Population dose assessment for radiation emergency in complex terrain

Gaussian plume model is used to assess environmental dose for abnormal radioactive release in nuclear facility. But there has a problem to use it for complex terrain. In this report, MATTEW and WINDO4 codes which had been verified were used to calculate wind field in the complex terrain. Under the base of these codes principle. Wind fields were obtained from the calculation of the finite difference approximation for advection-diffusion equations which satisfy the mass-conservative law. Particle concentrations and external doses were calculated by using PIC model which approximate the particle to radioactive cloud, and atmospheric diffusion of the particles from the random walk method. The results show that the adjusted wind fields and the distributions of the exposure dose vary with the topography of the complex terrain. (Author)