FILE - Workers move a newly-filled cask out of the Waste Encapsulation and Storage Facility on Jan. 20, 2026.
Courtesy of the Washington State Department Of Ecology
The pool of water that currently stores capsules full of cesium and strontium at Hanford looks eerie and glows a faint electric blue. These 1,936 highly radioactive capsules store a whopping one-third of the radioactivity load at Hanford.
They’re stored in a facility called the Waste Encapsulation and Storage Facility (WESF).
The worry at Hanford is that something like an earthquake could cause the pool to leak and dry up, putting the stainless steel capsules filled with hot, radioactive waste at risk. An event like that could have similar impacts to the 2011 Fukushima nuclear accident.
This week, federal contractors transferred about 100 of the capsules out of the pool to a specially engineered dry cask. The cask is the first of nearly 20 to be filled. It will take at least three years to finish the entire effort.
Ryan Miller, a spokesman with Washington State’s Department of Ecology, which regulates the project, said state officials are excited to see it move forward.
“It’s really integral to our goal, our continuing goal, of cleaning up the Hanford site, reducing risks to the surrounding environment and communities,” he said.
This radioactive waste was made during World War II and the Cold War. The cesium and strontium were originally stored amid the waste in underground tanks, but were filtered and removed during the 70s to lower the temperature of those tanks. The waste was put into capsules, which were then stored in the pool.
As these giant casks are filled with the capsules, helium is added to cool them. The casks will be stored at Hanford for the foreseeable future.
Anna King is a reporter with Northwest Public Broadcasting.
This story comes to you from the Northwest News Network, a collaboration between public media organizations in Oregon and Washington.
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