【摘要】 氚是核设施气态流出物中重要的放射性核素，作为低能纯β核素，目前多采用累积取样、实验室分析的方式进行监测。气载流出物中的氚取样后未经纯化的制样测量，可能会存在其他核素干扰的问题。对气载流出物中的碳-14对氚的测量干扰进行定量分析，可为气载流出物中氚的准确测量提供参考。通过氚、碳-14取样特点分析确定取样阶段的干扰，制备并测量单核素和氚碳双标记样品，明确碳-14对氚测量阶段的干扰影响。取样阶段，碳-14在氚的水捕集液中的吸收量随温度变化而变化，在10℃时CO₂在300 mL氚捕集液中的溶解度为0.70 g。测量阶段，碳-14对氚的影响会因液闪谱仪的设计工作原理而异，如Quantulus1220型超低水平液闪谱仪，在氚测量模式下不能忽略碳-14的计数贡献；而LSA2000A型低水平液闪谱仪，在氚测量模式下可以不考虑碳-14的计数贡献。更多还原

【Abstract】 Tritium is an important radionuclide in gaseous emissions from nuclear facilities. As a low-energy pure β radionuclide, tritium is mostly monitored by cumulative sampling and laboratory analysis. After tritium is sampled in airborne effluent and measured without purification, there may be interference from other radionuclides. The interference of carbon-14 in airborne effluent on tritium measurement is quantitatively analyzed, which provides reference for accurate and quantitative monitoring of tritium in airborne effluent. According to the sampling characteristics of tritium and carbon-14, the interference in the sampling stage is determined, and the mono-nuclear and tritium-carbon double-labeled samples are prepared and measured to determine the interference effect of carbon-14 on tritium measurement stage. In the sampling stage, the influence of carbon-14 on tritium varies with the temperature, and the solubility of CO₂ in tritium capture solution is 0.70 g at 10 ℃. In the measurement stage, the influence of carbon-14 on tritium will vary according to the design and working principle of liquid scintillation spectrometer. For example, if Quantulus1220 ultra-low level liquid scintillation spectrometer is used, the counting contribution of carbon-14 can not be ignored in tritium measurement mode; If LSA2000A liquid scintillation spectrometer is used, the counting contribution of carbon-14 can be ignored in tritium measurement mode.更多还原