81 FR 54131 - Southern Nuclear Operating Company; Farley Nuclear Plant, Units 1 and 2, and Vogtle Electric Generating Plant, Units 1 and 2; Use of Optimized ZIRLOTM

NUCLEAR REGULATORY COMMISSION

Federal Register Volume 81, Issue 157 (August 15, 2016)

The U.S. Nuclear Regulatory Commission (NRC) is issuing an exemption in response to a March 16, 2016, request from Southern Nuclear Operating Company (SNC or the licensee) in order to use Optimized ZIRLO\TM\ fuel rod cladding material at the Farley Nuclear Plant (FNP), Units 1 and 2, and the Vogtle Electric Generating Plant (VEGP), Units 1 and 2.

[Federal Register Volume 81, Number 157 (Monday, August 15, 2016)]
[Notices]
[Pages 54131-54133]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2016-19363]


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NUCLEAR REGULATORY COMMISSION

[Docket Nos. 50-348, 50-364, 50-424, and 50-425; NRC-2016-0169]


Southern Nuclear Operating Company; Farley Nuclear Plant, Units 1 
and 2, and Vogtle Electric Generating Plant, Units 1 and 2; Use of 
Optimized ZIRLOTM Fuel Rod Cladding Material

AGENCY: Nuclear Regulatory Commission.

ACTION: Exemption; issuance.

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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is issuing an 
exemption in response to a March 16, 2016, request from Southern 
Nuclear Operating Company (SNC or the licensee) in order to use 
Optimized ZIRLO\TM\ fuel rod cladding material at the Farley Nuclear 
Plant (FNP), Units 1 and 2, and the Vogtle Electric Generating Plant 
(VEGP), Units 1 and 2.

DATES: The exemption was issued on August 4, 2016.

ADDRESSES: Please refer to Docket ID NRC-2016-0169 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 Web site: Go to http://www.regulations.gov and search for Docket ID NRC-2016-0169. Address 
questions about NRC dockets to Carol Gallagher; telephone: 301-415-
3463; 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 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]. The 
ADAMS accession number for each document referenced (if that document 
is available in ADAMS) is provided the first time that a document is 
referenced.
     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 Martin, Office of Nuclear 
Reactor Regulation, U.S. Nuclear Regulatory Commission, Washington DC 
20555-0001; telephone: 301-415-1493, email: [email protected].

SUPPLEMENTARY INFORMATION:

I. Background

    Southern Nuclear Operating Company is the holder of Renewed 
Facility Operating License Nos. NPF-2, NPF-8, NPF-68, and NPF-81, which 
authorize operation of FNP, Units 1 and 2, and VEGP, Units 1 and 2, 
respectively. The licenses provide, among other things, that each 
facility is subject to all rules, regulations, and orders of the NRC 
now or hereafter in effect.
    The FNP and VEGP units are pressurized-water reactors located in 
Houston County, Alabama, and Burke County, Georgia, respectively.

II. Request/Action

    Pursuant to Sec.  50.12 title 10 of the Code of Federal Regulations 
(10 CFR), ``Specific exemptions,'' the licensee has requested by letter 
dated March 16, 2016 (ADAMS Accession No. ML16076A217), an exemption 
from 10 CFR 50.46, ``Acceptance criteria for emergency core cooling 
systems [ECCS] for light-water nuclear power reactors,'' and 10 CFR 
part 50, appendix K, ``ECCS Evaluation Models,'' to allow the use of 
fuel rods clad with Optimized ZIRLO\TM\. The regulations in 10 CFR 
50.46(a) require that the calculated cooling performance following 
postulated loss-of-coolant accidents (LOCAs) at reactors fueled with 
zircaloy or ZIRLO[supreg] cladding conforms to the criteria set forth 
in 10 CFR 50.46(b). In addition, 10 CFR part 50, appendix K, requires, 
in part, that the Baker-Just equation be used to predict the rates of 
energy release, hydrogen generation, and cladding oxidation from the 
metal/water reaction. The Baker-Just equation assumes the use of 
zircaloy materials that have different chemical compositions from 
Optimized ZIRLO\TM\. As written, these regulations presume only the use 
of zircaloy or ZIRLO[supreg] fuel rod cladding and do not contain 
provisions for use of fuel rods with other cladding materials. 
Therefore, an exemption from the requirements of 10 CFR 50.46 and 10 
CFR part 50, appendix K, is needed to

[[Page 54132]]

support the use of a different fuel rod cladding material. Accordingly, 
the licensee requested an exemption to allow the use of Optimized 
ZIRLO\TM\ fuel rod cladding at FNP and VEGP.

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 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. However, 10 CFR 
50.12(a)(2) states that the Commission will not consider granting an 
exemption unless special circumstances are present as set forth in 10 
CFR 50.12(a)(2). Under 10 CFR 50.12(a)(2)(ii), special circumstances 
are present when application of the regulation in the particular 
circumstances would not serve, or is not necessary to achieve, the 
underlying purpose of the rule.

A. Special Circumstances

    Special circumstances, in accordance with 10 CFR 50.12(a)(2)(ii), 
are present whenever application of the regulation in the particular 
circumstances is not necessary to achieve the underlying purpose of the 
rule. The underlying purpose of 10 CFR 50.46 and 10 CFR part 50, 
appendix K, is to establish acceptance criteria for ECCS performance to 
provide reassurance of safety in the event of a LOCA. Although the 
wording of the regulations in 10 CFR 50.46 and 10 CFR part 50, appendix 
K, is not expressly applicable to Optimized ZIRLOTM, the 
evaluations described in the following sections of this exemption show 
that the purpose of the regulations is met by this exemption in that 
subject to certain conditions, the acceptance criteria are valid for 
Optimized ZIRLO\TM\ fuel cladding material, Optimized ZIRLO\TM\ would 
maintain better post-quench ductility, and the Baker-Just equation 
conservatively bounds LOCA scenario metal-water reaction rates and is 
applicable to Optimized ZIRLO\TM\. Because the underlying purposes of 
10 CFR 50.46 and 10 CFR part 50, appendix K, can be achieved through 
the application of these requirements to the use of Optimized 
ZIRLOTM fuel rod cladding material, the special 
circumstances required by 10 CFR 50.12(a)(2)(ii) for the granting of an 
exemption exist.

B. Authorized by Law

    This exemption would allow the use of fuel rods clad with Optimized 
ZIRLO\TM\ in future core reload applications for FNP and VEGP. The 
regulations in 10 CFR 50.12 allow the NRC to grant exemptions from the 
requirements of 10 CFR part 50 provided that the exemptions are 
authorized by law. The NRC staff determined that special circumstances 
exist to grant the proposed exemption and that granting the exemption 
would not result in a violation of the Atomic Energy Act of 1954, as 
amended. Therefore, the exemption is authorized by law.

C. No Undue Risk to Public Health and Safety

    The provisions of 10 CFR 50.46 establish acceptance criteria for 
ECCS performance. Westinghouse Electric Company, LLC (Westinghouse), 
Topical Report ``WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-A, 
``Optimized ZIRLO\TM\,'' '' dated July 2006, contain the justification 
to use Optimized ZIRLOTM fuel rod cladding material, in 
addition to Zircaloy-4 and ZIRLO[supreg]. The complete topical report 
is not publicly available because it contains proprietary information; 
however, a redacted version and the NRC safety evaluation are available 
in ADAMS under Accession No. ML062080569. The NRC staff found that the 
Westinghouse topical report demonstrates the applicability of the ECCS 
acceptance criteria to Optimized ZIRLO\TM\, subject to the compliance 
with the specific conditions of approval established therein. The NRC 
staff reviewed the March 16, 2016, application against these specific 
conditions and concluded that the licensee is in compliance with all of 
the applicable conditions. The NRC staff's review of these specific 
conditions for FNP and VEGP can be found in ADAMS under Accession No. 
ML16179A386.
    Ring compression tests performed by Westinghouse on Optimized 
ZIRLOTM were reviewed and approved by the NRC staff in 
Topical Report WCAP-14342-A & CENPD-404-NP-A, Addendum 1-A, and 
demonstrate an acceptable retention of post-quench ductility up to the 
10 CFR 50.46 limits of 2,200 degrees Fahrenheit and 17 percent 
equivalent clad reacted. Furthermore, the NRC staff has concluded that 
oxidation measurements provided by Westinghouse illustrate that oxide 
thickness (and associated hydrogen pickup) for Optimized ZIRLO\TM\ at 
any given burnup would be less than that for both zircaloy and 
ZIRLO[supreg] (ADAMS Package Accession No. ML073130555). Hence, the NRC 
staff concludes that Optimized ZIRLOTM would be expected to 
maintain acceptable post-quench ductility.
    The provisions of 10 CFR part 50, appendix K, paragraph I.A.5, 
``Metal-Water Reaction Rate,'' serve to ensure that cladding oxidation 
and hydrogen generation are limited appropriately during a LOCA and are 
conservatively accounted for in the ECCS evaluation model. That 
regulation 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. Since the use of the Baker-Just 
equation presumes the use of zircaloy-clad fuel, strict application of 
the rule would not permit use of the equation for Optimized 
ZIRLOTM cladding for determining acceptable fuel 
performance. As concluded in the NRC staff's safety evaluation for the 
associated topical report, Westinghouse demonstrated that the Baker-
Just model is conservative in all post-LOCA scenarios with respect to 
the use of the Optimized ZIRLOTM as a fuel cladding 
material.
    The NRC-approved topical report has demonstrated that predicted 
chemical, thermal, and mechanical characteristics of the Optimized 
ZIRLOTM alloy cladding are bounded by those approved for 
ZIRLO[supreg] 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 (TSs) 
and the core operating limits report.
    Based on the above, no new accident precursors are created by using 
Optimized ZIRLOTM; therefore, the probability of postulated 
accidents is not increased. Also, based on the above, the consequences 
of postulated accidents are not increased. Therefore, there is no undue 
risk to public health and safety due to using Optimized ZIRLO\TM\.

D. Consistent With Common Defense and Security

    The proposed exemption would allow the use of Optimized ZIRLO\TM\ 
fuel rod cladding material at FNP and VEGP. This change to the plant 
configuration is adequately controlled by TS requirements and is not 
related to security issues. Because the common defense and security is 
not impacted by this exemption, the exemption is consistent with the 
common defense and security.

E. Environmental Considerations

    The NRC staff determined that the exemption discussed herein meets 
the eligibility criteria for the categorical exclusion set forth in 10 
CFR 51.22(c)(9) because it is related to a requirement concerning the 
installation or use of a

[[Page 54133]]

facility component located within the restricted area, as defined in 10 
CFR part 20, and issuance of this exemption involves: (i) No 
significant hazards consideration, (ii) no significant change in the 
types or a significant increase in the amounts of any effluents that 
may be released offsite, and (iii) no significant increase in 
individual or cumulative occupational radiation exposure. Therefore, in 
accordance with 10 CFR 51.22(b), no environmental impact statement or 
environmental assessment need be prepared in connection with the NRC's 
consideration of this exemption request. The basis for the NRC staff's 
determination is discussed as follows, with an evaluation against each 
of the requirements in 10 CFR 51.22(c)(9)(i)-(iii).
Requirements in 10 CFR 51.22(c)(9)(i)
    The NRC staff evaluated whether the exemption involves no 
significant hazards consideration using the standards described in 10 
CFR 50.92(c), as presented below:

    1. Does the proposed exemption involve a significant increase in 
the probability or consequences of an accident previously evaluated?
    Response: No.
    The proposed change would allow the use of Optimized 
ZIRLOTM clad nuclear fuel in the reactors. The NRC 
approved Topical Report WCAP-12610-P-A & CENPD-404-P-A, Addendum 1-
A, ``Optimized ZIRLOTM,'' prepared by Westinghouse, 
addresses Optimized ZIRLOTM and demonstrates that 
Optimized ZIRLOTM has essentially the same properties as 
currently licensed ZIRLO[supreg]. The fuel cladding itself is not an 
accident initiator and does not affect accident probability. Use of 
Optimized ZIRLOTM fuel cladding has been shown to meet 
all 10 CFR 50.46 acceptance criteria and, therefore, will not 
increase the consequences of an accident.
    Therefore, the proposed change does not involve a significant 
increase in the probability or consequences of an accident 
previously evaluated.
    2. Does the proposed exemption create the possibility of a new 
or different kind of accident from any accident previously 
evaluated?
    Response: No.
    Use of Optimized ZIRLOTM clad fuel will not result in 
changes in the operation or configuration of the facility. Topical 
Report WCAP-12610-P-A & CENPD-404-P-A demonstrate that the material 
properties of Optimized ZIRLOTM are similar to those of 
ZIRLO[supreg]. Therefore, Optimized ZIRLOTM fuel rod 
cladding will perform similarly to those fabricated from 
ZIRLO[supreg], and, therefore, precludes the possibility of the fuel 
becoming an accident initiator and causing a new or different type 
of accident.
    Therefore, the proposed change does not create the possibility 
of a new or different kind of accident from any accident previously 
evaluated.
    3. Does the proposed exemption involve a significant reduction 
in a margin of safety?
    Response: No.
    The proposed change will not involve a significant reduction in 
the margin of safety because it has been demonstrated that the 
material properties of Optimized ZIRLOTM are not 
significantly different from those of ZIRLO[supreg]. Optimized 
ZIRLOTM is expected to perform similarly to ZIRLO[supreg] 
for all normal operating and accident scenarios, including both LOCA 
and non-LOCA scenarios. For LOCA scenarios, plant-specific 
evaluations have been performed, which allow the use of fuel 
assemblies with fuel rods containing Optimized ZIRLOTM. 
These LOCA evaluations address the NRC safety evaluation report 
conditions and limitations for Optimized ZIRLOTM fuel rod 
cladding and provide continued compliance with the acceptance 
criteria of 10 CFR 50.46.

    Therefore, the proposed change does not involve a significant 
reduction in a margin of safety.
    Based on the above, the NRC staff concludes that the proposed 
exemption involves no significant hazards consideration. Accordingly, 
the requirements of 10 CFR 51.22(c)(9)(i) are met.
Requirements in 10 CFR 51.22(c)(9)(ii)
    The proposed exemption would allow the use of Optimized ZIRLO\TM\ 
fuel rod cladding material in the reactors. Optimized ZIRLO\TM\ has 
essentially the same material properties and performance 
characteristics as the currently licensed ZIRLO[supreg] cladding. 
Therefore, the use of Optimized ZIRLO\TM\ fuel rod cladding material 
will not significantly change the types of effluents that may be 
released offsite or significantly increase the amount of effluents that 
may be released offsite. Therefore, the requirements of 10 CFR 
51.22(c)(9)(ii) are met.
Requirements in 10 CFR 51.22(c)(9)(iii)
    The proposed exemption would allow the use of Optimized ZIRLO\TM\ 
fuel rod cladding material in the reactors. Optimized ZIRLO\TM\ has 
essentially the same material properties and performance 
characteristics as the currently licensed ZIRLO[supreg] cladding. 
Therefore, the use of Optimized ZIRLO\TM\ fuel rod cladding material 
will not significantly increase individual occupational radiation 
exposure or significantly increase cumulative occupational radiation 
exposure. Therefore, the requirements of 10 CFR 51.22(c)(9)(iii) are 
met.
Conclusion
    Based on the above, the NRC staff concludes that the proposed 
exemption meets the eligibility criteria for the categorical exclusion 
set forth in 10 CFR 51.22(c)(9). Therefore, in accordance with 10 CFR 
51.22(b), no environmental impact statement or environmental assessment 
need be prepared in connection with the NRC's proposed issuance of this 
exemption.

IV. Conclusions

    Accordingly, the Commission has determined that, pursuant to 10 CFR 
50.12(a), the exemption is authorized by law, will not present an undue 
risk to the public health and safety, is consistent with the common 
defense and security, and that special circumstances are present to 
warrant issuance of the exemption. Therefore, the Commission hereby 
grants SNC an exemption from the requirements of 10 CFR 50.46 and 10 
CFR part 50, appendix K, paragraph I.A.5, to allow the application of 
these criteria to, and the use of, Optimized ZIRLO\TM\ fuel rod 
cladding material at FNP and VEGP.

    Dated at Rockville, Maryland, this 4th day of August 2016.

    For the Nuclear Regulatory Commission.
Anne T. Boland,
Director, Division of Operating Reactor Licensing, Office of Nuclear 
Reactor Regulation.
[FR Doc. 2016-19363 Filed 8-12-16; 8:45 am]
BILLING CODE 7590-01-P