ANISOTROPY AT THE C-WELLS COMPLEX NEAR YUCCA MOUNTAIN

Understanding saturated flow and transport near the proposed high-level nuclear waste repository at Yucca Mountain is critical to a successful License Application. Because radionuclides released from the proposed repository at Yucca Mountain must travel through the saturated fractured tuff and the saturated alluvium before reaching the compliance boundary, it is important to characterize the hydrogeologic properties of the downgradient media. Since the completion of the C-Wells multi-borehole complex in 1983, several single and cross-hole tracer and pumping tests have been conducted to gain a better understanding of the hydrogeology of the region. A number of published studies have assigned transmissivities, storativities, and anisotropy ratios to the saturated zone in this area. In this analysis, reviews of several studies are used in conjunction with an independent re-analysis of the data to suggest a distribution of anisotropy ratios between 0.05 and 20 used in the Finite Element Heat and Mass Transfer (FEHM) stochastic flow model of the saturated zone.