用高斯模型计算大气中放射性核素云团的扩散

CALCULATION OF DIFFUSION OF RADIONUCLIDES CLOUD IN ATMOSPHERE USING THE GAUSSIAN MODEL

本文介绍用高斯模型计算大气中放射性核素云团的扩散。在星际边界层中尺度运动范围内 ,在局地直角坐标系中 ,采用蒙特卡罗 (MonteCarlo)方法和高斯公式法 ,在北纬 2 0°～ 3 0°、东经 72°～ 1 1 5°区域内的特定风场中 ,对位于北纬 2 7°、东经 72°离地面高 1 0 0m的放射性点源瞬时释放的放射性核素云团在大气中的迁移和扩散过程进行了计算 ,得到了云团中心的运动轨迹、在地面上放射性核素浓度中心的相对浓度、放射性核素云团在地面上的相对浓度分布及其等值线分布图等结果。文中还计算了印度新德里和中国昆明地面上该放射性核素云团相对浓度的分布 ,为对可能发生的核事件的监测提供参考数据。

Presented here is the calculation of diffusion of radionuclides cloud in atmosphere using the Gaussian model. The calculation is taken in the range of medium scale motion at the interplanetary frontier and in local Cartesian coordinates. In the area of 20°～30° north latitude and 72°～115° east longitude,at specific wind velocity,the transport and diffusion of the radionuclides cloud in air,which come from an instantaneous point source with height of 100 m at 27° north latitude,72° east longitude,are calculated using the Monte Carlo method and Gaussian equation. The trajectory of the radionuclides cloud core, the relative concentration of the radionuclides concentration center on the surface,the distribution of the relative concentration of the radionuclides on the surface,and its isopleth have been obtained. For the same radionuclides cloud,the relative concentration distribution in New Delhi in India and Kunming in China has been evaluated,respectively. These calculated results can provide information for monitoring possible nuclear incidents.