A method is proposed to measure the process margin of the main steam inlet and outlet pipe of a nuclear power plant by using an industrial photogrammetry system. This method includes steps of preparation,image acquisi...A method is proposed to measure the process margin of the main steam inlet and outlet pipe of a nuclear power plant by using an industrial photogrammetry system. This method includes steps of preparation,image acquisition,image processing,and result analysis,as well as the final processing margin analysis,and so on. In particular,it suggests a specific method for target-point layout and design of shooting network for the main steam inlet and outlet pipe measurement,and then uses a method of sub-section photography and collation to measure the inner and outer surfaces of the nuclear power interface pipe. The machining tolerance analysis shows that the method can effectively test whether the machining tolerance data of the interface pipe's top surface,outer surface and the inner surface reach a critical value,which provides a reliable reference for the next step in this process,and it is a type of machining tolerance detection method worthy of popularisation.展开更多
Flow accelerated corrosion（FAC） is the main failure cause of the secondary circuit carbon steel piping in nuclear power plants.The piping failures caused by FAC have resulted in numerous unplanned outages and tragic...Flow accelerated corrosion（FAC） is the main failure cause of the secondary circuit carbon steel piping in nuclear power plants.The piping failures caused by FAC have resulted in numerous unplanned outages and tragic fatalities.The existing researches focus on the main factors contributing to FAC,which include metallurgical factors,environmental factors and hydrodynamic factors. Some effective FAC management methods and programs with long term monitoring and inspection data analysis are recommended.But a comprehensive FAC management system should be developed in order to mitigate and manage FAC systematically.In this paper,the FAC influencing factors are analyzed in combination with the operating conditions of the secondary circuit piping in the Third Qinshan Nuclear Power Plant（TQNPP）,China（Third Qinshan Nuclear Power Company Limited,China）.A comprehensive FAC mitigation and management system is developed for TQNPP secondary circuit piping.The system is composed of five processes,viz.materials substitution,water chemical optimization,long-term monitor strategy for the susceptible piping,integrity evaluation of the local thinning defects,and repair or replacement.With the implementation of the five processes,the material of FAC sensitive pipe fittings are modified from carbon steel to stainless steel,N_2H_4 and NH_3 are finally selected as the water chemical regulator of secondary circuit,the secondary circuit pips are classified according to FAC susceptibility in order to conduct long term monitoring strategy,and an integrity evaluation flow for local thinning caused by FAC in carbon steel piping is developed.If the component with local thinning defects is not fit-for-service,corresponding repair or replacement should be conducted.The comprehensive FAC mitigation and management system with five interrelated processes would be a cost-effective method of increasing personnel safety,plant safety and availability.展开更多
According to the nuclear safety regulations, this paper discusses the mechanical analysis method for piping system. Peps program has advantages of stress analysis and evaluation for nuclear piping. First, this paper i...According to the nuclear safety regulations, this paper discusses the mechanical analysis method for piping system. Peps program has advantages of stress analysis and evaluation for nuclear piping. First, this paper introduces the Peps software, and discusses the process of stress analysis and evaluation for nuclear piping using the general finite element software;Secondly, taking nuclear class 2/3 piping system as an example, it uses Peps4.0 program to calculate the piping stress in variety of working conditions, such as weight, pressure, thermal expansion, earthquake, time-history force, and etc. Finally, the paper calculates the maximum stress and stress ratio according to the ASME.展开更多
基金Supported by the National Natural Science Foundation of China(No.41301598)the Open Fund Program of Henan Engineering Laboratory of Pollution Control and Coal Chemical Resource Comprehensive Utilization(No.502002-B07,502002-A-04)
文摘A method is proposed to measure the process margin of the main steam inlet and outlet pipe of a nuclear power plant by using an industrial photogrammetry system. This method includes steps of preparation,image acquisition,image processing,and result analysis,as well as the final processing margin analysis,and so on. In particular,it suggests a specific method for target-point layout and design of shooting network for the main steam inlet and outlet pipe measurement,and then uses a method of sub-section photography and collation to measure the inner and outer surfaces of the nuclear power interface pipe. The machining tolerance analysis shows that the method can effectively test whether the machining tolerance data of the interface pipe's top surface,outer surface and the inner surface reach a critical value,which provides a reliable reference for the next step in this process,and it is a type of machining tolerance detection method worthy of popularisation.
文摘Flow accelerated corrosion（FAC） is the main failure cause of the secondary circuit carbon steel piping in nuclear power plants.The piping failures caused by FAC have resulted in numerous unplanned outages and tragic fatalities.The existing researches focus on the main factors contributing to FAC,which include metallurgical factors,environmental factors and hydrodynamic factors. Some effective FAC management methods and programs with long term monitoring and inspection data analysis are recommended.But a comprehensive FAC management system should be developed in order to mitigate and manage FAC systematically.In this paper,the FAC influencing factors are analyzed in combination with the operating conditions of the secondary circuit piping in the Third Qinshan Nuclear Power Plant（TQNPP）,China（Third Qinshan Nuclear Power Company Limited,China）.A comprehensive FAC mitigation and management system is developed for TQNPP secondary circuit piping.The system is composed of five processes,viz.materials substitution,water chemical optimization,long-term monitor strategy for the susceptible piping,integrity evaluation of the local thinning defects,and repair or replacement.With the implementation of the five processes,the material of FAC sensitive pipe fittings are modified from carbon steel to stainless steel,N_2H_4 and NH_3 are finally selected as the water chemical regulator of secondary circuit,the secondary circuit pips are classified according to FAC susceptibility in order to conduct long term monitoring strategy,and an integrity evaluation flow for local thinning caused by FAC in carbon steel piping is developed.If the component with local thinning defects is not fit-for-service,corresponding repair or replacement should be conducted.The comprehensive FAC mitigation and management system with five interrelated processes would be a cost-effective method of increasing personnel safety,plant safety and availability.
文摘According to the nuclear safety regulations, this paper discusses the mechanical analysis method for piping system. Peps program has advantages of stress analysis and evaluation for nuclear piping. First, this paper introduces the Peps software, and discusses the process of stress analysis and evaluation for nuclear piping using the general finite element software;Secondly, taking nuclear class 2/3 piping system as an example, it uses Peps4.0 program to calculate the piping stress in variety of working conditions, such as weight, pressure, thermal expansion, earthquake, time-history force, and etc. Finally, the paper calculates the maximum stress and stress ratio according to the ASME.
