VERNON, Vt. — The Nuclear Regulatory Commission is evaluating responses from Entergy Nuclear about its plans to ship hundreds of thousands of gallons of radioactive water to a processing facility in Idaho and the radioactive exposure to its truck drivers.
Earlier this year, the Commission asked Entergy to flesh out a plan for disposing of 200,000 gallons of radioactive water in the torus, a large, doughnut-shaped structure at the bottom of the reactor core that holds 1.1 million gallons of water.
But in a series of questions that Commission staff posed to Entergy, it was clear the federal regulators wanted additional information about the risk of radioactive exposure the water posed to the workers who came in contact with the torus water, in particular the truckers who would be transporting the radioactive water thousands of miles to Idaho.
Entergy said they expected the truck driver would not sleep in his cab, and would take breaks, so that his exposure would not be for a continuous 24 hours.
The Commission faulted Entergy for only taking one sample or reading of the radioactivity level in the water in the torus, with the federal regulators saying they wanted additional samples for a more accurate reading and analysis of the various radionuclides in the water.
In addition, Entergy may include in its plans what it is calling the “infiltration water” — groundwater that is seeping into the turbine building and becoming contaminated with radioactivity in the process. Entergy has been shipping that water, which it says is “slightly” radioactive, to a different facility in Tennessee.
Last month, Entergy disclosed that it had asked the Shumlin administration if it could discharge the infiltration water to its storm drains, and thus into the Connecticut River. The state replied that it would evaluate the request.
Neil Sheehan, a spokesman for the Nuclear Regulatory Commission, said that Entergy had transferred reactor coolant water to the torus after the reactor was shut down, and Commission documents showed that radioactivity increased substantially.
Martin Cohn, Entergy spokesman, said Tuesday that Entergy was looking for “different ways of dealing with our water.” He said the torus now also held “process” water from other nuclear systems at the plant, part of the overall strategy of shutting down as many systems as possible as Entergy readies Vermont Yankee for decades of “cold and dark” storage.
Cohn said that Entergy had been able to negotiate a lower price for disposing of the contaminated water with Energy Solutions, a company in Tennessee.
“As a result, this wasn’t as much of a priority anymore,” he said of the Idaho request. Cohn said the focus at the plant now was building the new pad to hold the spent nuclear fuel.
Transfer is expected to begin in 2018, and be completed in 2020.
Cohn said that the Commission’s request for additional information was “routine.”
“We’re doing our due diligence to understand the radioactivity levels that would be associated with the shipments, including potential impacts on the drivers operating the trucks carrying the liquids,” Sheehan wrote in an email. “These are long trips to Idaho. We note that the drive is projected to take roughly 46.4 hours. We want to ensure the radiation dose calculations for the driver properly reflect that amount of exposure.”