The Resonance Effect of External Vertical Vibration on a Single Nuclear-Coupled Boiling Channel System With Forced Flows

The present study adopts the single nuclear-coupled boiling channel model integrated with oscillating vertical seismic accelerations to investigate the seismic-induced effect on a single nuclear-coupled boiling channel system. The nonlinear dynamics and stabilities of a single nuclear-coupled boiling channel are investigated through nonlinear analyses. The void-reactivity feedback would destabilize the system as that reported in the literatures. The natural frequencies of the stable states are widely explored. The results indicate that the natural frequency of initial state could depend on the parameters of phase change number and subcooling number. It tends to increase as the increase in the phase change number (operating power) or the decrease in the subcooling number (inlet subcooling). Notably, the system natural frequencies distributed in the stable region are located within the common range of seismic vibration frequency. For the concern of reactor safety, the present study investigates the seismic-induced resonance effect on a nuclear-coupled boiling channel system. The results illustrate that the resonance oscillations could be triggered if the external vibration frequency is the same as the system natural frequency. Moreover, the strength of resonance effect may depend on the inherent stability characteristics of the initial states.