Solvent system containing CMPO as the extractant in a diluent mixture containing n-dodecane and isodecanol for actinide partitioning runs

• 0.2 M CMPO in isodecanol(10%)–dodecane system was evaluated for actinide partitioning.
• The D values were of the order DNp4 + > DPu4 + > DUO22 + > DAm3 +.
• The metal–ligand stoichiometry for Pu4 + and UO22 + is 1:1; Am3 + is 3–4 CMPO molecules.
• Lanthanides, Zr, Mo, Rh, Pd are co-extracted to different extents along with actinides from FBR-SHLW.

0.2 M CMPO in isodecanol(10%)–dodecane system was taken for evaluating the extraction behavior of actinides in different oxidation states. The order of decrease in distribution ratio at fixed acidity was found to be M4 + > MO22 + > M3 + (M = actinide ion). The metal–ligand stoichiometry was determined by slope analysis. Though, increasing isodecanol content decreases the distribution ratio, no perturbation was found on OUO moiety as revealed by UV–vis spectroscopy. Application of van't Hoff equation to the extraction data at different temperatures enabled the determination of thermodynamic parameters. The radiolytic stability of the solvent system was evaluated by dose dependent study (gamma exposure in the range of 0–500 kGy). Finally the solvent system was used for actinide partitioning from simulated high level waste (SHLW) of fast breeder reactor (FBR) fuel.