Experimental Study on the Heat Transfer Characteristics of Debris Bed Remelting Process

Abstract

The researches of IVR (In-Vessel Retention) primarily focuse on natural convection in steady-state molten pools. However, the dynamic process from particulate debris bed melting to molten pool is also critical. The debris beds remelting process may exhibit intermediate states that potentially exceed steady-state thermal loads, while simultaneously serving as the initial condition for steady-state molten pools. This study conducted experimental investigations on single-component and two-component debris bed remelting processes using the COREM-HT experimental facility. The results included phenomenological characteristics, temperature evolution and heat flux distribution. In both experiments, no transient heat flux exceeding the final state was observed. Notably, two crust layer observed on the wall differed from conventional steady-state molten pool configurations with single oxide crust. These findings offer significant references for IVR research.

Keywords: the debris bed, remelting, experiment, IVR, Severe accident