Characterization of a spent-fuel-pit rupture based on water-level monitoring

In the course of the Fukushima accident, there were concerns raised with regard to the safety of the spent fuel. This concern was further justified by the very short grace time available in high-density fuel pools if the active cooling gets interrupted or the integrity of the shell is compromised. The purpose of this study is to provide a theoretical-calculation procedure for predicting the spent-fuel system's shell integrity and the elevation of the water level. Based on water-level monitoring during a given nuclear event, the rupture was characterized in terms of the mean cross-section and the elevation of the crack, while the water-level elevation was predicted for the period after the initiating events.