PITTSBURGH (AP) — A frigid arctic air mass that brought record low temperatures to Pennsylvania, closing schools, courts and even some ski slopes is also being investigated as the possible cause of a nuclear reactor shutdown.
The dense mass of ultra-cold air began moving into the state on Monday afternoon, which is when one of two reactors shut down at FirstEnergy Corp.'s Beaver Valley Nuclear Power Station in Shippingport, about 25 miles northwest of Pittsburgh.
"There are many potential reasons this could happen and the cold weather is one of them," FirstEnergy spokeswoman Jennifer Young said. "But there are hundreds of other causes we're considering."
Western Pennsylvania temperatures were in the mid-20s Monday before dipping precipitously after noon.
The temperature in Pittsburgh fell to minus-7 degrees late Monday night — a record low for that date — and continued falling to minus-9 on Tuesday, another record. The previous record low for Jan. 7 was minus-5, in 1884. (The all-time low of 22 degrees below zero was set on Jan. 19, 1994.)
The reactor shut down about 5 p.m. Monday when the National Weather Service said temperatures had fallen to about zero.
Nuclear Regulatory Commission spokesman Neil Sheehan called the shutdown "uneventful" and safe, but noted a fire suppression system was activated, dousing an electrical transformer with water. The transformer remained frozen Tuesday.
The transformer converts power created by the reactor to electrical voltage. The transformer's failure prompted the reactor to shut down. The reactor remained shut Tuesday as an investigation into the cause continues, Young said.
The NRC has an inspector at the plant, who will oversee FirstEnergy's investigation, any repairs and the reactor's eventual return to service, Young said. That could take several days, if the transformer must be replaced, Sheehan said.
By mid-afternoon Tuesday, temperatures in and around Pittsburgh hit zero and were forecast to climb into the low single digits by nightfall, with a high in the mid-20s expected Wednesday..
Most schools, courts and many government offices closed in western Pennsylvania, where wind chills reached minus-30 to minus-40 during the coldest morning hours, and were still expected to be in the minus-teens Tuesday night.