Toxic waste suspected to be leaking from third Hanford nuclear tank | Columbia Basin

HANFORD – The Department of Energy (DOE) announced Thursday that a third, aging underground tank at the Hanford nuclear site may be leaking highly radioactive and hazardous chemical waste into the ground. “This is of great concern to the Washington State Department of Environmental Protection and must be addressed urgently,” said Department of Environmental Protection Director Laura Watson. The state agency that oversees Hanford is closely monitoring the situation.

Since World War II, when the Hanford site in eastern Washington began putting radioactive waste into underground tanks, at least 68 of the 149 single-wall tanks have been suspected of leaking or leaking waste into the ground. So far, only two tanks have been found to be leaking after liquid waste was removed. None of those tanks have been completely emptied, despite an agreement with the Department of Environmental Protection two years ago requiring the department to look for ways to speed up the recovery of waste from the leaking tanks.

The agreed order also required the development of a response plan for future leaks, but that plan is still incomplete. The Department of Energy and the Department of Environmental Protection are currently discussing next steps for the most recent tank, Tank T-101. Watson stressed that the state does not believe that tank poses an immediate danger to workers or the public.

Tank T-101 is part of a group of 16 underground tanks known as the T Tank Farm. According to a 2013 DOE notice, Tank T-111 was previously found to be leaking waste into the ground. In 2021, the DOE announced that Tank B-109 in the B Tank Farm was also leaking. One of the smaller waste storage tanks at Hanford, Tank T-101 was built between 1943 and 1944 and has contained waste since 1945, with additional waste added through 1979. It currently contains about 93,000 gallons of waste, mostly in the form of sludge and salt cake, as well as an estimated 7,000 gallons of liquid waste that could not be removed during the DOE's campaign to pump liquid waste from all single-wall tanks to reduce leaks.

The Department of Energy estimates that Tank T-101 could leak up to 200 gallons of waste per year. By comparison, Tank T-111 leaks between 150 and 300 gallons annually, and Tank B-109 leaks about 3.5 gallons per day, or about 1,275 gallons per year.

The groundwater beneath the T Tank Farm is about 160 feet deep, and authorities estimate that in a few decades the leak from Tank T-111 could reach groundwater, which would then flow toward the Columbia River. Hanford's single-walled tanks, as well as 27 newer double-walled tanks, contain a total of 56 million gallons of waste from the chemical processing of uranium that was irradiated at the 580-square-mile nuclear reservation near Richland to extract nearly two-thirds of the plutonium used in the nation's nuclear weapons program from World War II through the Cold War.

Currently, waste from the single-walled tanks is being transferred to the limited space of the newer double-walled tanks, where it will continue to be stored until it can be processed for disposal. The Hanford vitrification plant is expected to begin converting some of the least radioactive waste in the tanks into a stable glass form in August 2025.

Tank T-101 was not previously on the list of suspected leaking tanks when irregularities were discovered during ongoing monitoring of the tank's integrity and integrity by DOE contractor Washington River Protection Solutions. A camera inserted into a riser pipe – a pipe that runs from the ground into the enclosed tank – showed that the accumulation of liquid waste above the waste in the tank appeared to be smaller than usual. This prompted a more thorough evaluation of the data, including checking for liquid trapped in pockets within the solid waste. The DOE's tank storage contractor concluded that the tank was “most likely” leaking, according to DOE spokesman Ed Dawson.

“The total volume of waste affected is relatively small, and the waste is seeping into a large underground area that is contaminated by previous discharges of millions of gallons of waste to soil landfills and leaks from multiple tanks,” the Energy Department said in a notice to Hanford employees on Thursday.

The Department of Energy has a state-of-the-art groundwater treatment facility, the 200 West Groundwater Pump and Treat System, that removes certain types of chemical and radioactive contaminants from groundwater in the T Tank Farm area. In addition, as part of the agreement reached after the discovery of the leak at Tank B-109, the Department of Energy is required to build a surface barrier over the T and B Tank Farms to prevent rain and meltwater from carrying the contaminants deeper into the soil toward groundwater. The T Farm already has a barrier covering some of its tanks, but it does not reach the most recent tank of concern, Tank T-101. Both barriers are scheduled to be completed by 2028. Design work is currently underway for the T Tank Farm barrier.

“The latest tank suspected of leaking is another indication of the growing threat that the aging and failing infrastructure at the Hanford site poses to Washington's environment and surrounding communities,” Watson said. She stressed that it is urgent that the Department of Energy speed up the process of removing the waste from the tanks, converting it into an immobile, solid form and disposing of it permanently before more tanks leak.

Source: Tri-City Herald