWA-4540(d)(7) for the 2023 Edition.
Paragraph (b)(2)(lii)
This proposed rule would add new paragraph (b)(2)(lii) to require
preservice and inservice examination of nozzles fabricated from weld
buildups, to require use of ultrasonic procedures and personnel
compliant with Mandatory Appendix VIII, and to require the flaw
acceptance criteria of IWB-3514 for Examination Category B-F welds.
Paragraph (b)(2)(liii)
This proposed rule would add new paragraph (b)(2)(liii) to require
that reasonable protection from deterioration of radiographic film
specified in IWA-6310(b) shall include the provisions in IWA-6320 and
the reproduction must be retained as a lifetime record in accordance
with IWA-6330, IWA-6340, and IWA-6350.
Paragraph (g)(4)(iv)
The NRC proposes to revise Sec. 50.55a(g)(4)(iv) correct the
reference from ``(a)(1)(iv) of this section'' to ``(a)(1)(iii) of this
section''.
Paragraph (g)(6)(ii)(D)(9)
This proposed rule would revise paragraph (g)(6)(ii)(D)(9) to
extend the applicability of this paragraph to include the latest
edition incorporated by reference in paragraph (a)(1)(ii) of this
section of Supplement 15, Section XI, Division 1, Mandatory Appendix
VIII.
Paragraph (g)(6)(ii)(F)(2)(iv)
This proposed rule would revise paragraph (g)(6)(ii)(F)(2)(iv) to
include Inspection Item B-3.
Paragraph 50.55a(g)(6)(ii)(F)(2)(v)
This proposed rule would revise paragraph (g)(6)(ii)(F)(2)(v) to
correct the reference from ASME BPV Code Case N-770-5 to ASME BPV Code
Case N-770-7.
Paragraph 50.55a(g)(6)(ii)(F)(4)
This proposed rule would revise paragraph (g)(6)(ii)(F)(4) to
correct the reference from ASME BPV Code Case N-770-5 to ASME BPV Code
Case N-770-7.
Paragraph 50.55a(g)(6)(ii)(F)(2)(10)
This proposed rule would revise paragraph (g)(6)(ii)(F)(10); to
correct the reference from ASME BPV Code Case N-770-5 to ASME BPV Code
Case N-770-7.
Paragraph (g)(6)(ii)(F)(13)
This proposed rule would revise paragraph (g)(6)(ii)(F)(13) to
include Inspection Item B-3.
VI. Generic Aging Lessons Learned Report
In December 2010, the NRC issued NUREG-1801, Revision 2, ``Generic
Aging Lessons Learned (GALL) Report'' (ML103490041), for applicants to
use in preparing license renewal applications. The GALL Report provides
aging management programs (AMPs) that the NRC has concluded are
sufficient for aging management in accordance with the license renewal
rule, as required in Sec. 54.21(a)(3). In addition, NUREG-1800,
Revision 2, ``Standard Review Plan for Review of License Renewal
Applications for Nuclear Power Plants'' (ML103490036), was issued in
December 2010, to ensure the quality and uniformity of NRC reviews of
license renewal applications and to present a well-defined basis on
which the NRC evaluates the applicant's AMPs and activities. In 2011,
the NRC also issued NUREG-1950, ``Disposition of Public Comments and
Technical Bases for Changes in the License Renewal Guidance Documents
NUREG-1801 and NUREG-1800'' (ML11116A062), which describes the
technical bases for the changes in Revision 2 of the GALL Report and
Revision 2 of the standard review plan (SRP) for review of license
renewal applications.
Revision 2 of the GALL Report, in Sections XI.M1, XI.S1, XI.S2,
XI.M3, XI.M5, XI.M6, XI.M11B, and XI.S3, describes the evaluation and
technical bases for determining the sufficiency of ASME BPV Code
Subsections IWB, IWC, IWD, IWE, IWF, or IWL for managing aging during
the period of extended operation (i.e., up to 60 years of operation).
In addition, many other AMPs in the GALL Report rely, in part but to a
lesser degree, on the requirements specified in the ASME BPV Code,
Section XI. Revision 2 of the GALL Report also states that the 1995
Edition through the 2004 Edition of the ASME BPV Code, Section XI,
Subsections IWB, IWC, IWD, IWE, IWF, or IWL, as modified and limited by
Sec. 50.55a, were found to be acceptable editions and addenda for
complying with the requirements of Sec. 54.21(a)(3), unless
specifically noted in certain sections of the GALL Report. The GALL
Report further states that future Federal Register documents that amend
Sec. 50.55a will discuss the acceptability of editions and addenda
more recent than the 2004 Edition for their applicability to license
renewal. In a final rule issued on June 21, 2011 (76 FR 36232),
subsequent to Revision 2 of the GALL Report, the NRC also found that
the 2004 Edition with the 2005 Addenda through the 2007 Edition with
the 2008 Addenda of Section XI of the ASME BPV Code, Subsections IWB,
IWC, IWD, IWE, IWF, or IWL, as subject to the conditions in Sec.
50.55a, are acceptable for the AMPs in the GALL Report and the
conclusions of the GALL Report remain valid with the augmentations
specifically noted in the GALL Report. In a final rule issued on July
18, 2017 (82 FR 32934), the NRC further found that the 2009 Addenda
through the 2017 Edition of Section XI of the ASME BPV Code,
Subsections IWB, IWC, IWD, IWE, IWF, or IWL, as subject to the
conditions in Sec. 50.55a, are acceptable for the AMPs in the GALL
Report. In a final rule issued on May 4, 2020 (85 FR 26540), the NRC
further found that Subsections IWB, IWC, IWD, IWE, IWF, or IWL of
Section XI of the 2015 Edition and the 2017 Edition of the ASME BPV
Code, as subject to the conditions in Sec. 50.55a, are acceptable for
the AMPs in the GALL Report. In a final rule issued on October 27, 2022
(87 FR 65128), the NRC further found that Subsections IWB, IWC, IWD,
IWE, IWF, or IWL of Section XI of the 2019 Edition of the ASME BPV
Code, as subject to the conditions in Sec. 50.55a, are acceptable for
the AMPs in the GALL Report. In a final rule issued on August 30, 2024
(89 FR 70449), the NRC found that Subsections IWB, IWC, IWD, IWE, IWF,
or IWL of Section XI of the 2021 Edition of the ASME BPV Code, as
subject to the conditions in Sec. 50.55a, are acceptable for the AMPs
in the GALL Report.
In July 2025, the NRC issued NUREG-2191, Revision 1, ``Generic
Aging Lessons Learned for Subsequent License Renewal (GALL-SLR)
Report'' (ML25113A021 and ML25113A022), for applicants to use in
preparing applications for subsequent license renewal. The GALL-SLR
Report provides AMPs that are sufficient for aging management for the
subsequent period of extended operation (i.e., up to 80 years of
operation), as required in Sec. 54.21(a)(3). The NRC also issued
NUREG-2192, Revision 1, ``Standard Review Plan for Review of Subsequent
License Renewal Applications for Nuclear Power Plants'' (SRP-SLR), in
[[Page 9750]]
July 2025 (ML25113A023). In a similar manner as the GALL Report does,
the GALL-SLR Report, in Sections XI.M1, XI.S1, XI.S2, XI.M3, XI.11B,
and XI.S3, describes the evaluation and technical bases for determining
the sufficiency of ASME BPV Code Subsections IWB, IWC, IWD, IWE, IWF,
or IWL for managing aging during the subsequent period of extended
operation. Many other AMPs in the GALL-SLR Report rely, in part but to
a lesser degree, on the requirements specified in the ASME BPV Code,
Section XI. The GALL-SLR Report also indicates that the 1995 Edition
through the 2023 Edition (if and when published) of the ASME BPV Code,
Section XI, Subsections IWB, IWC, IWD, IWE, IWF, or IWL, as subject to
the conditions in Sec. 50.55a, are acceptable for complying with the
requirements of Sec. 54.21(a)(3), unless specifically noted in certain
sections of the GALL-SLR Report.
Evaluation With Respect to Aging Management
The NRC evaluated whether those AMPs in the GALL Report and GALL-
SLR Report that rely upon Subsections IWB, IWC, IWD, IWE, IWF, or IWL
of Section XI in the editions and addenda of the ASME BPV Code
incorporated by reference into Sec. 50.55a, in general continue to be
acceptable if the AMP relies upon these Subsections in the 2023
Edition. The NRC finds that the 2023 Edition of Section XI of the ASME
BPV Code, Subsections IWB, IWC, IWD, IWE, IWF, or IWL, as subject to
the conditions of this proposed rule, are acceptable for the AMPs in
the GALL Report and GALL-SLR Report with the exception of augmentation,
as specifically noted in those reports, and the NRC finds that the
conclusions of the GALL Report and GALL-SLR Report remain valid.
Accordingly, an applicant for license renewal (including subsequent
license renewal) may use, in its plant-specific license renewal
application, Subsections IWB, IWC, IWD, IWE, IWF, or IWL of Section XI
of the 2023 Edition of the ASME BPV Code, as subject to the conditions
in this proposed rule, without additional justification. Similarly, a
licensee approved for license renewal that relied on the AMPs may use
Subsections IWB, IWC, IWD, IWE, IWF, or IWL of Section XI of the 2023
Edition of the ASME BPV Code. However, applicants must assess and
follow applicable NRC requirements with regard to licensing basis
changes and evaluate the possible impact on the elements of existing
AMPs.
Some of the AMPs in the GALL Report and GALL-SLR Report recommend
augmentation of certain Code requirements in order to ensure adequate
aging management for license renewal. The technical and regulatory
aspects of the AMPs for which augmentations are recommended also apply
if the 2023 Edition of Section XI of the ASME BPV Code is used to meet
the requirements of Sec. 54.21(a)(3). The NRC evaluated the changes in
the 2023 Edition of Section XI of the ASME BPV Code to determine if the
augmentations described in the GALL Report and GALL-SLR Report remain
necessary. The NRC's evaluation has concluded that the augmentations
described in the GALL and GALL-SLR Reports are necessary to ensure
adequate aging management.
For example, GALL-SLR Report AMP XI.S3, ``ASME Section XI,
Subsection IWF,'' recommends that volumetric examination consistent
with that of the ASME BPV Code, Section XI, Table IWB-2500-1,
Examination Category B-G-1 should be performed to detect cracking for
high strength structural bolting (actual measured yield strength
greater than or equal to 150 kilopound per square inch (ksi)) (1,034
megapascals (MPA)) in sizes greater than 1 inch nominal diameter. The
GALL-SLR Report also indicates that this volumetric examination may be
waived with adequate plant-specific justification. This guidance for
aging management in the GALL-SLR Report is the augmentation of the
visual examination specified in Subsection IWF of the 2023 Edition of
the ASME BPV Code, Section XI.
A license renewal applicant may either augment its AMPs as
described in the GALL Report and GALL-SLR Report (for operation up to
60 and 80 years respectively) or propose alternatives for the NRC to
review as part of the applicant's plant-specific justification for its
AMPs.
VII. Regulatory Flexibility Certification
As required by the Regulatory Flexibility Act of 1980, 5 U.S.C.
605(b), the Commission certifies that this rule, if adopted, will not
have a significant economic impact on a substantial number of small
entities. This proposed rule affects only the licensing and operation
of nuclear power plants. The companies that own these plants do not
fall within the scope of the definition of ``small entities'' set forth
in the Regulatory Flexibility Act or the size standards established by
the NRC (10 CFR 2.810).
VIII. Regulatory Analysis
The NRC has prepared a draft regulatory analysis on this proposed
regulation. The analysis examines the costs and benefits of the
alternatives considered by the NRC. The NRC requests public comment on
the draft regulatory analysis. The draft regulatory analysis is
available as indicated in the ``Availability of Documents'' section of
this document. Comments on the draft regulatory analysis may be
submitted to the NRC as indicated under the ADDRESSES caption of this
document.
IX. Backfitting and Issue Finality
A. Proposed Incorporation by Reference of the 2023 BPV Code Edition
Introduction
The NRC's Backfit Rule in Sec. 50.109 states that the NRC shall
require the backfitting of a facility only when it finds the action to
be justified under specific standards stated in the rule. Section
50.109(a)(1) defines backfitting as the modification of or addition to
systems, structures, components, or design of a facility; the design
approval or manufacturing license for a facility; or the procedures or
organization required to design, construct, or operate a facility. Any
of these modifications or additions may result from a new or amended
provision in the NRC's rules or the imposition of a regulatory position
interpreting the NRC's rules that is either new or different from a
previously applicable NRC position after issuance of the construction
permit or the operating license or the design approval.
Section 50.55a requires nuclear power plant licensees to:
Construct ASME BPV Code Class 1, 2, and 3 components in
accordance with the rules provided in Section III, Division 1, of the
ASME BPV Code (``Section III'').
Inspect, examine, and repair or replace Class 1, 2, 3,
Class MC, and Class CC components in accordance with the rules provided
in Section XI, Division 1, of the ASME BPV Code (``Section XI'').
Test Class 1, 2, and 3 pumps and valves in accordance with
the rules provided in the ASME OM Code.
Inspect, examine, repair or replace, and test Class 1, 2,
and 3 dynamic restraints (snubbers) in accordance with the rules
provided in either the ASME OM Code or Section XI, depending on the
code edition.
This rulemaking proposes to incorporate by reference the 2023
Edition of the ASME BPV Code, Section III, Division 1, and ASME BPV
Code, Section XI, Division 1.
The ASME BPV and OM Codes are national consensus standards
developed by participants with broad and varied
[[Page 9751]]
interests, in which all interested parties (including the NRC and
utilities) participate. A consensus process involving a wide range of
stakeholders is consistent with the NTTAA, inasmuch as the NRC has
determined that there are sound regulatory reasons for establishing
regulatory requirements for design, maintenance, ISI, and IST by
rulemaking. The process also facilitates early stakeholder
consideration of backfitting issues.
Overall Backfitting Considerations: Section III of the ASME BPV Code
Incorporation by reference of more recent editions and addenda of
Section III of the ASME BPV Code does not affect a plant that has
received a construction permit or an operating license or a design that
has been approved. This is because the edition and addenda to be used
in constructing a plant are, under Sec. 50.55a, determined based on
the date of the construction permit or combined license, and are not
changed thereafter, except voluntarily by the licensee. The
incorporation by reference of more recent editions and addenda of
Section III ordinarily applies only to applicants after the effective
date of the final rule incorporating these new editions and addenda.
Therefore, incorporation by reference of a more recent edition and
addenda of Section III does not constitute ``backfitting'' as defined
in Sec. 50.109(a)(1).
Overall Backfitting Considerations: Section XI of the ASME BPV Code
Incorporation by reference of more recent editions and addenda of
Section XI of the ASME BPV Code affects the ISI program of operating
reactors. However, the Backfit Rule generally does not apply to
incorporation by reference of later editions of the ASME BPV Code
(Section XI). As previously mentioned, the NRC's longstanding
regulatory practice has been to incorporate later versions of the ASME
Codes into Sec. 50.55a. Under Sec. 50.55a, licensees must
periodically update their ISI and program to the latest edition of
Section XI of the ASME BPV Code incorporated by reference into Sec.
50.55a 18 months before the start of a new code of record interval.
Therefore, when the NRC approves and requires the use of a later
version of the Code for ISI, it is implementing this longstanding
regulatory practice and requirement.
Other circumstances where the NRC does not apply the Backfit Rule
to the approval and requirement to use later code editions and addenda
are as follows:
1. When the NRC takes exception to a later ASME BPV Code or OM Code
provision but merely retains the current existing requirement,
prohibits the use of the later code provision, limits the use of the
later code provision, or supplements the provisions in a later code,
the Backfit Rule does not apply because the NRC is not imposing new
requirements. However, the NRC explains any such exceptions to the code
in the preamble to and regulatory analysis for the rule.
2. When an NRC exception relaxes an existing ASME BPV Code or OM
Code provision but does not prohibit a licensee from using the existing
code provision, the Backfit Rule does not apply because the NRC is not
imposing new requirements.
3. Modifications and limitations imposed during previous routine
updates of Sec. 50.55a have established a precedent for determining
which modifications or limitations are backfits, or require a backfit
analysis (e.g., final rule dated September 10, 2008 (73 FR 52730), and
a correction dated October 2, 2008 (73 FR 57235)). The application of
the backfit requirements to modifications and limitations in the
current rule are consistent with the application of backfit
requirements to modifications and limitations in previous rules.
The incorporation by reference and adoption of a requirement
mandating the use of a later ASME BPV Code or OM Code may constitute
backfitting in some circumstances. In these cases, the NRC would
perform a backfit analysis or prepare documented evaluation in
accordance with Sec. 50.109. These include the following:
1. When the NRC endorses a later provision of the ASME BPV Code or
OM Code that takes a substantially different direction from the
existing requirements, the action is treated as a backfit (e.g., 61 FR
41303; August 8, 1996).
2. When the NRC requires implementation of a later ASME BPV Code or
OM Code provision on an expedited basis, the action is treated as a
backfit. This applies when implementation is required sooner than it
would be required if the NRC simply endorsed the Code without any
expedited language (e.g., 64 FR 51370; September 22, 1999).
3. When the NRC takes an exception to an ASME BPV Code or OM Code
provision and imposes a requirement that is substantially different
from the existing requirement as well as substantially different from
the later Code (e.g., 67 FR 60520; September 26, 2002).
Detailed Backfitting Discussion: Proposed Changes Beyond Those
Necessary To Incorporate by Reference the New ASME BPV Code Provisions
This section discusses the backfitting considerations for all the
proposed changes to Sec. 50.55a that go beyond the minimum changes
necessary and are required to adopt the new ASME Code edition into
Sec. 50.55a.
ASME BPV Code, Section III
1. Revise Sec. 50.55a(b)(1)(xiv) to extend the applicability of
the conditions through the latest edition of the ASME BPV Code, Section
III incorporated by reference in paragraph (a)(1)(i). The NRC is
proposing to revise this condition to apply to the latest edition
incorporated by reference, which is not a change to NRC position and,
therefore, is not a backfit.
2. Add Sec. 50.55a(b)(1)(xv) to include provisions to require that
protection from deterioration of radiographic film specified in Note
(3) of Table NCA-4134.17-1 and Note (1) of Table NCA-4134.17-2 of the
2023 Edition of the ASME BPV Code, Section III shall include the
provisions specified in NCA-4134.17(c), and the reproduction must be
retained as a lifetime or nonpermanent record in accordance with Table
NCA-4134.17-1 or NCA-4134.17-2, as applicable, of the 2023 Edition. The
proposed conditions on Note (3) of Table NCA-4134.17-1 and Note (1) of
Table NCA-4134.17-2 of the 2023 Edition specify that existing
provisions in NCA-4134.17(c) allow digitization of radiographic film
before the original film's deterioration to protect and preserve the
record as required. This is not a new or changed NRC position.
Therefore, the addition of this proposed condition to maintain the
radiographic film or digitized radiographic film as a permanent record
is not a backfit.
ASME BPV Code, Section XI
1. Remove and reserve Sec. 50.55a(a)(1)(iii)(A) to delete the
incorporation by reference of ASME BPV Code Case N-513-3, Mandatory
Appendix I. The mandatory appendix was previously referenced in Sec.
50.55a(b)(2)(xxxiv), but that reference was removed from this condition
in a previous rulemaking. The NRC is proposing to remove this
incorporation by reference, which is not a change to NRC position and,
therefore, is not a backfit.
2. Revise Sec. 50.55a(b)(2)(xii) to limit the applicability of the
condition to the 2001 Edition through the 2021 Edition of ASME BPV
Code, Section XI. The
[[Page 9752]]
2023 Edition added provisions that satisfied the conditions in this
paragraph. The NRC is proposing to not apply this condition to the 2023
Edition incorporated by reference, which is not a change to NRC
position and, therefore, is not a backfit.
3. Revise Sec. 50.55a(b)(2)(xviii) to remove and reserve a
provision and clarify a provision.
a. The current provision in Sec. 50.55a(b)(2)(xviii)(A) is being
removed as the NRC believes that the NDE recertification rate is
acceptable. Removing this condition allows licensees to voluntarily
apply the less stringent requirements for recertification of Level I
and II NDE personnel to 5-year intervals as stated in the ASME BPV
Code, Section XI. Therefore, this is not a backfit.
b. The current provision in Sec. 50.55a(b)(2)(xviii)(D) is being
revised to clarify that the alternatives listed in paragraphs
(b)(2)(xviii)(D)(1) and (2) are applicable to editions and addenda
later than the 2010 Edition. This is not a change in NRC position and,
therefore, is not a backfit.
4. Revise Sec. 50.55a(b)(2)(xxv) to correct an error in the title.
The current title of this section incorrectly states, ``Section XV
Condition,'' and the NRC proposes to correct the title to state,
``Section XI Condition.'' This is an editorial correction and,
therefore, is not a backfit.
5. Revise Sec. 50.55a(b)(2)(xxviii) to clarify that the condition
applies to A-4300(b)(1) for the 2021 Edition of the ASME BPV Code,
Section XI, and earlier, and applies to Y-3100(c) in the 2023 Edition.
In the 2023 Edition, ASME moved the fatigue crack growth law for
ferritic steels in air from A-4300 to Y-3100. This is not a change in
NRC position and, therefore, is not a backfit.
6. Revise Sec. 50.55a(b)(2)(xxxi) to reformat the existing
condition into two separate provisions and add four new provisions.
a. The current condition continues to apply and is being
reformatted into two separate provisions. This is not a change to NRC
position and, therefore, is not a backfit.
b. Appendix W of the 2023 Edition of the ASME BPV Code, Section XI,
was revised to remove the prohibition on the use of mechanical clamps
for several types of piping. The NRC continues to prohibit the use of
mechanical clamps in these four specific types of piping. This is not a
new or changed position and, therefore, is not a backfit.
7. Revise Sec. 50.55a(b)(2)(xxxiv) to extend the applicability of
the condition to the 2023 Edition of the ASME BPV Code, Section XI. The
NRC is proposing to revise this condition to apply to the 2023 Edition
incorporated by reference, which is not a change to NRC position and,
therefore, is not a backfit.
8. Revise Sec. 50.55a(b)(2)(xliv) to correct errors, extend its
applicability to the 2023 Edition of the ASME BPV Code, Section XI, and
add a provision.
a. Subarticle Y-2400 and Articles Y-2200 and Y-3200 are all
incorrect references. The NRC is proposing to fix these errors. This is
an editorial correction, not a change in position, and, therefore, not
a backfit.
b. The NRC is proposing to revise this condition to extend to the
2023 Edition, which is not a change in position and, therefore, is not
a backfit.
c. The NRC is proposing to prohibit the use of paragraph Y-4322.
The NRC's position is that the relevant code case should govern
whenever there are overlapping requirements between the ASME BPV Code
and a code case. The crack growth laws in paragraph Y-4322 are
duplicated in Code Case N-909. The prohibiting of the use of this
paragraph does not modify the requirements with regards to crack growth
laws and, therefore, is not a backfit.
9. Revise Sec. 50.55a(b)(2)(xlv) to extend the applicability of
the condition through the latest edition of the ASME BPV Code, Section
XI. The NRC is proposing to revise this condition to apply to the
latest edition incorporated by reference, which is not a change to NRC
position and, therefore, is not a backfit.
10. Revise Sec. 50.55a(b)(2)(xlvi) to extend the applicability of
the condition through the latest edition of the ASME BPV Code, Section
XI. The NRC is proposing to revise this condition to apply to the
latest edition incorporated by reference, which is not a change to NRC
position and, therefore, is not a backfit.
11. Revise Sec. 50.55a(b)(2)(xlviii) to extend the applicability
of the condition through the latest edition of the ASME BPV Code,
Section XI. The NRC is proposing to revise this condition to apply to
the latest edition incorporated by reference, which is not a change to
NRC position and, therefore, is not a backfit.
12. Add Sec. 50.55a(b)(2)(li) to prohibit the use of IWA-
4540(d)(7) in the 2023 Edition of the ASME BPV Code, Section XI, for
exempting pressure testing of Class 2 and 3 welds that have a surface
or volumetric examination performed. This is a new condition that
retains the NRC's current position to perform pressure testing of most
welds regardless of the non-destructive examination performed. The
proposed condition on IWA-4540(d)(7) does not constitute a new or
changed NRC position. Therefore, the addition of this proposed
condition is not a backfit.
13. Add Sec. 50.55a(b)(2)(lii) to condition Figure IWB-2500-7(d)
of the 2023 Edition of the ASME BPV Code, Section XI, to require
preservice and inservice volumetric examination of nozzles fabricated
from weld buildups. This new condition retains a requirement from
previous code editions; it does not constitute a new or changed NRC
position. Therefore, the addition of this proposed condition is not a
backfit.
14. Add Sec. 50.55a(b)(2)(liii) to include provisions to require
that protection from deterioration of radiographic film specified in
IWA-6310(b) of the 2023 Edition of ASME BPV Code, Section XI, shall
include the provisions specified in IWA-6320, and the reproduction must
be retained as a lifetime record in accordance with IWA-6330, IWA-6340,
and IWA-6350 of the ASME BPV Code, Section XI. The proposed condition
on IWA-6310(b) of the 2023 Edition specifies that existing provisions
in IWA-6320 allow digitization of radiographic film before the original
film's deterioration to protect and preserve the lifetime record as
required. This is not a new or changed NRC position. Therefore, the
addition of this proposed condition to maintain the radiographic film
or digitized radiographic film as a permanent record is not a backfit.
15. Revise Sec. 50.55a(g)(6)(ii)(D)(9) to allow for qualification
of volumetric evaluation in accordance with Section XI, Division 1,
Mandatory Appendix VIII, Supplement 15, in the 2021 Edition through the
latest edition of the ASME BPV Code, Section XI. The NRC is proposing
to allow licensees the further option to utilize the 2023 Edition of
Supplement 15 for the volumetric qualification requirements of Code
Case N-729-6, which is a voluntary alternative and, therefore, is not a
backfit.
16. Revise Sec. 50.55a(g)(6)(ii)(F)(2)(iv) to include inspection
item B-3 in the list of categorization options for identification of
cold leg temperature welds. Inspection item B-3 was previously part of
inspection item B-1. The NRC is proposing to revise this condition to
include inspection item B-3, which maintains the same requirements and
only clarifies the expansion of categorization options for licensees
and, therefore, is not a backfit.
17. Revise Sec. 50.55a(g)(6)(ii)(F)(13) to include inspection item
B-3 in the list of encoded volumetric exams. Inspection item B-3 was
previously part of inspection item B-1. The NRC is proposing to revise
this condition to
[[Page 9753]]
include inspection item B-3, which maintains the same requirements and
only clarifies the expansion of categorization options for licensees
and, therefore, is not a backfit.
Conclusion
The NRC finds that incorporation by reference into Sec. 50.55a of
the 2023 Edition of the ASME BPV Code, subject to the identified
conditions, does not constitute backfitting or represent an
inconsistency with any issue finality provisions in 10 CFR part 52.
B. Proposed Incorporation by Reference of Three Regulatory Guides
The provisions in this proposed rule would allow licensees and
applicants to voluntarily apply NRC-approved code cases, sometimes with
NRC-specified conditions. The approved code cases are listed in three
RGs that are proposed to be incorporated by reference into Sec.
50.55a. An applicant's or a licensee's voluntary application of an
approved code case does not constitute backfitting, because there is no
imposition of a new requirement or new position.
Similarly, voluntary application of an approved code case by a 10
CFR part 52 applicant or licensee does not represent NRC imposition of
a requirement or action and therefore is not inconsistent with any
issue finality provision in 10 CFR part 52. The NRC is not proposing to
revise any conditions on previously approved code cases, and approval
of new code cases with conditions on their voluntary use does not
represent an imposition of a new requirement and is therefore not a
backfit. For these reasons, the NRC finds that this proposed rule does
not involve any provisions requiring the preparation of a backfit
analysis or documentation demonstrating that one or more of the issue
finality criteria in 10 CFR part 52 are met.
The NRC finds that the proposed incorporation by reference into
Sec. 50.55a of the three RGs containing the latest NRC-approved code
cases does not constitute backfitting or represent an inconsistency
with any issue finality provisions in 10 CFR part 52.
X. Plain Writing
The Plain Writing Act of 2010 (Pub. L. 111-274) requires Federal
agencies to write documents in a clear, concise, and well-organized
manner. The NRC has written this document to be consistent with the
Plain Writing Act as well as the Presidential Memorandum, ``Plain
Language in Government Writing,'' published June 10, 1998 (63 FR
31885). The NRC requests comment on this document with respect to the
clarity and effectiveness of the language used.
XI. Environmental Assessment and Proposed Finding of No Significant
Environmental Impact
The NRC 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, if adopted, would not be a major
Federal action significantly affecting the quality of the human
environment and, therefore, an environmental impact statement is not
required.
The determination of this environmental assessment is that there
will be no significant effect on the quality of the human environment
from this action. Public stakeholders should note, however, that
comments on any aspect of this environmental assessment may be
submitted to the NRC as indicated under the ADDRESSES caption.
A. Proposed Incorporation by Reference of the 2023 BPV Code Edition
This proposed rule is in accordance with the NRC's policy to
incorporate by reference in Sec. 50.55a new editions of the ASME BPV
and OM Codes to provide updated rules for construction and inspecting
components and testing pumps, valves, and dynamic restraints (snubbers)
in light-water nuclear power plants. The ASME Codes are national
voluntary consensus standards and are required by the NTTAA to be used
by Government agencies unless the use of such a standard is
inconsistent with applicable law or otherwise impractical. The proposed
rule does not significantly increase the probability or consequences of
accidents, no changes are being made in the types of effluents that may
be released off-site, and there is no significant increase in public
radiation exposure. This proposed rule does not involve non-
radiological plant effluents and has no other environmental impact.
Therefore, no significant environmental impacts are associated with
this action.
B. Proposed Incorporation by Reference of Three Regulatory Guides
NRC-approved code cases provide an equivalent level of safety as
the ASME codes. Therefore, this proposed action does not result in
increases in the probability or consequences of accidents. There also
are no significant, non-radiological impacts associated with this
action because no changes would be made affecting non-radiological
plant effluents and because no changes would be made in activities that
would adversely affect the environment. The determination of this
environmental assessment is that there would be no significant impact
from this action.
XII. Paperwork Reduction Act
This proposed rule amends a collection of information subject to
the Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.). The
proposed rule would reduce the burden for the existing information
collection. This proposed rule has been submitted to the Office of
Management and Budget (OMB) for review and approval of the paperwork
requirements.
Type of submission: Revision.
The title of the information collection: Codes and Standards.
The form number if applicable: Not applicable.
How often the collection is required or requested: On occasion.
Who will be required or asked to respond: Operating power reactor
licensees and applicants who choose to implement Code Case N-752-2.
An estimate of the number of annual responses: 1.
The estimated number of annual respondents: 3.33.
An estimate of the total number of hours needed annually to comply
with the information collection requirement or request: One-time
recordkeeping burden of 1,800 hours, recurring annual recordkeeping
burden reduction of 5,390 hours.
Abstract: This proposed rule, in part, approves the implementation
of Code Case N-752-2, with conditions as specified in RG 1.147. In
order to implement the code case, licensees and applicants would be
required to evaluate the safety-significant functions of their SSCs,
and would need to follow requirements for on-going evaluations to
ensure safety standards are maintained and that records of
categorization decisions be kept.
The NRC is seeking public comment on the potential impact of the
information collection(s) contained in this proposed rule and on the
following issues:
1. Is the proposed information collection necessary for the proper
performance of the functions of the NRC, including whether the
information will have practical utility? Please explain your response.
2. Is the estimate of the burden of the proposed information
collection accurate? Please explain your response.
3. Is there a way to enhance the quality, utility, and clarity of
the information to be collected? Please explain your response.
4. How can the burden of the proposed information collection on
[[Page 9754]]
respondents be minimized, including the use of automated collection
techniques or other forms of information technology?
A copy of the OMB clearance package is available in ADAMS under
Accession No. ML25225A001 or may be viewed free of charge by contacting
the NRC's Public Document Room reference staff at 1-800-397-4209, at
301-415-4737, or by email to [email protected]. You may obtain
information and comment on submissions related to the OMB clearance
package by searching on https://www.regulations.gov under Docket ID
NRC-2020-0029.
You may submit comments on any aspect of these proposed information
collection(s), including suggestions for reducing the burden and on the
above issues, by the following methods:
Federal rulemaking website: Go to https://www.regulations.gov and search for Docket ID NRC-2020-0029.
Mail comments to: FOIA, Library, and Information
Collections Branch, Office of the Chief Information Officer, Mail Stop:
T-6 A10M, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001
or to the OMB reviewer at OMB Office of Information and Regulatory
Affairs (3150-0264), Attention: Desk Officer for the Nuclear Regulatory
Commission, 725 17th Street NW, Washington, DC 20503.
Submit comments by March 30, 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.
Public Protection Notification
The NRC may not conduct or sponsor, and a person is not required to
respond to, a collection of information unless the document requesting
or requiring the collection displays a currently valid OMB control
number.
XIII. Executive Orders
The following are E.O.s that are related to this proposed rule:
A. Executive Order 12866: Regulatory Planning and Review (as Amended by
Executive Order 14215: Ensuring Accountability for All Agencies)
This action is not a significant regulatory action and therefore
was not submitted to OMB for review.
B. Executive Order 14154: Unleashing American Energy
The NRC has examined this proposed rule and has determined that it
is consistent with the policies and directives outlined in E.O. 14154.
C. Executive Order 14192: Unleashing Prosperity Through Deregulation
This action is a deregulatory action as defined by E.O. 14192.
Details on the estimated costs of this proposed rule can be found in
Section VIII of this document, ``Regulatory Analysis.''
D. Executive Order 14270: Zero-Based Regulatory Budgeting To Unleash
American Energy
E.O. 14270, ``Zero-Based Regulatory Budgeting to Unleash American
Energy,'' requires the NRC to insert a conditional sunset date into all
new or amended NRC regulations provided the regulations are (1)
promulgated under the Atomic Energy Act of 1954, as amended (AEA), the
Energy Reorganization Act of 1974, as amended, or the Nuclear Waste
Policy Act of 1982, as amended; (2) not statutorily required; and (3)
not part of the NRC's permitting regime. The NRC determined that the
regulatory changes proposed in this rule are necessary for reasonable
assurance of adequate protection of public health and safety and part
of the NRC's regulatory permitting scheme authorized by the AEA.
Therefore, the NRC views this rulemaking to be outside the scope of
E.O. 14270 and did not insert conditional sunset dates for the
regulatory changes in this proposed rule.
XIV. Voluntary Consensus Standards
The National Technology Transfer and Advancement Act of 1995,
Public Law 104-113, requires that Federal agencies use technical
standards that are developed or adopted by voluntary consensus
standards bodies unless using such a standard is inconsistent with
applicable law or is otherwise impractical. In this proposed rule, the
NRC is continuing to use the ASME BPV Code by incorporating by
reference the 2023 Edition of the BPV Code. In addition, the NRC is
continuing to use the ASME BPV and OM Code Cases, which are ASME-
approved voluntary alternatives to compliance with various provisions
of the ASME BPV and OM Codes. The NRC's approval of the ASME Code Cases
is accomplished by amending the NRC's regulations to incorporate by
reference the latest revisions of the following, which are the subject
of this rulemaking, into Sec. 50.55a: RG 1.84, Revision 41; RG 1.147,
Revision 22; and RG 1.192, Revision 6. The RGs list the ASME Code Cases
that the NRC has approved for use. The ASME Code Cases are voluntary
consensus standards as described in the National Technology Transfer
and Advancement Act of 1995 and OMB Circular A-119. The ASME Code
editions and code cases constitute voluntary consensus standards, in
which all interested parties (including the NRC and licensees of
nuclear power plants) participate. The NRC invites comment on the
applicability and use of other standards.
XV. Incorporation by Reference--Reasonable Availability to Interested
Parties
The NRC proposes to incorporate by reference the 2023 Edition of
the ASME BPV Code for nuclear power plants. As described in the
``Background'' and ``Discussion'' sections of this document, this
material contains standards for the inspection of nuclear power plant
components.
The NRC also proposes to incorporate by reference three NRC RGs
that list new and revised ASME Code cases that the NRC has approved as
voluntary alternatives to certain provisions of NRC-required editions
and addenda of the ASME BPV Code and the ASME OM Code. The draft
regulatory guides, DG-1446, DG-1447, and DG-1448, will correspond to
final RG 1.84, Revision 41; RG 1.147, Revision 22; and RG 1.192,
Revision 6, respectively.
RG 1.84, ``Design, Fabrication, and Materials Code Case
Acceptability, ASME Section III,'' Revision 41 (DG-1446), would allow
nuclear power plant licensees and applicants for construction permits,
operating licenses, combined licenses, standard design certifications,
standard design approvals, and manufacturing licenses to use the code
cases listed in this revised RG as voluntary alternatives to ASME
engineering standards for the construction of nuclear power plant
components. DG-1446 updates the discussion language of the document and
does not list any new code cases.
RG 1.147, ``Inservice Inspection Code Case Acceptability,
ASME Section XI, Division 1,'' Revision 22 (DG-1447), would allow
nuclear power plant licensees and applicants for construction permits,
operating licenses, combined licenses, standard design certifications,
standard design approvals, and manufacturing licenses to use the code
cases newly listed in this revised RG as voluntary alternatives to ASME
engineering standards for the inservice inspection of nuclear power
plant components.
RG 1.192, ``Operation and Maintenance [OM] Code Case
Acceptability, ASME OM Code,'' Revision 6 (DG-1448), would allow
nuclear power plant licensees and applicants for construction permits,
[[Page 9755]]
operating licenses, combined licenses, standard design certifications,
standard design approvals, and manufacturing licenses to use the code
cases newly listed in this revised RG as voluntary alternatives to ASME
engineering standards for the inservice examination and testing of
nuclear power plant components.
The NRC is required by law to obtain approval for incorporation by
reference from the Office of the Federal Register (OFR). The OFR's
requirements for incorporation by reference are set forth in 1 CFR part
51. On November 7, 2014, the OFR adopted changes to its regulations
governing incorporation by reference (79 FR 66267). The OFR regulations
require an agency to include in a proposed rule a discussion of the
ways that the materials the agency proposes to incorporate by reference
are reasonably available to interested parties or how it worked to make
those materials reasonably available to interested parties. The
discussion in this section complies with the requirement for proposed
rules as set forth in 1 CFR 51.5(a)(1).
The NRC considers ``interested parties'' to include all potential
NRC stakeholders, not only the individuals and entities regulated or
otherwise subject to the NRC's regulatory oversight. These NRC
stakeholders are not a homogenous group, so the considerations for
determining ``reasonable availability'' vary by class of interested
parties. The NRC identified six classes of interested parties with
regard to the material to be incorporated by reference in an NRC rule:
Individuals and small entities regulated or otherwise
subject to the NRC's regulatory oversight. This class includes
applicants and potential applicants for licenses and other NRC
regulatory approvals, and who are subject to the material to be
incorporated by reference. In this context, ``small entities'' has the
same meaning as set out in Sec. 2.810.
Large entities otherwise subject to the NRC's regulatory
oversight. This class includes applicants and potential applicants for
licenses and other NRC regulatory approvals, and who are subject to the
material to be incorporated by reference. In this context, a ``large
entity'' is one that does not qualify as a ``small entity'' under Sec.
2.810.
Non-governmental organizations with institutional
interests in matters regulated by the NRC.
Other Federal agencies, States, local governmental bodies
(within the meaning of Sec. 2.315(c)).
Federally recognized and State-recognized Indian tribes.
Members of the general public (i.e., individual,
unaffiliated members of the public who are not regulated or otherwise
subject to the NRC's regulatory oversight) who need access to the
materials that the NRC proposes to incorporate by reference in order to
participate in the rulemaking.
The 2023 Edition of the ASME BPV Code may be viewed, by
appointment, at the Technical Library, which is located at Two White
Flint, 11545 Rockville Pike, Rockville, Maryland 20852. You may submit
your request to the Technical Library via email at
[email protected] between 8:00 a.m. and 4:00 p.m. eastern time,
Monday through Friday, except Federal holidays. In addition, as
described in the ``Availability of Documents'' section of this
document, documents related to this proposed rule are available online
in the NRC's ADAMS Public Documents collection at https://www.nrc.gov/reading-rm/adams.html.
Interested parties may purchase a copy of the ASME materials from
ASME at Three Park Avenue, New York, NY 10016, or at the ASME website
https://www.asme.org/shop/standards. The materials also are accessible
through third-party subscription services such as IHS (15 Inverness Way
East, Englewood, CO 80112; https://global.ihs.com) and Thomson Reuters
Techstreet (3916 Ranchero Dr., Ann Arbor, MI 48108; https://www.techstreet.com). The purchase prices for individual documents range
from $325 to $720 and the cost to purchase all documents is
approximately $9,000.
For the class of interested parties constituting members of the
public who wish to gain access to the materials to be incorporated by
reference in order to participate in the rulemaking, the NRC recognizes
that the $9,000 cost may be so high that the materials could be
regarded as not reasonably available for purposes of commenting on this
proposed rule, despite the NRC's actions to make the materials
available at the NRC's PDR. Accordingly, the NRC requested that ASME
consider enhancing public access to these materials during the public
comment period. On January 21, 2026, the ASME agreed to make the
materials available online in a read-only electronic access format
during the public comment period (ML26023A041). Therefore, the 2023
Edition of the ASME BPV Code Edition for nuclear power plants that the
NRC proposes to incorporate by reference in this rulemaking is
available in read-only format at the ASME website https://go.asme.org/NRC-ASME.
The three draft RGs that the NRC proposes to incorporate by
reference in this proposed rule are available without cost and can be
read online or downloaded online. The draft RGs can be viewed, by
appointment, at the NRC Technical Library, which is located at Two
White Flint North, 11545 Rockville Pike, Rockville, Maryland 20852;
telephone: 301-415-7000; email: [email protected].
Because the three draft RGs, and eventually, the final RGs, are
available in various forms at no cost, the NRC determines that the
three draft RGs, DG-1446, DG-1447, and DG-1448, and final RG 1.84,
Revision 41; RG 1.147, Revision 22; and RG 1.192, Revision 6, once
approved by the OFR for incorporation by reference, are reasonably
available to all interested parties.
The materials are available to all interested parties in multiple
ways and in a manner consistent with their interest in this proposed
rule. Therefore, the NRC concludes that the materials the NRC proposes
to incorporate by reference in this proposed rule are reasonably
available to all interested parties.
XVI. Availability of Guidance
The NRC will not be issuing guidance for this rulemaking.
XVII. Availability of Documents
The documents identified in the following table are available to
interested persons through one or more of the following methods, as
indicated in Table IV.
[[Page 9756]]
Table IV--Availability of Documents
------------------------------------------------------------------------
ADAMS Accession No./web
Document link/ Federal Register
Citation
------------------------------------------------------------------------
Proposed Rule Documents
------------------------------------------------------------------------
Rulemaking: Proposed Rule: Regulatory ML25182A128.
Analysis for Approval of the 2023 Edition
of the American Society of Mechanical
Engineers Boiler and Pressure Vessel Code
and Code Cases, Revision 41, February 27,
2026.
Rulemaking: Proposed Rule: Unofficial ML25182A125.
Redline Strikeout of the NRC's Proposed
Rule: Approval of the 2023 Edition of the
American Society of Mechanical Engineers
Boiler and Pressure Vessel Code and Code
Cases, Revision 41, February 27, 2026.
------------------------------------------------------------------------
Executive Orders
------------------------------------------------------------------------
Executive Order 12866, ``Regulatory 58 FR 51735.
Planning and Review,'' October 4, 1993.
Executive Order 14125, ``Ensuring 90 FR 10447.
Accountability for All Agencies,''
February 18, 2025.
Executive Order 14154, ``Unleashing 90 FR 8353.
American Energy,'' January 29, 2025.
Executive Order 14192, ``Unleashing 90 FR 9065.
Prosperity Through Deregulation,''
February 6, 2025.
Executive Order 14270, ``Zero-Based 90 FR 15643.
Regulatory Budgeting to Unleash American
Energy,'' April 15, 2025.
Executive Order 14300, ``Ordering the 90 FR 22587.
Reform of the Nuclear Regulatory
Commission,'' May 29, 2025.
------------------------------------------------------------------------
Related Documents
------------------------------------------------------------------------
ASME Letter to NRC, ``ASME Request for ML24296A006
Including Specific Code Cases in Draft
Revision 22 of Regulatory Guide 1.147 and
Draft Revision 1 of Regulatory Guide
1.246,'' October 18, 2024.
ASME Letter to NRC, ``ASME NDE Level I and ML25099A046.
II Personnel Recertification,'' August 23,
2024.
EPRI Technical Report 3002018615, https://
``Technical Basis for Nondestructive restservice.epri.com/
Examination Experience Requirements for publicdownload/
ASME Section XI, Appendix VII,'' September 000000003002018615/0/
2021. Product.
Direct final rule--Approval of American 90 FR 46319.
Society of Mechanical Engineers
Unconditioned Code Cases, September 26,
2025.
Final Rule--American Society of Mechanical 89 FR 70449.
Engineers 2021-2022 Code Editions, August
30, 2024.
Final Rule--American Society of Mechanical 89 FR 58039.
Engineers Code Cases and Update Frequency,
July 17, 2024.
Final Rule--American Society of Mechanical 85 FR 26540.
Engineers 2015-2017 Code Editions
Incorporation by Reference, May 4, 2020.
Final Rule--Incorporation by Reference of 82 FR 32934.
American Society of Mechanical Engineers
Codes and Code Cases, July 18, 2017.
Final Rule--Incorporation by Reference, 79 FR 66267.
November 7, 2014.
Final Rule--American Society of Mechanical 76 FR 36232.
Engineers (ASME) Codes and New and Revised
ASME Code Cases, June 21, 2011.
Final Rule--Industry Codes and Standards; 73 FR 57235.
Amended Requirements; Correction, October
2, 2008.
Final Rule--Industry Codes and Standards; 73 FR 52730.
Amended Requirements, September 10, 2008.
Final Rule--Industry Codes and Standards; 67 FR 60520.
Amended Requirements, September 26, 2002.
Proposed Rule--Industry Codes and 64 FR 51370.
Standards; Amended Requirements, September
22, 1999.
Codes and Standard for Nuclear Power 61 FR 41303.
Plants; Subsection IWE and Subsection IWL,
August 8, 1996.
Final Policy Statement--Use of 60 FR 42622.
Probabilistic Risk Assessment Methods in
Nuclear Regulatory Activities, August 16,
1995.
``Impacts of Embrittlement on Reactor ML21314A228.
Pressure Vessel Integrity from a Risk-
Informed Perspective, Final Report,''
March 8, 2022.
NEI 05-04/07-12/12-06 Appendix X, ``Close- ML17086A451.
Out of Facts and Observations (F&Os),''
February 2017.
NEI 17-07, Revision 2, ``Performance of PRA ML19231A182.
Reviews using the ASME/ANS PRA Standard,''
August 2019.
NRC Information Notice 2025-01, ``Lessons ML24323A057.
Learned When Implementing ASME Code Case N-
752,'' February 10, 2025.
NRC Letter to NEI, ``U.S. Nuclear ML17079A427.
Regulatory Commission Acceptance on
Nuclear Energy Institute Appendix X to
Guidance 05-04, 07-12, and 12-13 Close-Out
of Facts and Observations (F&Os),'' May 3,
2017.
NUREG-1800, Revision 2, ``Standard Review ML103490036.
Plan for Review of License Renewal
Applications for Nuclear Power Plants,''
December 2010.
NUREG-1801, Revision 2, ``Generic Aging ML103490041.
Lessons Learned (GALL) Report,'' December
2010.
NUREG-1950, ``Disposition of Public ML11116A062.
Comments and Technical Bases for Changes
in the License Renewal Guidance Documents
NUREG-1801 and NUREG-1800,'' April 2011.
NUREG-2191, Vols. 1 and 2, Revision 1, ML25113A021.
``Generic Aging Lessons Learned for ML25113A022.
Subsequent License Renewal (GALL-SLR)
Report,'' July 2025.
NUREG-2192, Revision 1, ``Standard Review ML25113A023.
Plan for Review of Subsequent License
Renewal Applications for Nuclear Power
Plants,'' July 2025.
OMB Supporting Statements, February 9, 2026 ML25225A001.
[[Page 9757]]
PNNL-29761, ``Nondestructive Examination ML20079E343.
(NDE) Training and Qualifications:
Implications of Research on Human Learning
and Memory, Instruction, and Expertise,''
March 2020.
Regulatory Issue Summary 2007-06, ML070650428.
``Regulatory Guide 1.200 Implementation,''
March 22, 2007.
Presidential Memorandum, ``Plain Language 63 FR 31885.
in Government Writing,'' June 10, 1998.
RG 1.28, Quality Assurance Program Criteria ML23177A002.
(Design and Construction), Revision 6,
September 2023.
RG 1.84, Design, Fabrication, and Materials ML23291A008.
Code Case Acceptability, ASME Section III,
Revision 40, March 2024.
RG 1.147, Inservice Inspection Code Case ML23291A003.
Acceptability, ASME Section XI, Division
1, Revision 21, March 2024.
RG 1.192, Operation and Maintenance Code ML23291A006.
Case Acceptability, ASME OM Code, Revision
5, March 2024.
RG 1.193, ASME Code Cases Not Approved for ML23291A007.
Use, Revision 8, March 2024.
RG 1.193, ASME Code Cases Not Approved for ML25083A257.
Use, Revision 9 (DG-1449), December 2025.
RG 1.200, An Approach for Determining the ML070240001.
Technical Adequacy of Probabilistic Risk
Assessment Results for Risk-Informed
Activities, Revision 1, January 2007.
RG 1.200, An Approach for Determining the ML090410014.
Technical Adequacy of Probabilistic Risk
Assessment Results for Risk-Informed
Activities, Revision 2, March 2009.
RG 1.200, Acceptability of Probabilistic ML20238B871.
Risk Assessment Results for Risk-Informed
Activities, Revision 3, December 2020.
RG 1.262, ASME Code Cases Approved for Use ML25091A013.
Without Conditions, Revision 0, July 2025.
Rulemaking: Proposed Rule: Email from ML26023A041.
Kathryn Hyam (ASME) to Christian Araguas
(NRC), Request for Limited Public Access
of Code for Public Comment Period, January
21, 2026.
SECY-22-0019, ``Rulemaking Plan for the ML21314A215.
Revision of Embrittlement and Surveillance
Requirements for High-Fluence Nuclear
Power Plants in Long-Term Operation,''
March 8, 2022.
Staff Requirements--Affirmation Session, ML003755050.
11:30 a.m., Friday, September 10, 1999,
Commissioners' Conference Room, One White
Flint North, Rockville, Maryland (Open to
Public Attendance), September 10, 1999.
``Wolf Creek Generating Station, Unit 1-- ML20111A337.
Request for Relief from Requirements of
the American Society of Mechanical
Engineers Boiler and Pressure Vessel Code
Case N-666-1 (EPID L-2019-LLR-0077),''
April 27, 2020.
------------------------------------------------------------------------
ASME Codes, Standards, and Code Cases
------------------------------------------------------------------------
ASME BPV Code, Section III, Division 1: https://go.asme.org/NRC-
2023 Edition. ASME.
ASME BPV Code, Section XI, Division 1: 2023 https://go.asme.org/NRC-
Edition. ASME.
ASME Codes and Standards, Operation and https://cstools.asme.org/
Maintenance of Nuclear Power Plants (OM) csconnect/
Code Cases. CommitteePages.cfm?Committ
ee=O10300000&Action=26676.
------------------------------------------------------------------------
Additional Documents Proposed to be Incorporated by Reference
The NRC proposes to incorporate by reference three NRC RGs, as set
forth in Table V, that list new and revised ASME Code Cases that the
NRC is proposing to approve as voluntary alternatives to certain
provisions of NRC-required editions and addenda of the ASME BPV Code
and the ASME OM Code.
Table V--Draft Regulatory Guides Proposed To Be Incorporated by
Reference in 10 CFR 50.55a
------------------------------------------------------------------------
Document ADAMS Accession No.
------------------------------------------------------------------------
RG 1.84, Design, Fabrication, and ML25079A307
Materials Code Case Acceptability, ASME
Section III, Revision 41 (DG-1446),
December 2025.
RG 1.147, Inservice Inspection Code Case ML25080A261
Acceptability, ASME Section XI,
Division 1, Revision 22 (DG-1447),
December 2025.
RG 1.192, Operation and Maintenance Code ML25083A254
Case Acceptability, ASME OM Code,
Revision 6 (DG-1448), December 2025.
------------------------------------------------------------------------
Code Cases for Approval in This Proposed Rule
The ASME OM Code Cases that the NRC is proposing to approve as
alternatives to certain provisions of the ASME OM Code, as set forth in
Table VI, are made available for read-only access at the URL listed in
Table IV. The ASME BPV Code Cases that the NRC is proposing to approve
as alternatives to certain provisions of the ASME BPV Code, as set
forth in Table VI, are being made available by the ASME for read-only
access during the public comment period on https://go.asme.org/NRC-ASME.
The ASME is making the code cases listed in Table VI available for
limited, read-only access at the request of the NRC. The NRC believes
that stakeholders need to be able to read these code cases in order to
provide meaningful comment on the three RGs (listed in Table V) that
the NRC is
[[Page 9758]]
proposing to incorporate by reference into Sec. 50.55a. It is the
NRC's position that the listed code cases, as modified by any
conditions contained in the three RGs and thus serving as alternatives
to requirements in Sec. 50.55a, would be legally-binding regulatory
requirements. An applicant or licensee must comply with a listed code
case and any conditions to be within the scope of the NRC's approval of
the code case as a voluntary alternative for use. These requirements
cannot be fully understood without knowledge of the code case to which
the proposed condition applies, and to this end, the NRC has requested
that the ASME provide limited, read-only access to the code cases in
order to facilitate meaningful public comment.
Table VI--ASME Code Cases Proposed for NRC Approval
----------------------------------------------------------------------------------------------------------------
Boiler and pressure vessel code Section XI
-----------------------------------------------------------------------------------------------------------------
Code case No. Published with supplement Title
----------------------------------------------------------------------------------------------------------------
N-508-5................................. 6 (2021 Edition)........... Rotation of Snubbers and Pressure
Retaining Items for the Purpose of
Testing or Preventive Maintenance.
N-666-3................................. 0 (2023 Edition)........... Weld Overlay of Class 1, 2, and 3 Socket
Welded Connections.
N-716-4................................. 1 (2023 Edition)........... Alternative Classification and
Examination Requirements.
N-752-2................................. 6 (2023 Edition)........... Risk-Informed Categorization and
Treatment for Repair/Replacement
Activities in Class 2 and 3 Systems.
N-778-1................................. 0 (2023 Edition)........... Alternative Requirements for Preparation
and Submittal of Inservice Inspection
Plans, Schedules, and Preservice and
Inservice Inspection Summary Reports.
N-806-2................................. 3 (2023 Edition)........... Analytical Evaluation of Metal Loss in
Class 2 and 3 Metallic Piping Buried in
a Back-Filled Trench.
N-830-1................................. 3 (2021 Edition)........... Direct Use of Fracture Toughness for Flaw
Evaluations of Pressure Boundary
Materials in Class 1 Ferritic Steel
Components.
N-926................................... 6 (2021 Edition)........... Alternative Examination Requirements for
Unbonded Post-Tensioning Systems of
Class CC Components.
N-930................................... 0 (2023 Edition)........... Alternative Experience Requirements for
Nondestructive Examination Personnel for
Ultrasonic Examination.
----------------------------------------------------------------------------------------------------------------
Operation and maintenance code
----------------------------------------------------------------------------------------------------------------
Code case No. Edition.................... Title
----------------------------------------------------------------------------------------------------------------
OMN-32, Revision 1...................... 2022....................... Alternative Requirements for Range and
Accuracy of Pressure, Flow, and
Differential Pressure Instruments Used
in Pump Test.
OMN-34.................................. 2022....................... Use of a Pump Curve for Testing.
----------------------------------------------------------------------------------------------------------------
The NRC may post materials related to this document, including
public comments, on the Federal rulemaking website at https://www.regulations.gov under Docket ID NRC-2020-0029. In addition, the
Federal rulemaking website allows members of the public to receive
alerts when changes or additions occur in a docket folder. To
subscribe: (1) navigate to the docket folder (NRC-2020-0029); (2) click
the ``Subscribe'' button; and (3) enter an email address and click on
the ``Subscribe'' button.
List of Subjects in 10 CFR Part 50
Administrative practice and procedure, Antitrust, Backfitting,
Classified information, Criminal penalties, Education, Emergency
planning, Fire prevention, Fire protection, Incorporation by reference,
Intergovernmental relations, Nuclear power plants and reactors,
Penalties, Radiation protection, Reactor siting criteria, Reporting and
recordkeeping requirements, Whistleblowing.
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 NRC is proposing
to amend 10 CFR part 50 as follows:
PART 50--DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION
FACILITIES
0
1. The authority citation for part 50 is revised to read as follows:
Authority: Atomic Energy Act of 1954, secs. 11, 101, 102, 103,
104, 105, 108, 122, 147, 149, 161, 181, 182, 183, 184, 185, 186,
187, 189, 223, 234 (42 U.S.C. 2014, 2131, 2132, 2133, 2134, 2135,
2138, 2152, 2167, 2169, 2201, 2231, 2232, 2233, 2234, 2235, 2236,
2237, 2239, 2273, 2282); Energy Reorganization Act of 1974, secs.
201, 202, 206, 211 (42 U.S.C. 5841, 5842, 5846, 5851); Nuclear Waste
Policy Act of 1982, sec. 306 (42 U.S.C. 10226); National
Environmental Policy Act of 1969 (42 U.S.C. 4332); 44 U.S.C. 3504
note.
0
2. In Sec. 50.55a:
0
a. In paragraph (a)(1) introductory text, remove ``Codes/'' and add in
its place ``codes-standards''.
0
b. In paragraph (a)(1)(i)(E)(20), remove the word ``and'';
0
c. Revise paragraph (a)(1)(i)(E)(21);
0
d. Add paragraph (a)(1)(i)(E)(22);
0
e. In paragraph (a)(1)(ii)(C)(56), remove the word ``and'';
0
f. Revise paragraph (a)(1)(ii)(C)(57);
0
g. Add paragraph (a)(1)(ii)(C)(58);
0
h. Remove and reserve paragraph (a)(1)(iii)(A);
0
i. In paragraph (a)(1)(v)(B)(5), remove the word ``and'';
0
j. Revise paragraph (a)(1)(v)(B)(6);
0
k. Add paragraphs (a)(1)(v)(B)(7) through (9);
0
l. Revise paragraphs (a)(3)(i) through (iv);
0
m. Revise paragraph (b)(1)(xiv);
0
n. Add paragraph (b)(1)(xv);
0
o. Revise paragraph (b)(2)(xii);
0
p. Remove and reserve paragraph (b)(2)(xviii)(A);
0
q. Revise paragraphs (b)(2)(xviii)(D), (b)(2)(xxv), (b)(2)(xxviii),
(b)(2)(xxxi), and (b)(2)(xxxiv)(B);
0
r. In paragraph (b)(2)(xliii), remove the phrase ``Licenses shall'' and
add in its place the phrase ``Licensees shall'';
0
s. Revise paragraph (b)(2)(xliv);
0
t. Revise paragraphs (b)(2)(xlv), (b)(2)(xlvi), and (b)(2)(xlviii);
0
u. Add paragraphs (b)(2)(li), (b)(2)(lii), and (b)(2)(liii);
0
v. In paragraph (g)(4)(iv), remove the reference ``(a)(1)(iv) of this
section'' and add in its place the reference ``(a)(1)(iii) of this
section''; and
[[Page 9759]]
0
w. Revise paragraphs (g)(6)(ii)(D)(9), (g)(6)(ii)(F)(2)(iv) and (v),
(g)(6)(ii)(F)(4), (g)(6)(ii)(F)(10), and (g)(6)(ii)(F)(13).
The revisions and additions read as follows:
Sec. 50.55a Codes and Standards.
(a) * * *
(1) * * *
(i) * * *
(E) * * *
(21) 2021 Edition (including Subsection NCA; and Division 1
subsections NB through NG and Appendices); and
(22) 2023 Edition (including Subsection NCA; and Division 1
subsections NB through NG and Appendices), with Errata 23-2471, ``NB-
5332(a)(2) (from R/N 22-1562),'' dated April 4, 2024.
(ii) * * *
(C) * * *
(57) 2021 Edition; and
(58) 2023 Edition.
(iii) * * *
(A) [Reserved]
* * * * *
(v) * * *
(B) * * *
(6) NQA-1--2015;
(7) NQA-1--2017;
(8) NQA-1--2019; and
(9) NQA-1--2022.
* * * * *
(3) * * *
(i) NRC Regulatory Guide 1.84, Revision 41. NRC Regulatory Guide
1.84, Revision 41, ``Design, Fabrication, and Materials Code Case
Acceptability, ASME Section III,'' issued December 2025, with the
requirements in paragraph (b)(4) of this section.
(ii) NRC Regulatory Guide 1.147, Revision 22. NRC Regulatory Guide
1.147, Revision 22, ``Inservice Inspection Code Case Acceptability,
ASME Section XI, Division 1,'' issued December 2025, which lists ASME
Code Cases that the NRC has approved in accordance with the
requirements in paragraph (b)(5) of this section.
(iii) NRC Regulatory Guide 1.192, Revision 6. NRC Regulatory Guide
1.192, Revision 6, ``Operation and Maintenance Code Case Acceptability,
ASME OM Code,'' issued December 2025, which lists ASME Code Cases that
the NRC has approved in accordance with the requirements in paragraph
(b)(6) of this section.
(iv) NUREG-2228. NUREG-2228, ``Weld Residual Stress Finite Element
Analysis Validation: Part II--Proposed Validation Procedure,''
published July 2020 (including Errata September 22, 2021), which is
referenced in RG 1.147, Revision 22.
* * * * *
(b) * * *
(1) * * *
(xiv) Section III condition: Repairs to Stamped Components.
Applicants or licensees applying the provisions of NCA-8151, NCA-8500
and Nonmandatory Appendix NN in the 2021 Edition of Section III through
the latest edition and addenda incorporated by reference in paragraph
(a)(1)(i) of this section are required to meet all of the requirements
in Nonmandatory Appendix NN.
(xv) Section III condition: Protection from Deterioration of
Radiographic Film and Lifetime Record Retention.
(A) Protection from deterioration of radiographic film specified in
Note (3) of Table NCA-4134.17-1 of the 2023 Edition of Section III
shall include the provisions specified in NCA-4134.17(c), and the
reproduction must be retained as a lifetime record in accordance with
Table NCA-4134.17-1 of Section III.
(B) Protection from deterioration of radiographic film specified in
Note (1) of Table NCA-4134.17-2 of the 2023 Edition of Section III
shall include the provisions specified in NCA-4134.17(c), and the
reproduction must be retained as a nonpermanent record in accordance
with Table NCA-4134.17-2 of Section III.
(2) * * *
(xii) Section XI condition: Underwater welding. The provisions in
IWA-4660, ``Underwater Welding,'' of Section XI, 2001 Edition through
the 2021 Edition, are approved for use on irradiated material with the
following conditions:
* * * * *
(xviii) Section XI condition: NDE personnel certification--
(A) [Reserved]
* * * * *
(D) NDE personnel certification: Fourth provision. The use of
Appendix VII, Table VII-4110-1 and Appendix VIII, Subarticle VIII-2200
of the 2011 Addenda through the latest edition incorporated by
reference in paragraph (a)(1)(ii) of this section is prohibited. When
using ASME BPV Code, Section XI editions and addenda later than the
2010 Edition, licensees and applicants must use the prerequisites for
ultrasonic examination personnel certifications described in (1) and
(2) below or the Appendix VII, Table VII-4110-1 and Appendix VIII,
Subarticle VIII-2200 in the 2010 Edition.
* * * * *
(xxv) Section XI Condition: Mitigation of defects by modification.
Use of the provisions of IWA-4340 must be subject to the following
conditions:
* * * * *
(xxviii) Section XI condition: Analysis of flaws. Licensees using
the 2021 Edition or earlier of the ASME BPV Code, Section XI, Appendix
A, must use the following conditions when implementing Equation (2) in
A-4300(b)(1). Licensees using the 2023 Edition of the ASME BPV Code,
Section XI, Appendix A, must use the following conditions when
implementing Equation (2) in Y-3100(c):
* * * * *
(xxxi) Section XI condition: Mechanical clamping devices. When
installing a mechanical clamping device on an ASME BPV Code class
piping system, the following conditions apply.
(A) Appendix W of Section XI shall be treated as a mandatory
appendix and all of the provisions of Appendix W shall be met for the
mechanical clamping device being installed.
(B) Use of IWA-4131.1(c) of the 2010 Edition of Section XI and IWA-
4131.1(d) of the 2011 Addenda of the 2010 Edition and later versions of
Section XI is prohibited on small item Class 1 piping and portions of a
piping system that form the containment boundary.
(C) The use of Nonmandatory Appendix W for ASME Class 1 piping is
prohibited.
(D) The use of Nonmandatory Appendix W for portions of a piping
system that forms the containment boundary is prohibited.
(E) The use of Nonmandatory Appendix W for piping larger than NPS 2
(DN 50) when the nominal operating temperature or pressure exceeds 200
[deg]F (95 [deg]C) or 275 pounds per square inch gauge (1,900
kilopascals) is prohibited.
(F) The use of Nonmandatory Appendix W for piping larger than NPS 6
(DN 150) is prohibited.
* * * * *
(xxxiv) * * *
(B) Use of Nonmandatory Appendix U, Supplement U-S1 of the ASME BPV
Code, Section XI, 2021 Edition through the 2023 Edition is prohibited.
* * * * *
(xliv) Section XI condition: Nonmandatory Appendix Y. When using
Nonmandatory Appendix Y of the ASME BPV Code, Section XI, 2021 Edition
through the 2023 Edition, the following conditions apply:
(A) Use of Nonmandatory Appendix Y, Subarticle Y-2200 is
prohibited.
(B) Use of Nonmandatory Appendix Y, Subarticle Y-2400 is
prohibited.
(C) Use of Nonmandatory Appendix Y, Subarticle Y-3200 is
prohibited.
(D) Use of Nonmandatory Appendix Y, Paragraph Y-4322 is prohibited.
(xlv) Section XI condition: Pressure Testing of Containment
Penetration
[[Page 9760]]
Piping After Repair/Replacement Activities. Applicants or licensees
applying the provision of IWA-4540(a) and (e) of the 2021 Edition
through the latest edition and addenda incorporated by reference in
paragraph (a)(1)(ii) of the ASME Code, Section XI, are required to
perform a VT-2 examination of the area affected by the repair/
replacement activity during the Type C test in appendix J to this part.
(xlvi) Section XI condition: Contracted Repair/Replacement
Organization Fabricating Items Offsite of the Owner's Facility. When
applicants or licensees apply the provision of IWA-4143 in the 2021
Edition through the latest edition and addenda incorporated by
reference in paragraph (a)(1)(ii) of Section XI of the ASME Code, a
contracted Repair/Replacement Organization fabricating ASME Code,
Section III parts, appurtenances, piping subassemblies, and supports
offsite of the Owner's facility (e.g., vendor facility) without an ASME
Certificate of Authorization and without applying an ASME Stamp/
Certification Mark is prohibited.
* * * * *
(xlviii) Section XI condition: Analytical Evaluations of
Degradation. Applicants or licensees using the 2021 Edition through the
latest edition and addenda incorporated by reference in paragraph
(a)(1)(ii) of Section XI of the ASME Code must submit analytical
evaluations performed as required by IWB-3132.3 and IWC-3122.3 to the
Nuclear Regulatory Commission.
* * * * *
(li) Section XI condition: Pressure Testing Following Repair/
Replacement Activity. The use of the provisions in IWA-4540(d)(7) of
the 2023 Edition of Section XI for exemption of performing a pressure
test for Class 2 and 3 welds that have had a surface or volumetric
examination performed is prohibited.
(lii) Section XI condition: Preservice and Inservice Volumetric
Examination of Nozzles Fabricated from Weld Buildups. When using
provisions in Figure IWB-2500-7(d) of the 2023 Edition of Section XI,
preservice and inservice volumetric examination of nozzles fabricated
from weld buildups is required. The volumetric examination (ultrasonic)
of weld buildups shall be performed with procedures and personnel in
accordance with Mandatory Appendix VIII using acceptance criteria of
IWB-3514 for Category B-F welds.
(liii) Section XI condition: Protection from Deterioration of
Radiographic Film and Lifetime Record Retention. Protection from
deterioration of radiographic film specified in provision IWA-6310(b)
of the 2023 Edition of Section XI shall include the provisions
specified in IWA-6320, and the reproduction must be retained as a
lifetime record in accordance with IWA-6330, IWA-6340, and IWA-6350.
* * * * *
(g) * * *
(6) * * *
(ii) * * *
(D) * * *
(9) Volumetric Qualifications. Volumetric examinations of Table 1
of ASME Code Case N-729-6 may be qualified in accordance with Section
XI, Division 1, Mandatory Appendix VIII, Supplement 15, in the 2021
Edition through the latest edition and addenda incorporated by
reference in paragraph (a)(1)(i) of this section, in lieu of
subparagraphs (a) through (j) of 2500 of ASME Code Case N-729-6.
* * * * *
(F) * * *
(2) * * *
(iv) All other butt welds that rely on Alloy 82/182 for structural
integrity shall be categorized as Inspection Items A-1, A-2, B-1, B-2,
or B-3, as appropriate.
(v) Paragraph -1100(e) of ASME BPV Code Case N-770-7 shall not be
used to exempt welds that rely on Alloy 82/182 for structural integrity
from any requirement of this section.
* * * * *
(4) Examination coverage. When implementing Paragraph -2500(a) of
ASME BPV Code Case N-770-7, essentially 100 percent of the required
volumetric examination coverage shall be obtained, including greater
than 90 percent of the volumetric examination coverage for
circumferential flaws. Licensees are prohibited from using Paragraphs -
2500(c) and -2500(d) of ASME BPV Code Case N-770-7 to meet examination
requirements.
* * * * *
(10) Examination technique. Note 14(b) of Table 1 and Note (b) of
Figure 5(a) of ASME BPV Code Case N-770-7 may only be implemented if
the requirements of Note 14(a) of Table 1 of ASME BPV Code Case N-770-7
cannot be met.
* * * * *
(13) Encoded ultrasonic examination. Ultrasonic examinations of
non-mitigated or cracked mitigated dissimilar metal butt welds in the
reactor coolant pressure boundary must be performed in accordance with
the requirements of Table 1 for Inspection Item A-1, A-2, B-1, B-2, B-
3, E, F-2, J, K, N-1, N-2 and O. Essentially 100 percent of the
required inspection volume shall be examined using an encoded method.
* * * * *
Dated: February 10, 2026.
For the Nuclear Regulatory Commission.
Jeremy Groom,
Acting Director, Office of Nuclear Reactor Regulation.
[FR Doc. 2026-03993 Filed 2-26-26; 8:45 am]
BILLING CODE 7590-01-P