San Onofre may restart in June but may never hit full capacity
A Southern California Edison executive said Thursday that the company is hoping to have the shuttered San Onofre nuclear plant back up and running in June, but even then the plant will have to run at a reduced capacity for the immediate future -- and perhaps forever.
The reduced operation is meant to compensate for manufacturing defects that led to the plant's closure three months ago.
Stephen Pickett, the company’s executive vice president of external relations, said Edison is preparing to propose a plan to the U.S. Nuclear Regulatory Commission that would have the plant's reactor Unit 2 fired back up in early to mid-June and Unit 3 one to three weeks later.
The NRC will need to sign off on the plan before the plant can restart.
The plant has been closed since Jan. 31, when a steam generator tube in the plant's reactor Unit 3 sprung a leak, releasing a small amount of radioactive steam. Since then, more than 500 of the plant’s 39,000 tubes have been taken out of service due to excessive wear.
Pickett characterized the problem as a "manufacturing defect" but said Edison has yet to determine whether the issue was caused by design problems or the way the equipment was put together.
San Onofre’s four steam generators were replaced within the last two years or so at a cost of $671 million, a figure to be recovered from ratepayers.
Pickett said the flow of steam through the tubes is causing some longer tubes to vibrate and rub against each other in Unit 3. Initially, officials said the wear in Unit 2 was of a less unusual type, with tubes rubbing against support structures. But later testing found two tubes at Unit 2 with the same type of wear.
He said the vibration appears to be caused by the level of steam flow through the tubes, which is causing certain longer tubes to vibrate and rub against each other.
In the near term, operating the plant at less than full capacity is the only way to make sure that the issues do not resurface, Pickett said.
The revelation came a day after Edison International’s quarterly earnings report, which estimated that the company's cost for inspections and repairs -- primarily plugging the degraded tubes to take them out of service -- will be between $55 million and $65 million.
Officials said they hope to recoup those costs under Edison’s $137 million warranty with Mitsubishi Heavy Industries, which made the steam generators.
The company also reported that it incurred costs of $30 million for replacement power through March 31, but did not give an estimate of what total replacement power costs will be.
"To the extent that the plant is not operating at full power, replacement power will have to be acquired elsewhere, so those costs will continue to rise," Pickett said.
Mitsubishi’s warranty does not cover replacement power.
A Mitsubishi spokesman said the company could not comment on Edison's cost estimates but said that Mitsubishi "will work diligently with our customer on issues such as future indemnification in accordance with our contractual agreements."
Some quickly cried foul on Edison's planned timeline.
Shaun Burnie, a nuclear consultant with the environmental group Friends of the Earth, which has put out reports alleging that design changes led to the problems and that Edison sidestepped NRC review, said he doesn't think operating the plant below full capacity will solve the problem.
"It's pretty clear on the political side that this is Edison's attempt to strongarm the NRC into giving rapid approval," he said.
San Onofre, when operating at full capacity, can provide power to 1.4 million households.
-- Abby Sewell
Photo: Beachgoers outside the darkened San Onofre nuclear energry plant. Credit: Associated Press