The Pilgrim Nuclear Power Station in Plymouth remained shut down Sunday, days after operators discovered leaks in three steam valves that prevent radioactivity from reaching the environment, according to plant officials.
The plant was shut down Thursday as a precaution after the leaks were discovered during scheduled testing, said Entergy spokesman Patrick O’Brien in a statement Sunday.
“There was and is no impact to the safety of the public or plant staff,” O’Brien said.
On Thursday, plant operators found three of eight main steam isolation valves were leaking and repaired two of them but were unsuccessful with the third, Neil Sheehan, a spokesman for the Nuclear Regulatory Commission, said in a phone interview Sunday.
The repairs were observed by commission inspectors who are stationed full time at the plant, said Sheehan.
In the event of a severe accident, the plant’s main steam isolation valves would close and prevent radioactivity from getting out into the environment, said Sheehan.
It was unclear when the power station would open again.
Sheehan said he did not have information about when it would reopen, and O’Brien said in his statement that the plant’s return is “100% is market sensitive and we do not make that time public.”
Sheehan said the commission’s inspectors are monitoring plant operators during efforts to bring the plant back online. He said the incident will not change the commission’s oversight of Pilgrim, which is already “on the highest level of scrutiny” by the agency.
“The company is taking the appropriate steps in trying to address it,” said Sheehan.
Thursday’s incident was the third time since August 2015 that Pilgrim has been shut down due to problems related to these valves, according to event reports issued by the Nuclear Regulatory Commission.
In August 2015, a steam valve closed unexpectedly, and plant workers had to repair the damage, according to the commission. Last August,the commission reported that a steam valve failed during testing.
Sheehan said Sunday that commission inspectors will follow up on the company’s responses to those earlier problems with the steam valves at Pilgrim.
The aging Pilgrim, which has a poor safety record and is set to be closed in May 2019, has a “safety culture problem,” according to a commission memo released to the media earlier this month.
The memo, first obtained by The Cape Cod Times, reported that plant staff were “overwhelmed” and struggling to improve performance.
The memo’s author recently completed part of an inspection of Pilgrim that the agency referred to as a “top-to-bottom review” of the plant.
According to a statement from the commission, a two-week inspection that ended Dec. 9 was intended to evaluate the company’s efforts to address underlying issues that have affected the plant’s safety performance.
The commission’s inspection team will return to the plant next month for an additional week of work, which was planned before the plant’s shutdown Thursday.
Sheehan and O’Brien said they did not know whether the inspectors looked at the valves that were the focus of the repair. O’Brien said these valves are tested quarterly by plant operators to ensure they meet technical specifications.
Pilgrim critics said the most recent shutdown is more evidence that the plant must be closed immediately.
“Pilgrim has passed its expiration date,” said Mary Lampert, founder and director of Pilgrim Watch.
Diane Turco, the director of the environmental group Cape Downwinders, said her group will protest at the plant when the commission’s inspectors return.
“This is just the hallmark signature of a repetitive degrading nuclear reactor that threatens us all,” said Turco in a statement.John Hilliard can be reached at firstname.lastname@example.org.