SAFE - a Systems Approach For Engineered Barriers

"Scientific objectives are:
1. To deploy and refine advanced monitoring technologies for simultaneous imaging of THMC variables (pH, temperature, pore-water pressure, swelling etc) within the laboratory. We will embed state-of-the-art micro-to-nano scale wireless devices into bentonite, and combine these with micro-scale geophysical and magnetic monitoring surveys, to illuminate 2D and 3D heterogeneities in THMC behaviour.
2. To integrate these monitoring technologies with experiments to gain a predictive understanding of the THMC evolution of clay-based engineered barriers, and their interfaces, up to the upper-bound of realistic environmental conditions. Interfaces will comprise joints within the clay as well as interfaces to the surrounding rock, cement and waste container. Experiments and modelling will focus on the effects of strong gradients in temperature (150 degrees C), low pH cements and high salinity (10-40 g/l) across the EBS interfaces, and on the fingering of flow along joints and interfaces that may give rise to a heterogeneous THMC system response."

"We have shown that the erosion of bentonite is far lower than anticipated in current safety cases for nuclear waste disposal. This increases confidence in the safety of geological disposal facilities for nuclear waste such as those currently being licensed in Sweden and Finland.

We have adapted MEMS devices for reliable montoring of environmental conditions in nuclear waste deposition shafts during operation of a repository."