NRC to examine Pilgrim shutdown record
PLYMOUTH — Federal regulators plan to take a hard look at Pilgrim Nuclear Power Station's record for unplanned shutdowns in light of last week's forced power-down, which kept the plant offline for more than four days.
The nuclear plant was back in service and producing electricity for the New England grid shortly before 2 p.m. Monday, after problems that forced operators to manually shut down the plant early last Thursday were addressed.
Forced Pilgrim shutdowns
- May 22, 2012: Condenser lost vacuum pressure. Power returned on May 27.
- Jan. 10, 2013: Dual trip of both recirculation pumps. Power returned Jan. 17
- Jan. 20, 2013: Leaking safety relief valve. Power returned Jan. 24.
- Feb. 8, 2013: Loss of off-site power and main generator load reject because of storm. Power returned Feb. 16.
- Aug. 22, 2013: Breaker trip caused water pumps to reactor to shut down. Power returned Aug. 26.
Source: Nuclear Regulatory Commission
Plant technicians fixed some wiring related to a tripped breaker that had cut off power to water pumps that cool the reactor.
For the 41-year-old plant, owned and operated by Entergy Corp., it marks the fifth shutdown in the past 15 months.
And although the cause of the shutdown was identified and addressed, its ramifications will continue to be examined by federal nuclear regulators.
Neil Sheehan, spokesman for the Nuclear Regulatory Commission, said the shutdown record is higher than the average.
"We're still assessing how this will be handled in terms of the performance indicators," Sheehan said.
Federal regulators have a set of standards that plants must meet. If they don't, their operations are watched more closely. Currently 23 of the 100 nuclear power reactors operating in the United States require that tighter level of oversight.
David Lochbaum, director of the Nuclear Safety Project for the Union of Concerned Scientists, said the average nuclear reactor in the U.S. experiences about one unplanned shutdown a year, resulting from weather or a component malfunction.
He called the Nuclear Regulatory Commission's performance indicators "the public's safety net for excessive numbers of shutdowns."
"When the number of any reactor exceeds three (in roughly a year), the NRC sends more inspectors to the site to turn over rocks looking for common causes: Is the high number of shutdowns due to inadequate budget, insufficient staffing, aging equipment or any fixable cause, or is it merely due to coincidence and bad luck?"
Lochbaum said the NRC "has tools like sanctions" to compel fixes at plants that fall short.
Sheehan said the NRC is not concerned about the thoroughness of Entergy's investigation into the problem that shut down the plant last week, or how the repairs were done. But, he added, "we will continue to evaluate how this forced outage will affect the plant's performance indicators."
Carol Wightman, spokeswoman for Entergy, said the company will do whatever is required by federal regulators. "If shutting down is the right thing, that's what we'll do," Wightman said. "Safety is our highest priority."
Pilgrim produces about 15 percent of the electricity used in Massachusetts, enough to power nearly 700,000 homes.
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