IOW a small nuclear weapon.

Considering all the factors, as outlined in the references, necessary to even get to a weak reaction called fizzle, it is remarkable that a simple process like a sonic boom would do the job. Thinking it through at even the most fundamental level leaves me rather nervous!

Thanks for the link, Jack.

Any body know how many of the two thousand, or so, atom bomb tests were atmospheric?

And how many of those were in major urban centers?

Two I know of until Fukushima.

I thought when I first saw the photo above, "looks like a mushroom cloud to me". But what do I know?; I am 'just' an ordinary citizen.
In about 2 years when the salmon start showing up in the Columbia River and you won't even need a geiger counter to know they are too radio active to eat; and then when some of the tsunami debris starts to wash up on our beaches, it will be interest to see how the various governments of the moment try and spin that mess.

Major issues remain at Fukushima, the fate of Libya's resistance is still up in the air, Syria is cracking down on dissidents, we have major storms in the eastern US, and where is the media? At last count, NBC / MSNBC was sending 200 reporters to the royal wedding!

Priorities.

Wait, our corporate media assured us this was a gas explosion of hydrogen. What's happened to trust in this world?
I'll tell you one thing: The irony here has hit Level 7.
Let's say this was a nuclear explosion and the super-heated plutonium entered the jet stream where it rode over to Oregon and came down on us. That would be bad right?
Here's the ironic twist: Our government has spent billions scaring the hell out of us about terrorism, etc...Remember Condi talking about mushroom clouds before we went into Iraq?
Well, that was a case where the corporations stood to gain from the fear, but this? A population concerned about nuclear power because we could be breathing in plutonium from Japan? That would affect the nuclear power industry. Big corporations could lose - it's time to play this one the other way.
Result: The same massive government/corporate/media complex that sold us Iraq based on fear and lies, is now lying about this, but this time everything is okay: "Don't worry about it. Everything is fine. There's no point in being alarmed because unwarranted fear can be bad for you." And that is ironic.

Maybe we should have tried the same technique on the government back in the pre-Iraq days: "Hey, so what if Saddam has weapons of mass destruction? Saddam's weapons can't reach all the way over to Oregon. They'll disperse to safe levels that are barely detectable. Besides, even if they did there are worse things. Do you know how many people die from coal every year?"

Bill, it might have been the source of the shock wave. This analysis is rather new, isn't it? The idea that criticality, let alone Prompt Criticality ( an expression in the category of "Terminate with extreme prejudice!) can be initiated by a shock wave in an ordinary environment has to give one great pause. Further, the speaker did not state it is conclusive. It will have to be tested, and that presents even further, great difficulties. Personally, I rather doubt it can be proven, unassailably, because it would have to pass the falsifiability test.

But scientists, if nothing else, are very clever.

Official lies are usually not completely lies, they tend to be half truths. Unfortunately we mostly don't have a clue which is which, and even if we unravel one half-truth, it doesn't mean we have the tools to unravel the others.

Just a minor explosion...

This is an excellent link, and the guy knows what he is talking about.

What he is describing is a world class dirty bomb. Not a nuclear detonation to blast apart a city, but a way to spread one of the most deadly materials known to man.

The design of the pool, like he described, created a gun that would pulverize the nuclear material into a fine dust and blast it up into the winds to be carried around the world.

This is nothing like the iodine problem. This is a Dirty Bomb like no other!

Disaster planning scenarios think of a small device with some smuggled nuclear material from the East spread around a city with a conventional explosion. As far as I know, (not researched) no one has planned for a fuel pool going dry and a secondary explosion creating criticality and a whole fuel pool being blown sky high.
Stay tuned!

The dirty bomb is what I had in mind but setting one off with sound? Wow!

There is technology that might just do it.

http://en.wikipedia.org/wiki/Sonic_weapon

American nuclear problems?

http://www.huffingtonpost.com/2011/04/27/ohio-nuclear-radiation-perry_n_854243.html

Lawrence the sound issues is just a measurement of speed (the speed of the chemical reaction. Sound has nothing to do with the creating the explosion.

25 years ago today, the world was still blissfully ignorant to the horrors unfolding at Chernobyl. I don’t know when the Russians were planning on breaking the ominous news to the rest of the world that they had managed to accidently detonate the biggest dirty bomb ever—irradiating the planet. But a few days later, an editorial cartoon showed a half melted planet with a Russian communications tower. The cloud caption read, “Eeeerrh excuse me comrades, we have a small problem”. I cut it out and put it on my fridge, next to the Gary Larson ‘Far Side’ cartoon, wherein the Lone Ranger apparently retired, with his mask hanging on the wall, is sitting in an easy chair with a dictionary of “ Indian speak” on his lap. He is looking up ‘Kimosobi’, the definition--- a horse’s ass.

There are a lot of Kimosobies out there.

Prompt criticality in a spent fuel pool is physically impossible. The enrichment is not high enough and as the fuel melts it becomes diluted in the morass of metal, etc.

The simpler, and therefore more plausible, and physically possible reason is that the hydrogen built up to a higher concentration before an ignition source ignited the hydrogen-air mixture.

OK "dave", and blew the still very radioactive fuel into small particles straight up to be carried by the wind. How do you define a "Dirty Bomb"?

I was not remarking on the Dirty Bomb discussion. Sorry if that was not clear. I was commenting on the cause of the explosion as described in the original post on the Blog. Regardless of the cause the explosion was a terrible event.