VERNON — The first truck containing contaminated groundwater has departed from Vermont Yankee, and many more will follow.
At a Feb. 25 meeting in Brattleboro, Entergy administrators disclosed that they have begun shipping the fluid - which is flowing with unexpected intensity into the plant's turbine building - to a disposal site in Tennessee.
Officials have said the water is contaminated with relatively low levels of tritium, a radioactive isotope of hydrogen. But as the liquid leaves the Vernon plant in quantities of roughly 5,000 gallons per load, area residents shouldn't expect to see any convoys or even specially marked trucks.
“They're not placarded - in other words, we don't have to put on the side of the truck, 'radioactive material,' because the levels are so low,” said Joe Lynch, Entergy Vermont Yankee government affairs manager. “That's both under NRC rules and the (U.S.) Department of Transportation. But we use a trucking company that has a specialty in transporting this type of material.”
Administrators also defended the use of swimming pools to store contaminated water on site. Vermont Yankee spokesman Marty Cohn said the pools were one way to lessen the water problem's impact on Vermont Yankee's decommissioning trust fund.
“The whole reason for the storage was, we were negotiating prices to ensure that we were getting the best price for the transportation,” Cohn said.
Since Vermont Yankee ceased producing power at the end of 2014, Entergy has been dealing with large quantities of water seeping into the shutdown nuclear plant's turbine building. The water problem is exacerbated by the fact that, because there is no longer any heat generated by plant operations, there is very little evaporation.
“We've witnessed, since the shutdown, an increased rate (of groundwater intrusion),” Lynch told Vermont Nuclear Decommissioning Citizens Advisory Panel members at their Feb. 25 meeting. “We did expect this, but not at the current rates that are coming in. So this has posed some challenges for us.”
The Nuclear Regulatory Commission has said the water-intrusion rate averages a few hundred gallons daily but has spiked to 1,500 gallons. Lynch used even bigger numbers, saying officials “have seen influxes as high as 2,500 to 3,000 gallons per day depending on seasonal changes and inflows.”
Lynch said plant administrators have been trying to stem the water flow. Attempts to seal leaks have been “minimally effective,” he said, and Entergy is considering installing intercept wells meant to pump groundwater away from the building.
Because the liquid is contaminated via its contact with the turbine building, Entergy can't discharge it into the Connecticut River. Lynch noted that “all the water that is collected on site or used on site needs to be processed and disposed of.”
That has led to some stopgap storage methods, including heavy duty industrial bladders and several commercially available swimming pools. Federal officials and plant administrators have said the pools are safe for short-term use, and they're now apparently being phased out.
“The pools are very temporary,” Lynch told advisory panel members. “We had as many as six; we're down to four right now. It's a priority for us to move that water to the next phase, which is disposal.”
That's what has started to happen. Lynch said the first shipment of contaminated groundwater departed on Feb. 25, and the plan is to proceed with two to four shipments totaling 10,000 to 20,000 gallons weekly.
When Entergy catches up on disposal of Vermont Yankee's groundwater inventories, there still will be plenty of water left to ship. Administrators said the focus eventually will shift to getting rid of “process” water, meaning water that has been used in plant systems.
The water shipments are going to Energy Solutions in Oak Ridge, Tenn. NRC spokesman Neil Sheehan said the company “is a licensed waste broker, and therefore separate NRC approval is not required.”
Sheehan noted, though, that radioactive waste shipments “are periodically inspected” by the NRC. “As for precautions, Entergy will have to adhere to NRC requirements for properly packaging and inspecting any (radioactive) waste shipments,” he said. “Once the material is on the road, Department of Transportation shipping regulations would come into play.”
Lynch added that “we can't just use any old trucking firm. They have to have a license. They have to have a mitigation plan. If something happens, they need to know what to do.”
All of this will come at a cost to Vermont Yankee's decommissioning trust fund, but Entergy is not yet saying what that cost will be. Lynch promised a detailed financial breakdown at an advisory panel meeting scheduled for March 24.
“The decommissioning cost estimate did account for water management,” Lynch said. “I think the timing of when we expected we'd be dealing with it is sooner than what we assumed in the cost estimate. Now, we're trying to assess what that impact is. We've been working very hard to lower the cost. That's one of the reasons why we had to store it.”
One byproduct of the water problem appears to be additional communication between Entergy and Vermont officials. Since the issue surfaced, Entergy administrators have talked with officials from the state Department of Health, Agency of Natural Resources, and Public Service Department.
Those discussions will continue.
“Part of the results of those briefings was to initiate frequent and regular meetings to discuss not only the groundwater-intrusion issue and process-water issues but other issues as they might arise,” said Bill Irwin, the Health Department's radiological and toxicological sciences chief. “We're going to start with weekly meetings, and if it needs to tail off, it will. It all depends on what's going on at the site.”
Trey Martin, deputy secretary for the Agency of Natural Resources, said his office has no jurisdiction over shipments of strictly radiological waste. But he's happy to have more regular contact with Entergy going forward, no matter the issue.
“I fully support that and think it's absolutely necessary,” Martin said.
Irwin seemed to take a philosophical approach to the groundwater problem.
“We expect that this is not the first and not the last complication that is going to arise during decommissioning,” Irwin said. “And it's best if they are faced openly and clearly.”