[Federal Register Volume 75, Number 245 (Wednesday, December 22, 2010)]
[Notices]
[Pages 80546-80547]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-32144]
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NUCLEAR REGULATORY COMMISSION
[ Docket Nos. 50-280 and 50-281; NRC-2010-0283]
Virginia Electric and Power Company; Surry Power Station Unit
Nos. 1 and 2; Exemption
1.0 Background
Virginia Electric and Power Company (the licensee) is the holder of
Facility Operating License Nos. DPR-32 and DPR-37 which authorizes
operation of the Surry Power Station (SURRY) Unit Nos. 1 and 2. The
license provides, among other things, that the facility is subject to
all rules, regulations, and Orders of the U.S. Nuclear Regulatory
Commission (NRC, the Commission) now or hereafter in effect.
The facility consists of a pressurized-water reactor located in
Surry County, Virginia.
2.0 Request/Action
Pursuant to Title 10 of the Code of Federal Regulations (10 CFR),
Section 50.12, ``Specific exemptions,'' the Virginia Electric and Power
Company (VEPCO), by letter dated February 10, 2010,\1\ 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 to 10 CFR Part 50, ``ECCS
Evaluation Models'' (Appendix K). The regulations in 10 CFR 50.46
contain acceptance criteria for the ECCS for reactors fueled with
zircaloy or ZIRLOTM cladding. In addition, Appendix K to 10
CFR Part 50 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
assumed the use of a zirconium alloy different than Optimized
ZIRLOTM. The exemption request relates solely to the
specific types of cladding material specified in these regulations. As
written, the regulations presume the use of zircaloy or
ZIRLOTM fuel rod cladding. Thus, an exemption from the
requirements of 10 CFR 50.46 and Appendix K is needed to support the
use of different fuel rod cladding material. Therefore, the licensee
requested an exemption that would allow the use of Optimized
ZIRLOTM fuel rod cladding at SURRY. The NRC staff will
prepare a separate safety evaluation, fully addressing VEPCO's
application for a related license amendment.
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\1\ VEPCO letter to NRC, Agencywide Documents Access and
Management System (ADAMS) Accession No. ML100470738.
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3.0 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.
[[Page 80547]]
Authorized by Law
This exemption would allow the use of Optimized ZIRLOTM
fuel rod cladding material at SURRY. As stated above, 10 CFR 50.12
allows the NRC to grant exemptions from the requirements of 10 CFR Part
50. The NRC staff has determined that granting of the licensee's
proposed exemption will not result in a violation of the Atomic Energy
Act of 1954, as amended, or the Commission's regulations. Therefore,
the exemption is authorized by law.
No Undue Risk to Public Health and Safety
The underlying purpose of 10 CFR 50.46 is to establish acceptance
criteria for adequate ECCS performance. By letter dated June 10, 2005,
the NRC staff issued a safety evaluation (SE) \2\ approving Addendum 1
to Westinghouse Topical Report WCAP-12610-P-A and CENPD-404-P-A,
``Optimized ZIRLOTM (these topical reports are non-publicly
available because they contain proprietary information),'' wherein the
NRC staff approved the use of Optimized ZIRLOTM as a fuel
cladding material. The NRC staff approved the use of Optimized
ZIRLOTM as a fuel cladding material based on: (1)
Similarities with standard ZIRLOTM, (2) demonstrated
material performance, and (3) a commitment to provide irradiated data
and validate fuel performance models ahead of burnups achieved in batch
application. The NRC staff's safety evaluation for Optimized
ZIRLOTM includes 10 conditions and limitations for its use.
As previously documented in the NRC staff's review of topical reports
submitted by Westinghouse Electric Company, LLC (Westinghouse), and
subject to compliance with the specific conditions of approval
established therein, the NRC staff finds that the applicability of
these ECCS acceptance criteria to Optimized ZIRLOTM has been
demonstrated by Westinghouse. Ring compression tests performed by
Westinghouse on Optimized ZIRLOTM (NRC-reviewed, approved,
and documented in Appendix B of WCAP-12610-P-A and CENPD-404-P-A,
Addendum 1-A, ``Optimized ZIRLOTM'') demonstrate an
acceptable retention of post-quench ductility up to 10 CFR 50.46 limits
of 2200 degrees Fahrenheit and 17 percent equivalent clad reacted.
Furthermore, the NRC staff has concluded that oxidation measurements
provided by the licensee illustrate that oxide thickness (and
associated hydrogen pickup) for Optimized ZIRLOTM at any
given burnup would be less than both zircaloy-4 and ZIRLOTM.
Hence, the NRC staff concludes that Optimized ZIRLOTM would
be expected to maintain better post-quench ductility than
ZIRLOTM. This finding is further supported by an ongoing
loss-of-coolant accident (LOCA) research program at Argonne National
Laboratory, which has identified a strong correlation between cladding
hydrogen content (due to in-service corrosion) and post-quench
ductility.
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\2\ ADAMS Accession No. ML051670408.
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The underlying purpose of 10 CFR Part 50, Appendix K, Section
I.A.5, ``Metal-Water Reaction Rate,'' is to ensure that cladding
oxidation and hydrogen generation are appropriately limited during a
LOCA and conservatively accounted for in the ECCS evaluation model.
Appendix K states that the rates of energy release, hydrogen
concentration, and cladding oxidation from the metal-water reaction
shall be calculated using the Baker-Just equation. Since 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. However, the NRC staff has found that metal-water reaction
tests performed by Westinghouse on Optimized ZIRLOTM
demonstrate conservative reaction rates relative to the Baker-Just
equation and are bounding for those approved for ZIRLOTM
under anticipated operational occurrences and postulated accidents.
Based on the above, no new accident precursors are created by using
Optimized ZIRLOTM; thus, 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
ZIRLOTM.
Consistent With Common Defense and Security
The proposed exemption would allow the use of Optimized
ZIRLOTM fuel rod cladding material at SURRY. This change to
the plant configuration has no relation to security issues. Therefore,
the common defense and security is not impacted by this exemption.
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 Appendix K to 10 CFR
Part 50 is to establish acceptance criteria for ECCS performance. The
wording of the regulations in 10 CFR 50.46 and Appendix K is not
directly applicable to Optimized ZIRLOTM, even though the
evaluations above show that the intent of the regulation is met.
Therefore, since the underlying purposes of 10 CFR 50.46 and Appendix K
are achieved through 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 from certain
requirements of 10 CFR 50.46 and Appendix K exist.
4.0 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. Also, special circumstances are present.
Therefore, the Commission hereby grants VEPCO an exemption from certain
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, for
SURRY, Unit Nos. 1 and 2.
Pursuant to 10 CFR 51.32, the Commission has determined that the
granting of this exemption will not have a significant effect on the
quality of the human environment as published in the Federal Register
on October 5, 2010 (75 FR 61528).
This exemption is effective upon issuance.
Dated at Rockville, Maryland, this 15th day of December 2010.
For the Nuclear Regulatory Commission.
Joseph G. Giitter,
Director, Division of Operating Reactor Licensing, Office of Nuclear
Reactor Regulation.
[FR Doc. 2010-32144 Filed 12-21-10; 8:45 am]
BILLING CODE 7590-01-P