An Assessment of Steam-Explosion-Induced Containment Failure. Part III: Expansion and Energy Partition

Energy partition during the energy release phase of a steam explosion in the lower plenum of a pressurized water reactor is considered. The results indicate that explosions that are energetic enough to be considered challenging to upper vessel head integrity would also fail the lower head, thus drastically reducing the upward directed mechanical energy release. Even for smaller explosions, structural deformation, system compliance, and venting mechanisms strongly affect the logistics of energy partition in favor of dissipation.