中文摘要：

以某铀矿排风井为对象建立物理模型,通过建立核素氡扩散数学模型,利用CFD方法耦合求解得到不同大气风速（0.5,1.0,2.0,4.0 m/s）和下垫面粗糙度（0.1 m,1.0 m）下的大气风场结构及核素氡的浓度分布状况。研究结果表明：大气风速和下垫面粗糙度对核素氡的迁移扩散具有重要的影响;当大气风速小于0.5 m/s时,此时地面粗糙度对核素氡迁移扩散起主导作用。地面粗糙度越大,近距离的氡气浓度越高,局部污染越严重,主要污染范围在100 m以内;当大气风速大于2.0 m/s时,大气风速对核素氡迁移扩散起主导作用。大气风速越大,氡气迁移扩散能力越强,污染距离越大,局部污染较轻,主要污染范围在400 m以内。文中数值计算方法和结论可以为铀矿区辐射防护及新建铀矿山选址提供参考。

英文摘要：

Uranium mine ventilation shaft physical model and dispersion mathematical model of radon were built, CFD methods were used to solve equations and get the atmospheric wind field structure and distributions of radionuclide concentrations of radon on the atmospheric wind speeds （0.5, 1.0, 2.0, 4.0 m/s） and underlying surface roughness conditions （0.1 m, 1.0 m）. The numerical results show that the atmospheric wind speeds and surface roughness have important effects on the dispersion of radon. When the atmospheric wind speed is less than 0.5 m/s, the underlying surface roughness has the dominant effects on the dispersion of radionuclides. The greater the surface roughness, the higher the concentration of radon and more serious the local pollution, so the main pollution is within the region of 100 m. When the atmospheric wind speed is greater than 2.0 m/s, atmospheric air speeds have the pronounced effects on dispersion of radon. The faster the atmospheric wind speed, the stronger the diffusion capacity and the farther the distance, so the main pollution is within the region of 400 m. Numerical methods and results in this work can provide some reference basis for uranium areas radiation protection and new uranium mining site-selecting.