Treatment of radioactive spent extraction solvent by supercritical water oxidation

Radioactive spent extraction solvent was treated by supercritical water oxidation. In this work, influences of reaction conditions on total organic carbon (TOC) removal, the volume percentage of CO2 yielded, and the distributions of radionuclides in gas, liquid and solid phase have been investigated. The results show that the TOC removal and the volume percentage of CO2 would be increased up to above 99% under optimal conditions. More than 88% of thorium and 67% of uranium were precipitated in solid phase, the rest remained in the liquid effluent, and no thorium and uranium were detected in gas phase.