Short communication on the Influence of the temperature between 30 and 70 degrees C on the hydration of SON68 nuclear waste glass in a vapour phase

摘要

The hydration of S0N68 glass (non-radioactive surrogate for R7T7 glass, the French industrial glass for high-level radioactive waste management) was studied at between 30 and 70 degrees C at a relative humidity of 95% for a period of 6 months. The hydration thicknesses were shown to increase with temperature and did not exceed a few nanometres at 30 and 50 degrees C, or a few tens of nanometres at 70 degrees C. The temperature dependence of hydration rates followed Arrhenius law and enabled the determination of an activation energy. This is 62 +/- 13 kJ.mol(-1), which is compatible with a hydration mechanism involving a hydrolysis of the silicate bonds. All these results are discussed, taking into account data available in the literature. (C) 2020 Published by Elsevier B.V.