A recently released study conducted by the Woods Hole Oceanographic Institution finds that any wastewater  discharge allowed as part of the decommissioning of the Pilgrim Nuclear Power Station has a “high probability” of lingering in Cape Cod Bay for more than a month.

The study looked at the potential for the wastewater to spread toward Cape Cod communities against the likelihood the current would carry it out to sea, and according to the Institute’s modeling the former scenario is the more probable.

“Our numerical simulations suggest it is unlikely that the bulk of plume waters will leave the Bay in less than a month,” study leader Irina Rypina said in a statement.

It’s also likely that the wastewater could drift near the shores and coastal waters of Dennis, Wellfleet, and Provincetown, according to the study, and “if the release were to happen in the spring and summer, a small portion of a plume might leave the Bay in less than a month, passing north of Provincetown and then flowing southward along the outer Cape.”

To arrive at their findings, the team at WHOI used a “state-of-the-art, high-resolution ocean circulation model” employed by the National Oceanic and Atmospheric Administration to figure out how discharged water might move, and compared the model to information gleaned from drifting sensors and free-floating buoys used to measure ocean current. The study focused on the potential movement of wastewater in the upper six feet of seawater at various points in the year.

“We found virtually no out-of-the-Bay transport in winter and fall and slightly larger, but still low, probability of some of the plume exiting the Bay in spring and summer,” Rypina said.

The study did not investigate what health risks emptying nuclear wastewater into the Bay might pose to marine life or how it might impact local industries like fishing and recreation.

In 2023, analysis conducted by Florida-based Holtec International, the plant’s owner, and the Massachusetts Department of Public Health found that the about 900,000 gallons of wastewater stored at Pilgrim is contaminated with “four gamma emitters (Manganese-54, Cobalt-60, Zinc-65 and Cesium-137) and Tritium (H-3 a beta radiation emitter).”

According to “frequently asked questions about water discharged at Pilgrim Nuclear Power Plant” information sheet provided by the Nuclear Regulatory Commission, nuclear wastewater discharge is a normal part of plant operations and decommissioning.

“The controlled release of liquid effluents at nuclear power plants, within specified regulatory limits, is an activity that occurs throughout the operation and decommissioning of a facility,” the agency wrote, noting that the NRC considers “such releases as part of the agency’s safety and environmental determinations, ensuring that it is safe for people and the environment.”

A spokesperson for Holtec told the Herald that Pilgrim had “safely” discharged millions of gallons of water during the decades it’s been there, with little environmental impact.

“Those discharges were done within the safe federal and state limits and reported to the NRC and publicly available on their website. This includes studies to determine any potential impact to sea life and the Bay which showed that safety has always remained and plant impact has been negligible,” the spokesperson said.

The Pilgrim Nuclear Power Station, located in Plymouth, shut down in May of 2019 after 47 years of operation. Owned then by Louisiana-based Entergy Corporation, the plant was purchased by a subsidiary of Holtec in 2019 with an aim toward cleaning up the 1,700-acre site and offering it for industrial and commercial development.

At the time of its purchase, Holtec President and CEO Kris Singh assured Bay State residents that the project would “replicate the superb record of public health and safety and environmental protection that typified the plant’s 47 years of operations.”

However, in the early 80s, then-Nuclear Regulatory Commissioner James Asselstine described Pilgrim as one of the worst run and least safe nuclear power plants in the country. During a hearing before the U.S. Senate Committee on Labor and Human Resources in 1988, then-State Sen. William Golden called the facility “one of the worst-managed nuclear plants in the country.”

In response to the study, U.S. Sen. Ed Markey, who chairs the Senate’s Environment and Public Works Subcommittee on Clean Air, Climate, and Nuclear Safety, said in a statement that the findings confirm concerns expressed by the residents of the Cape, who have been questioning the wisdom of dumping plant wastewater into the Bay “for years.”

When Holtec bought the plant, Markey said, Singh promised both the Senator and impacted communities that the process of decommissioning would be “open and transparent.”

“In the years since, Holtec has fallen woefully short on this commitment. In light of these recent findings, I urge Holtec to develop a wastewater discharge plan that is informed and guided by scientific fact and community input,” Markey said.

Holtec’s attempt to seek authorization to “empty all the wastewater held in the spent fuel pool, reactor cavity, and dryer separator pit” at Pilgrim was halted by the state’s Department of Environmental Protection in May, with officials citing the state’s Clean Waters Act. The company is appealing that decision.

This 2011 file photo shows the Pilgrim Nuclear Power Station in Plymouth. (AP Photo/Steven Senne, File)