While there is still no restart timetable available for Southern California Edison’s (SCE) majority-owned San Onofre nuclear power plant near San Clemente, Calif., the U.S. Nuclear Regulatory Commission has spelled out what must occur prior to restart.
NRC said March 27 that it has issued a confirmatory action letter to this Edison International (NYSE: EIX) subsidiary, which runs the plant.
“This Confirmatory Action Letter formalizes commitments that Southern California Edison has made to ensure that the cause of the tube wear in both steam generators is understood and appropriately addressed in order to ensure safe operation,” NRC Region IV Administrator Elmo Collins said in a news release. “Until we are satisfied that has been done, the plant will not be permitted to restart.”
“We welcome the NRC’s letter, which is a formal step in the process of restarting Units 2 and 3,” said SCE President Ron Litzinger. “Our number one priority is, and always has been, the health and safety of the public and our employees. The utility will only bring the units on line when we and the NRC are satisfied that it is safe to do so.”
On Jan. 31, operators performed a rapid shutdown of the Unit 3 reactor after indications of a steam generator tube leak. Unit 2 has been shut down since Jan. 9 for a planned refueling and maintenance outage. Subsequent inspections at both units have identified unusual wear in many of the tubes of the steam generators, which were replaced in January 2010 at Unit 2 and January 2011 in Unit 3.
With the prospect of this 2,200-MW pressurized water reactor plant being idle for part of the summer peak season, the California Independent System Operator (Cal-ISO) has been drafting contingency plans that include postponing retirement of certain fossil generation units.
SCE said it has found that tubes are vibrating and rubbing against adjacent tubes and against support structures inside the steam generators. SCE officials are still working to determine why this is occurring.