Effect of Host-Rock Dissolution and Precipitation on Permeability in a Nuclear Waste Repository in Tuff

摘要

A study has been conducted to determine whether thermally induced, host-rock mineral dissolution and precipitation processes could decrease the isolation capability of a potential high-level nuclear waste repository in tuff by significantly altering the permeability of the formation. Conservative assumption and precipitation. Porosity changes were calculated as a function of time, depth, emplaced waste power density, and water flux for both matrix and fracture flow. Cumulative porosity changes were shown to be very small, and net decreases in porosity were shown to occur only in the vicinity of the repository horizon if the groundwater vaporizes. The differences in permeability for both matrix and fracture flow resulting from these small cumulative porosity were shown to occur only in the vicinity of the repository horizon if the groundwater vaporizes. The differences in permeability for both matrix and fracture flow resulting from these small cumulative porosity changes should have no significant effect on the overall hydrologic patterns at the site at Yucca Mountain, Nevada. 40 references, 16 figures, 4 tables. (ERA citation 10:001332)