[Federal Register Volume 72, Number 246 (Wednesday, December 26, 2007)]
[Notices]
[Pages 73045-73047]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-24975]


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NUCLEAR REGULATORY COMMISSION

[Docket No. 50-317]


Calvert Cliffs Nuclear Power Plant, Inc.; Calvert Cliffs Nuclear 
Power Plant, Unit No. 1; Exemption

1.0 Background

    Calvert Cliffs Nuclear Power Plant, Inc. (the licensee), is the 
holder of Renewed Facility Operating License Nos. DPR-53 and DPR-69, 
which authorize operation of the Calvert Cliffs Nuclear Power Plant, 
Unit Nos. 1 and 2 (Calvert Cliffs 1 and 2), respectively. The license 
provides, among other things, that the facility is subject to all 
rules, regulations, and orders of the Nuclear Regulatory Commission 
(NRC, the Commission) now or hereafter in effect.
    The facility consists of two pressurized-water reactors located in 
Calvert County, Maryland.

2.0 Request/Action

    Title 10 of the Code of Federal Regulations (10 CFR), Part 50, 
Section 50.46, ``Acceptance criteria for emergency core cooling systems 
for light-water nuclear power reactors,'' requires, in part, that 
``Each boiling or pressurized light-water nuclear power reactor fueled 
with uranium oxide pellets within cylindrical zircaloy or ZIRLO \TM\ 
cladding must be provided with an emergency core cooling system (ECCS) 
that must be designed so that its calculated cooling performance 
following postulated loss-of-coolant accidents [LOCAs] conforms to the 
criteria set forth in paragraph (b) of this section.'' Appendix K, 
``ECCS Evaluation Models,'' to 10 CFR Part 50 requires, in part, that 
the rate of energy release, hydrogen generation, and cladding oxidation 
from the metal/water reaction shall be calculated using the Baker-Just 
equation. The Baker-Just equation assumes that the cladding material is 
composed of either zircaloy or ZIRLO \TM\.
    By letter dated February 23, 2007, the licensee requested an 
exemption from the requirements of 10 CFR 50.46 and Appendix K to 10 
CFR Part 50 to allow the use of lead fuel assemblies (LFAs) clad with 
advanced zirconium-based alloys manufactured by Westinghouse Electric 
Company and M5 \TM\ alloy manufactured by AREVA. The advanced 
zirconium-based and M5 \TM\ alloys are proprietary alloys and are 
chemically different from either zircaloy or ZIRLO \TM\ fuel cladding 
materials, which are approved for use. Therefore, a plant-specific 
exemption from these regulations is required to support the use of LFAs 
that are not manufactured with zircaloy or ZIRLO \TM\.
    Previously, by letter dated April 11, 2003, the NRC staff approved 
the irradiation of 8 LFAs, four Westinghouse LFAs and four AREVA LFAs, 
for 2 operating cycles in the core of Calvert Cliffs 2. These LFAs were 
inserted into the Unit 2 core in April of 2003 and remained there 
during Operating Cycles 15 and 16. Subsequently, by letter dated 
November 9, 2006, the NRC staff approved the irradiation of 4 LFAs, two 
Westinghouse LFAs and two AREVA LFAs, for a third operating cycle in 
either Calvert Cliffs 1 or Calvert Cliffs 2. The licensee subsequently 
inserted these 4 LFAs into the core of Calvert Cliffs 2 during their 
spring 2007 refueling outage for operating cycle 17 which is currently 
ongoing. The remaining 4 LFAs, two Westinghouse LFAs and two AREVA 
LFAs, were discharged to the spent fuel pool for detailed post-
irradiation examinations during the spring 2007 Unit 2 refueling 
outage.
    In the licensee's letter of February 23, 2007, the licensee 
requested the exemption to support the re-insertion of the remaining 4 
LFAs, two

[[Page 73046]]

Westinghouse LFAs and two AREVA LFAs, for a third operating cycle. 
These LFAs would be placed in high-duty core locations in Calvert 
Cliffs 1 for operating cycle 19 in order to gain high burnup 
experience. The licensee requested to irradiate the LFAs beyond the 
current burnup limit to a peak rod average of 70,000 MWD/MTU for 
Calvert Cliffs Unit 1.

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 Section 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.

Authorized by Law

    This exemption would allow the licensee to re-insert up to four 
LFAs, two Westinghouse LFAs and two AREVA LFAs, which contain some fuel 
rods clad with advanced zirconium-based and M5 \TM\ alloys that do not 
meet the definition of Zircaloy or ZIRLO \TM\ as specified by 10 CFR 
50.46, into the core of Calvert Cliffs 1. 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 purposes of 10 CFR 50.46 is to establish acceptance 
criteria for ECCS performance. Previously, the Westinghouse safety 
evaluation (WCAP-15874-NP, Revision 0, ``Safety Analysis Report for Use 
of Improved Zirconium-based Cladding Materials in Calvert Cliffs Unit 2 
Batch T Lead Fuel Assemblies,'' dated April 2002) and approved 
Framatome ANP Topical Report (BAW-10227P-A, ``Evaluation of Advanced 
Cladding and Structural Material (M5) in PWR Reactor Fuel,'' Framatome 
Cogema Fuels, February 2000) demonstrated the acceptability of the 
advanced zirconium-based and M5 \TM\ cladding under LOCA conditions. 
The unique features of the LFAs were evaluated for effects on the LOCA 
analysis. The results showed that the LFAs would not adversely affect 
the ECCS performance. Since the four LFAs will be located at high-duty 
other than LOCA-limiting core locations, the licensee concludes that 
the LOCA safety analyses will remain bounding for these LFAs for 
Calvert Cliffs 1.
    Paragraph I.A.5 of Appendix K to 10 CFR Part 50 states that the 
rates of energy, 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 the advanced zirconium-based and M5 \TM\ alloys for 
determining acceptable fuel performance. The underlying intent of this 
portion of the Appendix is to ensure that analysis of fuel response to 
LOCAs is conservatively calculated. The Westinghouse safety evaluation 
and approved AREVA topical report show that, due to the similarities in 
the chemical composition of the advanced zirconium-based and M5 \TM\ 
alloys and zircaloy, the application of the Baker-Just equation in the 
analysis of the advanced zirconium-based and M5 \TM\ clad fuel rods 
will continue to conservatively bound all post-LOCA scenarios. Thus, 
the application of Appendix K, Paragraph I.A.5 is not necessary to 
achieve its underlying purpose in these circumstances.
    Based on the acceptable performance of 8 LFAs in the Calvert Cliffs 
2 reactor core during operating cycles 15 and 16, the staff concludes 
that the licensee has demonstrated that the four LFAs will perform 
adequately under LOCA conditions, and thus the LFAs are acceptable for 
operation for Calvert Cliffs 1 operating cycle 19. Based on the above, 
the staff concludes that it is acceptable to grant an exemption from 
the requirements of 10 CFR 50.46, and Appendix K to 10 CFR Part 50 for 
Calvert Cliffs 1.
    Based on the above, no new accident precursors are created by the 
exemption to allow use of advanced zirconium-based and M5 \TM\ alloy 
clad fuel, 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 [since 
risk is probability x consequences] to public health and safety.

Consistent With Common Defense and Security

    The proposed exemption would allow the use of LFAs with advanced 
cladding materials. This change to the plant core 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 
licensee stated that the wording of the regulations renders the 
criteria of 10 CFR 50.46 and Appendix K inapplicable to the advanced 
zirconium-based and M5 \TM\ alloy clad fuel, even though the approved 
Westinghouse safety evaluation and AREVA topical report shows that the 
intent of the regulations are met. Therefore, since the underlying 
purpose of 10 CFR 50.46 and Appendix K to 10 CFR Part 50 is achieved 
with the use of the advanced zirconium-based and M5 \TM\ alloy clad 
fuel, the special circumstances required by 10 CFR 50.12(a)(2)(ii) for 
granting of an exemption from 10 CFR 50.46 and Appendix K exist.

4.0 Conclusion

    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, and is consistent with the common 
defense and security. Also, special circumstances are present. 
Therefore, the Commission hereby grants the licensee an exemption from 
the requirements of 10 CFR 50.46 and 10 CFR Part 50, Appendix K with 
respect to the use of LFAs with advanced zirconium-based and M5 \TM\ 
alloy clad fuel.
    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 (72 FR 71449).
    This exemption is effective upon issuance.

    Dated at Rockville, Maryland, this 17th day of December 2007.


[[Page 73047]]


    For the Nuclear Regulatory Commission.
Catherine Haney,
Director, Division of Operating Reactor Licensing, Office of Nuclear 
Reactor Regulation.
 [FR Doc. E7-24975 Filed 12-21-07; 8:45 am]
BILLING CODE 7590-01-P