Research on base isolation design of nuclear island plant of a new-type metal-cooled fast reactor

Abstract

This paper establishes a 3D finite element model of a new-type metal-cooled fast reactor (MCFR) nuclear island plant for applied research of base isolation technology, and the research includes the base isolation scheme for the split base layer structure, the selection from different types of isolation bearings, etc. According to the mechanical characteristics of different isolation bearings and rigidity distribution of the structure itself, the layout of isolation bearing scheme is carried out. Dynamic analysis of nuclear plan has been done based on ANSYS, and the optimal isolation scheme is determined by repeated trial calculation, isolation design schemes adjustment, acceleration and displacement of key nodes comparison. The results show that: applying base isolation design to the nuclear island plant, natural vibration period of the structure increases, acceleration response of the key nodes of the superstructure and displacement between the layers of the structure significantly decreases, seismic resistance of the nuclear island plant is improved significantly; isolation effect of the scheme with multiple types of isolation bearings is much better than that of the scheme with only rubber bearings.