Environmental group demands full San Onofre review
An environmental group filed a legal petition with the U.S. Nuclear Regulatory Commission on Monday to keep the troubled San Onofre nuclear plant closed pending extensive review by regulators and the public.
Operators shut the plant down four months ago because of unusual equipment problems.
Friends of the Earth demanded in the filings that Southern California Edison obtain an amendment to its operating license before the NRC allows the plant to fire up again.
The group contends that when Edison replaced the plant's steam generators, it failed to report a series of design changes that should have been reviewed by the NRC, and sidestepped public scrutiny of the changes.
The new steam generators had been operating for less than two years when issues with the equipment led to what would become the longest shutdown in the plant's history.
The Friends of the Earth petition also accuses the NRC of turning a blind eye toward the plant, saying that the agency "willingly acceded" to Edison's "attempt to avoid any public review of its decision to install significantly different steam generators built by a company that was unfamiliar with the particular needs of a steam generator in the San Onofre type of reactor."
Edison has said that the design changes were made to keep up with industry standards and that it kept the NRC informed. The NRC is looking at the design changes as part of its probe into the plant's issues.
Arnie Gundersen, a consultant for Friends of the Earth, argued that some of the design changes -- including the addition of more tubes and the removal of a support structure -- may have led to the unusual wear on the steam generator tubes.
The wear is a safety concern because tube ruptures can release radiation. The plant has been shuttered since one tube sprung a small leak on Jan. 31, which led to the discovery of many more that were wearing out more quickly than expected.
Since then, Edison, the NRC and Mitsubishi Heavy Industries, the manufacturer of the steam generators, have been probing the extent and the cause of the wear, and the NRC has ordered Edison to keep the plant shuttered until it has determined the cause and how to fix it.
More than 1,300 tubes -- about 3% of all those in the plant's two working reactor units -- have been taken out of service because of the wear issues.
Edison officials suspect the rate of steam flow among the tubes is causing excessive vibration, causing the tubes to rub against each other. Officials have yet to pinpoint the exact cause however.
Edison Chief Executive Ted Craver said the new steam generators were designed to prevent such vibration, but that "the implementation of the design doesn't appear to be meeting the specification."
The NRC is expected to present the preliminary findings of its investigation Monday night in San Juan Capistrano, while Edison officials are still trying to hammer out a plan to fix the issue and restart the plant. Craver said earlier this month that he expects the plant to remain out of service at least through the summer.
The solution to the tube wear issue might involve running the plant at reduced power to avoid the problematic vibration, Edison has said.
The motions filed by Friends of the Earth seek to bar the NRC from authorizing the plant's reactivation until it goes through the license amendment process, including a trial-like public hearing on the problem and its fixes. (Edison did receive a license amendment when it installed the new steam generators, but using a more streamlined process, and Friends of the Earth contends that the company failed to report all of the important design changes).
The group argued that the hearing process would not lengthen the amount of time that the plant would remain closed, and even if it did, the delay was justified. A stay, the group said, was "necessary to protect public safety."
-- Abby Sewell
Photo: An environmental group is seeking to keep the San Onofre nuclear power plant closed. Credit: Allen J. Schaben / Los Angeles Times