Changes must be made to Hanford Site’s Waste Encapsulation Storage Facility (WESF) to support moving 1,936 capsules of cesium and strontium out of underwater storage at the facility to dry storage nearby.
The Department of Energy released more information about the project as it pursues a related modification to the dangerous waste portion of the Hanford Facility Resource Conservation and Recovery Act permit issued by the Washington state Department of Ecology.
The Waste Encapsulation Storage Facility was added to one end of B Plant in central Hanford in 1973 to encapsulate cesium and strontium from the site’s tank waste and store the capsules in concrete pool cells. The cesium and strontium, now in 22-inch-long stainless-steel containers, were extracted to reduce the temperature of waste in the tanks. Water is used at WESF to keep the capsules cool and protect workers from radiation, but the DOE Office of Inspector General said in 2014 the capsules could be at risk if a severe earthquake caused loss of power or water in the pool.
To prepare to move the capsules to dry storage, six of the hot cells at WESF are being closed and a seventh hot cell will be modified to package the capsules for dry storage. Packaging and loading equipment will be added to allow capsules to be sealed into steel containers called universal capsule sleeves. Up to six capsules will be loaded into each sleeve.
The remaining hot cell will be fitted with a new cover block to allow a crane to transfer the packaged capsules to the WESF truck port. There the sleeves will be loaded into portable storage canisters, with up to six sleeves in each canister. The canisters will be loaded into concrete casks designed to shield radiation. The truck port will need to be modified for the work, including to support the weight of the loaded concrete casks.
