Previous nuclear power plant (NPP) severe accidents have raised great concern in Southeast Asia on the issue of transboundary atmospheric dispersion of an accidental release from an external NPP. This study presents the inter-comparison of atmospheric dispersion calculations performed by different calculation codes employing Lagrangian particle model or Gaussian puff model with Southeast Asia weather data during the northeast monsoon period. The test case is a hypothetical accident in Fangchenggang NPP with a hypothetical source term. Radionuclide concentration and radiation dose distribution maps along with specified values at specific locations are compared to demonstrate the similarities and differences of each calculation code. All calculation codes can generally capture the dispersion pathway, though only those employing Lagrangian particle model can record microscale changes in wind direction. Analysis of predicted exposure extent and lead time shows that radioactive plume contributing to the radiation dose of several μSv/day can reach one or more ASEAN countries within the 24-h timeframe. This information can be used to design appropriate risk communication strategy to dispel unnecessary public anxiety or to plan for more extensive radiation monitoring capability. For this purpose, Gaussian puff model can be used to provide initial information which can be later confirmed by Lagrangian particle model.

先前的核电厂（NPP）严重事故已引起东南亚对外部核电厂意外释放的跨界大气扩散问题的极大关注。这项研究提出了使用拉格朗日粒子模型或高斯吹气模型的不同计算代码与东北季风期间东南亚天气数据进行的大气弥散计算的相互比较。该测试用例是防城港核电厂的一个假设事故，带有假设来源术语。比较了放射性核素浓度和辐射剂量分布图以及在特定位置的指定值，以证明每个计算代码的相似之处和不同之处。所有计算代码通常都可以捕获色散路径，尽管只有采用拉格朗日粒子模型的人才能记录风向的微小变化。对预测的暴露程度和提前期的分析表明，造成辐射剂量达几微希沃特/天的放射性羽流可以在24小时内到达一个或多个东盟国家。该信息可用于设计适当的风险交流策略，以消除不必要的公众焦虑或计划更广泛的辐射监控功能。为此，可以使用高斯粉扑模型来提供初始信息，这些信息随后可以通过拉格朗日粒子模型进行确认。对预测的暴露程度和提前期的分析表明，造成辐射剂量达几微希沃特/天的放射性羽流可以在24小时内到达一个或多个东盟国家。该信息可用于设计适当的风险交流策略，以消除不必要的公众焦虑或计划更广泛的辐射监控功能。为此，可以使用高斯粉扑模型来提供初始信息，这些信息随后可以通过拉格朗日粒子模型进行确认。对预测的暴露程度和提前期的分析表明，导致辐射剂量达几微希沃特/天的放射性羽流可以在24小时内到达一个或多个东盟国家。该信息可用于设计适当的风险交流策略，以消除不必要的公众焦虑或计划更广泛的辐射监控功能。为此，可以使用高斯粉扑模型来提供初始信息，这些信息随后可以通过拉格朗日粒子模型进行确认。