[Federal Register Volume 83, Number 218 (Friday, November 9, 2018)]
[Proposed Rules]
[Pages 56156-56196]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-24076]



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Vol. 83

Friday,

No. 218

November 9, 2018

Part II





 Nuclear Regulatory Commission





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10 CFR Part 50





 American Society of Mechanical Engineers 2015-2017 Code Editions 
Incorporation by Reference; Proposed Rule

  Federal Register / Vol. 83 , No. 218 / Friday, November 9, 2018 / 
Proposed Rules  

[[Page 56156]]


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NUCLEAR REGULATORY COMMISSION

10 CFR Part 50

[NRC-2016-0082]
RIN 3150-AJ74


American Society of Mechanical Engineers 2015-2017 Code Editions 
Incorporation by Reference

AGENCY: Nuclear Regulatory Commission.

ACTION: Proposed rule.

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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is proposing to 
amend its regulations to incorporate by reference the 2015 and 2017 
Editions of the American Society of Mechanical Engineers (ASME) Boiler 
and Pressure Vessel Code (BPV Code) and the 2015 and 2017 Editions of 
the ASME Operation and Maintenance of Nuclear Power Plants, Division 1: 
OM: Section IST (OM Code), respectively, for nuclear power plants. The 
NRC is also proposing to incorporate by reference two revised ASME code 
cases. This action is in accordance with the NRC's policy to 
periodically update the regulations to incorporate by reference new 
editions of the ASME Codes and is intended to maintain the safety of 
nuclear power plants and to make NRC activities more effective and 
efficient.

DATES: Submit comments by January 23, 2019. Comments received after 
this date will be considered if it is practical to do so, but the NRC 
is able to ensure consideration only for comments received on or before 
this date.

ADDRESSES: You may submit comments by any of the following methods 
(unless this document describes a different method for submitting 
comments on a specific subject):
     Federal Rulemaking Website: Go to http://www.regulations.gov and search for Docket ID NRC-2016-0082. Address 
questions about NRC dockets to Carol Gallagher; telephone: 301-415-
3463; email: [email protected]. For technical questions contact 
the individuals listed in the FOR FURTHER INFORMATION CONTACT section 
of this document.
     Email comments to: [email protected]. If you do 
not receive an automatic email reply confirming receipt, then contact 
us at 301-415-1677.
     Fax comments to: Secretary, U.S. Nuclear Regulatory 
Commission at 301-415-1101.
     Mail comments to: Secretary, U.S. Nuclear Regulatory 
Commission, Washington, DC 20555-0001, ATTN: Rulemakings and 
Adjudications Staff.
     Hand deliver comments to: 11555 Rockville Pike, Rockville, 
Maryland 20852, between 7:30 a.m. and 4:15 p.m. (Eastern Time) Federal 
workdays; telephone: 301-415-1677.
    For additional direction on obtaining information and submitting 
comments, see ``Obtaining Information and Submitting Comments'' in the 
SUPPLEMENTARY INFORMATION section of this document.

FOR FURTHER INFORMATION CONTACT: James G. O'Driscoll, Office of Nuclear 
Material Safety and Safeguards, telephone: 301-415-1325, email: 
James.O'[email protected]; or Keith Hoffman, Office of Nuclear Reactor 
Regulation, telephone: 301-415-1294, email: [email protected]. Both 
are staff of the U.S. Nuclear Regulatory Commission, Washington, DC 
20555-0001.

SUPPLEMENTARY INFORMATION: 

Executive Summary

A. Need for the Regulatory Action

    The NRC is proposing to amend its regulations to incorporate by 
reference the 2015 and 2017 Editions of the ASME BPV Code and the 2015 
and 2017 Editions of the ASME OM Code, respectively, for nuclear power 
plants. The NRC is also proposing to incorporate by reference two ASME 
code cases.
    This proposed rule is the latest in a series of rulemakings to 
amend the NRC's regulations to incorporate by reference revised and 
updated ASME Codes for nuclear power plants. The ASME periodically 
revises and updates its codes for nuclear power plants by issuing new 
editions, and this rulemaking is in accordance with the NRC's policy to 
update the regulations to incorporate those new editions into the NRC's 
regulations. The incorporation of the new editions will maintain the 
safety of nuclear power plants, make NRC activities more effective and 
efficient, and allow nuclear power plant licensees and applicants to 
take advantage of the latest ASME Codes. The ASME is a voluntary 
consensus standards organization, and the ASME Codes are voluntary 
consensus standards. The NRC's use of the ASME Codes is consistent with 
applicable requirements of the National Technology Transfer and 
Advancement Act (NTTAA). Additional discussion of voluntary consensus 
standards and the NRC's compliance with the NTTAA is set forth in 
Section VIII of this document, ``Voluntary Consensus Standards.''

B. Major Provisions

    Major provisions of this proposed rule include:
     Incorporation by reference of ASME Codes (2015 and 2017 
Editions of the BPV Code and the OM Code) into NRC regulations and 
delineation of NRC requirements for the use of these codes, including 
conditions.
     Incorporation by reference of two revised ASME Code Cases 
and delineation of NRC requirements for the use of these code cases, 
including conditions.
     Incorporation by reference of Electric Power Research 
Institute (EPRI), Materials Reliability Project (MRP) Topical Report, 
``Materials Reliability Program: Topical Report for Primary Water 
Stress Corrosion Cracking Mitigation by Surface Stress Improvement'' 
(MRP-335, Revision 3-A), which provides requirements for the mitigation 
of primary water stress corrosion cracking (PWSCC) on Reactor Vessel 
Head penetrations and Dissimilar Metal Butt Welds.

C. Costs and Benefits

    The NRC prepared a draft regulatory analysis to determine the 
expected costs and benefits of this proposed rule. The regulatory 
analysis identifies costs and benefits in both a quantitative fashion 
as well as in a qualitative fashion.
    The analysis concludes that this proposed rule would result in a 
net quantitative averted cost to the industry and the NRC. This 
proposed rule, relative to the regulatory baseline, would result in a 
net averted cost for industry of $3.64 million based on a 7 percent net 
present value (NPV) and $4.17 million based on a 3 percent NPV. The 
estimated incremental industry averted cost per reactor unit ranges 
from $37,900 based on a 7 percent NPV to $43,300 based on a 3 percent 
NPV. The NRC benefits from the proposed rulemaking alternative because 
of the averted cost of not reviewing and approving Code alternative 
requests on a plant-specific basis under Sec.  50.55a(z) of title 10 of 
the Code of Federal Regulations (10 CFR). The NRC net benefit ranges 
from $2.81 million based on a 7 percent NPV to $3.49 million based on a 
3 percent NPV.
    Qualitative factors that were considered include regulatory 
stability and predictability, regulatory efficiency, and consistency 
with the NTTAA. Table 38 in the draft regulatory analysis includes a 
discussion of the costs and benefits that were considered 
qualitatively. If the results of the regulatory analysis were based 
solely on quantified costs and benefits, then the

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regulatory analysis would show that the rulemaking is justified because 
the total quantified benefits of the proposed regulatory action do not 
equal or exceed the costs of the proposed action. Further, if the 
qualitative benefits (including the safety benefit, cost savings, and 
other non-quantified benefits) are considered together with the 
quantified benefits, then the benefits outweigh the identified 
quantitative and qualitative impacts.
    With respect to regulatory stability and predictability, the NRC 
has had a decades-long practice of approving and/or mandating the use 
of certain parts of editions and addenda of these ASME Codes in Sec.  
50.55a through the rulemaking process of ``incorporation by 
reference.'' Retaining the practice of approving and/or mandating the 
ASME Codes continues the regulatory stability and predictability 
provided by the current practice. Retaining the practice also assures 
consistency across the industry, and provides assurance to the industry 
and the public that the NRC will continue to support the use of the 
most updated and technically sound techniques developed by the ASME to 
provide adequate protection to the public. In this regard, the ASME 
Codes are voluntary consensus standards developed by participants with 
broad and varied interests and have undergone extensive external review 
before being reviewed by the NRC. Finally, the NRC's use of the ASME 
Codes is consistent with the NTTAA, which directs Federal agencies to 
adopt voluntary consensus standards instead of developing ``government-
unique'' (i.e., Federal agency-developed) standards, unless 
inconsistent with applicable law or otherwise impractical.
    For more information, please see the draft regulatory analysis 
(Accession No. ML18150A267 in the NRC's Agencywide Documents Access and 
Management System (ADAMS)).

Table of Contents

I. Obtaining Information and Submitting Comments
    A. Obtaining Information
    B. Submitting Comments
II. Background
III. Discussion
    A. ASME BPV Code, Section III
    B. ASME BPV Code, Section XI
    C. ASME OM Code
IV. Section-by-Section Analysis
V. Generic Aging Lessons Learned Report
VI. Specific Request for Comment
VII. Plain Writing
VIII. Voluntary Consensus Standards
IX. Incorporation by Reference--Reasonable Availability to 
Interested Parties
X. Environmental Assessment and Final Finding of No Significant 
Environmental Impact
XI. Paperwork Reduction Act Statement
XII. Regulatory Analysis
XIII. Backfitting and Issue Finality
XIV. Regulatory Flexibility Certification
XV. Availability of Documents

I. Obtaining Information and Submitting Comments

A. Obtaining Information

    Please refer to Docket ID NRC-2016-0082 when contacting the NRC 
about the availability of information for this proposed rule. You may 
obtain information related to this proposed rule by any of the 
following methods:
     Federal Rulemaking Website: Go to http://www.regulations.gov and search for Docket ID NRC-2016-0082.
     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 [email protected]. For 
the convenience of the reader, instructions about obtaining materials 
referenced in this document are provided in the ``Availability of 
Documents'' section.
     NRC's PDR: You may examine and purchase copies of public 
documents at the NRC's PDR, Room O1-F21, One White Flint North, 11555 
Rockville Pike, Rockville, Maryland 20852.

B. Submitting Comments

    Please include Docket ID NRC-2016-0082 in your comment submission.
    The NRC cautions you not to include identifying or contact 
information that you do not want to be publicly disclosed in your 
comment submission. The NRC will post all comment submissions at http://www.regulations.gov as well as enter the comment submissions into 
ADAMS. The NRC does not routinely edit comment submissions to remove 
identifying or contact information.
    If you are requesting or aggregating comments from other persons 
for submission to the NRC, then you should inform those persons not to 
include identifying or contact information that they do not want to be 
publicly disclosed in their comment submission. Your request should 
state that the NRC does not routinely edit comment submissions to 
remove such information before making the comment submissions available 
to the public or entering the comment into ADAMS.

II. Background

    The ASME develops and publishes the ASME BPV Code, which contains 
requirements for the design, construction, and inservice inspection 
(ISI) of nuclear power plant components; and the ASME OM Code,\1\ which 
contains requirements for inservice testing (IST) of nuclear power 
plant components. Until 2012, the ASME issued new editions of the ASME 
BPV Code every 3 years and addenda to the editions annually, except in 
years when a new edition was issued. Similarly, the ASME periodically 
published new editions and addenda of the ASME OM Code. Starting in 
2012, the ASME decided to issue editions of its BPV and OM Codes (no 
addenda) every 2 years with the BPV Code to be issued on the odd years 
(e.g., 2013, 2015, etc.) and the OM Code to be issued on the even years 
\2\ (e.g., 2012, 2014, etc.). The new editions and addenda typically 
revise provisions of the Codes to broaden their applicability, add 
specific elements to current provisions, delete specific provisions, 
and/or clarify them to narrow the applicability of the provision. The 
revisions to the editions and addenda of the Codes do not significantly 
change Code philosophy or approach.
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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 2017 and are referred to collectively in this rule as the 
``OM Code.''
    \2\ The 2014 Edition of the ASME OM Code was delayed and was 
designated the 2015 Edition. Similarly, the 2016 Edition of the OM 
Code was delayed and was designated the 2017 Edition.
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    The NRC's practice is to establish requirements for the design, 
construction, operation, ISI (examination), and IST of nuclear power 
plants by approving the use of editions and addenda of the ASME BPV and 
OM Codes (ASME Codes) in Sec.  50.55a. The NRC approves or mandates the 
use of certain parts of editions and addenda of these ASME Codes in 
Sec.  50.55a through the rulemaking process of ``incorporation by 
reference.'' Upon incorporation by reference of the ASME Codes into 
Sec.  50.55a, the provisions of the ASME Codes are legally-binding NRC 
requirements as delineated in Sec.  50.55a, and subject to the 
conditions on certain specific ASME Codes' provisions that are set 
forth in Sec.  50.55a. The editions and addenda of the ASME BPV and OM 
Codes were last incorporated by reference into the NRC's regulations in 
a final rule dated July 18, 2017 (82 FR 32934).
    The ASME Codes are consensus standards developed by participants 
with broad and varied interests

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(including the NRC and licensees of nuclear power plants). The ASME's 
adoption of new editions of, and addenda to, the ASME Codes does not 
mean that there is unanimity on every provision in the ASME Codes. 
There may be disagreement among the technical experts, including the 
NRC's representatives on the ASME Code committees and subcommittees, 
regarding the acceptability or desirability of a particular Code 
provision included in an ASME-approved Code edition or addenda. If the 
NRC believes that there is a significant technical or regulatory 
concern with a provision in an ASME-approved Code edition or addenda 
being considered for incorporation by reference, then the NRC 
conditions the use of that provision when it incorporates by reference 
that ASME Code edition or addenda. In some instances, the condition 
increases the level of safety afforded by the ASME Code provision, or 
addresses a regulatory issue not considered by the ASME. In other 
instances, where research data or experience has shown that certain 
Code provisions are unnecessarily conservative, the condition may 
provide that the Code provision need not be complied with in some or 
all respects. The NRC's conditions are included in Sec.  50.55a, 
typically in paragraph (b) of that section. In a Staff Requirements 
Memorandum (SRM) dated September 10, 1999, the Commission indicated 
that NRC rulemakings adopting (incorporating by reference) a voluntary 
consensus standard must identify and justify each part of the standard 
that is not adopted. For this rulemaking, the provisions of the 2015 
and 2017 Editions of Section III, Division 1; and the 2015 and 2017 
Editions of Section XI, Division 1, of the ASME BPV Code; and the 2015 
and 2017 Editions of the ASME OM Code that the NRC is not adopting, or 
is only partially adopting, are identified in the Discussion, 
Regulatory Analysis, and Backfitting and Issue Finality sections of 
this document. The provisions of those specific editions and code cases 
that are the subject of this proposed rule that the NRC finds to be 
conditionally acceptable, together with the applicable conditions, are 
also identified in the Discussion, Regulatory Analysis, and Backfitting 
and Issue Finality sections of this document.
    The ASME Codes are voluntary consensus standards, and the NRC's 
incorporation by reference of these Codes is consistent with applicable 
requirements of the NTTAA. Additional discussion on the NRC's 
compliance with the NTTAA is set forth in Section VIII of this 
document, ``Voluntary Consensus Standards.''

III. Discussion

    The NRC follows a three-step process to determine acceptability of 
new provisions in new editions to the Codes and the need for conditions 
on the uses of these Codes. This process was employed in the review of 
the Codes that are the subjects of this proposed rule. First, the NRC 
staff actively participates with other ASME committee members with full 
involvement in discussions and technical debates in the development of 
new and revised Codes. This includes a technical justification of each 
new or revised Code. Second, the NRC's committee representatives 
discuss the Codes and technical justifications with other cognizant NRC 
staff to ensure an adequate technical review. Third, the NRC position 
on each Code is reviewed and approved by NRC management as part of this 
proposed rule amending Sec.  50.55a to incorporate by reference new 
editions of the ASME Codes and conditions on their use. This regulatory 
process, when considered together with the ASME's own process for 
developing and approving the ASME Codes, provides reasonable assurance 
that the NRC approves for use only those new and revised Code edition 
and addenda, with conditions as necessary, that provide reasonable 
assurance of adequate protection to the public health and safety, and 
that do not have significant adverse impacts on the environment.
    The NRC reviewed changes to the Codes in the editions identified in 
this proposed rule. The NRC concluded, in accordance with the process 
for review of changes to the Codes, that these editions of the Codes, 
are technically adequate, consistent with current NRC regulations, and 
approved for use with the specified conditions upon the conclusion of 
the rulemaking process.
    The NRC is proposing to amend its regulations to incorporate by 
reference:
     The 2015 and 2017 Editions to the ASME BPV Code, Section 
III, Division 1 and Section XI, Division 1, with conditions on their 
use.
     The 2015 and 2017 Editions to Division 1 of the ASME OM 
Code, with conditions on their use.
     ASME BPV Code Case N-729-6, ``Alternative Examination 
Requirements for PWR [Pressurized Water Reactor] Reactor Vessel Upper 
Heads With Nozzles Having Pressure-Retaining Partial-Penetration Welds 
Section XI, Division 1,'' ASME approval date: March 3, 2016, with 
conditions on its use.
     ASME BPV Code Case N-770-5, ``Alternative Examination 
Requirements and Acceptance Standards for Class 1 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,'' ASME approval date: November 7, 2016, with 
conditions on its use.
     ``Materials Reliability Program: Topical Report for 
Primary Water Stress Corrosion Cracking Mitigation by Surface Stress 
Improvement'' (MRP-335, Revision 3-A), EPRI approval date: November 
2016.
    The current regulations in Sec.  50.55a(a)(1)(i) incorporate by 
reference ASME BPV Code, Section III, 1963 Edition through the 1970 
Winter Addenda; and the 1971 Edition (Division 1) through the 2013 
Edition (Division 1), subject to the conditions identified in current 
Sec.  50.55a(b)(1)(i) through (b)(1)(ix). This proposed rule would 
revise Sec.  50.55a(a)(1)(i) to incorporate by reference the 2015 and 
2017 Editions (Division 1) of the ASME BPV Code, Section III.
    The current regulations in Sec.  50.55a(a)(1)(ii) incorporate by 
reference ASME BPV Code, Section XI, 1970 Edition through the 1976 
Winter Addenda; and the 1977 Edition (Division 1) through the 2013 
Edition (Division 1), subject to the conditions identified in current 
Sec.  50.55a(b)(2)(i) through (b)(2)(xxix). This proposed rule would 
revise Sec.  50.55a(a)(1)(ii) to remove exclusions from the 
incorporation by reference of specific paragraphs of the 2011a Addenda 
and the 2013 Edition of ASME BPV Code, Section XI, as explained in this 
document. This proposed rule would also revise Sec.  50.55a(a)(1)(ii) 
to incorporate by reference 2015 and 2017 Editions (Division 1) of the 
ASME BPV Code, Section XI. It would also clarify the wording and add, 
remove, or revise some of the conditions as explained in this document.
    The current regulations in Sec.  50.55a(a)(1)(iv) incorporate by 
reference ASME OM Code, 1995 Edition through the 2012 Edition, subject 
to the conditions currently identified in Sec.  50.55a(b)(3)(i) through 
(b)(3)(xi). This proposed rule would revise Sec.  50.55a(a)(1)(iv) to 
incorporate by reference the 2015 and 2017 Editions of Division 1 of 
the ASME OM Code. As a result, the NRC regulations would incorporate by 
reference in Sec.  50.55a the 1995 Edition through the 2017 Edition of 
the ASME OM Code. In the

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introduction discussion of its Codes, ASME specifies that errata to 
those Codes may be posted on the ASME website under the Committee Pages 
to provide corrections to incorrectly published items, or to correct 
typographical or grammatical errors in those Codes. ASME notes that an 
option is available to automatically receive an email notification when 
errata are posted to a Code. Users of the ASME BPV Code and ASME OM 
Code should be aware of errata when implementing the specific 
provisions of those Codes.
    The proposed regulations in Sec.  50.55a (a)(4) would include the 
Electric Power Research Institute, Materials Reliability Program, 3420 
Hillview Avenue, Palo Alto, CA 94304-1338; telephone: 1-650-855-200; 
http://www.epri.com, as a new source of documentation to be 
incorporated by reference in Sec.  50.55a.
    Each of the proposed NRC conditions and the reasons for each 
proposed condition are discussed in the following sections of this 
document. The discussions are organized under the applicable ASME Code 
and Section.

A. ASME BPV Code, Section III

10 CFR 50.55a(a)(1)(E) Rules for Construction of Nuclear Facility 
Components--Division 1
    The NRC proposes to revise Sec.  50.55a(a)(1)(i)(E) to incorporate 
by reference the 2015 and 2017 Editions of the ASME BPV Code, Section 
III, including Subsection NCA and Division 1 Subsections NB through NH 
(for the 2015 Edition) and Subsections NB through NG (for the 2017 
Edition) and Appendices. As stated in Sec.  50.55a(a)(1)(i), the 
Nonmandatory Appendices are excluded and not incorporated by reference. 
The Mandatory Appendices are incorporated by reference because they 
include information necessary for Division 1. However, the Mandatory 
Appendices also include material that pertains to other Divisions that 
have not been reviewed and approved by the NRC. Although this 
information is included in the sections and appendices being 
incorporated by reference, the NRC notes that the use of Divisions 
other than Division 1 has not been approved, nor are they required by 
NRC regulations and, therefore, such information is not relevant to 
current applicants and licensees. Therefore, this proposed rule would 
clarify that current applicants and licensees may only use the sections 
of the Mandatory Appendices that pertain to Division 1. The NRC is not 
taking a position on the non-Division 1 information in the appendices 
and is including it in the incorporation by reference only for 
convenience.
10 CFR 50.55a(b)(1)(v) Section III Condition: Independence of 
Inspection
    The 1995 Edition through the 2009b Addenda of the 2007 Edition of 
ASME BPV Code, Section III, Subsection NCA, endorsed the NQA-1-1994 
Edition in NCA-4000, ``Quality Assurance.'' Paragraph (a) of NCA-
4134.10, ``Inspection,'' states, ``The provisions of NQA-1 Basic 
Requirement 10 and Supplement 10S-1, shall apply, except for paragraph 
3.1, and the requirements of Inservice Inspection.'' Paragraph 3.1, 
``Reporting Independence,'' of Supplement 10S-1, of NQA-1, states, 
``Inspection personnel shall not report directly to the immediate 
supervisors who are responsible for performing the work being 
inspected.'' In the 2010 Edition through the latest ASME BPV Code 
Editions of NCA, the Code removed the paragraph 3.1 exception for 
reporting independence.
    Based on the above changes to the Code, the NRC is proposing to 
revise the condition to reflect that this condition is applicable only 
for the 1995 Edition through 2009b Addenda of the 2007 Edition, where 
the NQA-1-1994 Edition is referenced.
10 CFR 50.55a(b)(1)(vi) Section III Condition: Subsection NH
    The NRC proposes to revise this existing condition since Subsection 
NH of Section III Division 1 no longer exists in the 2017 Edition of 
ASME BPV Code, Section III Division 1. The change is to reflect that 
Subsection NH existed from the 1995 Addenda through 2015 Edition of 
Section III Division 1. In 2015, Subsection NH contents also were 
included in Section III Division 5 Subpart B. In the 2017 Edition of 
the ASME Code, Subsection NH was deleted from Division 1 of Section III 
and became part of Division 5 of Section III. Division 5 of Section III 
is not incorporated by reference in Sec.  50.55a. Therefore, the NRC 
proposes to revise the condition to make it applicable to the 1995 
Addenda through all Editions and addenda up to and including the 2013 
Edition.
10 CFR 50.55a(b)(1)(x) Section III Condition: Visual Examination of 
Bolts, Studs, and Nuts
    The visual examination is one of the processes for acceptance of a 
bolt, stud or nut to ensure its structural integrity and its ability to 
perform its intended function. The 2015 Edition of the ASME Code 
contains this requirement, however the 2017 Edition does not require 
these visual examinations to be performed in accordance with NX-5100 
and NX-5500. Therefore, the NRC proposes to add two conditions to 
ensure adequate procedures remain and qualified personnel remain 
capable of determining the structural integrity of these components.
10 CFR 50.55a(b)(1)(x) Section III Condition: Visual Examination of 
Bolts, Studs, and Nuts, First Provision
    The NRC is adding Sec.  50.55a(b)(1)(x) to condition the provisions 
of NB-2582, NC-2582, ND-2582, NE-2582, NF-2582, NG-2582 in the 2017 
Edition of Section III. The condition is that the visual examinations 
are required to be performed in accordance with procedures qualified to 
NB-5100, NC-5100, ND-5100, NE-5100, NF-5100, and NG-5100, and personnel 
qualified to NB-5500, NC-5500, ND-5500, NE-5500, NF-5500, and NG-5500, 
respectively. The 2015 Edition of the ASME Code contains this 
requirement. The visual examination is one of the processes for 
acceptance of the final product to ensure its structural integrity and 
its ability to perform its intended function. The 2017 Edition does not 
require these visual examinations to be performed in accordance with 
NX-5100 and NX-5500. All other final examinations (MT, PT, UT and RT) 
for acceptance of the final product in the 2017 Edition require the 
procedures and personnel to be qualified to NX-5100 and NX-5500.
    Therefore, the NRC proposes to add Sec.  50.55a(b)(1)(x)(A) to 
condition the provisions of NB-2582, NC-2582, ND-2582, NE-2582, NF-
2582,and NG-2582 in the 2017 Edition of Section III to require that 
procedures are qualified to NB-5100, NC-5100, ND-5100, NE-5100, NF-
5100, and NG-5100, and personnel are qualified to NB-5500, NC-5500, ND-
5500, NE-5500, NF-5500, and NG-5500, respectively, in order to ensure 
adequate procedures and personnel remain capable of determining the 
structural integrity of these components. This is particularly 
important for small bolting, studs and nuts that only receive a visual 
examination. As stated in NX-4123 of Section III, only inspections 
performed in accordance with Article NX-4000 (e.g., marking, 
dimensional measurement, fitting, alignment) are exempted from NX-5100 
and NX-5500, and may be qualified in accordance with the Certificate 
Holder's Quality Assurance Program.

[[Page 56160]]

10 CFR 50.55a(b)(1)(x) Section III Condition: Visual Examination of 
Bolts, Studs, and Nuts, Second Provision
    The 2017 Edition requires that the final surfaces of threads, 
shanks, and the heads be visually examined against ASTM F788, for 
bolting material, and ASTM F812, for nuts, for workmanship, finish, and 
appearance. This examination is for acceptance of the final product to 
ensure its structural integrity, especially for small bolting that only 
receives a visual examination. However, performing an inspection for 
workmanship or appearance to the bolting specification is not 
necessarily sufficient to ensure the integrity of the bolts and nuts 
for their intended function in a reactor. The visual examination in 
Section III for bolting and nuts is intended to determine structural 
integrity for its intended function, which may entail quality 
requirements more stringent than the bolting specifications. As 
specified in the 2015 Edition of Section III: ``discontinuities such as 
laps, seams, or cracks that would be detrimental to the intended 
service are unacceptable.''
    Therefore, the NRC proposes to add Sec.  50.55a(b)(1)(x)(B) to 
condition the provisions of NB-2582, NC-2582, ND-2582, NE-2582, NF-
2582, and NG-2582 in the 2017 Edition of Section III, to require use of 
the acceptance criteria from NB-2582, NC-2582, ND-2582, NE-2582, NF-
2582, and NG-2582 in the 2015 Edition of Section III.
10 CFR 50.55a(b)(1)(xi) Section III Condition: Mandatory Appendix XXVI
    The NRC proposes to add a new paragraph with conditions on the use 
of ASME BPV Code, Section III, Appendix XXVI for installation of high 
density polyethylene (HDPE) pressure piping. This Appendix is new in 
the 2015 Edition of Section III, and electrofusion joining was added to 
this Appendix in the 2017 Edition of Section III. The 2015 Edition of 
Section III is the first time the ASME Code has provided rules for the 
use of polyethylene piping. The NRC has determined that the conditions 
that follow in Sec.  50.55a(b)(1)(xi)(A) through (E) are necessary in 
order to utilize polyethylene piping in Class 3 safety-related 
applications. The conditions in Sec.  50.55a(b)(1)(xi)(A) and (B) 
pertain to butt fusion joints and apply to both the 2015 and 2017 
Editions of Section III. The conditions in Sec.  50.55a(b)(1)(xi)(C) 
through (E) pertain to electrofusion joints and apply only to the 2017 
Edition of Section III.
    Both NRC and industry-funded independent research programs have 
shown that joint failure is the most likely cause of structural failure 
in HDPE piping systems. Poorly manufactured joints are susceptible to 
early structural failure driven by ``slow crack growth,'' a form of 
subcritical creep crack growth that is active in HDPE. The 5 provisions 
below are aimed at ensuring the highest quality for joints in HDPE 
systems and reducing the risk of poor joint fabrication. These 
provisions minimize the risk of joint structural failure and the 
resulting potential loss of system safety function.
10 CFR 50.55a(b)(1)(xi)(A) Mandatory Appendix XXVI: First Provision
    The NRC proposes to add a new paragraph (b)(1)(xi)(A), which 
specifies the essential variables to be used in qualifying fusing 
procedures for butt fusion joints in polyethylene piping installed in 
accordance with ASME Section III, Mandatory Appendix XXVI. The NRC does 
not endorse the use of a standardized fusing procedure specification. A 
fusion procedure specification will need to be generated for each butt 
fusion joint with the essential variables, as listed. The same 
variables will be listed for operator performance qualifications.
    Per ASME BPV Code Section IX, QF-252, essential variables are those 
that will affect the mechanical properties of the fused joint, if 
changed, and require requalification of the Fusing Procedure 
Specification (FPS), Standard Fusing Procedure Specification (SFPS), or 
Manufacturer Qualified Electrofusion Procedure Specification (MEFPS) 
when any change exceeds the specified limits of the values recorded in 
the FPS for that variable. Fourteen essential variables for HDPE butt 
fusion joints for nuclear applications have been identified by NRC and 
industry experts through extensive research and field experience. Ten 
of these essential variables are the same as those identified in ASME 
BPV Code, Section IX, Table QF-254, which applies to all HDPE butt 
fusions and is not limited to nuclear applications. The other 4 
variables deemed essential by the NRC are: Diameter, cross-sectional 
area, ambient temperature, and fusing machine carriage model. These 4 
additional variables are recognized by industry experts as being 
essential for butt fusion joints in nuclear safety applications, and 
have been included in a proposal to list essential variables for butt 
fusion in the 2019 Edition of ASME BPV Code, Section III, Mandatory 
Appendix XXVI.
    For nuclear applications, the use of HDPE is governed by ASME BPV 
Code, Section III, Mandatory Appendix XXVI. The NRC has determined that 
to ensure butt fusion joint quality is adequate for nuclear safety 
applications, referencing ASME BPV Code, Section IX in ASME BPV Code, 
Section III, Mandatory Appendix XXVI is not sufficient, because ASME 
BPV Code, Section IX is not incorporated into NRC regulations. 
Therefore, the NRC is including the essential variables for HDPE butt 
fusion as a condition on the use of ASME BPV Code Section III, 
Mandatory Appendix XXVI. This provision addresses the fact that the 
essential variables for HDPE butt fusion are not listed in the 2015 and 
2017 Editions of ASME BPV Code, Section III, Mandatory Appendix XXVI. 
Proposals to incorporate these essential variables for butt fusion in 
the 2019 Edition of the Code have already been drafted and circulated 
within the ASME Code Committees. In the meantime, the NRC is proposing 
to add this provision to ensure butt fusion joint quality for nuclear 
safety applications.
10 CFR 50.55a(b)(1)(xi)(B) Mandatory Appendix XXVI: Second Provision
    The NRC proposes to add a new paragraph (b)(1)(xi)(B), which will 
require both bend tests and high speed tensile impact testing (HSTIT) 
to qualify fusing procedures for joints in polyethylene piping 
installed in accordance with ASME BPV Code, Section III, Mandatory 
Appendix XXVI. The NRC requires both bend tests and HSTIT to qualify 
the fusion procedures. There is data that suggests that HSTIT may not 
distinguish between an acceptable and unacceptable HDPE butt fusion 
joint and, therefore, should not be considered as a stand-alone test.
    The NRC has performed limited confirmatory research on the ability 
of short-term mechanical tests to predict the in-service behavior of 
HDPE butt fusion joints. Based on this research as well as research 
results from The Welding Institute in the UK, the NRC lacks conclusive 
evidence that either of the two tests proposed in XXVI-4342(d) and 
XXVI-4342(e) is always a reliable predictor of joint quality. As a 
result, the NRC has determined that the combination of both test 
results provides increased and sufficient indication of butt fusion 
joint quality. Consequently, the NRC is proposing to add a condition 
that requires both tests specified in in XXVI-4342(d) and XXVI-4342(e) 
to be performed as part of performance qualification tests, instead of 
only one or the other.
10 CFR 50.55a(b)(1)(xi)(C) Mandatory Appendix XXVI: Third Provision
    The NRC is proposing to add a new paragraph (b)(1)(xi)(C), which 
specifies the essential variables to be used in

[[Page 56161]]

qualifying fusing procedures for electrofusion of fusion joints in 
polyethylene piping that is to be installed in accordance with ASME BPV 
Code, Section III, Mandatory Appendix XXVI. The NRC does not endorse 
the use of a standardized fusing procedure specification. A fusion 
procedure specification will need to be generated for each 
electrofusion joint with the essential variables as listed. The same 
variables will be listed for operator performance qualifications.
    Per ASME BPV Code, Section IX, QF-252: ``Essential variables are 
those that will affect the mechanical properties of the fused joint, if 
changed, and require requalification of the FPS, SFPS, or MEFPS when 
any change exceeds the specified limits of the values recorded in the 
FPS for that variable.'' Sixteen essential variables for HDPE 
electrofusion for nuclear applications have been identified by NRC and 
industry experts through extensive research and field experience. 
Twelve of these essential variables are the same as those identified in 
ASME BPV Code, Section IX Table QF-255, which applies to all HDPE 
electrofusion and is not limited to nuclear applications. The other 4 
variables deemed essential by the NRC are: fitting polyethylene 
material, pipe wall thickness, power supply, and processor. These 4 
additional variables are recognized by industry experts as being 
essential for electrofusion joints in nuclear safety applications, and 
have been included in a proposal to list essential variables for 
electrofusion in the 2019 Edition of ASME BPV Code, Section III 
Mandatory Appendix XXVI.
    For nuclear applications, the use of HDPE is governed by ASME BPV 
Code, Section III Mandatory Appendix XXVI. The NRC has determined that, 
to ensure electrofusion joint quality is adequate for nuclear safety 
applications, referencing ASME BPV Code, Section IX in ASME BPV Code, 
Section III Mandatory Appendix XXVI is not sufficient, because ASME BPV 
Code, Section IX is not incorporated into NRC regulations. Therefore, 
the NRC is including the essential variables for HDPE electrofusion as 
a condition on the use of ASME Section III, Mandatory Appendix XXVI. 
This provision addresses the fact that the essential variables for HDPE 
electrofusion are not listed in the 2015 and 2017 Editions of ASME BPV 
Code, Section III, Mandatory Appendix XXVI. Proposals to incorporate 
these essential variables for electrofusion in the 2019 Edition of the 
Code have already been drafted and circulated within the ASME Code 
Committees. In the meantime, the NRC proposes to add this provision to 
ensure electrofusion joint quality for nuclear safety applications.
10 CFR 50.55a(b)(1)(xi)(D) Mandatory Appendix XXVI: Fourth Provision
    The NRC is proposing to add a new paragraph (b)(1)(xi)(D), which 
will require both crush tests and electrofusion bend tests to qualify 
fusing procedures for electrofusion joints in polyethylene piping 
installed in accordance with the 2017 Edition of ASME BPV Code, Section 
III, Mandatory Appendix XXVI. The NRC proposes to require both crush 
tests and electrofusion bend tests to qualify the electrofusion 
procedures. The operating experience data on electrofusion joints is 
extremely limited and also indicates some failures. In order to ensure 
structural integrity of electrofusion joints in safety related 
applications, the NRC is proposing to require that both crush tests and 
electrofusion bend tests be performed to demonstrate an acceptable HDPE 
electrofusion joint test.
    Furthermore, a demonstration that the system or repair will not 
lose the ability to perform its safety function during its service life 
must be provided for systems that use electrofusion joints. The NRC 
lacks conclusive evidence regarding the ability of short-term 
mechanical tests to predict the in-service behavior of HDPE 
electrofusion joints in nuclear safety related applications. The NRC 
considers that either of the 2 tests (crush test or electrofusion bend 
test) proposed in XXVI-2332(a) and XXVI-2332(b), separately, may not be 
a reliable predictor of electrofusion joint quality. As a result, the 
NRC has determined that the combination of both test results provides 
increased and sufficient indication of electrofusion joint quality. 
Consequently, the NRC is proposing to add a condition that requires 
that both tests (crush test and electrofusion bend test) specified in 
in XXVI-2332(a) and XXVI-2332(b) be performed as part of performance 
qualification tests, instead of only one or the other.
10 CFR 50.55a(b)(1)(xi)(E) Mandatory Appendix XXVI: Fifth Provision
    The NRC is proposing to add a new paragraph (b)(1)(xi)(E), which 
prohibits the use of electrofusion saddle fittings and electrofusion 
saddle joints. The NRC believes that the failure of electrofusion 
saddle joints can result in a gross structural rupture leading to loss 
of safety function for the system where such a joint is present. 
Consequently, only full 360[deg] seamless sleeve electrofusion 
couplings (Electrofusion coupling, as shown in Table XXVI-3311-1 of the 
ASME BPV Code, Section III, 2017 Edition) and full 360[deg] 
electrofusion socket joints (as shown in the top image in Figure XXVI-
4110-2 of ASME BPV Code, Section III, 2017 Edition) are permitted.
    Very limited information and operational experience is available 
for electrofusion joints in nuclear safety applications, and some 
Department of Energy operational experience indicates that failures 
have occurred in electrofusion joints. The NRC has determined that the 
failure of a saddle type electrofusion joint could result in structural 
separation of the electrofusion saddle coupling from the HDPE pipe it 
is attached to, resulting in a potential loss of flow and loss of 
safety function in the system. As a result, the NRC is proposing to add 
a condition that will only allow full 360[deg] seamless sleeve type 
electrofusion couplings, attached with a socket type electrofusion 
joint. The failure of such a joint is far less likely to result in a 
total loss of flow and safety function. For full 360[deg] seamless 
sleeve type electrofusion couplings attached with a socket type 
electrofusion joint, full separation of the coupling from the pipe is 
highly unlikely.
10 CFR 50.55a(b)(1)(xii) Section III Condition: Certifying Engineer
    The NRC is proposing to add a new condition Sec.  50.55a(b)(1)(xii) 
Section III Condition: Certifying Engineer. In the 2017 Edition of ASME 
BPV Code, Section III, Subsection NCA, the following Subsections were 
updated to replace the term ``registered professional engineer,'' with 
term ``certifying engineer'' to be consistent with ASME BPV Code 
Section III Mandatory Appendix XXIII.

 NCA-3255 ``Certification of the Design Specifications''
 NCA-3360 ``Certification of the Construction Specification, 
Design Drawings, and Design Report''
 NCA-3551.1 ``Design Report''
 NCA-3551.2 ``Load Capacity Data Sheet''
 NCA-3551.3 ``Certifying Design Report Summary'' and
 NCA-3555 ``Certification of Design Report''
 Table NCA-4134.17-2, ``Nonpermanent Quality Assurance 
Records''
 NCA-5125, ``Duties of Authorized Nuclear Inspector 
Supervisors''
 NCA-9200, ``Definitions''

    The NRC reviewed these changes and has determined that the use of a 
certifying engineer in lieu of a registered professional engineer is 
only applicable

[[Page 56162]]

for non-U.S. nuclear facilities. Therefore, the term ``certifying 
engineer'' is not applicable to U.S. nuclear facilities regulated by 
the NRC. As a result, the NRC is proposing to add a new condition to 
Sec.  50.55a (b)(1), that would not allow applicants and licensees to 
use a certifying engineer in lieu of a registered professional engineer 
for code-related activities that are applicable to U.S. nuclear 
facilities regulated by the NRC.

B. ASME BPV Code, Section XI

10 CFR 50.55a(b)(2) Conditions on ASME BPV Code, Section XI
    The NRC proposes to amend the regulations in Sec.  50.55a(b)(2) to 
incorporate by reference the 2015 and the 2017 Editions (Division 1) of 
the ASME BPV Code, Section XI. The current regulations in Sec.  
50.55a(b)(2) incorporate by reference ASME BPV Code, Section XI, 1970 
Edition through the 1976 Winter Addenda; and the 1977 Edition (Division 
1) through the 2013 Edition (Division 1), subject to the conditions 
identified in current Sec.  50.55a(b)(2)(i) through (b)(2)(xxix). The 
proposed amendment would revise the introductory text to Sec.  
50.55a(b)(2) to incorporate by reference the 2015 Edition (Division 1) 
and the 2017 Edition (Division 1) of the ASME BPV Code, Section XI, 
clarify the wording, and revise or provide some additional conditions, 
as explained in this document.
10 CFR 50.55a(b)(2)(vi) Effective Edition and Addenda of Subsection IWE 
and Subsection IWL
    The NRC proposes to remove existing condition Sec.  
50.55a(b)(2)(vi). A final rule was published in the Federal Register 
(61 FR 41303) on August 8, 1996, which incorporated by reference the 
ASME BPV Code, Section XI, Subsection IWE and Subsection IWL for the 
first time. The associated statements of consideration for that rule 
identified the 1992 Edition with 1992 Addenda of Subsection IWE and 
Subsection IWL as the earliest version that the NRC found acceptable. A 
subsequent rule published on September 22, 1999 (64 FR 51370), included 
the 1995 Edition with the 1996 Addenda as an acceptable edition of the 
ASME BPV Code. The statements of considerations for a later rule 
published on September 26, 2002 (67 FR 60520), noted that the 1992 
Edition with the 1992 Addenda, or the 1995 Edition with the 1996 
Addenda of Subsection IWE and IWL must be used when implementing the 
initial 120-month interval for the ISI of Class MC and Class CC 
components, and that successive 120-month interval updates must be 
implemented in accordance with Sec.  50.55a(g)(4)(ii).
    This requirement was in place to expedite the initial containment 
examinations in accordance with Subsections IWE and IWL, which were 
required to be completed during the 5-year period from September 6, 
1996, to September 9, 2001. Now that there is an existing framework in 
place for containment examinations in accordance with Subsections IWE 
and IWL, there is no need for a condition specific to the initial 
examination interval. The examinations conducted during the initial 
interval can be conducted in accordance with Sec.  50.55a(g)(4).
10 CFR 50.55a(b)(2)(vii): Section XI Condition: Section XI References 
to OM Part 4, OM Part 6, and OM Part 10 (Table IWA-1600-1).
    The NRC proposes to remove the condition found in Sec.  
50.55a(b)(2)(vii) of the current regulations. This paragraph describes 
the editions and addenda of the ASME OM Code to be used with the 
Section XI references to OM Part 4, OM Part 6, and OM Part 10 in Table 
IWA-1600-1 of Section XI. The condition is applicable to the ASME BPV 
Code, Section XI, Division 1, 1987 Addenda, 1988 Addenda, or 1989 
Edition. Paragraph (g)(4)(ii) requires that a licensee's successive 
120-month inspection intervals comply with the requirements of the 
latest edition and addenda of the Code incorporated by reference in 
Sec.  50.55a(b)(2). Because licensees are no longer using these older 
editions and addenda of the Code referenced in this paragraph, this 
condition can be removed.
10 CFR 50.55a(b)(2)(ix) Metal Containment Examinations
    The NRC proposes to revise Sec.  50.55a(b)(2)(ix), to require 
compliance with new condition Sec.  50.55a(b)(2)(ix)(K). The proposed 
condition will ensure containment leak-chase channel systems are 
properly inspected in accordance with the applicable requirements. The 
NRC specifies the application of this condition to all editions and 
addenda of Section XI, Subsection IWE, of the ASME BPV Code, prior to 
the 2017 Edition, that are incorporated by reference in paragraph (b) 
of Sec.  50.55a.
10 CFR 50.55a(b)(2)(ix)(K) Metal Containment Examinations
    The NRC proposes to add Sec.  50.55a(b)(2)(ix)(K) to ensure 
containment leak-chase channel systems are properly inspected.
    Regulations in Sec.  50.55a(g), ``Inservice Inspection 
Requirements,'' require that licensees implement the inservice 
inspection program for pressure retaining components and their integral 
attachments of metal containments and metallic liners of concrete 
containments in accordance with Subsection IWE of Section XI of the 
applicable edition and addenda of the ASME Code, incorporated by 
reference in paragraph (b) of Sec.  50.55a and subject to the 
applicable conditions in paragraph (b)(2)(ix). The regulatory condition 
in Sec.  50.55a(b)(2)(ix)(A) or equivalent provision in Subsection IWE 
of the ASME Code (2006 and later editions and addenda only) requires 
that licensees shall evaluate the acceptability of inaccessible areas 
when conditions exist in accessible areas that could indicate the 
presence of, or result in, degradation to such inaccessible areas.
    The containment floor weld leak-chase channel system forms a metal-
to-metal interface with the containment shell or liner, the test 
connection end of which is at the containment floor level. Therefore, 
the leak-chase system provides a pathway for potential intrusion of 
moisture that could cause corrosion degradation of inaccessible 
embedded areas of the pressure-retaining boundary of the basemat 
containment shell or liner within it. In addition to protecting the 
test connection, the cover plates and plugs and accessible components 
of the leak-chase system within the access box are also intended to 
prevent intrusion of moisture into the access box and into the 
inaccessible areas of the shell/liner within the leak-chase channels, 
thereby protecting the shell and liner from potential corrosion 
degradation that could affect leak-tightness.
    The containment ISI program required by Sec.  50.55a to be 
implemented in accordance with Subsection IWE, of the ASME Code, 
Section XI, subject to regulatory conditions, requires special 
consideration of areas susceptible to accelerated corrosion degradation 
and aging, and barriers intended to prevent intrusion of moisture and 
water accumulation against inaccessible areas of the containment 
pressure-retaining metallic shell or liner. The containment floor weld 
leak-chase channel system is one such area subject to accelerated 
degradation and aging if moisture intrusion and water accumulation is 
allowed on the embedded shell and liner within it. Therefore, the leak-
chase channel system is subject to the inservice inspection 
requirements of Sec.  50.55a(g)(4).
    The NRC Information Notice (IN) 2014-07, ``Degradation of Leak-
Chase

[[Page 56163]]

Channel Systems for Floor Welds of Metal Containment Shell and Concrete 
Containment Metallic Liner,'' (ADAMS Accession No. ML14070A114) 
discusses examples of licensees that did not conduct the required 
inservice inspections. The IN also summarizes the NRC's basis for 
including the leak-chase components within the scope of Subsection IWE, 
of the ASME Code, Section XI, and how licensees could fulfill the 
requirements. The NRC guidance explains that 100 percent of the 
accessible components of the leak-chase system should be inspected 
during each inspection period. There are three inspection periods in 
one ten-year inspection interval.
    After issuance of IN 2014-07, the NRC received feedback during a 
public meeting between NRC and ASME management, held on August 22, 2014 
(ADAMS Accession No. ML14245A003), noting that the IN guidance appeared 
to be in conflict with ASME Section XI Interpretation XI-1-13-10. In 
response to the comment during the public meeting, the NRC issued a 
letter to ASME (ADAMS Accession No. ML14261A051), which stated that the 
NRC found the provisions in the IN to be consistent with the 
requirements in the ASME Code; and the NRC staff may consider adding a 
condition to Sec.  50.55a to clarify the expectations. The ASME 
responded to the NRC's letter (ADAMS Accession No. ML15106A627) and 
noted that a condition in the regulations may be appropriate to clarify 
the NRC's position.
    Based on the operating experience summarized in IN 2014-07, and the 
industry feedback, the NRC has determined that a new condition is 
necessary in Sec.  50.55a(b)(2)(ix) to clarify the NRC's expectations 
and to ensure steel containment shells and liners receive appropriate 
examinations. In the 2017 Edition of the ASME Code, a provision was 
added that clearly specifies the examination of leak-chase channels. 
The provision requires 100 percent examination of the leak-chase 
channel closures over a ten-year inspection interval, as opposed to 100 
percent during each inspection period. Although the examination 
frequency is relaxed compared to the NRC's position as identified in IN 
2014-07, the NRC finds the provision in the 2017 Edition acceptable 
because the examination includes provisions for scope expansion and 
examinations of additional closures if degradation is identified within 
an inspection period. The NRC chose to align the condition with the 
acceptable provision in the latest approved edition of the ASME Code. 
This proposed condition would be applicable to all editions and addenda 
of the ASME Code prior to the 2017 Edition.
10 CFR 50.55a(b)(2)(xvii) Section XI Condition: Reconciliation of 
Quality Requirements
    The NRC proposes to remove the condition found in the current Sec.  
50.55a(b)(2)(xvii). This paragraph describes requirements for 
reconciliation of quality requirements when purchasing replacement 
items. When licensees use the 1995 Addenda through 1998 Edition of ASME 
BPV Code, Section XI, this condition required replacement items to be 
purchased in accordance with the licensee's quality assurance program 
description required by 10 CFR 50.34(b)(6)(ii), in addition to the 
reconciliation provisions of IWA-4200. The NRC has accepted without 
conditions the content of IWA-4200 in versions of the Code since the 
1999 Addenda of Section XI. Paragraph 50.55a(g)(4)(ii) requires that 
licensee's successive 120-month inspection intervals comply with the 
requirements of the latest edition and addenda of the Code incorporated 
by reference in Sec.  50.55a(b)(2). Subsequently, licensees are no 
longer using these older editions and addenda of the Code referenced in 
this paragraph therefore this condition can be removed. Section 
50.55a(b)(2)(xvii) would be designated as [Reserved].
10 CFR 50.55a(b)(2)(xviii)(D) NDE Personnel Certification: Fourth 
Provision
    The NRC proposes to amend the condition found in Sec.  
50.55a(b)(2)(xviii) to extend the applicability of the condition 
through the latest edition incorporated by reference in paragraph 
(a)(1)(ii) of this section of ASME BPV Code, Section XI. This current 
condition prohibits those licensees which use ASME BPV Code, Section 
XI, 2011 Addenda through the 2013 Edition from using Appendix VII, 
Table VII-4110-1 and Appendix VIII, Subarticle VIII-2200. The condition 
requires licensees and applicants using these versions of Section XI to 
use the prerequisites for ultrasonic examination personnel 
certifications in Appendix VII, Table VII-4110-1 and Appendix VIII, 
Subarticle VIII-2200 in the 2010 Edition. This condition was added when 
the 2010 through the 2013 Edition was incorporated by reference. When 
ASME published the 2015 Edition and the 2017 Editions, Appendix VII, 
Table VII-4110-1 and Appendix VIII, Subarticle VIII-2200 of ASME BPV 
Code, Section XI were not modified in a way that would make it possible 
for the NRC to remove this condition. Therefore, the NRC is proposing 
to retain this condition to apply to the latest edition incorporated by 
reference in paragraph (a)(1)(ii) of Sec.  50.55a.
10 CFR 50.55a(b)(2)(xx)(B) Section XI Condition: System Leakage Tests: 
Second Provision
    The NRC proposes to amend the condition found in Sec.  
50.55a(b)(2)(xx)(B) to clarify the NRC's expectations related to the 
nondestructive examination (NDE) required when a system leakage test is 
performed (in lieu of a hydrostatic test) following repair and 
replacement activities performed by welding or brazing on a pressure 
retaining boundary using the 2003 Addenda through the latest edition 
and addenda of ASME BPV Code, Section XI incorporated by reference in 
paragraph (a)(1)(ii) of Sec.  50.55a. Industry stakeholders have 
expressed confusion on what was required by the current regulation with 
regard to the Code edition/addenda that the requirements for NDE and 
pressure testing were required to satisfy under this condition. The NRC 
is proposing to modify the condition to clarify that the NDE method 
(e.g., surface, volumetric, etc.) and acceptance criteria of the 1992 
or later of ASME BPV Code, Section III shall be met. The actual 
nondestructive examination and pressure testing may be performed using 
procedures and personnel meeting the requirements of the licensee's/
applicant's current ISI code of record. This condition was first put in 
place by the NRC in a final rule, which became effective October 10, 
2008 (73 FR 52730). The NRC determined the condition was necessary 
because the ASME BPV Code eliminated the requirement to perform the 
Section III NDE when performing a system leakage test in lieu of a 
hydrostatic test following repairs and replacement activities performed 
by welding or brazing on a pressure retaining boundary in the 2003 
Addenda of ASME BPV Code, Section XI. When ASME published the 2015 
Edition and the 2017 Editions, IWA-4520 was not modified in a way that 
would make it possible for the NRC to remove this condition. Therefore, 
the NRC is proposing to retain this condition to apply to the latest 
edition incorporated by reference in paragraph (a)(1)(ii) of Sec.  
50.55a.
10 CFR 50.55a(b)(2)(xx)(C) Section XI Condition: System Leakage Tests: 
Third Provision
    The NRC proposes to add Sec.  50.55a(b)(2)(xx)(C) to provide 2 
conditions for the use of the alternative

[[Page 56164]]

Boiling Water Reactor (BWR) Class 1 system leakage test described in 
IWB-5210(c) and IWB-5221(d) of the 2017 Edition of ASME Section XI. 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.
    The alternative BWR Class 1 system leakage test was intended to 
address concerns that performing the ASME-required pressure test for 
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-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 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 longstanding 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's 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 creates 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 IN No. 
98-13, ``Post-Refueling Outage Reactor Pressure Vessel Leakage Testing 
Before Core Criticality,'' dated April 20, 1998. The IN was issued in 
response to a licensee that had conducted an ASME BPV Code, Section XI, 
leakage test of the reactor pressure vessel (RPV) and subsequently 
discovered that it had violated 10 CFR part 50, appendix G, paragraph 
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 IN references NRC 
Inspection Report 50-254(265)-97027 (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 has determined that pressure testing with the core 
critical is acceptable under the following conditions: When 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 verifying the integrity of 
the overall RCPB. The NRC also notes the alternative BWR Class 1 system 
leakage test 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 has 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. It is 
more difficult to control temperature and pressure when there is 
significant production of decay heat (e.g., after a mid-cycle outage), 
and may reduce the margin available to prevent exceeding the plant 
pressure-temperature limits.
    When the pressure test is conducted using nuclear heat, the scope 
of repairs should be relatively small in order to minimize the 
personnel safety risk and to avoid rushed examinations. The alternative 
BWR Class 1 system leakage test does not place any restrictions on the 
size or scope of the repairs for which the alternative may be used, 
provided the alternative test pressure is not used to satisfy 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 14 days or less. This would tend to limit the 
scope of repairs, and also limit the use of the code case to outages 
where there is a significant production of decay heat. Therefore, the 
first condition on the alternative BWR Class 1 system leakage test 
states: ``The use of nuclear heat to conduct the BWR Class 1 system 
leakage test is prohibited (i.e.

[[Page 56165]]

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 the alternative BWR Class 
1 system leakage test indicates that the lower test pressure provides 
more than 90 percent of the flow that 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, the alternative BWR 
Class 1 system leakage test 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. Some types of defects could result in immediate 
leakage, such as an improperly torqued bolted connection; however other 
types of defects, such as weld defects or tight cracks, could present a 
more torturous path for leakage and result in delayed leakage. Due to 
the uncertainty in the amount of time required for leakage to occur to 
an extent that it would be readily detectable by visual examination, 
the NRC has determined that it is appropriate to conservatively specify 
a longer hold time of 1 hour for non-insulated components. Therefore, 
the second condition for the alternative BWR Class 1 system leakage 
test would require a one hour hold time for non-insulated components.
10 CFR 50.55a(b)(2)(xxi) Section XI Condition: Table IWB-2500-1 
Examination Requirements
    The NRC proposes to remove the condition found in Sec.  
50.55a(b)(2)(xxi)(A) to allow licensees to use the current editions of 
ASME BPV Code, Section XI, Table IWB 2500-1, Examination Category B-D, 
Full Penetration Welded Nozzles in Vessels, Items B3.40 and B3.60 
(Inspection Program A) and Items B3.120 and B3.140 (Inspection Program 
B). These inspection categories concern pressurizer and steam generator 
nozzle inner radius section examinations. Previously, the condition 
required licensees to use the 1998 Edition, which required examination 
of the nozzle inner radius when using the 1999 Addenda through the 
latest edition and addenda incorporated by reference in paragraph 
(a)(1)(ii) of Sec.  50.55a. As these inspection requirements were 
removed in the ASME BPV Code in 1999, this change would effectively 
eliminate the requirement to examine the nozzle inner radii in steam 
generators and pressurizers.
    The requirements for examinations of inner nozzle radii in several 
components were developed in the ASME BPV Code in reaction to the 
discovery of thermal fatigue cracks in the inner-radius section of 
boiling water reactor feedwater nozzles in the late 1970's and early 
1980's. As described in NUREG/CR-7153, ``Expanded Materials Degradation 
Assessment (EMDA),'' (ADAMS Accession Nos. ML14279A321, ML14279A461, 
ML14279A349, ML14279A430, and ML14279A331), and NUREG-0619-Rev-1, ``BWR 
Feedwater Nozzle and Control Rod Drive Return Line Nozzle Cracking: 
Resolution of Generic Technical Activity A-10 (Technical Report),'' 
(ADAMS Accession No. ML031600712), the service-induced flaws that have 
been observed are cracks at feedwater nozzles associated with mixing of 
lower-temperature water with hot water in a BWR vessel with rare 
instances of underclad and shallow cladding cracking appearing in 
pressurized water reactor (PWR) nozzles. Feedwater nozzle inner radius 
cracking has not been detected since the plants changed operation of 
the low flow feedwater controller. Significant inspections and repairs 
were required in the late 1970s and early 1980s to address these 
problems. The redesign of safe end/thermal sleeve configurations and 
feedwater spargers, coupled with changes in operating procedures, has 
been effective to date. No further occurrences of nozzle fatigue 
cracking have been reported for PWRs or BWRs.
    When the new designs and operating procedures appeared to have 
mitigated the nozzle inner radius cracking, the ASME BPV Code, Section 
XI requirements to inspect steam generator and pressurizer nozzle inner 
radii were removed in the 1999 Addenda of ASME BPV Code, Section XI. 
Since the NRC imposed the condition requiring that these areas be 
inspected in 2002, no new cracking has been identified in steam 
generator or pressurizer nozzle inner radii. The NRC finds that the 
complete absence of cracking since the operational change provides 
reasonable assurance that the observed cracking was the result of 
operational practices that have been discontinued. Because the inner 
radius inspections were instituted solely based on the observed 
cracking and since the cracking mechanism has now been resolved through 
changes in operation, the NRC finds that the intended purpose of the 
steam generator and pressurizer inner radius exams no longer exists and 
that the exams can be discontinued.
    In addition to operating experience, the NRC has reviewed the 
nozzle inner radii examinations as part of approving alternatives and 
granting relief requests concerning inspections of the pressurizer and 
steam generator nozzle inner radii. In the safety evaluations for 
proposed alternatives, the NRC has concluded that the fatigue analysis 
for a variety of plants shows that there is reasonable assurance that 
there will not be significant cracking at the steam generator or 
pressurizer nozzle inner radii before the end of the operating licenses 
of the nuclear power plants.
    Therefore, based on the design changes, operating experiences, and 
analysis done by industry and the NRC, the NRC proposes to remove Sec.  
55.55a(b)(2)(xxi)(A), which requires the inspection of pressurizer and 
steam generator nozzle inner radii.
10 CFR 50.55a(b)(2)(xxi)(B) Section XI Condition: Table IWB-2500-1 
Examination Requirements
    The NRC is proposing to add a new paragraph (b)(2)(xxi)(B) that 
will place conditions on the use of the provisions of IWB-2500(f) and 
(g) and Notes 6 and 7 of Table IWB-2500-1 of the 2017 Edition of ASME 
BPV Code, Section XI. These provisions would allow licensees of BWRs to 
reduce the number of Item Number B3.90 and B3.100 components to be 
examined from 100 percent to 25 percent. These conditions would require 
licensees using the provisions of IWB-2500(f) to maintain the 
evaluations that determined the plant satisfied the criteria of IWB-
2500(f) as records in accordance with IWA-1400. The conditions would 
prohibit use of a new provision in Section XI, 2017 Edition, Table 
2500-1 Category B-D, Full Penetration Welded Nozzles in Vessels, Items 
B3.90 and B3.100, specific to BWR nuclear power plants with renewed 
operating licenses or renewed combined licensees in accordance with 10 
CFR part 54. The final condition would not allow the use of these 
provisions to eliminate preservice or inservice volumetric examinations 
of plants with a Combined Operating License pursuant to 10 CFR part 52, 
or a plant that receives its operating license after October 22, 2015.

[[Page 56166]]

    The addition of these provisions addresses the incorporation of 
Code Case N-702, ``Alternative Requirements for Boiling Water Reactor 
(BWR) Nozzle Inner Radius and Nozzle-to-Shell Welds Section XI, 
Division 1 into the Code. The proposed conditions are consistent with 
those proposed for Regulatory Guide 1.147, ``Inservice Inspection Code 
Case Acceptability, ASME Section XI, Division 1,'' Revision 19.
    The NRC finds that eliminating the volumetric preservice or 
inservice examination, as would be allowed by implementing the 
provisions of IWB-2500(g) and Note 7 of Table IWB-2500-1, should be 
predicated on good operating experience for the existing fleet, which 
has not found any inner radius cracking in the nozzles within scope of 
the code case. New reactor designs do not have any operating 
experience; therefore, the proposed condition will ensure that new 
reactors would perform volumetric examinations of nozzle inner radii to 
gather operating experience.
10 CFR 50.55a(b)(2)(xxv) Section XI Condition: Mitigation of Defects by 
Modification
    The NRC proposes to amend the condition found in Sec.  
50.55a(b)(2)(xxv) to allow the use of IWA-4340 of ASME BPV Code, 
Section XI, 2011 Addenda through 2017 Edition with conditions. The 
modification of Sec.  50.55a(b)(2)(xxv) would add paragraph (A) and 
would continue the prohibition of IWA-4340 for Section XI editions and 
addenda prior to the 2011 Addenda. It would also add paragraph (B), 
which would contain the three conditions that the NRC is proposing to 
place on the use of IWA-4340 of Section XI, 2011 Addenda through 2017 
Edition.
10 CFR 50.55a(b)(2)(xxv)(A) Mitigation of Defects by Modification: 
First Provision
    The NRC proposes to add paragraph (b)(2)(xxv)(A), which would 
continue the prohibition of IWA-4340 for Section XI editions and 
addenda prior to the 2011 Addenda. IWA-4340 as originally incorporated 
into Section XI, Subsubarticle IWA-4340 did not include critical 
requirements that were incorporated into later editions of Section XI 
such as: (a) Characterization of the cause and projected growth of the 
defect; (b) verification that the flaw is not propagating into material 
credited for structural integrity; (c) prohibition of repeated 
modifications where a defect area grew into the material required for 
the modification; and (d) pressure testing. Therefore, the NRC 
prohibited the use of IWA-4340 in its original form. This new paragraph 
would be necessary to maintain the prohibition because the NRC, as 
described in the following paragraph, is proposing to allow the use of 
IWA-4340 of Section XI, 2011 Addenda through 2017 Edition.
10 CFR 50.55a(b)(2)(xxv)(B) Mitigation of Defects by Modification: 
Second Provision
    The NRC proposes to add paragraph (b)(2)(xxv)(B) to allow the use 
of IWA-4340 of Section XI, 2011 Addenda through 2017 Edition with three 
conditions. The NRC finds that IWA-4340 as incorporated into later 
editions of Section XI was improved with requirements such as: (a) 
Characterization of the cause and projected growth of the defect; (b) 
verification that the flaw is not propagating into material credited 
for structural integrity; (c) prohibition of repeated modifications 
where a defect area grew into the material required for the 
modification; and (d) pressure testing. With inclusion of these 
requirements and those stated in the following conditions, the NRC 
concludes that there are appropriate requirements in place to provide 
reasonable assurance that the modification will provide an adequate 
pressure boundary, even while considering potential growth of the 
defect. The conditions and the basis for each are as follows:
     The first proposed condition would prohibit the use of 
IWA-4340 on crack-like defects or those associated with flow 
accelerated corrosion. The design requirements and potentially the 
periodicity of follow-up inspections might not be adequate for crack-
like defects that could propagate much faster than defects due to loss 
of material. Therefore, the NRC proposes to prohibit the use of IWA-
4340 on crack-like defects. Loss of material due to flow accelerated 
corrosion is managed by licensee programs based on industry standards. 
The periodicity of follow-up inspections is best managed by plant-
specific flow accelerated corrosion programs. In addition, subparagraph 
IWA-4421(c)(2) provides provisions for restoring minimum required wall 
thickness by welding or brazing, including loss of material due to flow 
accelerated corrosion.
     The second proposed condition would require the design of 
a modification that mitigates a defect to incorporate a loss of 
material rate either 2 times the actual measured corrosion rate in the 
location, or 4 times the estimated maximum corrosion rate for the 
piping system. Corrosion rates are influenced by local conditions 
(e.g., flow rate, discontinuities). The condition to extrapolate a loss 
of material rate either 2 times the actual measured corrosion rate in 
the location, or 4 times the estimated maximum corrosion rate for the 
system is consistent with ASME Code Cases N-786-1, ``Alternative 
Requirements for Sleeve Reinforcement of Class 2 and 3 Moderate Energy 
Carbon Steel Piping,'' and N-789, ``Alternative Requirements for Pad 
Reinforcement of Class 2 and 3 Moderate Energy Carbon Steel Piping for 
Raw Water Service.'' The NRC concludes that these multipliers are 
appropriate if the wall thickness measurements in the vicinity of the 
defect were only obtained once. In contrast, if wall thickness 
measurements were obtained in two or more refueling outage cycles, the 
NRC concludes that there is a sufficient span of time to be able to 
trend the corrosion rate into the future. This conclusion is based in 
part on the follow-up wall thickness measurements that are conducted 
subsequent to installation of the modification.
     The third proposed condition would require the Owner to 
perform a wall thickness examination in the vicinity of the 
modification and relevant pipe base metal during each refueling outage 
cycle to detect propagation of the flaw into the material credited for 
structural integrity of the item, unless the examinations in the two 
refueling outage cycles subsequent to the installation of the 
modification are capable of validating the projected flaw growth. The 
NRC concludes that the provision allowed by subparagraph IWA-4340(g) to 
conduct follow-up wall thickness measurements only to the extent that 
they demonstrate that the defect has not propagated into the material 
credited for structural integrity is not sufficient because it does not 
provide a verification of the projected flaw growth. Subparagraph IWA-
4340(h) does not fully address the NRC's concern because it allows for 
projected flaw growth to be based on ``prior Owner or industry 
experiences with the same conditions'' instead of specific measurements 
in the location of the modification. The proposed condition allows for 
only conducting examinations in the two refueling outages subsequent to 
the installation of the modification, consistent with subparagraph IWA-
4340(g), if the measurements are capable of projecting the flaw growth.

[[Page 56167]]

10 CFR 50.55a(b)(2)(xxvi) Section XI Condition: Pressure Testing Class 
1, 2 and 3 Mechanical Joints
    The NRC proposes to amend the condition found in Sec.  
50.55a(b)(2)(xxvi) to clarify the NRC's expectations related to the 
pressure testing of ASME BPV Code Class 1, 2, and 3 mechanical joints 
disassembled and reassembled during the performance of an ASME BPV 
Code, Section XI activity. Industry stakeholders have expressed 
confusion with the current regulatory requirements with regard to when 
a pressure test was required and which year of the Code the pressure 
testing should be in compliance with in accordance with this condition. 
The NRC proposes to modify the condition to clarify that all mechanical 
joints in Class 1, 2 and 3 piping and components greater than NPS-1 
that are disassembled and reassembled during the performance of a 
Section XI activity (e.g., a repair/replacement activity) shall be 
pressure tested in accordance with IWA-5211(a). The pressure testing 
shall be performed using procedures and personnel meeting the 
requirements of the licensee's/applicant's current code of record. This 
condition was first put in place by the NRC in the final rule effective 
November 1, 2004 (69 FR 58804). The NRC determined that the condition 
was necessary because the ASME BPV Code eliminated the requirements to 
pressure test Class 1, 2, and 3 mechanical joints undergoing repair and 
replacement activities in the 1999 Addenda. The NRC finds that pressure 
testing of mechanical joints affected by repair and replacement 
activities is necessary to ensure and verify the leak tight integrity 
of the system pressure boundary.
10 CFR 50.55a(b)(2)(xxxii) Section XI Condition: Summary Report 
Submittal
    The NRC proposes to amend the condition found in Sec.  
50.55a(b)(2)(xxxii) to address the use of Owner Activity Reports. 
Through the 2013 Edition of ASME BPV Code, Section XI, Owners were 
required to prepare Summary Reports of preservice and inservice 
examinations and repair replacement activities. This condition was 
added when the 2013 Edition was incorporated by reference because up 
until that time, Owners were required to submit these reports to the 
regulatory authority having jurisdiction of the plant site. The 2013 
Edition removed the requirement for submittal from IWA-6240(c), to 
state that submittal was only mandatory if required by the authority. 
The NRC added the condition in paragraph (b)(2)(xxxii) to require 
submittal of Summary Reports. In the 2015 Edition of ASME BPV Code, 
Section XI the title of these reports was changed from Summary Reports 
to Owner Activity Reports. Therefore, the NRC is proposing to amend the 
condition to also require the submittal of Owner Activity Reports.
10 CFR 50.55a(b)(2)(xxxiv) Section XI Condition: Nonmandatory Appendix 
U
    The NRC proposes to amend the requirements in current paragraph 
(b)(2)(xxxiv) to make the condition applicable to the latest edition 
incorporated by reference in paragraph (a)(1)(ii) of Sec.  50.55a. The 
current condition in paragraph (b)(2)(xxxiv)(A) requires repair and 
replacement activities temporarily deferred under the provisions of 
Nonmandatory Appendix U to be performed during the next scheduled 
refueling outage. This condition was added when the 2013 Edition was 
incorporated by reference. When ASME published the 2015 Edition and the 
2017 Editions, Nonmandatory Appendix U was not modified in a way that 
would make it possible for the NRC to remove this condition. Therefore, 
the NRC is proposing to retain this condition to apply to the latest 
edition incorporated by reference in paragraph (a)(1)(ii) of Sec.  
50.55a. The current condition in paragraph (b)(2)(xxxiv)(B) requires a 
mandatory appendix in ASME Code Case N-513-3 to be used as the 
referenced appendix for paragraph U-S1-4.2.1(c). This condition was 
also added when the 2013 Edition was incorporated by reference. The 
omission that made this condition necessary was remedied in the 2017 
Edition. Therefore, the NRC is proposing to retain this condition to 
apply to only to the 2013 and the 2015 Editions.
10 CFR 50.55a(b)(2)(xxxv) Section XI Condition: Use of RTT0 
in the KIa and KIc Equations
    The NRC proposes to re-designate the requirements in current 
paragraph (b)(2)(xxxv), that address the use of the 2013 Edition of 
ASME BPV Code, Section XI, Appendix A, paragraph A-4200, as 
(b)(2)(xxxv)(A). The ASME BPV Code has addressed the NRC concern 
related to this condition in the 2015 Edition; however, it is still 
relevant to licensees/applicants using the 2013 Edition. The NRC 
proposes to add a new paragraph (b)(2)(xxv)(B) to condition the use of 
2015 Edition of ASME BPV Code, Section XI, Appendix A, paragraph A-
4200(c), to require the use of the equation RTKIa = T0 + 
90.267 exp(-0.003406T0) in lieu of the equation (a), shown in the Code. 
Paragraph A-4200(c) was added in the 2015 Edition to provide for an 
alternative method in establishing a fracture-toughness-based reference 
temperature, RTT0, for pressure retaining materials, using 
fracture toughness test data. Equation (b) was derived from test data 
using the International System of Units (SI units). Equation (a) was a 
converted version of equation (b) using U.S Customary units. 
Unfortunately, an error was made in the conversion, which makes 
equation (a) incorrect. The equation shown in this paragraph for 
RTKIa is the correct formula.
10 CFR 50.55a(b)(2)(xxxvi) Section XI Condition: Fracture Toughness of 
Irradiated Materials
    The NRC proposes to amend the condition found in Sec.  
50.55a(b)(2)(xxxvi) to extend the applicability to use of the 2015 and 
2017 Editions of ASME BPV Code, Section XI. This current condition 
requires licensees using ASME BPV Code, Section XI, 2013 Edition, 
Appendix A, paragraph A-4400, to obtain NRC approval before using 
irradiated T0 and the associated RTT0 in 
establishing fracture toughness of irradiated materials. This condition 
was added when the 2013 Edition was incorporated by reference because 
the newly introduced A-4200(b) could mislead the users of Appendix A 
into adopting methodology that is not accepted by the NRC. When ASME 
published the 2015 Edition and the 2017 Editions, Appendix A of the 
ASME BPV Code, Section XI was not modified in a way that would make it 
possible for the NRC to remove this condition. Therefore, the NRC is 
proposing to retain this condition to apply to the 2015 and 2017 
Editions.
10 CFR 50.55a(b)(2)(xxxviii) Section XI Condition: ASME Code Section XI 
Appendix III Supplement 2
    The NRC proposes to add Sec.  50.55a(b)(2)(xxxviii) to condition 
ASME BPV Code, Section XI Appendix III Supplement 2. Supplement 2 is 
closely-based on ASME Code Case N-824, which was incorporated by 
reference with conditions in Sec.  50.55a(b)(2)(xxxvii). The conditions 
on ASME BPV Code, Section XI Appendix III Supplement 2 are consistent 
with the conditions on ASME Code Case N-824, published in July 18, 2017 
(82 FR 32934).
    The conditions are derived from research into methods for 
inspecting Cast Austenitic Stainless Steel (CASS) components; these 
methods are published in NUREG/CR-6933, ``Assessment of Crack Detection 
in

[[Page 56168]]

Heavy-Walled Cast Stainless Steel Piping Welds Using Advanced Low-
Frequency Ultrasonic Methods,'' (ADAMS Accession Nos. ML071020410 and 
ML071020414), and NUREG/CR-7122, ``An Evaluation of Ultrasonic Phased 
Array Testing for Cast Austenitic Stainless Steel Pressurizer Surge 
Line Piping Welds,'' (ADAMS Accession No. ML12087A004). These NUREG/CR 
reports show that CASS materials less than 1.6 inches thick can be 
reliably inspected for flaws 10 percent through-wall or deeper if 
encoded phased-array examinations are performed using low ultrasonic 
frequencies and a sufficient number of inspection angles. Additionally, 
for thicker welds, flaws greater than 30 percent through-wall in depth 
can be detected using low frequency encoded phased-array ultrasonic 
inspections.
    The NRC, using NUREG/CR-6933 and NUREG/CR-7122, has determined that 
sufficient technical basis exists to condition ASME BPV Code, Section 
XI, Appendix III Supplement 2. The NUREG/CR reports show that CASS 
materials produce high levels of coherent noise and that the noise 
signals can be confusing and mask flaw indications. The optimum 
inspection frequencies for examining CASS components of various 
thicknesses as described in NUREG/CR-6933 and NUREG/CR-7122 are 
reflected in proposed condition Sec.  50.55a(b)(2)(xxxviii)(A). As 
NUREG/CR-6933 shows that the grain structure of CASS can reduce the 
effectiveness of some inspection angles, the NRC finds sufficient 
technical basis for the use of ultrasound using angles including, but 
not limited to, 30 to 55 degrees, with a maximum increment of 5 
degrees. This is reflected in proposed condition Sec.  
50.55a(b)(2)(xxxviii)(B).
10 CFR 50.55a(b)(2)(xxxix)(A) Defect Removal: First Provision
    The NRC proposes to add Sec.  50.55a(b)(2)(xxxix)(A) to place 
conditions on the use of ASME BPV Code, Section XI, IWA-4421(c)(1). The 
condition establishes that the final configuration of the item will be 
in accordance with the original Construction Code, later editions and 
addenda of the Construction Code, or a later different Construction 
Code, as well as meeting the Owner's Requirements or revised Owner's 
Requirements. This condition would ensure that welding, brazing, 
fabrication, and installation requirements, as well as design 
requirements for material, design or configuration changes, are 
consistent with the Construction Code and Owner's Requirements. This 
condition retains the intent of the revision to Section XI that: (a) 
Replacements in kind are acceptable; (b) replacements with alternative 
configurations are acceptable as long as Construction Code and Owner's 
Requirements are met; and (c) defect removal is required; however, this 
can be accomplished by replacing all or a portion of the item 
containing the defect.
10 CFR 50.55a(b)(2)(xxxix)(B) Defect Removal: Second Provision
    The NRC proposes to add Sec.  50.55a(b)(2)(xxxix)(B) to place 
conditions on the use of ASME BPV Code, Section XI, IWA-4421(c)(2). The 
inclusion of subparagraph IWA-4421(c)(2) is intended to address wall 
thickness degradation where the missing wall thickness is restored by 
weld metal deposition. This repair activity restores the wall thickness 
to an acceptable condition; however, it does not ``remove'' the 
degraded wall thickness (i.e., the defect); rather, restoration of wall 
thickness by welding or brazing mitigates the need to remove the 
defect. However, increasing the wall thickness of an item to reclassify 
a crack from a defect to a flaw \3\ is not acceptable because there are 
no provisions in subparagraph IWA-4421(c)(2) for analyses and ongoing 
monitoring of potential crack growth. Therefore, this proposed 
condition would prohibit the use of subparagraph IWA-4421(c)(2) rather 
than replacement for crack-like defects.
---------------------------------------------------------------------------

    \3\ As defined in ASME BPV Code, Section XI, Article IWA-9000, a 
``flaw'' is as an imperfection or unintentional discontinuity that 
is detectable by nondestructive examination and a ``defect'' is 
defined as a flaw of such size, shape, orientation, location, or 
properties as to be rejectable.
---------------------------------------------------------------------------

10 CFR 50.55a(b)(2)(xl) Section XI Condition: Prohibitions on Use of 
IWB-3510.4(b)
    The NRC proposes to add Sec.  50.55a(b)(2)(xl) to prohibit the use 
of ASME BPV Code, Section XI, Subparagraphs IWB-3510.4(b)(4) and IWB-
3510.4(b)(5), which allow use of certain acceptance standard tables for 
high yield strength ferritic materials because they are not supported 
by the fracture toughness data.
    The ASME BPV Code, Section XI, Subarticle IWB-3500 provides 
acceptance standards for pressure retaining components made of ferritic 
steels. Subparagraph IWB-3510.4 specifies material requirements for 
ferritic steels for application of the acceptance standards. In prior 
editions of the ASME BPV Code, Section XI, the material requirements 
for ferritic steels for which the acceptance standards of IWB-3500 
apply are included in a note under the title of tables that specify 
allowable flaw sizes (e.g., Table IWB-3510-1 ``Allowable Planar 
Flaws''). Subparagraph IWB-3510.4 separates ferritic materials into 
three groups: (a) Those with a minimum yield strength of 50 ksi or 
less, (b) five ferritic steels with these material designations: SA-508 
Grade 2 Class 2 (former designation: SA-508 Class 2a), SA-508 Grade 3 
Class 2 (former designation: SA-508 Class 3a), SA-533 Type A Class 2 
(former designation: SA-533 Grade A Class 2), SA-533 Type B Class 2 
(former designation: SA-533 Grade B Class 2), and SA-508 Class 1, and 
(c) those with greater than 50 ksi but not exceeding 90 ksi. The 
material requirements for ferritic steels with a minimum yield strength 
of 50 ksi or less and those with greater than 50 ksi but not exceeding 
90 ksi are explicitly specified. However, there are no material 
requirements for the five ferritic steels identified above.
    The NRC finds Subparagraph IWB-3510.4(a) acceptable because it is 
consistent with the current material requirements for ferritic steels 
having a minimum yield strength of 50 ksi or less. The NRC finds 
Subparagraph IWB-3510.4(c) acceptable because it is consistent with the 
current material requirements for ferritic steels having a minimum 
yield strength of greater than 50 ksi to 90 ksi.
    The NRC does not find Subparagraphs IWB-3510.4(b)(4) and (5) 
acceptable for the following reasons. The NRC plotted the ASME BPV 
Code, Section XI static plain-strain fracture toughness 
(KIC) curve in relevant figures in an ASME conference paper, 
PVP2010-25214, ``Fracture Toughness of Pressure Boundary Steels with 
Higher Yield Strength'' that shows dynamic fracture toughness 
(KID) data for materials listed in IWB-3510.4 (b)(1) to IWB-
3510.4 (b)(4). The NRC confirmed that the materials listed in IWB-
3510.4 (b)(1) and IWB-3510.4 (b)(3) are acceptable because the data are 
above the KIC curve with adequate margin to compensate for 
the limited data size. Additionally, the NRC has approved the use of 
the materials listed in IWB-3510.4 (b)(1) and IWB-3510.4 (b)(3) in a 
licensing and a design certification application. For the material 
listed in IWB-3510.4 (b)(2), KID data was demonstrated to be 
above the crack arrest fracture toughness (KIa). The NRC has 
previously determined the KIa fracture toughness standard to 
be acceptable. Hence, the materials listed in IWB-3510.4 (b)(2) are 
acceptable. However, the technical basis document does not provide 
sufficient data to support exclusion of the fracture

[[Page 56169]]

toughness requirements for the materials specified in Subparagraphs 
IWB-3510.4(b)(4) and IWB-3510.4(b)(5).
    This proposed condition does not change the current material 
requirements because licensees/applicants may continue to use testing 
to show that the two prohibited materials meet the material 
requirements.
10 CFR 50.55a(b)(2)(xli) Section XI Condition: Preservice Volumetric 
and Surface Examinations Acceptance
    The NRC proposes to add Sec.  50.55a(b)(2)(xli) to prohibit the use 
of ASME BPV Code, Section XI, Subparagraphs IWB-3112(a)(3) and IWC-
3112(a)(3) in the 2013 through 2017 Edition. The NRC is prohibiting 
these items consistent with a final rule that approved ASME BPV Code 
Cases for use, dated January 17, 2018, (83 FR 2331).
    During the review of public comments that were submitted on the 
proposed rule, dated March 2, 2016, (81 FR 10780), the NRC identified 
inconsistencies between Regulatory Guide 1.193, ``ASME Code Cases Not 
Approved for Use,'' Revision 5, and a then concurrent proposed rule to 
incorporate by reference the 2009-2013 Editions of the ASME BPV Code 
(80 FR 56819), dated December 2, 2015.
    Specifically, conditions that pertain to the staff's disapproval of 
Code Case N-813, ``Alternative Requirements for Preservice Volumetric 
and Surface Examination,'' in the ASME BPV Code Regulatory Guide 1.193 
proposed rule were not included in the ASME BPV 2009-2013 Editions 
proposed rule; however, the content of Code Case N-813 had been 
incorporated in the 2013 Edition of the ASME Code, Section XI. In order 
to resolve this conflict, the NRC excluded from the incorporation by 
reference those applicable portions of Section IX in the 2011a Addenda 
and the 2013 Edition, in Sec.  50.55a(a)(1)(ii)(C)(52) and (53) 
respectively. This allowed the NRC to develop an appropriate regulatory 
approach for the treatment of these provisions that is consistent with 
the ASME BPV Code Regulatory Guide 1.193 rulemaking, in which the NRC 
found the acceptance of preservice flaws by analytical evaluation 
unacceptable.
    Code Case N-813 is a proposed alternative to the provisions of the 
2010 Edition of the ASME Code, Section XI, paragraph IWB-3112. 
Paragraph IWB-3112 does not allow the acceptance of flaws detected in 
the preservice examination by analytical evaluation. Code Case N-813 
would allow the acceptance of these flaws through analytical 
evaluation. Per paragraph IWB-3112, any preservice flaw that exceeds 
the acceptance standards of Table IWB-3410-1 must be removed. While it 
is recognized that operating experience has shown that large through-
wall flaws and leakages have developed in previously repaired welds as 
a result of weld residual stresses, the NRC has the following concerns 
regarding the proposed alternative in Code Case N-813:
    (1) The requirements of paragraph IWB-3112 were developed to ensure 
that defective welds were not placed in service. The NRC finds that a 
preservice flaw detected in a weld that exceeds the acceptance 
standards of Table IWB-3410-1 demonstrates poor workmanship and/or 
inadequate welding practice and procedures. The NRC finds that such an 
unacceptable preservice flaw needs to be removed and the weld needs to 
be repaired before it is placed in service.
    (2) Under Code Case N-813, large flaws would be allowed to remain 
in service because paragraph IWB-3132.3, via paragraph IWB-3643, allows 
a flaw up to 75 percent through-wall to remain in service. The NRC 
finds that larger flaws could grow to an unacceptable size between 
inspections, reducing structural margin and potentially challenging the 
structural integrity of safety-related Class 1 and Class 2 piping.
    Paragraph C-3112(a)(3) of Code Case N-813, provides the same 
alternatives for Class 2 piping as that of Paragraph B-3122(a)(3). The 
NRC has the same concerns for Class 2 piping as for Class 1 piping.
    Therefore, for the acceptance of preservice flaws by analytical 
evaluation, the NRC proposes to add a condition that prohibits the use 
of IWB-3112(a)(3) and IWC-3112(a)(3) in the 2013 Edition of ASME BPV 
Code Section XI through the latest edition and addenda incorporated by 
reference in paragraph (a)(1)(ii) of Sec.  50.55a.
10 CFR 50.55a(b)(2)(xlii) Section XI Condition: Steam Generator Nozzle-
to-Component Welds and Reactor Vessel Nozzle-to-Component Welds
    The NRC proposes to add Sec.  50.55a(b)(2)(xlii) to require that 
the examination of Steam Generator Nozzle-to-Component welds and 
Reactor Vessel Nozzle-to-Component welds must be a full volume 
examination and that the ultrasonic examination procedures, equipment, 
and personnel must be qualified by performance demonstration in 
accordance with Mandatory Appendix VIII of ASME Code, Section XI. These 
proposed conditions are consistent with the conditions on ASME Code 
Case N-799 in Regulatory Guide 1.147, Revision 18, which was 
incorporated by reference in Sec.  50.55a in the final rule that 
approved ASME BPV Code Cases for use, dated January 17, 2018 (83 FR 
2331). The NRC is adding this condition in order to be consistent with 
that final rule.
    During the review of the public comments that were submitted on the 
proposed rule, dated March 2, 2016, (81 FR 10780), the NRC identified 
inconsistencies between Regulatory Guide 1.147, and a then concurrent 
proposed rule to incorporate by reference the 2009-2013 Editions of the 
ASME BPV Code (80 FR 56819), dated December 2, 2015.
    Specifically, conditions that pertain to Code Case N-799, 
``Dissimilar Metal Welds Joining Vessel Nozzles to Components,'' in the 
ASME BPV Code Regulatory Guide 1.147 proposed rule were not included in 
the ASME BPV 2009-2013 Editions proposed rule. However, the content of 
Code Case N-799 had been incorporated in the 2013 Edition of the ASME 
Code, Section XI. In order to resolve this conflict, the NRC excluded 
from the incorporation by reference those applicable portions of 
Section IX in the 2011a Addenda and the 2013 Edition, in Sec.  
50.55a(a)(1)(ii)(C)(52) and (53), respectively. This allowed the NRC to 
develop an appropriate regulatory approach for the treatment of these 
provisions that is consistent with the ASME BPV Code Regulatory Guide 
1.147 final rule, in which the NRC required that the examination of the 
aforementioned welds must be full volume and that the ultrasonic 
examination procedures, equipment, and personnel must be qualified by 
performance demonstration in accordance with Mandatory Appendix VIII of 
ASME Code, Section XI.
    Of particular interest to the NRC is the condition requiring the 
examination of dissimilar metal welds between vessel nozzles and 
components to be full volume and the condition for requiring 
performance demonstration in accordance with Mandatory Appendix VIII of 
ASME Code, Section XI. The following focuses on the AP1000 design, 
although a similar issue exists for the reactor vessel-to-reactor 
coolant pump connection for the Advanced Boiling Water Reactor (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 steam generator nozzle to reactor coolant 
pump casing (SG-to-RCP) weld is a dissimilar metal (low alloy steel to

[[Page 56170]]

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 therefore subject to the examination requirements of ASME 
Section XI, Subsection IWB. However, prior to the development of Code 
Case N-799 (since incorporated into ASME Section XI, IWB-2500, as part 
of the 2011 Addenda), the examination requirements for the SG-to-RCP 
welds were not addressed in the ASME Code.
    The NRC's first concern is that the examinations required by Code 
Case N-799 do not provide assurance that the integrity of the SG-to-RCP 
welds will be maintained throughout the operating life of the AP1000 
plant. Traditionally, 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, 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 NRC finds 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 vessels nozzles larger than NPS 4 and 
piping. As such, the NRC finds that the examination requirements 
proposed in Code Case N-799 are not appropriate for the SG-to-RCP weld 
because the service conditions of this weld 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. 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 NRC finds that the effects of 
these additional operating loads and stresses are unknown. Absent 
operating experience or a bounding analysis, the NRC finds that it is 
inappropriate to allow a reduced examination volume at this time. 
Therefore, the NRC is proposing that the examination of the 
aforementioned welds must be full volume.
    The NRC's second concern is that the examinations required by Code 
Case N-799 do not provide assurance that inservice degradation can be 
detected for this dissimilar metal weld that includes CASS. Code Case 
N-799 does not require the use of performance demonstration in 
accordance with Mandatory Appendix VIII of the ASME Code, Section XI. 
The NRC finds that ultrasonic inspection of CASS material is difficult 
due to the grain structure of the material. In order to have a 
meaningful ultrasonic examination to detect and size inservice 
degradation, the ultrasonic examination procedures, equipment, and 
personnel must be qualified by performance demonstration in accordance 
with Mandatory Appendix VIII of ASME Code, Section XI. This is 
consistent with current practices for other ultrasonic examinations of 
dissimilar metal welds in the operating fleet.
    When considering these proposed conditions, the NRC recognizes that 
factors exist that may limit the ultrasonic examination volume that can 
be qualified by performance demonstration. For example, the qualified 
volume would be limited in components with wall thicknesses beyond the 
crack detection and sizing capabilities of a through wall ultrasonic 
performance-based qualification. To address the scenario in which the 
examination volume that can be qualified by performance demonstration 
is less than 100 percent of the volume, the NRC is proposing to allow 
an ultrasonic examination of the qualified volume, provided that a flaw 
evaluation is performed to demonstrate the integrity of the examination 
volume that cannot be qualified by performance demonstration. The flaw 
evaluation should be of the largest hypothetical crack that could exist 
in the volume not qualified for ultrasonic examination. The licensee's 
revised examination plan would be subject to prior NRC approval as an 
alternative in accordance with Sec.  50.55a(z). The NRC believes that 
this proposed condition provides assurance that the integrity of the 
welds in question will be maintained, despite a limited examination 
capability.
    Finally, these proposed conditions are consistent with the 
conditions described in Regulatory Guide 1.147, Revision 18, which 
conditionally accepts Code Case N-799. Because Code Case N-799 has been 
incorporated into ASME Section XI, the NRC's conditions on the Code 
Case will be carried over as a condition on the ASME Code.
    Therefore, in order to ensure that the examinations of Steam 
Generator Nozzle-to-Component welds and Reactor Vessel Nozzle-to-
Component welds will be examinations of the full volume of the welds 
and that the ultrasonic examination procedures, equipment, and 
personnel are qualified by performance demonstration, in accordance 
with Mandatory Appendix VIII of ASME Code, Section XI, the NRC proposes 
to add conditions to the provisions of Table IWB-2500-1, Examination 
Category B-F, Pressure Retaining Dissimilar Metal Welds in Vessel 
Nozzles, Item B5.11 (NPS 4 or Larger Nozzle-to-Component Butt Welds) of 
the 2013 Edition through the latest edition and addenda incorporated by 
reference in paragraph (a)(1)(ii) of Sec.  50.55a. The NRC also 
proposes to add a condition to the provision of Table IWB-2500-1, Item 
B5.71 (NPS 4 or Larger Nozzle-to-Component Butt Welds) of the 2011 
Addenda through the latest edition and addenda incorporated by 
reference in paragraph (a)(1)(ii) of Sec.  50.55a.

C. ASME OM Code

10 CFR 50.55a(b)(3), Conditions on ASME OM Code
    The new Appendix IV in the 2017 Edition of the ASME OM Code 
provides improved preservice testing (PST) and IST of active air 
operated valves (AOVs) within the scope of the ASME OM Code. Appendix 
IV specifies quarterly stroke-time testing of AOVs, where practicable. 
These are similar to the current requirements in Subsection ISTC, 
``Inservice Testing of Valves in Light-Water Reactor Nuclear Power 
Plants,'' of the ASME OM Code. In addition, Appendix IV specifies a 
preservice performance assessment test for AOVs with low safety 
significance, and initial and periodic performance assessment testing 
for AOVs with high safety significance on a sampling basis over a 
maximum 10-year interval.
    The ASME developed the improved PST and IST provisions for AOVs in 
Appendix IV to the ASME OM Code in response to lessons learned from 
operating experience and test programs for AOVs and other power-
operated valves (POVs) used at nuclear power plants. Over the years, 
the NRC has issued numerous generic communications to address 
weaknesses with AOVs and other POVs in performing their safety 
functions. For example, the NRC issued Generic Letter (GL) 88-14, 
``Instrument Air Supply System Problems Affecting Safety-Related 
Equipment,'' to request that licensees verify that AOVs will perform

[[Page 56171]]

as expected in accordance with all design-basis events. The NRC 
provided the results of studies of POV issues in several documents, 
including NUREG/CR-6654, ``A Study of Air-Operated Valves in U.S. 
Nuclear Power Plants'' (ADAMS Accession No. ML003691872). The NRC has 
issued several information notices to alert licensees to IST experience 
related to POV performance, including IN 86-50, ``Inadequate Testing To 
Detect Failures of Safety-Related Pneumatic Components or Systems;'' 
and IN 85-84, ``Inadequate Inservice Testing of Main Steam Isolation 
Valves.'' The NRC issued IN 96-48, ``Motor-Operated Valve Performance 
Issues,'' which described lessons learned from motor-operated valve 
(MOV) programs that are applicable to other POVs. Based on operating 
experience with the capability of POVs to perform their safety 
functions, the NRC established Generic Safety Issue 158, ``Performance 
of Safety-Related Power-Operated Valves Under Design-Basis 
Conditions,'' to evaluate whether additional regulatory actions were 
necessary to address POV performance issues. In Regulatory Issue 
Summary 2000-03, ``Resolution of Generic Safety Issue (GSI) 158, 
`Performance of Safety Related Power-Operated Valves Under Design-Basis 
Conditions','' dated March 15, 2000, the NRC closed GSI-158 by 
specifying attributes for an effective POV testing program that 
incorporates lessons learned from MOV research and testing programs. 
More recently, the NRC issued IN 2015-13, ``Main Steam Isolation Valve 
Failure Events,'' to alert nuclear power plant applicants and licensees 
to examples of operating experience where deficiencies in licensee 
processes and procedures can contribute to the failure of main steam 
isolation valves (MSIVs), which may be operated by air actuators or 
combined air/hydraulic actuators. The NRC considers that the improved 
IST provisions specified in Appendix IV to the ASME OM Code will 
address the POV performance issues identified by operating experience 
with AOVs, including MSIVs, at nuclear power plants.
    Paragraph IV-3800, ``Risk-Informed AOV Inservice Testing,'' allows 
the establishment of risk-informed AOV IST that incorporates risk 
insights in conjunction with functional margin to establish AOV 
grouping, acceptance criteria, exercising requirements, and testing 
intervals. Risk-informed AOV IST includes initial and periodic 
performance assessment testing of high-safety significant AOVs with the 
results of that testing used to confirm the capability of low-safety 
significant AOVs within the same AOV group. For example, paragraph IV-
3600, ``Grouping of AOVs for Performance Assessment Testing,'' states 
that test results shall be evaluated for all AOVs in a group. Paragraph 
IV-6500, ``Performance Assessment Test Corrective Action,'' specifies 
that correction action be taken in accordance with the Owner's 
corrective action requirements if AOV performance is unacceptable. The 
NRC considers that these provisions in Appendix IV will provide 
assurance that all AOVs within the scope of Appendix IV will be 
addressed for their operational readiness initially and on a periodic 
basis. The NRC is proposing to revise the last sentence of Sec.  
50.55a(b)(3) to specify that when implementing the ASME OM Code, 
conditions are applicable only as specified in (b)(3).
10 CFR 50.55a(b)(3)(ii) OM Condition: Motor-Operated Valve (MOV) 
Testing
    The NRC proposes to amend Sec.  50.55a(b)(3)(ii) to specify that 
the condition applies to the latest edition and addenda of the ASME OM 
Code incorporated by reference in Sec.  50.55a(a)(1)(iv). This will 
allow future rulemakings to revise Sec.  50.55a(a)(1)(iv) to 
incorporate the latest edition of the ASME OM Code without the need to 
revise Sec.  50.55a(b)(3)(ii).
10 CFR 50.55a(b)(3)(iv) OM Condition: Check Valves (Appendix II)
    The NRC proposes to amend Sec.  50.55a(b)(3)(iv) to accept the use 
of Appendix II, ``Check Valve Condition Monitoring Program,'' in the 
2017 Edition of the ASME OM Code without conditions based on its 
updated provisions. For example, Appendix II in the 2017 Edition of the 
ASME OM Code incorporates Table II, ``Maximum Intervals for Use When 
Applying Interval Extensions,'' as well as other conditions currently 
specified in Sec.  50.55a(b)(3)(iv). The NRC also proposes to update 
Sec.  50.55a(b)(3)(iv) to apply Table II to Appendix II of the ASME OM 
Code, 2003 Addenda through the 2015 Edition. Further, the NRC proposes 
to remove the outdated conditions in paragraphs (b)(3)(iv)(A) through 
(D) based on their application to older editions and addenda of the 
ASME OM Code that are no longer applied at nuclear power plants, and on 
the incorporation of those conditions in recent editions and addenda of 
the ASME OM Code.
10 CFR 50.55a(b)(3)(viii) OM Condition: Subsection ISTE
    The NRC proposes to amend Sec.  50.55a(b)(3)(viii) to specify that 
the condition on the use of Subsection ISTE, ``Risk-Informed Inservice 
Testing of Components in Light-Water Reactor Nuclear Power Plants,'' 
applies to the latest edition and addenda of the ASME OM Code 
incorporated by reference in Sec.  50.55a(a)(1)(iv). This will allow 
future rulemakings to revise Sec.  50.55a(a)(1)(iv) to incorporate the 
latest edition of the ASME OM Code without the need to revise Sec.  
50.55a(b)(3)(viii).
10 CFR 50.55a(b)(3)(ix) OM Condition: Subsection ISTF
    The NRC proposes to amend Sec.  50.55a(b)(3)(ix) to specify that 
Subsection ISTF, ``Inservice Testing of Pumps in Water-Cooled Reactor 
Nuclear Power Plants--Post-2000 Plants,'' of the ASME OM Code, 2017 
Edition, is acceptable without conditions. The NRC also proposes to 
amend Sec.  50.55a(b)(3)(ix) to specify that licensees applying 
Subsection ISTF in the 2015 Edition of the ASME OM Code shall satisfy 
the requirements of Mandatory Appendix V, ``Pump Periodic Verification 
Test Program,'' of the ASME OM Code, in addition to the current 
requirement to satisfy Appendix V when applying Subsection ISTF in the 
2012 Edition of the ASME OM Code. Subsection ISTF in the 2017 Edition 
of the ASME OM Code has incorporated the provisions from Appendix V 
such that this condition is not necessary for the 2017 Edition of the 
ASME OM Code.
10 CFR 50.55a(b)(3)(xi) OM Condition: Valve Position Indication
    The NRC proposes to amend Sec.  50.55a(b)(3)(xi) for the 
implementation of paragraph ISTC-3700, ``Position Verification 
Testing,'' in the ASME OM Code to apply to the 2012 Edition through the 
latest edition and addenda of the ASME OM Code incorporated by 
reference in Sec.  50.55a(a)(1)(iv). This will allow future rulemakings 
to revise Sec.  50.55a(a)(1)(iv) to incorporate the latest edition and 
addenda of the ASME OM Code without the need to revise Sec.  
50.55a(b)(3)(xi). In addition, the NRC proposes to clarify that this 
condition applies to all valves with remote position indicators within 
the scope of Subsection ISTC, ``Inservice Testing of Valves in Water-
Cooled Reactor Nuclear Power Plants,'' including MOVs within the scope 
of Mandatory Appendix III, ``Preservice and Inservice Testing Active 
Electric Motor-Operated Valve Assemblies in Water-Cooled Reactor 
Nuclear Power Plants.'' ISTC-3700

[[Page 56172]]

references Mandatory Appendix III for valve position testing of MOVs. 
The development of Mandatory Appendix III was intended to verify valve 
position indication as part of the diagnostic testing performed on the 
intervals established by the appendix. This clarification will ensure 
that verification of valve position indication is understood to be 
important for all valves with remote position indication addressed in 
Subsection ISTC and all of its mandatory appendices.
10 CFR 50.55a(b)(3)(xii) OM Condition: Air-Operated Valves (Appendix 
IV)
    The NRC proposes to include new Sec.  50.55a(b)(3)(xii) to require 
the application of the provisions in Appendix IV of the 2017 Edition of 
the ASME OM Code, when implementing the ASME OM Code, 2015 Edition. The 
new Appendix IV in the 2017 Edition of the ASME OM Code provides 
improved PST and IST of active AOVs within the scope of the ASME OM 
Code. This condition would provide consistency in the implementation of 
these two new editions of the ASME OM Code.
10 CFR 50.55a(f): Preservice and Inservice Testing Requirements
    The NRC regulations in Sec.  50.55a(f) specify that systems and 
components of boiling and pressurized water-cooled nuclear power 
reactors must meet the requirements for preservice and inservice 
testing of the ASME BPV Code and ASME OM Code. Paragraph (f) in Sec.  
50.55a states that the requirements for inservice inspection of Class 
1, Class 2, Class 3, Class MC, and Class CC components (including their 
supports) are located in paragraph (g) in Sec.  50.55a. Applicants and 
licensees should note that requirements for inservice examination and 
testing of dynamic restraints (snubbers) are located in paragraph 
(b)(3)(v) in Sec.  50.55a. The NRC staff is considering this 
clarification of the location of inservice examination and testing 
requirements for dynamic restraints in Sec.  50.55a(f) and (g) for a 
future rulemaking.
10 CFR 50.55a(f)(4)(i): Applicable IST Code: Initial 120-Month Interval
    Several stakeholders submitted public comments on the Sec.  50.55a 
2009-2013 proposed rule requesting that the time schedule for complying 
with the latest ASME Code edition and addenda in Sec.  50.55a(f)(4)(i) 
and (g)(4)(i) for the IST and ISI programs, respectively, be relaxed 
from the current time interval of 12 months to a new time interval of 
24 months prior to the applicable milestones in those paragraphs. The 
ASME reiterated this request during an NRC/ASME management public 
teleconference that was held on March 16, 2016. During that 
teleconference, ASME discussed the challenges associated with meeting 
the 12-month time schedule in order to submit timely relief or 
alternative requests for NRC review. These comments were outside the 
scope of the proposed Sec.  50.55a ASME 2009-2013 rule. However, the 
NRC staff indicated that the request would be considered in a future 
rulemaking.
    In evaluating the suggested change, the NRC has determined that the 
primary benefit from the relaxation of this Sec.  50.55a(f)(4)(i) 
requirement is that licensees of new nuclear power plants will have 
more time to prepare their initial IST program and procedures and any 
proposed relief or alternative requests to the applicable edition of 
the ASME OM Code. In preparing this proposed rule, the NRC has 
determined that relaxation of the time schedule for satisfying the 
latest edition of the ASME OM Code for the initial 120-month IST 
interval to be appropriate. However, the NRC considers that a 24-month 
time schedule would be contrary to the intent of the requirement to 
apply the latest edition of the ASME OM Code that is published every 24 
months because it could result in licensees applying an outdated 
edition in the initial 120-month IST interval. Therefore, the NRC 
proposes to extend the time schedule to satisfy the latest edition and 
addenda of the ASME OM Code from the current 12 months to 18 months for 
the initial 120-month IST interval.
10 CFR 50.55a(f)(4)(ii): Applicable IST Code: Successive 120-Month 
Intervals
    As discussed in the previous section, several stakeholders 
submitted public comments on the Sec.  50.55a 2009-2013 proposed rule, 
requesting that the time schedule for complying with the latest ASME 
Code edition in Sec.  50.55a(f)(4)(ii) and (g)(4)(ii) for the IST and 
ISI programs, respectively, be relaxed from the current time period of 
12 months to a new time period of 24 months prior to the applicable 
milestones in those paragraphs. The ASME reiterated this request during 
an NRC/ASME management public teleconference that was held on March 16, 
2016. During that teleconference, ASME discussed the challenges 
associated with meeting the 12-month time schedule in order to submit 
timely relief or alternative requests for NRC review. These comments 
were outside the scope of the proposed Sec.  50.55a ASME 2009-2013 
rule. However, the NRC staff indicated that the proposed change would 
be considered for a future rulemaking. In evaluating the proposed 
change, the NRC has determined that the primary benefit from the 
relaxation of this Sec.  50.55a(f)(4)(ii) requirement is that licensees 
of nuclear power plants will have more time to update their successive 
IST programs and procedures, and to prepare any proposed relief or 
alternative requests to the applicable edition of the ASME OM Code. In 
addition, licensees of each nuclear power plant will not need to review 
ASME OM Code editions incorporated by reference in Sec.  50.55a after 
the relaxed 18-month time period before the start of the IST program 
interval compared to the 12-month time period required by the current 
regulations. In preparing this proposed rule, the NRC has determined 
that relaxation of the time schedule for satisfying the latest edition 
of the ASME OM Code for the successive 120-month IST interval to be 
appropriate. However, the NRC considers that a 24-month time schedule 
would be contrary to the intent of the requirement to apply the latest 
edition of the ASME OM Code that is published every 24 months. 
Therefore, the NRC proposes to extend the time schedule to satisfy the 
latest edition and addenda of the ASME OM Code from the current 12 
months to 18 months for successive 120-month IST intervals.
10 CFR 50.55a(f)(7), Inservice Testing Reporting Requirements
    The NRC proposes to add Sec.  50.55a(f)(7) to require nuclear power 
plant applicants and licensees to submit their IST Plans and interim 
IST Plan updates related to pumps and valves, and IST Plans and interim 
Plan updates related to snubber examination and testing to NRC 
Headquarters, the appropriate NRC Regional Office, and the appropriate 
NRC Resident Inspector.
    The ASME OM Code states in paragraph (a) of ISTA-3200, 
``Administrative Requirements,'' that IST Plans shall be filed with the 
regulatory authorities having jurisdiction at the plant site. However, 
the ASME is planning to remove this provision from the ASME OM Code in 
a future edition because this provision is more appropriate as a 
regulatory requirement rather than a Code requirement. This change is 
being proposed in this rulemaking rather than in a future rulemaking to 
ensure that there will not be a period of time when this requirement is 
not in effect. The NRC staff needs these IST Plans for use in 
evaluating relief and alternative requests, and deferral of quarterly 
testing to cold shutdowns and refueling outages. Therefore proposed 
condition is an administrative change that would

[[Page 56173]]

relocate the provision from the ASME OM Code to Sec.  50.55a.
10 CFR 50.55a(g)(4)(i): Applicable ISI Code: Initial 120-Month Interval
    The NRC proposes to amend Sec.  50.55a(g)(4)(i) to relax the time 
schedule for complying with the latest edition of the ASME BPV Code for 
the initial 120-month ISI program interval, respectively, from 12 
months to 18 months. The basis for the relaxation of the time schedule 
discussed previously for the requirement in Sec.  50.55a(f)(4)(i) to 
comply with the latest edition and addenda of ASME Section XI Code for 
the initial 120-month ISI program is also applicable to the relaxation 
of the time period for complying with the latest edition and addenda of 
the ASME BPV Code for the initial 120-month ISI program.
10 CFR 50.55a(g)(4)(ii): Applicable ISI Code: Successive 120-Month 
Intervals
    The NRC proposes to amend Sec.  50.55a(g)(4)(ii) to relax the time 
schedule for complying with the latest edition and addenda of the ASME 
BPV Code for the successive 120-month ISI program intervals, 
respectively, from 12 months to 18 months. The basis for the relaxation 
of the time schedule discussed above for the requirement in Sec.  
50.55a(f)(4)(ii) to comply with the latest edition and addenda of the 
ASME Section XI Code for the successive 120-month ISI programs is also 
applicable to the relaxation of the time period for complying with the 
latest edition and addenda of the ASME BPV Code for the successive 120-
month ISI programs. The NRC is proposing to amend the regulation in 
Sec.  50.55a(g)(4)(ii) to provide up to an 18 month period for 
licensees to update their Appendix VIII program for those licensees 
whose ISI interval commences during the 12 through 18-month period 
after the effective date of this rule.
10 CFR 50.55a(g)(6)(ii)(C): Augmented ISI Requirements: Implementation 
of Appendix VIII to Section XI
    The NRC proposes to remove the language found in Sec.  
50.55a(g)(6)(ii)(C) from the current regulations. This paragraph 
describes requirements for initial implementation of older supplements 
in ASME BPV Code, Section XI Appendix VIII. Because the implementation 
dates have passed, and because licensees are no longer using these 
older editions and addenda of the Code that are referenced in this 
paragraph, the NRC proposes to remove the condition.
ASME BPV Code Case N-729-6
    On September 10, 2008, the NRC issued a final rule to update Sec.  
50.55a to incorporate by reference the 2004 Edition of the ASME BPV 
Code (73 FR 52730). As part of the final rule, Sec.  
50.55a(g)(6)(ii)(D) implemented an augmented inservice inspection 
program for the examination of RPV upper head penetration nozzles and 
associated partial penetration welds. The program required the 
implementation of ASME BPV Code Case N-729-1, with certain conditions.
    The application of ASME BPV Code Case N-729-1 was necessary because 
the inspections required by the 2004 Edition of the ASME BPV Code, 
Section XI were not written to address degradation caused by primary 
water stress corrosion cracking (PWSCC) of the RPV upper head 
penetration nozzles and associated welds. The safety consequences of 
inadequate inspections of the subject nozzles can be significant. The 
NRC's determination that the ASME BPV Code-required inspections are 
inadequate is based upon operating experience and analysis, because 
nickel-based Alloy 600/82/182 material in the RPV head penetration 
nozzles and associated welds are susceptible to PWSCC. The absence of 
an effective inspection regime could, over time, result in unacceptable 
circumferential cracking, or the degradation of the RPV upper head or 
other reactor coolant system components by leakage-assisted corrosion. 
These degradation mechanisms increase the probability of a loss-of-
coolant accident.
    Examination frequencies and methods for RPV upper head penetration 
nozzles and welds are provided in ASME BPV Code Case N-729-1. The use 
of code cases is voluntary, so these provisions were developed, in 
part, with the expectation that the NRC would incorporate the code case 
by reference into Sec.  50.55a. Therefore, the NRC adopted rule 
language in Sec.  50.55a(g)(6)(ii)(D), requiring implementation of ASME 
BPV Code Case N-729-1, with conditions, in order to enhance the 
examination requirements in the ASME BPV Code, Section XI for RPV upper 
head penetration nozzles and welds. The examinations conducted in 
accordance with ASME BPV Code Case N-729-1 provide reasonable assurance 
that ASME BPV Code allowable limits will not be exceeded and that PWSCC 
will not lead to failure of the RPV upper head penetration nozzles or 
welds. However, the NRC concluded that certain conditions were needed 
in implementing the examinations in ASME BPV Code Case N-729-1. These 
conditions are set forth in Sec.  50.55a(g)(6)(ii)(D).
    On March 3, 2016, the ASME approved the sixth revision of ASME BPV 
Code Case N-729, (N-729-6). This revision changed certain requirements 
based on a consensus review of the inspection techniques and 
frequencies. These changes were deemed necessary by the ASME to 
supersede the previous requirements under previous versions of N-729 to 
establish an effective long-term inspection program for the RPV upper 
head penetration nozzles and associated welds in PWRs. The major 
changes in the latest revisions are the inclusion of peening mitigation 
and extending the replaced head volumetric inspection frequency. Other 
minor changes were also made to address editorial issues and to clarify 
the code case requirements.
    The NRC proposes to update the requirements of Sec.  
50.55a(g)(6)(ii)(D) to require licensees of PWRs to implement ASME BPV 
Code Case N-729-6, with certain conditions. The NRC conditions have 
been modified to address the changes in ASME BPV Code Case N-729-6 from 
the latest NRC-approved ASME Code Case N-729 revision in Sec.  
50.55a(g)(6)(ii)(D), revision 4, (N-729-4). The NRC's revisions to the 
conditions on ASME BPV Code Case N-729-4 that support the 
implementation of N-729-6 are discussed in the next sections.
10 CFR 50.55a(g)(6)(ii)(D) Augmented ISI Requirements: Reactor Vessel 
Head Inspections
    The NRC proposes to revise the paragraphs in Sec.  
50.55a(g)(6)(ii)(D) as summarized in the following discussions, which 
identify the changes in requirements associated with the proposed 
update from ASME BPV Code Case N-729-4 to N-729-6. The major changes in 
the code case revision allowing peening as a mitigation method and 
extend the PWSCC-resistant RPV upper head inspection frequency from 10 
years to 20 years. Additionally, the code case revision changed the 
volumetric inspection requirement for plants with previous indications 
of PWSCC and allowed the use of the similarities in sister plants to 
extend inspection intervals. The NRC is not able to fully endorse these 
two new items, therefore the NRC is proposing new conditions. The NRC 
has determined that one previous condition restricting the use of 
Appendix I of the code case could be relaxed. Further, the code case 
deadline for baseline examinations of February 10, 2008 is well in the 
past, therefore the NRC is

[[Page 56174]]

proposing a condition that would ensure new plants can perform baseline 
examinations without the need for an alternative to these requirements 
under Sec.  50.55a(z). Finally, the NRC is proposing to add a condition 
that would allow other licensees to use a volumetric leak path 
assessment in lieu of a surface examination.
10 CFR 50.55a(g)(6)(ii)(D)(1) Implementation
    The NRC proposes to revise Sec.  50.55a(g)(6)(ii)(D)(1) to change 
the version of ASME BPV Code Case N-729 from N-729-4 to N-729-6 for the 
reasons previously set forth. Due to the incorporation of N-729-6, the 
date to establish applicability for licensed PWRs will be changed to 
anytime within one year of the effective date of the final rule. This 
is to allow some flexibility for licensees to implement the 
requirements. No new inspections are required, therefore this allows 
licensees to phase in the new program consistent with their needs and 
outage schedules. The NRC is also including wording to allow licensee's 
previous NRC-approved alternatives to remain valid. The NRC has 
completed a review of the currently effective proposed alternatives and 
finds that each effective proposed alternative can remain effective 
through the update from ASME Code Case N-729-4 to N-729-6 with the 
proposed NRC conditions.
10 CFR 50.55a(g)(6)(ii)(D)(2) Appendix I Use
    The NRC proposes to revise Sec.  50.55a(g)(6)(ii)(D)(2). The NRC 
has determined that the current condition, that the use of Appendix I 
is not permitted, is no longer necessary. However the NRC is proposing 
a new condition that the analyses required by the code case for missed 
coverage both above and below the J groove weld include the analysis 
described in I-3000. The NRC's basis for revising the condition is 
that, based on its reviews of alternatives proposed by licensees 
related to this issue, over a period in excess of 10 years, it has 
become apparent to the NRC staff that the I-3000 method produces 
satisfactory results and is correctly performed by licensees. The NRC 
also notes that the probabilistic approach has not been proposed by 
licensees and that it has not been evaluated (including the acceptance 
criteria) by the NRC.
    The NRC staff finds the proposed change to the condition will have 
minimal impact on safety, while minimizing the regulatory burden of NRC 
review and approval of a standardized method to provide reasonable 
assurance of structural integrity of a reduced inspection area.
10 CFR 50.55a(g)(6)(ii)(D)(4) Surface Exam Acceptance Criteria
    The NRC proposes to revise Sec.  50.55a(g)(6)(ii)(D), the current 
condition on surface examination acceptance criteria, to update the 
ASME BPV Code Case reference. The NRC proposes to modify the condition 
Sec.  50.55a(g)(6)(ii)(D)(4) by changing the referenced version of the 
applicable ASME BPV Code Case N-729 from N 729-4 to N-729-6.
10 CFR 50.55a(g)(6)(ii)(D)(5) Peening
    The NRC proposes to add a new condition that will allow licensees 
to obtain inspection relief for peening of their RPV upper heads in 
accordance with the latest NRC-approved requirements, contained in 
Electric Power Research Institute (EPRI), Materials Reliability Project 
(MRP) Topical Report, ``Materials Reliability Program: Topical Report 
for Primary Water Stress Corrosion Cracking Mitigation by Surface 
Stress Improvement,'' (MRP-335, Revision 3-A) (ADAMS Accession No. 
ML16319A282). This document provides guidelines for the NRC-approved 
performance criteria, qualification requirements, inspection frequency, 
and scope. A licensee may peen any component in accordance with the 
requirements and limitations of the ASME Code. However, in order to 
obtain NRC-approved inspection relief for a RPV head mitigated with 
peening, as described in MRP-335, Revision 3-A, this proposed condition 
establishes MRP-335, Revision 3-A as the requirement for performance 
criteria, qualifications and inspections. Otherwise the requirements of 
an unmitigated RPV upper head inspection program shall apply.
    As part of this proposed condition, the NRC is removing two of the 
requirements contained in MRP-335, Revision 3-A: (1) The submission of 
a plant-specific alternative to the code case will not be required; and 
(2) Condition 5.4 will not be required.
    Hence, the NRC's proposed condition combines the use of the latest 
NRC-accepted performance criteria, qualification and inspection 
requirements in MRP-335, Revision 3-A, would allow licensees to not 
have to submit a plant-specific proposed alternative to adopt the 
inspection frequency of peened RPV head penetration nozzles in MRP-335, 
Revision 3-A, and does not require licensees to adhere to NRC Condition 
5.4 of MRP-335, Revision 3-A. By combining these points in the proposed 
condition, it alleviates the need to highlight nine areas in N-729-6 
that do not conform to the current NRC-approved requirements for 
inspection relief provided in MRP-335, Revision 3-A.
    Because the NRC proposes to require MRP-335, Revision 3-A, within 
this proposed condition on the requirements in the ASME Code Case, the 
NRC is incorporating by reference MRP-335, Revision 3-A, into Sec.  
50.55a(a)(4)(i).
10 CFR 50.55a(g)(6)(ii)(D)(6) Baseline Examinations
    The NRC proposes to add a new condition to address baseline 
examinations. Note 7(c) of Table 1 of ASME BPV Code Case N-729-6 
requires baseline volumetric and surface examinations for plants with 
an RPV upper head with less than 8 effective degradation years (EDY) by 
no later than February 10, 2008. This requirement has been in place 
since ASME BPV Code Case N-729-1 was first required by this section, 
and it was a carryover requirement from the First Revised NRC Order EA-
03-009. However, since any new RPV upper head replacements would occur 
after 2008, this requirement can no longer be met. While it is not 
expected that a new head using A600 nozzles would be installed, the NRC 
is conditioning this section to prevent the need for a licensee to 
submit a proposed alternative for such an event, should it occur. The 
NRC proposed condition would instead require a licensee to perform a 
baseline volumetric and surface examination within 2.25 reinspection 
years not to exceed 8 calendar years, as required under N-729-6, Table 
1 for the regular interval of inspection frequency.
10 CFR 50.55a(g)(6)(ii)(D)(7) Sister Plants
    The NRC proposes to add a new condition to address the use of the 
term sister plants for the examinations of RPV upper heads. The use of 
``sister plants'' under ASME BPV Code Case N-729-6 would allow 
extension of the volumetric inspection of replaced RPV heads with 
resistant materials from the current 10-year inspection frequency to a 
period of up to 40 years.
    As part of mandating the use of ASME BPV Code Case N-729-6 in this 
proposed rule, the NRC is approving the ASME Code's extension of the 
volumetric inspection frequency from every 10 years to every 20 years. 
The NRC finds that the documents, ``Technical Basis for Reexamination 
Interval Extension for Alloy 690 PWR Reactor Vessel Top Head 
Penetration

[[Page 56175]]

Nozzles (MRP-375)'' and improvement factors ``Recommended Factors of 
Improvement for Evaluating Primary Water Stress Corrosion Cracking 
(PWSCC) Growth Rates of Thick-Wall Alloy 690 Materials and Alloy 52, 
152, and Variants Welds (MRP-386),'' provide a sound basis for a 20-
year volumetric inspection interval and a 5-year bare metal visual 
inspection interval for alloy 690/52/152 materials subject to this code 
case thereby providing reasonable assurance of the structural integrity 
of the RPV heads.
    However, at the present time, the NRC is proposing a condition to 
prohibit the concept of ``sister plants''. If used, this concept would 
increase the inspection interval for plants with sisters from 20 years 
to 40 years. The NRC is currently evaluating both the definition of 
sister plants and factors of improvement between the growth of PWSCC in 
alloys 600/82/182 and 690/52/152.
    It is currently unclear to the NRC staff whether the criteria for 
sister plants (i.e., same owner) are appropriate criteria. The NRC 
staff also questions whether other criteria such as environment, alloy 
heat, and numbers of sister plants in a particular group should be 
included in the definition.
    The NRC staff continues to review information on PWSCC growth rates 
and factors of improvement for alloy 690/52/152 and 600/82/182 as 
proposed in MRP-386. While the NRC staff has concluded that crack 
growth in alloy 690/52/152 is sufficiently slower than in alloy 600/82/
182 to support an inspection interval of 20 years, work continues in 
assessing whether the data and analyses support a 40-year interval.
    Public comments concerning both the definition of sister plants and 
crack growth rate factors of improvement are being solicited during the 
comment period of this proposed rule.
10 CFR 50.55a(g)(6)(ii)(D)(8) Volumetric Leak Path
    The NRC proposes to add a new condition to substitute a volumetric 
leak path assessment for the required surface exam of the partial 
penetration weld of Paragraph -3200(b). The NRC finds that the use of a 
volumetric leak path assessment is more useful to confirm a possible 
leakage condition through the J-groove weld than a surface examination 
of the J-groove weld. While a surface examination may detect surface 
cracking, it will not confirm that such an indication is a flaw that 
caused leakage. A positive volumetric leak path assessment will provide 
a clear confirmation of leakage, either through the nozzle, weld or 
both. The NRC notes, that since all nozzles have had a volumetric 
examination, a baseline volumetric leak path assessment is available 
for comparison, and therefore provides additional assurance of 
effectiveness of the volumetric leak path assessment technique. As 
such, to eliminate the need for potential proposed alternatives 
requiring NRC review and authorization, this condition is proposed to 
increase regulatory efficiency.
ASME BPV Code Case N-770-5
    On June 21, 2011 (76 FR 36232), the NRC issued a final rule 
including Sec.  50.55a(g)(6)(ii)(F), requiring the implementation of 
ASME BPV Code Case N-770-1, ``Alternative Examination Requirements and 
Acceptance Standards for Class 1 PWR Piping and Vessel Nozzle Butt 
Welds Fabricated with UNS N06082 or UNS N86182 Weld Filler Material 
With or Without Application of Listed Mitigation Activities,'' with 
certain conditions. On November 7, 2016, the ASME approved the fifth 
revision of ASME BPV Code Case N 770 (N-770-5). The major changes from 
N-770-2, the last revision to be mandated by Sec.  50.55a(g)(6)(ii)(F), 
to N-770-5 included extending the inspection frequency for cold leg 
temperature dissimilar metal butt welds greater than 14-inches in 
diameter to once per inspection interval not to exceed 13 years, 
performance criteria and inspections for peening mitigated welds, and 
inservice inspection requirements for excavate and weld repair 
mitigations. Minor changes were also made to address editorial issues, 
to correct figures, or to add clarity. The NRC finds that the updates 
and improvements in N-770-5 are sufficient to update Sec.  
50.55a(g)(6)(ii)(F).
    The NRC, therefore, is updating the requirements of Sec.  
50.55a(g)(6)(ii)(F) to require licensees to implement ASME BPV Code 
Case N-770-5, with conditions. The previous NRC conditions have been 
modified to address the changes in ASME BPV Code Case N-770-5 and to 
ensure that this regulatory framework will provide adequate protection 
of public health and safety. The following sections discuss each of the 
NRC's revisions to the conditions on ASME BPV Code Case N-770-2 that 
support the implementation of N-770-5.
10 CFR 50.55a(g)(6)(ii)(F)(1) Augmented ISI Requirements: Examination 
Requirements for Class 1 Piping and Nozzle Dissimilar-Metal Butt 
Welds--(1) Implementation
    The NRC proposes to revise this condition to mandate the use of 
ASME BPV Code Case N-770-5, as conditioned by this section, in lieu of 
the current requirement to mandate ASME BPV Code Case N-770-2. The 
wording of this condition will allow a licensee to adopt this change 
anytime during the first year after the publication of the final rule. 
This is to provide flexibility for a licensee to adapt to the new 
requirements. Finally, included in this provision is an allowance for 
all previous NRC-approved licensee's alternatives to the requirements 
of this section to remain valid, regardless of the version of ASME BPV 
Code Case N-770 they were written against. The NRC has reviewed all 
currently applicable licensee alternatives to this code case and has 
found that the change from Code Case N-770-2 to N-770-5 required by 
this proposed regulation neither invalidates nor degrades plant safety 
associated with the continued use of existing alternatives. Therefore, 
to provide regulatory efficiency, the NRC finds that all previous NRC-
approved alternatives will remain valid for their specifically NRC-
approved duration of applicability.
10 CFR 50.55a(g)(6)(ii)(F)(2) Categorization
    The NRC proposes to revise this condition to include the 
categorization of welds mitigated by peening. This condition currently 
addresses the categorization for inspection of unmitigated welds and 
welds mitigated by various processes.
    The new section, to this revised condition, is to categorize 
dissimilar metal butt welds mitigated by peening. ``Topical Report for 
Primary Water Stress Corrosion Cracking Mitigation by Surface Stress 
Improvement,'' MRP-335, is the technical basis summary document for the 
application of peening in upper heads and dissimilar metal butt welds 
to address primary water stress corrosion cracking. The NRC conducted a 
comprehensive review of this document for generic application. The 
requirements contained in the NRC-approved version of this report, MRP-
335, Revision 3-A differ in several respects from the requirements 
contained in ASME BPV Code Case N-770-5. As such, to avoid confusion 
with multiple conditions, the NRC proposes to accept categorization of 
welds as being mitigated by peening, if said peening follows the 
performance criteria, qualification requirements, and inspection 
guidelines of MRP-335, Revision 3-A. Once implemented, the inspection 
guidelines of MRP-335, Revision 3-A would provide inspection relief 
from the requirements of an unmitigated dissimilar metal butt weld.

[[Page 56176]]

As part of this proposed condition, the NRC is removing the need for 
the licensee to submit a plant-specific proposed alternative to 
implement the inspection relief in accordance with MRP-335, Revision 3-
A.
    Because MRP-335, Revision 3-A, is being proposed to be used as a 
condition against the requirements in the ASME Code Case, the NRC is 
incorporating by reference MRP-335, Revision 3-A, into Sec.  
50.55a(a)(4)(i).
    The requirements for categorization of all other mitigated or non-
mitigated welds remain the same.
    As noted previously, all of these requirements, except for the 
categorization of peening, were in the previous conditions for mandated 
use of ASME BPV Code Cases N-770-2 and N-770-1.
10 CFR 50.55a(g)(6)(ii)(F)(3) Baseline Examinations
    The NRC proposes to delete this condition. The current condition 
regarding baseline inspections was considered unnecessary, as all 
baseline volumetric examinations are expected to have been completed. 
If a baseline examination is required, the licensee can follow the 
examination requirements in ASME BPV Code Case N-770-5. This condition 
number is reserved, to maintain the NRC condition numbering from the 
past rulemaking, and in this way, limit the need for additional updates 
to current procedures and documentation, when no substantive change has 
occurred.
10 CFR 50.55a(g)(6)(ii)(F)(4) Examination Coverage
    The NRC proposes to revise this condition to make an editorial 
change to update the reference to ASME BPV Code Case N-770-2 to N-770-
5.
10 CFR 50.55a(g)(6)(ii)(F)(6) Reporting Requirements
    The NRC proposes to revise this condition to address the deletion 
of wording in Paragraph -3132.3(d) of ASME BPV Code Case N-770-5 and 
relax the requirement for submitting the summary report to the NRC. The 
purpose of this condition is to obtain timely notification of 
unanticipated flaw growth in a mitigated butt weld in the reactor 
coolant pressure boundary. While NRC onsite and regional inspectors 
provide a plant-specific role in assessing the current safe operation 
of a specific plant, the NRC staff in the Office of Nuclear Reactor 
Regulation is also responsible for assessing the generic impact of the 
potential reduced effectiveness of a mitigation technique across the 
fleet. In order to address these concerns, the NRC has found that, in 
the event that a dissimilar metal butt weld is degraded, it is 
necessary for the NRC staff to obtain timely notification of the flaw 
growth and a report summarizing the evaluation, along with inputs, 
methodologies, assumptions, and causes of the new flaw or flaw growth 
within 30 days of the plant's return to service. This is a relaxation 
from the previous requirement to provide a report prior to entering 
mode 4 prior to plant startup. In its review of the prior condition, 
the NRC has determined that the burden associated with the submission 
of a report prior to entry into mode 4 exceeded the immediate safety 
benefit from the report. The NRC also has determined that a timely 
notification regarding the event was sufficient to begin the 
determination of whether an immediate generic safety concern exists. 
Further, the NRC has found the submittal of a report within 30 days is 
both necessary and sufficient to allow for the evaluation of any long-
term impacts of the flaw growth on the overall inspection programs for 
that specific mitigation type.
    The NRC has found that the deletion of the following sentence from 
Paragraph -3132.3(d), ``Any indication in the weld overlay material 
characterized as stress corrosion cracking is unacceptable,'' did not 
have a sufficiently identified technical basis to support its removal. 
Given that the NRC's approval of weld overlays is based on the 
resistance of the overlay material to cracking, any flaw growth into 
this material should call into question the effectiveness of that 
specific mitigation method. However, the NRC recognizes that there 
could be instances were NDE measurement uncertainty may require a 
conservative call on flaw size that may lead to the assumption of flaw 
growth. Rather than automatically assume this flaw growth is 
unacceptable, as stated in the previous requirement mandated under ASME 
BPV Code Case N-770-2, the NRC has found that reasonable assurance of 
plant safety could be assured by reporting this condition to the NRC 
for evaluation, in accordance with this condition. This relaxation of 
the previous requirement allows for regulatory flexibility in assessing 
the safety significance of any potential flaw growth.
10 CFR 50.55a(g)(6)(ii)(F)(9) Deferral
    The NRC proposes to revise this condition to address the potential 
deferrals of volumetric inspections for welds mitigated by peening as 
well as for welds mitigated by the excavate and weld technique. 
Volumetric inspections performed once per interval or on a ten-year 
basis can, in some instances, be deferred to the end of the current 
ten-year inservice inspection interval. As such, this could allow an 
inspection frequency, which is assumed to be approximately 10 years to 
be extended to as much as 20 years. While there are certain conditions 
that would warrant such an extension, the NRC finds, in the following 
two instances, that allowing such deferrals would provide an 
unacceptable reduction in the margin for safety.
    For welds peened in accordance with the performance and 
qualification criteria of MRP-335, Revision 3-A, the long-term 
inservice inspection interval, as required by MRP-335, Revision 3-A 
Table 4-1, is once per inspection interval. Note 11 of Table 4-1 would 
allow deferral of peened welds beyond the 10-year inspection frequency. 
This deferral would be beyond the NRC technical basis of Paragraph 
4.6.3 in the NRC Safety Evaluation of MRP-335, Revision 3-A. Therefore, 
the NRC proposes to revise this condition to prohibit the deferral of 
examinations of peened welds, without the submission of a plant-
specific proposed alternative for NRC review and approval.
    For welds mitigated with the excavate and weld repair technique, 
specifically inspection items M-2, N-1 and N-2, Note 11 of Table 1 of 
ASME BPV Code Case N-770-5 would allow the deferral of the second 
inservice examination to the end of the 10-year inservice inspection 
interval. The NRC finds the deferral of the second inservice exam 
unacceptable. If a weld was mitigated near the end of a 10-year 
inservice inspection interval, the first post mitigation examination 
might occur at the beginning of the next 10-year inservice inspection 
interval. Since the welds are required to be examined once per 
interval, the second post mitigation exam would be in the next 
interval. Because Note 11 allows the exams to be deferred, in such 
cases, it could approach twenty years between the first and second post 
mitigation exams. The NRC finds that a requirement to perform a second 
post mitigation exam within 10 years of the initial post mitigation 
exam to be more consistent with the reinspection timeline for other 
mitigations, such as full structural weld overlay and is therefore 
acceptable to the NRC. However, the NRC finds that, after the initial 
and second post mitigation examinations, provided the examination 
volumes show no indications of crack growth or new cracking, allowance 
for deferral of examination of these welds, as deemed appropriate, by 
the plant owner is

[[Page 56177]]

acceptable. As such, this proposed condition only restricts the 
deferral of the second inservice examination.
    Given the two new issues identified above, the NRC proposes to 
revise NRC Condition Sec.  50.55a (g)(6)(ii)(F)(9) Deferral to prohibit 
the deferral of volumetric inspections of welds mitigated by peening 
under MRP-335, Revision 3-A and the first 10-year inservice inspection 
examination for welds mitigated by the excavate and weld repair 
technique, inspection items M-2, N-1 and N-2 only.
10 CFR 50.55a(g)(6)(ii)(F)(10) Examination Technique
    The NRC proposes to revise this condition to make an editorial 
change to update the reference to ASME BPV Code Case N-770-2 to N-770-
5.
10 CFR 50.55a(g)(6)(ii)(F)(11) Cast Stainless Steel
    The NRC proposes to amend Sec.  50.55a(g)(6)(ii)(F)(11) to provide 
licensees with an alternative to meeting the current condition. The 
alternative would be to use ASME Code Case N-824 when examining 
dissimilar metal welds where inspections through a cast austenitic 
stainless steel component is required. The existing condition requires 
licensees to have a qualified program in place to inspect dissimilar 
metal butt welds with CASS materials from the CASS side by 2022. The 
NRC recognizes that there is no current Supplement 9 inspection 
guideline that would meet this requirement. At an NRC public meeting on 
April 17, 2018, the NRC and industry representatives discussed the 
estimated number of welds that would be covered by the condition. Given 
this information, the NRC has determined that rather than requiring a 
full qualification program to be developed within this timeframe, ASME 
Code Case N-824 would provide an acceptable alternative and provide 
reasonable assurance of public health and safety.
    ASME BPV Code Case N-824 incorporates best practices for the 
inspection of cast stainless steel from NUREG/CR-7122 and NUREG/CR-
6933. NUREG/CR-7122 showed that pressurizer surge line sized piping 
welds may be inspectable with existing dissimilar metal butt weld 
inspection procedures. NUREG/CR-6933 showed that large-bore cast 
stainless steel may be inspectable using specialized low-frequency 
inspection procedures. Therefore, the NRC will modify the condition to 
allow the use of ASME Code Case N-824, as conditioned in RG 1.147, as 
an option to the development of Appendix VIII, Supplement 9 or similar 
qualifications, or, when examining dissimilar metal welds where 
inspections through a cast austenitic stainless steel component is 
required to obtain volumetric inspection coverage.
10 CFR 50.55a(g)(6)(ii)(F)(13) Encoded Ultrasonic Examination
    The NRC proposes to revise this current condition, which requires 
the encoded examination of unmitigated and mitigated cracked butt welds 
under the scope of ASME BPV Code Case N-770-5. In particular, the 
proposed revision is being expanded to address changes in ASME BPV Code 
Case N-770-5 to include inspection categories B-1, B-2 for cold leg 
welds, which were previously under the single inspection category B, 
and the new inspection categories N-1, N-2 and O for cracked welds 
mitigated with the excavate and weld repair technique. The inclusion of 
these weld categories is in line with the previous basis for this 
condition.
    Further, the NRC proposes to relax the requirement for 100 percent 
of the required inspection volume to be encoded. The new requirement 
would allow essentially 100 percent of the required inspection volume 
to be encoded under the definition of essentially 100 percent in ASME 
BPV Code Case N-460. This code case allows the reduction to 90 percent 
coverage only if a physical limitation or impediment to full coverage 
is encountered during the inspection. The NRC finds this relaxation 
appropriate, given the potential that the physical size of the encoding 
equipment may reduce attainable coverage, when compared to manual 
techniques. The NRC staff finds that the reduction in safety associated 
with this potential minor decrease in coverage is minimal. Adoption of 
the revised proposed condition will reduce unnecessary preparation and 
submittal of requests for NRC review and approval of alternatives to 
this requirement.
10 CFR 50.55a(g)(6)(ii)(F)(14) Excavate and Weld Repair Cold Leg
    The NRC proposes to add a new condition to address the initial 
inspection of cold leg operating temperature welds after being 
mitigated by the excavate and weld repair technique. The excavate and 
weld repair technique is a new mitigation category introduced in ASME 
BPV Code Case N-770-5. The first inspection requirement for inspection 
item M-2, N-1 and N-2 welds, after being mitigated, is during the 1st 
or 2nd refueling outages after mitigation. The NRC finds that the ASME 
BPV Code Case N-770-5 language does not provide separate inspection 
programs between the cold leg and the hot leg temperature for the first 
volumetric inspection. The NRC determines that, at hot leg 
temperatures, one fuel cycle is sufficient for a preexisting, 
nondetectable, crack to grow to detectable size (10 percent through 
wall). However, at cold leg temperatures, crack growth is sufficiently 
slow that preexisting, undetected, cracks are unlikely to reach 
detectable size in a single fuel cycle. Therefore, in order to ensure 
the effectiveness of the initial volumetric examination to verify no 
unanticipated flaw growth in the mitigated weld prior to extending the 
inspection frequency to 10 years or beyond, the NRC proposes to add a 
condition to require the first examination to be performed during the 
second refueling outage following the mitigation of cold leg operating 
temperature welds.
10 CFR 50.55a(g)(6)(ii)(F)(15) Cracked Excavate and Weld Repair
    The NRC proposes to add a new condition to address the long-term 
inspection frequency of cracked welds mitigated by the excavate and 
weld repair technique, i.e. inspection category N-1. The long-term 
volumetric inspection frequency for the cracked N-1 welds under ASME 
BPV Code Case N-770-5 is a 25 percent sample each 10-year inspection 
interval. In comparison, the NRC notes that the long-term volumetric 
inspection frequency of a non-cracked weld mitigated with the excavate 
and weld repair technique without stress improvement (inspection 
category M-2) is 100 percent each 10-year inspection interval. Due to 
not attaining surface stress improvement, M-2 welds could potentially 
have cracking initiate at any time over the remaining life of the 
repair. Therefore, a volumetric inspection frequency of once per 10-
year inspection frequency is warranted to verify weld structural 
integrity. However, every N-1 categorized weld already has a pre-
existing crack, but Code Case N-770-5 would allow a 25 percent sample 
inspection frequency each 10-year inservice inspection interval. This 
could allow some N-1 welds with preexisting flaws to not be 
volumetrically inspected for the remainder of plant life. The NRC finds 
insufficient technical basis to support the difference in inspection 
frequency between N-1 and M-2 welds. Therefore, the NRC proposes a 
condition on N-1 inspection category welds that would require the same 
long-term inspection frequency, as that determined acceptable by the 
ASME BPV Code Case N-770-5 for M-2 welds, i.e., non-cracked 360 degree 
excavate

[[Page 56178]]

and weld repair with no stress improvement credited.
10 CFR 50.55a(g)(6)(ii)(F)(16) Partial Arc Excavate and Weld Repair
    The NRC proposes to add a new condition to prevent the use of the 
inspection criteria for partial arc excavate and weld repair technique 
contained in ASME BPV Code Case N-770-5. The NRC staff notes that ASME 
BPV Code Case N-847 which describes the process of installing an 
excavate and weld repair has not been included in RG 1.147 and has not 
been incorporated by reference into Sec.  50.55a. As a result, 
licensees must propose an alternative to the ASME Code to make a repair 
using the excavate and weld repair technique. Therefore, preventing the 
use of the inspection criteria contained in ASME BPV Code Case N-770-5, 
proposes no additional burden on the licensee when viewed in light of 
the requirement to propose an alternative to the ASME BPV Code to use 
the excavate and weld repair technique. The NRC's basis for this 
condition is that initial research into stress fields and crack growth 
associated with the ends of the repair indicated that the potential for 
crack growth rates to exceed those expected in the absence of the 
repair. The NRC also notes that there is potential for confusion 
regarding the inspection interval for these welds associated with 
whether Note 5 can be applied.

IV. Section-by-Section Analysis

Paragraph (a)(1)(i)

    This proposed rule would revise paragraph (a)(1)(i) by removing the 
abbreviation definition for ASME BPV Code in the first sentence.

Paragraph (a)(1)(i)(E)

    This proposed rule would add new paragraphs (a)(1)(i)(E)(18) and 
(19) to include the 2015 and 2017 Editions of the ASME BPV Code.

Paragraph (a)(1)(ii)

    This proposed rule would revise paragraphs (a)(1)(ii) to remove the 
acronym ``BPV'' and replace it with ``Boiler and Pressure Vessel.''

Paragraph (a)(1)(ii)(C)

    This proposed rule would revise paragraphs (a)(1)(ii)(C)(52) and 
(53) to remove parenthetical language and would add new paragraphs 
(a)(1)(ii)(C)(54) and (55) to include the 2015 and 2017 Editions of the 
ASME BPV Code.

Paragraph (a)(1)(iii)(C)

    This proposed rule would revise the reference from Code Case N-729-
4 to N-729-6.

Paragraph (a)(1)(iii)(D)

    This proposed rule would revise the reference from Code Case N-770-
2 to N-770-5.

Paragraph (a)(1)(iv)

    This proposed rule would remove parenthetical language from 
paragraph (a)(1)(iv).

Paragraph (a)(1)(iv)(C)

    This proposed rule would add new paragraphs (a)(1)(iv)(C)(2) and 
(3) to include the 2015 and 2017 Editions of the ASME BPV Code.

Paragraph (a)(4)

    This proposed rule would add a new paragraph (a)(4) to incorporate 
by reference the Electric Power Research Institute, Materials 
Reliability Program, 3420 Hillview Avenue, Palo Alto, CA 94304-1338; 
telephone: 1-650-855-2000; http://www.epri.com.

Paragraph (a)(4)(i)

    This proposed rule would add a new paragraph (a)(4)(i) to 
incorporate by reference the Materials Reliability Program: Topical 
Report for Primary Water Stress Corrosion Cracking Mitigation by 
Surface Stress Improvement (MRP-335, Revision 3-A), EPRI approval date: 
November 2016. Paragraph (a)(4)(ii) would be added and resereved.

Paragraph (b)(1)

    This proposed rule would change the reference from the 2013 to the 
2017 Edition of the ASME BPV Code.

Paragraph (b)(1)(ii)

    This proposed rule would change the word ``Note'' to ``Footnote'' 
in Table 1 of paragraph (b)(1)(ii) and revise the last reference in the 
table from the 2013 Edition to the 2017 Edition of the ASME BPV Code.

Paragraph (b)(1)(iii)

    This proposed rule would change the references from the 2008 
Addenda to the 2017 Edition of the ASME BPV Code.

Paragraph (b)(1)(v)

    This proposed rule would revise paragraph (b)(1)(v) to limit the 
condition so that it applies only for the 1995 Edition through the 
2009b Addenda of the 2007 Edition, where the NQA-1-1994 Edition is 
incorporated by reference in paragraph (a)(1) of this section.

Paragraph (b)(1)(vi)

    This proposed rule would revise paragraph (b)(1)(vi) to replace 
``the latest edition and addenda'' with ``all editions and addenda up 
to and including the 2013 Edition.''

Paragraph (b)(1)(vii)

    This proposed rule would revise paragraph (b)(1)(vii) to replace 
``the 2013 Edition'' with ``all editions and addenda up to and 
including the 2017 Edition.''

Paragraph (b)(1)(x)

    This proposed rule would add new paragraph (b)(1)(x) and its 
subparagraphs (A) and (B) to include two conditions necessary to 
maintain adequate standards for visual examinations of bolts, studs, 
and nuts.

Paragraph (b)(1)(xi)

    This proposed rule would add new paragraph (b)(1)(xi) and its 
subparagraphs (A) through (E) to include five conditions that are 
necessary to install safety-related Class 3 HDPE pressure piping in 
accordance with ASME BPV Code, Section III, Mandatory Appendix XXVI. 
The first two conditions apply to the 2015 and 2017 Editions of Section 
III. The third, fourth, and fifth conditions apply only to the 2017 
Edition of Section III.

Paragraph (b)(1)(xii)

    This proposed rule would add new paragraph (b)(1)(xii) which 
applies to the use of certifying engineers.

Paragraph (b)(2)

    This proposed rule would revise paragraph (b)(2) to change the 
reference from the 2013 Edition to the 2017 Edition of the ASME BPV 
Code.

Paragraph (b)(2)(vi)

    This proposed rule would remove and reserve paragraph (b)(2)(vi).

Paragraph (b)(2)(vii)

    This proposed rule would remove and reserve paragraph (b)(2)(vii).

Paragraph (b)(2)(ix)

    This proposed rule would revise paragraph (b)(2)(ix) to add 
references to new paragraph (b)(2)(ix)(K) of this section, where 
applicable. It would also replace ``the latest edition and addenda'' 
with ``the 2015 Edition.''

Paragraph (b)(2)(ix)(K)

    This proposed rule would add new paragraph (b)(2)(ix)(K) to require 
visual examination of the moisture barrier materials installed in 
containment leak chase channel system closures at

[[Page 56179]]

concrete floor interfaces. This condition will be applicable to all 
editions and addenda of Section XI, Subsection IWE, of the ASME BPV 
Code, prior to the 2017 Edition, that are incorporated by reference in 
paragraph (b) of this section.

Paragraph (b)(2)(xvii)

    This proposed rule would remove and reserve paragraph (b)(2)(xvii).

Paragraph (b)(2)(xviii)(D)

    This proposed rule would revise paragraph (b)(2)(xviii)(D) to 
extend the applicability to users of the latest edition incorporated by 
reference in paragraph (a)(1)(ii) of this section.

Paragraph (b)(2)(xx)(B)

    This proposed rule would revise paragraph (b)(2)(xx)(B) to clarify 
the NRC's expectations for system leakage tests performed in lieu of a 
hydrostatic pressure test, following repair/replacement activities 
performed by welding or brazing on a pressure retaining boundary using 
the 2003 Addenda through the latest edition and addenda of ASME BPV 
Code, Section XI incorporated by reference in paragraph (a)(1)(ii) of 
this section.

Paragraph (b)(2)(xx)(C)

    This proposed rule would add new paragraph (b)(2)(xx)(C) and 
subparagraphs (1) and (2) to include two conditions on the use of the 
alternative BWR Class 1 system leakage test described in IWA-
5213(b)(2), IWB-5210(c) and IWB-5221(d) of the 2017 Edition of ASME BPV 
Code, Section XI.

Paragraph (b)(2)(xxi)(A)

    This proposed rule would remove and reserve paragraph 
(b)(2)(xxi)(A).

Paragraph (b)(2)(xxi)(B)

    This proposed rule would add new paragraph (b)(2)(xxi)(B) and its 
subparagraphs (1) through (3) that will include conditions on the use 
of the provisions of IWB-2500(f) and (g) and Notes 6 and 7 of Table 
IWB-2500-1 of the 2017 Edition of ASME BPV Code, Section XI.

Paragraph (b)(2)(xxv)

    This proposed rule would revise paragraph (b)(2)(xxv) introductory 
text and add new subparagraphs (A) and (B) that would prohibit the use 
of IWA-4340 in Section XI editions and addenda earlier than the 2011 
Edition and would allow the use of IWA-4340 in addenda and editions 
from the 2011 Addenda through the latest edition incorporated by 
reference in this section under certain conditions.

Paragraph (b)(2)(xxvi)

    This proposed rule would revise paragraph (b)(2)(xxvi) to clarify 
the NRC's expectations for pressure testing of ASME BPV Code Class 1, 
2, and 3 mechanical joints disassembled and reassembled during the 
performance of an ASME BPV Code, Section XI activity.

Paragraph (b)(2)(xxxii)

    This proposed rule would revise the reporting requirements in 
paragraph (b)(2)(xxxii).

Paragraph (b)(2)(xxxiv)

    This proposed rule would revise paragraph (b)(2)(xxxiv) and its 
subparagraph (B) to extend the applicability from the 2013 Edition 
through the latest edition incorporated by reference in paragraph 
(a)(1)(ii) of this section.

Paragraph (b)(2)(xxxv)

    This proposed rule would revise paragraph (b)(2)(xxxv) to designate 
the introductory text of paragraph (b)(2)(xxxv) minus the paragraph 
heading as subparagraph (A) and it would also add new subparagraph (B).

Paragraph (b)(2)(xxxvi)

    This proposed rule would revise the condition in paragraph 
(b)(2)(xxxvi) to also include the use of the 2015 and 2017 Editions of 
ASME BPV Code, Section XI.

Paragraph (b)(2)(xxxviii)

    This proposed rule would add new paragraph (b)(2)(xxxviii) and its 
subparagraphs (A) and (B) that contain two conditions on the use of 
ASME BPV Code, Section XI, Appendix III, Supplement 2.

Paragraph (b)(2)(xxxix)

    This proposed rule would add new paragraph (b)(2)(xxxix) and its 
subparagraphs (A) and (B) that contain conditions on the use of IWA-
4421(c)(1) and IWA-4421(c)(2) of Section XI, in the 2017 Edition.

Paragraph (b)(2)(xl)

    This proposed rule would add new paragraph (b)(2)(xl) to include 
the requirements for the prohibitions on the use of IWB-3510.4(b).

Paragraph (b)(2)(xli)

    This proposed rule would add new paragraph (b)(2)(xli) to include 
the requirements for the prohibitions on the use of IWB-3112(a)(3) and 
IWC-3112(a).

Paragraph (b)(2)(xlii)

    This proposed rule would add new paragraph (b)(2)(xlii) to include 
the requirements for the use of the provisions in Table IWB-2500-1, 
Examination Category B-F, Pressure Retaining Dissimilar Metal Welds in 
Vessel Nozzles, Item B5.11 and Item B5.71.

Paragraph (b)(3)

    This proposed rule would revise paragraph (b)(3) to include 
Appendix IV in the list of Mandatory Appendices and it would also 
remove the reference to the ``2012 Edition'' and replace it with ``the 
latest edition and addenda of the ASME OM Code incorporated by 
reference.'' It would also revise the last sentence in the paragraph 
for clarity.

Paragraph (b)(3)(ii)

    This proposed rule would revise paragraph (b)(3)(ii) to remove the 
reference to the ``2011 Addenda, and 2012 Edition'' and replace it with 
``the latest edition and addenda of the ASME OM Code incorporated by 
reference in paragraph (a)(1)(iv) of this section.''

Paragraph (b)(3)(iv)

    This proposed rule would revise paragraph (b)(3)(iv) to update the 
conditions for use of Appendix II of the ASME OM Code, 2003 Addenda 
through the 2015 Edition.

Paragraph (b)(3)(viii)

    This proposed rule would revise paragraph (b)(3)(viii) to remove 
the reference to the ``2011 Addenda, or 2012 Edition'' and replace it 
with ``the latest edition and addenda of the ASME OM Code incorporated 
by reference in paragraph (a)(1)(iv) of this section.''

Paragraph (b)(3)(ix)

    This proposed rule would revise paragraph (b)(3)(ix) to update the 
conditions for use of Subsection ISTF of the ASME OM Code, through the 
2012 Edition or 2015 Edition.

Paragraph (b)(3)(xi)

    This proposed rule would revise paragraph (b)(3)(xi) to extend the 
applicability of the reference to the ASME OM Code, 2012 Edition 
through the latest edition and addenda of the ASME OM Code incorporated 
by reference in paragraph (a)(1)(iv). It would also provide additional 
clarity regarding obturator positions for valves with remote position 
indication.

Paragraph (b)(3)(xii)

    This proposed rule would add a new paragraph (b)(3)(xii) for air-
operated valves (Appendix IV).

Paragraphs (f)(4)(i) and (ii)

    This proposed rule would revise paragraphs (f)(4)(i) and (ii) to 
change the

[[Page 56180]]

time frame for complying with the latest edition and addenda of the 
ASME OM Code from 12 months to 18 months, both for the initial and 
successive IST programs.

Paragraph (f)(7)

    This proposed rule would add new paragraph (f)(7) to include the 
requirements for inservice testing reporting.

Paragraph (g)(4)

    This proposed rule would revise paragraph (g)(4) to remove the 
phrase ``subject to the condition referenced in paragraph (b)(2)(vi) of 
this section.''

Paragraph (g)(4)(i)

    This proposed rule would revise paragraph (g)(4)(i) to change the 
time frame for complying with the latest edition and addenda of the 
ASME BPV Codes, from 12 months to 18 months, for ISI programs.

Paragraph (g)(4)(ii)

    This proposed rule would revise paragraph (g)(4)(ii) to change the 
time frames for complying with the latest edition and addenda of the 
ASME BPV Codes, from 12 months to 18 months, for successive ISI 
programs. It also would remove the date of August 17, 2017, and replace 
that date with the effective date of the final rule.

Paragraph (g)(6)(ii)(C)

    This proposed rule would remove and reserve paragraph 
(g)(6)(ii)(C).

Paragraph (g)(6)(ii)(D)(1)

    This proposed rule would revise paragraph (g)(6)(ii)(D)(1) to 
remove the date of August 17, 2017, and replace that date with the 
effective date of the final rule. It would also update the reference 
from Code Case N-729-4 to Code Case N-729-6. It would also be revised 
to include the conditions in paragraphs (2) through (8) and that 
licensees must be in compliance with these conditions by no later than 
1 year from the effective date of the final rule.

Paragraph (g)(6)(ii)(D)(2)

    This proposed rule would revise paragraph (g)(6)(ii)(D)(2) in its 
entirety.

Paragraph (g)(6)(ii)(D)(4)

    This proposed rule would revise paragraph (g)(6)(ii)(D)(4) to 
update the reference to ASME BPV Code Case N-729 from revision 4 to 
revision 6.

Paragraphs (g)(6)(ii)(D)(5) through (8)

    This proposed rule would add new paragraphs (g)(6)(ii)(D)(5) 
through (8) to include the requirements for peening, baseline 
examinations, sister plants, and volumetric leak path.

Paragraph (g)(6)(ii)(F)(1)

    This proposed rule would revise paragraph (g)(6)(ii)(F)(1) to 
remove the date of August 17, 2017, and replace that date with the 
effective date of the final rule. It would also update the reference 
from Code Case N-770-2 (revision 2) to Code Case N-770-5 (revision 5). 
It would also be revised to include the conditions in paragraphs 
(g)(6)(ii)(F)(2) through (16) of this section and that licensees must 
be in compliance with these conditions by no later than 1 year from the 
effective date of the final rule.

Paragraph (g)(6)(ii)(F)(2)

    This proposed rule would revise paragraph (g)(6)(ii)(F)(2) to 
include subparagraphs (i) through (v).

Paragraph (g)(6)(ii)(F)(3)

    This proposed rule would remove and reserve paragraph 
(g)(6)(ii)(F)(3).

Paragraph (g)(6)(ii)(F)(4)

    This proposed rule would revise paragraph (g)(6)(ii)(F)(4) to 
change the reference from ASME BPV Code Case N-770-2 (revision 2) to 
Code Case N-770-5 (revision 5).

Paragraph (g)(6)(ii)(F)(6)

    This proposed rule would revise paragraph (g)(6)(ii)(F)(6) to 
provide greater clarity of the requirements that must be met.

Paragraph (g)(6)(ii)(F)(9)

    This proposed rule would revise paragraph (g)(6)(ii)(F)(9) to 
include subparagraphs (i) through (iii).

Paragraph (g)(6)(ii)(F)(10)

    This proposed rule would revise paragraph (g)(6)(ii)(F)(10) from 
ASME BPV Code Case N-770-2 (revision 2) to N-770-5 (revision 5).

Paragraph (g)(6)(ii)(F)(11)

    This proposed rule would revise paragraph (g)(6)(ii)(F)(11) to 
include an alternative to meeting the current condition.

Paragraph (g)(6)(ii)(F)(13)

    This proposed rule would revise paragraph (g)(6)(ii)(F)(13) to 
include inspection categories B-1, B-2, N-1, N-2 and O.

Paragraph (g)(6)(ii)(F)(14) through (16)

    This proposed rule would add new paragraphs (g)(6)(ii)(F)(14) 
through (16) to contain the new requirements: Excavate and weld repair 
cold leg, cracked excavate and weld repair, and partial arc excavate 
and weld repair.

V. Generic Aging Lessons Learned Report

Background

    In December 2010, the NRC issued ``Generic Aging Lessons Learned 
(GALL) Report,'' NUREG-1801, Revision 2 (ADAMS Accession No. 
ML103490041), for applicants to use in preparing license renewal 
applications. The GALL report provides aging management programs (AMPs) 
that the NRC has concluded are sufficient for aging management in 
accordance with the license renewal rule, as required in Sec.  
54.21(a)(3). In addition, ``Standard Review Plan for Review of License 
Renewal Applications for Nuclear Power Plants,'' NUREG-1800, Revision 2 
(ADAMS Accession No. ML103490036), was issued in December 2010, to 
ensure the quality and uniformity of NRC staff reviews of license 
renewal applications and to present a well-defined basis on which the 
NRC staff evaluates the applicant's aging management programs and 
activities. In April 2011, the NRC also issued ``Disposition of Public 
Comments and Technical Bases for Changes in the License Renewal 
Guidance Documents NUREG-1801 and NUREG-1800,'' NUREG-1950 (ADAMS 
Accession No. ML11116A062), which describes the technical bases for the 
changes in Revision 2 of the GALL report and Revision 2 of the standard 
review plan (SRP) for review of license renewal applications.
    Revision 2 of the GALL report, in Sections XI.M1, XI.S1, XI.S2, 
XI.M3, XI.M5, XI.M6, XI.M11B and XI.S3, describes the evaluation and 
technical bases for determining the sufficiency of ASME BPV Code 
Subsections IWB, IWC, IWD, IWE, IWF, or IWL for managing aging during 
the period of extended operation (i.e., up to 60 years of operation). 
In addition, many other AMPs in the GALL report rely, in part but to a 
lesser degree, on the requirements specified in the ASME BPV Code, 
Section XI. Revision 2 of the GALL report also states that the 1995 
Edition through the 2004 Edition of the ASME BPV Code, Section XI, 
Subsections IWB, IWC, IWD, IWE, IWF, or IWL, as modified and limited by 
Sec.  50.55a, were found to be acceptable editions and addenda for 
complying with the requirements of Sec.  54.21(a)(3), unless 
specifically noted in certain sections of the GALL report. The GALL 
report further states that future Federal Register documents that amend 
Sec.  50.55a will discuss the acceptability of editions

[[Page 56181]]

and addenda more recent than the 2004 Edition for their applicability 
to license renewal. In a final rule issued on June 21, 2011 (76 FR 
36232), subsequent to Revision 2 of the GALL report, the NRC also found 
that the 2004 Edition with the 2005 Addenda through the 2007 Edition 
with the 2008 Addenda of Section XI of the ASME BPV Code, Subsections 
IWB, IWC, IWD, IWE, IWF, or IWL, as subject to the conditions in Sec.  
50.55a, are acceptable for the AMPs in the GALL report and the 
conclusions of the GALL report remain valid with the augmentations 
specifically noted in the GALL report. In a final rule issued on July 
18, 2017 (82 FR 32934), the NRC further finds that the 2009 Addenda 
through the 2013 Edition of Section XI of the ASME BPV Code, 
Subsections IWB, IWC, IWD, IWE, IWF, or IWL, as subject to the 
conditions in Sec.  50.55a, will be acceptable for the AMPs in the GALL 
report.
    In July 2017, the NRC issued ``Generic Aging Lessons Learned for 
Subsequent License Renewal (GALL-SLR) Report,'' NUREG-2191 (ADAMS 
Accession Nos. ML17187A031 and ML17187A204), for applicants to use in 
preparing applications for subsequent license renewal. The GALL-SLR 
report provides AMPs that are sufficient for aging management for the 
subsequent period of extended operation (i.e., up to 80 years of 
operation), as required in Sec.  54.21(a)(3). The NRC also issued 
``Standard Review Plan for Review of Subsequent License Renewal 
Applications for Nuclear Power Plants,'' (SRP-SLR), NUREG-2192 in July 
2017 (ADAMS Accession No. ML17188A158). In a similar manner as the GALL 
report does, the GALL-SLR report, in Sections XI.M1, XI.S1, XI.S2, 
XI.M3, XI.11B, and XI.S3, describes the evaluation and technical bases 
for determining the sufficiency of ASME BPV Code Subsections IWB, IWC, 
IWD, IWE, IWF, or IWL for managing aging during the subsequent period 
of extended operation. Many other AMPs in the GALL-SLR report rely, in 
part but to a lesser degree, on the requirements specified in the ASME 
BPV Code, Section XI. The GALL-SLR report also indicates that the 1995 
Edition through the 2013 Edition of the ASME BPV Code, Section XI, 
Subsections IWB, IWC, IWD, IWE, IWF, or IWL, as subject to the 
conditions in Sec.  50.55a, are acceptable for complying with the 
requirements of Sec.  54.21(a)(3), unless specifically noted in certain 
sections of the GALL-SLR report.

Evaluation With Respect to Aging Management

    As part of this proposed rule, the NRC evaluated whether those AMPs 
in the GALL report and GALL-SLR report which rely upon Subsections IWB, 
IWC, IWD, IWE, IWF, or IWL of Section XI in the editions and addenda of 
the ASME BPV Code incorporated by reference into Sec.  50.55a, in 
general continue to be acceptable if the AMP relies upon these 
Subsections in the 2015 Edition and the 2017 Edition. In general the 
NRC finds that the 2015 Edition and the 2017 Edition of Section XI of 
the ASME BPV Code, Subsections IWB, IWC, IWD, IWE, IWF, or IWL, as 
subject to the conditions of this proposed rule, are acceptable for the 
AMPs in the GALL report and GALL-SLR report and the conclusions of the 
GALL report and GALL-SLR report remain valid with the exception of 
augmentation, specifically noted in those reports. Accordingly, an 
applicant for license renewal (including subsequent license renewal) 
may use, in its plant-specific license renewal application, Subsections 
IWB, IWC, IWD, IWE, IWF, or IWL of Section XI of the 2015 Edition and 
the 2017 Edition of the ASME BPV Code, as subject to the conditions in 
this proposed rule, without additional justification. Similarly, a 
licensee approved for license renewal that relied on the AMPs may use 
Subsections IWB, IWC, IWD, IWE, IWF, or IWL of Section XI of the 2015 
Edition and the 2017 Edition of the ASME BPV Code. However, applicants 
must assess and follow applicable NRC requirements with regard to 
licensing basis changes and evaluate the possible impact on the 
elements of existing AMPs.
    Some of the AMPs in the GALL report and GALL-SLR report recommend 
augmentation of certain Code requirements in order to ensure adequate 
aging management for license renewal. The technical and regulatory 
aspects of the AMPs for which augmentations are recommended also apply 
if the 2015 Edition and the 2017 Edition of Section XI of the ASME BPV 
Code are used to meet the requirements of Sec.  54.21(a)(3). The NRC 
staff evaluated the changes in the 2015 Edition and the 2017 Edition of 
Section XI of the ASME BPV Code to determine if the augmentations 
described in the GALL report and GALL-SLR report remain necessary; the 
NRC staff's evaluation has concluded that the augmentations described 
in the GALL and GALL-SLR reports are necessary to ensure adequate aging 
management.
    For example, GALL-SLR report AMP XI.S3, ``ASME Section XI, 
Subsection IWF'', recommends that volumetric examination consistent 
with that of ASME BPV Code, Section XI, Table IWB-2500-1, Examination 
Category B-G-1 should be performed to detect cracking for high strength 
structural bolting (actual measured yield strength greater than or 
equal to 150 kilopound per square inch (ksi)) in sizes greater than 1 
inch nominal diameter. The GALL-SLR report also indicates that this 
volumetric examination may be waived with adequate plant-specific 
justification. This guidance for aging management in the GALL-SLR 
report is the augmentation of the visual examination specified in 
Subsection IWF of the 2015 Edition and the 2017 Edition of ASME BPV 
Code, Section XI.
    A license renewal applicant may either augment its AMPs as 
described in the GALL report and GALL-SLR report (for operation up to 
60 and 80 years respectively), or propose alternatives for the NRC to 
review as part of the applicant's plant-specific justification for its 
AMPs.

VI. Specific Request for Comment

    The NRC is considering changes to Sec.  50.55a(g)(6)(ii)(D) 
Augmented ISI requirements: Reactor vessel head inspections. As 
previously discussed in the document, the NRC proposes to add a new 
condition to address the use of the term ``sister plants'' for the 
examinations of RPV upper heads. The use of sister plants under ASME 
BPV Code Case N-729-6 would allow extension of the volumetric 
inspection of replaced RPV heads with resistant materials from the 
current 10-year inspection frequency to a period of up to 40 years. The 
NRC is proposing a condition to prohibit the use of the concept of 
sister plants. The NRC is evaluating both the definition of sister 
plants and factors of improvement between the growth of PWSCC in alloys 
600/82/182 and 690/52/152. It is unclear whether the current criteria 
for sister plants (i.e., same owner) are appropriate. The NRC also 
questions whether other criteria, such as environment, alloy heat, and 
number of sisters in a particular group, should be included in the 
definition. The NRC continues to review information on PWSCC growth 
rates and factors of improvement for alloy 690/52/152 and 600/82/182 as 
proposed in MRP-386. While the NRC has concluded that crack growth in 
alloy 690/52/152 is sufficiently slower than in alloy 600/82/182 to 
support an inspection interval of 20 years, work continues in assessing 
whether the data and analyses support a 40-year interval.

[[Page 56182]]

    The NRC is interested in receiving public input that addresses 
whether there are reasonable changes to the definition of the term 
``sister plants'' that would better identify heads with enough material 
similarities such that examination of one head can be representative of 
all others in the group.

VII. Plain Writing

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

VIII. Voluntary Consensus Standards

    The National Technology Transfer and Advancement Act of 1995, 
Public Law 104-113 (NTTAA), and implementing guidance in U.S. Office of 
Management and Budget (OMB) Circular A-119 (February 10, 1998), 
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. The NTTAA requires Federal agencies to use 
industry consensus standards to the extent practical; it does not 
require Federal agencies to endorse a standard in its entirety. Neither 
the NTTAA nor Circular A-119 prohibit an agency from adopting a 
voluntary consensus standard while taking exception to specific 
portions of the standard, if those provisions are deemed to be 
``inconsistent with applicable law or otherwise impractical.'' 
Furthermore, taking specific exceptions furthers the Congressional 
intent of Federal reliance on voluntary consensus standards because it 
allows the adoption of substantial portions of consensus standards 
without the need to reject the standards in their entirety because of 
limited provisions that are not acceptable to the agency.
    In this proposed rule, the NRC is continuing its existing practice 
of establishing requirements for the design, construction, operation, 
ISI (examination) and IST of nuclear power plants by approving the use 
of the latest editions and addenda of the ASME BPV and OM Codes (ASME 
Codes) in Sec.  50.55a. The ASME Codes are voluntary consensus 
standards, developed by participants with broad and varied interests, 
in which all interested parties (including the NRC and licensees of 
nuclear power plants) participate. Therefore, the NRC's incorporation 
by reference of the ASME Codes is consistent with the overall 
objectives of the NTTAA and OMB Circular A-119.
    As discussed in Section III of this document, this proposed rule 
would condition the use of certain provisions of the 2015 and 2017 
Editions to the ASME BPV Code, Section III, Division 1 and the ASME BPV 
Code, Section XI, Division 1, as well as the 2015 and 2017 Editions to 
the ASME OM Code. In addition, the NRC is proposing to not adopt 
(``excludes'') certain provisions of the ASME Codes as discussed in 
this document, and in the regulatory and backfit analysis for this 
proposed rule. The NRC believes that this proposed rule complies with 
the NTTAA and OMB Circular A-119 despite these conditions and 
``exclusions.''
    If the NRC did not conditionally accept ASME editions, addenda, and 
code cases, the NRC would disapprove them entirely. The effect would be 
that licensees and applicants would submit a larger number of requests 
for the use of alternatives under Sec.  50.55a(z), requests for relief 
under Sec.  50.55a(f) and (g), or requests for exemptions under Sec.  
50.12 and/or Sec.  52.7. These requests would likely include broad-
scope requests for approval to issue the full scope of the ASME Code 
editions and addenda which would otherwise be approved as proposed in 
this proposed rule (i.e., the request would not be simply for approval 
of a specific ASME Code provision with conditions). These requests 
would be an unnecessary additional burden for both the licensee and the 
NRC, inasmuch as the NRC has already determined that the ASME Codes and 
Code Cases that are the subject of this proposed rule are acceptable 
for use (in some cases with conditions). For these reasons, the NRC 
concludes that this proposed rule's treatment of ASME Code editions and 
addenda, and code cases and any conditions placed on them does not 
conflict with any policy on agency use of consensus standards specified 
in OMB Circular A-119.
    The NRC did not identify any other voluntary consensus standards 
developed by U.S. voluntary consensus standards bodies for use within 
the U.S. that the NRC could incorporate by reference instead of the 
ASME Codes. The NRC also did not identify any voluntary consensus 
standards developed by multinational voluntary consensus standards 
bodies for use on a multinational basis that the NRC could incorporate 
by reference instead of the ASME Codes. The NRC identified codes 
addressing the same subject as the ASME Codes for use in individual 
countries. At least one country, Korea, directly translated the ASME 
Code for use in that country. In other countries (e.g., Japan), ASME 
Codes were the basis for development of the country's codes, but the 
ASME Codes were substantially modified to accommodate that country's 
regulatory system and reactor designs. Finally, there are countries 
(e.g., the Russian Federation) where that country's code was developed 
without regard to the ASME Code. However, some of these codes may not 
meet the definition of a voluntary consensus standard because they were 
developed by the state rather than a voluntary consensus standards 
body. Evaluation by the NRC of the countries' codes to determine 
whether each code provides a comparable or enhanced level of safety 
when compared against the level of safety provided under the ASME Codes 
would require a significant expenditure of agency resources. This 
expenditure does not seem justified, given that substituting another 
country's code for the U.S. voluntary consensus standard does not 
appear to substantially further the apparent underlying objectives of 
the NTTAA.
    In summary, this proposed rule satisfies the requirements of the 
NTTAA and OMB Circular A-119.

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

    The NRC proposes to incorporate by reference four recent editions 
to the ASME Codes for nuclear power plants and two revised ASME Code 
Cases. As described in the ``Background'' and ``Discussion'' sections 
of this document, these materials contain standards for the design, 
fabrication, and inspection of nuclear power plant components. The NRC 
also proposes to incorporate by reference an EPRI Topical Report. As 
described in the ``Background'' and ``Discussion'' sections of this 
document, this report contains proposed requirements related to the two 
revised ASME Code Cases.
    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

[[Page 56183]]

reasonably available to interested parties or how it worked to make 
those materials reasonably available to interested parties. The 
discussion in this section complies with the requirement for proposed 
rules as set forth in Sec.  51.5(a)(1).
    The NRC considers ``interested parties'' to include all potential 
NRC stakeholders, not only the individuals and entities regulated or 
otherwise subject to the NRC's regulatory oversight. These NRC 
stakeholders are not a homogenous group but vary with respect to the 
considerations for determining reasonable availability. Therefore, the 
NRC distinguishes between different classes of interested parties for 
the purposes of determining whether the material is ``reasonably 
available.'' The NRC considers the following to be classes of 
interested parties in NRC rulemakings with regard to the material to be 
incorporated by reference:
     Individuals and small entities regulated or otherwise 
subject to the NRC's regulatory oversight (this class also includes 
applicants and potential applicants for licenses and other NRC 
regulatory approvals) and who are subject to the material to be 
incorporated by reference by rulemaking. In this context, ``small 
entities'' has the same meaning as a ``small entity'' under Sec.  
2.810.
     Large entities otherwise subject to the NRC's regulatory 
oversight (this class also includes applicants and potential applicants 
for licenses and other NRC regulatory approvals) and who are subject to 
the material to be incorporated by reference by rulemaking. In this 
context, ``large entities'' are those which do not qualify as a ``small 
entity'' under Sec.  2.810.
     Non-governmental organizations with institutional 
interests in the matters regulated by the NRC.
     Other Federal agencies, states, local governmental bodies 
(within the meaning of Sec.  2.315(c)).
     Federally-recognized and State-recognized \4\ Indian 
tribes.
---------------------------------------------------------------------------

    \4\ State-recognized Indian tribes are not within the scope of 
Sec.  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.
---------------------------------------------------------------------------

     Members of the general public (i.e., individual, 
unaffiliated members of the public who are not regulated or otherwise 
subject to the NRC's regulatory oversight) who may wish to gain access 
to the materials which the NRC proposes to incorporate by reference by 
rulemaking in order to participate in the rulemaking process.
    The NRC makes the materials to be incorporated by reference 
available for inspection to all interested parties, by appointment, at 
the NRC Technical Library, which is located at Two White Flint North, 
11545 Rockville Pike, Rockville, Maryland 20852; telephone: 301-415-
7000; email: [email protected].
    Interested parties may obtain a copy of the EPRI Topical Report 
free of charge from EPRI from their website at www.epri.com.
    Interested parties may purchase a copy of the ASME materials from 
ASME at Three Park Avenue, New York, NY 10016, or at the ASME website 
https://www.asme.org/shop/standards. The materials are also accessible 
through third-party subscription services such as IHS (15 Inverness Way 
East, Englewood, CO 80112; https://global.ihs.com) and Thomson Reuters 
Techstreet (3916 Ranchero Dr., Ann Arbor, MI 48108; http://www.techstreet.com). The purchase prices for individual documents range 
from $225 to $720 and the cost to purchase all documents is 
approximately $9,000.
    For the class of interested parties constituting members of the 
general public who wish to gain access to the materials to be 
incorporated by reference in order to participate in the rulemaking, 
the NRC recognizes that the $9,000 cost may be so high that the 
materials could be regarded as not reasonably available for purposes of 
commenting on this rulemaking, despite the NRC's actions to make the 
materials available at the NRC's PDR. Accordingly, the NRC sent a 
letter to the ASME requesting that they consider enhancing public 
access to these materials during the public comment period (ADAMS 
Accession No. ML17310A186). In a May 30, 2018, email to the NRC, the 
ASME agreed to make the materials available online in a read-only 
electronic access format during the public comment period (ADAMS 
Accession No. ML18157A113). Therefore, the four editions to the ASME 
Codes for nuclear power plants, and the two ASME Code Cases which the 
NRC proposes to incorporate by reference in this rulemaking are 
available in read-only format at the ASME website http://go.asme.org/NRC.
    The NRC concludes that the materials the NRC proposes to 
incorporate by reference in this proposed rule are reasonably available 
to all interested parties because the materials are available to all 
interested parties in multiple ways and in a manner consistent with 
their interest in the materials.

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

    This proposed rule action is in accordance with the NRC's policy to 
incorporate by reference in Sec.  50.55a new editions and addenda of 
the ASME BPV and OM Codes to provide updated rules for constructing and 
inspecting components and testing pumps, valves, and dynamic restraints 
(snubbers) in light-water nuclear power plants. The ASME Codes are 
national voluntary consensus standards and are required by the NTTAA to 
be used by government agencies unless the use of such a standard is 
inconsistent with applicable law or otherwise impractical. The National 
Environmental Policy Act (NEPA) requires Federal agencies to study the 
impacts of their ``major Federal actions significantly affecting the 
quality of the human environment,'' and prepare detailed statements on 
the environmental impacts of the proposed action and alternatives to 
the proposed action (42 U.S.C. 4332(C); NEPA Sec. 102(C)).
    The NRC has determined under NEPA, as amended, and the NRC's 
regulations in subpart A of 10 CFR part 51, that this proposed rule is 
not a major Federal action significantly affecting the quality of the 
human environment and, therefore, an environmental impact statement is 
not required. The rulemaking does not significantly increase the 
probability or consequences of accidents, no changes are being made in 
the types of effluents that may be released off-site, and there is no 
significant increase in public radiation exposure. The NRC concludes 
that the increase in occupational exposure would not be significant. 
This proposed rule does not involve non-radiological plant effluents 
and has no other environmental impact. Therefore, no significant non-
radiological impacts are associated with this action. The determination 
of this environmental assessment is that there will be no significant 
off-site impact to the public from this action. Therefore, a finding of 
no significant impacts (FONSI) is appropriate.

XI. Paperwork Reduction Act Statement

    This proposed rule contains new or amended collections of 
information subject to the Paperwork Reduction Act of 1995 (44 U.S.C. 
3501 et seq.). This proposed rule has been submitted to the Office of 
Management and Budget for review and approval of the information 
collections.

[[Page 56184]]

    Type of submission, new or revision: Revision.
    The title of the information collection: Domestic Licensing of 
Production and Utilization Facilities: Incorporation by Reference of 
American Society of Mechanical Engineers Codes and Code Cases.
    The form number if applicable: Not applicable.
    How often the collection is required or requested: On occasion.
    Who will be required or asked to respond: Power reactor licensees 
and applicants for power reactors under construction.
    An estimate of the number of annual responses: -53.
    The estimated number of annual respondents: 103.
    An estimate of the total number of hours needed annually to comply 
with the information collection requirement or request: -12,640.
    Abstract: This proposed rule is the latest in a series of 
rulemakings to amend the NRC's regulations to incorporate by reference 
revised and updated ASME Codes for nuclear power plants. The number of 
operating nuclear power plants has decreased and the NRC has increased 
its estimate of the burden associated with developing alternative 
requests. Overall, the reporting burden for Sec.  50.55a has increased.
    The U.S. Nuclear Regulatory Commission is seeking public comment on 
the potential impact of the information collections contained in this 
proposed rule and on the following issues:
    1. Is the proposed information collection necessary for the proper 
performance of the functions of the NRC, including whether the 
information will have practical utility?
    2. Is the estimate of the burden of the proposed information 
collection accurate?
    3. Is there a way to enhance the quality, utility, and clarity of 
the information to be collected?
    4. How can the burden of the proposed information collection on 
respondents be minimized, including the use of automated collection 
techniques or other forms of information technology?
    A copy of the OMB clearance package and proposed rule is available 
in ADAMS (Accession Nos. ML18150A267 and ML18150A265) or may be viewed 
free of charge at the NRC's PDR, One White Flint North, 11555 Rockville 
Pike, Room O-1 F21, Rockville, MD 20852. You may obtain information and 
comment submissions related to the OMB clearance package by searching 
on http://www.regulations.gov under Docket ID NRC-2016-0082.
    You may submit comments on any aspect of these proposed information 
collection(s), including suggestions for reducing the burden and on the 
previously stated issues, by the following methods:
     Federal Rulemaking website: Go to http://www.regulations.gov and search for Docket ID NRC-2016-0082.
     Mail comments to: Information Services Branch, Office of 
the Chief Information Officer, U.S. Nuclear Regulatory Commission, 
Washington, DC 20555-0001 or to the OMB reviewer at: OMB Office of 
Information and Regulatory Affairs (3150-0011), Attn: Desk Officer for 
the Nuclear Regulatory Commission, 725 17th Street NW, Washington, DC 
20503; email: [email protected].
    Submit comments by December 10, 2018. Comments received after this 
date will be considered if it is practical to do so, but the NRC staff 
is able to ensure consideration only for comments received on or before 
this date.

Public Protection Notification

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

XII. Regulatory Analysis

    The NRC has prepared a draft regulatory analysis on this proposed 
rule. The analysis examines the costs and benefits of the alternatives 
considered by the Commission. The NRC requests public comments on the 
draft regulatory analysis, (ADAMS Accession No. ML18150A267). Comments 
on the draft analysis may be submitted to the NRC by any method 
provided in the ADDRESSES section of this document.

XIII. Backfitting and Issue Finality

Introduction

    The NRC's Backfit Rule in Sec.  50.109 states that the NRC shall 
require the backfitting of a facility only when it finds the action to 
be justified under specific standards stated in the rule. Section 
50.109(a)(1) defines backfitting as the modification of or addition to 
systems, structures, components, or design of a facility; the design 
approval or manufacturing license for a facility; or the procedures or 
organization required to design, construct, or operate a facility. Any 
of these modifications or additions may result from a new or amended 
provision in the NRC's rules or the imposition of a regulatory position 
interpreting the NRC's rules that is either new or different from a 
previously applicable NRC position after issuance of the construction 
permit or the operating license or the design approval.
    Section 50.55a requires nuclear power plant licensees to:
     Construct ASME BPV Code Class 1, 2, and 3 components in 
accordance with the rules provided in Section III, Division 1, of the 
ASME BPV Code (``Section III'').
     Inspect Class 1, 2, 3, Class MC, and Class CC components 
in accordance with the rules provided in Section XI, Division 1, of the 
ASME BPV Code (``Section XI'').
     Test Class 1, 2, and 3 pumps, valves, and dynamic 
restraints (snubbers) in accordance with the rules provided in the ASME 
OM Code.
    This rulemaking proposes to incorporate by reference the 2015 and 
2017 Editions to the ASME BPV Code, Section III, Division 1 and ASME 
BPV Code, Section XI, Division 1, as well as the 2015 and 2017 Editions 
to the ASME OM Code.
    The ASME BPV and OM Codes are national consensus standards 
developed by participants with broad and varied interests, in which all 
interested parties (including the NRC and utilities) participate. A 
consensus process involving a wide range of stakeholders is consistent 
with the NTTAA, inasmuch as the NRC has determined that there are sound 
regulatory reasons for establishing regulatory requirements for design, 
maintenance, ISI, and IST by rulemaking. The process also facilitates 
early stakeholder consideration of backfitting issues. Thus, the NRC 
believes that the NRC need not address backfitting with respect to the 
NRC's general practice of incorporating by reference updated ASME 
Codes.

Overall Backfitting Considerations: Section III of the ASME BPV Code

    Incorporation by reference of more recent editions and addenda of 
Section III of the ASME BPV Code does not affect a plant that has 
received a construction permit or an operating license or a design that 
has been approved. This is because the edition and addenda to be used 
in constructing a plant are, under Sec.  50.55a, determined based on 
the date of the construction permit, and are not changed thereafter, 
except voluntarily by the licensee. The incorporation by reference of 
more recent editions and addenda of Section III ordinarily applies only 
to applicants after the effective date of the final rule incorporating 
these new editions and

[[Page 56185]]

addenda. Thus, incorporation by reference of a more recent edition and 
addenda of Section III does not constitute ``backfitting'' as defined 
in Sec.  50.109(a)(1).

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

    Incorporation by reference of more recent editions and addenda of 
Section XI of the ASME BPV Code and the ASME OM Code affects the ISI 
and IST programs of operating reactors. However, the Backfit Rule 
generally does not apply to incorporation by reference of later 
editions and addenda of the ASME BPV Code (Section XI) and OM Code. As 
previously mentioned, the NRC's longstanding regulatory practice has 
been to incorporate later versions of the ASME Codes into Sec.  50.55a. 
Under Sec.  50.55a, licensees shall revise their ISI and IST programs 
every 120 months to the latest edition and addenda of Section XI of the 
ASME BPV Code and the ASME OM Code incorporated by reference into Sec.  
50.55a 12 months before the start of a new 120-month ISI and IST 
interval. Thus, when the NRC approves and requires the use of a later 
version of the Code for ISI and IST, it is implementing this 
longstanding regulatory practice and requirement.
    Other circumstances where the NRC does not apply the Backfit Rule 
to the approval and requirement to use later Code editions and addenda 
are as follows:
    1. When the NRC takes exception to a later ASME BPV Code or OM Code 
provision but merely retains the current existing requirement, 
prohibits the use of the later Code provision, limits the use of the 
later Code provision, or supplements the provisions in a later Code. 
The Backfit Rule does not apply because the NRC is not imposing new 
requirements. However, the NRC explains any such exceptions to the Code 
in the Statement of Considerations and regulatory analysis for the 
rule.
    2. When an NRC exception relaxes an existing ASME BPV Code or OM 
Code provision but does not prohibit a licensee from using the existing 
Code provision. The Backfit Rule does not apply because the NRC is not 
imposing new requirements.
    3. Modifications and limitations imposed during previous routine 
updates of Sec.  50.55a have established a precedent for determining 
which modifications or limitations are backfits, or require a backfit 
analysis (e.g., final rule dated September 10, 2008 [73 FR 52731], and 
a correction dated October 2, 2008 [73 FR 57235]). The application of 
the backfit requirements to modifications and limitations in the 
current rule are consistent with the application of backfit 
requirements to modifications and limitations in previous rules.
    The incorporation by reference and adoption of a requirement 
mandating the use of a later ASME BPV Code or OM Code may constitute 
backfitting in some circumstances. In these cases, the NRC would 
perform a backfit analysis or documented evaluation in accordance with 
Sec.  50.109. These include the following:
    1. When the NRC endorses a later provision of the ASME BPV Code or 
OM Code that takes a substantially different direction from the 
existing requirements, the action is treated as a backfit (e.g., 61 FR 
41303; August 8, 1996).
    2. When the NRC requires implementation of a later ASME BPV Code or 
OM Code provision on an expedited basis, the action is treated as a 
backfit. This applies when implementation is required sooner than it 
would be required if the NRC simply endorsed the Code without any 
expedited language (e.g., 64 FR 51370; September 22, 1999).
    3. When the NRC takes an exception to an ASME BPV Code or OM Code 
provision and imposes a requirement that is substantially different 
from the existing requirement as well as substantially different from 
the later Code (e.g., 67 FR 60529; September 26, 2002).

Detailed Backfitting Discussion: Proposed Changes Beyond Those 
Necessary To Incorporate by Reference the New ASME BPV and OM Code 
Provisions

    This section discusses the backfitting considerations for all the 
proposed changes to Sec.  50.55a that go beyond the minimum changes 
necessary and required to adopt the new ASME Code Addenda into Sec.  
50.55a.
ASME BPV Code, Section III
    1. Add Sec.  50.55a(b)(1)(x) to require compliance with two new 
conditions related to visual examination of bolts studs and nuts. 
Visual examination is one of the processes for acceptance of the final 
product to ensure its structural integrity and its ability to perform 
its intended function. The 2015 Edition of the ASME Code contains 
requirements for visual inspection of these components, however, the 
2017 Edition does not require these visual examinations to be performed 
in accordance with NX-5100 and NX-5500. Therefore, the NRC proposes to 
add two conditions to ensure adequate procedures remain and qualified 
personnel remain capable of determining the structural integrity of 
these components. Since the proposed conditions restore requirements 
that were removed from the latest edition of the ASME Code, the 
proposed conditions does not constitute a new or changed NRC position. 
Therefore, the revision of this condition is not a backfit
    2. Add Sec.  50.55a(b)(1)(xi) to require conditions on the use of 
ASME BPV Code, Section III, Appendix XXVI for installation of high 
density polyethylene (HDPE) pressure piping. This Appendix is new in 
the 2015 Edition of Section III, since it is the first time the ASME 
BPV Code has provided rules for the use of polyethylene piping. The use 
of HDPE is newly allowed by the Code, which provides alternatives to 
the use of current materials. Therefore, this proposed change is not a 
backfit.
    3. Add Sec.  50.55a(b)(1)(xii) to prohibit applicants and licensees 
from using a certifying engineer in lieu of a registered professional 
engineer for code related activities that are applicable to U.S. 
nuclear facilities regulated by the NRC. In the 2017 Edition of ASME 
BPV Code, Section III, Subsection NCA, the several Subsections were 
updated to replace the term ``registered professional engineer,'' with 
term ``certifying engineer'' to be consistent with ASME BPV Code 
Section III Mandatory Appendix XXIII.
    The NRC reviewed these changes and has determined that the use of a 
certifying engineer in lieu of a registered professional engineer is 
only applicable for non-U.S. nuclear facilities. Since the use of a 
certifying engineer is newly allowed by the Code, the addition of the 
condition that prohibits the use of a certifying engineer in lieu of a 
registered professional engineer for code related activities is not a 
backfit.
ASME BPV Code, Section XI
    1. Revise Sec.  50.55a(b)(2)(ix) to require compliance with new 
condition Sec.  50.55a(b)(2)(ix)(K). The NRC has developed proposed 
condition Sec.  50.55a(b)(2)(ix)(K) to ensure containment leak-chase 
channel systems are properly inspected. This condition serves to 
clarify the NRC's existing expectations, as described in inspection 
reports and IN 2014-07, and will be applicable to all editions of the 
ASME Code, prior to the 2017 Edition. The NRC considers this condition 
a clarification of the existing expectations and, therefore, does not 
consider this condition a backfit.
    As noted previously, after issuance of the IN, the NRC received 
feedback during an August 22, 2014, public meeting between NRC and ASME

[[Page 56186]]

management (ADAMS Accession No. ML14245A003), noting that the IN 
guidance appeared to be in conflict with ASME Section XI Interpretation 
XI-1-13-10. In response to the comment during the public meeting, the 
NRC issued a letter to ASME (ADAMS Accession No. ML14261A051) which 
stated the NRC believes the IN is consistent with the requirements in 
the ASME Code and restated the existing NRC staff position. ASME 
responded to the NRC's letter (ADAMS Accession No. ML15106A627) and 
noted that a condition in the regulations may be appropriate to clarify 
the NRC staff's position.
    2. Revise Sec.  50.55a(b)(2)(xx)(B) to clarify the condition with 
respect to the NRC's expectations for system leakage tests performed in 
lieu of a hydrostatic pressure test following repair/replacement 
activities performed by welding or brazing on a pressure retaining 
boundary using the 2003 Addenda through the latest edition and addenda 
of ASME BPV Code, Section XI incorporated by reference in paragraph 
Sec.  50.55a(a)(1)(ii). This provision requires the licensee perform 
the applicable nondestructive testing that would be required by the 
1992 Edition or later of ASME BPV Code, Section III. The nondestructive 
examination method (e.g. surface, volumetric, etc.) and acceptance 
criteria of the 1992 Edition or later of Section III shall be met and a 
system leakage test be performed in accordance with IWA-5211(a). The 
actual nondestructive examination and pressure testing may be performed 
using procedures and personnel meeting the requirements of the 
licensee's/applicant's current ISI code of record required by Sec.  
50.55a(g)(4). The proposed condition does not constitute a new or 
changed NRC position. Therefore, the revision of this condition is not 
a backfit.
    3. Add Sec.  50.55a(b)(2)(xx)(C) to place two conditions on the use 
of the alternative BWR Class 1 system leakage test described in IWA-
5213(b)(2), IWB-5210(c) and IWB-5221(d) of the 2017 Edition of ASME 
Section XI. This is a new pressure test allowed by the Code at a 
reduced pressure as an alternative to the pressure test currently 
required. This allows a reduction in the requirements which is 
consistent with several NRC-approved alternatives/relief requests. 
Therefore, this proposed change is not a backfit.
    4. Add Sec.  50.55a(b)(2)(xxi)(B) to require the plant-specific 
evaluation demonstrating the criteria of IWB-2500(f) are met be 
maintained in accordance with the Owners requirements, to prohibit use 
of the provisions of IWB-2500(f) and Table IWB-2500-1 Note 6 for of 
Examination Category B-D Item Numbers B3.90 and B3.100 for plants with 
renewed licenses and to restrict the provisions of IWB-2500(g) and 
Table IWB-2500-1 Notes 6 and 7 for examination of Examination Category 
B-D Item Numbers B3.90 and B3.100 use to eliminate the preservice or 
inservice volumetric examination of plants with a Combined Operating 
License pursuant to 10 CFR part 52, or a plant that receives its 
operating license after October 22, 2015. This proposed revision 
applies the current requirements for use of these provisions as 
currently described in ASME Code Case N-702, which are currently 
allowed through Regulatory Guide 1.147, Revision 19. Therefore, the NRC 
does not consider the clarification to be a change in requirements. 
Therefore, this proposed change is not a backfit.
    5. Revise the condition found in Sec.  50.55a(b)(2)(xxv) to allow 
the use of IWA-4340 of Section XI, 2011 Addenda through 2017 Edition 
with conditions.
    Add Sec.  50.55a(b)(2)(xxv)(A) which will continue the prohibition 
of IWA-4340 for Section XI editions and addenda prior to the 2011 
Addenda. This prohibition applies the current requirements for use of 
these provision, therefore, the NRC does not consider the addition of 
Sec.  50.55a(b)(2)(xxv)(A) to be a change in requirements. Therefore, 
this proposed change is not a backfit.
    Add Sec.  50.55a(b)(2)(xxv)(B) which will allow the use of IWA-4340 
of Section XI, 2011 Addenda through 2017 Edition with three conditions.
     The first proposed condition would prohibit the use of 
IWA-4340 on crack-like defects or those associated with flow 
accelerated corrosion.
    The design requirements and potentially the periodicity of followup 
inspections might not be adequate for crack-like defects that could 
propagate much faster than defects due to loss of material. Prior to 
the change to allow the use of IWA-4340, the provisions of this 
subsubarticle were not permitted for any type of defects. By 
establishment of the new conditions, the NRC proposes to allow the use 
of IWA-4340 for defects such as wall loss due to general corrosion. 
Establishing a condition to not allow the use of IWA-4340 for crack-
like defects does not constitute a new or changed NRC position. 
Therefore, the revision of this condition associated with crack-like 
defects is not a backfit.
    As established in NUREG-1801, ``Generic Aging Lessons Learned 
(GALL) Report'', Revision 2, effective management of flow accelerated 
corrosion entails: (a) An analysis to determine critical locations, (b) 
limited baseline inspections to determine the extent of thinning at 
these locations, (c) use of a predictive Code (e.g., CHECKWORKS); and 
(d) follow-up inspections to confirm the predictions, or repairing or 
replacing components as necessary. These provision are not included in 
IWA-4340. In addition, subparagraph IWA-4421(c)(2) provides provisions 
for restoring minimum required wall thickness by welding or brazing, 
which can be used to mitigate a defect associated with flow accelerated 
corrosion. The proposed condition related to flow accelerated corrosion 
does not constitute a new or changed NRC position. Therefore, the 
revision of this condition is not a backfit.
     The second proposed condition would require the design of 
a modification that mitigates a defect to incorporate a loss of 
material rate either 2 times the actual measured corrosion rate in that 
pipe location, or 4 times the estimated maximum corrosion rate for the 
piping system. This condition is consistent with Code Case N-789, 
``Alternative Requirements for Pad Reinforcement of Class 2 and 3 
Moderate-Energy Carbon Steel Piping, Section XI, Division 1,'' Section 
3, ``Design.'' The NRC has endorsed Code Case 789 in Regulatory Guide 
1.147, ``Inservice Inspection Code Case Acceptability, ASME Section XI, 
Division 1.'' The proposed condition does not constitute a new or 
changed NRC position. Therefore, the revision of this condition is not 
a backfit.
     The third proposed condition would require the Owner to 
perform a wall thickness examination in the vicinity of the 
modification and relevant pipe base metal during each refueling outage 
cycle to detect propagation of the flaw unless the projected flaw 
propagation has been validated in two refueling outage cycles 
subsequent to the installation of the modification. This condition is 
consistent with Code Case N-789, Section 8, ``Inservice Monitoring,'' 
which requires followup wall thickness measurements to verify that the 
minimum design thicknesses are maintained. The followup examination 
requirements in IWA-4340 are inconsistent with the NRC endorsement of 
Code Case 789 in Regulatory Guide 1.147 in that the inspections can be 
limited to demonstrating that the flaw has not propagated into material 
credited for structural integrity without validating the project flaw 
growth. The proposed condition does not constitute a new or changed NRC 
position. Therefore, the

[[Page 56187]]

revision of this condition is not a backfit.
    6. Revise Sec.  50.55a(b)(2)(xxvi) to require that a system leakage 
test be conducted after implementing a repair replacement activity on a 
mechanical joint greater than NPS-1. The revision will also clarify 
what Code edition/addenda may be used when conducting the pressure 
test. This proposed revision clarifies the current requirements, which 
the NRC considers to be consistent with the meaning and intent of the 
current requirements. Therefore, the NRC does not consider the 
clarification to be a change in requirements. Therefore, this proposed 
change is not a backfit.
    7. Revise Sec.  50.55a(b)(2)(xxxii) to clarify the requirement to 
submit Summary Reports pre-2015 Edition and Owner Activity Reports in 
the 2015 Edition of the ASME BPV Code. This proposed revision clarifies 
the current requirements, which the NRC considers to be consistent with 
the meaning and intent of the current requirements. Therefore, the NRC 
does not consider the clarification to be a change in requirements. 
Therefore, this proposed change is not a backfit.
    8. Add Sec.  50.55a(b)(2)(xxxv)(B) which would condition the use of 
2015 Edition of ASME BPV Code, Section XI, Appendix A, paragraph A-
4200(c), to define RTKIa in equation (a) as RTKIa 
= T0 + 90.267 exp(-0.003406T0) in lieu of the equation shown in the 
Code. When the equation was converted from SI units to U.S. Customary 
units a mistake was made which makes the equation erroneous. The 
equation shown above for RTKIa is the correct formula. This 
is part of the newly revised Code, and the proposed addition of this 
condition is not a new requirement and therefore not a backfit.
    9. Revise Sec.  50.55a(b)(2)(xxxvi) to extend the applicability to 
use of the 2015 and 2017 Editions of Section XI of the ASME BPV Code. 
The condition was added in the 2009-2013 rulemaking and ASME did not 
make changes in the 2015 or 2017 Editions of the ASME BPV Code; 
therefore, the condition still applies but is not new to this proposed 
rule. The NRC considers this revision to the condition to be consistent 
with the meaning and intent of the current requirements. Therefore, the 
NRC does not consider the clarification to be a change in requirements. 
Therefore, this proposed change is not a backfit.
    10. Add Sec.  50.55a(b)(2)(xxxviii) to condition ASME BPV Code, 
Section XI, Appendix III, Supplement 2. Supplement 2 is closely-based 
on ASME Code Case N-824, which was incorporated by reference with 
conditions in Sec.  50.55a(a)(3)(ii). The conditions on ASME BPV Code, 
Section XI, Appendix III, Supplement 2 are consistent with the 
conditions on ASME Code Case N-824. Therefore, the NRC does not 
consider this a new requirement. Therefore, this proposed change is not 
a backfit.
    11. Add Sec.  50.55a(b)(2)(xxxix) to condition the use of Section 
XI, IWA-4421(c)(1) and IWA-4421(c)(2). The NRC considers these 
conditions necessary as part of the allowance to use IWA-4340. The 
proposed condition on the use of IWA-4421(c)(1) and IWA-4421(c)(2) does 
not constitute a new or changed NRC position. Therefore, the addition 
of this proposed condition is not a backfit.
    12. Add Sec.  50.55a(b)(2)(xl) to prohibit the use of ASME BPV 
Code, Section XI, Subparagraphs IWB-3510.4(b)(4) and IWB-3510.4(b)(5). 
The proposed condition does not change the current material 
requirements because the currently required testing to meet the 
material requirements for those materials addressed by the new 
condition would continue to be performed per the existing requirements. 
Therefore this condition on the use of IWB-3510.4(b) does not 
constitute a new or changed NRC position. Therefore, the addition of 
this proposed condition is not a backfit.
    13. Add Sec.  50.55a(b)(2)(xli) to prohibit the use of ASME BPV 
Code, Section XI, Subparagraphs IWB-3112(a)(3) and IWC-3112(a)(3) in 
the 2013 Edition of Section XI through the latest edition and addenda 
incorporated by reference in paragraph (a)(1)(ii). The proposed 
condition is consistent with the NRC`s current prohibition of these 
items discussed in Regulatory Guide 1.193 in the discussion of ASME 
Code Case N-813. Therefore, this condition does not constitute a new or 
changed NRC position. Therefore, the addition of this proposed 
condition is not a backfit.
    14. Add Sec.  50.55a(b)(2)(xlii) to provide conditions for 
Examination Category B-F, Item B5.11 and Item B5.71 in the 2011a 
Addenda through the latest edition and addenda incorporated by 
reference in previous paragraphs (a)(1)(ii) of this section. The 
proposed conditions are consistent with the conditions on ASME Code 
Case N-799 in Regulatory Guide 1.147. Therefore, these conditions do 
not constitute a new or changed NRC position. Therefore, the addition 
of these proposed conditions is not a backfit.
    15. Revise Sec.  50.55a(g)(6)(ii)(D) to implement Code Case N-729-
6. On March 3, 2016, the ASME approved the sixth revision of ASME BPV 
Code Case N-729, (N-729-6). The NRC proposes to update the requirements 
of Sec.  50.55a(g)(6)(ii)(D) to require licensees to implement ASME BPV 
Code Case N-729-6, with conditions. The ASME BPV Code Case N-729-6 
contains similar requirements as N-729-4; however, N-729-6 also 
contains new requirements to address peening mitigation and inspection 
relief for replaced reactor pressure vessel heads with nozzles and 
welds made of more crack resistant materials. The new NRC conditions on 
the use of ASME BPV Code Case N-729-6 address operational experience, 
clarification of implementation, and the use of alternatives to the 
code case.
    The current regulatory requirements for the examination of 
pressurized water reactor upper RPV heads that use nickel-alloy 
materials are provided in Sec.  50.55a(g)(6)(ii)(D). This section was 
first created by rulemaking, dated September 10, 2008, (73 FR 52730) to 
require licensees to implement ASME BPV Code Case N-729-1, with 
conditions, instead of the examinations previously required by the ASME 
BPV Code, Section XI. The action did constitute a backfit; however, the 
NRC concluded that imposition of ASME BPV Code Case N-729-1, as 
conditioned, constituted an adequate protection backfit.
    The General Design Criteria (GDC) for nuclear power plants 
(appendix A to 10 CFR part 50) or, as appropriate, similar requirements 
in the licensing basis for a reactor facility, provide bases and 
requirements for NRC assessment of the potential for, and consequences 
of, degradation of the reactor coolant pressure boundary (RCPB). The 
applicable GDC include GDC 14 (Reactor Coolant Pressure Boundary), GDC 
31 (Fracture Prevention of Reactor Coolant Pressure Boundary), and GDC 
32 (Inspection of Reactor Coolant Pressure Boundary). General Design 
Criterion 14 specifies that the RCPB be designed, fabricated, erected, 
and tested so as to have an extremely low probability of abnormal 
leakage, of rapidly propagating failure, and of gross rupture. General 
Design Criterion 31 specifies that the probability of rapidly 
propagating fracture of the RCPB be minimized. General Design Criterion 
32 specifies that components that are part of the RCPB have the 
capability of being periodically inspected to assess their structural 
and leak tight integrity.
    The NRC concludes that incorporation by reference of Code Case N-
729-6, as conditioned, into Sec.  50.55a as a mandatory requirement 
will continue to ensure reasonable assurance of adequate protection of 
public health and safety. Updating the regulations to require using 
ASME BPV Code Case N-

[[Page 56188]]

729-6, with conditions, ensures that potential flaws will be detected 
before they challenge the structural or leak tight integrity of the 
reactor pressure vessel upper head within current nondestructive 
examination limitations. The code case provisions and the NRC's 
proposed conditions on examination requirements for reactor pressure 
vessel upper heads are essentially the same as those established under 
ASME BPV Code Case N-729-4, as conditioned. Exceptions include: (1) An 
introduction of examination relief for upper heads with Alloy 690 
penetration nozzles to be examined volumetrically every 20 years in 
accordance with Table 1 of ASME BPV Code Case N-729-6, (2) introduction 
of peening as a mitigation technique along with requirements for 
peening and inspection relief following peening and (3) substitution of 
a volumetric leak path examination for a required surface examination 
if a bare metal visual examination identifies a possible indication of 
leakage.
    The NRC continues to find that examinations of reactor pressure 
vessel upper heads, their penetration nozzles, and associated partial 
penetration welds are necessary for adequate protection of public 
health and safety and that the requirements of ASME BPV Code Case N-
729-6, as conditioned, represent an acceptable approach, developed, in 
part, by a voluntary consensus standards organization for performing 
future inspections. The proposed NRC conditions on Code Case N-729-6 
address newly defined provisions by the Code for peening and inspection 
relief for upper heads with Alloy 690 penetration nozzles which provide 
alternatives to the use of current requirements and provide 
clarification or relaxation of existing conditions. Therefore, the NRC 
concludes the proposed incorporation by reference of ASME BPV Code Case 
N-729-6, as conditioned, into Sec.  50.55a is not a backfit.
    16. Revise Sec.  50.55a(g)(6)(ii)(F), ``Examination requirements 
for Class 1 piping and nozzle dissimilar metal butt welds.'' On 
November 7, 2016, the ASME approved the fifth revision of ASME BPV Code 
Case N-770 (N-770-5). The NRC proposes to update the requirements of 
Sec.  50.55a(g)(6)(ii)(F) to require licensees to implement ASME BPV 
Code Case N-770-5, with conditions. The ASME BPV Code Case N-770-5 
contains similar baseline and ISI requirements for unmitigated nickel-
alloy butt welds, and preservice and ISI requirements for mitigated 
butt welds as N-770-2. However, N-770-5 also contains new provisions 
which extend the inspection frequency for cold leg temperature 
dissimilar metal butt welds greater than 14-inches in diameter to once 
per interval not to exceed 13 years, define performance criteria and 
examinations for welds mitigated by peening, and criteria for inservice 
inspection requirements for excavate and weld repair PWSCC mitigations. 
Minor changes were also made to address editorial issues, to correct 
figures, or to add clarity. The NRC's proposed conditions on the use of 
ASME BPV Code Case N-770-5 have been modified to address the changes in 
the code case, clarify reporting requirements and address the 
implementation of peening and excavate and weld repair PWSCC mitigation 
techniques.
    The current regulatory requirements for the examination of ASME 
Class 1 piping and nozzle dissimilar metal butt welds that use nickel-
alloy materials are provided in Sec.  50.55a(g)(6)(ii)(F). This section 
was first created by rulemaking, dated June 21, 2011 (76 FR 36232), to 
require licensees to implement ASME BPV Code Case N-770-1, with 
conditions. The NRC added Sec.  50.55a(g)(6)(ii)(F) to require 
licensees to implement ASME BPV Code Case N-770-1, with conditions, 
instead of the examinations previously required by the ASME BPV Code, 
Section XI. The action did constitute a backfit; however, the NRC 
concluded that imposition of ASME BPV Code Case N-770-1, as 
conditioned, constituted an adequate protection backfit.
    The GDC for nuclear power plants (appendix A to 10 CFR part 50) or, 
as appropriate, similar requirements in the licensing basis for a 
reactor facility, provide bases and requirements for NRC assessment of 
the potential for, and consequences of, degradation of the RCPB. The 
applicable GDC include GDC 14 (Reactor Coolant Pressure Boundary), GDC 
31 (Fracture Prevention of Reactor Coolant Pressure Boundary) and GDC 
32 (Inspection of Reactor Coolant Pressure Boundary). General Design 
Criterion 14 specifies that the RCPB be designed, fabricated, erected, 
and tested so as to have an extremely low probability of abnormal 
leakage, of rapidly propagating failure, and of gross rupture. General 
Design Criterion 31 specifies that the probability of rapidly 
propagating fracture of the RCPB be minimized. General Design Criterion 
32 specifies that components that are part of the RCPB have the 
capability of being periodically inspected to assess their structural 
and leak-tight integrity.
    The NRC concludes that incorporation by reference of Code Case N-
770-5, as conditioned, into Sec.  50.55a as a mandatory requirement 
will continue to ensure reasonable assurance of adequate protection of 
public health and safety. Updating the regulations to require using 
ASME BPV Code Case N-770-5, with conditions, ensures leakage would 
likely not occur and potential flaws will be detected before they 
challenge the structural or leak-tight integrity of these reactor 
coolant pressure boundary piping welds. All current licensees of U.S. 
pressurized water reactors will be required to implement ASME BPV Code 
Case N-770-5, as conditioned. The Code Case N-770-5 provisions for the 
examination requirements for ASME Class 1 piping and nozzle nickel-
alloy dissimilar metal butt welds are similar to those established 
under ASME BPV Code Case N-770-2, as conditioned, however, Code Case N-
770-5 includes provisions for two additional PWSCC mitigation 
techniques peening and excavate and weld repair along with requirements 
for performance of these techniques and examination of welds mitigated 
using them. Additionally, Code Case N-770-5 would allow for some 
relaxation in the re-examination or deferral of certain welds. However, 
the NRC's proposed condition would not allow this relaxation/deferral 
of examination requirements. The proposed NRC conditions on Code Case 
N-770-5 address newly defined provisions by the Code for examinations 
and performance criteria for mitigation by peening, examinations for 
mitigation by excavate and weld repair, and extension of the 
examination frequency for certain cold leg temperature welds which 
provide alternatives to the use of current requirements and provide 
clarification or relaxation of existing conditions. The proposed 
modification to the condition in Sec.  50.55a(g)(6)(ii)(F)(11) adds an 
alternative method for meeting the condition. Therefore, the NRC 
concludes the proposed incorporation by reference of ASME BPV Code Case 
N-770-5, as conditioned, into Sec.  50.55a is not a backfit.
ASME OM Code
    1. Revise the introductory text of paragraph (b)(3) to reference 
the 1995 Edition through the latest edition and addenda of the ASME OM 
Code incorporated by reference in Sec.  50.55a(a)(1)(iv), and to 
include Appendix IV of the ASME OM Code in the list of mandatory 
appendices incorporated by reference in Sec.  50.55a. The revision of 
Sec.  50.55a to incorporate by reference updated editions of the ASME 
OM Code is consistent with long-standing NRC policy and does not 
constitute a backfit.

[[Page 56189]]

    2. Revise Sec.  50.55a(b)(3)(ii) to specify that the condition on 
MOV testing applies to the latest edition and addenda of the ASME OM 
Code incorporated by reference in Sec.  50.55a(a)(1)(iv). This will 
allow future rulemakings to revise Sec.  50.55a(a)(1)(iv) to 
incorporate the latest edition of the ASME OM Code without the need to 
revise Sec.  50.55a(b)(3)(ii). This is an administrative change to 
simplify future rulemakings and, therefore, is not a backfit.
    3. Revise Sec.  50.55a(b)(3)(iv) to (1) accept the use of Appendix 
II in the 2017 Edition of the ASME OM Code without conditions; (2) 
update Sec.  50.55a(b)(3)(iv) to apply Table II to Appendix II of the 
ASME OM Code, 2003 Addenda through the 2015 Edition; and (3) remove the 
outdated conditions in paragraphs (A) through (D) of Sec.  
50.55a(b)(3)(iv). These changes reflect improvements to Appendix II in 
the 2017 Edition of the ASME OM Code, and the removal of outdated 
conditions on previous editions and addenda of the ASME OM Code. The 
relaxation of conditions in Sec.  50.55a(b)(3)(iv) to reflect the 
updated ASME OM Code is not a backfit.
    4. Revise Sec.  50.55a(b)(3)(viii) to specify that the condition on 
Subsection ISTE applies to the latest edition and addenda of the ASME 
OM Code incorporated by reference in Sec.  50.55a(a)(1)(iv). This will 
allow future rulemakings to revise Sec.  50.55a(a)(1)(iv) to 
incorporate the latest edition of the ASME OM Code without the need to 
revise Sec.  50.55a(b)(3)(viii). This is an administrative change to 
simplify future rulemakings and, therefore, is not a backfit.
    5. Revise Sec.  50.55a(b)(3)(ix) to specify that Subsection ISTF of 
the ASME OM Code, 2017 Edition, is acceptable without conditions, and 
that licensees applying Subsection ISTF in the 2015 Edition of the ASME 
OM Code shall satisfy the requirements of Appendix V of the ASME OM 
Code. Subsection ISTF in the 2017 Edition of the ASME OM Code has 
incorporated the provisions from Appendix V such that its reference to 
Subsection ISTF in the 2017 Edition of the ASME OM Code is not 
necessary. This is an update to the condition to apply to the 2015 
Edition (in addition to the 2012 Edition), and a relaxation to remove 
the applicability of the condition to the 2017 Edition of the ASME OM 
Code. Therefore, the update to this condition is not a backfit.
    6. Revise Sec.  50.55a(b)(3)(xi) for the implementation of 
paragraph ISTC-3700 on valve position indication in the ASME OM Code to 
apply to the 2012 Edition through the latest edition and addenda of the 
ASME OM Code incorporated by reference in Sec.  50.55a(a)(1)(iv). This 
will allow future rulemakings to revise Sec.  50.55a(a)(1)(iv) to 
incorporate the latest edition of the ASME OM Code without the need to 
revise Sec.  50.55a(b)(3)(xi). In addition, the NRC proposes to clarify 
that this condition applies to all valves with remote position 
indicators within the scope of Subsection ISTC and all mandatory 
appendices. This is an administrative change to simplify future 
rulemakings and clarify the condition and, therefore, is not a backfit.
    7. Establish Sec.  50.55a(b)(3)(xii) to require the application of 
the AOV provisions in Appendix IV of the 2017 Edition of the ASME OM 
Code, when implementing the ASME OM Code, 2015 Edition. This will 
provide consistency between the implementation of these two new 
editions of the ASME OM Code and, therefore, this condition is not a 
backfit.
    8. Revise Sec.  50.55a(f)(4)(i) and (ii) to relax the time schedule 
for complying with the latest edition and addenda of the ASME OM Code 
for the initial and successive IST programs from 12 months to 18 
months. This relaxation of the time schedule for the IST programs is 
not a backfit.
    9. Add Sec.  50.55a(f)(7), ``Inservice Testing Reporting 
Requirements,'' to state that IST Plans and interim IST Plan updates 
for pumps and valves; and IST Plans and interim Plan updates related to 
snubber examination and testing must be submitted to the NRC. This 
requirement is currently in the ASME OM Code, but the ASME is planning 
to remove this from the ASME OM Code in the future. Therefore, this is 
not a backfit because the NRC is not imposing a new requirement.
    10. Revise Sec.  50.55a(g)(4)(i) and (ii) to relax the time 
schedule for complying with the latest edition and addenda of the ASME 
BPV Code for the initial and successive ISI programs from 12 months to 
18 months. This relaxation of the time schedule for the ISI programs is 
not a backfit.
Conclusion
    The NRC finds that incorporation by reference into Sec.  50.55a of 
the 2015 and 2017 Editions of Section III, Division 1, of the ASME BPV 
Code subject to the identified conditions; the 2015 and 2017 Edition of 
Section XI, Division 1, of the ASME BPV Code, subject to the identified 
conditions; the 2015 and 2017 Editions of the ASME OM Code subject to 
the identified conditions, and the two Code Cases N-729-6 and N-770-5 
subject to identified conditions does not constitute backfitting or 
represent an inconsistency with any issue finality provisions in 10 CFR 
part 52.

XIV. Regulatory Flexibility Certification

    Under the Regulatory Flexibility Act of 1980 (5 U.S.C. 605(b)), the 
NRC certifies that this proposed rule does not impose a significant 
economical impact on a substantial number of small entities. This 
proposed rule affects only the licensing and operation of commercial 
nuclear power plants. A licensee who is a subsidiary of a large entity 
does not qualify as a small entity. The companies that own these plants 
are not ``small entities'' as defined in the Regulatory Flexibility Act 
or the size standards established by the NRC (Sec.  2.810), as the 
companies:
     Provide services that are not engaged in manufacturing, 
and have average gross receipts of more than $6.5 million over their 
last 3 completed fiscal years, and have more than 500 employees;
     Are not governments of a city, county, town, township or 
village;
     Are not school districts or special districts with 
populations of less than 50; and
     Are not small educational institutions.

XV. Availability of Documents

    The NRC is making the documents identified in Table 1 available to 
interested persons through one or more of the following methods, as 
indicated. To access documents related to this action, see the 
ADDRESSES section of this document.

[[Page 56190]]



                   Table 1--Availability of Documents
------------------------------------------------------------------------
                  Document                       ADAMS accession No.
------------------------------------------------------------------------
Proposed Rule Documents:
    Regulatory Analysis (includes            ML18150A267.
     backfitting discussion in Appendix A).
Related Documents:
    Letter from Brian Thomas, NRC, to        ML17310A186.
     William Berger, ASME; ``Public Access
     to Material the NRC Seeks to
     Incorporate by Reference into its
     Regulations-Revised Request;'' January
     8, 2018.
    Email from Christian Sanna, ASME, to     ML18157A113.
     Brian Thomas, NRC; May 30, 2018.
    Memorandum from Wallace Norris, NRC, to  ML14245A003.
     David Rudland, NRC; ``Summary of
     August 22, 2014, Public Meeting
     Between ASME and NRC--Information
     Exchange;'' September 8, 2014.
    Letter from John Lubinski, NRC, to       ML14261A051.
     Kevin Ennis, ASME; ``NRC Information
     Notice 2014-07 Regarding Inspection of
     Containment Leak-Chase Channels;''
     March 3, 2015.
    Letter from Ralph Hill, ASME, to John    ML15106A627.
     Lubinski, NRC; ``ASME Code, Section XI
     Actions to Address Requirements for
     Examination of Containment Leak-Chase
     Channels;'' April 13, 2015.
    NUREG/CR-6654, ``A Study of Air-         ML003691872.
     Operated Valves in U.S. Nuclear Power
     Plants,'' February 2000.
    NRC Generic Letter 88-14, ``Instrument   ML031130440.
     Air Supply System Problems Affecting
     Safety-Related Equipment,'' August
     1988.
    NRC Regulatory Issue Summary 2000-03,    ML003686003.
     ``Resolution of Generic Safety Issue
     (GSI) 158, `Performance of Safety
     Related Power-Operated Valves Under
     Design-Basis Conditions','' March 2000.
    NRC Information Notice 1986-050,         ML031220684.
     ``Inadequate Testing To Detect
     Failures of Safety-Related Pneumatic
     Components or Systems;'' June 1986.
    NRC Information Notice 1985-084,         ML031180213.
     ``Inadequate Inservice Testing of Main
     Steam Isolation Valves,'' October 1985.
    NRC Information Notice 1996-048,         ML031060093.
     ``Motor-Operated Valve Performance
     Issues,'' August 1996.
    NRC Information Notice 1996-048,         ML031050431.
     Supplement 1, ``Motor-Operated Valve
     Performance Issues,'' July 1998.
    NRC Information Notice 1998-13, ``Post-  ML031050237.
     Refueling Outage Reactor Pressure
     Vessel Leakage Testing Before Core
     Criticality,'' April 1998.
    NRC Information Notice 2014-07,          ML14070A114.
     ``Degradation of Leak-Chase Channel
     Systems For Floor Welds Of Metal
     Containment Shell And Concrete
     Containment Metallic Liner,'' May 2014.
    NRC Information Notice 2015-13, ``Main   ML15252A122.
     Steam Isolation Valve Failure
     Events,'' December 2015.
    NRC Inspection Report 50-254/97027,      ML15216A276.
     March 1998.
    NUREG-0800, Section 5.4.2.2, Revision    ML052340627.
     1, ``Steam Generator Tube Inservice
     Inspection,'' July 1981.
    NUREG-0800, Section 5.4.2.2, Revision    ML070380194.
     2, ``Steam Generator Program,'' March
     2007.
    NRC Regulatory Guide 1.83, Revision 1,   ML003740256.
     ``Inservice Inspection of Pressurized
     Water Reactor Steam Generator Tubes,''
     July 1975 (withdrawn in 2009).
    RG 1.147, ``Inservice Inspection Code    ML18114A225.
     Case Acceptability, ASME Section XI,
     Division 1,'' Revision 19.
    NUREG/CR-7153, ``Expanded Materials      ML14279A321.
     Degradation Assessment (EMDA),''        ML14279A461.
     October 2014.                           ML14279A349 .
                                             ML14279A430.
                                             ML14279A331.
    NUREG-0619, Rev. 1, ``BWR Feedwater      ML031600712.
     Nozzle and Control Rod Drive Return
     Line Nozzle Cracking: Resolution of
     Generic Technical Activity A-10
     (Technical Report),'' November 1980.
    NUREG-1801, Rev 2, ``Generic Aging       ML103490041.
     Lessons Learned (GALL) Report,''
     December 2010.
    NUREG-1800, Rev. 2, ``Standard Review    ML103490036.
     Plan for Review of License Renewal
     Applications for Nuclear Power
     Plants,'' December 2010.
    NUREG-2191, ``Generic Aging Lessons      ML17187A031.
     Learned for Subsequent License Renewal  ML17187A204.
     (GALL-SLR) Report,'' July 2017.
    NUREG-1950, ``Disposition of Public      ML11116A062.
     Comments and Technical Bases for
     Changes in the License Renewal
     Guidance Documents NUREG-1801 and
     NUREG-1800,'' April 2011.
    NUREG/CR-6933, ``Assessment of Crack     ML071020410.
     Detection in Heavy-Walled Cast          ML071020414.
     Stainless Steel Piping Welds Using
     Advanced Low-Frequency Ultrasonic
     Methods,'' March 2007.
    NUREG/CR-7122, ``An Evaluation of        ML12087A004.
     Ultrasonic Phased Array Testing for
     Cast Austenitic Stainless Steel
     Pressurizer Surge Line Piping Welds,''
     March 2012.
    NUREG-2192, ``Standard Review Plan for   ML17188A158.
     Review of Subsequent License Renewal
     Applications for Nuclear Power
     Plants,'' July 2017.
    Gupta KK, Hoffmann CL, Hamilton AM,      http://
     DeLose F. Fracture Toughness of          proceedings.asmedigitalcol
     Pressure Boundary Steels With Higher     lection.asme.org/
     Yield Strength. ASME. ASME Pressure      proceeding.aspx?articleid=
     Vessels and Piping Conference, ASME      1619041.
     2010 Pressure Vessels and Piping
     Conference: Volume 7 ():45-58.
     doi:10.1115/PVP2010-25214.
ASME Codes, Standards, and Code Cases:
    ASME BPV Code, Section III, Division 1:  http://go.asme.org/NRC-
     2015 Edition and 2017 Edition.           ASME.

[[Page 56191]]

 
    ASME BPV Code, Section XI, Division 1:   http://go.asme.org/NRC-
     2011a Addenda, 2013 Edition, 2015        ASME.
     Edition, and 2017 Edition.
    ASME OM Code, Division 1: 2015 Edition   http://go.asme.org/NRC-
     and 2017 Edition.                        ASME.
    ASME BPV Code Case N-729-6.............  http://go.asme.org/NRC-
                                              ASME.
    ASME BPV Code Case N-770-5.............  http://go.asme.org/NRC-
                                              ASME.
EPRI Topical Report:
    EPRI Topical Report, '' Materials        https://www.epri.com/#/
     Reliability Program: Topical Report      pages/product/
     for Primary Water Stress Corrosion       000000003002009241/
     Cracking Mitigation by Surface Stress    ?lang=en.
     Improvement (MRP-335, Revision 3-A),''
     November 2016.
------------------------------------------------------------------------

    Throughout the development of this rulemaking, the NRC may post 
documents related to this proposed rule, including public comments, on 
the Federal rulemaking website at http://www.regulations.gov under 
Docket ID NRC-2016-0062. The Federal rulemaking website allows you to 
receive alerts when changes or additions occur in a docket folder. To 
subscribe: 1) Navigate to the docket folder for NRC-2011-0088; 2) click 
the ``Sign up for Email Alerts'' link; and 3) enter your email address 
and select how frequently you would like to receive emails (daily, 
weekly, or monthly).

List of Subjects in 10 CFR Part 50

    Administrative practice and procedure, Antitrust, Backfitting, 
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 forth in the preamble, and under the authority 
of the Atomic Energy Act of 1954, as amended; the Energy Reorganization 
Act of 1974, as amended; and 5 U.S.C. 553, the NRC proposes to adopt 
the following amendments to 10 CFR part 50:

PART 50--DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION 
FACILITIES

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

    Authority:  Atomic Energy Act of 1954, secs. 11, 101, 102, 103, 
104, 105, 108, 122, 147, 149, 161, 181, 182, 183, 184, 185, 186, 
187, 189, 223, 234 (42 U.S.C. 2014, 2131, 2132, 2133, 2134, 2135, 
2138, 2152, 2167, 2169, 2201, 2231, 2232, 2233, 2234, 2235, 2236, 
2237, 2239, 2273, 2282); Energy Reorganization Act of 1974, secs. 
201, 202, 206, 211 (42 U.S.C. 5841, 5842, 5846, 5851); Nuclear Waste 
Policy Act of 1982, sec. 306 (42 U.S.C. 10226); National 
Environmental Policy Act of 1969 (42 U.S.C. 4332); 44 U.S.C. 3504 
note; Sec. 109, Public Law 96-295, 94 Stat. 783.

0
2. In Sec.  50.55a:
0
a. In paragraph (a)(1)(i), remove the phrase ``(referred to herein as 
ASME BPV Code)'';
0
b. In paragraph (a)(1)(i)(E)(16), remove the word ``and'';
0
c. In paragraph (a)(1)(i)(E)(17), at the end of the sentence, remove 
the punctuation ``.'' and add in its place the punctuation ``,'';
0
d. Add paragraphs (a)(1)(i)(E)(18) and (19);
0
e. In paragraph (a)(1)(ii), remove the acronym ``BPV Code'' and add in 
its place the words ``Boiler and Pressure Vessel Code'';
0
f. Revise paragraphs (a)(1)(ii)(C)(52) and (53);
0
g. Add paragraphs (a)(1)(ii)(C)(54) and (55);
0
h. Revise paragraphs (a)(1)(iii)(C) and (D);
0
i. In paragraph (a)(1)(iv), remove the phrase ``(various edition titles 
referred to herein as ASME OM Code)'';
0
j. In paragraph (a)(1)(iv)(C)(1), at the end of the sentence, remove 
the punctuation ``.'' and add in its place the punctuation ``,'';
0
k. Add paragraphs (a)(1)(iv)(C)(2) and (3), and paragraph (a)(4);
0
l. In paragraph (b)(1), remove the number ``2013'' and add in its place 
the number ``2017'';
0
m. In paragraph (b)(1)(ii), in Table I, remove the number ``2013'' in 
the last entry in the first column and add in its place the number 
``2017'', and remove the word ``Note'' wherever it appears in the 
second column and add in its place the word ``Footnote'';
0
n. In paragraph (b)(1)(iii), remove the phrase ``2008 Addenda'' 
wherever it appears and add in its place the phrase ``2017 Edition'';
0
o. In paragraph (b)(1)(v), remove the phrase ``the latest edition and 
addenda'' and add in its place the phrase ``2009b Addenda of the 2007 
Edition, where the NQA-1-1994 Edition is'';
0
p. In paragraph (b)(1)(vi), remove the phrase ``the latest edition and 
addenda'' and add in its place the phrase ``all editions and addenda up 
to and including the 2013 Edition'';
0
q. In paragraph (b)(1)(vii), remove the phrase ``the 2013 Edition'' and 
add in its place the phrase ``all editions and addenda up to and 
including the 2017 Edition'';
0
r. Add paragraphs (b)(1)(x) through (xii);
0
s. In paragraph (b)(2), remove the number ``2013'' and add in its place 
the number ``2017'';
0
t. Remove and reserve paragraphs (b)(2)(vi), (vii), and (xvii);
0
u. Revise paragraph (b)(2)(ix) introductory text;
0
v. Add paragraph (b)(2)(ix)(K);
0
w. In paragraph (b)(2)(xviii)(D), remove the phrase ``and 2013 Edition 
of Section XI of the ASME BPV Code'' and add in its place the phrase 
``through the latest edition incorporated by reference in paragraph 
(a)(1)(ii) of this section'';
0
x. Revise paragraph (b)(2)(xx)(B) and add paragraph (b)(2)(xx)(C);
0
y. Remove and reserve paragraph (b)(2)(xxi)(A), and add paragraph 
(b)(2)(xxi)(B);
0
z. Revise paragraphs (b)(2)(xxv), (xxvi), (xxxii) and (xxxiv) 
introductory text;
0
aa. In paragraph (b)(2)(xxxiv)(B) add the phrase ``of the 2013 and the 
2015 Editions'' after the phrase ``Appendix U'';
0
bb. Revise paragraph (xxxv);
0
cc. In paragraph (b)(2)(xxxvi), remove the word ``Edition'' and add in 
its place the phrase ``through 2017 Editions'';
0
dd. Add paragraphs (b)(2)(xxxviii) through (xlii);
0
ee. In paragraph (b)(3) introductory text, add the Roman numeral ``IV'' 
in sequential order, remove the phrase ``2012 Edition, as specified'' 
and add in its place the phrase ``latest edition and addenda of the 
ASME OM Code incorporated by reference'' and revise the last sentence 
in the paragraph;
0
ff. In paragraph (b)(3)(ii), remove the phrase ``, 2011 Addenda, and 
2012 Edition'' and add in its place the phrase ``through the latest 
edition and addenda

[[Page 56192]]

of the ASME OM Code incorporated by reference in paragraph (a)(1)(iv) 
of this section'';
0
gg. Revise paragraph (b)(3)(iv) introductory text and remove and 
reserve paragraphs (b)(3)(iv)(A) through (D);
0
hh. In paragraph (b)(3)(viii), remove the phrase ``, 2011 Addenda, and 
2012 Edition'' and add in its place the phrase ``through the latest 
edition and addenda of the ASME OM Code incorporated by reference in 
paragraph (a)(1)(iv) of this section'';
0
ii. Revise paragraphs (b)(3)(ix) and (xi);
0
jj. Add paragraph (b)(3)(xii);
0
kk. In paragraphs (f)(4)(i) and (ii), remove the number ``12'' wherever 
it appears and add in its place the number ``18'';
0
ll. Add paragraph (f)(7);
0
mm. In paragraph (g)(4) introductory text, remove the phrase ``, 
subject to the condition listed in paragraph (b)(2)(vi) of this 
section'';
0
nn. In paragraph (g)(4)(i), remove the number ``12'' wherever it 
appears and add in its place the number ``18'';
0
oo. In paragraph (g)(4)(ii), in the first sentence remove the number 
``12'' and add in its place the number ``18''; remove the date ``August 
17, 2017'' wherever it appears and add in its place ``[DATE 75 DAYS 
AFTER EFFECTIVE DATE OF FINAL RULE]'';
0
pp. Remove and reserve paragraph (g)(6)(ii)(C);
0
qq. Revise paragraphs (g)(6)(ii)(D)(1), (2) and (4), and add paragraphs 
(g)(6)(ii)(D)(5) through (8);
0
rr. Revise paragraphs (g)(6)(ii)(F)(1) and (2), and remove and reserve 
paragraph (g)(6)(ii)(F)(3);
0
ss. Revise paragraphs (g)(6)(ii)(F)(4), (6), (9) through (11), and 
(13), and add paragraphs (g)(6)(ii)(F)(14) through (16).
    The revisions and additions read as follows:


Sec.  50.55a  Codes and standards.

    (a)* * *
    (1)* * *
    (i)* * *
    (E)* * *
    (18) 2015 Edition (including Subsection NCA; and Division 1 
subsections NB through NH and Appendices), and
    (19) 2017 Edition (including Subsection NCA; and Division 1 
subsections NB through NG and Appendices).
* * * * *
    (ii)* * *
    (C)* * *
    (52) 2011a Addenda,
    (53) 2013 Edition,
    (54) 2015 Edition, and
    (55) 2017 Edition.
* * * * *
    (iii)* * *
    (C) ASME BPV Code Case N-729-6. ASME BPV Code Case N-729-6, 
``Alternative Examination Requirements for PWR Reactor Vessel Upper 
Heads With Nozzles Having Pressure-Retaining Partial-Penetration Welds 
Section XI, Division 1'' (Approval Date: March 3, 2016), with the 
conditions in paragraph (g)(6)(ii)(D) of this section.
    (D) ASME BPV Code Case N-770-5. ASME BPV Code Case N-770-5, 
``Alternative Examination Requirements and Acceptance Standards for 
Class 1 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'' (Approval 
Date: November 7, 2016), with the conditions in paragraph (g)(6)(ii)(F) 
of this section.
* * * * *
    (iv)* * *
    (C)* * *
    (2) 2015 Edition, and
    (3) 2017 Edition.
* * * * *
    (4) Electric Power Research Institute, Materials Reliability 
Program, 3420 Hillview Avenue, Palo Alto, CA 94304-1338; telephone: 1-
650-855-2000; http://www.epri.com.
    (i) ``Materials Reliability Program: Topical Report for Primary 
Water Stress Corrosion Cracking Mitigation by Surface Stress 
Improvement (MRP-335, Revision 3-A)'', EPRI approval date: November 
2016.
    (ii) [Reserved]
* * * * *
    (b)* * *
    (1)* * *
    (x) Section III Condition: Visual examination of bolts, studs and 
nuts. Applicants or licensees applying the provisions of NB-2582, NC-
2582, ND-2582, NE-2582, NF-2582, NG-2582 in the 2017 Edition of Section 
III, must apply paragraphs (b)(1)(x)(A) through (B) of this section.
    (A) Visual examination of bolts, studs, and nuts: First provision. 
When applying the provisions of NB-2582, NC-2582, ND-2582, NE-2582, NF-
2582, NG-2582 in the 2017 Edition of Section III, the visual 
examinations are required to be performed in accordance with procedures 
qualified to NB-5100, NC-5100, ND-5100, NE-5100, NF-5100, NG-5100 and 
performed by personnel qualified in accordance with NB-5500, NC-5500, 
ND-5500, NE-5500, NF-5500, and NG-5500.
    (B) Visual examination of bolts, studs, and nuts: Second provision. 
When applying the provisions of NB-2582, NC-2582, ND-2582, NE-2582, NF-
2582, NG-2582 in the 2017 Edition of Section III, the acceptance 
criteria from NB-2582, NC-2582, ND-2582, NE-2582, NF-2582, NG-2582 in 
the 2015 Edition of Section III shall be used.
    (xi) Section III condition: Mandatory Appendix XXVI. When applying 
the 2015 and 2017 Editions of Section III, Mandatory Appendix XXVI, 
``Rules for Construction of Class 3 Buried Polyethylene Pressure 
Piping,'' applicants or licensees must meet the following conditions:
    (A) Mandatory Appendix XXVI: First provision. When performing 
fusing procedure qualification tests and operator performance 
qualification tests in accordance with XXVI-4330 and XXVI-4340 the 
following essential variables shall be used for the performance 
qualification tests of butt fusion joints:
    (1) Joint Type: A change in the type of joint from that qualified, 
except that a square butt joint qualifies as a mitered joint.
    (2) Pipe Surface Alignment: A change in the pipe outside diameter 
(O.D.) surface misalignment of more than 10 percent of the wall 
thickness of the thinner member to be fused.
    (3) PE Material: Each lot of polyethylene source material to be 
used in production (XXVI-2310(c)).
    (4) Wall Thickness: Each thickness to be fused in production (XXVI-
2310(c)).
    (5) Diameter: Each diameter to be fused in production (XXVI-
2310(c)).
    (6) Cross-sectional Area: Each combination of thickness and 
diameter (XXVI-2310(c)).
    (7) Position: Maximum machine carriage slope when greater than 20 
degrees from horizontal (XXVI-4321(c)).
    (8) Heater Surface Temperature: A change in the heater surface 
temperature to a value beyond the range tested (XXVI-2321).
    (9) Ambient Temperature: A change in ambient temperature to less 
than 50 [deg]F (10 [deg]C) or greater than 125 [deg]F (52 [deg]C) 
(XXVI-4412(b)).
    (10) Interfacial Pressure: A change in interfacial pressure to a 
value beyond the range tested (XXVI-2321).
    (11) Decrease in Melt Bead Width: A decrease in melt bead size from 
that qualified.
    (12) Increase in Heater Removal Time: An increase in heater plate 
removal time from that qualified.
    (13) Decrease in Cool-down Time: A decrease in the cooling time at 
pressure from that qualified.
    (14) Fusing Machine Carriage Model: A change in the fusing machine 
carriage model from that tested (XXVI-2310(d)).

[[Page 56193]]

    (B) Mandatory Appendix XXVI: Second provision. When performing 
qualification tests of butt fusion joints in accordance with XXVI-4342, 
both the bend test and the high speed tensile impact test shall be 
successfully completed.
    (C) Mandatory Appendix XXVI: Third provision. When performing 
fusing procedure qualification tests and operator performance 
qualification tests in accordance with 2017 Edition of BPV Code Section 
III XXVI-4330 and XXVI-4340, the following essential variables shall be 
used for the performance qualification tests of electrofusion joints:
    (1) Joint Design: A change in the design of an electrofusion joint.
    (2) Fit-up Gap: An increase in the maximum radial fit-up gap 
qualified.
    (3) Pipe PE Material: A change in the PE designation or cell 
classification of the pipe from that tested (XXVI-2322(a)).
    (4) Fitting PE Material: A change in the manufacturing facility or 
production lot from that tested (XXVI-2322(b)).
    (5) Pipe Wall Thickness: Each thickness to be fused in production 
(XXVI-2310(c)).
    (6) Fitting Manufacturer: A change in fitting manufacturer.
    (7) Pipe Diameter: Each diameter to be fused in production (XXVI-
2310(c)).
    (8) Cool-down Time: A decrease in the cool time at pressure from 
that qualified.
    (9) Fusion Voltage: A change in fusion voltage.
    (10) Nominal Fusion Time: A change in the nominal fusion time.
    (11) Material Temperature Range: A change in material fusing 
temperature beyond the range qualified.
    (12) Power Supply: A change in the make or model of electrofusion 
control box (XXVI-2310(f)).
    (13) Power Cord: A change in power cord material, length, or 
diameter that reduces current at the coil to below the minimum 
qualified.
    (14) Processor: A change in the manufacturer or model number of the 
processor. (XXVI-2310(f)).
    (15) Saddle Clamp: A change in the type of saddle clamp.
    (16) Scraping Device: A change from a clean peeling scraping tool 
to any other type of tool.
    (D) Mandatory Appendix XXVI: Fourth provision. Performance of crush 
tests in accordance with 2017 BPV Code Section III XXVI-2332(a) and 
XXVI-2332(b) and electrofusion bend tests in accordance with 2017 BPV 
Code Section III XXVI-2332(b) are required to qualify fusing procedures 
for electrofusion joints in polyethylene piping installed in accordance 
with 2017 Edition of ASME BPV Code Section III, Mandatory Appendix 
XXVI.
    (E) Mandatory Appendix XXVI: Fifth provision. Electrofusion saddle 
fittings and electrofusion saddle joints are not permitted for use. 
Only full 360-degree seamless sleeve electrofusion couplings and full 
360-degree electrofusion socket joints are permitted.
    (xii) Section III condition: Certifying Engineer. When applying the 
2017 and later editions of ASME BPV Code Section III, the NRC does not 
permit applicants and licensees to use a certifying engineer in lieu of 
a registered professional engineer for Code-related activities that are 
applicable to U.S. nuclear facilities regulated by the NRC.
    (2)* * *
    (ix) Section XI condition: Metal containment examinations. 
Applicants or licensees applying Subsection IWE, 1992 Edition with the 
1992 Addenda, or the 1995 Edition with the 1996 Addenda, must satisfy 
the requirements of paragraphs (b)(2)(ix)(A) through (E) and 
(b)(2)(ix)(K) of this section. Applicants or licensees applying 
Subsection IWE, 1998 Edition through the 2001 Edition with the 2003 
Addenda, must satisfy the requirements of paragraphs (b)(2)(ix)(A) and 
(B) and (b)(2)(ix)(F) through (I) and (b)(2)(ix)(K) of this section. 
Applicants or licensees applying Subsection IWE, 2004 Edition, up to 
and including the 2005 Addenda, must satisfy the requirements of 
paragraphs (b)(2)(ix)(A) and (B) and (b)(2)(ix)(F) through (H) and 
(b)(2)(ix)(K) of this section. Applicants or licensees applying 
Subsection IWE, 2004 Edition with the 2006 Addenda, must satisfy the 
requirements of paragraphs (b)(2)(ix)(A)(2) and (b)(2)(ix)(B) and 
(b)(2)(ix)(K) of this section. Applicants or licensees applying 
Subsection IWE, 2007 Edition through the 2015 Edition, must satisfy the 
requirements of paragraphs (b)(2)(ix)(A)(2) and (b)(2)(ix)(B) and (J) 
and (K) of this section. Applicants or licensees applying Subsection 
IWE, 2017 Edition, must satisfy the requirements of paragraphs 
(b)(2)(ix)(A)(2) and (b)(2)(ix)(B) and (J) of this section.
* * * * *
    (K) Metal Containment Examinations: Eleventh provision. A general 
visual examination of containment leak chase channel moisture barriers 
must be performed once each interval, in accordance with the completion 
percentages in Table IWE 2411 1 of the 2017 Edition. Examination shall 
include the moisture barrier materials (caulking, gaskets, coatings, 
etc.) that prevent water from accessing the embedded containment liner 
within the leak chase channel system. Caps of stub tubes extending 
above the concrete floor interface may be inspected, provided the 
configuration of the cap functions as a moisture barrier as described 
previously. Leak chase channel system closures need not be disassembled 
for performance of examinations if the moisture barrier material is 
clearly visible without disassembly, or coatings are intact. The 
closures are acceptable if no damage or degradation exists that would 
allow intrusion of moisture against inaccessible surfaces of the metal 
containment shell or liner within the leak chase channel system. 
Examinations that identify flaws or relevant conditions shall be 
extended in accordance with paragraph IWE 2430 of the 2017 Edition.
    (xx)* * *
    (B) System leakage tests: Second provision. The nondestructive 
examination method and acceptance criteria of the 1992 or later of 
Section III shall be met when performing system leakage tests (in lieu 
of a hydrostatic test) in accordance with IWA-4520 after repair and 
replacement activities performed by welding or brazing on a pressure 
retaining boundary using the 2003 Addenda through the latest edition 
and addenda of Section XI incorporated by reference in paragraph 
(a)(1)(ii) of this section. The nondestructive examination and pressure 
testing may be performed using procedures and personnel meeting the 
requirements of the licensee's/applicant's current ISI code of record.
    (C) Section XI condition: System leakage tests: Third provision. 
The use of the provisions for an alternative BWR pressure test at 
reduced pressure to satisfy IWA-4540 requirements as described in IWA-
5213(b)(2), IWB-5210(c) and IWB-5221(d) of Section XI, 2017 Edition may 
be used subject to the following conditions:
    (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.
    (2) In lieu of the test condition holding time of IWA-5213(b)(2), 
after pressurization to test conditions, and before the visual 
examinations commence, the holding time shall be 1 hour for non-
insulated components.
* * * * *
    (xxi)* * *
    (A) [Reserved]

[[Page 56194]]

    (B) Section XI condition: Table IWB-2500-1 examination. Use of the 
provisions of IWB-2500(f) and (g) and Table IWB-2500-1 Notes 6 and 7 of 
the 2017 Edition of ASME Section XI for examination of Examination 
Category B-D Item Numbers B3.90 and B3.100 shall be subject to the 
following conditions:
    (1) A plant-specific evaluation demonstrating the criteria of IWB-
2500(f) are met must be maintained in accordance with IWA-1400(l).
    (2) The use of the provisions of IWB-2500(f) and Table IWB-2500-1 
Note 6 for examination of Examination Category B-D Item Numbers B3.90 
is prohibited for plants with renewed licenses in accordance with 10 
CFR part 54.
    (3) The provisions of IWB-2500(g) and Table IWB-2500-1 Notes 6 and 
7 for examination of Examination Category B-D Item Numbers B3.90 and 
B3.100 shall not be used to eliminate the preservice or inservice 
volumetric examination of plants with a Combined Operating License 
pursuant to 10 CFR part 52, or a plant that receives its operating 
license after October 22, 2015.
* * * * *
    (xxv) Section XI condition: Mitigation of defects by modification. 
Use of the provisions of IWA-4340 shall be subject to the following 
conditions:
    (A) Mitigation of defects by modification: First provision. The use 
of the provisions for mitigation of defects by modification in IWA-4340 
of Section XI 2001 Edition through the 2010 Addenda, is prohibited.
    (B) Mitigation of defects by modification: Second provision. The 
use of the provisions for mitigation of defects by modification in IWA-
4340 of Section XI 2011 Edition through the 2017 Edition may be used 
subject to the following conditions:
    (1) The use of the provisions in IWA 4340 to mitigate crack-like 
defects or those associated with flow accelerated corrosion are 
prohibited.
    (2) The design of a modification that mitigates a defect shall 
incorporate a loss of material rate either 2 times the actual measured 
corrosion rate in that pipe location (established based on wall 
thickness measurements conducted at least twice in two prior 
consecutive or nonconsecutive refueling outage cycles in the 10 year 
period prior to installation of the modification), or 4 times the 
estimated maximum corrosion rate for the piping system.
    (3) The Owner shall perform a wall thickness examination in the 
vicinity of the modification and relevant pipe base metal during each 
refueling outage cycle to detect propagation of the flaw into the 
material credited for structural integrity of the item unless the 
examinations in the two refueling outage cycles subsequent to the 
installation of the modification are capable of validating the 
projected flaw growth.
    (xxvi) Section XI condition: Pressure testing Class 1, 2, and 3 
mechanical joints. When using the 2001 Edition through the latest 
edition and addenda incorporated by reference in paragraph (a)(1)(ii) 
of this section, licensees shall pressure test mechanical joints in 
Class 1, 2, and 3 piping and components greater than NPS-1 which are 
disassembled and reassembled during the performance of a Section XI 
activity (e.g., repair/replacement activity), in accordance with IWA-
5211(a). The pressure test and examiners shall meet the requirements of 
the licensee's/applicant's current ISI code of record.
* * * * *
    (xxxii) Section XI condition: Summary report submittal. When using 
ASME BPV Code, Section XI, 2010 Edition through the latest edition and 
addenda incorporated by reference in paragraph (a)(1)(ii) of this 
section, Summary Reports and Owner's Activity Reports described in IWA-
6230 must be submitted to the NRC. Preservice inspection reports for 
examinations prior to commercial service shall be submitted prior to 
the date of placement of the unit into commercial service. For 
preservice and inservice examinations performed following placement of 
the unit into commercial service, reports shall be submitted within 90 
calendar days of the completion of each refueling outage.
* * * * *
    (xxxiv) Section XI condition: Nonmandatory Appendix U. When using 
Nonmandatory Appendix U of the ASME BPV Code, Section XI, 2013 Edition 
through the latest edition incorporated by reference in paragraph 
(a)(1)(ii) of this section, the following conditions apply:
* * * * *
    (xxxv) Section XI condition: Use of RTT0 in the 
KIa and KIc equations.
    (A) When using the 2013 Edition of the ASME BPV Code, Section XI, 
Appendix A, paragraph A-4200, if T0 is available, then 
RTT0 may be used in place of RTNDT for 
applications using the KIc equation and the associated 
KIc curve, but not for applications using the KIa 
equation and the associated KIa curve.
    (B) When using the 2015 Edition of the ASME BPV Code, Section XI, 
Appendix A, paragraph A-4200 subparagraph (c) RTKIa shall be 
defined as RTKIa = T0 + 90.267 exp(-0.003406T0).
* * * * *
    (xxxviii) Section XI condition: ASME Code Section XI Appendix III 
Supplement 2. Licensees applying the provisions of ASME Code Section XI 
Appendix III Supplement 2, ``Welds in Cast Austenitic Materials,'' are 
subject to the following conditions:
    (A) ASME Code Section XI Appendix III Supplement 2: First 
provision. In lieu of Paragraph (c)(1)(-c)(-2), licensees shall use a 
search unit with a center frequency of 500 kHz with a tolerance of +/-
20 percent.
    (B) ASME Code Section XI Appendix III Supplement 2: Second 
provision. In lieu of Paragraph (c)(1)(-d), the search unit shall 
produce angles including, but not limited to, 30 to 55 degrees with a 
maximum increment of 5 degrees.
    (xxxix) Section XI condition: Defect Removal. The use of the 
provisions for removal of defects by welding or brazing in IWA-
4421(c)(1) and IWA-4421(c)(2) of Section XI, 2017 Edition may be used 
subject to the following conditions:
    (A) Defect removal requirements: First provision. The provisions of 
subparagraph IWA 4421(c)(1) shall not be used to contain or isolate a 
defective area without removal of the defect.
    (B) Defect removal requirements: Second provision. The provisions 
of subparagraph IWA 4421(c)(2) shall not be used for crack-like 
defects.
    (xl) Section XI condition: Prohibitions on use of IWB-3510.4(b). 
The use of ASME BPV Code, Section XI, subparagraphs IWB-3510.4(b)(4) 
and IWB-3510.4(b)(5) is prohibited.
    (xli) Section XI condition: Preservice Volumetric and Surface 
Examinations Acceptance. The use of the provisions for accepting flaws 
by analytical evaluation during preservice inspection in IWB-3112(a)(3) 
and IWC-3112(a)(3) of Section XI, 2013 Edition through the latest 
edition and addenda incorporated by reference in paragraph (a)(1)(ii) 
of this section is prohibited.
    (xlii) Section XI condition: Steam Generator Nozzle-to-Component 
welds and Reactor Vessel Nozzle-to-Component welds. Licensees applying 
the provisions of Table IWB-2500-1, Examination Category B-F, Pressure 
Retaining Dissimilar Metal Welds in Vessel Nozzles, Item B5.11 (NPS 4 
or Larger Nozzle-to-Component Butt Welds) of the 2013 Edition through 
the latest edition and addenda incorporated by reference in paragraph 
(a)(1)(ii) of this section and Item B5.71 (NPS 4 or Larger Nozzle-to-
Component Butt Welds) of the 2011a Addenda through

[[Page 56195]]

the latest edition and addenda incorporated by reference in paragraph 
(a)(1)(ii) of this section must also meet the following conditions:
    (A) Ultrasonic examination procedures, equipment, and personnel 
shall be qualified by performance demonstration in accordance with 
Mandatory Appendix VIII.
    (B) When applying the examination requirements of Figure IWB-2500-
8, the volumetric examination volume shall be extended to include 100 
percent of the weld volume, except as provided in paragraph 
(b)(2)(xlii)(B)(1) of this section:
    (1) When the examination volume that can be qualified by 
performance demonstration is less than 100 percent of the weld volume, 
the licensee may ultrasonically examine the qualified volume and 
perform a flaw evaluation of the largest hypothetical crack that could 
exist in the volume and not be qualified for ultrasonic examination, 
subject to prior NRC authorization in accordance with paragraph (z) of 
this section.
    (2) [Reserved]
    (3)* * * When implementing the ASME OM Code, conditions are 
applicable only as specified in the following paragraphs:
* * * * *
    (iv) OM condition: Check valves (Appendix II). Licensees applying 
Appendix II of the ASME OM Code, 2003 Addenda through the 2015 Edition, 
is acceptable for use with the following requirements. Trending and 
evaluation shall support the determination that the valve or group of 
valves is capable of performing its intended function(s) over the 
entire interval. At least one of the Appendix II condition monitoring 
activities for a valve group shall be performed on each valve of the 
group at approximate equal intervals not to exceed the maximum interval 
shown in the following table:
* * * * *
    (A through D) [Reserved]
* * * * *
    (ix) OM condition: Subsection ISTF. Licensees applying Subsection 
ISTF, 2012 Edition or 2015 Edition, shall satisfy the requirements of 
Mandatory Appendix V, ``Pump Periodic Verification Test Program,'' of 
the ASME OM Code in that edition. Subsection ISTF, 2011 Addenda, is 
prohibited for use.
* * * * *
    (xi) OM condition: Valve Position Indication. When implementing 
paragraph ISTC-3700, ``Position Verification Testing,'' in the ASME OM 
Code, 2012 Edition through the latest edition and addenda of the ASME 
OM Code incorporated by reference in paragraph (a)(1)(iv) of this 
section, licensees shall verify that valve operation is accurately 
indicated by supplementing valve position indicating lights with other 
indications, such as flow meters or other suitable instrumentation, to 
provide assurance of proper obturator position for valves with remote 
position indication within the scope of Subsection ISTC and all 
mandatory appendices.
    (xii) OM condition: Air-operated valves (Appendix IV). When 
implementing ASME OM Code, 2015 Edition, licensees shall also apply the 
provisions in Appendix IV, ``Preservice and Inservice Testing of Active 
Pneumatically Operated Valve Assemblies in Nuclear Power Plants,'' of 
the 2017 Edition of the ASME OM Code.
* * * * *
    (f)* * *
    (7) Inservice Testing Reporting Requirements. Inservice Testing 
Program Test and Examination Plans (IST Plans) required by the ASME OM 
Code must be submitted to the NRC in accordance with Sec.  50.4. All 
required IST Plan submittals must be made within 90 days of their 
implementation. Electronic submission is preferred. In addition to the 
IST Plans for the preservice test period, initial inservice test 
interval, and successive inservice test intervals specified in the ASME 
OM Code, interim IST Plan updates that involve changes to the following 
must be submitted:
    (i) The edition and addenda of ASME OM Code that apply to required 
tests and examinations;
    (ii) The classification of components and boundaries of system 
classification;
    (iii) Identification of components subject to tests and 
examination;
    (iv) Identification of components exempt from testing or 
examination;
    (v) ASME OM Code requirements for components and the test or 
examination to be performed;
    (vi) ASME OM Code requirements for components that are not being 
satisfied by the tests or examinations; and justification for 
alternative tests or examinations;
    (vii) ASME OM Code Cases planned for use and the extent of their 
application; or
    (viii) Test or examination frequency or schedule for performance of 
tests and examinations, as applicable.
* * * * *
    (g)* * *
    (6)* * *
    (ii)* * *
    (C) [Reserved]
    (D) Augmented ISI requirements: Reactor vessel head inspections--
(1) Implementation. Holders of operating licenses or combined licenses 
for pressurized-water reactors as of or after [DATE 75 DAYS AFTER 
EFFECTIVE DATE OF FINAL RULE] shall implement the requirements of ASME 
BPV Code Case N-729-6 instead of ASME BPV Code Case N-729-4, subject to 
the conditions specified in paragraphs (g)(6)(ii)(D)(2) through (8) of 
this section, by no later than one year after [DATE 75 DAYS AFTER 
EFFECTIVE DATE OF FINAL RULE]. All previous NRC-approved alternatives 
from the requirements of paragraph (g)(6)(ii)(D) of this section remain 
valid.
    (2) Appendix I use. If Appendix I is used, Section I 3000 must be 
implemented to define an alternative examination area or volume.
* * * * *
    (4) Surface exam acceptance criteria. In addition to the 
requirements of paragraph 3132.1(b) of ASME BPV Code Case N-729-6, a 
component whose surface examination detects rounded indications greater 
than allowed in paragraph NB-5352 in size on the partial-penetration or 
associated fillet weld shall be classified as having an unacceptable 
indication and corrected in accordance with the provisions of paragraph 
3132.2 of ASME BPV Code Case N-729-6.
    (5) Peening. In lieu of inspection requirements of Table 1, Items 
B4.50 and B4.60, and all other requirements in ASME BPV Code Case N-
729-6 pertaining to peening, in order for a RPV upper head with nozzles 
and associated J-groove welds mitigated by peening to obtain inspection 
relief from the requirements of Table 1 for unmitigated heads, peening 
must meet the performance criteria, qualification, and inspection 
requirements stated in MRP-335, Revision 3-A, with the exception that a 
plant-specific alternative request is not required and NRC condition 
5.4 of MRP-335, Revision 3-A does not apply.
    (6) Baseline Examinations. In lieu of the requirements for Note 
7(c) the baseline volumetric and surface examination for plants with a 
RPV Head with less than 8 EDY shall be performed by 2.25 reinspection 
years (RIY) after initial startup not to exceed 8 years.
    (7) Sister Plants. Note 10 of ASME BPV Code Case N-729-6 shall not 
be implemented without prior NRC approval.
    (8) Volumetric Leak Path. In lieu of paragraph 3200(b) requirement 
for a surface examination of the partial penetration weld, a volumetric 
leak path

[[Page 56196]]

assessment of the nozzle may be performed in accordance with Note 6 of 
Table 1 of N-729-6.
* * * * *
    (F) Augmented ISI requirements: Examination requirements for Class 
1 piping and nozzle dissimilar-metal butt welds--(1) Implementation. 
Holders of operating licenses or combined licenses for pressurized-
water reactors as of or after [DATE 75 DAYS AFTER EFFECTIVE DATE OF 
FINAL RULE], shall implement the requirements of ASME BPV Code Case N-
770-5 instead of ASME BPV Code Case N-770-2, subject to the conditions 
specified in paragraphs (g)(6)(ii)(F)(2) through (16) of this section, 
by no later than one (1) year after [DATE 75 DAYS AFTER EFFECTIVE DATE 
OF FINAL RULE]. All NRC authorized alternatives from previous versions 
of paragraph (g)(6)(ii)(F) of this section remain applicable.
    (2) Categorization. (i) Welds that have been mitigated by the 
Mechanical Stress Improvement Process (MSIPTM) may be categorized as 
Inspection Items D or E, as appropriate, provided the criteria in 
Appendix I of the code case have been met.
    (ii) In order to be categorized as peened welds, in lieu of 
inspection category L requirements and inspections, welds must meet the 
performance criteria, qualification and inspection requirements as 
stated by MRP-335, Revision 3-A, with the exception that no plant-
specific alternative is required.
    (iii) Other mitigated welds shall be identified as the appropriate 
inspection item of the NRC authorized alternative or NRC-approved code 
case for the mitigation type in Regulatory Guide 1.147.
    (iv) All other butt welds that rely on Alloy 82/182 for structural 
integrity shall be categorized as Inspection Items A-1, A-2, B-1 or B-
2, as appropriate.
    (v) Paragraph -1100(e) of ASME BPV Code Case N-770-5 shall not be 
used to exempt welds that rely on Alloy 82/182 for structural integrity 
from any requirement of this section.
    (3) [Reserved]
* * * * *
    (4) Examination coverage. When implementing Paragraph -2500(a) of 
ASME BPV Code Case N-770-5, essentially 100 percent of the required 
volumetric examination coverage shall be obtained, including greater 
than 90 percent of the volumetric examination coverage for 
circumferential flaws. Licensees are prohibited from using Paragraphs -
2500(c) and -2500(d) of ASME BPV Code Case N-770-5 to meet examination 
requirements.
* * * * *
    (6) Reporting requirements. The licensee will promptly notify the 
NRC regarding any volumetric examination of a mitigated weld that 
detects growth of existing flaws in the required examination volume 
that exceed the previous IWB-3600 flaw evaluations, new flaws, or any 
indication in the weld overlay or excavate and weld repair material 
characterized as stress corrosion cracking. Additionally the licensee 
will submit to the NRC a report summarizing the evaluation, along with 
inputs, methodologies, assumptions, and causes of the new flaw or flaw 
growth within 30 days following plant startup.
* * * * *
    (9) Deferrals. (i) The initial inservice volumetric examination of 
optimized weld overlays, Inspection Item C-2, shall not be deferred.
    (ii) Volumetric inspection of peened dissimilar metal butt welds 
shall not be deferred.
    (iii) For Inspection Item M-2, N-1 and N-2 welds the second 
required inservice volumetric examination shall not be deferred.
    (10) Examination technique. Note 14(b) of Table 1 and Note (b) of 
Figure 5(a) of ASME BPV Code Case N-770-5 may only be implemented if 
the requirements of Note 14(a) of Table 1 of ASME BPV Code Case N-770-5 
cannot be met.
    (11) Cast stainless steel. Examination of ASME BPV Code Class 1 
piping and vessel nozzle butt welds involving cast stainless steel 
materials, will be performed with Appendix VIII, Supplement 9 
qualifications, or qualifications similar to Appendix VIII, Supplement 
2 or 10 using cast stainless steel mockups no later than the next 
scheduled weld examination after January 1, 2022, in accordance with 
the requirements of Paragraph -2500(a) or, as an alternative, using 
inspections that meet the requirements of ASME Code Case N-824 as 
conditioned in Regulatory Guide 1.147.
* * * * *
    (13) Encoded ultrasonic examination. Ultrasonic examinations of 
non-mitigated or cracked mitigated dissimilar metal butt welds in the 
reactor coolant pressure boundary must be performed in accordance with 
the requirements of Table 1 for Inspection Item A-1, A-2, B-1, B-2, E, 
F-2, J, K, N-1, N-2 and O for essentially 100 percent of the required 
inspection volume using an encoded method.
    (14) Excavate and weld repair cold leg. For cold leg temperature M-
2, N-1 and N-2 welds, initial volumetric inspection after application 
of an excavate and weld repair (EWR) shall be performed during the 
second refueling outage.
    (15) Cracked excavate and weld repair. In lieu of the examination 
requirements for cracked welds with 360 excavate and weld repairs, 
Inspection Item N-1 of Table 1, welds shall be examined during the 
first or second refueling outage following EWR. Examination volumes 
that show no indication of crack growth or new cracking shall be 
examined once each inspection interval thereafter.
    (16) Partial arc excavate and weld repair. Inspection Item O cannot 
be used without NRC review and approval.
* * * * *

    Dated at Rockville, Maryland, this 16th day of October, 2018.

    For the Nuclear Regulatory Commission.
Ho K. Nieh,
Director, Office of Nuclear Reactor Regulation.
[FR Doc. 2018-24076 Filed 11-8-18; 8:45 am]
 BILLING CODE 7590-01-P