An analysis of the radioactive contamination due to radon in a granite processing plant and its decontamination by ventilation

This work focuses on studying concentration distribution of 222Rn radioisotope in a granite processing plant. Using Computational Fluid Dynamic Techniques (CFD), the exposure of the workers to radiation was assessed and, in order to minimise this exposure, different decontamination scenarios using ventilation were analysed. Natural ventilation showed not sufficient to maintain radon concentration below acceptable limits, so a forced ventilation was used instead. Position of the granite blocks also revealed as a determining factor in the radioactive level distribution. Thus, a correct layout of the stored material and an adequate ventilation system can guarantee free of exposure to radiation zones within the studied workshop. This leads to a drastic fall in the exposure of the workers and consequently minimises their risk of developing aggressive illness like lung cancer. [Display omitted] •Handling granite in a confined space is dangerous for workers' health.•Adequate ventilation is important in guaranteeing lower radioactive levels.•The radiation exposure of workers is assessed using CFD.•If the material is properly stored radiation-free green zones are generated.•A proposal for decontamination techniques using ventilation is suggested.