SAN JUAN CAPISTRANO, Calif. -- Federal regulators disclosed Monday that the proposed restart of the long-shuttered San Onofre nuclear power plant in California could lead to an exhaustive review that might last months or even years.
The Nuclear Regulatory Commission is considering if the complex proposal submitted by operator Southern California Edison last week to repair and start the damaged Unit 2 reactor will require an amendment to San Onofre’s operating license, Regional Administrator Elmo Collins told reporters.
Such reviews can involve a thicket of hearings, appeals and other steps on safety and design issues that can take as long as two years to complete.
Edison contends such a review is not needed, and NRC officials have indicated previously that their review of the restart plan could be completed within months.
It’s "an open question" if a license amendment is needed, Collins said during a news conference.
Environmentalists have argued that a license amendment is needed to return the plant to service.
The problems at San Onofre center on four steam generators that were installed during a $670 million overhaul in 2009 and 2010.
The trouble began Jan. 31, when the Unit 3 reactor was shut down as a precaution after a break in a tube carrying radioactive water. Traces of radiation escaped at the time, but officials said there was no danger to workers or neighbors.
Unit 2 had been taken offline earlier that month for maintenance, but investigators later found unexpected -- in some cases extensive -- wear on hundreds of tubes inside steam generators in both units.
Tests found some tubes were so badly corroded that they could fail and possibly release radiation, a stunning finding inside the nearly new equipment.
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 tubes, and how it would be fixed and then monitored during operation.
Edison’s plan calls for operating Unit 2 at up to 70 percent power for five months then shutting it down for inspections. Company officials expressed confidence in the proposal, which followed more than 170,000 tube inspections over more than eight months.
Environmentalists and anti-nuclear activists have argued for months that restarting the plant would invite catastrophe. About 7.4 million Californians live within 50 miles of San Onofre’s twin domes.