Oh, I'd love to. I'm serious, because this is right in line with what I do.
We're looking at the ratio between uranium-235 and uranium-238. There are alpha spectroscopy and some mass spectroscopy methodologies that will allow us to determine what that ratio is. If the amount of U-235 is around 0.7%, it's natural. If it's less than 0.7%, by definition it's called depleted uranium. If it's 0.2%, then it was DU that was made in the U.S.