Numerical Simulation for Chemical Reactions of Actinide Elements in Aqueous Nitric Acid Solution

摘要

A computer code REACT incorporating 30 rate equations of reactions, i.e. radiolytic formation and decomposition of HNO2, redox and disproportionation reactions, was developed to simulate behavior of actinide elements in the aqueous nitric acid solution. Main aspects of REACT code were explained briefly and then calculated results were compared with reported data to evaluate the model in the systems of radiolytic accumulation of HNO2, stabilization process of Pu solution. The study showed that some radiolytic products other than HNO2 would play a significant role and should be taken into account for precise simulation of very slow valency change of Pu in the neat Pu solution particularly with high radiation power density. Some examples of calculation were also shown for systems of reduction of Pu and Np by uranous or HAN and oxidation of Np(V) to Np(VI).