[Federal Register Volume 89, Number 169 (Friday, August 30, 2024)]
[Rules and Regulations]
[Pages 70449-70469]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-19235]



 ========================================================================
 Rules and Regulations
                                                 Federal Register
 ________________________________________________________________________
 
 This section of the FEDERAL REGISTER contains regulatory documents 
 having general applicability and legal effect, most of which are keyed 
 to and codified in the Code of Federal Regulations, which is published 
 under 50 titles pursuant to 44 U.S.C. 1510.
 
 The Code of Federal Regulations is sold by the Superintendent of Documents. 
 
 ========================================================================
 

  Federal Register / Vol. 89, No. 169 / Friday, August 30, 2024 / Rules 
and Regulations  

[[Page 70449]]



NUCLEAR REGULATORY COMMISSION

10 CFR Part 50

[NRC-2018-0289]
RIN 3150-AK21


American Society of Mechanical Engineers 2021-2022 Code Editions

AGENCY: Nuclear Regulatory Commission.

ACTION: Final rule.

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

SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is amending its 
regulations to incorporate by reference the 2021 Edition of the 
American Society of Mechanical Engineers Boiler and Pressure Vessel 
Code and the 2022 Edition of the American Society of Mechanical 
Engineers Operation and Maintenance of Nuclear Power Plants, Division 
1, OM Code: Section IST, for nuclear power plants. This action is in 
accordance with the NRC's policy to periodically update the regulations 
to incorporate by reference new editions of the American Society of 
Mechanical Engineers Codes and is intended to maintain the safety of 
nuclear power plants and to make NRC activities more effective and 
efficient. This amendment also incorporates editorial changes that do 
not change the technical information.

DATES: This final rule is effective on September 30, 2024. The 
incorporation by reference of certain publications listed in the 
regulation is approved by the Director of the Federal Register as of 
September 30, 2024.

ADDRESSES: Please refer to Docket ID NRC-2018-0289 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-2018-0289. Address 
questions about NRC dockets to Helen Chang; telephone: 301-415-3228; 
email: [email protected]. For technical questions, contact the 
individual 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 Web-based ADAMS 
Search.'' For problems with ADAMS, please contact the NRC's Public 
Document Room (PDR) reference staff at 1-800-397-4209, at 301-415-4737, 
or by email to [email protected]. For the convenience of the reader, 
instructions about obtaining materials referenced in this document are 
provided in the ``Availability of Documents'' section.
     NRC's PDR: The PDR, where you may examine and order copies 
of publicly available documents, is open by appointment. To make an 
appointment to visit the PDR, please send an email to 
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.
     Technical Library: The Technical Library, which is located 
at Two White Flint North, 11545 Rockville Pike, Rockville, Maryland 
20852, is open by appointment. Interested parties may make appointments 
to examine documents by contacting the NRC Technical Library by email 
at [email protected] between 8 a.m. and 4 p.m. eastern time, 
Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT: Tyler Hammock, Office of Nuclear 
Material Safety and Safeguards, telephone: 301-415-1381, email: 
[email protected]; or Michael Benson, Office of Nuclear Reactor 
Regulation, telephone: 301-415-2425, email: [email protected]. 
Both are staff of the U.S. Nuclear Regulatory Commission, Washington, 
DC 20555-0001.

SUPPLEMENTARY INFORMATION:

Executive Summary

A. Need for the Regulatory Action

    The NRC is amending its regulations to incorporate by reference the 
2021 Edition of the American Society of Mechanical Engineers (ASME) 
Boiler and Pressure Vessel Code (BPV Code) and the 2022 Edition of the 
ASME Operation and Maintenance of Nuclear Power Plants, Division 1, OM 
Code: Section IST (OM Code), for nuclear power plants.
    The ASME periodically revises and updates its Codes for nuclear 
power plants by issuing new editions; this final rule is in accordance 
with the NRC's practice to incorporate those new editions into the 
NRC's regulations. This rule maintains the safety of nuclear power 
plants, makes NRC activities more effective and efficient, and allows 
nuclear power plant licensees and applicants to take advantage of the 
latest ASME BPV and OM Codes (ASME Codes). The ASME is a voluntary 
consensus standards organization, and the ASME Codes are voluntary 
consensus standards. The NRC's use of the ASME Codes is consistent with 
applicable requirements of the National Technology Transfer and 
Advancement Act (NTTAA). See also Section XIV of this document, 
``Voluntary Consensus Standards.''

B. Major Provisions

    Major provisions of this final rule include the incorporation by 
reference with conditions of the following ASME Codes into NRC 
regulations and delineation of NRC requirements for the use of these 
Codes:

 The 2021 Edition of the BPV Code
 The 2022 Edition of the OM Code

C. Costs and Benefits

    The NRC prepared a regulatory analysis to determine the expected 
costs and benefits of this final rule. The regulatory analysis 
identifies costs and benefits in both a quantitative fashion as well as 
in a qualitative fashion.
    Based on the analysis, the NRC concludes that this final rule 
results in a net quantitative averted cost to the industry and a net 
cost to the NRC. This final rule, relative to the regulatory baseline, 
results in a net averted cost for industry of $0.65 million based on a 
7-percent net present value (NPV) and $0.72 million based on a 3-
percent NPV. This final rule, relative to the regulatory baseline, 
results in a net cost to the NRC of $44 thousand based on a 7-percent 
NPV to $10 thousand based on a 3-percent NPV. Qualitative factors that 
were considered include regulatory

[[Page 70450]]

stability and predictability, regulatory efficiency, and consistency 
with the NTTAA. The regulatory analysis shows that the rulemaking is 
justified because the total quantified benefits of the regulatory 
action exceed the costs of the action. When the qualitative benefits 
(including the safety benefit and improvement in knowledge) are 
considered together with the quantified benefits, the benefits outweigh 
the identified quantitative and qualitative costs.
    The NRC has had a decades-long practice of approving and/or 
mandating the use of certain parts of editions and addenda of these 
ASME Codes in Sec.  50.55a. Continuing this practice in this final rule 
ensures regulatory stability and predictability. This practice also 
provides consistency across the industry and provides assurance to the 
industry and the public that the NRC will continue to support the use 
of the most updated and technically sound techniques developed by the 
ASME to provide adequate protection to the public. In this regard, the 
ASME Codes are voluntary consensus standards developed by technical 
committees composed of mechanical engineers and others who represent 
the broad and varied interests of their industries, from manufacturers 
and installers to insurers, inspectors, distributors, regulatory 
agencies, and end users. The standards undergo extensive external 
review before the NRC considers whether to incorporate them by 
reference. Finally, the NRC's use of the ASME Codes is consistent with 
the NTTAA, which directs Federal agencies to adopt voluntary consensus 
standards instead of developing ``government-unique'' (i.e., Federal 
agency-developed) standards, unless inconsistent with applicable law or 
otherwise impractical.
    For more information, please see the final regulatory analysis 
(ML24053A051) in the NRC's ADAMS.

Table of Contents

I. Background
II. Discussion
    A. ASME BPV Code, Section III
    B. ASME BPV Code, Section XI
    C. ASME OM Code
    D. Editorial Correction
III. Opportunities for Public Participation
IV. Public Comment Analysis
V. Section-by-Section Analysis
VI. Generic Aging Lessons Learned Report
VII. Regulatory Flexibility Certification
VIII. Regulatory Analysis
IX. Backfitting and Issue Finality
X. Plain Writing
XI. Environmental Assessment and Final Finding of No Significant 
Environmental Impact
XII. Paperwork Reduction Act
XIII. Congressional Review Act
XIV. Voluntary Consensus Standards
XV. Incorporation by Reference--Reasonable Availability to 
Interested Parties
XVI. Availability of Guidance
XVII. Availability of Documents

I. Background

    The ASME develops and publishes the ASME BPV Code, which contains 
requirements for the design, construction, and inservice inspection 
(ISI) of nuclear power plant components, and the ASME OM Code,\1\ which 
contains requirements for inservice testing (IST) of nuclear power 
plant components. Until 2012, the ASME issued new editions of the ASME 
BPV Code every 3 years and addenda to the editions annually, except in 
years when a new edition was issued. Similarly, the ASME periodically 
published new editions and addenda of the ASME OM Code. Starting in 
2012, the ASME decided to issue editions of its BPV and OM Codes (no 
addenda) every 2 years with the BPV Code to be issued on the odd years 
(e.g., 2013, 2015, etc.) and the OM Code to be issued on the even years 
\2\ (e.g., 2012, 2014, etc.). The new editions typically revise 
provisions of the ASME Codes to broaden their applicability, add 
specific elements to current provisions, delete specific provisions, 
and/or clarify them to narrow the applicability of the provision. The 
revisions to the editions of the ASME Codes do not significantly change 
code philosophy or approach.
---------------------------------------------------------------------------

    \1\ The editions and addenda of the ASME Operation and 
Maintenance of Nuclear Power Plants have had different titles from 
2005 to 2019 and are referred to collectively in this rule as the 
``OM Code.''
    \2\ The 2014 Edition of the ASME OM Code was delayed and was 
designated the 2015 Edition. Similarly, the 2016 Edition of the OM 
Code was delayed and was designated the 2017 Edition.
---------------------------------------------------------------------------

    The NRC's practice is to establish requirements for the design, 
construction, operation, ISI (examination), and IST of nuclear power 
plants by approving the use of editions of the ASME BPV and OM Codes 
(ASME Codes) in Sec.  50.55a of title 10 of the Code of Federal 
Regulations (10 CFR). The NRC approves or mandates the use of certain 
parts of editions of these ASME Codes in Sec.  50.55a through the 
rulemaking process of ``incorporation by reference.'' Upon 
incorporation by reference of the ASME Codes into Sec.  50.55a, the 
provisions of the ASME Codes are legally binding NRC requirements as 
delineated in Sec.  50.55a, and subject to the conditions on certain 
specific ASME Codes' provisions that are set forth in Sec.  50.55a. The 
editions of the ASME BPV and OM Codes were last incorporated by 
reference into the NRC's regulations in a final rule dated October 27, 
2022 (87 FR 65128).
    The ASME Codes are consensus standards developed by participants, 
including the NRC and licensees of nuclear power plants, who have broad 
and varied interests. The ASME's publication of new editions of the 
ASME Codes does not mean that there is unanimity on every provision in 
the ASME Codes. There may be disagreement among the technical experts, 
including the NRC's representatives on the ASME Code committees and 
subcommittees, regarding the acceptability or desirability of a 
particular code provision included in an ASME-approved Code edition. If 
the NRC believes that there is a significant technical or regulatory 
concern with a provision in an ASME-approved Code edition being 
considered for incorporation by reference, then the NRC conditions the 
use of that provision when it incorporates by reference that ASME Code 
edition into its regulations. In some instances, the condition 
increases the level of safety afforded by the ASME Code provision, or 
addresses a regulatory issue not considered by the ASME. In other 
instances, where research data or experience has shown that certain 
code provisions are unnecessarily conservative, the condition may 
provide that the code provision need not be complied with in some or 
all respects. The NRC's conditions are included in Sec.  50.55a, 
typically in paragraph (b) of that section. In a Staff Requirements 
Memorandum dated September10, 1999 (ML003755050), the Commission 
indicated that NRC rulemakings adopting (incorporating by reference) a 
voluntary consensus standard must identify and justify each part of the 
standard that is not adopted. For this final rule, the provisions of 
the 2021 Edition of Section III, Division 1; the 2021 Edition of 
Section XI, Division 1, of the ASME BPV Code; and the 2022 Edition of 
the ASME OM Code that the NRC are not adopting, or are only partially 
adopting, are identified in the ``Discussion,'' ``Regulatory 
Analysis,'' and ``Backfitting and Issue Finality'' sections of this 
document. The provisions of those specific editions and Code Cases that 
are the subject of this final rule that the NRC finds to be 
conditionally acceptable, together with the applicable conditions, are 
also identified in the ``Discussion,'' ``Regulatory Analysis,'' and 
``Backfitting and Issue Finality'' sections of this document.

[[Page 70451]]

    The ASME Codes are voluntary consensus standards, and the NRC's 
incorporation by reference of these Codes is consistent with applicable 
requirements of the NTTAA. Additional discussion on the NRC's 
compliance with the NTTAA is set forth in Section XIV of this document, 
``Voluntary Consensus Standards.''

II. Discussion

    The NRC regulations incorporate by reference ASME Codes for nuclear 
power plants. This final rule is the latest in a series of rulemakings 
to amend the NRC's regulations to incorporate by reference revised and 
updated ASME Codes for nuclear power plants. This final rule is 
intended to maintain the safety of nuclear power plants and make NRC 
activities more effective and efficient.
    The NRC follows a three-step process to determine acceptability of 
new provisions in new editions of the Codes and the need for conditions 
on the uses of these Codes. This process was employed in the review of 
the Codes that are the subjects of this rule. First, the NRC actively 
participates with other ASME committee members with full involvement in 
discussions and technical debates in the development of new and revised 
Codes. This includes a technical justification of each new or revised 
Code. Second, the NRC's committee representatives discuss the Codes and 
technical justifications with other cognizant staff to ensure an 
adequate technical review. Third, the NRC position on each Code is 
reviewed and approved by NRC management as part of this rule amending 
Sec.  50.55a to incorporate by reference new editions of the ASME Codes 
and conditions on their use. This regulatory process, when considered 
together with the ASME's own process for developing and approving the 
ASME Codes, assures that the NRC approves for use only those new and 
revised code editions, with conditions as necessary, that provide 
reasonable assurance of adequate protection to the public health and 
safety, and that do not have significant adverse impacts on the 
environment.
    The NRC reviewed changes to the Codes in the editions identified in 
this final rule. The NRC concluded, in accordance with the process for 
review of changes to the Codes, that these editions of the Codes are 
technically adequate, consistent with current NRC regulations, and 
approved for use with the specified conditions.
    The NRC is amending its regulations to incorporate by reference:
     The 2021 Editions of the ASME BPV Code, Section III, 
Division 1 and Section XI, Division 1, with conditions on their use.
     The 2022 Edition of Division 1 of the ASME OM Code, with 
conditions on its use.
    The current regulations in Sec.  50.55a(a)(1)(i) incorporate by 
reference ASME BPV Code, Section III, 1963 Edition through the 1970 
Winter Addenda; and the 1971 Edition (Division 1) through the 2019 
Edition (Division 1), subject to the conditions identified in current 
Sec.  50.55a(b)(1)(i) through (xiii). This final rule revises Sec.  
50.55a(a)(1)(i) to incorporate by reference the 2021 Edition (Division 
1) of the ASME BPV Code, Section III.
    The current regulations in Sec.  50.55a(a)(1)(ii) incorporate by 
reference ASME BPV Code, Section XI, 1974 Edition through the 1975 
Summer Addenda, the 1995 Edition (Division 1) through the 1997 Addenda 
(Division 1), and the 2001 Edition (Division 1) through the 2019 
Edition (Division 1), subject to the conditions identified in current 
Sec.  50.55a(b)(2)(i) through (xliii). This final rule revises Sec.  
50.55a(a)(1)(ii) to incorporate by reference the 2021 Edition (Division 
1) of the ASME BPV Code, Section XI. It also clarifies the wording and 
adds, removes, or revises some of the conditions as explained in this 
rule.
    The current regulations in Sec.  50.55a(a)(1)(iv) incorporate by 
reference ASME OM Code, 1995 Edition through the 2020 Edition (with 
some omissions of specific editions and addenda), subject to the 
conditions currently identified in Sec.  50.55a(b)(3)(i) through (xi). 
This final rule revises Sec.  50.55a(a)(1)(iv) to incorporate by 
reference the 2022 Edition of Division 1 of the ASME OM Code.
    In the introductory discussion of its Codes, ASME specifies that 
errata to those Codes may be posted on the ASME website under the 
Committee Pages to provide corrections to incorrectly published items, 
or to correct typographical or grammatical errors in those Codes. Users 
of the ASME BPV Code and ASME OM Code should be aware of errata when 
implementing the specific provisions of those Codes. Applicants and 
licensees should monitor errata to determine when they might need to 
submit a request for an alternative under Sec.  50.55a(z) to implement 
provisions specified in errata to their ASME Code of Record.
    The NRC reviewed changes to the Codes in the editions identified in 
this final rule and published a proposed rule in the Federal Register 
setting forth the NRC's proposal to incorporate by reference the ASME 
Codes, together with proposed conditions on their use (88 FR 53384; 
August 8, 2023). The NRC also proposed to correct minor editorial and 
administrative errors, including spacing and typos. After consideration 
of the public comments received on the proposed rule (public comments 
are discussed in Section IV of this document, ``Public Comment 
Analysis''), the NRC concludes, in accordance with the process for 
review of changes to the Codes, that these editions of the Codes are 
technically adequate, consistent with current NRC regulations, and 
approved for use with the specified conditions set forth in this final 
rule. Each of the NRC conditions and the reasons for each condition are 
discussed in the following sections of this document. The discussions 
are organized under the applicable ASME Code and Section.

A. ASME BPV Code, Section III

    Section 50.55a(a)(1)(i)(E) Rules for Construction of Nuclear 
Facility Components-Division 1.
    The NRC is revising Sec.  50.55a(a)(1)(i)(E) to incorporate by 
reference the 2021 Edition of the ASME BPV Code, Section III, including 
Subsection NCA and Division 1 Subsections NB through NG and Appendices. 
As stated in Sec.  50.55a(a)(1)(i), the Nonmandatory Appendices are 
excluded and not incorporated by reference. The Mandatory Appendices 
are incorporated by reference because they include information 
necessary for Division 1. However, the Mandatory Appendices also 
include material that pertains to other Divisions that have not been 
reviewed and approved by the NRC. Although this information is included 
in the sections and appendices being incorporated by reference, the NRC 
notes that the use of Divisions other than Division 1 has not been 
approved, nor are they required by NRC regulations and, therefore, such 
information is not relevant to NRC applicants and licensees. The NRC is 
not taking a position on the non-Division 1 information in the 
appendices and is including it in the incorporation by reference only 
for convenience. Therefore, this final rule revises the introductory 
text to Sec.  50.55a(a)(1)(i)(E) to reference the 2021 Edition of the 
ASME BPV Code, Section III, including Subsection NCA and Division 1 
Subsections NB through NG and Appendices.
    Users of Section III of the ASME BPV Code are reminded that ASME 
has relocated certain overpressure protection requirements for safety 
and relief valves to Section XIII, ``Rules for

[[Page 70452]]

Overpressure Protection,'' of the ASME BPV Code, such as Part 9, 
``Capacity and Flow Resistance Certification.'' ASME prepared Section 
XIII of the BPV Code to consolidate the overpressure protection 
requirements into one BPV Code Section to benefit all stakeholders by 
advancing the technology with participation from a broader group of 
subject matter experts. This relocation collects overpressure 
protection requirements into a single location rather than specifying 
them in various sections and divisions of the ASME BPV Code. ASME 
stated that it did not intend a technical change by this relocation of 
the overpressure protection requirements. Where appropriate, Section 
III of the ASME BPV Code specifies a direct citation to the relocated 
overpressure protection requirements in Section XIII of the ASME BPV 
Code.
Section 50.55a(b)(1)(iv) Section III Condition: Quality Assurance
    The NRC is incorporating by reference Subsection NCA of 2021 
Edition BPV Code, ASME Section III with the exception that Subpart 2.19 
in NQA-1-2017, NQA-1-2019, and NQA-1-2022 is not approved for use.
    With regards to the implementation of NCA-3126, NCA-3127, NCA-
4255.3, and NCA-4254.3 for the procurement of calibration and testing 
services, the NRC reminds the users of the ASME Code that the 
procurement of commercial grade calibration and testing services 
remains subject to NRC requirements in 10 CFR part 21 and in appendix B 
to 10 CFR part 50.
    For implementation of procurement of calibration and testing 
services, the NRC published a Regulatory Guide (RG), RG 1.28 Rev. 6, 
``Quality Assurance Program Criteria (Design and Construction),'' 
(ML23177A002) that, among other things, endorsed Nuclear Energy 
Institute (NEI) 14-05A, ``Guidelines for the Use of Accreditation in 
Lieu of Commercial Grade Surveys for Procurement of Laboratory 
Calibration and Test Services,'' Revision 1, issued November 2020 (88 
FR 62292). As described in the RG, licensees and suppliers of basic 
components can take credit for the International Laboratory 
Accreditation Cooperation accreditation process as described in NEI 14-
05A, Revision 1, in lieu of performing on-site commercial grade surveys 
as part of the commercial grade dedication of calibration and testing 
services. The NRC's endorsement is for use of NEI 14-05A, Revision 1, 
in lieu of Subpart 2.19 in NQA-1-2017, NQA-1-2019, and NQA-1-2022, 
which RG 1.28 found to not incorporate the controls and conditions 
necessary for use. Specifically, Subpart 2.19 allows the laboratory 
accreditation to be performed remotely, which the NRC has determined is 
not adequate to meet the requirements of appendix B to 10 CFR part 50. 
Therefore, the NRC is adding a condition to prohibit the use of Subpart 
2.19 in NQA-1-2017, NQA-1-2019, and NQA-1-2022.
Section 50.55a(b)(1)(vi) Section III Condition: Subsection NH
    The NRC is revising this condition to change the word ``sleeves'' 
to ``sheaths'' and to note that this condition is not applicable to the 
2015 Edition and later editions as Subsection NH has been deleted from 
Section III Division 1.
Section 50.55a(b)(1)(xi) Section III Condition: Mandatory Appendix XXVI
    The NRC is revising this condition. When applying the 2015 and 2017 
Editions of Section III, Mandatory Appendix XXVI, ``Rules for 
Construction of Class 3 Buried Polyethylene Pressure Piping,'' 
applicants or licensees must meet the first provision, as noted in 
Sec.  50.55a(b)(1)(xi)(A). When applying the 2015 through 2021 Editions 
of Section III, Mandatory Appendix XXVI, ``Rules for Construction of 
Class 3 Buried Polyethylene Pressure Piping,'' applicants or licensees 
must meet the second provision, as noted in Sec.  50.55a(b)(1)(xi)(B). 
When applying the 2017 Edition of Section III, Mandatory Appendix XXVI, 
``Rules for Construction of Class 3 Buried Polyethylene Pressure 
Piping,'' applicants or licensees must meet the third provision, as 
noted in Sec.  50.55a(b)(1)(xi)(C).
    As a result of a public comment received, the NRC has modified the 
second provision, Sec.  50.55a(b)(1)(xi)(B), to provide more clarity in 
the first sentence, and replaced the second sentence to clarify that, 
in the event of breakage in a specimen that is away from the fusion 
zone, a retest may be required only if the base material failed at less 
than the minimum required base material yield strength.
Section 50.55a(b)(1)(xiii) Section III Condition: Preservice Inspection 
of Steam Generator Tubes
    The NRC is revising Sec.  50.55a(b)(1)(xiii) including the first 
provision, Sec.  50.55a(b)(1)(xiii)(A), and second provision, Sec.  
50.55a(b)(1)(xiii)(B), to extend the applicability of the conditions 
through the latest edition of the ASME BPV Code, Section III 
incorporated by reference in paragraph (a)(1)(i). The 2021 Edition of 
Section III was not updated to include the provisions of this 
condition. Therefore, the NRC is revising this condition to apply to 
the latest edition incorporated by reference.
Section 50.55a(b)(1)(xiv) Section III Condition: Repairs to Stamped 
Components
    The NRC is adding a condition that if Nonmandatory Appendix NN is 
used for the elimination of surface defects and repairs of stamped 
components prior to the completion of Form N-3 Data Report, all 
applicable requirements of Nonmandatory Appendix NN shall be met. The 
2021 Edition included Nonmandatory Appendix NN and stated in the 
provisions of NCA-8151 and NCA-8500 in the 2021 Edition of Section III 
that guidance for the elimination of surface defects and repairs of 
stamped components prior to the completion of Form N-3 Data Report is 
contained within Nonmandatory Appendix NN.
    The section titled ``Organization of Section III'' within Section 
III and the ``Introduction'' to Section III Appendices state that 
``Mandatory Appendices are referred to in the Section III rules and 
contain requirements that must be followed in construction. 
Nonmandatory Appendices provide additional information or guidance when 
using Section III.'' In addition, Nonmandatory Appendix NN states, 
``This Appendix provides guidance for the removal of external surface 
defects from piping, pumps, and valves and performing repairs to 
stamped components after certification and prior to completion of the 
N-3 Data Report.''
    Since this Nonmandatory Appendix is not required to be followed by 
the ASME Code, all or none of the requirements in this Appendix may be 
performed and the certificate holder or owner potentially could make 
repairs that do not meet the code requirements, introduce flaws or 
retain defects, or not disposition defects that can compromise the 
structural integrity of the component and not properly document the 
repair. It should be noted that Nonmandatory Appendix NN was developed 
by combining Code Cases N-801-3 and N-870-1 into the Nonmandatory 
Appendix NN. The NRC-approved Code Cases N-801-3 and N-870-1 in RG 
1.84, Revision 39. Licensees that used Code Cases N-801-3 and N-870-1 
were required to meet all the requirements in the applicable Code 
Cases. The NRC considers the information in Nonmandatory Appendix NN as 
requirements, consistent with the Code Cases, that are necessary to 
ensure

[[Page 70453]]

certificate holders make satisfactory repairs to stamped ASME Code, 
Section III components. Therefore, the NRC is adding Sec.  
50.55a(b)(1)(xiv) to condition the provision of NCA-8151, NCA-8500, and 
Nonmandatory Appendix NN to require that all the requirements in 
Nonmandatory Appendix NN shall be met when used.

B. ASME BPV Code, Section XI

Section 50.55a(a)(1)(ii) ASME BPV Code, Section XI
    The NRC is amending the regulations in Sec.  50.55a(a)(1)(ii)(C) to 
incorporate by reference the 2021 Edition (Division 1) of the ASME BPV 
Code, Section XI. The current regulations in Sec.  50.55a(a)(1)(ii)(C) 
incorporate by reference ASME BPV Code, Section XI, the 1974 Edition 
through the 1975 Summer Addenda, the 1995 Edition (Division 1) through 
the 1997 Edition (Division 1), and the 2001 Edition (Division 1) 
through the 2019 Edition (Division 1), subject to the conditions 
identified in Sec.  50.55a(b)(2).
Section 50.55a(b)(2) Conditions on ASME BPV Code Section XI
    The NRC is revising the definition of Section XI in Sec.  
50.55a(b)(2) to refer to the editions of the ASME BPV Code, Section XI 
incorporated by reference in paragraph (a)(1)(ii).
Section 50.55a(b)(2)(viii) Section XI Condition: Concrete Containment 
Examinations
    The NRC is limiting the existing conditions in Sec.  
50.55a(b)(2)(viii)(H) and Sec.  50.55a(b)(2)(viii)(I), the eighth and 
ninth provisions for concrete containment examinations, to prior 
Editions of the ASME Code. Revisions to IWA-6230 require the 
information described in the existing Sec.  50.55a(b)(2)(viii)(H) 
condition be included in the required Owner's Activity Report (OAR). 
Revisions to IWL-2512 require the technical evaluation discussed in 
IWL-2512(b) be completed every 5 years. Since these new Section XI 
provisions in the 2021 Edition address the requirement in the existing 
NRC condition, it is appropriate for the NRC to limit the applicability 
of the existing conditions to the prior editions.
Section 50.55a(b)(2)(ix) Section XI Condition: Metal Containment 
Examinations
    The NRC is limiting the applicability of the existing condition in 
Sec.  50.55a(b)(2)(ix)(A)(2), the first provision for metal containment 
examinations, to prior Editions of the ASME Code. Revisions to IWA-6230 
require the information described in the existing Sec.  
50.55a(b)(2)(ix) condition be included in the required OAR. Since this 
new Section XI provision in the 2021 Edition addresses the requirement 
in the existing NRC condition, it is appropriate for the NRC to limit 
the applicability of the existing condition to the earlier editions.
Section 50.55a(b)(2)(xv) Section XI Condition: Appendix VIII Specimen 
Set and Qualification Requirements
    The NRC is eliminating this condition as it is no longer applicable 
to any licensee. This condition only applied to the use of the 1995 
through the 2001 Editions of ASME Code Section XI, Appendix VIII. 
Additionally, Sec.  50.55a(b)(2)(xv) requires licensees using ASME Code 
Section XI Editions later than the 2001 Edition through the 2006 
Addenda to use the 2001 Edition of Appendix VIII. This condition 
therefore only applied to licensees using the 1995 to the 2006 Addenda 
of ASME Code Section XI.
    The 2007 edition of ASME Code Section XI was incorporated by 
reference in Sec.  50.55a in the rulemaking dated June 21, 2011 (76 FR 
36231). Given the requirement to update ISI programs every 120 months, 
no licensee is still using the 2001 Edition of Appendix VIII. This 
condition is therefore unnecessary.
Section 50.55a(b)(2)(xxxiv) Section XI Condition: Nonmandatory Appendix 
U
    The NRC is amending Sec.  50.55a(b)(2)(xxxiv) to prohibit the use 
of Nonmandatory Appendix U, Supplement U-S1 in the 2021 Edition of 
Section XI. Nonmandatory Appendix U, Supplement U-S1 provides licensees 
with a methodology for temporary acceptance of flaws in moderate energy 
Class 2 and 3 piping. However, Code Case N-513 provides the same rules. 
The NRC position is that licensees should use the more frequently 
updated Code Case N-513 when seeking to temporarily accept flaws in 
moderate energy Class 2 and 3 piping. As the ASME continues to update 
Code Case N-513, there can be different requirements between the 
version allowed by Nonmandatory Appendix U and the NRC-approved version 
of the Code Case. Furthermore, duplicative rules may create regulatory 
confusion both for licensees and NRC inspection staff, as well as 
impose a burden on the NRC to review and compare the two documents to 
ensure reasonable assurance of safety under all potential combinations 
of alternatives. Therefore, this condition clarifies that the 
appropriate reference for temporary acceptance of flaws in moderate 
energy Class 2 and 3 piping is Code Case N-513, as dispositioned in the 
latest version of RG 1.147 incorporated by reference in Sec.  
50.55a(a)(3)(ii).
    The NRC is modifying the existing condition in Sec.  
50.55a(b)(2)(xxxiv) to update the version of ASME BPV Code Case N-513 
to the latest version approved in RG 1.147 at the time the case was 
incorporated into the licensee's inservice inspection program. The NRC 
is renumbering this existing condition to Sec.  
50.55a(b)(2)(xxxiv)(A)(2) and revising Sec.  50.55a(b)(2)(xxxiv)(B) to 
reflect the added condition on Nonmandatory Appendix U, Supplement U-
S1. The purpose of this change is for regulatory efficiency to minimize 
changes to this condition in future rulemakings and maintain the 
requirement consistent with the latest NRC-approved version of Code 
Case N-513.
Section 50.55a(b)(2)(xxxvi) Section XI Condition: Fracture Toughness of 
Irradiated Materials
    The NRC is amending Sec.  50.55a(b)(2)(xxxvi), to require 
determination of the Master Curve parameters T0 and 
RTT0 as prescribed in ASME BPV Code, Section III, NB-2331, 
subparagraph (a)(5). This change eliminates the requirement to submit 
such determinations to the NRC for review and replaces that submittal 
requirement with an acceptable method for determining these fracture 
toughness parameters.
    Although this specific change to Sec.  50.55a(b)(2)(xxxvi) was not 
in the proposed rule, the proposed rule requested comments on the NRC's 
proposal to condition the 2021 Edition of the ASME Code, Section XI to 
require that analytical evaluation reports continue to be submitted to 
the NRC. The proposed rule noted that analytical reports provide the 
NRC operating experience data to monitor degradation trends across the 
industry to ensure public health and safety and that similar reporting 
requirements can be found in 50.55a, including Sec.  
50.55a(b)(2)(xxxii). In the proposed rule, the NRC specifically asked 
for comments on how the NRC could effectively leverage the information 
provided in such reports in a way that is transparent to stakeholders 
and ensures structural integrity of nuclear components without 
incurring excessive administrative burden for plant owners.
    The NRC is making this change in response to a public comment that 
reviewed the history of the codification of Master Curve methods and 
NRC's regulatory treatment of those

[[Page 70454]]

requirements. The NRC determined that use of the NB-2331(a)(5) is a 
consistent, technically justified regulatory approach to the Master 
Curve under Sec.  50.55a(z).
Section 50.55a(b)(2)(xliii) Section XI Condition: Regulatory Submittal 
Requirements
    The NRC is modifying Sec.  50.55a(b)(2)(xliii)(A), to clarify that 
the analysis for an out-of-limit condition described in Section XI, 
IWB-3720(a) is not subject to NRC review and approval.
    Although this specific modification was not in the proposed rule, 
the proposed rule requested comments on the NRC's proposal to condition 
the 2021 Edition of the ASME Code, Section XI to require that 
analytical evaluation reports continue to be submitted to the NRC. The 
proposed rule noted that analytical reports provide the NRC and 
operating experience data to monitor degradation trends across the 
industry to ensure public health and safety and that similar reporting 
requirements can be found in 50.55a, including 50.55a(b)(2)(xliii).
    The NRC agreed in part with a public comment stating that 
Nonmandatory Appendix E has been reviewed and approved by the NRC 
through incorporation by reference. The NRC agreed that the original 
submission requirement in IWB-3720 was not clear on whether review and 
approval by the regulatory authority was needed. The immediate safety 
impacts of a pressure-temperature limit excursion on vessel integrity 
are assessed through the NRC's reactor oversight process, so there is 
no need to specify NRC review and approval of the analysis in Sec.  
50.55a. While NRC review and approval is no longer required, licensees 
are still be required to submit the analysis to the NRC.
    The NRC also is deleting the conditions at Sec.  
50.55a(b)(2)(xliii)(B) and (C). This change eliminates the requirement 
to submit determination of T0 and RTT0 under 
Nonmandatory Appendix A, A-4200(c) and Nonmandatory Appendix G, G-
2110(c) to NRC for review and approval. The NRC is replacing that 
submittal requirement with an acceptable method for determining these 
fracture toughness parameters in new condition Sec.  50.55a(b)(2)(l). 
The NRC is making this change due to a public comment that reviewed the 
history of the codification of Master Curve methods and NRC's 
regulatory treatment of those requirements. The NRC determined that use 
of the ASME BPV Code, Section III, NB-2331, subparagraph (a)(5) 
referenced in new condition Sec.  50.55a(b)(2)(l) is a consistent, 
technically justified regulatory approach to the Master Curve.
Section 50.55a(b)(2)(xliv) Section XI Condition: Nonmandatory Appendix 
Y
    The NRC is adding Sec.  50.55a(b)(2)(xliv) to prohibit the use of 
Y-2200, Y-2420, and Y-3200 in the 2021 Edition of Section XI. These 
articles provide three crack growth laws for use in Section XI flaw 
evaluations. However, Code Cases N-809, N-889, and N-643 respectively 
provide the same crack growth laws. The NRC's position is that 
licensees must use the more frequently updated Code Cases when seeking 
to use these crack growth laws in Section XI flaw evaluations. 
Furthermore, duplicative rules may create regulatory confusion for 
licensees and additional burden on the NRC to review and compare the 
two documents to provide reasonable assurance of safety when using the 
curves and defined variables. Therefore, this condition clarifies that 
the appropriate references for crack growth laws are the respective 
Code Cases as dispositioned in the latest edition of RG 1.147 
incorporated by reference in Sec.  50.55a(a)(3)(ii).
Section 50.55a(b)(2)(xlv) Section XI Condition: Pressure Testing of 
Containment Penetration Piping After Repair/Replacement Activities
    The NRC is adding Sec.  50.55a(b)(2)(xlv) to require that when 
applying the provisions of IWA-4540(a) and (e) of the 2021 Edition of 
the ASME Code, Section XI, a VT-2 (i.e., visual examination during 
system walkdown) of the area affected by the repair/replacement 
activity shall be conducted during the Type C test in appendix J to 10 
CFR part 50. The 2021 Edition of the ASME Code, Section XI, revised 
IWA-4540(a) and (e) by incorporating the requirements of Code Case N-
751. The NRC conditioned Code Case N-751 in RG 1.147, Revision 19, to 
require that nondestructive examination must be performed in accordance 
with IWA-4540(a)(2) of the 2002 Addenda of Section XI. This includes a 
VT-2 in accordance with IWA-5211.
    Upon incorporating Code Case N-751 and the NRC condition in RG 
1.147, the revised IWA-4540(a) and (e) did not fully address the NRC 
condition in RG 1.147 concerning performing the VT-2. The revised IWA-
4540(a) moved the pressure testing requirements for ``[R]epair/
replacement activities performed by welding or brazing on piping, 
including isolation valves, designated Class 2, that penetrates a 
containment vessel and where the balance of the piping system inside 
and outside the containment is not within the scope of Section XI'' to 
IWA-4540(e). Therefore, the specific requirement in IWA-4540(a) to 
require a VT-2 during pressure testing is not required. In addition, 
IWA-4540(e) in the 2021 Edition of ASME Code, Section XI states that 
for pressure testing of these locations, a Type C test in appendix J to 
10 CFR part 50, system leakage test in accordance with IWA-5211(a), or 
pneumatic test in accordance with IWA-5211(c), shall be performed. The 
NRC notes that IWA-5211 requires the VT-2, while neither IWA-5211(a) or 
(c) require a VT-2. IWA-4540(e) also states that if ``there is 
detectable leakage during the Type C test in appendix J to 10 CFR part 
50, the brazed joints or welds shall be tested to confirm there is no 
leakage through the brazed joints or welds.'' The NRC notes that the 
Type C test in appendix J to 10 CFR part 50 does not require a VT-2 of 
the piping to verify the leakage or absence thereof, but only a 
decrease in pressure.
    Therefore, the NRC is adding Sec.  50.55a(b)(2)(xlv) to condition 
provisions IWA-4540(a) and (e) of the 2021 Edition of the ASME Code, 
Section XI, to require that a VT-2 of the area affected by the repair/
replacement activity be conducted during the Type C test in appendix J 
to 10 CFR part 50 to be consistent with the previous NRC condition for 
Code Case N-751.
Section 50.55a(b)(2)(xlvi) Section XI Condition: Contracted Repair/
Replacement Organization Fabricating Items Offsite of the Owner's 
Facilities
    The NRC is adding Sec.  50.55a(b)(2)(xlvi) to prohibit a contracted 
Repair/Replacement Organization, when applying the provisions of IWA-
4143 in the 2021 Edition of the ASME Code, Section XI, from fabricating 
an item offsite of the Owner's facility (e.g., vendor facility) without 
an ASME Certificate of Authorization and without applying an ASME 
Stamp/Certification Mark.
    IWA-4143 in the 2021 Edition of the ASME Code, Section XI, allows 
an Owner to procure ASME Code, Section III parts, appurtenances, piping 
subassemblies, and supports (hereinafter referred to as items) with no 
ASME Stamp/Certification Mark from a Repair/Replacement Organization 
that does not have an ASME Certificate of Authorization and conducts 
fabrication activities offsite of the Owner's facility. Therefore, a 
contracted Repair/Replacement Organization would have been able to 
fabricate an item offsite (at a vendor facility) without an ASME 
Certificate of Authorization and not apply a Stamp/Certification Mark 
on the item. This contradicts NCA-8330 in

[[Page 70455]]

ASME Code, Section III, which only allows an item with no ASME Stamp/
Certification Mark applied to the item for an organization with an ASME 
Certificate of Authorization, since the organization with an ASME 
Certificate of Authorization is required to follow additional controls 
of the part in NCA-8330(a)(1) through (3). IWA-4131 in the 2021 Edition 
of the ASME Code, Section XI, does not provide controls of these items 
through completion of installation for an organization that does not 
have an ASME Certificate of Authorization. IWA-4131 in the 2019 Edition 
of the ASME Code, Section XI, has a restriction that fabrication (of 
parts) by the Owner or the Owner's contracted Repair/Replacement 
Organization (not possessing an ASME Certificate of Authorization) may 
occur only at the Owner's facility. The condition is consistent with 
IWA-4143 of the 2019 Edition of the ASME Code, Section XI, which 
allowed a Repair/Replacement Organization with a quality assurance 
program that complies with IWA-4142 to fabricate parts, appurtenances, 
piping assemblies, and supports at the Owner's facilities without 
application of an ASME Stamp/Certification Mark.
    Therefore, the NRC is adding Sec.  50.55a(b)(2)(xlvi) to condition 
the provision of IWA-4143 of the 2021 Edition of the ASME Code, Section 
XI, by prohibiting a contracted Repair/Replacement Organization from 
fabricating a part offsite of the Owner's facility (e.g., vendor 
facility) without an ASME Certificate of Authorization and without 
applying an ASME Stamp/Certification Mark.
Section 50.55a(b)(2)(xlvii) Section XI Condition: Weld Overlay Design 
Crack Growth Analysis
    The NRC is adding Sec.  50.55a(b)(2)(xlvii) to require stress 
corrosion crack growth analysis of the weld overlay material in 
Nonmandatory Appendix Q of ASME Code, Section XI. In the 2021 Edition, 
a change was made to Subparagraph Q-3000(a) to specifically note that 
stress corrosion crack growth analysis is not required within the weld 
overlay material. While these overlay materials are expected to be more 
stress corrosion crack resistant, Article Q-2000 does not require all 
overlay materials to be impervious to potential cracking. If the 
licensee can justify that the material would not experience stress 
corrosion cracking growth expected over design life of the overlay, the 
licensee should document this conclusion in the design. The NRC 
therefore adds this condition to require the analysis of a hypothetical 
flaw in determining the design and design life of a weld overlay under 
Nonmandatory Appendix Q.
Section 50.55a(b)(2)(xlviii) Section XI Condition: Analytical 
Evaluations of Degradation
    The NRC is adding Sec.  50.55a(b)(2)(xlviii) to require that 
analytical evaluations performed in accordance with IWB-3132.3 and IWC-
3132.3 be submitted to the NRC. The 2019 Edition of the ASME BPV Code, 
Section XI, IWB-3134, Review by Authorities, requires that 
``[a]nalytical evaluation of examination results as required by IWB-
3132.3 shall be submitted to the regulatory authority having 
jurisdiction at the plant site.'' IWC-3125, Review by Authorities, 
requires that ``[t]he analytical evaluation of examination results as 
required by IWC-3122.3 shall be submitted to the regulatory authority 
having jurisdiction at the plant site.'' The 2021 Edition of the ASME 
Code, Section XI, eliminates the provisions of IWB-3134 and IWC-3125 in 
their entirety. The NRC finds that flaw evaluations provide significant 
regulatory information in the following areas: the condition of the 
degradation of the affected component, the cause of the degradation, 
operating experience, methodology used, performance monitoring, and 
regulatory oversight. For example, the flaw evaluation predicts the 
flaw size with growth during a certain time period. The final flaw size 
should not exceed the allowable flaw size, and the affected component 
would need to be inspected prior to the final flaw size exceeding the 
allowable flaw size. The NRC needs to monitor the safety of plant 
operation, considering the flaw may grow during the plant operation. 
The flaw evaluation provides key information for the NRC's oversight. 
Accordingly, the NRC is adding Sec.  50.55a(b)(2)(xlviii) to retain the 
requirement from the 2019 Edition of the ASME BPV Code, Section XI, 
that analytical evaluations performed in accordance with IWB-3132.3 and 
IWC-3132.3 be submitted to the NRC.
Section 50.55a(b)(2)(xlix) Section XI Condition: Analytical Evaluations 
of Flaws in Cladding
    The NRC is adding Sec.  50.55a(b)(2)(xlix) to prohibit the use of 
IWB-3600(b)(1) in the 2021 Edition of ASME BPV Code, Section XI 
(Division 1), for the inlay and onlay that are subject to the augmented 
inspection requirements in paragraph Sec.  50.55a(g)(6)(ii)(F).
    IWB-3600(b)(1) in the 2021 Edition of the Code addresses the 
provision that a flaw, which lies entirely in the cladding of Class 1 
components, need not be analytically evaluated. In the 2021 Edition of 
the Code, this provision has been relocated from IWB-3610 to IWB-3600. 
In the code editions and addenda prior to the 2021 Edition since the 
1988 Addenda, this provision in IWB-3610 for Class 1 vessels has not 
been applicable to the analytical evaluation for piping that is 
separately addressed in IWB-3640. Based on the relocation of the 
provision to IWB-3600, the 2021 Edition of the Code without a condition 
would have allowed that a flaw, which lies entirely in the cladding of 
piping, need not be analytically evaluated.
    In comparison, paragraph Sec.  50.55a(g)(6)(ii)(F) addresses the 
augmented inspection requirements for Class 1 pressurized water reactor 
(PWR) piping and vessel nozzle butt welds. As part of the requirements, 
paragraph Sec.  50.55a(g)(6)(ii)(F)(7) describes the examination 
evaluation and acceptance standards for the inlay and onlay of the butt 
welds. Specifically, the condition in the paragraph requires that, for 
Inspection Items G, H, J, and K of Code Case N-770, when applying the 
acceptance standards of IWB-3514 for planar flaws contained within the 
inlay or onlay, the thickness ``t'' in IWB-3514 be the thickness of the 
inlay or onlay.
    Accordingly, when a flaw lies entirely in the inlay or onlay 
subject to the augmented inspections in paragraph Sec.  
50.55a(g)(6)(ii)(F)(7), the flaw is required to be evaluated in 
accordance with IWB-3514 by using the thickness of the inlay or onlay 
as the thickness ``t'' in IWB-3514. Based on paragraph Sec.  
50.55a(g)(6)(ii)(F)(7), if a flaw in the inlay or onlay is not 
acceptable in accordance with IWB-3514 as conditioned by the paragraph, 
analytical evaluation of the flaw must be performed in accordance with 
IWB-3600 or repair/replacement activities must be performed in 
accordance with IWA-4000.
    As discussed above, the use of IWB-3600(b)(1) in the 2021 Edition 
of ASME BPV Code, Section XI (Division 1) for the inlay and onlay is 
not consistent with paragraph Sec.  50.55a(g)(6)(ii)(F)(7) and the 
related provisions of analytical evaluation that are specified in IWB-
3600 in the code editions and addenda prior to the 2021 Edition. 
Therefore, the NRC is adding a condition to prohibit the use of IWB-
3600(b)(1) in the 2021 Edition of the Code for the inlay and onlay that 
are subject to the augmented inservice inspection requirements for 
Class 1 piping and nozzle dissimilar-metal butt welds in paragraph 
Sec.  50.55a(g)(6)(ii)(F).

[[Page 70456]]

Section 50.55a(b)(2)(l) Section XI Condition: Determination of Master 
Curve T0
    The NRC is adding Sec.  50.55a(b)(2)(l), which was not in the 
proposed rule, to require T0 and RTT0 applied 
under Nonmandatory Appendix A, A-4200(c) and Nonmandatory Appendix G, 
G-2110(c) be determined as prescribed in ASME BPV Code, Section III, 
NB-2331, subparagraph (a)(5). The NRC is adding this condition to 
replace the previous conditions Sec.  50.55a(b)(2)(xliii)(B) and (C), 
which required licensees to submit the determination of T0 
and RTT0 for NRC review and approval. The NRC is making this 
change due to a public comment that reviewed the history of the 
codification of Master Curve methods and NRC's regulatory treatment of 
those requirements. The NRC determined that use of the NB-2331(a)(5) is 
a consistent, technically justified regulatory approach to the Master 
Curve.
Section 50.55a(g)(4)(ii) Section XI Applicable ISI Code: Successive 
120-Month Intervals
    The NRC is updating Sec.  50.55a(g)(4)(ii), which was not in the 
proposed rule, to allow licensees to delay the update of their Appendix 
VIII program by up to 18 months after the effective date of this final 
rule. The NRC recognizes that updating an Appendix VIII program is a 
complex and time-consuming process. Allowing licensees to delay the 
update is consistent with previous final rules that incorporated the 
ASME Codes by reference. The NRC is making this change due to a public 
comment. A public comment was received that indicated that the NRC 
mistakenly did not update this provision in the final rule 
incorporating by reference the 2019 and 2020 Editions of the ASME Code 
or the proposed rule to incorporate by reference the 2021 and 2022 
Editions of the ASME Code.
Section 50.55a(g)(6)(ii)(D)(9) Section XI Condition: Volumetric 
Qualifications
    The NRC is adding Sec.  50.55a(g)(6)(ii)(D)(9) to allow licensees 
the option to utilize Supplement 15 of Mandatory Appendix VIII in the 
2021 Edition of Section XI, incorporated by reference in Sec.  50.55a, 
for volumetric qualification of examinations required by Table 1 of 
ASME Code Case N-729-6. The ASME in combination with the Electric Power 
Research Institute Nondestructive Evaluation Center developed expanded 
qualifications similar to other volumetric qualification requirements 
in Mandatory Appendix VIII to replace the requirements described in 
ASME Code Case N-729-6. The NRC found these qualification requirements 
acceptable, in addition to the current requirements of ASME Code Case 
N-729-6. Therefore, to reduce the burden of requiring an update to all 
programs immediately, the NRC is adding a condition to allow either 
qualification program to be used. In future Sec.  50.55a rulemakings, 
in which N-729 is further revised or incorporated into the ASME Code, 
the NRC expects that the Supplement 15 requirements of Mandatory 
Appendix VIII will be required. Additionally, as licensees adopt the 
2021 Edition as an ISI Code of Record for their ISI Interval, 
Supplement 15 of Mandatory Appendix VIII will be a requirement. The NRC 
expects that with this transitional time, that has no immediate impact 
or burden, licensees will be able to update their programs as necessary 
in as efficient manner as possible.
Section 50.55a(g)(6)(ii)(F) Augmented ISI Requirements: Examination 
Requirements for Class 1 Piping and Nozzle Dissimilar-Metal Butt Welds
    The NRC is updating the requirements for the augmented inspection 
of dissimilar-metal butt welds in U.S. PWRs from ASME Code Case N-770-5 
to N-770-7. This change will require condition Sec.  
50.55a(g)(6)(ii)(F)(1) to be updated, and condition Sec.  
50.55a(g)(6)(ii)(F)(8) to be modified to retain an inspection frequency 
for optimized butt welds consistent with ASME Code Case N-770-5.
    The NRC is updating NRC condition Sec.  50.55a(g)(6)(ii)(F)(1) 
Implementation by changing the reference of ASME Code Case N-770-5 to 
N-770-7. Additionally, the implementation requirement will be changed 
from no later than 1 year after June 3, 2020, to no later than 1 year 
after the rule effective date.
    The NRC is modifying the existing condition Sec.  
50.55a(g)(6)(ii)(F)(8) to retain, in part, the volumetric examination 
frequency of ASME Code Case N-770-5, which was changed in N-770-6. In 
N-770-5, the Frequency of Examination for Inspection Item C-2 welds 
(uncracked butt welds reinforced by optimized weld overlay of Alloy 52/
152 material) is ``100% of these welds shall be examined once each 
inspection interval. For any overlays that have an analyzed life of 
less than 10 [years], the inspection interval shall be less than or 
equal to the analyzed life.''
    In N-770-5, the Frequency of Examination for Inspection Item F-2 
welds (cracked butt weld reinforced by optimized weld overlay of Alloy 
52/152 material) is ``[o]nce during the first or second refueling 
outage following overlay. Examination volumes that show no indication 
of crack growth or new cracking shall be examined once each inspection 
interval. For any overlays that have an analyzed life of less than 10 
years, the inspection interval shall be less than or equal to the 
analyzed life.''
    The current NRC condition Sec.  50.55a(g)(6)(ii)(F)(8) states that 
initial inservice examination of Inspection Item C-2 welds shall be 
performed between the third refueling outage and no later than 10 years 
after application of the overlay. In N-770-7, the Frequency of 
Examination for Inspection Item C-2 welds is--

[e]xamine all welds no sooner than the third refueling outage and no 
later than 10 years following optimized weld overlay. After the 
first interval, examination volumes that show no indication of 
cracking shall be placed into a population to be examined on a 
sample basis. Twenty-five percent of this population shall be added 
to the ISI Program in accordance with -2410 and shall be examined 
once each inspection interval [Note (10)]. For any optimized weld 
overlays that have an analyzed life of less than 10 years, the 
inspection interval shall be less than or equal to the analyzed 
life.

    In N-770-7, the Frequency of Examination for Inspection Item F-2 
welds is--

[o]nce during the first or second refueling outage following 
optimized weld overlay. Weld overlay examination volumes that show 
no indication of crack growth or new cracking shall be placed into a 
population to be examined on a sample basis. Twenty-five percent of 
this population shall be added to the ISI Program in accordance with 
-2410 and shall be examined once each inspection interval [Note 
(10)]. For any optimized weld overlays that have an analyzed life of 
less than 10 years, the inspection interval shall be less than or 
equal to the analyzed life.

    The NRC continues to find that the long-term frequency for 
examination of optimized weld overlays shall be 100 percent of the 
welds each inspection interval, consistent with N-770-5 and the current 
regulation. Optimized weld overlays still structurally rely upon 25 
percent of the primary water stress corrosion cracking material of the 
original butt weld to provide structural integrity for the weld. 
Further, the deposition of a more crack resistant material such as 
Alloy 52/152 acts as a crack growth restriction, allowing growth along 
the susceptible original weld material rather than through the more 
crack resistant material that would provide leakage as a defense-in-
depth measure to identify cracking. A 25-percent sample inspection 
could allow optimized weld overlayed welds to have cracks develop into 
the structural

[[Page 70457]]

retaining material of an ASME Class 1 butt weld in the reactor coolant 
system. This condition is not true of full structural weld overlays, 
which the NRC has found can utilize a long-term examination frequency 
of a 25-percent sample. Because the design of the optimized weld 
overlay reduces the effectiveness of the defense-in-depth leak 
initiation method of identifying potential cracking, a volumetric 
examination of each weld is required to provide reasonable assurance of 
structural integrity for these optimized weld overlays. Therefore, the 
NRC is modifying the condition to state that after initial examination 
for Inspection Items C-2 and F-2 welds, optimized weld overlay 
examination volumes that show no indication of crack growth or new 
cracking shall be examined once each inspection interval.
    ASME Code Case N-770-7 also creates a new Inspection Item category 
for auxiliary head adapter (AHA) butt welds, B-3. Some Westinghouse 4-
loop plants have AHA butt welds connected to the upper reactor vessel 
closure head. The new Inspection Item B-3 caries the same inspection 
requirements of B-1, which the AHA butt welds fall under currently. The 
update to a new Inspection Item category was made to facilitate a 
change to the scope expansion requirements in the event that a crack 
was found in an AHA butt weld.
    The purpose of a scope expansion examination is if a crack is found 
in one weld, examinations of similar welds should be performed to 
ensure no generic issues are identified with that type of location or 
operating condition. The Inspection Item category that AHA butt welds 
currently fall under, B-1, could trigger scope expansion examinations 
in any, and potentially all, unmitigated reactor coolant system welds. 
The AHA butt welds are approximately 6-inches in diameter and are 
located on top of the reactor pressure vessel head in a low or no flow 
area. This location, while being of the same weld material, is not 
generally operating under the same conditions as the rest of the 
reactor coolant butt welds in the primary system of a Westinghouse PWR. 
Therefore, the ASME Code revised and issued Code Case N-770, Revision 
7, to include the new category and modify the scope expansion rules to 
reflect this change. The NRC agrees with the change to address the 
intent of scope expansion if a flaw were to be identified in an AHA 
butt weld. Therefore, the NRC is updating the augmented inservice 
inspection requirements of Sec.  50.55a(g)(6)(ii)(F)(1) to mandate the 
use of N-770-7 in lieu of N-770-5.

C. ASME OM Code

Section 50.55a(a)(1)(iv), ASME Operation and Maintenance Code
    The NRC is amending the regulations in Sec.  50.55a(a)(1)(iv)(C) to 
incorporate by reference the 2022 Edition of the ASME OM Code for 
nuclear power plants. The NRC is streamlining Sec.  50.55a wherever 
possible to provide clearer IST regulatory requirements for nuclear 
power plant licensees and applicants. In the following paragraphs, the 
NRC includes certain changes that are part of the Sec.  50.55a 
streamlining efforts.
Section 50.55a(b)(3)(ii) OM Condition: Motor-Operated Valve (MOV) 
Testing
    The NRC is modifying Sec.  50.55a(b)(3)(ii) by removing conditions 
(A), (B), and (C) where licensees are implementing the 2022 Edition of 
the ASME OM Code as incorporated by reference in Sec.  50.55a, because 
Appendix III, ``Preservice and Inservice Testing of Active Electric MOV 
Assemblies in Water-Cooled Reactor Nuclear Power Plants,'' to the 2022 
Edition of the ASME OM Code appropriately incorporates the requirements 
specified in those conditions. Condition (D) has not been incorporated 
into the 2022 Edition of the ASME OM Code. Therefore, condition (D) in 
Sec.  50.55a(b)(3)(ii) will continue to apply to all editions and 
addenda of the ASME OM Code incorporated by reference in Sec.  50.55a.
Section 50.55a(b)(3)(iii) OM Condition: Check Valves
    The NRC is revising Sec.  50.55a(b)(3)(iii) by removing condition 
(B), ``Check valves,'' which states that licensees must perform bi-
directional testing of check valves within the IST program where 
practicable. New reactors are applying more recent editions of the ASME 
OM Code that require bi-directional testing of check valves. Therefore, 
condition (B) is not needed in Sec.  50.55a(b)(3)(iii). The NRC is 
reserving condition (B) in Sec.  50.55a(b)(3)(iii) for possible future 
use.
Section 50.55a(b)(3)(iii) OM Condition: Flow-Induced Vibration
    The NRC is revising Sec.  50.55a(b)(3)(iii) by removing condition 
(C), ``Flow-induced vibration,'' which states that licensees shall 
monitor flow-induced vibration from hydrodynamic loads and acoustic 
resonance during preservice testing or inservice testing to identify 
potential adverse flow effects on components within the scope of the 
IST program. Based on regulatory experience with new reactor licensing, 
the NRC considers that flow-induced vibration is appropriately 
addressed during the licensing phase and initial testing program at 
each new reactor nuclear power plant. Therefore, condition (C) is not 
needed in Sec.  50.55a(b)(3)(iii). The NRC is reserving paragraph (C) 
in Sec.  50.55a(b)(3)(iii) for possible future use.
Section 50.55a(b)(3)(vii) OM Condition: Snubber Visual Examination 
Interval Extension
    The NRC is adding Sec.  50.55a(b)(3)(vii) to clarify use of ASME OM 
Code, Subsection ISTD, ``Preservice and Inservice Requirements for 
Dynamic Restraints (Snubbers) in Water-Cooled Reactor Nuclear Power 
Plants,'' paragraph ISTD-4253, ``Additional Requirements for 10-year 
Interval,'' and Note 7 of the Table ISTD-4252-1, ``Visual Examination 
Table,'' with ASME OM Code Case OMN-15, Revision 2, ``Performance-Based 
Requirements for Extending the Snubber Operational Readiness Testing 
Interval at LWR Power Plants.'' OM Code Case OMN-15, Revision 2, 
Section 3.4, ``Code Case OMN-13,'' states that ``this Code Case [OMN-
15] shall not be used in conjunction with Code Case OMN-13, 
`Performance-Based Requirements for Extending Snubber Inservice Visual 
Examination Interval at LWR Power Plants.''' OM Code Case OMN-13 is 
incorporated in paragraph ISTD-4253 and Note 7 of Table ISTD-4252-1 of 
the 2022 Edition of the ASME OM Code. The use of OM Code Case OMN-13 is 
prohibited in conjunction with the use of OM Code Case OMN-15. However, 
the specific language of paragraph ISTD-4253 and Note 7 of Table ISTD-
4252-1 does not clarify that the use of paragraph ISTD-4253 and Note 7 
of Table ISTD-4252-1 is optional. The NRC is clarifying the language in 
the ASME OM Code by stating that when implementing Subsection ISTD, 
paragraph ISTD-4253, and Note 7 of Table ISTD-4252-1, in the 2022 
Edition of the ASME OM Code, incorporated by reference in paragraph 
(a)(1)(iv) of this section, to extend snubber visual examination beyond 
two refueling cycles (48 months), the licensee is prohibited from 
applying OM Code Case OMN-15, Revision 2.
Section 50.55a(b)(3)(x) OM Condition: Class 1 Pressure Relief Valve 
Sample Expansion
    The NRC is adding Sec.  50.55a(b)(3)(x) to clarify subparagraph (1) 
in paragraph (c), Requirements for Testing Additional Valves, of 
Section I-1320, ``Test Frequencies, Class 1 Pressure Relief

[[Page 70458]]

Valves,'' in the ASME OM Code, Appendix I, ``Inservice Testing of 
Pressure Relief Devices in Water-Cooled Reactor Nuclear Power Plants,'' 
which states that for each valve tested for which the as-found set-
pressure (first test actuation) exceeds the greater of either the plus/
minus tolerance limit of the Owner-established set-pressure acceptance 
criteria of I-1310(e) or 3 percent of valve nameplate set-
pressure, two additional valves shall be tested from the same valve 
group. The expansion of the test sample provides reasonable assurance 
that a degradation mechanism that might cause multiple Class 1 Pressure 
Relief Valves to be incapable of performing their safety functions will 
be identified. Typically, it is expected that variations in actual 
valve performance will result in an Owner-established set-pressure 
acceptance criteria for Class 1 Pressure Relief Valves exceeding the 
default 3-percent valve nameplate set-pressure. The NRC has no concerns 
with the language of paragraph I-1320(c)(1) where the Owner-established 
set-pressure acceptance criteria are greater than the 3-percent default 
value. Based on plant-specific valve performance, the Owner might need 
to establish set-pressure acceptance criteria for Class 1 Pressure 
Relief Valves lower than the default 3-percent value. The failure of a 
Class 1 Pressure Relief Valve to meet the Owner-established set-
pressure acceptance criteria can signify that the valve is incapable of 
performing its safety function. In such cases, it is important to 
determine whether other Class 1 Pressure Relief Valves also have 
performance problems that could cause them to be unable to perform 
their safety functions. However, the specific language of paragraph I-
1320(c)(1) might be interpreted to not require an expansion of the test 
sample where the default 3-percent value is greater than the Owner-
established set-pressure acceptance criteria. This might lead in an 
unsafe situation where the licensee is unaware that multiple Class 1 
Pressure Relief Valves are incapable of performing their safety 
functions. To resolve this concern, the NRC is clarifying the language 
in paragraph I-1320(c)(1).
    Based on a public comment requesting to clarify the proposed rule 
language, the NRC revised 10 CFR 50.55a(b)(3)(x) to specify two 
additional valves to be tested from the same group if expanding the 
test sample is required. If the Owner has not established design set-
pressure acceptance criteria, then for each valve tested for which the 
as-found set-pressure (first actuation) exceeds 3 percent 
of valve nameplate set-pressure, two additional valves shall be tested 
from the same valve group. The specification of the Owner-established 
``design'' set-pressure acceptance criteria allows the licensee to 
establish specific criteria for testing purposes.

D. Editorial Correction

Section 50.55a(d) Quality Group B Components
    The NRC is making an editorial correction to Sec.  50.55a(d), 
``Quality Group B components,'' by replacing the colon at the end of 
the second sentence of the introductory paragraph with a period. When 
the introductory paragraph of Sec.  50.55a(d) was expanded to include a 
reference to 10 CFR part 52, the new second sentence of the 
introductory paragraph incorrectly placed a colon at the end of the 
sentence rather than a period. The use of a colon implies that items 
(1) and (2) in Sec.  50.55a(d) only apply to 10 CFR part 52 plants. 
However, item (1) of Sec.  50.55a(d) specifies a requirement for 
applicants under 10 CFR part 50.

III. Opportunities for Public Participation

    The proposed rule was published on August 8, 2023, for a 75-day 
comment period (88 FR 53384). The public comment period closed on 
October 23, 2023.
    During the public comment period, the NRC held a public meeting on 
September 6, 2023, to discuss the proposed rule, to answer questions on 
specific provisions of the proposed rule, and to encourage public input 
on the proposed rule. The public meeting summary is available in ADAMS 
as provided in the ``Availability of Documents'' section of this 
document.

IV. Public Comment Analysis

    The NRC published the proposed rule for public comment in the 
Federal Register. A comment submission is a communication or document 
submitted to the NRC by an individual or entity, with one or more 
individual comments addressing a subject or issue. The NRC received 
three comment submission(s) in response to the opportunity for public 
comment on the proposed rule, with an individual comment total of 22. 
These comment submissions were submitted by the following commenters 
(listed in order of receipt):

1. Inservice Testing Owners' Group (ISTOG)
2. American Society of Mechanical Engineers (ASME)
3. Electric Power Research Institute (EPRI)

    Due to the large number of comments received and the length of the 
NRC's response, a summary of the NRC's response to comments in areas of 
particular interest to stakeholders is included in this final rule. 
This includes comments that prompted the NRC to make more than 
editorial changes in this final rule from what the NRC had proposed. 
The public comment submittals are available from the Federal rulemaking 
website at https://www.regulations.gov under Docket ID NRC-2018-0289. A 
discussion of all comments and complete NRC responses are presented in 
a separate document, ``Final Rule--Comment Response Document ASME 2021-
2022 Code Editions Update,'' as provided in the ``Availability of 
Documents'' section of this document.

V. Section-by-Section Analysis

    This section describes the primary revisions made by this final 
rule; minor editorial and administrative corrections to correct 
spacing, administrative errors, and typos are not identified in this 
analysis.

Paragraph (a)(1)(i)(E)

    This final rule revises paragraphs (a)(1)(i)(E)(19) and (20) and 
add new paragraph (a)(1)(i)(E)(21) to include the 2021 Edition of the 
ASME BPV Code.

Paragraph (a)(1)(ii)(C)

    This final rule revises paragraphs (a)(1)(ii)(C)(55) and (56) and 
adds new paragraph (a)(1)(ii)(C)(57) to include the 2021 Edition.

Paragraph (a)(1)(iii)(D)

    This final rule revises paragraph (a)(1)(iii)(D) to update ASME BPV 
Code Case N-770-5 to N-770-7 and to update the approval date to 
December 4, 2020.

Paragraph (a)(1)(iv)(C)

    This final rule revises paragraph (a)(1)(iv)(C) to add the 2022 
Edition of the ASME OM Code.

Paragraph (b)(1)(iv)

    This final rule revises and redesignates existing paragraph 
(b)(1)(iv) as paragraph (b)(1)(iv) introductory text, adds new 
paragraphs (b)(1)(iv)(A) and (B), and removes and reserves paragraph 
(b)(1)(iv)(B).

Paragraph (b)(1)(vi)

    This final rule revises paragraph (b)(1)(vi) to revise ``sleeves'' 
to ``sheaths'' and adds a new sentence that this condition is not 
applicable to 2015 and later Editions.

[[Page 70459]]

Paragraph (b)(1)(xi)

    This final rule revises the introductory text to paragraph 
(b)(1)(xi) to clarify the applicable conditions and adds two new 
conditions specific to polyethylene pressure piping when applying the 
2015 through 2021 Editions. The rule also revises paragraph 
(b)(1)(xi)(B) to add the 2015 to 2021 Editions of BPV Code Section III. 
In response to a public comment, the NRC has modified the language from 
the proposed paragraph (b)(1)(xi)(B) to provide more clarity. See 
Section II of this document, ``Discussion,'' for more information.

Paragraph (b)(1)(xiii)

    This final rule revises the introductory text to paragraph 
(b)(1)(xiii) and paragraphs (b)(1)(xiii)(A) and (B) to update the 
applicability of the latest edition and addenda incorporated by 
reference in Sec.  50.55a(a)(1).

Paragraph (b)(1)(xiv)

    This final rule adds new paragraph (b)(1)(xiv) to require that 
Nonmandatory Appendix NN be used in its entirety.

Paragraph (b)(2)

    This final rule revises the introductory text of paragraph (b)(2) 
to clarify the editions incorporated by reference in paragraph 
(a)(1)(ii).

Paragraph (b)(2)(viii)

    This final rule revises paragraph (b)(2)(viii) to update the 
applicability of paragraphs (b)(2)(viii)(H) and (b)(2)(viii)(I) through 
the 2019 Edition.

Paragraph (b)(2)(ix)

    This final rule revises paragraph (b)(2)(ix) to update the 
applicability of paragraph (b)(2)(ix)(A)(2).

Paragraph (b)(2)(xv)

    This final rule eliminates and reserves the condition at paragraph 
(b)(2)(xv).

Paragraph (b)(2)(xxxiv)

    This final rule removes the introductory text to paragraph 
(b)(2)(xxxiv), leaving only the heading; redesignates paragraphs 
(b)(2)(xxiv)(A) and (B) to (b)(2)(xxiv)(A)(1) and (b)(2)(xxiv)(A)(2); 
revises paragraph (b)(2)(xxxiv)(A)(1) and (b)(2)(xxxiv)(A)(2) to 
require use of the latest version of ASME BPV Code Case N-513 approved 
in RG 1.147 at the time the case was incorporated into the licensee's 
inservice inspection program; and adds new paragraph (b)(2)(xxxiv)(B) 
to prohibit the use of Nonmandatory Appendix U, Supplement U-S1 in the 
2021 Edition of Section XI. In response to a public comment, the NRC 
has modified the language from the proposed paragraph 
(b)(2)(xxxiv)(A)(2), to provide more clarity. See Section II of this 
document, ``Discussion,'' for more information.

Paragraph (b)(2)(xxxvi)

    This final rule revises this condition in paragraph (b)(2)(xxxvi) 
to require that T0 and RTT0 be determined as 
specified in the 2021 Edition of ASME BPV Code, Section III, NB-2331, 
subparagraph (a)(5). In response to a public comment, the NRC has 
modified the language in (b)(2)(xxxvi), which was not in the proposed 
rule, to allow the use of Master Curve methods, as specified in NB-
2331(a)(5) without obtaining approval from the NRC under Sec.  
50.55a(z). See Section II of this document, ``Discussion,'' for more 
information.

Paragraph (b)(2)(xliii)

    This final rule revises the introductory text to include language 
from paragraph (b)(2)(xliii)(A), removes paragraphs (A) through (C), 
and removes the requirement for NRC review and approval. In response to 
a public comment, the NRC has modified the language from paragraph 
(b)(2)(xliii), which was not in the proposed rule. See Section II of 
this document, ``Discussion,'' for more information.

Paragraph (b)(2)(xliv)

    This final rule adds new paragraph (b)(2)(xliv) to prohibit the use 
of Y-2200, Y-2440, and Y-3200 in the 2021 Edition of Section XI.

Paragraph (b)(2)(xlv)

    This final rule adds new paragraph (b)(2)(xlv) to condition the 
provision of IWA-4540(a) and (e) of the 2021 Edition of the ASME Code, 
Section XI, to require that a VT-2 examination of the area affected by 
the repair/replacement activity be conducted during the Type C test in 
appendix J to 10 CFR part 50.

Paragraph (b)(2)(xlvi)

    This final rule adds new paragraph (b)(2)(xlvi) to prohibit a 
contracted Repair/Replacement Organization without an ASME Certificate 
of Authorization and not applying an ASME Stamp/Certification Mark from 
fabricating ASME Code, Section III parts, appurtenances, piping 
subassemblies, and supports offsite of the Owner's facility (e.g., 
vendor facility) when applying the provisions of IWA-4143 in the 2021 
Edition of the ASME Code, Section XI.

Paragraph (b)(2)(xlvii)

    This final rule adds new paragraph (b)(2)(xlvii) to require stress 
corrosion crack growth analysis of the weld overlay material under 
subparagraph Q-3000(a) of Nonmandatory Appendix Q in the 2021 Edition 
of the ASME Code, Section XI.

Paragraph (b)(2)(xlviii)

    This final rule adds new paragraph (b)(2)(xlviii) to require that 
analytical evaluations performed in accordance with IWB-3132.3 and IWC-
3132.3 be submitted to the NRC.

Paragraph (b)(2)(xlix)

    This final rule adds new paragraph (b)(2)(xlix) to prohibit the use 
of IWB-3600(b)(1) in the 2021 Edition of ASME BPV Code, Section XI 
(Division 1) for the inlay and onlay that are subject to the augmented 
inspection requirements in paragraph (g)(6)(ii)(F).

Paragraph (b)(2)(l)

    This final rule adds new paragraph (b)(2)(l) to require users of 
the 2017 Edition of Section XI through the latest Edition and 
implementing Nonmandatory Appendix A, A-4200(c) and Nonmandatory 
Appendix G, G-2110(c) to determine T0 and RTT0 as 
specified in the 2021 Edition of the ASME BPV Code, Section III, NB-
2331, subparagraph (a)(5). In response to a public comment, the NRC has 
added new paragraph (b)(2)(l), which did not appear in the proposed 
rule, to allow the use of Master Curve methods, including NB-
2331(a)(5), and to align with changes in paragraph (b)(2)(xliii) of 
this section. See Section II of this document, ``Discussion,'' for more 
information.

Paragraph (b)(3)(ii)

    This final rule revises the introductory text to paragraph 
(b)(3)(ii) to exclude conditions (A), (B), and (C) from being 
applicable to the 2022 Edition of the ASME OM Code because those 
conditions have been incorporated into that edition of the ASME OM 
Code.

Paragraph (b)(3)(iii)

    This final rule revises paragraph (b)(3)(iii) to remove and reserve 
for future use the conditions in paragraphs (b)(3)(iii)(B) and (C) 
because those conditions are required by other regulations for new 
reactors.

Paragraph (b)(3)(vii)

    This final rule replaces reserved paragraph (b)(3)(vii) with a new 
condition on ASME OM Code, Subsection ISTD, paragraph ISTD-4253, and 
Note 7 of the Table ISTD-4252-1

[[Page 70460]]

related to snubbers to be consistent with the accepted provisions in OM 
Code Case OMN-15.

Paragraph (b)(3)(x)

    This final rule creates a new paragraph (b)(3)(x) to clarify the 
requirement for expanding the test sample for Class 1 Pressure Relief 
Valves specified in ASME OM Code, Appendix I, paragraph I-1320(c)(1). 
In response to a public comment, the NRC has modified the language from 
the proposed paragraph (b)(3)(x) for clarity regarding inservice valve 
testing. See Section II of this document, ``Discussion,'' for more 
information.

Paragraph (d)

    This final rule revises the introductory text of paragraph (d) by 
correcting an editorial error. The colon is replaced with a period, at 
the end of the second sentence.

Paragraph (g)(4)(ii)

    This final rule revises paragraph (g)(4)(ii) to update the dates to 
conform with this rule. In response to a public comment, the NRC has 
modified the language in paragraph (g)(4)(ii), which was not in the 
proposed rule, to allow licensees to delay the update of their Appendix 
VIII program by up to 18 months after the effective date of this final 
rule. See Section II of this document, ``Discussion,'' for more 
information.

Paragraph (g)(6)(ii)(D)(9)

    This final rule adds new paragraph (g)(6)(ii)(D)(9) to allow 
licensees the option to utilize Supplement 15 of Mandatory Appendix 
VIII, in the 2021 Edition of Section XI incorporated by reference in 
Sec.  50.55a, for volumetric qualification of examinations required by 
Table 1 of ASME Code Case N-729-6.

Paragraph (g)(6)(ii)(F)(1)

    This final rule revises paragraph (g)(6)(ii)(F)(1) to update the 
requirements for the augmented inspection of dissimilar-metal butt 
welds in U.S. PWRs from ASME Code Case N-770-5 to N-770-7 and updates 
the dates to conform with this rule.

Paragraph (g)(6)(ii)(F)(8)

    This final rule modifies the existing condition in paragraph 
(g)(6)(ii)(F)(8) to retain, in part, the volumetric examination 
frequency of ASME Code Case N-770-5, which was changed in N-770-6.

VI. Generic Aging Lessons Learned Report

Background

    In December 2010, the NRC issued ``Generic Aging Lessons Learned 
(GALL) Report,'' NUREG-1801, Revision 2 (ML103490041), for applicants 
to use in preparing license renewal applications. The GALL Report 
provides aging management programs (AMPs) that the NRC has concluded 
are sufficient for aging management in accordance with the license 
renewal rule, as required in Sec.  54.21(a)(3). In addition, ``Standard 
Review Plan for Review of License Renewal Applications for Nuclear 
Power Plants,'' NUREG-1800, Revision 2 (ML103490036), was issued in 
December 2010, to ensure the quality and uniformity of NRC reviews of 
license renewal applications and to present a well-defined basis on 
which the NRC evaluates the applicant's AMPs and activities. In April 
2011, the NRC also issued ``Disposition of Public Comments and 
Technical Bases for Changes in the License Renewal Guidance Documents 
NUREG-1801 and NUREG-1800,'' NUREG-1950 (ML11116A062), which describes 
the technical bases for the changes in Revision 2 of the GALL Report 
and Revision 2 of the standard review plan (SRP) for review of license 
renewal applications.
    Revision 2 of the GALL Report, in Sections XI.M1, XI.S1, XI.S2, 
XI.M3, XI.M5, XI.M6, XI.M11B, and XI.S3, describes the evaluation and 
technical bases for determining the sufficiency of ASME BPV Code 
Subsections IWB, IWC, IWD, IWE, IWF, or IWL for managing aging during 
the period of extended operation (i.e., up to 60 years of operation). 
In addition, many other AMPs in the GALL Report rely, in part but to a 
lesser degree, on the requirements specified in the ASME BPV Code, 
Section XI. Revision 2 of the GALL Report also states that the 1995 
Edition through the 2004 Edition of the ASME BPV Code, Section XI, 
Subsections IWB, IWC, IWD, IWE, IWF, or IWL, as modified and limited by 
Sec.  50.55a, were found to be acceptable editions and addenda for 
complying with the requirements of Sec.  54.21(a)(3), unless 
specifically noted in certain sections of the GALL Report. The GALL 
Report further states that future Federal Register documents that amend 
Sec.  50.55a will discuss the acceptability of editions and addenda 
more recent than the 2004 Edition for their applicability to license 
renewal. In a final rule issued on June 21, 2011 (76 FR 36232), 
subsequent to Revision 2 of the GALL Report, the NRC also found that 
the 2004 Edition with the 2005 Addenda through the 2007 Edition with 
the 2008 Addenda of Section XI of the ASME BPV Code, Subsections IWB, 
IWC, IWD, IWE, IWF, or IWL, as subject to the conditions in Sec.  
50.55a, are acceptable for the AMPs in the GALL Report and the 
conclusions of the GALL Report remain valid with the augmentations 
specifically noted in the GALL Report. In a final rule issued on July 
18, 2017 (82 FR 32934), the NRC further found that the 2009 Addenda 
through the 2017 Edition of Section XI of the ASME BPV Code, 
Subsections IWB, IWC, IWD, IWE, IWF, or IWL, as subject to the 
conditions in Sec.  50.55a, are acceptable for the AMPs in the GALL 
Report. In a final rule issued on May 4, 2020 (85 FR 26540), the NRC 
further found that Subsections IWB, IWC, IWD, IWE, IWF, or IWL of 
Section XI of the 2015 Edition and the 2017 Edition of the ASME BPV 
Code, as subject to the conditions in Sec.  50.55a, are acceptable for 
the AMPs in the GALL Report. In a final rule issued on October 27, 2022 
(87 FR 65128), the NRC further found that Subsections IWB, IWC, IWD, 
IWE, IWF, or IWL of Section XI of the 2019 Edition of the ASME BPW 
Code, as subject to the conditions in Sec.  50.55a, are acceptable for 
the AMPs in the GALL Report.
    In July 2017, the NRC issued ``Generic Aging Lessons Learned for 
Subsequent License Renewal (GALL-SLR) Report,'' NUREG-2191 (ML17187A031 
and ML17187A204), for applicants to use in preparing applications for 
subsequent license renewal. The GALL-SLR Report provides AMPs that are 
sufficient for aging management for the subsequent period of extended 
operation (i.e., up to 80 years of operation), as required in Sec.  
54.21(a)(3). The NRC also issued ``Standard Review Plan for Review of 
Subsequent License Renewal Applications for Nuclear Power Plants'' 
(SRP-SLR), NUREG-2192, in July 2017 (ML17188A158). In a similar manner 
as the GALL Report, the GALL-SLR Report, in Sections XI.M1, XI.S1, 
XI.S2, XI.M3, XI.11B, and XI.S3, describes the evaluation and technical 
bases for determining the sufficiency of ASME BPV Code Subsections IWB, 
IWC, IWD, IWE, IWF, or IWL for managing aging during the subsequent 
period of extended operation. Many other AMPs in the GALL-SLR Report 
rely, in part but to a lesser degree, on the requirements specified in 
the ASME BPV Code, Section XI. The GALL-SLR Report also indicates that 
the 1995 Edition through the 2013 Edition of the ASME BPV Code, Section 
XI, Subsections IWB, IWC, IWD, IWE, IWF, or IWL, as subject to the 
conditions in

[[Page 70461]]

Sec.  50.55a, are acceptable for complying with the requirements of 
Sec.  54.21(a)(3), unless specifically noted in certain sections of the 
GALL-SLR Report.

Evaluation With Respect to Aging Management

    As part of this final rule, the NRC evaluated whether those AMPs in 
the GALL Report and GALL-SLR Report that rely upon Subsections IWB, 
IWC, IWD, IWE, IWF, or IWL of Section XI in the editions and addenda of 
the ASME BPV Code incorporated by reference into Sec.  50.55a, in 
general continue to be acceptable if the AMP relies upon these 
Subsections in the 2021 Edition. The NRC finds that the 2021 Edition of 
Section XI of the ASME BPV Code, Subsections IWB, IWC, IWD, IWE, IWF, 
or IWL, as subject to the conditions of this rule, are acceptable for 
the AMPs in the GALL Report and GALL-SLR Report with the exception of 
augmentation, as specifically noted in those reports, and the NRC finds 
that the conclusions of the GALL Report and GALL-SLR Report remain 
valid. Accordingly, an applicant for license renewal (including 
subsequent license renewal) may use, in its plant-specific license 
renewal application, Subsections IWB, IWC, IWD, IWE, IWF, or IWL of 
Section XI of the 2021 Edition of the ASME BPV Code, as subject to the 
conditions in this final rule, without additional justification. 
Similarly, a licensee approved for license renewal that relied on the 
AMPs may use Subsections IWB, IWC, IWD, IWE, IWF, or IWL of Section XI 
of the 2021 Edition of the ASME BPV Code. However, applicants must 
assess and follow applicable NRC requirements with regard to licensing 
basis changes and evaluate the possible impact on the elements of 
existing AMPs.
    Some of the AMPs in the GALL Report and GALL-SLR Report recommend 
augmentation of certain Code requirements in order to ensure adequate 
aging management for license renewal. The technical and regulatory 
aspects of the AMPs for which augmentations are recommended also apply 
if the 2021 Edition of Section XI of the ASME BPV Code is used to meet 
the requirements of Sec.  54.21(a)(3). The NRC evaluated the changes in 
the 2021 Edition of Section XI of the ASME BPV Code to determine if the 
augmentations described in the GALL Report and GALL-SLR Report remain 
necessary; the NRC's evaluation has concluded that the augmentations 
described in the GALL and GALL-SLR Reports are necessary to ensure 
adequate aging management.
    For example, GALL-SLR Report AMP XI.S3, ``ASME Section XI, 
Subsection IWF,'' recommends that volumetric examination consistent 
with that of the ASME BPV Code, Section XI, Table IWB-2500-1, 
Examination Category B-G-1 should be performed to detect cracking for 
high strength structural bolting (actual measured yield strength 
greater than or equal to 150 kilopound per square inch (ksi)) (1034 
megapascals (MPA)) in sizes greater than 1-inch nominal diameter. The 
GALL-SLR Report also indicates that this volumetric examination may be 
waived with adequate plant-specific justification. This guidance for 
aging management in the GALL-SLR Report is the augmentation of the 
visual examination specified in Subsection IWF of the 2021 Edition of 
the ASME BPV Code, Section XI.
    A license renewal applicant may either augment its AMPs as 
described in the GALL Report and GALL-SLR Report (for operation up to 
60 and 80 years respectively) or propose alternatives for the NRC to 
review as part of the applicant's plant-specific justification for its 
AMPs.

VII. Regulatory Flexibility Certification

    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).

VIII. Regulatory Analysis

    The NRC has prepared a final regulatory analysis on this 
regulation. The analysis examines the costs and benefits of the 
alternatives considered by the NRC. The regulatory analysis is 
available as indicated in the ``Availability of Documents'' section of 
this document.

IX. Backfitting and Issue Finality

Introduction

    The NRC's Backfit Rule in Sec.  50.109 states that the NRC shall 
require the backfitting of a facility only when it finds the action to 
be justified under specific standards stated in the rule. Section 
50.109(a)(1) defines backfitting as the modification of or addition to 
systems, structures, components, or design of a facility; the design 
approval or manufacturing license for a facility; or the procedures or 
organization required to design, construct, or operate a facility. Any 
of these modifications or additions may result from a new or amended 
provision in the NRC's rules or the imposition of a regulatory position 
interpreting the NRC's rules that is either new or different from a 
previously applicable NRC position after issuance of the construction 
permit or the operating license or the design approval.
    Section 50.55a requires nuclear power plant licensees to--
     Construct ASME BPV Code Class 1, 2, and 3 components in 
accordance with the rules provided in Section III, Division 1, of the 
ASME BPV Code (``Section III'').
     Inspect, examine, and repair or replace Class 1, 2, 3, 
Class MC, and Class CC components in accordance with the rules provided 
in Section XI, Division 1, of the ASME BPV Code (``Section XI'').
     Test Class 1, 2, and 3 pumps and valves in accordance with 
the rules provided in the ASME OM Code.
     Inspect, examine, repair, or replace, and test Class 1, 2, 
and 3 dynamic restraints (snubbers) in accordance with the rules 
provided in either the ASME OM Code or Section XI, depending on the 
Code edition.
    This rulemaking incorporates by reference the 2021 Edition of the 
ASME BPV Code, Section III, Division 1, and ASME BPV Code, Section XI, 
Division 1, as well as the 2022 Edition of the ASME OM Code.
    The ASME BPV and OM Codes are national consensus standards 
developed by participants with broad and varied interests, in which all 
interested parties (including the NRC and utilities) participate. A 
consensus process involving a wide range of stakeholders is consistent 
with the NTTAA, inasmuch as the NRC has determined that there are sound 
regulatory reasons for establishing regulatory requirements for design, 
maintenance, ISI, and IST by rulemaking. The process also facilitates 
early stakeholder consideration of backfitting issues. Therefore, the 
NRC finds that the NRC need not address backfitting with respect to the 
NRC's general practice of incorporating by reference updated ASME 
Codes.

Overall Backfitting Considerations: Section III of the ASME BPV Code

    Incorporation by reference of more recent editions and addenda of 
Section III of the ASME BPV Code does not affect a plant that has 
received a construction permit or an operating license or a design that 
has been approved. This is because the edition and addenda to be used 
in constructing

[[Page 70462]]

a plant are, under Sec.  50.55a, determined based on the date of the 
construction permit or combined license, and are not changed 
thereafter, except voluntarily by the licensee. The incorporation by 
reference of more recent editions and addenda of Section III ordinarily 
applies only to applicants after the effective date of the final rule 
incorporating these new editions and addenda. Therefore, incorporation 
by reference of a more recent edition and addenda of Section III does 
not constitute ``backfitting'' as defined in Sec.  50.109(a)(1).

Overall Backfitting Considerations: Section XI of the ASME BPV Code and 
the ASME OM Code

    Incorporation by reference of more recent editions and addenda of 
Section XI of the ASME BPV Code and the ASME OM Code affects the ISI 
and IST programs of operating reactors. However, the Backfit Rule 
generally does not apply to incorporation by reference of later 
editions of the ASME BPV Code (Section XI) and OM Code. As previously 
mentioned, the NRC's longstanding regulatory practice has been to 
incorporate later versions of the ASME Codes into Sec.  50.55a. Under 
Sec.  50.55a, licensees must periodically update their ISI and IST 
programs to the latest edition of Section XI of the ASME BPV Code and 
the ASME OM Code incorporated by reference into Sec.  50.55a 18 months 
before the start of a new code of record interval. Therefore, when the 
NRC approves and requires the use of a later version of the Code for 
ISI and IST, it is implementing this longstanding regulatory practice 
and requirement.
    Other circumstances where the NRC does not apply the Backfit Rule 
to the approval and requirement to use later Code editions are as 
follows:
    1. When the NRC takes exception to a later ASME BPV Code or OM Code 
provision but merely retains the current existing requirement, 
prohibits the use of the later Code provision, limits the use of the 
later Code provision, or supplements the provisions in a later Code, 
the Backfit Rule does not apply because the NRC is not imposing new 
requirements. However, the NRC explains any such exceptions to the Code 
in the preamble to and regulatory analysis for the rule.
    2. When an NRC exception relaxes an existing ASME BPV Code or OM 
Code provision but does not prohibit a licensee from using the existing 
Code provision, the Backfit Rule does not apply because the NRC is not 
imposing new requirements.
    3. Modifications and limitations imposed during previous routine 
updates of Sec.  50.55a have established a precedent for determining 
which modifications or limitations are backfits, or require a backfit 
analysis (e.g., final rule dated September 10, 2008 (73 FR 52731), and 
a correction dated October 2, 2008 (73 FR 57235)). The application of 
the backfit requirements to modifications and limitations in the 
current rule are consistent with the application of backfit 
requirements to modifications and limitations in previous rules.
    The incorporation by reference and adoption of a requirement 
mandating the use of a later ASME BPV Code or OM Code may constitute 
backfitting in some circumstances. In these cases, the NRC would 
perform a backfit analysis or documented evaluation in accordance with 
Sec.  50.109. These include the following:
    1. When the NRC endorses a later provision of the ASME BPV Code or 
OM Code that takes a substantially different direction from the 
existing requirements, the action is treated as a backfit (e.g., 61 FR 
41303; August 8, 1996).
    2. When the NRC requires implementation of a later ASME BPV Code or 
OM Code provision on an expedited basis, the action is treated as a 
backfit. This applies when implementation is required sooner than it 
would be required if the NRC simply endorsed the Code without any 
expedited language (e.g., 64 FR 51370; September 22, 1999).
    3. When the NRC takes an exception to an ASME BPV Code or OM Code 
provision and imposes a requirement that is substantially different 
from the existing requirement as well as substantially different from 
the later Code (e.g., 67 FR 60529; September 26, 2002).

Detailed Backfitting Discussion: Changes Beyond Those Necessary To 
Incorporate by Reference the New ASME BPV and OM Code Provisions

    This section discusses the backfitting considerations for all the 
changes to Sec.  50.55a that go beyond the minimum changes necessary 
and required to adopt the new ASME Code edition into Sec.  50.55a.

ASME BPV Code, Section III

    1. Revise Sec.  50.55a(b)(1)(iv) to not approve Subpart 2.19 in 
NQA-1-17, NQA-1-19, and NQA-1-22 for use. This revision clarifies 
current requirements and is consistent with the meaning and intent of 
current requirements. The condition does not constitute a new or 
changed NRC position. Therefore, this condition is not a backfit.
    2. Revise Sec.  50.55a(b)(1)(vi) to change the word ``sleeves'' to 
``sheaths'' and to note that this condition is not applicable to 2015 
and later Editions. This condition is not applicable to 2015 and later 
Editions as Subsection NH is deleted from Section III Division 1. The 
revisions to clarify a word and clarification of Code edition 
applicability do not constitute a change in NRC position. Therefore, 
this is not a backfit.
    3. Revise Sec.  50.55a(b)(1)(xi) to revise this condition regarding 
the applicability to specific Code editions. When applying the 2015 and 
2017 Editions of Section III, Mandatory Appendix XXVI, ``Rules for 
Construction of Class 3 Buried Polyethylene Pressure Piping,'' 
applicants or licensees must meet the first provision, as noted in 
Sec.  50.55a(b)(1)(xi)(A). When applying the 2015 through 2021 Editions 
of Section III, Mandatory Appendix XXVI, ``Rules for Construction of 
Class 3 Buried Polyethylene Pressure Piping,'' applicants or licensees 
must meet the second provision, as noted in Sec.  50.55a(b)(1)(xi)(B). 
When applying the 2017 Edition of Section III, Mandatory Appendix XXVI, 
``Rules for Construction of Class 3 Buried Polyethylene Pressure 
Piping,'' applicants or licensees must meet the third provision, as 
noted in Sec.  50.55a(b)(1)(xi)(C). The revision is only for Code 
editions applicability and does not constitute a new or changed NRC 
position. Therefore, this change is not a backfit.
    4. Revise Sec.  50.55a(b)(1)(xiii) including the first provision, 
Sec.  50.55a(b)(1)(xiii)(A), and second provision, Sec.  
50.55a(b)(1)(xiii)(B), to extend the applicability of the conditions 
through the latest edition of the ASME BPV Code, Section III 
incorporated by reference in paragraph (a)(1)(i). The NRC is revising 
this condition to apply to the latest edition incorporated by 
reference, which is not a change to NRC position and, therefore, is not 
a backfit.
    5. Add Sec.  50.55a(b)(1)(xiv) to condition the use of the 
provisions of NCA-8151, NCA-8500, and Nonmandatory Appendix NN in the 
2021 Edition of Section III, to require that when Nonmandatory Appendix 
NN is used for the elimination of surface defects and repairs of 
stamped components prior to the completion of Form N-3 Data Report, all 
applicable requirements of Nonmandatory Appendix NN shall be met. The 
condition on Nonmandatory Appendix NN does not constitute a new or 
changed NRC position. Therefore, the

[[Page 70463]]

addition of this condition is not a backfit.

ASME BPV Code, Section XI

    1. Revise Sec.  50.55a(b)(2)(viii), to remove the applicability of 
Sec.  50.55a(b)(2)(viii)(H) and (I) from the 2021 Edition. This change 
to Sec.  50.55a(b)(2)(viii) removes conditions that are no longer 
applicable to the 2021 Edition due to updates to the BPV Code that 
addressed the condition. Since this change accepts the relevant code 
provisions in the 2021 Edition as-is, it is not a backfit.
    2. Revise Sec.  50.55a(b)(2)(ix), to remove the applicability of 
Sec.  50.55a(b)(2)(ix)(A)(2) from the 2021 Edition. This change to 
Sec.  50.55a(b)(2)(ix) removes a condition that is no longer applicable 
to the 2021 Edition due to updates to the BPV Code that addressed the 
condition. Since this change accepts the relevant code provisions in 
the 2021 Edition as-is, it is not a backfit.
    3. Remove and reserve Sec.  50.55a(b)(2)(xv). This condition was 
applicable to older Editions of Section XI that are no longer in use by 
licensees. Removing this condition does not modify current licensee 
inservice inspection requirements and, therefore, is not a backfit.
    4. Revise Sec.  50.55a(b)(2)(xxxiv)(A) to modify the cited version 
of ASME Code Case N-513 to the latest version approved in RG 1.147 at 
the time the case was incorporated into the licensee's program. The new 
conditions at paragraphs (b)(2)(xxxiv)(A)(1) and (A)(2) are the 
existing conditions with an added clarification of which version of 
Code Case N-513 licensees must use when complying with the conditions. 
This clarification is a restatement of the requirements in Sec.  
50.55a(b)(5) and is therefore not a backfit.
    5. Add Sec.  50.55a(b)(2)(xxxiv)(B) to prohibit the use of 
Nonmandatory Appendix U, Supplement U-S1. Supplement U-S1 of 
Nonmandatory Appendix U is obsolete relative to Code Case N-513, as 
included in the latest revision of RG 1.147 incorporated by reference 
in Sec.  50.55a(a)(3)(ii). Licensees have adopted the updated rules in 
Code Case N-513 for temporary acceptance of flaws in moderate energy 
Class 2 and 3 piping. This revision does not modify the current 
inservice inspection regulatory requirements and, therefore, is not a 
backfit.
    6. Revise Sec.  50.55a(b)(2)(xxxvi) to delete the requirement to 
submit the analyses for NRC approval and instead follow the 
requirements of NB-2331, subparagraph (a)(5). The revision to this 
condition allows licensees to use T0 and RTT0 in 
licensing basis calculations by application of a specific method 
without NRC review and approval under paragraph (z). Licensees retain 
the option of obtaining approval under paragraph (z) to implement 
alternative methods. Therefore, this change is not a backfit.
    7. Revise Sec.  50.55a(b)(2)(xliii)(A) to clarify that NRC review 
and approval is not required for out-of-limit evaluation submissions. 
This revision only clarifies that NRC approval of the analysis is not a 
prerequisite for licensee activities. This revision does not result in 
a change to licensee requirements and is, therefore, not a backfit.
    The submittal requirements of Sec.  50.55a(b)(2)(xliii)(B) and (C) 
are removed because they are replaced by new condition Sec.  
50.55a(b)(2)(l). The new condition states that licensees must follow 
the requirements of NB-2331, subparagraph (a)(5) when calculating 
T0 and RTT0. With this revision, licensees now 
have the option to implement an acceptable method for determining 
T0 and RTT0 without NRC review and approval. 
Therefore, this change is not a backfit.
    8. Add Sec.  50.55a(b)(2)(xliv) to prohibit the use of Article Y-
2200, Subarticle Y-2440, and Article Y-3200 in Nonmandatory Appendix Y. 
These articles have corresponding Code Cases, which have been included 
in the latest revision of RG 1.147 incorporated by reference in Sec.  
50.55a(a)(3)(ii). Licensees have adopted the crack growth laws in the 
corresponding Code Cases: Cases N-809, N-889, and N-643, respectively. 
The condition on Nonmandatory Appendix Y does not constitute a new or 
changed NRC position. Therefore, the addition of this condition is not 
a backfit.
    9. Add Sec.  50.55a(b)(2)(xlv) to condition the provision of IWA-
4540(a) and (e) of the 2021 Edition of the ASME Code, Section XI, to 
require that a VT-2 examination be performed of the area affected by 
the repair/replacement activity during the Type C test in appendix J to 
10 CFR part 50. The condition on IWA-4540(a) and (e) does not 
constitute a new or changed NRC position. Therefore, the addition of 
this condition is not a backfit.
    10. Add Sec.  50.55a(b)(2)(xlvi) to condition the provision of IWA-
4143 of the 2021 Edition of the ASME Code, Section XI, by prohibiting a 
contracted Repair/Replacement Organization from fabricating a part 
offsite of the Owner's facility (e.g., vendor facility) without an ASME 
Certificate of Authorization and without applying an ASME Stamp/
Certification Mark. The condition on IWA-4143 does not constitute a new 
or changed NRC position. Therefore, the addition of this condition is 
not a backfit.
    11. Add Sec.  50.55a(b)(2)(xlvii) to prevent a new exemption in the 
2021 Edition of subparagraph Q-3000(a) of the requirement to remove 
stress corrosion crack growth analysis of the overlay material. This is 
a new condition that retains the previous requirements and allowances 
of the previous approved version of Nonmandatory Appendix Q, and 
accordingly, is not a new or changed position. Therefore, the addition 
of this condition is not a backfit.
    12. Add Sec.  50.55a(b)(2)(xlviii) to require submission of 
analytical evaluations performed under IWB-3132.3 and IWC-3122.3 to the 
NRC. This is a new condition that retains the requirements of the 
previous approved version of Section XI, and accordingly, is not a new 
or changed position. Therefore, the addition of this condition is not a 
backfit.
    13. Add Sec.  50.55a(b)(2)(xlix) to prohibit the use of IWB-
3600(b)(1) in the 2021 Edition of the Code for the inlay and onlay that 
are subject to the augmented inspections specified in paragraph 
(g)(6)(ii)(F) of this section. The condition on the analytical 
evaluation of a flaw in the inlay or onlay does not constitute a new or 
changed NRC position. Therefore, the addition of this condition is not 
a backfit.
    14. Add Sec.  50.55a(b)(2)(l) to require licensees using 
Nonmandatory Appendix A, A-4200(c) and Nonmandatory Appendix G, G-
2110(c) to determine T0 and the associated RTT0 
according to the requirements of NB-2331, subparagraph (a)(5). This 
condition replaces the former condition Sec.  50.55a(b)(2)(xliii)(B) 
and (C), which required licensees to submit determination of 
T0 and RTT0 to the NRC for review and approval. 
Licensees retain the option of obtaining approval under paragraph (z) 
to implement alternative methods Therefore, the new condition is not a 
backfit.
    15. Add Sec.  50.55a(g)(6)(ii)(D)(9) to allow licensees the option 
to utilize Supplement 15 of Mandatory Appendix VIII in the 2021 Edition 
or later of Section XI, incorporated by reference in Sec.  50.55a, for 
volumetric qualification of examinations required by Table 1 of ASME 
Code Case N-729-6. Providing licensees the option of using either the 
qualification program in ASME Code Case N-729-6 or Supplement 15 of 
Mandatory Appendix VIII does not constitute a new or changed NRC 
position. Therefore, this addition is not a backfit.
    16. Modify Sec.  50.55a(a)(1)(iii)(D) and Sec.  50.55a(g)(6)(ii)(F) 
to update the

[[Page 70464]]

requirements for the augmented inspection of dissimilar-metal butt 
welds in U.S. PWRs from ASME Code Case N-770-5 to N-770-7. This change 
requires one condition to be updated, Sec.  50.55a(g)(6)(ii)(F)(1), and 
one condition modified to retain an inspection frequency for optimized 
butt welds consistent with ASME Code Case N-770-5. The current 
regulatory requirements for the examination frequency of Inspection 
Items C-2 and F-2 welds have not changed. The change in examination 
categorization for B-3 provides no change to inspection frequency or 
requirements. The change in scope expansion requirements is a reduction 
in the requirements if a flaw is identified in an AHA butt weld 
consistent with the regulatory purpose of examination scope expansion. 
Therefore, the update and modification of previous conditions are not 
backfits.

ASME OM Code

    1. Revise Sec.  50.55a(b)(3)(ii) by removing conditions (A), (B), 
and (C) where licensees are implementing the 2022 Edition of the ASME 
OM Code as incorporated by reference in Sec.  50.55a, because Appendix 
III to the 2022 Edition of the ASME OM Code appropriately incorporates 
the requirements specified in those conditions. The revisions do not 
modify the current IST regulatory requirements and, therefore, are not 
backfits.
    2. Delete condition (B) in Sec.  50.55a(b)(3)(iii), which states 
that licensees of new reactors must perform bi-directional testing of 
check valves within the IST program where practicable. The licensees of 
new reactors are required to apply more recent editions of the ASME OM 
Code that require bi-directional testing of check valves. Therefore, 
condition (B) is not needed in Sec.  50.55a(b)(3)(iii). This change 
does not modify the current IST regulatory requirements and, therefore, 
is not a backfit.
    3. Delete condition (C) in Sec.  50.55a(b)(3)(iii), which states 
that licensees of new reactors shall monitor flow-induced vibration 
from hydrodynamic loads and acoustic resonance during preservice 
testing or inservice testing to identify potential adverse flow effects 
on components within the scope of the IST program. Based on regulatory 
experience with new reactor licensing, the NRC considers that flow-
induced vibration is appropriately addressed during the licensing phase 
and initial testing program at each new reactor nuclear power plant. 
Therefore, condition (C) is not needed in Sec.  50.55a(b)(3)(iii). This 
change does not modify the current IST regulatory requirements and, 
therefore, is not a backfit.
    4. Create a new Sec.  50.55a(b)(3)(vii) to clarify use of ASME OM 
Code, Subsection ISTD, paragraph ISTD-4253, and Note 7 of the Table 
ISTD-4252-1, with the ASME OM Code Case OMN-15, Revision 2. This 
modification reflects a clarification of ASME OM Code, Subsection ISTD, 
paragraph ISTD-4253 and Table ISTD-4252-1, is not a new or changed NRC 
position, and therefore, is not a backfit.
    5. Create a new Sec.  50.55a(b)(3)(x) to clarify ASME OM Code, 
Appendix I, paragraph I-1320(c)(1), which states that for each valve 
tested for which the as-found set-pressure (first test actuation) 
exceeds the greater of either the plus/minus tolerance limit of the 
Owner-established design set-pressure acceptance criteria of paragraph 
I-1310(e) or 3 percent of valve nameplate set-pressure, two 
additional valves shall be tested from the same valve group. The 
expansion of the test sample provides reasonable assurance that a 
degradation mechanism that might cause multiple Class 1 Pressure Relief 
Valves to be incapable of performing their safety functions will be 
identified. However, the specific language of paragraph I-1320(c)(1) 
might be interpreted to not require an expansion of the test sample 
where the default 3-percent value is greater than the Owner-established 
set-pressure acceptance criteria. This modification reflects a 
clarification of ASME OM Code, Appendix I, paragraph I-1320(c)(1), is 
not a new or changed NRC position, and, therefore, is not a backfit.

ASME Editorial Correction

    1. Replace the colon at the end of the second sentence of the 
introductory paragraph of Sec.  50.55a(d) with a period. This is an 
editorial correction and, therefore, not a backfit.

Conclusion

    The NRC finds that incorporation by reference into Sec.  50.55a of 
the 2021 Edition of Section III, Division 1, of the ASME BPV Code 
subject to the identified conditions; the 2021 Edition of Section XI, 
Division 1, of the ASME BPV Code, subject to the identified conditions; 
and the 2022 Edition of the ASME OM Code subject to the identified 
conditions, does not constitute backfitting or represent an 
inconsistency with any issue finality provisions in 10 CFR part 52.

X. Plain Writing

    The Plain Writing Act of 2010 (Pub. L. 111-274) requires Federal 
agencies to write documents in a clear, concise, and well-organized 
manner. The NRC has written this document to be consistent with the 
Plain Writing Act as well as the Presidential Memorandum, ``Plain 
Language in Government Writing,'' published June 10, 1998 (63 FR 
31885).

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

    The NRC has determined under the National Environmental Policy Act 
of 1969, as amended, and the Commission's regulations in subpart A of 
10 CFR part 51, that this rule is not a major Federal action 
significantly affecting the quality of the human environment and, 
therefore, an environmental impact statement is not required.
    This final rule is in accordance with the NRC's policy to 
incorporate by reference in Sec.  50.55a new editions of the ASME BPV 
and OM Codes to provide updated rules for construction and inspecting 
components and testing pumps, valves, and dynamic restraints (snubbers) 
in light-water nuclear power plants. The ASME Codes are national 
voluntary consensus standards and are required by the NTTAA to be used 
by Government agencies unless the use of such a standard is 
inconsistent with applicable law or otherwise impractical. The rule 
does not significantly increase the probability or consequences of 
accidents, no changes are being made in the types of effluents that may 
be released offsite, and there is no significant increase in public 
radiation exposure. This rule does not involve non-radiological plant 
effluents and has no other environmental impact. Therefore, no 
significant non-radiological impacts are associated with this action.
    The determination of this environmental assessment is that there is 
no significant effect on the quality of the human environment from this 
action.

XII. 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 number 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

[[Page 70465]]

collection displays a currently valid OMB control number.

XIII. Congressional Review Act

    This final rule is a rule as defined in the Congressional Review 
Act (5 U.S.C. 801-808). However, the OMB has not found it to be a major 
rule as defined in the Congressional Review Act.

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 rule, the NRC is 
continuing to use the ASME BPV and OM Codes by incorporating by 
reference the 2021 Edition of the BPV Code and the 2022 Edition of the 
OM Code. The ASME Code editions 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 two recent editions to the 
ASME Codes for nuclear power plants: 2021 Edition of the American 
Society of Mechanical Engineers Boiler and Pressure Vessel Code and the 
2022 Edition of the American Society of Mechanical Engineers Operation 
and Maintenance of Nuclear Power Plants, Division 1, OM Code: Section 
IST, for nuclear power plants. As described in the ``Background'' and 
``Discussion'' sections of this document, these materials contain 
standards for the design, fabrication, and inspection of nuclear power 
plant components.
    The NRC is required by law to obtain approval for incorporation by 
reference from the Office of the Federal Register (OFR). The OFR's 
requirements for incorporation by reference are set forth in 1 CFR part 
51. On November7, 2014, the OFR adopted changes to its regulations 
governing incorporation by reference (79 FR 66267). The OFR regulations 
require an agency to discuss, in the preamble of the final rule, the 
ways that the materials it incorporates by reference are reasonably 
available to interested parties and how interested parties can obtain 
the materials. The discussion in this section complies with the 
requirement for final rules as set forth in Sec.  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 but vary with respect to the 
considerations for determining reasonable availability. Therefore, the 
NRC distinguishes between different classes of interested parties for 
the purposes of determining whether the material is ``reasonably 
available.'' The NRC considers the following to be classes of 
interested parties in NRC rulemakings with regard to the material to be 
incorporated by reference:
     Individuals and small entities regulated or otherwise 
subject to the NRC's regulatory oversight (this class also includes 
applicants and potential applicants for licenses and other NRC 
regulatory approvals) and who are subject to the material to be 
incorporated by reference by rulemaking. In this context, ``small 
entities'' has the same meaning as a ``small entity'' under Sec.  
2.810.
     Large entities otherwise subject to the NRC's regulatory 
oversight (this class also includes applicants and potential applicants 
for licenses and other NRC regulatory approvals) and who are subject to 
the material to be incorporated by reference by rulemaking. In this 
context, ``large entities'' are those that do not qualify as a ``small 
entity'' under Sec.  2.810.
     Non-governmental organizations with institutional 
interests in the matters regulated by the NRC.
     Other Federal agencies, States, local governmental bodies 
(within the meaning of Sec.  2.315(c)).
     Federally recognized and State-recognized \3\ Indian 
Tribes.
---------------------------------------------------------------------------

    \3\ State-recognized Indian Tribes are not within the scope of 
Sec.  2.315(c). However, for purposes of the NRC's compliance with 1 
CFR 51.5, the term ``interested parties'' includes a broad set of 
stakeholders, including State-recognized Indian Tribes.
---------------------------------------------------------------------------

     Members of the public (i.e., individual, unaffiliated 
members of the public who are not regulated or otherwise subject to the 
NRC's regulatory oversight) who may wish to gain access to the 
materials that the NRC is incorporate by reference by rulemaking in 
order to participate in the rulemaking process.
    The 2021 Edition of the ASME BPV Code and the 2022 Edition of the 
ASME OM Code may be viewed, by appointment, at the Technical Library, 
which is located at Two White Flint, 11545 Rockville Pike, Rockville, 
Maryland 20852. You may submit your request to the Technical Library 
via email at [email protected] between 8 a.m. and 4 p.m. eastern 
time, Monday through Friday, except Federal holidays. In addition, as 
described in Section XVII of this document, documents related to this 
final rule are available online in the NRC's ADAMS Public Documents 
collection at https://www.nrc.gov/reading-rm/adams.html.
    Interested parties may purchase a copy of the ASME materials from 
ASME at Three Park Avenue, New York, NY 10016, or at the ASME website 
https://www.asme.org/shop/standards. The materials are also accessible 
through third-party subscription services such as Accuris IHS (15 
Inverness Way East, Englewood, CO 80112; https://store.accuristech.com 
(formerly https://global.ihs.com)) and Thomson Reuters Techstreet (3916 
Ranchero Dr., Ann Arbor, MI 48108; https://store.accuristech.com 
(formerly https://www.techstreet.com)). The purchase prices for 
individual documents range from $325 to $720, and the cost to purchase 
all documents is approximately $9,000.
    For the class of interested parties constituting members of the 
public who wish to gain access to the materials to be incorporated by 
reference in order to participate in the rulemaking, the NRC recognizes 
that the $9,000 cost may be so high that the materials could be 
regarded as not reasonably available for purposes of commenting on this 
rulemaking, despite the NRC's actions to make the materials available 
at the NRC's PDR. Accordingly, the NRC requested that ASME consider 
enhancing public access to these materials during the public comment 
period. On March 2, 2023, the ASME agreed to make the materials 
available online in a read-only electronic access format during the 
public comment period (ML23068A033).
    During the public comment period, the ASME made publicly available 
the two editions of the ASME Codes for nuclear power plants that the 
NRC proposed to incorporate by reference. These materials were 
available publicly in a read-only format at the ASME website, https://go.asme.org/NRC-ASME.
    The materials are available to all interested parties in multiple 
ways and in a manner consistent with their interest in this final rule. 
Therefore, the NRC concludes that the materials the NRC is 
incorporating by reference in this final rule are reasonably available 
to all interested parties.

XVI. Availability of Guidance

    The NRC will not be issuing guidance for this final rule. The ASME 
BPV Code and OM Code provide direction for the

[[Page 70466]]

performance of activities to satisfy the Code requirements for design, 
inservice inspection, and inservice testing of nuclear power plant 
structures, systems, and components. In addition, the NRC provides 
guidance in this document for the implementation of the new conditions 
on the ASME BPV Code and OM Code, as necessary. The NRC has a number of 
SRPs that provide guidance to NRC reviewers and make communication and 
understanding of NRC review processes available to members of the 
public and the nuclear power industry. NUREG-0800, ``Review of Safety 
Analysis Reports for Nuclear Power Plants,'' has numerous sections 
which discuss implementation of various aspects of the ASME BPV Code 
and OM Code (e.g., Sections 3.2.2, 3.8.1, 3.8.2, 3.9.3, 3.9.6, 3.9.7, 
3.9.8, 3.13, 5.2.1.1, 5.2.1.2, 5.2.4, and 6.6). The NRC also publishes 
regulatory guides and generic communications (i.e., regulatory issue 
summaries and information notices) to communicate and clarify NRC 
technical or policy positions on regulatory matters which may contain 
guidance relative to this final rule.
    Revision 3 of NUREG-1482, ``Guidelines for Inservice Testing at 
Nuclear Power Plants,'' provides guidance for the development and 
implementation of IST programs at nuclear power plants (ML20202A473). 
With direction provided in the ASME BPV and OM Codes, and guidance in 
this document, the NRC has determined that preparation of a separate 
guidance document is not necessary for this update to Sec.  50.55a. 
However, the NRC will consider preparing a revision to NUREG-1482 in 
the future to address the latest edition of the ASME OM Code 
incorporated by reference in Sec.  50.55a.

XVII. Availability of Documents

    The documents identified in the following table are available to 
interested persons through one or more of the following methods, as 
indicated.

                                            Availability of Documents
----------------------------------------------------------------------------------------------------------------
                    Document                         ADAMS Accession No./web link/ Federal Register citation
----------------------------------------------------------------------------------------------------------------
                                              Final Rule Documents
----------------------------------------------------------------------------------------------------------------
Final Rule--Regulatory Analysis ASME 2021-2022   ML24053A051.
 Code Editions Update, July 2024.
Final Rule--Public Comment Response Document     ML24053A058.
 ASME 2021-2022 Code Editions Update, July 2024.
Annotated Comment Submissions for the ASME 2021- ML24053A089.
 2022 Code Editions Update, July 2024.
----------------------------------------------------------------------------------------------------------------
                                             Proposed Rule Documents
----------------------------------------------------------------------------------------------------------------
Proposed Rule--Federal Register Notice for       88 FR 53384.
 American Society of Mechanical Engineers 2021-
 2022 Code Editions, August 2023.
Proposed Rule--Regulatory Analysis for American  ML23032A316.
 Society of Mechanical Engineers 2021-2022 Code
 Editions Update, July 2023.
Proposed Rule--Unofficial Redline Strikeout of   ML23032A318.
 the NRC's Proposed Rule: Proposed Rule to
 Incorporate by Reference American Society of
 Mechanical Engineers Codes, July 2023.
Proposed Rule--Summary of the Public Meeting on  ML23265A245.
 the ASME 2021-2022 Code Editions Rulemaking,
 September 6, 2023.
----------------------------------------------------------------------------------------------------------------
                                                Related Documents
----------------------------------------------------------------------------------------------------------------
Regulatory Guide (RG), RG 1.28, Revision 6,      ML23177A002.
 ``Quality Assurance Program Criteria (Design
 and Construction),'' September 2023.
Rulemaking: Proposed Rule: Email from Kathryn    ML23068A033.
 Hyam (ASME) to Louise Lund (NRC), Request for
 Limited Public Access of Code for Public
 Comment Period, March 2, 2023.
Staff Requirements--Affirmation Session, 11:30   ML003755050.
 a.m., Friday, September 10, 1999,
 Commissioners' Conference Room, One White
 Flint North, Rockville, Maryland (Open to
 Public Attendance).
Regulatory Guide 1.147, Revision 20,             ML21181A222.
 ``Inservice Inspection Code Case
 Acceptability, ASME Section XI, Division 1,''
 December 2021.
NUREG-1482, Revision 3, ``Guidelines for         ML20202A473.
 Inservice Testing at Nuclear Power Plants,''
 July 2020.
NUREG-1800, Revision 2, ``Standard Review Plan   ML103490036.
 for Review of License Renewal Applications for
 Nuclear Power Plants,'' December 2010.
NUREG-1801, Revision 2, ``Generic Aging Lessons  ML103490041.
 Learned (GALL) Report,'' December 2010.
NUREG-1950, ``Disposition of Public Comments     ML11116A062.
 and Technical Bases for Changes in the License
 Renewal Guidance Documents NUREG-1801 and
 NUREG-1800,'' April 2011.
NUREG-2191, Volumes 1 and 2, ``Generic Aging     ML17187A031
 Lessons Learned for Subsequent License Renewal  ML17187A204.
 (GALL-SLR) Report,'' July 2017.
NUREG-2192, ``Standard Review Plan for Review    ML17188A158.
 of Subsequent License Renewal Applications for
 Nuclear Power Plants,'' July 2017.
Final Rule--American Society of Mechanical       87 FR 65128.
 Engineers 2019-2020 Code Editions, October 27,
 2022.
Final Rule--American Society of Mechanical       76 FR 36232.
 Engineers (ASME) Codes and New and Revised
 ASME Code Cases, June 21, 2011.
Final Rule--Incorporation by Reference,          79 FR 66267.
 November 7, 2014.
Final Safety Evaluation Enclosure for NEI 14-    ML20322A019.
 05A, Revision 1, November 23, 2020.
Nuclear Energy Institute (NEI) 14-05A,           ML20135H229.
 ``Guidelines for the Use of Accreditation in
 Lieu of Commercial Grade Surveys for
 Procurement of Laboratory Calibration and Test
 Services,'' Revision 1, May 2020.
Final Guide--Regulatory Guide: Quality           88 FR 62292.
 Assurance Program Criteria (Design and
 Construction), September 11, 2023.
----------------------------------------------------------------------------------------------------------------
                                      ASME Codes, Standards, and Code Cases
----------------------------------------------------------------------------------------------------------------
American Society of Mechanical Engineers.......  https://www.asme.org/shop/standards.
Accuris IHS (formerly IHS).....................  https://store.accuristech.com.

[[Page 70467]]

 
Thomson Reuters Techstreet.....................  https://store.accuristech.com.
----------------------------------------------------------------------------------------------------------------

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. In Sec.  50.55a:
0
a. In paragraph (a)(1)(i)(E)(19), remove the word ``and'';
0
b. Revise paragraph (a)(1)(i)(E)(20);
0
c. Add paragraph (a)(1)(i)(E)(21);
0
d. In paragraph (a)(1)(ii)(C)(55), remove the word ``and'';
0
e. Revise paragraph (a)(1)(ii)(C)(56);
0
f. Add paragraph (a)(1)(ii)(C)(57);
0
g. Revise paragraphs (a)(1)(iii)(D), (a)(1)(iv)(C), (b)(1)(iv) and 
(vi), (b)(1)(xi) introductory text, (b)(1)(xi)(B), and (b)(1)(xiii);
0
h. Add paragraph (b)(1)(xiv);
0
i. Revise paragraphs (b)(2) introductory text and (b)(2)(viii) and 
(ix);
0
j. Remove and reserve paragraph (b)(2)(xv);
0
k. Revise paragraphs (b)(2)(xxxiv), (xxxvi), and (xliii);
0
l. Add paragraphs (b)(2)(xliv) through (l);
0
m. Revise paragraph (b)(3)(ii) introductory text;
0
n. Remove and reserve paragraphs (b)(3)(iii)(B) and (C);
0
o. Add paragraphs (b)(3)(vii) and (x);
0
p. At the end of paragraph (d) introductory text, remove the colon and 
add in its place a period;
0
q. In paragraph (g)(4)(ii), remove the date ``June 3, 2020'' wherever 
it appears and add its place ``September 30, 2024'';
0
r. Add paragraph (g)(6)(ii)(D)(9); and
0
s. Revise paragraphs (g)(6)(ii)(F)(1) and (8).
    The revisions and additions read as follows:


Sec.  50.55a  Codes and standards.

    (a) * * *
    (1) * * *
    (i) * * *
    (E) * * *
    (20) 2019 Edition (including Subsection NCA; and Division 1 
subsections NB through NG and Appendices); and
    (21) 2021 Edition (including Subsection NCA; and Division 1 
subsections NB through NG and Appendices).
    (ii) * * *
    (C) * * *
    (56) 2019 Edition; and
    (57) 2021 Edition.
    (iii) * * *
    (D) ASME BPV Code Case N-770-7. ASME BPV Code Case N-770-7, 
``Alternative Examination Requirements and Acceptance Standards for 
Class 1 PWR Piping and Vessel Nozzle Butt Welds Fabricated with UNS 
N06082 or UNS W86182 Weld Filler Material With or Without Application 
of Listed Mitigation Activities Section XI, Division 1'' (Approval 
Date: December 4, 2020), with the conditions in paragraph (g)(6)(ii)(F) 
of this section.
* * * * *
    (iv) * * *
    (C) Operation and Maintenance of Nuclear Power Plants, ``Division 
1: OM Code: Section IST'':
    (1) 2012 Edition;
    (2) 2017 Edition;
    (3) 2020 Edition; and
    (4) 2022 Edition.
* * * * *
    (b) * * *
    (1) * * *
    (iv) Section III condition: Quality Assurance. When applying 
editions and addenda later than the 1989 Edition of Section III, an 
applicant or licensee may use the requirements of NQA-1, ``Quality 
Assurance Requirements for Nuclear Facility Applications,'' that is 
both incorporated by reference in paragraph (a)(1)(v) of this section 
and specified in either NCA-4000 or NCA-7000 of that Edition and 
Addenda of Section III, with the exceptions in paragraph (b)(1)(iv)(A) 
of this section, provided that the administrative, quality, and 
technical provisions contained in that Edition and Addenda of Section 
III are used in conjunction with the applicant's or licensee's appendix 
B to this part quality assurance program; and that the applicant's or 
licensee's Section III activities comply with those commitments 
contained in the applicant's or licensee's quality assurance program 
description. Where NQA-1 and Section III do not address the commitments 
contained in the applicant's or licensee's appendix B quality assurance 
program description, those licensee commitments must be applied to 
Section III activities.
    (A) Subpart 2.19 in NQA-1-2017, NQA-1-2019, and NQA-1-2022 is not 
approved for use.
    (B) [Reserved]
* * * * *
    (vi) Section III condition: Subsection NH. The provisions in 
Subsection NH, ``Class 1 Components in Elevated Temperature Service,'' 
1995 Addenda through all editions and addenda up to and including the 
2013 Edition incorporated by reference in paragraph (a)(1) of this 
section, may only be used for the design and construction of Type 316 
stainless steel pressurizer heater sheaths where service conditions do 
not cause the components to reach temperatures exceeding 900 [deg]F. 
This condition is not applicable to the 2015 Edition and later 
editions.
* * * * *
    (xi) Section III condition: Mandatory Appendix XXVI. When applying 
the 2015 and 2017 Editions of Section III, Mandatory Appendix XXVI, 
``Rules for Construction of Class 3 Buried Polyethylene Pressure 
Piping,'' applicants or licensees must meet the first provision in 
paragraph (b)(1)(xi)(A)

[[Page 70468]]

of this section. When applying the 2015 through 2021 Editions of 
Section III, Mandatory Appendix XXVI, ``Rules for Construction of Class 
3 Buried Polyethylene Pressure Piping,'' applicants or licensees must 
meet the second provision in paragraph (b)(1)(xi)(B) of this section. 
When applying the 2017 Edition of Section III, Mandatory Appendix XXVI, 
``Rules for Construction of Class 3 Buried Polyethylene Pressure 
Piping,'' applicants or licensees must meet the third provision in 
paragraph (b)(1)(xi)(C) of this section.
* * * * *
    (B) Mandatory Appendix XXVI: Second provision. When performing 
procedure qualification for high speed tensile impact testing of butt 
fusion joints in accordance with XXVI-2300 or XXVI-4330 of the 2015 
through 2021 Editions of BPV Code Section III, breaks in the specimen 
that are away from the fusion zone require the test plot yield strength 
to be evaluated to confirm sound base material. If the base material 
failed (broke) at less than minimum required base material yield 
strength, a retest is required.
* * * * *
    (xiii) Section III condition: Preservice Inspection of Steam 
Generator Tubes. Applicants or licensees applying the provisions of NB-
5283 and NB-5360 in the 2019 Edition of Section III through the latest 
edition and addenda incorporated by reference in paragraph (a)(1)(i) of 
this section, must apply paragraphs (b)(1)(xiii)(A) and (B) of this 
section.
    (A) Preservice Inspection of Steam Generator Tubes: First 
provision. When applying the provisions of NB-5283 in the 2019 Edition 
of Section III through the latest edition and addenda incorporated by 
reference in paragraph (a)(1)(i) of this section, a full-length 
preservice examination of 100 percent of the steam generator tubing in 
each newly installed steam generator must be performed prior to plant 
startup.
    (B) Preservice Inspection of Steam Generator Tubes: Second 
provision. When applying the provisions of NB-5360 in the 2019 Edition 
of Section III through the latest edition and addenda incorporated by 
reference in paragraph (a)(1)(i) of this section, flaws revealed during 
preservice examination of steam generator tubing performed in 
accordance with paragraph (b)(1)(xiii)(A) of this section must be 
evaluated using the criteria in the design specifications.
    (xiv) Section III condition: Repairs to Stamped Components. 
Applicants or licensees applying the provisions of NCA-8151, NCA-8500 
and Nonmandatory Appendix NN in the 2021 Edition of Section III, are 
required to meet all of the requirements in Nonmandatory Appendix NN.
    (2) Conditions on ASME BPV Code, Section XI. As used in this 
section, references to Section XI refer to Section XI, Division 1, in 
the editions and addenda of the ASME BPV Code incorporated by reference 
in paragraph (a)(1)(ii) of this section, subject to the following 
conditions:
* * * * *
    (viii) Section XI condition: Concrete containment examinations. 
Applicants or licensees applying Subsection IWL, 2001 Edition through 
the 2004 Edition, up to and including the 2006 Addenda, must apply 
paragraphs (b)(2)(viii)(E) through (G) of this section. Applicants or 
licensees applying Subsection IWL, 2007 Edition up to and including the 
2008 Addenda must apply paragraph (b)(2)(viii)(E) of this section. 
Applicants or licensees applying Subsection IWL, 2007 Edition with the 
2009 Addenda through the 2019 Edition, must apply paragraphs 
(b)(2)(viii)(H) and (I) of this section.
    (ix) Section XI condition: Metal containment examinations. 
Applicants or licensees applying Subsection IWE, 2001 Edition up to and 
including the 2003 Addenda, must satisfy the requirements of paragraphs 
(b)(2)(ix)(A) and (B), (F) through (I), and (K) of this section. 
Applicants or licensees applying Subsection IWE, 2004 Edition, up to 
and including the 2005 Addenda, must satisfy the requirements of 
paragraphs (b)(2)(ix)(A) and (B), (F) through (H), and (K) of this 
section. Applicants or licensees applying Subsection IWE, 2004 Edition 
with the 2006 Addenda, must satisfy the requirements of paragraphs 
(b)(2)(ix)(A)(2) and (b)(2)(ix)(B) and (K) of this section. Applicants 
or licensees applying Subsection IWE, 2007 Edition through the 2015 
Edition, must satisfy the requirements of paragraphs (b)(2)(ix)(A)(2) 
and (b)(2)(ix)(B), (J), and (K) of this section. Applicants or 
licensees applying Subsection IWE, 2017 Edition, through the 2019 
Edition, must satisfy the requirements of paragraphs (b)(2)(ix)(A)(2) 
and (b)(2)(ix)(B) and (J) of this section. Applicants or licensees 
applying Subsection IWE, 2021 Edition, through the latest edition and 
addenda incorporated by reference in paragraph (a)(1)(ii) of this 
section must satisfy the requirements of paragraphs (b)(2)(ix)(B) and 
(J) of this section.
* * * * *
    (xxxiv) Section XI condition: Nonmandatory Appendix U. (A) When 
using Nonmandatory Appendix U of the ASME BPV Code, Section XI, 2013 
Edition through the 2019 Edition, the following conditions apply:
    (1) The repair or replacement activities temporarily deferred under 
the provisions of Nonmandatory Appendix U must be performed during the 
next scheduled refueling outage.
    (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 NRC Regulatory Guide 1.147 at the time the 
case was incorporated into the licensee's program.
    (B) Use of Nonmandatory Appendix U, Supplement U-S1 of the ASME BPV 
Code, Section XI, 2021 Edition is prohibited.
* * * * *
    (xxxvi) Section XI condition: Fracture toughness of irradiated 
materials. When using the 2013 Edition through the latest edition 
incorporated by reference in paragraph (a)(1)(ii) of this section of 
the ASME BPV Code, Section XI, Appendix A paragraph A-4400, the 
licensee shall determine irradiated T0 and the associated 
RTT0 as specified in the 2021 Edition of ASME BPV Code, 
Section III, NB-2331, subparagraph (a)(5).
* * * * *
    (xliii) Section XI condition: Regulatory Submittal Requirements. 
Licenses shall submit to the NRC the analytical evaluation determining 
the effects of an out-of-limit condition on the structural integrity of 
the Reactor Coolant System, as described in IWB-3720(a).
    (xliv) Section XI condition: Nonmandatory Appendix Y. When using 
Nonmandatory Appendix Y of the ASME BPV Code, Section XI, 2021 Edition, 
the following conditions apply:
    (A) Use of Nonmandatory Appendix Y, Article Y-2200 is prohibited.
    (B) Use of Nonmandatory Appendix Y, Subarticle Y-2440 is 
prohibited.
    (C) Use of Nonmandatory Appendix Y, Article Y-3200 is prohibited.
    (xlv) Section XI condition: Pressure Testing of Containment 
Penetration Piping After Repair/Replacement Activities. Applicants or 
licensees applying the provision of IWA-4540(a) and (e) of the 2021 
Edition of the ASME Code, Section XI, are required to perform a VT-2 
examination of the area affected by the repair/replacement activity 
during the Type C test in appendix J to this part.
    (xlvi) Section XI condition: Contracted Repair/Replacement

[[Page 70469]]

Organization Fabricating Items Offsite of the Owner's Facility. When 
applicants or licensees apply the provision of IWA-4143 in the 2021 
Edition of Section XI of the ASME Code, a contracted Repair/Replacement 
Organization fabricating ASME Code, Section III parts, appurtenances, 
piping subassemblies, and supports offsite of the Owner's facility 
(e.g., vendor facility) without an ASME Certificate of Authorization 
and without applying an ASME Stamp/Certification Mark is prohibited.
    (xlvii) Section XI condition: Weld Overlay Design Crack Growth 
Analysis. Under Subparagraph Q-3000(a) stress corrosion crack growth 
analysis is required within the weld overlay material.
    (xlviii) Section XI condition: Analytical Evaluations of 
Degradation. Applicants or licensees using the 2021 Edition of Section 
XI must submit analytical evaluations performed as required by IWB-
3132.3 and IWC-3132.3 to the Nuclear Regulatory Commission.
    (xlix) Section XI condition: Analytical Evaluations of Flaws in 
Cladding. The use of IWB-3600(b)(1) in the 2021 Edition of ASME BPV 
Code, Section XI (Division 1) is prohibited for the inlay and onlay 
that are subject to the augmented inspection requirements in paragraph 
(g)(6)(ii)(F) of this section.
    (l) Section XI condition: Determination of the Master Curve 
T0. When using the 2017 Edition of Section XI through the 
latest Edition incorporated by reference in this section and 
implementing Nonmandatory Appendix A, A-4200(c) and Nonmandatory 
Appendix G, G-2110(c), the licensee shall determine T0 and 
the associated RTT0 as specified in the 2021 Edition of ASME 
BPV Code, Section III, NB-2331, subparagraph (a)(5).
    (3) * * *
    (ii) OM condition: Motor-Operated Valve (MOV) testing. Licensees 
must comply with the provisions for testing MOVs in ASME OM Code, ISTC 
4.2, 1995 Edition with the 1996 and 1997 Addenda, or ISTC-3500, 1998 
Edition through the latest edition and addenda incorporated by 
reference in paragraph (a)(1)(iv) of this section, and must establish a 
program to ensure that MOVs continue to be capable of performing their 
design basis safety functions. Licensees implementing ASME OM Code, 
Mandatory Appendix III, ``Preservice and Inservice Testing of Active 
Electric Motor-Operated Valve Assemblies in Water-Cooled Reactor 
Nuclear Power Plants,'' of the 2009 Edition, through the latest edition 
and addenda of the ASME OM Code incorporated by reference in paragraph 
(a)(1)(iv) of this section shall comply with the following conditions 
(with the exception of conditions in paragraphs (b)(3)(ii)(A) through 
(C) of this section when implementing the 2022 Edition of the ASME OM 
Code):
* * * * *
    (vii) OM condition: Snubber visual examination interval extension. 
When implementing Subsection ISTD, paragraph ISTD-4253, and Note 7 of 
Table ISTD-4252-1, in the 2022 Edition of the ASME OM Code, 
incorporated by reference in paragraph (a)(1)(iv) of this section, to 
extend snubber visual examination beyond 2 refueling cycles (48 
months), the licensee is prohibited from applying OM Code Case OMN-15, 
Revision 2, to extend the operational readiness testing interval of 
snubbers.
* * * * *
    (x) OM condition: Class 1 Pressure Relief Valve Sample Expansion. 
When implementing paragraph I-1320(c)(1) in Appendix I, ``Inservice 
Testing of Pressure Relief Devices in Water-Cooled Reactor Nuclear 
Power Plants,'' of the editions and addenda of the ASME OM Code, 
incorporated by reference in paragraph (a)(1)(iv) of this section, the 
requirement for sample expansion of Class 1 Pressure Relief Valves 
shall be implemented such that for each valve tested for which the as-
found set-pressure (first test actuation) exceeds the plus/minus 
tolerance limit of the Owner-established design set-pressure acceptance 
criteria of paragraph I-1310(e), two additional valves shall be tested 
from the same group. If the Owner has not established design set-
pressure acceptance criteria, then for each valve tested for which the 
as-found set-pressure (first actuation) exceeds 3 percent 
of valve nameplate set-pressure, two additional valves shall be tested 
from the same valve group.
* * * * *
    (g) * * *
    (6) * * *
    (ii) * * *
    (D) * * *
    (9) Volumetric Qualifications. Volumetric examinations of Table 1 
of ASME Code Case N-729-6 may be qualified in accordance with Section 
XI, Division 1, Mandatory Appendix VIII, Supplement 15, in the 2021 
Edition, in lieu of subparagraphs (a) through (j) of 2500 of ASME Code 
Case N-729-6.
* * * * *
    (F) * * *
    (1) Implementation. Holders of operating licenses or combined 
licenses for pressurized water reactors as of or after September 30, 
2024, shall implement the requirements of ASME BPV Code Case N-770-7 
instead of ASME BPV Code Case N-770-5, subject to the conditions 
specified in paragraphs (g)(6)(ii)(F)(2) through (16) of this section, 
by no later than one year after September 30, 2024. All NRC authorized 
alternatives from previous versions of paragraph (g)(6)(ii)(F) of this 
section remain applicable.
* * * * *
    (8) Optimized weld overlay examination. Following initial inservice 
volumetric inspection for Inspection Items C-2 and F-2 of Table 1 of 
ASME Code Case N-770-7, for weld overlay examination volumes that show 
no indication of crack growth or new cracking, in lieu of sample 
population, 100 percent of these optimized weld overlayed welds shall 
be added to the ISI program in accordance with -2410 of ASME Code Case 
N-770-7 and shall be examined once each inspection interval.
* * * * *

    Dated: August 7, 2024.

    For the Nuclear Regulatory Commission.
Andrea Veil,
Director, Office of Nuclear Reactor Regulation.
[FR Doc. 2024-19235 Filed 8-29-24; 8:45 am]
BILLING CODE 7590-01-P