放射性核素大气弥散模式研究综述

摘要

放射性核素大气弥散模式可以模拟正常工况和事故工况下,放射性核素在不同尺度下的大气输送与扩散,为核电站选址、辐射环境监测和核事故应急提供科学依据。归纳了目前广泛用于模拟核素大气弥散的各种模式,介绍了这些模式的研究进展和适用范围。结果表明：对于区域范围小于2 km的弥散,一般可采用CFD（Computational fluid dynamics）湍流模式;对于20 km范围内的局地扩散,一般可采用高斯模式;而对于中尺度（20—200 km）和大尺度（200 km以上）弥散,则采用拉格朗日模式或欧拉模式。为了避免各种模式本身的局限性,采用嵌套模式将是较好的选择。最后,对放射性核素大气弥散模式发展前景进行了讨论。%The radionuclides atmospheric dispersion modes can be used to simulate transportation and diffusion of radionuclides in different scales under normal and accident conditions,and it can provide scientific references for selecting the nuclear power plant location,monitoring the radiation environment and managing nuclear accident.The current advance and suitability of different radionuclides atmospheric dispersion modes were summarized.The results indicate that computational fluid dynamics（CFD）turbulence modes and Gaussian modes are often used for dispersion within the scope of 2 km and 20 km respectively,while Lagrangian modes and Euler modes are used for dispersion of mid-scale（20-200 km）and large-scale（more than 200 km）.Nested modes should be employed in order to avoid the intrinsic limitations of modes.Finally,the prospect of radionuclides atmospheric dispersion modes is discussed.