[Federal Register Volume 86, Number 20 (Tuesday, February 2, 2021)]
[Proposed Rules]
[Pages 7820-7838]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-00890]


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

NUCLEAR REGULATORY COMMISSION

10 CFR Part 50

[NRC-2017-0025]
RIN 3150-AJ94


Approval of American Society of Mechanical Engineers' Code Cases

AGENCY: Nuclear Regulatory Commission.

ACTION: Proposed rule.

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

SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is proposing to 
amend its regulations to incorporate by reference proposed revisions of 
three regulatory guides, which would approve new, revised, and 
reaffirmed Code Cases published by the American Society of Mechanical 
Engineers. The NRC is also incorporating by reference one NRC NUREG 
associated with a proposed condition on one of the regulatory guides. 
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 is also 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.

DATES: Submit comments on the proposed rule, documents to be 
incorporated by reference, and related guidance by April 5, 2021. 
Submit comments specific to the information

[[Page 7821]]

collections aspects of this rule by March 4, 2021. Comments received 
after these dates will be considered if it is practical to do so, but 
the NRC is able to ensure consideration only of comments received on or 
before these dates.

ADDRESSES: You may submit comments on the proposed rule, documents to 
be incorporated by reference, and related guidance by any of the 
following methods (unless this document describes a different method 
for submitting comments on a specific subject):
     Federal Rulemaking Website: Go to https://www.regulations.gov and search for Docket ID NRC-2017-0025. 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: Juan Lopez, Office of Nuclear Material 
Safety and Safeguards; telephone: 301-415-2338; email: 
[email protected]; or 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

    The purpose of this regulatory action is to incorporate by 
reference into the NRC's regulations the latest revisions of three 
regulatory guides (RGs) (currently in draft form for comment). This 
regulatory action is also incorporating by reference one NRC report, 
NUREG-2228, that is associated with a proposed conditon in one of the 
regulatory guides. NUREG-2228 was published for public comment on 
September 13, 2018 (83 FR 46524). The three draft RGs identify new, 
revised, and reaffirmed Code Cases published by the American Society of 
Mechanical Engineers (ASME), which 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 Code for Operation and Maintenance of Nuclear Power Plants (OM 
Code) currently incorporated by reference into the NRC's regulations.

B. Major Provisions

    The three draft RGs that the NRC proposes to incorporate by 
reference are RG 1.84, ``Design, Fabrication, and Materials Code Case 
Acceptability, ASME Section III,'' Revision 39 (Draft Regulatory Guide 
(DG)-1366); RG 1.147, ``Inservice Inspection Code Case Acceptability, 
ASME Section XI, Division 1,'' Revision 20 (DG-1367); and RG 1.192, 
``Operation and Maintenance [OM] Code Case Acceptability, ASME OM 
Code,'' Revision 4 (DG-1368). The NRC also proposes to incorporate by 
reference NUREG-2228, ``Weld Residual Stress Finite Element Analysis 
Validation: Part II--Proposed Validation Procedure,'' which provides 
the procedure for validating the weld residual stress analysis 
methodology associated with ASME Code Case N-847. 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 newly listed in these revised RGs as 
voluntary alternatives to 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 7 (DG-
1369). This document lists Code Cases that the NRC has not approved for 
generic use and will 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 outweigh the costs by a range from approximately 
$5.19 million (7-percent net present value) to $6.20 million (3-percent 
net present value).

                                          Table 1--Cost Benefit Summary
----------------------------------------------------------------------------------------------------------------
                                                                            Total averted costs (costs)
                                                                 -----------------------------------------------
                            Attribute                                             7% Net present  3% Net present
                                                                   Undiscounted        value           value
----------------------------------------------------------------------------------------------------------------
Industry Implementation.........................................              $0              $0              $0
Industry Operation..............................................       5,100,000       3,790,000       4,470,000
                                                                 -----------------------------------------------
    Total Industry Costs........................................       5,100,000       3,790,000       4,470,000
NRC Implementation..............................................       (430,000)       (420,000)       (420,000)
NRC Operation...................................................       2,460,000       1,820,000       2,150,000
                                                                 -----------------------------------------------
    Total NRC Costs.............................................       2,030,000       1,400,000       1,730,000
                                                                 -----------------------------------------------
        Net.....................................................       7,130,000       5,190,000       6,200,000
----------------------------------------------------------------------------------------------------------------

    The 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; (2) consistency with the provisions of the 
National Technology Transfer and Advancement Act of 1995, which 
encourages Federal regulatory agencies to consider adopting voluntary

[[Page 7822]]

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 regulatory analysis (Agencywide Documents Access and 
Management System (ADAMS) Accession No. ML20133K152).

Table of Contents

I. Obtaining Information and Submitting Comments
    A. Obtaining Information
    B. Submitting Comments
II. Background
III. Discussion
    A. Code Cases Proposed To Be Approved for Unconditional Use
    B. Code Cases Proposed To Be Approved for Use With Conditions
    1. ASME BPV Code, Section III Code Cases (DG-1366/RG 1.84)
    2. ASME BPV Code, Section XI Code Cases (DG-1367/RG 1.147)
    3. OM Code Cases (DG-1368/RG 1.192)
C. ASME Code Cases Not Approved for Use (DG-1369/RG 1.193)
IV. Section-by-Section Analysis
V. Regulatory Flexibility Certification
VI. Regulatory Analysis
VII. Backfitting and Issue Finality
VIII. Plain Writing
IX. Environmental Assessment and Proposed Finding of No Significant 
Environmental Impact
X. Paperwork Reduction Act Statement
XI. Voluntary Consensus Standards
XII. Incorporation by Reference--Reasonable Availability to 
Interested Parties
XIII. Availability of Documents

I. Obtaining Information and Submitting Comments

A. Obtaining Information

    Please refer to Docket ID NRC-2017-0025 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-2017-0025.
     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 ``ADAMS Public Documents'' and 
then 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.
     Attention: The PDR, where you may examine and order copies 
of public documents is currently closed. You may submit your request to 
the PDR via email at [email protected] or call 1-800-397-4209 
between 8:00 a.m. and 4:00 p.m. (EST), Monday through Friday, except 
Federal holidays.

B. Submitting Comments

    Please include Docket ID NRC-2017-0025 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

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

    \1\ The editions and addenda of the ASME Code for Operation and 
Maintenance of Nuclear Power Plants have had different titles from 
2005 to 2017, and are referred to as the ``OM Code'' collectively in 
this rule.
---------------------------------------------------------------------------

    The NRC approves the ASME BPV and OM Codes in Sec.  50.55a, ``Codes 
and standards,'' of title 10 of the Code of Federal Regulations (10 
CFR) through the process of incorporation by reference. As such, each 
provision of the ASME Codes incorporated by reference into and mandated 
by Sec.  50.55a constitutes a legally-binding NRC requirement imposed 
by rule. As noted previously, the ASME Code Cases, for the most part, 
represent alternative approaches for complying with provisions of the 
ASME BPV and OM Codes. Accordingly, the NRC periodically amends Sec.  
50.55a to incorporate by reference the NRC's RGs listing approved ASME 
Code Cases that may be used as voluntary alternatives to the BPV and OM 
Codes.\2\
---------------------------------------------------------------------------

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

    This proposed rule is the latest in a series of rules that 
incorporate by reference new versions of several RGs identifying new, 
revised, and reaffirmed,\3\ and unconditionally or conditionally 
acceptable ASME Code Cases that the NRC 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 16, 2020 (85 FR 
14736) 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 38; RG 
1.147, ``Inservice Inspection Code Case Acceptability, ASME Section XI, 
Division 1,'' Revision 19; and RG 1.192, ``Operation and Maintenance 
Code Case Acceptability, ASME OM Code,'' Revision 3.
---------------------------------------------------------------------------

    \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 specific the ASME Code provisions 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.

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

[[Page 7823]]

III. Discussion

    This proposed rule would incorporate by reference NUREG-2228 and 
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''). Regulatory Guide 
1.84, Revision 39 (DG-1366) would supersede the incorporation by 
reference of Revision 38; RG 1.147, Revision 20 (DG-1367) would 
supersede the incorporation by reference of Revision 19; and RG 1.192, 
Revision 4 (DG-1368) would supersede the incorporation by reference of 
Revision 3.
    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 0 through 7 to the 2015 Edition of the ASME BPV Code, 
Supplements 0 through 7 to the 2017 Edition of the ASME BPV Code, 
Supplements 0 and 1 to the 2019 Edition of the ASME BPV Code, and the 
OM Code Cases listed in the 2020 Edition of the ASME OM Code.
    The latest editions and addenda of the ASME BPV and OM Codes that 
the NRC has approved for use are referenced in Sec.  50.55a. The ASME 
also 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. Because the NRC is proposing 
to require the use of NUREG-2228, ``Weld Residual Stress Finite Element 
Analysis Validation: Part II--Proposed Validation Procedure,'' within a 
condition on Code Case N-847, the NRC is also incorporating by 
reference NUREG-2228. The ASME publishes the OM Code Cases and lists 
the Code Cases in the 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 Code 
Cases by the edition of the ASME BPV Code or ASME OM Code under which 
they were published by the ASME.
    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 the NRC's RGs constitutes acceptance 
of its technical position for applications that are not precluded by 
regulatory or other requirements or by the recommendations in these or 
other RGs. 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 (i.e., 
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). Hence, if a Section III Code Case is implemented by an 
applicant or a licensee and a later version of the Code Case is 
incorporated by reference into Sec.  50.55a and listed in the RG, the 
applicant or licensee may use either version of the Code Case (subject, 
however, to whatever change requirements apply to its licensing basis 
(e.g., Sec.  50.59)) until the next mandatory inservice inspection or 
inservice testing update.
    A licensee's inservice inspection and inservice testing programs 
must be updated every 10 years to the latest edition and addenda of the 
ASME BPV Code, Section XI, and the OM Code, respectively, that were 
incorporated by reference into Sec.  50.55a and in effect 18 months 
prior to the start of the next inspection and testing interval. 
Licensees that were using a Code Case prior to the effective date of 
its revision may continue to use the previous version for the remainder 
of the 120-month inservice inspection or inservice testing interval. 
This relieves licensees of the burden of having to update their 
inservice inspection or inservice testing 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 during the subsequent inservice inspection 
or inservice testing interval 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 the first 
time.
    If an applicant or a licensee applied a Code Case before it was 
listed as superseded, 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 120-month inservice inspection or 
inservice testing update interval expires, after which the continued 
use of the Code Case is prohibited unless NRC authorization is given 
under Sec.  50.55a(z). If a Code Case is incorporated by reference into 
Sec.  50.55a and later a revised version is issued by the ASME because 
experience has shown that the design analysis, construction method, 
examination method, or testing method is inadequate, the NRC will amend 
Sec.  50.55a and the relevant RG to remove the approval of the 
superseded Code Case. Applicants and licensees should not begin to 
implement such superseded Code Cases in advance of the rulemaking.

[[Page 7824]]

A. 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
----------------------------------------------------------------------------------------------------------------
             Code Case No.                      Published with supplement                      Title
----------------------------------------------------------------------------------------------------------------
                                   Boiler and Pressure Vessel Code Section III
                                         (addressed in DG-1366, Table 1)
----------------------------------------------------------------------------------------------------------------
N-249-17..............................  0 (2019 Edition)........................  Additional Materials for
                                                                                   Subsection NF, Classes 1, 2,
                                                                                   3, and MC Supports Fabricated
                                                                                   without Welding, Section III,
                                                                                   Division 1.
N-539-1...............................  0 (2017 Edition)........................  UNS N08367 in Class 2 and 3
                                                                                   Valves, Section III, Division
                                                                                   1.
N-692-1...............................  6 (2015 Edition)........................  Use of Standard Welding
                                                                                   Procedures, Section III,
                                                                                   Division 1.
N-721-1...............................  5 (2017 Edition)........................  Alternative Rules for Linear
                                                                                   Piping Supports, Section III,
                                                                                   Division 1.
N-801-3...............................  1 (2017 Edition)........................  Rules for Repair of N-Stamped
                                                                                   Class 1, 2, and 3 Components,
                                                                                   Section III, Division 1.
N-822-4...............................  7 (2015 Edition)........................  Application of the ASME
                                                                                   Certification Mark, Section
                                                                                   III, Divisions 1, 2, 3, and
                                                                                   5.
N-855.................................  2 (2015 Edition)........................  SB-148 C95800 Valves for Class
                                                                                   3 Construction, Section III,
                                                                                   Division 1.
N-856.................................  2 (2015 Edition)........................  SA-494 Grade CW-12MW (UNS
                                                                                   N30002) Nickel Alloy Castings
                                                                                   for Construction of NPS 2\1/
                                                                                   2\ and Smaller Flanged Valves
                                                                                   for Class 3 Construction,
                                                                                   Section III, Division 1.
N-859.................................  5 (2015 Edition)........................  Construction of ASME B16.9
                                                                                   Wrought Buttwelding Fittings
                                                                                   and ASME B16.11 Forged
                                                                                   Fittings Made From SB-366 UNS
                                                                                   N04400 Material for Section
                                                                                   III, Class 3 Construction,
                                                                                   Section III, Division 1.
N-863-1...............................  1 (2017 Edition)........................  Post Weld Heat Treatment
                                                                                   (PWHT) of Valve Seal Welds
                                                                                   for P4 and P5A Materials,
                                                                                   Section III, Division 1.
N-866.................................  0 (2017 Edition)........................  Alternative Materials for
                                                                                   Construction of Section III,
                                                                                   Class 2 Vessels, Section III,
                                                                                   Division 1.
N-870-1...............................  4 (2017 Edition)........................  Rules for the Elimination of
                                                                                   External Surface Defects on
                                                                                   Class 1, 2, and 3 Piping,
                                                                                   Pumps, or Valves After
                                                                                   Component Stamping and Prior
                                                                                   to Completion of the N-3 Data
                                                                                   Report, Section III, Division
                                                                                   1.
N-879.................................  1 (2017 Edition)........................  Use of Micro-Alloyed Carbon
                                                                                   Steel Bar in Patented
                                                                                   Mechanical Joints and
                                                                                   Fittings, Classes 1, 2, and
                                                                                   3, Section III, Division 1.
N-884.................................  0 (2019 Edition)........................  Procedure to Determine Strain
                                                                                   Rate for Use with the
                                                                                   Environmental Fatigue Design
                                                                                   Curve Method and the
                                                                                   Environmental Fatigue
                                                                                   Correction Factor, Fen,
                                                                                   Method as Part of an
                                                                                   Environmental Fatigue
                                                                                   Evaluation for Components
                                                                                   Analyzed per the NB-3200
                                                                                   Rules, Section III, Division
                                                                                   1.
N-887.................................  6 (with errata issued in 3/19E).........  Alternatives to the
                                                                                   Requirements of NB-4424.2(a),
                                                                                   Figure NB-4250-2, and Figure
                                                                                   NB-4250-3, Section III,
                                                                                   Division 1.
N-891.................................  0 (2019 Edition)........................  Alternative Requirements to
                                                                                   Appendix XXVI, XXVI-2400,
                                                                                   XXVI-4130, and XXVI-4131 for
                                                                                   Inspection and Repair of
                                                                                   Indentations for Polyethylene
                                                                                   Pipe and Piping Components,
                                                                                   Section III, Division 1.
----------------------------------------------------------------------------------------------------------------
                                   Boiler and Pressure Vessel Code Section XI
                                         (addressed in DG-1367, Table 1)
----------------------------------------------------------------------------------------------------------------
N-561-3...............................  0 (2019 Edition)........................  Alternative Requirements for
                                                                                   Wall Thickness Restoration of
                                                                                   Class 2 and High Energy Class
                                                                                   3 Carbon Steel Piping,
                                                                                   Section XI, Division 1.
N-638-10..............................  1 (2019 Edition)........................  Similar and Dissimilar Metal
                                                                                   Welding Using Ambient
                                                                                   Temperature Machine GTAW
                                                                                   Temper Bead Technique,
                                                                                   Section XI, Division 1.
N-653-2...............................  2 (2015 Edition)........................  Qualification Requirements for
                                                                                   Full Structural Overlaid
                                                                                   Wrought Austenitic Piping
                                                                                   Welds, Section XI, Division
                                                                                   1.
N-702-1...............................  1 (2019 Edition)........................  Alternative Requirements for
                                                                                   Boiling Water Reactor (BWR)
                                                                                   Nozzle Inner Radius and
                                                                                   Nozzle-to-Shell Welds,
                                                                                   Section XI, Division 1.
N-716-2...............................  0 (2017 Edition)........................  Alternative Piping
                                                                                   Classification and
                                                                                   Examination Requirements,
                                                                                   Section XI, Division 1.
N-768.................................  0 (2019 Edition)........................  Alternative Volumetric
                                                                                   Coverage Requirements for
                                                                                   Ultrasonic Examination of
                                                                                   Class 1 and 2 Pressure Vessel
                                                                                   Weld Joints Greater Than 2
                                                                                   in. (50 mm) in Thickness,
                                                                                   Section XI, Division 1.
N-786-3...............................  1 (2017 Edition)........................  Alternative Requirements for
                                                                                   Sleeve Reinforcement of Class
                                                                                   2 and 3 Moderate Energy
                                                                                   Carbon Steel Piping, Section
                                                                                   XI, Division 1.
N-789-3...............................  1 (2017 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.................................  2 (2015 Edition)........................  Reference Fatigue Crack Growth
                                                                                   Rate Curves for Austenitic
                                                                                   Stainless Steels in
                                                                                   Pressurized Reactor Water
                                                                                   Environments, Section XI,
                                                                                   Division 1.
N-845-1...............................  6 (2015 Edition)........................  Qualification Requirements for
                                                                                   Bolts and Studs, Section XI,
                                                                                   Division 1.
N-848-1...............................  0 (2017 Edition)........................  Alternative Characterization
                                                                                   Rules for Quasi-Laminar
                                                                                   Flaws, Section XI, Division
                                                                                   1.
N-851.................................  0 (2015 Edition)........................  Alternate Method for
                                                                                   Establishing the Reference
                                                                                   Temperature for Pressure
                                                                                   Retaining Materials, Section
                                                                                   XI, Division 1.
N-858.................................  2 (2017 Edition)........................  Alternative Volumetric
                                                                                   Coverage Requirements for
                                                                                   Ultrasonic Examination of
                                                                                   Class 1 Nozzle-to-Vessel
                                                                                   Welds, Section XI, Division
                                                                                   1.
N-865.................................  2 (2017 Edition)........................  Alternative Requirements for
                                                                                   Pad Reinforcement of Class 2
                                                                                   and 3 Atmospheric Storage
                                                                                   Tanks, Section XI, Division
                                                                                   1.
N-867.................................  0 (2017 Edition)........................  Clarification of NDE Practical
                                                                                   Examination Requirements,
                                                                                   Section XI, Division 1.
N-873.................................  1 (2017 Edition)........................  Examination Requirements for
                                                                                   the Core Makeup Tanks,
                                                                                   Section XI, Division 1.

[[Page 7825]]

 
N-874.................................  7 (2017 Edition)........................  Temporary Acceptance of
                                                                                   Leakage Through Brazed Joints
                                                                                   of Class 3 Copper, Copper-
                                                                                   Nickel, and Nickel-Copper
                                                                                   Moderate Energy Piping,
                                                                                   Section XI, Division 1.
N-877.................................  2 (2017 Edition)........................  Alternative Characterization
                                                                                   Rules for Multiple Subsurface
                                                                                   Radially Oriented Planar
                                                                                   Flaws, Section XI, Division
                                                                                   1.
N-882.................................  6 (2017 Edition)........................  Alternative Requirements for
                                                                                   Attaching Nonstructural
                                                                                   Electrical Connections to
                                                                                   Class 2 and 3 Components,
                                                                                   Section XI, Division 1.
N-885.................................  0 (2019 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 B-N-3,
                                                                                   Removable Core Support
                                                                                   Structures, Section XI,
                                                                                   Division 1.
N-892.................................  0 (2019 Edition)........................  Alternative Requirement for
                                                                                   Form OAR-1, Owner's Activity
                                                                                   Report, Completion Time,
                                                                                   Section XI, Division 1.
----------------------------------------------------------------------------------------------------------------
                                         Operation and Maintenance Code
                                         (addressed in DG-1368, Table 1)
----------------------------------------------------------------------------------------------------------------
OMN-13, Revision 3....................  2020 Edition............................  Performance-Based Requirements
                                                                                   for Extending Snubber
                                                                                   Inservice Visual Examination
                                                                                   Interval at LWR Power Plants.
OMN-15, Revision 3....................  2020 Edition............................  Performance-Based Requirements
                                                                                   for Extending the Snubber
                                                                                   Operational Readiness Testing
                                                                                   Interval at LWR Power Plants.
OMN-17, Revision 1....................  2020 Edition............................  Alternative Requirements for
                                                                                   Testing ASME Class 1 Pressure
                                                                                   Relief/Safety Valves.
OMN-22................................  2020 Edition............................  Smooth Running Pumps.
OMN-23................................  2020 Edition............................  Alternative Requirements for
                                                                                   Testing Pressure Isolation
                                                                                   Valves.
OMN-24................................  2020 Edition............................  Alternative Requirements for
                                                                                   Testing ASME Class 2 and 3
                                                                                   Pressure Relief Valves (For
                                                                                   Relief Valves in a Group of
                                                                                   One).
OMN-25................................  2020 Edition............................  Alternative Requirements for
                                                                                   Testing Appendix I Pressure
                                                                                   Relief Valves.
OMN-26................................  2020 Edition............................  Alternate Risk-Informed and
                                                                                   Margin Based Rules for
                                                                                   Inservice Testing of Motor
                                                                                   Operated Valves.
OMN-27................................  2020 Edition............................  Alternative Requirements for
                                                                                   Testing Category A Valves
                                                                                   (Non-PIV/CIV).
----------------------------------------------------------------------------------------------------------------

B. Code Cases Approved for Use With Conditions

    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-1366 (RG 1.84), DG-1367 (RG 1.147), and DG-
1368 (RG 1.192). This section provides the NRC's evaluation of the Code 
Cases and the reasons for the NRC's conditions. Notations indicate the 
conditions duplicated from previous versions of the RG.
    The NRC requests public comment on these Code Cases and the 
proposed conditions. It should also 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
----------------------------------------------------------------------------------------------------------------
             Code Case No.                     Published with  supplement                      Title
----------------------------------------------------------------------------------------------------------------
                                   Boiler and Pressure Vessel Code Section III
                                         (addressed in DG-1366, Table 2)
----------------------------------------------------------------------------------------------------------------
N-71-20...............................  6 (2015 Edition)........................  Additional Materials for
                                                                                   Subsection NF, Class 1, 2, 3,
                                                                                   and MC Supports Fabricated by
                                                                                   Welding, Section III,
                                                                                   Division 1.
N-155-3...............................  5 (2015 Edition)........................  Fiberglass Reinforced
                                                                                   Thermosetting Resin Pipe,
                                                                                   Section III, Division 1.
N-755-4...............................  1 (2017 Edition)........................  Use of Polyethylene (PE) Class
                                                                                   3 Plastic Pipe, Section III,
                                                                                   Division 1.
N-779.................................  9 (2007 Edition)........................  Alternative Rules for
                                                                                   Simplified Elastic-Plastic
                                                                                   Analysis Class 1, Section
                                                                                   III, Division 1.
N-852.................................  0 (2015 Edition)........................  Application of the ASME NPT
                                                                                   Stamp, Section III, Divisions
                                                                                   1, 2, 3, and 5.
N-883.................................  5 (2017 Edition)........................  Construction of Items Prior to
                                                                                   the Establishment of a
                                                                                   Section III, Division 1
                                                                                   Owner, Section III, Division
                                                                                   1.
N-886.................................  6 (2017 Edition)........................  Use of Polyethylene Pipe for
                                                                                   Class 3, Section III,
                                                                                   Division 1.
----------------------------------------------------------------------------------------------------------------
                                   Boiler and Pressure Vessel Code Section XI
                                         (addressed in DG-1367, Table 2)
----------------------------------------------------------------------------------------------------------------
N-513-5...............................  6 (2017 Edition)........................  Evaluation Criteria for
                                                                                   Temporary Acceptance of Flaws
                                                                                   in Moderate Energy Class 2 or
                                                                                   3 Piping and Gate Valves,
                                                                                   Section XI, Division 1.
N-516-5...............................  6 (2015 Edition)........................  Underwater Welding, Section
                                                                                   XI, Division 1.

[[Page 7826]]

 
N-705-1...............................  2 (2017 Edition)........................  Evaluation Criteria for
                                                                                   Temporary Acceptance of
                                                                                   Degradation in Moderate
                                                                                   Energy Class 2 or 3 Vessels
                                                                                   and Tanks, Section XI,
                                                                                   Division 1.
N-766-3...............................  2 (2017 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-831-1...............................  7 (2017 Edition)........................  Ultrasonic Examination in Lieu
                                                                                   of Radiography for Welds in
                                                                                   Ferritic or Austenitic Pipe,
                                                                                   Section XI, Division 1.
N-847.................................  0 (2017 Edition)........................  Partial Excavation and
                                                                                   Deposition of Weld Metal for
                                                                                   Mitigation of Class 1 Items,
                                                                                   Section XI, Division 1.
N-864.................................  2 (2017 Edition)........................  Reactor Vessel Threads in
                                                                                   Flange Examinations, Section
                                                                                   XI, Division 1.
N-869.................................  6 (2017 Edition)........................  Evaluation Criteria for
                                                                                   Temporary Acceptance of Flaws
                                                                                   in Class 2 or 3 Piping,
                                                                                   Section XI, Division 1.
N-876.................................  2 (2017 Edition)........................  Austenitic Stainless Steel
                                                                                   Cladding and Nickel Base
                                                                                   Cladding Using Ambient
                                                                                   Temperature Automatic or
                                                                                   Machine Dry Underwater Laser
                                                                                   Beam Welding (ULBW) Temper
                                                                                   Bead Technique, Section XI,
                                                                                   Division 1.
N-878.................................  1 (2017 Edition)........................  Alternative to QA Program
                                                                                   Requirements of IWA-4142,
                                                                                   Section XI, Division 1.
N-880.................................  2 (2017 Edition)........................  Alternative to Procurement
                                                                                   Requirements of IWA-4143 for
                                                                                   Small Nonstandard Welded
                                                                                   Fittings, Section XI,
                                                                                   Division 1.
N-889.................................  7 (2017 Edition)........................  Reference Stress Corrosion
                                                                                   Crack Growth Rate Curves for
                                                                                   Irradiated Austenitic
                                                                                   Stainless Steel in Light-
                                                                                   Water Reactor Environments,
                                                                                   Section XI, Division 1.
N-890.................................  0 (2019 Edition)........................  Materials Exempted From G-
                                                                                   2110(b) Requirement, Section
                                                                                   XI, Division 1.
----------------------------------------------------------------------------------------------------------------
                                         Operation and Maintenance Code
                                         (addressed in DG-1368, Table 2)
----------------------------------------------------------------------------------------------------------------
OMN-1, Revision 2.....................  2020 Edition............................  Alternative Rules for
                                                                                   Preservice and Inservice
                                                                                   Testing of Active Electric
                                                                                   Motor-Operated Valve
                                                                                   Assemblies in Light-Water
                                                                                   Reactor Power Plants.
OMN-3.................................  2020 Edition............................  Requirements for Safety
                                                                                   Significance Categorization
                                                                                   of Components Using Risk
                                                                                   Insights for Inservice
                                                                                   Testing of LWR Power Plants.
OMN-4.................................  2020 Edition............................  Requirements for Risk Insights
                                                                                   for Inservice Testing of
                                                                                   Check Valves at LWR Power
                                                                                   Plants.
OMN-9.................................  2020 Edition............................  Use of a Pump Curve for
                                                                                   Testing.
OMN-12................................  2020 Edition............................  Alternative Requirements for
                                                                                   Inservice Testing Using Risk
                                                                                   Insights for Pneumatically
                                                                                   and Hydraulically Operated
                                                                                   Valve Assemblies in Light-
                                                                                   Water Reactor Power Plants
                                                                                   (OM-Code 1998, Subsection
                                                                                   ISTC).
OMN-18................................  2020 Edition............................  Alternate Testing Requirements
                                                                                   for Pumps Tested Quarterly
                                                                                   Within 20% of
                                                                                   Design Flow.
OMN-19................................  2020 Edition............................  Alternative Upper Limit for
                                                                                   the Comprehensive Pump Test.
OMN-20................................  2020 Edition............................  Inservice Test Frequency.
----------------------------------------------------------------------------------------------------------------

1. ASME BPV Code, Section III Code Cases (DG-1366/RG 1.84)
Code Case N-71-20 [Supplement 6, 2015 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-71-20 are the same as the 
conditions on N-71-19 that were approved by the NRC in Revision 38 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 39 of RG 1.84.
Code Case N-155-3 [Supplement 5, 2015 Edition]
    Type: Revised.
    Title: Fiberglass Reinforced Thermosetting Resin Pipe, Section III, 
Division 1.
    The proposed conditions on Code Case N-155-3 are the same as the 
conditions on N-155-2 that were approved by the NRC in Revision 38 of 
RG 1.84. When the ASME revised N-155-2, 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 39 
of RG 1.84.
Code Case N-755-4 [Supplement 1, 2017 Edition]
    Type: Revised.
    Title: Use of Polyethylene (PE) Class 3 Plastic Pipe, Section III, 
Division 1.
    This Code Case is applicable only to butt fusion joints and the 
content was incorporated into Mandatory Appendix XXVI in 2015 Edition 
of Section III of the ASME Code. The relevant provisions of Code Case 
N-755-4 are the same as those in Mandatory Appendix XXVI. Therefore, 
the NRC is applying the same conditions to Code Case N-755-4. The NRC 
has determined that these conditions are necessary to ensure structural 
integrity of the polyethylene piping and fusion joints when the 
polyethylene piping is used in Class 3 safety-related applications.
Code Case N-779 [Supplement 9, 2007 Edition]
    Type: New.
    Title: Alternative Rules for Simplified Elastic-Plastic Analysis 
Class 1, Section III, Division 1.
    The NRC finds the Code Case satisfactory and technically acceptable 
for use only with code editions Summer 1979 and later. This Code Case, 
as written, is not acceptable for use with editions of Section III 
earlier than the Summer 1979 edition, which included the term Delta T1 
in NB-3600 Equation 10, because the Code Case is based on equations 
used in the Summer 1979 edition and later editions of the Code.
Code Case N-852 [Supplement 0, 2015 Edition]
    Type: New.
    Title: Application of the ASME NPT Stamp, Section III, Divisions 1, 
2, 3, and 5.

[[Page 7827]]

    The NRC approved this Code Case with conditions in a Sec.  50.55a 
rulemaking issued in 2017 (82 FR 32934, Sept. 18, 2017), and the 
supplement was not modified in a way that would make it possible for 
the NRC to remove the conditions. Therefore, the NRC is including a 
condition that this Code Case can only be used for the service life of 
a component that had the horizontally arranged NPT Code Symbol Stamp 
applied during the time period from January 1, 2005, through December 
31, 2015.
Code Case N-883 [Supplement 5, 2017 Edition]
    Type: New.
    Title: Construction of Items Prior to the Establishment of a 
Section III, Division 1 Owner, Section III, Division 1.
    This Code Case allows certificate holders to construct all items 
prior to the establishment of an Owner. Code Case N-883 was developed 
to address international stakeholders and identify the ASME as a global 
standard development organization. The NRC's main concern is that 
without the designation of an Owner, the NRC would not be able to 
provide regulatory oversight of the ASME certificate holder 
manufacturing the items, which is not consistent with appendix B to 10 
CFR part 50 and the requirements in Sec.  50.55(a) for a basic 
component. During discussions with the ASME staff on this Code Case, it 
was determined that the NRC would condition this Code Case based on 
regulatory oversight, as would other regulatory bodies depending on 
each countries' specific regulations. This is evident as this Code Case 
specifies that the ``the items have been constructed by [ASME] 
Certificate Holders who are specifically authorized by the Regulatory 
Authority having jurisdiction over the Owner's facility to construct 
items using this Case.'' The proposed condition, ``This Code Case may 
be used for the construction of items by a holder of a construction 
permit, operating license, or combined license under 10 CFR part 50 or 
part 52,'' provides this specific regulatory authorization thereby 
ensuring the appropriate regulatory oversight.
Code Case N-886 [Supplement 6, 2017 Edition]
    Type: New.
    Title: Use of Polyethylene Pipe for Class 3, Section III, Division 
1.
    This Code Case is applicable for the use of polyethylene pipe in 
Section III, Class 3, Division 1 above ground applications. This Code 
Case refers to Mandatory Appendix XXVI of Section III of the ASME Code. 
The 2015 Edition of Appendix XXVI contains requirements for butt fusion 
joints for buried piping. The 2017 Edition of Appendix XXVI contains 
requirements for butt fusion and electrofusion joints for buried 
piping. Therefore, all the conditions as noted in Section III of the 
2015-2017 Code Edition rule related to buried piping Mandatory Appendix 
XXVI apply to this Code Case. The same conditions as buried piping also 
apply to above ground application. Two additional conditions are needed 
for above ground applications, one on fire protection and one on carbon 
black distribution to protect from windows and delamination. A 
condition on fire protection is needed because polyethylene material is 
combustible and above ground uses are more susceptible to fire hazards. 
In addition, a condition requiring homogeneous carbon black 
distributiuon is needed because experiments have shown that 
inhomogeneous carbon black distribution can lead to windows and 
delamination.
2. ASME BPV Code, Section XI Code Cases (DG-1367/RG 1.147)
Code Case N-513-5 [Supplement 6, 2017 Edition]
    Type: Revised.
    Title: Evaluation Criteria for Temporary Acceptance of Flaws in 
Moderate Energy Class 2 or 3 Piping and Gate Valves, Section XI, 
Division 1.
    Code Case N-513-5 contains provisions to permit temporary 
acceptance of flaws, in moderate energy Class 2 or 3 piping, including 
elbows, pipe bends, reducers, expanders, branch tees, and gate valves 
without performing a repair/replacement activity for a limited period. 
The Code Case contains provisions regarding the scope, flaw 
characterization, periodic leakage monitoring, flaw evaluation, and 
augmented examinations. The NRC finds that the provisions of N-513-5 
are acceptable except for the augmented examination provisions in 
Section 5 of the Code Case.
    When a licensee applies N-513-5 to disposition a through-wall leak 
or wall thinning in a piping system, Section 5 of the Code Case 
requires augmented examinations for flaws and significant flaws. The 
augmented examination requirements in N-513-5 are the same as in Code 
Case, N-513-3.
    In 2018, the NRC found an instance where a licensee misinterpreted 
the provisions in Section 5 of N-513-3 and did not perform the required 
augmented examinations to disposition a through-wall leak in a service 
water system pipe. Other licensees have similarly misinterpreted the 
augmented examination provisions in Section 5 of N-513-3. The NRC found 
that the issue stems from the definition of the terms ``flaw'' and 
``significant flaw'' in Sections 5(b) and 5(c) of N-513-3, 
respectively. The NRC, therefore, proposes two conditions to define 
``flaw'' and ``significant flaw'' as those terms are used in Section 5 
of N-513-5. Licensees would be required to apply these definitions to 
Section 5 when using the Code Case.
    The first proposed condition defines a ``flaw'' as a non-through-
wall planar or nonplanar flaw with a wall thickness less than 87.5 
percent of the nominal wall thickness of the pipe or the design minimum 
wall thickness. The NRC notes that the pipe wall thickness at the time 
of the plant construction may deviate from the nominal pipe wall 
thickness slightly as part of manufacturing process. The generally 
accepted deviation is 12.5 percent of the nominal pipe wall thickness 
or the design minimum wall thickness.
    The second proposed condition defines ``significant flaw'' as any 
pipe location that does not satisfy the provisions of Section 3 of N-
513-5 or if any detected flaw that has a depth greater than 75 percent 
of the pipe wall thickness. The NRC staff notes that the criterion of 
the 75 percent wall thickness criterion originates from the provisions 
of IWC/IWD-3643 of the ASME Code, Section XI, which prohibits a flaw 
that exceeds 75 percent of the pipe wall thickness to remain in 
service. Under Section 5 of N-513-5, a planar flaw that exceeds 75 
percent of the pipe wall thickness may remain in service; however, the 
licensee must perform an augmented examination.
Code Case N-516-5 [Supplement 6, 2015 Edition]
    Type: Revised.
    Title: Underwater Welding, Section XI, Division 1.
    In the rulemaking for the 2009 Addenda through 2013 Editions of the 
ASME Code (82 FR 32934, Sept. 18, 2017), the NRC-specified conditions 
that should be applied to Section XI, Article IWA-4660 when performing 
underwater welding on irradiated materials. These conditions provide 
guidance on what level of neutron irradiation and/or helium content 
would require review and approval by the NRC because of the impact of 
neutron fluence on weldability. These conditions provide separate 
criteria for three generic classes of material: Ferritic material, 
austenitic material other than P-No. 8 (e.g., nickel-based alloys) and 
austenitic P-No. 8

[[Page 7828]]

material (e.g., stainless steel alloys). These conditions are currently 
located in Sec.  50.55a(b)(2)(xii)(A) and (B). The conditions located 
in Sec.  50.55a(b)(2)(xii)(A) and (B) are identical to the conditions 
that were imposed on Code Case N-516-4 that were approved by the NRC in 
Revision 19 of RG 1.147. When the ASME revised N-516, the Code Case was 
not modified in a way that would make it possible for the NRC to remove 
the conditions. Therefore, the conditions will be retained in Revision 
20 of RG 1.147 by stating the provisions of Sec.  50.55a(b)(2)(xii)(A) 
and (B) must be met when applying this Code Case.
Code Case N-705-1 [Supplement 2, 2017 Edition]
    Type: Revised.
    Title: Evaluation Criteria for Temporary Acceptance of Degradation 
in Moderate Energy Class 2 or 3 Vessels and Tanks, Section XI, Division 
1.
    The proposed condition on Code Case N-705-1 is identical to the 
condition on N-705 that was approved by the NRC in Revision 19 of RG 
1.147. When the ASME revised N-705, 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 20 of RG 1.147.
Code Case N-766-3 [Supplement 2, 2017 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-766-3 are identical to the 
conditions on N-766-1 that were approved by the NRC in Revision 19 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 20 
of RG 1.147.
Code Case N-831-1 [Supplement 7, 2017 Edition]
    Type: Revised.
    Title: Ultrasonic Examination in Lieu of Radiography for Welds in 
Ferritic or Austenitic Pipe, Section XI, Division 1.
    The proposed condition on Code Case N-831-1 is identical to the 
condition on N-831 that was approved by the NRC in Revision 19 of RG 
1.147. When ASME revised N-831, 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 20 of RG 1.147.
Code Case N-847 [Supplement 0, 2017 Edition]
    Type: New.
    Title: Partial Excavation and Deposition of Weld Metal for 
Mitigation of Class 1 Items, Section XI, Division 1.
    ASME Code Case N-847 provides guidelines for a repair/mitigation 
process for welds. The process, excavation and weld repair (EWR), 
removes susceptible material from the outside diameter of the pipe, and 
replaces it with more resistant weld material. This technique allows 
for the potential of two mitigation methods, the use of more crack 
resistant material and the potential for compressive stresses on the 
inside surface of the repaired/mitigated weld to arrest or prevent 
cracking. Finally, the excavation can be done 360-degrees around the 
weld or only for a partial arc of the weld.
    The Code Case would allow for application of this process to both 
BWR and PWR designs. However, the EWR process, as defined in this code 
case, has certain challenges addressing the cracking mechanisms in 
these operating enviornments and materials. In addition the regulatory 
requirements or guidelines related to the Code Case vary depending on 
the design of the reactor. For PWR designs, the inservice inspection 
rules are provided by Sec.  50.55a(g)(6)(ii)(F), which mandates the 
implementation of a version of ASME Code Case N-770. For BWR designs, 
the inservice inspection guidelines are provided by Generic Letter 88-
01, ``NRC Position on Intergranular Stress Corrosion Cracking (IGSCC) 
in BWR Austenitic Stainless Steel Piping'' or BWRVIP-75-A, ``BWR Vessel 
and Internals Project Technical Basis for Revisions to Generic Letter 
88-01 Inspection Schedules.'' Therefore, the NRC is proposing six 
conditions to ensure the inservice inspection frequency guidelines of 
the code case are inline with the previous requirements and guidance, 
which are based on the effectiveness of the overall design of the 
repair/mitigation to address the various cracking mechanisms of these 
operating reactor designs.
    The first proposed condition is a continuation of the condition of 
Sec.  50.55a(g)(6)(ii)(F)(16) which requires that a partial arc EWR, as 
described in Inspection Item O of ASME Code Case N-770-5, cannot be 
used without NRC review and approval for PWR designs. The NRC notes 
that the issues addressed in the final rule incorporating by reference 
the 2015 and 2017 Editions of the ASME BPV Code and the 2015 and 2017 
Editions of the ASME OM Code remain applicable, and futher apply to BWR 
design application of a partial arc EWR. These concerns are for the 
effectiveness of the repair through a weld residual stress calculation 
and flaw growth analysis to confirm design of the mitigation for the 
required inspection interval, non-destructive examination uncertainty 
analysis of the as-found flaw remaining in the reactor coolant pressure 
boundary, and the potential for further crack initiation or growth. 
Therefore, the NRC requires, through the first condition, that approval 
of the use of this Code Case is only for the application of the 360-
degee EWR.
    The second proposed condition is related to Figure 1A and Figure 1B 
of the Code Case. The NRC has experience with relief request 
submittals, where the details associated with the configuration of the 
prep area, where the defect is being removed, have shown sharp bottom 
edges and steep walls. This geometry can result in welding issues, 
which could result in unfused material, leading to stress risers, which 
may promote cracking. Therefore, the NRC requires, through the second 
condition, that the intersection points at the interface between EWR 
metal and existing base metal must be rounded to minimize stress 
concentration.
    The third proposed condition is related to Section 2(d)(2) of the 
Code Case which discusses the flaw evaluations required for the design 
considerations of the EWR. In recent testing conducted for the NRC 
measurable stress corrosion cracking (SCC) growth was detected past the 
interface between the SCC-susceptible and less susceptible material. It 
was demonstrated that the crack can branch and propagate in a direction 
normal to the original direction along a SCC-susceptible path. In the 
Alloy 52M deposited onto Alloy 182 specimens tested, this occurred in 
the diluted region of the Alloy 52M material as well as the weld metal. 
Therefore, the NRC requires, through the third condition, that flaw 
analysis include the potential for crack growth through the dilution 
zone. As NRC-approved crack growth rates are not available for all 
material types (e.g., Alloy 690 weld material), the alternative 
requirements for development of crack growth rates should be consistent 
with ASME Section XI Appendix C, ``Flaw Growth Rate Due to Stress 
Corrosion Cracking,'' C-3220(a).
    The fourth proposed condition is related to Section 2 of the Code 
Case. The NRC is requiring the use of

[[Page 7829]]

NUREG-2228, ``Weld Residual Stress Finite Element Analysis Validation: 
Part II--Proposed Validation Procedure,'' because it provides a proven 
method for validating the weld residual stress analysis methodology. 
Because the NRC requires the use of NUREG-2228 within this condition on 
the requirements in the Code Case, the NRC is incorporating by 
reference NUREG-2228 into Sec.  50.55a(a)(3)(iv).
    The fifth condition is related to the longer term volumetric 
inspection frequencies of Table 1, including notes (1), (3), and (4). 
These notes provide the BWR design inspection frequency of various EWR 
types based on Generic Letter 88-01 (1988) as supplemented by Generic 
Letter 88-01, Supplement 1 (1992), ``NRC Position on Intergranular 
Stress Corrosion Cracking (IGSCC) in BWR Austenitic Stainless Steel 
Piping'' or BWRVIP-75-A, ``BWR Vessel and Internals Project Technical 
Basis for Revisions to Generic Letter 88-01 Inspection Schedules.'' The 
NRC has concluded that the inspection requirements for EWRs for BWRs 
need to be augmented.
    The first volumetric examination following application of BWR EWR-
2A, EWR-1B, and EWR-2B welds is performed to verify effectiveness of 
the repair/mitigation before the new weld can be placed in a longer 
term volumetric inspection frequency. The Code Case allows licensees 
the option of performing this examination during the first or second 
refueling outage after installation. However, based on the lower 
operating temperatures of a BWR (approximately 546 degree F to 558 
degree F), and hence the potential slow crack growth rate of the 
remaining flaw left in service, the NRC has concluded that the 
examination should occur during the second refueling outage after the 
EWR application to provide adequate time for any potential measurable 
flaw growth to occur or in the case of an EWR-2A, for crack initiation 
and growth to occur.
    The long term volumetric inspections for BWRs require modification 
because: (a) For EWR-1A EWRs, the augmented inspection requirements are 
consistent with the conditions of the inspection frequencies of Code 
Case N-770-5. These inspection frequency requirements were previously 
developed by the NRC based on the capabilities of the EWR process to 
address stress corrosion cracking while providing significant credit 
for the use of hydrogen water chemistry/noble metal chemical addition 
controls; and (b) for EWR-1B EWRs, due to the design which would allow 
a crack to be left in service, should not be allowed to go uninspected 
for the remainder of plant life. Therefore, the NRC requires the long 
term volumetric inspection of these welds at each 10-year inservice 
inspection interval. The NRC notes that this condition is consistent 
with the NRC condition established in Sec.  50.55a for Inspection Item 
N-1 EWRs (EWR that meets stress criteria; however, a crack is present).
    The sixth condition is related to Table 1, Note (1), and the option 
to use an unspecified alternative to determine examination frequencies 
and scope expansion criteria. Note (1) specifies the use of NRC Generic 
Letter 88-01 and includes BWRVIP-75-A as an example of an alternative. 
The NRC has concluded that NRC Generic Letter 88-01, (1988) as 
supplemented by Generic Letter 88-01, Supplement 1 (1992), or BWRVIP-
75-A, represent sufficient requirements, subject to the fifth condition 
above, to determine examination frequencies and scope expansion 
criteria. However, Note (1) would allow the use of other, unknown 
alternatives and does not provide criteria to ensure alternatives are 
adequate for this purpose. Therefore, to ensure that licensees use an 
adequate standard to determine examination frequencies and scope 
expansion criteria, the sixth condition requires that licensees must 
not use an alternative other than those specified in Note (1).
Code Case N-864 [Supplement 2, 2017 Edition]
    Type: New.
    Title: Reactor Vessel Threads in Flange Examinations, Section XI, 
Division 1.
    Code Case N-864 proposes to eliminate the required ASME Code, 
Section XI examination for the reactor vessel threads-in-flange for all 
inservice inspection intervals. The NRC has previously granted 
alternatives under Sec.  50.55a(z) that eliminate the reactor pressure 
vessel threads-in-flange examinations (ASME Section XI, Examination 
Category B-G-1, Item No. B6.40) for up to two inservice inspection 
intervals through the NRC's alternative request process. For 
alternatives that requested elimination of the examination for a second 
consecutive ten-year inservice inspection interval, the NRC has been 
requesting additional information on activities performed to ensure 
that the condition of the reactor pressure vessel threads-in-flange 
receives some level of monitoring. These activities typically have been 
care and maintenance of the reactor vessel threads-in-flange (and 
studs) whenever the closure head is removed. The NRC has limited 
approval of such requests to two subsequent inservice inspection 
intervals because the NRC has determined that complete elimination of 
the examinations does not provide adequate protection against long-term 
degradation of the threads-in-flange. The NRC is proposing conditions 
on the use of Code Case N-864 that are consistent with the limits the 
NRC has placed on similar alternatives requests.
    The first proposed condition in Code Case N-864 requires that the 
reactor pressure vessel threads-in-flange examinations (ASME Section 
XI, Examination Category B-G-1, Item No. B6.40) must be performed in at 
least every third 10-year ISI interval. The first proposed condition 
also limits the application of Code Case N-864 at facilities that have 
been authorized under 10 CFR 50.55a(z) to use alternatives that 
eliminate reactor pressure vessel threads-in-flange examinations to 
ensure that the required examination is performed at least every third 
10-year inservice inspection interval.
    The second proposed condition in Code Case N-864 ensures that 
sufficient monitoring and maintenance activities are performed when the 
Code Case is applied.
Code Case N-869 [Supplement 6, 2017 Edition]
    Type: New.
    Title: Evaluation Criteria for Temporary Acceptance of Flaws in 
Class 2 or 3 Piping, Section XI, Division 1.
    Code Case N-869 contains provisions for temporary acceptance of 
flaws, including through-wall flaws in Class 2 or 3 piping including 
elbows, pipe bends, reducers, and branch tees, whose maximum operating 
pressure is greater than 275 psig, and does not exceed 600 psig, 
without performing a repair/replacement activity. The Code Case 
contains provisions regarding the scope, flaw characterization, 
periodic leakage monitoring, flaw evaluation, and augmented 
examinations. The NRC finds that the Code Case provides reasonable 
assurance that structural integrity of degraded piping will be 
maintained until the next scheduled refueling outage. However, the NRC 
finds that the augmented examination provisions in Section 5 of the 
Code Case are inadequate and need additional requirements.
    When a licensee applies N-869 to disposition a through-wall leak or 
wall thinning in a piping system, Section 5 of the Code Case requires 
augmented examinations for flaws and significant flaws. The augmented 
examination

[[Page 7830]]

requirements in N-869 are the same as in Code Case N-513-3.
    In 2018, the NRC found an instance where a licensee misinterpreted 
the provisions in Section 5 of N-513-3 and did not perform the required 
augmented examinations to disposition a through-wall leak in a service 
water system pipe. Other licensees have similarly misinterpreted the 
augmented examination provisions in Section 5 of N-513-3. The NRC found 
that the issue stems from the definition of the terms ``flaw'' and 
``significant flaw'' in Sections 5(b) and 5(c) of N-513-3, 
respectively. The NRC, therefore, proposes two conditions to define 
``flaw'' and ``significant flaw'' as those terms are used in Section 5 
of N-869. Licensees would be required to apply these definitions to 
Section 5 when using the Code Case.
    The first proposed condition defines a ``flaw'' as a non-through-
wall planar or nonplanar flaw with a wall thickness less than 87.5 
percent of the nominal wall thickness of the pipe or the design minimum 
wall thickness. The NRC notes that the pipe wall thickness at the time 
of the plant construction may deviate from the nominal pipe wall 
thickness slightly as part of manufacturing process. The generally 
accepted deviation is 12.5 percent of the nominal pipe wall thickness 
or the design minimum wall thickness.
    The second proposed condition defines ``significant flaw'' as any 
pipe location that does not satisfy the provisions of Section 3 of N-
869 or if any detected flaw that has a depth greater than 75 percent of 
the pipe wall thickness. The NRC staff notes that the criterion of the 
75 percent wall thickness criterion originates from the provisions of 
IWC/IWD-3643 of the ASME Code, Section XI, which prohibit a flaw that 
exceeds 75 percent of the pipe wall thickness to remain in service. 
Under Section 5 of N-869, a planar flaw that exceeds 75 percent of the 
pipe wall thickness may remain in service; however, the licensee needs 
to perform an augmented examination.
Code Case N-876 [Supplement 2, 2017 Edition]
    Type: New.
    Title: Austenitic Stainless Steel Cladding and Nickel Base Cladding 
Using Ambient Temperature Automatic or Machine Dry Underwater Laser 
Beam Welding (ULBW) Temper Bead Technique, Section XI, Division 1.
    Some irradiated stainless steel reactor vessel internal components 
are susceptible to experiencing irradiation assisted stress corrosion 
cracking. Code Case N-876 provides guidelines for repair welding the 
irradiated stainless steel components inside the reactor vessel. Code 
Case N-876 provides an alternative to the cladding temper bead repair 
rules of Section XI, IWA-4400, which requires preheat and postweld heat 
treatment. This alternative establishes new rules governing ambient 
temperature temper bead cladding repairs using the ULBW process.
    The NRC is proposing two conditions on this Code Case. The first 
proposed condition that must be applied when performing ULBW on 
irradiated materials provides guidance on what level of neutron 
irradiation and/or helium content would require review and approval by 
the NRC because of the impact of neutron fluence on weldability. The 
second proposed condition limits the depth of the cladding repair due 
to concerns with the fracture toughness of the base metal.
    The technical basis for imposing conditions on the welding of 
irradiated materials are that neutrons can generate helium atoms within 
the metal lattice through transmutation of various isotopes of boron 
and/or nickel. At high temperatures, such as occurs during welding, 
these helium atoms rapidly diffuse though the metal lattice, coalescing 
and forming helium bubbles at the grain boundaries. In sufficient 
concentration, these helium bubbles can cause grain boundary cracking 
that occurs in the fusion zones and heat affected zones during the 
heat-up/cooldown cycle.
    The first proposed condition applies conditions already applicable 
to Code Case N-516-5 ``Underwater Welding Section XI, Division 1,'' 
that the provisions of Sec.  50.55a(b)(2)(xii)(A) and (B) must be met. 
This regulation provides limits on specific levels of neutron 
irradiation and/or helium content, above which welding is prohibited 
without prior NRC review and approval. The NRC is proposing to apply 
the same condition to uses of Code Case N-876.
    The second proposed condition is necessary because the Code Case 
does not require impact testing of the base metal heat affected zone 
(HAZ) to verify adequate fracture toughness. The Code Case allows the 
depth of the repair cavity into the ferritic base metal to be up to \1/
4\''. This would allow welding directly to the base metal, thus it will 
affect the fracture toughness of the base metal in the HAZ. Therefore, 
the NRC is proposing a condition restricting the use of the Code Case 
to repairs where at least \1/8\'' of cladding remains. The basis for 
the \1/8\'' limit is that this amount of austenitic material between 
the ferritic base metal and the first weld layer has generally been 
considered to sufficiently limit the heat input to the base metal such 
that deleterious effects on the fracture toughness will not occur; 
therefore, impact testing of the base metal is not necessary. The NRC 
notes that Code Case N-803, which is approved without conditions, 
allows repair of ferritic base material using nonferritic weld filler 
material based on welding procedure qualifications performed using 
tensile tests, side bends, and impact tests, and could be used to 
perform a cladding repair in which excavation into the base metal is 
required.
Code Case N-878 [Supplement 1, 2017 Edition]
    Type: New.
    Title: Alternative to QA Program Requirements of IWA-4142, Section 
XI, Division 1.
    Code Case N-878 provides alternatives to the quality assurance 
requirements in IWA-4142 for procurement of Class 1, 2, or 3 non-welded 
fittings. This Code Case addresses the testing and certification of 
material used in the manufacture of non-welded fittings, but does not 
address how the licensee must ensure that the procured non-welded 
fittings meet the design and testing requirements of the ASME Code, 
Section III, NB/NC/ND-3671.7 for Class 1, 2, or 3 applications. 
Verification that the Section III requirements for the design and 
testing of these non-welded fittings have been met prior to use is 
essential in ensuring the structural integrity of these Class 1, 2 and 
3 systems is maintained. Therefore, the NRC is proposing conditions for 
the licensee to verify the design and testing activities associated 
with qualification of non-welded fittings required by Section III, NB/
NC/ND-3671.7 that are performed by the fabricator.
Code Case N-880 [Supplement 2, 2017 Edition]
    Type: New.
    Title: Alternative to Procurement Requirements of IWA-4143 for 
Small Nonstandard Welded Fittings, Section XI, Division 1.
    Code Case N-880 provides alternatives to the material procurement 
requirements of IWA-4142 and IWA-4143 for small nonstandard welded 
fittings. This Code Case does not address how the licensee must ensure 
the procured welded fittings meet the design and testing requirements 
of the ASME Code, Section III, NB/NC/ND-3671.7 for Class 1, 2, or 3 
applications. Verification that the Section III requirements for the 
design and testing

[[Page 7831]]

of these welded fittings have been met prior to use is essential in 
ensuring the structural integrity of these Class 1, 2 and 3 systems is 
maintained. Therefore, the NRC is proposing conditions requiring the 
licensee to verify the design and testing activities associated with 
qualification of welded fittings required by Section III, NB/NC/ND-
3671.7 that are performed by the fabricator.
Code Case N-889 [Supplement 7, 2017 Edition]
    Type: New.
    Title: Reference Stress Corrosion Crack Growth Rate Curves for 
Irradiated Austenitic Stainless Steel in Light-Water Reactor 
Environments, Section XI, Division 1.
    Code Case N-889 provides a new crack growth rate (CGR) law for 
irradiation-assisted stress corrosion cracking. The Code Case is 
applicable to wrought austenitic stainless steels and associated weld 
metals, as well as cast austenitic stainless steels. The proposed CGR 
law requires the user to first calculate irradiated yield stress from 
the dose to the material. There are two yield stress models: One for 
Molybdenum bearing stainless steels and one for stainless steels 
without Molybdenum. Once irradiated yield stress has been determined, 
the user calculates the CGR as a function of applied crack driving 
force and temperature.
    The staff identified three concerns with the technical basis of 
this Code Case. The first concern relates to the limited CGR data at 
dose levels greater than 20 displacements per atom (dpa). The proposed 
CGR law indicates that the irradiated yield stress (and, consequently, 
the CGR) increases with fluence up to a dose of 20 dpa, at which point 
the irradiated yield's stress ceases to increase appreciably with 
further dose accumulation. While the data at dose levels greater than 
20 dpa does show a plateau behavior in the CGR, the staff's analyses of 
that data suggests that areas of high CGR were averaged over the 
industry calculation of CGR, which increases the uncertainty in the 
high dose CGRs. Therefore, due to the limited data and the associated 
high uncertainty at high fluence, the staff's confidence in CGRs at 
dose levels greater than 20 dpa is low.
    The second concern is the effects of uncertainty in the irradiated 
yield strength value for an individual material-heat. This topic is 
discussed in Section 4.7 of the technical basis report for Code Case N-
889. The NRC also conducted separate analyses. While the results of the 
NRC's findings are generally consistent with the results in Section 
4.7, the interpretation of their significance is not consistent. For 
materials with yield strengths greater than 600 MPa (i.e., more highly-
irradiated materials), the expected CGR for a material with a yield 
strength in the 95th percentile is less than two times the CGR 
predicted by the Code Case, which is not a significant difference. 
However, for materials with yield strength values less than 250 MPa 
(i.e., unirradiated or minimally irradiated materials), the expected 
CGR for a material in the 95th percentile can be more than five times 
greater than the CGR predicted by the Code Case. Hence, the NRC's 
concern is that the CGRs for individual low yield strength materials, 
or materials with low fluence, could be significantly underpredicted by 
the Code Case.
    The final concern is related to the data used in the development of 
the irradiated yield stress model. The methodology for addressing cold 
work in this model was developed in MRP-135, Revision 1, while the 
model itself was developed in MRP-211, Revision 0. The database 
underlying the model included hundreds of yield strength measurements 
on initially annealed and cold-worked Types 304, 316, and 347/348 
stainless steel materials. However, most of the data were for annealed 
Type 304 and cold-worked Type 316 stainless steels. Revision 1 of MRP-
211 contained additional yield strength data, including significantly 
more data for cold-worked Types 304 and 347 stainless steel. The 
authors of the Code Case, as documented in Section 4.5 of the 
Additional Basis Report dated February 5, 2018, evaluated the Code Case 
yield stress model with some of this additional data and found 
agreement between the model and the additional data. However, the Code 
Case authors excluded new data for cold-worked Type 304 and 347 
stainless steel materials. Therefore, the technical basis document for 
Code Case N-889 does not directly address whether cold-worked Type 304 
and 347 (non-Molybdenum bearing) materials are adequately predicted by 
the irradiated yield strength model in the Code Case. Therefore, the 
NRC is proposing three conditions on this Code Case.
    The first proposed condition states that this Code Case may not be 
applied for neutron exposures greater than 20 dpa. This condition 
addresses the NRC concern that there is sparse data with high 
uncertainty beyond 20 dpa. Given that the predicted CGR saturates at 
higher fluence, this condition prevents potential underprediction of 
the CGR in this fluence regime.
    The second proposed condition states that at dose levels below 0.75 
dpa, the user must use the higher of the Code Case N-889 or the Section 
XI, Nonmandatory Appendix C, C-8520 CGR predictions. This condition 
addresses the NRC concern related to possible underprediction of CGR in 
Code Case N-889 for materials with calculated irradiated yield strength 
less than 250 MPa.
    The final proposed condition states that the irradiated yield 
stress model for cold-worked Molybdenum bearing materials must be used 
for cold-worked non-Molybdenum bearing stainless steels (including Type 
204 and 247 stainless steels). This condition addresses the NRC concern 
that data for cold-worked non-Molybdenum bearing steels were not 
appropriately considered during development of Code Case N-889. The NRC 
performed its own evaluation of cold-worked Type 304 and 347 stainless 
steels in the MRP-211 database and found that the yield strength was 
better predicted by the Code Case's Molybdenum bearing model than with 
the Code Case's non-Molybdenum bearing model.
Code Case N-890 [Supplement 0, 2019 Edition]
    Type: New.
    Title: Materials Exempted From G-2110(b) Requirements, Section XI, 
Division 1.
    Code Case N-890 provides an alternative to Section XI, G-2110(b) 
which removes the requirement of, ``obtaining fracture toughness data 
for at least three heats,'' for using the static fracture toughness 
curve (KIc) curve for specific materials with a minimum 
specified yield strength at room temperature between 50 kilopound per 
square inch (ksi) and 90 ksi. Code Case N-890 would allow the toughness 
of four ferritic steels (SA-508 Grade 2 Class 2, SA-508 Grade 3 Class 
2, SA-533 Type A Class 2 and SA-533 Type B Class 2) with specified 
minimum yield strength greater than 50 ksi to be characterized by 
Figure G-2110-1 (i.e., the Section XI KIc curve).
    The NRC identified one technical concern when reviewing the 
technical basis of this Code Case. The technical basis provided 
appropriate data to justify use of the KIc curve for several 
materials listed in the Code Case. However, for SA-533 Type B, Class 2 
materials, the NRC observed that in the technical basis document, there 
is no fracture toughness data associated with the weld and heat 
affected zone to support exclusion of the fracture toughness testing 
requirements for these materials.

[[Page 7832]]

    As such, the proposed NRC condition requires the user to comply 
with the provisions of Section III, NB-2300 and Section III, G-2110(b) 
to demonstrate the applicability of the ASME KIc curve to 
SA-533 Type B, Class 2 material. These provisions require the user to 
generate the necessary toughness data to demonstrate that the ASME 
KIc curve is a conservative representation of the actual 
material toughness.
3. ASME Operation and Maintenance Code Cases (DG-1368/RG 1.192)
Code Case OMN-1, Revision 2 [2020 Edition]
    Type: Reaffirmed.
    Title: Alternative Rules for Preservice and Inservice Testing of 
Active Electric Motor-Operated Valve Assemblies in Light-Water Reactor 
Power Plants.
    The proposed conditions on Code Case OMN-1, Revision 2 [2020 
Edition] are identical to the conditions on OMN-1, Revision 2 [2017 
Edition] that were approved by the NRC in Revision 3 of RG 1.192. The 
OMN-1, Revision 2 was reaffirmed by the ASME in the 2020 Edition with 
no change to the Code Case. Therefore, the conditions would be retained 
in Revision 4 of RG 1.192.
Code Case OMN-3 [2020 Edition]
    Type: Reaffirmed.
    Title: Requirements for Safety Significance Categorization of 
Components Using Risk Insights for Inservice Testing of LWR Power 
Plants.
    The proposed conditions on Code Case OMN-3 [2020 Edition] are 
identical to the conditions on OMN-3 [2017 Edition] that were approved 
by the NRC in Revision 3 of RG 1.192. The OMN-3 was reaffirmed by the 
ASME in the 2020 Edition with no change to the Code Case. Therefore, 
the conditions would be retained in Revision 4 of RG 1.192.
Code Case OMN-4 [2020 Edition]
    Type: Reaffirmed.
    Title: Requirements for Risk Insights for Inservice Testing of 
Check Valves at LWR Power Plants.
    The proposed conditions on Code Case OMN-4 [2020 Edition] are 
identical to the conditions on OMN-4 [2017 Edition] that were approved 
by the NRC in Revision 3 of RG 1.192. The OMN-4 was reaffirmed by the 
ASME in the 2020 Edition with no change to the Code Case. Therefore, 
the conditions would be retained in Revision 4 of RG 1.192.
Code Case OMN-9 [2020 Edition]
    Type: Reaffirmed.
    Title: Use of a Pump Curve for Testing.
    The proposed conditions on Code Case OMN-9 [2020 Edition] are 
identical to the conditions on OMN-9 [2017 Edition] that were approved 
by the NRC in Revision 3 of RG 1.192. The OMN-9 was reaffirmed by the 
ASME in the 2020 Edition with no change to the Code Case. Therefore, 
the conditions would be retained in Revision 4 of RG 1.192.
Code Case OMN-12 [2020 Edition]
    Type: Reaffirmed.
    Title: Alternative Requirements for Inservice Testing Using Risk 
Insights for Pneumatically and Hydraulically Operated Valve Assemblies 
in Light-Water Reactor Power Plants (OM-Code 1998, Subsection ISTC).
    The proposed conditions on Code Case OMN-12 [2020 Edition] are 
identical to the conditions on OMN-12 [2017 Edition] that were approved 
by the NRC in Revision 3 of RG 1.192. The OMN-12 was reaffirmed by the 
ASME in the 2020 Edition with no change to the Code Case. Therefore, 
the conditions would be retained in Revision 4 of RG 1.192.
Code Case OMN-18 [2020 Edition]
    Type: Reaffirmed.
    Title: Alternate Testing Requirements for Pumps Tested Quarterly 
Within 20% of Design Flow.
    The proposed conditions on Code Case OMN-18 [2020 Edition] are 
identical to the conditions on OMN-18 [2017 Edition] that were approved 
by the NRC in Revision 3 of RG 1.192. The OMN-18 was reaffirmed by the 
ASME in the 2020 Edition with no change to the Code Case. Therefore, 
the conditions would be retained in Revision 4 of RG 1.192.
Code Case OMN-19 [2020 Edition]
    Type: Reaffirmed.
    Title: Alternative Upper Limit for the Comprehensive Pump Test.
    The proposed conditions on Code Case OMN-19 [2020 Edition] are 
identical to the conditions on OMN-19 [2017 Edition] that were approved 
by the NRC in Revision 3 of RG 1.192. The OMN-19 was reaffirmed by the 
ASME in the 2020 Edition with no change to the Code Case. Therefore, 
the conditions would be retained in Revision 4 of RG 1.192.
Code Case OMN-20 [2020 Edition]
    Type: Reaffirmed.
    Title: Inservice Test Frequency.
    The proposed conditions on Code Case OMN-20 [2020 Edition] are 
identical to the conditions on OMN-20 [2017 Edition] that were approved 
by the NRC in Revision 3 of RG 1.192. The OMN-20 was reaffirmed by the 
ASME in the 2020 Edition with no change to the Code Case. Therefore, 
the conditions would be retained in Revision 4 of RG 1.192.

C. ASME Code Cases Not Approved for Use (DG-1369/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.

IV. Section-by-Section Analysis

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

Paragraph (a)(3) Introductory Text

    This proposed rule would add a reference to NUREG-2228 that is 
acceptable as specified in the conditions when implementing Code Cases 
listed in certain NRC regulatory guides.

Paragraph (a)(3)(i)

    This proposed rule would revise the reference to ``NRC Regulatory 
Guide 1.84, Revision 38,'' by removing ``Revision 38'' and adding in 
its place ``Revision 39'' and change 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 19'' by removing ``Revision 19'' and adding in 
its place ``Revision 20'' and change 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 3'' by removing ``Revision 3'' and adding in its 
place ``Revision 4'' and change the month and year for the document's 
revision date.

Paragraph (a)(3)(iv)

    This proposed rule would add new paragraph (a)(3)(iv) to reference

[[Page 7833]]

NUREG-2228, ``Weld Residual Stress Finite Element Analysis Validation: 
Part II--Proposed Validation Procedure,'' dated July 2020, which is 
referenced in RG 1.147, Revision 20.

Paragraph (b)(3)(iv), Table II

    This proposed rule would capitalize the word ``(Years)'' in two of 
the three column headings.

V. Regulatory Flexibility Certification

    As required by the Regulatory Flexibility Act (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 
(10 CFR 2.810).

VI. Regulatory Analysis

    The NRC has prepared a draft regulatory analysis on 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 analysis may be submitted to the NRC as 
indicated under the ADDRESSES section of this document.

VII. 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.

VIII. 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 
31883). The NRC requests comment on this document with respect to the 
clarity and effectiveness of the language used.

IX. 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; therefore, an environmental impact statement is not 
required.
    The determination of this environmental assessment is that there 
will be no significant effect on the quality of the human environment 
from this action. Interested parties should note, however, that 
comments on any aspect of this environmental assessment may be 
submitted to the NRC as indicated under the ADDRESSES section of this 
document.
    As voluntary alternatives to the ASME Code, NRC-approved Code Cases 
provide an equivalent level of safety. Therefore, the probability or 
consequences of accidents is not changed. There are also no 
significant, non-radiological impacts associated with this action 
because no changes would be made affecting non-radiological plant 
effluents and because no changes would be made in activities that would 
adversely affect the environment. The determination of this 
environmental assessment is that there will be no significant offsite 
impact to the public from this action.

X. Paperwork Reduction Act Statement

    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 (OMB) for approval of the information 
collections.
    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: On occasion.
    Who will be required or asked to report: Operating power reactor 
licensees and applicants for power reactors under construction.
    An estimate of the number of annual responses: -28 (reduction).
    The estimated number of annual respondents: -28 (reduction).
    An estimate of the total number of hours needed annually to 
complete the requirement or request: -6,720 hours (reduction of 
reporting and recordkeeping hours).
    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 
incorporation by reference of these Code Cases will reduce the number 
of alternative requests submitted by licensees under Sec.  50.55a(z) by 
an estimated 28 requests annually.
    The NRC is seeking public comment on the potential impact of the 
information collections contained in this proposed rule and on the 
following issues:
    1. Is the proposed information collection necessary for the proper 
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 OMB clearance package and proposed rule is available 
in ADAMS under Accession No. ML20132A240 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-2017-0025.

[[Page 7834]]

    You may submit comments on any aspect of these proposed information 
collections, including suggestions for reducing the burden and on the 
four issues, by the following methods:
     Federal Rulemaking Website: Go to https://www.regulations.gov and search for Docket ID NRC-2017-0025.
     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 on this collection of information by March 4, 2021. 
Comments received after this date will be considered if it is practical 
to do so, but the NRC staff 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.

XI. 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 39; RG 1.147, Revision 20; RG 1.192, Revision 4; and NUREG-
2228. 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.

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

    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-1366, DG-1367, and DG-1368, will correspond to 
final RG 1.84, Revision 39; RG 1.147, Revision 20; and RG 1.192, 
Revision 4, respectively. The NRC also proposes to incorporate by 
reference NUREG-2228, which is referenced in DG-1367 (RG 1.147, 
Revision 20). As described in this document, this report pertains to a 
proposed condition on Code Case N-847.
    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 10 CFR 2.810.
     Large entities otherwise subject to the NRC's regulatory 
oversight. This class includes applicants and potential applicants for 
licenses and other NRC regulatory approvals, and who are subject to the 
material to be incorporated by reference. In this context, a ``large 
entity'' is one that does not qualify as a ``small entity'' under 10 
CFR 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 10 CFR 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 NUREG-2228 and 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 NUREG-2228 and 
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]. The final RGs, if approved by the OFR for 
incorporation by reference, will also be available for inspection at 
the OFR, as described in 10 CFR 50.55a(a).
    Because access to 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-1366, DG-1367, and DG-1368, and final RG 1.84, Revision 39; RG 
1.147, Revision 20; and RG 1.192, Revision 4, once approved by the OFR 
for incorporation by reference, are reasonably available to all 
interested parties.

XIII. Availability of Documents

    The documents identified in the following tables are available to 
interested persons through one or more of the following methods, as 
indicated. 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-2017-0025. The Federal rulemaking website allows you

[[Page 7835]]

to receive alerts when changes or additions occur in a docket folder. 
To subscribe: (1) Navigate to the docket folder (NRC-2017-0025); (2) 
click the ``Sign up for Email Alerts'' link; and (3) enter your email 
address and select how frequently you would like to receive emails 
(daily, weekly, or monthly).

                                     Table III--Rulemaking Related Documents
----------------------------------------------------------------------------------------------------------------
                                                             ADAMS Accession No.  or Federal Register citation,
                      Document title                                             or website
----------------------------------------------------------------------------------------------------------------
Final Rule -- ``Incorporation by Reference of ASME BPV and  68 FR 40469.
 OM Code Cases,'' July 8, 2003.
Final Rule -- ``Incorporation by Reference of American      82 FR 32934.
 Society of Mechanical Engineers Codes and Code Cases,''
 July 18, 2017.
Zorita Internals Research Project (MRP-440) Testing of      Available for purchase.
 Highly-Irradiated Baffle Plate Material 3002016015 Final
 Report, October 2019.
ASME Code, Section III, NB-2330, ``Test Requirements and    Available for purchase.
 Acceptance Standards,'' July 2017.
BWRVIP-75-A, ``BWR Vessel and Internals Project, Technical  Available for purchase.
 Basis for Revisions to Generic Letter 88-01 Inspection
 Schedules,'' October 2005.
Final Rule -- ``Approval of American Society of Mechanical  85 FR 14736.
 Engineers' Code Cases,'' March 16, 2020.
RG 1.193, ASME Code Cases Not Approved for Use, Revision 7  ML20120A627.
 (DG-1369).
Rulemaking--Proposed Rule--Regulatory Analysis for the      ML20133K152.
 American Society of Mechanical Engineers Code Cases, RG
 1.84, Rev 39; RG 1.147, Rev 20; RG 1.192, Rev 4; and RG
 1.193, Rev 7.
GL-88-01, Supplement 1, ``NRC Position on Intergranular     https://www.nrc.gov/reading-rm/doc-collections/gen-
 Stress Corrosion Cracking (IGSCC) in BWR Austenitic         comm/gen-letters/1988/gl88001s1.html.
 Stainless Steel Piping (Generic Letter 88-01, Supplement
 1),'' February 4, 1992.
GL-88-01, ``NRC Position on IGSCC in BWR Austenitic         https://www.nrc.gov/reading-rm/doc-collections/gen-
 Stainless Steel Piping (Generic Letter No. 88-01),''        comm/gen-letters/1988/gl88001.html.
 January 25, 1988.
Final Rule--``Approval of American Society of Mechanical    85 FR 26540.
 Engineers 2015-20017 Code Editions, Incorporataion by
 Reference,'' May 4, 2020.
----------------------------------------------------------------------------------------------------------------

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 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 NRC also proposes to incorporate by reference NUREG-2228, as 
set forth in Table V, that is referenced within a condition in RG 
1.147, Revision 20.

           Table IV--Draft Regulatory Guides Proposed To Be Incorporated by Reference in 10 CFR 50.55a
----------------------------------------------------------------------------------------------------------------
                      Document title                           ADAMS Accession No./ Federal Register citation
----------------------------------------------------------------------------------------------------------------
RG 1.84, Design, Fabrication, and Materials Code Case       ML20120A633.
 Acceptability, ASME Section III, Revision 39, (DG-1366).
RG 1.147, Inservice Inspection Code Case Acceptability,     ML20120A631.
 ASME Section XI, Division 1, Revision 20, (DG-1367).
RG 1.192, Operation and Maintenance Code Case               ML20120A629.
 Acceptability, ASME OM Code, Revision 4, (DG-1368).
----------------------------------------------------------------------------------------------------------------


              Table V--Related Documents Proposed To Be Incorporated by Reference in 10 CFR 50.55a
----------------------------------------------------------------------------------------------------------------
                      Document title                                         ADAMS Accession No.
----------------------------------------------------------------------------------------------------------------
NUREG-2228, ``Weld Residual Stress Finite Element Analysis  ML20212L592.
 Validation: Part II--Proposed Validation Procedure,''
 July 2020.
----------------------------------------------------------------------------------------------------------------

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 VI, are being made available by the ASME for read-only access 
during the public comment period on https://go.asme.org/NRC-ASME-CC.
    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 VI, are being made available for read-only access during the 
public comment period by the ASME on https://go.asme.org/NRC-ASME-CC.
    The ASME is making the Code Cases listed in Table VI 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, are 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

[[Page 7836]]

ASME provide limited, read-only access to the Code Cases in order to 
facilitate meaningful public comment.

                               Table VI--ASME Code Cases Proposed for NRC Approval
----------------------------------------------------------------------------------------------------------------
             Code Case No.                             Supplement                              Title
----------------------------------------------------------------------------------------------------------------
                                   Boiler and Pressure Vessel Code Section III
----------------------------------------------------------------------------------------------------------------
N-71-20...............................  6 (2015 Edition)........................  Additional Materials for
                                                                                   Subsection NF, Class 1, 2, 3,
                                                                                   and MC Supports Fabricated by
                                                                                   Welding, Section III,
                                                                                   Division 1.
N-155-3...............................  5 (2015 Edition)........................  Fiberglass Reinforced
                                                                                   Thermosetting Resin Pipe,
                                                                                   Section III, Division 1.
N-249-17..............................  0 (2019 Edition)........................  Additional Materials for
                                                                                   Subsection NF, Classes 1, 2,
                                                                                   3, and MC Supports Fabricated
                                                                                   without Welding Section III,
                                                                                   Division 1.
N-539-1...............................  0 (2017 Edition)........................  UNS N08367 in Class 2 and 3
                                                                                   Valves, Section III, Division
                                                                                   1.
N-692-1...............................  6 (2015 Edition)........................  Use of Standard Welding
                                                                                   Procedures, Section III,
                                                                                   Division 1.
N-721-1...............................  5 (2017 Edition)........................  Alternative Rules for Linear
                                                                                   Piping Supports, Section III,
                                                                                   Division 1.
N-755-4...............................  1 (2017 Edition)........................  Use of Polyethylene (PE) Class
                                                                                   3 Plastic Pipe, Section III,
                                                                                   Division 1.
N-779.................................  9 (2007 Edition)........................  Alternative Rules for
                                                                                   Simplified Elastic-Plastic
                                                                                   Analysis Class 1, Section
                                                                                   III, Division 1.
N-801-3...............................  1 (2017 Edition)........................  Rules for Repair of N-Stamped
                                                                                   Class 1, 2, and 3 Components,
                                                                                   Section III, Division 1.
N-822-4...............................  7 (2015 Edition)........................  Application of the ASME
                                                                                   Certification Mark, Section
                                                                                   III, Divisions 1, 2, 3, and
                                                                                   5.
N-852.................................  0 (2015 Edition)........................  Application of the ASME NPT
                                                                                   Stamp, Section III, Divisions
                                                                                   1, 2, 3, and 5.
N-855.................................  2 (2015 Edition)........................  SB-148 C95800 Valves for Class
                                                                                   3 Construction, Section III,
                                                                                   Division 1.
N-856.................................  2 (2015 Edition)........................  SA-494 Grade CW-12MW (UNS
                                                                                   N30002) Nickel Alloy Castings
                                                                                   for Construction of NPS 2\1/
                                                                                   2\ and Smaller Flanged Valves
                                                                                   for Class 3 Construction,
                                                                                   Section III, Division 1.
N-859.................................  5 (2015 Edition)........................  Construction of ASME B16.9
                                                                                   Wrought Buttwelding Fittings
                                                                                   and ASME B16.11 Forged
                                                                                   Fittings Made From SB-366 UNS
                                                                                   N04400 Material for Section
                                                                                   III, Class 3 Construction,
                                                                                   Section III, Division 1.
N-863-1...............................  1 (2017 Edition)........................  Post Weld Heat Treatment
                                                                                   (PWHT) of Valve Seal Welds
                                                                                   for P4 and P5A Materials,
                                                                                   Section III, Division 1.
N-866.................................  0 (2017 Edition)........................  Alternative Materials for
                                                                                   Construction of Section III,
                                                                                   Class 2 Vessels, Section III,
                                                                                   Division 1.
N-870-1...............................  4 (2017 Edition)........................  Rules for the Elimination of
                                                                                   External Surface Defects on
                                                                                   Class 1, 2, and 3 Piping,
                                                                                   Pumps, or Valves After
                                                                                   Component Stamping and Prior
                                                                                   to Completion of the N-3 Data
                                                                                   Report, Section III, Division
                                                                                   1.
N-879.................................  1 (2017 Edition)........................  Use of Micro-Alloyed Carbon
                                                                                   Steel Bar in Patented
                                                                                   Mechanical Joints and
                                                                                   Fittings, Classes 1, 2, and
                                                                                   3, Section III, Division 1.
N-883.................................  5 (2017 Edition)........................  Construction of Items Prior to
                                                                                   the Establishment of a
                                                                                   Section III, Division 1
                                                                                   Owner, Section III, Division
                                                                                   1.
N-884.................................  0 (2019 Edition)........................  Procedure to Determine Strain
                                                                                   Rate for Use with the
                                                                                   Environmental Fatigue Design
                                                                                   Curve Method and the
                                                                                   Environmental Fatigue
                                                                                   Correction Factor, Fen,
                                                                                   Method as Part of an
                                                                                   Environmental Fatigue
                                                                                   Evaluation for Components
                                                                                   Analyzed per the NB-3200
                                                                                   Rules, Section III, Division
                                                                                   1.
N-886.................................  6 (2017 Edition)........................  Use of Polyethylene Pipe for
                                                                                   Class 3, Section III,
                                                                                   Division 1.
N-887.................................  6 (2017 Edition with errata dated August  Alternatives to the
                                         30, 2019).                                Requirements of NB-4424.2(a),
                                                                                   Figure NB-4250-2, and Figure
                                                                                   NB-4250-3 Section III,
                                                                                   Division 1.
N-891.................................  0 (2019 Edition)........................  Alternative Requirements to
                                                                                   Appendix XXVI, XXVI-2400,
                                                                                   XXVI-4130, and XXVI-4131 for
                                                                                   Inspection and Repair of
                                                                                   Indentations for Polyethylene
                                                                                   Pipe and Piping Components,
                                                                                   Section III, Division 1.
----------------------------------------------------------------------------------------------------------------
                                   Boiler and Pressure Vessel Code, Section XI
----------------------------------------------------------------------------------------------------------------
N-513-5...............................  6 (2017 Edition)........................  Evaluation Criteria for
                                                                                   Temporary Acceptance of Flaws
                                                                                   in Moderate Energy Class 2 or
                                                                                   3 Piping and Gate Valves,
                                                                                   Section XI, Division 1.
N-516-5...............................  6 (2015 Edition)........................  Underwater Welding, Section
                                                                                   XI, Division 1.
N-561-3...............................  0 (2019 Edition)........................  Alternative Requirements for
                                                                                   Wall Thickness Restoration of
                                                                                   Class 2 and High Energy Class
                                                                                   3 Carbon Steel Piping,
                                                                                   Section XI, Division 1.
N-638-10..............................  1 (2019 Edition)........................  Similar and Dissimilar Metal
                                                                                   Welding Using Ambient
                                                                                   Temperature Machine GTAW
                                                                                   Temper Bead Technique,
                                                                                   Section XI, Division 1.
N-653-2...............................  1 (2017 Edition)........................  Qualification Requirements for
                                                                                   Full Structural Overlaid
                                                                                   Wrought Austenitic Piping
                                                                                   Welds, Section XI, Division
                                                                                   1.
N-702-1...............................  1 (2019 Edition)........................  Alternative Requirements for
                                                                                   Boiling Water Reactor (BWR)
                                                                                   Nozzle Inner Radius and
                                                                                   Nozzle-to-Shell Welds,
                                                                                   Section XI, Division 1.
N-705-1...............................  2 (2017 Edition)........................  Evaluation Criteria for
                                                                                   Temporary Acceptance of
                                                                                   Degradation in Moderate
                                                                                   Energy Class 2 or 3 Vessels
                                                                                   and Tanks, Section XI,
                                                                                   Division 1.
N-716-2...............................  0 (2017 Edition)........................  Alternative Piping
                                                                                   Classification and
                                                                                   Examination Requirements,
                                                                                   Section XI, Division 1.
N-766-3...............................  2 (2017 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-768.................................  0 (2019 Edition)........................  Alternative Volumetric
                                                                                   Coverage Requirements for
                                                                                   Ultrasonic Examination of
                                                                                   Class 1 and 2 Pressure Vessel
                                                                                   Weld Joints Greater Than 2
                                                                                   in. (50 mm) in Thickness,
                                                                                   Section XI, Division 1.
N-786-3...............................  1 (2017 Edition)........................  Alternative Requirements for
                                                                                   Sleeve Reinforcement of Class
                                                                                   2 and 3 Moderate Energy
                                                                                   Carbon Steel Piping, Section
                                                                                   XI, Division 1.
N-789-3...............................  1 (2017 Edition)........................  Alternative Requirements for
                                                                                   Pad Reinforcement of Class 2
                                                                                   and 3 Moderate Energy Carbon
                                                                                   Steel Piping for Raw Water
                                                                                   Service, Section XI, Division
                                                                                   1.

[[Page 7837]]

 
N-809.................................  2 (2015 Edition)........................  Reference Fatigue Crack Growth
                                                                                   Rate Curves for Austenitic
                                                                                   Stainless Steels in
                                                                                   Pressurized Reactor Water
                                                                                   Environments, Section XI,
                                                                                   Division 1.
N-831-1...............................  1 (2019 Edition)........................  Ultrasonic Examination in Lieu
                                                                                   of Radiography for Welds in
                                                                                   Ferritic or Austenitic Pipe,
                                                                                   Section XI, Division 1.
N-845-1...............................  6 (2015 Edition)........................  Qualification Requirements for
                                                                                   Bolts and Studs, Section XI,
                                                                                   Division 1.
N-847.................................  0 (2017 Edition)........................  Partial Excavation and
                                                                                   Deposition of Weld Metal for
                                                                                   Mitigation of Class 1 Items,
                                                                                   Section XI, Division 1.
N-848-1...............................  0 (2017 Edition)........................  Alternative Characterization
                                                                                   Rules for Quazi-Laminar
                                                                                   Flaws, Section XI, Division
                                                                                   1.
N-851.................................  0 (2015 Edition)........................  Alternate Method for
                                                                                   Establishing the Reference
                                                                                   Temperature for Pressure
                                                                                   Retaining Materials, Section
                                                                                   XI, Division 1.
N-858.................................  2 (2017 Edition)........................  Alternative Volumetric
                                                                                   Coverage Requirements for
                                                                                   Ultrasonic Examination of
                                                                                   Class 1 Nozzle-to-Vessel
                                                                                   Welds, Section XI, Division
                                                                                   1.
N-864.................................  2 (2017 Edition)........................  Reactor Vessel Threads in
                                                                                   Flange Examinations, Section
                                                                                   XI, Division 1.
N-865.................................  2 (2017 Edition)........................  Alternative Requirements for
                                                                                   Pad Reinforcement of Class 2
                                                                                   and 3 Atmospheric Storage
                                                                                   Tanks, Section XI, Division
                                                                                   1.
N-867.................................  0 (2017 Edition)........................  Clarification of NDE Practical
                                                                                   Examination Requirements,
                                                                                   Section XI, Division 1.
N-869.................................  6 (2017 Edition)........................  Evaluation Criteria for
                                                                                   Temporary Acceptance of Flaws
                                                                                   in Class 2 or 3 Piping,
                                                                                   Section XI, Division 1.
N-873.................................  1 (2017 Edition)........................  Examination Requirements for
                                                                                   the Core Makeup Tanks,
                                                                                   Section XI, Division 1.
N-874.................................  7 (2017 Edition)........................  Temporary Acceptance of
                                                                                   Leakage Through Brazed Joints
                                                                                   of Class 3 Copper, Copper-
                                                                                   Nickel, and Nickel-Copper
                                                                                   Moderate Energy Piping,
                                                                                   Section XI, Division 1.
N-876.................................  2 (2017 Edition)........................  Austenitic Stainless Steel
                                                                                   Cladding and Nickel Base
                                                                                   Cladding Using Ambient
                                                                                   Temperature Automatic or
                                                                                   Machine Dry Underwater Laser
                                                                                   Beam Welding (ULBW) Temper
                                                                                   Bead Technique, Section XI,
                                                                                   Division 1.
N-877.................................  2 (2017 Edition)........................  Alternative Characterization
                                                                                   Rules for Multiple Subsurface
                                                                                   Radially Oriented Planar
                                                                                   Flaws, Section XI, Division
                                                                                   1.
N-878.................................  1 (2017 Edition)........................  Alternative to QA Program
                                                                                   Requirements of IWA-4142,
                                                                                   Section XI, Division 1.
N-880.................................  2 (2017 Edition)........................  Alternative to Procurement
                                                                                   Requirements of IWA-4143 for
                                                                                   Small Nonstandard Welded
                                                                                   Fittings, Section XI,
                                                                                   Division 1.
N-882.................................  6 (2017 Edition)........................  Alternative Requirements for
                                                                                   Attaching Nonstructural
                                                                                   Electrical Connections to
                                                                                   Class 2 and 3 Components,
                                                                                   Section XI, Division 1.
N-885.................................  0 (2019 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 B-N-3,
                                                                                   Removable Core Support
                                                                                   Structures Section XI,
                                                                                   Division 1.
N-889.................................  7 (2017 Edition)........................  Reference Stress Corrosion
                                                                                   Crack Growth Rate Curves for
                                                                                   Irradiated Austenitic
                                                                                   Stainless Steel in Light-
                                                                                   Water Reactor Environments,
                                                                                   Section XI, Division 1.
N-890.................................  0 (2019 Edition)........................  Materials Exempted From G-
                                                                                   2110(b) Requirement, Section
                                                                                   XI, Division 1.
N-892.................................  0 (2019 Edition)........................  Alternative Requirement for
                                                                                   Form OAR-1, Owner's Activity
                                                                                   Report, Completion Time,
                                                                                   Section XI, Division 1.
----------------------------------------------------------------------------------------------------------------
                                         Operation and Maintenance Code
----------------------------------------------------------------------------------------------------------------
             Code Case No.                             Edition \4\                             Title
----------------------------------------------------------------------------------------------------------------
OMN-13, Revision 3....................  2020 Edition............................  Performance-Based Requirements
                                                                                   for Extending Snubber
                                                                                   Inservice Visual Examination
                                                                                   Interval at LWR Power Plants.
OMN-15, Revision 3....................  2020 Edition............................  Performance-Based Requirements
                                                                                   for Extending the Snubber
                                                                                   Operational Readiness Testing
                                                                                   Interval at LWR Power Plants.
OMN-17, Revision 1....................  2020 Edition............................  Alternative Requirements for
                                                                                   Testing ASME Class 1 Pressure
                                                                                   Relief/Safety Valves.
OMN-22................................  2020 Edition............................  Smooth Running Pumps.
OMN-23................................  2020 Edition............................  Alternative Requirements for
                                                                                   Testing Pressure Isolation
                                                                                   Valves.
OMN-24................................  2020 Edition............................  Alternative Requirements for
                                                                                   Testing ASME Class 2 and 3
                                                                                   Pressure Relief Valves (For
                                                                                   Relief Valves in a Group of
                                                                                   One).
OMN-25................................  2020 Edition............................  Alternative Requirements for
                                                                                   Testing Appendix I Pressure
                                                                                   Relief Valves.
OMN-26................................  2020 Edition............................  Alternate Risk-Informed and
                                                                                   Margin Based Rules for
                                                                                   Inservice Testing of Motor
                                                                                   Operated Valves.
OMN-27................................  2020 Edition............................  Alternative Requirements for
                                                                                   Testing Category A Valves
                                                                                   (Non-PIV/CIV).
----------------------------------------------------------------------------------------------------------------

List of Subjects in 10 CFR Part 50

    Antitrust, Classified information, Criminal penalties, Fire 
protection, Incorporation by reference, Intergovernmental relations, 
Nuclear power plants and reactors, Radiation protection, Reactor siting 
criteria, Reporting and recordkeeping requirements.
---------------------------------------------------------------------------

    \4\ The column labelled ``Edition'' in this table refers to the 
point in time a Code Case was issued. For example, an entry 
associated with the 2017 Edition means the Code Case was issued at 
the same time as the 2017 Edition of the Code.
---------------------------------------------------------------------------

    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. 553, the NRC is proposing to 
adopt the following amendments to 10 CFR part 50:

PART 50--DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION 
FACILITIES

0
1. The authority citation for part 50 continues to read as follows:


[[Page 7838]]


    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 paragraph (a)(3) introductory text;
0
b. In paragraph (a)(3)(i), remove the phrase ``Revision 38'' and add in 
its place the phrase ``Revision 39'' and remove the phrase ``October 
2019'' and add in its place the phrase ``MONTH/YEAR'';
0
c. In paragraph (a)(3)(ii), remove the phrase ``Revision 19'' and add 
in its place the phrase ``Revision 20'' and remove the phrase ``October 
2019'' and add in its place the phrase ``MONTH/YEAR'';
0
d. In paragraph (a)(3)(iii), remove the phrase ``Revision 3'' and add 
in its place the phrase ``Revision 4'' and remove the phrase ``October 
2019'' and add in its place the phrase ``MONTH/YEAR'';
0
e. Add paragraph (a)(3)(iv); and
0
f. In paragraph (b)(3)(iv), Table II, remove the word ``(years)'' in 
the second and third column headings and add in their places the word 
``(Years)''.
    The revision and addition read as follows:


Sec.  50.55a  Codes and standards.

    (a) * * *
    (3) U.S. Nuclear Regulatory Commission (NRC) Public Document Room, 
11555 Rockville Pike, Rockville, Maryland 20852; telephone: 1-800-397-
4209; email: [email protected]; https://www.nrc.gov/reading-rm/doc-collections/reg-guides/. The use of Code Cases listed in the NRC 
regulatory guides in paragraphs (a)(3)(i) through (iii) of this section 
is acceptable with the specified conditions in those guides when 
implementing the editions and addenda of the ASME BPV Code and ASME OM 
Code incorporated by reference in paragraph (a)(1) of this section. The 
NRC report in paragraph (a)(3)(iv) of this section is acceptable as 
specified in the conditions when implementing Code Cases listed in the 
NRC regulatory guides in paragraphs (a)(3)(i) through (iii).
* * * * *
    (iv) NUREG-2228. NUREG-2228, ``Weld Residual Stress Finite Element 
Analysis Validation: Part II--Proposed Validation Procedure,'' dated 
July 2020, which is referenced in RG 1.147, Revision 20.
* * * * *

     Dated December 23, 2020.

    For the Nuclear Regulatory Commission.
Ho K. Nieh,
Director, Office of Nuclear Reactor Regulation.
[FR Doc. 2021-00890 Filed 2-1-21; 8:45 am]
BILLING CODE 7590-01-P