TEPCO now admits that there is a gap in the shield plug on the Containment Vessel of Reactor 3, and the water may have leaked from the equipment hatch flange into the reactor building.
What a surprise. Last November, TEPCO sent a Packbot inside the Reactor 3 building and had it survey the guide rails in front of the same equipment hatch. The robot detected the maximum 1.6 sievert/hour radiation, and the guide rails filled with water and sludge-like material. The robot was seen trying to wipe off the water with cloth. There was no further announcement from TEPCO on this, until today (April 19, 2012).
This time, TEPCO sent out two of its employees for a 4-minute work of inserting an image scope through the gap to get the image of the floor in front of the equipment hatch flange.
Now the company shows us the photograph that the Packbot took last November, showing the gap between the shield plug and the CV.
From TEPCO's Photos for Press page in English, 4/19/2012 (emphasis is mine):
Inspection of the equipment hatch of PCV in Unit 3 of Fukushima Daiichi Nuclear Power Station
［Object］To check the situation of water leakage from the equipment hatch of PCV at the northeast on the first floor, as the water injected to the PCV has been leaked to the reactor building.....read more