Heat transfer of film boiling on the molten metal after water injection

Abstract

In-Vessel Retention (IVR) strategy with in-vessel water injection could mitigate the thermal focusing effect of the light metallic layer, and reduce the possibility of vessel failure and the release of fission products. Water injection on the molten Zirconium-Stainless steel metallic pool experiment (ATOM) has been performed to investigate the effect of water injection on the heat transfer of the molten pool. After water injection, a film boiling is formed on the top of the molten pool. With Taylor instability, a simplified model is used to derive the form of the film boiling. By fitting it with the ATOM experiment data, a new correlation of water injection on the prototype material for the possible stratified layer molten pool is obtained. The ATOM correlation could predict the experimental results well. The maximum relative error for the ATOM experiment is 28.5%, for the ELIAS experiment is 77.3%, and for the ANAIS experiment is 15.0%. By applicating the ATOM correlation of the heat transfer coefficient as a function of surface temperature to the reactor case, it is found that the vessel failure might not occur with the large aspect ratio (H/D) in the light metallic layer and with the top boundary condition of a water layer.