NRC launches special inspection on storm-related outage at Pilgrim

The Nuclear Regulatory Commission (NRC) said Feb. 2 that it has launched a special inspection at the Entergy (NYSE:ETR) Pilgrim nuclear plant in Plymouth, Mass., to look into issues surrounding a storm-induced unplanned shutdown on Jan. 27.

Pilgrim is a roughly 670-MW boiling water reactor (BWR) located about 40 miles south of Boston. The unit was still listed at zero generation early Feb. 3, according to NRC’s daily reactor status report.

The six-member team was to arrive on-site Feb. 2. The NRC team will be assigned with reviewing equipment issues that occurred during the shutdown, including the partial loss of off-site power; the failure of a condensate pump motor associated with the plant’s High-Pressure Coolant Injection (HPCI) system; and the malfunctioning of one of the plant’s four safety relief valves.

Pilgrim, like other nuclear power plants, transmits power to the grid but also receives power back for operational purposes.

During the recent major winter storm, one of two 345-kV lines that provide off-site power to the plant tripped. In response, plant operators began reducing power. At about 50% power, the second 345-kV line also tripped, resulting in a reactor shutdown, or scram, at about 4 a.m.

A third off-site power line, a 23-kV line, remained available, NRC said.

Operators started the plant’s two emergency diesel generators and transferred electrical loads for safety systems to those on-site power supplies due to concerns with off-site power. The transfer was performed by the operators prior to the loss of the off-site power lines.

“The Pilgrim reactor was safely shut down following the loss of two off-site power lines,” NRC Region I Administrator Dan Dorman said. “Nevertheless, we want to examine more closely the challenges that surfaced during the event, including safety system and equipment problems and the loss of the two off-site power lines.”

An inspection report documenting the team’s findings will be issued within 45 days after the completion of the review.

About Wayne Barber 4201 Articles
Wayne Barber, Chief Analyst for the GenerationHub, has been covering power generation, energy and natural resources issues at national publications for more than 20 years. Prior to joining PennWell he was editor of Generation Markets Week at SNL Financial for nine years. He has also worked as a business journalist at both McGraw-Hill and Financial Times Energy. Wayne also worked as a newspaper reporter for several years. During his career has visited nuclear reactors and coal mines as well as coal and natural gas power plants. Wayne can be reached at wayneb@pennwell.com.