Iran has started enriching uranium at its underground Natanz plant with a second type of advanced centrifuge, the IR-4, the UN nuclear watchdog said in a report obtained by Reuters on Tuesday, in a further breach of Tehran's deal with major powers.
Last year Iran started moving three cascades, or clusters, of different advanced models from an above-ground plant at Natanz to the below-ground Fuel Enrichment Plant (FEP). It is already enriching underground with IR-2m centrifuges. The deal only lets it enrich there with first-generation IR-1 machines.