The Pilgrim nuclear power plant will undergo more federal inspections after regulators downgraded the facility.
Company officials expected the downgrade for up to three months, but the Nuclear Regulatory Commission (NRC) released the news last Tuesday.
“This will lead to Pilgrim moving to the degraded cornerstone column … and result in still more inspections by the NRC,” said spokesman Neil Sheehan.
The latest downgrading of Pilgrim comes four months after engineers and crews made an October “scram,” or unplanned shutdown, when the plant lost power from a 345-kilovolt NStar line that provides electricity to the plant.
That shutdown – the second such incident in 2013 – lasted a week. Pilgrim was offline more than 80 days in 2013, with 46 of those days from scheduled refueling and maintenance.
Dave Lochbaum, a nuclear engineer and the director of nuclear safety at the Cambridge-based Union of Concerned Scientists, viewed the latest downgrade in a positive light.
“For people living around the plant, you prefer good grades on a report card, but the good news is that the NRC is going to send a lot of troops to make sure Entergy fixes the problem,” Lochbaum said. “There’s an awful lot of incentive for Entergy to fix the problems and send those NRC inspectors back home.”
In a report filed with the NRC and released last month, Entergy Corp. – the Louisiana company that operates Pilgrim and 10 other nuclear plants in the U.S. – said the root cause of the October shutdown was a buckled wooden tower support for an electric transmission line.
Entergy said that NStar replaced the defective wooden pole and inspected two others.
In November, NRC Chairwoman Allison Macfarlane toured the Plymouth plant and said the NRC closed down other nuclear plants for poor performance.
She compared Pilgrim to the Fort Calhoun nuclear station in Nebraska, which the agency shut down two years ago.
“It’s not in the worst shape,” Macfarlane said about Pilgrim, “but it’s been headed in that direction (of Fort Calhoun), and we want to make sure they don’t get there.”
Entergy has said it has conducted “rigorous reviews” of the shutdowns to identify needed improvements.
Pilgrim is one of the oldest operating nuclear power plants in the U.S. Built by Boston Edison, it went online in 1972. Entergy bought the plant in 1999 and secured a new 20-year license in 2012, after a six-year license review.