Southern California Edison (SCE) on Oct. 19 started required equipment testing using a temporary boiler to produce steam required in the non-nuclear portions of the two-unit, 2,200 MW San Onofre Nuclear Generating Station. The current testing, which is not part of the plant restart, is required for Unit 2 upgrades completed this past January, which included installing a new reactor vessel head. The temporary boiler is being run on diesel fuel.
During the seven-day testing period, the reactor cooling water system will pump water through its normal flow path. The pumping energy will heat up and pressurize the reactor water to normal levels. SCE said these conditions are necessary to conduct the planned testing of the new equipment. In accordance with the requirements of the Nuclear Regulatory Commission’s (NRC) Confirmatory Action Letter, the reactor will remain shut down and the steam generators will not be producing steam to run the power plant.
Both units of the San Onofre plant are currently shut down. Unit 2 was taken out of service Jan. 9 for a planned outage. Unit 3 was safely taken offline Jan. 31 after station operators detected a leak in a steam generator tube.
SCE submitted its response to the NRC’s Confirmatory Action Letter on Oct. 4, along with its restart plan for Unit 2. Unit 2 cannot be restarted until all plans have been approved by the NRC and will remain shut down until the NRC is satisfied that it is safe to operate. Unit 3 remains shut down for continued inspections, analysis and testing.
Subscribe to Nuclear Power International magazine