OK, this is not good news... sorry to be the bearer of bad news...
I have to say first that the following is my interpretation of reported events, and subject to the accuracy of those reports. Yes, I have experience
in the construction/management of nuclear power, and I have pretty extensive study of nuclear technology, but I am not
waving a PhD from MIT or
anything like that.
So far it seems pretty evident that there has been a partial controlled meltdown at units #1 and #3. In order to maintain their status and allow them
to safely shut down, coolant must
be maintained until they can burn themselves out. This process could take days, weeks, or even months... and
I feel days is a very unlikely prospect. If they cannot continue the cooling to remove the heat from the decaying uranium (and the byproducts as
well), both reactors will melt down in an uncontrolled free-running reaction, melting the reactor vessel itself and exposing the surrounding area to
Unit #2 appears
to have sustained a crack. This crack will manifest itself two ways: firstly, it will leak a large amount of radiation into the
surrounding area. Secondly, and more dire, it cannot be cooled without exposing the fuel to the atmosphere. This would release a massive amount of
radiation at lethal levels into the surrounding area.
However, that is not the worst. If the reactor is not cooled, it will sustain an uncontrolled complete melt-down. This itself will melt the reactor
vessel, resulting in the same massive radiation.
Japan is damned if they do and damned if they don't.
The levels around Unit #2 will skyrocket; the area will become uninhabitable very soon. I do not see how workers can continue to work to maintain
reactors #1 and #3. That means we will shortly have three uncontrolled meltdowns.
There are only two things inside that reactor building that can possibly cause an explosion: chemicals (like hydrogen) and a catastrophic failure of a
pressure vessel. The nuclear fuel cannot, under any situation, explode like a nuclear weapon. If, as has been reported, the explosion at Unit #2 was
not caused by hydrogen, then it had to be a pressure explosion, and the main thing under pressure is: the reactor itself.
If, as it appears, there was a small crack in reactor #2 that was leaking water, then the continuing heat from the partial meltdown could have still
been raising the pressure faster than the crack could relieve it. An uncontrolled build-up of pressure inside the reactor could cause a catastrophic
failure of the reactor itself, especially since it already contained a compromised area (the original crack). This would lead to completely dry fuel
rods and a complete meltdown, accompanied by massive releases of radioactive material.
I have been looking for a white plume of steam. That may not occur under this situation, since there was apparently little water surrounding the
reactor core to begin with.
There will be gamma, beta, and neutron radiation from such an event. Like Chernobyl, this area will be uninhabitable for quite some time. As for
exactly what will happen as a result of this event, I am afraid we are in uncharted territory here. It looks like we will get to test those meltdown
proof floors after all.
I fear Japan has just lost at least part of the country.
For the US, without the plume of superheated steam, less neutron emission will rise into the atmosphere, meaning less chance of airborne
contamination. That's the good news. The bad news is that with this massive a release, at least some of the I-131 could drift across the Pacific. It
will decay some during the trip, and will also dissipate, so any dosages here should be low. The cesium, again, is practically irrelevant.
Plutonium or uranium will likely not affect any other countries, as they are pretty heavy elements and will not stay aloft long if they manage to get
aloft in the first place.
Gamma radiation from the plants themselves will not affect any countries beyond Japan at all. There will be some associated with the I-131, but not a
tremendous amount. Potassium iodide may be offered along the coast, mainly west of the cascade range; take advantage of it.
If anyone is in northern Japan... if you can get away from these plants, please do so now. Listen to the authorities; they know what type of radiation
is being released and how much. Help each other; you are a proud and noble people and you are fighting a monster that would dwarf Godzilla, with a
tenacity that should make you proud.
May God have mercy...