随机游走大气扩散模型在核事故应急中的开发和应用

Development and application of random walk model of atmospheric diffusion in emergency response of nuclear accidents

烟羽浓度预测是核事故早期应急响应放射性后果评价系统的主要内容之一。描述了大气扩散本身随机的特点,介绍了自行开发随机游走大气扩散模型Random Walk,并与现有欧共体开发的核应急决策支持系统RODOS中的拉格朗日烟团模型RIMPUFF进行比较验证。结果表明,两者计算结果相当吻合,但Random Walk计算出的烟羽范围比RIMPUFF计算出的稍小。随机游走大气扩散模型Ran- dom Walk能够较好的模拟核事故发生条件下的大气扩散过程,可以作为核事故应急决策系统的一个大气扩散模块,为早期应急和后果评价提供更接近实际的信息。

Plume concentration prediction is one of the main contents of radioactive conse- quence assessment for early emergency to nuclear accidents. This paper describes ran- dom characteristics of atmospheric diffusion itself, introduces random walk model of at- mospheric diffusion （Random Walk）, and compare with Lagrangian puff model （RIM- PUFF） in the nuclear emergency decision support system （RODOS） developed by Euro- pean Community for verifuation. The results show the concentrations calculated by the two models are quite close except that plume area calculated by Random Walk is a little smaller than that by RIMPUFF. The random walk model for atmospheric diffusion can simulate the atmospheric diffusion in case of nuclear accidents and provide more actual information for early emergency and consequence assessment as one atmospheric diffu- sion module of the nuclear emergency decision suooort system.