Iran has begun enriching uranium with the second of three cascades, or clusters, of advanced IR-6 centrifuges recently installed at an underground plant at Natanz, a report by the U.N. nuclear watchdog said on Wednesday.
Like the first of those three cascades of up to 174 machines each, the second is enriching uranium to up to 5% fissile purity and the third has not been fed with nuclear material, the confidential report to member states said.
A separate report on Monday said the first cascade had been brought onstream.