小型自然循环铅冷快堆SNCLFR-100一回路主冷却系统热工安全分析

发布时间：2018-01-13 06:01

本文关键词：小型自然循环铅冷快堆SNCLFR-100一回路主冷却系统热工安全分析　出处：《中国科学技术大学》2017年博士论文　论文类型：学位论文

【摘要】：铅冷快堆具备良好的增殖核燃料和嬗变核废料潜力,拥有突出的经济性和固有安全性,被第四代国际核能论坛(GIF)视为有望成为首个实现工业示范化的第四代核能系统。小型自然循环铅冷快堆一回路主冷却系统采用全自然循环驱动,可进一步简化铅冷快堆的系统设计,避免液态金属泵制造和运行给铅冷快堆技术研发带来的一系列挑战,具有良好的发展前景。掌握自然循环铅冷快堆一回路主冷却系统的热工安全特性是研发该新型反应堆亟需探索和研究的核心技术之一。本文针对自然循环铅冷快堆一回路主冷却系统热工安全分析的需求,从热工设计与分析程序开发、三维稳态热工水力特性研究和瞬态热工安全性能分析等方面开展100Wth小型自然循环铅冷快堆SNCLFR-100—回路主冷却系统的热工安全分析研究,论文的主要工作包括:(1)针对小型自然循环铅冷快堆一回路主冷却系统的设计特点,建立了物性、传热和压降模型,单通道模型,闭式并联多通道模型和最热通道模型等热工水力分析模型;基于上述模型开发了具备热工水力设计和稳态热工性能分析双重功能的STAC程序;并开展了程序相关模块和主体功能的初步验证,验证结果表明,STAC程序的计算结果具有良好的准确性和可信度;最后基于STAC程序对SNCLFR-100—回路主冷却系统温度分布、寿期初和寿期末的堆芯温度分布及—回路主冷却系统自然循环能力进行了分析研究。(2)基于SNCLFR-100—回路主冷却系统设计方案,建立了其四分之一整体CFD分析模型和全堆芯CFD分析模型,开发了稳态燃料棒热传导模型和稳态主热交换器换热模型,并进行了湍流模型选取、多孔介质模型使用和堆芯释热方式应用的数值模拟方案研究;利用ANSYS FLUENT开展了额定工况下整体三维热工水力特性分析和全堆芯自然循环流量分配特性研究,对—回路主冷却系统内冷却剂的流动和换热现象、堆芯入口流量分配特性进行了较深入的分析,并对一回路主冷却系统的设计提出了相应的优化建议;最后基于理论计算和CFD模拟,对全堆芯流量分配方案进行了初步优化设计,实现了堆芯各组件流量份额和功率份额的匹配。(3)利用热工水力系统安全分析程序ATHLET对SNCLFR-100—回路主冷却系统的瞬态热工水力特性进行了分析,重点研究了无保护超功率事故(UTOP)、无保护失热阱事故(ULOHS)和无保护超功率叠加失热阱事故(UTOP+ULOHS)3类严重事故下反应堆—回路主冷却系统的安全响应特性。研究结果表明:SNCLFR-100具有良好的固有安全性,各事故下堆芯安全的最大挑战来自于包壳材料无法承受过高的温度而失效。(4)针对现有的系统安全分析程序和CFD程序在分析小型自然循环铅冷快堆一回路主冷却系统内复杂三维流动现象时均存在局限性的问题,基于系统安全分析程序ATHLET和CFD程序ANSYS FLUENT提出了耦合三维特性的瞬态热工安全分析方法,并基于该方法开展了 SNCLFR-100的全厂断电事故(SBO)分析,重点研究了事故工况下上腔室的热分层现象以及一维和三维热工水力现象的耦合反馈。本文旨在研发自然循环铅冷快堆一回路主冷却系统热工水力设计、热工安全分析工具,研究自然循环铅冷快堆一回路主冷却系统的稳态和瞬态热工安全特性,相关研究成果可进一步丰富铅冷快堆热工水力设计和热工安全分析工具,掌握小型自然循环铅冷快堆的热工安全特性,具有一定的学术意义和工程应用价值。
[Abstract]:With the proliferation of lead cooled fast reactor nuclear fuel and nuclear waste transmutation has good potential, the economy and the inherent safety of prominent, is the fourth generation of international nuclear Forum (GIF) as is expected to become the first to achieve industrial demonstration of fourth generation nuclear energy systems. The primary cooling system of small natural circulation lead cooled fast reactor by nature the driving cycle, the system design can be further simplified lead cooled fast reactor, to avoid a series of challenges of liquid metal pump manufacturing and operation to bring the lead cooled fast reactor technology research and development, with good prospects for development. Grasp the thermal safety characteristics of natural circulation lead cooled fast reactor primary cooling system is one of the core technology research and development of the new reactors need to explore and study. Based on the analysis of natural circulation thermal safety lead cooled fast reactor primary cooling system, the thermal design and analysis of program development, the three-dimensional steady state thermal Study on analysis of thermal safety 100Wth small natural circulation lead cooled fast reactor SNCLFR-100 circuit cooling system to carry out the research on hydraulic characteristics and transient thermal safety performance analysis, the main work of this paper includes: (1) for small natural circulation lead cooled fast reactor primary cooling system design features is built up, and the heat transfer the pressure drop model, single channel model, closed parallel multi channel model and the hot channel model of thermal hydraulic analysis model; based on the above model is developed with the thermal hydraulic design and performance analysis of steady state thermal dual function STAC program; and to carry out a preliminary verification program module and the main function, the verification results show that the calculation of the STAC program the result has a good accuracy and reliability; finally, based on the STAC program for temperature distribution of SNCLFR-100 main loop cooling system, life at the beginning of the period and the ending of the core The temperature distribution and the main loop cooling system of natural circulation ability are analyzed. The design scheme of SNCLFR-100 (2) - the main loop cooling system based on a quarter of the overall CFD whole core analysis model and CFD analysis model, developed a steady fuel rod heat conduction model and steady-state main heat exchanger model, and the choice of turbulence model, scheme of numerical simulation of porous medium model and the core heat release application; carried out under the rated condition the whole three-dimensional thermal hydraulic characteristics analysis and whole core research on distribution characteristics of natural circulation flow rate by ANSYS FLUENT, the main loop in the cooling system of the coolant flow and heat transfer phenomena, pile the core entrance flow distribution characteristics are analyzed deeply, and puts forward corresponding suggestions on Design of primary cooling system; finally, based on theoretical calculation and CFD simulation On the whole, the core flow distribution scheme for a preliminary optimization design, implementation, core components and power flow share share. (3) the analysis of transient thermal hydraulic characteristics of ATHLET program on SNCLFR-100 - circuit cooling system with thermal hydraulic system safety are analyzed, focusing on the protection of non super power accident (UTOP), unprotected loss of heat sink accident (ULOHS) and unprotected loss of heat sink of super power superposition accident (UTOP+ULOHS) security response characteristics of reactor - the main cooling system of 3 kinds of circuit under severe accident. The results show that SNCLFR-100 has good inherent safety, the biggest challenge from the core safety accident in the cladding materials cannot withstand high temperature and failure. (4) according to the procedures and CFD procedures in the analysis of small natural circulation lead cooled fast reactor primary cooling system in complex three-dimensional flow analysis system of existing security The phenomenon are limitations, system security analysis program ATHLET and CFD program ANSYS FLUENT proposed a safety analysis method of 3D transient thermal coupling based on the characteristics, and based on this method to carry out a blackout accident of SNCLFR-100 (SBO) analysis, feedback coupling focuses on the thermal stratification of the upper chamber and accident conditions one dimensional and three-dimensional thermal hydraulic phenomena. This paper aims to develop the natural circulation lead cooled fast reactor thermal hydraulic design of primary cooling system, thermal safety analysis tools, research on natural circulation lead cooled fast reactor primary cooling system in the steady state and transient thermal safety characteristics, the research results can further enrich the lead cooled fast reactor thermal hydraulic design and thermal safety thermal safety analysis tools, master the characteristics of natural circulation of small lead cooled fast reactor, has a certain academic significance and engineering application value.

【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TL433

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