The tubes are a critical safety barrier — if one or more break, there is the potential that radioactivity could escape into the atmosphere. Also, serious leaks can drain cooling water from a reactor.
Last week, an environmental group claimed the utility misled the NRC about design changes that it said are the likely culprit in excessive tube wear. The report by nuclear consultants Fairewinds Associates, and produced for nuclear watchdog Friends of the Earth, warned that a more detailed study is needed on the tubing before the reactors are restarted.
Friends of the Earth issued a statement Wednesday with another environmental group, San Clemente Green, urging the chairman to make a "full determination" of problems at the plant. Meanwhile, some officials in nearby communities have been calling for the plant to shut down permanently.
The equipment is relatively new — the generators were installed in a multimillion-dollar makeover in 2009 and 2010.
The plant is owned by SCE, San Diego Gas & Electric and the City of Riverside. The Unit 1 reactor operated from 1968 to 1992, when it was shut down and dismantled.
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