Transport dynamic of strontium in groundwater: Safety Assessment study

One of the activities of the Safety Assessment is the evaluation of the impact of a nuclear facility on the environment. The radionuclide transport into groundwater is subjected to different phenomena (e.g. groundwater dynamic, surface stream dynamic, the interaction between surface water and groundwater, radionuclide interaction with environmental matrix, etc.) that influence the risk of contamination of water. The investigation of the source term is fundamental to understand its impact on radionuclide transport. In this paper, in situ surveys and modelling were coupled to investigate the dynamic of strontium in an Italian nuclear site. On-site measurements have identified low quantities of strontium in monitoring wells, and through the modelling, the possible migration pathway of this radionuclide was identified. For a primary safety evaluation purpose, a parametric detailed analysis was carried out to identify which hydrogeological parameters and which artificial structure present in the area could influence the dynamic of strontium in the investigated site. In particular, the effect of the Cavour artificial channel on the strontium migration and dilution was demonstrated. The coupling of monitoring activities, periodically performed in the area, and the modelling activities, focused on the detailed relationships between the Cavour artificial channel and the underground water flow, contributes to better evaluate the possible radiological risk for population and environment and to support future safety studies.