An Experimental Study of Dynamic Debris Bed Remelting Process in the Lower Head of Reactor Pressure Vessel

Abstract

In the late phase of a reactor severe accident, the dynamic process of debris bed remelting is a critical process, which may threaten the RPV integrity.  Therefore, the melting process of the low melting-point material (simulating metallic component of corium) of a two-component particulate bed and the influential factors were investigated based on a self-built dedicated COREM experimental platform for debris bed remelting.  And the complete melting process of a two-component particulate was conducted in one case.  The experimental results showed that the temperature rises gradually with heating and the highest temperature occurred in the lower center of the particulate bed.  The melting rate and temperature rise with increasing initial debris mass, decreasing fraction of low melting-point material or concentrating of high melting-point material distribution.  The work presented in this paper enhances the understanding of the debris bed remelting process.

Keywords: The debris bed, Remelting, Experiment, IVR, Severe accident