LOS ANGELES (AP) - The troubled San Onofre nuclear power plant operated for three decades with equipment that might have temporarily cut off the plant's emergency power supply in the event of an earthquake, government filings revealed Tuesday.
The disclosure by Southern California Edison about a possible backup power problem comes amid a probe into excessive wear on tubing that has sidelined the seaside plant for nearly four months.
The company disabled the equipment, a vibration sensor, and reported to federal regulators that the problem was being analyzed as a threat to plant safety. Other back-up systems were in place during that time.
"Engineers are continuing to analyze the condition and have not reached a final conclusion if the sensor would actually cause a shutdown during an earthquake," a company statement said.