建立了某气体稳压型研究堆在失水事故(LOCA)下局部破口及整体系统的数值仿真模型。针对主管道破口进行数值分析,研究系统流量、压力和破口流量的关系,获得破口的特性参数。通过在系统仿真模型中耦合破口特性参数,对隔离及卸压2种事故下防止稳压器上部气体进入反应堆的应对方案进行了研究。结果表明,破口截面的流量主要取决于系统的压力,采用卸压方案要优于隔离方案。 A numerical simulation model of partial breakout and global system of a gas-stabilized research reactor under a water-losing accident (LOCA) was established. According to the numerical analysis of the main pipeline breach, the relationship between system flow, pressure and breaking flow is studied, and the characteristic parameters of breach are obtained. Through the coupling break characteristic parameters in the system simulation model, the countermeasures to prevent the upper part of the regulator from entering the reactor under the two kinds of accidents of isolation and pressure relief were studied. The results show that the flow of the cross-section is mainly determined by the pressure of the system. The pressure relief scheme is superior to the isolation scheme.