核设施周围大气中多形态氚的测量  

Measurement of atmospheric tritium in different chemical forms in the vicinity of nuclear facilities

作　　者：秦来来 夏正海 谷韶中 马玉华 邓珂[1,2] 刘佳煜 马兆伟[1,2] 张钦 杨果 卫飞 吴胜伟[2] 包广粮 刘桂民[2] 刘卫 QIN Lailai;XIA Zhenghai;GU Shaozhong;MA Yuhua;DENG Ke;LIU Jiayu;MA Zhaowei;ZHANG Qin;YANG Guo;WEI Fei;WU Shengwei;BAO Guangliang;LIU Guimin;LIU Wei(University of Chinese Academy of Sciences,Beijing 100049,China;Shanghai Institute of Applied Physics,Chinese Academy of Sciences,Jiading Campus,Shanghai 201800,China;CNNC Nuclear Power Operations Management Co.,Ltd,Haiyan 314300,China;Shanghai Tech University,Shanghai 200031,China)

机构地区：[1]中国科学院大学,北京100049 [2]中国科学院上海应用物理研究所嘉定园区,上海201800 [3]中核核电运行管理有限公司环境应急处,海盐314300 [4]上海科技大学,上海200031

出　　处：《核技术》2018年第10期75-81,共7页Nuclear Techniques

摘　　要：大气中氚主要以氚化水(HTO)、氚化氢(HT)以及氚化甲烷(CH_3T)的形态存在,其危害与其化学形态相关。为了准确评价核设施周围大气中不同化学形态的氚水平,基于高温催化氧化和低温冷阱捕集的原理,建立了一套适用于核设施周围大气中多形态氚的取样及测量方法,并对秦山核电站周围大气中不同形态氚进行了初步测量。该方法中催化剂在大气环境下对HT和CH_3T的催化氧化效率≥99%,冷阱对水样的收集效率≥95%,具备了同时采集和测量HTO、HT和CH_3T的功能。基于秦山核电站周围大气中氚的初步测量结果发现:秦山核电站周围大气中存在HTO、CH_3T和HT三种形态的氚,且HTO>CH_3T>HT,CH_3T和HT浓度与环境本底水平相当,由此表明,建立的取样和测量方法有较高的灵敏度,可以用于核设施周边大气中环境水平氚的采样测量。[Background] Tritium in the atmosphere exists mainly as tritiated water（HTO）, tritiated hydrogen（HT） and tritiated methane（CH3T）. Radiation hazard of tritium is related to its chemical form. Atmospheric tritium in these three chemical forms should be measured simultaneously in the vicinity of nuclear facilities. [Purpose] This study aims to evaluate the level of atmospheric tritium in these three chemical forms accurately. [Methods] Based on the principle of high temperature catalytic oxidation and low temperature cold trap collection, a novel atmospheric tritium sampling system and measurement method were developed. Catalytic efficiencies for hydrogen and methane at different temperatures were measured. Concentrations of hydrogen and methane that needed were evaluated. And the concentrations of atmospheric tritium in the vicinity of Qinshan nuclear power plant（QNPP） were preliminary measured. [Results] Catalytic efficiencies for hydrogen and methane by using self-developed atmospheric sampling system could up to be about 99%, and water vapor collecting efficiency could be more than 95%. The concentrations of atmospheric tritium in the vicinity of QNPP, displayed in a decreasing order, were HTO, CH3T and HT. [Conclusion] The novel atmospheric tritium sampling system had the ability to collect HTO, HT and CH3T simultaneously. Atmospheric tritium in forms of HTO, HT and CH3T were firstly measured in the vicinity of QNPP. The concentrations of HT and CH3T measured were comparable to the background levels, which indicated that the sampling system and measurement method in this paper had a very high sensitivity and could be applied to atmospheric tritium sampling within environmental levels in different forms.

关 键 词：氚化水(HTO) 氚化氢(HT) 氚化甲烷(CH3T) 多形态氚取样系统 

分 类 号：TL99[核科学技术—核技术及应用]