低温等离子体处理^(14)C烷烃类化合物的实验研究  

Experimental Study of Low Temperature Plasma Treatment of^(14)C Alkanes Compounds

作　　者：裴鉴禄 李永国[1] 夏胤 陈泽翔 张计荣[1] 李昕 陈建利[1] 梁书玮 PEI Jianlu;LI Yongguo;XIA Yin;CHEN Zexiang;ZHANG Jirong;LI Xin;CHEN Jianli;LIANG Shuwei(CNNC Key Laboratory on Radioactive Gas Purification Technology,China Institute for Radiation Protection,Taiyuan 030006,China)

机构地区：[1]中核集团放射性气体净化技术重点实验室,中国辐射防护研究院,山西太原030006

出　　处：《原子能科学技术》2024年第5期990-997,共8页Atomic Energy Science and Technology

基　　金：中核集团“青年英才”项目(JY22040604);中国辐射防护研究院创新团队项目(YC22010603)。

摘　　要：压水堆中的^(14)C气态流出物主要以烷烃类化合物的形式存在。本研究以^(14)C烷烃类化合物中占比最大且化学性质最稳定的^(14)CH_(4)作为处理目标,引入低温等离子体技术,对其放电行为和CH_(4)处理性能进行探究。结果表明:在常温常压、输出电压17.89 kV、气体流速0.83 cm/s的最优条件下,等离子体的CH_(4)处理效率可达99.37%,CO_(2)选择性可达46.99%;通过提高输出电压、反应温度以及降低气体流速均能有效提升等离子体的CH_(4)处理性能;除CO_(2)外,等离子体处理CH_(4)过程中伴随产生的副产物有30余种,以有机物为主;等离子体处理CH_(4)的动力学过程符合准一级反应动力学模型,相应的速率常数为1.1048 m^(3)/(kW·h)。以上结果表明,等离子体技术在^(14)C废气处理和监测领域,尤其是^(14)C烷烃类化合物处理方面具有广阔的发展前景。^(14)C has become the nuclide that contributes the most to the annual effective dose to the surrounding public among the radioactive effluents during normal operation of nuclear power plants,but for a long time,domestic nuclear power units have not been equipped with airborne^(14)C treatment facilities,it is important and urgent to seek technical methods to reduce^(14)C emissions based on potential and actual needs under the requirements of the existing emission limits.Domestic nuclear power units under construction and in operation are mainly pressurized water reactors(more than 95%of the total),and the airborne^(14)C in this type of reactors mainly exists in the form of alkane compounds.Therefore,in this study,^(14)CH_(4),which accounts for the largest proportion of^(14)C alkane compounds and has the most stable chemical properties,was taken as the treatment target,and low-temperature plasma technology was introduced to investigate its discharge behavior and CH_(4)treatment performance.The results show that under the optimal conditions of normal temperature and pressure,output voltage of 17.89 kV,and gas flow rate of 0.83 cm/s,the plasma’s CH_(4)treatment efficiency can reach 99.37%,and the CO_(2)selectivity can reach 46.99%.The plasma’s CH_(4)treatment performance can be improved by increasing the output voltage,reaction temperature,and decreasing the gas flow rate.However,since increasing the reaction temperature would bring problems about energy consumption,safety,and equipment complexity,increasing the reaction temperature is not the first choice.In addition to CO_(2),there are more than thirty kinds of by-products produced in the process of plasma treatment of CH_(4),which are dominated by organic substances.The kinetics process of plasma treatment of CH_(4)is in accordance with the quasi-primary reaction kinetics model,and the corresponding rate constants are 1.1048 m^(3)/(kW·h).The above results indicate that plasma technology has a broad development prospect in the field of airborne^(14)C treatment

关 键 词：^(14)C 等离子体 甲烷 压水堆 

分 类 号：TL941.2[核科学技术—辐射防护及环境保护] X771[环境科学与工程—环境工程]