Nuclear Glass Alteration in Clay: Assessment of the Effect of Direct Contact between the Materials through Experimental and Modeling Approach

ABSTRACTA new approach is proposed for discussing the reliability and predictability of the models intended to evaluate the performance of glass packages under geological disposal conditions. The r(t) model developed by the CEA is used in this study to simulate original laboratory test results, and the validity of the predictions is then verified experimentally. This approach allows us to check that the key mechanisms are correctly simulated, even if they are simplified. A review of the experimental results (glass alteration kinetics and morphology of the alteration film) suggests that physically separating the glass and clay under geological disposal conditions could considerably diminish the silica pump effect attributed to reactive clays such as Boom clay or FoCa7 clay.