[Federal Register Volume 90, Number 185 (Friday, September 26, 2025)]
[Rules and Regulations]
[Pages 46319-46330]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-18769]


=======================================================================
-----------------------------------------------------------------------

NUCLEAR REGULATORY COMMISSION

10 CFR Part 50

[NRC-2024-0163]
RIN 3150-AL20


Approval of American Society of Mechanical Engineers 
Unconditioned Code Cases

AGENCY: Nuclear Regulatory Commission.

ACTION: Direct final rule.

-----------------------------------------------------------------------

SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is amending its 
regulations to incorporate by reference a regulatory guide that 
approves unconditioned code cases published by the American Society of 
Mechanical Engineers (ASME). This action allows nuclear power plant 
applicants and licensees to use the code cases as voluntary 
alternatives to engineering standards for nuclear power plant 
components. These standards are set forth in the ASME Boiler and 
Pressure Vessel Code and ASME Operation and Maintenance of Nuclear 
Power Plants, which are currently incorporated by reference into the 
NRC's regulations.

DATES: The final rule is effective January 26, 2026, unless significant 
adverse comments are received by November 25, 2025. If the direct final 
rule is withdrawn as a result of such comments, timely notice of the 
withdrawal will be published in the Federal Register. 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. Comments received on this direct final rule will also 
be considered to be comments on a companion proposed rule published in 
the Proposed Rules section of this issue of the Federal Register. The 
incorporation by reference of certain material listed in the regulation 
is approved by the Director of the Federal Register as of January 26, 
2026.

ADDRESSES: Please refer to Docket ID NRC-2024-0163 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-2024-0163. Address 
questions about NRC dockets to Helen Chang; telephone: 301-415-3228; 
email: [email protected]. For technical questions, contact the 
individuals listed in the FOR FURTHER INFORMATION CONTACT section of 
this document.
     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 of this document.
     NRC's PDR: The PDR, where you may examine and order copies 
of publicly available documents, is open by appointment. To make an 
appointment to visit the PDR, please send an email to 
[email protected] or call 1-800-397-4209 or 301-415-4737, between 8 
a.m. and 4 p.m. eastern time, Monday through Friday, except Federal 
holidays.
    You can read a plain language description of this final rule at 
https://www.regulations.gov/docket/NRC-2024-0163. For additional 
direction on obtaining information and submitting comments, see 
``Obtaining Information and Submitting Comments'' in the SUPPLEMENTARY 
INFORMATION section of this document.

[[Page 46320]]


FOR FURTHER INFORMATION CONTACT: Nicole Fields, Office of Nuclear 
Material Safety and Safeguards, telephone: 630-829-9570, email: 
[email protected]; or 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:

Table of Contents

I. Obtaining Information and Submitting Comments
II. Rulemaking Procedure
III. Background
IV. Discussion
V. Section-by-Section Analysis
VI. Regulatory Flexibility Certification
VII. Regulatory Analysis
VIII. Backfitting and Issue Finality
IX. Plain Writing
X. Environmental Assessment and Final Finding of No Significant 
Environmental Impact
XI. Paperwork Reduction Act
XII. Regulatory Planning and Review (Executive Order 12866)
XIII. Congressional Review Act
XIV. Voluntary Consensus Standards
XV. Incorporation by Reference--Reasonable Availability to 
Interested Parties
XVI. Availability of Documents

I. Obtaining Information and Submitting Comments

A. Obtaining Information

    Please refer to Docket ID NRC-2024-0163 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-2024-0163.
     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 of this document.
     NRC's PDR: The PDR, where you may examine and order copies 
of publicly available documents, is open by appointment. To make an 
appointment to visit the PDR, please send an email to 
[email protected] or call 1-800-397-4209 or 301-415-4737, between 8 
a.m. and 4 p.m. eastern time, 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-2024-0163 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. Rulemaking Procedure

    Because the NRC considers this action to be noncontroversial, the 
NRC is using the ``direct final rule procedure'' for this rule. This 
amendment is effective on January 26, 2026. However, if the NRC 
receives significant adverse comments on this direct final rule by 
November 25, 2025, then the NRC will publish a document that withdraws 
this action. If the direct final rule is withdrawn, the NRC will 
address the comments in a subsequent final rule or as otherwise 
appropriate.
    A significant adverse comment is a comment where the commenter 
explains why the rule would be inappropriate, including challenges to 
the rule's underlying premise or approach, or would be ineffective or 
unacceptable without a change. A comment is adverse and significant if:
    (1) The comment opposes the rule and provides a reason sufficient 
to require a substantive response in a notice-and-comment process. For 
example, a substantive response is required when:
    (a) The comment causes the NRC staff to reevaluate (or reconsider) 
its position or conduct additional analysis;
    (b) The comment raises an issue serious enough to warrant a 
substantive response to clarify or complete the record; or
    (c) The comment raises a relevant issue that was not previously 
addressed or considered by the NRC.
    (2) The comment proposes a change or an addition to the rule, and 
it is apparent that the rule would be ineffective or unacceptable 
without incorporation of the change or addition.
    (3) The comment causes the NRC staff to make a change (other than 
editorial) to the rule.
    For detailed instructions on filing comments, please see the 
ADDRESSES section of this document.

III. Background

    The American Society of Mechanical Engineers (ASME) develops and 
publishes the ASME Boiler and Pressure Vessel Code (BPV Code), which 
contains requirements for the design, construction, and inservice 
inspection (ISI) of nuclear power plant components, and the ASME 
Operation and Maintenance of Nuclear Power Plants, Division 1, OM Code: 
Section IST (OM Code), which contains requirements for inservice 
testing (IST) of nuclear power plant components. In response to ASME 
BPV and OM Code user requests, the ASME develops code cases that 
provide voluntary alternatives to specific BPV and OM Code 
requirements.
    The NRC approves the ASME BPV and OM Codes for use in title 10 of 
the Code of Federal Regulations (10 CFR) 50.55a, ``Codes and 
standards,'' through the process of incorporation by reference. As 
such, each provision of the ASME BPV and OM Codes incorporated by 
reference into and mandated by 10 CFR 50.55a(a)(1) 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 10 CFR 50.55a(a)(3) to 
incorporate by reference NRC Regulatory Guides (RGs) listing approved 
ASME code cases that may be used as voluntary alternatives to the BPV 
and OM Codes. The NRC staff also maintains RG 1.193, ``ASME Code Cases 
Not Approved for Use,'' which is not incorporated by reference into 10 
CFR 50.55a, but does provide guidance on which ASME code cases the NRC 
has determined not to be acceptable for use on a generic basis.
    Section III of the ASME BPV Code applies to new construction and 
repair/replacement activities (i.e., the edition

[[Page 46321]]

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). 
Hence, if a Section III code case is implemented by an applicant or a 
licensee and a later revision of the code case is approved for use by 
the RGs listed in 10 CFR 50.55a(a)(3), the applicant or licensee may 
use either version of the code case, as described in 10 CFR 
50.55a(b)(4)(ii). The licensee is still subject, however, to whatever 
change requirements apply to its licensing basis (e.g., 10 CFR 50.59).
    A licensee's ISI and IST programs must be updated periodically to 
the latest edition and addenda of the ASME BPV Code, Section XI, and 
the OM Code, respectively, that were incorporated by reference into 10 
CFR 50.55a and in effect no more than 18 months before the start of the 
code of record interval, as required by 10 CFR 50.55a(f)(4)(ii) and 10 
CFR 50.55a(g)(4)(ii). Licensees that were using a code case prior to 
the effective date of a final rule incorporating by reference a 
regulatory guide in 10 CFR 50.55a(a)(3) may continue to use the 
previous version for the remainder of the code of record interval. 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 NRC has a separate process to address a situation 
where a code case has been revised because of a safety issue with the 
original code case. Code cases apply to specific editions and addenda, 
and code cases may be revised if they are no longer accurate or 
adequate, so licensees choosing to continue using a code case during 
the subsequent code of record interval must implement the latest 
version approved for use by the RGs listed 10 CFR 50.55a(a)(3) as 
required by 10 CFR 50.55a(b)(5), 10 CFR 50.55a(b)(6), 10 CFR 
50.55a(f)(4)(ii), and 10 CFR 50.55a(g)(4)(ii).
    If a code case has been annulled, applicants or licensees must not 
apply that code case unless it was applied prior to being listed as 
annulled. If an applicant or a licensee applied a code case before it 
was listed as annulled, the applicant or licensee may continue to use 
the code case until the applicant or licensee updates its construction 
code of record for Section III (in the case of an applicant, updates 
its application) or until the licensee's code of record interval 
expires, for Section XI and the OM Code, after which the continued use 
of the code case is prohibited unless NRC authorization is given under 
10 CFR 50.55a(z).
    If a code case is approved for use by the RGs incorporated by 
reference in 10 CFR 50.55a(a)(3) and ASME later issues a revised 
version or annuls the code case because experience has shown that the 
design analysis, construction method, examination method, or testing 
method is inadequate, the NRC will amend 10 CFR 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. Licensees should consult the rules for 
applying code cases in paragraphs 10 CFR 50.55a(b)(4) through (6).
    In previous rulemakings for ASME code cases, the NRC incorporated 
by reference several RGs (RG 1.84, Revision 40, ``Design, Fabrication, 
and Materials Code Case Acceptability, ASME Section III''; RG 1.147, 
Revision 21, ``Inservice Inspection Code Case Acceptability, ASME 
Section XI, Division 1''; and RG 1.192, Revision 5, ``Operation and 
Maintenance [OM] Code Case Acceptability, ASME OM Code''), which 
identified new, revised, and reaffirmed ASME code cases that the NRC 
finds acceptable or conditionally acceptable for use. In this final 
rule, the NRC incorporates by reference RG 1.262, ``ASME Code Cases 
Approved for Use Without Conditions.'' This new approach to the ASME 
code case rulemaking implements Commission direction in SRM-SECY-21-
0029 regarding streamlining 10 CFR 50.55a rulemaking activities. The 
NRC considers these code cases to be noncontroversial and not to need 
regulatory conditions, such that issuing a direct final rule is an 
appropriate rulemaking process. This approach may allow the NRC to 
approve such code cases in a more efficient manner than was possible 
under the former. Potentially controversial code cases or those with 
proposed NRC regulatory conditions will be addressed using a proposed 
rule and final rule process. In developing RG 1.262, 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 will approve 
these ASME code cases for use by incorporating RG 1.262 by reference 
into 10 CFR 50.55a.

IV. Discussion

A. Rule Objective and Scope

    This final rule incorporates by reference RG 1.262, which lists 
ASME BPV and OM code cases that the NRC finds to be acceptable. This RG 
supplements the most recent revisions of RG 1.84, RG 1.147, and RG 
1.192, which are also incorporated by reference in 10 CFR 50.55a, by 
providing additional acceptable code cases.
    To accommodate the incorporation by reference of RG 1.262 into 10 
CFR 50.55a, the NRC is making one-time conforming structural changes 
and improvements to 10 CFR 50.55a, related to code cases. These 
structural changes do not change the use of code cases by applicants 
and licensees; they only accommodate that code cases associated with 
ASME BPV Code, Section III; ASME BPV Code, Section XI; and ASME OM 
Code, may now be approved by the NRC either in RG 1.84, RG 1.147, and 
RG 1.192, respectively, or in the new RG 1.262. Accordingly, 10 CFR 
50.55a(b)(4), ``Conditions on Design, Fabrication, and Materials Code 
Cases''; 10 CFR 50.55a(b)(5), ``Conditions on inservice inspection Code 
Cases''; and 10 CFR 50.55a(b)(6), ``Conditions on ASME OM Code Cases''; 
are being revised to accommodate this new paradigm, while maintaining 
the same requirements when applying ASME BPV Code, Section III; ASME 
BPV Code, Section XI; and ASME OM Code cases, respectively.
    Throughout 10 CFR 50.55a, there are currently references to code 
cases specifically located in RG 1.84, RG 1.147, and RG 1.192. As 
applicable, those references--in paragraphs (b)(2) and (3), (c)(3), 
(d)(2), (e)(2), (f)(2) through (4), and (g)(2) through (4) and (6)--
have been broadened to include all of the NRC regulatory guides as 
incorporated by reference in 10 CFR 50.55a(a)(3). This structural 
change simplifies the regulations and does not change which code cases 
are available for use, as applicable to the specific ASME Code.
    The ASME code cases that are the subject of this final rule are the 
new and revised Section III and Section XI code cases as listed in 
Supplements 3 through 6 to the 2021 Edition and Supplements 0 through 3 
to the 2023 Edition of the ASME BPV Code, and the ASME OM Code Case 
OMN-23, Revision 1, which is listed on the ASME Codes & Standards 
Connect website. In this rule, the NRC also dispositioned the ASME BPV 
Code Cases N-788-2 and N-939 as was requested by ASME by letter to the 
NRC dated October 18, 2024.

[[Page 46322]]

    The NRC incorporates by reference specific editions and addenda of 
the ASME BPV and OM Codes in 10 CFR 50.55a as regulatory requirements. 
The ASME develops and publishes code cases that provide alternatives to 
existing Code requirements. This final rule incorporates by reference 
RG 1.262, Revision 0, ``ASME Code Cases Approved for Use Without 
Conditions,'' which allows nuclear power plant licensees and applicants 
for construction permits, operating licenses, combined licenses, 
standard design certifications, standard design approvals, and 
manufacturing licenses under 10 CFR part 50, ``Domestic Licensing of 
Production and Utilization Facilities,'' and part 52, ``Licenses, 
Certifications, and Approvals for Nuclear Power Plants,'' to use the 
code cases listed in RG 1.262 as acceptable alternatives to the 
applicable ASME BPV and OM Codes for the construction, ISI, and IST of 
nuclear power plant components. The ASME publishes the OM code cases 
and lists the code cases on the ASME website. In contrast, the ASME 
publishes BPV code cases in supplements to the current BPV Code 
edition. This final rule identifies the BPV code cases by the edition 
of the ASME BPV Code under which they were published by the ASME, and 
the OM code case by its applicability as specified by the ASME.

B. Use of ASME Code Cases

    The following general guidance applies to the use of the ASME code 
cases approved in RG 1.262, Revision 0, incorporated by reference into 
10 CFR 50.55a as part of this final rule. Specifically, the use of the 
code cases listed in this RG are acceptable when implementing the 
editions and addenda of the ASME BPV and OM Codes incorporated by 
reference in 10 CFR 50.55a.
    The approval of a code case in this RG constitutes acceptance of 
its technical position for applications that are not precluded by 
regulatory or 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 RG are acceptable for use within the limits specified in 
the code cases by the ASME. An applicant or licensee is not required to 
apply ASME code cases at its nuclear power plant. However, if an 
applicant or licensee determines that a code case will be implemented, 
the applicant or licensee must comply with the provisions of that code 
case fully without deviation or must submit a request for relief or an 
alternative to the provisions of the code case under the process 
specified in 10 CFR 50.55a. An applicant or licensee that decides not 
to apply the code case must apply or reapply the Code requirements and 
address any omitted Code activities.
    The ``Background'' section of this notice discusses in detail the 
revision and annulment of ASME code cases and the requirements in 10 
CFR 50.55a(b) for which version of the code case must be applied by 
applicants and licensees. The addition of RG 1.262 to 10 CFR 50.55a 
does not change this process, but applicants and licensees should note 
that now a code case may be approved in one RG that is incorporated by 
reference and a later revision of that code case may be approved in a 
different RG also incorporated by reference. However, applicants and 
licensees are still subject to the requirements of paragraphs 10 CFR 
50.55a(b)(4) through (6) when determining which version of the code 
case must be applied. Applicants and licensees should review the new 
and newly revised code cases in RG 1.262, along with the code cases in 
RG 1.84, RG 1.147, and RG 1.192 to determine the most recently approved 
revisions. This should also be done when future revisions of RG 1.84, 
RG 1.147, and RG 1.192 are incorporated by reference.

C. Table of Approved ASME Code Cases

    The code cases discussed in Table I are new, revised, or reaffirmed 
code cases that the NRC approves for use without conditions.

                             Table I--Code Cases Approved for Use Without Conditions
----------------------------------------------------------------------------------------------------------------
              Code case No.                        Published with supplement                    Title
----------------------------------------------------------------------------------------------------------------
                                   Boiler and Pressure Vessel Code Section III
                                  (addressed in RG 1.262, Revision 0, Table 1)
----------------------------------------------------------------------------------------------------------------
N-637-2..................................  4 (2021 Edition)........................  Use of 44Fe-25Ni-21Cr-Mo
                                                                                      (Alloy UNS N08904) Plate,
                                                                                      Bar, Fittings, Welded
                                                                                      Pipe, and Welded Tube,
                                                                                      Classes 2 and 3.
N-801-4..................................  0 (2023 Edition)........................  Rules for Repair of N-
                                                                                      Stamped Class 1, 2, 3, and
                                                                                      MC Components.
N-928....................................  0 (2023 Edition)........................  Use of ASTM A508/A508M in
                                                                                      Lieu of SA[dash]508.
N-931....................................  0 (2023 Edition)........................  Performance and
                                                                                      Qualification Criteria for
                                                                                      Mitigation of Stress
                                                                                      Corrosion Cracking by
                                                                                      Surface Stress
                                                                                      Improvement.
N-933....................................  2 (2023 Edition)........................  Materials Exempted from
                                                                                      Stress-Rupture Test.
----------------------------------------------------------------------------------------------------------------
                                   Boiler and Pressure Vessel Code Section XI
                                  (addressed in RG 1.262, Revision 0, Table 2)
----------------------------------------------------------------------------------------------------------------
N-513-6..................................  4 (2021 Edition)........................  Evaluation Criteria for
                                                                                      Temporary Acceptance of
                                                                                      Flaws in Moderate Energy
                                                                                      Class 2 or 3 Piping and
                                                                                      Gate Valves.
N-516-6..................................  1 (2023 Edition)........................  Underwater Welding.
N-532-6..................................  0 (2023 Edition)........................  Repair/Replacement Activity
                                                                                      Documentation Requirements
                                                                                      and Inservice Inspection
                                                                                      Summary Report Preparation
                                                                                      and Submission.
N-639-1..................................  3 (2021 Edition)........................  Alternative Calibration
                                                                                      Block Material.
N-786-5..................................  1 (2023 Edition)........................  Alternative Requirements
                                                                                      for Sleeve Reinforcement
                                                                                      of Class 2 and 3
                                                                                      Moderate[dash]Energy
                                                                                      Carbon Steel Piping.
N-788-2..................................  5 (2023 Edition)........................  Certification of Ultrasonic
                                                                                      Examination Personnel by
                                                                                      Third Party NDE
                                                                                      Certification
                                                                                      Organizations.
N-809-2..................................  1 (2023 Edition)........................  Reference Fatigue Crack
                                                                                      Growth Rate Curves for
                                                                                      Austenitic Stainless
                                                                                      Steels in Pressurized
                                                                                      Water Reactor
                                                                                      Environments.
N-888-2..................................  3 (2023 Edition)........................  Similar and Dissimilar
                                                                                      Metal Welding Using
                                                                                      Ambient Temperature SMAW
                                                                                      or Machine GTAW Temper
                                                                                      Bead Technique.
N-892-1..................................  0 (2023 Edition)........................  Alternative Requirement for
                                                                                      Form OAR-1, Owner's
                                                                                      Activity Report, or
                                                                                      Inservice Inspection
                                                                                      Summary Report Completion
                                                                                      Time.

[[Page 46323]]

 
N-894....................................  3 (2023 Edition)........................  Repair of Class 1, 2, and 3
                                                                                      Austenitic Stainless Steel
                                                                                      with Thermal Fatigue
                                                                                      Cracking.
N-922....................................  4 (2021 Edition)........................  Alternative Requirements
                                                                                      for Application of
                                                                                      Structural Factors to
                                                                                      Secondary Stresses for
                                                                                      Analytical Evaluation of
                                                                                      Flaws in Piping in
                                                                                      Accordance with IWB-3644,
                                                                                      IWC-3644, and IWD-3644.
N-923....................................  4 (2021 Edition)........................  Mechanical Piping Joints.
N-932....................................  1 (2023 Edition)........................  Alternative Requirements
                                                                                      for Acceptance of
                                                                                      Containment Base Metal
                                                                                      Corrosion or Erosion.
N-939....................................  6 (2023 Edition)........................  Alternative Requirements
                                                                                      for Use of Mandatory
                                                                                      Appendix XI for Repair/
                                                                                      Replacement Activities for
                                                                                      Aboveground Class 3
                                                                                      Polyethylene Piping.
----------------------------------------------------------------------------------------------------------------
                                         Operation and Maintenance Code
                                  (addressed in RG 1.262, Revision 0, Table 3)
----------------------------------------------------------------------------------------------------------------
OMN-23, Revision 1.......................  2001 to 2022 Editions...................  Alternative Rules for
                                                                                      Testing Pressure Isolation
                                                                                      Valves.
----------------------------------------------------------------------------------------------------------------

V. Section-by-Section Analysis

    The following paragraphs in 10 CFR 50.55a are revised:
Paragraph (a)(3)
    This final rule revises the introductory text to paragraph (a)(3) 
to accommodate the changes in paragraphs (a)(3)(iv) and (v). This final 
rule also redesignates current paragraph (a)(3)(iv) to new paragraph 
(a)(3)(v) and adds new paragraph (a)(3)(iv) to incorporate by reference 
NRC Regulatory Guide 1.262, Revision 0, published July 2025.
Paragraph (b)(2)(xxxiv)(A)(2)
    This final rule revises paragraph (b)(2)(xxxiv)(A)(2) by replacing 
the reference to RG 1.147 with the phrase ``the appropriate NRC 
regulatory guides, as incorporated by reference in paragraph (a)(3) of 
this section'' to broaden and include all of the NRC regulatory guides 
as incorporated by reference in 10 CFR 50.55a(a)(3).
Paragraph (b)(3)(ii)(C)
    This final rule revises paragraph (b)(3)(ii)(C) by replacing the 
reference to RG 1.192 with the phrase ``the appropriate NRC regulatory 
guides, as incorporated by reference in paragraph (a)(3) of this 
section'' to broaden and include all the NRC regulatory guides as 
incorporated by reference in 10 CFR 50.55a(a)(3).
Paragraph (b)(4)
    This final rule broadens the code case conditions currently in 
paragraph (b)(4) to also apply to the code cases in Table 1 of RG 
1.262. This ensures that these code case conditions will apply to all 
BPV Section III code cases as listed in the regulatory guides 
incorporated by reference in paragraph (a)(3). A correction was also 
made to the introductory text to paragraph (b)(4) to add applicants, 
who were already included in the conditions in paragraphs (b)(4)(i), 
(b)(4)(ii), and (b)(4)(iii).
Paragraph (b)(5)
    This final rule broadens the code case conditions currently in 
paragraph (b)(5) to also apply to the code cases in Table 2 of RG 
1.262. This ensures that these code case conditions will apply to all 
BPV Section XI code cases as listed in the regulatory guides 
incorporated by reference in paragraph (a)(3). An editorial change to 
the introductory text of paragraph (b)(5) was made to add the word 
conditions for clarity and for consistency with paragraph (b)(4).
Paragraph (b)(6)
    This final rule broadens the code case conditions currently in 
paragraph (b)(6) to also apply to the code cases in Table 3 of RG 
1.262. This ensures that these code case conditions will apply to all 
OM code cases as listed in the regulatory guides incorporated by 
reference in paragraph (a)(3). An editorial change to the introductory 
text of paragraph (b)(6) was made to add the word conditions for 
clarity and for consistency with paragraph (b)(4).
Paragraph (c)(3)(iv)
    This final rule replaces the reference in paragraph (c)(3)(iv) to 
the specific NRC regulatory guide RG 1.84 and generalizes the reference 
to include all of the appropriate NRC regulatory guides as incorporated 
by reference in 10 CFR 50.55a(a)(3).
Paragraph (d)(2)(iii)
    This final rule replaces the reference in paragraph (d)(2)(iii) to 
the specific NRC regulatory guide RG 1.84 and generalizes the reference 
to include all of the appropriate NRC regulatory guides as incorporated 
by reference in 10 CFR 50.55a(a)(3).
Paragraph (e)(2)(iii)
    This final rule replaces the reference in paragraph (e)(2)(iii) to 
the specific NRC regulatory guide RG 1.84 and generalizes the reference 
to include all of the appropriate NRC regulatory guides as incorporated 
by reference in 10 CFR 50.55a(a)(3).
Paragraph (f)
    This final rule replaces the references in paragraphs (f)(2), 
(f)(3)(iii)(A) and (B), (f)(3)(iv)(A) and (B), and (f)(4)(i), (ii), and 
(iv) to the specific NRC regulatory guide, RG 1.147 or RG 1.192, and 
generalizes the reference to include all of the appropriate NRC 
regulatory guides as incorporated by reference in 10 CFR 50.55a(a)(3).
Paragraph (g)
    This final rule replaces the references in paragraphs (g)(2)(i) and 
(ii); (g)(3)(i) and (ii); (g)(4)(i), (ii), and (iv); and 
(g)(6)(ii)(F)(2)(iii) to the specific NRC regulatory guide, RG 1.147 or 
RG 1.192, and generalizes the reference to include all of the 
appropriate NRC regulatory guides as incorporated by reference in 10 
CFR 50.55a(a)(3).

VI. Regulatory Flexibility Certification

    Under the Regulatory Flexibility Act (5 U.S.C. 605(b)), the NRC 
certifies that this rule does not have a significant economic impact on 
a substantial number of small entities. This final 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).

VII. Regulatory Analysis

    The NRC's convention for regulatory analysis for most rulemakings 
is to perform a regulatory analysis for the

[[Page 46324]]

proposed and final rule that examines the costs and benefits of the 
alternatives considered by the NRC. However, for NRC rulemakings 
incorporating by reference into 10 CFR 50.55a the latest ASME BPV and 
OM Codes and associated regulatory guides listing code cases, the NRC 
utilizes a different approach in determining whether to prepare a 
regulatory analysis to support the proposed or final ASME Code 
rulemaking. The NRC need not prepare a regulatory analysis for those 
ASME Code rulemakings that do not impose additional conditions or 
exceptions beyond those in the updated ASME Code provisions.
    The NRC believes this is appropriate for several reasons:
     The ASME Codes are voluntary consensus standards, 
developed with participation by interested parties, including 
representatives from the NRC, the nuclear power industry, and 
licensees.
     It has been longstanding NRC policy to incorporate later 
versions of the ASME Code into its regulations. Further, it is a 
condition of NRC licenses to adopt revisions to some parts of the ASME 
Code on a periodic basis. Through this practice, the NRC has 
established an expectation that future revisions to the ASME Code, 
developed through the consensus standards process, will be incorporated 
by reference into the NRC's regulations. Thus, licensees know when 
receiving their operating licenses that incorporating updates to the 
ASME Code is part of the regulatory process. Endorsement of the ASME 
Code is consistent with the National Technology Transfer and 
Advancement Act, inasmuch as the NRC has determined that there are 
sound reasons for establishing requirements for design, maintenance, 
ISI, and IST by rulemaking.
     In a typical incorporation of the ASME Code and associated 
regulatory guides listing code cases, the NRC incorporation by 
reference can involve hundreds, if not thousands, of individual 
provisions. Evaluating the benefit and cost of each individual 
provision in a regulatory analysis would be prohibitive, and the value 
gained by performing such an exercise would be limited.
    However, where the NRC either: (i) imposes conditions or exceptions 
on the use of an ASME Code provision or (ii) requires that licensees 
adopt provisions of the ASME Code on an expedited schedule, then the 
NRC prepares a regulatory analysis that is limited to the consideration 
of those provisions or circumstances for which the NRC is imposing 
conditions. Both cases--the NRC's imposition of a new condition on an 
ASME Code provision already incorporated by the NRC or required 
adoption of provisions on an expedited schedule--represent situations 
where a regulatory analysis would be justified as a matter of 
regulatory policy. By contrast, the NRC need not prepare a regulatory 
analysis if the NRC is proposing a new condition on a new Code 
provision that is not present in an earlier Code Edition.
    Finally, if the NRC determines that one or more new ASME Code 
provisions are a significant departure from existing NRC-incorporated 
Code Editions, then the NRC will prepare a regulatory analysis for 
those new Code provisions. The NRC's ongoing review and endorsement of 
the ASME Code in 10 CFR 50.55a is based on the reliability of the ASME 
Code as a consensus standard with incremental changes. Any significant 
changes in the ASME Code could challenge the basis of previous 
regulatory analyses, and in those cases a new regulatory analysis would 
be performed.
    This final rule incorporates by reference a new NRC RG that lists 
the ASME BPV and OM code cases that the NRC finds to be acceptable 
without conditions. Therefore, the NRC has not prepared a regulatory 
analysis for this action.

VIII. Backfitting and Issue Finality

    The provisions in this final rule allow licensees and applicants to 
voluntarily apply NRC-approved code cases. The approved code cases are 
listed in an RG that is incorporated by reference into 10 CFR 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 the NRC imposition 
of a requirement or action and, therefore, is not inconsistent with any 
issue finality provision in 10 CFR part 52. For these reasons, the NRC 
finds that this final 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.

IX. 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).

X. Environmental Assessment and Final Finding of No Significant 
Environmental Impact

    The Commission has determined under the National Environmental 
Policy Act of 1969, as amended, and the Commission's regulations in 
subpart A of 10 CFR part 51, that this rule, 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.
    As voluntary alternatives to the ASME Code, NRC-approved code cases 
provide an equivalent level of safety. Therefore, the probability or 
consequences of accidents is not changed. 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 offsite 
impact to the public from this action.

XI. Paperwork Reduction Act

    This final rule does not contain any new or amended collections of 
information subject to the Paperwork Reduction Act of 1995 (44 U.S.C. 
3501 et seq.). Existing collections of information were approved by the 
Office of Management and Budget (OMB), approval numbers 3150-0011, 
3150-0151, and 3150-0264.

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.

XII. Regulatory Planning and Review (Executive Order 12866)

    Executive Order (E.O.) 12866, as amended by E.O. 14215, provides 
that the Office of Information and Regulatory Affairs (OIRA) will 
determine whether a regulatory action is significant as defined by E.O. 
12866 and will review all significant regulatory actions. OIRA 
determined that this direct final rule is

[[Page 46325]]

not a significant regulatory action under E.O. 12866.

XIII. Congressional Review Act

    This final rule is a rule as defined in the Congressional Review 
Act (5 U.S.C. 801-808). OMB has found that it does not meet the 
criteria at 5 U.S.C. 804(2).

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 final rule, 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 RG 1.262, Revision 0. The RG lists ASME code cases that the 
NRC has approved for use without conditions. The ASME code cases are 
voluntary consensus standards as described in the National Technology 
Transfer and Advancement Act of 1995 and defined in OMB Circular A-119. 
The ASME code cases constitute voluntary consensus standards, in which 
all interested parties (including the NRC and licensees of nuclear 
power plants) participate.

XV. Incorporation by Reference--Reasonable Availability to Interested 
Parties

    The NRC is incorporating by reference RG 1.262, Revision 0, which 
lists ASME code cases that the NRC has approved for use without 
conditions as voluntary alternatives to certain provisions of NRC-
required editions and addenda of the ASME BPV and OM Codes.
    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. The discussion in this section complies with the requirement for 
rules as set forth in 1 CFR 51.5(b)(2).
    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 10 CFR 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 10 
CFR 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 10 CFR 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 is incorporating by reference in order to 
participate in the rulemaking.
    The RG that the NRC is incorporating by reference in this final 
rule is available without cost and can be accessed from the NRC's 
public website at https://www.nrc.gov/reading-rm/doc-collections/reg-guides/index.html. The RG can be viewed, by appointment, at the PDR, 
where you may examine and order copies of publicly available documents. 
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.
    Because access to the RG is available in various forms at no cost, 
the NRC determines that the RG is reasonably available to all 
interested parties. Additionally, as discussed in the ``Availability of 
Documents'' section of this document, the ASME code cases listed in RG 
1.262 are being made available concurrently with the publication of 
this direct final rule.

                       Table II--Material To Be Incorporated by Reference in 10 CFR 50.55a
----------------------------------------------------------------------------------------------------------------
                         Document                                            ADAMS accession No.
----------------------------------------------------------------------------------------------------------------
RG 1.262, ASME Code Cases Approved for Use Without          ML25091A013.
 Conditions, Revision 0, July 2025.
----------------------------------------------------------------------------------------------------------------

XVI. Availability of Documents

    The documents identified in the following table are available to 
interested persons as indicated.

                                      Table III--Availability of Documents
----------------------------------------------------------------------------------------------------------------
                                                                ADAMS accession No./web link/Federal Register
                         Document                                                 citation
----------------------------------------------------------------------------------------------------------------
SRM-SECY-21-0029, Rulemaking Plan on Relaxation of          ML21312A490.
 Inservice Testing and Inservice Inspection Program Update
 Frequencies Required in 10 CFR 50.55a, November 8, 2021.
RG 1.262, ASME Code Cases Approved for Use Without          ML25091A013.
 Conditions, Revision 0, July 2025.
RG 1.84, Design, Fabrication, and Materials Code Case       ML23291A008.
 Acceptability, ASME Section III, Revision 40, March 2024.
RG 1.147, Inservice Inspection Code Case Acceptability,     ML23291A003.
 ASME Section XI, Division 1, Revision 21, March 2024.

[[Page 46326]]

 
RG 1.192, Operation and Maintenance Code Case               ML23291A006.
 Acceptability, ASME OM Code, Revision 5, March 2024.
RG 1.193, ASME Code Cases Not Approved for Use, Revision    ML23291A007.
 8, March 2024.
ASME, ``ASME Request for Including Specific Code Cases in   ML24296A006.
 Draft Revision 22 of Regulatory Guide 1.147 and Draft
 Revision 1 of Regulatory Guide 1.246,'' October 18, 2024.
ASME Codes and Standards, Operation and Maintenance of      https://cstools.asme.org/csconnect/
 Nuclear Power Plants (OM) Code Cases.                       CommitteePages.cfm?Committee=O10300000&Action=26676
                                                             .
----------------------------------------------------------------------------------------------------------------

    The ASME OM code case that the NRC is approving as an alternative 
to certain provisions of the ASME OM Code, as set forth in Table I of 
this notice, is available for read-only access at the URL listed in 
Table III. The ASME is making the BPV code cases listed in Table I of 
this notice available for limited, read-only access at the request of 
the NRC at https://go.asme.org/NRC-ASME-CC. The NRC believes that 
stakeholders need to be able to read these code cases in order to fully 
understand the scope of this direct final rule, which will incorporate 
RG 1.262 by reference into 10 CFR 50.55a, and so the NRC has requested 
that the ASME provide reasonable access to the code cases listed in RG 
1.262 for a limited duration.
    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-2024-0163.

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 adopting 
the following amendments to 10 CFR part 50:

PART 50--DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION 
FACILITIES

0
1. The authority citation for part 50 continues 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; Sec. 109, Pub. L. 96-295, 94 Stat. 783.


0
2. Amend Sec.  50.55a by:
0
a. Revising the introductory text of paragraph (a)(3);
0
b. Revising paragraph (a)(3)(iv);
0
c. Adding paragraph (a)(3)(v); and
0
d. Revising paragraphs (b)(2)(xxxiv)(A)(2); (b)(3)(ii)(C); (b)(4), (5), 
and (6); (c)(3)(iv); (d)(2)(iii); (e)(2)(iii); (f)(2),(3), and (4); 
(g)(2), (3), and (4); and (g)(6)(ii)(F)(2)(iii).
    The revisions and addition read as follows:


Sec.  50.55a   Codes and standards.

    (a) * * *
    (3) U.S. Nuclear Regulatory Commission (NRC): Public Document Room, 
11555 Rockville Pike, Rockville, Maryland 20852; telephone: 1-800-397-
4209; email: [email protected]; https://www.nrc.gov/reading-rm/doc-collections/reg-guides/. The use of code cases listed in the NRC 
regulatory guides in paragraphs (a)(3)(i) through (iv) of this section 
is acceptable with the specified conditions in those guides when 
implementing the editions and addenda of the ASME BPV Code and ASME OM 
Code incorporated by reference in paragraph (a)(1) of this section. The 
NRC report in paragraph (a)(3)(v) of this section is acceptable as 
specified in the conditions when implementing code cases listed in the 
NRC regulatory guides in paragraphs (a)(3)(i) through (iii) of this 
section.
* * * * *
    (iii) * * *
    (iv) NRC Regulatory Guide 1.262, Revision 0. NRC Regulatory Guide 
1.262, Revision 0, ``ASME Code Cases Approved for Use Without 
Conditions,'' issued July 2025, which lists ASME Code Cases that the 
NRC has approved in accordance with the requirements in paragraphs 
(b)(4), (5), and (6) of this section.
    (v) 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 21.
* * * * *
    (b) * * *
    (2) * * *
    (xxxiv) * * *
    (A) * * *
    (2) In lieu of the appendix referenced in paragraph U-S1-4.2.1(c) 
of Appendix U, an approved version of the ASME BPV Code Case N-513 must 
be used in accordance with the appropriate NRC regulatory guides, as 
incorporated by reference in paragraph (a)(3) of this section, at the 
time the case was incorporated into the licensee's program.
* * * * *
    (3) * * *
    (ii) * * *
    (C) MOV risk categorization. When applying Appendix III to the ASME 
OM Code, licensees shall categorize MOVs according to their safety 
significance using the methodology described in ASME OM Code Case OMN-
3, ``Requirements for Safety Significance Categorization of Components 
Using Risk Insights for Inservice Testing of LWR Power Plants,'' 
subject to the conditions applicable to OMN-3 which are set forth in 
the appropriate NRC regulatory guides, as incorporated by reference in 
paragraph (a)(3) of this section, or using an MOV risk ranking 
methodology accepted by the NRC on a plant-specific or industry-wide 
basis in accordance with the conditions in the applicable safety 
evaluation.
* * * * *
    (4) Conditions on Design, Fabrication, and Materials Code Cases. 
Each manufacturing license, standard design

[[Page 46327]]

approval, and design certification application under part 52 of this 
chapter is subject to the following conditions. Applicants and 
licensees may apply the ASME BPV Code Cases listed in NRC Regulatory 
Guide 1.84 and Table 1 of NRC Regulatory Guide 1.262, as incorporated 
by reference in paragraph (a)(3) of this section, without prior NRC 
approval, subject to the following conditions:
    (i) Design, Fabrication, and Materials Code Case condition: 
Applying Code Cases. When an applicant or licensee initially applies a 
listed Code Case, the applicant or licensee must apply the most recent 
version of that Code Case incorporated by reference in paragraph (a) of 
this section.
    (ii) Design, Fabrication, and Materials Code Case condition: 
Applying different revisions of Code Cases. If an applicant or licensee 
has previously applied a Code Case and a later version of the Code Case 
is incorporated by reference in paragraph (a) of this section, the 
applicant or licensee may continue to apply the previous version of the 
Code Case as authorized or may apply the later version of the Code 
Case, including any NRC-specified conditions placed on its use, until 
it updates its Code of Record for the component being constructed.
    (iii) Design, Fabrication, and Materials Code Case condition: 
Applying annulled Code Cases. Application of an annulled Code Case is 
prohibited unless an applicant or licensee applied the listed Code Case 
prior to it being listed as annulled in an NRC regulatory guide, as 
incorporated by reference in paragraph (a)(3) of this section. If an 
applicant or licensee has applied a listed Code Case that is later 
listed as annulled in an NRC regulatory guide, as incorporated by 
reference in paragraph (a)(3) of this section, the applicant or 
licensee may continue to apply the Code Case until it updates its Code 
of Record for the component being constructed.
    (5) Conditions on inservice inspection Code Cases. Licensees may 
apply the ASME BPV Code Cases listed in NRC Regulatory Guide 1.147 and 
Table 2 of NRC Regulatory Guide 1.262, as incorporated by reference in 
paragraph (a)(3) of this section, without prior NRC approval, subject 
to the following conditions:
    (i) ISI Code Case condition: Applying Code Cases. When a licensee 
initially applies a listed Code Case, the licensee must apply the most 
recent version of that Code Case incorporated by reference in paragraph 
(a) of this section.
    (ii) ISI Code Case condition: Applying different revisions of Code 
Cases. If a licensee has previously applied a Code Case and a later 
version of the Code Case is incorporated by reference in paragraph (a) 
of this section, the licensee may continue to apply, to the end of the 
current code of record interval, the previous version of the Code Case, 
as authorized, or may apply the later version of the Code Case, 
including any NRC-specified conditions placed on its use. Licensees who 
choose to continue use of the Code Case during subsequent code of 
record intervals will be required to implement the latest version as 
incorporated by reference in paragraph (a)(3) of this section.
    (iii) ISI Code Case condition: Applying annulled Code Cases. 
Application of an annulled Code Case is prohibited unless a licensee 
previously applied the listed Code Case prior to it being listed as 
annulled in an NRC regulatory guide, as incorporated by reference in 
paragraph (a)(3) of this section. If a licensee has applied a listed 
Code Case that is later listed as annulled in an NRC regulatory guide, 
as incorporated by reference in paragraph (a)(3) of this section, the 
licensee may continue to apply the Code Case to the end of the current 
code of record interval.
    (6) Conditions on ASME OM Code Cases. Licensees may apply the ASME 
OM Code Cases listed in NRC Regulatory Guide 1.192 and Table 3 of NRC 
Regulatory Guide 1.262, as incorporated by reference in paragraph 
(a)(3) of this section, without prior NRC approval, subject to the 
following conditions:
    (i) OM Code Case condition: Applying Code Cases. When a licensee 
initially applies a listed Code Case, the licensee must apply the most 
recent version of that Code Case incorporated by reference in paragraph 
(a) of this section.
    (ii) OM Code Case condition: Applying different revisions of Code 
Cases. If a licensee has previously applied a Code Case and a later 
version of the Code Case is incorporated by reference in paragraph (a) 
of this section, the licensee may continue to apply, to the end of the 
current code of record interval, the previous version of the Code Case, 
as authorized, or may apply the later version of the Code Case, 
including any NRC-specified conditions placed on its use. Licensees who 
choose to continue use of the Code Case during subsequent code of 
record intervals will be required to implement the latest version as 
incorporated by reference in paragraph (a)(3) of this section.
    (iii) OM Code Case condition: Applying annulled Code Cases. 
Application of an annulled Code Case is prohibited unless a licensee 
previously applied the listed Code Case prior to it being listed as 
annulled in an NRC regulatory guide, as incorporated by reference in 
paragraph (a)(3) of this section. If a licensee has applied a listed 
Code Case that is later listed as annulled in an NRC regulatory guide, 
as incorporated by reference in paragraph (a)(3) of this section, the 
licensee may continue to apply the Code Case to the end of the current 
code of record interval.
    (c) * * *
    (3) * * *
    (iv) Reactor coolant pressure boundary condition: Use of Code 
Cases. The optional Code Cases applied to a component must be those 
listed in the appropriate NRC regulatory guides, as incorporated by 
reference in paragraph (a)(3) of this section.
* * * * *
    (d) * * *
    (2) * * *
    (iii) Quality Group B condition: Use of Code Cases. The optional 
Code Cases must be those listed in the appropriate NRC regulatory 
guides, as incorporated by reference in paragraph (a)(3) of this 
section.
    (e) * * *
    (2) * * *
    (iii) Quality Group C condition: Use of Code Cases. The optional 
Code Cases must be those listed in the appropriate NRC regulatory 
guides, as incorporated by reference in paragraph (a)(3) of this 
section.
    (f) * * *
    (2) Design and accessibility requirements for performing inservice 
testing in plants with CPs issued between 1971 and 1974. For a boiling 
or pressurized water-cooled nuclear power facility whose construction 
permit was issued on or after January 1, 1971, but before July 1, 1974, 
pumps and valves that are classified as ASME BPV Code Class 1 and Class 
2 must be designed and provided with access to enable the performance 
of inservice tests for operational readiness set forth in editions and 
addenda of Section XI of the ASME BPV Code incorporated by reference in 
paragraph (a)(1)(ii) of this section (or the optional ASME Code Cases 
listed in the appropriate NRC regulatory guides, as incorporated by 
reference in paragraph (a)(3) of this section) in effect 6 months 
before the date of issuance of the construction permit. The pumps and 
valves may meet the inservice test requirements set forth in subsequent 
editions of this Code

[[Page 46328]]

and addenda that are incorporated by reference in paragraph (a)(1)(ii) 
of this section (or the optional ASME Code Cases listed in the 
appropriate NRC regulatory guides, as incorporated by reference in 
paragraph (a)(3) of this section), subject to the applicable conditions 
listed therein.
    (3) Design and accessibility requirements for performing inservice 
testing in plants with CPs issued after 1974. For a boiling or 
pressurized water-cooled nuclear power facility whose construction 
permit under this part or design approval, design certification, 
combined license, or manufacturing license under part 52 of this 
chapter was issued on or after July 1, 1974:
    (i)-(ii) [Reserved]
    (iii) IST design and accessibility requirements: Class 1 pumps and 
valves.
    (A) Class 1 pumps and valves: First provision. In facilities whose 
construction permit was issued before November 22, 1999, pumps and 
valves that are classified as ASME BPV Code Class 1 must be designed 
and provided with access to enable the performance of inservice testing 
of the pumps and valves for assessing operational readiness set forth 
in the editions and addenda of Section XI of the ASME BPV Code 
incorporated by reference in paragraph (a)(1)(ii) of this section (or 
the optional ASME Code Cases listed in the appropriate NRC regulatory 
guides, as incorporated by reference in paragraph (a)(3) of this 
section) applied to the construction of the particular pump or valve or 
the summer 1973 Addenda, whichever is later.
    (B) Class 1 pumps and valves: Second provision. In facilities whose 
construction permit under this part, or design certification, design 
approval, combined license, or manufacturing license under part 52 of 
this chapter, issued on or after November 22, 1999, pumps and valves 
that are classified as ASME BPV Code Class 1 must be designed and 
provided with access to enable the performance of inservice testing of 
the pumps and valves for assessing operational readiness set forth in 
editions and addenda of the ASME OM Code (or the optional ASME OM Code 
Cases listed in the appropriate NRC regulatory guides, as incorporated 
by reference in paragraph (a)(3) of this section), incorporated by 
reference in paragraph (a)(1)(iv) of this section at the time the 
construction permit, combined license, manufacturing license, design 
certification, or design approval is issued.
    (iv) IST design and accessibility requirements: Class 2 and 3 pumps 
and valves.
    (A) Class 2 and 3 pumps and valves: First provision. In facilities 
whose construction permit was issued before November 22, 1999, pumps 
and valves that are classified as ASME BPV Code Class 2 and Class 3 
must be designed and be provided with access to enable the performance 
of inservice testing of the pumps and valves for assessing operational 
readiness set forth in the editions and addenda of Section XI of the 
ASME BPV Code incorporated by reference in paragraph (a)(1)(ii) of this 
section (or the optional ASME BPV Code Cases listed in the appropriate 
NRC regulatory guides, as incorporated by reference in paragraph (a)(3) 
of this section) applied to the construction of the particular pump or 
valve or the Summer 1973 Addenda, whichever is later.
    (B) Class 2 and 3 pumps and valves: Second provision. In facilities 
whose construction permit under this part, or design certification, 
design approval, combined license, or manufacturing license under part 
52 of this chapter, issued on or after November 22, 1999, pumps and 
valves that are classified as ASME BPV Code Class 2 and 3 must be 
designed and provided with access to enable the performance of 
inservice testing of the pumps and valves for assessing operational 
readiness set forth in editions and addenda of the ASME OM Code (or the 
optional ASME OM Code Cases listed in the appropriate NRC regulatory 
guides, as incorporated by reference in paragraph (a)(3) of this 
section), incorporated by reference in paragraph (a)(1)(iv) of this 
section at the time the construction permit, combined license, or 
design certification is issued.
    (v) IST design and accessibility requirements: Meeting later IST 
requirements. All pumps and valves may meet the test requirements set 
forth in subsequent editions of codes and addenda or portions thereof 
that are incorporated by reference in paragraph (a) of this section, 
subject to the conditions listed in paragraph (b) of this section.
    (4) Inservice testing standards requirement for operating plants. 
Throughout the service life of a boiling or pressurized water-cooled 
nuclear power facility, pumps and valves that are within the scope of 
the ASME OM Code must meet the inservice test requirements (except 
design and access provisions) set forth in the ASME OM Code and addenda 
that become effective subsequent to editions and addenda specified in 
paragraphs (f)(2) and (3) of this section and that are incorporated by 
reference in paragraph (a)(1)(iv) of this section, to the extent 
practical within the limitations of design, geometry, and materials of 
construction of the components. The inservice test requirements for 
pumps and valves that are within the scope of the ASME OM Code but are 
not classified as ASME BPV Code Class 1, Class 2, or Class 3 may be 
satisfied as an augmented IST program. This use of an augmented IST 
program is acceptable without prior NRC approval provided the basis for 
deviations from the ASME OM Code, as incorporated by reference in this 
section, demonstrates an acceptable level of quality and safety, or 
that implementing the Code provisions would result in hardship or 
unusual difficulty without a compensating increase in the level of 
quality and safety, where documented and available for NRC review. When 
using the 2006 Addenda or later of the ASME BPV Code, Section XI, the 
inservice examination, testing, and service life monitoring 
requirements for dynamic restraints (snubbers) must meet the 
requirements set forth in the applicable ASME OM Code as specified in 
paragraph (b)(3)(v)(B) of this section. When using the 2005 Addenda or 
earlier edition or addenda of the ASME BPV Code, Section XI, the 
inservice examination, testing, and service life monitoring 
requirements for dynamic restraints (snubbers) must meet the 
requirements set forth in either the applicable ASME OM Code or ASME 
BPV Code, Section XI as specified in paragraph (b)(3)(v) of this 
section.
    (i) Applicable IST Code: Initial code of record interval. Inservice 
tests to verify operational readiness of pumps and valves, whose 
function is required for safety, conducted during the initial code of 
record interval must comply with the requirements in the latest edition 
and addenda of the ASME OM Code incorporated by reference in paragraph 
(a)(1)(iv) of this section on the date no more than 18 months before 
the date of issuance of the operating license under this part, or no 
more than 18 months before the date scheduled for initial loading of 
fuel under a combined license under part 52 of this chapter (or the 
optional ASME OM Code Cases listed in the appropriate NRC regulatory 
guides, as incorporated by reference in paragraph (a)(3) of this 
section, subject to the conditions listed in paragraph (b) of this 
section).
    (ii) Applicable IST Code: Successive code of record intervals. 
Inservice tests to verify operational readiness of pumps and valves, 
whose function is required for safety, conducted during successive code 
of record intervals must comply with the requirements of the latest 
edition and addenda of the ASME OM Code incorporated by reference in

[[Page 46329]]

paragraph (a)(1)(iv) of this section no more than18 months before the 
start of the code of record interval (or the optional ASME Code Cases 
listed in the appropriate NRC regulatory guides, as incorporated by 
reference in paragraph (a)(3) of this section), subject to the 
conditions listed in paragraph (b) of this section.
    (iii) [Reserved]
    (iv) Applicable IST Code: Use of later Code editions and addenda. 
Inservice tests of pumps and valves may meet the requirements set forth 
in subsequent editions and addenda that are incorporated by reference 
in paragraph (a)(1)(iv) of this section, subject to the conditions 
listed in paragraph (b) of this section, and subject to NRC approval. 
Portions of editions or addenda may be used, provided that all related 
requirements of the respective editions or addenda are met. NRC 
approval is not required when updating the IST code of record before 
the start of an IST interval in which the updated IST code of record 
will be used and when using the latest edition incorporated by 
reference in (a)(1)(iv) of this section in its entirety, subject to the 
conditions listed in paragraph (b) of this section (or the optional 
ASME Code Cases listed in the appropriate NRC regulatory guides, as 
incorporated by reference in paragraph (a)(3) of this section).
* * * * *
    (g) * * *
    (2) Accessibility requirements--(i) Accessibility requirements for 
plants with CPs issued between 1971 and 1974. For a boiling or 
pressurized water-cooled nuclear power facility whose construction 
permit was issued on or after January 1, 1971, but before July 1, 1974, 
components that are classified as ASME BPV Code Class 1 and Class 2 and 
supports for components that are classified as ASME BPV Code Class 1 
and Class 2 must be designed and be provided with the access necessary 
to perform the required preservice and inservice examinations set forth 
in editions and addenda of Section III or Section XI of the ASME BPV 
Code incorporated by reference in paragraph (a)(1) of this section (or 
the optional ASME BPV Code Cases listed in the appropriate NRC 
regulatory guides, as incorporated by reference in paragraph (a)(3) of 
this section) in effect 6 months before the date of issuance of the 
construction permit.
    (ii) Accessibility requirements for plants with CPs issued after 
1974. For a boiling or pressurized water-cooled nuclear power facility, 
whose construction permit under this part, or design certification, 
design approval, combined license, or manufacturing license under part 
52 of this chapter, was issued on or after July 1, 1974, components 
that are classified as ASME BPV Code Class 1, Class 2, and Class 3 and 
supports for components that are classified as ASME BPV Code Class 1, 
Class 2, and Class 3 must be designed and provided with the access 
necessary to perform the required preservice and inservice examinations 
set forth in editions and addenda of Section III or Section XI of the 
ASME BPV Code incorporated by reference in paragraph (a)(1) of this 
section (or the optional ASME BPV Code Cases listed in the appropriate 
NRC regulatory guides, as incorporated by reference in paragraph (a)(3) 
of this section) applied to the construction of the particular 
component.
    (iii) Accessibility requirements: Meeting later Code requirements. 
All components (including supports) may meet the requirements set forth 
in subsequent editions of codes and addenda or portions thereof that 
are incorporated by reference in paragraph (a) of this section, subject 
to the conditions listed therein.
    (3) Preservice examination requirements--(i) Preservice examination 
requirements for plants with CPs issued between 1971 and 1974. For a 
boiling or pressurized water-cooled nuclear power facility whose 
construction permit was issued on or after January 1, 1971, but before 
July 1, 1974, components that are classified as ASME BPV Code Class 1 
and Class 2 and supports for components that are classified as ASME BPV 
Code Class 1 and Class 2 must meet the preservice examination 
requirements set forth in editions and addenda of Section III or 
Section XI of the ASME BPV Code incorporated by reference in paragraph 
(a)(1) of this section (or the optional ASME BPV Code Cases listed in 
the appropriate NRC regulatory guides, as incorporated by reference in 
paragraph (a)(3) of this section) in effect 6 months before the date of 
issuance of the construction permit.
    (ii) Preservice examination requirements for plants with CPs issued 
after 1974. For a boiling or pressurized water-cooled nuclear power 
facility, whose construction permit under this part, or design 
certification, design approval, combined license, or manufacturing 
license under part 52 of this chapter, was issued on or after July 1, 
1974, components that are classified as ASME BPV Code Class 1, Class 2, 
and Class 3 and supports for components that are classified as ASME BPV 
Code Class 1, Class 2, and Class 3 must meet the preservice examination 
requirements set forth in the editions and addenda of Section III or 
Section XI of the ASME BPV Code incorporated by reference in paragraph 
(a)(1) of this section (or the optional ASME BPV Code Cases listed in 
the appropriate NRC regulatory guides, as incorporated by reference in 
paragraph (a)(3) of this section) applied to the construction of the 
particular component.
    (iii)-(iv) [Reserved]
    (v) Preservice examination requirements: Meeting later Code 
requirements. All components (including supports) may meet the 
requirements set forth in subsequent editions of codes and addenda or 
portions thereof that are incorporated by reference in paragraph (a) of 
this section, subject to the conditions listed therein.
    (4) Inservice inspection standards requirement for operating 
plants. Throughout the service life of a boiling or pressurized water-
cooled nuclear power facility, components (including supports) that are 
classified as ASME BPV Code Class 1, Class 2, and Class 3 must meet the 
requirements, except design and access provisions and preservice 
examination requirements, set forth in Section XI of editions and 
addenda of the ASME BPV Code that become effective subsequent to 
editions specified in paragraphs (g)(2) and (3) of this section and 
that are incorporated by reference in paragraph (a)(1)(ii) or (iv) of 
this section for snubber examination and testing of this section, to 
the extent practical within the limitations of design, geometry, and 
materials of construction of the components. Components that are 
classified as Class MC pressure retaining components and their integral 
attachments, and components that are classified as Class CC pressure 
retaining components and their integral attachments, must meet the 
requirements, except design and access provisions and preservice 
examination requirements, set forth in Section XI of the ASME BPV Code 
and addenda that are incorporated by reference in paragraph (a)(1)(ii) 
of this section subject to the condition listed in paragraph (b)(2)(vi) 
of this section and the conditions listed in paragraphs (b)(2)(viii) 
and (ix) of this section, to the extent practical within the limitation 
of design, geometry, and materials of construction of the components. 
When using the 2006 Addenda or later of the ASME BPV Code, Section XI, 
the inservice examination, testing, and service life monitoring 
requirements for dynamic restraints (snubbers) must meet the 
requirements set forth in the applicable ASME OM Code as specified in 
paragraph (b)(3)(v)(B) of this section.

[[Page 46330]]

When using the 2005 Addenda or earlier edition or addenda of the ASME 
BPV Code, Section XI, the inservice examination, testing, and service 
life monitoring requirements for dynamic restraints (snubbers) must 
meet the requirements set forth in either the applicable ASME OM Code 
or ASME BPV Code, Section XI as specified in paragraph (b)(3)(v) of 
this section.
    (i) Applicable ISI Code: Initial code of record interval. Inservice 
examination of components and system pressure tests conducted during 
the initial code of record interval must comply with the requirements 
in the latest edition and addenda of the ASME BPV Code incorporated by 
reference in paragraph (a) of this section on the date no more than 18 
months before the date of issuance of the operating license under this 
part, or no more than 18 months before the date scheduled for initial 
loading of fuel under a combined license under part 52 of this chapter 
(or the optional ASME Code Cases listed in the appropriate NRC 
regulatory guides, as incorporated by reference in paragraph (a)(3) of 
this section), subject to the conditions listed in paragraph (b) of 
this section. Licensees may, at any time in their code of record 
interval, elect to use the Appendix VIII in the latest edition and 
addenda of the ASME BPV Code incorporated by reference in paragraph (a) 
of this section, subject to any applicable conditions listed in 
paragraph (b) of this section. Licensees using this option must also 
use the same edition and addenda of Appendix I, Subarticle I-3200, as 
Appendix VIII, including any applicable conditions listed in paragraph 
(b) of this section.
    (ii) Applicable ISI Code: Successive code of record intervals. 
Inservice examination of components and system pressure tests conducted 
during successive code of record intervals must comply with the 
requirements of the latest edition and addenda of the ASME BPV Code 
incorporated by reference in paragraph (a) of this section no more than 
18 months before the start of the code of record interval (or the 
optional ASME Code Cases listed in the appropriate NRC regulatory 
guides, as incorporated by reference in paragraph (a)(3) of this 
section), subject to the conditions listed in paragraph (b) of this 
section. However, a licensee whose inservice inspection interval 
commences during the 12 through 18-month period after September 30, 
2024, may delay the update of their Appendix VIII program by up to 18 
months after September 30, 2024. Alternatively, licensees may, at any 
time in their code of record interval, elect to use the Appendix VIII 
in the latest edition and addenda of the ASME BPV Code incorporated by 
reference in paragraph (a) of this section, subject to any applicable 
conditions listed in paragraph (b) of this section. Licensees using 
this option must also use the same edition and addenda of Appendix I, 
Subarticle I-3200, as Appendix VIII, including any applicable 
conditions listed in paragraph (b) of this section.
    (iii) Applicable ISI Code: Optional surface examination 
requirement. When applying editions and addenda prior to the 2003 
Addenda of Section XI of the ASME BPV Code, licensees may, but are not 
required to, perform the surface examinations of high-pressure safety 
injection systems specified in Table IWB-2500-1, Examination Category 
B-J, Item Numbers B9.20, B9.21, and B9.22.
    (iv) Applicable ISI Code: Use of subsequent Code editions and 
addenda. Inservice examination of components and system pressure tests 
may meet the requirements set forth in subsequent editions and addenda 
that are incorporated by reference in paragraph (a) of this section, 
subject to the conditions listed in paragraph (b) of this section, and 
subject to Commission approval. Portions of editions or addenda may be 
used, provided that all related requirements of the respective editions 
or addenda are met. NRC approval is not required when updating the ISI 
code of record before the start of an ISI interval in which the updated 
ISI code of record will be used and when using the latest edition 
incorporated by reference in (a)(1)(iv) of this section in its 
entirety, subject to the conditions listed in paragraph (b) of this 
section (or the optional ASME Code Cases listed in the appropriate NRC 
regulatory guides, as incorporated by reference in paragraph (a)(3) of 
this section).
    (v) Applicable ISI Code: Metal and concrete containments. For a 
boiling or pressurized water-cooled nuclear power facility whose 
construction permit under this part or combined license under part 52 
of this chapter was issued after January 1, 1956, the following are 
required:
    (A) Metal and concrete containments: First provision. Metal 
containment pressure retaining components and their integral 
attachments must meet the inservice inspection, repair, and replacement 
requirements applicable to components that are classified as ASME Code 
Class MC;
    (B) Metal and concrete containments: Second provision. Metallic 
shell and penetration liners that are pressure retaining components and 
their integral attachments in concrete containments must meet the 
inservice inspection, repair, and replacement requirements applicable 
to components that are classified as ASME Code Class MC; and
    (C) Metal and concrete containments: Third provision. Concrete 
containment pressure retaining components and their integral 
attachments, and the post-tensioning systems of concrete containments, 
must meet the inservice inspections, repair, and replacement 
requirements applicable to components that are classified as ASME Code 
Class CC.
* * * * *
    (6) * * *
    (ii) * * *
    (F) * * *
    (2) * * *
    (iii) Other mitigated welds shall be identified as the appropriate 
inspection item of the NRC authorized alternative or NRC-approved code 
case for the mitigation type in the appropriate NRC regulatory guides, 
as incorporated by reference in paragraph (a)(3) of this section.
* * * * *

    Dated: September 2, 2025.

    For the Nuclear Regulatory Commission.
Gregory Bowman,
Acting Director, Office of Nuclear Reactor Regulation.
[FR Doc. 2025-18769 Filed 9-25-25; 8:45 am]
BILLING CODE 7590-01-P