In 1972, two chemical elements which generate a lot of heat were removed from the high level waste tanks at Hanford. Called cesium and strontium, these elements had to be taken out of single shell waste tanks to reduce the temperature of the waste inside those tanks. Both elements were ultimately placed in sturdy, stainless steel containers which were then put into Hanford’s Waste Encapsulation Storage Facility (WESF). WESF is located in Hanford’s 200-East Area, and is adjacent to the B Plant processing facility.
The containers holding the cesium and strontium at WESF are stored in pools filled with water. The water is needed to protect workers from dangers associated with cesium and strontium, but it also helps to keep these elements cool. Interestingly, the water in these pools glows a color of blue in an effect known as the Cherenkov Glow, as the radioactive cesium and strontium decay and lose their radioactivity to become stable atoms.
Within the water pools at WESF, there are currently 1335 containers filled with cesium and another 601 containers that have strontium inside. The Department of Energy will continue to safely store the capsules until they can be safely removed and placed in a national repository.