From what I hear every nuclear centrifuge creates a unique signature in its radiation and is easily traceable as to how it was made leading to where it came from.

What I am trying to say is Russia and the United States are the only countries able to produce High Quality plutonium ( say P-34 ). If this device was made of plutonium of a lesser quality we would know by the type of radiation in the cloud and what country is capable of producing it.
Jerry Garcia 2007 Reviewed by Jerry Garcia 2007 on . Chavez accepts Russian nuclear offer Chavez accepts Russian nuclear offer Mon, 29 Sep 2008 08:03:48 GMT Venezuelan President Chavez (L), Russian PM Putin Venezuelan President Hugo Chavez has accepted a Russian offer to help expand his country's civilian nuclear program. "We are interested in developing nuclear energy." AP quoted Chavez as saying. "Russia is ready to support Venezuela in the development of nuclear energy with peaceful purposes and we already have a commission working on it." In a meeting with Chavez last Rating: 5