核电厂气态流出物监测样品分析中的核素衰变校正应用探讨

在放射性样品分析工作中，样品测量阶段、闲置阶段、采样阶段都涉及到核素衰变校正。根据放射性核素的衰变规律，阐明了这三种类型的衰变校正方法原理及其系数的计算。针对核电厂气态流出物中短半衰期的放射性惰性气体和碘核素的监测分析工作，研究了对监测样品分析结果进行衰变校正的必要性。基于实验测量结果，探讨了衰变校正对γ能谱分析法中核素的活度浓度探测下限的影响。介绍并分析了核电厂气态流出物监测样品分析工作中的衰变校正方案，对于短半衰期放射性惰性气体和碘核素，采用合理保守的衰变校正方案，可减少监测分析中的偏差，同时又可保证统计排放量的偏保守性。

Application study of radioactive decay corrections to the analysis of gaseous effluents monitoring samples from nuclear power plant

In the analysis of radioactive samples, radionuclides decay correction methods could be classified into three different stages(types): correction for decay during the counting period, correction for decay prior to the starting time of counting, and the correction for decay during the sampling duration. Based on the law of radioactive decay, the principles of three different types of decay correction methods are explained. Aiming at the gaseous effluents monitoring and samples analysis in nuclear power plants, for the short half-life radionuclides of noble gases & iodines, the necessity of decay corrections which were applied to the specific activity results is analyzed and the decay correction factors of three different types are calculated. For gamma-ray spectrometry, experimental results reveal that the Minimum Detectable Concentration(MDC) of radionuclide is directly related to the decay corrections. The application scheme of decay corrections for gaseous effluents monitoring samples analysis in nuclear power plants is introduced and studied. For the short half-life radionuclides of noble gases & iodines, the monitoring analytical data deviation was reduced by the implementation of the reasonable conservative corrections scheme, and the conservativeness of statistical emissions could be ensured too.