So there was a leak at San Onofre, not just a possibility of a leak.
LA Times (2/1/2012):
Southern California -- this just in
Small leak at San Onofre nuclear power plant investigated
February 1, 2012 | 7:15 am
Southern California Edison officials continued their investigation Wednesday of a small water leak in one of two units at the San Onofre nuclear power plant.
The unit was shut down at 5:30 p.m. Tuesday after a sensor detected a leak in a steam generator tube; an assessment of the leak will determine its cause.
The shutdown was ordered out of precaution, Southern California Edison spokesman Gil Alexander said.
He said the incident was so minor "it wouldn't even qualify as the least severe" infraction under Nuclear Regulatory Commission guidelines.
The leak posed no risk to workers and did not require an evacuation, Alexander said.
The unit has a generating capacity of 1,100 megawatts power and is able to meet the needs of 700,000 Southern California homes.
The shutdown is not expected to affect customer's power supply.