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[Federal Register Volume 77, Number 43 (Monday, March 5, 2012)]
[Notices]
[Pages 13156-13158]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-5226]

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NUCLEAR REGULATORY COMMISSION

[NRC-2012-0034; Docket No. 50-400]

Carolina Power & Light Company; Shearon Harris Nuclear Power 
Plant, Unit 1; Exemption

1.0 Background

    Carolina Power & Light Company, the licensee, doing business as 
Progress Energy Carolinas Inc., is the holder of Renewed Facility 
Operating License No. NPF-63, which authorizes operation of the Shearon 
Harris Nuclear Power Plant (HNP), Unit 1. 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 one 
pressurized-water reactor (PWR) located in New Hill, North Carolina.

2.0 Request/Action

    Title 10 of the Code of Federal Regulations (10 CFR) 50.46, 
``Acceptance criteria for emergency core cooling systems for light-
water nuclear power reactors,'' requires, among other items, 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 to 10 CFR Part 
50, ``ECCS Evaluation Models,'' requires, among other items, 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 regulations of 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.
    The licensee intends to load the M5 \TM\ cladding fuel assemblies 
into the core of HNP, Unit 1 during Refueling Outage 17, currently 
scheduled for spring 2012. The AREVA fuel design consists of low 
enriched uranium oxide fuel within M5 \TM\ zirconium alloy cladding. 
Since the chemical composition of the M5 \TM\ alloy differs from the 
specifications for zircaloy or ZIRLO, a plant-specific exemption is 
required to allow the use of the M5 \TM\ alloy as a cladding material 
or in other assembly structural components. Therefore, by letter dated 
January 19, 2011 (Agencywide Documents Access and Management System 
Accession No. ML110250473), the licensee requested an exemption from 
the requirements of 10 CFR 50.46 and Appendix K to 10 CFR part 50 in 
order to use the fuel rods clad with AREVA's M5 \TM\ alloy.

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

[[Page 13157]]

(2) when special circumstances are present.

Authorized by Law

    This exemption would allow the use of M5 \TM\ advanced alloy, in 
lieu of zircaloy or ZIRLO, for fuel rod cladding in fuel assemblies at 
HNP, Unit 1. As stated above, 10 CFR 50.12 allows the NRC to grant 
exemptions from the requirements of 10 CFR 50.46 and Appendix K to 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 and 10 CFR part 50, 
Appendix K, are to ensure that facilities have adequate acceptance 
criteria for the ECCS, and to ensure that cladding oxidation and 
hydrogen generation are appropriately limited during a LOCA and 
conservatively accounted for in the ECCS evaluation model, 
respectively. Topical Reports (TRs) BAW-10227(P)-A, ``Evaluation of 
Advanced Cladding and Structural Material (M5) in PWR Reactor Fuel,'' 
which was approved by the NRC in February 2000, and BAW-10240(P)-A, 
``Incorporation of M5 Properties in Framatome ANP Approved Methods,'' 
which was approved by the NRC in May 2004, demonstrated that the 
effectiveness of the ECCS will not be affected by a change from 
zircaloy to M5 \TM\. In addition, the TRs also demonstrated that the 
Baker-Just equation (used in the ECCS evaluation model to determine the 
rate of energy release, cladding oxidation, and hydrogen generation) is 
conservative in all post-LOCA scenarios with respect to the use of M5 
\TM\ advanced alloy as a fuel rod cladding material or in other 
assembly structural components. Based on the above, no new accident 
precursors are created by using M5 \TM\ advanced alloy, thus, the 
probability of postulated accidents is not increased. Also, based on 
the above, the consequences of postulated accidents are not increased. 
In addition, the licensee will use NRC-approved methods for the reload 
design process for HNP Unit 1 reloads with M5 \TM\. Therefore, there is 
no undue risk to public health and safety due to using M5 \TM\.

Consistent With Common Defense and Security

    The proposed exemption results in changes to the operation of the 
plant by allowing the use of the M5 \TM\ alloy as fuel cladding 
material or in other assembly structural components in lieu of zircaloy 
or ZIRLO. This change to the fuel material used in the plant has no 
relation to security issues. Therefore, the common defense and security 
are not impacted by this exemption request.

Special Circumstances

    Special circumstances, in accordance with 10 CFR 50.12, are present 
whenever application of the regulation in the particular circumstances 
would not serve the underlying purpose of the rule, or is not necessary 
to achieve the underlying purpose of the rule. In this circumstance 
neither 10 CFR 50.46 nor 10 CFR part 50, Appendix K, explicitly allows 
the use of M5 \TM\ as a fuel rod cladding material or in use of other 
assembly structural components.
    The underlying purpose of 10 CFR 50.46 is to ensure that facilities 
have adequate acceptance criteria for the ECCS. The staff's review and 
approval of TR BAW-10227(P)-A addressed all of the important aspects of 
M5 \TM\ with respect to ECCS Performance Requirements: (1) 
Applicability of 10 CFR 50.46(b) fuel acceptance criteria, (2) M5 \TM\ 
material properties including fuel rod ballooning and rupture strains, 
and (3) steam oxidation kinetics and applicability of Baker-Just weight 
gain correlation. A subsequent NRC-approved TR, BAW-10240(P)-A, further 
addressed M5 \TM\ material properties with respect to LOCA 
applications.
    The underlying purpose of 10 CFR Part 50, Appendix K, paragraph 
I.A.5, 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 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. In TR BAW-
10227(P)-A, Framatome demonstrated that the Baker-Just model is 
conservative in all post-LOCA scenarios with respect to the use of the 
M5 \TM\ advanced alloy as a fuel rod cladding material or in other 
assembly structural components, and that the amount of hydrogen 
generated in an M5 \TM\ core during a LOCA will remain within the HNP 
Unit 1 design basis.
    The M5 \TM\ alloy is a proprietary zirconium-based alloy comprised 
of primarily zirconium (~99 percent) and niobium (~1 percent). The 
elimination of tin has resulted in superior corrosion resistance and 
reduced irradiation-induced growth relative to both standard zircaloy 
(1.7 percent tin) and low-tin zircaloy (1.2 percent tin). The addition 
of niobium increases ductility, which is desirable to avoid brittle 
failures.
    The NRC staff has reviewed the licensee's advanced cladding 
material, M5 \TM\, for PWR fuel mechanical designs as described in TR 
BAW-10227(P)-A. In the safety evaluation for TR BAW-10227(P)-A, the 
staff concluded that, to the extent specified in the staff's 
evaluation, the M5 \TM\ properties and mechanical design methodology 
are acceptable for referencing in fuel reload licensing applications. 
Application of the requirements of 10 CFR 50.46 and 10 CFR part 0 
Appendix K, paragraph I.A. 5 is not necessary to achieve their 
underlying purpose. The underlying purposes of 10 CFR 50.46 and 10 CFR 
part 50, Appendix K, paragraph I.A.5 are achieved through the use of 
the M5 \TM\ advanced alloy as a fuel rod cladding material or in other 
assembly structural components. Thus, the special circumstances 
required by 10 CFR 50.12(a)(2)(ii) for the granting of an exemption 
from 10 CFR 50.46 and 10 CFR part 50, Appendix K, exist.

Summary

    The NRC staff has reviewed the licensee's request to use the M5 
\TM\ advanced alloy for fuel rod cladding and in other assembly 
structural components in lieu of zircaloy or ZIRLO. Based on the NRC 
staff's evaluation, as set forth above, the NRC staff concludes that 
the exemption is authorized by law, will not present an undue risk to 
public health and safety, and is consistent with the common defense and 
security. In addition, the NRC staff concludes that the application of 
10 CFR 50.46 and 10 CFR Part 50, Appendix K, is not necessary to 
achieve the underlying purpose of the regulations. Therefore, pursuant 
to 10 CFR 50.12(a), the NRC staff concludes that the use of the M5 \TM\ 
advanced alloy for fuel rod cladding and in other assembly structural 
components is acceptable and the exemption from 10 CFR 50.46 and 10 CFR 
Part 50, Appendix K, is justified.

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

[[Page 13158]]

CFR part 50, Appendix K, for HNP Unit 1.
    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 (February 15, 2012; 77 FR 8903). This 
exemption is effective upon issuance.

    Dated at Rockville, Maryland, this 24th day of February 2012.

    For the Nuclear Regulatory Commission.
Michele G. Evans,
Director, Division of Operating Reactor Licensing, Office of Nuclear 
Reactor Regulation.
[FR Doc. 2012-5226 Filed 3-2-12; 8:45 am]
BILLING CODE 7590-01-P
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