The Oyster Creek nuclear plant in Lacey Township was shut down early today after a power failure, according to plant owner Exelon.

Electrical service from the outside grid was disrupted at around 3:41 a.m., and the plant’s emergency diesel generators kicked in and powered the plant’s safety systems, said a statement from the Nuclear Regulatory Commission.

The problem appeared to be a grounded 230-kilovolt line, according to the NRC.

Jersey Central Power & Light crews fixed the problem a little after 5:30 a.m., Exelon said.

Afterwards the plant was taken to cold shutdown, in which the reactor and associated systems are cooled down and depressurized, according to the NRC.

The plant will likely start up again in a matter of days, said Exelon spokeswoman Suzanne D’Ambrosio.

“We make sure the plant is shut down and cooled down and then if there’s any little maintenance we need to do we may take advantage of down time to do that,” D’Ambrosio said. “Obviously with the hot summer it’s in our best interest to get running as soon as possible, but it’s a very slow and deliberate process.”

Oyster Creek produces 636 megawatts of electricity at full power, enough electricity for about 600,000 homes.