Impact of the thermal load on the farfield and galleries of a HLW-repository

Due to the thermal impact by high level waste placed in a repository, the repository and its surroundings are subject to additional thermal load. This load may have an impact on the repository structures and buildings as well as on the surrounding geological rock formations.Two particular points are considered here: the lining of the galleries and tunnels and the long term behaviour of the geological formations at large scale. As the temperature load on the rock and the construction elements like lining and reinforcements is expected to be non-negligible in comparison to in situ conditions at construction time, its influence has to be studied to predict the repository behaviour.The thermal effects have been addressed using a thermo-mechanically coupled FE-code with classic elasto-plastic material laws.It is found that the thermal impact leads to deformation in the rock mass above the repository up to the ground surface. Furthermore, the loading on the galleries lining is important already during a relatively early stage after waste emplacement and has to be considered for dimensioning of the structures.