KENNEWICK — The Department of Energy and Washington state have reached an agreement on steps to address radioactive waste suspected of leaking into the ground from a third storage tank at the Hanford nuclear site in Eastern Washington.
Similar to the agreement on the first two huge underground tanks known to be leaking at the nuclear reservation, DOE is not required to immediately empty the tank.
The tank has been holding a stew of radioactive and other chemical waste for almost 80 years.
Instead of draining the tank, an addition to the original order will include the steps that must be taken with Tank T-101, such as evaluating whether active ventilation could be used to evaporate liquid waste in the tank.
“This updated agreed order is a legally binding document,” Stephanie Schleif, the Nuclear Waste Program manager for the Washington state Department of Ecology, said in a statement Wednesday.
“This is an important step forward because it lays out the steps (Department of) Energy must take to address this leak and any future single shell-tank leaks.”
The 580-square-mile Hanford site next to Richland has 149 single-shell underground tanks to hold radioactive waste left from chemically separating plutonium from uranium fuel irradiated at Hanford reactors to supply the nation’s nuclear weapons program from World War II through the Cold War.
Their waste is being emptied into the limited space of 27 newer tanks with double steel shells for storage until it can be treated for permanent disposal.
No immediate emptying of tank
The expanded agreed order does not require any of the three tanks to be immediately emptied to stop suspected leaking.
To date, 68 of the single-shell tanks are suspected of leaking or spilling waste into the ground in central Hanford in the past, but only three are known or suspected to be actively leaking after a push to empty pumpable liquid.
However, DOE is required by the agreed order to negotiate a new deadline by the end of January for emptying as much waste as possible from Tank T-101.
DOE and Ecology also are in continuing talks on new deadlines for when Tanks B-109 and T-111 must be emptied to regulatory standards.
DOE now is required to have all single-shell tanks emptied of as much waste as possible by 2040, although that overall date is expected to be extended. To date 21 of the single-shell tanks have been emptied to regulatory standards.
The leak in Tank T-101 presents no increased health or safety risk to the Hanford workforce, said Ed Dawson, spokesperson for DOE at Hanford.
“We are continuously looking at investments we make to drive the risk profile (for the Hanford site) down as fast as we can,” said DOE Hanford manager Brian Vance, at a public meeting on tank waste in July in Hood River, Ore.
DOE has moved to a process of installing tank retrieval equipment for a complete tank farm, or group of tanks, at one time, which it says is more efficient than a previous process of installing infrastructure tank by tank for retrieval.
It emptied waste to regulatory standards from the last of four tanks in the AX Tank Farm in July, with infrastructure installed to move onto the six tanks in A Farm next.
To install infrastructure to retrieve waste from an individual leaking tank and move the waste to a double shell tank would require using money budgeted for another project, such as the vitrification plant now being commissioned to treat tank waste for disposal or groundwater treatment, Vance said.
“The total volume of waste involved is relatively small and the waste is leaking into a large underground area contaminated by past discharges of millions of gallons of waste to soil disposal sites and leaks from multiple tanks,” DOE said in a message to Hanford employees in July.
DOE has a state-of-the-art groundwater treatment plant, the 200 West Groundwater Pump and Treat System, that is removing some types of chemical and radioactive contaminants from groundwater in the area of the T Tank Farm, DOE said then.
Groundwater at Hanford moves toward the Columbia River.
Requirements for leaking waste tank
The required steps under the expanded agreed order to include Tank T-101 are similar to the steps for the first two actively leaking tanks.
In addition to seeing if evaporation inside the tank is feasible and setting a new deadline to empty the tank, DOE must evaluate conditions in and around the tank to determine if additional work is needed to keep rain and snow melt from infiltrating the tank.
It was already required by the agreed order to cover the T and B tank farms with surface barriers by 2028 to prevent rain or snow melt from seeping into the tanks. Tank T-101 is the second tank in the T Tank Farm known to be leaking and the other tank is in the B Tank Farm.
DOE evaluated installing a ventilation system in Tank B-109 and decided not to pursue that method to evaporate liquid waste.
The order as originally written also required the development of a plan to address future leaks discovered from single shell tanks. Because that has not been completed yet, the order was expanded to include Tank T-101.
The plan for all single-shell tanks is being finalized now and should go out for public comment in early 2025 as part of the Hanford Sitewide Permit, said Ryan Miller, spokesperson for the Department of Ecology.
Hanford Tank T-101 waste leak
DOE told the Department of Ecology in August that Tank T-101, built in 1943-’44, likely was leaking an estimated 200 gallons of waste into the ground a year.
That compares to Tank T-111 in the same tank farm, which is estimated to be leaking 150 to 300 gallons a year and Tank B-109, which is estimated to be leaking about 3.5 gallons a day, or about 1,275 gallons a year, according to DOE.
Heart of America Northwest, a Seattle based Hanford watchdog group, disagrees with DOE, saying at the Hood River public meeting that it believes Tank T-111 is leaking at a much higher rate.
Tank T-101 holds an estimated 7,000 gallons of liquid waste that could not be removed during DOE’s earlier campaign to pump as much liquid waste as possible out of single shell tanks to reduce leaking.
Tank T-101, which has had no additional waste added since 1979, had as much liquid waste as possible pumped out in 1993. Most of the 93,000 gallons of waste left in the tank is sludge and saltcake.
It is one of the smaller waste storage tanks at Hanford, with a capacity of 530,000 gallons. Some single shell tanks have a capacity of 1 million gallons.
The three known or suspected leaking tanks at Hanford are a reminder that the risks increase the longer waste remains in aging tanks, Miller said.
The Department of Ecology continues to advocate for robust budgets from Congress.
Strong budgets reduce the overall cost of maintaining and cleaning up of Hanford by 10s of billions of dollars, allows cleanup to be completed sooner and reduce environmental risks, he said.
