Design, modelling, 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, USA 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 reexamination of Culebra geology and stratigraphy, have led to a significant refinement of the conceptual model for transport in the Culebra. The test design was the direct result of interpretations of past tests and was continuously refined during the tests as additional insight was gained from evaluation and interpretation of new data. This step-wise approach was valuable for designing a robust test, but the approach could be improved by adopting an even more evolutionary strategy over a longer time frame. (author)