RICHLAND, Wash. — A Hanford Site building that was critical to transferring radioactive sludge away from the Columbia River is coming down.

The demolition of the K West Reactor Annex is another key step toward completing cleanup at the former plutonium production reactor, the U.S. Department of Energy reported in a press release Tuesday, Aug. 15.

The project includes draining and removing the reactor’s spent-fuel basin where the sludge was stored, then placing the reactor building in interim safe storage.

“The annex building accomplished its mission to support the safe packaging and transfer of sludge from the basin in 2019,” according to Mark French, Department of Energy Richland Operations Office division director for Hanford’s Central Plateau Cleanup Project. “Now, removal of the facility allows us to continue the progress we’ve already made to reduce risk in Hanford’s K Area and along the river.”

Crews with contractor Central Plateau Cleanup Co. have been moving and sorting radioactive debris into underwater bins in the 1.2-million-gallon basin since last summer, the press releases stated. Workers using underwater cameras and specialized tools place the contaminated material into steel tubes, which will be filled with grout, a concrete-like substance, and removed during basin demolition.

Workers recently finished installing a system to pump out and filter the contaminated water from the basin, the DOE reported in the press release. They will transfer the water to Hanford’s Effluent Treatment Facility by tanker truck for disposal. Testing activities on the system are underway, and draining of the basin could begin by the end of this year.

“While we still have plenty of work to do, it’s exciting to see how far we’ve come,” according to Mike Kruzic, CPCCo 100 K Closure Projects manager. “I’m proud of our team and their continued focus on safety over speed.”

Following removal of the spent fuel basin, workers will construct a safe storage enclosure over the main K West Reactor building, a process known as “cocooning.” According to the press release, the enclosure will protect the building while the radioactivity in the deactivated reactor core decays over the next several decades, making it safer to complete disposition of the reactor in the future.

K West will be the eighth and final Hanford reactor to be cocooned following the cocooning of the nearby K East Reactor in October 2022.