ABSTRACT
Andra, The French National Agency for Radioactive Waste Management has built an Underground Research Laboratory (URL) for studying the feasibility of radioactive waste disposal in Jurassic-age Callovo-Oxfordian argillaceous rock. One of the objectives of the many investigations performed since 1994, was to characterise the hydrogeological parameters of the formations surrounding the argillaceous rock, especially the Oxfordian and Dogger limestone.
This article focuses on Hydrogeological investigations performed in the Oxfordian limestone at the URL scale. These consist of:
Initial measurements in deep boreholes, including hydrogeological testing with and without packers, piezometric head measurements, geophysical logging and fluid conductivity logging;
Interference tests between the two access shafts to the laboratory and a network of four monitoring boreholes.
