Problems with the steam generators and miles of tubing at the San Onofre nuclear plant are the most severe found in comparable generators in the US and much more severe than previously reported, according to a new report.
The report by Fairewinds Associates (and commissioned by Friends of the Earth) also provides an analysis of leaked documents (pdf) by plant owner Southern California Edison that shows, despite assertions by the company and the Nuclear Regulatory Commission, thousands of tubes inside both San Onofre reactors are severely damaged.
Friends of the Earth, along with other nuclear experts and many concerned local residents, say the reactors at San Onofre should remain shut down.
San Onofre, on the Pacific Coast between Los Angeles and San Diego, has been shut down since January, after a leak of radiation from one of the almost 20,000 thin, tightly-packed tubes that lead from the plant’s four steam generators to its turbines. In an attempt to stop further leaks, Edison has plugged 1,317 of the tubes that show wear. According to NRC data on 31 reactors with comparable replacement steam generators, San Onofre has more than three and a half times the number of steam tubes plugged as a safety measure than at all the other reactors combined.
In addition to the unprecedented scale of plugging at San Onofre, Fairewinds’ analysis of the leaked data from Edison shows that more than 4,000 tubes are showing significant wear, while only 1,317 have been plugged. Fairewinds concludes that plugging the tubes will not eliminate the cause of damage. In fact, operating the reactors with the remaining unplugged but worn tubes could create cascading tube failures, leading to domino-like catastrophic failure that would release significant radiation to a large area of Southern California.
“Edison and the NRC have admitted that the problems with San Onofre’s steam tubes are an anomaly, but they haven’t been forthcoming about just how historically off-the-charts the damage is in comparison to the rest of the nuclear industry,” said Arnie Gundersen, a nuclear engineer at Fairewinds and co-author of the report.
"This reveals a far greater problem than has been previously disclosed, and raises serious questions about whether it is safe to restart either unit," said Daniel Hirsch, a nuclear expert at UC-Santa Cruz, to Agence France-Presse.
Meanwhile, local anti-nuclear activists are pressing government authorities to set up a watchdog group to oversee the San Onofre plant.
The groups, including Residents Organized for a Safe Environment (ROSE), have launched a letter-writing campaign to the California attorney general, demanding that their voices have a seat at the table when it comes to nuclear safety.
“We are aware of what happened when a committee like this was formed at Diablo Canyon,” said Gene Stone, an organizer with ROSE. “It has taken a very long time for a very small amount of good to come out it. We will not tolerate a San Onofre safety committee filled with people from Southern California Edison or Pacific Gas and Electric and the nuclear industry. We demand true public participation.”
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