Modeling of stoichiometric uranium dioxide grain growth during isothermal sintering

The process of stoichiometric uranium dioxide grain growth during isothermal sintering is considered. A threedimensional $\mathrm{UO}_2$ grain growth model based on physical concepts described in the article was developed. This model allows one to estimate the influence of pores carried by grain boundaries on uranium dioxide grain growth kinetic by taking into account the mass transfer caused by surface diffusion, evaporation, condensation, initial particle size distribution, and its evolution. Analytical equations used in this model allow one to simplify the calculation structure. This simplification reduces the calculation time and provides an ability to solve such practical problems as influence of the processing method on evolution of the average grain size in a pellet. The grain growth model was verified according to available experimental data.