摘要
以小型化、长寿命、自然循环为铅基快堆的设计目标,构建100 MWt铅基快堆堆芯模型并开展冷却剂选型研究,选取Pb同位素/混合物及Pb-Bi混合物,分析比较了采用不同冷却剂堆芯的物理特性与自然循环特性。结果表明:得益于^(208)Pb在高能区小的非弹性散射截面与中低能区极小的中子俘获截面,加之Bi较小的中子俘获截面,采用^(208)Pb-Bi冷却的铅基快堆堆芯在30满功率年运行周期内的燃耗反应性损失最小,增殖性能最佳,且具备负值较大的空泡系数、冷却剂温度系数和较大的有效缓发中子份额,可装载较低富集度或较少量燃料,有利于堆芯小型化、长寿命和固有安全性;^(208)Pb-Bi相比Pb冷却的铅基快堆具备更强的自然循环能力、更弱的材料腐蚀、更宽的运行温度区间,有利于反应堆安全运行与维护。高^(208)Pb丰度的铅可以从钍矿石及钍铀矿石中提取,极大降低了^(208)Pb的分离提取难度。
[Background]Small long life natural circulation lead-based fast reactor has broad development prospects in the fields such as marine nuclear power,portable power,thermal-electric co-generation in remote areas,seawater desalination,et al.,and is one of the important development directions of lead-based fast reactor.[Purpose]This study aims at the coolant selection for the design goals of long life,miniaturization and natural circulation of lead-based fast reactors.[Methods]First of all,refer to the ALFRED design scheme of EU small lead based demonstration fast reactor,a 100 MWt lead-based fast reactor core model was taken as design paramenters.Then,Pb element/mixture and Pb-Bi mixtures were selected for study by using three dimensional transport Monte Carlo code(RMC)developed by the reactor engineering calculation and analysis laboratory of Tsinghua University.High temperature nuclear database ADS-2.0 released by the International Atomic Energy Agency was employed to calculate and analyze the burnup characteristics,reactivity coefficient and effective delayed neutron fraction of lead based fast reactor cores with different coolants.Finally,the neutronics characteristics of different coolant cores and the natural circulation characteristics of different coolants were analyzed and compared.[Results]The results show that the neutron capture cross-section combined with Bi is smaller due to the small inelastic scattering cross-section of ^(208)Pb in the high-energy region and the extremely small neutron capture cross-section in the middle and low energy regions.The ^(208)Pb-Bi cooled lead-based fast reactor core has the lowest burnup reactivity loss and the best breeding performance with large negative void coefficient,coolant temperature coefficient and large effective delayed neutron fraction in at 30 EFPY operating cycle.[Conclusions]The ^(208)Pb-Bi cooled lead-based fast reactor core can be loaded with a lower enrichment or a smaller amount of fuel,which is beneficial to miniaturization,long life and inherent safety of the core;compared with Pb,^(208)Pb-Bi cooled lead-based fast reactor has stronger natural circulation capability,weaker material corrosion,and wider operating temperature range,which is conduvtive to the safe operation and maintenance of reactor.
作者
余清远
肖豪
刘紫静
赵鹏程
于涛
YU Qingyuan;XIAO Hao;LIU Zijing;ZHAO Pengcheng;YU Tao(School of Nuclear Science and Technology,University of South China,Hengyang 421001,China)
出处
《核技术》
CAS
CSCD
北大核心
2022年第3期73-80,共8页
Nuclear Techniques
基金
国家自然科学基金(No.12005097)
国家级大学生创新与实验研究计划(No.S202010555037)资助。
关键词
铅基快堆
冷却剂
物理特性
自然循环
Lead-based fast reactor
Coolant selection
Neutronics characteristics
Natural circulation
