NorthStar Group Services has requested approval from the U.S. Nuclear Regulatory Commission to switch the means of transport to disposal of 200,000 gallons of contaminated wastewater from the Vermont Yankee nuclear power plant.
The company plans to move the wastewater primarily by rail to a disposal site in Idaho, rather than by truck as previously authorized by the federal regulator.
Then-owner Entergy closed the single-reactor nuclear facility in December 2014. In 2016, it asked the NRC to approve alternate disposal of wastewater from the reactor torus, or suppression chamber, which contains low levels of fission and activation products. The plan then was to use tanker trucks to ship the wastewater from Vermont Yankee to a US Ecology facility at Grand View, Idaho, where it would be solidified with clay for on-site disposal.
The NRC signed off on the request in June 2017, but none of the 200,000 gallons of wastewater has been shipped to date.
Entergy in January completed its sale of the plant to NorthStar, which now is fully responsible for decommissioning, site restoration, and spent fuel management at the property. The New York City-based demolition company wants to ship the wastewater by train to a US Ecology rail transfer facility in Mayfield, Idaho. The material would then be loaded into tanker trucks for the remaining 35-mile trip to the disposal site.
There is no single source for the wastewater, according to NorthStar CEO Scott State. The company also wants to ship contaminated groundwater that has been seeping into the plant’s turbine building to the US Ecology facility. Prior to the sale, Entergy had shipped hundreds of thousands of gallons of the groundwater to an EnergySolutions disposal facility in Tennessee. NorthStar has not shipped any of the groundwater since taking ownership of Vermont Yankee.
“Since this request is a slight change to that approved method, they wanted confirmation from us that it was acceptable,” NRC spokesman Neil Sheehan said by email on July 26. “That is why we are evaluating the new option.”
A decision is expected in the “near future,” according to Sheehan.
State said rail transport would increase safety and decrease costs compared to use of tanker trucks, without discussing details. Wastewater will be shipped as decommissioning proceeds.
“These shipments will occur throughout the project duration. For rail transport times in transit can vary widely due to a multitude of logistics. Generally speaking, bulk material on cross country rail transport can take a few weeks,” State told RadWaste Monitor by email. “The total number of water shipment from VY by rail will be fewer than if done by truck, as a rail tanker capacity is 4 to 5 times that of a truck tanker. US Ecology will not handle the shipments until they are received in Idaho for processing and disposal.”
NorthStar continues to deal with groundwater seepage into the turbine building, State said. The level of water intrusion “remains predictable with no significant changes beyond minor seasonal variations,” he said.
Nuclear power plants generally are allowed the release wastewater of this type into the closest body of surface water, Sheehan stated. However, an agreement with the state of Vermont prohibits Vermont Yankee from releasing any radioactivity in the form of effluent.
Under federal regulations for alternate disposal, the licensee was required to show that radioactive doses for the public and workers would be “as low as reasonably achievable.” That would be a few millirem annually for the public, according to the NRC. The prior approach for transport, management, and disposal of the Vermont Yankee wastewater met that limit, the agency determined.
“Since most of the dose in this situation would have happened to the truck driver, shipping by rail reduces the dose to the public (in this case mostly to the truck drivers) from a dose of up to about 3 millirems per year to much less than 1 millirem per year,” Sheehan wrote.
NorthStar plans to complete decommissioning at Vermont Yankee no later than 2030, and possibly by 2026, at a cost of $495 million. The deal with Entergy included acquisition of the plant’s decommissioning trust fund, which held $506.7 million last October.
NorthStar has already demolished the facility’s cooling towers, and is now removing debris from that operation. Ongoing work includes segmentation of the reactor vessel internals and preparing to ship turbine parts to disposal.
