Analysis of kinetic data for the dissolution of UO₂ fuel pellets in nitric acid

In the present study, the dissolution kinetics of UO₂ pellets in nitric acid has been investigated. Kinetic rate expressions based on Langmuir-Hinshelwood mechanism have been developed to describe the kinetics of dissolution of UO₂ pellet in nitric acid. Effects of concentration of nitric acid, temperature of the reaction mixture and mixing intensity on the rate of dissolution have also been studied. Analysis of experimental data revealed that the reaction to be in the chemical reaction controlled regime under the experimental conditions with an activation energy estimated to be about 80 kJ mol^-1. (author)