Application of Monte Carlo method to calculate the effective delayed neutron fraction in molten salt reactor

作     者：Gui-Feng Zhu Rui Yan Hong-Hua Peng Rui-Min Ji Shi-He Yu Ya-Fen Liu Jian Tian Bo Xu 

作者机构：Shanghai Institute of Applied PhysicsChinese Academy of Sciences 

出 版 物：《Nuclear Science and Techniques》 (核技术（英文）)

年 卷 期：2019年第30卷第2期

页      面：143-152页

核心收录：

学科分类：08[工学] 0827[工学-核科学与技术] 

基　　金：supported by the Chinese TMSR Strategic Pioneer Science and Technology Project(No.XDA02010000) the Frontier Science Key Program of the Chinese Academy of Sciences(No.QYZDY-SSW-JSC016) 

主　　题：Monte Carlo Effective delayed neutron fraction Molten salt reactor 

摘      要：Delayed neutron loss is an important parameter in the safety analysis of molten salt reactors. In this study,to obtain the effective delayed neutron fraction under flow condition, a delayed neutron precursor transport was implemented in the Monte Carlo code MCNP. The moltensalt reactor experiment(MSRE) model was used to analyze the reliability of this method. The obtained flow losses of reactivity for 235 U and 233 U fuels in the MSRE are223 pcm and 100.8 pcm, respectively, which are in good agreement with the experimental values(212 pcm and100.5 pcm, respectively). Then, six groups of effective delayed neutron fractions in a small molten salt reactor were calculated under different mass flow rates. The flow loss of reactivity at full power operation is approximately105.6 pcm, which is significantly lower than that of the MSRE due to the longer residence time inside the active core. The sensitivity of the reactivity loss to other factors,such as the residence time inside or outside the core and flow distribution, was evaluated as well. As a conclusion,the sensitivity of the reactivity loss to the residence time inside the core is greater than to other parameters.