On the hydration of unsaturated barriers for high-level nuclear waste disposal

The paper addresses the topic of the effects of hydration and temperature on the final state of an engineered barrier composed of compacted bentonite. In particular the distributions of water content and dry density are examined. Those issues are explored with reference to a long-duration field test that reproduces at full scale the behaviour of an unsaturated compacted bentonite barrier subjected to hydration and thermal ef-fects. The state of the barrier is discussed at two different stages using data from two separate dismantling op-erations. It is observed that the state of the barrier is not homogenous even after reaching saturation. It is shown that coupled THM analyses are able to predict satisfactorily the state and evolution of the barrier throughout