[en] Highlights: • Rigorously RF and GH rate theories were used to calculate water exchange mechanism. • Pressure dependence and solvent response to the rate constant were evaluated. • Polarization effects are explicitly included in the potential models. • This work is both novel and can be impactful to the chemical physics community. We report a classical rate theory approach to predict the exchange mechanism that occurs between water and aqueous uranyl ion. Using our water and ion-water polarizable force field and molecular dynamics techniques, we computed the potentials of mean force for the uranyl ion-water pair as a function of different pressures at ambient temperature. These potentials of mean force were used to calculate rate constants using transition rate theory; the transmission coefficients also were examined using the reactive flux method and Grote-Hynes approach. The computed activation volumes are positive; thus, the mechanism of this particular water-exchange is a dissociative process.