Simulated alteration tests on non-radioactive SON 68 nuclear glass in the presence of corrosion products and environmental materials

Alteration tests with non-radioactive French SON 68 (R7T7-type) nuclear glass in the presence of simulated metal canister corrosion products (CP) or environmental materials (EM) were simulated using the lixiver2 computer code. The code incorporates hypotheses concerning glass alteration in aqueous media based on the first-order kinetic law for total silicon with variable silicon retention in the gel and silicon diffusion in the gel interstitial water, coupled with silicon adsorption and diffusion in the materials in contact with the glass. The canister CP are considered as a localized medium with a mass adsorption capacity Rad, while the EM are considered as a porous medium with a diffusion coefficient Dp and a distribution coefficient Kd. Lixiver2 simulates these media in one-dimensional Cartesian geometry. The Kd values determined by simulating alteration tests logically increase with the aggressiveness of the materials with respect to the glass.