PROVINCETOWN — A Woods Hole oceanographer has completed an extensive study of probable pathways the contaminated water will take if one million gallons from the Pilgrim Nuclear Power Station’s spent fuel pool, reactor cavity, and other systems are released into Cape Cod Bay.
The study follows up on findings presented in March that projected the flow of the water from the discharge canal at Pilgrim southward. The new results show one stream of the water would flow to the bay’s interior and circulate, while a second stream would head toward Race Point in Provincetown and flow south, hugging the coast of the Outer Cape.
Scientist Irina Rypina drew on data gathered over 30 years by 417 drifter buoys in the bay. She applied six different methods of analysis to the data. “Each technique highlights different aspects of the problem, but the results agree and reinforce each other, so that together they tell a coherent story about the likely fate of the dissolved components in Pilgrim Nuclear Power Station’s wastewater,” Rypina wrote in an article detailing her work, “Spreading Pathways of Pilgrim Nuclear Power’s Wastewater in and Around Cape Cod Bay.”
The results, which Rypina gave to the Independent, will be published in the December issue of the Journal of Environmental Radioactivity.
“The study was motivated by the closing of the Pilgrim Nuclear Power Station and the proposal to release the water into the bay,” Rypina said in a phone interview last week. “I wanted to take a scientific approach and try to understand if that was to happen, what would be the fate of this wastewater.”
Holtec Decommissioning International, the company that purchased the Plymouth plant when it shut down and is now decommissioning it, announced late last year that it planned to release more than one million gallons of radioactive water that remain onsite into Cape Cod Bay. The company has stated that the water would first be treated to reduce the levels of contamination to within allowable federal limits, then diluted and released in batches via a channel running from the plant into the bay.
The plan has prompted public opposition, with concerns about health and environmental effects compounded by worries about potential economic impacts, since the region’s main sources of income are tourism and fishing.
Holtec has agreed to delay the release while it studies other options, which include shipping the wastewater to a disposal facility, evaporating it using diesel generators, and onsite storage. Holtec spokesman Patrick O’Brien said in an email on Monday that the company will probably employ a combination of all four options.
That contradicts what company president Krishna Singh said in a June letter to U.S. Sen. Edward Markey: that shipping it offsite, which would cost about $20 million, was off the table.
Rypina said that she does not mean to take sides in the debate over the release of the water. Her study is simply to determine spreading pathways created by the ocean flow based on probabilities. The information would help in making a more informed decision, she said.
Rypina’s models show the water would initially spread in all directions from the release point. The southward portion then splits. The stream that heads toward Race Point in Provincetown would likely arrive a few days after release, then form a strong southward current along the back shore. The plume flowing north from the plant would ultimately take a sharp turn and also head toward Race Point.
The remainder of the southward flow would go into the bay, traveling slowly along the bay’s interior and circulating near Dennis and Brewster for several days.
As the plume from Pilgrim travels inside the bay and along the Outer Cape, it would be diluted by as much as 100 times from initial concentrations at the point of release. But that may not be enough to avoid accumulation of contaminants, according to the study. “Although the plume will be significantly diluted, the passing of the plume in close proximity to the coast has the potential to lead to the accumulation of some radionuclides in the sediments, and the long flushing times of the southern/eastern Bay further enhances this concern,” wrote Rypina.
Rypina noted that details about which radionuclides are present in the water at Pilgrim have been vague. “The wastewater likely contains several types of radionuclides, including cesium-137, strontium-90, cobalt-60, tritium, and the isotopes of plutonium whose half-lives range from tens to tens of thousands of years,” she wrote, citing research related to radionuclides generally found in wastewater from nuclear power plants.
Strontium-90, Rypina wrote, which is a common product of nuclear power activities, behaves in a similar fashion to calcium, “so would end up preferentially in carbonate shells of shellfish and the bones of fish.”
Recent studies have shown that radioactive cesium can accumulate in beach sand and over time wash back into the ocean with the tides, Rypina wrote.
Holtec’s Senior Compliance Manager David Noyes told the Nuclear Decommissioning Citizens Advisory Panel that he would provide information on both nonradioactive and radioactive contaminants in the water at the panel’s Nov. 28 meeting.
Lobsterman Josiah Mayo, who lives in North Truro and fishes out of Provincetown, was surprised Holtec has not yet publicly disclosed both the radioactive and nonradioactive contaminants in the plant’s water. There are already “notable irregularities in the waters of the bay,” Mayo said, referring to the low oxygen levels that have been causing lobsters and scallops to die. “Where we have things going on in the bay, why add this? I can’t imagine there’s any lobsterman that thinks it’s a good idea.”
Mayo also brought up the possible effects of negative public perceptions associated with the release. “I’m probably not going to have an issue with eating lobster, but it’s still not a good look,” Mayo said. “I know some people will say, ‘You know what? I’m not going to eat lobster and clams from Cape Cod Bay.’ ”
Mike Rego, a lobsterman in the bay, is a fourth-generation fisherman who lives in North Truro. He said a release into the bay from Pilgrim “would be catastrophic.” In addition to contending with low oxygen levels, Rego said fishermen have also had invasive algae to contend with. “I think the bay is just too delicate a place,” said Rego when asked his view of a possible release from the Pilgrim plant. “If it gets stalled in the bay, what’s it going to do to the lobsters and krill? Who is going to want to eat Cape Cod Bay lobsters, fish, scallops, or shellfish?”
While plans and protests continue here, a similar battle over the release of contaminated water is shaping up around the Indian Point nuclear power plant in New York, which is also owned by Holtec and in the process of being decommissioned.
Legislators in Ulster County have written to the regional director of the New York State Dept. of Environmental Conservation, the New York State Public Service Commission, and the Nuclear Regulatory Commission to express opposition to Holtec’s request to “dump irradiated water containing radionuclide tritium and other contaminants into the Hudson River.”
Seven municipalities in the mid-Hudson region rely on the Hudson River for their drinking water, the legislators said. They called the contamination “avoidable” since there are other methods to safely contain and dispose of the wastewater.
Rypina believes further research should be done. One limitation of her research using drifters, she noted, is that most are recording currents approximately three feet below the surface. The data also do not take into consideration the seasons, the weather, or wind conditions, which can affect the direction of the currents.
“The wastewater transport studied here is just one part of the story,” said Rypina. The radioactive contaminants will need to be considered in a more complete assessment of potential releases from the Pilgrim nuclear plant, she said.
O’Brien has said the water will still be in use at the plant through the first quarter of next year. Any planned release would be done after that.