San Onofre Nuclear Generating Station Units 2 and 3 are located in San Clemente, California approximately 45 miles south of Long Beach, California. The Combustion Engineering PWRs are operated by Southern California Edison Company (a wholly owned subsidiary of Edison International), which also owns 75% of both units. The other owners of both units are: San Diego Gas & Electric Company (20%), a wholly owned subsidiary of Sempra Energy; the Public Utilities Department of the City of Anaheim (3.2%); and Riverside Public Utilities (1.8%). Unit 2 is licensed to operate until February 16, 2022. Unit 3 is licensed to operate until November 15, 2022. Unit 1 (a Westinghouse PWR) was shutdown in November 1992 and dismantlement is essentially complete. The remaining decommissioning activities at Unit 1 are not scheduled to be finished until December 2030.
The ISFSI for the site began accepting SNF from Unit 1 in October 2003, from Unit 2 in March 2007, and from Unit 3 in March 2008 — all pursuant to a general license. The ISFSI is located approximately 750 feet northwest of the reactor buildings and outside the plant’s security perimeter but within its own controlled area. The ISFSI contains two adjacent concrete pads that currently house 55 storage modules. One pad is over 43 feet wide, 293 feet long, and holds 31 casks; the other pad is over 60 feet wide and currently holds 24 casks in a double row configuration (the photo only shows 16 of the 24 double row casks). Eventually the ISFSI will expand, covering the area where Unit 1 was previously located, to accommodate additional storage. The cask manufacturer is Transnuclear — the NUHOMS cask system and the 24PT canister type. In February 2012, Southern California Edison announced plans to change to the 32PTH canister type beginning in September 2014.
All SNF from Unit 1 (as well as Greater-than-Class-C (GTCC) waste from the reactor vessel internals) was transferred to the on-site ISFSI between October 2003 and September 2004. The SNF fuel from Unit 1 that was stored in fuel pools at Units 2 and 3 were transferred to the on-site ISFSI between May and June 2005. In total there are 395 SNF assemblies from Unit 1 stored in 17 casks at the San Onofre ISFSI (plus one cask containing the GTCC waste). An additional 270 SNF assemblies from Unit 1 are being stored at the GE Morris wet fuel pool in Morris, Illinois — they were shipped there before the San Onofre ISFSI was constructed. As of the end of October 2011, there are 432 SNF assemblies from Unit 2 stored in 18 casks. As of the end of July 2010, there were 288 SNF assemblies from Unit 3 stored in 12 more casks. (The fuel pools are Units 2 and 3 are each capable of storing 1,542 SNF assemblies; however, as of May 2011, only 1,221 assemblies are in wet storage at Unit 2 and 1,229 assemblies are in wet storage at Unit 3.) As of the end of October 2011, the San Onofre ISFSI is storing a total of 1,115 SNF assemblies in 47 casks (plus one cask containing the GTCC waste from Unit 1). As of the end of 2010, there were 2,850 metric tons of SNF stored at the four nuclear power plant sites located in the State of California — Diablo Canyon, Humbolt Bay, Rancho Seco and San Onofre.
Additional information regarding the San Onofre site is available at the following websites:
Additional information regarding the San Onofre ISFSI is available from the following NRC inspection report issued in May 2011.