Cutaway view of the Bure laboratory
Since granite was abandoned as a possible host rock for a disposal facility, France has been focusing its research on clay. The drifts of the underground laboratory at Bure, on the boundary between Meuse and Haute-Marne, were dug in 2004 and 2005 from a main shaft. They are situated at depths of 445 m and 490 m in a layer of Callovo-Oxfordian argillite, a medium that still holds fossil water from the era when the Paris basin was formed. The laboratory studies the chemical reactions, mechanical effects and circulation of water that could bring radioelements back up to the surface.