海岛下垫面对核事故核素扩散影响规律研究

为研究核事故发生后气载核素在海洋环境中的扩散，以海岛核电厂为研究对象，采用计算流体动力学（CFD）模拟的方法对海岛核电厂各下垫面要素、风速变化、喷口速度变化进行了模拟，并用风洞实验验证CFD模拟的准确性。结果表明，山体会对地面最大扩散因子产生显著影响；平台的高度增加时，地面最大扩散因子降低，出现距离更靠近喷口；风速的增大会使得面最大扩散因子出现位置后移；喷口速度增大会使得地面最大扩散因子变小，其出现位置后移；在喷口速度变化的情况下，地面最大扩散因子的CFD模拟值和高斯烟羽模型计算值呈倍数关系，并以此对高斯烟羽模型进行了修正。 

Effect of Island Underlying Surface on Radionuclide Atmospheric Dispersion under Nuclear Accidents

In order to study the diffusion of airborne nuclides in marine environment after a nuclear accident, this paper took the island nuclear power plant as the research object, and simulated the underlying surface elements, wind speed changes and nozzle velocity changes of the island nuclear power plant by using computational fluid dynamics (CFD) simulation method, and verified the accuracy of CFD simulation by wind tunnel experiments. The results show that the mountain around the nuclear power plant has a significant effect on the maximum ground diffusion factor. When the height of the platform increases, the maximum ground diffusion factor decreases, which is closer to the nozzle. The increasing of the wind speed will cause the position of the maximum ground diffusion factor to shift back. As the nozzle velocity increases, the maximum diffusion factor on the ground becomes smaller and its position shifts back. Under the condition that the velocity of the nozzle changes, the CFD simulation value of the ground maximum diffusion factor has a multiple relationship with the calculated value of the Gaussian plume model.