San Onofre Reactor Leak Is Repaired

The San Onofre nuclear power plant should be back up to full power this weekend after shutting down one of its reactors for a week and repairing a minor leak, a spokesman said Thursday.

At no time was the public in danger nor were there any power interruptions, said Ray Golden, a spokesman for Southern California Edison, which operates the plant.

“I would characterize it as a minor leak,” Golden said. “You strive not to have any leakage, but the system is designed with redundancy in mind, and this was a demonstration of how the system works and how to effectively deal with it.”

Golden said the leak did not “rise to the level of significance” that merited immediate public notification. It was, however, reported to Nuclear Regulatory Commission officials stationed at the plant and included in the NRC’s daily report, which was available to the public Monday.

The problem was first noticed late last week, he said, when workers tracked a slight change in the water level in unit No. 3, one of the plant’s two operating nuclear reactors. An inspection, Golden said, revealed a pinhole-sized leak where two pieces of piping were welded together in an ordinarily closed water purification system.

As a result of the leak, he said, a small amount of mildly radioactive water was dropping onto the floor of an airtight containment building protected by 4- to 7-foot-thick walls.

“There was no release to the oceans or the sewer systems or the environment,” Golden said of the contaminated water, which, he said, was automatically collected by special drains designed for the purpose and transported into a storage tank.

The impaired reactor -- which had been running for 340 consecutive days -- was shut down about 8 p.m. Saturday so that the needed repairs could be made. “It’s been years since we’ve had this type of leak,” Golden said.

He estimated that the plant would be back up to full power by Sunday night.