Study on applicability of DIDPA solvent to Talspeak method

Fujiwara, Takeshi; Morita, Yasuji  

In the 4-Group Partitioning Process developed in Japan Atomic Energy Research Institute (presently: Japan Atomic Energy Agency), the transuranic element and the rare earth elements are extracted from high-level liquid waste by diisodecylphosphoric acid (DIDPA). The concentration of the rare earth elements are about 50 times higher than that of Am and Cm in high-level liquid waste. It is, therefore, necessary to separate each other for the transmutation of Am and Cm, or volume reduction of the waste form of the long-lived nuclide. On the other hand, the Talspeak method is a separation method by the solvent extraction that gives selective stripping of Am and Cm from the solvent that contains the rare earth elements using di-2-ethylhexylphosphoric acid (DEHPA) as an extractant. In the present study, application of the DIDPA to the Talspeak method was examined for various conditions to separate Am from the rare earth elements by the batch examination.