Since eight years ago when President Trump pulled out of a nuclear deal with Tehran, Iran has accumulated 22,000 pounds, or 11 tons, of enriched uranium. But the fate of Iran’s stockpile remains a mystery, two months after the United States began a war meant to prevent Iran from ever building an atomic bomb.

Uranium can light cities or destroy them. Low concentrations can power nuclear reactors. Higher concentrations, from a process called enrichment, can make nuclear bombs.

Uranium enrichment gets increasingly easy and fast as concentrations rise. It’s much harder to get to 20 percent from 0 percent than to 60 percent from 20 percent, or even to 90 percent — the preferred level for making nuclear arms.

In June 2025, during the 12-day war, the United States bombed Iran’s enrichment plants at Natanz and Fordow, as well as its uranium storage tunnels at Isfahan. One month later, Iran suspended cooperation with the I.A.E.A., ending the monitoring of the nation’s enrichment sites.

https://www.nytimes.com/interactive/2026/04/29/science/iran-enriched-uranium-stockpile-nuclear-energy-bomb.html?smid=nytcore-ios-share