Behavior of HPC nuclear waste disposal structures in leaching environment

Nuclear waste disposal is a subject of concern for the French national agency for nuclear waste management (Andra). One of the solutions envisaged by Andra (in accordance with the French law (June 28th 2006)) to take care of nuclear wastes is long-term underground storage. The storage structures would be high-performance concrete tunnels. The safety level of these structures for the next 1000 years has to be demonstrated by Andra. To do this, scenarios compatible with the geological and hydrological environment of the tunnel will be considered including chemical and physical evolutions. Among them is water saturation of the disposal structure leading to a concrete leaching process combined with a ground convergence towards the concrete vault, which is studied here. The corresponding research program is presented; it includes chemical and chemo-mechanical aspects and a simulation of the long-term behavior of disposal cell.