CNN just sent out a breaking news alert saying the Japanese government confirmed it is assuming the possibility a meltdown is underway not only at at the #1 reactor at the Fukushima I site, but at #3 reactor. Meanwhile, it turns out that the #1 reactor (the one first reporting problems) (probably) did not use MOX fuel, but the #3 reactor, which is now apparently melting down, did. Rescue workers are pumping in seawater and boron (which is used in control rods) to try to stop the (assumed) meltdown.
MOX fuel is a mixture of reprocessed oxide of uranium mixed with plutonium. It allows the use of weapons-grade plutonium to create fuel for civilian nuclear power plants, and also uranium to be reprocessed so that a much, much larger percentage of energy can be generated.
The #3 reactor started loading MOX fuel in September, 2010. I presume that means the #1 reactor is using uranium. Uranium alone is much less toxic; plutonium is generally said by scientists to be the most toxic substance humans have documented.
The International Atomic Energy Agency issued a statement that was vague on details, given that it was giving me a 404 error — it’s either been taken down or their site is overloaded. This is what the CNN article says about the Japanese government’s statement:
Chief Cabinet Secretary Yukio Edano told reporters there is a “possibility” of a meltdown at the plant’s No. 1 reactor, adding, “It is inside the reactor. We can’t see.” He then added that authorities are also “assuming the possibility of a meltdown” at the facility’s No. 3 reactor.
[Link.]
This is fairly ridiculous double-speak; they’ve been assuming the possibility of a meltdown since the beginning. I believe this is a less committal way of the government saying they are assuming a meltdown has occurred.
Like the rest of the world.
I had previously thought that the fuel at all the reactors at the Fukushima I plant was mixed-oxide, or MOX fuel, which is a mixture of oxides of plutonium and uranium. But the BBC story implies that is not true in #1. The BBC story says the following (the “second reactor” they refer to is #3):
[T]he BBC’s Chris Hogg in Tokyo says the second reactor is a different type which uses MOX (plutonium plus uranium) fuel and the consequences of a problem there are potentially more severe.
Quoted by Kyodo, Tepco [which operates the plant] said the tops of the MOX fuel rods were 3m above water.
Meanwhile, Tepco said at least 15 people at a nearby hospital were found to have been exposed to radioactivity.
And the firm also confirmed that four of its workers were injured in Saturday’s explosion, but that their injuries were not life-threatening.
[Link.]
Three meters above water is bad. MOX, in this context, is bad.