This week TEPCO released new photos which show the progress made removing debris off of the top of the Unit 3 reactor building. These photos show some of the damage to the operating floor of the reactor building including locations where the floors have been damaged and the rebar is exposed.
The investigation conducted by the utility also found that the shield plug which covers the primary containment vessel was deformed.
The utility assumes that the shield plug was damaged after the ceiling crane feel on the plug after a hydrogen explosion destroyed the reactor building.
The shield plug is around 600 mm thick, and the edges have been found to be displaced by 300 mm.