[Federal Register Volume 81, Number 157 (Monday, August 15, 2016)]
[Notices]
[Pages 54131-54133]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-19363]
-----------------------------------------------------------------------
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.
-----------------------------------------------------------------------
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