液态燃料氯盐快堆最小需求燃耗分析

为探究采用增殖燃烧模式运行的液态燃料氯盐快堆的平均卸料燃耗深度，基于中子平衡分析方法，选取5种常用氯盐，提出在线清除裂变气体和难溶裂变产物方案来维持增殖燃烧运行模式，主要研究分析了氯盐的重金属密度和在线处理方案对最小需求燃耗的影响以及无限栅元模型下维持增殖燃烧模式可接受的堆芯中子损失项。分析表明68NaCl-32UCl₃和20UCl₃-80UCl₄的最小需求燃耗分别是30.47%FIMA（FIMA是指已裂变原子数与初始的总装料金属原子数之比）和10.28%FIMA；清除裂变气体和难溶裂变产物后，60NaCl-40UCl₃可接受的中子损失项从3.49%提高到10.68%。结果表明氯盐的重金属密度对最小需求燃耗有明显影响，同时清除裂变气体和难溶裂变产物能够较大提高燃料盐系统的中子经济性，以及提高增殖燃烧模式运行可接受的堆芯中子损失项。 

Minimum Required Burnup Analysis of Liquid-fueled Molten Chlorine Salt Fast Reactor

In order to explore the average discharge burnup depth of liquid-fueled molten chlorine salt fast reactor operating in the breed-and-burn mode, based on the neutron balance analysis method, five common chlorine salts are selected, and the scheme of online removal of fission gas and insoluble fission products is proposed to maintain the breed-and-burn operation mode. The effects of heavy metal density of chloride salt and online treatment scheme on minimum required burnup and acceptable core neutron loss term for maintaining the breed-and-burn mode in the infinite cell model are mainly studied and analyzed. The analysis shows that the minimum required burnup of 68NaCl-32UCl₃ and 20UCl₃-80UCl₄ is 30.47% FIMA (FIMA refers to the ratio of the number of fissioned atoms to the total number of initially loaded metal atoms) and 10.28% FIMA respectively; After removing fission gas and insoluble fission products, the acceptable neutron loss term for 60NaCl-40UCl₃ is increased from 3.49% to 10.68%. The results show that the density of heavy metals in chloride salts has a significant impact on the minimum required burnup, and the removal of fission gases and insoluble fission products can greatly improve the neutron economy of the fuel salt system, and at the same time, improve the acceptable core neutron loss term for the breed-and-burn operation mode.