My understanding is that Iran needs high performance centrifuges to enrich Uranium as they do not have an abundance of the stuff, unlike the Manhattan Project.

My understanding is that Iran needs high performance centrifuges to enrich Uranium as they do not have an abundance of the stuff, unlike the Manhattan Project. They were able to pile up 50 tons of uranium and light up a lightbulb while other experiments were carried out in parallel to enrich uranium and synthesize plutonium.