Entergy: Radiation monitors did their job
Vermont Gov. Peter Shumlin’s administration wants more information from the Nuclear Regulatory Commission about what it called the failure of radiation monitors at the Vermont Yankee nuclear plant.
But Entergy Nuclear, owner of Vermont Yankee, said Saturday that while the monitors were not reporting properly, they still performed their function in controlling the ventilation of the reactor building.
Robert Williams, spokesman for Entergy, said the four monitors were “showing spurious signals, but they were still able to perform their safety function.”
He added, “To be perfectly clear, the monitors did not fail. They did not fail; they were generating false signals.”
According to Entergy’s preliminary report to the NRC, the monitors showed high levels of radiation in the primary containment isolation system. A worker was sent in to check the reading, and verified radiation levels to be normal.
Williams said the plant had many radiation monitors, not just the ones that reported false signals.
Entergy decided as a precaution to replace the four monitors, which malfunctioned June 14 and again July 11, according to a report posted by the Nuclear Regulatory Commission last week.
Darren Springer, deputy commissioner of the Department of Public Safety, released a letter Friday he had sent to the NRC’s Region One administrator, William Dean. In the letter Springer asked for more information about the radiation monitors and questioning the 60-day period allowed for Entergy to file a report.
Springer couldn’t be reached for comment Saturday.
“Failure of the radiation monitoring equipment is a serious issue, and could have under other circumstances led to significant harm if the failed equipment had not detected a radiation release at the plant,” Springer wrote to Dean.
The radiation monitors that had erroneous spikes were associated with the ventilation system.
According to the NRC notification of the problem, “the cause of the spurious spikes is attributed to an unknown source of electrical noise,” and the report noted the problem had been entered into Vermont Yankee’s “corrective action plan.”
Springer said the state wanted a full accounting of the information Vermont Yankee provided to the NRC about the incidents. His letter also asked for information on the age and functionality of the failed monitors and if they were considered when NRC relicensed Vermont Yankee in 2012 for another 20 years of operation.
Springer said the state felt that such a “potentially serious equipment failure” should not be allowed a 60-day reporting requirement rather than immediate notification.
“Common sense would dictate that radiation monitoring equipment be functioning properly 100 percent of the time, and that such equipment failures would be immediately reported to regulators and corrected,” he wrote to the NRC.