BRATTLEBORO, Vt. — Entergy Nuclear officials continue to be dogged with questions about groundwater leaking into the radioactive turbine building at the shuttered Vermont Yankee nuclear plant.
Entergy spokesman Joe Lynch told the Vermont Nuclear Decommissioning Citizens Advisory Panel last week that the rate of the water coming into the building — and getting contaminated — has reached the lowest level since the problem was discovered in January 2015.
Lynch said efforts at sealing the foundation of the large turbine building appeared to finally be paying off and the rate of infiltration had dropped to 200 to 300 gallons a day, down from about 2,500 to 3,000 gallons a day shortly after Vermont Yankee shut down in December 2014.
But Lynch, who has given regular updates about the problem to the panel, said it has cost Entergy $3.2 million so far for disposal and handling costs.
More than 623,000 gallons of water have been shipped to Tennessee for treatment and disposal, at a cost of $2.5 million, with the balance in handling costs, he said.
Entergy had budgeted $10 million in its overall decommissioning budget of $1.2 billion toward water processing, Lynch said, although some of the costs are coming out of contingency funds included in the overall budget.
State Rep. Laura Sibilia of Dover, one of the newer members of the 17-member advisory panel, asked what would happen to the water once the turbine building is partially demolished as is expected to happen under the current decommissioning plan.
NorthStar Group Services, which has proposed buying Vermont Yankee from Entergy, says it only needs to demolish 4 feet of the turbine building’s foundation below the surface.
After the meeting, Lynch said the contaminated turbine building foundation would have to be cleaned of any radiation before it is filled with “rubblized” concrete or other materials, as part of NorthStar’s decommissioning plan.
But Sibilia said after the meeting she still had questions after Lynch’s explanation, and said it was important to also hear from NorthStar about its exact plans.
Lynch said he wasn’t sure what had finally reduced the amount of water, since in the past, sealing one part of the foundation just pushed the groundwater to another spot, causing leaks.
The water infiltration wasn’t a noticeable problem while Vermont Yankee was operating, he said, since the residual heat in the turbine building evaporated the water.
The water leaking into the building goes into a series of sumps and is collected for transportation, Lynch said.