Glitches and violations at Pilgrim station since January 2015

Jan. 27, 2015: Forced shutdown during blizzard is aggravated by several mechanical failures, including failure of diesel-driven air compressor, leaking of a safety relief valve used to depressurize the reactor, failure of manually operated relief valves and failure of a high-pressure coolant system.

April 2015: During refueling, 10 contract workers enter main condenser of the reactor to deal with a faulty gasket without wearing proper protective body gear and respirators.

May 22, 2015: Unplanned shutdown during a return to power after refueling because of problems with a main condenser that uses water from Cape Cod Bay to cool steam from the reactor.

 

Aug. 22, 2015: Automatic shutdown, avoiding a potentially dangerous situation when a valve that regulates steam transfer from the reactor to the turbine closes when it should remain open.

October 2015: NRC finds that on eight occasions between 2012 and 2015, both meteorological towers, which report wind speed, direction and air temperature during a radiological emergency, were not operating. Pilgrim operators would have been forced to rely on the National Weather Service in Taunton for data.

November 2015: Report by NRC inspectors identifies failure of workers to monitor the alarm system adequately, to perform required test on second emergency generator after first one failed and to adequately assess operability of plant’s shutdown transformer.

January 2016: Water leak in core spray system that helps cool down reactor after sudden shutdown. The leak had allowed air bubbles to enter the system, which could have hindered water flow. The leak occurred in January 2015 but was not entered into an action plan until January 2016.

February 2016: Entergy reports that security officer at Pilgrim failed to conduct assigned fire watches more than 200 times between 2012 and 2014 in areas that required hourly checks because fire-suppression systems were inoperable. The worker then falsified logs to make it look as if the watches had been done.

Aug. 18, 2016: The main steam isolation valve, one of eight designed to close quickly to prevent radioactivity from leaking into the environment during a nuclear incident, fails during testing. It is part of the same valve system that caused Pilgrim to shut down in August 2015.

Sept. 6, 2016: Reactor manually shuts down after water levels in the reactor fluctuate unexpectedly because of a malfunctioning regulator valve. Three days later, plant operators report the plant leaked 2,680 cubic feet of hydrogen into the environment.