Southern California Edison and Mitsubishi put together an "Anti Vibration Bar Design Team" that held numerous meetings when it became apparent that the new design of the steam generators at San Onofre could lead to the tubes vibrating, causing damaging wear. But the companies decided not to make possible changes identified by the team.
That's according to information from Massachusetts Congressman Ed Markey, ranking member of the House Natural Resources Committee. Markey joined California Senator Barbara Boxer in sending a letter to the head of the Nuclear Regulatory Commission this week, calling for a federal investigation after uncovering documents that she says suggest Edison and the manufacturer of the plant's ailing steam generators were aware of design problems before the equipment was installed.
Markey quotes from the document that the only specific reason for the decision not to implement the potential design modifications was the desire to avoid a more lengthy license amendment process that would have involved adjudicatory hearings.
One day after U.S Senator Barbara Boxer accused Southern California Edison of knowing its steam generators at the San Onofre Nuclear Generating Station were flawed before they were installed, SCE sharply denyied that it knowingly installed the faulty equipment.
In a statement out Thursday, SCE says "it would never, and did not, install steam generators that it believed would not perform safely."
Edison says that is simply not accurate" and pointed out the equipment carried a 20-year warranty against defects.
The NRC responded to Boxer/Markey's letter with a statement that the agency will "review all available information in making a judgement as to whether the plant would meet our safety standards if restart were permitted."
An NRC meeting is set for next Tuesday evening in Capistrano Beach to share NRC'S progress in considering San Onofre's restart plan. However NRC spokesman Victor Dricks said the letter from Boxer and Markey will not be discussed at that meeting.
A hearing on Thursday at which industry experts testified before the NRC about the restart plan made no mention of the issue raised in the letter from Boxer and Markey.
The NRC is scheduled to make a decision in April or May on whether to allow Edison to move forward with its plan to restart the plant at reduced power.
San Onofre has been shut down for more than a year after unusual damage was found in steam generator tubes that carry radioactive water.