Iran expands uranium enrichment effort NATANZ, Iran - Iran announced a dramatic expansion of uranium enrichment Monday, saying it has begun operating 3,000 centrifuges — nearly 10 times the previously known number — in defiance of U.N. demands it halt its nuclear program or face increased sanctions. U.S. experts say 3,000 centrifuges are in theory enough to produce a nuclear weapon, perhaps within a year. But they doubted Iran really had so many up and running, a difficult technical feat given the country's ... Read More