Iran has increased the level of uranium enrichment using advanced equipment at its underground Fordow facility, the United Nations' International Atomic Energy Agency said in a report on Saturday seen by Reuters.
The confidential report to member states added that the agency had verified that Iran had begun feeding a batch of 166 IR-6 centrifuges with uranium hexafluoride gas enriched up to 5%.
Reuters had quoted a few weeks ago, a report by the International Atomic Energy Agency, that Iran would boost the pace of uranium enrichment, as it prepares to operate a set of advanced "IR-6" centrifuges at the underground Fordow site, which can easily switch between enrichment levels.
The confidential report to member states said that IAEA inspectors verified last Saturday that Iran was preparing to inject uranium hexafluoride gas, the material that enriches centrifuges, into the second of two IR6 groups at the Fordow facility, which is located in the belly of Mt.
Iran told the International Atomic Energy Agency on Monday that the "passivation" of the chain - a process that precedes enrichment and also involves injecting uranium hexafluoride into the devices - had begun on Sunday.
More importantly, only the series of 166 machines contains so-called "modified subheads" that facilitate the transition to enrichment with other purity grades.
Enhancing uranium enrichment at Fordow is the latest of several steps that Iran had long threatened to take but refrained from implementing until the International Atomic Energy Agency's Board of Governors last month adopted a resolution criticizing Tehran for its failure to explain the presence of uranium traces at undisclosed sites.
In response to this decision, Iran ordered the removal of the agency's cameras installed under the 2015 agreement and proceeded with the installation of IR6 centrifuges at an underground plant in Natanz, where the agreement allows it to enrich but only using the less efficient IR1 machines. The agreement does not allow uranium enrichment at Fordow.