How empty are Hanford’s nuclear waste tanks? Not enough, says watchdog

RICHLAND, Wash. — A Hanford watchdog group is objecting as the Department of Energy takes the first step toward a plan to fill underground, radioactive waste storage tanks with concrete-like grout and leave them permanently in place.

The C Tank Farm, which would be closed first, has not had enough radioactive waste removed to have tanks filled with grout, said Tom Carpenter, executive director of Seattle-based Hanford Challenge.

“This would be a serious setback for the cleanup at Hanford if the DOE is allowed to turn Hanford into the nation’s high-level nuclear waste dump,” Carpenter said. “This will be challenged.”

Geoffrey Fettus, a senior attorney at the Natural Resources Defense Council, said that “the people of the Pacific Northwest deserve better, and we’ll be there with them opposing this unsound and unsafe effort.”

DOE has completed a draft evaluation of the waste remaining in the C Tank Farm, concluding that radioactive waste has been removed to the extent possible and that the remaining waste, if grouted in place, would meet requirements for disposing of it as low-level radioactive waste.

The draft evaluation is a step toward classifying the waste as low-level to allow it to be left in place as tanks are filled with grout and then covered with an above-ground cap to prevent precipitation from infiltrating.

An all-day meeting is planned starting at 9 a.m. Monday at the Richland Public Library to explain the draft document and its findings. A public comment period started June 4.

DOE worked steadily to empty most of the waste in the 16 tanks of C Tank Farm from 2003 until late 2017.

The federal court-enforced consent decree requires DOE to get as much radioactive waste from the tanks as possible, with an overall goal of getting an average of 99 percent of waste removed from the 149 single-shell tanks at Hanford.

It is roughly the equivalent of a little less than an inch of waste if it were spread evenly across the bottom of a tank.

In the C Tank Farm, about 96 percent of the volume of the waste was removed, according to DOE.

The 16 tanks held 1.8 million gallons of mostly sludge and salt cake when retrieval of solids began. They now hold an estimated 64,000 gallons of waste.

DOE was required to use up to three different technologies at each tank until each technology was no longer able to remove waste under the terms of the federal court-enforced consent decree.

Technologies included various methods to spray high-pressure streams of liquid on the waste within the enclosed tanks and move it toward a pump for removal, different vacuuming systems, and soaking hardened waste in water or a caustic chemical.

Much of the remaining waste is difficult to retrieve safely without exposing workers to radiation or damaging the walls and floor of the tanks, which already are prone to leaking. Some of the remaining waste is clinging to the walls of the tank.

Hanford Challenge is not proposing that workers be put in harm’s way, Carpenter said.

In 10 to 20 years, there could be better technology to retrieve remaining waste, provided the tanks have not already been filled with grout to make that impossible, he said.

In the meantime, the solid waste in the tanks could be monitored and DOE could focus on the more pressing issue of removing waste from its other leak-prone, single-shell tanks, Carpenter said. Just one tank in addition to the 16 C Farm tanks has been emptied to regulatory standards.

Grout has not been shown to effectively contain nuclear waste for periods of more than 100 years, according to Hanford Challenge. Water can infiltrate grout, and grout can break down quickly in the presence of caustic materials such as nuclear waste, it said.

Plutonium would reach the groundwater and then the Columbia Point at some point in the future, Carpenter said.

The draft proposal would challenge the consensus that Hanford’s tank waste should be vitrified, or immobilized in glass, according to Hanford Challenge.

“Hanford is proposing shortcuts to the cleanup that will save money, but will in the end further damage the environment and impact human health and safety and future generations,” Carpenter said.

DOE said in its announcement of the draft report and public meeting that “closing the emptied tanks would be a significant achievement in DOE’s Hanford cleanup mission. DOE has a record of safely and successfully closing emptied underground waste tanks at the Savannah River Site in South Carolina and the Idaho National Laboratory.”

DOE will have to make a decision on whether tanks could be filled with grout or must be dug up. The Washington state Department of Ecology, a Hanford regulator, also would have to agree that tanks could be grouted.