[Federal Register Volume 71, Number 221 (Thursday, November 16, 2006)]
[Notices]
[Pages 66804-66805]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-19370]
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NUCLEAR REGULATORY COMMISSION
[Docket Nos. 50-317 and 50-318]
Calvert Cliffs Nuclear Power Plant, Inc.; Calvert Cliffs Nuclear
Power Plant, Unit Nos. 1 and 2; 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 in 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
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.
By letter dated January 19, 2006, 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 fuel rods clad with advanced zirconium-
based alloys from Westinghouse Electric Company and M5 alloy from
Framatome ANP, Inc. The advanced zirconium-based and M5 alloys are
proprietary alloys and are chemically different from zircaloy or ZIRLO
fuel cladding materials, which are approved for use.
The licensee has requested the exemption to support the re-
insertion of up to four lead fuel assemblies (LFAs) in the core of
either Calvert Cliffs 1 or Calvert Cliffs 2 during the next operating
cycle, which is cycle 19 for Unit 1 and cycle 17 for Unit 2. The NRC
staff has previously approved the irradiation of 8 LFAs for 2 operating
cycles (cycles 15 and 16) in Calvert Cliffs 2, as documented in NRC
letter dated April 11, 2003. The licensee has indicated that the LFAs
placed back in the core for a third cycle will not exceed the peak fuel
rod burnup limitation of 60,000 MWD/MTU and will meet all applicable
reload design criteria. The LFAs will be placed in low duty cycle
locations on the core periphery to assess the grid-to-rod fretting
performance. The other four LFAs will be discharged to the spent fuel
pool for detailed post-irradiation examinations. Because the core
design is not complete yet, the licensee indicated that, if the Calvert
Cliffs 2 cycle 17 core cannot accommodate the LFAs, then the planned
alternative is to design the Calvert Cliffs 1 cycle 19 core so that the
LFAs can be inserted.
In summary, 10 CFR 50.46 and 10 CFR Part 50, Appendix K make no
provisions for use of fuel rods clad in a material other than zircaloy
or ZIRLO. Since the material specifications of the advanced zirconium-
based and M5 alloys differ from the specification for Zircaloy or
ZIRLO, a plant-specific exemption is required to support the use of the
four LFAs in Unit 1 or 2.
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, which contain some fuel rods clad with advanced zirconium-based
and M5 alloys that do not meet the definition of Zircaloy or ZIRLO as
specified by 10 CFR 50.46, in either Calvert Cliffs 1 or 2. 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
[[Page 66805]]
the advanced zirconium-based and M5 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 current four LFAs will be located at
non-limiting core locations, the licensee concludes that the LOCA
safety analyses will remain bounding for these LTAs for Calvert Cliffs
Units 1 and 2.
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 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 Framatome ANP topical report show that due to the similarities
in the chemical composition of the advanced zirconium-based and M5
alloys and zircaloy, the application of the Baker-Just equation in the
analysis of the advanced zirconium-based and M5 clad fuel rods will
continue to conservatively bound all post-LOCA scenarios. Thus,
application of Appendix K, Paragraph I.A.5 is not necessary for the
licensee to achieve its underlying purpose in these circumstances.
Based on the above, no new accident precursors are created by the
exemption to allow use of advanced zirconium-based and M5 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 cladding, even though the Westinghouse safety
evaluation and the approved Framatome ANP topical reports show 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 cladding, 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 alloy cladding
(already irradiated for two cycles at Calvert Cliffs 1 during cycle 19
or Calvert Cliffs 2 during cycle 17).
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 (71 FR 64747).
This exemption is effective upon issuance.
Dated at Rockville, Maryland, this 9th day of November 2006.
For The Nuclear Regulatory Commission
Catherine Haney,
Director, Division of Operating Reactor Licensing, Office of Nuclear
Reactor Regulation.
[FR Doc. E6-19370 Filed 11-15-06; 8:45 am]
BILLING CODE 7590-01-P