Bulletin of the Atomic Scientists

Satellite imagery shows that Iran could have transferred to Isfahan up to 540 kilograms—possibly all—of its highly-enriched uranium inventory before the June strikes last year.

Working with a team of visual investigators that included the Bulletin, the French newspaper Le Monde has analyzed a previously unreported satellite image of the Iranian nuclear site at Isfahan, showing a large truck loaded with containers. In a Le Monde article published Saturday, experts said they could not be certain what the containers held. But the timing of the image, the type of load, and other indirect evidence suggest that Iran may have placed a significant quantity of highly enriched uranium—possibly all of its inventory—at the facility ahead of the June 2025 strikes by Israel and the United States against Iranian nuclear sites.

The International Atomic Energy Agency (IAEA) has mentioned the possible presence of highly enriched uranium at the Isfahan nuclear complex several times—a presence implicitly acknowledged by Iran’s own recent declarations. The IAEA has made multiple requests but was unable to access the underground tunnel complex at Isfahan, which was spared during Israeli and American military strikes in June. The satellite image could be the first publicly available evidence of the presence of highly enriched uranium at Isfahan.

According to Le Monde investigators, who have reviewed many satellite images of the entrance to Isfahan and other Iranian nuclear sites, it is the first time they have seen this type of convoy at the facility. Le Monde informed the Bulletin about the image on March 19. What follows is a detailed visual and technical analysis supporting my assessment that the cargo may have been highly enriched uranium.
Satellite view of the Isfahan Nuclear Technology Center and tunnel entrances.South tunnel entrance of the Isfahan underground complex near the Isfahan Nuclear Technology Center, Iran. (Bulletin / Google Earth)

The context. In June 2022, Iran turned off IAEA surveillance cameras at key nuclear sites in Iran, including monitoring devices at Natanz and Fordow. The shutdown was a direct retaliation for a resolution passed by the IAEA board of governors that criticized Iran for not explaining the presence of uranium traces at three sites it had not declared to be part of its nuclear program. Then, in February 2023, Bloomberg reported that IAEA monitors at Fordow had detected traces of uranium enriched to 84 percent of uranium 235, a fissile isotope that can be used in nuclear weapons, just 6 percent shy of weapon-grade level.

The IAEA never confirmed the report, saying that it was talking with Iran about recent findings there. Iran denied it, and cameras were gradually restored to operation at Iranian nuclear facilities in May 2023.

The last confirmed physical visit by IAEA Director General Rafael Grossi to the Natanz Fuel Enrichment Plant (FEP) and Fordow Fuel Enrichment Plant (FFEP) occurred on November 15, 2024. Since then, the IAEA has relied on its own estimates, based on Iran’s declarations, intelligence from member states, and high-resolution commercial satellite imagery.

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much more @

https://thebulletin.org/2026/03/analysis-iran-likely-transferred-highly-enriched-uranium-to-isfahan-before-the-june-strikes/