Comsol Modelling of Uniform Corrosion of Used Nuclear Fuel Canisters

Uniform corrosion of copper can occur in spent nuclear fuel canisters placed in deep geological repositories (DGR). To estimate the minimum thickness for safe design of canisters, it is necessary to analyze the corrosion rate. Copper Corrosion Model (CCM) has been used to model the corrosion process taking into account processes including adsorption/desorption, precipitation/dissolution, oxidation, and parameters including oxygen concentration, chloride, moisture and associated rate constants. In this work, CCM has been incorporated in COMSOL and validated with CCM. Once validated, the COMSOL model was used to examine the sensitivity of various parameters with respect to copper corrosion. It was found that initial chloride concentration, adsorption/desorption of cupric ions are parameters that most effect copper corrosion. The developed model can be used to simulate the uniform corrosion process under DGR conditions with more complexity including variation in temperature, saturation and pressure, and aid in the design of copper canisters