[Poohbah]

But my understanding is that we CAN detect origins of virtually any element due to various idiosyncrasies geographically. Is that true?

It's possible, but not 100% certain. It's not the geographic origin, but instead how the plutonium is "cooked" in the nuclear reactor (plutonium is not mined; it is made by bombarding Uranium 238 in a reactor). If we have a sample of the material in question (such as, for example, an assay from a bomb pit that we helped Ivan scrap under the Nunn-Lugar program, or just simple espionage), we'll figure out where it was made.

[Quix]

Thanks.

Evidently you are not reading as far as . . . or you are stuidiously avoiding by other question about responses.