[Federal Register Volume 66, Number 50 (Wednesday, March 14, 2001)]
[Notices]
[Pages 14939-14940]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-6304]
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NUCLEAR REGULATORY COMMISSION
[Docket No. 50-318]
Calvert Cliffs Nuclear Power Plant, Inc., Calvert Cliffs Nuclear
Power Plant, Unit No. 2; Exemption
1.0 Background
Calvert Cliffs Nuclear Power Plant, Inc. (CCNPPI or the licensee)
is the holder of Facility Operating License No. DPR-69, which
authorizes operation of Calvert Cliffs Nuclear Power Plant, Unit 2
(CCNPP2). 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
Calvert County in Maryland.
2.0 Purpose
Title 10 of the Code of Federal Regulations (10 CFR), Part 50,
Section 50.46 and Appendix K identify requirements for calculating
emergency core cooling system (ECCS) performance for reactors
containing fuel with zircaloy or ZIRLO cladding, and 10 CFR 50.44
relates, in part, to the generation of hydrogen gas from a metal-water
reaction between the reactor coolant and reactor fuel having zircaloy
or ZIRLO cladding.
The licensee has requested a temporary exemption to 10 CFR 50.44,
10 CFR 50.46, and Appendix K that would enable CCNPP2 to operate in
Cycle 14 with a core containing a lead fuel (test) assembly (LFA)
including fuel rods with advanced zirconium alloy cladding.
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 Sec. 50.12(a)(2),
special circumstances include, among other things, when application of
the regulation in the particular circumstance would not serve, or 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 requirements for the calculation of ECCS
performance and
[[Page 14940]]
acceptance criteria for that performance in order to assure that the
ECCS functions to transfer heat from the reactor core following a loss-
of-coolant-accident (LOCA) such that (1) fuel and clad damage that
could interfere with continued effective core cooling is prevented, and
(2) clad metal-water reaction is limited to negligible amounts. The
licensee has performed a calculation demonstrating adequate ECCS
performance for CCNPP2 and has shown that use of the lead fuel assembly
does not have a significant impact on that previous calculation. The
lead fuel assembly, with the zirconium-based alloy cladding, meets the
same design basis as the Zircaloy-4 fuel which is currently in the
CCNPP2 reactor core and has similar thermal-hydraulic characteristics.
Because the LFA will be placed in a non-limiting location (Technical
Specification 4.2.1 limits placement of the LFA to a non-limiting
location in the core), the placement scheme and the similarity of the
advanced alloys to Zircaloy-4 will assure that the behavior of the fuel
rods clad with these alloys are bounded by the fuel performance and
safety analyses performed for the Zircaloy-4 clad rods currently in the
Unit 2 core. No safety limits will be changed or setpoints altered as a
result of using the lead fuel assembly.
In similar reviews of applications to use advanced fuel, the staff
found that fuels with advanced cladding do not introduce a mixed core
penalty in licensing safety analyses, provided that the resident fuel
and the LFA were of like geometry. The LFA and fuel currently in use at
CCNPP2 are of like geometry. Therefore, the staff concludes that use of
the LFA will not introduce a mixed core penalty into the safety
analyses for CCNPP2.
Based on the above, the staff finds that the licensee has achieved
the underlying purpose of 10 CFR 50.46 and 10 CFR part 50, appendix K
with respect to use of the LFA at CCNPP2.
The underlying purpose of 10 CFR 50.44 is to ensure that means are
provided for the control of hydrogen gas that may be generated
following a postulated LOCA. The small number of fuel rods in the lead
fuel assembly containing advanced zirconium-based claddings in
conjunction with the chemical similarity of the advanced claddings to
zircaloy and ZIRLO ensures that previous calculations of hydrogen
production resulting from a metal-water reaction would not be
significantly changed. The licensee calculated the metal-water reaction
rate for the advanced zirconium-based cladding material and determined
that the amount of hydrogen generated will be within the design basis.
As such, the licensee has achieved the underlying purpose of 10 CFR
50.44.
The staff examined the licensee's rationale to support the
exemption request and concurred that the use of an LFA in the Unit 2
core for Cycle 14 would meet the underlying purpose of 10 CFR 50.44, 10
CFR 50.46, and 10 CFR part 50, appendix K. Application of these
regulations in these circumstances would not serve the underlying
purpose of the rule.
Therefore, the staff concludes that granting an exemption under the
special circumstances of 10 CFR 50.12(a)(2)(ii) is appropriate and that
an LFA containing fuel rods with advanced zirconium alloy cladding may
be used in CCNPP Unit 2, Cycle 14.
4.0 Conclusion
Accordingly, the Commission has determined that, pursuant to 10 CFR
50.12(a), the exemption is authorized by law, will not endanger life or
property or common defense and security, and is, otherwise, in the
public interest. Also, special circumstances are present. Therefore,
the Commission hereby grants CCNPPI an exemption from the requirements
of 10 CFR part 50, Secs. 50.44, 50.46, and 10 CFR part 50, appendix K,
for CCNPP2.
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 (66 FR 11608).
This exemption is effective upon issuance.
Dated at Rockville, Maryland, this 6th day of March 2001.
For the Nuclear Regulatory Commission.
John A. Zwolinski,
Director, Division of Licensing Project Management, Office of Nuclear
Reactor Regulation.
[FR Doc. 01-6304 Filed 3-13-01; 8:45 am]
BILLING CODE 7590-01-P