KPBS Special Coverage: Trouble At San Onofre

Southern California Edison has announced it will retire the San Onofre Nuclear Generating Station, which has been offline since a small radiation leak in January 2012 led to the discovery of excessive wear on hundreds of steam generator tubes that carry radioactive water.

Here's your manual to how it all began and the latest developments.

The Beginning

The 'Small Leak' That Started It All

San Onofre Nuclear Generating Station takes its Unit 3 reactor offline after an equipment problem sent a small, non-hazardous amount of radioactive gas into an auxiliary building and possibly into the atmosphere, authorities said.

San Onofre's Problems Deepen

San Onofre operator, Southern California Edison says it found more tube wear in Unit 2, similar though less serious than in Unit 3. As the chairman of the Nuclear Regulatory Commission says the plant will not restart until the root cause is discovered, California’s energy agencies gear up efforts to get substitute power from decommissioned power plants.

Unanswered Questions

Attempts To Restart

Report Critical Of Restarting Steam Generators

A new report introduced to a U.S. Senate committee contends the steam generators at San Onofre are in much worse shape than publicly acknowledged, finding 400 times as many damaged steam generator tubes as in a typical nuclear reactor with new steam generators.

NRC Responds To Problems At San Onofre

The Nuclear Regulatory Commission rejected a petition from Friends of the Earth asking for a license amendment for San Onore before considering a plan to restart the troubled plant. The amendment would have required public hearings.

San Onofre's Future Still Hangs In The Balance

Almost one year since the San Onofre Nuclear Generating Station was abruptly shut down due to a unexpected equipment problems, the discussion continues over Southern California Edison's proposal to partially restart the plant.

Permanently Offline

San Onofre To Be Permanently Closed

Southern California Edison announces it is retiring the remaining reactors at the San Onofre Nuclear Generating Station. Decommissioning the plant will take 40 years and cost 1,100 jobs.