NRC to Probe Big Water Leak at San Onofre Nuclear Plant

The Nuclear Regulatory Commission will investigate a major water leak and power outage that forced the shutdown of the 17-year-old Unit 1 reactor at the San Onofre nuclear power plant, the commission announced Friday.

No radiation was released in the leak Thursday morning, officials said. Hot, highly pressurized water from the non-radioactive loop that powers the unit’s turbines spewed for six hours after a valve blew, according to Dave Barron, a spokesman for Southern California Edison.

The leak developed after a power outage that blacked out some of the plant’s instrumentation prompted a shutdown of the unit, he said.

Commission officials said they were paying special attention to the incident because it involves the plant’s oldest unit, which has been upgraded several times since it began operations in 1968.

Though Edison officials said the unit could be returned to service in two to three days, the commission ordered that it remain shut down until the incident can be investigated.

The unit will be kept out of service for about three months after the investigation for scheduled refueling and modifications, Barron said.