LOS ANGELES (AP) -- A federal board Friday ordered the operator of a shuttered nuclear power plant in California to turn over dozens of pages of documents that were withheld when the company submitted a plan to restart one of its damaged twin reactors.
The records at issue were prepared by industry experts who have helped Southern California Edison investigate why the San Onofre plant's nearly new steam generators caused excessive wear to hundreds of tubes that carry radioactive water.
The plant was shut in January after a leak in a generator tube released traces of radiation.
In a seven-page order, the Atomic Safety and Licensing Board said it needs the documents for a case related to Edison's restart proposal.
However, the records would not become public. The board — an arm of the Nuclear Regulatory Commission — told the company to prepare an agreement under which the records would be shared only among parties in that case.
In a statement, the company said it would "provide documents consistent with the order." On its website, the company said some of the documents prepared by Edison vendors were redacted by those companies to protect "proprietary information." Edison said the omitted information does not affect the reports' conclusions.
The Nuclear Regulatory Commission has promised a transparent, thorough review of the restart proposal, which focuses on how the utility would operate faulty steam generators installed during a $670 million overhaul in 2009 and 2010. "We don't experiment with safety," NRC Regional Administrator Elmo Collins told reporters in October.
But anti-nuclear activists have complained the NRC is denying the public a voice in the plant's future.
The board is reviewing a case filed by Friends of the Earth, a group critical of the nuclear power industry. The group wants federal regulators to require Edison to seek an amendment to its operating license before it could restart the plant, a process that could take up to two years.
The order follows a hearing Monday in which company representatives and board members sparred over of the records' release.
Steve Frantz, an attorney representing Edison, objected to the disclosure, saying the board was improperly widening the scope of its review. "I don't believe that these documents are necessary to resolve the issue," he said, according to a transcript.
After a three-month investigation, the NRC announced earlier this year that a botched computer analysis resulted in design flaws that caused excessive vibration and resulted in heavy wear in many tubes.
Edison's proposal calls for operating Unit 2 at up to 70 percent power, which engineers believe will stop the vibration. It would run for five months, then be shut down for inspections. The future of its twin reactor, the heavily damaged Unit 3, is unclear.
Anti-nuclear activists have argued for months that restarting the plant, located between San Diego and Los Angeles, would invite catastrophe. About 7.4 million Californians live within 50 miles of San Onofre's twin domes.
In a March letter, federal regulators outlined a series of benchmarks Edison must reach to restart the plant, including determining the cause of vibration and friction that damaged scores of generator tubes, and how it would be fixed and then monitored during operation.