Nearly half of Iran’s uranium enriched to up to 60% purity, just short of weapons grade, was stored in a tunnel complex at Isfahan and is likely still there, International Atomic Energy Agency (IAEA) chief Rafael Grossi said Monday, according to Reuters.
The tunnel complex appears to be the only site not heavily damaged during attacks carried out last June by Israel and the US on Iran’s nuclear facilities.
Diplomats have long said the Isfahan facility has been used to store uranium enriched to 60%. The IAEA confirmed in a report to member states last month that such material was stored there, though the report did not specify the quantity.
The IAEA estimates that when Israel launched its first strikes in June, Iran possessed 440.9 kilograms of uranium enriched to 60%. According to an IAEA yardstick, if enriched further that amount would be enough fissile material for 10 nuclear weapons.
“What we believe is that Isfahan had until our last inspection a bit more than 200 kg, maybe a little bit more than that, of 60% uranium," Grossi told reporters in Paris.
He said the stockpile was “mainly" stored at Isfahan and suggested that some material located elsewhere may have been destroyed during the attacks.
“The widespread assumption is that the material is still there. So we haven't seen - and not only us, I think in general all those observing the facility through satellite imagery and other means to see what's going on there - movement indicating that the material could have been transferred," Grossi said.
Iran has not informed the IAEA about the status or location of its highly enriched uranium since the June strikes, and has not allowed agency inspectors to return to the nuclear facilities that were bombed.
All three known Iranian uranium enrichment plants that had been operating before the attacks, two at Natanz and one at Fordow, were destroyed or severely damaged in June.
Grossi said that some of the enriched uranium may also remain at another site.
“There is an amount (of 60% uranium) in Natanz also, which we believe is still there," he said.
Last week, Grossi expressed concerns over Iran’s stockpile of near-weapons-grade enriched uranium, as well as its refusal to allow IAEA inspections.
“I have been very clear and consistent in my reports on Iran’s nuclear program: While there has been no evidence of Iran building a nuclear bomb, its large stockpile of near-weapons-grade enriched uranium and refusal to grant my inspectors full access are cause for serious concern," Grossi wrote in a post on social media.
“For these reasons," he added my previous reports indicate that unless and until Iran assists the IAEA in resolving the outstanding safeguards issues, the Agency will not be in a position to provide assurance that Iran’s nuclear program is exclusively peaceful," he added.