Kinetics study on the dissolution of UO2 particles by microwave and conventional heating in 4 mol/L nitric acid

The dissolution of UO2 particles in 4 mol·L−1 nitric acid medium at temperatures of 90–110°C by microwave heating and conventional heating has been investigated, respectively. It is found that the dissolution ratios of UO2 particles by microwave heating were 10%–40% higher than that by conventional heating. Kinetics research shows that the dissolution of UO2 particles in 4 mol·L−1 nitric acid is controlled by the diffusion control model for microwave heating and by the surface reaction control model for conventional heating. The diffusion control model for the dissolution of UO2 particles by microwave heating could be explained by the diffuseness on the surface of UO2 particles.