Molten Pool Coolability: COMECO Experiments

A series of experiments, named COMECO (COrium MElt COolability) were conducted at RIT (Royal Institute of Technology) in which molten core pools were quenched by establishing a water layer onto the top of the molten pool and by injection of water from the bottom delivered through a downcomer from the water overlayer. For this experimental program the following approach was adopted. We reasoned that since water addition from the bottom has been shown to be a more efficient mode of cooling in the DECOBI (Paladino, 1999) and in the COMET (Alsmeyer, 1998) experiments for melt coolability, water should be channeled to the bottom of the debris bed, with a downcomer, to accelerate the coolability process. The primary objective was to obtain data, which will provide a phenomenological basis for assessing the improvement in the coolability of a core melt pool by provision of downcomers as well as steam generation rate from the interactions between core debris and water. This paper summarizes the experimental results along with related analysis.