https://www.aa.com.tr/en/americas/us-weighs-special-forces-operation-to-seize-irans-enriched-uranium-stockpile-report/3873626
"The operation would be extraordinarily complex. Much of Iran's uranium stockpile, estimated at around 450 kilograms (992 pounds) enriched to 60%, lies buried beneath nuclear sites already bombed in last summer's US strikes..."