This study presents a probabilistic safety analysis(PSA)method for the external event of extreme snowfall on a floating nuclear power plant(FNPP)deployed in the Bohai Sea.We utilized the Weibull and Gumbel extreme val...This study presents a probabilistic safety analysis(PSA)method for the external event of extreme snowfall on a floating nuclear power plant(FNPP)deployed in the Bohai Sea.We utilized the Weibull and Gumbel extreme value distributions to fit the collected meteorological data and obtained a hazard curve for the event of an extreme snowfall where the FNPP is located,providing a basis for the frequency of extreme snowfall-initiating events.Our analysis indicates that extreme snowfall primarily affects the ventilation openings of the equipment,leading to the failure of devices such as the diesel generators.Additionally,extreme snowfall can result in a loss of off-site power(LOOP).Therefore,the developed extreme snowfall PSA model is mainly based on the LOOP event tree,considering responses such as snowfall removal by personnel.Our calculations indicate a core damage frequency(CDF)of 1.13×10^(-10) owing to extreme snowfall,which is relatively low.The results of the cut-set analysis indicate that valve failures in the core makeup tank(CMT),passive residual heat removal system(PRS),and in-containment refueling water storage tank(IRWST)significantly contribute to the CDF.展开更多
The main technical backgrounds and requirements are introduced with regard to earthquake ground motion design parameters in several domestic and American standards,codes and guides involved in the seismic analysis and...The main technical backgrounds and requirements are introduced with regard to earthquake ground motion design parameters in several domestic and American standards,codes and guides involved in the seismic analysis and design activities of nuclear power plants in China.Based on the research results from site seismic safety evaluation of domestic nuclear power plant projects in the last years,characteristics and differences of site specific design spectra are analyzed in comparison with standard response spectra,and the suitability of standard response spectra for domestic nuclear power plant projects is discussed.展开更多
This article describes the basic conditions of nuclear power plants or projects in China, which have been built up, or under construction, or approved by the State Council. Excellent operating indexes of the existing ...This article describes the basic conditions of nuclear power plants or projects in China, which have been built up, or under construction, or approved by the State Council. Excellent operating indexes of the existing nuclear power plants and the capability of independent design, manufacture, construction and operation are briefly enumerated. There are over thirty nuclear power plant sites in the coastal and inland areas, which have been checked or preevaluated. This proves that a solid foundation for large-scaled development of nuclear power industry has been laid and nuclear power will certainly play an important role in power supply and environment protection of China.展开更多
The Floating nuclear power plant grid is composed of power generation,in-station power supply and external power delivery.To ensure the safety of the nuclear island,the in-station system adopts a special power supply ...The Floating nuclear power plant grid is composed of power generation,in-station power supply and external power delivery.To ensure the safety of the nuclear island,the in-station system adopts a special power supply mode,while the external power supply needs to be adapted to different types of external systems.Because of frequent single phase-ground faults and various fault forms,the fault line selection protection should be accurate,sensitive and adaptive.This paper presents a fault line selection method in cooperation with multi-mode grounding control.Based on the maximum united energy entropy ratio(MUEER),the optimal wavelet basis function and decomposition scale are adaptively chosen,while the fault line is selected by wavelet transform modulus maxima(WTMM).For high-impedance faults(HIFs),to enlarge the fault feature,the system grounding mode can be switched by the multi-mode grounding control.Based on the characteristic of HIFs,the fault line can be selected by comparing phase differences of zero-sequence current mutation and fault phase voltage mutation before and after the fault.Simulation results using MATLAB/Simulink show the effectiveness of the proposed method in solving the protection problems.展开更多
Uganda principally depends on hydropower for electricity generation. However, expansion of hydropower resources islimited, and with growing population and demand for electricity, the government of Uganda is considerin...Uganda principally depends on hydropower for electricity generation. However, expansion of hydropower resources islimited, and with growing population and demand for electricity, the government of Uganda is considering integration of nuclearpower into its energy mix. With the current and projected grid capacity, SMR （small modular reactor） technology is attractive sincecapacity can be added incrementally. This paper therefore presents results for SMR site selection in Uganda. Starting with twentyregional areas established by the Ugandan government, a site selection process is outlined which uses four levels of screening andranking. First, exclusion criteria including seismicity, volcanic activity, water resources, and transportation distances were applied.This reduced the potential regional areas down to eight. Next, MAUT （multi-attribute utility theory） weighting was assigned to theseeight areas for： （1） distance to large population centers, （2） ease of transportation, and （3） distance to seismically or volcanically activeareas. From this ranking, four regional areas stood out and were then selected. These regions were then compared using variousattributes including access to water and integration with the developing national grid. In the final step, the lead candidate region wassubdivided into subzones to further refine the selection process.展开更多
文摘This study presents a probabilistic safety analysis(PSA)method for the external event of extreme snowfall on a floating nuclear power plant(FNPP)deployed in the Bohai Sea.We utilized the Weibull and Gumbel extreme value distributions to fit the collected meteorological data and obtained a hazard curve for the event of an extreme snowfall where the FNPP is located,providing a basis for the frequency of extreme snowfall-initiating events.Our analysis indicates that extreme snowfall primarily affects the ventilation openings of the equipment,leading to the failure of devices such as the diesel generators.Additionally,extreme snowfall can result in a loss of off-site power(LOOP).Therefore,the developed extreme snowfall PSA model is mainly based on the LOOP event tree,considering responses such as snowfall removal by personnel.Our calculations indicate a core damage frequency(CDF)of 1.13×10^(-10) owing to extreme snowfall,which is relatively low.The results of the cut-set analysis indicate that valve failures in the core makeup tank(CMT),passive residual heat removal system(PRS),and in-containment refueling water storage tank(IRWST)significantly contribute to the CDF.
基金funded by the Basic Science Research Foundation of IEM(Grant No.2006A02)the National Natural Sciences Foundation of China (90715038)
文摘The main technical backgrounds and requirements are introduced with regard to earthquake ground motion design parameters in several domestic and American standards,codes and guides involved in the seismic analysis and design activities of nuclear power plants in China.Based on the research results from site seismic safety evaluation of domestic nuclear power plant projects in the last years,characteristics and differences of site specific design spectra are analyzed in comparison with standard response spectra,and the suitability of standard response spectra for domestic nuclear power plant projects is discussed.
文摘This article describes the basic conditions of nuclear power plants or projects in China, which have been built up, or under construction, or approved by the State Council. Excellent operating indexes of the existing nuclear power plants and the capability of independent design, manufacture, construction and operation are briefly enumerated. There are over thirty nuclear power plant sites in the coastal and inland areas, which have been checked or preevaluated. This proves that a solid foundation for large-scaled development of nuclear power industry has been laid and nuclear power will certainly play an important role in power supply and environment protection of China.
基金Project Supported by National Natural Science Foundation of China(No.51877089).Research on the mechanism and fault ride-through integrated strategies of an active power router in hybrid AC and DC distribution grids.
文摘The Floating nuclear power plant grid is composed of power generation,in-station power supply and external power delivery.To ensure the safety of the nuclear island,the in-station system adopts a special power supply mode,while the external power supply needs to be adapted to different types of external systems.Because of frequent single phase-ground faults and various fault forms,the fault line selection protection should be accurate,sensitive and adaptive.This paper presents a fault line selection method in cooperation with multi-mode grounding control.Based on the maximum united energy entropy ratio(MUEER),the optimal wavelet basis function and decomposition scale are adaptively chosen,while the fault line is selected by wavelet transform modulus maxima(WTMM).For high-impedance faults(HIFs),to enlarge the fault feature,the system grounding mode can be switched by the multi-mode grounding control.Based on the characteristic of HIFs,the fault line can be selected by comparing phase differences of zero-sequence current mutation and fault phase voltage mutation before and after the fault.Simulation results using MATLAB/Simulink show the effectiveness of the proposed method in solving the protection problems.
文摘Uganda principally depends on hydropower for electricity generation. However, expansion of hydropower resources islimited, and with growing population and demand for electricity, the government of Uganda is considering integration of nuclearpower into its energy mix. With the current and projected grid capacity, SMR （small modular reactor） technology is attractive sincecapacity can be added incrementally. This paper therefore presents results for SMR site selection in Uganda. Starting with twentyregional areas established by the Ugandan government, a site selection process is outlined which uses four levels of screening andranking. First, exclusion criteria including seismicity, volcanic activity, water resources, and transportation distances were applied.This reduced the potential regional areas down to eight. Next, MAUT （multi-attribute utility theory） weighting was assigned to theseeight areas for： （1） distance to large population centers, （2） ease of transportation, and （3） distance to seismically or volcanically activeareas. From this ranking, four regional areas stood out and were then selected. These regions were then compared using variousattributes including access to water and integration with the developing national grid. In the final step, the lead candidate region wassubdivided into subzones to further refine the selection process.
