Kennewick — The Department of Energy proposes to close the first group of radioactive waste storage tanks at Hanford in August 2031, a delay from an unrealistic deadline of June 2019.
The deadline would cover the 16 underground, single-shell tanks in the group called the C Tank Farm.
Hanford has 149 single-shell tanks, most of them with only pumpable liquids removed so far.
Fifteen of the C Farm tanks have been emptied of liquids, sludge and salt cake to regulatory standards.
After the remaining C Farm tank is emptied, the next step is to close them, either by removing the tanks from the ground or, as DOE proposes, filling them with grout and leaving them buried in the center of the nuclear reservation.
DOE submitted a proposed closure plan last week based on grouting and a schedule to the state Department of Ecology. Ecology is the regulator for the project.
“We are certainly interested in moving up the final date if that is possible,” said John Price, the Department of Ecology’s Tri-Party Agreement section manager.
The June 2019 date was set in the Tri-Party Agreement, a legally binding agreement between DOE, the Department of Ecology and the U.S. Environmental Protection Agency. At one point DOE had expected to have the C Farm tanks emptied by 2006, but the work to get high-level radioactive waste out of closed, underground tanks proved more difficult than anticipated.
In 2016, a federal judge refocused priorities in a court-enforced consent decree, which would give DOE until 2024 to have all tanks in the C Tank Farm emptied. The consent decree deadline requiring only that the 16 C Farm Tanks be emptied by 2024 takes precedence over the Tri-Party Agreement 2019 deadline to have the tanks closed.
DOE and the state Department of Ecology tentatively agreed in 2016 to delay the Tri-Party Agreement deadline for closing the C Farm tanks, with the schedule and proposal submitted this week by DOE the first step.
“DOE submitted these proposed dates in accordance with the Tri-Party Agreement to the Washington State Department of Ecology and looks forward to discussing and coming to agreement on a set of dates for safely completing this work,” DOE said in a statement.
Both DOE and the state are required to give the public a chance to comment on the plan and schedule before it is approved. The state has not said whether it agrees that grouting is the best method to close the tanks.
“We need to do a careful review of their proposal,” Price said. “We need to take public comment on their proposal and we need to do our best to make it finish earlier.”
The DOE proposal calls for the first significant work to close the tanks – starting to put grout into one of the four smaller waste storage tanks at the C Tank Farm – to begin by a new deadline of April 2021.
The tank farm has four tanks with a 55,000-gallon capacity and 12 tanks with a 530,000-gallon capacity. They were built from 1944 to 1945.
Work to grout half of the larger tanks would be required to start by July 2020, and work to grout the final six larger tanks would be required to start by December 2024.
The proposal requires other work to close the C Tank Farm, including stabilizing a vault and some ancillary equipment.
DOE said in its submittal to the Department of Ecology that its proposed closure program allows lessons learned from one closure to be applied to the planning of the next closure.
It also improves the ability of DOE to pay for and perform closure work within budget and workforce constraints, it said.
Closing the tanks should minimize the need for maintenance of the tanks, Price said. It also will protect the environment by minimizing the likelihood of waste escaping from the tanks or water getting into them.
No public hearings or comment periods have been set yet on the closure plan and schedule.
