Class 1* Permit Modification for Southern California Edison; San Onofre Nuclear Generating Station

The California Department of Toxic Substances Control (DTSC) approves of the Class 1* Permit Modification (Permit Modification) regarding an extension to the closure schedule for a partial closure of the San Onofre Nuclear Generating Station (SONGS) facility located at 5000 Old Pacific Coast Highway, San Clemente, CA 92672. Although closure activities have begun, there were additional demolition and disposal activities necessary for the closure and the extension request is to complete the ongoing closure activities of the South Yard Facility (Sections A&B) hazardous waste storage units at SONGS. The date for final closure of the units has been extended to March 31, 2027. The remaining activities for closure of these units include sampling in accordance with the approved sampling plan, laboratory analysis of the samples, and submittal of the final closure report. Background: SONGS is a nuclear power generating facility undergoing decommissioning located on the coast of Southern California in San Diego County. SONGS began operation in 1968 and is operated and primarily owned by Southern California Edison. The facility operated three pressurized water nuclear reactors (Unit 1, 2, and 3) and several smaller standby diesel generating units which all ceased operation by 2013. The decommissioning and decontamination of the facility will result in the generation of hazardous waste, some of which will be contaminated with radio nuclides, referred to as mixed waste or combined waste. The mixed waste and combined waste include, but are not limited to, used oil, chemical solvents, lead solids, and asbestos which are to be stored in sealed containers and shipped offsite within one year from the date they are placed in a permitted storage unit. SONGS was first authorized by DTSC in 1989 to operate a hazardous waste storage facility under a grant of interim status. The first Hazardous Waste Facility Permit (Permit) issued to SONGS became effective on January 31, 2005, and was permitted for ten years. A Permit Renewal became effective on May 23, 2016, that allowed the facility to continue to store hazardous waste while it undergoes decommissioning. SONGS notified DTSC that closure of the LSAW and HSAW storage areas would begin in July of 2023. SONGS requested an extension to the 180-day timeframe allowed to complete closure in December of 2023. Project Activities: The year of final closure of the HazMat Pads A&B storage units has been extended to March 31, 2027. There are no proposed changes to the closure activities other than to extend the closure schedule for decommissioning the hazardous materials storage units at SONGS. The Permit Modification does not include any other changes to closure requirements, operational changes, or significant ground disturbing activities at the facility.