ML25091A012

Direct Final Rule: Dfr for the Approval of American Society of Mechanical Engineers Unconditioned Code Cases (Rin 3150-AL20; NRC-2024-0163)

ML25091A012
Person / Time
Issue date:	09/02/2025
From:	Gregory Bowman Office of Nuclear Reactor Regulation
To:
References
RIN 3150-AL20, NRC-2024-0163, 90FR46319
Download: ML25091A012 (43)

Text

[7590-01-P]

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 NRCs 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 If the direct final rule is withdrawn as a result of such comments, timely notice of the withdrawal will be published in the Federal Register.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

2 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: Helen.Chang@nrc.gov. For technical questions, contact the individuals listed in the FOR FURTHER INFORMATION CONTACT section of this document.

NRCs 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 NRCs Public Document Room (PDR) reference staff at 1-800-397-4209, at 301-415-4737, or by email to PDR.Resource@nrc.gov. 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.

NRCs 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 PDR.Resource@nrc.gov or call 1-800-397-4209 or 301-415-4737, between 8 a.m. and 4 p.m. eastern time, Monday through Friday, except

3 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.

FOR FURTHER INFORMATION CONTACT: Nicole Fields, Office of Nuclear Material Safety and Safeguards, telephone: 630-829-9570, email: Nicole.Fields@nrc.gov; or Jay Collins, Office of Nuclear Reactor Regulation, telephone: 301-415-4038, email:

Jay.Collins@nrc.gov. 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

4 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.

NRCs 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 NRCs Public Document Room (PDR) reference staff at 1-800-397-4209, at 301-415-4737, or by email to PDR.Resource@nrc.gov. 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.

NRCs 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 PDR.Resource@nrc.gov 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.

5 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 rules underlying premise or approach, or would be ineffective or unacceptable without a change. A comment is adverse and significant if:

6

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

7 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 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 licensees 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,

8 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 licensees 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,

9 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.

10 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 referencesin 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

11 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.

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.

12 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

13 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 ICode Cases Approved for Use Without Conditions Boiler and Pressure Vessel Code Section III (addressed in RG 1.262, Revision 0, Table 1)

Code Case No.

Published with Supplement Title 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-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)

Code Case No.

Published with Supplement Title 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

14 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-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, Owners Activity Report, or Inservice Inspection Summary Report Completion Time 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)

Code Case Applicability Title OMN-23, Revision 1 2001 to 2022 Editions Alternative Rules for Testing Pressure Isolation Valves

15 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

16 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)

17 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.

18 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 NRCs convention for regulatory analysis for most rulemakings is to perform a regulatory analysis for the 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 NRCs regulations. Thus, licensees know when receiving their operating licenses that incorporating updates to the ASME Code is part of the regulatory process.

19 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 casesthe NRCs imposition of a new condition on an ASME Code provision already incorporated by the NRC or required adoption of provisions on an expedited schedulerepresent 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 NRCs 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.

20 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 applicants or a licensees 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).

21 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 Commissions 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

22 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 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 NRCs approval of the ASME code cases is accomplished by amending the

23 NRCs 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 ReferenceReasonable 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 OFRs 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 NRCs 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 NRCs 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

24 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 NRCs 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 NRCs 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 PDR.Resource@nrc.gov 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

25 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 IIMaterial To Be Incorporated by Reference in 10 CFR 50.55a DOCUMENT ADAMS Accession No.

RG 1.262, ASME Code Cases Approved for Use Without Conditions, Revision 0, July 2025 ML25091A013 XVI. Availability of Documents The documents identified in the following table are available to interested persons as indicated.

Table IIIAvailability of Documents DOCUMENT ADAMS Accession No. /

Web link / Federal Register Citation SRM-SECY-21-0029, Rulemaking Plan on Relaxation of Inservice Testing and Inservice Inspection Program Update Frequencies Required in 10 CFR 50.55a, November 8, 2021 ML21312A490 RG 1.262, ASME Code Cases Approved for Use Without Conditions, Revision 0, July 2025 ML25091A013 RG 1.84, Design, Fabrication, and Materials Code Case Acceptability, ASME Section III, Revision 40, March 2024 ML23291A008 RG 1.147, Inservice Inspection Code Case Acceptability, ASME Section XI, Division 1, Revision 21, March 2024 ML23291A003 RG 1.192, Operation and Maintenance Code Case Acceptability, ASME OM Code, Revision 5, March 2024 ML23291A006 RG 1.193, ASME Code Cases Not Approved for Use, Revision 8, March 2024 ML23291A007

26 ASME, ASME Request for 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 ML24296A006 ASME Codes and Standards, Operation and Maintenance of Nuclear Power Plants (OM) Code Cases https://cstools.asme.org/csco nnect/CommitteePages.cfm?

Committee=O10300000&Acti on=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.

27 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

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.

2. Amend § 50.55a by:

a. Revising the introductory text of paragraph (a)(3);

b. Revising paragraph (a)(3)(iv);

c. Adding paragraph (a)(3)(v); and

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:

§ 50.55a Codes and standards.

(a) * *

• 28 (3) U.S. Nuclear Regulatory Commission (NRC): Public Document Room, 11555 Rockville Pike, Rockville, Maryland 20852; telephone: 1-800-397-4209; email:

pdr.resource@nrc.gov; 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), (b)(5), and (b)(6) of this section.

(v) NUREG-2228. NUREG-2228, Weld Residual Stress Finite Element Analysis Validation: Part IIProposed 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

29 (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 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

30 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

31 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

32 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

33 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 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

34 (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,

35 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

36 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 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

37 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

38 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

39 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)

40 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. 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

41 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.

42 (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;

43 (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.

/RA/

Gregory Bowman, Acting Director Office of Nuclear Reactor Regulation.