Top-quality, weapons-grade material is the only kind that can used to build a true nuclear-fission bomb, and is both hard to obtain and harder to turn into an explosive.
But its weapons-grade material could be removed and turned into a dirty bomb, or even a crude nuclear device.
In the '80s, Saddam Hussein bought several hundred tons of yellowcake, which can be enriched in gas centrifuges to produce weapons-grade uranium.
Condoleezza Rice in Guardian Unlimited There is a history of Iran not answering important questions about what is going on and there is Iran pursuing nuclear technologies that can lead to nuclear weapons-grade material,Rice told reporters aboard her plane as she headed to Moscow.
Stephen Harper in Toronto Sun The regime's latest moves bring Iran considerably closer to possessing weapons-grade material,Harper said in a statement Wednesday. "Iran's past history of deliberately concealing aspects of its nuclear program makes this latest move even...