[Federal Register Volume 84, Number 146 (Tuesday, July 30, 2019)]
[Notices]
[Pages 36959-36961]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-16147]


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NUCLEAR REGULATORY COMMISSION

[Docket Nos. 50-390 and 50-391; NRC-2019-0138]


Tennessee Valley Authority; Watts Bar Nuclear Plant, Units 1 and 
2

AGENCY: Nuclear Regulatory Commission.

ACTION: Exemption; issuance.

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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC or the Commission) 
has issued an exemption in response to a July 23, 2018, request from 
Tennessee Valley Authority (TVA or the licensee) to implement Optimized 
ZIRLO\TM\ fuel rod cladding at the Watts Bar Nuclear Plant (Watts Bar), 
Units 1 and 2.

DATES: The exemption was issued on July 25, 2019.

ADDRESSES: Please refer to Docket ID NRC-2019-0138 when contacting the 
NRC about the availability of

[[Page 36960]]

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-2019-0138. Address 
questions about NRC docket IDs 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 Documents collection at https://www.nrc.gov/reading-rm/adams.html. To begin the search, select ``ADAMS Public Documents'' and 
then select ``Begin Web-based ADAMS Search.'' For problems with ADAMS, 
please contact the NRC's Public Document Room (PDR) reference staff at 
1-800-397-4209, 301-415-4737, or by email to [email protected]. 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. In addition, for the convenience of the reader, the ADAMS 
accession numbers are provided in a table in the ``Availability of 
Documents'' section of this document.
     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: Robert Schaaf, Office of Nuclear 
Reactor Regulation, U.S. Nuclear Regulatory Commission, Washington, DC 
20555-0001; telephone: 301-415-6020, email: [email protected].

SUPPLEMENTARY INFORMATION:

I. Background

    TVA is the holder of Facility Operating License Nos. NPF-90 and 
NPF-96, which authorize operation of Watts Bar, Units 1 and 2, 
respectively. The licenses provide, among other things, that the 
facilities are subject to all rules, regulations, and orders of the NRC 
now or hereafter in effect. The facilities consist of pressurized-water 
reactors located in Spring City, Tennessee.

II. Request/Action

    By application dated July 23, 2018 (ADAMS Accession No. 
ML18205A492), TVA, pursuant to section 50.12 of title 10 of the Code of 
Federal Regulations (10 CFR), ``Specific exemptions,'' requested an 
exemption from certain requirements of 10 CFR 50.46, ``Acceptance 
criteria for emergency core cooling systems [ECCS] for light-water 
nuclear power reactors,'' and appendix K, ``ECCS Evaluation Models,'' 
to 10 CFR part 50 to allow the use of fuel rod cladding with Optimized 
ZIRLOTM alloy for future reload applications. The 
regulations in 10 CFR 50.46 contain acceptance criteria for the ECCS 
for reactors fueled with zircaloy or ZIRLOTM fuel rod 
cladding material. In addition, 10 CFR part 50, appendix K, requires 
that the Baker-Just equation be used to predict the rates of energy 
release, hydrogen concentration, and cladding oxidation from the metal/
water reaction. The Baker-Just equation assumes the use of a zirconium 
alloy, which is a material different from Optimized ZIRLOTM. 
The licensee requested the exemption because these regulations do not 
have provisions for the use of fuel rod cladding material other than 
zircaloy or ZIRLOTM. Because the material specifications of 
Optimized ZIRLOTM differ from the specifications for 
zircaloy or ZIRLOTM, a plant-specific exemption is required 
to support the reload applications for Watts Bar, Units 1 and 2.
    This exemption request relates solely to the specific type of 
cladding material specified in these regulations for use in light-water 
reactors. As written, the regulations presume use of either Zircaloy or 
ZIRLO\TM\ \1\ fuel rod cladding. The exemption is required because 
Optimized ZIRLO\TM\ has a slightly different composition than Zircaloy 
or ZIRLO\TM\. Therefore, TVA has requested an exemption to consider 
Optimized ZIRLO\TM\ as an approved fuel rod cladding material. TVA is 
not seeking an exemption from the acceptance and analytical criteria of 
10 CFR 50.46 and appendix K to 10 CFR part 50. The requirements 
regarding the acceptance and analytical criteria will be maintained.
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    \1\ ``Optimized ZIRLO'' and ``ZIRLO'' are trademarks or 
registered trademarks of Westinghouse Electric Company, LLC.
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    Along with the exemption request, the submittal from TVA described 
above also contains a license amendment request to modify Technical 
Specifications 4.2.1, ``Fuel Assemblies,'' and 5.9.5, ``Core Operating 
Limits Report (COLR),'' to allow the use of Optimized 
ZIRLOTM as an approved fuel rod cladding material. This 
exemption and the proposed Technical Specification changes are subject 
to a concurrent review that is being documented in the safety 
evaluation with the license amendments (ADAMS Accession No. 
ML19112A004).
    The NRC has previously approved exemption requests that were 
similar in nature to that requested by TVA. Precedent exemptions have 
been approved for other pressurized-water reactor plants, including 
Beaver Valley Power Station, Units 1 and 2 (ADAMS Accession Nos. 
ML18022B116 and ML17313A550); Palo Verde Nuclear Generating Station, 
Units 1, 2, and 3 (ADAMS Accession Nos. ML17319A107 and ML17319A214); 
and Wolf Creek Generating Station, Unit 1 (ADAMS Accession Nos. 
ML16179A293 and ML16179A440).

III. Discussion

    Pursuant to 10 CFR 50.12, the Commission may, upon application by 
any interested person or upon its own initiative, grant exemptions from 
the requirements of 10 CFR part 50 when: (1) The exemptions are 
authorized by law, will not present an undue risk to public health or 
safety, and are consistent with the common defense and security; and 
(2) when special circumstances are present. Under 10 CFR 50.12(a)(2), 
special circumstances include, among other things, when application of 
the specific regulation in the particular circumstance would not serve, 
or is not necessary to achieve, the underlying purpose of the rule. The 
requested exemption to apply the acceptance criteria to Optimized 
ZIRLO\TM\ fuel rod cladding rather than Zircaloy or ZIRLO\TM\ at Watts 
Bar, Units 1 and 2, satisfies the criteria as described below.

A. Special Circumstances

    The special circumstance that necessitates the request for 
exemption to 10 CFR 50.46 and appendix K to 10 CFR part 50 is that 
neither of these regulations explicitly allows the use of Optimized 
ZIRLO\TM\ fuel rod cladding material. The ultimate objective of 10 CFR 
50.46 is to ensure that nuclear power reactors fueled with uranium 
oxide pellets within Zircaloy or ZIRLO\TM\ cladding must be provided 
with ECCS that must be designed to provide core cooling following 
postulated loss-of-coolant accidents. It has been demonstrated in the 
NRC-approved Westinghouse Topical Report WCAP-14342-A & CENPD-404-NP-A, 
Addendum 1-A (ADAMS Accession No. ML062080569) that the effectiveness 
of the ECCS will not be affected by a change from Zircaloy or ZIRLO\TM\ 
clad fuel to Optimized ZIRLO\TM\ clad fuel. Normal reload safety 
analyses will confirm that there is no adverse impact on ECCS 
performance.

[[Page 36961]]

    The objective of 10 CFR 50.46(b)(2) and (b)(3) and paragraph I.A.5 
of appendix K to 10 CFR part 50 is to ensure that cladding oxidation 
and hydrogen generation are appropriately limited during a loss-of-
coolant accident and conservatively accounted for in the ECCS 
evaluation model. Appendix K of 10 CFR 50 requires that the Baker-Just 
equation be used in the ECCS evaluation model to determine the rate of 
energy release, cladding oxidation, and hydrogen generation. 
Westinghouse has shown in Addendum 1-A to WCAP-12610-P-A that the 
Baker-Just model is conservative in all post-loss-of-coolant accident 
scenarios with respect to the use of the Optimized ZIRLO\TM\ advanced 
alloy as a fuel cladding material.

B. The Exemption Is Authorized by Law

    The NRC has the authority under 10 CFR 50.12 to grant exemptions 
from the requirements of 10 CFR part 50 upon showing proper 
justification. The fuel that will be irradiated at Watts Bar, Units 1 
and 2, contains cladding material that does not conform to the cladding 
material that is explicitly defined in 10 CFR 50.46 and implicitly 
defined in appendix K to 10 CFR part 50. However, the criteria of these 
sections will continue to be satisfied for the operation of the Watts 
Bar, Units 1 and 2, core containing Optimized ZIRLO\TM\ fuel cladding.

C. The Exemption Presents No Undue Risk to Public Health and Safety

    The standards for exemption are also satisfied since the exemption 
will not present an undue risk to public health and safety. The NRC-
approved Westinghouse topical report discussed above has demonstrated 
that predicted chemical, thermal, and mechanical characteristics of the 
Optimized ZIRLO\TM\ alloy cladding are bounded by those approved for 
ZIRLO\TM\ under anticipated operational occurrences and postulated 
accidents. Reload cores are required to be operated in accordance with 
the operating limits specified in the Technical Specifications and 
COLR. Thus, the granting of this exemption request will not pose an 
undue risk to public health and safety.

D. The Exemption Is Consistent With the Common Defense and Security

    The exemption request is to allow the licensee to use an improved 
fuel rod cladding material. The licensee has documented compliance with 
the conditions and limitations of the NRC safety evaluation regarding 
the use of Optimized ZIRLO\TM\ fuel rod cladding at Beaver Valley Power 
Station, Units 1 and 2, and has committed to ensuring compliance for 
future reloads in the current application for Watts Bar, Units 1 and 2. 
Use of Optimized ZIRLO\TM\ fuel rod cladding in the Watts Bar, Units 1 
and 2, cores will not affect plant operations and is consistent with 
common defense and security.

E. Environmental Considerations

    A review has determined that the proposed amendments would change a 
requirement with respect to installation or use of a facility component 
located within the restricted area, as defined in 10 CFR part 20, or 
would change an inspection or surveillance requirement. However, the 
proposed amendments do not involve (i) a significant hazards 
consideration, (ii) a significant change in the types or significant 
increase in the amounts of any effluents that may be released offsite, 
or (iii) a significant increase in individual or cumulative 
occupational radiation exposure. Accordingly, the proposed amendments 
meet the eligibility criterion for categorical exclusion set forth in 
10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b), no 
environmental impact statement or environmental assessment need be 
prepared in connection with the proposed amendments.

IV. Conclusion

    Accordingly, the Commission has determined that, pursuant to 10 CFR 
50.12, the exemption is authorized by law, will not present an undue 
risk to the public health and safety, and is consistent with the common 
defense and security. Therefore, the Commission hereby grants TVA an 
exemption from the requirements of 10 CFR 50.46 and appendix K to 10 
CFR part 50 to allow the use of Optimized ZIRLOTM fuel rod 
cladding material at Watts Bar, Units 1 and 2. As stated in this 
notice, this exemption relates solely to the cladding material 
specified in these regulations.

    Dated at Rockville, Maryland, this 25th day of July 2019.

    For the Nuclear Regulatory Commission.
Blake D. Welling,
Deputy Director, Division of Operating Reactor Licensing, Office of 
Nuclear Reactor Regulation.
[FR Doc. 2019-16147 Filed 7-29-19; 8:45 am]
 BILLING CODE 7590-01-P