Three-dimensional numerical modeling of pollutant transport at local-scale complex terrain

The wind field and atmospheric dispersion models for a nuclear accident have been developed for estimating the overall wind patterns and the concentration distributions of pollutants over a complex terrain. A field tracer experiment was carried out for validating the atmospheric dispersion model and analyzing the environmental characteristics of a nuclear power plant site located in complex coastal terrain. SF6 was released as tracer gas and air samples were analyzed by gas chromatography. The wind fields were found to be one of the most important factors for calculating the concentration of the pollutants in the atmosphere. Several numerical experiments using various combinations of measured wind data were performed for obtaining accurate concentration distributions compared with the analyzed values of the tracer gas. In a comparative study, the calculated concentration distributions were compared with in situ measurements.