Development of separation process for Mo by extraction with di-2-ethylhexylphosphoric acid

Morita, Yasuji  ; Yamagishi, Isao ; Tsubata, Yasuhiro   ; Matsumura, Kazumi; Sakurai, Koji*; Iijima, Takahiko

Solvent extraction process with di-2-ethylhexylphosphoric acid has been developed for the purpose of Mo separation from high-level radioactive liquid wastes (HLLW). Mo has very low solubility in borosilicate glasses and makes so-called yellow phase when it contained beyond the solubility. After extraction and back-extraction data of Mo and other fission products were obtained by batch extraction tests, continuous extraction tests with simulated HLLW were performed using mixer-settler twice. At the second test, reduction of Y extraction yield and increase of Mo and Zr back-extraction yield were obtained compared with the results of the first tests, but those values should be still improved. Process simulation technique was developed using simulation code named PARC-MA, and the optimized process condition was obtained by the simulation.