SETFICS process

The SETFICS process (Solvent Extraction for Trivalent /-elements Intragroup Separation in CMPO-Complexant System) was initially proposed by research teams of the former Japan Nuclear Cycle Development Institute (JNC, today JAEA) to separate An(III) from PUREX raffinates. It uses a TRUEX solvent (composed of CMPO and TBP, respectively dissolved at 0.2 and 1.2 M in -dodecane) to coextract trivalent actinides and lanthanides, and a sodium nitrate concentrated solution (4 M NaN03) containing DTPA (0.05 M) to selectively strip the TPEs at pH 2 and keep the Ln(III) extracted by the TRUEX solvent (239). However, the DFs for heavy Ln(III) are rather poor. An optimized version of the SETFICS process has recently been proposed as an alternative process to extraction chromatography for the recovery of Am(III) and Cm(III) in the New Extraction System for TRU Recovery (NEXT) process. NEXT basically consists of a front-end crystallization of uranium, a simplified PUREX process using TBP for the recovery of U, Np, and Pu, and a back-end Am(III) + Cm(III) recovery step (240, 241). 

FIGURE 3.24 SETFICS process flowsheet tested by JNC on an inactive surrogate PUREX raffinate. (Courtesy of Hirano, H., Koma, K., Koyama, T., 7th Information Exchange Meeting on Actinide and Fission Product Partitioning and Transmutation, October 2002, Jeju, Republic of Korea.)... 

FIGURE 3.25 SETFICS process flowsheet tested at JAEA (CPF) on a highly active feed. (Courtesy of Nakahara, M., Sano, Y., Koma, Y., Kamiya, M., Shibata, A., Koizumi, T., Koyama, T. 2007. Journal of Nuclear Science and Technology, 44, 373-381, 2007.)... 

Shadrin, A., Kamachev, V., Kvasnitsky, I., Romanovsky, V., Bondin, V., Krivitsky, Y., Alekseenko, S. 2007. Extraction reprocessing of HLW by modified SETFICS-process. Global 2007 Advanced Nuclear Fuel Cycles and Systems, September, Boise, ID. 

Koma, Y., Watanabe, M., Nemoto, S., Tanaka, Y. A counter current experiment for the separation of trivalent actinides and lanthanides by the SETFICS process. Solvent Extr. IonExeh. (1998), 16 (6), 1357-1367. 

Shadrin, A., Babain, V., Kamachev, V., Koyama, T., Kamiya, N. Fluoropole-732 as a diluent for SETFICS-process. Proc. Int. Conf. Global 03, Atomic Nuclear Society, La Grange Park, IL, November 16-22, 2003, pp. 728-731. 

A SETFICS countercurrent hot test was recently conducted with high loading of salt-free flowsheet (in order to reduce the solvent volume and the amount of waste stream by 50%) in the JAEA Chemical Process Facility (CPF) as part of the feasibility demonstration of the NEXT process. The solvent consisted of CMPO and TBP,... 

As in the SETFICS and TALSPEAK processes, the DIAMEX-SANEX/HDEHP process involves selectively back-extracting the trivalent actinides by a hydrophilic polyamino-carboxylate complexing agent, HEDTA, in a citric acid buffered solution (pH 3). However, the combination of HDEHP and DMDOHEMA at high acidity promotes the coextraction of some block transition metals, such as Pd(II), Fe(III), Zr(IV), and Mo(VI), which must be dealt with by specific stripping steps (as described on Figure 3.26) that increase the total volume of the output streams ... 

Historically, pairs of processes have been developed throughout the world to achieve An(III)/Ln(III) partitioning TRUEX + TALSPEAK in the United States, TRPO + CYANEX in China, DIDPA + DIDPA in Japan, and DIAMEX + BTP or DIAMEX + ALINA in Europe, but cross combinations of processes are possible. The one-cycle processes (e.g., SETFICS and DIAMEX-SANEX/HDEHP) appear more attractive and more compact than the two-cycle processes, as they do not use two different solvent loops to carry out the separation of An(III) from Ln(III), but they sometimes generate much larger aqueous streams than the feed input. 

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