A PARAMETRIC STUDY OF GEOMETRIC EFFECT ON THE DEBRIS DISPERSAL FROM A REACTOR CAVITY DURING HIGH-PRESSURE MELT EJECTION

Abstract

In order to formulate an empirical correlation to evaluate the debris dispersal fraction from a reactor cavity during high pressure melt ejection (HPME) accident in Nuclear Power Plants, a number of low temperature simulant experiments employing mocks-up of reactor cavities have been performed. Due to the dependency of the debris dispersal process on the cavity geometry, the experimental data from a specific cavity geometry show a limitation for their application to different cavity configurations. To predict the debris dispersal fraction for different types of cavity geometry, a new correlation has been developed, which includes geometric parameters explicitly. It is found that important parameters in the debris dispersal process from the cavity are the available entrainment time as well as the particle flight time. For validation of the proposed correlation, a series of experiments varying geometric factors of the cavity flow area and the cavity exit height have been carried out in two scaled-down HPME facilities. The experimental results show good agreement with the predictions by the developed correlation.