Status of Iran's uranium enrichment: Explained

Iran's uranium enrichment program has been a focal point of international tensions, particularly after the US and Israel conducted airstrikes on Iranian nuclear facilities in June 2023. Before these strikes, Iran was enriching uranium to up to 60% purity, which is a step away from the roughly 90% purity required for a nuclear weapon, according to the International Atomic Energy Agency (IAEA).

The IAEA estimates Iran had 440.9 kg of uranium enriched to 60% at the time of the attacks, enough to potentially construct 10 nuclear weapons if further enriched.

The IAEA, which had access to all declared nuclear sites, including Iran's enrichment plants, until the US-Israeli bombing, has been unable to verify the fate of Iran's enriched uranium since then. Iran has not provided information on how much of its enriched uranium survived the attacks or disclosed its whereabouts. The only above-ground enrichment plant, at Natanz, was destroyed, while the others at Natanz and Fordow were heavily damaged and are presumed out of operation.

However, Iran had recently opened a new enrichment facility at Isfahan, a network of tunnels believed largely unaffected by the airstrikes. The IAEA is uncertain about the status of this facility or its potential nuclear material. While some of Iran's 60% enriched uranium may have been destroyed in the strikes, the IAEA estimates that around 200 kg remains in the Isfahan complex, along with some at Natanz.

US Vice President Kamala Harris questioned Iran's claim of not seeking nuclear weapons by pointing out the practicality of 60% enriched uranium, which is close to the threshold for weapons-grade material. She suggested that a meaningful reduction in Iran's enrichment capacity would be necessary to satisfy US demands and end the conflict. However, the exact steps Iran would need to take to reduce its enrichment capacity remain unclear, as the details of its current program are largely unknown.