小型自然循环铅冷快堆超功率失热阱并发瞬态分析

Transient Analysis on Overpower and Loss of Heat Sink of A Small Natural Circulation Lead-Cooled Fast Reactor

基于100 MW级小型自然循环铅冷快堆(SNCLFR-100)建立一回路冷却系统模型,利用RELAP5程序进行初始稳态运行验证。对有/无保护超功率失热阱并发、有保护超功率失热阱并发事故进行瞬态安全分析。结果显示:在有保护超功率失热阱并发事故过程中,停堆保护作用使反应堆处于安全状态;而对于无保护情况,由于反应性负反馈作用,500 s内反应堆实现自动停堆,冷却剂、包壳及燃料芯块温度均低于安全限值。瞬态模拟验证了该新型反应堆良好的自然循环特性与固有安全性。

Small natural circulation lead-cooled fast reactor has a good property of passive safety and economic. The primary cooling system model was established, based on the concept of a 100MWth small natural circulation lead-cooled fast reactor （SNCLFR-100）. With RELAP5 code, initial state and transient conditions were analyzed, including the protected transient of overpower and loss of heat sink, and the unprotected transient of overpower and loss of heat sink. The results show that during the protected transient of overpower and loss of heat sink process, the reactor is safe with the help of reactor trip protection system. As for the unprotected one, the reactor shuts itself down on account of the strong negative feedback of reactivity in 500s, and the temperatures of coolant, cladding and fuel pellet are below the safety limits. The simulations of the two transient could verity the inherent safety of this new reactor.