Kinetics of reductive reextraction of plutonium in two-phase system using various reagents

The results of the study of the reductive reextraction kinetics of plutonium by different reagents in the system: nitric acid-water-tributilphosphate-tetrachloromethane are presented. Tetravalent uranium, hydrozine, hydroxylamine and ascorbic acid were used ar reducers. The dependences of reductive reextraction rate on component concentration and temperature are obtained. The rate of plutonium reductive reextraction in the system: water-nitric acid-tributilphosphate-tetrachloromethane increases with decrease of nitric acid concentration. A transfer from process limitation with chemical state in the area of mixed and diffusional kinetics is observed. Equilibrium distribution of plutonium microquantities under the investigated conditions in the presence of tetravalent uranium or ascorbic acid is determined by plutonium(3). On the basis of experimental data, a proposition is made on the reduction process mechanisms in the two-phase system