[Federal Register Volume 89, Number 137 (Wednesday, July 17, 2024)]
[Rules and Regulations]
[Pages 58039-58058]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-15288]



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 Rules and Regulations
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  Federal Register / Vol. 89, No. 137 / Wednesday, July 17, 2024 / 
Rules and Regulations  

[[Page 58039]]



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: Final rule.

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

SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is amending its 
regulations to incorporate by reference revisions of three regulatory 
guides to approve new, revised, and reaffirmed code cases published by 
the American Society of Mechanical Engineers. This action allows 
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 regulatory guides as voluntary alternatives to 
engineering standards for the construction, inservice inspection, and 
inservice testing of nuclear power plant components. These engineering 
standards are set forth in the American Society of Mechanical Engineers 
Boiler and Pressure Vessel Code and American Society of Mechanical 
Engineers Operation and Maintenance Code, which are currently 
incorporated by reference into the NRC's regulations. Further, this 
final rule announces the availability of a related regulatory guide, 
not incorporated by reference into the NRC's regulations, that lists 
code cases that the NRC has not approved for use. Finally, this 
rulemaking provides more flexibility to licensees by expanding the code 
of record interval from ten years to two consecutive inservice testing 
and inservice inspection intervals.

DATES: This final rule is effective on August 16, 2024. The 
incorporation by reference of certain material listed in this rule is 
approved by the Director of the Federal Register as of August 16, 2024. 
The incorporation by reference of certain other material listed in the 
rule was approved by the Director of the Federal Register as of April 
4, 2022, and November 28, 2022.

ADDRESSES: 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. 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.
     NRC's Agencywide Documents Access and Management System 
(ADAMS): You may obtain publicly available documents online in the 
ADAMS Public Documents collection at https://www.nrc.gov/reading-rm/adams.html. To begin the search, select ``Begin Web-based ADAMS 
Search.'' For problems with ADAMS, please contact the NRC's Public 
Document Room (PDR) reference staff at 1-800-397-4209, at 301-415-4737, 
or by email to [email protected]. For the convenience of the reader, 
instructions about obtaining materials referenced in this document are 
provided in the ``Availability of Documents'' section.
     NRC's PDR: The PDR, where you may examine and order copies 
of publicly available documents, is open by appointment. To make an 
appointment to visit the PDR, please send an email to 
[email protected] or call 1-800-397-4209 or 301-415-4737, between 8 
a.m. and 4 p.m. eastern time (ET), Monday through Friday, except 
Federal holidays.
     Technical Library: The Technical Library, which is located 
at Two White Flint North, 11545 Rockville Pike, Rockville, Maryland 
20852, is open by appointment only. Interested parties may make 
appointments to examine documents by contacting the NRC Technical 
Library by email at [email protected] between 8 a.m. and 4 p.m. 
ET, Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT: Tyler Hammock, Office of Nuclear 
Material Safety and Safeguards, telephone: 301-415-1381, email: 
[email protected]; or Bruce Lin, Office of Nuclear Regulatory 
Research, telephone: 301-415-2446, [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 rulemaking incorporates by reference the latest revisions of 
three regulatory guides (RGs) into the NRC's regulations. The three 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 of 
Nuclear Power Plants, Division 1, OM Code: Section IST (OM Code) 
currently incorporated by reference into the NRC's regulations.
    This rulemaking also revises the current NRC requirement for 
nuclear power plant licensees to update the codes of record for their 
inservice examination and testing (IST) and inservice inspection (ISI) 
programs. Currently, licensees are required to update the code of 
record every 10 years. This rulemaking would revise the requirement so 
that licensees would update the code of record after completion of an 
ISI and IST interval, with a maximum of two consecutive ISI and IST 
intervals before licensees are required to update the code of record. 
This revision applies to licensees that are implementing the 2017 
Edition, or later editions, of the ASME OM Code and the 2017 Edition, 
or later editions, of the ASME BPV Code, Section XI, as incorporated by 
reference into Sec.  50.55a of title 10 of the Code of Federal 
Regulations (10 CFR) ``Codes and standards'' as the codes of record of 
their IST/ISI programs. This revision to the NRC's regulations 
implements Commission direction in staff requirements memorandum (SRM)

[[Page 58040]]

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.
    Following completion of this code case rulemaking and the ASME 
2021-2022 Code Editions rulemaking, the NRC plans to streamline 
approval of code cases that do not require conditions and are unlikely 
to receive significant and adverse public comments by using the direct 
final rule process. The code cases that either require conditions or 
are likely to receive significant and adverse comments will be combined 
with the Code Editions rulemakings, which will continue to follow the 
traditional proposed rule and comment rulemaking process.

B. Major Provisions

    The NRC is incorporating by reference the following three RGs: RG 
1.84, Design, Fabrication, and Materials Code Case Acceptability, ASME 
Section III, Revision 40; RG 1.147, Inservice Inspection Code Case 
Acceptability, ASME Section XI, Division 1, Revision 21; and RG 1.192, 
Operation and Maintenance [OM] Code Case Acceptability, ASME OM Code, 
Revision 5. This action allows 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 
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 
RG 1.193, ``ASME Code Cases Not Approved for Use,'' Revision 8, which 
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 is revising the requirements in Sec.  50.55a(f)(4) and 
(g)(4) to refer to the term ``code of record interval'' instead of 
``120-month interval.'' This term, as well as others, is defined in new 
definitions in Sec.  50.55a(y). Under the new rules, licensees may 
maintain the same code of record in their IST and ISI programs for two 
consecutive IST or ISI intervals. As a result of public comments on the 
proposed rule, the NRC made changes in the final rule to allow 
licensees to take advantage of this new flexibility provided their IST 
or ISI programs implement the 2017 Edition of the ASME OM Code or ASME 
BPV Code, Section XI, respectively. Also, as a result of public 
comments, the NRC revised the final rule to update the language of 
Sec.  50.55a(f)(4)(iv) and (g)(4)(iv) to allow licensees to use a later 
edition of ASME OM Code and ASME BPV Code, Section XI, as incorporated 
by reference into Sec.  50.55a, at the start of a new IST or ISI 
interval without submitting a request to the NRC for approval. As a 
result of these changes, licensees have the option to update their 
codes of record at the end of each ISI or IST interval or after two 
consecutive ISI or IST intervals.

C. Costs and Benefits

    The NRC prepared a final regulatory analysis to determine the 
expected quantitative costs and benefits of this final rule, as well as 
qualitative factors to be considered in the NRC's rulemaking decision. 
The analysis concluded that this final rule would result in net savings 
to the industry and the NRC. As shown in table I, the estimated total 
net benefit relative to the regulatory baseline and the quantitative 
benefits would outweigh the costs by a range from approximately $45.6 
million (7-percent net present value) to $56.2 million (3-percent net 
present value).

                                          Table I--Cost Benefit Summary
----------------------------------------------------------------------------------------------------------------
                                                                           Total averted costs (costs)
                                                               -------------------------------------------------
                           Attribute                                             7% Net present   3% Net present
                                                                 Undiscounted        value            value
----------------------------------------------------------------------------------------------------------------
Industry Implementation.......................................              $0               $0               $0
Industry Operation............................................      55,160,000       39,020,000       48,080,000
                                                               -------------------------------------------------
    Total Industry Costs......................................      55,160,000       39,020,000       48,080,000
NRC Implementation............................................               0                0                0
NRC Operation.................................................       9,300,000        6,550,000        8,070,000
                                                               -------------------------------------------------
    Total NRC Costs...........................................       9,300,000        6,550,000        8,070,000
                                                               -------------------------------------------------
        Net...................................................      64,460,000       45,570,000       56,150,000
----------------------------------------------------------------------------------------------------------------

    The final 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 final regulatory analysis concludes that this final 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 
final regulatory analysis as indicated in Section XVI, ``Availability 
of Documents.''

Table of Contents

I. Background
II. Discussion
III. Opportunities for Public Participation
IV. Public Comment Analysis
V. Section-by-Section Analysis
VI. Regulatory Flexibility Certification
VII. Regulatory Analysis
VIII. Backfitting and Issue Finality
IX. Plain Writing

[[Page 58041]]

X. Environmental Assessment and Final Finding of No Significant 
Environmental Impact
XI. Paperwork Reduction Act
XII. Congressional Review Act
XIII. Voluntary Consensus Standards
XIV. Incorporation by Reference--Reasonable Availability to 
Interested Parties
XV. Availability of Guidance
XVI. Availability of Documents

I. Background

A. 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 
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 final 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, that incorporated by 
reference into Sec.  50.55a the previous 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. 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 changes from the original plan in response to 
new information and changed circumstances that affected the 
implementation of SRM-SECY-21-0029. The changes described in SECY-22-
0075 included combining the ASME code case and the IST and ISI code of 
record update rulemakings and also making conforming and clarifying 
changes. One such change was adding a definition section (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) would be 
differentiated from both the ISI and IST intervals (the ASME interval 
described by the licensee's code of record).
    In this final rulemaking, along with incorporating by reference 
three regulatory guides on ASME code cases, the NRC is including rule 
language that specifies that licensees may update their IST and ISI 
codes of record every two consecutive IST intervals or ISI intervals 
provided the licensee implements the 2017 Edition, or later edition or 
addenda, of ASME BPV Code and the 2017 Edition, or later edition, of 
the ASME OM Code, as incorporated by reference into 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 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. 
Licensees implementing the 2017 Edition, or later edition, of ASME BPV 
Code, Section XI and the 2017 Edition, or later edition, of ASME OM 
Code may immediately utilize the extended code of record interval. The 
starting date for the 20- or 24-year code of record update interval 
begins on the date that the licensee had previously incorporated the 
2017 Edition, or later edition, as its code of record for the IST or 
ISI program. Following completion of their current IST or ISI programs, 
these licensees may choose to maintain the same code of record for the 
successive IST or ISI interval or update the edition. Licensees 
choosing to update the editions at the start of a new IST or ISI 
interval may do so without NRC approval, per the new language in Sec.  
50.55a(f)(4)(iv) and (g)(4)(iv). Licensees seeking to use a later 
edition in the middle of an IST or ISI interval must still submit an 
exemption request for NRC review and approval.
    In Revision 5 to RG 1.192, the NRC is conditionally accepting 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 2017 Edition 
of the ASME OM Code or later editions, as incorporated by reference in 
Sec.  50.55a, as the code of record for their IST program. In Revision 
21 to RG 1.147, the NRC is conditionally accepting 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 2017 Edition of the ASME BPV Code or 
later editions, as incorporated by reference in Sec.  50.55a, as the 
code of record for their ISI program.

[[Page 58042]]

As a result of public comments, the NRC added a new condition requiring 
that these code cases be implemented at the start of a new IST or ISI 
interval. Implementation of these code cases in the middle of an IST or 
ISI interval creates complications related to existing testing and 
examination schedules and alternatives that were approved assuming a 
10-year IST or ISI interval. Licensees seeking to apply these code 
cases in the middle of an IST or ISI interval would need to obtain an 
exemption under Sec.  50.12.

II. Discussion

A. Incorporation by Reference of Three Regulatory Guides

    This final rule incorporates 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 supersedes the 
incorporation by reference of Revision 39; RG 1.147, Revision 21 
supersedes the incorporation by reference of Revision 20; and RG 1.192, 
Revision 5 supersedes the incorporation by reference of Revision 4.
    The ASME Code Cases that are the subject of this final rule are the 
new and revised Section III and Section XI Code Cases as listed in 
Supplements 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 rulemaking. In response, the NRC included 
these three code cases within the scope of this rulemaking. The NRC is 
also including OMN-31 within the scope of this rulemaking to provide 
consistency between the ISI and IST programs.
     RG 1.84, Revision 40, includes new information reviewed by 
the NRC on the Section III Code Cases listed in Supplements 2 through 7 
to the 2019 Edition, and Supplements 0 through 3 to the 2021 Edition of 
the ASME BPV Code.
     RG 1.147, Revision 21, includes information reviewed by 
the NRC on the Section XI Code Cases listed in Supplements 2 through 7 
to the 2019 Edition, Supplements 0 through 2 to the 2021 Edition, and 
selected Code Cases from Supplement 3 to the 2021 Edition of the ASME 
BPV Code.
     RG 1.192, Revision 5, includes information reviewed by the 
NRC on OM Code Cases listed in the 2022 Edition of the OM Code and on 
the ASME Codes & Standards (C&S) Connect website.
    The ASME publishes code cases that provide alternatives to existing 
code requirements that the ASME developed and approved. This final rule 
incorporates 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 
final rule identifies the BPV Code Cases by the edition of the ASME BPV 
Code under which they were published by the ASME and the OM Code 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 final 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 inadequate 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 version 
of the code case they originally implemented or they may apply the 
later version of the code case, including any NRC-specified conditions 
placed on its use.
    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

[[Page 58043]]

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 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.

B. ASME Code Cases Approved for Unconditional Use

    The code cases discussed in table II are new, revised, or 
reaffirmed code cases in which the NRC is not imposing any conditions. 
The table identifies the regulatory guide listing the applicable code 
case that the NRC approves for use.

                     Table II--Acceptable Code Cases
------------------------------------------------------------------------
 Boiler and Pressure Vessel Code Section III (addressed in RG 1.84, Rev.
                              40, table 1)
-------------------------------------------------------------------------
  Code case No.      Published with 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.
------------------------------------------------------------------------
               Boiler and Pressure Vessel Code Section XI
                (addressed in RG 1.147, Rev. 21, table 1)
------------------------------------------------------------------------
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-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.

[[Page 58044]]

 
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 RG 1.192, Rev. 5, table 1)
-------------------------------------------------------------------------
    Code case      Most recent code edition \4\           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.
------------------------------------------------------------------------

C. ASME 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 to 
provide an acceptable level of quality and safety. Accordingly, the NRC 
imposed conditions on the use of these code cases to modify, limit, or 
clarify their requirements. The conditions specify, for each applicable 
code case, the additional activities that must be performed, the limits 
on the activities specified in the code case, and/or the supplemental 
information needed to provide clarity. These ASME Code Cases, listed in 
table III, are included in table 2 of RG 1.84, RG 1.147, and RG 1.192. 
This section provides the NRC's evaluation of the code cases and the 
reasons for the NRC's conditions. Notations indicate the conditions 
duplicated from previous versions of the RG.

             Table III--Conditionally Acceptable Code Cases
------------------------------------------------------------------------
 Boiler and Pressure Vessel Code Section III (addressed in RG 1.84, Rev.
                              40, table 2)
-------------------------------------------------------------------------
  Code case No.      Published with supplement            Title
------------------------------------------------------------------------
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 RG 1.147, Rev. 21, table 2)
------------------------------------------------------------------------
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 Nonstandard
                                                  Welded Fittings,
                                                  Section XI, Division
                                                  1.

[[Page 58045]]

 
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 RG 1.192, Rev. 5, table 2)
-------------------------------------------------------------------------
                    Most recent OM code edition
  Code case No.                 \5\                       Title
------------------------------------------------------------------------
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 (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 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 condition is 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 updated 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 imposing 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 (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 is 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 is 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 removes 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 ASME Code's 
desire to eliminate the provision for newly constructed plants to 
submit first time applications of N-716 to the NRC. ASME adopted a 
general policy to make ASME standards, including this code case, more 
generally applicable internationally. However, the NRC's opinion is 
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 for applications of N-716. The review 
would confirm the absence of new degradation mechanisms and evaluate 
any available operating experience, as well as any risk-related 
information for the new plants, prior to the initial application of the 
code case to new plants. Therefore, the NRC is imposing a condition 
that this code case is not approved for use by plants issued an

[[Page 58046]]

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 revising the conditions on N-754-1 to remove the 
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 develops 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 would have 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) can 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 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 is imposing this condition 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 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 are 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 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 are 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 N-880 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 imposing a 
condition 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. Therefore, 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 imposing 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 a 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 Conditions 2 and 3. Therefore, 
those conditions are retained in Revision 21 of RG 1.147.
Code Case N-899 [Supplement 3, 2019 Edition]
Type: New

[[Page 58047]]

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 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 the above discussion, the NRC is imposing 
the condition that only the standard weld residual stress distributions 
with repairs in 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 above. 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 imposing the following 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 a 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 thermal 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 thermal 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 imposing 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 licensees 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) determines which 
edition or addenda the licensee should apply to inservice inspection 
programs for a successive ISI interval. This regulation, along with the 
definitions in Sec.  50.55a(y), assumes a 10-year inservice inspection 
interval, unless the licensee's code of record is the 2017 Edition of 
ASME BPV Section XI or later.
    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.
    The proposed rule applied the flexibilities of this code case to 
licensees using the 2019 Edition of Section XI or later. However, in 
response to multiple commenters, the NRC performed an analysis between 
the 2019 Edition of Section XI and the 2017 Edition of Section XI and 
determined that no safety significant changes exist between the two 
editions. Because no safety significant changes were identified between 
the 2019 and 2017 editions, the NRC concluded that it would be 
appropriate to extend the flexibility to licensees on the 2017 Edition.
    In response to a comment, the NRC is adding a requirement that 
licensees implement Code Case N-921 only at the beginning of an ISI 
interval. For licensees already using the 2017 Edition, or later, of 
Section XI,

[[Page 58048]]

implementation of Code Case N-921 must wait until the start of the next 
ISI interval. There are complications associated with extending the ISI 
interval mid-interval. For instance, licensees wanting to extend the 
ISI interval mid-interval would need to evaluate all NRC-approved 
alternatives to determine if they should be resubmitted, especially 
considering that NRC may have granted the alternative assuming a 10-
year ISI interval. See Section II.F, ``Mid-Interval Discussion and 
Example,'' for a more detailed discussion of performing mid-interval 
updates. Further, Code Case N-921 specifies requirements in terms of 
three 4-year periods, so licensees would need to reconcile their 
inspection schedules accordingly. Therefore, this final rule specifies 
that Code Case N-921 can only be implemented following a routine update 
of the ISI program (i.e., cannot be implemented mid-interval) and 
requires the licensee's ISI code of record to be the 2017 Edition, or 
later, of the BPV Code.
    In response to a public comment, the NRC added a condition on Code 
Case N-921 to allow the exceptions described in Section XI, IWB-
2411(a), IWC-2411(a), and IWD-2411(a). These provisions provide 
exceptions to the inspection period requirements of tables IWB-2411-1, 
IWC-2411-1, and IWD-2411-1, respectively. These exceptions, which are 
in the Code provisions applicable to this alternative, were left out of 
the code case. The NRC approved these exceptions in the original code 
provisions through incorporation by reference of ASME BPV Code Section 
XI, without conditions. Therefore, the NRC agreed with the commenter 
and added a condition that the same exceptions of IWB-2411(a), IWC-
2411(a), and IWD-2411(a) should apply to table 1 of Code Case N-921.
    In response to a public comment, the NRC added a condition on Code 
Case N-921 that the code case cannot be used to modify examination 
schedules for augmented inspections under Sec.  50.55a(g)(6)(ii). Code 
Case N-921 only provides alternative to Section XI requirements, not 
NRC regulations. Licensees must continue implementing the augmented 
inspections as specified in Sec.  50.55a(g)(6)(ii) and the associated 
code cases. The NRC staff intends to continue participating in ASME 
Code committee discussions on this matter. The NRC may revisit the 
relationship between Code Case N-921 and the augmented inspection 
program in a future rulemaking.
ASME Operation and Maintenance Code Cases (RG 1.192)
Code Case OMN-31 [2022 Edition]
Type: New
Title: Alternative to Allow Extension of ISTA-3120 Inservice 
Examination and Test Intervals From 10 Years to 12 Years

    For the same reasons explained for Section XI Code Case N-921 
above, including the response to public comments, the NRC is 
restricting the use of OMN-31 to licensees implementing the ASME OM 
Code, 2017 Edition, or later, as the code of record for the IST 
Program, as well as imposing a condition that licensees may only begin 
implementing Code Case OMN-31 at the beginning of an IST interval as 
specified in ASME OM Code, paragraph ISTA-3120. See Section II.F, 
``Mid-Interval Discussion and Example,'' for a more detailed discussion 
of performing mid-interval updates.
    As indicated in RG 1.192, this OM Code Case may be applied by 
licensees implementing the 2017 Edition, or later, of the ASME OM Code 
incorporated by reference in Sec.  50.55a, as the code of record for 
the IST Program, contrary to the ASME OM Code Case Applicability Index, 
dated July 1, 2022. The NRC is also imposing a condition that licensees 
may only begin implementing Code Case OMN-31 at the beginning of an IST 
interval as specified in ASME OM Code, paragraph ISTA-3120.
Other OM Code Cases in Table 2 of Revision 5 to RG 1.192
    No changes were made to the OM Code Cases listed in table 2 of the 
Revision 5 to RG 1.192 (except for 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 Revision 5 to RG 1.192 (except 
for 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 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 Revision 5 of RG 1.192.

D. ASME Code Cases Not Approved for Use (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. 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), 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 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,

[[Page 58049]]

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.
    Therefore, neither 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 OM Code to be applied in each ISI or IST interval, 
respectively. The changes to these code of record requirements in this 
rulemaking are focused on that aspect alone.
    The NRC does not intend the extension of the code of record 
interval to affect the orderly implementation of IST and ISI programs. 
Therefore, the final 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, 2017 Edition, and 
OM Code, 2017 Edition, as incorporated by reference in Sec.  50.55a, 
the final 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, 2017 Edition, or later 
editions and addenda, and ASME OM Code, 2017 Edition, or later 
editions, as incorporated by reference in Sec.  50.55a, the final rule 
specifies that the code of record interval for the ISI and IST programs 
is two consecutive ISI 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 intervals beyond the 25-year maximum 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 25-year maximum code of 
record interval.
    In response to public comments, the NRC does not intend for 
licensees with codes of record of ASME BPV Code, Section XI, 2017 
Edition, or later editions and addenda, and ASME OM Code, 2017 Edition, 
or later editions, as incorporated by reference into Sec.  50.55a, to 
be required to maintain the same code of record for the two consecutive 
ASME intervals. Accordingly, the NRC modified Sec.  50.55a(f)(4)(iv) 
and (g)(4)(iv) to ensure that licensees and applicants maintain the 
ability to update their code of record at the end of each ASME interval 
without NRC approval. These licensees also may implement the extended 
code of record interval immediately when the rule becomes effective. 
The code of record interval for these licensees, per the definitions in 
Sec.  50.55a(y), is two consecutive IST or ISI intervals (not 20 or 24 
years). Therefore, these licensees may update their code of record 
either at the end of the current IST or ISI interval or at the end of 
the subsequent IST or ISI 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 provided clarifying language by introducing 
certain definitions in Sec.  50.55a(y). The definitions include IST 
code of record, ISI code of record, code of record interval, IST 
interval, ISI program, IST program, and ISI interval. The NRC updated 
the language throughout Sec.  50.55a to be consistent with the 
definitions.
    The NRC requested feedback on the proposed definitions and if more 
definitions were warranted. In general, commenters supported the 
proposed definitions. One commenter recommended that the definition for 
code of record be two specific definitions (IST code of record and ISI 
code of record) and requested that the NRC determine where the snubber 
program should be discussed. As a response to these specific comments, 
the NRC is providing two definitions for code of record: IST code of 
record and ISI code of record. Also, the NRC modified the IST code of 
record definition to include the snubber program.
    In the 2006 Addenda of the ASME BPV Code, Section XI, ASME moved 
the requirements for snubbers to Subsection ISTD, ``Preservice and 
Inservice Requirements for Dynamic Restraints (Snubbers) in Water-
Cooled Reactor Nuclear Power Plants,'' of the OM Code. Inservice 
examination, testing, and service life monitoring of dynamic restraints 
(snubbers) must meet the inservice examination and testing requirements 
set forth in the applicable ASME OM Code or ASME BPV Code, Section XI, 
as specified in Sec.  50.55a(b)(3)(v)(A) and (B). When using the 2006 
Addenda or later of the ASME BPV Code, Section XI, the inservice 
examination, testing, and service life monitoring requirements for 
dynamic restraints (snubbers) must meet the requirements set forth in 
the applicable ASME OM Code as specified in Sec.  50.55a(b)(3)(v)(B). 
When using the 2005 Addenda or earlier edition or addenda of the ASME 
BPV Code, Section XI, ASME OM Code, 1995 Edition through latest edition 
and addenda may be used for the inservice examination, testing, and 
service life monitoring requirements for dynamic restraints (snubbers), 
in place of the requirements of the applicable ASME BPV Code, Section 
XI, as specified in Sec.  50.55a(b)(3)(v). Nuclear power plant 
licensees are transitioning to the 2006 Addenda and later editions of 
the ASME OM Code at their next IST Code of Record update. Licensees are 
encouraged to discuss their plans regarding the snubber programs with 
their NRC project manager when preparing to implement IST programs with 
extended intervals.
    With respect to relief from impractical IST requirements as 
requested in accordance with Sec.  50.55a(f)(5)(iv), neither the 
rulemaking language regarding the code of record interval nor 
application of Code Cases OMN-31 or N-921 extend the approval timeframe 
for previously granted relief requests. At the end of the Inservice 
Examination and Test Interval, the licensee would

[[Page 58050]]

reassess whether the IST requirement continues to be impractical and 
submit an updated relief request as necessary. The NRC is implementing 
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 likely 
authorized based on the IST or ISI interval. Neither the rulemaking 
language regarding the code of record interval nor application of Code 
Cases OMN-31 or N-921 extend the approval timeframe for existing 
alternatives. Licensees should refer to the NRC safety evaluation to 
determine the timeframe for which the alternative is authorized and 
resubmit the request in an appropriate timeframe to maintain compliance 
with IST and ISI requirements. Licensees may request future 
alternatives based upon the code of record interval.
    In addition, the NRC updated references to the 10-year service 
period in appendix J to 10 CFR part 50 to be consistent with the 
definitions in Sec.  50.55a(y), in which the NRC is allowing 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 revising 
appendix J to directly reference the interval defined in 10 CFR 50.55a, 
to accommodate a 12-year ISI interval. For the reasons stated in SECY-
22-0075, the NRC made this revision without changing the intent or 
basis for the Type A test requirement in appendix J.
    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 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 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.

F. Mid-Interval Discussion and Example

    The NRC recognizes that a licensee might consider updating its code 
of record for the ISI/IST program to a more recent Code edition (such 
as 2017 Edition or later) during an ISI/IST interval to take advantage 
of the allowance in the rule to double the code of record interval. 
Similarly, a licensee might consider implementing Code Case N-921 
during an ISI interval or Code Case OMN-31 during an IST interval. The 
staff notes that complications may arise because of reconciling Section 
XI and OM Code requirements and requests that were granted or 
authorized for a 10-year ISI/IST interval relative to the edition 
previously specified in the licensee's ISI/IST program. The NRC will 
review mid-interval requests by licensees to update to a more recent 
edition of the ASME Code as the new code of record for the ISI/IST 
program per the existing process described in 10 CFR 50.55a(g)(4)(iv) 
or 50.55a(f)(4)(iv) and Regulatory Issue Summary 2004-12. Licensees 
making such requests should evaluate the impact of updating the code of 
record on their ISI/IST program, including the completed ISI/IST 
activities and planned ISI/IST activities. Licensees should review 
previously authorized alternatives under 10 CFR 50.55a(z) and determine 
if they need to be resubmitted because of the specific duration 
specified in the request and authorization. The licensee should also 
review any previously granted relief requests for their duration and 
the need for resubmittal, as applicable. If such reviews and approvals 
are completed, licensees may take advantage of the extended code of 
record interval afforded by the rule.
    The staff notes that the code of record interval is defined as two 
consecutive ISI/IST Intervals (rather than 20 or 24 years). A licensee 
that updates the code of record during an ISI/IST interval would be 
able to maintain the same code of record for the remainder of the 
current ISI/IST interval and the entirety of the subsequent ISI/IST 
interval. At the end of the subsequent ISI/IST interval, however, the 
licensee must update its code of record, since two consecutive ISI/IST 
intervals have passed. For example, a licensee begins a new ISI/IST 
interval in January 2020. In 2025, the licensee requests to implement 
the 2017 edition of ASME BPV Code Section XI or OM Code under 10 CFR 
50.55a(g)(4)(iv) or (f)(4)(iv). If the NRC approves the request, the 
ISI/IST interval would end in January 2030 (i.e., 10 years from January 
2020 when the ISI/IST interval began), while the code of record 
interval would extend to 2040. If the licensee chooses to implement 
Code Case N-921 or OMN-31 in January 2030, the ISI/IST interval and the 
code of record interval would extend to 2042.
    Upon the effective date of this final rule, a licensee already 
implementing the 2017 Edition, or later edition, of the ASME Code for 
the ISI/IST program would continue with its ongoing 10-year ISI/IST 
interval with the 2017 Edition, or later edition, as the code of record 
for the ISI/IST program. At the end of the ongoing 10-year ISI/IST 
interval, the licensee would assess the ISI/IST program as required in 
the ASME Code, including the need to resubmit requests for alternatives 
or relief that expired at the end of the 10-year ISI/IST interval. At 
that time, the licensee could remain on the same Code edition as the 
code of record for the subsequent ISI/IST interval, and NRC approval 
would not be required to do so. At the end of that ISI/IST interval, 
the licensee would update its code of record to the latest Code edition 
incorporated by reference in 10 CFR 50.55a 18 months before the 
beginning date of the next ISI/IST interval and submit any alternative 
or relief requests for the next ISI/IST interval.

III. Opportunities for Public Participation

    The proposed rule was published in the Federal Register on March 6, 
2023 (88 FR 13717) for a 60-day comment period ending May 5, 2023. On 
May 3, 2023, the NRC published notification in the Federal Register (88 
FR 27712) extending the public comment period by an additional 42 days 
to end on June 16, 2023. The NRC held a public meeting on March 20, 
2023, and developed a public meeting summary (ML23083B303).

IV. Public Comment Analysis

    The NRC published the proposed rule and noticed the draft 
regulatory guides for public comment in the Federal Register. The NRC 
received 13 comment submissions. A comment submission is a 
communication or document submitted to the NRC by an individual or 
entity, with one or more individual comments addressing a subject or 
issue. Private citizens provided two comment submissions, nuclear 
industry organizations provided seven comment submissions, business/
trade associations provided three comment submissions, and one comment

[[Page 58051]]

submission was submitted anonymously.
    The comment submissions generally addressed the code cases and 
their proposed conditions. Many of the comments objected to the 
proposed conditions for Code Case N-921 (five comments), Code Case OMN-
31 (three comments), and the rule language associated with the code 
edition requirements for implementing the extended code of record 
intervals (four comments). The NRC received two comments objecting to 
the fact that the proposed rule language on the extended code of record 
interval did not allow for licensees and applicants to update their 
code of record following completion of a single IST or ISI interval 
without first receiving NRC approval. The NRC received one comment that 
was outside the scope of this rulemaking.
    The public comment submittals are available from the Federal e-
Rulemaking website at https://www.regulations.gov under Docket ID NRC-
2018-0291. The NRC prepared a summary and analysis of public comments 
received on the proposed rule and draft regulatory guides, which is 
available as indicated in Section XVI, ``Availability of Documents,'' 
of this document. Responses to the public comments, including a summary 
of how the final rule text or the regulatory guides changed as a result 
of the public comments, can be found in the public comment analysis.
    For more information about the associated guidance documents, see 
Section XVI, ``Availability of Guidance,'' of this document.

V. Section-by-Section Analysis

    This section describes the primary revisions made by this final 
rule; minor editorial and administrative corrections to correct 
spacing, administrative errors, and typos are not identified in this 
analysis.
    The NRC revised the following paragraphs in Sec.  50.55a as 
follows:

Paragraph (a)(3)(i)

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

Paragraph (b)(5)(iii)

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

Paragraph (b)(6)(ii)

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

Paragraph (b)(6)(iii)

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

Paragraph (f)(4)(i)

    This final rule revises the heading and text of paragraph (f)(4)(i) 
by replacing the text ``120-month'' with the text ``code of record.'' 
This final rule also inserts 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 final rule revises the heading and text of paragraph 
(f)(4)(ii) by replacing the text ``120-month'' with the text ``code of 
record.'' This final rule also inserts 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)(4)(iv)

    This final rule revises paragraph (f)(4)(iv) by adding language 
describing when licensees may update their code of record without NRC 
approval.

Paragraph (f)(5)(iv)

    This final rule amends 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 final rule amends 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 final rule amends 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 final rule revises paragraph (g)(4)(i) to replace the text 
``120-month interval'' with the text ``code of record interval,'' 
replace the text ``120-month inspection interval'' with the text ``code 
of record interval,'' replace the text ``120-month ISI interval'' with 
the text ``code of record interval,'' insert the text ``BPV'' into the 
text ``ASME Code incorporated by reference'' 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 final rule revises paragraph (g)(4)(ii) by replacing the text 
``120-month intervals'' with ``code of record intervals,'' replacing 
the text ``120-month inspection interval'' with ``code of record 
interval,'' inserting the text ``BPV'' into the text ``ASME Code 
incorporated by reference'' to clarify the language, and inserting 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)(iv)

    This final rule revises paragraph (g)(4)(iv) by adding language 
describing when licensees may update their code of record without NRC 
approval.

Paragraph (g)(5)(i)

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

Paragraph (g)(5)(ii)

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

[[Page 58052]]

Paragraph (g)(5)(iii)

    This final rule amends paragraph (g)(5)(iii) by replacing the text 
``120-month inspection interval'' with ``inservice inspection 
interval.''

Paragraph (g)(5)(iv)

    This final rule amends paragraph (g)(5)(iv) by replacing the text 
``120-month inspection interval'' with ``inservice inspection 
interval.''

Paragraph (y)

    This final rule adds paragraph (y) to provide definitions of 
important terms used in Sec.  50.55a: code of record interval, 
inservice examination and test (IST) code of record, inservice 
examination and test (IST) interval, inservice examination and testing 
(IST) program, inservice inspection (ISI) code of record, inservice 
inspection (ISI) interval, and inservice inspection (ISI) program.

Appendix J to 10 CFR Part 50

    This final rule revises 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 
final rule also removes footnote 2 and redesignates footnote 3 as 
footnote 2.

VI. Regulatory Flexibility Certification

    Under the Regulatory Flexibility Act (5 U.S.C. 605(b)), the NRC 
certifies that this rule does not have a significant economic impact on 
a substantial number of small entities. This final rule affects only 
the licensing and operation of nuclear power plants. The companies that 
own these plants do not fall within the scope of the definition of 
``small entities'' set forth in the Regulatory Flexibility Act or the 
size standards established by the NRC (10 CFR 2.810).

VII. Regulatory Analysis

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

VIII. Backfitting and Issue Finality

    The provisions in this final rule 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 
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 final rule does not involve any provisions requiring 
the preparation of a backfit analysis or documentation demonstrating 
that one or more of the issue finality criteria in 10 CFR part 52 are 
met.

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

    The 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. The NRC's 
longstanding regulatory practice has been to incorporate later versions 
of the ASME Codes into Sec.  50.55a. Under the former Sec.  50.55a, 
licensees were required to 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 revised this requirement 
to allow licensees to update to the latest edition and addenda before 
the start of every other ISI and IST interval. The NRC also revised 
Sec.  50.55a(f)(4)(iv) and (g)(4)(iv) to allow licensees to use a later 
edition of ASME BPV Code Section XI or ASME OM Code without submitting 
a request for NRC approval, provided that the licensee implements the 
later edition at the start of a new ISI or IST interval. These 
revisions, taken together, constitute 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.  50.55a(f)(4)(iv) or (g)(4)(iv).

Conclusion

    The NRC finds that the incorporation by reference into Sec.  50.55a 
of the three RGs containing the latest NRC-approved code cases and the 
revision of Sec.  50.55a to allow the extended code of record interval, 
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).

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

    The Commission has determined under the National Environmental 
Policy Act of 1969, as amended, and the Commission's regulations in 
subpart A of 10 CFR part 51, that this rule, if adopted, would not be a 
major Federal action significantly affecting the quality of the human 
environment and, therefore, an environmental impact statement is not 
required.
    The determination of this environmental assessment is that there 
will be no significant effect on the quality of the human environment 
from this action. The NRC did not receive public comments regarding any 
aspect of this environmental assessment.
    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 non-radiological 
plant effluents and because no changes would be made in activities that 
would adversely affect the environment. The determination of this 
environmental assessment is that there would be no significant offsite 
impact to the public from this action.

XI. Paperwork Reduction Act

    This final rule contains new or amended collections of information 
subject to the Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et 
seq.). The collections of information were approved by the Office of 
Management and Budget, approval number 3150-0264.
    The burden to the public for the information collection(s) is 
estimated to average 162 hours per response, including the time for 
reviewing

[[Page 58053]]

instructions, searching existing data sources, gathering, and 
maintaining the data needed, and completing and reviewing the 
information collection.
    The information collection is being conducted to document the plans 
for a select number of newly licensed operating power reactors to 
implement Code Case N-716-3. Information will be used by the NRC to 
verify applicability of the code case to the new plants including 
absence of degradation mechanisms and evaluate with any available 
operating experience, as well as risk-related information for the new 
plants, prior to application of the Code Case. Responses to this 
collection of information are voluntary under Sec.  50.55a(z).
    You may submit comments on any aspect of the information 
collection(s), including suggestions for reducing the burden, 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: 
T6-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.

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.

X. Congressional Review Act

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

XIII. Voluntary Consensus Standards

    The National Technology Transfer and Advancement Act of 1995, 
Public Law 104-113, requires that Federal agencies use technical 
standards that are developed or adopted by voluntary consensus 
standards bodies unless using such a standard is inconsistent with 
applicable law or is otherwise impractical. In this final rule, the NRC 
is continuing to use the ASME BPV and OM Code Cases, which are ASME-
approved voluntary alternatives to compliance with various provisions 
of the ASME BPV and OM Codes. As discussed in Section II.A. of this 
document, 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.
    NUREG-2228, ``Weld Residual Stress Finite Element Analysis 
Validation: Part II--Proposed Validation Procedure,'' published July 
2020 (including errata issued on September 22, 2021), referenced in the 
amendatory text of this rule, was previously approved for incorporation 
by reference in Sec.  50.55a. The ASME BPV Code, Section XI, and ASME 
OM Code, referenced in the amendatory text of this rule, were 
previously approved for incorporation by reference in Sec.  50.55a.

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

    The NRC is incorporating by reference three NRC RGs that list 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. These regulatory guides are RG 1.84, 
Revision 40; RG 1.147, Revision 21; and RG 1.192, Revision 5.
    The NRC is required by law to obtain approval for incorporation by 
reference from the Office of the Federal Register (OFR). The OFR's 
requirements for incorporation by reference are set forth in 1 CFR part 
51. The discussion in this section complies with the requirement for 
rules as set forth in 1 CFR 51.5(b)(2).
    The NRC considers ``interested parties'' to include all potential 
NRC stakeholders, not only the individuals and entities regulated or 
otherwise subject to the NRC's regulatory oversight. These NRC 
stakeholders are not a homogenous group, so the considerations for 
determining ``reasonable availability'' vary by class of interested 
parties. The NRC identified six classes of interested parties with 
regard to the material to be incorporated by reference in an NRC rule:
     Individuals and small entities regulated or otherwise 
subject to the NRC's regulatory oversight. This class includes 
applicants and potential applicants for licenses and other NRC 
regulatory approvals, and who are subject to the material to be 
incorporated by reference. In this context, ``small entities'' has the 
same meaning as set out in 10 CFR 2.810.
     Large entities otherwise subject to the NRC's regulatory 
oversight. This class includes applicants and potential applicants for 
licenses and other NRC regulatory approvals, and who are subject to the 
material to be incorporated by reference. In this context, a ``large 
entity'' is one that does not qualify as a ``small entity'' under 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 is incorporating by reference in order to 
participate in the rulemaking.
    The three RGs that the NRC is incorporating by reference in this 
final rule are available without cost and can be read online or 
downloaded online. The three 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 access to the three final RGs is available in various forms 
at no cost, the NRC determines that the three final RGs (RG 1.84, 
Revision 40; RG 1.147, Revision 21; and RG 1.192, Revision 5) are 
reasonably available to all interested parties.

[[Page 58054]]



  Table IV--Regulatory Guides To Be Incorporated by Reference in 10 CFR
                                 50.55a
------------------------------------------------------------------------
                                             Adams accession No./Federal
                 Document                         Register citation
------------------------------------------------------------------------
RG 1.84, Design, Fabrication, and           ML23291A008
 Materials Code Case Acceptability, ASME
 Section III, Revision 40.
RG 1.147, Inservice Inspection Code Case    ML23291A003
 Acceptability, ASME Section XI, Division
 1, Revision 21.
RG 1.192, Operation and Maintenance Code    ML23291A006
 Case Acceptability, ASME OM Code,
 Revision 5.
------------------------------------------------------------------------

XV. Availability of Guidance

    The NRC is issuing revised guidance, RG 1.193, ``ASME Code Cases 
Not Approved for Use,'' Revision 8, for the implementation of the 
requirements in this final rule. The guidance is available as indicated 
in Section XVI, ``Availability of Documents,'' of this document. You 
may access information and comment submissions related to the guidance 
by searching on https://www.regulations.gov under Docket ID NRC-2018-
0291.
    The regulatory guide lists code cases that the NRC has not approved 
for generic use and will not be incorporated by reference into the 
NRC's regulations.

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 V--Availability of Documents
------------------------------------------------------------------------
                                             Adams accession No./Federal
                 Document                         Register citation
------------------------------------------------------------------------
RG 1.84, Design, Fabrication, and           ML23291A008
 Materials Code Case Acceptability, ASME
 Section III, Revision 40, dated March,
 2024.
RG 1.147, Inservice Inspection Code Case    ML23291A003
 Acceptability, ASME Section XI, Division
 1, Revision 21, dated March, 2024.
RG 1.192, Operation and Maintenance Code    ML23291A006
 Case Acceptability, ASME OM Code,
 Revision 5, dated March, 2024.
RG 1.193, ASME Code Cases Not Approved for  ML23291A007
 Use, Revision 8, dated March, 2024.
Rulemaking--Proposed Rule--Draft            ML22243A006
 Regulatory 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.
Final Rule: Final Regulatory Analysis,      ML23291A333
 American Society of Mechanical Engineers
 Code Cases RG 1.84 Rev 40, RG 1.147 Rev
 21, RG 1.192 Rev 5, and Revision of
 Inservice Inspection and Inservice
 Testing Code of Record Frequency Update
 dated March, 2024.
Final Rule: NRC Responses to Public         ML23291A328
 Comments, American Society of Mechanical
 Engineers Code Cases RG 1.84 Rev 40, RG
 1.147 Rev 21, RG 1.192 Rev 5, and
 Revision of Inservice Inspection and
 Inservice Testing Code of Record
 Frequency Update, dated March, 2024.
Rulemaking--Proposed Rule--Federal          ML22243A005
 Register Notice--American Society of
 Mechanical Engineers Code Cases and
 Update Frequency, RG 1.84, Rev. 40; RG
 1.147, Rev. 21; RG 1.192 Rev 5, dated
 February 2023.
Proposed Rule--American Society of          88 FR 13717
 Mechanical Engineers Code Cases and
 Update Frequency, RG 1.84, Rev. 40; RG
 1.147, Rev. 21; RG 1.192, Rev 5, dated
 March 6, 2023.
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          ML20273A286
 Relaxation of 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- ML22124A178
 0029 Inservice Testing and Inservice
 Inspection Program Rulemakings Update
 [NRC-2018-0291/3150-AK23],'' dated August
 10, 2022.
Regulatory Issue Summary 2004-12,           ML042090436
 ``Clarification on Use of Later Editions
 and Addenda to the ASME OM Code and
 Section XI,'' dated July 28, 2004.
Public Meeting Summary for Proposed Rule:   ML23083B303
 ASME Code Cases 40-21-5 and Update
 Frequency, dated March 20, 2023.
Rulemaking--Proposed Rule--OMB Supporting   ML22243A007
 Statement 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 February 2023.
Rulemaking--Final Rule--OMB Supporting      ML23291A341
 Statement 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 December 2023.
ASME OM Code Case Applicability Index,      ML22279A967
 dated July 1, 2022.
ASME Letter to NRC, ``ASME Request for      ML22046A112
 Including Specific Code Cases in Draft
 Revision 21 of Regulatory Guide 1.147,''
 dated December 22, 2021.
NUREG-2228, ``Weld Residual Stress Finite   ML20212L592
 Element Analysis Validation: Part II-
 Proposed Validation Procedure,'' dated
 July 2020.
Final Rule--``Codes and Standards for       41 FR 6256
 Nuclear 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         44 FR 57912
 Production and Utilization Facilities;
 Codes and Standards for Nuclear
 Powerplants,'' October 9, 1979.
Codes and Standards for Nuclear Power       61 FR 41303
 Plants; Subsection IWE and Subsection
 IWL, August 8, 1996.
Proposed Rule--Industry Codes and           64 FR 51370
 Standards; Amended Requirements,
 September 22, 1999.
Final Rule--Industry Codes and Standards;   67 FR 60520
 Amended Requirements, September 26, 2002.
Final Rule--``Incorporation by Reference    68 FR 40469
 of ASME BPV and OM Code Cases,'' July 8,
 2003.
Final Rule--``Approval of American Society  87 FR 11934
 of Mechanical Engineers Code Cases,''
 March 3, 2022.
Final Rule--``American Society of           87 FR 65128
 Mechanical Engineers 2019-2020 Code
 Editions Incorporation by Reference,''
 October 27, 2022.
------------------------------------------------------------------------


[[Page 58055]]

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 amending 
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. Revise and republish paragraph (a)(3):
0
c. Revise paragraphs (b)(5) and (6);
0
d. Revise paragraphs (f)(4)(i) and (ii), and (f)(4)(iv);
0
e. 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
f. In paragraph (f)(7), remove the text ``120-month IST Program 
interval'', and add, in its place, the text ``inservice examination and 
test interval'';
0
g. Revise paragraphs (g)(4) and (5); and
0
h. 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 the NRC at 
NRC Technical Library, 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 or email [email protected]. The material may be obtained 
from the following sources in this paragraph (a).
* * * * *
    (3) U.S. Nuclear Regulatory Commission (NRC): Public Document Room, 
11555 Rockville Pike, Rockville, Maryland 20852; telephone: 1-800-397-
4209; email: [email protected]; https://www.nrc.gov/reading-rm/doc-collections/reg-guides/. The use of code cases listed in the NRC 
regulatory guides in paragraphs (a)(3)(i) through (iii) of this section 
is acceptable with the specified conditions in those guides when 
implementing the editions and addenda of the ASME BPV Code and ASME OM 
Code incorporated by reference in paragraph (a)(1) of this section. The 
NRC report in paragraph (a)(3)(iv) of this section is acceptable as 
specified in the conditions when implementing code cases listed in the 
NRC regulatory guides in paragraphs (a)(3)(i) through (iii) of this 
section.
    (i) NRC Regulatory Guide 1.84, Revision 40. NRC Regulatory Guide 
1.84, Revision 40, ``Design, Fabrication, and Materials Code Case 
Acceptability, ASME Section III,'' issued March 2024, with the 
requirements in paragraph (b)(4) of this section.
    (ii) NRC Regulatory Guide 1.147, Revision 21. NRC Regulatory Guide 
1.147, Revision 21, ``Inservice Inspection Code Case Acceptability, 
ASME Section XI, Division 1,'' issued March 2024, which lists ASME Code 
Cases that the NRC has approved in accordance with the requirements in 
paragraph (b)(5) of this section.
    (iii) NRC Regulatory Guide 1.192, Revision 5. NRC Regulatory Guide 
1.192, Revision 5, ``Operation and Maintenance Code Case Acceptability, 
ASME OM Code,'' issued March 2024, which lists ASME Code Cases that the 
NRC has approved in accordance with the requirements in paragraph 
(b)(6) of this section.
    (iv) NUREG-2228. NUREG-2228, ``Weld Residual Stress Finite Element 
Analysis Validation: Part II--Proposed Validation Procedure,'' 
published July 2020 (including Errata September 22, 2021), which is 
referenced in RG 1.147, Revision 21.
* * * * *
    (b) * * *
    (5) Conditions on inservice inspection Code Cases. Licensees may 
apply the ASME BPV Code Cases listed in NRC Regulatory Guide 1.147, as 
incorporated by reference in paragraph (a)(3)(ii) of this section, 
without prior NRC approval, subject to the following:
    (i) ISI Code Case condition: Applying Code Cases. When a licensee 
initially applies a listed Code Case, the licensee must apply the most 
recent version of that Code Case incorporated by reference in paragraph 
(a) of this section.
    (ii) ISI Code Case condition: Applying different revisions of Code 
Cases. If a licensee has previously applied a Code Case and a later 
version of the Code Case is incorporated by reference in paragraph (a) 
of this section, the licensee may continue to apply, to the end of the 
current code of record interval, the previous version of the Code Case, 
as authorized, or may apply the later version of the Code Case, 
including any NRC-specified conditions placed on its use. Licensees who 
choose to continue use of the Code Case during subsequent code of 
record intervals will be required to implement the latest version 
incorporated by reference into this section as listed in tables 1 and 2 
of NRC Regulatory Guide 1.147, as incorporated by reference in 
paragraph (a)(3)(ii) of this section.
    (iii) ISI Code Case condition: Applying annulled Code Cases. 
Application of an annulled Code Case is prohibited unless a licensee 
previously applied the listed Code Case prior to it being listed as 
annulled in NRC Regulatory Guide 1.147. If a licensee has applied a 
listed Code Case that is later listed as annulled in NRC Regulatory 
Guide 1.147, the licensee may continue to apply the Code Case to the 
end of the current code of record interval.
    (6) Conditions on ASME OM Code Cases. Licensees may apply the ASME 
OM Code Cases listed in NRC Regulatory Guide 1.192, as incorporated by 
reference in paragraph (a)(3)(iii) of this section, without prior NRC 
approval, subject to the following:
    (i) OM Code Case condition: Applying Code Cases. When a licensee 
initially applies a listed Code Case, the licensee must apply the most 
recent version of that Code Case incorporated by reference in paragraph 
(a) of this section.
    (ii) OM Code Case condition: Applying different revisions of Code

[[Page 58056]]

Cases. If a licensee has previously applied a Code Case and a later 
version of the Code Case is incorporated by reference in paragraph (a) 
of this section, the licensee may continue to apply, to the end of the 
current code of record interval, the previous version of the Code Case, 
as authorized, or may apply the later version of the Code Case, 
including any NRC-specified conditions placed on its use. Licensees who 
choose to continue use of the Code Case during subsequent code of 
record intervals will be required to implement the latest version 
incorporated by reference into this section as listed in tables 1 and 2 
of NRC Regulatory Guide 1.192, as incorporated by reference in 
paragraph (a)(3)(iii) of this section.
    (iii) OM Code Case condition: Applying annulled Code Cases. 
Application of an annulled Code Case is prohibited unless a licensee 
previously applied the listed Code Case prior to it being listed as 
annulled in NRC Regulatory Guide 1.192. If a licensee has applied a 
listed Code Case that is later listed as annulled in NRC Regulatory 
Guide 1.192, the licensee may continue to apply the Code Case to the 
end of the current code of record interval.
* * * * *
    (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 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. However, a licensee whose inservice 
inspection interval commences during the 12 through 18-month period 
after June 3, 2020, may delay the update of their Appendix VIII program 
by up to 18 months after June 3, 2020. Alternatively, licensees may, at 
any time in their code of record interval, elect to use the Appendix 
VIII in the latest edition and addenda of the ASME BPV Code 
incorporated by reference in paragraph (a) of this section, subject to 
any applicable conditions listed in paragraph (b) of this section. 
Licensees using this option must also use the same edition and addenda 
of Appendix I, Subarticle I-3200, as Appendix VIII, including any 
applicable conditions listed in paragraph (b) of this section.
* * * * *
    (iv) Applicable IST Code: Use of later Code editions and addenda. 
Inservice tests of pumps and valves may meet the requirements set forth 
in subsequent editions and addenda that are incorporated by reference 
in paragraph (a)(1)(iv) of this section, subject to the conditions 
listed in paragraph (b) of this section, and subject to NRC approval. 
Portions of editions or addenda may be used, provided that all related 
requirements of the respective editions or addenda are met. NRC 
approval is not required when updating the IST code of record before 
the start of an IST interval in which the updated IST code of record 
will be used and when using the latest edition incorporated by 
reference in (a)(1)(iv) of this section in its entirety, subject to the 
conditions listed in paragraph (b) of this section (or the optional 
ASME Code Cases listed in 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).
* * * * *
    (g) * * *
    (4) Inservice inspection standards requirement for operating 
plants. Throughout the service life of a boiling or pressurized water-
cooled nuclear power facility, components (including supports) that are 
classified as ASME BPVC Code Class 1, Class 2, and Class 3 must meet 
the requirements, except design and access provisions and preservice 
examination requirements, set forth in Section XI of editions and 
addenda of the ASME BPV Code that become effective subsequent to 
editions specified in paragraphs (g)(2) and (3) of this section and 
that are incorporated by reference in paragraph (a)(1)(ii) or (iv) of 
this section for snubber examination and testing of this section, to 
the extent practical within the limitations of design, geometry, and 
materials of construction of the components. Components that are 
classified as Class MC pressure retaining components and their integral 
attachments, and components that are classified as Class CC pressure 
retaining components and their integral attachments, must meet the 
requirements, except design and access provisions and preservice 
examination requirements, set forth in Section XI of the ASME BPV Code 
and addenda that are incorporated by reference in paragraph (a)(1)(ii) 
of this section subject to the condition listed in paragraph (b)(2)(vi) 
of this section and the conditions listed in paragraphs (b)(2)(viii) 
and (ix) of this section, to the extent practical within the limitation 
of design, geometry, and materials of construction of the components. 
When using the 2006 Addenda or later of the ASME BPV Code, Section XI, 
the inservice examination, testing, and service life monitoring 
requirements for dynamic restraints (snubbers) must meet the 
requirements set forth in the applicable ASME OM Code as specified in 
paragraph (b)(3)(v)(B) of this section. When using the 2005 Addenda or 
earlier edition or addenda of the ASME BPV Code, Section XI, the 
inservice examination, testing, and service life monitoring 
requirements for dynamic restraints (snubbers) must meet the 
requirements set forth in either the applicable ASME OM Code or ASME 
BPV Code, Section XI as specified in paragraph (b)(3)(v) of this 
section.
    (i) Applicable ISI Code: Initial code of record interval. Inservice 
examination of components and system pressure tests conducted during 
the initial code of record interval must comply with the requirements 
in the latest edition and addenda of the ASME BPV Code incorporated by 
reference in paragraph (a) of this section on the date no more than 18 
months before the date of issuance of the operating license under this 
part, or no more than 18 months before the date scheduled for initial 
loading of fuel under a combined license under part 52 of this chapter 
(or the optional ASME Code Cases listed in 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 58057]]

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. However, a licensee whose inservice 
inspection interval commences during the 12 through 18-month period 
after June 3, 2020, may delay the update of their Appendix VIII program 
by up to 18 months after June 3, 2020. Alternatively, licensees may, at 
any time in their code of record interval, elect to use the Appendix 
VIII in the latest edition and addenda of the ASME BPV Code 
incorporated by reference in paragraph (a) of this section, subject to 
any applicable conditions listed in paragraph (b) of this section. 
Licensees using this option must also use the same edition and addenda 
of Appendix I, Subarticle I-3200, as Appendix VIII, including any 
applicable conditions listed in paragraph (b) of this section.
    (iii) Applicable ISI Code: Optional surface examination 
requirement. When applying editions and addenda prior to the 2003 
Addenda of Section XI of the ASME BPV Code, licensees may, but are not 
required to, perform the surface examinations of high-pressure safety 
injection systems specified in Table IWB-2500-1, Examination Category 
B-J, Item Numbers B9.20, B9.21, and B9.22.
    (iv) Applicable ISI Code: Use of subsequent Code editions and 
addenda. Inservice examination of components and system pressure tests 
may meet the requirements set forth in subsequent editions and addenda 
that are incorporated by reference in paragraph (a) of this section, 
subject to the conditions listed in paragraph (b) of this section, and 
subject to Commission approval. Portions of editions or addenda may be 
used, provided that all related requirements of the respective editions 
or addenda are met. NRC approval is not required when updating the ISI 
code of record before the start of an ISI interval in which the updated 
ISI code of record will be used and when using the latest edition 
incorporated by reference in (a)(1)(iv) of this section in its 
entirety, subject to the conditions listed in paragraph (b) of this 
section (or the optional ASME Code Cases listed in 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).
    (v) Applicable ISI Code: Metal and concrete containments. For a 
boiling or pressurized water-cooled nuclear power facility whose 
construction permit under this part or combined license under part 52 
of this chapter was issued after January 1, 1956, the following are 
required:
    (A) Metal and concrete containments: First provision. Metal 
containment pressure retaining components and their integral 
attachments must meet the inservice inspection, repair, and replacement 
requirements applicable to components that are classified as ASME Code 
Class MC;
    (B) Metal and concrete containments: Second provision. Metallic 
shell and penetration liners that are pressure retaining components and 
their integral attachments in concrete containments must meet the 
inservice inspection, repair, and replacement requirements applicable 
to components that are classified as ASME Code Class MC; and
    (C) Metal and concrete containments: Third provision. Concrete 
containment pressure retaining components and their integral 
attachments, and the post-tensioning systems of concrete containments, 
must meet the inservice inspections, repair, and replacement 
requirements applicable to components that are classified as ASME Code 
Class CC.
    (5) Requirements for updating ISI programs--(i) ISI program update: 
Applicable ISI code of record. The inservice inspection program for a 
boiling or pressurized water-cooled nuclear power facility must be 
revised by the licensee, as necessary, to meet the requirements of 
paragraph (g)(4) of this section.
    (ii) ISI program update: Conflicting ISI Code requirements with 
technical specifications. If a revised inservice inspection program for 
a facility conflicts with the technical specifications for the 
facility, the licensee must apply to the Commission for amendment of 
the technical specifications to conform the technical specifications to 
the revised program. The licensee must submit this application, as 
specified in Sec.  50.4, at least six months before the start of the 
code of record intervalduring which the provisions become applicable, 
as determined by paragraph (g)(4) of this section.
    (iii) ISI program update: Notification of impractical ISI Code 
requirements. If the licensee has determined that conformance with a 
Code requirement is impractical for its facility the licensee must 
notify the NRC and submit, as specified in Sec.  50.4, information to 
support the determinations. Determinations of impracticality in 
accordance with this section must be based on the demonstrated 
limitations experienced when attempting to comply with the Code 
requirements during the inservice inspection interval for which the 
request is being submitted. Requests for relief made in accordance with 
this section must be submitted to the NRC no later than 12 months after 
the expiration of the initial or subsequent inservice inspection 
interval for which relief is sought.
    (iv) ISI program update: Schedule for completing impracticality 
determinations. Where the licensee determines that an examination 
required by Code edition or addenda is impractical, the basis for this 
determination must be submitted for NRC review and approval not later 
than 12 months after the expiration of the initial or subsequent 
inservice inspection interval for which relief is sought.
* * * * *
    (y) Definitions. As used in this section:
    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 examination and test programs and inservice 
inspection programs, respectively.
    (1) For licensees with codes of record prior to ASME BPV Code, 
Section XI, 2017 Edition, and OM Code, 2017 Edition, as incorporated by 
reference in paragraph (a) of this section, the code of record interval 
is the same as the inservice inspection interval or inservice 
examination and test interval.
    (2) For licensees with codes of record of ASME BPV Code, Section 
XI, 2017 Edition and OM Code, 2017 Edition, or later, as incorporated 
by reference in

[[Page 58058]]

paragraph (a) of this section, the code of record interval is two 
consecutive inservice inspection or inservice examination and test 
intervals.
    Inservice examination and test (IST) code of record means the 
specific edition(s) and addenda of the ASME OM Code required by 
(f)(4)(i) or (ii) of this section, subject to the conditions listed in 
paragraph (b) of this section, and applicable NRC endorsed code cases, 
for inservice test to verify operational readiness of pumps, valves, 
and dynamic restraints, whose function is required for safety.
    Inservice examination and test (IST) interval 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).
    Inservice examination and testing (IST) program 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:
    (1) 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.
    (2) Relief requested under paragraph (f)(5)(iii) of this section 
and granted under paragraph (f)(6)(i) of this section.
    (3) Augmented IST requirements as applied by the Commission under 
paragraph (f)(6)(ii) of this section.
    (4) Alternatives authorized under paragraph (z) of this section.
    Inservice inspection (ISI) code of record means the specific 
edition(s) and addenda of the ASME BPV Code, Section XI, required by 
paragraphs (g)(4)(i) or (ii) of this section, subject to the conditions 
listed in paragraph (b) of this section, and applicable NRC endorsed 
code cases, for the inservice examination of components and system 
pressure tests.
    Inservice inspection (ISI) interval means the inservice inspection 
interval described in 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.
    Inservice inspection (ISI) program 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:
    (1) The requirements of IWA-2400 of ASME BPV Code, Section XI, 1991 
Addenda and later.
    (2) Relief requested under paragraph (g)(5)(iii) of this section 
and granted under paragraph (g)(6)(i) of this section.
    (3) The augmented inspection program described in paragraph 
(g)(6)(ii) of this section.
    (4) Alternatives authorized under paragraph (z) of this section.
* * * * *

0
3. In appendix J to part 50, in section III of option A:
0
a. Remove footnote 2;
0
b. Redesignate footnote 3 as new footnote 2; and
0
c. Revise paragraph D.1.(a).
    The revision reads 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 inservice inspection interval, as defined in Sec.  
50.55a(y). The third test of each set shall be conducted when the 
plant is shut down for the final plant inservice inspections of the 
inservice inspection interval.
* * * * *

    Dated: July 5, 2024.

Nuclear Regulatory Commission.
Andrea Veil,
Director, Office of Nuclear Reactor Regulation.
[FR Doc. 2024-15288 Filed 7-16-24; 8:45 am]
BILLING CODE 7590-01-P