Marysvale natural analogue study: results to date

The Marysvale Natural Analogue Study is being conducted by the Office of Crystalline Repository Development for the U.S. Department of Energy. The major focus of this study is the elucidation of the mass transport of nuclides in an inactive hydrothermal system within granitic rock. Of particular concern are: (1) radionuclide migration by diffusion and/or fluid transport; (2) effects of fractures on the movement of groundwater and radionuclides; (3) absorption characteristics of the host rock and its constituent mineral phases; (4) possible complexing of radionuclides with groundwater and rock components; (5) precipitation/solubility of these various ligands; and (6) the effect upon rock strength and permeability by the interaction of heat, groundwater, and radionuclides. The objective is to quantify, or even qualify, these important factors which would be extremely helpful in selecting a suitable repository site that would avoid adverse conditions and/or take advantage of favorable ones