Iran’s Enriched Uranium Stockpile at Isfahan Remains Unverified

The IAEA estimates Iran holds 440.9 kg (972 lb) of 60 % enriched uranium—enough for up to ten weapons—and that roughly 200 kg (440 lb) resides in tunnels at the Isfahan Nuclear Technology Center, which has not been inspected since the June 2025 attacks.

The IndependentCBC NewsForeign PolicyGrossi Claims Bulk of Iran’s Uranium Stockpile is Hidden in Isfahan Tunnels

In June 2025 Israel and the United States launched a 12-day campaign that hit three Iranian nuclear sites, including Isfahan. Satellite images show 18 blue containers entering an Isfahan tunnel on 9 June, four days before the strikes. Following the attacks, IAEA inspectors were denied access, ending on-site verification.

The Independent

Iran’s total 60 % enriched uranium totals 440.9 kg (972 lb). Roughly 200 kg (440 lb) is believed to be in Isfahan tunnels, with the remainder at Natanz and Fordow. The stockpile could theoretically support ten nuclear warheads.

The Independent

IAEA Director General Rafael Grossi says Iran must permit inspections to verify the material and seal status. President Donald Trump argues the war seeks to stop a nuclear-armed Iran, despite IAEA findings that enriched uranium likely remains. Russian President Vladimir Putin offered to remove or dilute the uranium, an offer Trump said he prefers to focus on ending the war in Ukraine. Iran’s NPT delegate asserts all enriched uranium is under IAEA supervision, while the United Arab Emirates representative links Iran’s missile attacks to nuclear concerns and urges cooperation.

The IndependentThe HillCBC NewsGrossi Claims Bulk of Iran’s Uranium Stockpile is Hidden in Isfahan Tunnels

U.S. claims that the strikes “obliterated” Iran’s nuclear program conflict with Grossi’s assessment that a substantial enriched uranium stock likely remains. Iranian officials label the U.S. narrative a false justification for further aggression. International observers argue that without on-site verification, diplomatic progress lacks a factual basis.

Grossi Claims Bulk of Iran’s Uranium Stockpile is Hidden in Isfahan Tunnels

Sources differ on the Isfahan quantity: some cite roughly half of the 972 lb total, others specify 440 lb, while market analyses mention about 1,000 lb. No independent inspection has verified seal integrity or the exact inventory.

The Independent

• “We haven’t been able to inspect or to reject that the material is there and that the seals—the IAEA seals—remain there,” — Rafael Grossi, IAEA Director General

Foreign Policy

• “I hope we’ll be able to do that, so what I tell you is our best estimate.” — Rafael Grossi

Foreign Policy

• “He told me he’d like to be involved with the enrichment — if he can help us get it. I said, ‘I’d much rather have you be involved with ending the war with Ukraine.’ To me, that would be more important,” — Donald Trump, President of the United States

The Hill

• “All of Iran’s enriched uranium has been under the IAEA’s “fullest supervision”, Iran’s delegate says.” — Iranian delegate, NPT review conference

Uranium under IAEA watch, Iran insists; UAE questions credibility

The IAEA continues talks with Russia and other partners on removing or down-blending the Isfahan material. A viable solution will require Iran to allow full inspections and demonstrable political will from all sides. The five-year NPT review later this year is expected to shape any future agreement.

Grossi Claims Bulk of Iran’s Uranium Stockpile is Hidden in Isfahan Tunnels