[Federal Register Volume 86, Number 18 (Friday, January 29, 2021)]
[Notices]
[Page 7577]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-01984]


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NUCLEAR REGULATORY COMMISSION

[NRC-2019-0253]


Final Revision to Branch Technical Position 7-19 Guidance for 
Evaluation of Defense in Depth and Diversity To Address Common-Cause 
Failure Due to Latent Design Defects in Digital Safety Systems

AGENCY: Nuclear Regulatory Commission.

ACTION: Standard review plan-final section revision; issuance.

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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is issuing a 
final revision to Branch Technical Position (BTP) 7-19, ``Guidance for 
Evaluation of Defense in Depth and Diversity to Address Common-Cause 
Failure due to Latent Design Defects in Digital Safety Systems'' of 
NUREG-0800, ``Standard Review Plan for the Review of Safety Analysis 
Reports for Nuclear Power Plants: LWR Edition.''

DATES: The update to this BTP takes effect on January 29, 2021.

ADDRESSES: Please refer to Docket ID NRC-2019-0253 when contacting the 
NRC about the availability of information regarding this document. You 
may obtain publicly available information related to this document 
using any of the following methods:
     Federal Rulemaking Website: Go to https://www.regulations.gov/ and search for Docket ID NRC-2019-0253. Address 
questions about Docket IDs in Regulations.gov to Jennifer Borges; 
telephone: 301-287-9127; email: [email protected]. For technical 
questions, contact the individual listed in the FOR FURTHER INFORMATION 
CONTACT section of this document.
     NRC's Agencywide Documents Access and Management System 
(ADAMS): You may obtain publicly available documents online in the 
ADAMS Public Document collection at https://www.nrc.gov/reading-rm/adams.html. To begin the search, select ``Begin Web-based ADAMS 
Search.'' For problems with ADAMS, contact the NRC's Public Document 
Room (PDR) reference staff at 1-800-397-4209, 301-415-4737, or by email 
to [email protected]. The ADAMS accession number for each document 
referenced (if it is available in ADAMS) is provided the first time 
that it is mentioned in this document.
     Attention: The PDR, where you may examine and order copies 
of public documents, is currently closed. You may submit your request 
to the PDR via email at [email protected] or call 1-800-397-4209 or 
301-415-4737, between 8:00 a.m. and 4:00 p.m. (EST), Monday through 
Friday, except Federal holidays.
    The NRC posts its issued staff guidance on the NRC's public website 
at https://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr0800/.

FOR FURTHER INFORMATION CONTACT: Mark D. Notich, Office of New 
Reactors, U.S. Nuclear Regulatory Commission, Washington, DC 20555-
0001; telephone: 301-415-3053, email: [email protected].

SUPPLEMENTARY INFORMATION:

I. Background

    On January 14, 2020 (85 FR 2152), the NRC published for public 
comment a proposed revision of BTP 7-19, ``Guidance for Evaluation of 
Potential Common Cause Failure Due to Latent Software Defects in 
Digital Instrumentation and Control Systems'' of NUREG-0800, ``Standard 
Review Plan for the Review of Safety Analysis Reports for Nuclear Power 
Plants: LWR Edition.'' The public comment period closed on March 16, 
2020. Eight public comments were received regarding draft Revision 8 of 
BTP 7-19. The final Revision 8 to NUREG-0800, BTP 7-19, ``Guidance for 
Evaluation of Defense in Depth and Diversity to Address Common-Cause 
Failure due to Latent Design Defects in Digital Safety Systems'' is 
available in ADAMS under Accession No. ML20339A647. A summary of the 
public comments and the NRC staff's disposition of the comments are 
available in ADAMS Accession No. ML20126G430. The redline/strikeout 
comparison between the draft version of BTP 7-19 and this final 
version, including revisions made in response to public comments and to 
improve organization, is shown in ML20364A212.

II. Backfitting, Forward Fitting, and Issue Finality

    Chapter 7 of the SRP provides guidance to the staff for reviewing 
instrumentation and controls information provided in applications for 
licensing actions. Part of Chapter 7, BTP 7-19 provides guidance for 
the evaluation of diversity and defense-in-depth in digital computer-
based instrumentation and control systems.
    Issuance of this BTP revision does not constitute backfitting as 
defined in section 50.109 of title 10 of the Code of Federal 
Regulations (10 CFR), (the backfit rule), and as described in 
Management Directive (MD) 8.4, ``Management of Backfitting, Forward 
Fitting, Issue Finality, and Information Requests;'' constitute forward 
fitting as that term is defined and described in MD 8.4; or affect 
issue finality of any approval issued under 10 CFR part 52, ``Licenses, 
Certificates, and Approvals for Nuclear Power Plants.'' The NRC's 
position is based upon the following considerations.
    First, the SRP provides guidance to the NRC staff on how to review 
an application for NRC regulatory approval in the form of licensing. 
Changes in guidance intended for use by only the staff are not matters 
that constitute backfitting as that term is defined in 10 CFR 
50.109(a)(1); constitute forward fitting as that term is defined and 
described in MD 8.4; or affect issue finality of any approval issued 
under 10 CFR part 52, ``Licenses, Certificates, and Approvals for 
Nuclear Power Plants.''
    Second, the NRC staff does not intend to use the guidance in this 
BTP SRP section to support NRC staff actions in a manner that would 
constitute backfitting or forward fitting. If, in the future, the NRC 
seeks to impose a position in this SRP section in a manner that 
constitutes backfitting or forward fitting or affects the issue 
finality for a 10 CFR part 52 approval, then the NRC will address the 
backfitting provision in 10 CFR 50.109, the forward fitting provision 
of MD 8.4, or the applicable issue finality provision in 10 CFR part 
52, respectively.

III. Congressional Review Act

    This action is not a rule as defined in the Congressional Review 
Act (5 U.S.C. 801-808). OMB's clearance of BTP 7-19 as a non-major rule 
is shown in ADAMS Accession No. ML21025A022.

    Dated: January 26, 2021.

    For the Nuclear Regulatory Commission.
Dennis C. Morey,
Chief, Licensing Project Branch, Division of Operating Reactors, Office 
of Nuclear Reactor Regulation.
[FR Doc. 2021-01984 Filed 1-28-21; 8:45 am]
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