Wang Wei-Hsung
Department of Radiological and Environmental Management, School of Health Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, IN 47907-2051, USA.
Health Phys. 2003 Nov;85(5 Suppl):S101-7. doi: 10.1097/00004032-200311002-00012.
The objective of this study was to establish a delayed air sampling method to verify the integrity of an existing HEPA filter system in a ventilated fume hood. (238U,232Th)O2 microspheres were generated to fabricate cement nuclear fuel pellets in a HEPA-filtered hood. To comply with the air effluent concentration limits by NRC, the capture efficiency of the HEPA filter was examined. An in-line isokinetic air sampling system was installed downstream of the HEPA filter. Utilizing a gas flow proportional counter, 212Pb was used as a surrogate to indicate any possible penetration of the (238U,232Th)O2 particles through the HEPA filter. Based on the experimental results, this delayed sampling method proved to be an easy and effective way to validate the integrity of the HEPA filter.
本研究的目的是建立一种延迟空气采样方法，以验证通风通风橱中现有高效空气过滤器（HEPA）系统的完整性。在配备HEPA过滤器的通风橱中制备（238U，232Th）O2微球，用于制造水泥核燃料芯块。为符合美国核管理委员会（NRC）规定的空气排放浓度限值，对HEPA过滤器的捕集效率进行了检测。在HEPA过滤器下游安装了在线等速空气采样系统。利用气体流量正比计数器，以212Pb作为替代物，指示（238U，232Th）O2颗粒是否可能穿透HEPA过滤器。基于实验结果，这种延迟采样方法被证明是验证HEPA过滤器完整性的一种简单有效的方法。
