Equilibrium data in Th(NO3)4 - UO2(NO3)2 Tbp/Varsol - HNO3 - H2O system. Parameters optimization for the 232Th - 233U separation

The extraction behavior of thorium and uranium in Tbp diluent systems was studied . The main purpose of this paper is to achieve the best separation conditions of macro quantities of uranium from thorium nitrate solutions. The experimental work was started with the determination of the equilibrium diagram for uranium and for thorium . The temperature effect , Tbp concentration and organic / aqueous ratio were checked. Experiments with fluoride and aluminum ions in the feed solution were also carried out. From the obtained and the existing distribution data it was possible to elaborate the correspondent flow sheets f or the uranium and thorium recovery from simulated spen thorium fuel solutions. (author)