In October 2015 the California Coastal Commission approved an application by Southern California Edison to construct an independent spent fuel storage installation (ISFSI) at the San Onofre Nuclear Generation Station (SONGS). The purpose of the ISFSI is to safely store spent nuclear fuel assemblies until the federal Nuclear Regulatory Commission (NRC) approves transfer to a permitted long-term offsite nuclear waste storage facility. No such facility currently exists.
Once a nuclear power plant like SONGS is permanently shut down, the fuel assemblies must first be removed from the reactor and placed in a cooling pool, where they must remain for about 5 years as they gradually lose radioactivity. After this time they can be removed from the pool and placed in dry storage casks, which are typically steel cylinders filled with inert gas and surrounded by concrete. A storage facility designed to hold these dry storage casks is called an ISFSI. SONGS has had cooling pools since the facility was constructed in the 1970s and has had an ISFRI for several years to store spent nuclear fuel from Unit 1 (shut down in 1992) and some spent fuel from Unit 2 and 3. The recent project approved by the California Coastal Commission is to expand the existing ISFRI to hold all the spent fuel assemblies from Units 2 and 3. The existing ISFSI is located at the location of the original (now decommissioned and dismantled) Unit 1 reactor. The ISFSI expansion will be adjacent to the existing ISFSI.
Unit 2 and 3 fuel assemblies will remain in cooling pools until approximately 2017 or 2018 when they will have lost enough radioactivity to begin to be safely loaded into dry storage casks and transferred to the new ISFSI. That transfer operation is scheduled to take about 2 to 3 years. Dry cask storage is currently scheduled to continue in the ISFSI until about 2030, after which time the casks will begin to be transferred (pending availability) to a permitted long-term offsite storage facility. That transfer process is schedule to continue until about 2050. After that time, the SONGS ISFSI facility can be decommissioned.
The Surfrider Foundation is extremely concerned about the present plans that will leave nuclear waste in storage at SONGS as close as 150 feet from the ocean for a projected 35 years. On the other hand, we realize that the ISFSI is apparently the safest intermediate-term storage option currently available until a long-term offsite storage facility is permitted and built. We will continue to closely follow the decommissioning and spent fuel storage process and will press for the facility operator Southern California Edison and the NRC to remove all radioactive materials from the SONGS site as soon as possible.
Background info: http://www.nrc.gov/waste/spent-fuel-storage/faqs.htmlnrc.gov/waste/spent-fuel-storage/faqs.html