Staking out Uranium in the Swiss Alps

Through routine monitoring, the Institute for Applied Radiophysics in Lausanne identified unusually high concentrations of naturally-occurring uranium in the soil of the valley. Using porewater and soil depth profiling, radiochemical characterization of the soil and state-of-the-art techniques such as X-ray Absorption Spectroscopy at the Swiss Light Source, it was possible to pinpoint the origin of the uranium, its mechanism of accumulation in the soil as well as the nature of its binding to the soil matrix. The Environmental Microbiology Laboratory determined that the uranium was present in its oxidized form despite the oxygen-poor conditions of the soil. Follow-up work will focus on evaluating the potential risk of catastrophic release of the uranium and determining whether the Dischma valley is unique or whether there are other examples of such uranium anomalies in the Swiss Alps.