Unit 3 of the San Onofre Nuclear Generating Station (SONGs) in California remains offline as its operator Southern California Edison (SCE) plans to repair a steam generator tube leak.

SONGs 3 was shut down as a precautionary measure on Tuesday 31 January after sensors detected a possible leak in one of the unit’s steam generator tubes. The RSG units are new; they were delivered and replaced in 2010.

Operators shut down the unit and isolated the component that contained the leaking tube within four hours of detecting the indications.

Pete Dietrich, senior vice president and chief nuclear officer for SCE said in an update, 2 February: “There was no threat then, nor is there now any danger to the public or to plant workers.” The company said that operators were cooling down unit 3 and reducing pressure in the plant, which is the method to stop the tube from leaking. They are meticulously following prescribed procedures written specifically for addressing a tube leak condition.

SONGs unit 2, which is twinned with unit 3, is currently offline for a planned maintenance, refueling and technology upgrade outage..

FilesReactor-by-reactor Fukushima Daiichi restoration progress summary as of 2 February, from JAIF