Simulation of the Dispersion of Radioactive Effluents over the Kori site using Field Tracer Experiment

Abstract

Field tracer experiments have been conducted at the Kori nuclear site for the purpose of analyzing the site-specific atmospheric dispersion characteristics and validating a real-time radiological dose assessment system FAD AS. Field tracer experiments were performed for three years from 2000 to 2002. Tracer gas SF6 was released at the top of the meteorological tower of the site and sampled by 140 automatic sequential gas samplers. The samplers were disposed at sampling points along the traffic roads around the site. The coordinates of all the sampling points were investigated by GPS. The concentration of the sampled gas was analyzed by gas chromatography. And the measured concentration distribution was compared with the distribution simulated by FAD AS. During the experiments, meteorological data was measured at several sampling points including the release point. The measured meteorological data were used for the numerical simulation by FAD AS. The comparative study between the measured and the simulated concentration was conducted. Due to the effects of the complex terrain of the Kori site, the degree of agreement between the measure and the simulated concentration is somewhat lower than that of the site of a flat terrain. The analysis of the site-specific field tracer experiment provides the useful information for the realistic application of an atmospheric dispersion model for a nuclear site.