山地型内陆核电厂厂址特征下气载放射性污染物大气扩散模型与规律

Nuclear energy is the inevitable choice of low-carbon economy in China. Nuclear power plants(NPPs) in China were concentrated in coastal areas. However, with the increasing scarcity of coastal site and strong demand for nuclear power by the inland provinces, inland NPPs construction is also planned. Compared with the coastal site, the preselected inland sites are most in the mountains, and still have higher frequency of wind, more complex terrain, and poor atmospheric dispersion conditions. Also higher population density within a certain range is another problem. These made the mountain-type inland NPPs need more accurate simulation method for the atmospheric diffusion of radioactive pollutants. The research based on mountain-type inland NPPs site characteristics, using the Monte Carlo method and wind tunnel experiment for atmospheric diffusion with the object of airborne radioactive material. Firstly, atmospheric dispersion model is framed in the research based on Monte Carlo method. secondly, diffusion model is modified and verified by the experiments result which simulate a typical nuclear power plant airborne pollutant dispersion using the wind tunnel. Finally, the inland NPPs radioactive substances atmospheric diffusion have be analyzed with the atmospheric dispersion model. To inverse the mountain-type inland NPPs emission limits of major radioactive source term by the result. The research aims to address the plight of the airborne pollutants atmospheric diffusion simulation in mountain-type inland NPPs site caused by its special environment. It lays foundation for the effective solution of airborne pollutants diffusion in complex situations and radioactive source term emissions.

核能是我国发展低碳经济的必然选择。我国核电目前集中在沿海地区，随着沿海厂址日益稀缺及内陆省份对核电强烈需求，内陆核电也纳入规划之中。与滨海厂址相比，内陆预选厂址多位于山区，静风频率较高，下垫面复杂，大气扩散条件差，且人口密度较高。使得内陆核电厂排放的放射性污染物在大气中的扩散需要更精确、更符合实际情况的模拟方法。本项目基于山地型内陆核电厂厂址特征，以核电厂常见气载放射性污染物为对象，采用蒙特卡罗方法及环境风洞实验开展大气扩散模型与规律研究。首先，基于蒙特卡罗方法建立大气扩散模型；其次，利用风洞实验模拟典型核电厂气载污染物扩散，对扩散模型进行修正；再次，将模型应用至山地型内陆核电厂放射性污染物大气扩散模拟，并反演内陆核电厂主要放射性源项的排放限值。本项目旨在解决山地型内陆核电厂厂址特殊环境为气载污染物扩散模拟与分析带来的难题，为有效模拟复杂情况下气载放射性污染物扩散及源项排放奠定基础。

核能是我国发展低碳经济的必然选择。随着沿海厂址日益稀缺及内陆省份对核电强烈需求，内陆核电也纳入规划之中。与滨海厂址相比，内陆预选厂址多位于山区，静风频率较高，下垫面地形复杂，大气扩散条件差。本项目基于山地型内陆核电厂厂址特征，以核电厂常见气载放射性物质为对象，采用蒙特卡罗方法开展大气扩散模型与规律研究。首先，基于蒙特卡罗方法建立大气扩散模型，同时基于CFD方法模拟了大气边界层条件及近距离扩散问题；其次，利用模拟典型核电厂气载污染物扩散与实际实验对比，并对扩散模型进行修正，验证了其有效性；再次，将模型应用至山地型内陆核电厂放射性污染物大气扩散，反演了主要放射性源项的排放限值，并对蒙特卡罗模型中关键数据进行了敏感性分析。本项目有效解决了山地型内陆核电厂厂址特殊环境为气载污染物扩散模拟与分析带来的难题，为有效模拟复杂情况下气载放射性污染物扩散及源项排放奠定基础。