Description
The host rock, the Opalinus Clay (which also includes the so-called Murchisonae beds), is a moderately over-consolidated claystone which forms a layer somewhat more than 100 m thick and dips to the south-east at about 5º. The siting area is located at the edge of the zone influenced by the Alps. Tectonically, it is subject to a slight compressive stress but is not significantly deformed. It also lies within one of the seismically quiet areas of Switzerland, with a small uplift and erosion rate and average heat flow. The formations above and below the Opalinus Clay (upper and lower confining units) mostly have a low hydraulic conductivity and form a supplementary geological barrier between the host rock and the regional aquifers, strengthening the barrier function of the host rock. Because of its almost constant thickness, lateral extent and lithological continuity, the host rock offers a large element of flexibility in locating a repository.
OPA Category
Category as used in the OPA assessment
OPA Number
Number as used in the OPA assessment
Waste Relevance
Classes of waste to which this FEP is relevant
NEA V1 IFEP Reference(s)
Related IFEPs from the NEA V1 IFEP list from 1999