液态锂铅合金中氢同位素测量研究进展  

Research Progress of Hydrogen Isotope Solubility Measurement in Liquid Li-Pb Alloy

作　　者：武文浩 郭莉[2] 张志[2] 宋江锋[2] 陈长安[2] 王广西[1] WU Wenhao;GUO Li;ZHANG Zhi;SONG Jiangfeng;CHEN Chang’an;WANG Guangxi(College of Nuclear Technology and Automation Engineering,Chengdu University of Technology,Chengdu 610200,China;Institute of Materials,China Academy of Engineering Physics,Jiangyou 621700,China)

机构地区：[1]成都理工大学核技术与自动化工程学院,成都610200 [2]中国工程物理研究院材料研究所,江油621700

出　　处：《材料导报》2021年第19期19125-19133,共9页Materials Reports

基　　金：国家磁约束核聚变能发展研究专项(2015GB109004)。

摘　　要：液态锂铅合金可兼作中子倍增剂、氚增殖剂以及冷却剂,因此液态锂铅合金包层被认为是一种在示范堆(DEMO)或聚变电站中颇有应用前景的增殖包层设计。为了连续监测锂铅增殖包层模块中氚的输运情况,准确、快速测量液态增殖剂的产氚率,需要实时在线测量流动液态增殖剂中氢同位素的浓度。现有传感器都是通过一定手段测定液态金属中的氢分压,然后代入Sieverts定律计算氢同位素浓度,其中氢同位素溶解度系数与同位素浓度的准确测量息息相关。目前氢溶解度系数测量方法主要分为定容法和渗透法,各团队对锂铅合金中氢同位素溶解度系数的测定数值差异较大。一方面由于氢同位素在液态锂铅合金中的溶解度极低,实验误差的影响不可忽视;另一方面杂质效应也会导致溶解度系数的差异,来自空气、水、CO中的氧会引入到锂铅中形成Li_(2)O,而与氧的反应会消耗液态锂铅合金中的Li,使Li活性降低,进而降低氢同位素的溶解度,因此氧含量以及其他杂质的控制对于锂铅合金的实际应用至关重要。近几年已开发的液态锂铅中氢同位素在线测量传感器主要包括金属渗透窗传感器和固体电解质传感器。金属渗透窗传感器结构简单,可靠性高,研究者们主要从材料选择和器件结构优化等方面不断尝试,并取得了丰硕的成果。目前的研究证实了动态测量模式在液态锂铅中氢同位素浓度快速在线测量方面的可行性,需解决的问题是如何避免金属探头材料的氧化,保证长期工作的稳定性。固体电解质测氢传感技术相对成熟,但陶瓷材料韧性较差,测试时需要通入参考气体,并且在器件结构设计和材料选择方面要求更高。还有一些液态金属在线测氢技术,探头采用多孔陶瓷来收集气体,主要用于铝液中氢浓度的测量。对于液态锂铅合金测氢,仍需探索材料的发气性与锂铅材料�Liquid Li-Pb alloy can be used as neutron multiplier,tritium breeder and coolant.Therefore,the liquid Li-Pb alloy cladding is considered as a kind of breeder cladding which has a good prospect in DEMO or fusion power plants.In order to monitor the tritium transportation continuously in Li-Pb breeder cladding module and measure the tritium production rate of the liquid breeder accurately,we need to measure the concentration of hydrogen isotopes on-line in the flowing liquid breeder.The mechanism of the existing sensor is that,to measure the partial pressure of hydrogen in liquid metal by some means,and then to use the Sieverts law for calculation.Especially,the solubility coefficient of hydrogen isotopes is closely related to the accurate measurement of isotope concentration in liquid Li-Pb alloy.At present,the measurement values of hydrogen isotopes solubility coefficient of Li-Pb alloy by teams are quite different.On one hand,due to the extremely low solubility of hydrogen isotopes in liquid Li-Pb alloy,the influence of experimental error cannot be ignored;on the other hand,impurity effect will lead to the difference of solubility coefficient.Oxygen from air,water,CO will be introduced into Li-Pb to form Li_(2)O.The reaction with oxygen will consume Li in liquid Li-Pb,which will lead to the decrease of Li activity and the solubility.Therefore,the content control of oxygen or other impurities is important for the practical application of Li-Pb.In recent years,the liquid Li-Pb hydrogen isotope sensors for on-line measurement mainly include metal permeation based sensor and solid electrolyte sensor.The former sensor has simple structure and high reliability.Researchers have made great achievements in material selection and device structure optimization.The current study has confirmed the feasibility of the dynamic measurement mode in the rapid on-line measurement of hydrogen isotope concentration in liquid Li-Pb.Nevertheless the problem to be solved is how to avoid the oxidation of metal probe mate-rials and ensure

关 键 词：液态锂铅合金 氢同位素 溶解度 在线测量 传感器 

分 类 号：TL62[核科学技术—核技术及应用]