熔盐冷却空间堆的初步中子学设计  

Preliminary neutronics design of space nuclear reactor based on molten salt cooling

作　　者：李婷[1] 庄坤 尚文 汤晓斌[1] LI Ting;ZHUANG Kun;SHANG Wen;TANG Xiaobin(College of Materials Science and Technology,Nanjing University of Aeronautics and Astronautics,Nanjing 211106,China)

机构地区：[1]南京航空航天大学材料科学与技术学院,南京211106

出　　处：《核技术》2020年第8期34-42,共9页Nuclear Techniques

基　　金：南京市留学人员科技创新项目(No.YQR19037);中国博士后基金站前特别资助项目(No.2019TQ0148);中央高校基本科研业务费(No.NS2019036);空间核技术应用与辐射防护工信部重点实验室开放基金(No.NJ2020017-1)资助。

摘　　要：空间核反应堆(Space Nuclear Reactor,SNR)电源在深空探索中具有重要优势而受到国内外的广泛关注。与传统液态金属、气体和热管冷却方式不同,熔盐冷却剂可溶解裂变材料并具有良好的传热性质,因此可作为SNR方案中的冷却剂。基于国内外SNR设计方案,利用SERPENT蒙特卡罗程序和ENDF/B-Ⅶ.1数据库进行了基于熔盐冷却的空间堆方案的初步中子学设计,研究了不同燃料、包壳材料以及棒间距对燃料棒kinf的影响,以及不同熔盐冷却剂组成、反射层材料对SNR堆芯keff的影响,最终给出一种基于氟化盐7LiF-BeF2-UF4(66.4-32.7-0.9 mol%)冷却UC燃料(质量分数为80%的235U)的SNR初步堆芯方案。结果表明:燃料棒kinf与燃料棒材料密切相关,且随燃料中235U富集度的增大、棒间距的减小而增大,不同的熔盐冷却剂、反射层材料对堆芯keff有较大影响,但冷却剂中UF4的235U富集度对堆芯keff不敏感。[Background] Space nuclear reactor(SNR) has attracted more and more attention worldwide due to its significant advantages in deep space exploration. Different from the traditional liquid metal, gas and heat pipe cooling methods, molten salt coolant can dissolve fission materials with good heat transfer properties, hence can be used as a coolant in SNR scheme. [Purpose] This study aims at the preliminary neutronics design for molten salt cooled SNR. [Methods] Based on the design scheme of SNR, Monte Carlo code SERPENT and database ENDF/B-Ⅶ.1 were employed for preliminary neutron design of SNR with molten salt cooling. The effects of different fuel,cladding materials, rod pitch on the kinf of fuel rods and effects of different molten salts, reflector materials on the keff of core were investigated. Finally, a preliminary SNR core scheme based on fluoride salt 7LiF-BeF2-UF4(66.4-32.7-0.9 mol%) to cool UC fuel(235U, mass fraction at 80%) was proposed. [Results] The results show that keff of fuel rods is closely related to the fuel material, it increases with the235 U enrichment of fuel and decreases with the rod pitch.[Conclusions] Different molten salts and reflector materials have great influences on keff of reactor core, but the 235U enrichment of UF+4 in coolant is not sensitive to keff.

关 键 词：空间核反应堆电源 熔盐冷却 中子学 反应性系数 

分 类 号：TL32[核科学技术—核技术及应用]