旨在从中子学角度分析液态重金属快堆燃料棒和控制棒的物理特性,以支撑其结构设计及材料选型.使用快中子反应堆分析程序 SARAX对燃料棒的液铀比选择、径向功率分布、包壳材料选型、反射层材料选型,控制棒径向结构设计、吸收体材料选型、慢化结构设计进行计算分析.计算结果表明:燃料棒栅元 Kinf 与液铀比呈线性关系,液铀比的选择更多需要考虑载热因素.燃料棒包壳优先选择铁素体/马氏体钢材料.活性段轴向两端反射层材料可选择钢类材料.基于 Pu迁移现象分析结果,当前物理计算程序中均未耦合 Pu 迁移现象,计算得到的功率分布相对均匀,导致燃料中心温度计算结果偏不保守.控制棒采用细棒设计能有效降低自屏效应,但会降低空间利用率.快堆常用 B4C作为吸收体材料.控制棒吸收体外包裹慢化体能使中子能谱软化,B-10 中子吸收截面大幅上升,提高控制棒价值.同一外径下,纯吸收体芯块的棒价值小于使用慢化体(ZrH2)包裹的芯块.
Liquid Heavy Metal Reactor Fuel Rod and Control Rod Design
The aim of the paper is to analyse the physical properties of liquid heavy metal fast reactor fuel rods and control rods from a neutronics point of view to support their structural design and material selection.In this paper,the liquid-uranium ratio selection,radial power distribution,cladding material selection,reflective layer material selection for fuel rods,radial structural design of control rods,absorber material selection,and moderated structural design are computationally analysed using the fast neutron reactor analysis program SARAX.Calculation results show that:the Keff of the fuel rod grid element is linearly related to the liquid-uranium ratio,and the selection of the liquid-uranium ratio needs to consider the heat-carrying factor more.The fuel rod cladding is preferred to be made of ferritic/martensitic steel materials.The materials for the reflective layer at the axial ends of the fuel may be chosen to be made of steel materials.Based on the results of the analysis of the Pu migration phenomenon,none of the current physical calculation procedures are coupled with the Pu migration phenomenon,and the power distribution obtained from the calculation is relatively homogeneous,which leads to a bias of unconservative results in the calculation of the fuel centre temperature.The use of thin rod design for control rods can effectively reduce the self-screening effect,but the use of thin rod structure will lead to lower space utilisation.B4 C is commonly used as the absorber material in fast reactors.The wrapping of the control rod absorber with a moderator softens the neutron energy spectrum and increases the B-10 neutron absorption cross section significantly,increasing the value of the control rod.At the same outer diameter,the rod value of a pure absorber core block is less than that of a core block wrapped with a moderator(ZrH2).
liquid heavy metal reactorfuel rod designcontrol rod design
万方数据
维普
