[Federal Register Volume 85, Number 6 (Thursday, January 9, 2020)]
[Pages 1184-1185]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-00124]




Supplemental Guidance Regarding the Chromium-Coated Zirconium 
Alloy Fuel Cladding Accident Tolerant Fuel Concept

AGENCY: Nuclear Regulatory Commission.

ACTION: Interim staff guidance; issuance.


SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is issuing 
Interim Staff Guidance (ISG) ATF-ISG-2020-01, ``Supplemental Guidance 
Regarding the Chromium-Coated Zirconium Alloy Fuel Cladding Accident 
Tolerant Fuel Concept.'' This ISG is intended to facilitate the NRC 
staff's understanding of the in-reactor phenomena important

[[Page 1185]]

to safety for the chromium-coated zirconium alloy fuel cladding 
concepts, as well as to provide guidance for NRC staff reviewing vendor 
applications. Chromium-coated zirconium alloy fuel cladding concepts 
are being pursued by several U.S. fuel vendors as part of the U.S. 
Department of Energy's accident tolerant fuel program.

DATES: This guidance is effective on February 10, 2020.

ADDRESSES: Please refer to Docket ID NRC-2019-0208 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-2019-0208. Address 
questions about NRC docket IDs in Regulations.gov to Jennifer Borges; 
telephone: 301-287-9127; email: [email protected]. For technical 
questions, contact the individual(s) 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 Documents collection at https://www.nrc.gov/reading-rm/adams.html. To begin the search, select ``Begin Web-based ADAMS 
Search.'' For problems with ADAMS, please contact the NRC's Public 
Document Room (PDR) reference staff at 1-800-397-4209, 301-415-4737, or 
by email to [email protected]. The ISG, ``Supplemental Guidance 
Regarding the Chromium-Coated Zirconium Alloy Fuel Cladding Accident 
Tolerant Fuel Concept,'' is available in ADAMS under Accession No. 
     NRC's PDR: You may examine and purchase copies of public 
documents at the NRC's PDR, Room O1-F21, One White Flint North, 11555 
Rockville Pike, Rockville, Maryland 20852.

FOR FURTHER INFORMATION CONTACT: Tekia Govan, Office of Nuclear Reactor 
Regulation, telephone: 301-415-6197 email: [email protected] and 
Michael Orenak, Office of Nuclear Reactor, telephone: 301-415-3229, 
email: [email protected]. Both are staff of the U.S. Nuclear 
Regulatory Commission, Washington, DC 20555-0001.


I. Background

    On October 24, 2019, (84 FR 57058) the NRC requested public 
comments on draft ATF ISG-2019-01 (ADAMS Accession No. ML19276G621). 
The NRC received comments from the Nuclear Energy Institute by letter 
dated November 25, 2019 (ADAMS Accession No. ML19344C125). No other 
comments were submitted. The NRC staff considered those comments in 
developing the final ATF-ISG 2019-01. Detailed responses to the 
comments can be found in Appendix E of the final ATF-ISG 2019-01.
    This ISG is intended to provide guidance for NRC staff reviewing 
applications involving fuel products with chromium-coated zirconium 
alloy cladding. For coated claddings of this type, a phenomena 
identification and ranking table (PIRT) was generated for the NRC by 
Pacific Northwest National Laboratory; the guidance provided in this 
ISG extensively references the PIRT report, ``Degradation and Failure 
Phenomena of Accident Tolerant Fuel Concepts: Chromium Coated Zirconium 
Alloy Cladding,'' issued June 2019. The suggested cladding properties 
specified acceptable fuel design limits and new failure mechanisms 
sections from the PIRT are replicated in Appendices B and C. These 
appendices supersede Sections 5.1 and 5.2 of the PIRT report.
    This ISG is not intended as stand-alone review guidance, but 
instead supplements NUREG-0800, ``Standard Review Plan,'' Section 4.2, 
``Fuel System Design,'' and discusses the potential impact of coated 
claddings on reviews performed under Standard Review Plan (SRP), 
Section 4.3, ``Nuclear Design,'' Section 4.4, ``Thermal and Hydraulic 
Design,'' and Chapter 15, ``Transient and Accident Analysis.'' In 
addition to the guidance provided in this ISG, reviewers of coated 
cladding applications should familiarize themselves with the PIRT 
report and with the relevant sections of the SRP.
    The PIRT report and this ISG focus primarily on metallic chromium 
coatings applied to a zirconium alloy base metal, with some additional 
discussion that is applicable to chromium-based ceramic coatings. 
Reviewers of submittals on ceramic chromium-coated zirconium alloy 
claddings should carefully read the PIRT to determine the applicability 
to the review.
    This ISG does not apply to reviews of fuel products other than 
metallic or ceramic chromium-based coatings on a zirconium alloy 

II. Backfit Discussion

    This ISG intends to provide guidance for the NRC staff reviewing 
applications involving fuel products with chromium-coated zirconium 
alloy cladding. Issuance of this ISG does not constitute a backfit as 
defined in section 50.109(a)(1) of title 10 of the Code of Federal 
Regulations (10 CFR) and is not otherwise inconsistent with the issue 
finality provisions in 10 CFR part 52. As discussed in the 
``Backfitting'' section of the final ATF-ISG-2020-01, the ISG positions 
do not constitute backfitting, inasmuch as the ISG is guidance directed 
to the NRC staff with respect to its regulatory responsibilities. 
Applicants and potential applicants are not, with certain exceptions, 
the subject of either the Backfit Rule or any issue finality provisions 
under 10 CFR part 52. The NRC staff has no intention to impose the ISG 
positions on existing nuclear power plant licensees either now or in 
the future (absent a voluntary request for a change from the licensee).

III. Congressional Review Act

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

    Dated at Rockville, Maryland, this 3rd day of January 2020.

    For the Nuclear Regulatory Commission.
Tekia V. Govan,
Project Manager, Oversight and Support Branch, Division of Reactor 
Oversight, Office of Nuclear Reactor Regulation.
[FR Doc. 2020-00124 Filed 1-8-20; 8:45 am]