Regulators are launching a special inspection at Southern California Edison's San Onofre nuclear plant to make sure the utility fixed electrical problems with crucial backup power systems, the Nuclear Regulatory Commission said Wednesday.
The visit next week by a three-person team marks the third special inspection in the last 12 months for the coastal facility near San Clemente.
"We are concerned about the number of failures and want to take a look at the way the licensee has responded to the issue," said Elmo E. Collins, the commission's administrator for states in the West and southern Midwest.
Nuclear watchdogs expressed alarm.
"The safety culture at San Onofre is nearing the shambles stage," said Rochelle Becker, executive director of the Alliance for Nuclear Responsibility, which focuses on safety at California's nuclear plants.
The commission will hold a public meeting to discuss San Onofre's performance tonight at the Country Plaza Inn in San Clemente.
In March, Edison workers found a loose electrical connection on an emergency battery that rendered it inoperable, commission spokesman Victor Dricks said. The batteries are part of a backup power system to keep the control room and safety systems functioning.
Regulators said similar problems had occurred since 2005. Inspectors will be at the plant for several days beginning Monday, and will submit a report within 45 days, the commission said.
Although Dricks called the San Onofre Nuclear Generating Station "a good performer," he added that "this is the third special inspection that we've done in the last year. It's uncommon to have that many."
Last summer, the commission conducted a special inspection after an incident that forced the shutdown of one of the plant's two reactors. The commission blamed the shutdown on a failed pipe connection in a compressed air system that controls safety valves -- a problem that automatically took the reactor offline.
In early January, the agency announced a separate special inspection to focus on the failure of an emergency generator during several tests.
Edison, a unit of Rosemead-based Edison International, "welcomes and supports" the new inspection, the utility said in a statement. "We believe the commission's independent assessments provide important oversight of U.S. nuclear plant operation and should reassure the public regarding nuclear generation safety."
