The Department of Energy’s Office of Environmental Management (EM) announced this week that preparations are well underway for the transfer of nearly 2,000 highly radioactive cesium and strontium capsules from the Waste Encapsulation and Storage Facility (WESF) to interim dry storage at the Hanford Site near Richland, Wash.
Over the past several months, EM’s Richland Operations Office contractor Central Plateau Cleanup Company completed a number of modifications to the facility needed to install a system that will move the capsules from the underwater basin into dry-storage casks, onto trucks, and into a new storage area close to the facility.
Final construction activities at the dry-storage area were completed last fall. Additional upgrades are needed at WESF’s truck transfer area to enable the half-mile trip to the dry-storage concrete pad.
A YouTube video of the transfer process is available here.
Background: The 1,335 cesium capsules and 601 strontium capsules have been stored in an underwater basin at WESF since the mid-1970s. Cesium (in the form of cesium chloride, mostly Cs-137, with minor amounts of the much longer-lived Cs-135) and strontium (as Sr-90 in strontium fluoride) were removed from Hanford’s underground waste storage tanks to reduce the internal temperature. While the capsules are currently in safe storage in the underwater basin, moving them to dry storage eliminates a longer-term risk of a radioactive release in the unlikely event of a loss of water from the basin during a beyond-design-basis earthquake. Dry storage will also reduce operating costs.
“Transferring the capsules to the new dry-storage pad will not only enable the planned deactivation of the aging WESF facility, but also save as much as $6 million in annual operating costs,” said Gary Pyles, Richland Operations Office project manager.
Mock-ups: EM also noted that progress continues at a full-scale mock-up about 15 miles south of WESF at Hanford’s Maintenance and Storage Facility. It is designed to replicate the areas of WESF that the capsules will be moved through while transferring them into dry-storage casks and putting the casks on trucks. The mock-up includes a replica shielded hot cell, an operating canyon, and a truck loading area. It is designed to look and feel exactly like the real thing so that workers can test and practice to get comfortable with the system before going live in the WESF facility.
Workers at the mock-up recently installed four mechanical manipulators that are part of a system that will transfer the underwater capsules from the basin to stainless-steel-and-concrete casks for transfer to the new storage area. Fabrication of other capsule transfer test equipment is almost complete, with the system components expected to arrive at the mock-up for installation and testing this spring.