[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
Federal Register
________________________________________________________________________
This section of the FEDERAL REGISTER contains regulatory documents
having general applicability and legal effect, most of which are keyed
to and codified in the Code of Federal Regulations, which is published
under 50 titles pursuant to 44 U.S.C. 1510.
The Code of Federal Regulations is sold by the Superintendent of Documents.
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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.
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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
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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
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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
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Total NRC Costs........................................... 9,300,000 6,550,000 8,070,000
-------------------------------------------------
Net................................................... 64,460,000 45,570,000 56,150,000
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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.
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\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.
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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\
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\2\ See Federal Register final rule, ``Incorporation by
Reference of ASME BPV and OM Code Cases'' (68 FR 40469; July 8,
2003).
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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.
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\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.
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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
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Boiler and Pressure Vessel Code Section III (addressed in RG 1.84, Rev.
40, table 1)
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Code case No. Published with supplement Title
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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)
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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