Development of a CMPO based extraction process for partitioning of minor actinides and demonstration with geneuine fast reactor fuel solution (155 GWd/Te)

A method has been developed for partitioning of minor actinides from fast reactor (FR) fuel solution by a TRUEX solvent composed of 0.2 M n -octyl(phenyl)- N , N -diisobutylcarbamoyl-methylphosphine oxide (CMPO)-1.2 M tri- n -butylphosphate (TBP) in n -dodecane ( n -DD), and subsequently demonstrated with genuine fast reactor dissolver solution (155 GWd/Te) using a novel 16-stage ejector mixer settler in hot cells. Cesium, plutonium and uranium present in the dissolver solution were removed, prior to minor actinide partitioning, by using ammonium molybdophosphate impregnated XAD-7 (AMP-XAD), methylated poly(4-vinylpyridine) (PVP-Me), and macroporous bifunctional phosphinic acid (MPBPA) resins respectively. Extraction of europium(III) and cerium(III) from simulated and real dissolver solution, and their stripping behavior from loaded organic phase was studied in batch method using various citric acid–nitric acid formulations. Based on these results, partitioning of minor actinides from fast reactor dissolver solution was demonstrated in hot cells. The extraction and stripping profiles of 154 Eu, 144 Ce, 106 Ru and 137 Cs, and mass balance of 241 Am(III) achieved in the demonstration run have been reported in this paper.