Pipe Problems Shut Down Nuclear Power Plant

As Californians scour their coast for debris generated by Japan’s Fukushima nuclear power plant disaster last year, the San Onofre nuclear power plant has announced its twin towers won’t be generating any electricity at all this summer due to the mysterious corrosion afflicting many of the plant’s new steam pipes. Engineers with Southern California Edison suspect that unexpected vibrations, caused by steam rushing through the pipes, are causing the pipes to rub against each other. But until the cause of the problem can be nailed down, the two reactors ​— ​which together provide nearly 20 percent of the region’s electricity ​— ​can’t be restarted. Even under the best-case scenario, only one of the generators could resume extremely limited production by the summer’s end.

In the meantime, the Public Utility Commission approved rate increases allowing SCE to charge ratepayers the $54 million the utility company says is needed to conduct offshore seismic tests to ensure San Onofre can withstand the greatest likely seismic threat. Similar studies were approved earlier this year for the Diablo Canyon nuclear power plant located near Avila Beach. Although a new fault was discovered four years ago just a mile off the coast from Diablo Canyon, PG&E officials and Nuclear Regulatory Commission (NRC) staff insist the plant was built to withstand any ground movement the newly discovered fault can dish out. The new studies may, in fact, bear that out, but last week the federal Government Accountability Office took the NRC to task for not updating its risk-assessment methodology for five of the nation’s 104 nuclear power plants.

And last week a federal judge in Washington, D.C., ruled that the NRC’s analysis of on-site spent-fuel-rod storage at the nation’s nuclear facilities was inadequate. The NRC has adopted a new rule allowing spent fuel to be stored at nuclear reactors for 250 years after the plant stopped production. Prior to that, the limit was 60 years. The NRC allowed the extension after the federal government deep-sixed plans to build a permanent nuclear-waste storage facility at Nevada’s Yucca Mountain.

Absent such a long-term facility, the judge ruled that the NRC needed to conduct far more detailed and site specific analysis of the safety risks posed by long-term storage at each nuclear generator. The NRC is currently evaluating its legal options, but the commission’s just-appointed new chairperson — Allison MacFarlane — is a geologist by training whose opposition to the Yucca Mountain facility is well known.