典型事故工况下超临界水堆CSR1000的非能动安全特性研究

Study on Passive Safety Characteristics of Supercritical Water Reactor CSR1000 under Typical Accident Conditions

超临界水堆是第四代反应堆中仅有的水冷堆,具有热效率高、系统简化、经济性好、有效防止核扩散等特点。本文结合压力容器式超临界水堆CSR1000的特点,设计了一套完全非能动的安全系统,用以提升CSR1000反应堆的安全性,系统包括堆芯补水箱、余热排出系统、自动泄压系统、重力驱动冷却系统和非能动安全壳冷却系统。将这套非能动安全系统应用于中国超临界水堆CSR1000,并采用经过验证的系统分析程序SCTRAN对CSR1000的三种典型事故(卡泵事故、失流事故和失水事故)进行了安全分析。分析结果显示,在发生瞬态和事故时,非能动安全系统的设备各司其职,快速动作,可以保证反应堆的堆芯安全。事故工况下,反应堆的最高包壳温度为850℃,低于相应的包壳温度限值。计算结果验证了非能动安全系统的可行性。

Supercritical water-cooled reactor(SCWR)is the only water-cooled reactor among the six Generation-Ⅳreactor concepts.It is characterized by considerable advantages such as high thermal efficiency,system simplicity and enhanced safety.In consideration of the core design of the pressure vessel of SCWR,a new passive safety system is proposed.It composes the high pressure reactor make-up tank(RMT),the isolation condenser system(ICS),the automatic depressurization system(ADS),the gravity driven core cooling system(GDCS),the passive containment cooling system(PCCS).The geometric parameters and trip conditions of the passive safety system are also determined.The passive safety system is applied to the Chinese SCWR concept,CSR1000,and the safety performance of CSR1000 is then studied with SCTRAN.Accidents of pump seizure,’loss of coolant flow accidents(LOFA),loss of coolant accidents(LOCA)are analyzed for the CSR1000.The passive safety devices response quickly and work quite well with each other under accident condition.The maximum cladding surface temperatures(MOST),which is the most important safety criterion,in the transients and accidents are respectively 780℃and 850℃,which stay well below the safety margin.The analyses have shown that the core design of the CSR1000 is feasible and the proposed passive safety system is verified to be capable of mitigating the consequences of the selected abnormalities.