东部区域核事故核素大气扩散特征研究

为分析核事故时东部不同地区放射性核素大气扩散特征的差异性,通过利用区域尺度天气预报模式WRF和高斯大气扩散模式研究了东部区域尺度以及部分核电厂周边的大气弥散因子分布特征。结果表明:东部区域尺度计算网格中心点周边500 m和5000 m处大气弥散因子的最大值分别为10-3 s·m-3量级和10-4 s·m-3量级；不同核电厂距离中心点500 m处的大气弥散因子最大值在10-4 s·m-3量级,距离区域中心点5000 m处的大气弥散因子最大值在10-6～10-4 s·m-3量级之间；针对不同核电厂距离中心点500 m处和5000 m处大气弥散因子比较发现,前者昌江核电厂大气弥散因子最大值最高；后者秦山核电厂大气弥散因子最大值最高。可见不同地区的核电厂受气象场影响其大气扩散特征存在差异。

A Study On the Atmosphere Dispersion Characteristics of Nuclear Accidents in the Eastern Region

In order to analysis the difference of atmosphere dispersion characteristics of radionuclide in different region of Eastern Region when nuclear accident happens, the regional weather scale weather prediction model WRF and Gaussian atmospheric diffusion model was used to investigate the distribution characteristics of atmospheric dispersion factors in the eastern region and around some nuclear power plants. The results show that the maximum values of atmospheric dispersion factors at 500 m and 5000 m around the center point of the grid at the eastern regional scale are in the order of 10-3 s·m-3 and 10-4 s·m-3, respectively. For different nuclear power plants, the maximum atmospheric dispersion factor at a distance of 500 meters from the center point is 10-4 s·m-3, while that at a distance of 5000 meters from the center point ranges from 10-6 to 10-4 s·m-3. Comparing the atmospheric dispersion factors at 500 meters and 5000 meters away from the center point of different nuclear power plants, it was found that the former has the highest maximum atmospheric dispersion factor at Changjiang Nuclear Power Plant, but the latter has the highest maximum atmospheric dispersion factor at Qinshan Nuclear Power Plant. It is concluded that there are differences in the atmospheric diffusion characteristics of nuclear power plant in different regions affected by the weather field.