Kinetics and mechanisms of redox reactions of U, Pu, and Np in tributyl phosphate solutions

Abstract

Published data on the kinetics of oxidation and reduction of U, Pu, and Np ions with various reagents [HNO3, HNO2, U(IV), etc.] in organic solutions of tributyl phosphate (TBP) are summarized. The rate equations, rate constants, and thermodynamic functions of activation of the reactions are presented. For the majority of reactions, the rate equations in TBP solutions are similar in the form to those for aqueous solutions, which suggests similar reaction mechanisms. A characteristic feature of the reactions in TBP solutions is the dependence of their rate on the H2O concentration, suggesting participation of water molecules in the charge transfer between the reactants.