Experimental Study on Contact Melting of a Metal Plate by a Crusted Corium Considering Intermetallic Interactions

Under severe reactor accident conditions, the solidified crust of a relocated corium pool may undergo contact melting of internal metallic structures. This process, significantly influenced by complex intermetallic interactions, deviates markedly from conventional analysis. This study provides the first experimental investigation into the influence of the eutectic reaction on the horizontal contact melting process between a crusted melt and a metal plate. Tin is used as a simulant material to replicate intra-reactor mechanisms via its eutectic reaction with copper. Analysis of temperature response and melting velocity revealed that the eutectic reaction drastically enhances heat transfer efficiency during contact conduction, increasing the temperature change rate by up to a factor of 5.36 and substantially accelerating melting initiation. Furthermore, the three-dimensional heat conduction effect of the heat source caused an initial increase in melting rate, while melt relocation subsequently reduced the contact melting speed. Based on experimental data, this work provides an in-depth analysis of melt migration and relocation during contact melting, offering a valuable experimental basis for developing severe accident models.