Lawrence Scott Sheets tells how radiation detectors in Georgia (the ex-soviet republic not the US state) foiled at least one attempt at smuggling:

Dadayan made only feeble efforts to conceal his stash of HEU, hiding it in a cellophane bag tucked inside a metal tea box. But several specialists I spoke to speculated that because his HEU, according to U.S. analyses, also contained the chemical compounds UO2 and U3O8 (which emit more radiation than U-235), it set off the radiation detectors the Georgians had at the border. The guards say that when the sensors sounded, Dadayan tossed the satchel containing the tea box filled with bomb-grade uranium onto the ground. He said he’d never seen the substance in the box before and that the cellophane bag had only been for food scraps. So sloppy were his smuggling efforts that, according to Armenian court records, his notebook contained scribblings mentioning “U308” and the amount of money—believed by Georgian officials to be $15,000—that he was to receive for acting as a nuclear mule. Dadayan was handed over to the Armenian government, tried, and sentenced in 2004 to two and a half years in prison.

Interesting and very relevant topic; one that needs to be discussed robustly here in Australia. Every time I hear someone poo-hooing the idea that the components of nuclear or radiological weapons could be smuggled into Australia - or New Zealand, for that matter - I think of that intelligence expert who, in Singapore in late 1941, said that the Imperial Japanese were nothing to worry about because their all troops were puny, short-sighted, hissed when they spoke and were equipped with shoddy out-of-date weapons. Yeah. Right.

Not impressed by that ill-behaved link though; does that mean I’ll get Christmas cards from NSA?

But you probably already know that already. I didn’t pay much attention in science class when I was at school so I had to look it up.

From what I’ve read, weapons grade uranium would typically be around 90% uranium-235 with some uranium-238 and uranium-234. If the uranium feedstock used in the enrichment process is contaminated with uranium from reprocessed reactor fuel then you’ll also get some uranium-232 and -236.

The presence of absence of uranium-232 matters because it’s is very radioactive. That means that it’s easier to smuggle uranium if it’s not contaminated with uranium-232 (or so I’m told).

I found this article helpful.

If anyone thinks I’m confused about this, the comments box is all yours.

uranium 232

?????