City New Service
A nuclear reactor at San Onofre Nuclear Generating Station remained off-line today for the second consecutive day due to an equipment problem that sent a small, non-hazardous amount of radioactive gas into an auxiliary building and possibly into the atmosphere, authorities said.
The leak in a steam-generator tube in Unit 3 at the power plant just north of Camp Pendleton was detected about 6 p.m. Tuesday, according to the U.S. Nuclear Regulatory Commission.
An alarm alerted station personnel to the presence of radioactivity in the ancillary structure, and they immediately began shutting down the reactor, NRC spokesman Victor Dricks said.
Gil Alexander, a spokesman for facility operator Southern California Edison, said that radioactive water was passing through a crack inside the generators at a rate of 80 to 100 gallons per day when Edison began the shutdown early Tuesday evening.
Since the equipment-housing building into which the gas leaked is not airtight, it is possible a "very, very low level" of radioactivity escaped into the environment, according to Dricks, who said those traces would be "barely measurable against (existing) background levels" and would pose no danger to the public.
As of Wednesday night, Southern California Edison, which operates the facility, said that sensitive monitoring instruments continued to show no change in radiation levels that would be detectable off-site.
SONGS crews will fully evaluate the cause of the mishap and the steps required to repair it before resuming operations, according to Edison.
Once the problem is resolved, it will likely take several days for the reactor to be restarted, the Rosemead-based utility advised.
At the time of the accident, the other reactor at the plant already was powered down for routine maintenance, refueling and technology upgrades. Still, the utility had ample reserve power to meet customer needs, according to SCE officials.