Seismic analysis of nuclear reactor core

A 3-D homogenization model is proposed to study the overall dynamic behaviour of a nuclear reactor core under seismic excitation. Finite element method is employed for detailed analysis. As the fluid–structure interaction in the core gives rise to a non-conservative force, the mass and stiffness matrices of the system are non-symmetrical. Both Wilson-θ direct integration method and QZ method were used to calculate the seismic response of the reactor core. Results of responses of the fluid pressure and the beam deflection under excitation of EI-Centro and Tangshan seismic waves are presented. In order to validate the model, analytic solution of the dynamic response of a single beam immersed in an infinite fluid is also given.