Numerical Simulation of Influence of Vegetation on Atmospheric Diffusion of Radon Emanating From Uranium Tailings Impoundment

摘要

Using the numerical simulation method, this thesis studies the radon concentration distribution in downwind area of the flat ground uranium tailings impoundment with and without vegetation on the beach face under the wind speed of 0.5, 1.0, 2.0 and 4.0 m/s. The numerical results show that the radon concentration decreases gradually with the increasing wind speed and distance from uranium tailings impoundment. As the wind speed is 0.5 m/s, the radon concentration is higher in downwind area of uranium tailings impoundment, and accumulation range is larger and local pollution also becomes more serious. However, radon concentration and accumulation range falls rapidly with wind speed increased to 4.0 m/s. At the same wind speed, radon concentration under the condition of beach face with vegetation is higher than the one without vegetation within 600 m range of uranium tailings impoundment along the downwind direction, but radon concentration is lower under the condition of beach face with vegetation out of 600 m range. It illustrates that vegetation can inhibit radon diffusion to some extent.