氩气回路中甲烷和二氧化碳杂质的分析方法研究

Study on analysis of methane and carbon dioxide impurities in loop of argon

本文1∶1地模拟了正在建造的中国实验快中子反应堆的气体回路,建立了一个工程上可行的5、0 m长的、有多条固定管线和阀门的快堆覆盖气体放射性氩气取样系统、计算机控制的阀门进样以及氩气中杂质CH4和CO2的间断性在线分析方法。通过热导检测器出口气体可以排放入通风系统的办法,避免了使用氢火焰离子化检测器以后,放射性气体氩气扩散排放到气体分析实验室产生工作环境的放射性污染问题。其检出限、测量精度和准确度满足了中国实验快堆规定的氩气中杂质CH4和CO2的分析要求。并达到了美国试验和材料协会(ASTM)在快堆覆盖气体杂质的标准中提出的分析氩气中杂质CH4和CO2的标准。

This work simulates with 1 ： 1 a gas loop which is being constructed in a fast neutron reactor and represents a feasihle method in engineering to realize a discontinuous on-line analysis for determining methane and carbon dioxide impurities in cover gas systems of radioactive argon by using a gas chromatograph and a multlple-pipeline sampling system which have a 50 miters distance, and a valve sampling system by using computer. The method that the exhaust gas from thermal conductivity detectors exhausts to vent system directly can avoid that radioactive argon exhausts to gas-analytical experiment laboratory, where it causes radioactive contamination in a work environment, by using a flame ionization detector. The detection limit, precison and accuracy satisfied a demand of analyzing methane and carbon dioxide impurities in argon for china CEFR reactor. The detection limit arrives at a standard of ASTM （American society for testing and materials） too, which is a standard for analyzing carbon monoxide in cover gas argon for fast neutron reactor.