核设施气态放射性氙在线监测系统研制

Development of an online radioactive xenon gas monitoring system for nuclear facilities

目的 当前,大气环境中的放射性氙^(131)mXe、^(133)mXe、^(133)Xe和135Xe等同位素主要来源于各种反应堆的运行活动及反应堆重特大事故泄露,为提升核设施场所及其流出物中放射氙在线监测能力,研制高灵敏氙在线监测系统用于核设施场所及气态流出物中放射性氙活度浓度监测、预警和报警。方法 采用氙膜分离浓缩技术,氙高效选择吸附技术和低本底特征伽马能谱分析方法建立了一套核设施气态放射性氙在线监测系统。结果 放射性氙在线监测系统在取样1 h,测量1h的运行模式下,对^(133)Xe的最小可探测活度浓度约为(1.43±0.03) Bq/m^(3)。结论 该系统可较好地用于核动力厂和同位素生产堆等核设施场所及气态流出物中氙活度浓度的在线监测,有助于提升人员、环境及核设施安全水平。

Objective Nowadays,radioactive xenon isotopes,including ^(131)mXe,^(133)mXe,^(133)Xe,and ^(135)Xe,are primarily released into the atmosphere through various reactor operation and major accidents of reactors.To improve the online monitoring capability of xenon in nuclear facilities and their gaseous effluents,a highly sensitive online xenon monitoring system was developed to monitor,warn,and alarm the activity concentration of radioactive xenon.Methods The online monitoring system for radioactive xenon gas in nuclear facilities was established using xenon membrane separation and concentration,xenon high-efficiency selective adsorption,and low-background gamma-ray spectrometry analysis methods.Results Under the operation mode of one-hour sampling and one-hour measuring,the minimum detectable activity concentration of the radioactive xenon online monitoring system for ^(133)Xe was approximately(1.43±0.03)Bq/m^(3).Conclusion This system can be effectively used for online monitoring of xenon activity concentration in nuclear facilities such as nuclear power plants and isotope production reactors,as well as in gaseous effluents.It helps improve the safety level of personnel,the environment,and nuclear facilities.