Publications Details
Design, modeling, and current interpretations of the H-19 and H-11 tracer tests at the WIPP site
Site-characterization studies at the Waste Isolation Pilot Plant (WIPP) site in southeastern New Mexico, US identified ground-water flow in the Culebra Dolomite Member of the Rustler Formation as the most likely geologic pathway for radionuclide transport to the accessible environment in the event of a breach of the WIPP repository through inadvertent human intrusion. The results of recent tracer tests, as well as hydraulic tests, laboratory measurements, and re-examination of Culebra geology and stratigraphy, have led to a significant refinement of the conceptual model for transport in the Culebra. Tracer test results and geologic observations suggest that flow occurs within fractures, and to some extent within interparticle porosity and vugs connected by microfractures. Diffusion occurs within all connected porosity. Numerical simulations suggest that the data from the tracer tests cannot be simulated with heterogeneous single-porosity models; significant matrix diffusion appears to be required. The low permeability and lack of significant tracer recovery from tracers injected into the upper Culebra suggest that transport primarily occurs in the lower Culebra.