A small fire broke out Friday at the San Onofre Nuclear Generating Station, which has been shut down while officials investigate extremely rapid tube wear that caused a minor radiation leak in January.

Plant operator Southern California Edison said the fire never represented a threat to the public and was quickly extinguished, according to a post in the Los Angeles Times.

From the Times article:

According to a statement from plant operator Southern California Edison, the fire occurred on the non-radiological side of the plant, and no one was hurt. The plant’s fire department extinguished the blaze.

Operations personnel declared an “unusual event” at 12:49 p.m. and immediately notified the U.S. Nuclear Regulatory Commission, according to Edison’s statement, which said there was no threat to the public or workers. The fire started at 12:34 p.m. and was extinguished in about 45 minutes.

The cause of the fire is under investigation, and the extent of the damage was not immediately clear. …

Also Friday, Mitsubishi Heavy Industries, the manufacturer of the malfunctioning steam generators, announced a timeline for its own evaluation of the issues at the plant. Mitsubishi announced a target date of May 31 for wrapping up its evaluation of the problems in Unit 2 and Aug. 31 for Unit 3.

The commission has said Edison must understand the issues at Unit 3 before Unit 2 can restart. Mitsubishi’s timeline led the anti-nuclear group Friends of the Earth to call for the plant to stay offline through the summer, but Edison and NRC officials said Mitsubishi’s analysis is separate from Edison’s probe into the problems at the plant, and the two may be on different timetables.

NRC Chairman Gregory Jaczko said at a news conference Friday that regardless of the timeline, the agency stands by its position that the plant can’t restart until the problems are fully understood.

While the plant recently made progress improving its safety culture, San Onofre still ranked highest in the nation last year for substantiated safety complaints at nuclear plants, according to figures from federal regulators.

And in the first two months of this year, the plant again generated more safety complaints from workers than any of the country’s other 64 nuclear plants.

Edison, meanwhile, says safety has always been its top concern.

“Our No. 1 priority is, and always has been, the health and safety of the public and our employees,” said Edison’s president, Ron Litzinger, in a recent video message about San Onofre.

— NICK GERDA

Join the conversation: In lieu of comments, we encourage readers to engage with us across a variety of mediums. Join our Facebook discussion. Message us via our website or staff page. Send us a secure tip. Share your thoughts in a community opinion piece.