Pilgrim nuclear plant remains shut for repairs

By Erin Ailworth, Globe Staff

The Pilgrim Nuclear Power Station in Plymouth, which shut down after losing power to its safety systems during the weekend snowstorm, once again has electricity, but will remain out-of-commission while repair work is done on a leaky safety relief valve that caused a problem at the plant last month, federal regulatory officials said,

The power, provided by local utilities, returned at midnight on Tuesday, according to a statement from the US Nuclear Regulatory Commission.

“Our resident inspectors assigned to Pilgrim will continue to closely follow the repair work and other activities as the company plans to return the unit to service,” the Commission statement said.

Pilgrim, which is owned by Entergy Corp. of Louisiana, first lost power Friday night when three offsite power lines were knocked out of service during the storm, according to regulatory filings and the NRC. The plant was taken offline, and diesel generators powered its safety systems. Electricity temporarily returned to the plant on Sunday morning, but went out again when plant operators believe a transformer was struck by falling ice.

Entergy representatives did not immediately be reached for comment. But Entergy spokeswoman Carol Wightman said Sunday that Pilgrim would only come back online once it had gone through testing and maintenance. She could not say when that would be.

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

The leaky safety valve that is now being repaired caused one of the January shutdowns. The other happened when the plant’s recirculation pumps, used to adjust power levels, stopped working.