There was an “unusual event” at the Salem 2 nuclear reactor in Lower Alloways Creek, NJ, after a valve improperly opened during troubleshooting, allowing the release of about 25 gallons of water from the plant’s cooling system, officials said.
The unusual event occurred at 9:48 p.m. last Monday and the declaration lifted at 1 a.m. Tuesday, said Joe Delmar, spokesman for the plant’s operator, PSEG Nuclear.
Delmar said no employees suffered injuries in the incident and there was no threat to the public outside of the plant.
The incident took place as workers were preparing the plant to return to service. Salem 2 went off line Oct. 22 for a scheduled refueling and maintenance outage.
An unusual event is the lowest of four emergency classifications that can end up declared at a nuclear reactor as defined by the Nuclear Regulatory Commission (NRC), the federal agency which oversees operations of the nation’s nuclear power plants.
A relief valve on a system that supplies water to the reactor coolant system improperly opened during troubleshooting by plant workers, Delmar said.
The leak was approximately less than 25 gallons. The release had an impact on the pressure level inside the reactor coolant system.
Workers stopped the leak in less than a minute, but because the leak was greater than 10 gallons a minute, federal rules mandated the declaration of an unusual event.
Delmar said the reactor coolant system contains more than 90,000 gallons of water.
There was no release to the environment of the slightly radioactive water, Delmar said. The water went into a holding tank.
He said he could not give an estimate when the plant would restart.
The reactor is at PSEG Nuclear’s Artificial Island generating complex on the banks of the Delaware River in Lower Alloways Creek Township.
The reactor is one of three operated by PSEG Nuclear at the Island.
The plants — Salem 2 and its neighbors, Salem 1 and Hope Creek — produce enough electricity to power 3 million homes.
Salem 1 and Hope Creek were operating at full power Tuesday morning, Delmar said.
Together, the three plants comprise the second-largest nuclear generating complex in the United States.