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.
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.