VERNON — Even as Vermont Yankee administrators continue to struggle with a groundwater problem, swimming pools are no longer part of the solution.
At a March 9 press conference updating the Vernon nuclear plant's decommissioning process, officials said they've stopped using commercially available swimming pools to store contaminated groundwater that has seeped into the turbine building.
The pools were “a prudent and cost-effective near-term way of storing the water,” said Joe Lynch, Vermont Yankee's government affairs manager. But he added that such storage is no longer needed.
“They are now all drained, and now water is stored either in very large industrial bladders or in steel tanks located outside the turbine building,” Lynch said. “So we're better positioned to be able to start moving that water offsite.”
Plant owner Entergy has begun moving that water because it has been flowing at a higher-than-expected rate - sometimes thousands of gallons per day - into the turbine building. The liquid has a low level of radioactivity because of the presence of tritium, a radioactive isotope of hydrogen that is present in the building.
The first tanker truck full of Vermont Yankee water departed for a treatment facility in Tennessee several weeks ago. Lynch said two more 5,000-gallon shipments went south the week of March 7, and he added that “we'll ramp that up” in coming weeks.
Lynch also disclosed that Entergy has asked federal officials to allow a second facility, U.S. Ecology in Idaho, to accept Vermont Yankee's water. The Nuclear Regulatory Commission (NRC) may act on that request as soon as next month, he said.
The Idaho option would allow Entergy to get rid of more water faster, because, Lynch said, the Tennessee facility will accept no more than 20,000 gallons per week. Plus, “having multiple options helps us, because it keeps the cost down,” he said.
It's not yet clear what that cost will be, though the money is coming from Vermont Yankee's decommissioning trust fund. Lynch said he expects to soon disclose more financial information related to the groundwater problem.
“When we started this, the cost looked somewhat prohibitive,” he said. “But we have been able to move that cost down substantially.”
Lynch said the shipping process has been made somewhat easier by the presence of three, 20,000 gallon steel tanks outside the turbine building. Trucks can load directly from those tanks.
Shipping the water away, however, won't solve the problem. That's because groundwater has continued to seep into the turbine building's lower level, officials said.
“Typically, we're seeing it under 1,000 (gallons per day), but we're in a season now where we would expect increased groundwater,” Lynch said. “So we really need to also take care of the problem of mitigating it long-term.”
Entergy has attempted to seal cracks in the building, with mixed results. Lynch said the company still is looking into diverting the water by drilling wells near the building, but that is a complex proposition.
“We're working with a couple of very highly qualified hydrogeologists that do this for a living. They're trying to help us locate the wells,” he said. “Then you'd have to determine how many gallons per minute that you have to pump. Then you have to have the storage.”
While the groundwater issue continues, it is somewhat limited in scope: Lynch said the problem has not spread to other structures. “The other building that would have a deep foundation would be the reactor building, and there's no water intrusion in that area that I'm aware of right now,” he said.
Lynch's presentation was just one part of a decommissioning update provided March 9 at Entergy's Joint Information Center on Old Ferry Road in Brattleboro.
Most of the session focused on upcoming emergency changes at Vermont Yankee resulting from regulatory changes approved by the NRC. The federal agency ruled late last year that a decreased risk of accidents at the shutdown plant meant that Entergy could downsize its emergency planning.
Mike McKenney, Vermont Yankee's emergency preparedness manager, said the plant will be implementing its “permanently defueled” emergency plan April 19, when the NRC-approved changes take effect.
Vermont Yankee will retain an emergency response organization after that date, McKenney said, but it will be much smaller. That's true both in terms of manpower and the company's footprint, as the facilities on Old Ferry Road - Entergy's Joint Information Center and emergency operations facility - will be vacated.
“At that point, the (plant's) control room will become our main emergency response facility,” McKenney said.
Cohn said Entergy still is considering its options for the Old Ferry Road properties. For tax purposes, Brattleboro has valued the land and buildings combined at more than $2 million. The properties likely will be put on the market, and “frankly, we've received a lot of inquiries,” Vermont Yankee spokesman Marty Cohn said.
In addition to the internal changes happening next month, McKenney addressed the many outside changes related to revised emergency planning. Vermont Yankee's emergency planning zone, which now touches 18 towns in three states, will be downsized to the boundaries of the plant itself.
Most importantly, that means Entergy no longer will be federally mandated to provide financial support for the former emergency zone towns and state governments. But it also means the end of many familiar Vermont Yankee accoutrements such as tone-alert radios, emergency-preparedness calendars and Entergy-maintained sirens.
Last year, Entergy offered towns a choice: The company could remove those sirens or leave them in place to be used for other emergency purposes, though towns choosing the latter option would be responsible for future siren maintenance.
After hearing back from all of those towns, “out of the 37 sirens, we'll be removing 23,” McKenney said. “And we'll be starting that removal shortly after April 19.”
Vernon is the only Vermont town where officials chose to keep the sirens, McKenney said. Other towns retaining the warning devices for local use are Gill and Leyden in Massachusetts and Chesterfield, Hinsdale, and Winchester in New Hampshire.