IAEA estimates Iran's enriched uranium stockpile despite challenges, reports enrichment levels of up to 60%

The quarterly report by the International Atomic Energy Agency (IAEA) on Iran's nuclear programme, dated 31 May, was officially released by the agency on 11 June. According to the report, titled Verification and monitoring in the Islamic Republic of Iran in light of United Nations Security Council resolution 2231 (2015) , Iran's total enriched uranium stockpile is estimated to be 3,241 kg: a 273.2 kg increase since the previous report in February. The total stockpile includes uranium in the form of uranium hexafluoride gas (UF6), uranium oxides and their intermediate products, uranium in fuel assemblies and rods, and in liquid and solid scrap.

Of the total stockpile, enriched uranium in the form of UF6 is estimated to be 3,206.3 kg. This includes 1,367.9 kg of uranium enriched up to 2% U-235, 1,773.2 kg enriched up to 5% U-235, 62.8 kg enriched up to 20% U-235, and 2.4 kg enriched up to 60% U-235.

Notably, the increase of 273.2 kg in the total stockpile since the previous report is significantly lower than the increase of 524.9 kg in the reporting period between November 2020 and February this year. One of the likely factors affecting the relatively low increase in the stockpile amount could be the sabotage incident at the Natanz Uranium Enrichment Complex in April that resulted in damage to several IR-1 centrifuges at the underground fuel enrichment plant (FEP) at Natanz. Another likely factor could be the diversion of the low-enriched uranium (LEU) stockpile towards producing uranium up to 20% and 60%.

Monitoring challenges