Heat transfer characteristics of two-layer corium pool with additional metallic layer heat source

Abstract

Due to material oxidation, activation, and the presence of fission products and uranium, the metallic layer in a two-layer corium pool contains internal heat sources. This study investigated the influence of these additional heat sources on heat transfer characteristics using 3D CFD simulations, analyzing temperature distributions and wall heat flux patterns. The results reveal that the thickest solidified layer typically forms in the upper-middle section of the oxide layer rather than the cooler lower region. Beyond a certain height, the solidified layer rapidly diminishes, leading to significant wall erosion. While the Nu relationship established for conditions without metallic layer heat sources remains applicable when such sources are present, parameter c substantially impacts the metallic layer's heat transfer behavior. However, heat transfer correlations like the Nu relationship developed for heat-source-free conditions may not be valid when heat sources exist. Even experimental data from studies focusing solely on metallic layer with internal heat sources cannot be directly applied to analyze heat transfer in two-layer corium pools. The coefficient f was proposed to quantify the effect of metallic layer heat sources on heat transfer characteristics.