Mont Terri

The Mont Terri Project is an international research project for the hydrogeological, geochemical and geotechnical characterization of a clay/shale formation suitable for geologic disposal of radioactive waste (Zuidema, 2007; Bossart and Thury, 2007). The project, which was officially initiated in 1996, utilizes an underground rock laboratory, which lies north of the town of St-Ursanne in Northwestern Switzerland and is located at a depth of ~300 m below the surface in argillaceous claystone (Opalinus Clay). The rock laboratory is located in and beside the security gallery (initially the reconnaissance gallery) of the Mont Terri motorway tunnel which was opened to traffic at the end of 1998. The rock laboratory consists mainly of eight small niches along the security gallery, excavated in 1996, the gallery 98 and 5 lateral niches, excavated in 1997/98, a gallery for the EZ-A experiment, excavated in 2003, the gallery 04 and 4 lateral niches, excavated in 2004, and lastly, the gallery 08 and side galleries for the FE Heater Test and MB test, excavated in 2008.

Summary schematic of the Mont Terri URL with side galleries and drifts for testing. Three specific experiments of relevance to UFD are highlighted.

The Mont Terri Project essentially operates as a collaborative program providing open access to an existing URL. The research program consists of a series of individual experiments and is divided into annual project phases. Mont Terri partner organizations may select and conduct experiments, may participate in experiments conducted by others, and they have access to all project results from past and ongoing efforts. Planning, steering and financing is the responsibility of the partners participating in the experiment. (Larger field experiments are therefore often conducted by more than one organization.)