Long-Term Behavior of Bituminized Waste: Modelling of Auto-Irradiation and Leaching

Abstract

ABSTRACTDuring interim storage, the main evolution factor of the bituminized wastes is radiolysis under auto-irradiation, while in deep disposal conditions, after radioactive decrease, site resaturation with water, and container corrosion, the main factor of evolution is leaching by water.This paper presents two models, designed to describe respectively radiolytic gas evacuation, and bituminized waste alteration under leaching.The first model is based on the integration of simple descriptions of gas production by radiolysis, gas diffusive transport, bubble nucleation and ripening, and bubble transport under buoyancy and viscosity.The second model is based on simple descriptions of water adsorption and solubilization at the surface, water diffusion into the matrix, water uptake by the most soluble salts, salt grain swelling and alteration of matrix waterproofing, diffusive transport of salts out of the waste.