TEPCO’s Risky Operation at Fukushima - The Nation

[Sirveri]

50. Plutonium IS reactive, in that it oxidizes quickly.

The same is true of Uranium. Hence the OX part of MOX. OX = Oxide, it has already been preferential reacted with oxygen to form a stable compound.

Just because an object is reactive, does not make it a volatile compound capable of creating a chemical explosion. The idea that the 'science on plutonium is still being studied', doesn't make any sense. What specifically do you argue that they are studying about the properties of plutonium that would have bearing on the ability of it to spontaneously chemically explode? The spontaneous fission probability of the substance is well understood by physics, and I can give you probability rates for it with half life if desired.

Even if #4 had a big hole in the roof (which I haven't seen, though I admit it's possible due to shutdown maintenance, though the before pictures I am viewing do not show any large hole), that doesn't mean that it wasn't possible for there to be a gas pocket buildup elsewhere in the building that could have produced enough for to achieve an explosion. TEPCO claims the hydrogen that caused the explosion came from unit #3, which was adjacent to unit #4. This explanation is also a plausible source for the hydrogen.