[Federal Register Volume 88, Number 43 (Monday, March 6, 2023)]
[Proposed Rules]
[Pages 13717-13735]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-03742]
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Proposed Rules
Federal Register
________________________________________________________________________
This section of the FEDERAL REGISTER contains notices to the public of
the proposed issuance of rules and regulations. The purpose of these
notices is to give interested persons an opportunity to participate in
the rule making prior to the adoption of the final rules.
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Federal Register / Vol. 88 , No. 43 / Monday, March 6, 2023 /
Proposed Rules
[[Page 13717]]
NUCLEAR REGULATORY COMMISSION
10 CFR Part 50
[NRC-2018-0291]
RIN 3150-AK23
American Society of Mechanical Engineers Code Cases and Update
Frequency
AGENCY: Nuclear Regulatory Commission.
ACTION: Proposed rule.
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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is proposing to
amend its regulations to incorporate by reference proposed revisions of
three regulatory guides, which would approve new, revised, and
reaffirmed code cases published by the American Society of Mechanical
Engineers. This proposed action would allow nuclear power plant
licensees and applicants for construction permits, operating licenses,
combined licenses, standard design certifications, standard design
approvals, and manufacturing licenses to use the code cases listed in
these draft regulatory guides as voluntary alternatives to engineering
standards for the construction, inservice inspection, and inservice
testing of nuclear power plant components. The NRC is requesting
comments on this proposed rule and on the draft versions of the three
regulatory guides proposed to be incorporated by reference. The NRC
also is making available a related draft regulatory guide that lists
code cases that the NRC has not approved for use. This draft regulatory
guide will not be incorporated by reference into the NRC's regulations.
In addition, this rulemaking proposes to extend the time periods
required for licensees to update their codes of record.
DATES: Submit comments by May 5, 2023. Comments received after this
date will be considered if it is practical to do so, but the NRC is
able to ensure consideration only for comments received before this
date.
ADDRESSES: You may submit comments by any of the following methods
(unless this document describes a different method for submitting
comments on a specific subject); however, the NRC encourages electronic
comment submission through the Federal rulemaking website:
Federal rulemaking website: Go to https://www.regulations.gov and search for Docket ID NRC-2018-0291. Address
questions about NRC dockets to Dawn Forder; telephone: 301-415-3407;
email: [email protected]. For technical questions contact the
individuals listed in the FOR FURTHER INFORMATION CONTACT section of
this document.
Email comments to: [email protected]. If you do
not receive an automatic email reply confirming receipt, then contact
us at 301-415-1677.
Mail comments to: Secretary, U.S. Nuclear Regulatory
Commission, Washington, DC 20555-0001, ATTN: Rulemakings and
Adjudications Staff.
For additional direction on obtaining information and submitting
comments, see ``Obtaining Information and Submitting Comments'' in the
SUPPLEMENTARY INFORMATION section of this document.
FOR FURTHER INFORMATION CONTACT: Dennis Andrukat, Office of Nuclear
Material and Safeguards, telephone: 301-415-3561, email:
[email protected] and Bruce Lin, Office of Nuclear Regulatory
Research, telephone: 301-415-2446, email: [email protected]. Both are
staff of the U.S. Nuclear Regulatory Commission, Washington, DC 20555-
0001.
SUPPLEMENTARY INFORMATION:
Executive Summary
A. Need for the Regulatory Action
This regulatory action proposes to incorporate by reference into
the NRC's regulations the latest revisions of three regulatory guides
(RGs) (currently in draft form for comment). The three draft RGs
identify new, revised, and reaffirmed code cases published by the
American Society of Mechanical Engineers (ASME) that the NRC has
determined are acceptable for use as voluntary alternatives to
compliance with certain provisions of the ASME Boiler and Pressure
Vessel Code (BPV Code) and the ASME Operation and Maintenance (OM) of
Nuclear Power Plants, Division 1, OM Code: Section IST (OM Code)
currently incorporated by reference into the NRC's regulations.
This regulatory action also proposes to revise the current NRC
requirement for nuclear power plant licensees to update the codes of
record for their inservice testing (IST) and inservice inspection (ISI)
programs every 10 years, for licensees that are implementing the 2020
Edition, or later editions, of the ASME OM Code and the 2019 Edition,
or later editions, of the ASME BPV Code, Section XI, as incorporated by
reference in Sec. 50.55a, ``Codes and standards,'' of title 10 of the
Code of Federal Regulations (10 CFR). This proposed revision to the
NRC's regulations follows Commission direction in staff requirements
memorandum (SRM) SRM-SECY-21-0029 (dated November 8, 2021) in response
to SECY-21-0029, ``Rulemaking Plan on Revision of Inservice Testing and
Inservice Inspection Program Update Frequencies Required in 10 CFR
50.55a,'' dated March 15, 2021. This rule proposes additional changes
to Sec. 50.55a to promote clarity and consistency, including adding
definitions of important terms and revising the reference to the 10-
year service period in 10 CFR part 50, appendix J, ``Primary Reactor
Containment Leakage Testing for Water-Cooled Power Reactors.'' This
rulemaking does not address all aspects of SRM-SECY-21-0029.
Specifically, the NRC staff will consider options for streamlining ASME
Code Case rulemakings in the future.
B. Major Provisions
The NRC proposes to incorporate by reference into the NRC's
regulations the following regulatory guides: RG 1.84, ``Design,
Fabrication, and Materials Code Case Acceptability, ASME Section III,''
Revision 40 (Draft Regulatory Guide (DG)-1405); RG 1.147, ``Inservice
Inspection Code Case Acceptability, ASME Section XI, Division 1,''
Revision 21 (DG-1406); and RG 1.192, ``Operation and Maintenance [OM]
Code Case Acceptability, ASME OM Code,'' Revision 5 (DG-1407). This
proposed action would allow nuclear power plant licensees and
applicants for construction permits, operating licenses, combined
licenses, standard design
[[Page 13718]]
certifications, standard design approvals, and manufacturing licenses
to use the code cases newly listed in these revised RGs as voluntary
alternatives to ASME engineering standards for the construction,
inservice inspections, and inservice testing of nuclear power plant
components. The NRC also notes the availability of a proposed version
of RG 1.193, ``ASME Code Cases Not Approved for Use,'' Revision 8 (DG-
1408). This document lists code cases that the NRC has not approved for
generic use and would not be incorporated by reference into the NRC's
regulations.
The NRC prepared a draft regulatory analysis to determine the
expected quantitative costs and benefits of this proposed rule, as well
as qualitative factors to be considered in the NRC's rulemaking
decision. The analysis concluded that this proposed rule would result
in net savings to the industry and the NRC. As shown in Table 1, the
estimated total net benefit relative to the regulatory baseline and the
quantitative benefits would outweigh the costs by a range from
approximately $34.3 million (7-percent net present value) to $40.5
million (3-percent net present value).
Table 1--Cost Benefit Summary
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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.................................. 36,710,000 29,890,000 35,110,000
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Total Industry Costs............................ 36,710,000 29,890,000 35,110,000
NRC Implementation.................................. (510,000) (430,000) (480,000)
NRC Operation....................................... 6,380,000 4,860,000 5,860,000
-----------------------------------------------------------
Total NRC Costs................................. 5,870,000 4,430,000 5,380,000
Net......................................... 42,580,000 34,320,000 40,490,000
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The draft regulatory analysis also considered the following
qualitative considerations: (1) flexibility and decreased uncertainty
for licensees when making modifications or preparing to perform
inservice inspection or inservice testing; (while continuing to ensure
safety; (2) consistency with the provisions of the National Technology
Transfer and Advancement Act of 1995, which encourages Federal
regulatory agencies to consider adopting voluntary consensus standards
as an alternative to de novo agency development of standards affecting
an industry; (3) consistency with the NRC's policy of evaluating the
latest versions of consensus standards in terms of their suitability
for endorsement by regulations and regulatory guides; and (4)
consistency with the NRC's goal to harmonize with international
standards to improve regulatory efficiency for both the NRC and
international standards groups.
The draft regulatory analysis concludes that this proposed rule
should be adopted because it is justified when integrating the cost-
beneficial quantitative results and the positive and supporting
nonquantitative considerations in the decision. For more information,
please see the draft regulatory analysis as indicated in Section XVI,
Availability of Documents, of this document.
Table of Contents
I. Obtaining Information and Submitting Comments
A. Obtaining Information
B. Submitting Comments
II. Background
III. Discussion
A. Proposed Incorporation by Reference of Three Regulatory
Guides
B. Code Cases Proposed To Be Approved for Unconditional Use
C. Code Cases Approved for Use With Conditions
D. ASME Code Cases Not Approved for Use (DG-1408/RG 1.193)
E. Proposed Revision to Code of Record Update Requirements
IV. Specific Requests for Comments
V. Section-by-Section Analysis
VI. Regulatory Flexibility Certification
VII. Regulatory Analysis
VIII. Backfitting and Issue Finality
IX. Plain Writing
X. Environmental Assessment and Proposed Finding of No Significant
Environmental Impact
XI. Paperwork Reduction Act Statement
XII. Voluntary Consensus Standards
XIII. Incorporation by Reference
XIV. Availability of Guidance
XV. Public Meeting
XVI. Availability of Documents
I. Obtaining Information and Submitting Comments
A. Obtaining Information
Please refer to Docket ID NRC-2018-0291 when contacting the NRC
about the availability of information for this action. You may obtain
publicly available information related to this action by any of the
following methods:
Federal Rulemaking Website: Go to https://www.regulations.gov and search for Docket ID NRC-2018-0291.
NRC's Agencywide Documents Access and Management System
(ADAMS): You may obtain publicly available documents online in the
ADAMS Public Documents collection at https://www.nrc.gov/reading-rm/adams.html. To begin the search, select ``Begin Web-based ADAMS
Search.'' For problems with ADAMS, please contact the NRC's Public
Document Room (PDR) reference staff at 1-800-397-4209, 301-415-4737, or
by email to [email protected]. For the convenience of the reader,
instructions about obtaining materials referenced in this document are
provided in the ``Availability of Documents'' section.
NRC's PDR: You may examine and purchase copies of public
documents, by appointment, at the NRC's PDR, Room P1 B35, One White
Flint North, 11555 Rockville Pike, Rockville, Maryland 20852. To make
an appointment to visit the PDR, please send an email to
[email protected] or call 1-800-397-4209 or 301-415-4737, between
8:00 a.m. and 4:00 p.m. eastern time (ET), Monday through Friday,
except Federal holidays.
B. Submitting Comments
The NRC encourages electronic comment submission through the
Federal rulemaking website (https://www.regulations.gov). Please
include
[[Page 13719]]
Docket ID NRC-2018-0291 in your comment submission.
The NRC cautions you not to include identifying or contact
information that you do not want to be publicly disclosed in your
comment submission. The NRC will post all comment submissions at
https://www.regulations.gov as well as enter the comment submissions
into ADAMS. The NRC does not routinely edit comment submissions to
remove identifying or contact information.
If you are requesting or aggregating comments from other persons
for submission to the NRC, then you should inform those persons not to
include identifying or contact information that they do not want to be
publicly disclosed in their comment submission. Your request should
state that the NRC does not routinely edit comment submissions to
remove such information before making the comment submissions available
to the public or entering the comment into ADAMS.
II. Background
A. Proposed Incorporation by Reference of Three Regulatory Guides
The ASME develops and publishes the ASME BPV Code, which contains
requirements for the design, construction, and inservice inspection of
nuclear power plant components, and the ASME OM Code,\1\ which contains
requirements for preservice and inservice testing of nuclear power
plant components. In response to BPV and OM Code user requests, the
ASME develops code cases that provide voluntary alternatives to BPV and
OM Code requirements under special circumstances.
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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
its 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 proposed rule is the latest in a series of rules that
incorporate by reference new versions of several RGs that identify new,
revised, and reaffirmed \3\ ASME Code Cases that the NRC
unconditionally or conditionally approves for use. In developing these
RGs, the NRC reviews the ASME BPV and OM Code Cases, determines the
acceptability of each code case, and publishes its findings in the RGs.
The RGs are revised periodically as new code cases are published by the
ASME. The NRC incorporates by reference the RGs listing acceptable and
conditionally acceptable ASME Code Cases into Sec. 50.55a. The NRC
published a final rule dated March 3, 2022 (87 FR 11934), that
incorporated by reference into Sec. 50.55a the most recent versions of
the RGs, which are RG 1.84, ``Design, Fabrication, and Materials Code
Case Acceptability, ASME Section III,'' Revision 39; RG 1.147,
``Inservice Inspection Code Case Acceptability, ASME Section XI,
Division 1,'' Revision 20; and RG 1.192, ``Operation and Maintenance
Code Case Acceptability, ASME OM Code,'' Revision 4.
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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. Proposed Revision to Code of Record Update Requirements
The NRC staff provided SECY-21-0029 to the Commission with a
proposed rulemaking plan for revising the IST and ISI code of record
update requirements in Sec. 50.55a. The Commission issued SRM-SECY-21-
0029, directing the staff to proceed with the proposed rulemaking plan.
In SECY-22-0075, ``Staff Requirements-SECY-21-0029 Inservice Testing
and Inservice Inspection Program Rulemakings Update,'' dated August 10,
2022, the staff described deviations it was taking from the original
plan in response to new information and changed circumstances that
affected the implementation of SRM-SECY-21-0029. These changes included
combining the two proposed rulemakings (the ASME code case and the IST
and ISI code of record update requirements). These changes also
included making conforming and clarifying changes to address issues
encountered during the development of this proposed rule. One such
change was the addition of a definition section to the proposed rule
(Sec. 50.55a(y)) where ``code of record interval'' (the period of time
between the code of record updates required by Sec. 50.55a(f)(4) and
(g)(4) for the IST and ISI programs, respectively) was differentiated
from both the ISI and IST intervals (the ASME interval described by the
licensee's code of record).
In this proposed rule, along with incorporating by reference three
regulatory guides on ASME Code Cases, the NRC is providing a proposed
revision to Sec. 50.55a for public comment in accordance with the
Commission's direction in SRM-SECY-21-0029. This proposed rule would
specify that licensees are required to update their IST and ISI codes
of record every two consecutive IST intervals or ISI intervals, as
defined in the proposed rule, provided the licensee implements the 2020
Edition, or later edition, of the ASME OM Code and the 2019 Edition, or
later edition or addenda, of ASME BPV Code, Section XI, as incorporated
by reference in Sec. 50.55a, for their IST and ISI programs,
respectively. With this revised requirement to update the code of
record, the NRC does not intend that the code of record interval for an
IST or ISI program would exceed 25 years, even if ASME extends the IST
interval or the ISI interval beyond 12 years in the ASME OM Code or the
ASME BPV Code, respectively. The proposed 25-year maximum code of
record interval would allow the same code of record to be used for two
consecutive ISI or IST intervals, each up to 12 years, plus the one-
time 1-year extension for IST and ISI programs as specified in the ASME
OM Code and ASME BPV Code, respectively. If future editions of the ASME
OM Code or ASME BPV Code or future code cases extend the IST interval
or ISI interval, respectively, beyond 12 years, the NRC would need to
maintain the proposed 25-year maximum code of record interval.
In draft Revision 5 to RG 1.192, the NRC is proposing to
conditionally accept ASME OM Code Case OMN-31, ``Alternative to Allow
Extension of ISTA-3120 Inservice Examination and Test Intervals From 10
Years to 12 Years,'' as a voluntary alternative to the 10-year interval
specified in the ASME OM Code for applicants and licensees implementing
the 2020 Edition of the ASME OM Code or later editions as incorporated
by reference in Sec. 50.55a. In
[[Page 13720]]
draft Revision 21 to RG 1.147, the NRC is proposing to conditionally
accept ASME Code Case N-921, ``Alternative 12-yr Inspection Interval
Duration, Section XI, Division 1,'' as a voluntary alternative to the
10-year interval specified in Section XI, IWA-2400 of the ASME BPV Code
for applicants and licensees implementing the 2019 Edition of the ASME
BPV Code or later editions as incorporated by reference in Sec.
50.55a.
III. Discussion
A. Proposed Incorporation by Reference of Three Regulatory Guides
This proposed rule would incorporate by reference the latest
revisions of the NRC's RGs that list the ASME BPV and OM Code Cases
that the NRC finds to be acceptable, or acceptable with NRC-specified
conditions (``conditionally acceptable''). RG 1.84, Revision 40 (DG-
1405) would supersede the incorporation by reference of Revision 39; RG
1.147, Revision 21 (DG-1406) would supersede the incorporation by
reference of Revision 20; and RG 1.192, Revision 5 (DG-1407) would
supersede the incorporation by reference of Revision 4.
The ASME Code Cases that are the subject of this proposed rule are
the new and revised Section III and Section XI Code Cases as listed in
Supplements 2 through 7 to the 2019 Edition of the ASME BPV Code,
Supplements 0 through 2 and selected Code Cases from Supplement 3 to
the 2021 Edition of the ASME BPV Code, and the OM Code Cases listed in
the 2022 Edition of the ASME OM Code. By letter dated December 22,
2021, ASME requested that the NRC consider including Code Cases N-663-
1, N-885-1, and N-921 in this proposed rulemaking. In response, the NRC
included these three code cases within the scope of this proposed rule.
The NRC is also proposing to include OMN-31 within the scope of this
proposed rule to provide consistency between the ISI and IST programs.
The ASME publishes code cases that provide alternatives to existing
code requirements that the ASME developed and approved. This proposed
rule would incorporate by reference the most recent revisions of RGs
1.84, 1.147, and 1.192, which allow nuclear power plant licensees, and
applicants for combined licenses, standard design certifications,
standard design approvals, and manufacturing licenses under the
regulations that govern license certifications, to use the code cases
listed in these RGs as suitable alternatives to the ASME BPV and OM
Codes for the construction, inservice inspections, and inservice
testing of nuclear power plant components. The ASME makes the issued OM
Code Cases available on the OM Code website and provides an index
listing the issued OM Code Cases and their applicability in each ASME
OM Code edition. In contrast, the ASME publishes BPV Code Cases in a
separate document and at a different time than the ASME BPV Code
Editions. This proposed rule identifies the BPV Code Cases by the
edition of the ASME BPV Code under which they were published by the
ASME and the OM Code Cases by the most recent edition of the ASME OM
Code to which they apply.
The following general guidance applies to the use of the ASME Code
Cases approved in the latest versions of the RGs that are incorporated
by reference into Sec. 50.55a as part of this proposed rule.
Specifically, the use of the Code Cases listed in the latest versions
of RGs 1.84, 1.147, and 1.192 are acceptable with the specified
conditions when implementing the editions and addenda of the ASME BPV
and OM Codes incorporated by reference in Sec. 50.55a.
The approval of a code case in these RGs constitutes acceptance of
its technical position for applications that are not precluded by other
requirements. The applicant or licensee is responsible for ensuring
that use of the code case does not conflict with regulatory
requirements or licensee commitments. The code cases listed in the RGs
are acceptable for use within the limits specified in the code cases.
If the RG states an NRC condition on the use of a code case, then the
NRC condition supplements and does not supersede any condition(s)
specified in the code case, unless otherwise stated in the NRC
condition.
The ASME Code Cases may be revised for many reasons (e.g., to
incorporate operational examination and testing experience and to
update material requirements based on research results). On occasion,
an inaccuracy in an equation is discovered or an examination, as
practiced, is found not to be adequate to detect a newly discovered
degradation mechanism. Therefore, when an applicant or a licensee
initially implements a code case, Sec. 50.55a requires that the
applicant or the licensee implement the most recent version of that
code case, as listed in the RGs incorporated by reference. Code cases
superseded by revision are no longer acceptable for new applications
unless otherwise indicated.
Section III of the ASME BPV Code applies to new construction (e.g.,
the edition and addenda to be used in the construction of a plant are
selected based on the date of the construction permit and are not
changed thereafter, except voluntarily by the applicant or the
licensee). Section III may also be used for repair and replacement
activities under the provisions of Section XI of the ASME BPV Code.
Whether used for construction or later repair or replacement, when a
code case is first implemented by a licensee, the applicant implements
the latest edition incorporated by reference into Sec. 50.55a.
Thereafter, the applicant or licensee may continue to apply the
previous version of the code case or may apply the later version of the
code case, including any NRC-specified conditions placed on its use, as
an update to its code of record for the component.
Licensees that were using a code case prior to the effective date
of its revision may continue to use the previous version until the next
update to the code of record for the ISI or IST program, as applicable.
This relieves licensees of the burden of having to update their ISI or
IST program each time a code case is revised by the ASME and approved
for use by the NRC. Code cases apply to specific editions and addenda,
and code cases may be revised if they are no longer accurate or
adequate, so licensees choosing to continue using a code case into a
later code of record interval (e.g., after updating the edition and
addenda) for the ISI or IST program must implement the latest version
incorporated by reference into Sec. 50.55a and listed in the RGs.
The ASME may annul code cases that are no longer required, are
determined to be inaccurate or inadequate, or have been incorporated
into the BPV or OM Codes. A code case may be revised, for example, to
incorporate user experience. The older or superseded version of the
code case cannot be applied by the licensee or applicant for a first
use of that code case. If an applicant or a licensee applied a code
case before it was listed as superseded or annulled, the applicant or
the licensee may continue to use the code case until the applicant or
the licensee updates its construction code of record (in the case of an
applicant, updates its application) or until the licensee's code of
record interval for the ISI or IST program expires, after which the
continued use of the code case is prohibited unless NRC authorization
is given under Sec. 50.55a(z). If a code case is incorporated by
reference into Sec. 50.55a and later a revised version is issued by
the ASME because experience has shown that the design analysis,
construction method, examination
[[Page 13721]]
method, or testing method is inadequate, the NRC will amend Sec.
50.55a and the relevant RG to remove the approval of the superseded
code case. Applicants and licensees should not begin to implement such
superseded code cases in advance of the rulemaking. This proposed
rulemaking includes minor editorial changes to Sec. 50.55a(a) to align
with the Office of the Federal Register's guidance on the incorporation
by reference.
B. Code Cases Proposed To Be Approved for Unconditional Use
The code cases discussed in Table I are new, revised, or reaffirmed
code cases in which the NRC is not proposing any conditions. The table
identifies the draft regulatory guide listing the applicable code case
that the NRC proposes to approve for use.
Table I--Acceptable Code Cases
------------------------------------------------------------------------
------------------------------------------------------------------------
Boiler and Pressure Vessel Code Section III
(addressed in DG-1405, Table 1)
------------------------------------------------------------------------
Code case No. Published with Title
supplement
------------------------------------------------------------------------
N-351-1.................... 3 (2021 Edition).. Use of Standard Subsize
Charpy V-Notch Impact
Specimens, Section
III, Division 1;
Section III, Division
2; Section III,
Division 3.
N-893...................... 4 (2019 Edition).. Use of Alloy Steel Bar
and Mechanical Tubing
in Class 2 and 3
Patented Mechanical
Joints and Fittings,
Section III, Division
1.
N-900...................... 3 (2019 Edition).. Alternative Rules for
Level D Service Limits
of Class 1, 2, and 3
Piping Systems,
Section III, Division
1.
N-901...................... 4 (2019 Edition).. Use of ASME SA-494
Grade M35-1 for Line
Valve Bodies and
Bonnets, and Bodies,
Bonnets, and Yokes of
Pressure Relief Valves
for Class 2 and 3
Construction, Section
III, Division 1.
N-902...................... 5 (2019 Edition).. Thickness and Gradient
Factors for Piping
Fatigue Analyses,
Section III, Division
1.
N-904...................... 6 (2019 Edition).. Alternative Rules for
Simplified Elastic-
Plastic Analysis,
Section III, Division
1.
N-905...................... 6 (2019 Edition).. Alternate Design
Fatigue Curves to
Those Given in For
Section III
Appendices, Mandatory
Appendix I, Figures I-
9.1 and I-9.1M,
Section III, Division
1.
N-908...................... 7 (2019 Edition).. Use of Ferritic/
Austenitic Wrought
WPS32750/CRS32750
Fittings of Seamless
or Welded Construction
Conforming to SA-815,
Class 3, Section III,
Division 1.
N-910...................... 7 (2019 Edition).. Use of 25Cr-7Ni-4Mo-N
(Alloy UNS S32750
Austenitic/Ferritic
Duplex Stainless
Steel) Forgings,
Plate, and Welded and
Seamless Pipe and
Tubing Conforming to
SA-182, SA-240, SA-
789, or SA-790,
Section III, Division
1.
N-919...................... 2 (2021 Edition).. Alternative Fatigue
Evaluation Method to
Consider Environmental
Effects on Class 1
Components Section
III, Division 1.
N-920...................... 2 (2021 Edition).. Alternative Fatigue
Design Curves for
Ferritic Steels With
Ultimate Tensile
Strengths (UTS) <=80
ksi (552 MPa) and
Austenitic Steels,
Section III, Division
1.
------------------------------------------------------------------------
Boiler and Pressure Vessel Code Section XI
(addressed in DG-1406, Table 1)
------------------------------------------------------------------------
Code case No. Published with Title
supplement
------------------------------------------------------------------------
N-561-4.................... 0 (2021 Edition).. Alternative
Requirements for Wall
Thickness Restoration
of Class 2 and High
Energy Class 3 Carbon
Steel Piping, Section
XI, Division 1.
N-562-4.................... 0 (2021 Edition).. Alternative
Requirements for Wall
Thickness Restoration
of Class 3 Moderate
Energy Carbon Steel
Piping, Section XI,
Division 1.
N-597-5.................... 0 (2021 Edition).. Evaluation of Pipe Wall
Thinning, Section XI,
Division 1.
N-638-11................... 2 (2019 Edition).. Similar and Dissimilar
Metal Welding Using
Ambient Temperature
Machine GTAW Temper
Bead Technique,
Section XI, Division
1.
N-661-5.................... 0 (2021 Edition).. Alternative
Requirements for Wall
Thickness Restoration
of Class 2 and 3
Carbon Steel Piping
for Raw Water Service
Section XI, Division
1.
N-663-1.................... 3 (2021 Edition).. Alternative
Requirements for
Classes 1 and 2
Surface Examinations,
Section XI, Division
1.
N-733-1.................... 6 (2019 Edition).. Mitigation of Flaws in
NPS 3 (DN 80) and
Smaller Nozzles and
Nozzle Partial
Penetration Welds in
Vessels and Piping by
Use of a Mechanical
Connection
Modification, Section
XI, Division 1.
N-780-1.................... 1 (2021 Edition).. Alternative
Requirements for
Upgrade, Substitution,
or Reconfiguration of
Examination Equipment
When Using Appendix
VIII Qualified
Ultrasonic Examination
Systems, Section XI,
Division 1.
N-786-4.................... 0 (2021 Edition).. Alternative
Requirements for
Sleeve Reinforcement
of Class 2 and 3
Moderate Energy Carbon
Steel Piping, Section
XI, Division 1.
N-789-5.................... 1 (2021 Edition).. Alternative
Requirements for Pad
Reinforcement of Class
2 and 3 Moderate
Energy Carbon Steel
Piping for Raw Water
Service, Section XI,
Division 1.
N-809-1.................... 0 (2021 Edition).. Reference Fatigue Crack
Growth Rate Curves for
Austenitic Stainless
Steels in Pressurized
Reactor Water
Environments, Section
XI, Division 1.
N-853-1.................... 0 (2021 Edition).. PWR Class 1 Primary
Piping Alloy 600 Full
Penetration Branch
Connection Weld Metal
Buildup for Material
Susceptible to Primary
Water Stress Corrosion
Cracking, Section XI,
Division 1.
N-860...................... 6 (2019 Edition).. Inspection Requirements
and Evaluation
Standards for Spent
Nuclear Fuel Storage
and Transportation
Containment Systems,
Section XI, Division
1; Section XI,
Division 2.
N-865-2.................... 0 (2021 Edition).. Alternative
Requirements for Pad
Reinforcement of Class
2 and 3 Atmospheric
Storage Tanks, Section
XI, Division 1.
[[Page 13722]]
N-877-1.................... 5 (2019 Edition).. Alternative
Characterization Rules
for Multiple
Subsurface Radially
Oriented Planar Flaws,
Section XI, Division
1.
N-882-1.................... 0 (2021 Edition).. Alternative
Requirements for
Attaching
Nonstructural
Electrical Connections
to Class 2 and 3
Components, Section
XI, Division 1.
N-885-1.................... 3 (2021 Edition).. Alternative
Requirements for Table
IWB-2500-1,
Examination Category B-
N-1, Interior of
Reactor Vessel,
Category B-N-2, Welded
Core Support
Structures and
Interior Attachments
to Reactor Vessels,
Category BN-3,
Removable Core Support
Structures, Section
XI, Division 1.
N-888...................... 5 (2019 Edition).. Similar and Dissimilar
Metal Welding Using
Ambient Temperature
SMAW or Machine GTAW
Temper Bead Technique,
Section XI, Division
1.
N-896...................... 2 (2019 Edition).. Reference Crack Growth
Rate Curves for Stress
Corrosion Cracking of
Low Alloy Steels in
Boiling Water Reactor
Environments, Section
XI, Division 1.
N-911...................... 0 (2021 Edition).. Purchase, Exchange, or
Transfer of Material
Between Nuclear
Owners, Section XI,
Division 1.
N-912...................... 0 (2021 Edition).. Alternative
Requirements for
Qualification of
Material Suppliers and
Acceptance of
Materials, Section XI,
Division 1.
N-913...................... 0 (2021 Edition).. Alternative Examination
Requirements for Class
1 Pressure-Retaining
Welds in Control Rod
Drive Housings,
Section XI, Division
1.
N-917...................... 2 (2021 Edition).. Fatigue Crack Growth
Rate Curves for
Ferritic Steels in
Boiling Water Reactor
(BWR) Environments,
Section XI, Division
1.
------------------------------------------------------------------------
Operation and Maintenance Code
(addressed in DG-1407, Table 1)
------------------------------------------------------------------------
Code case Most recent code Title
edition \4\
------------------------------------------------------------------------
OMN-28..................... 2022 Edition...... Alternative Valve
Position Verification
Approach to Satisfy
ISTC-3700 for Valves
Not Susceptible to
Stem-Disk Separation.
OMN-29..................... 2022 Edition...... Pump Condition
Monitoring Program.
OMN-30..................... 2022 Edition...... Alternative Valve
Position Verification
Approach to Satisfy
ISTC-3700.
------------------------------------------------------------------------
C. Code Cases Approved for Use With Conditions
---------------------------------------------------------------------------
\4\ Each code case or ASME Applicability Index List indicates
the ASME OM Code editions and addenda to which the code case
applies, except where a condition is specified in Sec. 50.55a or RG
1.192 related to technical content or applicability. This table
indicates the latest OM Code edition at the time of this rulemaking.
---------------------------------------------------------------------------
The NRC has determined that certain code cases, as issued by the
ASME, are generally acceptable for use, but that the alternative
requirements specified in those code cases must be supplemented in
order to provide an acceptable level of quality and safety.
Accordingly, the NRC proposes to impose conditions on the use of these
code cases to modify, limit or clarify their requirements. The
conditions would specify, for each applicable code case, the additional
activities that must be performed, the limits on the activities
specified in the code case, and/or the supplemental information needed
to provide clarity. These ASME Code Cases, listed in Table II, are
included in Table 2 of DG-1405 (RG 1.84), DG-1406 (RG 1.147), and DG-
1407 (RG 1.192). This section provides the NRC's evaluation of the code
cases and the reasons for the NRC's proposed conditions. Notations
indicate the conditions duplicated from previous versions of the RG.
The NRC requests public comment on these code cases and the
proposed conditions. It also should be noted that this section only
addresses those code cases for which the NRC proposes to impose
condition(s), which are listed in the RG for the first time.
Table II--Conditionally Acceptable Code Cases
------------------------------------------------------------------------
------------------------------------------------------------------------
Boiler and Pressure Vessel Code Section III
(addressed in DG-1405, Table 2)
------------------------------------------------------------------------
Code case No. Published with Title
supplement
------------------------------------------------------------------------
N-71-21.................... 0 (2021 Edition).. Additional Materials
for Subsection NF,
Class 1, 2, 3, and MC
Supports Fabricated by
Welding, Section III,
Division 1.
N-570-3.................... 0 (2021 Edition).. Alternative Rules for
Linear Piping and
Linear Standard
Supports for Classes
1, 2, 3, and MC,
Section III, Division
1.
------------------------------------------------------------------------
Boiler and Pressure Vessel Code Section XI
(addressed in DG-1406, Table 2)
------------------------------------------------------------------------
Code case No. Published with Title
supplement
------------------------------------------------------------------------
N-711-2.................... 6 (2019 Edition).. Alternative Examination
Coverage Requirements
for Examination
Category B F, B J, C-F-
1, C-F-2, and R-A
Piping Welds, Section
XI, Division 1.
N-716-3.................... 5 (2019 Edition).. Alternative
Classification and
Examination
Requirements, Section
XI, Division 1.
N-754-2.................... 0 (2021 Edition).. Optimized Structural
Dissimilar Metal Weld
Overlay for Mitigation
of PWR Class 1 Items,
Section XI, Division
1.
[[Page 13723]]
N-766-4.................... 0 (2021 Edition).. Nickel Alloy Reactor
Coolant Inlay and
Onlay for Mitigation
of PWR Full
Penetration
Circumferential Nickel
Alloy Dissimilar Metal
Welds in Class 1
Items, Section XI,
Division 1.
N-847-1.................... 0 (2021 Edition).. Partial Excavation and
Deposition of Weld
Metal for Mitigation
of Class 1 Items,
Section XI, Division
1.
N-880-1.................... 0 (2021 Edition).. Alternative to
Procurement
Requirements of IWA-
4143 for Nonstandard
Welded Fittings,
Section XI, Division
1.
N-899...................... 3 (2019 Edition).. Weld Residual Stress
Distributions for
Piping and Vessel
Nozzle Butt Welds
Fabricated With UNS
N06082, UNS W86182,
UNS N06052, or UNS
W86152 Weld Filler
Material, Section XI,
Division 1.
N-906...................... 7 (2019 Edition).. Flaw Evaluation
Procedure for Cast
Austenitic Stainless
Steel Piping and
Adjacent Fittings,
Section XI, Division
1.
N-921...................... 3 (2021 Edition).. Alternative 12-yr
Inspection Interval
Duration, Section XI,
Division 1.
------------------------------------------------------------------------
Operation and Maintenance Code
(addressed in DG-1407, Table 2)
------------------------------------------------------------------------
Code case No............... Most recent OM Title
code edition \5\
------------------------------------------------------------------------
OMN-31..................... 2022 Edition...... Alternative to Allow
Extension of ISTA-3120
Inservice Examination
and Test Intervals
From 10 Years to 12
Years.
------------------------------------------------------------------------
ASME BPV Code, Section III Code Cases (DG-1405/RG 1.84)
---------------------------------------------------------------------------
\5\ Each code case or ASME Applicability Index List indicates
the ASME OM Code editions and addenda to which the code case
applies, except where a condition is specified in Sec. 50.55a or RG
1.192 related to technical content or applicability. This table
indicates the latest OM Code edition at the time of this rulemaking.
Conditions specified for other OM Code Cases listed in Table 2 of RG
1.192 have not changed in this rulemaking other than updating to the
latest OM Code edition.
---------------------------------------------------------------------------
Code Case N-71-21 [Supplement 0, 2021 Edition]
Type: Revised
Title: Additional Materials for Subsection NF, Class 1, 2, 3, and MC
Supports Fabricated by Welding, Section III, Division 1
The proposed conditions on Code Case N-71-21 are the same as the
conditions on N-71-20 that were approved by the NRC in Revision 39 of
RG 1.84. When the ASME revised N-71, the code case was not modified in
a way that would make it possible for the NRC to remove the conditions.
Therefore, the conditions would be retained in Revision 40 of RG 1.84.
Code Case N-570-3 [Supplement 0, 2021 Edition]
Type: Revised
Title: Alternative Rules for Linear Piping and Linear Standard Supports
for Classes 1, 2, 3, and MC, Section III, Division 1
Code Case N-570-3 would update references made to ANSI/AISC N690-
1994 and ANSI/AISC N690-1994 (R2004) Supplement 2 with ANSI/AISC N690-
18. A difference between ANSI/AISC N690-18 and ANSI/AISC N690-1994
(R2004) is that ANSI/AISC N690-18 allows the use of the Load and
Resistance Factor Design (LRFD) method or the Allowable Strength Design
(ASD) method, versus the allowable stress design method or plastic
design method contained in the ANSI/AISC N690-1994 (R2004) edition.
Code Case N-570-2 explicitly stated in paragraph 3.11 that the plastic
design method in Part 2 of ANSI/AISC N690-1994 (R2004) shall not be
used. It is the NRC's understanding that the alternative requirements
of code case N-570-3 for design are also intended to be limited to the
design for strength using the ASD method of ANSI/AISC N690-18, which is
similar to the allowable stress design method used in N-570-2; however,
the code case does not include such explicit qualifiers regarding the
use of ANSI/AISC N690-18. The alternative requirements for design in
Code Case N-570-3 would be limited to the design for strength using the
ASD method of ANSI/AISC N690-18. To provide clarity, the NRC is
proposing a condition: ``This Code Case shall not be used with the Load
and Resistance Factor Design method of ANSI/AISC N690-18.''
ASME BPV Code, Section XI Code Cases (DG-1406/RG 1.147)
Code Case N-711-2 [Supplement 6, 2019 Edition]
Type: Revised
Title: Alternative Examination Coverage Requirements for Examination
Category B F, B J, C-F-1, C-F-2, and R-A Piping Welds, Section XI,
Division 1
The condition on Code Case N-711-2 would be identical to the
condition on N-711-1 that was approved by the NRC in Revision 20 of RG
1.147. When the ASME revised N-711, the code case was not modified in a
way that would make it possible for the NRC to remove the condition.
Therefore, the condition would be retained in Revision 21 of RG 1.147.
Code Case N-716-3 [Supplement 5, 2019 Edition]
Type: Revised
Title: Alternative Classification and Examination Requirements, Section
XI, Division 1
Code Case N-716 provides rules for alternative classification and
examination requirements for piping welds and components. Revision 3 to
Code Case N-716 would remove the provision for plants issued an
operating license after January 1, 2012, to submit the application of
this Code Case for regulatory approval. The NRC is cognizant of the
committee's desire to eliminate the provision for newly constructed
plants to submit first time applications of N-716 to the NRC. It was
the Committee's intention to make this Code Case more generally
applicable internationally. However, the NRC is of the opinion that the
new designs may introduce additional variables, which in the absence of
substantial operating experience with these new plants, may introduce
uncertainty on the applicability of this Code Case to the new plants.
Hence, the NRC has determined there is a need to review the initial
proposals for new plants. The review would confirm the absence of new
degradation mechanisms, evaluate with available operating experience,
as well as the risk-related information for the new plants prior to the
initial application of the Code Case to new plants. Therefore, the NRC
is proposing a condition that this Code Case is not approved for use by
plants issued an
[[Page 13724]]
operating license or combined license after January 1, 2012. However,
plants issued an operating license or combined license after January 1,
2012, may submit an alternative to use this Code Case in accordance
with Sec. 50.55a(z) for review and approval prior to implementation.
Code Case N-754-2 [Supplement 0, 2021 Edition]
Type: Revised
Title: Optimized Structural Dissimilar Metal Weld Overlay for
Mitigation of PWR Class 1 Items, Section XI, Division 1
The NRC is proposing to revise the conditions on N-754-1 to remove
reference to the NRC's safety evaluation for the topical report
``Materials Reliability Program (MRP): Technical Basis for Preemptive
Weld Overlays for Alloy 82/182 Butt Welds in PWRs'' (MRP-169) and to
clarify the examination requirements.
The first condition deals with the use of this Code Case on a pipe
that implements NRC-approved leak-before-break (LBB) methodology. The
application of the LBB concept to a pipe is that if a flaw is developed
in a pipe with certain favorable material properties, the pipe will
most likely leak first before it fails catastrophically. The existing
leakage detection system in the nuclear plant will detect the leakage
and alert the operator. The operator has sufficient time to shut down
the plant safely to perform corrective actions. The NRC has approved
LBB for certain Class 1 reactor coolant system piping in pressurized
water reactor plants based on the plant-specific and piping-specific
LBB analysis, which shows that the probability of the piping rupture is
extremely low under conditions consistent with the design basis for the
piping as required in General Design Criterion 4 of 10 CFR part 50,
appendix A. The LBB methodology and analysis, including specific safety
margins, are reviewed and approved via the license amendment process.
The LBB implementation is documented in the plant final safety analysis
report. When an optimized weld overlay is installed onto pipes that are
approved for LBB, the licensee must verify that the safety margins
specified in the original LBB analysis are still satisfied.
The second condition states that the preservice and inservice
examinations of the overlaid pipe using this Code Case must be
performed in accordance with Sec. 50.55a(g)(6)(ii)(F). Paragraph 3(c)
of N-754-2 states that--
In lieu of all other Preservice and Inservice inspection
requirements, the examination requirements in accordance with N-770-2
(or later in accordance with [Paragraph] 5) shall be met. Alternately,
the requirements of [subparagraphs] (1) through (3) below may be used
to modify the provisions of N-770-2 (or later in accordance with
[Paragraph] 5).
As stated, if the inspection of the overlaid pipe performed in
accordance with N-770-2 cannot be met or performed, alternatives of
Paragraphs 3(c)(1), 3(c)(2) and 3(c)(3) of N-754-2 could be used. The
NRC identified the following issues regarding the statement in
Paragraph 3(c):
Paragraphs 3(c)(2) and 3(c)(3) of N-754-2 are related to
the design and analysis, not the inspection of the overlaid pipe.
Therefore, it is not clear how these two paragraphs can be used to
modify the inspection provisions of N-770-5.
The inspection provisions of Paragraph 3(c)(1) are allowed
to be different from the provisions of Note 14, Preservice Inspection
for Optimized Weld Overlays, and Note 18, Inservice Inspection of
Optimized Weld Overlays, of Table 1 of N-770. The NRC notes that 10 CFR
50.55a(g)(6)(ii)(F) mandates the use of N-770, as conditioned, for the
examination requirements for optimized weld overlays in dissimilar
metal butt welds. Therefore, for regulatory clarity regarding
preservice and inservice inspection requirements, the proposed
condition is provided.
Section 50.55a(g)(6)(ii)(F) mandates the implementation of
N-770-5, rather than N-770-2
Therefore, the NRC finds that this condition is needed to
clarify the examination requirements in Paragraph 3 of N-754-2 and to
ensure that N-770-5 is implemented as required by Sec.
50.55a(g)(6)(ii)(F).
Code Case N-766-4 [Supplement 0, 2021 Edition]
Type: Revised
Title: Nickel Alloy Reactor Coolant Inlay and Onlay for Mitigation of
PWR Full Penetration Circumferential Nickel Alloy Dissimilar Metal
Welds in Class 1 Items, Section XI, Division 1
The proposed conditions on Code Case N-766-4 are identical to the
conditions on N-766-3 that were approved by the NRC in the previous
revision of RG 1.147. When the ASME revised N-766, the code case was
not modified in a way that would make it possible for the NRC to remove
the conditions. Therefore, the conditions would be retained in Revision
21 of RG 1.147.
Code Case N-847-1 [Supplement 0, 2021 Edition]
Type: Revised
Title: Partial Excavation and Deposition of Weld Metal for Mitigation
of Class 1 Items, Section XI, Division 1
The proposed conditions on Code Case N-847-1 are identical to the
conditions on N-847 that were approved by the NRC in the previous
revision of RG 1.147. When the ASME revised N-847, the code case was
not modified in a way that would make it possible for the NRC to remove
the conditions. Therefore, the conditions would be retained in Revision
21 of RG 1.147.
Code Case N-880-1 [Supplement 0, 2021 Edition]
Type: Revised
Title: Alternative to Procurement Requirements of IWA-4143 for
Nonstandard Welded Fittings, Section XI, Division 1
Code Case N-880-1 removes the size limitation in the Case by
eliminating the NPS 2 size limit. The NRC does not agree with removing
the small size limitation (NPS 2 and under). The NRC is proposing to
continue to limit the scope of the code case to NPS 2 (DN 50) or
smaller fittings because there is insufficient technical basis to
expand the application to items larger than NPS 2 (DN 50). The only
justification provided for this change was that it is an arbitrary
limitation. However, the limitation to NPS 2 (DN 50) and under was
based on the capacity of the reactor coolant makeup system being able
to safely shutdown the plant if these fittings fail, and therefore, is
not an arbitrary limitation.
Without a condition, approval of the code case would allow the use
of these non-standard or specialized fittings in any Class 1, 2 and 3
systems, including the reactor coolant makeup system. Thus, the failure
of these fittings, which lack operating experience to demonstrate their
reliability, could also affect the reactor coolant makeup system's
ability to provide sufficient makeup capacity. Therefore, the NRC is
proposing a new condition to limit the use of Code Case N-880-1 to NPS
2 (DN 50) or smaller fittings.
Conditions 2 and 3 are identical to the conditions on N-880 that
were approved by the NRC in previous revision of RG 1.147. When the
ASME revised N-880, the code case was not modified in a way that would
make it possible for the NRC to remove the conditions. Therefore, the
conditions would be retained in Revision 21 of RG 1.147.
[[Page 13725]]
Code Case N-899 [Supplement 3, 2019 Edition]
Type: New
Title: Weld Residual Stress Distributions for Piping and Vessel Nozzle
Butt Welds Fabricated With UNS N06082, UNS W86182, UNS N06052, or UNS
W86152 Weld Filler Material, Section XI, Division 1
Code Case N-899 provides an alternative method for calculating the
values of weld residual stress as a function of distance through the
wall thickness for dissimilar metal butt welds in the reactor coolant
pressure boundary. The NRC notes that Code Case N-899 may be used in
conjunction with methodologies similar to those in Section XI,
nonmandatory Appendix A, Article A-3000 to calculate the crack tip
stress intensity factor, KI, for inside surface connected
flaws in piping or vessel nozzle butt welds fabricated with UNS N06082,
UNS W86182, UNS N06052, or UNS W86152 weld filler material.
In many cases, plants do not have information on the actual repairs
performed to Alloy 82/182 butt welds. However, operating experience and
records indicate that repairs were common, including some welds being
repaired multiple times. Weld repairs generally cause the weld residual
stress to become more severe. Given the uncertainty in whether a weld
repair exists or not, the NRC staff has generally found that it is
appropriate to assume that a repair is present for the purposes of flaw
evaluation. Therefore, consistent with the established NRC position for
the weld residual stress distribution analysis for the subject welds of
this code case, the inside surface repair residual stress distributions
of Code Case N-899 are acceptable for use provided all known and
documented repairs are bounded by the 50-percent through wall repair
assumed in the case. Based on this discussion, the NRC is proposing the
condition that only the standard weld residual stress distributions
with repairs included, Paragraphs -2331 and -2332, would be approved
for use and only if they bound all known or documented repairs
previously performed on the subject weld.
Similarly, the NRC also notes that when Paragraph -3000,
Calculation of Residual Stress Using Finite Element Analysis, is
applied as an option to use finite element analysis to calculate weld
residual stress distributions, the weld residual stress analysis should
incorporate a minimum of a 50 percent through-wall inside surface
connected weld repair as part of the analysis. This is consistent with
the NRC position on repairs and weld residual stress calculations
stated in this discussion. If documentation of a repair is found or a
previous repair is known, the weld residual stress analysis must be
evaluated to determine if it is bounded by the 50-percent repair by
modeling or flaw evaluation. The more conservative of either 50-percent
repair assumption or the combination of all known previous repairs
should be used in the development of the weld residual stress
distribution. Therefore, the NRC is proposing a condition: when
developing a plant-specific weld residual stress distribution, the
finite element analysis calculation of the weld residual stress
distribution must use the more bounding of either an assumed previous
inside surface repair of 50 percent through-wall or the combination of
all known or documented previous repairs.
Code Case N-906 [Supplement 7, 2019 Edition]
Type: New
Title: Flaw Evaluation Procedure for Cast Austenitic Stainless Steel
Piping and Adjacent Fittings, Section XI, Division 1
Code Case N-906 provides flaw evaluation procedure for cast
austenitic stainless steel piping and fittings adjacent to girth welds
as alternatives to the methods in Nonmandatory Appendix C, C-4210 and
C-6330. Paragraph 1(b) of Code Case N-906 states that the provisions of
this Case shall be applied to operating temperatures of 500 [deg]F to
625 [deg]F (260 [deg]C to 330 [deg]C). The paragraph also states that,
if a thermal transient below this range of temperatures occurs at the
flaw location, the appropriate toughness, Ji, at the minimum
transient temperature shall be used along with the applied stresses at
that minimum transient temperature. Accordingly, if a transient occurs
below the specified temperature range, the code case requires that the
flaw evaluation use the fracture toughness and applied stresses at the
minimum transient temperature.
However, the limiting fracture toughness and relevant applied
stress for the flaw under the transient may not be those at the minimum
transient temperature. For example, Figure 32 of NUREG/CR-4513,
Revision 2, ``Estimation of Fracture Toughness of Cast Stainless Steels
during Thermal Aging in LWR Systems,'' shows that the fracture
toughness of a cast austenitic stainless steel material at room
temperature may be higher than that at an elevated temperature.
Therefore, the NRC is proposing a condition to delete the reference to
the minimum transient temperature that is associated with the
appropriate fracture toughness and applied stresses for the flaw
evaluation. The condition also clarifies that the flaw evaluation must
use the fracture toughness and applied stresses that are limiting for
the flaw.
Code Case N-921 [Supplement 3, 2021 Edition]
Type: New
Title: Alternative 12-Year Inspection Interval Duration, Section XI,
Division 1
Code Case N-921 increases the inservice inspection interval defined
in Section XI, IWA-2400 from 10 years to 12 years. Section XI, IWA-2400
requires that licensees have an inservice inspection program that
includes, for example, inspection plans, inservice inspection interval
dates, and identification of code cases to be applied during the
interval. While IWA-2400 requires that plants specify the edition or
addenda of Section XI that will be applied during the interval, Section
XI does not prescribe what constitutes an appropriate edition or
addenda. In fact, IWA-2410 states that edition or addenda is ``as
required by the regulatory authority having jurisdiction at the plant
site.'' The regulation at Sec. 50.55a(g)(4)(ii) provides the
regulatory basis for licensees determining which edition or addenda to
apply to inservice inspection programs for a successive interval. This
regulation assumes a 10-year inservice inspection interval.
A licensee applying this code case is, therefore, required by Sec.
50.55a(4)(g)(ii) to update the code of record every 10 years. The
inservice inspection interval and the code of record update interval
should be synchronized to promote order and predictability in licensee
inservice inspection programs. As part of this rulemaking, the NRC also
is updating Sec. 50.55a to allow flexibility in how often the code of
record is updated, provided that licensees update to the 2019 Edition
of Section XI. The NRC, therefore, proposes to condition Code Case N-
921 to require updating to the 2019 Edition of Section XI. This
condition would ensure that the desired order and predictability in
licensee inservice inspection programs is maintained.
ASME Operation and Maintenance Code Cases (DG-1407/RG 1.192)
Code Case OMN-31 [2022 Edition]
Type: New
Title: Alternative to Allow Extension of ISTA-3120 Inservice
Examination
[[Page 13726]]
and Test Intervals From 10 Years to 12 Years
For the same reasons explained for Section XI Code Case N-921, the
NRC is restricting the use of OMN-31 to licensees implementing the ASME
OM Code, 2020 Edition. As indicated in DG-1407/RG 1.192, this OM Code
Case may be applied by licensees implementing the ASME OM Code, 2020
Edition through the latest edition of the ASME OM Code incorporated by
reference in Sec. 50.55a, contrary to the ASME OM Code Case
Applicability Index, dated July 1, 2022.
Other OM Code Cases in Table 2 of Proposed Revision 5 to RG 1.192
No changes were made to the OM Code Cases listed in Table 2 of the
proposed Revision 5 to RG 1.192 (with the exception of new Code Case
OMN-31, discussed previously) from the versions that were listed in OM
Code Cases listed in Table 2 of Revision 4 to RG 1.192. Therefore, the
conditions on the OM Code Cases listed in Table 2 of the proposed
Revision 5 to RG 1.192 (with the exception of new Code Case OMN-31) are
identical to the conditions on those OM Code Cases that were approved
by the NRC in Revision 4 of RG 1.192. The OM Code Cases listed in Table
2 of the proposed Revision 5 to RG 1.192 were re-affirmed by the ASME
for the 2022 Edition of the OM Code with no change to those OM Code
Cases. Therefore, the conditions on the OM Code Cases in Table 2 are
retained in proposed Revision 5 of RG 1.192.
D. ASME Code Cases Not Approved for Use (DG-1408/RG 1.193)
The ASME Code Cases that are currently issued by the ASME but not
approved for generic use by the NRC are listed in RG 1.193, ``ASME Code
Cases not Approved for Use.'' In addition to the ASME Code Cases that
the NRC has found to be technically or programmatically unacceptable,
RG 1.193 includes code cases on reactor designs for high-temperature
gas-cooled reactors and liquid metal reactors, reactor designs not
currently licensed by the NRC, and certain requirements in Section III,
Division 2, for submerged spent fuel waste casks, that are not endorsed
by the NRC. Regulatory Guide 1.193 complements RGs 1.84, 1.147, and
1.192. It should be noted that the NRC is not proposing to adopt any of
the code cases listed in RG 1.193.
E. Proposed Revision to Code of Record Update Requirements
Nuclear power plant licensees maintain their IST and ISI programs,
respectively, in accordance with the requirements of the ASME OM Code
and ASME BPV Code, Section XI, as incorporated by reference in Sec.
50.55a. The initial concept of a 10-year ISI interval first appeared in
the 1970 Edition of the ASME BPV Code, Section XI, in paragraph IS-240.
This 10-year interval (referred to as the ISI interval) is only related
to ASME ISI requirements. There is a corresponding 10-year IST interval
for the OM Code requirements.
Later, in a final rule published in February 1976 (41 FR 6256), the
NRC revised Sec. 50.55a to require IST code of record updates every 20
months and ISI code of record updates every 40 months. This requirement
was (and still is) independent from the ISI and IST intervals defined
by the respective codes. In the early years of the development of ISI
and IST programmatic requirements, the NRC requirement to update the
codes of record was not synchronized with the ASME concept of an IST or
ISI interval. In January 1979 (44 FR 3719), the NRC proposed changes to
Sec. 50.55a to extend the 20- and 40-month update intervals to 120
months (10 years), in order to promote consistency with the 10-year
interval in the ASME codes. The corresponding final rule was published
in October 1979 (44 FR 57912).
Paragraph IWA-2420 of the 1989 Edition and later of ASME BPV Code,
Section XI, requires that nuclear plant owners prepare inspection plans
and schedules for each ISI interval. These plans should include a
listing of all code cases to be applied during the ISI interval and
alternatives authorized under Sec. 50.55a(z). The proposed revision to
Sec. 50.55a in this rulemaking does not alter those requirements. In
defining the inspection program, Paragraph IWA-2410 of ASME BPV Code,
Section XI, states, ``The Code Edition and Addenda for preservice
inspection and for initial and successive inservice inspection
intervals shall be as required by the regulatory authority having
jurisdiction at the plant site.'' Therefore, while ASME BPV Code,
Section XI, requires plant owners to declare which edition of Section
XI will be applied during each ISI interval, the code does not specify
what constitutes an appropriate edition of Section XI.
Similarly, paragraph ISTA-3110, ``Test and Examination Plans,'' in
the 2020 Edition of the ASME OM Code requires that nuclear plant owners
prepare test plans for the preservice test period, initial IST
intervals, and subsequent IST intervals. These plans should include a
listing of all code cases to be applied during the IST interval, relief
granted under Sec. 50.55a(f), and alternatives authorized under Sec.
50.55a(z). Paragraph ISTA-3110 requires in subparagraph (a) that each
IST plan shall include ``the edition and addenda of this Section that
apply to the required tests and examinations.'' Therefore, while the
ASME OM Code requires nuclear power plant owners to declare which
edition and addenda of the OM Code will be applied during each IST
interval, the OM Code does not specify what constitutes an appropriate
edition and addenda of the OM Code.
Thus, neither the ASME BPV Code, Section XI, nor the OM Code
specify which edition to use. Rather, the NRC's regulations in Sec.
50.55a determine the appropriate edition and addenda of the ASME BPV
Code, Section XI, or the OM Code to be applied in each ISI or IST
interval respectively. The changes proposed to these code of record
requirements in this rulemaking are focused on that aspect alone.
The NRC does not intend the proposed extension of the update
interval to affect the orderly implementation of IST and ISI programs.
Therefore, the proposed rule is designed to synchronize the
requirements of ASME Codes and Sec. 50.55a as much as possible. For
licensees with codes of record prior to ASME BPV Code, Section XI, 2019
Edition, and OM Code, 2020 Edition, as incorporated by reference in
Sec. 50.55a, the proposed rule specifies that the code of record
interval for the ISI and IST programs shall be the same as the ISI
interval or IST interval. This is consistent with the current
requirements. For licensees with codes of record of ASME BPV Code,
Section XI, 2019 Edition, or later editions and addenda, and ASME OM
Code, 2020 Edition, or later editions, as incorporated by reference in
Sec. 50.55a, the proposed rule specifies that the code of record
interval for the ISI and IST programs shall be updated every two
consecutive ISI intervals or IST intervals, respectively.
With this revised requirement to update the code of record, the NRC
does not intend that the code of record interval for an IST or ISI
program will exceed 25 years, even if ASME extends the IST interval or
the ISI interval beyond 12 years in the ASME OM Code or the ASME BPV
Code, respectively. The 25-year maximum code of record interval allows
the same code of record to be used for two consecutive ISI or IST
intervals, each up to 12 years, plus the one-time, 1-year extension for
IST and ISI programs as specified in the ASME OM Code and ASME BPV
Code, respectively. The Commission has not approved extending the code
of record
[[Page 13727]]
intervals beyond the 25-year maximum proposed in this rulemaking. If
future editions of the ASME OM Code or ASME BPV Code or future code
cases extend the IST interval or ISI interval, respectively, beyond 12
years, the NRC would need to maintain the proposed 25-year maximum code
of record interval.
The concept of a 120-month interval is referenced repeatedly in
Sec. 50.55a. However, the current language is not consistent or well-
defined. As such, the NRC proposes to clarify the language by
introducing certain definitions in Sec. 50.55a(y). The proposed
definitions include code of record, code of record interval, inservice
examination and test interval, inservice inspection program, inservice
testing program, and inspection interval. The NRC also proposes to
update the language throughout Sec. 50.55a to be consistent with the
proposed definitions.
With respect to relief from impractical IST requirements as
requested in accordance with Sec. 50.55a(f)(5)(iv), the NRC proposes
that the duration of the granted relief be changed from the ``120-month
interval of operation'' to the standardized definitions of the
Inservice Examination and Test Interval. At the end of the Inservice
Examination and Test Interval, the licensee would reassess whether the
IST requirement continues to be impractical and submit an updated
relief request as necessary. The NRC is proposing similar revisions for
the ISI requirements in Sec. 50.55a(g)(5)(iii) and (iv).
With respect to alternative requests in accordance with Sec.
50.55a(z), the NRC will address the duration of each new authorized
alternative in the safety evaluation describing its review of the
request consistent with the current procedures for evaluating
alternative requests. Existing NRC-approved alternatives were approved
based on the IST or ISI interval. The proposed rulemaking language
regarding the code of record interval does not extend the approval
timeframe for these existing alternatives. Licensees seeking to extend
the timeframe of approved alternatives therefore would need to submit
an alternative request per Sec. 50.55a(z) to continue using previously
granted alternatives in a subsequent IST or ISI interval in the same
code of record update interval. Licensees may request future
alternatives based upon the code of record interval.
In addition, the NRC proposes to update references to the 10-year
service period in appendix J to 10 CFR part 50 to be consistent with
the definitions in the proposed Sec. 50.55a(y), in which the NRC
proposes to allow the ISI period to be extended to 12 years. The
current rules for Type A tests under Option A (prescriptive
requirements) explicitly reference the 10-year service period required
in Sec. 50.55a for inservice inspections. Consistent with the NRC's
stated goal of maintaining consistency across all NRC rules regarding
ISI and IST programs, the NRC is proposing revisions to appendix J to
10 CFR part 50 to directly reference the interval defined in a revised
10 CFR 50.55a, to accommodate a 12-year ISI interval. For the reasons
stated in SECY-22-0075, the NRC proposes to make this revision without
changing the intent or basis for the Type A test requirement in
appendix J to 10 CFR part 50.
Licensees are currently required to submit various documents, such
as IST plans and schedules or Section XI flaw evaluations, to the NRC
each IST or ISI interval. The language proposed in this rulemaking
regarding the code of record intervals does not alter those submittal
requirements in any way. Therefore, licensees should carefully
distinguish requirements that apply to the code of record interval from
those that apply to the IST or ISI interval. For example, Sec.
50.55a(f)(7) requires IST plans to be submitted within 90 days of their
implementation for the applicable 120-month IST program interval. This
proposed rule would revise the terms used in paragraph (f)(7) for
consistency with the new definitions, but submittal of IST plans would
still be required within 90 days of their implementation for the
applicable IST interval.
IV. Specific Requests for Comments
The NRC is seeking advice and recommendations from the public on
the proposed rule. We are particularly interested in comments and
supporting rationale from the public on the following:
The NRC proposes to add Sec. 50.55a(y) to include
definitions of certain terms that may be important for delineating
requirements related to IST and ISI programs. Are the proposed
definitions appropriate for their intended purpose? Should the NRC
consider defining other terms related to IST and ISI? Please provide
the basis for your response.
The NRC proposes to revise Sec. 50.55a(b)(5)(ii) and
(iii) to relate those requirements regarding superseded and annulled
code cases to the code of record interval, as defined in Sec.
50.55a(y) of the proposed rule. Should the NRC instead consider
relating those requirements to the ISI and IST interval? Please provide
the basis for your response.
V. Section-by-Section Analysis
The following paragraphs in Sec. 50.55a would be revised as
follows:
Paragraph (a)
This proposed rule would revise the introductory text to paragraph
(a) by removing ``standards'' and adding in its place ``materials'' or
``all approved materials'', as applicable, thereby aligning with the
latest guidance on incorporation by reference.
Paragraph (a)(3)(i)
This proposed rule would revise the reference to ``NRC Regulatory
Guide 1.84, Revision 39,'' by removing ``Revision 39'' and adding in
its place ``Revision 40'' and changing the month and year for the
document's revision date.
Paragraph (a)(3)(ii)
This proposed rule would revise the reference to ``NRC Regulatory
Guide 1.147, Revision 20'' by removing ``Revision 20'' and adding in
its place ``Revision 21'' and changing the month and year for the
document's revision date.
Paragraph (a)(3)(iii)
This proposed rule would revise the reference to ``NRC Regulatory
Guide 1.192, Revision 4'' by removing ``Revision 4'' and adding in its
place ``Revision 5'' and changing the month and year for the document's
revision date.
Paragraph (b)(5)(ii)
This proposed rule would amend paragraph (b)(5)(ii) by replacing
the text ``120-month interval'' with the text ``code of record
interval'' and ``120-month ISI program intervals'' with the text ``code
of record intervals.''
Paragraph (b)(5)(iii)
This proposed rule would amend paragraph (b)(5)(iii) by replacing
the text ``120-month interval'' with the text ``code of record
interval.''
Paragraph (b)(6)(ii)
This proposed rule would amend paragraph (b)(6)(ii) by replacing
the text ``120-month interval'' with the text ``code of record
interval'' and ``120-month ISI program'' with the text ``code of
record.''
Paragraph (b)(6)(iii)
This proposed rule would amend paragraph (b)(6)(iii) by replacing
the text ``120-month interval'' with the text ``code of record
interval.''
[[Page 13728]]
Paragraph (f)(4)(i)
This proposed rule would revise the heading and text of paragraph
(f)(4)(i) to replace the text ``120-month'' with the text ``code of
record.'' This proposed rule also would insert the text ``no more
than'' to clarify that licensees may consider ASME OM Code editions
incorporated by reference less than 18 months before the date of
issuance of the operating license or before the date of initial fuel
load.
Paragraph (f)(4)(ii)
This proposed rule would revise the heading and text of paragraph
(f)(4)(ii) to replace the text ``120-month'' with the text ``code of
record.'' This proposed rule also would insert the text ``no more
than'' to clarify that licensees may consider ASME OM Code editions
incorporated by reference less than 18 months before the start of the
code of record interval.
Paragraph (f)(5)(iv)
This proposed rule would amend paragraph (f)(5)(iv) by replacing
the text ``120-month interval of operation'' with the text ``inservice
examination and test interval.''
Paragraph (f)(7)
This proposed rule would amend paragraph (f)(7) by replacing the
text ``120-month IST Program interval'' with the text ``inservice
examination and test interval.''
Paragraph (g)(4) Introductory Text
This proposed rule would amend paragraph (g)(4) introductory text
by inserting the text ``BPV'' into the text ``ASME Code Class 1, Class
2, and Class 3'' to clarify the language.
Paragraph (g)(4)(i)
This proposed rule would revise paragraph (g)(4)(i) to replace the
text ``120-month inspection'' and ``120-month ISI'' with the text
``code of record''; insert the text ``BPV'' into the text ``ASME Code
Class 1, Class 2, and Class 3'' to clarify the language; and insert the
text ``no more than'' to clarify that licensees may use ASME BPV Code,
Section XI, editions incorporated by reference less than 18 months
before the start of the code of record interval.
Paragraph (g)(4)(ii)
This proposed rule would revise paragraph (g)(4)(ii) to replace the
text ``120-month,'' ``120-month inspection,'' and ``120-month ISI''
with ``code of record''; insert the text ``BPV'' into the text ``ASME
Code Class 1, Class 2, and Class 3'' to clarify the language; insert
the text ``no more than'' to clarify that licensees may use ASME BPV
Code, Section XI, editions incorporated by reference less than 18
months before the start of the code of record interval; remove outdated
language; and delete the term ``inservice'' to ensure consistency with
the definitions in the proposed Sec. 50.55a(y).
Paragraph (g)(5)(i)
This proposed rule would amend the heading for paragraph (g)(5)(i)
by replacing the text ``ISI Code editions and addenda'' with the text
``code of record.''
Paragraph (g)(5)(ii)
This proposed rule would amend paragraph (g)(5)(ii) by replacing
the text ``period'' with the text ``code of record interval.''
Paragraph (g)(5)(iii)
This proposed rule would amend paragraph (g)(5)(iii) by removing
the text ``120-month.'' This proposed rule also would delete the term
``inservice'' to ensure consistency with the definitions in the
proposed Sec. 50.55a(y).
Paragraph (g)(5)(iv)
This proposed rule would amend paragraph (g)(5)(iv) by removing the
text ``120-month.''
Paragraph (y)
This proposed rule would add paragraph (y) to provide definitions
of important terms used in Sec. 50.55a: Code of record, Code of record
interval, Inservice examination and test interval, Inservice inspection
program, Inservice examination and testing program, and Inspection
interval.
Appendix J to 10 CFR Part 50
This proposed rule would revise paragraph D.1.(a) in section III of
option A to replace the text ``10-year service period'' with the text
``inservice inspection interval, as defined in 10 CFR 50.55a(y),'' and
replace the text ``10-year plant'' with the text ``final plant''. This
proposed rule also would remove footnote 2 and redesignate footnote 3
as footnote 2.
VI. Regulatory Flexibility Certification
As required by the Regulatory Flexibility Act of 1980, 5 U.S.C.
605(b), the Commission certifies that this rule, if adopted, will not
have a significant economic impact on a substantial number of small
entities. This proposed rule affects only the licensing and operation
of nuclear power plants. The companies that own these plants do not
fall within the scope of the definition of ``small entities'' set forth
in the Regulatory Flexibility Act or the size standards established by
the NRC (Sec. 2.810).
VII. Regulatory Analysis
The NRC has prepared a draft regulatory analysis for this proposed
regulation. The analysis examines the costs and benefits of the
alternatives considered by the NRC. The NRC requests public comment on
the draft regulatory analysis. The regulatory analysis is available as
indicated in the ``Availability of Documents'' section of this
document. Comments on the draft regulatory analysis may be submitted to
the NRC as indicated under the ADDRESSES caption of this document.
VIII. Backfitting and Issue Finality
The provisions in this proposed rule would allow licensees and
applicants to voluntarily apply NRC-approved code cases, sometimes with
NRC-specified conditions. The approved code cases are listed in three
RGs that are proposed to be incorporated by reference into Sec.
50.55a. An applicant's or a licensee's voluntary application of an
approved code case does not constitute backfitting, because there is no
imposition of a new requirement or new position.
Similarly, voluntary application of an approved code case by a 10
CFR part 52 applicant or licensee does not represent NRC imposition of
a requirement or action, and therefore is not inconsistent with any
issue finality provision in 10 CFR part 52. For these reasons, the NRC
finds that this proposed rule does not involve any provisions requiring
the preparation of a backfit analysis or documentation demonstrating
that one or more of the issue finality criteria in 10 CFR part 52 are
met.
Other circumstances where the NRC does not apply the Backfit Rule
to the approval and requirement to use later code editions and addenda
are as follows:
1. When the NRC takes exception to a later ASME BPV Code or OM Code
provision but merely retains the current existing requirement,
prohibits the use of the later code provision, limits the use of the
later code provision, or supplements the provisions in a later code,
the Backfit Rule does not apply because the NRC is not imposing new
requirements. However, the NRC explains any such exceptions to the code
in the preamble to and regulatory analysis for the rule.
2. When an NRC exception relaxes an existing ASME BPV Code or OM
Code provision but does not prohibit a licensee from using the existing
code provision, the Backfit Rule does not
[[Page 13729]]
apply because the NRC is not imposing new requirements.
3. Modifications and limitations imposed during previous routine
updates of Sec. 50.55a have established a precedent for determining
which modifications or limitations are backfits, or require a backfit
analysis (e.g., final rule dated September 10, 2008 (73 FR 52731), and
a correction dated October 2, 2008 (73 FR 57235)). The application of
the backfit requirements to modifications and limitations in the
current rule are consistent with the application of backfit
requirements to modifications and limitations in previous rules.
The incorporation by reference and adoption of a requirement
mandating the use of a later ASME BPV Code or OM Code may constitute
backfitting in some circumstances. In these cases, the NRC would
perform a backfit analysis or prepare documented evaluation in
accordance with Sec. 50.109. These include the following:
1. When the NRC endorses a later provision of the ASME BPV Code or
OM Code that takes a substantially different direction from the
existing requirements, the action is treated as a backfit (e.g., 61 FR
41303; August 8, 1996).
2. When the NRC requires implementation of a later ASME BPV Code or
OM Code provision on an expedited basis, the action is treated as a
backfit. This applies when implementation is required sooner than it
would be required if the NRC simply endorsed the Code without any
expedited language (e.g., 64 FR 51370; September 22, 1999).
3. When the NRC takes an exception to an ASME BPV Code or OM Code
provision and imposes a requirement that is substantially different
from the existing requirement as well as substantially different from
the later Code (e.g., 67 FR 60529; September 26, 2002).
ISI/IST Update Backfitting Considerations: Section XI of the ASME BPV
Code and the ASME OM Code
Proposed revisions to the code of record intervals of Section XI of
the ASME BPV Code and the ASME OM Code are related to the ISI and IST
programs of operating reactors. However, the Backfit Rule generally
does not apply to incorporation by reference of later editions and
addenda of the ASME BPV Code (Section XI) and OM Code. As previously
mentioned, the NRC's longstanding regulatory practice has been to
incorporate later versions of the ASME Codes into Sec. 50.55a. Under
the current Sec. 50.55a, licensees must revise their ISI and IST
programs every 120 months to the latest edition and addenda of Section
XI of the ASME BPV Code and the ASME OM Code incorporated by reference
into Sec. 50.55a 18 months before the start of a new 120-month ISI and
IST interval. Thus, when the NRC approves and requires the use of a
later version of the Code for ISI and IST, it is implementing this
longstanding regulatory practice and requirement. The NRC is proposing
to revise the requirement to update to the latest edition and addenda
before the start of every other ISI and IST interval. This proposed
revision would be a voluntary relaxation, and thus not a backfit,
because licensees will continue to have the option to voluntarily
update before the start of each ISI or IST interval under Sec. Sec.
50.55a(f)(4)(iv) or (g)(4)(iv).
Conclusion
The NRC finds that the proposed incorporation by reference into
Sec. 50.55a of the three RGs containing the latest NRC-approved code
cases and the proposed revision of Sec. 50.55a to the identified ISI/
IST interval conditions, does not constitute backfitting or represent
an inconsistency with any issue finality provisions in 10 CFR part 52.
IX. Plain Writing
The Plain Writing Act of 2010 (Pub. L. 111-274) requires Federal
agencies to write documents in a clear, concise, and well-organized
manner. The NRC has written this document to be consistent with the
Plain Writing Act as well as the Presidential Memorandum, ``Plain
Language in Government Writing,'' published June 10, 1998 (63 FR
31885). The NRC requests comment on this document with respect to the
clarity and effectiveness of the language used.
X. Environmental Assessment and Proposed Finding of No Significant
Environmental Impact
The Commission has determined under the National Environmental
Policy Act of 1969, as amended, and the Commission's regulations in
subpart A of 10 CFR part 51, that this rule, if adopted, would not be a
major Federal action significantly affecting the quality of the human
environment, an environmental impact statement is not required.
The determination of this environmental assessment is that there
will be no significant effect on the quality of the human environment
from this action. Public stakeholders should note, however, that
comments on any aspect of this environmental assessment may be
submitted to the NRC as indicated under the ADDRESSES caption.
As voluntary alternatives to the ASME Code, NRC-approved code cases
provide an equivalent level of safety. The IST and ISI code of record
update frequency is changing the update frequency of a program.
Therefore, the probability or consequences of accidents is not changed.
There also are no significant, non-radiological impacts associated with
this action because no changes would be made affecting nonradiological
plant effluents and because no changes would be made in activities that
would adversely affect the environment. The determination of this
environmental assessment is that there would be no significant offsite
impact to the public from this action.
XI. Paperwork Reduction Act
This proposed rule contains new or amended collections of
information subject to the Paperwork Reduction Act of 1995 (44 U.S.C.
3501 et seq.). This proposed rule has been submitted to the Office of
Management and Budget for review and approval of the information
collection(s).
Type of submission, new or revision: Revision.
The title of the information collection: Domestic Licensing of
Production and Utilization Facilities: Updates to Incorporation by
Reference and Regulatory Guides.
The form number if applicable: Not applicable.
How often the collection is required or requested: On occasion.
Who will be required or asked to respond: Operating power reactor
licensees and applicants for power reactors under construction.
An estimate of the number of annual responses: 1.32 (0.66 reporting
and 0.66 recordkeeping).
The estimated number of annual respondents: 0.66.
An estimate of the total number of hours needed annually to comply
with the information collection requirement or request: 158.6.
Abstract: This proposed rule is the latest in a series of
rulemakings that incorporate by reference the latest versions of
several RGs identifying new and revised unconditionally or
conditionally acceptable ASME Code Cases that are approved for use.
The U.S. Nuclear Regulatory Commission is seeking public comment on
the potential impact of the information collection(s) contained in this
proposed rule and on the following issues:
1. Is the proposed information collection necessary for the proper
[[Page 13730]]
performance of the functions of the NRC, including whether the
information will have practical utility?
2. Is the estimate of the burden of the proposed information
collection accurate?
3. Is there a way to enhance the quality, utility, and clarity of
the information to be collected?
4. How can the burden of the proposed information collection on
respondents be minimized, including the use of automated collection
techniques or other forms of information technology?
A copy of the Office of Management and Budget (OMB) clearance
package is available in ADAMS under Accession No. ML22243A007 or can
obtained free of charge by contacting the NRC's Public Document
reference staff at 1-800-397-4209, 301-415-4737, or by email to
[email protected]. You may obtain information and comment
submissions related to the OMB clearance package by searching on
https://www.regulations.gov under Docket ID NRC-2018-0291.
You may submit comments on any aspect of these proposed information
collections, including suggestions for reducing the burden and on the
above issues, by the following methods:
Federal rulemaking website: Go to https://www.regulations.gov and search for Docket ID NRC-2018-0291.
Mail comments to: FOIA, Library, and Information
Collections Branch, Office of the Chief Information Officer, Mail Stop:
T-6 A10M, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001
or to the OMB reviewer at: OMB Office of Information and Regulatory
Affairs (3150-0011), Attn: Desk Officer for the Nuclear Regulatory
Commission, 725 17th Street NW, Washington, DC 20503; email:
[email protected].
Submit comments by April 5, 2023. Comments received after this date
will be considered if it is practical to do so, but the NRC is able to
ensure consideration only for comments received on or before this date.
Public Protection Notification
The NRC may not conduct or sponsor, and a person is not required to
respond to, a collection of information unless the document requesting
or requiring the collection displays a currently valid OMB control
number.
XII. Voluntary Consensus Standards
The National Technology Transfer and Advancement Act of 1995,
Public Law 104-113, requires that Federal agencies use technical
standards that are developed or adopted by voluntary consensus
standards bodies unless using such a standard is inconsistent with
applicable law or is otherwise impractical. In this proposed rule, the
NRC is continuing to use the ASME BPV and OM Code Cases, which are
ASME-approved voluntary alternatives to compliance with various
provisions of the ASME BPV and OM Codes. The NRC's approval of the ASME
Code Cases is accomplished by amending the NRC's regulations to
incorporate by reference the latest revisions of the following, which
are the subject of this rulemaking, into Sec. 50.55a: RG 1.84,
Revision 40; RG 1.147, Revision 21; and RG 1.192, Revision 5. The RGs
list the ASME Code Cases that the NRC has approved for use. The ASME
Code Cases are national consensus standards as defined in the National
Technology Transfer and Advancement Act of 1995 and OMB Circular A-119.
The ASME Code Cases constitute voluntary consensus standards, in which
all interested parties (including the NRC and licensees of nuclear
power plants) participate. The NRC invites comment on the applicability
and use of other standards.
XIII. Incorporation by Reference
The NRC proposes to incorporate by reference three NRC RGs that
list new and revised the ASME Code Cases that the NRC has approved as
voluntary alternatives to certain provisions of NRC-required editions
and addenda of the ASME BPV Code and the ASME OM Code. The draft
regulatory guides, DG-1405, DG-1406, and DG-1407, will correspond to
final RG 1.84, Revision 40; RG 1.147, Revision 21; and RG 1.192,
Revision 5, respectively.
RG 1.84, ``Design, Fabrication, and Materials Code Case
Acceptability, ASME Section III,'' Revision 40 (Draft Regulatory Guide
(DG)-1405), would allow nuclear power plant licensees and applicants
for construction permits, operating licenses, combined licenses,
standard design certifications, standard design approvals, and
manufacturing licenses to use the code cases newly listed in this
revised RG as voluntary alternatives to ASME engineering standards for
the construction of nuclear power plant components.
RG 1.147, ``Inservice Inspection Code Case Acceptability,
ASME Section XI, Division 1,'' Revision 21 (DG-1406), would allow
nuclear power plant licensees and applicants for construction permits,
operating licenses, combined licenses, standard design certifications,
standard design approvals, and manufacturing licenses to use the code
cases newly listed in this revised RG as voluntary alternatives to ASME
engineering standards for the inservice inspection of nuclear power
plant components.
RG 1.192, ``Operation and Maintenance [OM] Code Case
Acceptability, ASME OM Code,'' Revision 5 (DG-1407), action would allow
nuclear power plant licensees and applicants for construction permits,
operating licenses, combined licenses, standard design certifications,
standard design approvals, and manufacturing licenses to use the code
cases newly listed in this revised RG as voluntary alternatives to ASME
engineering standards for the inservice examination and testing of
nuclear power plant components.
The NRC is required by law to obtain approval for incorporation by
reference from the Office of the Federal Register (OFR). The OFR's
requirements for incorporation by reference are set forth in 1 CFR part
51. On November 7, 2014, the OFR adopted changes to its regulations
governing incorporation by reference (79 FR 66267). The OFR regulations
require an agency to include in a proposed rule a discussion of the
ways that the materials the agency proposes to incorporate by reference
are reasonably available to interested parties or how it worked to make
those materials reasonably available to interested parties. The
discussion in this section complies with the requirement for proposed
rules as set forth in 1 CFR 51.5(a)(1).
The NRC considers ``interested parties'' to include all potential
NRC stakeholders, not only the individuals and entities regulated or
otherwise subject to the NRC's regulatory oversight. These NRC
stakeholders are not a homogenous group, so the considerations for
determining ``reasonable availability'' vary by class of interested
parties. The NRC identified six classes of interested parties with
regard to the material to be incorporated by reference in an NRC rule:
Individuals and small entities regulated or otherwise
subject to the NRC's regulatory oversight. This class includes
applicants and potential applicants for licenses and other NRC
regulatory approvals, and who are subject to the material to be
incorporated by reference. In this context, ``small entities'' has the
same meaning as set out in Sec. 2.810.
Large entities otherwise subject to the NRC's regulatory
oversight. This class includes applicants and potential applicants for
licenses and other NRC regulatory approvals, and who are subject to the
material to be incorporated by reference. In this context, a ``large
entity'' is one that does
[[Page 13731]]
not qualify as a ``small entity'' under Sec. 2.810.
Non-governmental organizations with institutional
interests in the matters regulated by the NRC.
Other Federal agencies, States, local governmental bodies
(within the meaning of Sec. 2.315(c)).
Federally recognized and State-recognized Indian tribes.
Members of the general public (i.e., individual,
unaffiliated members of the public who are not regulated or otherwise
subject to the NRC's regulatory oversight) who need access to the
materials that the NRC proposes to incorporate by reference in order to
participate in the rulemaking.
The three draft RGs that the NRC proposes to incorporate by
reference in this proposed rule are available without cost and can be
read online or downloaded online. The draft RGs can be viewed, by
appointment, at the NRC Technical Library, which is located at Two
White Flint North, 11545 Rockville Pike, Rockville, Maryland 20852;
telephone: 301-415-7000; email: [email protected].
Because the three draft regulatory guides, and eventually, the
final regulatory guides, are available in various forms at no cost, the
NRC determines that the three draft regulatory guides, DG-1405, DG-
1406, and DG-1407, and final RG 1.84, Revision 40; RG 1.147, Revision
21; and RG 1.192, Revision 5, once approved by the OFR for
incorporation by reference, are reasonably available to all interested
parties.
XIV. Availability of Guidance
The NRC will not be issuing guidance for this rulemaking.
XV. Public Meeting
The NRC may conduct a public meeting on the proposed rule for the
purpose of describing the changes to the code of record update
frequency and its impact on the ISI and IST programs. The staff will
also answer questions from the public regarding this proposed rule.
The NRC will publish a notice of the location, time, and agenda of
the meeting, if held, in the Federal Register, on Regulations.gov, and
on the NRC's public meeting website within at least 10 calendar days
before the meeting. Stakeholders should monitor the NRC's public
meeting website for information about the public meeting at: https://www.nrc.gov/public-involve/public-meetings/index.cfm.
XVI. Availability of Documents
The documents identified in the following table are available to
interested persons through one or more of the following methods, as
indicated.
Table III--Rulemaking-Related Documents
------------------------------------------------------------------------
ADAMS accession No./
Document Federal Register
citation
------------------------------------------------------------------------
SRM-SECY-21-0029, ``Rulemaking Plan on ML21312A490.
Relaxation of Inservice Testing and Inservice
Inspection Program Update Frequencies Required
in 10 CFR 50.55a,'' dated November 8, 2021.
SECY-21-0029, ``Rulemaking Plan on Relaxation of ML20273A286.
Inservice Testing and Inservice Inspection
Program Update Frequencies Required in 10 CFR
50.55a,'' dated March 15, 2021.
SECY-22-0075, ``Staff Requirements-SECY-21-0029 ML22124A178.
Inservice Testing and Inservice Inspection
Program Rulemakings Update [NRC-2018-0291/3150-
AK23],'' dated August 10, 2022.
Rulemaking-Proposed Rule-Draft Regulatory ML22243A006.
Analysis for American Society of Mechanical
Engineers Code Cases, RG 1.84, Rev. 40; RG
1.147, Rev. 21; RG 1.192 Rev. 5; RG 1.193, Rev.
8, dated January 2023.
Rulemaking-Proposed Rule-OMB Clearance Package ML22243A007.
for American Society of Mechanical Engineers
Code Cases, RG 1.84, Rev. 40; RG 1.147, Rev.
21; RG 1.192 Rev. 5; RG 1.193, Rev. 8.
RG 1.193, ASME Code Cases Not Approved for Use, ML22196A065.
Revision 8 (DG-1408), dated January 2023.
ASME OM Code Case Applicability Index, dated ML22279A967N.
July 1, 2022.
ASME Letter to NRC, ``ASME Request for Including ML22046A112.
Specific Code Cases in Draft Revision 21 of
Regulatory Guide 1.147,'' dated December 22,
2021.
Final Rule--``Codes and Standards for Nuclear 41 FR 6256
Power Plants and Technical Information,''
February 12, 1976.
Proposed Rule--``Domestic Licensing of 44 FR 3719.
Production and Utilization Facilities Codes and
Standards for Nuclear Powerplants,'' January
18, 1979.
Final Rule--``Domestic Licensing of Production 44 FR 57912.
and Utilization Facilities; Codes and Standards
for Nuclear Powerplants,'' October 9, 1979.
Codes and Standards for Nuclear Power Plants; 61 FR 41303.
Subsection IWE and Subsection IWL, August 8,
1996.
Proposed Rule--Industry Codes and Standards; 64 FR 51370.
Amended Requirements, September 22, 1999.
Final Rule--Industry Codes and Standards; 67 FR 60529.
Amended Requirements, September 26, 2002.
Final Rule--``Incorporation by Reference of ASME 68 FR 40469.
BPV and OM Code Cases,'' July 8, 2003.
Final Rule--``Approval of American Society of 87 FR 11934.
Mechanical Engineers Code Cases,'' March 3,
2022.
Final Rule--``American Society of Mechanical 87 FR 65128.
Engineers 2019-2020 Code Editions Incorporation
by Reference,'' October 27, 2022.
------------------------------------------------------------------------
Documents Proposed To Be Incorporated by Reference
The NRC proposes to incorporate by reference three NRC RGs, as set
forth in Table IV, that list new and revised ASME Code Cases that the
NRC is proposing to approve as voluntary alternatives to certain
provisions of NRC-required editions and addenda of the ASME BPV Code
and the ASME OM Code.
Table IV--Draft Regulatory Guides Proposed To Be Incorporated by
Reference in 10 CFR 50.55a
------------------------------------------------------------------------
ADAMS accession No./
Document Federal Register
citation
------------------------------------------------------------------------
RG 1.84, Design, Fabrication, and Materials Code ML22195A282.
Case Acceptability, ASME Section III, Revision
40 (DG-1405).
RG 1.147, Inservice Inspection Code Case ML22195A284.
Acceptability, ASME Section XI, Division 1,
Revision 21 (DG-1406).
[[Page 13732]]
RG 1.192, Operation and Maintenance Code Case ML22196A063.
Acceptability, ASME OM Code, Revision 5 (DG-
1407).
------------------------------------------------------------------------
Code Cases for Approval in This Proposed Rule
The ASME BPV Code Cases that the NRC is proposing to approve as
alternatives to certain provisions of the ASME BPV Code, as set forth
in Table V, are being made available by the ASME for read-only access
during the public comment period on https://go.asme.org/NRC-ASME.
The ASME OM Code Cases that the NRC is proposing to approve as
alternatives to certain provisions of the ASME OM Code, as set forth in
Table V, are being made available for read-only access during the
public comment period by the ASME on https://go.asme.org/NRC-ASME.
The ASME is making the code cases listed in Table V available for
limited, read-only access at the request of the NRC. The NRC believes
that stakeholders need to be able to read these code cases in order to
provide meaningful comment on the three RGs (listed in Table IV) that
the NRC is proposing to incorporate by reference into Sec. 50.55a. It
is the NRC's position that the listed code cases, as modified by any
conditions contained in the three RGs and thus serving as alternatives
to requirements in Sec. 50.55a, would be legally-binding regulatory
requirements. An applicant or licensee must comply with a listed code
case and any conditions to be within the scope of the NRC's approval of
the code case as a voluntary alternative for use. These requirements
cannot be fully understood without knowledge of the code case to which
the proposed condition applies, and to this end, the NRC has requested
that the ASME provide limited, read-only access to the code cases in
order to facilitate meaningful public comment.
Table V--ASME Code Cases Proposed for NRC Approval
------------------------------------------------------------------------
------------------------------------------------------------------------
Boiler and Pressure Vessel Code Section III
------------------------------------------------------------------------
Code case No. Supplement Title
------------------------------------------------------------------------
N-351-1.................... 3 (2021 Edition).. Use of Standard Subsize
Charpy V-Notch Impact
Specimens, Section
III, Division 1;
Section III, Division
2; Section III,
Division 3.
N-893...................... 4 (2019 Edition).. Use of Alloy Steel Bar
and Mechanical Tubing
in Class 2 and 3
Patented Mechanical
Joints and Fittings,
Section III, Division
1.
N-900...................... 3 (2019 Edition).. Alternative Rules for
Level D Service Limits
of Class 1, 2, and 3
Piping Systems,
Section III, Division
1.
N-901...................... 4 (2019 Edition).. Use of ASME SA-494
Grade M35-1 for Line
Valve Bodies and
Bonnets, and Bodies,
Bonnets, and Yokes of
Pressure Relief Valves
for Class 2 and 3
Construction, Section
III, Division 1.
N-902...................... 5 (2019 Edition).. Thickness and Gradient
Factors for Piping
Fatigue Analyses,
Section III, Division
1.
N-904...................... 6 (2019 Edition).. Alternative Rules for
Simplified Elastic-
Plastic Analysis,
Section III, Division
1.
N-905...................... 6 (2019 Edition).. Alternate Design
Fatigue Curves to
Those Given in For
Section III
Appendices, Mandatory
Appendix I, Figures I-
9.1 and I-9.1M,
Section III, Division
1.
N-908...................... 7 (2019 Edition).. Use of Ferritic/
Austenitic Wrought
WPS32750/CRS32750
Fittings of Seamless
or Welded Construction
Conforming to SA-815,
Class 3, Section III,
Division 1.
N-910...................... 7 (2019 Edition).. Use of 25Cr-7Ni-4Mo-N
(Alloy UNS S32750
Austenitic/Ferritic
Duplex Stainless
Steel) Forgings,
Plate, and Welded and
Seamless Pipe and
Tubing Conforming to
SA-182, SA-240, SA-
789, or SA-790,
Section III, Division
1.
N-919...................... 2 (2021 Edition).. Alternative Fatigue
Evaluation Method to
Consider Environmental
Effects on Class 1
Components Section
III, Division 1.
N-920...................... 2 (2021 Edition).. Alternative Fatigue
Design Curves for
Ferritic Steels With
Ultimate Tensile
Strengths (UTS) <= 80
ksi (552 MPa) and
Austenitic Steels,
Section III, Division
1.
N-71-21.................... 0 (2021 Edition).. Additional Materials
for Subsection NF,
Class 1, 2, 3, and MC
Supports Fabricated by
Welding, Section III,
Division 1.
N-570-3.................... 0 (2021 Edition).. Alternative Rules for
Linear Piping and
Linear Standard
Supports for Classes
1, 2, 3, and MC,
Section III, Division
1.
------------------------------------------------------------------------
Boiler and Pressure Vessel Code Section XI
------------------------------------------------------------------------
Code case No. Supplement Title
------------------------------------------------------------------------
N-561-4.................... 0 (2021 Edition).. Alternative
Requirements for Wall
Thickness Restoration
of Class 2 and High
Energy Class 3 Carbon
Steel Piping, Section
XI, Division 1.
N-562-4.................... 0 (2021 Edition).. Alternative
Requirements for Wall
Thickness Restoration
of Class 3 Moderate
Energy Carbon Steel
Piping, Section XI,
Division 1.
N-597-5.................... 0 (2021 Edition).. Evaluation of Pipe Wall
Thinning, Section XI,
Division 1.
N-638-11................... 2 (2019 Edition).. Similar and Dissimilar
Metal Welding Using
Ambient Temperature
Machine GTAW Temper
Bead Technique,
Section XI, Division
1.
N-661-5.................... 0 (2021 Edition).. Alternative
Requirements for Wall
Thickness Restoration
of Class 2 and 3
Carbon Steel Piping
for Raw Water Service
Section XI, Division
1.
N-663-1.................... 3 (2021 Edition).. Alternative
Requirements for
Classes 1 and 2
Surface Examinations,
Section XI, Division
1.
[[Page 13733]]
N-733-1.................... 6 (2019 Edition).. Mitigation of Flaws in
NPS 3 (DN 80) and
Smaller Nozzles and
Nozzle Partial
Penetration Welds in
Vessels and Piping by
Use of a Mechanical
Connection
Modification, Section
XI, Division 1.
N-780-1.................... 1 (2021 Edition).. Alternative
Requirements for
Upgrade, Substitution,
or Reconfiguration of
Examination Equipment
When Using Appendix
VIII Qualified
Ultrasonic Examination
Systems, Section XI,
Division 1.
N-786-4.................... 0 (2021 Edition).. Alternative
Requirements for
Sleeve Reinforcement
of Class 2 and 3
Moderate Energy Carbon
Steel Piping, Section
XI, Division 1.
N-789-5.................... 1 (2021 Edition).. Alternative
Requirements for Pad
Reinforcement of Class
2 and 3 Moderate
Energy Carbon Steel
Piping for Raw Water
Service, Section XI,
Division 1.
N-809-1.................... 0 (2021 Edition).. Reference Fatigue Crack
Growth Rate Curves for
Austenitic Stainless
Steels in Pressurized
Reactor Water
Environments, Section
XI, Division 1.
N-853-1.................... 0 (2021 Edition).. PWR Class 1 Primary
Piping Alloy 600 Full
Penetration Branch
Connection Weld Metal
Buildup for Material
Susceptible to Primary
Water Stress Corrosion
Cracking, Section XI,
Division 1.
N-860...................... 6 (2019 Edition).. Inspection Requirements
and Evaluation
Standards for Spent
Nuclear Fuel Storage
and Transportation
Containment Systems,
Section XI, Division
1; Section XI,
Division 2.
N-865-2.................... 0 (2021 Edition).. Alternative
Requirements for Pad
Reinforcement of Class
2 and 3 Atmospheric
Storage Tanks, Section
XI, Division 1.
N-877-1.................... 5 (2019 Edition).. Alternative
Characterization Rules
for Multiple
Subsurface Radially
Oriented Planar Flaws,
Section XI, Division
1.
N-882-1.................... 0 (2021 Edition).. Alternative
Requirements for
Attaching
Nonstructural
Electrical Connections
to Class 2 and 3
Components, Section
XI, Division 1.
N-885-1.................... 3 (2021 Edition).. Alternative
Requirements for Table
IWB-2500-1,
Examination Category B-
N-1, Interior of
Reactor Vessel,
Category B-N-2, Welded
Core Support
Structures and
Interior Attachments
to Reactor Vessels,
Category BN-3,
Removable Core Support
Structures, Section
XI, Division 1.
N-888...................... 5 (2019 Edition).. Similar and Dissimilar
Metal Welding Using
Ambient Temperature
SMAW or Machine GTAW
Temper Bead Technique,
Section XI, Division
1.
N-896...................... 2 (2019 Edition).. Reference Crack Growth
Rate Curves for Stress
Corrosion Cracking of
Low Alloy Steels in
Boiling Water Reactor
Environments, Section
XI, Division 1.
N-911...................... 0 (2021 Edition).. Purchase, Exchange, or
Transfer of Material
Between Nuclear
Owners, Section XI,
Division 1.
N-912...................... 0 (2021 Edition).. Alternative
Requirements for
Qualification of
Material Suppliers and
Acceptance of
Materials, Section XI,
Division 1.
N-913...................... 0 (2021 Edition).. Alternative Examination
Requirements for Class
1 Pressure-Retaining
Welds in Control Rod
Drive Housings,
Section XI, Division
1.
N-917...................... 2 (201 Edition)... Fatigue Crack Growth
Rate Curves for
Ferritic Steels in
Boiling Water Reactor
(BWR) Environments,
Section XI, Division
1.
N-711-2.................... 6 (2019 Edition).. Alternative Examination
Coverage Requirements
for Examination
Category B F, B J, C-F-
1, C-F-2, and R-A
Piping Welds, Section
XI, Division 1.
N-716-3.................... 5 (2019 Edition).. Alternative
Classification and
Examination
Requirements, Section
XI, Division 1.
N-754-2.................... 0 (2021 Edition).. Optimized Structural
Dissimilar Metal Weld
Overlay for Mitigation
of PWR Class 1 Items,
Section XI, Division
1.
N-766-4.................... 0 (2021 Edition).. Nickel Alloy Reactor
Coolant Inlay and
Onlay for Mitigation
of PWR Full
Penetration
Circumferential Nickel
Alloy Dissimilar Metal
Welds in Class 1
Items, Section XI,
Division 1.
N-847-1.................... 0 (2021 Edition).. Partial Excavation and
Deposition of Weld
Metal for Mitigation
of Class 1 Items,
Section XI, Division
1.
N-880-1.................... 0 (2021 Edition).. Alternative to
Procurement
Requirements of IWA-
4143 for Small
Nonstandard Welded
Fittings, Section XI,
Division 1.
N-899...................... 3 (2019 Edition).. Weld Residual Stress
Distributions for
Piping and Vessel
Nozzle Butt Welds
Fabricated With UNS
N06082, UNS W86182,
UNS N06052, or UNS
W86152 Weld Filler
Material, Section XI,
Division 1.
N-906...................... 7 (2019 Edition).. Flaw Evaluation
Procedure for Cast
Austenitic Stainless
Steel Piping and
Adjacent Fittings,
Section XI, Division
1.
N-921...................... 3 (2021 Edition).. Alternative 12-yr
Inspection Interval
Duration, Section XI,
Division 1.
------------------------------------------------------------------------
Operation and Maintenance Code
------------------------------------------------------------------------
Code case No. Edition \6\ Title
------------------------------------------------------------------------
OMN-28..................... 2022 Edition...... Alternative Valve
Position Verification
Approach to Satisfy
ISTC-3700 for Valves
Not Susceptible to
Stem-Disk Separation.
OMN-29..................... 2022 Edition...... Pump Condition
Monitoring Program.
OMN-30..................... 2022 Edition...... Alternative Valve
Position Verification
Approach to Satisfy
ISTC-3700.
OMN-31..................... 2022 Edition...... Alternative to Allow
Extension of ISTA-3120
Inservice Examination
and Test Intervals
From 10 Years to 12
Years.
------------------------------------------------------------------------
Throughout the development of this rule, the NRC may post documents
related to this rule, including public comments, on the Federal
rulemaking website at https://www.regulations.gov under Docket ID NRC-
2018-0291. In addition, the Federal rulemaking website allows members
of the public to receive alerts when changes or additions occur in a
docket folder. To subscribe: (1) navigate to the docket folder (NRC-
[[Page 13734]]
2018-0291); (2) click the ``Subscribe'' link; and (3) enter an email
address and click on the ``Subscribe'' link.
---------------------------------------------------------------------------
\6\ Each code case or ASME Applicability Index List indicates
the ASME OM Code editions and addenda to which the code case
applies, except where a condition is specified in Sec. 50.55a or RG
1.192 related to technical content or applicability. This table
indicates the latest OM Code edition at the time of this rulemaking.
---------------------------------------------------------------------------
List of Subjects in 10 CFR Part 50
Administrative practice and procedure, Antitrust, Backfitting,
Classified information, Criminal penalties, Education, Emergency
planning, Fire prevention, Fire protection, Incorporation by reference,
Intergovernmental relations, Nuclear power plants and reactors,
Penalties, Radiation protection, Reactor siting criteria, Reporting and
recordkeeping requirements, Whistleblowing.
For the reasons set out in the preamble and under the authority of
the Atomic Energy Act of 1954, as amended; the Energy Reorganization
Act of 1974, as amended; and 5 U.S.C. 552 and 553, the NRC is proposing
to amend 10 CFR part 50 as follows:
PART 50--DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION
FACILITIES
0
1. The authority citation for part 50 continues to read as follows:
Authority: Atomic Energy Act of 1954, secs. 11, 101, 102, 103,
104, 105, 108, 122, 147, 149, 161, 181, 182, 183, 184, 185, 186,
187, 189, 223, 234 (42 U.S.C. 2014, 2131, 2132, 2133, 2134, 2135,
2138, 2152, 2167, 2169, 2201, 2231, 2232, 2233, 2234, 2235, 2236,
2237, 2239, 2273, 2282); Energy Reorganization Act of 1974, secs.
201, 202, 206, 211 (42 U.S.C. 5841, 5842, 5846, 5851); Nuclear Waste
Policy Act of 1982, sec. 306 (42 U.S.C. 10226); National
Environmental Policy Act of 1969 (42 U.S.C. 4332); 44 U.S.C. 3504
note; Sec. 109, Pub. L. 96-295, 94 Stat. 783.
0
2. In Sec. 50.55a:
0
a. Revise the introductory text of paragraph (a);
0
b. In paragraph (a)(3)(i):
0
i. Remove the text ``Revision 39'', wherever it appears, and add, in
its place, the text ``Revision 40''; and
0
ii. Remove the text ``issued December 2021'' and add, in its place, the
text ``issued January 2023'';
0
c. In paragraph (a)(3)(ii):
0
i. Remove the text ``Revision 20'', wherever it appears, and add, in
its place, the text ``Revision 21''; and
0
ii. Remove the text ``issued December 2021'' and add in its place the
text ``issued January 2023'';
0
d. In paragraph (a)(3)(iii):
0
i. Remove the text ``Revision 4'' and add, in its place, the text
``Revision 5'';
0
ii. Remove the text ``Revision 3'' and add, in its place, the text
``Revision 5''; and
0
iii. Remove the text ``issued December 2021'' and add, in its place,
the text ``issued January 2023'';
0
e. In paragraphs (b)(5)(ii) and (iii) and (b)(6)(ii) and (iii), remove
the text ``120-month interval'' and add in its place the text ``code of
record interval'', wherever it appears; and
0
f. In paragraphs (b)(5)(ii) and (b)(6)(ii), remove the text ``120-month
ISI program intervals'' and add in its place the text ``code of record
intervals'', wherever it appears;
0
g. Revise paragraphs (f)(4)(i) and (ii);
0
h. In paragraph (f)(5)(iv), remove the text ``120-month interval of
operation'', wherever it appears, and add in its place the text
``inservice examination and test interval'';
0
i. In paragraph (f)(7), remove the text ``120-month IST Program
interval'', wherever it appears, and add in its place the text
``inservice examination and test interval'';
0
j. In paragraph (g)(4) introductory text, remove the text ``ASME Code
Class 1, Class 2, and Class 3'' and add in its place the text ``ASME
BPV Code Class 1, Class 2, and Class 3'';
0
k. Revise paragraphs (g)(4)(i) and (ii);
0
l. In the heading for paragraph (g)(5)(i), remove the text ``ISI Code
editions and addenda'' and add in its place the text ``code of
record'';
0
m. In paragraph (g)(5)(ii), remove the text ``period'' and add in its
place the text ``code of record interval'';
0
n. In paragraph (g)(5)(iii), remove the text ``120-month'' and
``inservice'';
0
o. In paragraph (g)(5)(iv), remove the text ``120-month''; and
0
p. Add paragraph (y).
The revisions and additions read as follows:
Sec. 50.55a Codes and standards.
(a) Documents approved for incorporation by reference. The material
listed in this paragraph (a) is incorporated by reference into this
section with the approval of the Director of the Federal Register under
5 U.S.C. 552(a) and 1 CFR part 51. All approved material is available
for inspection at the Nuclear Regulatory Commission (NRC) and at the
National Archives and Records Administration (NARA). Contact NRC at:
the NRC Technical Library, which is located at Two White Flint North,
11545 Rockville Pike, Rockville, Maryland 20852; telephone: 301-415-
7000; email: [email protected]. For information on the
availability of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations.html or email [email protected]. The
material may be obtained from the following sources in this paragraph
(a).
* * * * *
(f) * * *
(4) * * *
(i) Applicable IST Code: Initial code of record interval. Inservice
tests to verify operational readiness of pumps and valves, whose
function is required for safety, conducted during the initial code of
record interval must comply with the requirements in the latest edition
and addenda of the ASME OM Code incorporated by reference in paragraph
(a)(1)(iv) of this section on the date no more than 18 months before
the date of issuance of the operating license under this part, or no
more than 18 months before the date scheduled for initial loading of
fuel under a combined license under part 52 of this chapter (or the
optional ASME OM Code Cases listed in NRC Regulatory Guide 1.192, as
incorporated by reference in paragraph (a)(3)(iii) of this section,
subject to the conditions listed in paragraph (b) of this section).
(ii) Applicable IST Code: Successive code of record intervals.
Inservice tests to verify operational readiness of pumps and valves,
whose function is required for safety, conducted during successive code
of record intervals must comply with the requirements of the latest
edition and addenda of the ASME OM Code incorporated by reference in
paragraph (a)(1)(iv) of this section no more than 18 months before the
start of the code of record interval (or the optional ASME Code Cases
listed in NRC Regulatory Guide 1.147 or NRC Regulatory Guide 1.192 as
incorporated by reference in paragraphs (a)(3)(ii) and (iii) of this
section, respectively), subject to the conditions listed in paragraph
(b) of this section.
* * * * *
(g) * * *
(4) * * *
(i) Applicable ISI Code: Initial code of record interval. Inservice
examination of components and system pressure tests conducted during
the initial code of record interval must comply with the requirements
in the latest edition and addenda of the ASME BPV Code incorporated by
reference in paragraph (a) of this section on the date no more than 18
months before the date of issuance of the operating license under this
part, or no more than 18 months before the date scheduled for initial
loading of fuel under a combined license under part 52 of this chapter
(or the optional ASME Code Cases listed in NRC Regulatory Guide 1.147,
when using ASME BPV Code, Section XI, or NRC Regulatory Guide 1.192,
when using the ASME OM Code, as incorporated by reference in paragraphs
(a)(3)(ii) and (iii) of this section, respectively), subject to the
conditions
[[Page 13735]]
listed in paragraph (b) of this section. Licensees may, at any time in
their code of record interval, elect to use the Appendix VIII in the
latest edition and addenda of the ASME BPV Code incorporated by
reference in paragraph (a) of this section, subject to any applicable
conditions listed in paragraph (b) of this section. Licensees using
this option must also use the same edition and addenda of Appendix I,
Subarticle I-3200, as Appendix VIII, including any applicable
conditions listed in paragraph (b) of this section.
(ii) Applicable ISI Code: Successive code of record intervals.
Inservice examination of components and system pressure tests conducted
during successive code of record intervals must comply with the
requirements of the latest edition and addenda of the ASME BPV Code
incorporated by reference in paragraph (a) of this section no more than
18 months before the start of the code of record interval (or the
optional ASME Code Cases listed in NRC Regulatory Guide 1.147, when
using ASME BPV Code, Section XI, or NRC Regulatory Guide 1.192, when
using the ASME OM Code, as incorporated by reference in paragraphs
(a)(3)(ii) and (iii) of this section), subject to the conditions listed
in paragraph (b) of this section. Licensees may, at any time in their
code of record interval, elect to use the Appendix VIII in the latest
edition and addenda of the ASME BPV Code incorporated by reference in
paragraph (a) of this section, subject to any applicable conditions
listed in paragraph (b) of this section. Licensees using this option
must also use the same edition and addenda of Appendix I, Subarticle I-
3200, as Appendix VIII, including any applicable conditions listed in
paragraph (b) of this section.
* * * * *
(y) Definitions. (1) Code of record means:
(i) For the ASME BPV Code, Section XI, the edition (and addenda)
implemented by a licensee in accordance with the requirements of this
section.
(ii) For the ASME OM Code, the edition (and addenda) implemented by
a licensee in accordance with the requirements of this section.
(iii) For the ASME BPV Code, Section III, the edition implemented
by a licensee in accordance with the requirements of this section,
which may vary by component.
(2) Code of record interval means the period of time between the
code of record updates required by paragraphs (f)(4) and (g)(4) of this
section for the inservice inspection and inservice examination and test
programs, respectively.
(i) For licensees with codes of record prior to ASME BPV Code,
Section XI, 2019 Edition, and OM Code, 2020 Edition, as incorporated by
reference in paragraph (a) of this section, the code of record interval
is the same as the inspection interval or inservice examination and
test interval.
(ii) For licensees with codes of record of ASME BPV Code, Section
XI, 2019 Edition and OM Code, 2020 Edition, or later, as incorporated
by reference in paragraph (a) of this section, the code of record
interval is two consecutive inservice inspection or inservice
examination and test intervals.
(3) Inservice examination and test (IST) interval, for the purposes
of this section, means the inservice examination and test interval
described by the licensee's code of record (paragraph ISTA-3120 of the
ASME OM Code, 2001 Edition through 2009 Edition, or paragraph ISTA-3120
of the ASME OM Code, 2012 Edition and later).
(4) Inservice inspection (ISI) program, for the purposes of this
section, means the set of all administrative and technical requirements
pertaining to periodic examination of nuclear components, as specified
in ASME BPV Code, Section XI, and this section, including but not
limited to:
(i) The requirements of IWA-2400 of ASME BPV Code, Section XI, 1991
Addenda and later.
(ii) Relief requested under paragraph (g)(5)(iii) of this section
and granted under paragraph (g)(6)(i) of this section.
(iii) The augmented inspection program described in paragraph
(g)(6) of this section.
(iv) Alternatives authorized under paragraph (z) of this section.
(5) Inservice examination and testing (IST) program, for the
purposes of this section, means the requirements for preservice and
inservice examination and testing of pumps, valves, and dynamic
restraints within the scope of this section to assess their operational
readiness in nuclear power plants, including but not limited to:
(i) The requirements specified in the ASME OM Code, as incorporated
by reference in this section, such as for test or examination,
responsibilities, methods, intervals, parameters to be measured and
evaluated, criteria for evaluating the results, corrective action,
personnel qualification, and recordkeeping.
(ii) Relief requested under paragraph (f)(5)(iii) of this section
and granted under paragraph (f)(6)(i) of this section.
(iii) Augmented IST requirements as applied by the Commission under
paragraph (f)(6)(ii) of this section.
(iv) Alternatives authorized under paragraph (z) of this section.
(6) Inspection interval, as used in this section, means the
inservice inspection interval described by the licensee's code of
record (Article IWA-2432 of ASME BPV Code, Section XI, 1989 Edition
with 1991 Addenda through the 2008 Addenda, or Article IWA-2431 of ASME
BPV Code, Section XI, 2009 Addenda and later).
* * * * *
0
3. In section III of option A of appendix J to part 50, remove and
reserve footnote 2 and revise paragraph D.1.(a) to read as follows:
Appendix J to Part 50--Primary Reactor Containment Leakage Testing for
Water-Cooled Power Reactors
* * * * *
Option A--Prescriptive Requirements
* * * * *
III. * * *
D. * * *
1. * * *
(a) After the preoperational leakage rate tests, a set of three
Type A tests shall be performed, at approximately equal intervals
during each inspection interval, as defined in Sec. 50.55a(y). The
third test of each set shall be conducted when the plant is shutdown
for the final plant inservice inspections of the inspection interval.
* * * * *
Dated: February 17, 2023.
For the Nuclear Regulatory Commission.
Michael F. King,
Acting Director, Office of Nuclear Reactor Regulation.
[FR Doc. 2023-03742 Filed 3-3-23; 8:45 am]
BILLING CODE 7590-01-P