The Columbia Generating Station in Richland remained off-line Monday after a "brief, minor fire" forced operators to shut down the nuclear energy plant manually Friday, an Energy Northwest official said Monday.

Rochelle Olson, Energy Northwest's corporate communications officer, said dripping oil sparked a fire in insulation around the plant's turbine system around 7:50 p.m. Friday. Operators used water and fire extinguishers to put out the flames, which Olson estimated at 1 to 2 inches tall.

"This was more like combustion material," she said.

No hazardous materials were released and no injuries occurred. The fire was extinguished at 8:06 p.m. Friday, Olson said. She described the oil as "typical oil," saying it "lubricates bearings and things."

The plant likely will remain off-line for the next few days while the area around the fire is inspected.

"We are anxious to bring the plant back on-line as soon as possible," Olson said in an e-mail.

The outage shouldn't affect Mid-Columbia power users, said Bonneville Power Administration spokeswoman Nanine Alexander. "We ... see to it to buy backup power," she said.

An official with the Nuclear Regulatory Commission said the agency was notified of the fire within an hour of its outbreak. He said the NRC will rely on Energy Northwest to perform an internal investigation into the fire cause and then will review that investigation.