Terrain and building effects on the transport of radioactive material at a nuclear site

• This study is to quantify the building and terrain effects on the atmospheric dispersion.
• Statistical methods with AERMOD-PRIME and CFD were used.
• To assess the risk in nuclear power plants, terrain and building effects have to be considered.

This study identified the terrain and building effects on the atmospheric dispersion of radioactive materials at the Wolsong Nuclear Site. To analyze the atmospheric dispersion of radioactive materials, the AERMOD-PRIME model, CFD model and meteorological data from 2010 were used. The terrain and building effects on the atmospheric dispersion of radioactive materials within a 1 km radius of the site were statistically significant. The maximum concentration of the radioactive material increased by 7 times compared to the concentration when the terrain and building effects were not considered. It was found that the terrain and building influenced the decrease in the concentration of radioactive material in a concentric circle with a 914 m radius from the center of the site. The concentration of radioactive material in a concentric circle with a 350 m radius was two-times higher than the concentration estimated at the backside of the building, which is the downwind side, without any consideration of the terrain and building effects. In consideration of the Korean situation, in which multiple nuclear reactors are built on the same nuclear site, it is necessary to evaluate the risk that may affect workers and nearby residents by reflecting the terrain and building effects.