San Onofre’s Unit One Shuts Down

Unit One at the San Onofre Nuclear Generating Station was shut down when an automatic cooling protection system gave a false reading, officials reported Friday.

Instrumentation reportedly gave false indication Thursday night of a low reactor coolant system flow, according to officials for Southern California Edison Co., which operates the station south of San Clemente.

An automatic protection system was activated when the false reading was made, Edison spokeswoman Melanie Savage said.

Savage said that even though it had been determined that the reading was incorrect, and coolant levels were normal, the unit would remain shut down until the plant operators could investigate the cause of the false reading.

Units Two and Three at the plant are operating at full power, and Edison officials expect to know Monday when Unit One will be brought back on-line, she said.