熔融不锈钢与液态钠相互作用的瞬态换热特性研究  

Study on Transient Heat Transfer Characteristics of Molten Stainless Steel and Liquid Sodium

作　　者：刘雅鹏 张大林[1] 陈宇彤 林悦 张熙司[2] 田文喜[1] 秋穗正[1] 苏光辉[1] LIU Yapeng;ZHANG Dalin;CHEN Yutong;LIN Yue;ZHANG Xisi;TIAN Wenxi;QIU Suizheng;SU Guanghui(State Key Laboratory of Multiphase Flow in Power Engineering,School of Nuclear Science and Technology,Xi’an Jiaotong University,Xi’an 710049,China;Department of Reactor Engineering Technology,China Institute of Atomic Energy,Beijing 102413,China)

机构地区：[1]西安交通大学动力工程及多相流国家重点实验室,核科学与技术学院,陕西西安710049 [2]中国原子能科学研究院反应堆工程技术研究所,北京102413

出　　处：《原子能科学技术》2024年第9期1893-1901,I0001,共10页Atomic Energy Science and Technology

基　　金：国家自然科学基金(12075184);中核集团“青年英才”项目。

摘　　要：钠冷快堆严重事故下,堆芯熔融物会与液态金属钠发生相互作用,如果导致堆芯区域内出现钠沸腾的现象,可能会导致堆芯的再临界,从而导致堆芯的进一步熔化。在重定位过程中,堆芯熔融物与液态钠的换热会导致钠出现沸腾,从而影响熔融物射流碎裂与碎片形成。因此,采用严重事故分析程序ACENA对COSA实验平台上开展的熔融不锈钢与液态钠的相互作用的实验进行分析,验证程序对熔融不锈钢与液态钠相互作用过程的瞬态换热特性的分析能力。验证结果表明:程序会高估熔融不锈钢射流与钠池接触时的换热,且不考虑熔融不锈钢外侧凝固形成的硬壳对换热的影响会导致对换热速率的高估。The sodium-cooled fast reactor(SFR)not only has the advantages of high coolant temperature,nuclear fuel breeding and nuclear waste transmutation capabilities,but also has the characteristics of good inherent safety.It is one of the fastest-growing and most experienced fourthgeneration reactor types.The main circuit system of the SFR is close to normal pressure,the coolant has good thermal conductivity and large boiling margin,the design of three circuits,the combination of active heat removal system and passive residual heat removal system,etc.,so that the SFR has good safety characteristics.However,the power density of the SFR is high.In accidents such as unprotected loss of flow(ULOF),if the decay heat cannot be removed by natural circulation in time,the liquid sodium in the core will boil explosively,which may cause the core to melt.Since the void reactivity of sodium is positive,the boiling of sodium in the core may lead to a risk of recriticality of the core,and causing the core to melt.The debris bed formed after the relocation of the molten debris is mainly cooled by the natural circulation of sodium,and the heat of the sodium pool is discharged to the outside of the reactor through an independent heat exchanger placed in the sodium pool,thereby realizing the long-term cooling of the debris bed.During the release and relocation of the core molten material,the molten material will interact with the sodium,affecting the release of the molten material and the formation of the debris bed,and ultimately affecting the long-term cooling of the debris bed under severe accidents.Therefore,the molten fuel-coolant interaction(MFCI)is a complex and significant issue in the safety analysis of severe accidents in SFR.In response to this phenomenon,many experiments on prototype materials and alternative materials were carried out,and a clear understanding of the fragmentation process,fragmentation mechanism,heat transfer mode,fragment size distribution and whether steam explosion occurs in the MFCI phenomenon was obtaine

关 键 词：钠冷快堆 熔融燃料与冷却剂相互作用 ACENA程序 

分 类 号：TL334[核科学技术—核技术及应用]