New testing of the contaminated water inside the Pilgrim Nuclear Power Station is set to begin in two weeks.
Collection of water samples is scheduled for June 4, according to Seth Pickering, a deputy regional director at the state Department of Environmental Protection.
Speaking Monday to the state’s advisory panel on Pilgrim, Pickering said plant owner Holtec International has agreed to test for radioactive materials that are difficult to detect — which a previous round of testing, last year, did not do.
“Holtec will also collect samples of hard-to-detect radionuclides in this sampling event,” he said in prepared remarks.
DEP will observe the sampling.
Also during the meeting, Holtec discussed new data the company has filed with federal regulators on radioactive tritium evaporating into the outdoor air.
Tritium released into the air from Pilgrim — or more precisely, the amount of radiation from tritium, measured in curies — nearly doubled in 2023 over the previous year.
But the radiation dose to a hypothetical person is still tens of thousands of times lower than the limit imposed by the U.S. Environmental Protection Agency, according to David Noyes, a compliance manager with Holtec Decommissioning International, a subsidiary of Holtec International.
The hypothetical person receiving that dose, he said, “would be somebody that is inhaling the gasses that are released from the plant at the highest potential concentration and the individual that is eating material from the deposition of that potential material.”
He showed a chart that indicated the 2023 dose was 0.00031 millirem, which is about 80,000 times less than the EPA limit of 25 millirem.
Airborne tritium emissions from Pilgrim last year were also lower than in 2019, the year the plant was shut down.
Opponents of Holtec’s plan to discharge the water into Cape Cod Bay say the exact amount of tritium in the water is irrelevant, because state law prohibits the release of industrial waste into a designated Ocean Sanctuary, including Cape Cod Bay.
Pickering, of DEP, said Pilgrim’s latest tritium data, as reported by Holtec, fall well within standards established by the U.S. Nuclear Regulatory Commission.
Holtec is seeking to dispose of the water as part of the decommissioning of the nuclear power plant. The company has proposed discharging about 1 million gallons of water into Cape Cod Bay and has applied for a permit modification to do so.
Water treatment can remove much of the contamination, but not all.
Last April, testing of pre-treated water showed it contained tritium, which is a radioactive isotope of hydrogen, and four “principle” gamma radiation emitters: manganese-54, cobalt-60, zinc-65, and cesium-137. Metals, volatile organic compounds, and PFAS chemicals were also detected.
One material last year’s testing did not cover was strontium-90, a radionuclide of particular health concern.
