[Federal Register Volume 88, Number 43 (Monday, March 6, 2023)]
[Proposed Rules]
[Pages 13717-13735]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-03742]


 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
 
 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
 ========================================================================
 

  Federal Register / Vol. 88 , No. 43 / Monday, March 6, 2023 / 
Proposed Rules  

[[Page 13717]]



NUCLEAR REGULATORY COMMISSION

10 CFR Part 50

[NRC-2018-0291]
RIN 3150-AK23


American Society of Mechanical Engineers Code Cases and Update 
Frequency

AGENCY: Nuclear Regulatory Commission.

ACTION: Proposed rule.

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

SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is proposing to 
amend its regulations to incorporate by reference proposed revisions of 
three regulatory guides, which would approve new, revised, and 
reaffirmed code cases published by the American Society of Mechanical 
Engineers. This proposed action would allow nuclear power plant 
licensees and applicants for construction permits, operating licenses, 
combined licenses, standard design certifications, standard design 
approvals, and manufacturing licenses to use the code cases listed in 
these draft regulatory guides as voluntary alternatives to engineering 
standards for the construction, inservice inspection, and inservice 
testing of nuclear power plant components. The NRC is requesting 
comments on this proposed rule and on the draft versions of the three 
regulatory guides proposed to be incorporated by reference. The NRC 
also is making available a related draft regulatory guide that lists 
code cases that the NRC has not approved for use. This draft regulatory 
guide will not be incorporated by reference into the NRC's regulations. 
In addition, this rulemaking proposes to extend the time periods 
required for licensees to update their codes of record.

DATES: Submit comments by May 5, 2023. Comments received after this 
date will be considered if it is practical to do so, but the NRC is 
able to ensure consideration only for comments received before this 
date.

ADDRESSES: You may submit comments by any of the following methods 
(unless this document describes a different method for submitting 
comments on a specific subject); however, the NRC encourages electronic 
comment submission through the Federal rulemaking website:
     Federal rulemaking website: Go to https://www.regulations.gov and search for Docket ID NRC-2018-0291. Address 
questions about NRC dockets to Dawn Forder; telephone: 301-415-3407; 
email: [email protected]. For technical questions contact the 
individuals listed in the FOR FURTHER INFORMATION CONTACT section of 
this document.
     Email comments to: [email protected]. If you do 
not receive an automatic email reply confirming receipt, then contact 
us at 301-415-1677.
     Mail comments to: Secretary, U.S. Nuclear Regulatory 
Commission, Washington, DC 20555-0001, ATTN: Rulemakings and 
Adjudications Staff.
    For additional direction on obtaining information and submitting 
comments, see ``Obtaining Information and Submitting Comments'' in the 
SUPPLEMENTARY INFORMATION section of this document.

FOR FURTHER INFORMATION CONTACT: Dennis Andrukat, Office of Nuclear 
Material and Safeguards, telephone: 301-415-3561, email: 
[email protected] and Bruce Lin, Office of Nuclear Regulatory 
Research, telephone: 301-415-2446, 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

    This regulatory action proposes to incorporate by reference into 
the NRC's regulations the latest revisions of three regulatory guides 
(RGs) (currently in draft form for comment). The three draft RGs 
identify new, revised, and reaffirmed code cases published by the 
American Society of Mechanical Engineers (ASME) that the NRC has 
determined are acceptable for use as voluntary alternatives to 
compliance with certain provisions of the ASME Boiler and Pressure 
Vessel Code (BPV Code) and the ASME Operation and Maintenance (OM) of 
Nuclear Power Plants, Division 1, OM Code: Section IST (OM Code) 
currently incorporated by reference into the NRC's regulations.
    This regulatory action also proposes to revise the current NRC 
requirement for nuclear power plant licensees to update the codes of 
record for their inservice testing (IST) and inservice inspection (ISI) 
programs every 10 years, for licensees that are implementing the 2020 
Edition, or later editions, of the ASME OM Code and the 2019 Edition, 
or later editions, of the ASME BPV Code, Section XI, as incorporated by 
reference in Sec.  50.55a, ``Codes and standards,'' of title 10 of the 
Code of Federal Regulations (10 CFR). This proposed revision to the 
NRC's regulations follows Commission direction in staff requirements 
memorandum (SRM) SRM-SECY-21-0029 (dated November 8, 2021) in response 
to SECY-21-0029, ``Rulemaking Plan on Revision of Inservice Testing and 
Inservice Inspection Program Update Frequencies Required in 10 CFR 
50.55a,'' dated March 15, 2021. This rule proposes additional changes 
to Sec.  50.55a to promote clarity and consistency, including adding 
definitions of important terms and revising the reference to the 10-
year service period in 10 CFR part 50, appendix J, ``Primary Reactor 
Containment Leakage Testing for Water-Cooled Power Reactors.'' This 
rulemaking does not address all aspects of SRM-SECY-21-0029. 
Specifically, the NRC staff will consider options for streamlining ASME 
Code Case rulemakings in the future.

B. Major Provisions

    The NRC proposes to incorporate by reference into the NRC's 
regulations the following regulatory guides: RG 1.84, ``Design, 
Fabrication, and Materials Code Case Acceptability, ASME Section III,'' 
Revision 40 (Draft Regulatory Guide (DG)-1405); RG 1.147, ``Inservice 
Inspection Code Case Acceptability, ASME Section XI, Division 1,'' 
Revision 21 (DG-1406); and RG 1.192, ``Operation and Maintenance [OM] 
Code Case Acceptability, ASME OM Code,'' Revision 5 (DG-1407). This 
proposed action would allow nuclear power plant licensees and 
applicants for construction permits, operating licenses, combined 
licenses, standard design

[[Page 13718]]

certifications, standard design approvals, and manufacturing licenses 
to use the code cases newly listed in these revised RGs as voluntary 
alternatives to ASME engineering standards for the construction, 
inservice inspections, and inservice testing of nuclear power plant 
components. The NRC also notes the availability of a proposed version 
of RG 1.193, ``ASME Code Cases Not Approved for Use,'' Revision 8 (DG-
1408). This document lists code cases that the NRC has not approved for 
generic use and would not be incorporated by reference into the NRC's 
regulations.
    The NRC prepared a draft regulatory analysis to determine the 
expected quantitative costs and benefits of this proposed rule, as well 
as qualitative factors to be considered in the NRC's rulemaking 
decision. The analysis concluded that this proposed rule would result 
in net savings to the industry and the NRC. As shown in Table 1, the 
estimated total net benefit relative to the regulatory baseline and the 
quantitative benefits would outweigh the costs by a range from 
approximately $34.3 million (7-percent net present value) to $40.5 
million (3-percent net present value).

                                          Table 1--Cost Benefit Summary
----------------------------------------------------------------------------------------------------------------
                                                                      Total averted costs (costs)
                                                     -----------------------------------------------------------
                      Attribute                                             7% Net present      3% Net present
                                                         Undiscounted            value               value
----------------------------------------------------------------------------------------------------------------
Industry Implementation.............................                  $0                  $0                  $0
Industry Operation..................................          36,710,000          29,890,000          35,110,000
                                                     -----------------------------------------------------------
    Total Industry Costs............................          36,710,000          29,890,000          35,110,000
NRC Implementation..................................           (510,000)           (430,000)           (480,000)
NRC Operation.......................................           6,380,000           4,860,000           5,860,000
                                                     -----------------------------------------------------------
    Total NRC Costs.................................           5,870,000           4,430,000           5,380,000
        Net.........................................          42,580,000          34,320,000          40,490,000
----------------------------------------------------------------------------------------------------------------

    The draft regulatory analysis also considered the following 
qualitative considerations: (1) flexibility and decreased uncertainty 
for licensees when making modifications or preparing to perform 
inservice inspection or inservice testing; (while continuing to ensure 
safety; (2) consistency with the provisions of the National Technology 
Transfer and Advancement Act of 1995, which encourages Federal 
regulatory agencies to consider adopting voluntary consensus standards 
as an alternative to de novo agency development of standards affecting 
an industry; (3) consistency with the NRC's policy of evaluating the 
latest versions of consensus standards in terms of their suitability 
for endorsement by regulations and regulatory guides; and (4) 
consistency with the NRC's goal to harmonize with international 
standards to improve regulatory efficiency for both the NRC and 
international standards groups.
    The draft regulatory analysis concludes that this proposed rule 
should be adopted because it is justified when integrating the cost-
beneficial quantitative results and the positive and supporting 
nonquantitative considerations in the decision. For more information, 
please see the draft regulatory analysis as indicated in Section XVI, 
Availability of Documents, of this document.

Table of Contents

I. Obtaining Information and Submitting Comments
    A. Obtaining Information
    B. Submitting Comments
II. Background
III. Discussion
    A. Proposed Incorporation by Reference of Three Regulatory 
Guides
    B. Code Cases Proposed To Be Approved for Unconditional Use
    C. Code Cases Approved for Use With Conditions
    D. ASME Code Cases Not Approved for Use (DG-1408/RG 1.193)
    E. Proposed Revision to Code of Record Update Requirements
IV. Specific Requests for Comments
V. Section-by-Section Analysis
VI. Regulatory Flexibility Certification
VII. Regulatory Analysis
VIII. Backfitting and Issue Finality
IX. Plain Writing
X. Environmental Assessment and Proposed Finding of No Significant 
Environmental Impact
XI. Paperwork Reduction Act Statement
XII. Voluntary Consensus Standards
XIII. Incorporation by Reference
XIV. Availability of Guidance
XV. Public Meeting
XVI. Availability of Documents

I. Obtaining Information and Submitting Comments

A. Obtaining Information

    Please refer to Docket ID NRC-2018-0291 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-2018-0291.
     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, 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: You may examine and purchase copies of public 
documents, by appointment, at the NRC's PDR, Room P1 B35, One White 
Flint North, 11555 Rockville Pike, Rockville, Maryland 20852. To make 
an appointment to visit the PDR, please send an email to 
[email protected] or call 1-800-397-4209 or 301-415-4737, between 
8:00 a.m. and 4:00 p.m. eastern time (ET), Monday through Friday, 
except Federal holidays.

B. Submitting Comments

    The NRC encourages electronic comment submission through the 
Federal rulemaking website (https://www.regulations.gov). Please 
include

[[Page 13719]]

Docket ID NRC-2018-0291 in your comment submission.
    The NRC cautions you not to include identifying or contact 
information that you do not want to be publicly disclosed in your 
comment submission. The NRC will post all comment submissions at 
https://www.regulations.gov as well as enter the comment submissions 
into ADAMS. The NRC does not routinely edit comment submissions to 
remove identifying or contact information.
    If you are requesting or aggregating comments from other persons 
for submission to the NRC, then you should inform those persons not to 
include identifying or contact information that they do not want to be 
publicly disclosed in their comment submission. Your request should 
state that the NRC does not routinely edit comment submissions to 
remove such information before making the comment submissions available 
to the public or entering the comment into ADAMS.

II. Background

A. Proposed Incorporation by Reference of Three Regulatory Guides

    The ASME develops and publishes the ASME BPV Code, which contains 
requirements for the design, construction, and inservice inspection of 
nuclear power plant components, and the ASME OM Code,\1\ which contains 
requirements for preservice and inservice testing of nuclear power 
plant components. In response to BPV and OM Code user requests, the 
ASME develops code cases that provide voluntary alternatives to BPV and 
OM Code requirements under special circumstances.
---------------------------------------------------------------------------

    \1\ The editions and addenda of the ASME Code for Operation and 
Maintenance of Nuclear Power Plants have had different titles from 
its initial issuance and are referred to as the ``OM Code'' 
collectively in this rule.
---------------------------------------------------------------------------

    The NRC approves the ASME BPV and OM Codes in Sec.  50.55a, ``Codes 
and standards,'' through the process of incorporation by reference. As 
such, each provision of the ASME Codes incorporated by reference into 
and mandated by Sec.  50.55a constitutes a legally-binding NRC 
requirement imposed by rule. As noted previously, the ASME Code Cases, 
for the most part, represent alternative approaches for complying with 
provisions of the ASME BPV and OM Codes. Accordingly, the NRC 
periodically amends Sec.  50.55a to incorporate by reference the NRC's 
RGs listing approved ASME Code Cases that may be used as voluntary 
alternatives to the BPV and OM Codes.\2\
---------------------------------------------------------------------------

    \2\ See Federal Register final rule, ``Incorporation by 
Reference of ASME BPV and OM Code Cases'' (68 FR 40469; July 8, 
2003).
---------------------------------------------------------------------------

    This proposed rule is the latest in a series of rules that 
incorporate by reference new versions of several RGs that identify new, 
revised, and reaffirmed \3\ ASME Code Cases that the NRC 
unconditionally or conditionally approves for use. In developing these 
RGs, the NRC reviews the ASME BPV and OM Code Cases, determines the 
acceptability of each code case, and publishes its findings in the RGs. 
The RGs are revised periodically as new code cases are published by the 
ASME. The NRC incorporates by reference the RGs listing acceptable and 
conditionally acceptable ASME Code Cases into Sec.  50.55a. The NRC 
published a final rule dated March 3, 2022 (87 FR 11934), that 
incorporated by reference into Sec.  50.55a the most recent versions of 
the RGs, which are RG 1.84, ``Design, Fabrication, and Materials Code 
Case Acceptability, ASME Section III,'' Revision 39; RG 1.147, 
``Inservice Inspection Code Case Acceptability, ASME Section XI, 
Division 1,'' Revision 20; and RG 1.192, ``Operation and Maintenance 
Code Case Acceptability, ASME OM Code,'' Revision 4.
---------------------------------------------------------------------------

    \3\ Code cases are categorized by the ASME as one of three 
types: new, revised, or reaffirmed. A new code case provides for a 
new alternative to a specific ASME Code provision or addresses a new 
need. The ASME defines a revised code case to be a revision 
(modification) to an existing code case to address, for example, 
technological advancements in examination techniques or to address 
NRC conditions imposed in one of the RGs that have been incorporated 
by reference into Sec.  50.55a. The ASME defines ``reaffirmed'' as 
an OM Code Case that does not have any change to technical content 
but includes editorial changes.
---------------------------------------------------------------------------

B. Proposed Revision to Code of Record Update Requirements

    The NRC staff provided SECY-21-0029 to the Commission with a 
proposed rulemaking plan for revising the IST and ISI code of record 
update requirements in Sec.  50.55a. The Commission issued SRM-SECY-21-
0029, directing the staff to proceed with the proposed rulemaking plan. 
In SECY-22-0075, ``Staff Requirements-SECY-21-0029 Inservice Testing 
and Inservice Inspection Program Rulemakings Update,'' dated August 10, 
2022, the staff described deviations it was taking from the original 
plan in response to new information and changed circumstances that 
affected the implementation of SRM-SECY-21-0029. These changes included 
combining the two proposed rulemakings (the ASME code case and the IST 
and ISI code of record update requirements). These changes also 
included making conforming and clarifying changes to address issues 
encountered during the development of this proposed rule. One such 
change was the addition of a definition section to the proposed rule 
(Sec.  50.55a(y)) where ``code of record interval'' (the period of time 
between the code of record updates required by Sec.  50.55a(f)(4) and 
(g)(4) for the IST and ISI programs, respectively) was differentiated 
from both the ISI and IST intervals (the ASME interval described by the 
licensee's code of record).
    In this proposed rule, along with incorporating by reference three 
regulatory guides on ASME Code Cases, the NRC is providing a proposed 
revision to Sec.  50.55a for public comment in accordance with the 
Commission's direction in SRM-SECY-21-0029. This proposed rule would 
specify that licensees are required to update their IST and ISI codes 
of record every two consecutive IST intervals or ISI intervals, as 
defined in the proposed rule, provided the licensee implements the 2020 
Edition, or later edition, of the ASME OM Code and the 2019 Edition, or 
later edition or addenda, of ASME BPV Code, Section XI, as incorporated 
by reference in Sec.  50.55a, for their IST and ISI programs, 
respectively. With this revised requirement to update the code of 
record, the NRC does not intend that the code of record interval for an 
IST or ISI program would exceed 25 years, even if ASME extends the IST 
interval or the ISI interval beyond 12 years in the ASME OM Code or the 
ASME BPV Code, respectively. The proposed 25-year maximum code of 
record interval would allow the same code of record to be used for two 
consecutive ISI or IST intervals, each up to 12 years, plus the one-
time 1-year extension for IST and ISI programs as specified in the ASME 
OM Code and ASME BPV Code, respectively. If future editions of the ASME 
OM Code or ASME BPV Code or future code cases extend the IST interval 
or ISI interval, respectively, beyond 12 years, the NRC would need to 
maintain the proposed 25-year maximum code of record interval.
    In draft Revision 5 to RG 1.192, the NRC is proposing to 
conditionally accept ASME OM Code Case OMN-31, ``Alternative to Allow 
Extension of ISTA-3120 Inservice Examination and Test Intervals From 10 
Years to 12 Years,'' as a voluntary alternative to the 10-year interval 
specified in the ASME OM Code for applicants and licensees implementing 
the 2020 Edition of the ASME OM Code or later editions as incorporated 
by reference in Sec.  50.55a. In

[[Page 13720]]

draft Revision 21 to RG 1.147, the NRC is proposing to conditionally 
accept ASME Code Case N-921, ``Alternative 12-yr Inspection Interval 
Duration, Section XI, Division 1,'' as a voluntary alternative to the 
10-year interval specified in Section XI, IWA-2400 of the ASME BPV Code 
for applicants and licensees implementing the 2019 Edition of the ASME 
BPV Code or later editions as incorporated by reference in Sec.  
50.55a.

III. Discussion

A. Proposed Incorporation by Reference of Three Regulatory Guides

    This proposed rule would incorporate by reference the latest 
revisions of the NRC's RGs that list the ASME BPV and OM Code Cases 
that the NRC finds to be acceptable, or acceptable with NRC-specified 
conditions (``conditionally acceptable''). RG 1.84, Revision 40 (DG-
1405) would supersede the incorporation by reference of Revision 39; RG 
1.147, Revision 21 (DG-1406) would supersede the incorporation by 
reference of Revision 20; and RG 1.192, Revision 5 (DG-1407) would 
supersede the incorporation by reference of Revision 4.
    The ASME Code Cases that are the subject of this proposed rule are 
the new and revised Section III and Section XI Code Cases as listed in 
Supplements 2 through 7 to the 2019 Edition of the ASME BPV Code, 
Supplements 0 through 2 and selected Code Cases from Supplement 3 to 
the 2021 Edition of the ASME BPV Code, and the OM Code Cases listed in 
the 2022 Edition of the ASME OM Code. By letter dated December 22, 
2021, ASME requested that the NRC consider including Code Cases N-663-
1, N-885-1, and N-921 in this proposed rulemaking. In response, the NRC 
included these three code cases within the scope of this proposed rule. 
The NRC is also proposing to include OMN-31 within the scope of this 
proposed rule to provide consistency between the ISI and IST programs.
    The ASME publishes code cases that provide alternatives to existing 
code requirements that the ASME developed and approved. This proposed 
rule would incorporate by reference the most recent revisions of RGs 
1.84, 1.147, and 1.192, which allow nuclear power plant licensees, and 
applicants for combined licenses, standard design certifications, 
standard design approvals, and manufacturing licenses under the 
regulations that govern license certifications, to use the code cases 
listed in these RGs as suitable alternatives to the ASME BPV and OM 
Codes for the construction, inservice inspections, and inservice 
testing of nuclear power plant components. The ASME makes the issued OM 
Code Cases available on the OM Code website and provides an index 
listing the issued OM Code Cases and their applicability in each ASME 
OM Code edition. In contrast, the ASME publishes BPV Code Cases in a 
separate document and at a different time than the ASME BPV Code 
Editions. This proposed rule identifies the BPV Code Cases by the 
edition of the ASME BPV Code under which they were published by the 
ASME and the OM Code Cases by the most recent edition of the ASME OM 
Code to which they apply.
    The following general guidance applies to the use of the ASME Code 
Cases approved in the latest versions of the RGs that are incorporated 
by reference into Sec.  50.55a as part of this proposed rule. 
Specifically, the use of the Code Cases listed in the latest versions 
of RGs 1.84, 1.147, and 1.192 are acceptable with the specified 
conditions when implementing the editions and addenda of the ASME BPV 
and OM Codes incorporated by reference in Sec.  50.55a.
    The approval of a code case in these RGs constitutes acceptance of 
its technical position for applications that are not precluded by other 
requirements. The applicant or licensee is responsible for ensuring 
that use of the code case does not conflict with regulatory 
requirements or licensee commitments. The code cases listed in the RGs 
are acceptable for use within the limits specified in the code cases. 
If the RG states an NRC condition on the use of a code case, then the 
NRC condition supplements and does not supersede any condition(s) 
specified in the code case, unless otherwise stated in the NRC 
condition.
    The ASME Code Cases may be revised for many reasons (e.g., to 
incorporate operational examination and testing experience and to 
update material requirements based on research results). On occasion, 
an inaccuracy in an equation is discovered or an examination, as 
practiced, is found not to be adequate to detect a newly discovered 
degradation mechanism. Therefore, when an applicant or a licensee 
initially implements a code case, Sec.  50.55a requires that the 
applicant or the licensee implement the most recent version of that 
code case, as listed in the RGs incorporated by reference. Code cases 
superseded by revision are no longer acceptable for new applications 
unless otherwise indicated.
    Section III of the ASME BPV Code applies to new construction (e.g., 
the edition and addenda to be used in the construction of a plant are 
selected based on the date of the construction permit and are not 
changed thereafter, except voluntarily by the applicant or the 
licensee). Section III may also be used for repair and replacement 
activities under the provisions of Section XI of the ASME BPV Code. 
Whether used for construction or later repair or replacement, when a 
code case is first implemented by a licensee, the applicant implements 
the latest edition incorporated by reference into Sec.  50.55a. 
Thereafter, the applicant or licensee may continue to apply the 
previous version of the code case or may apply the later version of the 
code case, including any NRC-specified conditions placed on its use, as 
an update to its code of record for the component.
    Licensees that were using a code case prior to the effective date 
of its revision may continue to use the previous version until the next 
update to the code of record for the ISI or IST program, as applicable. 
This relieves licensees of the burden of having to update their ISI or 
IST program each time a code case is revised by the ASME and approved 
for use by the NRC. Code cases apply to specific editions and addenda, 
and code cases may be revised if they are no longer accurate or 
adequate, so licensees choosing to continue using a code case into a 
later code of record interval (e.g., after updating the edition and 
addenda) for the ISI or IST program must implement the latest version 
incorporated by reference into Sec.  50.55a and listed in the RGs.
    The ASME may annul code cases that are no longer required, are 
determined to be inaccurate or inadequate, or have been incorporated 
into the BPV or OM Codes. A code case may be revised, for example, to 
incorporate user experience. The older or superseded version of the 
code case cannot be applied by the licensee or applicant for a first 
use of that code case. If an applicant or a licensee applied a code 
case before it was listed as superseded or annulled, the applicant or 
the licensee may continue to use the code case until the applicant or 
the licensee updates its construction code of record (in the case of an 
applicant, updates its application) or until the licensee's code of 
record interval for the ISI or IST program expires, after which the 
continued use of the code case is prohibited unless NRC authorization 
is given under Sec.  50.55a(z). If a code case is incorporated by 
reference into Sec.  50.55a and later a revised version is issued by 
the ASME because experience has shown that the design analysis, 
construction method, examination

[[Page 13721]]

method, or testing method is inadequate, the NRC will amend Sec.  
50.55a and the relevant RG to remove the approval of the superseded 
code case. Applicants and licensees should not begin to implement such 
superseded code cases in advance of the rulemaking. This proposed 
rulemaking includes minor editorial changes to Sec.  50.55a(a) to align 
with the Office of the Federal Register's guidance on the incorporation 
by reference.

B. Code Cases Proposed To Be Approved for Unconditional Use

    The code cases discussed in Table I are new, revised, or reaffirmed 
code cases in which the NRC is not proposing any conditions. The table 
identifies the draft regulatory guide listing the applicable code case 
that the NRC proposes to approve for use.

                     Table I--Acceptable Code Cases
------------------------------------------------------------------------
 
------------------------------------------------------------------------
               Boiler and Pressure Vessel Code Section III
                     (addressed in DG-1405, Table 1)
------------------------------------------------------------------------
       Code case No.           Published with             Title
                                  supplement
------------------------------------------------------------------------
N-351-1....................  3 (2021 Edition)..  Use of Standard Subsize
                                                  Charpy V-Notch Impact
                                                  Specimens, Section
                                                  III, Division 1;
                                                  Section III, Division
                                                  2; Section III,
                                                  Division 3.
N-893......................  4 (2019 Edition)..  Use of Alloy Steel Bar
                                                  and Mechanical Tubing
                                                  in Class 2 and 3
                                                  Patented Mechanical
                                                  Joints and Fittings,
                                                  Section III, Division
                                                  1.
N-900......................  3 (2019 Edition)..  Alternative Rules for
                                                  Level D Service Limits
                                                  of Class 1, 2, and 3
                                                  Piping Systems,
                                                  Section III, Division
                                                  1.
N-901......................  4 (2019 Edition)..  Use of ASME SA-494
                                                  Grade M35-1 for Line
                                                  Valve Bodies and
                                                  Bonnets, and Bodies,
                                                  Bonnets, and Yokes of
                                                  Pressure Relief Valves
                                                  for Class 2 and 3
                                                  Construction, Section
                                                  III, Division 1.
N-902......................  5 (2019 Edition)..  Thickness and Gradient
                                                  Factors for Piping
                                                  Fatigue Analyses,
                                                  Section III, Division
                                                  1.
N-904......................  6 (2019 Edition)..  Alternative Rules for
                                                  Simplified Elastic-
                                                  Plastic Analysis,
                                                  Section III, Division
                                                  1.
N-905......................  6 (2019 Edition)..  Alternate Design
                                                  Fatigue Curves to
                                                  Those Given in For
                                                  Section III
                                                  Appendices, Mandatory
                                                  Appendix I, Figures I-
                                                  9.1 and I-9.1M,
                                                  Section III, Division
                                                  1.
N-908......................  7 (2019 Edition)..  Use of Ferritic/
                                                  Austenitic Wrought
                                                  WPS32750/CRS32750
                                                  Fittings of Seamless
                                                  or Welded Construction
                                                  Conforming to SA-815,
                                                  Class 3, Section III,
                                                  Division 1.
N-910......................  7 (2019 Edition)..  Use of 25Cr-7Ni-4Mo-N
                                                  (Alloy UNS S32750
                                                  Austenitic/Ferritic
                                                  Duplex Stainless
                                                  Steel) Forgings,
                                                  Plate, and Welded and
                                                  Seamless Pipe and
                                                  Tubing Conforming to
                                                  SA-182, SA-240, SA-
                                                  789, or SA-790,
                                                  Section III, Division
                                                  1.
N-919......................  2 (2021 Edition)..  Alternative Fatigue
                                                  Evaluation Method to
                                                  Consider Environmental
                                                  Effects on Class 1
                                                  Components Section
                                                  III, Division 1.
N-920......................  2 (2021 Edition)..  Alternative Fatigue
                                                  Design Curves for
                                                  Ferritic Steels With
                                                  Ultimate Tensile
                                                  Strengths (UTS) <=80
                                                  ksi (552 MPa) and
                                                  Austenitic Steels,
                                                  Section III, Division
                                                  1.
------------------------------------------------------------------------
               Boiler and Pressure Vessel Code Section XI
                     (addressed in DG-1406, Table 1)
------------------------------------------------------------------------
       Code case No.           Published with             Title
                                  supplement
------------------------------------------------------------------------
N-561-4....................  0 (2021 Edition)..  Alternative
                                                  Requirements for Wall
                                                  Thickness Restoration
                                                  of Class 2 and High
                                                  Energy Class 3 Carbon
                                                  Steel Piping, Section
                                                  XI, Division 1.
N-562-4....................  0 (2021 Edition)..  Alternative
                                                  Requirements for Wall
                                                  Thickness Restoration
                                                  of Class 3 Moderate
                                                  Energy Carbon Steel
                                                  Piping, Section XI,
                                                  Division 1.
N-597-5....................  0 (2021 Edition)..  Evaluation of Pipe Wall
                                                  Thinning, Section XI,
                                                  Division 1.
N-638-11...................  2 (2019 Edition)..  Similar and Dissimilar
                                                  Metal Welding Using
                                                  Ambient Temperature
                                                  Machine GTAW Temper
                                                  Bead Technique,
                                                  Section XI, Division
                                                  1.
N-661-5....................  0 (2021 Edition)..  Alternative
                                                  Requirements for Wall
                                                  Thickness Restoration
                                                  of Class 2 and 3
                                                  Carbon Steel Piping
                                                  for Raw Water Service
                                                  Section XI, Division
                                                  1.
N-663-1....................  3 (2021 Edition)..  Alternative
                                                  Requirements for
                                                  Classes 1 and 2
                                                  Surface Examinations,
                                                  Section XI, Division
                                                  1.
N-733-1....................  6 (2019 Edition)..  Mitigation of Flaws in
                                                  NPS 3 (DN 80) and
                                                  Smaller Nozzles and
                                                  Nozzle Partial
                                                  Penetration Welds in
                                                  Vessels and Piping by
                                                  Use of a Mechanical
                                                  Connection
                                                  Modification, Section
                                                  XI, Division 1.
N-780-1....................  1 (2021 Edition)..  Alternative
                                                  Requirements for
                                                  Upgrade, Substitution,
                                                  or Reconfiguration of
                                                  Examination Equipment
                                                  When Using Appendix
                                                  VIII Qualified
                                                  Ultrasonic Examination
                                                  Systems, Section XI,
                                                  Division 1.
N-786-4....................  0 (2021 Edition)..  Alternative
                                                  Requirements for
                                                  Sleeve Reinforcement
                                                  of Class 2 and 3
                                                  Moderate Energy Carbon
                                                  Steel Piping, Section
                                                  XI, Division 1.
N-789-5....................  1 (2021 Edition)..  Alternative
                                                  Requirements for Pad
                                                  Reinforcement of Class
                                                  2 and 3 Moderate
                                                  Energy Carbon Steel
                                                  Piping for Raw Water
                                                  Service, Section XI,
                                                  Division 1.
N-809-1....................  0 (2021 Edition)..  Reference Fatigue Crack
                                                  Growth Rate Curves for
                                                  Austenitic Stainless
                                                  Steels in Pressurized
                                                  Reactor Water
                                                  Environments, Section
                                                  XI, Division 1.
N-853-1....................  0 (2021 Edition)..  PWR Class 1 Primary
                                                  Piping Alloy 600 Full
                                                  Penetration Branch
                                                  Connection Weld Metal
                                                  Buildup for Material
                                                  Susceptible to Primary
                                                  Water Stress Corrosion
                                                  Cracking, Section XI,
                                                  Division 1.
N-860......................  6 (2019 Edition)..  Inspection Requirements
                                                  and Evaluation
                                                  Standards for Spent
                                                  Nuclear Fuel Storage
                                                  and Transportation
                                                  Containment Systems,
                                                  Section XI, Division
                                                  1; Section XI,
                                                  Division 2.
N-865-2....................  0 (2021 Edition)..  Alternative
                                                  Requirements for Pad
                                                  Reinforcement of Class
                                                  2 and 3 Atmospheric
                                                  Storage Tanks, Section
                                                  XI, Division 1.

[[Page 13722]]

 
N-877-1....................  5 (2019 Edition)..  Alternative
                                                  Characterization Rules
                                                  for Multiple
                                                  Subsurface Radially
                                                  Oriented Planar Flaws,
                                                  Section XI, Division
                                                  1.
N-882-1....................  0 (2021 Edition)..  Alternative
                                                  Requirements for
                                                  Attaching
                                                  Nonstructural
                                                  Electrical Connections
                                                  to Class 2 and 3
                                                  Components, Section
                                                  XI, Division 1.
N-885-1....................  3 (2021 Edition)..  Alternative
                                                  Requirements for Table
                                                  IWB-2500-1,
                                                  Examination Category B-
                                                  N-1, Interior of
                                                  Reactor Vessel,
                                                  Category B-N-2, Welded
                                                  Core Support
                                                  Structures and
                                                  Interior Attachments
                                                  to Reactor Vessels,
                                                  Category BN-3,
                                                  Removable Core Support
                                                  Structures, Section
                                                  XI, Division 1.
N-888......................  5 (2019 Edition)..  Similar and Dissimilar
                                                  Metal Welding Using
                                                  Ambient Temperature
                                                  SMAW or Machine GTAW
                                                  Temper Bead Technique,
                                                  Section XI, Division
                                                  1.
N-896......................  2 (2019 Edition)..  Reference Crack Growth
                                                  Rate Curves for Stress
                                                  Corrosion Cracking of
                                                  Low Alloy Steels in
                                                  Boiling Water Reactor
                                                  Environments, Section
                                                  XI, Division 1.
N-911......................  0 (2021 Edition)..  Purchase, Exchange, or
                                                  Transfer of Material
                                                  Between Nuclear
                                                  Owners, Section XI,
                                                  Division 1.
N-912......................  0 (2021 Edition)..  Alternative
                                                  Requirements for
                                                  Qualification of
                                                  Material Suppliers and
                                                  Acceptance of
                                                  Materials, Section XI,
                                                  Division 1.
N-913......................  0 (2021 Edition)..  Alternative Examination
                                                  Requirements for Class
                                                  1 Pressure-Retaining
                                                  Welds in Control Rod
                                                  Drive Housings,
                                                  Section XI, Division
                                                  1.
N-917......................  2 (2021 Edition)..  Fatigue Crack Growth
                                                  Rate Curves for
                                                  Ferritic Steels in
                                                  Boiling Water Reactor
                                                  (BWR) Environments,
                                                  Section XI, Division
                                                  1.
------------------------------------------------------------------------
                     Operation and Maintenance Code
                     (addressed in DG-1407, Table 1)
------------------------------------------------------------------------
         Code case            Most recent code            Title
                                 edition \4\
------------------------------------------------------------------------
OMN-28.....................  2022 Edition......  Alternative Valve
                                                  Position Verification
                                                  Approach to Satisfy
                                                  ISTC-3700 for Valves
                                                  Not Susceptible to
                                                  Stem-Disk Separation.
OMN-29.....................  2022 Edition......  Pump Condition
                                                  Monitoring Program.
OMN-30.....................  2022 Edition......  Alternative Valve
                                                  Position Verification
                                                  Approach to Satisfy
                                                  ISTC-3700.
------------------------------------------------------------------------

C. Code Cases Approved for Use With Conditions
---------------------------------------------------------------------------

    \4\ Each code case or ASME Applicability Index List indicates 
the ASME OM Code editions and addenda to which the code case 
applies, except where a condition is specified in Sec.  50.55a or RG 
1.192 related to technical content or applicability. This table 
indicates the latest OM Code edition at the time of this rulemaking.
---------------------------------------------------------------------------

    The NRC has determined that certain code cases, as issued by the 
ASME, are generally acceptable for use, but that the alternative 
requirements specified in those code cases must be supplemented in 
order to provide an acceptable level of quality and safety. 
Accordingly, the NRC proposes to impose conditions on the use of these 
code cases to modify, limit or clarify their requirements. The 
conditions would specify, for each applicable code case, the additional 
activities that must be performed, the limits on the activities 
specified in the code case, and/or the supplemental information needed 
to provide clarity. These ASME Code Cases, listed in Table II, are 
included in Table 2 of DG-1405 (RG 1.84), DG-1406 (RG 1.147), and DG-
1407 (RG 1.192). This section provides the NRC's evaluation of the code 
cases and the reasons for the NRC's proposed conditions. Notations 
indicate the conditions duplicated from previous versions of the RG.
    The NRC requests public comment on these code cases and the 
proposed conditions. It also should be noted that this section only 
addresses those code cases for which the NRC proposes to impose 
condition(s), which are listed in the RG for the first time.

              Table II--Conditionally Acceptable Code Cases
------------------------------------------------------------------------
 
------------------------------------------------------------------------
               Boiler and Pressure Vessel Code Section III
                     (addressed in DG-1405, Table 2)
------------------------------------------------------------------------
       Code case No.           Published with             Title
                                  supplement
------------------------------------------------------------------------
N-71-21....................  0 (2021 Edition)..  Additional Materials
                                                  for Subsection NF,
                                                  Class 1, 2, 3, and MC
                                                  Supports Fabricated by
                                                  Welding, Section III,
                                                  Division 1.
N-570-3....................  0 (2021 Edition)..  Alternative Rules for
                                                  Linear Piping and
                                                  Linear Standard
                                                  Supports for Classes
                                                  1, 2, 3, and MC,
                                                  Section III, Division
                                                  1.
------------------------------------------------------------------------
               Boiler and Pressure Vessel Code Section XI
                     (addressed in DG-1406, Table 2)
------------------------------------------------------------------------
       Code case No.           Published with             Title
                                  supplement
------------------------------------------------------------------------
N-711-2....................  6 (2019 Edition)..  Alternative Examination
                                                  Coverage Requirements
                                                  for Examination
                                                  Category B F, B J, C-F-
                                                  1, C-F-2, and R-A
                                                  Piping Welds, Section
                                                  XI, Division 1.
N-716-3....................  5 (2019 Edition)..  Alternative
                                                  Classification and
                                                  Examination
                                                  Requirements, Section
                                                  XI, Division 1.
N-754-2....................  0 (2021 Edition)..  Optimized Structural
                                                  Dissimilar Metal Weld
                                                  Overlay for Mitigation
                                                  of PWR Class 1 Items,
                                                  Section XI, Division
                                                  1.

[[Page 13723]]

 
N-766-4....................  0 (2021 Edition)..  Nickel Alloy Reactor
                                                  Coolant Inlay and
                                                  Onlay for Mitigation
                                                  of PWR Full
                                                  Penetration
                                                  Circumferential Nickel
                                                  Alloy Dissimilar Metal
                                                  Welds in Class 1
                                                  Items, Section XI,
                                                  Division 1.
N-847-1....................  0 (2021 Edition)..  Partial Excavation and
                                                  Deposition of Weld
                                                  Metal for Mitigation
                                                  of Class 1 Items,
                                                  Section XI, Division
                                                  1.
N-880-1....................  0 (2021 Edition)..  Alternative to
                                                  Procurement
                                                  Requirements of IWA-
                                                  4143 for Nonstandard
                                                  Welded Fittings,
                                                  Section XI, Division
                                                  1.
N-899......................  3 (2019 Edition)..  Weld Residual Stress
                                                  Distributions for
                                                  Piping and Vessel
                                                  Nozzle Butt Welds
                                                  Fabricated With UNS
                                                  N06082, UNS W86182,
                                                  UNS N06052, or UNS
                                                  W86152 Weld Filler
                                                  Material, Section XI,
                                                  Division 1.
N-906......................  7 (2019 Edition)..  Flaw Evaluation
                                                  Procedure for Cast
                                                  Austenitic Stainless
                                                  Steel Piping and
                                                  Adjacent Fittings,
                                                  Section XI, Division
                                                  1.
N-921......................  3 (2021 Edition)..  Alternative 12-yr
                                                  Inspection Interval
                                                  Duration, Section XI,
                                                  Division 1.
------------------------------------------------------------------------
                     Operation and Maintenance Code
                     (addressed in DG-1407, Table 2)
------------------------------------------------------------------------
Code case No...............    Most recent OM             Title
                               code edition \5\
------------------------------------------------------------------------
OMN-31.....................  2022 Edition......  Alternative to Allow
                                                  Extension of ISTA-3120
                                                  Inservice Examination
                                                  and Test Intervals
                                                  From 10 Years to 12
                                                  Years.
------------------------------------------------------------------------

ASME BPV Code, Section III Code Cases (DG-1405/RG 1.84)
---------------------------------------------------------------------------

    \5\ Each code case or ASME Applicability Index List indicates 
the ASME OM Code editions and addenda to which the code case 
applies, except where a condition is specified in Sec.  50.55a or RG 
1.192 related to technical content or applicability. This table 
indicates the latest OM Code edition at the time of this rulemaking. 
Conditions specified for other OM Code Cases listed in Table 2 of RG 
1.192 have not changed in this rulemaking other than updating to the 
latest OM Code edition.
---------------------------------------------------------------------------

Code Case N-71-21 [Supplement 0, 2021 Edition]
Type: Revised
Title: Additional Materials for Subsection NF, Class 1, 2, 3, and MC 
Supports Fabricated by Welding, Section III, Division 1

    The proposed conditions on Code Case N-71-21 are the same as the 
conditions on N-71-20 that were approved by the NRC in Revision 39 of 
RG 1.84. When the ASME revised N-71, the code case was not modified in 
a way that would make it possible for the NRC to remove the conditions. 
Therefore, the conditions would be retained in Revision 40 of RG 1.84.
Code Case N-570-3 [Supplement 0, 2021 Edition]
Type: Revised
Title: Alternative Rules for Linear Piping and Linear Standard Supports 
for Classes 1, 2, 3, and MC, Section III, Division 1

    Code Case N-570-3 would update references made to ANSI/AISC N690-
1994 and ANSI/AISC N690-1994 (R2004) Supplement 2 with ANSI/AISC N690-
18. A difference between ANSI/AISC N690-18 and ANSI/AISC N690-1994 
(R2004) is that ANSI/AISC N690-18 allows the use of the Load and 
Resistance Factor Design (LRFD) method or the Allowable Strength Design 
(ASD) method, versus the allowable stress design method or plastic 
design method contained in the ANSI/AISC N690-1994 (R2004) edition. 
Code Case N-570-2 explicitly stated in paragraph 3.11 that the plastic 
design method in Part 2 of ANSI/AISC N690-1994 (R2004) shall not be 
used. It is the NRC's understanding that the alternative requirements 
of code case N-570-3 for design are also intended to be limited to the 
design for strength using the ASD method of ANSI/AISC N690-18, which is 
similar to the allowable stress design method used in N-570-2; however, 
the code case does not include such explicit qualifiers regarding the 
use of ANSI/AISC N690-18. The alternative requirements for design in 
Code Case N-570-3 would be limited to the design for strength using the 
ASD method of ANSI/AISC N690-18. To provide clarity, the NRC is 
proposing a condition: ``This Code Case shall not be used with the Load 
and Resistance Factor Design method of ANSI/AISC N690-18.''
ASME BPV Code, Section XI Code Cases (DG-1406/RG 1.147)
Code Case N-711-2 [Supplement 6, 2019 Edition]
Type: Revised
Title: Alternative Examination Coverage Requirements for Examination 
Category B F, B J, C-F-1, C-F-2, and R-A Piping Welds, Section XI, 
Division 1

    The condition on Code Case N-711-2 would be identical to the 
condition on N-711-1 that was approved by the NRC in Revision 20 of RG 
1.147. When the ASME revised N-711, the code case was not modified in a 
way that would make it possible for the NRC to remove the condition. 
Therefore, the condition would be retained in Revision 21 of RG 1.147.
Code Case N-716-3 [Supplement 5, 2019 Edition]
Type: Revised
Title: Alternative Classification and Examination Requirements, Section 
XI, Division 1

    Code Case N-716 provides rules for alternative classification and 
examination requirements for piping welds and components. Revision 3 to 
Code Case N-716 would remove the provision for plants issued an 
operating license after January 1, 2012, to submit the application of 
this Code Case for regulatory approval. The NRC is cognizant of the 
committee's desire to eliminate the provision for newly constructed 
plants to submit first time applications of N-716 to the NRC. It was 
the Committee's intention to make this Code Case more generally 
applicable internationally. However, the NRC is of the opinion that the 
new designs may introduce additional variables, which in the absence of 
substantial operating experience with these new plants, may introduce 
uncertainty on the applicability of this Code Case to the new plants. 
Hence, the NRC has determined there is a need to review the initial 
proposals for new plants. The review would confirm the absence of new 
degradation mechanisms, evaluate with available operating experience, 
as well as the risk-related information for the new plants prior to the 
initial application of the Code Case to new plants. Therefore, the NRC 
is proposing a condition that this Code Case is not approved for use by 
plants issued an

[[Page 13724]]

operating license or combined license after January 1, 2012. However, 
plants issued an operating license or combined license after January 1, 
2012, may submit an alternative to use this Code Case in accordance 
with Sec.  50.55a(z) for review and approval prior to implementation.
Code Case N-754-2 [Supplement 0, 2021 Edition]
Type: Revised
Title: Optimized Structural Dissimilar Metal Weld Overlay for 
Mitigation of PWR Class 1 Items, Section XI, Division 1

    The NRC is proposing to revise the conditions on N-754-1 to remove 
reference to the NRC's safety evaluation for the topical report 
``Materials Reliability Program (MRP): Technical Basis for Preemptive 
Weld Overlays for Alloy 82/182 Butt Welds in PWRs'' (MRP-169) and to 
clarify the examination requirements.
    The first condition deals with the use of this Code Case on a pipe 
that implements NRC-approved leak-before-break (LBB) methodology. The 
application of the LBB concept to a pipe is that if a flaw is developed 
in a pipe with certain favorable material properties, the pipe will 
most likely leak first before it fails catastrophically. The existing 
leakage detection system in the nuclear plant will detect the leakage 
and alert the operator. The operator has sufficient time to shut down 
the plant safely to perform corrective actions. The NRC has approved 
LBB for certain Class 1 reactor coolant system piping in pressurized 
water reactor plants based on the plant-specific and piping-specific 
LBB analysis, which shows that the probability of the piping rupture is 
extremely low under conditions consistent with the design basis for the 
piping as required in General Design Criterion 4 of 10 CFR part 50, 
appendix A. The LBB methodology and analysis, including specific safety 
margins, are reviewed and approved via the license amendment process. 
The LBB implementation is documented in the plant final safety analysis 
report. When an optimized weld overlay is installed onto pipes that are 
approved for LBB, the licensee must verify that the safety margins 
specified in the original LBB analysis are still satisfied.
    The second condition states that the preservice and inservice 
examinations of the overlaid pipe using this Code Case must be 
performed in accordance with Sec.  50.55a(g)(6)(ii)(F). Paragraph 3(c) 
of N-754-2 states that--
    In lieu of all other Preservice and Inservice inspection 
requirements, the examination requirements in accordance with N-770-2 
(or later in accordance with [Paragraph] 5) shall be met. Alternately, 
the requirements of [subparagraphs] (1) through (3) below may be used 
to modify the provisions of N-770-2 (or later in accordance with 
[Paragraph] 5).
    As stated, if the inspection of the overlaid pipe performed in 
accordance with N-770-2 cannot be met or performed, alternatives of 
Paragraphs 3(c)(1), 3(c)(2) and 3(c)(3) of N-754-2 could be used. The 
NRC identified the following issues regarding the statement in 
Paragraph 3(c):
     Paragraphs 3(c)(2) and 3(c)(3) of N-754-2 are related to 
the design and analysis, not the inspection of the overlaid pipe. 
Therefore, it is not clear how these two paragraphs can be used to 
modify the inspection provisions of N-770-5.
     The inspection provisions of Paragraph 3(c)(1) are allowed 
to be different from the provisions of Note 14, Preservice Inspection 
for Optimized Weld Overlays, and Note 18, Inservice Inspection of 
Optimized Weld Overlays, of Table 1 of N-770. The NRC notes that 10 CFR 
50.55a(g)(6)(ii)(F) mandates the use of N-770, as conditioned, for the 
examination requirements for optimized weld overlays in dissimilar 
metal butt welds. Therefore, for regulatory clarity regarding 
preservice and inservice inspection requirements, the proposed 
condition is provided.
     Section 50.55a(g)(6)(ii)(F) mandates the implementation of 
N-770-5, rather than N-770-2
     Therefore, the NRC finds that this condition is needed to 
clarify the examination requirements in Paragraph 3 of N-754-2 and to 
ensure that N-770-5 is implemented as required by Sec.  
50.55a(g)(6)(ii)(F).
Code Case N-766-4 [Supplement 0, 2021 Edition]
Type: Revised
Title: Nickel Alloy Reactor Coolant Inlay and Onlay for Mitigation of 
PWR Full Penetration Circumferential Nickel Alloy Dissimilar Metal 
Welds in Class 1 Items, Section XI, Division 1

    The proposed conditions on Code Case N-766-4 are identical to the 
conditions on N-766-3 that were approved by the NRC in the previous 
revision of RG 1.147. When the ASME revised N-766, the code case was 
not modified in a way that would make it possible for the NRC to remove 
the conditions. Therefore, the conditions would be retained in Revision 
21 of RG 1.147.
Code Case N-847-1 [Supplement 0, 2021 Edition]
Type: Revised
Title: Partial Excavation and Deposition of Weld Metal for Mitigation 
of Class 1 Items, Section XI, Division 1

    The proposed conditions on Code Case N-847-1 are identical to the 
conditions on N-847 that were approved by the NRC in the previous 
revision of RG 1.147. When the ASME revised N-847, the code case was 
not modified in a way that would make it possible for the NRC to remove 
the conditions. Therefore, the conditions would be retained in Revision 
21 of RG 1.147.
Code Case N-880-1 [Supplement 0, 2021 Edition]
Type: Revised
Title: Alternative to Procurement Requirements of IWA-4143 for 
Nonstandard Welded Fittings, Section XI, Division 1

    Code Case N-880-1 removes the size limitation in the Case by 
eliminating the NPS 2 size limit. The NRC does not agree with removing 
the small size limitation (NPS 2 and under). The NRC is proposing to 
continue to limit the scope of the code case to NPS 2 (DN 50) or 
smaller fittings because there is insufficient technical basis to 
expand the application to items larger than NPS 2 (DN 50). The only 
justification provided for this change was that it is an arbitrary 
limitation. However, the limitation to NPS 2 (DN 50) and under was 
based on the capacity of the reactor coolant makeup system being able 
to safely shutdown the plant if these fittings fail, and therefore, is 
not an arbitrary limitation.
    Without a condition, approval of the code case would allow the use 
of these non-standard or specialized fittings in any Class 1, 2 and 3 
systems, including the reactor coolant makeup system. Thus, the failure 
of these fittings, which lack operating experience to demonstrate their 
reliability, could also affect the reactor coolant makeup system's 
ability to provide sufficient makeup capacity. Therefore, the NRC is 
proposing a new condition to limit the use of Code Case N-880-1 to NPS 
2 (DN 50) or smaller fittings.
    Conditions 2 and 3 are identical to the conditions on N-880 that 
were approved by the NRC in previous revision of RG 1.147. When the 
ASME revised N-880, the code case was not modified in a way that would 
make it possible for the NRC to remove the conditions. Therefore, the 
conditions would be retained in Revision 21 of RG 1.147.

[[Page 13725]]

Code Case N-899 [Supplement 3, 2019 Edition]
Type: New
Title: Weld Residual Stress Distributions for Piping and Vessel Nozzle 
Butt Welds Fabricated With UNS N06082, UNS W86182, UNS N06052, or UNS 
W86152 Weld Filler Material, Section XI, Division 1

    Code Case N-899 provides an alternative method for calculating the 
values of weld residual stress as a function of distance through the 
wall thickness for dissimilar metal butt welds in the reactor coolant 
pressure boundary. The NRC notes that Code Case N-899 may be used in 
conjunction with methodologies similar to those in Section XI, 
nonmandatory Appendix A, Article A-3000 to calculate the crack tip 
stress intensity factor, KI, for inside surface connected 
flaws in piping or vessel nozzle butt welds fabricated with UNS N06082, 
UNS W86182, UNS N06052, or UNS W86152 weld filler material.
    In many cases, plants do not have information on the actual repairs 
performed to Alloy 82/182 butt welds. However, operating experience and 
records indicate that repairs were common, including some welds being 
repaired multiple times. Weld repairs generally cause the weld residual 
stress to become more severe. Given the uncertainty in whether a weld 
repair exists or not, the NRC staff has generally found that it is 
appropriate to assume that a repair is present for the purposes of flaw 
evaluation. Therefore, consistent with the established NRC position for 
the weld residual stress distribution analysis for the subject welds of 
this code case, the inside surface repair residual stress distributions 
of Code Case N-899 are acceptable for use provided all known and 
documented repairs are bounded by the 50-percent through wall repair 
assumed in the case. Based on this discussion, the NRC is proposing the 
condition that only the standard weld residual stress distributions 
with repairs included, Paragraphs -2331 and -2332, would be approved 
for use and only if they bound all known or documented repairs 
previously performed on the subject weld.
    Similarly, the NRC also notes that when Paragraph -3000, 
Calculation of Residual Stress Using Finite Element Analysis, is 
applied as an option to use finite element analysis to calculate weld 
residual stress distributions, the weld residual stress analysis should 
incorporate a minimum of a 50 percent through-wall inside surface 
connected weld repair as part of the analysis. This is consistent with 
the NRC position on repairs and weld residual stress calculations 
stated in this discussion. If documentation of a repair is found or a 
previous repair is known, the weld residual stress analysis must be 
evaluated to determine if it is bounded by the 50-percent repair by 
modeling or flaw evaluation. The more conservative of either 50-percent 
repair assumption or the combination of all known previous repairs 
should be used in the development of the weld residual stress 
distribution. Therefore, the NRC is proposing a condition: when 
developing a plant-specific weld residual stress distribution, the 
finite element analysis calculation of the weld residual stress 
distribution must use the more bounding of either an assumed previous 
inside surface repair of 50 percent through-wall or the combination of 
all known or documented previous repairs.
Code Case N-906 [Supplement 7, 2019 Edition]
Type: New
Title: Flaw Evaluation Procedure for Cast Austenitic Stainless Steel 
Piping and Adjacent Fittings, Section XI, Division 1

    Code Case N-906 provides flaw evaluation procedure for cast 
austenitic stainless steel piping and fittings adjacent to girth welds 
as alternatives to the methods in Nonmandatory Appendix C, C-4210 and 
C-6330. Paragraph 1(b) of Code Case N-906 states that the provisions of 
this Case shall be applied to operating temperatures of 500 [deg]F to 
625 [deg]F (260 [deg]C to 330 [deg]C). The paragraph also states that, 
if a thermal transient below this range of temperatures occurs at the 
flaw location, the appropriate toughness, Ji, at the minimum 
transient temperature shall be used along with the applied stresses at 
that minimum transient temperature. Accordingly, if a transient occurs 
below the specified temperature range, the code case requires that the 
flaw evaluation use the fracture toughness and applied stresses at the 
minimum transient temperature.
    However, the limiting fracture toughness and relevant applied 
stress for the flaw under the transient may not be those at the minimum 
transient temperature. For example, Figure 32 of NUREG/CR-4513, 
Revision 2, ``Estimation of Fracture Toughness of Cast Stainless Steels 
during Thermal Aging in LWR Systems,'' shows that the fracture 
toughness of a cast austenitic stainless steel material at room 
temperature may be higher than that at an elevated temperature. 
Therefore, the NRC is proposing a condition to delete the reference to 
the minimum transient temperature that is associated with the 
appropriate fracture toughness and applied stresses for the flaw 
evaluation. The condition also clarifies that the flaw evaluation must 
use the fracture toughness and applied stresses that are limiting for 
the flaw.
Code Case N-921 [Supplement 3, 2021 Edition]
Type: New
Title: Alternative 12-Year Inspection Interval Duration, Section XI, 
Division 1

    Code Case N-921 increases the inservice inspection interval defined 
in Section XI, IWA-2400 from 10 years to 12 years. Section XI, IWA-2400 
requires that licensees have an inservice inspection program that 
includes, for example, inspection plans, inservice inspection interval 
dates, and identification of code cases to be applied during the 
interval. While IWA-2400 requires that plants specify the edition or 
addenda of Section XI that will be applied during the interval, Section 
XI does not prescribe what constitutes an appropriate edition or 
addenda. In fact, IWA-2410 states that edition or addenda is ``as 
required by the regulatory authority having jurisdiction at the plant 
site.'' The regulation at Sec.  50.55a(g)(4)(ii) provides the 
regulatory basis for licensees determining which edition or addenda to 
apply to inservice inspection programs for a successive interval. This 
regulation assumes a 10-year inservice inspection interval.
    A licensee applying this code case is, therefore, required by Sec.  
50.55a(4)(g)(ii) to update the code of record every 10 years. The 
inservice inspection interval and the code of record update interval 
should be synchronized to promote order and predictability in licensee 
inservice inspection programs. As part of this rulemaking, the NRC also 
is updating Sec.  50.55a to allow flexibility in how often the code of 
record is updated, provided that licensees update to the 2019 Edition 
of Section XI. The NRC, therefore, proposes to condition Code Case N-
921 to require updating to the 2019 Edition of Section XI. This 
condition would ensure that the desired order and predictability in 
licensee inservice inspection programs is maintained.
ASME Operation and Maintenance Code Cases (DG-1407/RG 1.192)
Code Case OMN-31 [2022 Edition]
Type: New
Title: Alternative to Allow Extension of ISTA-3120 Inservice 
Examination

[[Page 13726]]

and Test Intervals From 10 Years to 12 Years

    For the same reasons explained for Section XI Code Case N-921, the 
NRC is restricting the use of OMN-31 to licensees implementing the ASME 
OM Code, 2020 Edition. As indicated in DG-1407/RG 1.192, this OM Code 
Case may be applied by licensees implementing the ASME OM Code, 2020 
Edition through the latest edition of the ASME OM Code incorporated by 
reference in Sec.  50.55a, contrary to the ASME OM Code Case 
Applicability Index, dated July 1, 2022.
Other OM Code Cases in Table 2 of Proposed Revision 5 to RG 1.192
    No changes were made to the OM Code Cases listed in Table 2 of the 
proposed Revision 5 to RG 1.192 (with the exception of new Code Case 
OMN-31, discussed previously) from the versions that were listed in OM 
Code Cases listed in Table 2 of Revision 4 to RG 1.192. Therefore, the 
conditions on the OM Code Cases listed in Table 2 of the proposed 
Revision 5 to RG 1.192 (with the exception of new Code Case OMN-31) are 
identical to the conditions on those OM Code Cases that were approved 
by the NRC in Revision 4 of RG 1.192. The OM Code Cases listed in Table 
2 of the proposed Revision 5 to RG 1.192 were re-affirmed by the ASME 
for the 2022 Edition of the OM Code with no change to those OM Code 
Cases. Therefore, the conditions on the OM Code Cases in Table 2 are 
retained in proposed Revision 5 of RG 1.192.

D. ASME Code Cases Not Approved for Use (DG-1408/RG 1.193)

    The ASME Code Cases that are currently issued by the ASME but not 
approved for generic use by the NRC are listed in RG 1.193, ``ASME Code 
Cases not Approved for Use.'' In addition to the ASME Code Cases that 
the NRC has found to be technically or programmatically unacceptable, 
RG 1.193 includes code cases on reactor designs for high-temperature 
gas-cooled reactors and liquid metal reactors, reactor designs not 
currently licensed by the NRC, and certain requirements in Section III, 
Division 2, for submerged spent fuel waste casks, that are not endorsed 
by the NRC. Regulatory Guide 1.193 complements RGs 1.84, 1.147, and 
1.192. It should be noted that the NRC is not proposing to adopt any of 
the code cases listed in RG 1.193.

E. Proposed Revision to Code of Record Update Requirements

    Nuclear power plant licensees maintain their IST and ISI programs, 
respectively, in accordance with the requirements of the ASME OM Code 
and ASME BPV Code, Section XI, as incorporated by reference in Sec.  
50.55a. The initial concept of a 10-year ISI interval first appeared in 
the 1970 Edition of the ASME BPV Code, Section XI, in paragraph IS-240. 
This 10-year interval (referred to as the ISI interval) is only related 
to ASME ISI requirements. There is a corresponding 10-year IST interval 
for the OM Code requirements.
    Later, in a final rule published in February 1976 (41 FR 6256), the 
NRC revised Sec.  50.55a to require IST code of record updates every 20 
months and ISI code of record updates every 40 months. This requirement 
was (and still is) independent from the ISI and IST intervals defined 
by the respective codes. In the early years of the development of ISI 
and IST programmatic requirements, the NRC requirement to update the 
codes of record was not synchronized with the ASME concept of an IST or 
ISI interval. In January 1979 (44 FR 3719), the NRC proposed changes to 
Sec.  50.55a to extend the 20- and 40-month update intervals to 120 
months (10 years), in order to promote consistency with the 10-year 
interval in the ASME codes. The corresponding final rule was published 
in October 1979 (44 FR 57912).
    Paragraph IWA-2420 of the 1989 Edition and later of ASME BPV Code, 
Section XI, requires that nuclear plant owners prepare inspection plans 
and schedules for each ISI interval. These plans should include a 
listing of all code cases to be applied during the ISI interval and 
alternatives authorized under Sec.  50.55a(z). The proposed revision to 
Sec.  50.55a in this rulemaking does not alter those requirements. In 
defining the inspection program, Paragraph IWA-2410 of ASME BPV Code, 
Section XI, states, ``The Code Edition and Addenda for preservice 
inspection and for initial and successive inservice inspection 
intervals shall be as required by the regulatory authority having 
jurisdiction at the plant site.'' Therefore, while ASME BPV Code, 
Section XI, requires plant owners to declare which edition of Section 
XI will be applied during each ISI interval, the code does not specify 
what constitutes an appropriate edition of Section XI.
    Similarly, paragraph ISTA-3110, ``Test and Examination Plans,'' in 
the 2020 Edition of the ASME OM Code requires that nuclear plant owners 
prepare test plans for the preservice test period, initial IST 
intervals, and subsequent IST intervals. These plans should include a 
listing of all code cases to be applied during the IST interval, relief 
granted under Sec.  50.55a(f), and alternatives authorized under Sec.  
50.55a(z). Paragraph ISTA-3110 requires in subparagraph (a) that each 
IST plan shall include ``the edition and addenda of this Section that 
apply to the required tests and examinations.'' Therefore, while the 
ASME OM Code requires nuclear power plant owners to declare which 
edition and addenda of the OM Code will be applied during each IST 
interval, the OM Code does not specify what constitutes an appropriate 
edition and addenda of the OM Code.
    Thus, neither the ASME BPV Code, Section XI, nor the OM Code 
specify which edition to use. Rather, the NRC's regulations in Sec.  
50.55a determine the appropriate edition and addenda of the ASME BPV 
Code, Section XI, or the OM Code to be applied in each ISI or IST 
interval respectively. The changes proposed to these code of record 
requirements in this rulemaking are focused on that aspect alone.
    The NRC does not intend the proposed extension of the update 
interval to affect the orderly implementation of IST and ISI programs. 
Therefore, the proposed rule is designed to synchronize the 
requirements of ASME Codes and Sec.  50.55a as much as possible. For 
licensees with codes of record prior to ASME BPV Code, Section XI, 2019 
Edition, and OM Code, 2020 Edition, as incorporated by reference in 
Sec.  50.55a, the proposed rule specifies that the code of record 
interval for the ISI and IST programs shall be the same as the ISI 
interval or IST interval. This is consistent with the current 
requirements. For licensees with codes of record of ASME BPV Code, 
Section XI, 2019 Edition, or later editions and addenda, and ASME OM 
Code, 2020 Edition, or later editions, as incorporated by reference in 
Sec.  50.55a, the proposed rule specifies that the code of record 
interval for the ISI and IST programs shall be updated every two 
consecutive ISI intervals or IST intervals, respectively.
    With this revised requirement to update the code of record, the NRC 
does not intend that the code of record interval for an IST or ISI 
program will exceed 25 years, even if ASME extends the IST interval or 
the ISI interval beyond 12 years in the ASME OM Code or the ASME BPV 
Code, respectively. The 25-year maximum code of record interval allows 
the same code of record to be used for two consecutive ISI or IST 
intervals, each up to 12 years, plus the one-time, 1-year extension for 
IST and ISI programs as specified in the ASME OM Code and ASME BPV 
Code, respectively. The Commission has not approved extending the code 
of record

[[Page 13727]]

intervals beyond the 25-year maximum proposed in this rulemaking. If 
future editions of the ASME OM Code or ASME BPV Code or future code 
cases extend the IST interval or ISI interval, respectively, beyond 12 
years, the NRC would need to maintain the proposed 25-year maximum code 
of record interval.
    The concept of a 120-month interval is referenced repeatedly in 
Sec.  50.55a. However, the current language is not consistent or well-
defined. As such, the NRC proposes to clarify the language by 
introducing certain definitions in Sec.  50.55a(y). The proposed 
definitions include code of record, code of record interval, inservice 
examination and test interval, inservice inspection program, inservice 
testing program, and inspection interval. The NRC also proposes to 
update the language throughout Sec.  50.55a to be consistent with the 
proposed definitions.
    With respect to relief from impractical IST requirements as 
requested in accordance with Sec.  50.55a(f)(5)(iv), the NRC proposes 
that the duration of the granted relief be changed from the ``120-month 
interval of operation'' to the standardized definitions of the 
Inservice Examination and Test Interval. At the end of the Inservice 
Examination and Test Interval, the licensee would reassess whether the 
IST requirement continues to be impractical and submit an updated 
relief request as necessary. The NRC is proposing similar revisions for 
the ISI requirements in Sec.  50.55a(g)(5)(iii) and (iv).
    With respect to alternative requests in accordance with Sec.  
50.55a(z), the NRC will address the duration of each new authorized 
alternative in the safety evaluation describing its review of the 
request consistent with the current procedures for evaluating 
alternative requests. Existing NRC-approved alternatives were approved 
based on the IST or ISI interval. The proposed rulemaking language 
regarding the code of record interval does not extend the approval 
timeframe for these existing alternatives. Licensees seeking to extend 
the timeframe of approved alternatives therefore would need to submit 
an alternative request per Sec.  50.55a(z) to continue using previously 
granted alternatives in a subsequent IST or ISI interval in the same 
code of record update interval. Licensees may request future 
alternatives based upon the code of record interval.
    In addition, the NRC proposes to update references to the 10-year 
service period in appendix J to 10 CFR part 50 to be consistent with 
the definitions in the proposed Sec.  50.55a(y), in which the NRC 
proposes to allow the ISI period to be extended to 12 years. The 
current rules for Type A tests under Option A (prescriptive 
requirements) explicitly reference the 10-year service period required 
in Sec.  50.55a for inservice inspections. Consistent with the NRC's 
stated goal of maintaining consistency across all NRC rules regarding 
ISI and IST programs, the NRC is proposing revisions to appendix J to 
10 CFR part 50 to directly reference the interval defined in a revised 
10 CFR 50.55a, to accommodate a 12-year ISI interval. For the reasons 
stated in SECY-22-0075, the NRC proposes to make this revision without 
changing the intent or basis for the Type A test requirement in 
appendix J to 10 CFR part 50.
    Licensees are currently required to submit various documents, such 
as IST plans and schedules or Section XI flaw evaluations, to the NRC 
each IST or ISI interval. The language proposed in this rulemaking 
regarding the code of record intervals does not alter those submittal 
requirements in any way. Therefore, licensees should carefully 
distinguish requirements that apply to the code of record interval from 
those that apply to the IST or ISI interval. For example, Sec.  
50.55a(f)(7) requires IST plans to be submitted within 90 days of their 
implementation for the applicable 120-month IST program interval. This 
proposed rule would revise the terms used in paragraph (f)(7) for 
consistency with the new definitions, but submittal of IST plans would 
still be required within 90 days of their implementation for the 
applicable IST interval.

IV. Specific Requests for Comments

    The NRC is seeking advice and recommendations from the public on 
the proposed rule. We are particularly interested in comments and 
supporting rationale from the public on the following:
     The NRC proposes to add Sec.  50.55a(y) to include 
definitions of certain terms that may be important for delineating 
requirements related to IST and ISI programs. Are the proposed 
definitions appropriate for their intended purpose? Should the NRC 
consider defining other terms related to IST and ISI? Please provide 
the basis for your response.
     The NRC proposes to revise Sec.  50.55a(b)(5)(ii) and 
(iii) to relate those requirements regarding superseded and annulled 
code cases to the code of record interval, as defined in Sec.  
50.55a(y) of the proposed rule. Should the NRC instead consider 
relating those requirements to the ISI and IST interval? Please provide 
the basis for your response.

V. Section-by-Section Analysis

    The following paragraphs in Sec.  50.55a would be revised as 
follows:

Paragraph (a)

    This proposed rule would revise the introductory text to paragraph 
(a) by removing ``standards'' and adding in its place ``materials'' or 
``all approved materials'', as applicable, thereby aligning with the 
latest guidance on incorporation by reference.

Paragraph (a)(3)(i)

    This proposed rule would revise the reference to ``NRC Regulatory 
Guide 1.84, Revision 39,'' by removing ``Revision 39'' and adding in 
its place ``Revision 40'' and changing the month and year for the 
document's revision date.

Paragraph (a)(3)(ii)

    This proposed rule would revise the reference to ``NRC Regulatory 
Guide 1.147, Revision 20'' by removing ``Revision 20'' and adding in 
its place ``Revision 21'' and changing the month and year for the 
document's revision date.

Paragraph (a)(3)(iii)

    This proposed rule would revise the reference to ``NRC Regulatory 
Guide 1.192, Revision 4'' by removing ``Revision 4'' and adding in its 
place ``Revision 5'' and changing the month and year for the document's 
revision date.

Paragraph (b)(5)(ii)

    This proposed rule would amend paragraph (b)(5)(ii) by replacing 
the text ``120-month interval'' with the text ``code of record 
interval'' and ``120-month ISI program intervals'' with the text ``code 
of record intervals.''

Paragraph (b)(5)(iii)

    This proposed rule would amend paragraph (b)(5)(iii) by replacing 
the text ``120-month interval'' with the text ``code of record 
interval.''

Paragraph (b)(6)(ii)

    This proposed rule would amend paragraph (b)(6)(ii) by replacing 
the text ``120-month interval'' with the text ``code of record 
interval'' and ``120-month ISI program'' with the text ``code of 
record.''

Paragraph (b)(6)(iii)

    This proposed rule would amend paragraph (b)(6)(iii) by replacing 
the text ``120-month interval'' with the text ``code of record 
interval.''

[[Page 13728]]

Paragraph (f)(4)(i)

    This proposed rule would revise the heading and text of paragraph 
(f)(4)(i) to replace the text ``120-month'' with the text ``code of 
record.'' This proposed rule also would insert the text ``no more 
than'' to clarify that licensees may consider ASME OM Code editions 
incorporated by reference less than 18 months before the date of 
issuance of the operating license or before the date of initial fuel 
load.

Paragraph (f)(4)(ii)

    This proposed rule would revise the heading and text of paragraph 
(f)(4)(ii) to replace the text ``120-month'' with the text ``code of 
record.'' This proposed rule also would insert the text ``no more 
than'' to clarify that licensees may consider ASME OM Code editions 
incorporated by reference less than 18 months before the start of the 
code of record interval.

Paragraph (f)(5)(iv)

    This proposed rule would amend paragraph (f)(5)(iv) by replacing 
the text ``120-month interval of operation'' with the text ``inservice 
examination and test interval.''

Paragraph (f)(7)

    This proposed rule would amend paragraph (f)(7) by replacing the 
text ``120-month IST Program interval'' with the text ``inservice 
examination and test interval.''

Paragraph (g)(4) Introductory Text

    This proposed rule would amend paragraph (g)(4) introductory text 
by inserting the text ``BPV'' into the text ``ASME Code Class 1, Class 
2, and Class 3'' to clarify the language.

Paragraph (g)(4)(i)

    This proposed rule would revise paragraph (g)(4)(i) to replace the 
text ``120-month inspection'' and ``120-month ISI'' with the text 
``code of record''; insert the text ``BPV'' into the text ``ASME Code 
Class 1, Class 2, and Class 3'' to clarify the language; and insert the 
text ``no more than'' to clarify that licensees may use ASME BPV Code, 
Section XI, editions incorporated by reference less than 18 months 
before the start of the code of record interval.

Paragraph (g)(4)(ii)

    This proposed rule would revise paragraph (g)(4)(ii) to replace the 
text ``120-month,'' ``120-month inspection,'' and ``120-month ISI'' 
with ``code of record''; insert the text ``BPV'' into the text ``ASME 
Code Class 1, Class 2, and Class 3'' to clarify the language; insert 
the text ``no more than'' to clarify that licensees may use ASME BPV 
Code, Section XI, editions incorporated by reference less than 18 
months before the start of the code of record interval; remove outdated 
language; and delete the term ``inservice'' to ensure consistency with 
the definitions in the proposed Sec.  50.55a(y).

Paragraph (g)(5)(i)

    This proposed rule would amend the heading for paragraph (g)(5)(i) 
by replacing the text ``ISI Code editions and addenda'' with the text 
``code of record.''

Paragraph (g)(5)(ii)

    This proposed rule would amend paragraph (g)(5)(ii) by replacing 
the text ``period'' with the text ``code of record interval.''

Paragraph (g)(5)(iii)

    This proposed rule would amend paragraph (g)(5)(iii) by removing 
the text ``120-month.'' This proposed rule also would delete the term 
``inservice'' to ensure consistency with the definitions in the 
proposed Sec.  50.55a(y).

Paragraph (g)(5)(iv)

    This proposed rule would amend paragraph (g)(5)(iv) by removing the 
text ``120-month.''

Paragraph (y)

    This proposed rule would add paragraph (y) to provide definitions 
of important terms used in Sec.  50.55a: Code of record, Code of record 
interval, Inservice examination and test interval, Inservice inspection 
program, Inservice examination and testing program, and Inspection 
interval.

Appendix J to 10 CFR Part 50

    This proposed rule would revise paragraph D.1.(a) in section III of 
option A to replace the text ``10-year service period'' with the text 
``inservice inspection interval, as defined in 10 CFR 50.55a(y),'' and 
replace the text ``10-year plant'' with the text ``final plant''. This 
proposed rule also would remove footnote 2 and redesignate footnote 3 
as footnote 2.

VI. Regulatory Flexibility Certification

    As required by the Regulatory Flexibility Act of 1980, 5 U.S.C. 
605(b), the Commission certifies that this rule, if adopted, will not 
have a significant economic impact on a substantial number of small 
entities. This proposed rule affects only the licensing and operation 
of nuclear power plants. The companies that own these plants do not 
fall within the scope of the definition of ``small entities'' set forth 
in the Regulatory Flexibility Act or the size standards established by 
the NRC (Sec.  2.810).

VII. Regulatory Analysis

    The NRC has prepared a draft regulatory analysis for this proposed 
regulation. The analysis examines the costs and benefits of the 
alternatives considered by the NRC. The NRC requests public comment on 
the draft regulatory analysis. The regulatory analysis is available as 
indicated in the ``Availability of Documents'' section of this 
document. Comments on the draft regulatory analysis may be submitted to 
the NRC as indicated under the ADDRESSES caption of this document.

VIII. Backfitting and Issue Finality

    The provisions in this proposed rule would allow licensees and 
applicants to voluntarily apply NRC-approved code cases, sometimes with 
NRC-specified conditions. The approved code cases are listed in three 
RGs that are proposed to be incorporated by reference into Sec.  
50.55a. An applicant's or a licensee's voluntary application of an 
approved code case does not constitute backfitting, because there is no 
imposition of a new requirement or new position.
    Similarly, voluntary application of an approved code case by a 10 
CFR part 52 applicant or licensee does not represent NRC imposition of 
a requirement or action, and therefore is not inconsistent with any 
issue finality provision in 10 CFR part 52. For these reasons, the NRC 
finds that this proposed rule does not involve any provisions requiring 
the preparation of a backfit analysis or documentation demonstrating 
that one or more of the issue finality criteria in 10 CFR part 52 are 
met.
    Other circumstances where the NRC does not apply the Backfit Rule 
to the approval and requirement to use later code editions and addenda 
are as follows:
    1. When the NRC takes exception to a later ASME BPV Code or OM Code 
provision but merely retains the current existing requirement, 
prohibits the use of the later code provision, limits the use of the 
later code provision, or supplements the provisions in a later code, 
the Backfit Rule does not apply because the NRC is not imposing new 
requirements. However, the NRC explains any such exceptions to the code 
in the preamble to and regulatory analysis for the rule.
    2. When an NRC exception relaxes an existing ASME BPV Code or OM 
Code provision but does not prohibit a licensee from using the existing 
code provision, the Backfit Rule does not

[[Page 13729]]

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 prepare documented evaluation in 
accordance with Sec.  50.109. These include the following:
    1. When the NRC endorses a later provision of the ASME BPV Code or 
OM Code that takes a substantially different direction from the 
existing requirements, the action is treated as a backfit (e.g., 61 FR 
41303; August 8, 1996).
    2. When the NRC requires implementation of a later ASME BPV Code or 
OM Code provision on an expedited basis, the action is treated as a 
backfit. This applies when implementation is required sooner than it 
would be required if the NRC simply endorsed the Code without any 
expedited language (e.g., 64 FR 51370; September 22, 1999).
    3. When the NRC takes an exception to an ASME BPV Code or OM Code 
provision and imposes a requirement that is substantially different 
from the existing requirement as well as substantially different from 
the later Code (e.g., 67 FR 60529; September 26, 2002).

ISI/IST Update Backfitting Considerations: Section XI of the ASME BPV 
Code and the ASME OM Code

    Proposed revisions to the code of record intervals of Section XI of 
the ASME BPV Code and the ASME OM Code are related to the ISI and IST 
programs of operating reactors. However, the Backfit Rule generally 
does not apply to incorporation by reference of later editions and 
addenda 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 
the current Sec.  50.55a, licensees must revise their ISI and IST 
programs every 120 months to the latest edition and addenda 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 120-month ISI and 
IST interval. Thus, 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. The NRC is proposing 
to revise the requirement to update to the latest edition and addenda 
before the start of every other ISI and IST interval. This proposed 
revision would be a voluntary relaxation, and thus not a backfit, 
because licensees will continue to have the option to voluntarily 
update before the start of each ISI or IST interval under Sec. Sec.  
50.55a(f)(4)(iv) or (g)(4)(iv).

Conclusion

    The NRC finds that the proposed incorporation by reference into 
Sec.  50.55a of the three RGs containing the latest NRC-approved code 
cases and the proposed revision of Sec.  50.55a to the identified ISI/
IST interval conditions, does not constitute backfitting or represent 
an inconsistency with any issue finality provisions in 10 CFR part 52.

IX. Plain Writing

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

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

    The Commission has determined under the National Environmental 
Policy Act of 1969, as amended, and the Commission's regulations in 
subpart A of 10 CFR part 51, that this rule, if adopted, would not be a 
major Federal action significantly affecting the quality of the human 
environment, an environmental impact statement is not required.
    The determination of this environmental assessment is that there 
will be no significant effect on the quality of the human environment 
from this action. Public stakeholders should note, however, that 
comments on any aspect of this environmental assessment may be 
submitted to the NRC as indicated under the ADDRESSES caption.
    As voluntary alternatives to the ASME Code, NRC-approved code cases 
provide an equivalent level of safety. The IST and ISI code of record 
update frequency is changing the update frequency of a program. 
Therefore, the probability or consequences of accidents is not changed. 
There also are no significant, non-radiological impacts associated with 
this action because no changes would be made affecting nonradiological 
plant effluents and because no changes would be made in activities that 
would adversely affect the environment. The determination of this 
environmental assessment is that there would be no significant offsite 
impact to the public from this action.

XI. Paperwork Reduction Act

    This proposed rule contains new or amended collections of 
information subject to the Paperwork Reduction Act of 1995 (44 U.S.C. 
3501 et seq.). This proposed rule has been submitted to the Office of 
Management and Budget for review and approval of the information 
collection(s).
    Type of submission, new or revision: Revision.
    The title of the information collection: Domestic Licensing of 
Production and Utilization Facilities: Updates to Incorporation by 
Reference and Regulatory Guides.
    The form number if applicable: Not applicable.
    How often the collection is required or requested: On occasion.
    Who will be required or asked to respond: Operating power reactor 
licensees and applicants for power reactors under construction.
    An estimate of the number of annual responses: 1.32 (0.66 reporting 
and 0.66 recordkeeping).
    The estimated number of annual respondents: 0.66.
    An estimate of the total number of hours needed annually to comply 
with the information collection requirement or request: 158.6.
    Abstract: This proposed rule is the latest in a series of 
rulemakings that incorporate by reference the latest versions of 
several RGs identifying new and revised unconditionally or 
conditionally acceptable ASME Code Cases that are approved for use.
    The U.S. Nuclear Regulatory Commission is seeking public comment on 
the potential impact of the information collection(s) contained in this 
proposed rule and on the following issues:
    1. Is the proposed information collection necessary for the proper

[[Page 13730]]

performance of the functions of the NRC, including whether the 
information will have practical utility?
    2. Is the estimate of the burden of the proposed information 
collection accurate?
    3. Is there a way to enhance the quality, utility, and clarity of 
the information to be collected?
    4. How can the burden of the proposed information collection on 
respondents be minimized, including the use of automated collection 
techniques or other forms of information technology?
    A copy of the Office of Management and Budget (OMB) clearance 
package is available in ADAMS under Accession No. ML22243A007 or can 
obtained free of charge by contacting the NRC's Public Document 
reference staff at 1-800-397-4209, 301-415-4737, or by email to 
[email protected]. You may obtain information and comment 
submissions related to the OMB clearance package by searching on 
https://www.regulations.gov under Docket ID NRC-2018-0291.
    You may submit comments on any aspect of these proposed information 
collections, including suggestions for reducing the burden and on the 
above issues, by the following methods:
     Federal rulemaking website: Go to https://www.regulations.gov and search for Docket ID NRC-2018-0291.
     Mail comments to: FOIA, Library, and Information 
Collections Branch, Office of the Chief Information Officer, Mail Stop: 
T-6 A10M, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001 
or to the OMB reviewer at: OMB Office of Information and Regulatory 
Affairs (3150-0011), Attn: Desk Officer for the Nuclear Regulatory 
Commission, 725 17th Street NW, Washington, DC 20503; email: 
[email protected].
    Submit comments by April 5, 2023. Comments received after this date 
will be considered if it is practical to do so, but the NRC is able to 
ensure consideration only for comments received on or before this date.

Public Protection Notification

    The NRC may not conduct or sponsor, and a person is not required to 
respond to, a collection of information unless the document requesting 
or requiring the collection displays a currently valid OMB control 
number.

XII. Voluntary Consensus Standards

    The National Technology Transfer and Advancement Act of 1995, 
Public Law 104-113, requires that Federal agencies use technical 
standards that are developed or adopted by voluntary consensus 
standards bodies unless using such a standard is inconsistent with 
applicable law or is otherwise impractical. In this proposed rule, the 
NRC is continuing to use the ASME BPV and OM Code Cases, which are 
ASME-approved voluntary alternatives to compliance with various 
provisions of the ASME BPV and OM Codes. The NRC's approval of the ASME 
Code Cases is accomplished by amending the NRC's regulations to 
incorporate by reference the latest revisions of the following, which 
are the subject of this rulemaking, into Sec.  50.55a: RG 1.84, 
Revision 40; RG 1.147, Revision 21; and RG 1.192, Revision 5. The RGs 
list the ASME Code Cases that the NRC has approved for use. The ASME 
Code Cases are national consensus standards as defined in the National 
Technology Transfer and Advancement Act of 1995 and OMB Circular A-119. 
The ASME Code Cases constitute voluntary consensus standards, in which 
all interested parties (including the NRC and licensees of nuclear 
power plants) participate. The NRC invites comment on the applicability 
and use of other standards.

XIII. Incorporation by Reference

    The NRC proposes to incorporate by reference three NRC RGs that 
list new and revised the ASME Code Cases that the NRC has approved as 
voluntary alternatives to certain provisions of NRC-required editions 
and addenda of the ASME BPV Code and the ASME OM Code. The draft 
regulatory guides, DG-1405, DG-1406, and DG-1407, will correspond to 
final RG 1.84, Revision 40; RG 1.147, Revision 21; and RG 1.192, 
Revision 5, respectively.
     RG 1.84, ``Design, Fabrication, and Materials Code Case 
Acceptability, ASME Section III,'' Revision 40 (Draft Regulatory Guide 
(DG)-1405), would allow nuclear power plant licensees and applicants 
for construction permits, operating licenses, combined licenses, 
standard design certifications, standard design approvals, and 
manufacturing licenses to use the code cases newly listed in this 
revised RG as voluntary alternatives to ASME engineering standards for 
the construction of nuclear power plant components.
     RG 1.147, ``Inservice Inspection Code Case Acceptability, 
ASME Section XI, Division 1,'' Revision 21 (DG-1406), would allow 
nuclear power plant licensees and applicants for construction permits, 
operating licenses, combined licenses, standard design certifications, 
standard design approvals, and manufacturing licenses to use the code 
cases newly listed in this revised RG as voluntary alternatives to ASME 
engineering standards for the inservice inspection of nuclear power 
plant components.
     RG 1.192, ``Operation and Maintenance [OM] Code Case 
Acceptability, ASME OM Code,'' Revision 5 (DG-1407), action would allow 
nuclear power plant licensees and applicants for construction permits, 
operating licenses, combined licenses, standard design certifications, 
standard design approvals, and manufacturing licenses to use the code 
cases newly listed in this revised RG as voluntary alternatives to ASME 
engineering standards for the inservice examination and testing of 
nuclear power plant components.
    The NRC is required by law to obtain approval for incorporation by 
reference from the Office of the Federal Register (OFR). The OFR's 
requirements for incorporation by reference are set forth in 1 CFR part 
51. On November 7, 2014, the OFR adopted changes to its regulations 
governing incorporation by reference (79 FR 66267). The OFR regulations 
require an agency to include in a proposed rule a discussion of the 
ways that the materials the agency proposes to incorporate by reference 
are reasonably available to interested parties or how it worked to make 
those materials reasonably available to interested parties. The 
discussion in this section complies with the requirement for proposed 
rules as set forth in 1 CFR 51.5(a)(1).
    The NRC considers ``interested parties'' to include all potential 
NRC stakeholders, not only the individuals and entities regulated or 
otherwise subject to the NRC's regulatory oversight. These NRC 
stakeholders are not a homogenous group, so the considerations for 
determining ``reasonable availability'' vary by class of interested 
parties. The NRC identified six classes of interested parties with 
regard to the material to be incorporated by reference in an NRC rule:
     Individuals and small entities regulated or otherwise 
subject to the NRC's regulatory oversight. This class includes 
applicants and potential applicants for licenses and other NRC 
regulatory approvals, and who are subject to the material to be 
incorporated by reference. In this context, ``small entities'' has the 
same meaning as set out in Sec.  2.810.
     Large entities otherwise subject to the NRC's regulatory 
oversight. This class includes applicants and potential applicants for 
licenses and other NRC regulatory approvals, and who are subject to the 
material to be incorporated by reference. In this context, a ``large 
entity'' is one that does

[[Page 13731]]

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 Indian tribes.
     Members of the general public (i.e., individual, 
unaffiliated members of the public who are not regulated or otherwise 
subject to the NRC's regulatory oversight) who need access to the 
materials that the NRC proposes to incorporate by reference in order to 
participate in the rulemaking.
    The three draft RGs that the NRC proposes to incorporate by 
reference in this proposed rule are available without cost and can be 
read online or downloaded online. The draft RGs can be viewed, by 
appointment, at the NRC Technical Library, which is located at Two 
White Flint North, 11545 Rockville Pike, Rockville, Maryland 20852; 
telephone: 301-415-7000; email: [email protected].
    Because the three draft regulatory guides, and eventually, the 
final regulatory guides, are available in various forms at no cost, the 
NRC determines that the three draft regulatory guides, DG-1405, DG-
1406, and DG-1407, and final RG 1.84, Revision 40; RG 1.147, Revision 
21; and RG 1.192, Revision 5, once approved by the OFR for 
incorporation by reference, are reasonably available to all interested 
parties.

XIV. Availability of Guidance

    The NRC will not be issuing guidance for this rulemaking.

XV. Public Meeting

    The NRC may conduct a public meeting on the proposed rule for the 
purpose of describing the changes to the code of record update 
frequency and its impact on the ISI and IST programs. The staff will 
also answer questions from the public regarding this proposed rule.
    The NRC will publish a notice of the location, time, and agenda of 
the meeting, if held, in the Federal Register, on Regulations.gov, and 
on the NRC's public meeting website within at least 10 calendar days 
before the meeting. Stakeholders should monitor the NRC's public 
meeting website for information about the public meeting at: https://www.nrc.gov/public-involve/public-meetings/index.cfm.

XVI. 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.

                 Table III--Rulemaking-Related Documents
------------------------------------------------------------------------
                                                   ADAMS accession No./
                    Document                         Federal Register
                                                         citation
------------------------------------------------------------------------
SRM-SECY-21-0029, ``Rulemaking Plan on            ML21312A490.
 Relaxation of Inservice Testing and Inservice
 Inspection Program Update Frequencies Required
 in 10 CFR 50.55a,'' dated November 8, 2021.
SECY-21-0029, ``Rulemaking Plan on Relaxation of  ML20273A286.
 Inservice Testing and Inservice Inspection
 Program Update Frequencies Required in 10 CFR
 50.55a,'' dated March 15, 2021.
SECY-22-0075, ``Staff Requirements-SECY-21-0029   ML22124A178.
 Inservice Testing and Inservice Inspection
 Program Rulemakings Update [NRC-2018-0291/3150-
 AK23],'' dated August 10, 2022.
Rulemaking-Proposed Rule-Draft Regulatory         ML22243A006.
 Analysis for American Society of Mechanical
 Engineers Code Cases, RG 1.84, Rev. 40; RG
 1.147, Rev. 21; RG 1.192 Rev. 5; RG 1.193, Rev.
 8, dated January 2023.
Rulemaking-Proposed Rule-OMB Clearance Package    ML22243A007.
 for American Society of Mechanical Engineers
 Code Cases, RG 1.84, Rev. 40; RG 1.147, Rev.
 21; RG 1.192 Rev. 5; RG 1.193, Rev. 8.
RG 1.193, ASME Code Cases Not Approved for Use,   ML22196A065.
 Revision 8 (DG-1408), dated January 2023.
ASME OM Code Case Applicability Index, dated      ML22279A967N.
 July 1, 2022.
ASME Letter to NRC, ``ASME Request for Including  ML22046A112.
 Specific Code Cases in Draft Revision 21 of
 Regulatory Guide 1.147,'' dated December 22,
 2021.
Final Rule--``Codes and Standards for Nuclear     41 FR 6256
 Power Plants and Technical Information,''
 February 12, 1976.
Proposed Rule--``Domestic Licensing of            44 FR 3719.
 Production and Utilization Facilities Codes and
 Standards for Nuclear Powerplants,'' January
 18, 1979.
Final Rule--``Domestic Licensing of Production    44 FR 57912.
 and Utilization Facilities; Codes and Standards
 for Nuclear Powerplants,'' October 9, 1979.
Codes and Standards for Nuclear Power Plants;     61 FR 41303.
 Subsection IWE and Subsection IWL, August 8,
 1996.
Proposed Rule--Industry Codes and Standards;      64 FR 51370.
 Amended Requirements, September 22, 1999.
Final Rule--Industry Codes and Standards;         67 FR 60529.
 Amended Requirements, September 26, 2002.
Final Rule--``Incorporation by Reference of ASME  68 FR 40469.
 BPV and OM Code Cases,'' July 8, 2003.
Final Rule--``Approval of American Society of     87 FR 11934.
 Mechanical Engineers Code Cases,'' March 3,
 2022.
Final Rule--``American Society of Mechanical      87 FR 65128.
 Engineers 2019-2020 Code Editions Incorporation
 by Reference,'' October 27, 2022.
------------------------------------------------------------------------

Documents Proposed To Be Incorporated by Reference

    The NRC proposes to incorporate by reference three NRC RGs, as set 
forth in Table IV, that list new and revised ASME Code Cases that the 
NRC is proposing to approve as voluntary alternatives to certain 
provisions of NRC-required editions and addenda of the ASME BPV Code 
and the ASME OM Code.

    Table IV--Draft Regulatory Guides Proposed To Be Incorporated by
                       Reference in 10 CFR 50.55a
------------------------------------------------------------------------
                                                   ADAMS accession No./
                    Document                         Federal Register
                                                         citation
------------------------------------------------------------------------
RG 1.84, Design, Fabrication, and Materials Code  ML22195A282.
 Case Acceptability, ASME Section III, Revision
 40 (DG-1405).
RG 1.147, Inservice Inspection Code Case          ML22195A284.
 Acceptability, ASME Section XI, Division 1,
 Revision 21 (DG-1406).

[[Page 13732]]

 
RG 1.192, Operation and Maintenance Code Case     ML22196A063.
 Acceptability, ASME OM Code, Revision 5 (DG-
 1407).
------------------------------------------------------------------------

Code Cases for Approval in This Proposed Rule

    The ASME BPV Code Cases that the NRC is proposing to approve as 
alternatives to certain provisions of the ASME BPV Code, as set forth 
in Table V, are being made available by the ASME for read-only access 
during the public comment period on https://go.asme.org/NRC-ASME.
    The ASME OM Code Cases that the NRC is proposing to approve as 
alternatives to certain provisions of the ASME OM Code, as set forth in 
Table V, are being made available for read-only access during the 
public comment period by the ASME on https://go.asme.org/NRC-ASME.
    The ASME is making the code cases listed in Table V available for 
limited, read-only access at the request of the NRC. The NRC believes 
that stakeholders need to be able to read these code cases in order to 
provide meaningful comment on the three RGs (listed in Table IV) that 
the NRC is proposing to incorporate by reference into Sec.  50.55a. It 
is the NRC's position that the listed code cases, as modified by any 
conditions contained in the three RGs and thus serving as alternatives 
to requirements in Sec.  50.55a, would be legally-binding regulatory 
requirements. An applicant or licensee must comply with a listed code 
case and any conditions to be within the scope of the NRC's approval of 
the code case as a voluntary alternative for use. These requirements 
cannot be fully understood without knowledge of the code case to which 
the proposed condition applies, and to this end, the NRC has requested 
that the ASME provide limited, read-only access to the code cases in 
order to facilitate meaningful public comment.

           Table V--ASME Code Cases Proposed for NRC Approval
------------------------------------------------------------------------
 
------------------------------------------------------------------------
               Boiler and Pressure Vessel Code Section III
------------------------------------------------------------------------
       Code case No.             Supplement               Title
------------------------------------------------------------------------
N-351-1....................  3 (2021 Edition)..  Use of Standard Subsize
                                                  Charpy V-Notch Impact
                                                  Specimens, Section
                                                  III, Division 1;
                                                  Section III, Division
                                                  2; Section III,
                                                  Division 3.
N-893......................  4 (2019 Edition)..  Use of Alloy Steel Bar
                                                  and Mechanical Tubing
                                                  in Class 2 and 3
                                                  Patented Mechanical
                                                  Joints and Fittings,
                                                  Section III, Division
                                                  1.
N-900......................  3 (2019 Edition)..  Alternative Rules for
                                                  Level D Service Limits
                                                  of Class 1, 2, and 3
                                                  Piping Systems,
                                                  Section III, Division
                                                  1.
N-901......................  4 (2019 Edition)..  Use of ASME SA-494
                                                  Grade M35-1 for Line
                                                  Valve Bodies and
                                                  Bonnets, and Bodies,
                                                  Bonnets, and Yokes of
                                                  Pressure Relief Valves
                                                  for Class 2 and 3
                                                  Construction, Section
                                                  III, Division 1.
N-902......................  5 (2019 Edition)..  Thickness and Gradient
                                                  Factors for Piping
                                                  Fatigue Analyses,
                                                  Section III, Division
                                                  1.
N-904......................  6 (2019 Edition)..  Alternative Rules for
                                                  Simplified Elastic-
                                                  Plastic Analysis,
                                                  Section III, Division
                                                  1.
N-905......................  6 (2019 Edition)..  Alternate Design
                                                  Fatigue Curves to
                                                  Those Given in For
                                                  Section III
                                                  Appendices, Mandatory
                                                  Appendix I, Figures I-
                                                  9.1 and I-9.1M,
                                                  Section III, Division
                                                  1.
N-908......................  7 (2019 Edition)..  Use of Ferritic/
                                                  Austenitic Wrought
                                                  WPS32750/CRS32750
                                                  Fittings of Seamless
                                                  or Welded Construction
                                                  Conforming to SA-815,
                                                  Class 3, Section III,
                                                  Division 1.
N-910......................  7 (2019 Edition)..  Use of 25Cr-7Ni-4Mo-N
                                                  (Alloy UNS S32750
                                                  Austenitic/Ferritic
                                                  Duplex Stainless
                                                  Steel) Forgings,
                                                  Plate, and Welded and
                                                  Seamless Pipe and
                                                  Tubing Conforming to
                                                  SA-182, SA-240, SA-
                                                  789, or SA-790,
                                                  Section III, Division
                                                  1.
N-919......................  2 (2021 Edition)..  Alternative Fatigue
                                                  Evaluation Method to
                                                  Consider Environmental
                                                  Effects on Class 1
                                                  Components Section
                                                  III, Division 1.
N-920......................  2 (2021 Edition)..  Alternative Fatigue
                                                  Design Curves for
                                                  Ferritic Steels With
                                                  Ultimate Tensile
                                                  Strengths (UTS) <= 80
                                                  ksi (552 MPa) and
                                                  Austenitic Steels,
                                                  Section III, Division
                                                  1.
N-71-21....................  0 (2021 Edition)..  Additional Materials
                                                  for Subsection NF,
                                                  Class 1, 2, 3, and MC
                                                  Supports Fabricated by
                                                  Welding, Section III,
                                                  Division 1.
N-570-3....................  0 (2021 Edition)..  Alternative Rules for
                                                  Linear Piping and
                                                  Linear Standard
                                                  Supports for Classes
                                                  1, 2, 3, and MC,
                                                  Section III, Division
                                                  1.
------------------------------------------------------------------------
               Boiler and Pressure Vessel Code Section XI
------------------------------------------------------------------------
       Code case No.             Supplement               Title
------------------------------------------------------------------------
N-561-4....................  0 (2021 Edition)..  Alternative
                                                  Requirements for Wall
                                                  Thickness Restoration
                                                  of Class 2 and High
                                                  Energy Class 3 Carbon
                                                  Steel Piping, Section
                                                  XI, Division 1.
N-562-4....................  0 (2021 Edition)..  Alternative
                                                  Requirements for Wall
                                                  Thickness Restoration
                                                  of Class 3 Moderate
                                                  Energy Carbon Steel
                                                  Piping, Section XI,
                                                  Division 1.
N-597-5....................  0 (2021 Edition)..  Evaluation of Pipe Wall
                                                  Thinning, Section XI,
                                                  Division 1.
N-638-11...................  2 (2019 Edition)..  Similar and Dissimilar
                                                  Metal Welding Using
                                                  Ambient Temperature
                                                  Machine GTAW Temper
                                                  Bead Technique,
                                                  Section XI, Division
                                                  1.
N-661-5....................  0 (2021 Edition)..  Alternative
                                                  Requirements for Wall
                                                  Thickness Restoration
                                                  of Class 2 and 3
                                                  Carbon Steel Piping
                                                  for Raw Water Service
                                                  Section XI, Division
                                                  1.
N-663-1....................  3 (2021 Edition)..  Alternative
                                                  Requirements for
                                                  Classes 1 and 2
                                                  Surface Examinations,
                                                  Section XI, Division
                                                  1.

[[Page 13733]]

 
N-733-1....................  6 (2019 Edition)..  Mitigation of Flaws in
                                                  NPS 3 (DN 80) and
                                                  Smaller Nozzles and
                                                  Nozzle Partial
                                                  Penetration Welds in
                                                  Vessels and Piping by
                                                  Use of a Mechanical
                                                  Connection
                                                  Modification, Section
                                                  XI, Division 1.
N-780-1....................  1 (2021 Edition)..  Alternative
                                                  Requirements for
                                                  Upgrade, Substitution,
                                                  or Reconfiguration of
                                                  Examination Equipment
                                                  When Using Appendix
                                                  VIII Qualified
                                                  Ultrasonic Examination
                                                  Systems, Section XI,
                                                  Division 1.
N-786-4....................  0 (2021 Edition)..  Alternative
                                                  Requirements for
                                                  Sleeve Reinforcement
                                                  of Class 2 and 3
                                                  Moderate Energy Carbon
                                                  Steel Piping, Section
                                                  XI, Division 1.
N-789-5....................  1 (2021 Edition)..  Alternative
                                                  Requirements for Pad
                                                  Reinforcement of Class
                                                  2 and 3 Moderate
                                                  Energy Carbon Steel
                                                  Piping for Raw Water
                                                  Service, Section XI,
                                                  Division 1.
N-809-1....................  0 (2021 Edition)..  Reference Fatigue Crack
                                                  Growth Rate Curves for
                                                  Austenitic Stainless
                                                  Steels in Pressurized
                                                  Reactor Water
                                                  Environments, Section
                                                  XI, Division 1.
N-853-1....................  0 (2021 Edition)..  PWR Class 1 Primary
                                                  Piping Alloy 600 Full
                                                  Penetration Branch
                                                  Connection Weld Metal
                                                  Buildup for Material
                                                  Susceptible to Primary
                                                  Water Stress Corrosion
                                                  Cracking, Section XI,
                                                  Division 1.
N-860......................  6 (2019 Edition)..  Inspection Requirements
                                                  and Evaluation
                                                  Standards for Spent
                                                  Nuclear Fuel Storage
                                                  and Transportation
                                                  Containment Systems,
                                                  Section XI, Division
                                                  1; Section XI,
                                                  Division 2.
N-865-2....................  0 (2021 Edition)..  Alternative
                                                  Requirements for Pad
                                                  Reinforcement of Class
                                                  2 and 3 Atmospheric
                                                  Storage Tanks, Section
                                                  XI, Division 1.
N-877-1....................  5 (2019 Edition)..  Alternative
                                                  Characterization Rules
                                                  for Multiple
                                                  Subsurface Radially
                                                  Oriented Planar Flaws,
                                                  Section XI, Division
                                                  1.
N-882-1....................  0 (2021 Edition)..  Alternative
                                                  Requirements for
                                                  Attaching
                                                  Nonstructural
                                                  Electrical Connections
                                                  to Class 2 and 3
                                                  Components, Section
                                                  XI, Division 1.
N-885-1....................  3 (2021 Edition)..  Alternative
                                                  Requirements for Table
                                                  IWB-2500-1,
                                                  Examination Category B-
                                                  N-1, Interior of
                                                  Reactor Vessel,
                                                  Category B-N-2, Welded
                                                  Core Support
                                                  Structures and
                                                  Interior Attachments
                                                  to Reactor Vessels,
                                                  Category BN-3,
                                                  Removable Core Support
                                                  Structures, Section
                                                  XI, Division 1.
N-888......................  5 (2019 Edition)..  Similar and Dissimilar
                                                  Metal Welding Using
                                                  Ambient Temperature
                                                  SMAW or Machine GTAW
                                                  Temper Bead Technique,
                                                  Section XI, Division
                                                  1.
N-896......................  2 (2019 Edition)..  Reference Crack Growth
                                                  Rate Curves for Stress
                                                  Corrosion Cracking of
                                                  Low Alloy Steels in
                                                  Boiling Water Reactor
                                                  Environments, Section
                                                  XI, Division 1.
N-911......................  0 (2021 Edition)..  Purchase, Exchange, or
                                                  Transfer of Material
                                                  Between Nuclear
                                                  Owners, Section XI,
                                                  Division 1.
N-912......................  0 (2021 Edition)..  Alternative
                                                  Requirements for
                                                  Qualification of
                                                  Material Suppliers and
                                                  Acceptance of
                                                  Materials, Section XI,
                                                  Division 1.
N-913......................  0 (2021 Edition)..  Alternative Examination
                                                  Requirements for Class
                                                  1 Pressure-Retaining
                                                  Welds in Control Rod
                                                  Drive Housings,
                                                  Section XI, Division
                                                  1.
N-917......................  2 (201 Edition)...  Fatigue Crack Growth
                                                  Rate Curves for
                                                  Ferritic Steels in
                                                  Boiling Water Reactor
                                                  (BWR) Environments,
                                                  Section XI, Division
                                                  1.
N-711-2....................  6 (2019 Edition)..  Alternative Examination
                                                  Coverage Requirements
                                                  for Examination
                                                  Category B F, B J, C-F-
                                                  1, C-F-2, and R-A
                                                  Piping Welds, Section
                                                  XI, Division 1.
N-716-3....................  5 (2019 Edition)..  Alternative
                                                  Classification and
                                                  Examination
                                                  Requirements, Section
                                                  XI, Division 1.
N-754-2....................  0 (2021 Edition)..  Optimized Structural
                                                  Dissimilar Metal Weld
                                                  Overlay for Mitigation
                                                  of PWR Class 1 Items,
                                                  Section XI, Division
                                                  1.
N-766-4....................  0 (2021 Edition)..  Nickel Alloy Reactor
                                                  Coolant Inlay and
                                                  Onlay for Mitigation
                                                  of PWR Full
                                                  Penetration
                                                  Circumferential Nickel
                                                  Alloy Dissimilar Metal
                                                  Welds in Class 1
                                                  Items, Section XI,
                                                  Division 1.
N-847-1....................  0 (2021 Edition)..  Partial Excavation and
                                                  Deposition of Weld
                                                  Metal for Mitigation
                                                  of Class 1 Items,
                                                  Section XI, Division
                                                  1.
N-880-1....................  0 (2021 Edition)..  Alternative to
                                                  Procurement
                                                  Requirements of IWA-
                                                  4143 for Small
                                                  Nonstandard Welded
                                                  Fittings, Section XI,
                                                  Division 1.
N-899......................  3 (2019 Edition)..  Weld Residual Stress
                                                  Distributions for
                                                  Piping and Vessel
                                                  Nozzle Butt Welds
                                                  Fabricated With UNS
                                                  N06082, UNS W86182,
                                                  UNS N06052, or UNS
                                                  W86152 Weld Filler
                                                  Material, Section XI,
                                                  Division 1.
N-906......................  7 (2019 Edition)..  Flaw Evaluation
                                                  Procedure for Cast
                                                  Austenitic Stainless
                                                  Steel Piping and
                                                  Adjacent Fittings,
                                                  Section XI, Division
                                                  1.
N-921......................  3 (2021 Edition)..  Alternative 12-yr
                                                  Inspection Interval
                                                  Duration, Section XI,
                                                  Division 1.
------------------------------------------------------------------------
                     Operation and Maintenance Code
------------------------------------------------------------------------
       Code case No.             Edition \6\              Title
------------------------------------------------------------------------
OMN-28.....................  2022 Edition......  Alternative Valve
                                                  Position Verification
                                                  Approach to Satisfy
                                                  ISTC-3700 for Valves
                                                  Not Susceptible to
                                                  Stem-Disk Separation.
OMN-29.....................  2022 Edition......  Pump Condition
                                                  Monitoring Program.
OMN-30.....................  2022 Edition......  Alternative Valve
                                                  Position Verification
                                                  Approach to Satisfy
                                                  ISTC-3700.
OMN-31.....................  2022 Edition......  Alternative to Allow
                                                  Extension of ISTA-3120
                                                  Inservice Examination
                                                  and Test Intervals
                                                  From 10 Years to 12
                                                  Years.
------------------------------------------------------------------------

    Throughout the development of this rule, the NRC may post documents 
related to this rule, including public comments, on the Federal 
rulemaking website at https://www.regulations.gov under Docket ID NRC-
2018-0291. In addition, the Federal rulemaking website allows members 
of the public to receive alerts when changes or additions occur in a 
docket folder. To subscribe: (1) navigate to the docket folder (NRC-

[[Page 13734]]

2018-0291); (2) click the ``Subscribe'' link; and (3) enter an email 
address and click on the ``Subscribe'' link.
---------------------------------------------------------------------------

    \6\ Each code case or ASME Applicability Index List indicates 
the ASME OM Code editions and addenda to which the code case 
applies, except where a condition is specified in Sec.  50.55a or RG 
1.192 related to technical content or applicability. This table 
indicates the latest OM Code edition at the time of this rulemaking.
---------------------------------------------------------------------------

List of Subjects in 10 CFR Part 50

    Administrative practice and procedure, Antitrust, Backfitting, 
Classified information, Criminal penalties, Education, Emergency 
planning, Fire prevention, Fire protection, Incorporation by reference, 
Intergovernmental relations, Nuclear power plants and reactors, 
Penalties, Radiation protection, Reactor siting criteria, Reporting and 
recordkeeping requirements, Whistleblowing.

    For the reasons set out in the preamble and under the authority of 
the Atomic Energy Act of 1954, as amended; the Energy Reorganization 
Act of 1974, as amended; and 5 U.S.C. 552 and 553, the NRC is proposing 
to amend 10 CFR part 50 as follows:

PART 50--DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION 
FACILITIES

0
1. The authority citation for part 50 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. Revise the introductory text of paragraph (a);
0
b. In paragraph (a)(3)(i):
0
i. Remove the text ``Revision 39'', wherever it appears, and add, in 
its place, the text ``Revision 40''; and
0
ii. Remove the text ``issued December 2021'' and add, in its place, the 
text ``issued January 2023'';
0
c. In paragraph (a)(3)(ii):
0
i. Remove the text ``Revision 20'', wherever it appears, and add, in 
its place, the text ``Revision 21''; and
0
ii. Remove the text ``issued December 2021'' and add in its place the 
text ``issued January 2023'';
0
d. In paragraph (a)(3)(iii):
0
i. Remove the text ``Revision 4'' and add, in its place, the text 
``Revision 5'';
0
ii. Remove the text ``Revision 3'' and add, in its place, the text 
``Revision 5''; and
0
iii. Remove the text ``issued December 2021'' and add, in its place, 
the text ``issued January 2023'';
0
e. In paragraphs (b)(5)(ii) and (iii) and (b)(6)(ii) and (iii), remove 
the text ``120-month interval'' and add in its place the text ``code of 
record interval'', wherever it appears; and
0
f. In paragraphs (b)(5)(ii) and (b)(6)(ii), remove the text ``120-month 
ISI program intervals'' and add in its place the text ``code of record 
intervals'', wherever it appears;
0
g. Revise paragraphs (f)(4)(i) and (ii);
0
h. In paragraph (f)(5)(iv), remove the text ``120-month interval of 
operation'', wherever it appears, and add in its place the text 
``inservice examination and test interval'';
0
i. In paragraph (f)(7), remove the text ``120-month IST Program 
interval'', wherever it appears, and add in its place the text 
``inservice examination and test interval'';
0
j. In paragraph (g)(4) introductory text, remove the text ``ASME Code 
Class 1, Class 2, and Class 3'' and add in its place the text ``ASME 
BPV Code Class 1, Class 2, and Class 3'';
0
k. Revise paragraphs (g)(4)(i) and (ii);
0
l. In the heading for paragraph (g)(5)(i), remove the text ``ISI Code 
editions and addenda'' and add in its place the text ``code of 
record'';
0
m. In paragraph (g)(5)(ii), remove the text ``period'' and add in its 
place the text ``code of record interval'';
0
n. In paragraph (g)(5)(iii), remove the text ``120-month'' and 
``inservice'';
0
o. In paragraph (g)(5)(iv), remove the text ``120-month''; and
0
p. Add paragraph (y).
    The revisions and additions read as follows:


Sec.  50.55a  Codes and standards.

    (a) Documents approved for incorporation by reference. The material 
listed in this paragraph (a) is incorporated by reference into this 
section with the approval of the Director of the Federal Register under 
5 U.S.C. 552(a) and 1 CFR part 51. All approved material is available 
for inspection at the Nuclear Regulatory Commission (NRC) and at the 
National Archives and Records Administration (NARA). Contact NRC at: 
the NRC Technical Library, which is located at Two White Flint North, 
11545 Rockville Pike, Rockville, Maryland 20852; telephone: 301-415-
7000; email: [email protected]. For information on the 
availability of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations.html or email [email protected]. The 
material may be obtained from the following sources in this paragraph 
(a).
* * * * *
    (f) * * *
    (4) * * *
    (i) Applicable IST Code: Initial code of record interval. Inservice 
tests to verify operational readiness of pumps and valves, whose 
function is required for safety, conducted during the initial code of 
record interval must comply with the requirements in the latest edition 
and addenda of the ASME OM Code incorporated by reference in paragraph 
(a)(1)(iv) of this section on the date no more than 18 months before 
the date of issuance of the operating license under this part, or no 
more than 18 months before the date scheduled for initial loading of 
fuel under a combined license under part 52 of this chapter (or the 
optional ASME OM Code Cases listed in NRC Regulatory Guide 1.192, as 
incorporated by reference in paragraph (a)(3)(iii) of this section, 
subject to the conditions listed in paragraph (b) of this section).
    (ii) Applicable IST Code: Successive code of record intervals. 
Inservice tests to verify operational readiness of pumps and valves, 
whose function is required for safety, conducted during successive code 
of record intervals must comply with the requirements of the latest 
edition and addenda of the ASME OM Code incorporated by reference in 
paragraph (a)(1)(iv) of this section no more than 18 months before the 
start of the code of record interval (or the optional ASME Code Cases 
listed in NRC Regulatory Guide 1.147 or NRC Regulatory Guide 1.192 as 
incorporated by reference in paragraphs (a)(3)(ii) and (iii) of this 
section, respectively), subject to the conditions listed in paragraph 
(b) of this section.
* * * * *
    (g) * * *
    (4) * * *
    (i) Applicable ISI Code: Initial code of record interval. Inservice 
examination of components and system pressure tests conducted during 
the initial code of record interval must comply with the requirements 
in the latest edition and addenda of the ASME BPV Code incorporated by 
reference in paragraph (a) of this section on the date no more than 18 
months before the date of issuance of the operating license under this 
part, or no more than 18 months before the date scheduled for initial 
loading of fuel under a combined license under part 52 of this chapter 
(or the optional ASME Code Cases listed in NRC Regulatory Guide 1.147, 
when using ASME BPV Code, Section XI, or NRC Regulatory Guide 1.192, 
when using the ASME OM Code, as incorporated by reference in paragraphs 
(a)(3)(ii) and (iii) of this section, respectively), subject to the 
conditions

[[Page 13735]]

listed in paragraph (b) of this section. Licensees may, at any time in 
their code of record interval, elect to use the Appendix VIII in the 
latest edition and addenda of the ASME BPV Code incorporated by 
reference in paragraph (a) of this section, subject to any applicable 
conditions listed in paragraph (b) of this section. Licensees using 
this option must also use the same edition and addenda of Appendix I, 
Subarticle I-3200, as Appendix VIII, including any applicable 
conditions listed in paragraph (b) of this section.
    (ii) Applicable ISI Code: Successive code of record intervals. 
Inservice examination of components and system pressure tests conducted 
during successive code of record intervals must comply with the 
requirements of the latest edition and addenda of the ASME BPV Code 
incorporated by reference in paragraph (a) of this section no more than 
18 months before the start of the code of record interval (or the 
optional ASME Code Cases listed in NRC Regulatory Guide 1.147, when 
using ASME BPV Code, Section XI, or NRC Regulatory Guide 1.192, when 
using the ASME OM Code, as incorporated by reference in paragraphs 
(a)(3)(ii) and (iii) of this section), subject to the conditions listed 
in paragraph (b) of this section. Licensees may, at any time in their 
code of record interval, elect to use the Appendix VIII in the latest 
edition and addenda of the ASME BPV Code incorporated by reference in 
paragraph (a) of this section, subject to any applicable conditions 
listed in paragraph (b) of this section. Licensees using this option 
must also use the same edition and addenda of Appendix I, Subarticle I-
3200, as Appendix VIII, including any applicable conditions listed in 
paragraph (b) of this section.
* * * * *
    (y) Definitions. (1) Code of record means:
    (i) For the ASME BPV Code, Section XI, the edition (and addenda) 
implemented by a licensee in accordance with the requirements of this 
section.
    (ii) For the ASME OM Code, the edition (and addenda) implemented by 
a licensee in accordance with the requirements of this section.
    (iii) For the ASME BPV Code, Section III, the edition implemented 
by a licensee in accordance with the requirements of this section, 
which may vary by component.
    (2) Code of record interval means the period of time between the 
code of record updates required by paragraphs (f)(4) and (g)(4) of this 
section for the inservice inspection and inservice examination and test 
programs, respectively.
    (i) For licensees with codes of record prior to ASME BPV Code, 
Section XI, 2019 Edition, and OM Code, 2020 Edition, as incorporated by 
reference in paragraph (a) of this section, the code of record interval 
is the same as the inspection interval or inservice examination and 
test interval.
    (ii) For licensees with codes of record of ASME BPV Code, Section 
XI, 2019 Edition and OM Code, 2020 Edition, or later, as incorporated 
by reference in paragraph (a) of this section, the code of record 
interval is two consecutive inservice inspection or inservice 
examination and test intervals.
    (3) Inservice examination and test (IST) interval, for the purposes 
of this section, means the inservice examination and test interval 
described by the licensee's code of record (paragraph ISTA-3120 of the 
ASME OM Code, 2001 Edition through 2009 Edition, or paragraph ISTA-3120 
of the ASME OM Code, 2012 Edition and later).
    (4) Inservice inspection (ISI) program, for the purposes of this 
section, means the set of all administrative and technical requirements 
pertaining to periodic examination of nuclear components, as specified 
in ASME BPV Code, Section XI, and this section, including but not 
limited to:
    (i) The requirements of IWA-2400 of ASME BPV Code, Section XI, 1991 
Addenda and later.
    (ii) Relief requested under paragraph (g)(5)(iii) of this section 
and granted under paragraph (g)(6)(i) of this section.
    (iii) The augmented inspection program described in paragraph 
(g)(6) of this section.
    (iv) Alternatives authorized under paragraph (z) of this section.
    (5) Inservice examination and testing (IST) program, for the 
purposes of this section, means the requirements for preservice and 
inservice examination and testing of pumps, valves, and dynamic 
restraints within the scope of this section to assess their operational 
readiness in nuclear power plants, including but not limited to:
    (i) The requirements specified in the ASME OM Code, as incorporated 
by reference in this section, such as for test or examination, 
responsibilities, methods, intervals, parameters to be measured and 
evaluated, criteria for evaluating the results, corrective action, 
personnel qualification, and recordkeeping.
    (ii) Relief requested under paragraph (f)(5)(iii) of this section 
and granted under paragraph (f)(6)(i) of this section.
    (iii) Augmented IST requirements as applied by the Commission under 
paragraph (f)(6)(ii) of this section.
    (iv) Alternatives authorized under paragraph (z) of this section.
    (6) Inspection interval, as used in this section, means the 
inservice inspection interval described by the licensee's code of 
record (Article IWA-2432 of ASME BPV Code, Section XI, 1989 Edition 
with 1991 Addenda through the 2008 Addenda, or Article IWA-2431 of ASME 
BPV Code, Section XI, 2009 Addenda and later).
* * * * *
0
3. In section III of option A of appendix J to part 50, remove and 
reserve footnote 2 and revise paragraph D.1.(a) to read as follows:

Appendix J to Part 50--Primary Reactor Containment Leakage Testing for 
Water-Cooled Power Reactors

* * * * *
Option A--Prescriptive Requirements
* * * * *
    III. * * *
    D. * * *
    1. * * *
    (a) After the preoperational leakage rate tests, a set of three 
Type A tests shall be performed, at approximately equal intervals 
during each inspection interval, as defined in Sec.  50.55a(y). The 
third test of each set shall be conducted when the plant is shutdown 
for the final plant inservice inspections of the inspection interval.
* * * * *

    Dated: February 17, 2023.

    For the Nuclear Regulatory Commission.
Michael F. King,
Acting Director, Office of Nuclear Reactor Regulation.
[FR Doc. 2023-03742 Filed 3-3-23; 8:45 am]
BILLING CODE 7590-01-P