Iran is testing an advanced centrifuge at its Natanz nuclear facility, diplomats in Vienna said Wednesday. The new centrifuge would help Iran boost its speed of uranium enrichment. Iran had 3,000 P-1 centrifuges - an old type of centrifuge - operating by November, but Reuters quoted diplomats tracking Iran's dossier as saying that it had started mechanical tests, without nuclear material inside, of a more efficient model at Natanz. "The Iranians have begun to run in the advanced model. It's not yet known what stage the testing has reached or exactly how many there are, although it appears to be several dozen," said a Western diplomat with access to intelligence. Reuters reported that a senior diplomat familiar with the International Atomic Energy Agency's file on Iran confirmed that it recently began testing centrifuges based on a "P-2" design, able to enrich uranium 2-3 times as fast as the P-1. The diplomat did not elaborate but said that the details would come out in a report IAEA chief Mohamed ElBaradei would deliver to the Vienna-based agency's Board of Governors and the UN Security Council later this month. It was unclear how successful Iran's tests of the new centrifuge had been.