Comparison of CALPUFF and HYSPLIT Models for Atmospheric Dispersion Simulations of Radioactive Materials

In this study, the atmospheric dispersion of radioactive material (Cs-137) was simulated with regard to its impact within a 50-km radius from the Kori Nuclear Power Plant (NKPP) based on two different types of models (the nonsteady-state puff model CALPUFF and the lagrangian model HYSPLIT) during the spring of 2012 (May 2012). The dispersion distribution of Cs-137 calculated in the CALPUFF model was similar to that of the HYSPLIT model, but the magnitudes of differences in its spatio-temporal concentrations between the two models were different. The Cs-137 concentrations simulated by the CALPUFF were significantly lower than those of the HYSPLIT due to a limitation of puff models (e.g. puff size growth over time). The CALPUFF had the advantage of determining the dispersion of radioactive materials and their impacts on the surrounding regions, compared with the HYSPLIT that had high concentrations of Cs-137 in only small local areas with the movement of air masses along the local winds.