In a molten salt reactor(MSR), the fuel is dissolved in fluoride salt. In this paper, the reactivity worth and reactivity initiated transient of Molten-Salt Reactor Experiment(MSRE) in the control rod failure events a...In a molten salt reactor(MSR), the fuel is dissolved in fluoride salt. In this paper, the reactivity worth and reactivity initiated transient of Molten-Salt Reactor Experiment(MSRE) in the control rod failure events are analyzed. The point kinetic coupling heat-transfer model with decay character of six-group delayed neutron precursors due to the fuel motion is applied. The relative power and temperature transient under reactivity step and ramp initiated at different power levels are studied. The results show that the reactor power and temperature increase to a maximum, where they begin to decrease to stable values. Comparing with full power level, the transient result at low power level is more serious. The results are of help in our study on safety characteristics of an MSR system.展开更多
Molten salt reactor(MSR) is a potential nuclear power reactor of Generation Ⅳ.The working process of the primary loop of an MSR is studied in this paper.A physical model is established to describe the coupled heat tr...Molten salt reactor(MSR) is a potential nuclear power reactor of Generation Ⅳ.The working process of the primary loop of an MSR is studied in this paper.A physical model is established to describe the coupled heat transfer for the MSR core channels,the temperature negative feedback and the neutron characteristics.The simulation code,NDPID,has been developed with the object-oriented method,conducting the neutron diffusion and transient analysis in a parallel way.The simulation data and diagrams of neutron,power,flow rate and temperature can be obtained via graphical user interface.The simulation results can be used for further study on MSRs of larger dimensions and more complicated geometry.展开更多
An integrated approach combining the development of an innovative catalyst and the research of a set of adequate operating conditions for the propane oxidative dehydrogenation （ODH） is described.The experimental set...An integrated approach combining the development of an innovative catalyst and the research of a set of adequate operating conditions for the propane oxidative dehydrogenation （ODH） is described.The experimental set-up,specially designed for steady-state and transient studies is presented.The preparation method,the characterization and the performances in steady-state and transient regimes of catalysts based on V2W4O194-Lindqvist isopolyanion used as a precursor and supported on alumina are reported.The influence of the preparation method of the catalyst and the role of water in the feed gas are more particularly discussed.展开更多
A computer model has been developed for prediction of the pressure in the pressurizer under transient conditions. In the model three separate thermodynamic regions which are not required to be in thermal equilibrium h...A computer model has been developed for prediction of the pressure in the pressurizer under transient conditions. In the model three separate thermodynamic regions which are not required to be in thermal equilibrium have been considered. The mathematical model derived from the general conservation equations includes all of the important thermal-hydraulics phenomena occurring in the pressurizer, i.e., stratification of the hot water and incoming cold water, bulk flashing and condensation, wall condensation, and interfacial heat and mass transfer, etc. The bubble rising and rain-out models are developed to describe bulk flashing and condensation, respectively. To obtain the wall condensation rate, a one-dimensional heat conduction equation is solved by the pivoting method. The presented model will predict the pressure-time behavior of a PWR pressurizer during a variety of transients. The results obtained from the proposed mathematical model are in good agreement with available data on the CHASHMA nuclear power plant’8 pressurizer performance.展开更多
熔盐堆作为第四代先进核能系统之一,在安全性、经济性、防核扩散和可持续性等方面具有独特的优势。为了保障熔盐堆运行安全,需要快速、准确地识别瞬态工况,目前的瞬态识别方法主要依赖于操作员人工识别,这会引入较大的人为因素,严重影...熔盐堆作为第四代先进核能系统之一,在安全性、经济性、防核扩散和可持续性等方面具有独特的优势。为了保障熔盐堆运行安全,需要快速、准确地识别瞬态工况,目前的瞬态识别方法主要依赖于操作员人工识别,这会引入较大的人为因素,严重影响核电安全。为了减少熔盐堆系统瞬态识别过程中引入的人为因素,提高熔盐堆运行安全,使用RELAP5-TMSR程序对美国橡树岭国家实验室建造运行的熔盐实验堆(Molten Salt Reactor Experiment,MSRE)的瞬态工况进行建模与仿真,产生数据集,基于K近邻(K-Nearest Neighbor,KNN)机器学习方法,建立了熔盐堆系统瞬态识别模型,并对识别模型在噪声下的鲁棒性进行了分析和优化。结果显示:基于KNN方法建立的熔盐堆系统瞬态识别模型在测试集上的F1分数达到99.99%;在噪声下的识别F1分数达到94.32%,具有较高的鲁棒性;进一步优化后的熔盐堆系统瞬态识别模型在噪声下的F1分数达到99.73%,能较为准确地识别MSRE的瞬态工况,满足熔盐堆系统瞬态识别需求。基于KNN方法的熔盐堆系统瞬态识别模型能够有效识别系统瞬态工况,可应用于熔盐堆智能运维,确保熔盐堆运行安全。展开更多
文摘In a molten salt reactor(MSR), the fuel is dissolved in fluoride salt. In this paper, the reactivity worth and reactivity initiated transient of Molten-Salt Reactor Experiment(MSRE) in the control rod failure events are analyzed. The point kinetic coupling heat-transfer model with decay character of six-group delayed neutron precursors due to the fuel motion is applied. The relative power and temperature transient under reactivity step and ramp initiated at different power levels are studied. The results show that the reactor power and temperature increase to a maximum, where they begin to decrease to stable values. Comparing with full power level, the transient result at low power level is more serious. The results are of help in our study on safety characteristics of an MSR system.
基金Supported by the National Nature Science Foundation of China(Nos.11075057.11035009 and 10979074)
文摘Molten salt reactor(MSR) is a potential nuclear power reactor of Generation Ⅳ.The working process of the primary loop of an MSR is studied in this paper.A physical model is established to describe the coupled heat transfer for the MSR core channels,the temperature negative feedback and the neutron characteristics.The simulation code,NDPID,has been developed with the object-oriented method,conducting the neutron diffusion and transient analysis in a parallel way.The simulation data and diagrams of neutron,power,flow rate and temperature can be obtained via graphical user interface.The simulation results can be used for further study on MSRs of larger dimensions and more complicated geometry.
基金supported by CNRS standing for Centre National de la Recherche Scientifique (France),CAPES standing for Coordenao de Aperfeioamento de Pessoal de Nível Superior (Brazil),CNPq standing for Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brazil) and FINEP standing for Financiadora de Estudos e Projetos (Brazil)
文摘An integrated approach combining the development of an innovative catalyst and the research of a set of adequate operating conditions for the propane oxidative dehydrogenation （ODH） is described.The experimental set-up,specially designed for steady-state and transient studies is presented.The preparation method,the characterization and the performances in steady-state and transient regimes of catalysts based on V2W4O194-Lindqvist isopolyanion used as a precursor and supported on alumina are reported.The influence of the preparation method of the catalyst and the role of water in the feed gas are more particularly discussed.
基金Shanghai institute for Nuclear Engineering Research and Design
文摘A computer model has been developed for prediction of the pressure in the pressurizer under transient conditions. In the model three separate thermodynamic regions which are not required to be in thermal equilibrium have been considered. The mathematical model derived from the general conservation equations includes all of the important thermal-hydraulics phenomena occurring in the pressurizer, i.e., stratification of the hot water and incoming cold water, bulk flashing and condensation, wall condensation, and interfacial heat and mass transfer, etc. The bubble rising and rain-out models are developed to describe bulk flashing and condensation, respectively. To obtain the wall condensation rate, a one-dimensional heat conduction equation is solved by the pivoting method. The presented model will predict the pressure-time behavior of a PWR pressurizer during a variety of transients. The results obtained from the proposed mathematical model are in good agreement with available data on the CHASHMA nuclear power plant’8 pressurizer performance.
文摘熔盐堆作为第四代先进核能系统之一,在安全性、经济性、防核扩散和可持续性等方面具有独特的优势。为了保障熔盐堆运行安全,需要快速、准确地识别瞬态工况,目前的瞬态识别方法主要依赖于操作员人工识别,这会引入较大的人为因素,严重影响核电安全。为了减少熔盐堆系统瞬态识别过程中引入的人为因素,提高熔盐堆运行安全,使用RELAP5-TMSR程序对美国橡树岭国家实验室建造运行的熔盐实验堆(Molten Salt Reactor Experiment,MSRE)的瞬态工况进行建模与仿真,产生数据集,基于K近邻(K-Nearest Neighbor,KNN)机器学习方法,建立了熔盐堆系统瞬态识别模型,并对识别模型在噪声下的鲁棒性进行了分析和优化。结果显示:基于KNN方法建立的熔盐堆系统瞬态识别模型在测试集上的F1分数达到99.99%;在噪声下的识别F1分数达到94.32%,具有较高的鲁棒性;进一步优化后的熔盐堆系统瞬态识别模型在噪声下的F1分数达到99.73%,能较为准确地识别MSRE的瞬态工况,满足熔盐堆系统瞬态识别需求。基于KNN方法的熔盐堆系统瞬态识别模型能够有效识别系统瞬态工况,可应用于熔盐堆智能运维,确保熔盐堆运行安全。
