Separation of Trivalent Actinides from High-Active Waste

摘要

A typical high-active waste (HAW) arising from reprocessing of (U_(0.3)Pu_(0.7))C fuel irradiated to the burn-up of 155 GWd/Te in a fast breeder test reactor (FBTR) was characterized. Partitioning of trivalent actinides from HAW was demonstrated using a solvent, 0.2 M n-octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) -1.2 M tri-n-butylphosphate (TBP) in n-dodecane (n-DD), in a mixer settler. The results established quantitative separation of trivalents (Am(III) + Ln(III)) from HAW and recovery (> 99 %) using a citric acid-nitric acid formulation. The mutual separation of lanthanides and actinides from the stripped product was studied by using bis(2-ethylhexyl)diglycolamic acid (HDEHDGA), synthesized in our laboratory.