A loose electrical connection that left a battery for safety systems inoperable for four years — from 2004 to 2008 — at the San Onofre nuclear plant has prompted federal regulators to increase their oversight of the operation. (Plant shown at right.)
The nuclear plant near San Clemente, run by Southern California Edison, remains safe, a spokesman for the Nuclear Regulatory Commission said. But “human performance” and “problem identification” issues that came to light because of maintenance and equipment troubles in recent years have prompted the agency to increase its scrutiny of the plant.
“The plant is safe,” said NRC spokesman Victor Dricks. “But there are performance deficiencies we’ve identified which have not been properly addressed yet. So we continue to focus attention on that site.”
In a statement Monday, Edison officials said they accept the findings of the NRC and will work with the agency to prevent such incidents in the future.
The loose battery connection, discovered in March, powered electrical breakers linked to safety systems, such as an emergency diesel generator. After an inspection prompted by the find, the agency’s inspectors decided to issue a “white finding.”
Problems labeled as white by the NRC are considered to be low to moderate safety concerns. But they are one level higher than “green” findings, which the plant has had a string of in recent years.
Green findings are considered to have very low safety significance. Higher than white is yellow, then red.
“This white finding was issued because of a safety concern, so it would be fair to say our safety concerns are increasing,” Dricks said. “Should people be concerned the plant is not being operated safely? No. We’re not anywhere near that level. We have confidence in the ability of Southern California Edison to operate the plant safely.”
San Onofre has had three “special inspections,” or team inspections, within one year by NRC following a string of problems: the loose battery connection found in March, as well as a faulty diesel generator and an improperly soldered joint in 2007. The soldering flaw prompted shut down of one reactor until the problem could be checked out. 
(Below, people listen during update on San Onofre by NRC in July in San Clemente.)
The white finding means a follow-up inspection for San Onofre early next year to make sure the electrical problem has been addressed.
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Two local groups with concerns about the San Onofre nuclear plant will hold a forum Thursday with a FEMA/Homeland Security official.
