Wednesday, March 30, 2011

Core On The Floor

We have news from a newspaper. In this case The Guardian - UK, which has some bad news about the Fukushima reactor accidents.

Richard Lahey, who was head of safety research for boiling-water reactors at General Electric when the company installed the units at Fukushima, told the Guardian workers at the site appeared to have "lost the race" to save the reactor, but said there was no danger of a Chernobyl-style catastrophe.

Workers have been pumping water into three reactors at the stricken plant in a desperate bid to keep the fuel rods from melting down, but the fuel is at least partially exposed in all the reactors.

At least part of the molten core, which includes melted fuel rods and zirconium alloy cladding, seemed to have sunk through the steel "lower head" of the pressure vessel around reactor two, Lahey said.

"The indications we have, from the reactor to radiation readings and the materials they are seeing, suggest that the core has melted through the bottom of the pressure vessel in unit two, and at least some of it is down on the floor of the drywell," Lahey said. "I hope I am wrong, but that is certainly what the evidence is pointing towards."
And if we should get unlucky and that mass of junk that was formerly a reactor core has a Criticality Accident? Well all kinds of bad things could happen. Will it be an all out nuclear explosion? No. But it could be a very small one. Which will spread the radioactive fission fragments around. Or the crud might hit a pool of water causing a steam explosion. Spreading the junk around. Or it might melt into the ground and the radioactivity will get spread into the ground water by natural flows. Or we could get lucky and nothing much worse than is already happening will continue to happen. At the current time I'm not voting for Lucky. I'm voting for Murphy.

For your amusement we have a map of the aquifers of the world in pdf so you can keep enlarging it until Japan gets to a reasonable size. Now compare it to this earthquake map of Japan. From my crude measurements it appears that Fukushima is just outside the Tokyo aquifer. Or it might be close enough that it will be a problem if the radioactive sludge reaches the aquifer. I look forward to seeing better maps in the next few days as the SHTF (or if you prefer - the news gets out).

So how about a recap? We have three reactors and four spent fuel rod pools in trouble, but everything is fine so far.


You know, I just had a funny thought. Of course we couldn't have a Chernobyl "style" event. There is no mass quantity of carbon to burn. But could we have a Chernobyl "quality" of event (radiation spread) if things go bad wrong? I think so.

Cross Posted at Classical Values

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