VERNON — Entergy has spent more than $2 million to dispose of groundwater leaking into a dormant turbine building at Vermont Yankee.
And the leaks show no sign of stopping, though administrators at the idled Vernon plant say they're continuing to find and address problem areas when possible.
There are still 500 to 600 gallons of water entering the turbine building each day, said Joe Lynch, a senior government affairs manager for Entergy. But that's actually an improvement from much more severe leaks officials had encountered during the past two years.
“I would like to say our goal is to eliminate it,” Lynch said. “At this point, I think our progress has been very good, but we're not quite at the point where we can claim victory.”
Entergy stopped power production at Vermont Yankee at the end of 2014, and administrators subsequently noticed large amounts of water leaking into the turbine building's below-ground levels.
News of the issue first emerged in a federal Nuclear Regulatory Commission inspection report in early 2016. At one point, there was so much water pouring into the building that administrators resorted to using commercially available swimming pools to store it temporarily.
The groundwater picks up a relatively small amount of radiological contamination via its contact with the turbine building, Entergy and federal regulators have said. So Entergy developed a plan to ship the tainted water via tanker truck to a disposal facility in Tennessee.
At the height of the water problem, there were four 5,000-gallon shipments leaving Vermont Yankee each week. Those shipments continue, though they've dwindled to about one per week.
To date, Entergy has shipped 608,000 gallons of water to Tennessee, Lynch told a meeting of the Vermont Nuclear Decommissioning Citizens Advisory Panel on Oct. 26 in Brattleboro.
Responding to questions about water management from panel members, Lynch said the cost of transportation and disposal is approximately $4 per gallon. That adds up to a $2.4 million price tag so far, and that money has come out of Vermont Yankee's decommissioning trust fund.
It wasn't immediately clear how much Entergy initially had budgeted for water management and to what extent the spending thus far exceeds that budgeted amount.
“In the original [decommissioning] cost estimate, we had a water-management cost,” Lynch said in a later interview. “I don't think it anticipated the intrusion at the rates that we're seeing. But nonetheless, we realized there was going to be some water that we were going to have to address.”
As contaminated water shipments continue, plant administrators also are continuing to try to stanch the flow of groundwater into the building.
Additional sealing work recently was completed. Lynch noted that the flow rate of 500 to 600 gallons per day is “a drastic reduction from where we were a couple years ago,” when flow rates were 2,500 to 3,000 gallons per day at times.
But Lynch said there has to be some indication that preventive work will yield significant improvement. “You're not going to spend a lot of money if it only gets you a very small, incremental change in the amount [of water],” he said.
Lynch also provided updates on several other Vermont Yankee decommissioning issues, including:
• Entergy has loaded 16 casks with spent fuel this year, giving the plant a total of 29 such casks. The plan is to have all of Vermont Yankee's spent fuel moved from a cooling pool to sealed casks by the end of next year - a key milestone in Entergy's proposed sale of the plant to NorthStar Group Services.
Crews continue to load about one cask per week, though Lynch said the project soon will go on hiatus for a planned maintenance project.
• Work is set to begin next month on a security downsizing project that will shrink the plant's high-security “protected area” from 10.5 acres to 1.3 acres.
Though NRC approval for the plan hasn't yet arrived, the state Public Utility Commission has signed off. “We now have received all the permits that we need to start construction,” Lynch said.
When the project is finished, the protected area will encompass only the plant's spent-fuel storage facility. The change is expected to save $1.2 million monthly, mostly in security costs.
• Though Entergy is regularly withdrawing money from Vermont Yankee's decommissioning trust fund, that fund continues to grow due to strong returns on investments.
Lynch said the fund stood at $575.6 million at the end of September, up $1 million from a month prior.
So far this year, Entergy has pulled $25.9 million out of the trust fund, but there has been $42.9 million in market gains.