In-Situ Testing of Nuclear Waste Glasses in a Clay Laboratory - Results After Two Years Corrosion

Abstract

ABSTRACTThe first retrieval of an in-situ experiment on the interaction waste form - clay host in the underground laboratory under the Mol site has been finished successfully. The test consisted in a two years exposure of various candidate simulated waste glasses at 90°C to Boom clay. The retrieval was done by overcoring. The experimental data showed satisfactorily correspondence between in-situ and laboratory simulation tests both for mass loss and surface analytical data, supporting the validity of the in-situ test as it was performed. The thickness of waste form dissolved within two years varies between 40 and 325 μm (case of the high-level waste glasses), depending on the composition. Matrix dissolution is expected to be the major mechanism of interaction.