LOS ANGELES (AP) — A tiny amount of radiation could have escaped from a Southern California nuclear power plant after a water leak prompted operators to shut down a reactor as a precaution, but plant workers and the public were not endangered, officials said Wednesday.
The leak was detected Tuesday afternoon in Unit 3 at San Onofre Nuclear Generating Station, about 45 miles north of San Diego. The seaside plant was taken off line while investigators tried to determine what happened.
While the leak wasn't large enough to require the plant to declare an emergency, any possible leak of radiation into the atmosphere is rare. Also concerning was that "many" tubes that carry pressurized radioactive water were damaged, according to a spokesman for the Nuclear Regulatory Commission.
The tubes are part of equipment that is virtually new, having been installed in 2010.
"The damage that they have found to many other tubes is unusual, and they are attempting to identify the reason," NRC spokesman Victor Dricks said.
News of the possible release of radioactivity was slow to emerge. Shortly after the incident, Southern California Edison issued a statement saying, "There has been no release to the atmosphere."
On Wednesday morning, however, Dricks said a small amount of radioactive gas "could have" escaped from a building that houses auxiliary equipment.
When asked, Southern California Edison spokesman Gil Alexander did not directly address why the plant used the language it did. He emphasized the relatively minor nature of the incident.
"I can't speak for the NRC but we would agree that there might have been an insignificant or extremely small release," Alexander said. He said the amount might not be detectable by monitors.
Dricks agreed, saying the radiation "would not pose a danger to anyone." The NRC was evaluating the plant's response to the leak, he said.
In November, nuclear watchdog and environmental groups criticized plant operators for taking more than an hour to notify the public of an ammonia leak in a storage tank that prompted the evacuation of some workers. There was no danger to the public, the company said at the time.
The Unit 3 reactor returned to full power in February 2011 after it was refueled and its two aging steam generators were replaced. The plant's other reactor, Unit 2, had similar work. The total retrofit cost more than $670 million.
Daniel Hirsch, who lectures on nuclear policy at the University of California, Santa Cruz, said he was concerned that the problem occurred with recently installed equipment.
"Edison has historically not been candid about the problems at San Onofre. That lack of transparency causes tremendous distrust and increases risk," Hirsch said.