Iran has resumed production of equipment for advanced centrifuges at a site the United Nations’ atomic-energy agency has been unable to monitor or gain access to for months, diplomats familiar with the activities said, presenting a new challenge for the Biden administration as it prepares for nuclear talks.
The renewed work has raised concerns among Western diplomats who say it could allow Iran to start secretly diverting centrifuge parts if Tehran chose to build a covert nuclear-weapons program, although they say there is no evidence at this point that it has done so.
Iran resumed work on a limited scale in late August at an assembly plant in Karaj, a city west of Tehran, and has since accelerated its production, allowing it to manufacture an unknown number of rotors and bellows for more advanced centrifuges, diplomats said. Iran had stopped work at Karaj in June after a sabotage attack that Tehran blamed on Israel, which hasn’t acknowledged responsibility.
According to the diplomats, Iran has now produced significant amounts of centrifuge parts since late August, with one of the diplomats saying it has produced parts for at least 170 advanced centrifuges. Centrifuges are used to spin enriched uranium into higher levels of purity either for civilian use or, at 90% purity, for nuclear weapons.
All of the recent work at Karaj has taken place without any official IAEA monitoring, the diplomats said. Iran significantly tightened security at Karaj after the June alleged sabotage, the latest in a series of explosions at its nuclear facilities over the past two years.
Iran’s production of centrifuges is a critical issue in talks beginning Nov. 29 to revive the nuclear deal, which the Biden administration is hoping to restore. Former President Donald Trump withdrew the U.S. from the accord in May 2018.