Comparative analysis of asphalt and geomembrane sealing systems for sustainable uranium pile remediation : Insights from hydrological modeling under climate change

Abstract

Uranium ore mining heaps in Saxony and Thuringia (Germany) have been primarily covered with mineral layers as part of remediation efforts. However, aging processes in these covers—driven by climatic factors, vegetation, and root penetration—can create cracks and pathways that increase radon emissions. In residential areas, elevated radon levels may exceed the guideline values set by radiation protection regulations. While asphalt seals and geomembranes are well-established as effective long-term solutions for creating convection-tight surface systems in landfill applications, their use has rarely been considered for uranium legacy sites. This study evaluates the long-term water balance and sealing effectiveness of asphalt and geomembranes at historical uranium mining site under future climate scenarios. Using the Hydrologic Evaluation of Landfill Performance (HELP) model, we simulated water behavior and potential infiltration rates across several sealing configurations, considering current and future climate projections. Our findings reveal that both sealing systems effectively minimize infiltration, surface runoff, and seepage, with negligible infiltration even under worst-case scenarios. The results underscore the robust environmental protection offered by these systems in mitigating radon emission and ensuring long-term environmental safety. This study contributes critical insights for selecting appropriate sealing systems in mining site remediation, offering sustainable solutions that address water conservation, climate resilience, and cleaner production principles.