安全壳冷却系统设计方案综述

Abstract

安全壳是核动力厂为防止放射性裂变产物释放的最后一道安全屏障，其主要功能是在事故工况期间和以后，限制放射性物质从堆芯和反应堆冷却剂系统释放到周围环境，此外，在运行工况和事故工况期间提供屏蔽，将运行工况下放射性物质的释放降至最低限度，并保护反应堆不受到外部事件的损害。为此，安全壳应设置执行功能的子系统和设施，主要有：安全壳构筑物及其延伸部分、安全壳隔离系统、能量控制设施(限制作用在安全壳内的压力、温度、机械载荷上)、放射性核素控制设施、可燃气体控制设施。其中，安全壳冷却系统被设计用来限制安全壳内的压力和温度，同时兼具放射性核素去除功能。本文调研分析了国内外核动力厂安全壳冷却系统设计方案和趋势，提出了安全壳冷却系统的设计方向：采用能动和非能动相结合的设计思潮，从而为新堆或小型堆的安全壳冷却系统方案设计提供参考价值。 Containment is the last safety barrier for nuclear power plant in order to prevent radioactive fission products, its main function is to limit the release of radioactive material from the reactor core and the reactor coolant system to the surrounding environment in the accident conditions. In addition, during the operation and accident conditions, it provides shields, reduces the release of radioactive material to a minimum, and protects the reactor from the damage of external events. Therefore, executive function of the subsystem and facilities shall be set up in the containment, mainly includ-ing: containment structure and its extension, the containment isolation system, the energy control facilities (limited role in the containment vessel pressure, temperature, and mechanical load), ra-dioactive nuclide control facilities, combustible gas control facilities. Among them, the containment cooling system is designed to limit the pressure and temperature inside the containment; at the same time, it has the function of radionuclide removal. This research considered the design scheme of containment cooling system in the nuclear power plant and put forward the design direction of containment cooling system by adopting the combination of active and non active design to provide the reference value for the design of new heap or small reactor containment cooling system.