The water gauges for the Reactors 2 and 3 are not to be trusted, said TEPCO's Matsumoto in the press conference on May 12 (I watched the live-recorded video) when the company officially acknowledged the meltdown of the Reactor 1.
If the water gauges for the Reactors 2 and 3 have been overstating the water levels, just like in the Reactor 1, it is very likely that all three reactors have hardly any water inside the Reactor Pressure Vessels (RPV), and the reactor cores are likely to have been melted.
Just like Michio Ishikawa of Japan Nuclear Technology Institute said on April 29.
About the water gauges for the Reactors 2 and 3:
"They are probably in the same condition as that of the Reactor 1. The numbers the gauges are currently showing are not very trustworthy. We need to monitor carefully with other parameters like pressure."
Weak points in the RPV and Containment Vessel:
"The RPV has more than 100 small pipes running through the bottom. Any one of them could have been damaged. We cannot completely deny that the [melted] fuel itself damaged the RPV. The Containment Vessel also has pipes, and it is possible that they got damaged when the pressure rose or when there was a hydrogen explosion."
To confirm, TEPCO does not deny that the fuels have all melted and went down?
"We don't deny that. How much of the fuels have melted we cannot say for certain, but our understanding is that they melted, and didn't retain the original shapes, and moved downward."
"We don't deny that part of the melted fuels may have damaged the RPV and escaped the RPV."
Any further danger if the melted fuel did escape the RPV and into the Containment Vessel:
"We're assuming it is being cooled by the water in the Containment Vessel."
If it is still within the Containment Vessel, that is.