The new enrichment further breaches Iran’s 2015 deal with major powers VIENNA: Iran has started enriching uranium with a third cascade, or cluster, of advanced IR-2m centrifuges at its underground plant at Natanz, the UN nuclear watchdog told its member states on Monday, further breaching Iran’s 2015 deal with major powers. “On 7 March 2021, the Agency verified ... that: Iran had begun feeding natural UF6 into the third cascade of 174 IR-2m centrifuges,” the International Atomic Energy Agency (IAEA) said in a report obtained by Reuters, referring to uranium hexafluoride, the feedstock for centrifuges. “The fourth cascade of 174 IR-2m centrifuges was installed but had yet to be fed with natural UF6; installation of a fifth cascade of IR-2m centrifuges was ongoing; and installation of a sixth cascade of IR-2m centrifuges had yet to begin,” it added