From Lateral Science:
Belgian mining engineers at Shinkolobwe unearthed this seven ton lump of rich uranium ore in 1922. It contained enough fissile material to construct two Hiroshima type atomic weapons.
The man's got some balls (though soon afterwards, they probably fell off!) Link - via Scribal Terror
HAHA! What a crazy guy.
100 kilos of HEU has a high chance (due to nucleic decay) of reaching critical mass on its own at any given moment. Natural Uranium... meh... not so much. In fact the stuff is reasonably okay to be around, although you don't want to eat it or be exposed to it for long periods of time.
2 billion years ago (much longer than the half-life of U235) there were a few natural nuclear meltdowns when huge deposits of Uranium surpassed the decay limits. This type of thing can't happen today because so much of the U is depleted in the earth's crust.
The guy in the picture probably lived a long life and if I had to bet didn't die of cancer. If anything he is pretty lucky to be one of the few humans on earth to come across such a large deposit of such an exceedingly rare element. Uranium is almost as rare as gold.
Thanks for pointing out the difference between HEU and Natural Uranium mrgoodbar.
If the caption is right, then doesn't that hunk have the equivalent radioactivity as 2 fissile nuclear weapons' worth?
Also, is natural uranium and depleted uranium almost the same? Either are low on the highly radioactive form U-235, but DU has also been shown to have residual radioactivity and can cause cancer in lab animals.