全厂断电事故工况下小型铅铋快堆余热排出能力评价

小型铅铋快堆的非能动余热排出系统（PRHRS）主要是为应对全厂断电（SBO）事故，但目前并不确定该PRHRS能否有效带走堆芯衰变热以保证堆芯安全，因此开展了数值分析研究评价PRHRS的余热排出能力。本文使用RELAP5 4.0程序开展了小型铅铋快堆SBO事故热工水力分析，首先进行稳态计算，之后将稳态结果作为初值进行瞬态计算。研究结果表明：在整个SBO事故中，包壳峰值温度最高为820 K，主容器与保护容器壁面最高温度分别为792 K和769 K，均未超过安全限值，表明此PRHRS可有效应对小型铅铋快堆SBO事故。本文研究可为小型铅铋快堆PRHRS的工程设计奠定技术基础。

Evaluation of Residual Heat Removal Capacity of Small Lead-bismuth Fast Reactor under SBO Accident

The passive residual heat removal system (PRHRS) of a small lead-bismuth fast reactor is mainly used to deal with station black-out (SBO) accident. However, it is uncertain whether the PRHRS can effectively remove core decay heat to ensure core safety. Therefore, numerical analysis was carried out to evaluate the residual heat removal capability of PRHRS. The RELAP5 4.0 code was used to simulate thermohydraulic characteristics of the small lead-bismuth fast reactor under the SBO accident. The steady-state calculation was carried out first, and then the steady-state results were taken as the initial values for transient calculation. The results show that in the whole SBO accident, the peak cladding temperature is 820 K and the maximum wall temperatures of main vessel and guard vessel are 792 K and 769 K respectively, which are within the safety limit, indicating that the PRHRS can effectively deal SBO accident. This study can lay a technical foundation for the PRHRS engineering design of the small lead-bismuth fast reactors.