After waxing breathless for a couple of weeks about a cloud of radioactivity which was going to come across the Pacific and kill us all, the American media has forgotten all about the Fukushima reactor problem, but that problem has not gone away. Tepco now says that the fuel rods at Number One reactor melted completely and are believed to have formed a puddle at the bottom of the reactor containment vessel. They even show a neat little picture of the situation as they believe it exists.
My training as a reactor technician in the Navy does not make me an expert on nuclear reactors, but it does lead me to believe that we are not getting the full story here. From what I know about reactors, if all the fuel melted into one big puddle, the one thing it absolutely would not do is lay there quietly at the bottom of the reactor vessel and cool down to a nice safe room temperature.
The fuel load could not possibly come together into one solid mass without restarting the fission reaction and creating one whole hell of a lot of heat.
They are saying that the melted fuel created holes in the containment vessel that allowed water to leak out of the reactor. Right. Water would pour out of the vessel, but melted fuel would not leak out. Of course, if the melted fuel ran out of the vessel and went God knows where, that would account for the reactor being cooled down. They admit that they are merely assuming that the fuel is in a cooled down puddle at the bottom of the vessel. I am rather assuming that it is not.
There was also a story at the same link yesterday about crews shoring up Building #4 because it was leaning and appeared to be in danger of falling over, which would scatter the spent fuel which is stored on the upper level of it. That has not been refuted, but the story has been removed from the website, which is a little bit unnerving.
Another story which has disappeared from the same website is one that discussed the concerns about Reactor #3, which appeared to have suffered a complete meltdown also and was, at this point, still at a temperature significantly higher than its normal operating temperature when generating electricity. Like the Building #4 issue, this has not been refuted, merely removed from the website.