Simulation of the effects of geochemical reactions on groundwater quality during planned flooding of the Konigstein uranium mine, Saxony, Germany

Uranium mining in southeastern Germany resulted in significant environmental risks. Closure of the mines and subsequent rises of water levels may result in heavy-metal and radionuclide-bearing mine waters penetrating aquifers that are used for water supply. While there are certain (geo-)technical constraints on the schedule with which flooding of the mines can proceed, this process must not result in aggravating the problem of metal release. Evaluation of the likely 'natural' geochemical situation of Konigstein mine after mining has ceased, and different scenarios for the release of metals indicates that rapid flooding, albeit avoiding unnecessary aeration of the waters, is likely to result in reducing conditions and consequently low U-solubilities.