The New England Coalition is asking state regulators to weigh that question, arguing that the radioactive material might be more safely and cheaply stored in special casks that could be buried at the shut-down Vernon plant.
Owner Entergy is seeking state approval for an aboveground storage facility. While a Vermont Yankee spokesman declined to respond to the coalition’s request, Entergy administrators already have said they considered — and ruled out — keeping spent fuel underground.
A subterranean storage facility “not only would be significantly more difficult and substantially more expensive to install than the aboveground … system, but also carries significant schedule and cost risks associated with an unproven system,” George Thomas, a Vermont Yankee senior project manager, told the state Public Service Board last year.
The board is weighing Entergy’s plan for a 93-by-76-foot concrete pad at Vermont Yankee. That pad would host spent nuclear fuel sealed in casks manufactured by Florida-based Holtec International.
Thirteen Holtec casks already are on a spent fuel pad at Yankee. But a majority of the plant’s spent fuel remains in a cooling pool inside the reactor building, and Entergy needs a second pad — to be constructed next to the first pad — for additional casks.
There is general consensus that the radioactive fuel is safer in dry casks than in the cooling pool. But Entergy’s storage plans have drawn some criticism, particularly among those who believe the proximity of stored spent fuel to the plant’s reactor building could impede decommissioning.
The New England Coalition’s underground storage proposal is a new twist on that theme. The Brattleboro-based activist group wants the Public Service Board to demand “a serious and open consideration of alternatives including state-of-the-art subsurface storage.”
Specifically, the coalition cites Holtec’s HI-STORM 100U model, touted as the “underground counterpart” of Entergy’s preferred casks. The coalition argues that the underground casks would be less visible as well as “waterproof; protected by the earth; designed for quicker and cheaper emplacement and removal of fuel; cheaper to decommission; and reducing emanated radiation.”
All of which is important, some say, because it’s not clear how long spent fuel will remain at Vermont Yankee. The federal government has not made good on its promise to develop a national repository for nuclear waste, leading to legal, financial and environmental issues at nuclear plants around the country.
Entergy’s current plan, based on federal guidance, is that the U.S. Department of Energy will begin removing spent fuel from Vermont Yankee in 2026 and finish in 2052. But some are skeptical, and the New England Coalition cited recent statements by Entergy executives that seem to echo that uncertainty.
“Given the serious nature of the proposed (spent fuel) project, Entergy should be required to examine all realistic alternatives in a professionally credible manner, and they should be required to produce a reviewable analysis in concert with a fully informed public,” said Clay Turnbull, a coalition trustee and staffer, in a written statement accompanying the group’s underground storage pitch.
The coalition’s request comes relatively late in the game. Entergy is expecting the Public Service Board to rule on its fuel pad request by May. The board held technical hearings last month in Montpelier.
Asked about the New England Coalition’s proposal, Vermont Yankee spokesman Marty Cohn said it would be inappropriate to comment “because it’s a legal proceeding before the Public Service Board.”
However, large portions of prefiled testimony from Thomas, the project manager, have been devoted to Entergy administrators’ rationale for the location of the spent fuel storage. In addition to detailing why the company ruled out alternate sites, Thomas has spoken directly about underground storage.
Entergy’s review of the HI-STORM 100U system found both financial and logistical difficulties. “Given the space constraints of (Vermont Yankee’s) protected area, it would be extremely difficult and expensive to excavate to the depths required to build the underground facility,” Thomas said in 2014 state testimony.
At that time, Thomas cited additional uncertainties because the underground storage system had not been used at other plants. In updated testimony filed last year, Thomas noted that two nuclear facilities had begun planning for or installing underground systems, but that did not change his opinion.
“The experience of other facilities substantiates the conclusion that the cost to install an underground dry cask storage system at Vermont Yankee would be considerably more expensive than the aboveground … system,” Thomas said.
Money is an issue not just for Entergy’s bottom line but also for Vermont Yankee’s decommissioning trust fund, which will help determine how soon decommissioning work begins. Thomas has said any delay in building the second storage pad would delay the transfer of spent fuel into dry casks, resulting in additional costs estimated at $1.7 million per month.
“These costs include site security; maintenance and support staff; insurance; electricity; fuel oil; NRC fees; taxes; and other costs that will be decreased or eliminated once fuel has been removed from the spent fuel pool and the site protected area reduced,” Thomas testified. “Entergy expects that these costs would be paid out of the plant’s nuclear decommissioning trust fund, delaying the time when major decommissioning activities could begin.”
Turnbull, though, argues that it’s more important to get fuel storage right than to get it done quickly. “The fastest way to satisfactory completion of any construction project,” he said, “is to measure twice and cut once.”