The Salt Waste Processing Facility (SWPF) at the U.S. Department of Energy’s (DOE’s) Savannah River Site has performed largely as expected, processing more than one million gallons of radioactive waste during its first eight months of operation. The SWPF is being used to treat the majority of the site’s remaining liquid radioactive waste, generated from the production of nuclear materials in the 1950s.

The salt waste contains soluble metal ions, radioactive cesium, concentrated salt supernate and a solid salt cake that has crystallized out of solution. The first batch of radioactive waste was transferred from Aerial view of the SWPF. Source: DOEAerial view of the SWPF. Source: DOEunderground storage tanks to the SWPF in October 2020 and the facility has processed more than 1 million gallons of waste to date.

A two-step cleanup process is applied to separate highly radioactive waste from the less-radioactive salt solution, starting with removal of strontium and actinides. A caustic side solvent extraction process is then applied to remove radioactive cesium. The resulting concentrated high-activity waste is sent to the site's Defense Waste Processing Facility, converted into a solid glass form through the vitrification process and stored in 10 ft tall stainless steel canisters. Decontaminated salt solution is mixed with cement-like grout at the Saltstone Production Facility for disposal onsite.

Nearly all of the salt waste inventory is expected to be processed by 2031.

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