Iran has been building advanced new centrifuges to enrich uranium, the UN's nuclear watchdog has confirmed, leaving Tehran's 2015 nuclear deal hanging by a thread. The International Atomic Energy Agency (IAEA) said 56 centrifuges had been installed or were being installed at the secretive Natanz plant in Iran. The equipment has been 'prepared for testing' with uranium hexafluoride, the IAEA said. Using it to enrich uranium would be a breach ...