Central Plateau Cleanup Company, the Department of Energy’s prime cleanup contractor for the Central Plateau area of the Hanford Site, near Richland, Wash., recently awarded a $9.5 million construction subcontract to Apollo Mechanical Contractors. Apollo will continue work on the site’s Waste Encapsulation and Storage Facility (WESF), where nearly 2,000 highly radioactive capsules containing cesium and strontium are stored underwater.
Apollo will modify the WESF and install equipment needed to transfer the radioactive capsules from a water-filled basin to safer interim dry storage. In the 1970s, to reduce the temperature of the waste inside Hanford’s waste tanks, cesium and strontium were removed from the tanks and moved to the WESF. The DOE expects that the transfer of the capsules to dry storage will be completed by 2025.
“While the 1,936 cesium and strontium capsules are currently in safe storage, WESF is an aging facility,” said Gary Pyles, project manager for the DOE’s Richland Operations Office. “Moving the capsules will enable the planned deactivation of WESF and will reduce the risk and significantly reduce the annual costs for storing the capsules.”
The work: Apollo will have two tasks: complete the necessary structural and utility-related modifications to WESF, and install the new cask storage system. These modifications will enable the safe transfer of the capsules from the basin to engineered stainless steel and concrete casks for dry storage. The casks will then be transported to a nearby capsule storage area.
Transferring the capsules from the WESF basin to dry storage reduces the risk of a radioactive release in the unlikely event of loss of water from the basin, according to the DOE,.
Over the past few months, the project team has poured the concrete foundation for the new capsule storage area near WESF and completed the construction of a full-scale mock-up that replicates WESF’s G Cell, canyon, and truck port through which the radioactive capsules will be transferred. The mock-up allows workers to safely train, test equipment, and develop procedures before performing the work in a radiological environment. A video of the pouring of the concrete storage pad ia available online. can be seen here.
The contractor: The DOE awarded the $10 billion, 10-year Central Plateau cleanup contract to Central Plateau Cleanup Company, a partnership of Amentum, Fluor, and Atkins, in December 2019. Transition of the cleanup work from the previous contract holder, CH2M Hill Plateau Remediation, was delayed, however, until October of last year due to COVID-19 and a lawsuit challenging the new contract award.