熔盐/辐照环境中细结构等静压石墨的结构和化学稳定性研究  

Microstructure and Chemical Stability of Fine-grained Isotropic Graphite under Molten Salt/Irradiation Environment

作　　者：靳根[1] 张鹤耀 连鹏飞[3] 程金星 王庆波 于艾 宋金亮[5] 唐忠锋[5] 刘占军[3] JIN Gen;ZHANG Heyao;LIAN Pengfei;CHENG Jinxing;WANG Qingbo;YU Ai;SONG Jinliang;TANG Zhongfeng;LIU Zhanjun(School of Nuclear Science and Technology,University of South China,Hengyang 421001,China;School of Microelectronics and Control Engineering,Changzhou University,Changzhou 213164,China;Institute of Coal Chemistry,Chinese Academy of Sciences,Taiyuan 030001,China;Beijing High-tech Institute,Beijing 100096,China;Shanghai Institute of Applied Physics,Chinese Academy of Sciences,Shanghai 201800,China)

机构地区：[1]南华大学核科学技术学院,湖南衡阳421001 [2]常州大学微电子与控制工程学院,江苏常州213164 [3]中国科学院山西煤炭化学研究所,山西太原030001 [4]北京高技术研究院,北京100096 [5]中国科学院上海应用物理研究所,上海201800

出　　处：《原子能科学技术》2021年第12期2331-2338,共8页Atomic Energy Science and Technology

基　　金：国家自然科学基金(52072397,51602336);2020年度中国科学院洁净能源创新研究院合作基金(DNL202012)。

摘　　要：熔盐堆以石墨作为反射体和慢化体,熔盐与石墨直接接触,石墨在熔盐中的腐蚀反应和辐照损伤是值得研究的问题。本文采用自主研发的细结构石墨,阻隔熔盐浸渗,采用3.0 MeV He;模拟中子辐照,研究不同温度及熔盐环境下石墨微观形貌、微结构和化学结构的变化。研究结果表明,高温环境下,由于高温的退火效应,石墨缺陷密度的增加及形貌的变化都远小于室温环境。辐照后的石墨与熔盐接触,其缺陷密度略微降低。这种微结构的改善与高温熔盐环境中的退火效应及熔盐固化引起内部微裂纹的闭合有关。辐照后的熔盐浸泡可在石墨C—C键结构中引入C—F键,且C—F键的形成与缺陷密度及缺陷类型密切相关。稳定的空位簇及间隙原子的迁移均会影响层间化合物的形成,从而产生限制C—F键形成的环境,进而降低由层间化合物的形成对石墨表面结构的破坏。Molten salt nuclear reactor(MSR) uses graphite as a neutron moderator or reflector, and the graphite is directly contacted with the molten salt. The irradiation stability of the graphite and chemical reaction corrosion between the graphite and salt is the critical researches to be studied. Microstructure, crystal structure, chemical bonding and property of the ion-implanted fine-grained isotropic graphite under different irradiation doses were studied by using the 3.0 MeV He;simulation. The results show that under high temperature, the increase of the defect concentration and surface morphology change are much less than those under the room temperature because of the high temperature annealing. The defect concentration decreases under the irradiation and molten salt environment. The improvement of microstructure is related to the annealing effect in high temperature molten salt environment and the closure of internal microcracks caused by molten salt solidification. The C—F bond could be detected by the long time molten salt immersion, which is closely related to the defect concentration and types. Vacancy cluster and migration of the interstitial atom affect the formation of the graphite intercalation compounds. It is all not avail to forming the C—F bonds, which decreases the destructive effect of the graphite surface structure.

关 键 词：熔盐堆 细结构等静压石墨 辐照行为 化学成键 

分 类 号：TB333[一般工业技术—材料科学与工程]