熔盐实验堆堆芯结构变化对反应性的影响分析  

Effect analysis of core structure changes on reactivity in molten salt experimental reactor

作　　者：于世和[1] 刘亚芬[1] 杨璞[1] 冀锐敏[1] 朱贵凤[1] 周波[1] 康旭忠[1] 严睿[1] 邹杨[1] YU Shihe;LIU Yafen;YANG;Pu JI Ruimin;ZHU Guifeng;ZHOU Bo;KANG Xuzhong;YAN Rui;ZOU Yang(Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China)

机构地区：[1]中国科学院上海应用物理研究所,上海201800

出　　处：《核技术》2019年第2期82-86,共5页Nuclear Techniques

基　　金：中国科学院战略性先导科技专项(No.XDA02010000);钍铀燃料循环特性和若干关键问题研究项目(No.QYZDY-SSW-JSC016)资助~~

摘　　要：熔盐堆采用液态燃料,由于燃料的流动性,堆芯结构的变化会直接影响堆芯活性区的燃料盐装载量,从而影响堆芯物理特性参数。本文基于蒙特卡罗程序MCNP(Monte Carlo N Particle Transport Code),以2 MW液态燃料钍基熔盐堆(Thorium Molten Salt Reactor-Liquid Fuel,TMSR-LF1)设计模型为参考,系统研究了套管破裂、石墨构件移动、石墨破损、燃料盐浸渗度等因素对堆芯反应性的影响。结果表明:对于堆芯套管破裂,堆芯引入正反应性,破裂位置离堆芯中心越近,引入的反应性越大;对于石墨构件移动,随着扇形石墨构件向外移动,堆芯反应性增加;对于堆芯石墨破损,破损发生后,原燃料盐流道被石墨堵住时,则堆芯反应性减小;对于堆芯石墨破损,破损发生后,新燃料盐流道形成时,当石墨破损半径较小时,堆芯反应性会增加,当石墨破损半径较大时,堆芯反应性会减小。对于堆芯石墨发生燃料盐浸渗,堆芯反应性增加,且燃料盐渗入量越大,反应性变化越大。本研究为2 MW TMSR-LF1安全分析提供参考依据。[Background] Liquid fuel is used in the molten salt reactor, altering core structure will cause direct change of fuel salt loading and affect the physical parameters of the reactor core duel to flowing fuel.[Purpose] This study aims at the influence of core structure changes on reactivity.[Methods] The 2 MW thorium molten salt reactorliquid fuel (TMSR-LF1) model was taken as the reference reactor, and the reactivity varitions were calculated by using MCNP (Monte Carlo N particle transport code) with consideration of parameter changes caused by channel tube rupture, graphite component movement, graphite damage, and fuel salt penetration.[Results] Computational results reveal that casing rupture leads to positive reactivity in reactor core, the closer the rupture location is to the core center, the greater the reactivity is introduced. When the graphite component moves outward, the reactivity of the reactor core increases. When core graphite is damaged, decrease of the reactivity appears in the case of the original fuel salt channel blocked by graphite. In the case of new fuel salt channel formed through the damaged graphite the reactivity will increase when the graphite damage radius is small, and decrease when the graphite damage radius is large. The permeability of fuel salts in the core increases reactivity, and the greater the permeability of fuel salts, the greater the impact on reactivity.[Conclusions] This study provides a basic reference for safety analysis of 2 MWTMSR-LF1.

关 键 词：熔盐堆 钍基熔盐堆 堆芯结构 反应性 

分 类 号：TL3[核科学技术—核技术及应用]