超宽浓度放射性参考气DT制备装置设计及性能研究  

Design and Performance Research of Preparation Device for Ultra-Wide Concentration Radioactive Reference Gas DT

作　　者：祝文辉 刘畅[1] 岳维宏[1] 吴展华[1] 曲延涛[1] ZHU Wenhui;LIU Chang;YUE Weihong;WU Zhanhua;QU Yantao(China Institute of Atomic Energy,Beijing 102413,China)

机构地区：[1]中国原子能科学研究院,北京102413

出　　处：《计量科学与技术》2022年第5期3-7,共5页Metrology Science and Technology

摘　　要：为了满足流气式氚电离室测试和校准需求,须制备不同活度浓度的放射性参考气DT。借助秦山第三核电有限公司CANDU6堆中的含氚重水慢化剂和树脂净化系统,利用液体闪烁计数测量-电解法获得慢化剂活度浓度,质谱法分析电解气氢同位素丰度,并基于PVT指数稀释法,研制了超宽浓度放射性参考气DT制备装置。装置设计有催化-氧化-液体闪烁计数法验证单元,尾气收集-再利用处理单元,同时,样品制备时采用同位素浸润、内壁电镀等措施降低装置壁吸附-记忆效应。装置具有体积小、活度浓度范围宽、低浓度DT壁吸附-记忆效应小、交叉污染小、不确定度小等优点。制备的放射性参考气DT在标准状态下的活度浓度范围为4.0×10^(4)~1.0×10^(14)Bq/m^(3),放射性参考气DT可满足国内不同类型不同用途的流气式氚电离室测试、校准等需求。To meet the testing and calibration requirements of the flow-through tritium ionization chamber,radioactive reference gas DT with different activity concentrations should be prepared.With the aid of the tritium-containing heavy water moderator and resin purification system in the CANDU6 reactor of Third Qinshan Nuclear Power Co.,Ltd.,the moderator activity concentration was obtained by liquid scintillation counting measurement-electrolysis method,and the hydrogen isotope abundance of the electrolytic gas was analyzed by mass spectrometry,and with the implementation of the PVT exponential dilution method,a preparation device for ultra-wide concentration radioactive reference gas DT was developed.The device was designed with a catalytic-oxidation-liquid scintillation counting verification unit and an exhaust gas collection-reuse processing unit,while isotope infiltration and inner wall electroplating and other measures were adopted for sample preparation to reduce the adsorption-memory effect on the device wall.The device has the advantages of small size,wide activity concentration range,low adsorption effect of low concentration DT,low cross-contamination,and low uncertainty.The prepared radioactive reference gas DT has an activity concentration range from 4.0×10^(4)~1.0×10^(14) Bq/m^(3) at the standard state,which can meet the needs of different types and applications of flow-through tritium ionization chamber testing and calibration in China.

关 键 词：放射性参考气DT 液体闪烁计数-电解 PVT指数稀释 壁吸附-记忆效应 

分 类 号：TL81[核科学技术—核技术及应用]