Field experiments with a Radioactive Dispersion Device (RDD) were performed by the National Radiation Protection Institute (NRPI) of the Czech Republic. We present the results of computer simulations of these experiments using a new microscale model, Charles University Large Eddy Microscale Model (CLMM). The model was first validated using wind tunnel data for the dispersion of continuous passive scalar release around a building with a similar aspect ratio to the building used in the experiments. The results for surface contamination by deposition are highly sensitivity to the particle size distribution, which in the present case has a large scatter.
Keywords: radioactive aerosols, particulate matter, atmospheric dispersion, large eddy simulation, LES, CFD, computational fluid dynamics, radioactive dispersion devices, dirty bombs, field experiments, deposition, surface contamination, radiation protection, Czech Republic, air quality, air pollution, dispersion modelling, microscale models, particle size distribution