E9-24053. Southern California Edison Company; San Onofre Nuclear Generating Station, Unit 2 and Unit 3; Environmental Assessment and Finding of No Significant Impact

The U.S. Nuclear Regulatory Commission (NRC) is considering issuance of a temporary exemption from Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Section 50.46 and 10 CFR 50, Appendix K, for Facility Operating License Nos. NPF-10 and NPF-15, issued to Southern California Edison Company (SCE, the licensee), for operation of the San Onofre Nuclear Generating Station (SONGS), Unit 2 and Unit 3, respectively, located in San Diego County, California. Therefore, as required by 10 CFR 51.21, the NRC is issuing this environmental assessment and finding of no significant impact.

Environmental Assessment

Identification of the Proposed Action

The requirements in 10 CFR 50.46 specifically, and 10 CFR 50, Appendix K implicitly, refer to the use of Zircaloy or ZIRLO cladding. Therefore, a temporary exemption is required to use fuel rods clad with an advanced zirconium-based alloy that is not either Zircaloy or ZIRLO. Unlike the current fuel assemblies, the lead fuel assemblies (LFAs) manufactured by AREVA NP will contain M5 alloy cladding material. The licensee has requested a temporary exemption to allow the use of M5 alloy cladding.

The temporary exemption would allow up to 16 LFAs manufactured by AREVA NP with M5 alloy cladding material to be inserted into the SONGS Unit 2 or Unit 3 reactor cores during the upcoming (Cycle 16) refueling outages for each unit. The temporary exemption would allow the LFAs to be used for up to three operating cycles (Cycles 16, 17, and 18). Currently, eight AREVA NP LFAs are scheduled for installation in SONGS Unit 2 for Cycle 16.

The proposed action is in accordance with the licensee's request for exemption dated January 30, 2009, as supplemented by letter dated March 16, 2009.

The Need for the Proposed Action

The proposed temporary exemption is needed by SCE to allow the use of M5 alloy clad LFAs to evaluate cladding material for use in future fuel assemblies and to provide a more robust design to eliminate grid to rod fretting fuel failures. The regulations specify standards and acceptance criteria only for fuel rods clad with Zircaloy or ZIRLO. Consistent with 10 CFR 50.46, a temporary exemption is required to use fuel rods clad with an advanced alloy that is not Zircaloy or ZIRLO. Therefore, the licensee needs a temporary exemption to insert up to 16 LFAs containing new cladding material into the SONGS Unit 2 or Unit 3 reactor cores.

Environmental Impacts of the Proposed Action

The NRC has completed its safety evaluation of the proposed action and concludes that the proposed exemption will not present any undue risk to the public health and safety. The safety evaluation performed by Framatome ANP, Inc., “BAW-10227P-A, Evaluation of Advanced Cladding and Structural Material (M5) in PWR Reactor Fuel, Framatome Cogema Fuels, February 2000,” demonstrates that the predicted chemical, mechanical, and material performance characteristics of the M5 cladding are within those approved for Zircaloy under anticipated operational occurrences and postulated accidents. Furthermore, the LFAs will be placed in non-limiting locations. In the unlikely event that cladding failures occur in the LFAs, the environmental impact would be minimal and is bounded by previous accident analyses.

The proposed action will not significantly increase the probability or consequences of accidents. No changes are being made in the types of effluents that may be released offsite. There is no significant increase in the amount of any effluent released offsite. There is no significant increase in occupational or public radiation exposure. Therefore, there are no significant radiological environmental impacts associated with the proposed action.

With regard to potential non-radiological impacts, the proposed action does not have a potential to affect any historic sites. It does not affect non-radiological plant effluents, does not affect any environmental resources, and has no other environmental impact. Therefore, there are no significant non-radiological environmental impacts associated with the proposed action.

Accordingly, the NRC concludes that there are no significant environmental impacts associated with the proposed action.

The details of the staff's safety evaluation will be provided in the exemption that will be issued as part of the letter to the licensee approving the exemption to the regulation.

Environmental Impacts of the Alternatives to the Proposed Action

As an alternative to the proposed action, the staff considered denial of the proposed action (i.e., the “no-action” alternative). Denial of the application would result in no change in current environmental impacts. The environmental impacts of the proposed action and the alternative action are similar.

Alternative Use of Resources

The action does not involve the use of any different resources than those previously considered in the Final Environmental Statement for SONGS Units 2 and 3, dated May 12, 1981.

Agencies and Persons Consulted

In accordance with its stated policy, on April 8, 2009, the NRC staff consulted with the California State official, Mr. Steve Hsu of the Radiologic Health Branch of the California Department of Public Health, regarding the environmental impact of the proposed action. The State official had no comments.

Finding of No Significant Impact

On the basis of the environmental assessment, the NRC concludes that the proposed action will not have a significant effect on the quality of the human environment. Accordingly, the NRC has determined not to prepare an environmental impact statement for the proposed action.

For further details with respect to the proposed action, see the licensee's letter dated January 30, 2009, as supplemented by letter dated March 16, 2009, Agency Documents Access and Management System (ADAMS) Accession Nos. ML090360738 and ML090780251, respectively. Documents may be examined, and/or copied for a fee, at the NRC's Public Document Room (PDR), located at One White Flint North, Public File Area O1 F21, 11555 Rockville Pike (first floor), Rockville, Maryland. Publicly available records will be accessible electronically from the ADAMS Public Electronic Reading Room on the Internet at the NRC Web site, http://www.nrc.gov/​reading-rm/​adams.html. Persons who do not have access to ADAMS or who encounter problems in accessing the documents located in ADAMS should contact the NRC PDR Reference staff by telephone at 1-800-397-4209 or 301-415-4737, or send an e-mail to [e-mail].

Dated at Rockville, Maryland, this 28th day of September 2009.

For the Nuclear Regulatory Commission.

James R Hall,

Senior Project Manager,

Plant Licensing Branch IV, Division of Operating Reactor Licensing, Office of Nuclear Reactor Regulation.