核事故下放射性核素多介质耦合弥散模型

建立了高斯烟团模型与欧拉输运扩散模型的耦合模型,以实现放射性核素在大气以及水体中弥散的耦合。通过对大气和水体弥散模型进行对比,验证了各个模块的正确性。基于该模型,对中国铅基研究实验堆发生燃料组件熔化事故释放的~(131)I进行仿真分析,对该核素在大气以及水体中的浓度分布进行评估。模拟结果表明:事故发生2 h后大气污染主要分布在10 km内,水域污染主要分布在10~20 km处;在该模拟条件下,铅基堆发生燃料组件熔化事故后对大气和水体造成的影响均低于国家限值。

A multi-medium coupling dispersion model of radionuclide in a nuclear accident

In order to predict the dispersion of radionuclides both in atmosphere and aquatorium, a new model was established to couple the Gaussian puff model and Eulerian model. The results of the coupling model presented good agreements with the references, which demonstrated the validity of all the modules. The coupling model was applied to the simulation of diffusion and concentration distribution of131I in atmospheric and aquatic medium in the fuel assembly meltdown accident of China lead-based experiment reactor. The results showed that the distribution range of atmospheric pollutions was within 10 km 2 h after accident, meanwhile distribution range of aquatic pollutions was between 10 km and 20 km. In the fuel assembly meltdown accident, the contaminant concentration in atmospheric and aquatic is still below the national standard limit.