Edison's San Onofre plan could make things worse, consultant says [Updated]
A consultant who has criticized Southern California Edison's handling of the troubled San Onofre nuclear plant issued a report Tuesday saying the utility's proposed solution for bringing the plant back online could make the issues worse.
The plant has been offline more than three months because of excessive wear in steam generator tubes that carry radioactive water. The wear appears to be occurring when the plant is running at full power and the rate of steam flows causes the tubes to vibrate and rub against each other and against support structures, Edison officials have said.
The company's executive vice president of external relations, Stephen Pickett, said earlier this month that running the plant at reduced power could eliminate the excessive vibration. The company may propose running at 50% to 80% capacity for a few months and then taking the reactors back offline for inspections.
But consultant Arnie Gundersen, who wrote the report for the environmental group Friends of the Earth, said running at reduced power "does not provide a remedy for the underlying structural problems" and "might actually create a resonate frequency within the steam generators at which some of the tubes will vibrate as bad or worse than they did originally."
Gundersen said the only sure solution would be to replace the steam generators entirely, which he estimated would take four years and cost $800 million.
Any proposal to restart the plant will require approval from the U.S. Nuclear Regulatory Commission.
[Updated at 1:50 p.m.: Also Tuesday, Sen. Barbara Boxer wrote to Edison and the NRC requesting documents relating to design changes in the steam generators, which were replaced within the last couple of years.
Gundersen has contended that design changes led to the tube wear issues and that Edison misled the NRC about the extent of the changes to avoid a full review by the NRC.
Edison and NRC officials have said that Edison did inform the NRC of planned design changes. But a special NRC inspection team looking at the tube wear issues is also looking into whether the design changes were "properly reviewed and approved," an NRC spokesman said Monday.
Boxer requested from the NRC a written summary describing the agency's plans to establish whether the steam genrator replacement required a license amendment, as well as documents relating to the NRC's review of design changes and Edison's determination that a license amendment was not necessary].
-- Abby Sewell
Photo: The San Onofre nuclear plant has been dark for more than three months. Credit: Los Angeles Times