小型铅基堆自然转强迫循环热工水力瞬态特性分析  

Thermal-hydraulic Transient Characteristics Analysis of Small Lead-based Reactor from Natural Circulation to Forced Circulation

作　　者：刘文斌 张光雨 王磊[1] 周涛[1] LIU Wenbin;ZHANG Guangyu;WANG Lei;ZHOU Tao(Key Laboratory of Neutronics and Radiation Safety,Institute of Nuclear Energy Safety Technology,Chinese Academyof Sciences,HefeiAnhui,230031,China;University of Scienceand Technology of China,Hefei Anhui,230027,China)

机构地区：[1]中国科学院核能安全技术研究所中子输运理论与辐射安全重点实验室,安徽合肥230031 [2]中国科学技术大学,安徽合肥230027

出　　处：《核科学与工程》2019年第5期722-729,共8页Nuclear Science and Engineering

基　　金：中国科学院青年创新促进会专项项目资助,中国科学院合肥物质科学研究院项目（KP-2017-19）,中国科学院信息化专项项目(XXH13506-104)

摘　　要：小型铅基堆运行于自然循环工况时为了大幅提升功率输出能力,运行工况需要由自然循环转换到强迫循环。然而在转换过程中,由于主泵的突然开启,流量迅速增加,导致堆芯功率以及反应性等参数剧烈波动,这会威胁到反应堆安全。因此,本文采用RELAP5/MOD4.0程序对10MW小型铅基堆进行仿真建模,分析了铅基堆在自然转强迫循环过渡过程的瞬态特性及其影响因素。计算结果表明,首先,初始功率水平越高,功率峰值越高,反应堆周期越小,这可能威胁反应堆的安全,因此需要依据核功率保护整定值选择出安全转换的最高初始功率水平(54%FP)。其次,采取人为干预措施或者逐次开启主泵措施可以有效减小功率等参数波动,提高了安全转换的最高初始自然循环功率水平,这对提升反应堆在转换过程中的安全性与可靠性具有重要意义。最后,制定了一套优化的运行控制策略能够确保其在较高功率水平下(70%FP)实现自然向强迫循环快速平稳安全地转换。In order to increase greatly the power output capability of the small lead-based reactor in natural circulation,the operational condition need be switched from natural circulation to forced circulation.However,in the process of conversion,due to the sudden opening of the main pump and the rapid increase of mass flow rate,the parameters,such as core power and reactivity,fluctuated dramatically,which will threaten the reactor safety.Therefore,the RELAP5/MOD4.0 code was used in this paper to simulate the 10 MW small lead-based reactor,and the transient characteristics of the lead-based reactor during the transition process and its influencing factors were analyzed.The calculation results showed that,firstly,when the initial power level was higher,the fluctuation and the peak value of the power will be higher,which could affect the safety of the reactor.Thus,the highest initial power level(54%FP)that kept the safety of the conversion process can be selected according to the setting value of nuclear power protection.Secondly,human intervention or turning on two main pumps one by one can effectively reduce the fluctuation of power and other parameters,and improve the maximum initial power level of safety conversion,which was of great significance to enhance the safety and reliability of the reactor during the conversion process.Finally,an optimized operation control strategy was formulated to ensure the fast,smooth and safe conversion from natural to forced circulation at a higher initial power level(70%FP).

关 键 词：铅基堆 自然循环 强迫循环 RELAP5 瞬态特性 

分 类 号：TL425[核科学技术—核技术及应用]