Extractants for exhaustive recovery of TPEs from radiochemical production waste

The use of the strong polydentate extractants, neutral (NOPCs, diphosphine dioxides and carbamoyl phosphine oxides) and acidic [poly-2-ethylhexylphosp honitrilic acid (P2EHPNA)] organophosphorus compounds, in recovery of trans plutonium and rare-earth elements from the waste of the first cycle was con sidered. Compounds of the first group exhibit enhanced extractive power due to bidentate coordination and the effect of anomalous aryl strengthening, and those of the second group, because of no dimerization. The extraction c onstants of bidentate NOPCs are by a factor of 10(5) higher than the corres ponding values for the strongest monodentate NOPCs, and the extraction cons tants of actinides(III) with P2EHPNA are by a factor of 10(8) higher than w ith DEHP. With the indicated extraction characteristics, TPEs can be recove red from solutions of any acidity without special treatment. Recovery proce dures based on bidentate NOPCs were tested on solutions of high-burnup fuel .