The effect of rock-water interaction on permeability

Current investigations for managing high-level nuclear wastes focus on studying deep geologic repositories. The Yucca Mountain Site Characterization Project of the US Department of Energy conducts studies on Yucca Mountain, Nevada, to determine its suitability as a potential high-level nuclear waste repository. The potential host rock in Yucca Mountain is a layer of devitrified Topopah Spring tuff that is densely welded, fractured, and lithophysae-poor. The suitability of a potential nuclear waste repository site depends on, among other factors, how the near-field environment affects the integrity of waste package materials and the transport of radioactive nuclides away from waste packages. Model calculations are needed to predict the near-field environment for the entire life-span of a repository. Radioactive decay heat from nuclear waste packages is likely to create coupled thermal-mechanical-hydrological-chemical (TMHC) processes in the near field of a repository. The coupled TMHC processes must be understood so they can be incorporated in the model calculations. One of the coupled TMHC processes is the effect of the rock-water interaction (a chemical-mineralogical process) on the fluid flow in the rock mass (a hydrological process)