The Study On The Fluid-structure Interaction Of The Build-in Refueling Tank Under Seismic Action Of Nuclear Power Plant

In the standard design of ACP1000, the ground acceleration of horizontal and vertical limiting safe seismic motion adopts 0.3g, its seismic action has increased significantly comparing with the past 2nd generation nuclear power plant, which was using 0.2g peak acceleration. And the ACP1000 built-in refueling tank reactor we studied actually contains four interconnected areas: the area between internal structure of ring wall and the inner containment and three areas within the ring wall, the shape of whole tank is more complicated.In this paper, ANSYS based simplified calculation method and ABAQUS based SPH method and CEL method are used to analyse and study fluid-structure interaction problems of built-in refueling tank, e.g. fluid-structure interaction problems. The SPH method is a kind of pure Japanese meshless particle method (elm). For SPH fluid, no node and unit needs to be defined. It's only treated as a set of mass density, velocity and energy of particles, and various materials of ABAQUS model can be used in the SPH method. And CEL method is a kind of grid numerical analysis method, eulerian method and Lagrangian method are used respectively to describe fluid and shell. The two methods are combined to describe the interaction between fluid and solid. In ABAQUS, it provides general contact to simulate the interaction between fluid and solid. However, in CEL method, due to the special shape ofbuilt-in refueling tank, it cannot round off the tank wall, instead, it just tries to reduce the size of the euler unit, in the practical analysis, sometime the water tank is leaking, and it becomes serious in 21 seconds after the quake. Therefore, in this paper, SPH method is highlighted as a fluid-structure interaction analysis method.In this paper, by comparing the calculation results of SPH method and CEL method, it's confirmed that SPH method is an effective fluid-solid coupling analysis method and it can meet the accuracy requirement of the design.At the same time, in this paper, the ANASYS based spectrum analysis method is utilized,which is a simplified calculation method. After comparing the reinforcement calculation results from SPH method, it's confirmed that the simplified calculation method is conservative and safe.