[George W. Bush]

Now that is interesting. They can determine where it came from.

I've read before that individual reactors have a fingerprint of sorts, trace elements that can uniquely identify the reactor that produced it. It has something to do with the variety of batches of stuff they run through a reactor which makes a unique trace elements signature.

I've tried to find out more about this but can't make a google search to find further info.

[mware]

You might want to check with ccmay. This is a copy of a post he sent me.

Yes. We can tell quite accurately where fissile materials come from, by minor differences in isotopic distributions and contaminants. Those nations with nuclear capabilities know this well, and moreover they know that we will treat nuclear attacks by "rogue" elements as if they came from the nation in whose territory the material originated.

[Sender]

Identifying the Source of Stolen Nuclear Materials

International Conference on Advances in Destructive and Non-Destructive Analysis for Environmental Monitoring and Nuclear Forensics

National Nuclear Security Administration

If it's your stuff, (insert terror-sponsoring state of your choice), we'll know. Expect a visit.