The summary that Donuel has posted above presents in my opinion an accurate picture of what appears to be happening at the Japan end, and correlates with what the Union of Concerned Scientists say in their morning summary.

Sandy-

You continue to muddy the waters with your basic misunderstanding about the fission process in a normal operating nuclear reactor. Please review some of the links above.

I also don't believe there will be nuclear explosion (equivalent to a nuclear bomb explosion) from a set of runaway reactors and spent fuel pools such as we are observing at the Fukushima 1 complex (with its 6 reactors). But there may be some kind of additional explosion or explosions as the reactors continue to melt down and the spent fuel pools continue to lose coolant which could fill the air with highly radioactive Cesium, Uranium, Plutonium and other isotopes. Do you disagree or do you just fail to comprehend what the potential danger is? I wish I knew a whole lot less about what might happen.

Now experts do disagree of exactly what might happen after a meltdown. The partial meltdown at Three Mile Island (and most people are unaware that there was such a meltdown since the report wasn't issued until a year later) was successfully contained within the containment dome. However, most experts now agree that the primary and secondary containment structures at Unit 2 at Fukushima are ruptured and that we are now in new territory with regard to what will happen next.

Charley Noble