Debris impact on emergency coolant recirculation

Under normal operation, nuclear reactor fuel is cooled by water circulating in the primary circuit. In the case of a loss-of-coolant accident, the reactor is stopped automatically. Residual fuel heat must then be evacuated, typically by use of a safety injection system and a reactor containment spray system. These systems are fed with water recovered from the bottom of the containment through sumps. However, because this water may contain debris (insulating material, concrete particles, paint), sumps are equipped with strainers. These strainers may become clogged, preventing emergency coolant recirculation. This could in turn lead to reactor core overheating, or melting in the most extreme circumstances. Participants at the workshop discussed the most recent research and developments in this field, as well as proposed and implemented solutions. These proceedings contain the papers presented at the workshop as well as a summary of the discussions that took place. (author)