[Federal Register Volume 83, Number 11 (Wednesday, January 17, 2018)]
[Rules and Regulations]
[Pages 2331-2354]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-00112]


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NUCLEAR REGULATORY COMMISSION

10 CFR Part 50

[NRC-2012-0059]
RIN 3150-AJ13


Approval of American Society of Mechanical Engineers' Code Cases

AGENCY: Nuclear Regulatory Commission.

ACTION: Final rule.

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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is amending its 
regulations to incorporate by reference (IBR) the latest revisions of 
three regulatory guides (RGs) approving new, revised, and reaffirmed 
Code Cases published by the American Society of Mechanical Engineers 
(ASME). This action allows nuclear power plant licensees and applicants 
for construction permits, operating licenses, combined licenses, 
standard design certifications, standard design approvals and 
manufacturing licenses to voluntarily use the Code Cases listed in 
these RGs as alternatives to engineering standards for the 
construction, inservice inspection (ISI), and inservice testing (IST) 
of nuclear power plant components. These engineering standards are set 
forth in the ASME's Boiler and Pressure Vessel (BPV) Codes and ASME 
Operation and Maintenance (OM) Codes, which are currently incorporated 
by reference into the NRC's regulations. This final rule announces the 
availability of the final versions of the three RGs that are being 
incorporated by reference. Further, the final rule announces the 
availability of a related RG, not incorporated by reference into the 
NRC's regulations that lists Code Cases that the NRC has not approved 
for use.

DATES: This final rule is effective on February 16, 2018. The 
incorporation by reference of certain publications listed in the 
regulation is approved by the Director of the Federal Register as of 
February 16, 2018.

ADDRESSES: Please refer to Docket ID NRC-2012-0059 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:
    <bullet> Federal Rulemaking Website: Go to http://www.regulations.gov and search for Docket ID NRC-2012-0059. Address 
questions about NRC dockets to Carol Gallagher; telephone: 301-415-
3463; email: <a href="/cdn-cgi/l/email-protection#da99bba8b5b6f49dbbb6b6bbbdb2bfa89ab4a8b9f4bdb5ac"><span class="__cf_email__" data-cfemail="357654475a591b7254595954525d5047755b47561b525a43">[email protected]</span></a>. For technical questions contact 
the individuals listed in the FOR FURTHER INFORMATION CONTACT section 
of this document.
    <bullet> NRC's Agencywide Documents Access and Management System 
(ADAMS): You may obtain publicly-available documents online in the 
ADAMS Public Documents collection at http://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 <a href="/cdn-cgi/l/email-protection#a2d2c6d08cd0c7d1cdd7d0c1c7e2ccd0c18cc5cdd4"><span class="__cf_email__" data-cfemail="a5d5c1d78bd7c0d6cad0d7c6c0e5cbd7c68bc2cad3">[email protected]</span></a>. For 
the convenience of the reader, instructions about obtaining materials 
referenced in this document are provided in the ``Availability of 
Documents'' section.
    <bullet> NRC's PDR: You may examine and purchase copies of public 
documents at the NRC's PDR, Room O1-F21, One White Flint North, 11555 
Rockville Pike, Rockville, Maryland 20852.

FOR FURTHER INFORMATION CONTACT: Jennifer Tobin, Office of Nuclear 
Reactor Regulation, telephone: 301-415-2328, email: 
<a href="/cdn-cgi/l/email-protection#145e717a7a7d7271663a407b767d7a547a66773a737b62"><span class="__cf_email__" data-cfemail="0e446b606067686b7c205a616c67604e607c6d20696178">[email protected]</span></a>; or Giovanni Facco, Office of Nuclear Regulatory 
Research, telephone: 301-415-6337; email: <a href="/cdn-cgi/l/email-protection#34735d5b42555a5a5d1a725557575b745a46571a535b42"><span class="__cf_email__" data-cfemail="c186a8aeb7a0afafa8ef87a0a2a2ae81afb3a2efa6aeb7">[email protected]</span></a>. Both 
are staff of the U.S. Nuclear Regulatory Commission, Washington, DC 
20555-0001.

SUPPLEMENTARY INFORMATION: 

Executive Summary

    The purpose of this regulatory action is to incorporate by 
reference into the NRC's regulations the latest revisions of three RGs. 
The three RGs identify new, revised, and reaffirmed Code Cases 
published by the ASME, which the NRC has determined are acceptable for 
use as alternatives to certain provisions of the ASME BPV Codes and 
ASME OM Codes, currently incorporated by reference into the NRC's 
regulations. The three RGs that the NRC is incorporating by reference 
are RG 1.84, ``Design, Fabrication, and Materials Code Case 
Acceptability, ASME Section III,'' Revision 37; RG 1.147, ``Inservice 
Inspection Code Case Acceptability, ASME Section XI, Division 1,'' 
Revision 18; and RG 1.192, ``Operation and Maintenance Code Case 
Acceptability, ASME OM Code,'' Revision 2. This regulatory action 
allows nuclear power plant licensees and applicants for construction 
permits, operating licenses, combined licenses, standard design 
certifications, standard design approvals, and manufacturing licenses 
to voluntarily use the Code Cases, newly listed in these revised RGs, 
as

[[Page 2332]]

alternatives to engineering standards for the design, construction, 
ISI, and IST, and repair/replacement of nuclear power plant components. 
In this notice, the NRC also notifies the public of the availability of 
RG 1.193, ``ASME Code Cases Not Approved for Use,'' Revision 5. The 
regulatory guide lists Code Cases that the NRC has not approved for 
generic use, and will not be incorporated by reference into the NRC's 
regulations.
    The NRC prepared a regulatory analysis (ADAMS Accession No. 
ML16285A013) to identify the benefits and costs associated with this 
final rule. The regulatory analysis prepared for this rulemaking was 
used to determine if the rule is cost-effective, overall, and to help 
the NRC evaluate potentially costly conditions placed on specific 
provisions of the ASME Code Cases, which are the subject of this 
rulemaking.

                      Table 1--Cost-Benefit Summary
------------------------------------------------------------------------
                                                        Alternative 2--
                                                            the rule
                                                        alternative net
                                                        benefits (costs)
                      Objective                           (net present
                                                           value, 7%
                                                         discount rate)
                                                          ($ million)
------------------------------------------------------------------------
Industry.............................................               2.42
NRC..................................................               2.52
Net Benefit..........................................               4.94
------------------------------------------------------------------------

    Table 1 summarizes the benefits and costs for the alternative of 
proceeding with the final rule (Alternative 2) and shows that the final 
rule is quantitatively cost-beneficial with a net benefit of $4.94 
million to both the industry and the NRC when compared to the 
regulatory baseline (Alternative 1). The regulatory analysis shows that 
implementing the final rule is quantitatively cost-effective and an 
efficient use of the NRC's and Industry's resources. Uncertainty 
analysis shows that the net benefit ranges from $2.86 million to $6.90 
million with a mean of $4.94 million. Because the rulemaking 
alternative is cost-effective, the rulemaking approach is recommended.
    There are several benefits associated with this final rule. Under 
this final rule, a licensee of a nuclear power plant would no longer be 
required to submit a Code Case alternative request under the new Sec.  
50.55a(z) of Title 10 of the Code of Federal Regulations (10 CFR), 
which would provide an averted cost of $7.75 million (7[dash]percent 
net present value) to the licensee. Additionally, the NRC would not 
receive Code Case alternative request submittals, which would provide 
an averted cost of $2.52 million (7[dash]percent net present value) to 
the NRC.

Table of Contents

I. Background
II. Discussion
    A. ASME Code Cases Approved for Unconditional Use
    B. ASME Code Cases Approved for Use with Conditions
    <bullet> ASME BPV Code, Section III Code Cases (RG 1.84)
    <bullet> ASME BPV Code, Section XI Code Cases (RG 1.147)
    <bullet> OM Code Cases (RG 1.192)
    C. ASME Code Cases not Approved for Use (RG 1.193)
III. Opportunities for Public Participation
IV. Public Comment Analysis
V. Section-by-Section Analysis
VI. Regulatory Flexibility Certification
VII. Regulatory Analysis
VIII. Backfitting and Issue Finality
IX. Plain Writing
X. Environmental Assessment and Final Finding of No Significant 
Environmental Impact
XI. Paperwork Reduction Act
XII. Congressional Review Act
XIII. Voluntary Consensus Standards
XIV. Incorporation by Reference--Reasonable Availability to 
Interested Parties
XV. Availability of Documents

I. Background

    The ASME develops and publishes the ASME BPV Code, which contains 
requirements for the design, construction, and ISI and examination of 
nuclear power plant components, and ASME's Nuclear Power Plants (OM) 
Code,\1\ which contains requirements for IST of nuclear power plant 
components. In response to BPV Code and OM Code user requests, the ASME 
develops Code Cases that provide alternatives to BPV Code and OM Code 
requirements under special circumstances.
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    \1\ The editions and addenda of the ASME Code for Operation and 
Maintenance of Nuclear Power Plants have had different titles from 
2005 to 2012, and are referred to collectively in this rule as the 
``OM Code.''
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    The NRC approves and can mandate the use of the ASME BPV Codes and 
OM Codes in Sec.  50.55a, ``Codes and standards,'' through the process 
of incorporation by reference. As such, each provision of the ASME 
Codes incorporated by reference into and mandated by Sec.  50.55a 
constitutes a legally[dash]binding NRC requirement imposed by the 
regulations. As noted previously, ASME Code Cases, for the most part, 
represent alternative approaches for complying with provisions of the 
ASME BPV Codes 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 alternatives to the BPV Codes and 
OM Codes.\2\
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    \2\ See Federal Register notice, ``Incorporation by Reference of 
ASME BPV and OM Code Cases'' (68 FR 40469; July 8, 2003).
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    This rulemaking is the latest in a series of rulemakings that 
incorporates 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 staff reviews 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 and are published 
by the ASME. The NRC incorporates by reference the RGs, listing 
acceptable and conditionally acceptable ASME Code Cases into Sec.  
50.55a. Currently, NRC RG 1.84, ``Design, Fabrication, and Materials 
Code Case Acceptability, ASME Section III,'' Revision 36; RG 1.147, 
``Inservice Inspection Code Case Acceptability, ASME Section XI, 
Division 1,'' Revision 17; and RG 1.192, ``Operation and Maintenance 
Code Case Acceptability, ASME OM Code,'' Revision 1, are incorporated 
into the NRC's regulations in Sec.  50.55a.
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    \3\ Code Cases are categorized by ASME as one of three types: 
new, revised, or reaffirmed. A new Code Case provides for a new 
alternative to specific 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 to be one that does not have any change to technical 
content, but includes editorial changes.
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II. Discussion

    This rule incorporates by reference the latest revisions of the NRC 
RGs that list ASME BPV and OM Code Cases that the NRC finds to be 
acceptable, or acceptable with NRC[dash]specified conditions 
(``conditionally acceptable''). Regulatory Guide 1.84, Revision 37, 
supersedes Revision 36; RG 1.147, Revision 18, supersedes Revision 17; 
and RG 1.192, Revision 2, supersedes Revision 1. The NRC also publishes 
a document (RG 1.193, ``ASME Code Cases Not Approved for Use'') that 
lists Code Cases that the NRC has not approved for generic use. The RG 
1.193 is not incorporated by reference into the NRC's regulations; 
however, in this final rule, the NRC notes the availability of RG 
1.193, Revision 5.
    The ASME Code Cases that are the subject of this rulemaking are the 
new, revised, and reaffirmed Section III and Section XI Code Cases 
listed in

[[Page 2333]]

Supplement 11 to the 2007 BPV Code through Supplement 10 to the 2010 
BPV Code, and the OM Code Cases published with the 2009 Edition through 
the 2012 Edition.
    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 rule 
incorporates by reference the latest revisions of RGs 1.84, 1.147, and 
1.192. This rule allows nuclear power plant licensees and applicants 
for construction permits, operating licenses, combined licenses, 
standard design certifications, standard design approvals, and 
manufacturing licenses, under the regulations that govern license 
certifications, to voluntarily use the Code Cases listed in these RGs 
as suitable alternatives to certain provisions of the ASME BPV and OM 
Codes for the construction, ISI, and IST of nuclear power plant 
components. This action is consistent with the provisions of the 
National Technology Transfer and Advancement Act of 1995 (NTTAA), 
Public Law 104-113, which encourages Federal regulatory agencies to 
consider adopting industry consensus standards as an alternative to de 
novo agency development of standards affecting an industry. This action 
is also consistent with the NRC policy of evaluating the latest 
versions of consensus standards, in terms of their suitability for 
endorsement by regulations or regulatory guides.
    The NRC follows a three-step process to determine acceptability of 
new, revised, and reaffirmed Code Cases, and the need for regulatory 
positions on the use of these Code Cases. This process was employed in 
the review of the Code Cases in Supplement 11 to the 2007 Edition 
through Supplement 10 to the 2010 Edition of the BPV Code and the 2009 
Edition through the 2012 Edition of the OM Code. The Code Cases in 
these supplements and OM Editions and Addenda are the subject of this 
rule. First, the ASME develops Code Cases through a consensus 
development process, as administered by the American National Standards 
Institute (ANSI), which ensures that the various technical interests 
(e.g., utility, manufacturing, insurance, regulatory) are represented 
on standards development committees and that their view points are 
addressed fairly. The NRC staff actively participates in discussions 
and technical debates of the task groups, working groups, subgroups, 
and standards committees regarding the development of new and revised 
standards. The Code Case process includes the development of a 
technical justification in support of each new or revised Code Case. 
The ASME committee meetings are open to the public and attendees are 
encouraged to participate. Task groups, working groups, and subgroups 
report to respective standards committees. The standards committee is 
the decisive consensus committee in that it ensures that the 
development process fully complies with the ANSI consensus process.
    Second, the standards committee transmits a first consideration 
letter ballot to every member of the standards committee, requesting 
comment or approval of new and revised Code Cases. Code Cases are 
approved by the standards committee from the first consideration letter 
ballot when: (1) At least two thirds of the eligible consensus 
committee membership vote approved; (2) there are no disapprovals from 
the standards committee; and (3) no substantive comments are received 
from the ASME oversight committees such as the Technical Oversight 
Management Committee (TOMC). The TOMC's duties, in part, are to oversee 
various standards committees to ensure technical adequacy and to 
provide recommendations in the development of codes and standards, as 
required. Code Cases that were disapproved or received substantive 
comments from the first consideration ballot are reviewed by the 
working level group(s) responsible for their development to consider 
the comments received. These Code Cases are approved by the standards 
committee on second consideration when at least two thirds of the 
eligible consensus committee membership vote approved, and there are no 
more than three disapprovals from the consensus committee.
    Third, the NRC reviews new, revised, and reaffirmed Code Cases to 
determine their acceptability for incorporation by reference in Sec.  
50.55a through the subject RGs. This rulemaking process, when 
considered together with the ANSI process for developing and approving 
the ASME codes and standards, and Code Cases, constitutes the NRC's 
basis that the Code Cases (with conditions as necessary) provide 
reasonable assurance of adequate protection to public health and 
safety.
    The staff concludes, in accordance with the process described, that 
the Code Cases are technically adequate (with conditions as necessary) 
and consistent with current NRC regulations, and the staff is 
referencing these Code Cases in the applicable RGs, thereby approving 
them for voluntary use, without conditions as addressed in Section A of 
this document; subject to the specified conditions, or as identified in 
Section B of this document. The staff reviewed the new, revised, and 
reaffirmed Code Cases identified in the three RGs being incorporated by 
reference into Sec.  50.55a in this rulemaking. Therefore, the NRC 
approves revising the Sec.  50.55a regulations to incorporate by 
reference the latest revisions of RGs 1.84, 1.147, and 1.192. 
Additionally, the NRC announces the availability of the latest revision 
of RG 1.193.

A. ASME Code Cases Approved for Unconditional Use

    The Code Cases that are discussed in Table I are new, revised, or 
reaffirmed Code Cases that the NRC is approving for use without 
conditions. The NRC concludes, in accordance with the process described 
for review of ASME Code Cases, that each of the ASME Code Cases listed 
in Table I are acceptable for use without conditions. Therefore, the 
NRC is approving for unconditional use the Code Cases listed in Table 
I. This table identifies the regulatory guide the applicable Code Case 
that the NRC is approving for use.
    The NRC revised RG 1.147, Revision 18 to approve Code Case N-786-1 
in Table 1 to address inconsistencies that were identified between the 
NRC's position in the proposed rule regarding the acceptability of Code 
Case N-786 and several licensee requests for alternatives to ASME Code 
requirements, in accordance with Title 10 of the Code of Federal 
Regulations (10 CFR) 50.55a(z), that have utilized Code Case N-786. The 
NRC had authorized the use of Code Case N-786 with modifications. The 
NRC erred in not listing N-786 in DG-1296, Table 2 ``Conditionally 
Acceptable Section XI Code Cases'' with appropriate conditions, in 
order to be consistent with modifications that the NRC has required for 
requested alternatives based on Code Case N-786. In response to 
modifications to N-786 by licensees requesting to use this code case as 
an alternative to ASME Code, ASME revised the code case. The revised 
Code Case, N-786-1 ``Alternative Requirements for Sleeve Reinforcement 
of Class 2 and 3 Moderate[dash]Energy Carbon Steel Piping Section XI, 
Division 1,'' includes modifications that address all of the NRC's 
concerns that the NRC identified in previously approved alternatives 
that were based on N-786. Therefore, the NRC has listed Code Case N-
786-1 in Table 1 of RG 1.147 Revision 18 in lieu of code Case N-786. 
There were no public comments

[[Page 2334]]

received on the inclusion of N-786 in the RG. Code Case N-786-1 is 
included in this final rule because it includes the latest ASME 
guidance and the NRC conditions on the use of this method of repair.

         Table I--ASME Code Cases Approved for Unconditional Use
------------------------------------------------------------------------
         Code Case No.              Supplement             Title
------------------------------------------------------------------------
               Boiler and Pressure Vessel Code Section III
              (addressed in RG 1.84, Revision 37, Table 1)
------------------------------------------------------------------------
N-284-3.......................  7 (10 Edition)...  Metal Containment
                                                    Shell Buckling
                                                    Design Methods,
                                                    Class MC, TC, and SC
                                                    Construction,
                                                    Section III,
                                                    Divisions 1 and 3.
N-500-4.......................  8 (10 Edition)...  Alternative Rules for
                                                    Standard Supports
                                                    for Classes 1, 2, 3,
                                                    and MC, Section III,
                                                    Division 1.
N-520-5.......................  10 (10 Edition)..  Alternative Rules for
                                                    Renewal of Active or
                                                    Expired N-type
                                                    Certificates for
                                                    Plants Not in Active
                                                    Construction,
                                                    Section III,
                                                    Division 1.
N-594-1.......................  8 (10 Edition)...  Repairs to P-4 and P-
                                                    5A Castings without
                                                    Postweld Heat
                                                    Treatment Class 1,
                                                    2, and 3
                                                    Construction,
                                                    Section III,
                                                    Division 1.
N-637-1.......................  3 (10 Edition)...  Use of 44Fe-25Ni-21Cr-
                                                    Mo (Alloy UNS
                                                    N08904) Plate, Bar,
                                                    Fittings, Welded
                                                    Pipe, and Welded
                                                    Tube, Classes 2 and
                                                    3, Section III,
                                                    Division 1.
N-655-2.......................  4 (10 Edition)...  Use of SA-738, Grade
                                                    B, for Metal
                                                    Containment Vessels,
                                                    Class MC, Section
                                                    III, Division 1.
N-763.........................  2 (10 Edition)...  ASTM A 709-06, Grade
                                                    HPS 70W (HPS 485W)
                                                    Plate Material
                                                    Without Postweld
                                                    Heat Treatment as
                                                    Containment Liner
                                                    Material or
                                                    Structural
                                                    Attachments to the
                                                    Containment Liner,
                                                    Section III,
                                                    Division 2.
N-777.........................  4 (10 Edition)...  Calibration of Cv
                                                    Impact Test
                                                    Machines, Section
                                                    III, Divisions 1, 2,
                                                    and 3.
N-785.........................  11 (07 Edition)..  Use of SA-479/SA-
                                                    479M, UNS S41500 for
                                                    Class 1 Welded
                                                    Construction,
                                                    Section III,
                                                    Division 1.
N-811.........................  7 (10 Edition)...  Alternative
                                                    Qualification
                                                    Requirements for
                                                    Concrete Level III
                                                    Inspection
                                                    Personnel, Section
                                                    III, Division 2.
N-815.........................  8 (10 Edition)...  Use of SA-358/SA-358M
                                                    Grades Fabricated as
                                                    Class 3 or Class 4
                                                    Welded Pipe, Class
                                                    CS Core Support
                                                    Construction,
                                                    Section III,
                                                    Division 1.
N-816.........................  8 (10 Edition)...  Use of Temper Bead
                                                    Weld Repair Rules
                                                    Adopted in 2010
                                                    Edition and Earlier
                                                    Editions, Section
                                                    III, Division 1.
N-817.........................  8 (10 Edition)...  Use of Die Forgings,
                                                    SB-247, UNS A96061
                                                    Class T6, With
                                                    Thickness <= 4.000
                                                    in. Material, Class
                                                    2 Construction (1992
                                                    Edition or Later),
                                                    Section III,
                                                    Division 1.
N-819.........................  8 (10 Edition)...  Use of Die Forgings,
                                                    SB-247, UNS A96061
                                                    Class T6, With
                                                    Thickness <= 4.000
                                                    in. Material, Class
                                                    2 Construction (1989
                                                    Edition with the
                                                    1991 Addenda or
                                                    Earlier), Section
                                                    III, Division 1.
N-822.........................  8 (10 Edition)...  Application of the
                                                    ASME Certification
                                                    Mark, Section III,
                                                    Divisions 1, 2, 3,
                                                    and 5.
------------------------------------------------------------------------
               Boiler and Pressure Vessel Code Section XI
              (addressed in RG 1.147, Revision 18, Table 1)
------------------------------------------------------------------------
N-609-1.......................  3 (10 Edition)...  Alternative
                                                    Requirements to
                                                    Stress-Based
                                                    Selection Criteria
                                                    for Category B-J
                                                    Welds, Section XI,
                                                    Division 1.
N-613-2.......................  4 (10 Edition)...  Ultrasonic
                                                    Examination of Full
                                                    Penetration Nozzles
                                                    in Vessels,
                                                    Examination Category
                                                    B-D, Reactor
                                                    Nozzle[dash]To[dash]
                                                    Vessel Welds, and
                                                    Nozzle Inside Radius
                                                    Section Figs. IWB-
                                                    2500-7(a), (b), (c),
                                                    and (d), Section XI,
                                                    Division 1.
N-652-2.......................  9 (10 Edition)...  Alternative
                                                    Requirements to
                                                    Categorize B-G-1, B-
                                                    G-2, and C-D Bolting
                                                    Examination Methods
                                                    and Selection
                                                    Criteria, Section
                                                    XI, Division 1.
N-653-1.......................  9 (10 Edition)...  Qualification
                                                    Requirements for
                                                    Full Structural
                                                    Overlaid Wrought
                                                    Austenitic Piping
                                                    Welds, Section XI,
                                                    Division 1.
N-694-2 \4\...................  1 (13 Edition)...  Evaluation Procedure
                                                    and Acceptance
                                                    Criteria for
                                                    [pressurized water
                                                    reactors] (PWR)
                                                    Reactor Vessel Head
                                                    Penetration Nozzles,
                                                    Section XI, Division
                                                    1.
N-730-1.......................  10 (10 Edition)..  Roll Expansion of
                                                    Class 1 Control Rod
                                                    Drive Bottom Head
                                                    Penetrations in
                                                    [boiling water
                                                    reactors] BWRs,
                                                    Section XI, Division
                                                    1.
N-769-2.......................  10 (10 Edition)..  Roll Expansion of
                                                    Class 1 In[dash]Core
                                                    Housing Bottom Head
                                                    Penetrations in
                                                    BWRs, Section XI,
                                                    Division 1.
N-771.........................  7 (10 Edition)...  Alternative
                                                    Requirements for
                                                    Additional
                                                    Examinations of
                                                    Class 2 or 3 Items,
                                                    Section XI, Division
                                                    1.
N-775.........................  2 (10 Edition)...  Alternative
                                                    Requirements for
                                                    Bolting Affected by
                                                    Borated Water
                                                    Leakage, Section XI,
                                                    Division 1.
N-776.........................  1 (10 Edition)...  Alternative to IWA-
                                                    5244 Requirements
                                                    for Buried Piping,
                                                    Section XI, Division
                                                    1.
N-786-1.......................  5 (10 Edition)...  Alternative
                                                    Requirements for
                                                    Sleeve Reinforcement
                                                    of Class 2 and 3
                                                    Moderate-Energy
                                                    Carbon Steel Piping,
                                                    Section XI, Division
                                                    1.

[[Page 2335]]

 
N-798.........................  4 (10 Edition)...  Alternative Pressure
                                                    Testing Requirements
                                                    for Class 1 Piping
                                                    Between the First
                                                    and Second Vent,
                                                    Drain, and Test
                                                    Isolation Devices,
                                                    Section XI, Division
                                                    1.
N-800.........................  4 (10 Edition)...  Alternative Pressure
                                                    Testing Requirements
                                                    for Class 1 Piping
                                                    Between the First
                                                    and Second Injection
                                                    Valves, Section XI,
                                                    Division 1.
N-803.........................  5 (10 Edition)...  Similar and
                                                    Dissimilar Metal
                                                    Welding Using
                                                    Ambient Temperature
                                                    Automatic or Machine
                                                    Dry Underwater Laser
                                                    Beam Welding (ULBW)
                                                    Temper Bead
                                                    Technique, Section
                                                    XI, Division 1.
N-805.........................  6 (10 Edition)...  Alternative to Class
                                                    1 Extended Boundary
                                                    End of Interval or
                                                    Class 2 System
                                                    Leakage Testing of
                                                    the Reactor Vessel
                                                    Head Flange O-Ring
                                                    Leak-Detection
                                                    System, Section XI,
                                                    Division 1.
N-823.........................  9 (10 Edition)...  Visual Examination,
                                                    Section XI, Division
                                                    1.
N-825 \5\.....................  3 (13 Edition)...  Alternative
                                                    Requirements for
                                                    Examination of
                                                    Control Rod Drive
                                                    Housing Welds,
                                                    Section XI, Division
                                                    1.
N-845 \6\.....................  6 (13 Edition)...  Qualification
                                                    Requirements for
                                                    Bolts and Studs,
                                                    Section XI, Division
                                                    1.
------------------------------------------------------------------------
                   Operation and Maintenance Code (OM)
              (addressed in RG 1.192, Revision 2, Table 1)
------------------------------------------------------------------------
OMN-2.........................  2012 Edition.....  Thermal Relief Valve
                                                    Code Case, OM Code-
                                                    1995, Appendix I.
OMN-5.........................  2012 Edition.....  Testing of Liquid
                                                    Service Relief
                                                    Valves without
                                                    Insulation.
OMN-6.........................  2012 Edition.....  Alternative Rules for
                                                    Digital Instruments.
OMN-7.........................  2012 Edition.....  Alternative
                                                    Requirements for
                                                    Pump Testing.
OMN-8.........................  2012 Edition.....  Alternative Rules for
                                                    Preservice and
                                                    Inservice Testing of
                                                    Power-Operated
                                                    Valves That Are Used
                                                    for System Control
                                                    and Have a Safety
                                                    Function per OM-10,
                                                    ISTC-1.1, or ISTA-
                                                    1100.
OMN-13, Revision 2............  2012 Edition.....  Performance-Based
                                                    Requirements for
                                                    Extending Snubber
                                                    Inservice Visual
                                                    Examination Interval
                                                    at [light water
                                                    reactor] LWR Power
                                                    Plants.
OMN-14........................  2012 Edition.....  Alternative Rules for
                                                    Valve Testing
                                                    Operations and
                                                    Maintenance,
                                                    Appendix I: BWR
                                                    [control rod drive]
                                                    CRD Rupture Disk
                                                    Exclusion.
OMN-15, Revision 2............  2012 Edition.....  Performance-Based
                                                    Requirements for
                                                    Extending the
                                                    Snubber Operational
                                                    Readiness Testing
                                                    Interval at LWR
                                                    Power Plants.
OMN-17........................  2012 Edition.....  Alternative Rules for
                                                    Testing ASME Class 1
                                                    Pressure Relief/
                                                    Safety Valves.
------------------------------------------------------------------------

B. ASME Code Cases Approved for Use With Conditions

    The Code Cases that are discussed in Table II, below, are new, 
revised or reaffirmed Code Cases, which the NRC is approving 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 is imposing conditions on the use of these 
Code Cases to modify, limit, or clarify their requirements. The 
conditions specify, for each applicable Code Case, the additional 
activities that must be performed, the limits on the activities 
specified in the Code Case, and the supplemental information needed to 
provide clarity. These ASME Code Cases with conditions are included in 
Table 2 of each RG (i.e., RG 1.84, RG 1.147, and RG 1.192). It is noted 
that both RG 1.147 and RG 1.192 have new ASME Code Cases with 
conditions; however, there are no new ASME Code Cases with conditions 
for RG 1.84.
---------------------------------------------------------------------------

    \4\ Code Case published in Supplement 1 to the 2013 Edition; 
included at the request of ASME.
    \5\ Code Case published in Supplement 3 to the 2013 Edition; 
included at the request of ASME.
    \6\ Code Case published in Supplement 6 to the 2013 Edition; 
included at the request of ASME.

            Table II--Code Cases Approved for Conditional Use
------------------------------------------------------------------------
         Code Case No.              Supplement             Title
------------------------------------------------------------------------
               Boiler and Pressure Vessel Code Section III
              (addressed in RG 1.84, Revision 37, Table 2)
------------------------------------------------------------------------
 No ASME Section III Code Cases are approved for conditional use in this
                                  rule.
               Boiler and Pressure Vessel Code Section XI
              (addressed in RG 1.147, Revision 18, Table 2)
------------------------------------------------------------------------
N-552-1.......................  10 (10 Edition)..  Alternative Methods--
                                                    Qualification for
                                                    Nozzle Inside Radius
                                                    Section from the
                                                    Outside Surface,
                                                    Section XI, Division
                                                    1.
N-576-2.......................  9 (10 Edition)...  Repair of Class 1 and
                                                    2 SB-163, UNS N06600
                                                    Steam Generator
                                                    Tubing, Section XI,
                                                    Division 1.
N-593-2.......................  8 (10 Edition)...  Examination
                                                    Requirements for
                                                    Steam Generator
                                                    Nozzle-to-Vessel
                                                    Welds, Section XI,
                                                    Division 1.

[[Page 2336]]

 
N-638-6.......................  6 (10 Edition)...  Similar and
                                                    Dissimilar Metal
                                                    Welding Using
                                                    Ambient Temperature
                                                    Machine GTAW Temper
                                                    Bead Technique,
                                                    Section XI, Division
                                                    1.
N-662-1.......................  6 (10 Edition)...  Alternative Repair/
                                                    Replacement
                                                    Requirements for
                                                    Items Classified in
                                                    Accordance with Risk-
                                                    Informed Processes,
                                                    Section XI, Division
                                                    1.
N-666-1.......................  9 (10 Edition)...  Weld Overlay of
                                                    Classes 1, 2, and 3
                                                    Socket Welded
                                                    Connections, Section
                                                    XI, Division 1.
N-749.........................  9 (10 Edition)...  Alternative
                                                    Acceptance Criteria
                                                    for Flaws in
                                                    Ferritic Steel
                                                    Components Operating
                                                    in the Upper Shelf
                                                    Temperature Range,
                                                    Section XI, Division
                                                    1.
N-754.........................  6 (10 Edition)...  Optimized Structural
                                                    Dissimilar Metal
                                                    Weld Overlay for
                                                    Mitigation of PWR
                                                    Class 1 Items,
                                                    Section XI, Division
                                                    1.
N-778.........................  6 (10 Edition)...  Alternative
                                                    Requirements for
                                                    Preparation and
                                                    Submittal of
                                                    Inservice Inspection
                                                    Plans, Schedules,
                                                    and Preservice and
                                                    Inservice Summary
                                                    Reports, Section XI,
                                                    Division 1.
N-789.........................  6 (10 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-795.........................  3 (10 Edition)...  Alternative
                                                    Requirements for BWR
                                                    Class 1 System
                                                    Leakage Test
                                                    Pressure Following
                                                    Repair/Replacement
                                                    Activities, Section
                                                    XI, Division 1.
N-799.........................  4 (10 Edition)...  Dissimilar Metal
                                                    Welds Joining Vessel
                                                    Nozzles to
                                                    Components, Section
                                                    XI, Division 1.
------------------------------------------------------------------------
                   Operation and Maintenance Code (OM)
              (addressed in RG 1.192, Revision 2, Table 2)
------------------------------------------------------------------------
OMN-1 Revision 1..............  2012 Edition.....  Alternative Rules for
                                                    Preservice and
                                                    Inservice Testing of
                                                    Active Electric
                                                    Motor Operated-Valve
                                                    Assemblies in
                                                    Light[dash]Water
                                                    Reactor Power
                                                    Plants.
OMN-3.........................  2012 Edition.....  Requirements for
                                                    Safety Significance
                                                    Categorization of
                                                    Components Using
                                                    Risk Insights for
                                                    Inservice Testing of
                                                    LWR Power Plants.
OMN-4.........................  2012 Edition.....  Requirements for Risk
                                                    Insights for
                                                    Inservice Testing of
                                                    Check Valves at LWR
                                                    Power Plants.
OMN-9.........................  2012 Edition.....  Use of a Pump Curve
                                                    for Testing.
OMN-12........................  2012 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-16 Revision 1.............  2012 Edition.....  Use of a Pump Curve
                                                    for Testing.
OMN-18........................  2012 Edition.....  Alternate Testing
                                                    Requirements for
                                                    Pumps Tested
                                                    Quarterly Within
                                                    <plus-minus>20% of
                                                    Design Flow.
OMN-19........................  2012 Edition.....  Alternative Upper
                                                    Limit for the
                                                    Comprehensive Pump
                                                    Test.
OMN-20........................  2012 Edition.....  Inservice Test
                                                    Frequency.
------------------------------------------------------------------------

    The NRC's evaluation of the Code Cases and the reasons for the 
NRC's conditions are discussed in the following paragraphs. Notations 
have been made to indicate the conditions duplicated from previous 
versions of the RG.
ASME BPV Code, Section III Code Cases (RG 1.84)
    There are no new or revised Section III Code Cases in Supplement 11 
to the 2007 Edition through Supplement 10 to the 2010 Edition that the 
NRC is conditionally approving in Revision 37 of RG 1.84.
ASME BPV Code, Section XI Code Cases (RG 1.147)
Code Case N-552-1 [Supplement 10, 2010 Edition]
    Type: Revised.
    Title: Alternative Methods--Qualification for Nozzle Inside Radius 
Section from the Outside Surface, Section XI, Division 1.
    The conditions on Code Case N-552-1 are identical to the conditions 
on N-552 that were approved by the NRC in Revision 16 of RG 1.147 in 
October 2010. The reasons for imposing these conditions in Code Case N-
576 continue to apply to N-576-2. Therefore, these conditions have been 
retained for this Code Case in Revision 18 of RG 1.147.
Code Case N-576-2 [Supplement 9, 2010 Edition]
    Type: Revised.
    Title: Repair of Class 1 and 2 SB-163, UNS N06600 Steam Generator 
Tubing, Section XI, Division 1.
    The conditions on Code Case N-576-2 are identical to the conditions 
on N-576-1 that were approved by the NRC in Revision 17 of RG 1.147 in 
October 2014. The reasons for imposing these conditions are not 
resolved by Code Case N-576-2 and, therefore, these conditions have 
been retained in Revision 18 of RG 1.147.
    Public comments on N-576-2 requested that the NRC revise the 
proposed condition to follow IWA-4200 in their code of record. In 
response, the NRC revised the ``note'' in the condition in Revision 18 
of RG 1.147 to eliminate the portion regarding reconciliation. The 
revised ``note'' will read: ``Note: Steam generator tube repair methods 
require prior NRC approval through the Technical Specifications. This 
Code Case does not address certain aspects of this repair, e.g., the 
qualification of the inspection and plugging criteria necessary for 
staff approval of the repair method.''

[[Page 2337]]

Code Case N-593-2 [Supplement 8, 2010 Edition]
    Type: Revised.
    Title: Examination Requirements for Steam Generator Nozzle-to-
Vessel Welds, Section XI, Division 1.
    The first condition on Code Case N-593-2 is identical to the 
condition on Code Case N-593 that was first approved by the NRC in 
Revision 13 of RG 1.147 in June 2003. The condition stated that, 
``Essentially 100 percent (not less than 90 percent) of the examination 
volume A-B-C-D-E-F-G-H [in Figure 1 of the Code Case] must be 
examined.'' The reasons for imposing this condition in Code Case N-593 
continue to apply to Code Case N-593-2. Therefore, this condition has 
been retained for this Code Case in Revision 18 of RG 1.147.
    The second condition on Code Case N-593-2 is new. Revision 2 of the 
Code Case reduces the weld examination volume by reducing the width 
examined on either side of the weld from t<INF>s</INF>/2 to \1/2\ in. 
The basis for this change in inspection volume is to revise the 
examination volume for steam generator nozzle[dash]to[dash]vessel welds 
(under Code Case N-593-2) to be consistent with that specified in Code 
Case N-613-1 for similar vessel nozzles.
    The NRC identified an issue with respect to Code Case N-593-2 
regarding its inconsistency with Code Case N-613-1. Code Case N-593-2 
and Code Case N-613-1 address certain types of nozzle-to-vessel welds. 
Code Case N-613-1 states that ``. . . Category B-D nozzle-to-vessel 
welds previously ultrasonically examined using the examination volumes 
of Figs. IWB-2500-7(a), (b), and (c) may be examined using the reduced 
examination volume (A-B-C-D-E-F-G-H) of Figs. 1, 2, and 3.'' The 
keywords are ``previously examined.'' Code Case N-613-1 requires the 
larger volume to have been previously examined before examinations 
using the reduced volume can be performed. This ensures that there are 
no detrimental flaws in the component adjacent to the weld that would 
be missed if the inspection was performed only on the reduced volume. 
However, Code Case N-593-2 allows a licensee to immediately implement 
the reduced volume. Accordingly, the NRC is approving Code Case N-593-2 
with a condition to require that the examination volume specified in 
Section XI, Table IWB-2500-1, Examination Category B-D, be used for the 
examination of steam generator nozzle[dash]to[dash]vessel welds at 
least once prior to use of the reduced volume, as allowed by the Code 
Case.
Code Case N-638-6 [Supplement 6, 2010 Edition]
    Type: Revised.
    Title: Similar and Dissimilar Metal Welding Using Ambient 
Temperature Machine GTAW Temper Bead Technique, Section XI, Division 1.
    Code Case N-638-6 allows the use of the automatic or machine gas-
tungsten arc welding (GTAW) temper bead technique. The GTAW is a proven 
method that can produce high-quality welds because it affords greater 
control over the weld area than many other welding processes.
    The NRC first approved Code Case N-638 (Revision 0) in 2003 
(Revision 13 of RG 1.147). Code Case N-638-4 was approved by the NRC in 
Revision 16 of RG 1.147 with two conditions. Code Case N-638-5 was not 
approved in RG 1.147 for generic use but has been approved through 
requests for an alternative to Sec.  50.55a. Code Case N-638-6 resolves 
one of the NRC's concerns that were raised when Code Case N-638-4 was 
considered for approval and, therefore, the NRC is deleting that 
condition from RG 1.147.
    Many of the provisions for developing and qualifying welding 
procedure specifications for the temper bead technique that were 
contained in earlier versions of the Code Case have been incorporated 
into ASME Section IX, ``Welding and Brazing Qualifications,'' QW-290, 
``Temper Bead Welding.'' Code Case N-638-6 retains the provisions not 
addressed by QW-290 and references QW-290 in lieu of specifying them 
directly in the Code Case.
    In addition to retaining one of the two conditions on Code Case N-
638-4, the NRC considered adding a new condition to address technical 
issues raised by certain provisions of Code Case N-638-6.
    The retained condition on Code Case N-638-6 pertains to the 
qualification of nondestructive evaluation (NDE) and is identical to 
the condition on N-638-4 that was approved by the NRC in Revision 17 of 
RG 1.147 in October 2014. The reasons for imposing this condition in 
Code Case N-638 continue to apply to N-638-6. Therefore, this condition 
has been retained in Revision 18 of RG 1.147.
    The new proposed condition (2) states that section 1(b)(1) of the 
Code Case shall not be used. Section 1(b)(1) would allow through-wall 
circumferential repair welds to be made using the temper bead technique 
without heat treatment. Revisions 1 through 5 of N-638 limited the 
depth of the weld to one-half of the ferritic base metal thickness and 
the previously stated condition will limit repairs to this previously 
approved value. Repairs exceeding one-half of the ferritic base metal 
thickness may represent significant repairs (e.g., replacement of an 
entire portion of the reactor coolant loop). At the time that this 
revision of the Code Case was approved by ASME, the NRC staff had 
concerns related to through-wall repairs. Subsequently, through further 
evaluation related to a separate rulemaking, the NRC resolved its 
concerns related to through-wall repairs. Therefore, the NRC determined 
that proposed Condition (2) is unnecessary and has removed this 
condition from the final RG 1.147, Revision 18.
Code Case N-662-1 [Supplement 6, 2010 Edition]
    Type: Revised.
    Title: Alternative Repair/Replacement Requirements for Items 
Classified in Accordance with Risk-Informed Processes, Section XI, 
Division 1.
    The condition on Code Case N-662-1 is identical to the condition on 
N-662 that was approved by the NRC in Revision 16 of RG 1.147 in 
October 2010. The reasons for imposing this condition were not resolved 
by Code Case N-662-1. Therefore, this condition has been retained for 
this Code Case in Revision 18 of RG 1.147.
Code Case N-666-1 [Supplement 9, 2010 Edition]
    Type: Revised.
    Title: Weld Overlay of Classes 1, 2, and 3 Socket Welded 
Connections, Section XI, Division 1.
    Code Case N-666 was unconditionally approved in Revision 17 of RG 
1.147. The NRC approves Code Case N-666-1 with one condition.
    The condition is that a surface examination must be performed on 
the completed weld overlay for Class 1 and Class 2 piping socket welds. 
Code Case N-666-1 contains provisions for the design, installation, 
evaluation, pressure testing, and examination of the weld overlays on 
Class 1, 2, and 3 socket welds. Section 5(a)(1) of the Code Case 
requires NDE of the completed weld overlay in accordance with the 
Construction Code. However, various Construction Codes have been used 
in the design and fabrication of the nuclear power plant fleet. The 
requirements for NDE have changed over the years, as more effective and 
reliable methods and techniques have been developed. In addition, 
Construction Code practices have evolved based on design and 
construction experience. The NRC is concerned that some of the 
Construction

[[Page 2338]]

Codes would not require a surface examination of the weld overlay and 
would, therefore, be inadequate for NDE of the completed weld overlay. 
The NRC believes that a VT-1 examination alone would not be adequate 
and that a surface or volumetric examination must be performed on the 
completed weld overlay for Class 1 and Class 2 piping socket welds. 
Fabrication defects must be dispositioned using the surface or 
volumetric examination criteria of the Construction Code, as identified 
in the Repair/Replacement Plan.
    Public commenters requested that the words ``and seal weld'' be 
removed from the condition because the phrase implies that the seal 
weld requires surface examination in addition to surface examination of 
the final overlay. The Code Case requires a visual examination of the 
seal weld, remaining socket weld, and adjacent base material before the 
weld overlay can be applied, which the NRC has determined is the 
appropriate examination prior to the application of the weld overlay. 
Therefore, proposed Condition (1) has been revised to remove ``and seal 
weld.''
    In the proposed rule, the NRC included a second condition, which 
required that if a surface or volumetric examination of the completed 
weld overlay was not required by the plant-specific Construction Code, 
that a VT-1 visual examination be performed of the weld overlay. 
Paragraph 5(a) of the Code Case requires ``visual and nondestructive 
examination of the final structural overlay weld.'' Paragraph 5(a)(1) 
of the Code Case specifically requires a VT-1 visual examination of the 
completed weld overlay. Public commenters requested that the NRC remove 
the second condition because it was redundant and unnecessary. The NRC 
staff agrees and thus Condition (2) has been removed from the final 
rule.
Code Case N-749 [Supplement 9, 2010 Edition]
    Type: New.
    Title: Alternative Acceptance Criteria for Flaws in Ferritic Steel 
Components Operating in the Upper Shelf Temperature Range, Section XI, 
Division 1.
    The NRC has determined that instead of the upper shelf transition 
temperature, T<INF>c</INF>, as defined in the Code Case, the following 
shall be used:

T<INF>c</INF> = 154.8 [deg]F + 0.82 x RT<INF>NDT</INF> (in U.S 
Customary Units), and
T<INF>c</INF> = 82.8 [deg]C + 0.82 x RT<INF>NDT</INF> (in International 
System (SI) Units).

    T<INF>c</INF> is the temperature above which the elastic plastic 
fracture mechanics (EPFM) method must be applied. Additionally, the NRC 
defines temperature T<INF>c1</INF> below, which the linear elastic 
fracture mechanics (LEFM) method must be applied:

T<INF>c1</INF> = 95.36 [deg]F + 0.703 x RT<INF>NDT</INF> (in U.S 
Customary Units), and
T<INF>c1</INF> = 47.7 [deg]C + 0.703 x RT<INF>NDT</INF> (in 
International System (SI) Units).

    Between T<INF>c1</INF> and T<INF>c</INF>, while the fracture mode 
is in transition from LEFM to EPFM, users should consider whether or 
not it is appropriate to apply the EPFM method. Alternatively, the 
licensee may use a different T<INF>c</INF> value, if it can be 
justified by plant[dash]specific Charpy curves.
    Code Case N-749 provides acceptance criteria for flaws in ferritic 
components for conditions when the material fracture resistance will be 
controlled by upper-shelf toughness behavior. These procedures may be 
used to accept a flaw in lieu of the requirements in Section XI, 
paragraphs IWB-3610 and IWB-3620, which use LEFM to evaluate flaws that 
exceed limits of Section XI, paragraph IWB-3500. Code Case N-749 
employs EPFM methods (J[dash]integral) and is patterned after the 
fracture methodology and acceptance criteria that currently exist in 
Section XI, paragraph IWB-3730(b), and Section XI, Nonmandatory 
Appendix K, ``Assessment of Reactor Vessels with Upper Shelf Charpy 
Impact Energy Levels.'' The Code Case states that the proposed 
methodology is applicable if the metal temperature of the component 
exceeds the upper shelf transition temperature, T<INF>c</INF>, which is 
defined as nil-ductility reference temperature (RT<INF>NDT</INF>) plus 
105 degrees F. The justification for this, as documented in the 
underlying White Paper, PVP2012-78190, ``Alternative Acceptance 
Criteria for Flaws in Ferritic Steel Components Operating in the Upper 
Shelf Temperature Range,'' is that the ASME BPV Code, Section XI, 
K<INF>1c</INF> curve will give a (T- RT<INF>NDT</INF>) value of 105 
degrees F at K<INF>1c</INF> of 200 ksi[radic]inch.
    Defining an upper shelf transition temperature purely based on LEFM 
data is not convincing because it ignores EPFM data and Charpy data and 
their relationship to the LEFM data. The NRC staff performed 
calculations on several randomly selected reactor pressure vessel 
surveillance materials with high upper-shelf energy values and low 
RT<INF>NDT</INF> values from three plants and found that using 
T<INF>c</INF>, as defined in the Code Case, is nonconservative because 
at the temperature of RT<INF>NDT</INF> + 105 degrees F, the Charpy 
curves show that most of the materials will not reach their respective 
upper-shelf energy levels. The NRC staff's condition is based on a 2015 
ASME Pressure Vessels and Piping Conference paper (PVP2015-45307) by 
Mark Kirk, Gary Stevens, Marjorie Erickson, William Server, and Hal 
Gustin entitled, ``Options for Defining the Upper Shelf Transition 
Temperature (Tc) for Ferritic Pressure Vessel Steels,'' where 
T<INF>c</INF> and T<INF>c1</INF> are defined as the intersections of 
specific toughness curves of LEFM data and EPFM data, as shown in that 
paper. Using the model in the 2015 PVP paper is justified because, in 
addition to its theoretically motivated approach in applying the 
temperature-dependent flow behavior of body-centered cubic materials, 
the model is also supported by numerous LEFM data and 809 EPFM data in 
the upper shelf region.
    While the T<INF>c</INF> proposed in Code Case N-749 is conservative 
based on the intersection of the mean curves of the two sets of data, 
the NRC determined that actual or bounding properties (on the 
conservative side) should be used instead of mean material properties 
for evaluating flaws detected in a ferritic component using the EPFM 
approach. This will prevent inaccurate component failure predictions 
using the EPFM approach, due to overestimated material properties. 
Further, the NRC's approach considers the temperature range for 
fracture mode transition between LEFM and EPFM. Based on the previous 
discussion, the NRC is imposing a condition on the use of Code Case N-
749 that: (1) The two equations for T<INF>c</INF> be used instead of 
T<INF>c</INF>, as proposed in the Code Case for requiring EPFM 
application, when the temperature is above T<INF>c</INF>, and (2) the 
two equations for T<INF>c1</INF> be used for requiring LEFM application 
when temperature is below T<INF>c1.</INF> Between T<INF>c1</INF> and 
T<INF>c</INF>, while the fracture mode is in transition between LEFM 
and EPFM, users should consider whether or not it is appropriate to 
apply the EPFM method.
    Alternatively, the licensee may use a different T<INF>c</INF> 
value, if it can be justified by plant-specific Charpy curves.
Code Case N-754 [Supplement 6, 2010 Edition]
    Type: New.
    Title: Optimized Structural Dissimilar Metal Weld Overlay for 
Mitigation of PWR Class 1 Items, Section XI, Division 1.
    The NRC approves Code Case N-754 with three conditions. Code Case 
N-754 provides requirements for installing optimized structural weld 
overlays (OWOL) on the outside surface of ASME Class 1 heavy-wall, 
large-diameter piping composed of ferritic, austenitic stainless steel, 
and nickel based alloy materials in pressurized water reactors

[[Page 2339]]

(PWRs) as a mitigation measure, where no known defect exists or the 
defect depth is limited to 50 percent through wall. The upper 25 
percent of the original pipe wall thickness is credited as a part of 
the OWOL design in the analyses performed, in support of these repairs. 
The technical basis supporting the use of OWOLs is provided in the 
Electric Power Research Institute (EPRI) Materials Reliability Project 
(MRP) Report MRP-169, Revision 1-A, entitled, ``Technical Basis for 
Preemptive Weld Overlays for Alloy 82/182 Butt Welds in PWRs.'' By 
letter dated August 9, 2010 (ADAMS Accession No. ML101620010), the NRC 
informed the Nuclear Energy Institute (NEI) that the staff found that 
MRP-169, Revision 1, as revised by letter dated February 3, 2010, 
adequately described: (1) Methods for the weld overlay design; (2) the 
supporting analyses of the design; (3) the experiments that verified 
the analyses; and (4) the inspection requirements of the dissimilar 
metal welds to be overlaid. However, the NRC identified the following 
conditions.
    The first condition requires that the conditions imposed on the use 
of OWOLs contained in the NRC final safety evaluation for MRP-169, 
Revision 1-A, must be satisfied. Eighteen limitations and conditions 
are described in the final safety evaluation that address issues such 
as fatigue crack growth rates, piping loads, design life of the weld 
overlay, and reexamination frequencies. The imposition of the 
conditions in the safety evaluation provide reasonable assurance that 
the structural integrity of the pipes repaired through the use of weld 
overlays will be maintained.
    Code Case N-754 references Code Case N-770-2, ``Alternative 
Examination Requirements and Acceptance Standards for Class 1 Pressure 
Water Reactor (PWR) Piping and Vessel Nozzle Butt Welds Fabricated With 
UNS N06082 or UNS W86182 Weld Filler Material With or Without 
Application of Listed Mitigation Activities, Section XI, Division 1.'' 
The reference to Code Case N-770-2 provides the ASME requirements for 
the performance of the preservice and ISI examinations of OWOLs, with 
additional requirements if the ultrasonic examination is qualified for 
axial flaws. The NRC approved Code Case N-770-2 with conditions in 
Sec.  50.55a(g)(6)(ii)(F) on July 18, 2017 (82 FR 32934). Accordingly, 
the second condition on the use of Code Case N-754 is that the 
preservice and inservice inspections of OWOLs must satisfy Sec.  
50.55a(g)(6)(ii)(F), i.e., meet the provisions of Code Case N-770-2.
    The third condition addresses a potential implementation issue in 
Code Case N-754 with respect to the deposition of the first layer of 
weld metal. The second sentence in paragraph 1.2(f)(2) states that 
``The first layer of weld metal deposited may not be credited toward 
the required thickness, but the presence of this layer shall be 
considered in the design analysis requirements in 2(b).'' The NRC found 
that, among licensees, there can be various interpretations of the 
words used in the ASME BPV Code and Code Cases. In this instance, the 
NRC determined that the word ``may'' needed to be changed to ``shall'' 
in the second sentence in paragraph 1.2(f)(2), as a condition for use 
of this Code Case. Accordingly, the NRC is adding a third condition to 
clarify that the first layer shall not be credited toward the required 
OWOL thickness unless the chromium content of the first layer is at 
least 24 percent.
Code Case N-778 [Supplement 6, 2010 Edition]
    Type: New.
    Title: Alternative Requirements for Preparation and Submittal of 
Inservice Inspection Plans, Schedules, and Preservice and Inservice 
Summary Reports, Section XI, Division 1.
    The NRC is approving Code Case N-778 with two conditions. Section 
XI, paragraph IWA-1400(d), in the editions and addenda currently used 
by the operating fleet, requires licensees to submit plans, schedules, 
and preservice and ISI summary reports to the enforcement and 
regulatory authorities having jurisdiction at the plant site. In the 
licensees' pursuit to decrease burden, they have alluded to the 
resources associated with the requirement to submit the items 
previously listed. Code Case N-778 was developed to provide an 
alternative to the requirements in the ASME BPV Code, in that the items 
previously listed would only have to be submitted if specifically 
required by the regulatory and enforcement authorities.
    The NRC reviewed its needs with respect to the submittal of the 
subject plans, schedules, and reports, and determined that it is not 
necessary to require the submittal of plans and schedules. The NRC made 
this determination because the latest up[dash]to[dash]date plans and 
schedules are available at the plant site and can be requested by the 
NRC at any time. However, the NRC determined that summary reports still 
need to be submitted. Summary reports provide valuable information 
regarding examinations that have been performed, conditions noted 
during the examinations, the corrective actions performed, and the 
status of the implementation of the ISI program. Accordingly, the NRC 
is approving Code Case N-778 with conditions to require that licensees 
continue to submit summary reports in accordance with paragraph IWA-
6240 of the 2009 Addenda of ASME Section XI, as addressed below.
    The two conditions are modeled on the requirements currently in 
paragraph IWA-6240 of the 2009 Addenda, Section XI. The requirements in 
Section XI do not specify when the reports are to be submitted to the 
regulatory authority; rather, the requirements only state that the 
reports shall be completed. The first condition requires that the 
preservice inspection summary report be submitted before the date of 
placement of the unit into commercial service. The second condition 
requires that the ISI summary report be submitted within 90 calendar 
days of the completion of each refueling outage. The conditions rely on 
the date of commercial service and the completion of a refueling outage 
to determine when the reports are needed to be submitted to the 
regulatory authority.
Code Case N-789 [Supplement 6, 2010 Edition]
    Type: New.
    Title: Alternative Requirements for Pad Reinforcement of Class 2 
and 3 Moderate[dash]Energy Carbon Steel Piping for Raw Water Service, 
Section XI, Division 1.
    The NRC is approving Code Case N-789 with one condition. For 
certain types of degradation, the Code Case provides requirements for 
the temporary repair of degraded moderate energy Class 2 and Class 3 
piping systems by external application of welded reinforcement pads. 
The Code Case does not require inservice monitoring for the pressure 
pad. However, the NRC determined that it is unacceptable to not monitor 
the pressure pad because there may be instances where an unexpected 
corrosion rate may cause the degraded area in the pipe to expand beyond 
the area that is covered by the pressure pad. This could lead to the 
pipe leaking and may challenge the structural integrity of the repaired 
pipe. Therefore, the NRC is approving Code Case N-789 with a condition 
to require a monthly visual examination of the installed pressure pad 
for evidence of leakage.
    In the proposed rule, the NRC expressed concern that the corrosion 
rate specified in paragraph 3.1(1) of the Code Case may not address 
certain scenarios. That paragraph would allow

[[Page 2340]]

either a corrosion rate of two times the actual measured corrosion rate 
at the reinforcement pad installation location or four times the 
estimated maximum corrosion rate for the system. To ensure that a 
conservative corrosion rate is used to provide sufficient margin, the 
NRC considered adding a second condition that requires that the design 
of the pressure pad use the higher of the two corrosion rates 
calculated, based on the same degradation mechanism as the degraded 
location. However, as a result of a public comment, the NRC 
reconsidered and determined that using a corrosion rate of either two 
times the actual measured corrosion rate in that location, or four 
times the estimated maximum corrosion rate for the system, already 
provides a sufficiently conservative estimate of the corrosion rate; 
therefore, a condition is not needed.
Code Case N-795 [Supplement 3, 2010 Edition]
    Type: New.
    Title: Alternative Requirements for BWR Class 1 System Leakage Test 
Pressure Following Repair/Replacement Activities, Section XI, Division 
1.
    The NRC is approving Code Case N-795 with two conditions. The first 
condition addresses a prohibition against the production of heat 
through the use of a critical reactor core to raise the temperature of 
the reactor coolant and pressurize the reactor coolant pressure 
boundary (RCPB) (sometimes referred to as nuclear heat). The second 
condition addresses the duration of the hold time when testing non-
insulated components to allow potential leakage to manifest itself 
during the performance of system leakage tests.
    Code Case N-795 was intended to address concerns that performing 
the ASME-required pressure test for boiling water reactors (BWRs) under 
shutdown conditions, (1) places the unit in a position of significantly 
reduced margin, approaching the fracture toughness limits defined in 
the Technical Specification Pressure[dash]Temperature (P-T) curves, and 
(2) requires abnormal plant conditions/alignments, incurring additional 
risks and delays, while providing little added benefit beyond tests, 
which could be performed at slightly reduced pressures under normal 
plant conditions. However, due to restrictions imposed by the pressure 
control systems, most BWRs cannot obtain reactor pressure corresponding 
to 100 percent rated power during normal startup operations at low 
power levels that would be conducive to performing examinations for 
leakage. The alternative test, provided by Code Case N-795, would be 
performed at slightly reduced pressures and normal plant conditions, 
which the NRC finds will constitute an adequate leak examination and 
would reduce the risk associated with abnormal plant conditions and 
alignments.
    However, the NRC has had a long-standing prohibition against the 
production of heat through the use of a critical reactor core to raise 
the temperature of the reactor coolant and pressurize the RCPB. A 
letter dated February 2, 1990, from James M. Taylor, Executive Director 
for Operations, NRC, to Messrs. Nicholas S. Reynolds and Daniel F. 
Stenger, Nuclear Utility Backfitting and Reform Group (ADAMS Accession 
No. ML14273A002), established the NRC position with respect to use of a 
critical reactor core to raise the temperature of the reactor coolant 
and pressurize the RCPB. In summary, the NRC's position is that testing 
under these conditions involves serious impediments to careful and 
complete inspections, and therefore, inherent uncertainty with regard 
to assuring the integrity of the RCPB. Further, the practice is not 
consistent with basic defense-in-depth safety principles.
    The NRC's position established in 1990, was reaffirmed in 
Information Notice No. 98-13, ``Post-Refueling Outage Reactor Pressure 
Vessel Leakage Testing Before Core Criticality,'' dated April 20, 1998. 
The Information Notice was issued in response to a licensee that had 
conducted an ASME BPV Code, Section XI, leakage test of the reactor 
pressure vessel and subsequently discovered that it had violated 10 CFR 
part 50, appendix G, IV.A.2.d. This regulation states that pressure 
tests and leak tests of the reactor vessel that are required by Section 
XI of the ASME Code must be completed before the core is critical. The 
Information Notice references NRC Inspection Report 50-254/97-27 (ADAMS 
Accession No. ML15216A276), which documents that licensee personnel 
performing VT-2 examinations of the drywell at one BWR plant covered 50 
examination areas in 12 minutes, calling into question the adequacy of 
the VT-2 examinations.
    The bases for the NRC's historical prohibition of pressure testing 
with the core critical can be summarized as follows:
    1. Nuclear operation of a plant should not commence before 
completion of system hydrostatic and leakage testing to verify the 
basic integrity of the RCPB, a principal defense-in-depth barrier to 
the accidental release of fission products. In accordance with the 
defense-in-depth safety precept, the nuclear power plant design 
provides for multiple barriers to the accidental release of fission 
products from the reactor.
    2. Hydrotesting must be done essentially water solid (i.e., free of 
pockets of air, steam or other gases) so that stored energy in the 
reactor coolant is minimized during a hydrotest or leaktest.
    3. The elevated reactor coolant temperatures, associated with 
critical operation, result in a severely uncomfortable and difficult 
working environment in plant spaces where the system leakage 
inspections must be conducted. The greatly increased stored energy in 
the reactor coolant, when the reactor is critical, increases the hazard 
to personnel and equipment in the event of a leak. As a result, the 
ability for plant workers to perform a comprehensive and careful 
inspection becomes greatly diminished.
    However, the NRC staff has determined that pressure testing with 
the core critical is acceptable, if performed after repairs of a 
limited scope, where only a few locations or a limited area needs to be 
examined, and when ASME Code Section XI, Table IWB-2500-1, Category B-P 
(the pressure test required once per cycle of the entire RCPB), has 
been recently performed, thus verifying the integrity of the overall 
RCPB. The NRC also notes that Code Case N-795 does not allow for the 
use of the alternative test pressure following repairs/replacements on 
the RPV, therefore it does not violate 10 CFR part 50, Appendix G. The 
NRC determined that the risk associated with nuclear heat at low power 
is comparable with the risk to the plant, when the test is performed 
without nuclear heat (with the core subcritical) during mid-cycle 
outages, when decay heat must be managed. Performing the pressure test 
under shutdown conditions at full operating pressure without nuclear 
heat requires securing certain key pressure control, heat removal, and 
safety systems. Under such conditions, it is more difficult to control 
temperature and pressure, when there is significant decay heat 
production, such as after a mid-cycle outage, which may reduce the 
margin available to prevent exceeding the plant pressure-temperature 
limits.
    The scope of repairs should be relatively small, when the pressure 
test is conducted using nuclear heat, in order to minimize the 
personnel safety risk and to avoid rushed examinations. Code Case N-795 
does not place any restrictions on the size or scope of the repairs for 
which the alternative may be used, other than the alternative test 
pressure may not be used to satisfy

[[Page 2341]]

pressure test requirements following repair/replacement activities on 
the reactor vessel. It is impractical to specify a particular number of 
welded or mechanical repairs that would constitute a ``limited scope.'' 
However, if the plant is still in a refueling outage and has already 
performed the ASME Section XI Category B-P pressure test of the entire 
RCPB, it is likely that subsequent repairs would be performed only on 
an emergent basis, and would generally be of a limited scope. 
Additionally, the overall integrity of the RCPB will have been recently 
confirmed via the Category B-P test. For mid-cycle maintenance outages, 
the first condition allows the use of nuclear heat to perform the test, 
if the outage duration is fourteen (14) days or less. This would tend 
to limit the scope of repairs, and also limit use of the Code Case to 
outages when decay heat was a significant problem. Therefore, the first 
condition on Code Case N-795 states:

``The use of nuclear heat to conduct the BWR Class 1 system leakage 
test is prohibited (i.e., the reactor must be in a non-critical 
state), except during refueling outages in which the ASME Section XI 
Category B-P pressure test has already been performed, or at the end 
of mid-cycle maintenance outages fourteen (14) days or less in 
duration.''

    With respect to the second condition and adequate pressure test 
hold time, the technical analysis supporting Code Case N-795 indicates 
that the lower test pressure provides more than 90 percent of the flow, 
which would result from the pressure corresponding to 100 percent 
power. However, a reduced pressure means a lower leakage rate, so 
additional time is required in order for there to be sufficient leakage 
to be observed by inspection personnel. Section XI, paragraph IWA-5213, 
``Test Condition Holding Time,'' does not require a holding time for 
Class 1 components, once test pressure is obtained. To account for the 
reduced pressure, Code Case N-795 would require a 15-minute hold time 
for non-insulated components. The NRC has determined that 15 minutes 
does not allow for an adequate examination, because it is not possible 
to predict the entire range of scenarios or types of defects that could 
result in leakage. While some types of defects could result in 
immediate leakage, such as an improperly torqued bolted connection; 
other types of defects, such as weld defects or tight cracks could 
represent a more torturous path for leakage and may result in delayed 
leakage. The staff determined that, due to the uncertainty in the time 
required for leakage to occur to an extent, it would be readily 
detectable by visual examination, hence, it is appropriate to 
conservatively specify a longer hold time of 1 hour for non-insulated 
components. Therefore, the final rule retains the one hour hold time 
for non-insulated components.
Code Case N-799 [Supplement 4, 2010 Edition]
    Type: New.
    Title: Dissimilar Metal Welds Joining Vessel Nozzles to Components, 
Section XI, Division 1.
    The NRC approves Code Case N-799 with four conditions. Code Case N-
799 is a new Code Case developed to provide examination requirements 
for the steam generator primary nozzle to pump casing attachment weld 
for AP-1000 plants and dissimilar metal welds joining vessel nozzles to 
pumps used in recent reactor designs (e.g., AP-1000, Advanced BWR). 
Nuclear power plant pump casings are typically manufactured from cast 
austenitic stainless steel (CASS) materials. The NRC is approving the 
Code Case with conditions to address the shortcomings in the Code Case 
with respect to requirements for ultrasonic examination.
    The CASS is an anisotropic and inhomogeneous material. The 
manufacturing process can result in varied and mixed structures. The 
large size of the anisotropic grains affects the propagation of 
ultrasound by causing severe attenuation, changes in velocity, and 
scattering of ultrasonic energy. Refraction and reflection of the sound 
beam occurs at the grain boundaries, which can result in specific 
volumes of material not being examined, or defects being missed or 
mischaracterized. The grain structure of the associated weldments also 
impacts the effectiveness and reliability of the examinations. 
Accordingly, it is paramount that robust examination techniques be 
used.
    Research has been conducted by several domestic and international 
organizations attempting to address the shortcomings associated with 
the use of conventional methods for the inspection of CASS materials. 
The results of a study at Pacific Northwest National Laboratory (PNNL) 
were published in NUREG/CR-6933, ``Assessment of Crack Detection in 
Heavy-Walled Cast Stainless Steel Piping Welds Using Advanced Low-
Frequency Ultrasonic Methods'' (ADAMS Accession No. ML071020409). The 
study demonstrated that additional measures were required to reliably 
detect and characterize flaws in CASS materials and their associated 
weldments.
    Performance demonstration requirements for CASS components and 
associated weldments have not yet been developed by the industry. To 
ensure that effective and reliable examinations are performed, the NRC 
is adopting the following four conditions on the Code Case.
    The first condition addresses the gap between the probe and 
component surface. Industry experience shows that effective ultrasonic 
examinations depend, to a great extent, on limiting the gap between the 
probe and component surface to less than 0.032[dash]inch. The BPV Code 
does not have any requirements with respect to surface smoothness and 
waviness. It has been demonstrated that reduced coupling and probe 
lift-off on ``rough'' surfaces have the potential to present a 
scattering effect at an interface where an acoustic beam impinges, to 
redirect and mode convert some energy, which when returned to the probe 
can be the source of spurious signals, or cause flaws to be mis-
characterized or missed altogether. Accordingly, the first condition 
requires that the scanning surfaces have a gap less than 0.032-inch 
beneath the ultrasonic testing probe. Gaps greater than 0.032[dash]inch 
must be considered to be unexamined, unless it can be demonstrated, on 
representative mockups, that a Section XI, Appendix VIII, Supplement 
10, demonstration can be passed.
    The second condition (No. 2a in DG-1296) is that the examination 
requirements of Section XI, Mandatory Appendix I, paragraph I-3200(c) 
must be applied. Code Case N-799 does not contain specific requirements 
regarding examination techniques. Paragraph I-3200(c) contains specific 
requirements that can be applied.
    The third condition (No. 2c in DG-1296) is that ultrasonic depth 
and sizing qualifications for CASS components must use the ASME BPV 
Code requirements in Section XI, Appendix VIII, Supplement 10. 
Supplement 10 contains qualification requirements for dissimilar metal 
welds, and the use of these requirements will ensure that robust 
techniques are applied.
    The fourth condition (No. 2e in DG-1296) is that cracks that are 
detected but cannot be depth-sized with performance-based procedures, 
equipment, and personnel qualifications consistent with ASME Code 
Section XI, Appendix VIII, shall be repaired or removed.
OM Code Cases (RG 1.192)
Code Case OMN-1, Revision 1 [2012 Edition]
    Type: Revised.
    Title: Alternative Rules for Preservice and Inservice Testing of 
Active Electric

[[Page 2342]]

Motor[dash]Operated Valve Assemblies in Light-Water Reactor Power 
Plants.
    The conditions on Code Case OMN-1, Revision 1 [2012 Edition] are 
identical to the conditions on OMN-1 [2006 Addenda] that were approved 
by the NRC in Revision 1 of RG 1.192 in October 2014. The reasons for 
imposing these conditions are not resolved by Code Case OMN-1, Revision 
1 [2012 Edition] and, therefore, these conditions have been retained in 
Revision 2 of RG 1.192.
Code Case OMN-3 [2012 Edition]
    Type: Reaffirmed.
    Title: Requirements for Safety Significance Categorization of 
Components Using Risk Insights for Inservice Testing of LWR Power 
Plants.
    The conditions on Code Case OMN-3 [2012 Edition] are identical to 
the conditions on OMN-3 [2004 Edition] that were approved by the NRC in 
Revision 1 of RG 1.192 in October 2014. The reasons for imposing these 
conditions are not resolved by Code Case OMN-3 [2012 Edition] and, 
therefore, these conditions have been retained in Revision 2 of RG 
1.192.
Code Case OMN-4 [2012 Edition]
    Type: Reaffirmed.
    Title: Requirements for Risk Insights for Inservice Testing of 
Check Valves at LWR Power Plants.
    The conditions on Code Case OMN-4 [2012 Edition] are identical to 
the conditions on OMN-4 [2004 Edition] that were approved by the NRC in 
Revision 1 of RG 1.192 in October 2014. The reasons for imposing these 
conditions are not resolved by Code Case OMN-4 [2012 Edition] and, 
therefore, these conditions have been retained in Revision 2 of RG 
1.192.
Code Case OMN-9 [2012 Edition]
    Type: Reaffirmed.
    Title: Use of a Pump Curve for Testing.
    The conditions on Code Case OMN-9 [2012 Edition] are identical to 
the conditions on OMN-9 [2004 Edition] that were approved by the NRC in 
Revision 1 of RG 1.192 in October 2014. The reasons for imposing these 
conditions are not resolved by Code Case OMN-9 [2012 Edition] and, 
therefore, these conditions have been retained in Revision 2 of RG 
1.192.
Code Case OMN-12 [2012 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 conditions on Code Case OMN-12 [2012 Edition] are identical to 
the conditions on OMN-12 [2004 Edition] that were approved by the NRC 
in Revision 1 of RG 1.192 in October 2014. The reasons for imposing 
these conditions are not resolved by Code Case OMN-12 [2012 Edition] 
and, therefore, these conditions have been retained in Revision 2 of RG 
1.192.
Code Case OMN-16, Revision 1 [2012 Edition]
    Type: Revised.
    Title: Use of a Pump Curve for Testing.
    Code Case OMN-16, 2006 Addenda, was approved by the NRC in 
Regulatory Guide 1.192, Revision 1. With respect to Code Case OMN-16, 
Revision 1, 2012 Edition, there was an editorial error in the 
publishing of this Code Case in that Figure 1 from the original Code 
Case (i.e., Rev. 0, 2006 Addenda) was omitted. Accordingly, the NRC 
approves OMN-16, Revision 1, with a condition requiring that Figure 1 
from the original Code Case be used when implementing OMN-16, Revision 
1.
Code Case OMN-18 [2012 Edition]
    Type: Reaffirmed.
    Title: Alternate Testing Requirements for Pumps Tested Quarterly 
Within <plus-minus<ls-thn-eq>20% of Design Flow.
    The ASME OM Code defines Group A pumps as those pumps that are 
operated continuously or routinely during normal operation, cold 
shutdown, or refueling operations. The OM Code specifies that each 
Group A pump undergoes a Group A test quarterly and a comprehensive 
test biennially. The OM Code requires that the reference value for a 
comprehensive test to be within 20 percent of pump design flow, while 
the reference value for a Group A test needs to be within 20 percent of 
the pump design flow, if practicable. The biennial comprehensive test 
was developed (first appeared in the 1995 Edition of the OM Code) 
because pump performance concerns demonstrated that more stringent 
periodic testing was needed at a flow rate within a more reasonable 
range of the pump design flow rate, than typically performed during the 
pump IST in the past.
    Currently, when performing either the quarterly Group A test or the 
biennial comprehensive pump test, licensees must comply with certain 
limits for the flow Acceptable Range, the flow Required Action Range, 
the differential pressure (or discharge pressure) Acceptable Range, and 
the differential pressure (or discharge pressure) Required Action 
Range. The limits for the quarterly Group A test are obtained by using 
a factor of 1.10 times the flow reference value (Q<INF>r</INF>) or the 
differential or discharge pressure reference value 
([Delta]P<INF>r</INF> or P<INF>r</INF>), as applicable to the pump 
type.<INF></INF> The limits for the biennial comprehensive pump test 
are obtained by using the factor of 1.03 times Q<INF>r</INF> or 
[Delta]P<INF>r</INF> (or P<INF>r</INF>), as applicable to the pump 
type, providing more restrictive test ranges and higher quality data.
    Code Case OMN-18, 2012 Edition, would remove the Code requirement 
to perform a biennial comprehensive pump test, where the quarterly 
Group A pump test is performed within <plus-minus>20 percent of the 
pump design flow rate, with instruments having the ability to obtain 
the accuracies required for the comprehensive pump test. The NRC finds 
the performance of a quarterly Group A pump test, at flow within <plus-
minus>20 percent of the pump design flow rate, will be sufficient to 
detect mechanical and hydraulic degradation of the tested pump. The NRC 
finds that this will satisfy the intent of the biennial comprehensive 
pump test, with the exception that the test acceptable ranges and 
required action ranges are less precise than required for the 
comprehensive test. Therefore, the NRC approves Code Case OMN-18, 2012 
Edition, with a condition to specify the use of a factor of 1.06 for 
the Group A test parameters, to be consistent with the test ranges for 
the comprehensive test. The NRC concludes that the factor of 1.06 will 
provide a reasonable test range, when applying Code Case OMN-18 to 
Group A pumps tested quarterly, within <plus-minus>20 percent of the 
pump design flow rate. The NRC finds that the quarterly Group A test 
for pumps within <plus-minus>20 percent of the pump design flow rate, 
combined with the provisions in the Code Case OMN-18 for the pump 
instrumentation and the conditions in RG 1.192 for the test ranges, 
will provide reasonable assurance of the operational readiness of these 
pumps, as an acceptable alternative to the comprehensive pump test 
provisions in the ASME OM Code.
Code Case OMN-19 [2012 Edition]
    Type: Reaffirmed.
    Title: Alternative Upper Limit for the Comprehensive Pump Test.
    A requirement for a periodic pump verification test was added in 
Mandatory Appendix V, ``Pump Periodic Verification Test Program,'' to 
the 2012 Edition of the OM Code. The mandatory appendix is based on the 
determination by the ASME that a pump periodic verification test is 
needed to confirm that a pump can meet the required (differential or 
discharge) pressure as applicable, at its highest

[[Page 2343]]

design basis accident flow rate. Code Case OMN-19, 2012 Edition, would 
allow an applicant or licensee to use a multiplier of 1.06 times the 
reference value in lieu of the 1.03 multiplier for the comprehensive 
pump test's upper Acceptable Range criteria and Required Action Range, 
High criteria reference in the ISTB test acceptance criteria tables. 
The NRC considers Code Case OMN-19 to be acceptable where the 
provisions of Appendix V for a pump periodic verification test as 
referenced by ISTB-1400 are also satisfied to detect mechanical and 
hydraulic degradation. Therefore, the NRC approves Code Case OMN-19, 
2012 Edition, with the condition that the provisions in paragraph ISTB-
1400 and Mandatory Appendix V be applied when implementing the Code 
Case.
Code Case OMN-20 [2012 Edition]
    Type: New.
    Title: Inservice Testing Frequency.
    Surveillance Requirement (SR) 3.0.3 from Technical Specification 
(TS) 5.5.6, ``Inservice Testing Program,'' allows licensees to apply a 
delay period before declaring the SR for TS equipment ``not met,'' if a 
licensee inadvertently exceeds or misses the time limit for performing 
the TS surveillance. Licensees have been applying SR 3.0.3 to inservice 
tests performed in accordance with the ASME Codes. The NRC has 
determined that licensees cannot use TS 5.5.6 to apply SR 3.0.3 to 
inservice tests under Sec.  50.55a(f) that are not associated with a TS 
surveillance. To invoke SR 3.0.3, the licensee must first discover that 
a TS surveillance was not performed at its specified frequency. 
Therefore, the delay period that SR 3.0.3 provides does not apply to 
non[dash]TS support components tested under Sec.  50.55a(f). The OM 
Code does not provide for inservice test frequency reductions or 
extensions. In order to provide inservice test frequency reductions or 
extensions that cannot be provided by SR 3.0.3 from TS 5.5.6, ASME 
developed OM Code Case OMN-20. The NRC has reviewed OM Code Case OMN-20 
and has found it acceptable for use. The NRC determined that OM Code 
Case OMN-20 may be applied to editions and addenda of the OM Code that 
are listed in Sec.  50.55a(a)(1)(iv). Therefore, the NRC has included a 
condition in RG 1.192, specifying that Code Case OMN-20 is applicable 
to editions and addenda of the OM Code listed in Sec.  
50.55a(a)(1)(iv).

C. ASME Code Cases Not Approved for Use (RG 1.193)

    The ASME Code Cases that are currently issued by the ASME, but not 
approved for generic use by the NRC are listed in RG 1.193, ``ASME Code 
Cases not Approved for Use.'' In addition to the ASME Code Cases that 
the NRC has found to be technically or programmatically unacceptable, 
RG 1.193 includes Code Cases on reactor designs for 
high[dash]temperature gas[dash]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; RG 1.193 confirms the 
Code Cases that are not approved for use. The NRC is not adopting any 
of the Code Cases listed in RG 1.193.

III. Opportunities for Public Participation

    The proposed rule and draft RGs were published in the Federal 
Register on March 2, 2016 (81 FR 10780), for a 75-day comment period. 
The public comment period closed on May 16, 2016.
    After the close of the public comment period, the NRC held a public 
meeting on August 22, 2016, to discuss the status of this proposed 
rule. The public meeting summary is available in ADAMS under Accession 
No. ML16265A001.

IV. Public Comment Analysis

    The NRC received a total of seven comment submissions on the 
proposed rule and draft RGs. Table III lists the commenters, their 
affiliation, and the ADAMS Accession Number for each submission.

                   Table III--Comment Submissions Received on the Proposed Rule and Draft RGs
----------------------------------------------------------------------------------------------------------------
                                                                                                ADAMS  accession
             Submission ID                     Commenter name              Affiliation                No.
----------------------------------------------------------------------------------------------------------------
1......................................  Paul Donavin.............  Private Citizen..........        ML16063A509
2......................................  Gregory Frederick and Dan  Electric Power Research          ML16126A524
                                          Patten.                    Institute.
3......................................  Anonymous................  Unknown..................        ML16133A422
4......................................  Charles Pierce...........  Southern Nuclear                 ML16137A857
                                                                     Operating Company.
5......................................  Ralph Hill III...........  ASME.....................        ML16138A835
6......................................  Mark Gowin...............  Private Citizen..........        ML16139A798
7......................................  David Helker.............  Exelon Generation                ML16153A432
                                                                     Company, LLC.
----------------------------------------------------------------------------------------------------------------

    The NRC reviewed every comment submission and identified 32 unique 
comments requiring the NRC's consideration and response. Comment 
summaries and the NRC's responses are presented in this section. At the 
end of each summary, the individual comments represented by the summary 
are identified in the form [XX-YY] where XX represents the Submission 
ID in Table III and YY represents the sequential comment within the 
submission.

Public Comments on Draft Regulatory Guides

Regulatory Guide 1.84, Revision 37 (DG-1295)
    No public comments were submitted regarding Regulatory Guide 1.84, 
Revision 37 (Draft Guide (DG)-1295), therefore no NRC response is 
needed.
Regulatory Guide 1.147, Revision 18 (DG-1296)
Code Case N-552-1
    Comment: The proposed conditions on N-552-1 were incorporated into 
the ASME BPV Code, Section XI, 2005 Addenda when Code Case N-552 was 
incorporated into the code. However, these conditions have never been 
incorporated into the Code Case itself. The proposed conditions are 
identical to those imposed on Code Case N-552 in Revision 16 of RG 
1.147. ASME does not object to these conditions. [ASME 5-2]
    NRC Response: The NRC agrees with this comment.
    No change was made to the final rule as a result of this comment.
Code Case N-576-2
    Comment: Because the NRC has adopted the 2008 Addenda with no 
conditions on IWA-4200, ASME recommends that the proposed

[[Page 2344]]

condition be revised to state ``. . . is to be performed in accordance 
with IWA-4200 of the code of record for the current ISI Program.'' 
[ASME 5-3]
    NRC Response: The NRC agrees, in part, with this comment. The NRC 
staff has adopted the 2008 Addenda with no conditions on IWA-4200. 
However, the staff does not agree that the proposed condition/note in 
Regulatory Guide 1.147 should be revised to state ``. . . is to be 
performed in accordance with IWA-4200 of the code of record for the 
current ISI program'', because there may be licensees whose code of 
record is prior to 2008 and such a condition is not necessary because 
licensees would be required to follow IWA-4200 in their code of record, 
if they were to adopt this Code Case. As a result, because use of the 
repair method described in this Code Case (N-576-2) requires the NRC's 
review and approval prior to implementation and licensees will be 
required to follow IWA-4200 in their code of record, the NRC modified 
the ``note'' on this Code Case to eliminate the portion of the ``note'' 
regarding reconciliation. The revised ``note'' now reads:
    ``Note: Steam generator tube repair methods require prior NRC 
approval through the Technical Specifications. This Code Case does not 
address certain aspects of this repair, e.g., the qualification of the 
inspection and plugging criteria necessary for staff approval of the 
repair method.''
Code Case N-638-6
    Comment: Condition 1 was incorporated into IWA-4673(a)(2) of the 
2013 Edition when N-638-6 was incorporated into the Code. This 
condition has also been incorporated into N-638-8, which has been 
published in the 2015 Code Case Book. Condition (2) was incorporated 
into IWA-4671(b)(1) of the 2013 Edition when N-638-6 was incorporated 
into the Code. Because there were no conditions imposed on the use of 
IWA-4673(a)(2) or IWA-4671(b)(1) in the draft rule, to incorporate by 
reference the 2013 Edition of the ASME BPV Code, Section XI, ASME 
recommends that both of the proposed conditions be removed and Code 
Case N-638-6 be moved to Table 1 of RG 1.147, Revision 18. [ASME 5-4]
    NRC Response: The NRC agrees, in part, with this comment. Regarding 
proposed Condition (1), the staff agrees that Condition (1) was 
incorporated into IWA-4673(a)(2) of the 2013 Edition of ASME BPV Code, 
Section XI, when ASME incorporated Code Case N-638-6 into the Section 
XI. Proposed Condition (1) was also addressed in Code Case N-638-8. 
However, Code Case N-638-6 does not address proposed Condition (1) and 
this version of the Code Case will be available for use by licensees 
who will not adopt the 2013 Edition of Section XI for several years. 
Therefore, the NRC determined that it is appropriate to include 
proposed Condition (1) in RG 1.147, Revision 18.
    Regarding proposed Condition (2), Paragraph 1(b)(1) of Code Case N-
638-6 contains changes from the previous version of the Code Case, 
which allows through-wall circumferential welds and includes additional 
requirements when performing repairs that utilize through-wall 
circumferential welds. At the time that this revision of the Code Case 
was approved by the ASME, the staff had concerns related to through-
wall repairs. Subsequently, the NRC resolved its concerns. Therefore, 
the NRC determined that proposed Condition (2) is unnecessary.
    The NRC has removed proposed Condition (2) on Code Case N-638-6 
from the final RG 1.147, Revision 18.
    No change was made to the final rule as a result of this comment.
Code Cases N-666 and N-666-1
    Comment: A new condition has been added to N-666, which is listed 
as a Superseded Code Case: A surface (magnetic particle or liquid 
penetrant) examination must be performed after installing the seal weld 
and weld overlay on Class 1 and 2 piping socket welds. The fabrication 
defects, if detected, must be dispositioned using the surface 
examination acceptance criteria of the Construction Code identified in 
the Repair/Replacement Plan.
    As stated in our comment on N-666-1, the phrase ``seal weld and'' 
should be removed from the first sentence. Also, the addition of a new 
condition to a Code Case that was previously unconditionally approved 
in the Reg. Guide, and is now superseded, seems inappropriate. Several 
plants would likely have this version of the Code Case in their Section 
XI ``tool box'' until the end of their current Inspection Interval, and 
would be apparently (but not obviously) bound by the new condition, 
upon issuance of the new revision to Regulatory Guide. The third 
paragraph under Section B. DISCUSSION, in the draft RG, includes the 
statement ``If a Code Case is implemented by a licensee and a later 
version of the Code Case is incorporated by reference into 10 CFR 
50.55a and listed in Tables 1 and 2 during the licensee's present 120-
month ISI program interval, that licensee may use either the later 
version or the previous version. An exception to this provision would 
be the inclusion of a limitation or condition on the use of the Code 
Case that is necessary, for example, to enhance safety.'' Perhaps this 
could be supplemented with another sentence such as, ``In this case, 
the condition will be entered for the superseded Code Case under Table 
5.'' [EPRI 2-4, Exelon 7-4]
    NRC Response: The NRC agrees with this comment. The condition shown 
in Table 5 of DG-1295 for Code Case N-666 was in error.
    The condition on Code Case N-666 in Table 5 from the final RG 
1.147, Revision 18 has been removed.
    No change was made to the final rule as a result of this comment.
    Comment: Condition 1--The construction code may not always require 
a surface examination (depending on the construction code) on socket 
welds. This condition is appropriate. However, the words ``and seal 
weld'' in the first sentence should be removed from the condition 
because it is inappropriate to require surface examination of non-
structural seal welds whose only function is to seal a leak. The ASME 
recommends revising this condition to remove the words ``and seal 
weld'' in the first sentence. Condition 2--This condition should be 
removed as 5(a)(1) already required a Visual VT-1 examination of 
completed weld overlays irrespective of the class of the joint. This 
condition is redundant and only causes confusion. ASME recommends 
removing this proposed condition. [EPRI 2-1, ASME 5-5]
    NRC Response: The NRC agrees with this comment. The function of the 
seal weld is to seal a leak so that sound weldment for the overlay can 
be applied. The code case requires a visual examination of the seal 
weld, remaining socket weld, and adjacent base material before the weld 
overlay can be applied, which the NRC has determined is the appropriate 
examination prior to the application of the weld overlay. Therefore, 
Condition 1 has been revised to remove ``and seal weld.'' Regarding 
Condition 2, the NRC agrees with the commenter. The code case requires 
a visual examination of the seal pass and the completed weld overlay 
and provides appropriate acceptance criteria. Therefore, the condition 
is redundant and unnecessary. Condition 2 has been removed from Code 
Case N-666 in Table 2 from the final RG 1.147, Revision 18.
    No change was made to the final rule as a result of this comment.

[[Page 2345]]

Code Case N-711
    Comment: ASME recommends that this Code Case N-711 be removed from 
RG 1.193, Table 2 and added to Table 2 of RG 1.147 with appropriate 
conditions to address NRC technical concerns with the use of this case. 
[ASME 5-10]
    NRC Response: The NRC disagrees with this comment. The NRC declines 
at this time to adopt the recommended changes to the regulatory guides. 
It would not be appropriate to include the Code Case in RG 1.147 
without first having sought public comment on the adoption of the Code 
Case. Nonetheless, the NRC has reviewed the information provided by 
ASME and will consider approval of the Code Case in future rulemaking 
activities.
    No change was made to the final rule as a result of this comment.
Code Case N-722-2
    Comment: ASME requests that the NRC identify any technical concerns 
with N-722-2 and list these concerns in R.G. 1.193, Table 2. [ASME 5-
11]
    NRC Response: The NRC disagrees with this comment. The NRC 
disagrees with the comment because the NRC does not provide comments in 
the Regulatory Guide 1.193 on ASME Code Cases, which the NRC mandates 
for use as augmented inservice inspection programs under Sec.  
50.55a(g)(6)(ii). Any conditions that the NRC finds necessary to 
require are included under the particular section of Sec.  
50.55a(g)(6)(ii)(D), (E) or (F), as applicable. This is to avoid 
confusion such that a stakeholder does not use versions of these ASME 
Code Cases in lieu of the mandated versions of the ASME Code Case in 
Sec.  50.55a(g)(6)(ii). However, in order to be responsive to the 
stakeholder comment, the NRC will provide the current concerns with the 
implementation of ASME Code Case N-722-2, as a response to this comment 
to be included in the Federal Register notice.
    The NRC currently finds ASME Code Case N-722-2 unacceptable as 
written due to the following main issues. First, the basis for the 
removal of the Parts Examined from N-722-1 was found to be in error. 
According to an ASME Code interpretation, XI-1-13-27, not all items 
removed in N-722-2 were covered by the inspection requirements of ASME 
Code Case N-770-1. The ASME Code Case N-722 will need to be revised 
with a new basis for the removal of Parts Examined to be considered for 
approval by the NRC. Second, Note 11 is not acceptable. The bases for 
this concern is the same basis as Sec.  50.55a(g)(6)(ii)(F)(2), which 
restricts the application of this material condition to exempt 
volumetric and visual examination requirements in N-770-1. The NRC is 
concerned that the wording of this exemption may allow insufficiently 
mitigated items to be exempt from currently required visual inspection 
requirements for components containing alloy 600/82/182 to maintain 
structural and leak-tight integrity. Once again though, it is not the 
intent of the NRC to include these items as conditions or limitations 
in the regulatory guide. The current wording to redirect the user to 
the applicable section of Sec.  50.55a(g)(6)(ii)(E) will remain, 
because versions of this ASME Code Case, as well as N-729 and N-770, 
are not alternatives to the Code requirements, but are mandated by 
Sec.  50.55a as augmented ISI requirements. For these reasons the NRC 
disagrees with the comment.
    No change was made to the final rule as a result of this comment.
Code Case N-749
    Comment: Public comment 5-6 raised two main points:
    1. The comment takes issue with the temperature, T<INF>c</INF>, 
above which the staff suggests that EPFM techniques should be used. The 
formula for T<INF>c</INF>, given in the staff's condition, differs from 
that proposed in Code Case N-749.
    2. The comment takes issue with the part of the staff's condition 
stating that ``Tc is the temperature above which elastic plastic 
fracture mechanics (EPFM) must be applied.'' Item 4 of the public 
comment suggests adopting a permissive rather than a perspective 
condition by replacing the word ``must'' with the word ``may'' in the 
preceding sentence. [ASME 5-6]
    NRC Response: The NRC disagrees with this comment. The staff's 
responses to these points are, as follows:
    Concerning point 1, the technical bases for the staff's proposed 
equation for T<INF>c</INF> are well documented, as discussed 
previously, and are well supported by data for RPV steels both before 
and after neutron irradiation. This documentation appears in PVP 2015-
45307. Conversely, the T<INF>c</INF> equation in the proposed Code Case 
relates only to the intersection of the ASME K<INF>Ic</INF> curve with 
a fracture toughness (K<INF>Ic</INF>) value of 220 MPa[radic]m, a value 
that does not correspond well to any known materials data and, 
moreover, does not account for the effects of irradiation 
embrittlement. The NRC staff's proposal for T<INF>c</INF> is thus 
better supported by materials data than is the Code Case value.
    Concerning point 2, in order for a permissive condition to be 
acceptable (e.g., the use of ``may''), it would need to be demonstrated 
that application of LEFM approaches to flaw assessment on the upper 
shelf fracture behavior is always conservative relative to the more 
technically correct EPFM approach. This has not been demonstrated in 
either Code Case N-749 or in its supporting technical basis document. 
As one example, an approach to using LEFM on the upper shelf fracture 
behavior would be to continue to use the ASME K<INF>Ic</INF> curve. At 
upper shelf temperatures, the K<INF>Ic</INF> curve over-estimates the 
fracture toughness relative to the ductile fracture toughness (i.e., 
J0.1 or J-R), which is non-conservative.
    No change was made to the final rule as a result of this comment.
Code Case N-754
    Comment: The third condition proposed for this Code Case inversely 
paraphrases existing statements in the Code Case, causing confusion to 
the user as to what the condition actually adds to the existing 
requirements. Further, by paraphrasing the requirements, essential 
technical requirements, such as chrome content in the dilution zone, 
are omitted which we do not believe is the intent of the condition. The 
Federal Register states that the reason for this condition is that ``In 
this instance, the NRC felt the word ``may'' needed to be changed to 
``shall'' in the second sentence in paragraph 1.2(f)(2) as a condition 
for use of this Code Case.'' In the English language, when the term 
``may'' is followed by the word ``not'', the phrase means the same as 
``shall not.'' However, if this phrase is truly a concern for some, 
then the condition should be written exactly as the Code Case except 
change the one word ``may'' to ``shall.'' [EPRI 2-2, ASME 5-7]
    NRC Response: The NRC disagrees with this comment. Condition (3) 
addresses the following two statements in Paragraph 1.2(f)(2) of Code 
Case N-754 that reads: ``. . . The first layer of weld metal deposited 
may not be credited toward the required thickness, but the presence of 
this layer shall be considered in the design analysis requirements in 
2(b). Alternatively, a first diluted layer may be credited toward the 
required thickness, provided the layer and the associated dilution zone 
contain at least 24% Cr [chromium] . . .'' The first sentence in 
Paragraph 1.2(f)(2) could be interpreted so that the first weld layer 
could be credited toward the required thickness because the word ``may 
not'' does not absolutely prohibit such action. In addition, the first 
sentence in the quoted statements does not have restriction on

[[Page 2346]]

the chromium contents for crediting the first weld layer toward the 
required thickness.
    The second sentence in the above quote limits the chromium content 
of at least 24 percent; however, the second sentence began with the 
word ``Alternatively.'' The word ``Alternatively'' implies that the 
requirement in the second sentence is optional, i.e., a licensee may 
choose to satisfy either the first sentence or the second sentence, but 
the licensee does not need to satisfy both.
    For example, a licensee deposits a first weld layer that contains 
less than 24 percent chromium. The licensee could consider the first 
layer, as part of the required weld overlay thickness, based on the 
first sentence above because the first sentence does not identify a 
specific chromium content. Therefore, it does not restrict the 
consideration of the first layer for the required weld overlay 
thickness. The second sentence in the above quote does require the 
chromium content to be at least 24 percent. However, the licensee could 
interpret that the second sentence does not apply to this case because 
the second sentence is an alternate, optional requirement based on the 
word ``Alternatively.''
    The staff finds that Condition (3) does not omit the essential 
technical requirements such as the chrome content in the dilution zone. 
Condition (3) requires that if the first weld layer cannot achieve a 
chromium content of at least 24 percent, it cannot be considered as 
part of the weld overlay thickness. The staff recognizes that Condition 
(3) provides the same requirements as in Paragraph 1.2(f)(2). However, 
the purpose of Condition (3) is to clarify the requirements in 
Paragraph 1.2(f)(2).
    No change was made to the final rule as a result of this comment.
Code Case N-784
    Comment: This Code Case enables personnel to receive credit for 
experience hours for laboratory practice beyond the required number of 
hours of laboratory training. For Level II certification, the total 
experience hours may be reduced from 800 to 400 if the experience 
consists of a combination of 80 hours of field experience and 320 hours 
laboratory practice by scanning specimens containing flaws in materials 
representative of those in actual power plant components. The field 
experience will likely be in nuclear plants but there is no requirement 
for UT examiners to obtain their experience in a nuclear plant. While 
the experience credited would be on samples and mockups, those samples 
would be required to contain actual flaws whereas over many hours of 
field experience, fewer flaws may be encountered. Further, to ensure 
the effectiveness of the laboratory practice, the Level II experience 
time would be credited only after the individual passed an Appendix 
VIII, Supplement 2 performance demonstration for length and depth 
sizing. Since other performance demonstrations are required for 
certification for vessels, ferritic piping and bolting, for example, it 
is considered reasonable to only require the Supplement 2 performance 
demonstration as a threshold for crediting the laboratory practice 
hours. EPRI will provide reports (Nondestructive Evaluation: Fast-Track 
NDE Work Force Enhancement, Volume 1; 1019119 and Nondestructive 
Evaluation: Fast-Track NDE Work Force Enhancement, Volume 2, 1021150) 
to the USNRC to support this Code Case and address the impact of the 
reduced experience. This case does not reduce the training hours. [ASME 
5-12]
    NRC Response: The NRC disagrees with this comment. The ASME BPV 
Code replaces field experience with training hours without a defined 
technical basis. While the NRC is open to evidence related to a 
technical basis for the substitution of laboratory experience as a 
substitute for hours of work experience, the impact of the substitution 
of laboratory hours for field experience and nuclear power plant 
familiarization is unknown. The two documents cited in the comment 
require 1,050 hours of hands-on practice with hundreds of hours of 
additional classwork, not only 320 hours of laboratory training. If 
future work showed that 320 hours would be sufficient or the Code Case 
was modified to be in line with these documents, the NRC would consider 
allowing the use of the Code Case.
    No change was made to the final rule as a result of this comment.
Code Case N-789
    Comment: The NRC Condition [2] does not allow the user to apply the 
actual corrosion rate for the pressure pad design. This reflects the 
staff position that the factors of 2 and 4 do not provide reasonable 
assurance that actual corrosion rate is bounded. However, the 
compensatory measures of inservice monitoring and the short acceptance 
period of one operating cycle verify and provide assurance that both 
structural and leak integrity will be maintained during the temporary 
acceptance period. Condition (2) is contrary to several NRC SERs that 
have evaluated and approved the Code Case for application at dozens of 
domestic plants. Those SERs require that the reinforcing pad be 
designed to accommodate twice the actual measured corrosion rate or if 
unknown, then 4 times the maximum experienced in that or a similar 
system at the same plant for the same degradation mechanism. Corrosion 
rates are dependent upon many system variables--one primary factor 
being the amount and frequency of fluid flow. To impose the rate that 
may occur on a seldom-used dead-leg of a system to an area of active 
flow, where the actual corrosion rate has been measured is technically 
inappropriate. Since the monthly monitoring imposed by Condition (1) 
was initiated for the same reason that this condition was proposed--
namely, the potential for an unexpected corrosion rate--this condition 
should be removed. [EPRI 2-3, ASME 5-8]
    NRC Response: The NRC agrees with this comment. The NRC determined 
that the current language in the Code Case, which requires using a 
corrosion rate of either two times the actual measured corrosion rate 
in that location, or four times the estimated maximum corrosion rate 
for the system, is reasonable and provides a conservative estimate of 
the corrosion rate. This conservatively estimated corrosion rate, 
coupled with proposed Condition (1) that requires enhanced inservice 
monitoring, provides reasonable assurance that should corrosion rates 
be more aggressive than originally predicted, there will be sufficient 
time to initiate corrective actions prior to excessive leakage or loss 
of structural integrity. Therefore, the NRC has determined that 
proposed Condition (2) is not necessary.
    The NRC has removed proposed Condition (2) on Code Case N-789 from 
the final RG 1.147, Revision 18.
    No change was made to the final rule as a result of this comment.
    Comment: Paragraph 3.2(i) of Code Case N-789 has a typographic 
error where it states ``. . . piping designed to NC-2650, ND-3650. . . 
.'' NC-2650 should be NC-3650. Code Case N-789-2 corrected this 
statement to read ``. . . piping designed to NC-3650 or ND-3650. . . 
.'' The use of this Code Case N-789 should be conditioned to require 
using the corrected language for paragraph 3.2(i) in N-789-2. 
[Anonymous 3-1, Exelon 7-1]
    NRC Response: The NRC agrees with the commenter. Code Case N-789 
Paragraph 3.2(i) contains a typographical error. The code case 
references NC-2650 and the correct reference is NC-3650. NC-2650 does 
not exist in ASME Code Section III and

[[Page 2347]]

NC-3650 is the correct portion of the Code to use for the design of 
reinforcing pads. The NRC does not believe that this typographical 
error represents a safety concern. In order to prevent the delay of 
issuance of the final rule by including a new condition on the code 
case, the NRC will address this issue in a future rulemaking.
    No change was made to the final rule as a result of this comment.
Code Case N-795
    Comment: The commenters requested that one or both proposed 
conditions on the use of this Code Case in DG-1296 be removed: (1) 
Prohibition of use of nuclear heat to perform the leakage test; and (2) 
Hold time for noninsulated components must be 1 hour versus 15 minutes 
required by Code Case N-795. [Southern 4-1, ASME 5-9, and Exelon 7-2]
    NRC Response: The NRC agrees, in part, with this comment. As 
discussed in detail in the proposed rule in 81 FR 10780, dated March 2, 
2016, the historical prohibition of the use of nuclear heat for 
pressure testing is based on concerns about the quality of the VT-2 
examinations performed with the core critical, due to the high 
temperatures in containment, which limit stay times for inspectors, and 
also concerns about personnel safety. However, the commenters 
emphasized that Code Case N-795 is only intended for use in the case of 
limited scope repairs, such as the replacement of a main steam relief 
valve pilot valve (involving a single mechanical joint) when the relief 
valve is found to be leaking during startup. Code Case N-795 states 
that the alternative test pressure may not be used to satisfy the 
requirements of Table IWB-2500-1, Category B-P (the pressure test 
required once per cycle of the entire reactor coolant pressure 
boundary). Code Case N-795 does not place any restrictions on the size 
or scope of the repairs for which the alternative may be used, other 
than the alternative test pressure may not be used to satisfy pressure 
test requirements, following repair/replacement activities on the 
reactor vessel.
    However, upon review of the public comments, the staff has 
determined that the risk associated with performing the pressure test 
with nuclear heat at low power is comparable with the risk to the 
plant, when the test is performed without nuclear heat (with the core 
subcritical) during mid-cycle outages when decay heat must be managed. 
Performing the pressure test under shutdown conditions at full 
operating pressure without nuclear heat requires securing certain key 
pressure control, heat removal, and safety systems. Under such 
conditions, it is more difficult to control temperature and pressure, 
when there is significant decay heat production, such as after a mid-
cycle outage, which may reduce the margin available to prevent 
exceeding the plant pressure-temperature limits.
    The NRC considers it desirable that the scope of repairs be 
relatively small when the pressure test is conducted using nuclear 
heat, in order to minimize the personnel safety risk and to avoid 
rushed examinations. The staff considers it impractical to specify a 
particular number of welded or mechanical repairs that would constitute 
a ``limited scope.'' However, if the plant is still in a refueling 
outage and has already performed the ASME Section XI Category B-P 
pressure test of the entire RCPB, it is likely that subsequent repairs 
would be performed only on an emergent basis and would generally be of 
a limited scope. Additionally, the overall integrity of the RCPB will 
have been recently confirmed via the Category B-P test. For mid-cycle 
maintenance outages, the staff proposes to modify the condition to 
incorporate a limit on the outage duration of fourteen (14) days. This 
would tend to limit the scope of repairs, and also limit use of the 
Code Case to outages when decay heat was a significant problem. 
Therefore, the first condition on Code Case N-795 in Table 2 of DG-
1296, which currently reads:

    1. The use of nuclear heat to conduct the BWR Class 1 system 
leakage test is prohibited (i.e., the reactor must be in a non-
critical state).
    a. This condition also applies to pressure testing of reactor 
coolant pressure boundary components repaired or replaced in 
accordance with Section XI, IWA-4000.

is modified to read:

    1. The use of nuclear heat to conduct the BWR Class 1 system 
leakage test is prohibited (i.e., the reactor must be in a non-
critical state), except during refueling outages in which the ASME 
Section XI Category B-P pressure test has already been performed, or 
at the end of mid-cycle maintenance outages fourteen (14) days or 
less in duration.
    With respect to the comment on the second condition, the NRC 
disagrees with this comment. A one hour hold time is not 
unreasonable for non-insulated components. Inspectors do not need to 
be in containment during the hold time. Comment 5-9 (ASME) discussed 
the technical basis for Code Case N-795, which stated that pressure 
testing at 87 percent of full operating pressure would only result 
in a 7 percent reduction in flow, while the hold time is being 
increased by 50 percent from 10 minutes to 15 minutes. However, it 
is not possible to predict the entire range of scenarios or types of 
defects that could result in leakage. While some types of defects 
could result in immediate leakage, such as an improperly torqued 
bolted connection, other types of defects, such as weld defects or 
tight cracks could represent a more torturous path for leakage and 
may result in delayed leakage. Because the visual examination may be 
conducted with the core critical, stay times for examiners in 
containment may be limited; therefore, it is desirable that any 
leakage be readily detectable. The staff determined that, due to the 
uncertainty in the time required for leakage to occur, to an extent 
that it would be readily detectable by visual examination, it is 
appropriate to conservatively specify a longer hold time of 1 hour 
for non-insulated components. Therefore, no changes are made to 
Condition (2) requiring a 1-hour hold time for non-insulated 
components.

    No change was made to the final rule as a result of this comment.
Code Case N-799
    Comment: This is a Code Case to define the examination volume/area 
where older Section XI codes (up through 2010 Edition) do not recognize 
the defined configuration. The conditions proposed in the Code Case are 
not included in the proposed rule to accept the 2013 Edition of Section 
XI and the Code Case configuration is defined in the 2013 Code Edition. 
Commenters believe that this results in inconsistent requirements for 
plants using older Code versions versus newer Code versions. The 
examination conditions proposed for this Code Case use are not 
appropriate for a volume of interest Code Case. If the NRC considers 
the conditions appropriate, commenters believe that they should be 
included in a revision to 10 CFR 50.55a to assure consistent 
application, regardless of Code year and Addenda being applied. 
Specifically Conditions (3) and (5) should be removed from the Code 
Case. [Southern 4-2, Southern 4-3, and Exelon 7-3]
    NRC Response: The NRC agrees, in part, with this comment.
    Regarding the removal of proposed Condition (3) from N-799, the NRC 
disagrees with the comment. The NRC doesn't find that the examination 
of the inner \1/3\ of the component-to-component weld depicted in 
Figure 1 of Code Case N-799 provides reasonable assurance that the 
integrity of the component-to-component welds will be maintained 
throughout the operating life of the plant. Code Case N-799 was written 
to support new plant construction to provide examination requirements 
for a weld configuration, which did not exist in Section XI (i.e., 
component-to-component welds). Specifically, the examination 
requirements described in Code Case N-

[[Page 2348]]

799 would apply to the steam generator nozzle-to-reactor coolant pump 
casing (SG-to-RCP) weld in the AP1000 design and the reactor vessel 
nozzle-to-recirculation pump weld in the Advanced Boiling Water Reactor 
(ABWR). The following discussion will focus on the AP1000 design, but 
the staff's overall concern is also applicable to the reactor vessel-
to-reactor coolant pump connection for the ABWR design.
    The AP1000 design is unique in that a reactor coolant pump is 
welded directly to each of the two outlet nozzles on the steam 
generator channel head. This SG-to-RCP weld is a dissimilar metal (low 
alloy steel to cast austenitic stainless steel with Alloy 52/152 weld 
metal) circumferential butt weld with a double sided weld joint 
configuration, similar to that of a reactor vessel shell weld. Also, 
this unique component-to-component weld is part of the reactor coolant 
pressure boundary and is, therefore, subject to the examination 
requirements of ASME Section XI, Subsection IWB.
    ASME Section XI, IWB-2500 requires a full volume examination of all 
component welds, except those welds found in piping and those found in 
nozzles welded to piping. However, for the component-to-component welds 
in question, Code Case N-799 only requires a licensee to perform a 
volumetric examination of the inner \1/3\ of the weld and a surface 
examination of the outer diameter. The staff notes that the 
requirements of Code Case N-799 are identical to those in ASME Section 
XI, Table IWB-2500-1, Examination Category B-F for welds between vessel 
nozzles larger than NPS 4 and piping. As such, the staff does not 
believe that examination requirements proposed in Code Case N-799 are 
appropriate for the component-to-component welds because the service 
conditions of the aforementioned welds are significantly different from 
those that would be experienced by a traditional vessel nozzle-to-
piping/safe end butt weld. Specifically, in addition to the operating 
environment (RCS pressure, temperature, and exposure to coolant) and 
loads expected on a traditional nozzle-to-safe end weld, each SG-to-RCP 
weld will support the full weight of a reactor coolant pump with no 
other vertical or lateral supports. The SG-to-RCP welds will also be 
subject to pump rotational forces and vibration loads from both the 
steam generator and the reactor coolant pump during service. In the 
absence of operating experience for the weld in question or a bounding 
analysis, which demonstrates that a potential fabrication defect in the 
outer \2/3\ of the weld will not experience subcritical crack growth, 
the effects of these additional operating loads and stresses are 
indeterminate. Absent either of the above, the staff finds that it is 
inappropriate to limit the examination volume to the inner \1/3\ of the 
weld as typical of a piping weld at this time. When the examination 
volume that can be qualified by performance demonstration is less than 
100 percent of the weld volume, a licensee should include an ultrasonic 
examination to examine the qualified volume and perform a flaw 
evaluation of the largest hypothetical crack that could exist in the 
volume not qualified for ultrasonic examination. No change was made to 
the rule as a result of this comment.
    The NRC agrees that performing the examination in accordance with 
Section XI, Appendix VIII, Supplement 10, for detection and sizing 
would eliminate the need for the requirement to perform a flaw 
evaluation, based on the largest hypothetical flaw in the unqualified 
examination volume. However, the NRC determined a full volume 
examination of the entire weld and heat affected zone is required to 
provide reasonable assurance of structural integrity of the component-
to component welds addressed by Code Case N-799. The NRC also 
determined that requiring the examination procedures to be qualified in 
accordance with Section XI, Appendix VIII, Supplement 10, would 
eliminate the need for several of the other conditions that were 
proposed for N-799. Therefore, the final regulatory guide was modified 
to specify only four conditions for Code Case N-799, as follows:

    (i) Ultrasonic examination procedures, equipment, and personnel 
shall be qualified by performance demonstration in accordance with 
Section XI, Appendix VIII, Supplement 10. When applying the 
examination requirements of Figure IWB-2500-8, the examination 
volume shall be extended to include 100 percent of the weld.
    (ii) Examination requirements of Section XI, Mandatory Appendix 
I, paragraph I-3200(c) must be applied.
    (iii) Ultrasonic depth and sizing qualifications for cast 
austenitic stainless steel components must follow Appendix VIII, 
Supplement 10, using representative cast austenitic stainless steel 
mockups containing representative cracks and be independent of other 
Supplement 10 qualifications.
    (iv) Cracks detected and not depth sized to Appendix VIII type 
performance-based procedures, equipment, and personnel 
qualifications shall be repaired or removed.

    The NRC agrees with the examination requirement regarding the 
consistency between the Code Case and the codes, where the Code Case 
that has been incorporated should be consistent. The NRC disagrees with 
the statement that the proposed conditions are not appropriate for a 
volume of interest Code Case. The NRC is planning to include this topic 
in a future rulemaking.
Code Case N-806
    Comment: ASME stated that it has taken action to address some of 
these concerns and has published Code Case N-806-1, providing 
additional requirements for determining wall thickness loss rates. The 
ASME recommends that the NRC consider developing conditions on the use 
of this case that would enable the endorsement of the case in Table 2 
of RG 1.147. [ASME 5-13]
    NRC Response: The NRC disagrees with this comment. The NRC 
recognizes that ASME has addressed the NRC's concerns regarding the 
derivation of the corrosion rate in predicting metal loss in piping and 
has incorporated the corrosion rate derivation in the published Code 
Case N-806-1. However, the current rulemaking is for Code Case N-806, 
which does not contain sufficient information regarding the corrosion 
rate. The ASME suggested that the NRC develop conditions on the use of 
the Code Case such that the NRC could approve the Code Case for RG 
1.147. The NRC has determined that approval of Code Case N-806 with 
conditions would require too many conditions to address several open 
issues regarding the relationship to the derivation of the corrosion 
rate, which still need to be resolved. Therefore, the NRC cannot 
approve Code Case N-806 in this rulemaking.
    No change was made to the final rule as a result of this comment.
Code Case N-813
    Comment: This Code Case should be removed from Table 2 of 
Regulatory Guide 1.193 and added to Table 1 of Regulatory Guide 1.147 
because of the following reasons.

    1. The requirements of Code Case N-813 are identical to changes 
made in the 2013 Edition of Section XI, which are being considered 
under a separate draft 10 CFR 50.55a rule. The NRC has not proposed 
any conditions on these requirements in the 2013 Edition. It is 
inappropriate for the NRC to impose conditions on the same 
requirements in Case N-813 as the requirements in the 2013 Edition.
    2. This Case permits acceptance of subsurface flaws detected 
during preservice examination using the same criteria applicable to 
flaws detected during inservice examination. There is no greater 
likelihood of subsurface flaws detected during preservice 
examination to grow unacceptably than there is for the same flaws to 
grow during inservice examination. Operating experience has

[[Page 2349]]

shown that the propensity for failure is increased by repairing such 
flaws, whereas leaving them in place has never been shown to be a 
precursor to failure. Without weld repair, there is no mechanism 
expected to produce unacceptable flaw growth, whereas repair welding 
itself has been repeatedly shown to cause flaws to grow to the point 
of failure. The provisions of this Case, and the identical 
provisions in the 2013 Edition, improve safety.
    3. The technical basis for this Code Case and accompanying Code 
revision states that the action is being sought to prevent the 
unnecessary excavation and weld repair of subsurface indications, 
which can be analytically shown to be benign over the expected 
service lifetime of a component. Based on operating experience, it 
is known that weld repairs and their associated stress fields often 
serve as points of initiation for inservice degradation mechanisms 
(e.g., intergranular stress corrosion cracking, primary water stress 
corrosion cracking, etc.). Hence, it is in the best interest of the 
long term safe operation of components being placed into service to 
eliminate the need for weld repairs where they are not necessary to 
correct fabrication problems, which will not challenge the 
operability of the component over its service lifetime. This can be 
achieved by permitting licensees to effectively utilize the flaw 
evaluation rules of IWB-3600 and IWC-3600, which are already 
accepted for the analysis of indications due to inservice 
degradation.
    4. It is important to note that any preservice flaw that has 
been evaluated as acceptable is required to receive successive 
examinations under IWB-2420(b) or IWC-2420(c) so if the flaw does 
grow, it will be detected during these examinations. [ASME 5-14]

    NRC Response: The NRC disagrees with this comment, in part. The NRC 
has recognized that the provisions in Code Case N-813 are identical to 
changes made in the 2013 Edition of the ASME BPV Code, Section XI. The 
NRC addressed the contents of the 2013 Edition of the ASME BPV Code, 
including the Code provisions identical to those allowed in Code Case 
N-813, in a separate rulemaking.
    The NRC recognizes that operating experience has shown that 
repairing a weld that contains fabrication defects may cause the defect 
to grow in the future. On the other hand, permitting a weld that 
contains a known unacceptable fabrication defect prior to deployment is 
not appropriate and is contrary to the fundamental engineering 
principle of a good design. The fundamental engineering design is that 
a component should not contain defects before placing it into service. 
The staff has accepted the provision of ASME BPV Code, Section III that 
permits acceptable flaws (i.e., small insignificant flaws) in a weld to 
exist before deployment. The staff's objection to Code Case N-813 is 
that the code case permits the existence of unacceptable flaws, which 
do not meet the ASME Code preservice acceptance criteria, in welds 
before their deployment. The code case allows these unacceptable flaws 
to be accepted by analytical evaluation. The code case places no limits 
on such flaws (i.e., a weld could have more than one unacceptable flaw 
or numerous welds within a piping run could have flaws that did not 
meet the preservice acceptance criteria), whereas the original fleet of 
nuclear plants had no unacceptable preservice flaws. The staff 
concludes that it cannot approve Code Case N-813 in this rulemaking. 
The NRC will continue to evaluate operating experience relative to this 
type of flaw to further inform decisions on possible approval of this 
code case in future rulemakings.
    No change was made to the final rule as a result of this comment.
Code Case N-818
    Comment: Code Case N-818 should be removed from Regulatory Guide 
1.193 and be allowed for use, as the reasons given in Regulatory Guide 
1.193 to disallow Code Case N-818 have the following issues: (a) The 
fact that the examination will be difficult should not be a reason to 
prohibit it as Mandatory Appendix I requires that the technique(s) to 
be applied for the volumetric procedure be demonstrated on specimens 
simulating geometric, material and surface conditions to be encountered 
during implementation. (b) The discussion that ultrasound may have 
difficulties discerning between planar and volumetric flaws is not 
relevant. There is no requirement in the Code Case to characterize the 
flaw by type (i.e., planar or volumetric). (c) The suggestion that its 
application should be limited to ferritic weldments defeats the purpose 
of Code Case N-818. [EPRI 2-5, Southern 4-4]
    NRC Response: The NRC disagrees with this comment, in part. At 
present, the NRC has not received any supporting documents from the 
industry to address the NRC's concern regarding this Code Case, such as 
a demonstration of the adequacy of a full volume ultrasonic examination 
for fabrication flaws in austenitic welds. Therefore, the wording of 
the reasons given in RG 1.193 should not refer to the inspection being 
difficult for austenitic materials and dissimilar metal welds, but 
should instead refer to there not being an established technical basis 
for the use of ultrasound to find fabrication flaws in these materials. 
Additionally, the discussion of planar vs. volumetric flaws will be 
removed from RG 1.193, as the Code Case does not require the examiner 
to discriminate between these types of flaws. The revised wording for 
RG 1.193 is:

    The NRC has been conducting research at Pacific Northwest 
National Laboratory on the examination of austenitic and ferritic 
welds. The work has shown that performing a full volume ultrasonic 
examination for fabrication flaws is significantly different from an 
inservice examination. For example, examination from two directions 
is necessary to detect certain circumferentially oriented 
fabrication flaws such as lack of fusion. The work has also shown 
that the second leg of a V-path can be applied to examine ferritic 
materials on a limited basis but to date the technical basis has not 
been established to show that these techniques will be effective on 
austenitic materials and dissimilar metal welds. Another finding is 
that surface conditions are critical with respect to detecting and 
characterizing fabrication flaws. In summary, the NRC finds that an 
analytical approach for the acceptance of certain fabrication flaws 
could be acceptable if appropriately justified and the scope limited 
to ferritic materials. The NRC finds that significant research will 
be required to demonstrate that full-volume ultrasonic examination 
for fabrication flaws is acceptable for austenitic and dissimilar 
metal welds.

Regulatory Guide 1.192, Revision 2 (DG-1297)
Code Case OMN-20
    Comment: Allow the use of Code Case OMN-20 for those plants that 
implement ASME OM Code 2015 Edition and earlier editions and addenda. 
[Gowin 6-1]
    NRC Response: The NRC agrees, in part, with this comment. Code Case 
OMN-20 cannot be implemented with the 2015 Edition of the ASME OM Code 
because the 2015 Edition has not been incorporated by reference into 
Sec.  50.55a. Code Case OMN-20 is currently applicable to the 2009 
Edition through the OMa-2011 Addenda and all earlier editions and 
addenda. Licensees who adopt the 2012 Edition of the ASME OM Code would 
not be able to use Code Case OMN-20, without submitting a relief 
request to the NRC for approval. For this reason, the NRC partially 
agrees with the comment. The NRC believes that Code Case OMN-20 should 
be allowed to be implemented with the 2012 Edition and earlier editions 
and addenda of the ASME OM Code. The RG 1.192 was updated to add a 
condition stating that Code Case OMN-20 is applicable to the editions 
and addenda of the ASME OM Code listed in Sec.  50.55a(a)(1)(iv).
    No change was made to the final rule as a result of this comment.

[[Page 2350]]

Public Comments on the Proposed Rule

    Comment: The ASME Code is updated every year. Preparations are 
underway to publish the 2017 edition. NRC is working on 2010 Edition. 
It appears that NRC is not in compliance with National Technology 
Transfer and Advancement Act of 1995 (NTTAA) by passive non-compliance. 
Since NRC has many participants in the Code process, they should be 
prepared to act as soon as final standards votes are counted. [Donavin 
1-1]
    NRC Response: The NRC disagrees with this comment. The NRC 
appreciates the ASME's efforts to consider the NRC's concerns as 
addressed in conditions to Sec.  50.55a. The NRC agrees that delays in 
approving new ASME Code editions and Code Cases can be 
counterproductive with respect to implementation of improvements in 
ASME Code requirements. The NRC continues to assess ways to improve the 
rulemaking process to find schedule efficiencies.
    No change was made to the final rule as a result of this comment.
    Comment: Many of the conditions are historical and are the result 
of a single reviewer's opinion. An example is the rules for the 1994 
edition where I watched an NRC reviewer living in Washington, DC 
telling a PhD from Tokyo, Japan, that his seismic analysis defending 
the edition was non conservative. If there are legitimate questions, 
these should be separated from the ``not sufficiently conservative'' or 
``insufficient information'' justifications. The Commission has set a 
precedent in CVR for SECY-15-0106. ASME has endeavored to address 
conditions with docketed letters and Code actions. [Donavin 1-2]
    NRC Response: The NRC disagrees with this comment. Although a 
single reviewer may state a contrary position, NRC reviews all Code 
Cases and comments with appropriate staff and management. Code Cases 
that the NRC finds to be conditionally acceptable are also listed in 
RGs 1.84, 1.147, and 1.192, which are the subject of this rulemaking, 
together with the conditions that must be used if the Code Case is 
applied. The NRC determined that this rule complies with the NTTAA and 
OMB Circular A-119, despite these conditions. If the NRC did not 
conditionally accept ASME Code Cases, it would disapprove these Code 
Cases entirely.
    No change was made to the final rule as a result of this comment.
    Comment: ASME believes that it is not clear whether the word 
``superseded'' applies to those Code Cases that are superseded by ASME 
or those Code Cases that are listed as superseded in Table 5 of 
Regulatory Guide 1.147.
    ASME recommends revising the second sentence of this paragraph to 
clarify that ``The older or superseded version of the Code Case, if 
listed in Table 5, cannot be applied by the licensee or applicant for 
the first time.'' [ASME 5-1]
    NRC Response: The NRC agrees with this comment. The proposed 
additional text will add clarity to the information presented in Table 
5. The final RG 1.147 in the introductory paragraph to Table 5, has 
been revised to include the statement, ``The older or superseded 
version of the Code Case, if listed in Table 5, cannot be applied by 
the licensee or applicant for the first time.'' at the end of the 
explanatory text above Table 5.
    No change was made to the final rule as a result of this comment.
    Comment: The Code Case [N-711] would permit each licensee to 
independently determine when achievement of a coverage requirement is 
impractical, and when Code-required coverage is satisfied. As a result, 
application of the Code Case for similar configurations at different 
plants could result in potentially significant quantitative variations. 
Furthermore, application of the Code Case is inconsistent with NRC's 
responsibility for determining whether examinations are impractical, 
and eliminates the NRC's ability to take exception to a licensee's 
proposed action and impose additional measures where warranted in 
accordance with 10 CFR 50.55a(g)(6)(i).
    ASME recommends that this case be removed from RG 1.193, Table 2 
and added to Table 2 of RG 1.147 with appropriate conditions to address 
NRC technical concerns with the use of this case. [ASME 5-10]
    NRC Response: The NRC agrees with this comment. However, this is a 
new proposal and cannot be included in this rulemaking because it was 
not provided for public comment. Rather than include the action in this 
rulemaking, the NRC intends to include it within the scope of the 
rulemaking that will incorporate by reference the 2015 edition of the 
ASME BPV Code.
    No change was made to the final rule as a result of this comment.
    Comment: In Section IV, ``Section-by-Section Analysis'' of the 
Proposed Rule dated March 2, 2016 (Federal Register Vol. 81, No. 41), 
ASME believes that it is not clear whether the word ``superseded'' 
applies to those Code Cases that are superseded by ASME or those Code 
Cases that are listed as superseded in Table 5 of Regulatory Guide 
1.147 and in Table 5 of Regulatory Guide 1.84. [ASME 5-1 and ASME 5-15]
    ASME provides the following recommendations:
    i. ASME recommends that the NRC clarify the above concern in the 
final rule.
    ii. ASME recommends that the NRC review requirements for superseded 
ASME Section III and OM Code Cases in RG 1.84 and RG 1.192 for similar 
clarification.
    NRC Response: The NRC agrees with this comment as noted in the 
response to Comment 5-1. In addition to that clarifying text being 
added in the introduction to Table 5 in RG 1.147, it will also be added 
to the introduction of Table 5 in RG 1.84. The RG 1.192 does not 
contain a table of superseded Code Cases, therefore, no change will be 
made to the RG 1.192.
    No change was made to the final rule as a result of this comment.

V. Section-by-Section Analysis

    The following paragraphs in Sec.  50.55a, which list the three RGs 
that are being incorporated by reference, are revised as follows:
    Paragraphs (a)(3)(i): The reference to ``NRC Regulatory Guide 1.84, 
Revision 36,'' is amended to remove ``Revision 36'' and add in its 
place ``Revision 37.''
    Paragraphs (a)(3)(ii): The reference to ``NRC Regulatory Guide 
1.147, Revision 17,'' is amended to remove ``Revision 17'' and add in 
its place ``Revision 18.''
    Paragraphs (a)(3)(iii): The reference to ``NRC Regulatory Guide 
1.192, Revision 1,'' is amended to remove ``Revision 1'' and add in its 
place ``Revision 2.''

Overall Considerations on the Use of ASME Code Cases

    This rulemaking amends Sec.  50.55a to incorporate by reference RG 
1.84, Revision 37, which supersedes Revision 36; RG 1.147, Revision 18, 
which supersedes Revision 17; and RG 1.192, Revision 2, which 
supersedes Revision 1. 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 
rulemaking.
    The approval of a Code Case in the NRC 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 and/or licensee are responsible for ensuring 
that use of the Code Case does not conflict with regulatory 
requirements or licensee

[[Page 2351]]

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 
the Code Case, 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. Hence, 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 only 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 RGs, the 
applicant or the licensee may use either version of the Code Case 
(subject, however, to whatever change requirements apply to its 
licensing basis (e.g., 10 CFR 50.59)).
    A licensee's ISI and IST programs must be updated every 10 years to 
the latest edition and addenda of Section XI and the OM Code, 
respectively, that were incorporated by reference into Sec.  50.55a and 
in effect 12 months prior to the start of the next inspection and 
testing interval. Licensees who 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 ISI or IST interval. This relieves 
licensees of the burden of having to update their ISI or IST program 
each time a Code Case is revised by the ASME and approved for use by 
the NRC. Code Cases apply to specific editions and addenda, and Code 
Cases may be revised if they are no longer accurate or adequate, so 
licensees choosing to continue using a Code Case during the subsequent 
ISI or IST 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. If an applicant or a licensee applied a Code 
Case before it was listed as annulled, the applicant or the licensee 
may continue to use the Code Case until the applicant or the licensee 
updates its construction Code of Record (in the case of an applicant, 
updates its application) or until the licensee's 120-month ISI or IST 
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 
annulled 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 annulled Code Case. Applicants and licensees 
should not begin to implement such annulled Code Cases in advance of 
the rulemaking.
    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 ISI or IST 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.

VI. Regulatory Flexibility Certification

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

VII. Regulatory Analysis

    The NRC has prepared a final regulatory analysis on this 
regulation. The analysis examines the costs and benefits of the 
alternatives considered by the NRC. The total estimated net benefit of 
this rule is $4.94 million (7% discount rate) and $5.68 million (3% 
discount rate). The regulatory analysis is available as indicated in 
the ``Availability of Documents'' section of this document.

VIII. Backfitting and Issue Finality

    The provisions in this rule allow licensees and applicants to 
voluntarily apply NRC-approved Code Cases, sometimes with NRC-specified 
conditions. The approved Code Cases are listed in the three RGs that 
are incorporated by reference into Sec.  50.55a.
    An applicant's or a licensee's voluntary application of an approved 
Code Case does not constitute backfitting, inasmuch as 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 
that is inconsistent with any issue finality provision in 10 CFR part 
52. The NRC finds that this 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.

IX. Plain Writing

    The Plain Writing Act of 2010 (Pub. L. 111-274) requires Federal 
agencies to write documents in a clear, concise, and well-organized 
manner. The NRC has written this document to be consistent with the 
Plain Writing Act as well as the Presidential Memorandum, ``Plain 
Language in Government Writing,'' published June 10, 1998 (63 FR 
31883).

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

    The Commission has determined under the National Environmental 
Policy Act of 1969, as amended, and the Commission's regulations in 
subpart A of 10 CFR part 51, that this rule, if adopted, would not be a 
major Federal action significantly affecting the quality of the human 
environment; therefore, an

[[Page 2352]]

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. As 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.

XI. Paperwork Reduction Act

    This final rule contains new or amended collections of information 
subject to the Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et 
seq.). The collection of information was approved by the Office of 
Management and Budget (approval number 3150-0011).
    The burden to the public for these information collections is 
estimated to average a reduction of 380 hours per response, including 
the time for reviewing instructions, searching existing data sources, 
gathering and maintaining the data needed, and completing and reviewing 
the information collection.
    The information collection is being conducted to document the plans 
for and the results of inservice inspection and inservice testing 
programs. The records are generally historical in nature and provide 
data on which future activities can be based. The practical utility of 
the information collection for the NRC is that appropriate records are 
available for auditing by NRC personnel to determine if ASME BPV and OM 
Code provisions for construction, inservice inspection, repairs, and 
inservice testing are being properly implemented in accordance with 
Sec.  50.55a of the NRC regulations, or whether specific enforcement 
actions are necessary. Responses to this collection of information are 
generally mandatory under Sec.  50.55a.
    You may submit comments on any aspect of the information 
collection(s), including suggestions for reducing the burden, by the 
following methods:
    <bullet> Federal Rulemaking Website: Go to http://www.regulations.gov and search for Docket ID NRC-2012-0059.
    <bullet> Mail comments to: Information Services Branch, Office of 
the Chief Information Officer, Mail Stop: T-2 F43, U.S. Nuclear 
Regulatory Commission, Washington, DC 20555-0001 or to Aaron Szabo, 
Desk Officer, Office of Information and Regulatory Affairs (3150-0011), 
NEOB-10202, Office of Management and Budget, Washington, DC 20503; 
telephone 202-395-3621, email: <a href="/cdn-cgi/l/email-protection#2847415a49775b5d4a45415b5b4147466847454a064d4758064f475e"><span class="__cf_email__" data-cfemail="f49b9d8695ab878196999d87879d9b9ab49b9996da919b84da939b82">[email protected]</span></a>.

Public Protection Notification

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

XII. Congressional Review Act

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

XIII. Voluntary Consensus Standards

    The National Technology Transfer and Advancement Act of 1995, 
Public Law 104-113, requires that Federal agencies use technical 
standards that are developed or adopted by voluntary consensus 
standards bodies, unless using such a standard is inconsistent with 
applicable law or is otherwise impractical. In this rule, the NRC is 
continuing to use ASME BPV and OM Code Cases, which are ASME-approved 
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 37; RG 1.147, Revision 18; and RG 
1.192, Revision 2. These 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.

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

    The NRC is incorporating by reference three NRC Regulatory Guides 
that list new and revised ASME Code Cases, which the NRC has approved 
as alternatives to certain provisions of NRC-required Editions and 
Addenda of the ASME BPV Code and the ASME OM Code.
    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 final 
rules, as set forth in 1 CFR 51.5(b).
    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 identifies six classes of interested parties with 
regard to the material to be incorporated by reference in an NRC rule:
    <bullet> Individuals and small entities regulated or otherwise 
subject to the NRC's regulatory oversight. This class includes 
applicants and potential applicants for licenses and other NRC 
regulatory approvals, and who are subject to the material to be 
incorporated by reference. In this context, ``small entities'' has the 
same meaning as set out in Sec.  2.810.
    <bullet> 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 which does not qualify as a ``small entity'' under 
Sec.  2.810.
    <bullet> Non-governmental organizations with institutional 
interests in the matters regulated by the NRC.
    <bullet> Other Federal agencies, states, local governmental bodies 
(within the meaning of Sec.  2.315(c)).
    <bullet> Federally-recognized and State-recognized \7\ Indian 
tribes.
---------------------------------------------------------------------------

    \7\ State-recognized Indian tribes are not within the scope of 
10 CFR 2.315(c). However, for purposes of the NRC's compliance with 
1 CFR 51.5, ``interested parties'' includes a broad set of 
stakeholders including State-recognized Indian tribes.

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

[[Page 2353]]

    <bullet> 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) and who need access to the 
materials that the NRC proposes to incorporate by reference in order to 
participate in the rulemaking.
    The three regulatory guides being incorporated by reference in this 
rule are available without cost and can be read online, downloaded, or 
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; e-mail: <a href="/cdn-cgi/l/email-protection#83cfeae1f1e2f1faadd1e6f0ecf6f1e0e6c3edf1e0ade4ecf5"><span class="__cf_email__" data-cfemail="cd81a4afbfacbfb4e39fa8bea2b8bfaea88da3bfaee3aaa2bb">[email protected]</span></a>; url: 
www.nrc.gov/reading-rm/doc-collections/.
    Because access to the three regulatory guides are available in 
various forms and at no cost, the NRC determines that the three 
regulatory guides, RG 1.84, Revision 37; RG 1.147, Revision 18; and RG 
1.192, Revision 2, once approved by the OFR for incorporation by 
reference, are reasonably available to all interested parties.

XV. Availability of Documents

    The documents identified in the following table are available to 
interested persons through one or more of the following methods, as 
indicated.

                 Table IV--Rulemaking Related Documents
------------------------------------------------------------------------
                                                 ADAMS accession No./
               Document title                 Federal Register citation/
                                                       web link
------------------------------------------------------------------------
Proposed Rule Documents:
    Proposed Rule--Federal Register notice,  81 FR 10780.
     March 2, 2016.
    Draft Regulatory Analysis..............  ML15041A816.
    Draft RG 1.84, Revision 37 (DG-1295)...  ML15027A002.
    Draft RG 1.147, Revision 18 (DG-1296)..  ML15027A202.
    Draft RG 1.192, Revision 2 (DG-1297)...  ML15027A330.
Final Rule Documents:
    Regulatory Analysis....................  ML16285A013.
    RG 1.84, Revision 37...................  ML16321A335.
    RG 1.147, Revision 18..................  ML16321A336.
    RG 1.192, Revision 2...................  ML16321A337.
Related Documents:
    Draft RG 1.193, ``ASME Code Cases Not    ML15028A003.
     Approved for Use,'' Revision 5. (DG-
     1298).
    Federal Register notice--                82 FR 32934.
     ``Incorporation by Reference of
     American Society of Mechanical
     Engineers Codes and Code Cases,'' July
     18, 2017.
    Federal Register notice--                80 FR 56820.
     ``Incorporation by Reference of
     American Society of Mechanical
     Engineers Codes and Code Cases,''
     September 18, 2015.
    Federal Register notice--                68 FR 40469.
     ``Incorporation by Reference of ASME
     BPV and OM Code Cases,'' July 8, 2003.
    Federal Register notice--``Fracture      60 FR 65456.
     Toughness Requirements for Light Water
     Reactor Pressure Vessels,'' December
     19, 1995.
    Information Notice No. 98-13, ``Post-    ML031050237.
     Refueling Outage Reactor Pressure
     Vessel Leakage Testing Before Core
     Criticality,'' April 20, 1998.
    Inspection Report 50-254/97-27.........  ML15216A276.
    Letter from James M. Taylor, Executive   ML14273A002.
     Director for Operations, NRC, to
     Messrs. Nicholas S. Reynolds and
     Daniel F. Stenger, Nuclear Utility
     Backfitting and Reform Group, February
     2, 1990.
    Materials Reliability Project Report     ML101660468.
     MRP-169 Technical Basis for Preemptive
     Weld Overlays for Alloy 82/182 Butt
     Welds in PWRs (Revision 1), EPRI, Palo
     Alto, CA: 2012. 1025295.
    NUREG/CR-6933, ``Assessment of Crack     ML071020409.
     Detection in Heavy-Walled Cast
     Stainless Steel Piping Welds Using
     Advanced Low-Frequency Ultrasonic
     Methods''.
    White Paper, PVP2012-78190,              http://
     ``Alternative Acceptance Criteria for    proceedings.asmedigitalcol
     Flaws in Ferritic Steel Components       lection.asme.org/
     Operating in the Upper Shelf             proceeding.aspx?articleid=
     Temperature Range,'' 2012.               1723450.
    White Paper PVP2015-45307, ``Options     http://
     for Defining the Upper Shelf             proceedings.asmedigitalcol
     Transition Temperature (Tc) for          lection.asme.org/
     Ferritic Pressure Vessel Steels,''       proceeding.aspx?articleid=
     2015.                                    2471884.
------------------------------------------------------------------------

List of Subjects in 10 CFR Part 50

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

    For the reasons set out in the preamble and under the authority of 
the Atomic Energy Act of 1954, as amended; the Energy Reorganization 
Act of 1974, as amended; and 5 U.S.C. 552 and 553, the NRC is adopting 
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:

    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

[[Page 2354]]

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, revise paragraphs (a)(3)(i) through (iii) to read 
as follows:


Sec.  50.55a  Codes and standards.

    (a) * * *
    (3) * * *
    (i) NRC Regulatory Guide 1.84, Revision 37. NRC Regulatory Guide 
1.84, Revision 37, ``Design, Fabrication, and Materials Code Case 
Acceptability, ASME Section III,'' dated March 2017, with the 
requirements in paragraph (b)(4) of this section.
    (ii) NRC Regulatory Guide 1.147, Revision 18. NRC Regulatory Guide 
1.147, Revision 18, ``Inservice Inspection Code Case Acceptability, 
ASME Section XI, Division 1,'' dated March 2017, which lists ASME Code 
Cases that the NRC has approved in accordance with the requirements in 
paragraph (b)(5) of this section.
    (iii) NRC Regulatory Guide 1.192, Revision 2. NRC Regulatory Guide 
1.192, Revision 2, ``Operation and Maintenance Code Case Acceptability, 
ASME OM Code,'' dated March 2017, which lists ASME Code Cases that the 
NRC has approved in accordance with the requirements in paragraph 
(b)(6) of this section.
* * * * *

    Dated at Rockville, Maryland, this 2nd day of August 2017.

    For the Nuclear Regulatory Commission.
Brian E. Holian,
Acting Director, Office of Nuclear Reactor Regulation.

    Editorial note:  This document was received for publication by 
the Office of the Federal Register on January 3, 2018.

[FR Doc. 2018-00112 Filed 1-16-18; 8:45 am]
 BILLING CODE P


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