基于CFD方法的核设施气载流出物取样代表性研究

Application of computational fluid dynamics method in the analysis of representative aerosol sampling in the pipeline of nuclearfacility

核设施气载流出物取样代表性的优劣,决定着对环境监测和辐射安全评价的准确性。应用计算流体力学(Computational Fluid Dynamics,CFD)方法,根据新版ISO 2889标准《核设施的烟道和通风管道中的放射性物质取样》中对取样位置的要求,对某核设施排气系统的流场进行了数值模拟并分析了不同取样位置的取样代表性。指出现有取样位置选取不尽合理的结论,通过对模拟结果进行分析,确定了合理取样位置,从而可以有效地监测放射性气载流出物的核素活度浓度,为辐射环境影响评价提供科学数据支持。

The representative sampling of radioactive gases and aerosols determines the accuracy of environmental monitoring and evaluation results of nuclear facilities.The gas pipeline flow field was simulated with CFD (Computational Fluid Dynamics,CFD).The results were compared with the requirements in ISO 2889.It shows the current sampling position does not meet the requirements described in ISO 2889.The proper positions which can facilitate effetive monitoring of radioactive effluents and provide scientific data support to environment evaluation are recommended.