CIEMAT Publications

Abstract

With the aim of assessing the behaviour of bentonite at temperatures higher than 100°C, which is the limit usually consider for its use as barrier in radioactive waste repositories, two thermo-hydraulic tests were carried out with compacted bentonite (10x10 cm). The heater at the bottom of the cells was set at 150°C and hydration through the top surface of the block took place during 2.5 years. The water was saline in one of the cells and diluted in the other. This report details the evolution during this time of the variables measured online: relative humidity and temperature inside the bentonite, radial pressure at the bentonite/cell contact and water intake. The dismantling operations are described, as well as the final state of the bentonite in terms of dry density, water content and degree of saturation. Finally, these results are compared with those obtained in tests previously performed under the same conditions except for the heater temperature, which was lower.