A precautionary shutdown of Unit 3 at San Onofre Nuclear Generating Station was begun this afternoon when sensors installed to detect a possible leak were set off in one of the unit’s steam generator tubes, according to a news release from Southern California Edison, which operates the power plant.
“The potential leak poses no imminent danger to the public or plant workers,” the utility company said in its statement. “There has been no release to the atmosphere.”
SCE Spokesman Gil Alexander said the sensors detected a leak of water from a closed loop used as part of the overall generator.
As of 6:30 p.m., no emergency classification has been needed or issued under the Nuclear Regulatory Commission as a result of the event, Alexander said.
However, the NRC was immediately informed of this development.
The power plant was forced to issue an alert November 1 and partially evacuate the facility when an ammonia leak was discovered. Though the leak was contained within hours, it was enough to cause Orange County to initiate its Emergency Operations Center.
As of today, Unit 2 is currently offline for a planned maintenance, refueling and technology upgrade outage.
Southern California Edison said it has ample reserve power to meet customer needs while Unit 3 is offline, the release said.
After the September 8 power outage, both reactors were tripped and taken offline as a precautionary measure. Alexander noted that when the generators were shut down, they took about three days to return to service.
San Onofre personnel will evaluate the cause of the leak and the steps required to repair it and resume operations, the news release said.
Read more: San Clemente Times – After Possible Leak Detected SONGS Shuts Down Unit 3 Generator