Nearly 22,000 Iranian gas centrifuges at Fordow, Natanz and Isfahan were knocked out in June strikes, leaving “no identifiable route” to weapon-grade output at those plants, the Institute for Science and International Security said citing the UN nuclear watchdog’s latest reports.
In a paper assessing the International Atomic Energy Agency’s (IAEA) September quarterly reports, ISIS said the attacks “destroyed or made inoperative all of Iran’s installed centrifuges… at Iran’s three enrichment sites,” and severely damaged Iran’s ability to manufacture centrifuges and uranium hexafluoride feedstock.
The group, led by nuclear expert David Albright, added that Fordow, Natanz and Esfahan held enriched uranium stocks before the strikes, but the IAEA has lost on-site visibility since inspectors withdrew for safety reasons in late June and Iran later suspended cooperation.
The IAEA’s reporting showed Iran’s stock of uranium enriched up to 60% U-235 reached 440.9 kg (uranium mass) on the eve of the June 13 bombardment, with additional inventories of 20%, 5% and up to 2% material also on hand.
The agency said the 60% stockpile -- considered highly enriched uranium -- requires verification every 30 days under standard safeguards practice and that “its verification… is overdue” because inspectors have not had access for more than two and a half months.
IAEA Director General Rafael Grossi told the Agency’s Board of Governors on Monday that Iran’s new domestic law curbing access “may create obligations domestically,” but “it cannot do so for the IAEA.”
He added that Iran’s NPT safeguards agreement remains in force and that inspection work must fully resume without delay. He said technical talks in Tehran and Vienna had made headway toward a practical arrangement, adding: “It is my sincere hope that within the next few days, it will be possible to come to a successful conclusion.”
ISIS said the IAEA reported Iran was in the process of declaring a new Isfahan Fuel Enrichment Plant (IFEP) at the Nuclear Reactors Fuel Company site before the war.
The think tank assessed the IFEP to be inside Esfahan’s mountain tunnel complex and said US strikes destroyed tunnel entrances and ventilation systems; while Iran has restored limited access to at least one portal, the plant “does not appear to be ready for operations.”
The IAEA planned a design-information visit on June 13 but canceled it as the attacks began.
Before the strikes, the IAEA counted “125 full-sized cascades” at the three declared enrichment plants, totaling more than 20,000 IR-1, IR-2m, IR-4 and IR-6 machines. ISIS estimated the installed total was closer to 22,000, including about 14,700 advanced centrifuges.
Based on satellite imagery cited by the IAEA, Fordow “suffered very significant damage,” Natanz’s underground halls were “extensively damaged,” and the above-ground pilot plant at Natanz was destroyed early in the conflict, ISIS said.
Since June 13, the IAEA said it has received no nuclear-material accountancy reports, no updated design information questionnaires, and has had no access to safeguarded sites other than the Bushehr nuclear power plant.
It reported a “loss of continuity of knowledge” over inventories of enriched uranium, as well as over centrifuge and heavy-water production since Iran halted JCPOA-related monitoring in 2021.
Grossi said only standard measures under Iran’s Comprehensive Safeguards Agreement were under discussion, because Tehran is not applying the Additional Protocol.
He also rejected claims that IAEA data had enabled attacks on Iranian facilities, calling such allegations an “absurd narrative,” and reiterated that the agency does not share confidential inspection information with any state.
European powers have moved to reimpose UN sanctions via the “snapback” mechanism, while Tehran has demanded international condemnation of the strikes on its nuclear sites.
