The thick and regionally extensive sequence of shales and associated clastic sedimentary rocks of Late Devonian and Early Mississippian age has been considered among the “nonsalt geologies” for deep subsurface containment of high-level radioactive wastes.

The disposal of radioactive waste in the proper geologic environment offers a high potential for isolating the waste from man's environment for the period of time required for the waste to decay to innocuous levels. As part of the National Waste Terminal Storage Program, the Savannah River Laboratory has responsibility for studies related to the storage of waste in the geologic environment in the Southeast.

Site suitability studies at LLL to date have considered repositories in bedded salt and shale.