Energy Dept. warns nuclear waste tank may be leaking in Washington state

The Department of Energy on Thursday said that it believes an underground nuclear waste tank in Washington state dating back to the 1940s is leaking waste produced by plutonium production.

Hanford Nuclear Reservation, the location of a decades-long, multibillion-dollar cleanup effort, is the most contaminated site of radioactive waste in the U.S., according to a report by The Associated Press.

While functional, it produced about 66 percent of the plutonium used for American nuclear weapons, including the bomb the U.S. dropped on Nagasaki, Japan, in 1945.

The tank identified by the Energy Department as the source of the leak was constructed during the Manhattan Project, which led to the U.S. development of nuclear weapons during World War II. Waste from the site’s operations were deposited in the tank from 1946 to 1976.

“There is no increased health or safety risk to the Hanford workforce or the public,” Geoff Tyree, a spokesman for the Energy Department, told the AP. “Contamination in this area is not new and mitigation actions have been in place for decades to protect workers, the public and the environment.”

The department has notified both the Environmental Protection Agency and the state Department of Ecology of the suspected leak, according to the AP. The department said all pumpable liquids had previously been removed from the tank with a small amount of waste remaining. The government first suspected a leak in March 2019 after a slight dip in its liquid waste level was recorded, and the federal government launched an investigation about a year later after detecting another decrease.

The announcement comes the week after the Department of Energy announced the successful stabilization of two underground structures at the site, which had been at risk of collapse, according to the AP. The structures were also used to store plutonium-contaminated liquids.

“With this work completed, Hanford has ensured the stability of these structures and reduced risks to workers and the environment,” Tyree said last Tuesday.

–Updated on May 4 at 5:45 a.m.