Review of intermediate-scale field tests in support of disposal of waste forms.

Nuclear waste has been generated from commercial nuclear reactors and from past nuclear weapons production activities. The safe disposal of this waste generally is planned to involve emplacement of packaged spent nuclear fuel (SNF) into the subsurface or reprocessing the used nuclear fuel and producing a sparingly soluble mineral or glass. The high-level waste form(s) would then be packaged and sent to a geologic repository.

Prediction of diffusion coefficients in porous media using tortuosity factors based on interfacial areas.

Determination of aqueous phase diffusion coefficients of solutes through porous media is essential for understanding and modeling contaminant transport. Prediction of diffusion coefficients in both saturated and unsaturated zones requires knowledge of tortuosity and constrictivity factors. No methods are available for the direct measurement of these factors, which are empirical in their definition.