State utility regulators, after denying a pair of records requests from activists and reporters, released a controversial study from a scientist about the cause of the catastrophic failure of the San Onofre nuclear power plant in early 2012.
Late Thursday, the California Public Utilities Commission made public a draft review by Robert J. Budnitz of the Lawrence Berkeley National Laboratory that looked into why steam generators failed at the San Onofre plant while similar equipment has been working well at another California nuclear power plant, Diablo Canyon.
Budnitz found that the generators at San Onofre, operated by Southern California Edison Co., were plagued by "one or more errors" at points in their design, fabrication, testing, installation and operation.
Identifying the specific error would require further study, Budnitz wrote.
The PUC made his draft findings public just hours after a San Diego consumer lawyer held a news conference alleging a PUC cover-up. Michael Aguirre said he is suing Gov. Jerry Brown for copies of communications with energy officials about a proposed agreement between the utility and some consumer groups over costs associated with the permanent closure of the plant.
Aguirre also said he also plans to ask federal prosecutors in Los Angeles and San Diego to convene a special grand jury.
The attorney said he was surprised to learn of the PUC's sudden reversal on his public records request.
"It's the right thing to do," he said, and should be followed by a continuing, detailed investigation.
For months, Aguirre has been arguing that a PUC-proposed settlement, which would make ratepayers responsible for $3.3 billion of the shutdown costs and Edison for $1.4 billion, was unfair to consumers. Participants in the negotiations, including some ratepayer activists, said the settlement was the best agreement possible and would provide the most benefit in the shortest amount of time to the customers of Edison and its San Onofre partner, San Diego Gas & Electric Co.