Pilgrim nuclear plant loses power again

By Erin Ailworth, Globe Staff

Pilgrim Nuclear Power Station in Plymouth once again lost power Sunday, after having it restored for several hours following an offsite outage Friday night. Three diesel generators are now providing back-up power to the facility’s safety systems, said Carol Wightman, a spokeswoman for Entergy Corp., the Louisiana company that owns Pilgrim.

“There’s no worker or public safety concern,” she said. “We’re troubleshooting the cause.”

Wightman said workers are still determining exactly what went wrong, but the outage may have been weather-related.

The plant was first shutdown late Friday when it lost its “offsite power supplies” in the middle of the snowstorm. Electricity returned to Pilgrim at 10:55 a.m. today, according to Entergy, but went back out later this afternoon, and before the facility was returned to service.

Wightman could not say exactly when the Pilgrim would be back online.

The shutdown is Pilgrim’s third this year, though the first two times -- both in January -- were caused by equipment issues at the plant, and not an offsite power loss.

A leaky safety valve caused one of the January shutdowns, while the other happened when the plant’s recirculation pumps, used to adjust power levels, stopped working.