摘要
为明确石墨表面的氟、氟化氚中的氟和单空位缺陷对氚吸附的影响机理,利用第一性原理模拟研究熔盐堆中石墨对氚的吸附,研究了在完整石墨和单空位石墨表面上氢原子(离子)、氟原子(离子)、氟气分子与氟化氢分子的吸附行为。研究发现:当氟和氢同时存在的时候,氟会优先和石墨表面的碳原子成键;石墨表面的单空位促使氟化氢在单空位处解离,以化学吸附形成存在;石墨表面吸附氢(或者氚)、氟后,表面会发生畸变;可预测熔盐堆运行过程中,氚会优先在反应堆中的石墨表面的单空位等反应活性强的地方吸附、积聚。
[Background] In molten salt reactor, the graphite can adsorb a mass of tritium. Fluorine is a constituent of molten salt, and neutron irradiation can induce a number of defects on the graphite in molten salt reactor. It is necessary to study the influence of fluorine and the defects of the graphite on tritium adsorption in molten salt reactor. [Purpose] This study aims to reveal the influence mechanism of fluorine and monovacancy defect on tritium adsorption on graphite surface. [Methods] Simulation study of the adsorption behaviors of hydrogen, fluorine and hydrogen fluoride on the surfaces of perfect graphene and vacancy-defected graphene were carried out by using first-principles calculations. [Results] The results indicate that fluorine preferentially bonds with carbon atoms when hydrogen and fluorine exist at the same time. The monovacancy on graphite surface prompts hydrogen fluoride molecule to dissolve and bond with carbon atom. Moreover, the graphite surface can be distorted after adsorbing hydrogen and fluorine. [Conclusion] Tritium generated from the molten salt reactor will be preferentially adsorbed and accumulate in the regions with more reactive activities such as monovacancy.
作者
吴喜军
钱楠
王广华
黄豫
邓柯
陈学坤
曾友石
吴胜伟
刘文冠
刘卫
WU Xijun;QIAN Nan;WANG Guanghua;HUANG Yu;DENG Ke;CHEN Xuekun;ZENG Youshi;WU Shengwei;LIU Wenguan;LIU Wei(School of Mathematics and Physics, University of South China, Hengyang 421001, China;Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Jiading Campus, Shanghai 201800, China)
出处
《核技术》
CAS
CSCD
北大核心
2018年第6期69-73,共5页
Nuclear Techniques
基金
国家自然科学基金(No.51601212)
中国科学院战略性先导科技专项(No.XDA0202020)资助~~
关键词
氚
氟
石墨
吸附
第一性原理
熔盐堆
Tritium
Fluorine
Graphite
Adsorption
First-principles calculation
Molten salt reactor
