Microstructural and Mineralogical Characterization of Selected Shales in Support of Nuclear Waste Respository Studies

The Sedimentary Rock Program at Oak Ridge National Laboratory (ORNL) has evaluated a variety of sedimentary rocks as potential host media for a U.S. civilian nuclear waste repository. Shale was selected as the sedimentary rock with the greatest potential, based on technical aspects related to geology, geochemistry, hydrology, thermal performance, rock mechanics, natural resources, waste package material degradation, repository costs, and systems studies (Croff et al.,1986). Other countries such as Belgium, Italy, Switzerland, and the United Kingdom are considering argillaceous formations as a potential host rock for high-level waste disposal (Gera, 1980).