Deal reached to address 2 leaking nuke waste tanks at Hanford

A deal to address two nuclear waste storage tanks at the Hanford Nuclear Reservation that are leaking radioactive materials into the soil was reached Thursday between the state and the U.S. Department of Energy.

The waste is left over from the production of plutonium for nuclear weapons at Hanford, near Richland.

From World War II through the Cold War, Hanford produced more than 70 tons of plutonium, including for the atomic bomb dropped on Nagasaki, Japan, at the end of World War II. When plutonium production ceased in 1989, the site’s mission shifted to cleaning up the chemical and radioactive waste left behind, including 56 million gallons of waste stored in 177 giant underground tanks.

The Department of Energy announced in April 2021 that Tank B-109 was leaking waste into the surrounding soil. Tank T-111 was discovered to be leaking in 2013.

“It’s been a priority for the state of Washington to address leaking tanks in a way that protects nearby communities and the Columbia River,” said Ecology Department Director Laura Watson. “We know that ongoing vigilance and commitment will be needed to fully address these risks.”

The Department of Energy manages the nation’s largest collection of radioactive waste, located on the 580-square-mile Hanford site.

Under the agreement, the Energy Department will:

• Cover the T and B tank farms with surface barriers to prevent rain or snowmelt from seeping into the tanks, and to slow the migration of leaked waste toward the groundwater.
• Develop a response plan for future leaks from older single-walled tanks, some of which date to World War II.
• Evaluate the viability of installing a ventilation system to evaporate liquid waste in Tank B-109.

Tank B-109 holds about 123,000 gallons of waste, with about 13,000 gallons of residual liquid form. T-111 holds an estimated 397,000 gallons of waste; about 37,000 gallons is liquid waste within sludge.

The Energy Department estimates Tank B-109 is leaking about 560 gallons of waste per year, and Tank T-111 is leaking about 300 gallons per year. The agency estimated it could take 25 or more years for waste from Tank B-109 to reach groundwater, and 70 or more years for Tank T-111 waste to reach groundwater.