TOPAZ-Ⅱ系统启动过程模拟

Start-up Simulation of TOPAZ-Ⅱ System

对前苏联热离子反应堆电源系统TOPAZ-Ⅱ进行相应的简化,分别建立了堆芯热工水力模型、中子物理学模型以及热排放系统模型。冷却剂回路采用一维热工水力模型,堆芯导热及翅片辐射导热计算采用二维分析模型。选用6组缓发中子点堆模型,考虑了二氧化铀燃料、热离子发电电极、慢化剂与反射层的温度反馈以及控制转鼓对反应性的控制,计算得到TOPAZ-Ⅱ在正常启动工况下的各处温度、功率、反应性反馈等参数的变化。计算结果与TITAM程序的计算结果符合较好,同时本程序可对启动过程进行更为精细的分析,可为控制系统的设计提供参考。

The thermionic reactor power system TOPAZ-Ⅱ of former Soviet Union was simplified.The core thermal-hydraulic model,neutron physics model and heat rejection system model were established,respectively.One-dimensional thermal-hydraulic model was used to model the coolant circuit.Two-dimensional analysis models for the core heat transfer and the radiator fin heat conduction with radiation were established.The point reactor kinetics equation with six-group delayed neutrons,taking the temperature feedbacks of UO_2 fuel,thermionic electrode,moderator and reflector and the control drum reactivity control into account,was applied.The changes of temperature,power and reactivity feedback of TOPAZ-Ⅱ under normal start-up procedure were obtained.The results are in good agreement with the corresponding results of TITAM code.Meanwhile,the developed code can be more precise in analyzing the start-up of TOPAZ-Ⅱ,and provide reference for the design of the control system.