PLYMOUTH - After a six-day shutdown to address steam leaks in a valve system designed to contain radiation during a nuclear accident, Pilgrim Nuclear Power Station was reconnected to the power grid Thursday night and was at 77 percent of full power by Friday morning.
The reactor had been shut down Dec. 16 following the discovery of leaks in three of the eight main steam isolation valves. Two were repaired, but the operators decided to shut down the reactor to address problems with the third.
The valve system is designed to close quickly to prevent radiation leaks during a nuclear accident.
This latest leak, which required a weld repair, marked the third time in 16 months that problems with the main steam isolation valve system caused the reactor to shut down.
The plant went into automatic emergency shutdown in August 2015 to prevent a buildup of reactor pressure after a steam isolation valve closed when it should have remained open. Just weeks after that incident, federal regulators shifted Pilgrim into its so-called Column 4 performance category - as low as a plant can go without being ordered to simply shut down.
This past August, one of the isolation valves failed to close quickly enough to meet federal standards during testing. The plant was shut down and the valve repaired.
The recent leaks were discovered during a "walk through" by plant operators conducted late last week. The reactor had been reduced to 25 percent power, at the time of the discovery, to conduct some required testing of the turbine system.
A spokesman for the Nuclear Regulatory Commission stressed that the three problems with the valve system were unrelated. "These were all separate and distinct issues that demanded attention and received it," Neil Sheehan wrote in an email. "That said, we are constantly assessing whether specific problems have broader implications, such as weaknesses in a plant's maintenance program."
Patrick O'Brien, spokesman for Entergy Corp., Pilgrim's owner-operator, said operators had taken the conservative approach in their decision to shut down the reactor to repair the valve. Other maintenance, which can only be done during a shutdown, had been conducted in addition to the valve repair, he said.
Karen Vale, a Pilgrim watchdog and coordinator for citizens group Cape Cod Bay Watch, disagreed with O'Brien's characterization. "There was nothing 'planned' about these steam isolation valve leaks," Vale wrote in an email. "It's totally irresponsible of Entergy and especially the NRC to keep pushing this plant forward considering the long list of problems it has experienced just in the past year."
Pilgrim is currently undergoing a three-week inspection, temporarily suspended for the holidays.
A team of 20 inspectors from around the country spent from Nov. 28 to Dec. 9 scouring systems and worker performance at Pilgrim, based on its poor performance status. They will return Jan. 9 for a final week.
In an in-house email outlining preliminary observations, which was mistakenly sent to citizen activist Diane Turco, president of the Cape Downwinders, the leader of the inspection team described staff as "overwhelmed."
On inspector Donald Jackson's list of findings were failure of plant workers to follow established industry procedures, broken equipment that never gets properly fixed, lack of required expertise among plant experts, failure of some staff to understand their roles and responsibilities, and a team of employees who appear to be struggling with keeping the nuclear plant running.
"The corrective actions in the recovery plan seem to have been hastily developed and implemented, and some have been circumvented as they were deemed too hard to complete," Jackson wrote of Entergy's plan to bring Pilgrim back up to acceptable standards. "We are observing current indications of a safety culture problem that a bunch of talking probably won't fix."
Plymouth selectmen demanded that a representative from the Nuclear Regulatory Commission attend a meeting and clarify the alarming information in the email, but Daniel Dorman, director of the NRC's northeast region, rejected that demand. Dorman said the email contained a series of initial observations that should have never made their way to the public.
Dorman said no meeting would take place until the inspection had been completed and the report filed. That would push the date for any discussion into February.
Entergy plans to shut Pilgrim down permanently on May 31, 2019. Opponents, however, have been clamoring to get the reactor shut down immediately.
"Neil Sheehan said this latest shutdown won't count against the company in any way because it wasn't an emergency shutdown - they look at it as 'planned maintenance.' We know that cannot be true because it is evident Entergy never plans on maintenance until something breaks," said Mary Lampert, director of the anti-Pilgrim group Pilgrim Watch.
Turco also pointed to the inspection email.
"We have a civic obligation to be outraged at this restart given evidence from the NRC email describing the serious lack of preventative maintenance and mismanagement that puts us all at unacceptable risk," Turco said.
- Follow Christine Legere on Twitter: @ChrisLegereCCT.