Seismic Performance Analysis Of Nuclear Power M310 Reactor Nuclear Island Ring Crane

Loop crane for nuclear power station is the important lifting equipment in reactor building,it is mainly used for lifting heavy equipment such as steam generator,reactor pressure vessel,regulator in construction stage,and all kinds of lif-ting services required for reactor shutdown and refueling at the operational stage.It is nuclear safety class I aseismic equipment in nuclear power plants.According to the requirements of the Technical Specification for Ring Crane,the crane of nuclear power plant should be able to withstand the safe shutdown earthquake(SSE)to ensure the safety of the construction and operation of the verification island.Based on an example of domestic ring crane of M310 nuclear power plant in China,the seismic performance of this type of ring crane is analyzed and studied through structural statics analysis,inherent characteristics analysis,safe shutdown seismic response analysis and maximum seismic response analysis,taking the requirements of "Code for Seismic Design of Nuclear Power Plant" and ASME"Manufacturing Standard for Bridge and Portal Cranes",the main work and conclusions of this paper include:1.Taking a domestic nuclear power plant as an example,the static analysis of the crane under various working conditions is carried out.It is found that the maximum deformation of the crane under various working conditions is 26.3 mm,and the maximum equivalent stress is 91.52 MPa,which are within the standard requirements.2.The inherent characteristics of the ring crane structure are analyzed and studied.It is concluded that the main contribution to the seismic action of the ring crane is the low-order integral mode of vibration.When the seismic force acts,the main vibration modes play a greater role in the structure.The low-order integral vibration modes should be considered in the research of ring crane similar to nuclear power.In the seismic analysis of ring crane,the first 50 natural frequencies of each mechanical model of the crane are selected as the calculation frequencies,which can generally meet the requirements of 90%of the total mass of vibration modes in the seismic code.3.The calculation and analysis of displacement response of ring crane under SSE load are carried out.It is concluded that the maximum total stress response of crane body under various working conditions is not more than 130 MPa,and the maximum displacement response is not more than 42 mm,which is far less than the yield limit of material.The ring crane independently developed in China has high safety margin in seismic design,and there is still much room for optimization in structural shape and material.4.The calculation and analysis of vertical reaction force and upward throwing force of ring crane under SSE load are carried out.It is concluded that the maximum vertical reaction force is about 800.9 kN and the upward throwing force is about-665.8 kN under various working conditions,and there is no upward throwing phenomenon.