No, it’s not. It’s leaking outside the primary containment vessel. As far as anyone knows, it’s still within the secondary containment, which is still inside the building, which is still inside the plant grounds.
Even at Chernobyl, which did not have a strong slab underlayment such as the Fukushima design does, the melted portion of the core did not “burn through” into the ground but stopped in a sub level. The likelihood of a “Brazil syndrome” is pretty vanishingly small here.
It’s statements like this which make you look uninformed and more frightened than sensible - there is nothing “supposedly” about it. As soon as the plant equipment detected an earthquake the control rods when in. They DID shut down. No ifs, ands, or buts about it.
This is true.
THIS is the more serious problem, really, but even there, nothing is going to blow up and spread chunks of fuel rod around the neighborhood like in Chernobyl. Worst case there is a melted puddle of goo in a dry pool throwing off heat and yes, some radioactive particles but still nothing as severe as Chernobyl. It’s not good, mind you, but not as bad was what happened in the Ukraine. The contamination will not be as bad, nor will it last as long because there are fewer sorts of radioisotopes being released. Cesium is probably the worst long-term one, but as long as no one tries to produce food in the immediate vicinity even the worst areas in the plant grounds will be safe for humans after a couple months.
The difference is that while Fukushima might become an “open core meltdown” it won’t become a “flaming chunks of core flung about the local neighborhood” kind of problem. The nuclear fuel will all stay in a pit. At Chernobyl there were fist-sized lumps of it launched out of the plant. Do you understand the difference now?
Ah, but what about radioactive vapors, you say? The massive explosion of an active core at Chernobyl was able to fling particles pretty high in the atmosphere, hence the radioactive cloud that floated over Europe. No explosion at Fukushima has been that powerful or destructive, so nothing released into the air went as high and it will not travel as far. Most of it is blowing out over the sea.
Is any of this good? No, it is a bad accident. Some of the workers at the plant are likely to die due to radiaton exposure and that’s a damn shame. Disrupting peoples’ lives by evacuation sucks. But let’s not exaggerate it and start yelling the sky is falling. Realistically, the quake alone killed more people, not to mention the tsunami.
Going forward what needs to happen is a thorough investigation of what happened at Fukushima so next time Something Awful Happens we’ll know how to handle it better.