Modelling the fate of uranium from inorganic phosphorus fertilizer applications in agriculture

We used the recently developed HP1 coupled geochemical transport code to calculate U-fluxes to groundwater originating from application of inorganic P-fertilizers to an agricultural field. The HP1 code was found to be a very convenient tool for studying interactions between water content and flow conditions, changes in pH, and retention of U. Results show that U will migrate considerable faster during transient flow conditions as compared to steady-state flow. A steady-state flow approach hence can only partially account for the various coupled physical and geochemical interactions in the vadose zone, whereas short-term variations involving considerable temporal variability require a transient model. Calculations of the radiological impact of U-containing groundwater demonstrate that the annual total dose owing to consumption of groundwater would not lead to values exceeding the natural background dose.