Southern California Edison (SCE) is continuing to perform extensive testing and inspections of the steam generators at the San Onofre Nuclear Generating Station located on the Pacific coast of California, US.
During these inspections, SCE engineers found some isolated areas of tube wear, and this resulted in the plugging of about 1% of the tubes preventively in Unit 2.
On 9 January 2012, Unit 2 was taken out of service for a planned refueling outage, inspections and maintenance.
During the Unit 2 planned outage, SCE engineers performed inspection, maintenance and repair work, including replacing the reactor head and modifying the steam turbine with new high-pressure turbine components that run more efficiently.
On January 31, a water leak was detected in one of the Unit 3 steam generator tubes, and the unit was safely taken off line.
SCE has decided not to restart Unit 2 until it is satisfied that the issue with Unit 3 will not occur in Unit 2.