Iran’s Highly Enriched Uranium Likely Remains Buried at Isfahan Amid Ongoing Conflict

IAEA Director General Rafael Grossi told the Associated Press that satellite imagery shows a truck carrying 18 blue containers entering a tunnel at the Isfahan Nuclear Technology Center on 9 June 2025. The containers are believed to hold highly enriched uranium (HEU). Grossi said the International Atomic Energy Agency “has not been able to inspect or to reject that the material is there and that the seals — the IAEA seals — remain there,” and that “our best estimate” is that a large portion of the stockpile is still in the tunnels.

Times of IsraelTimes of IsraelThe IndependentGrossi Claims Bulk of Iran’s Uranium Stockpile is Hidden in Isfahan TunnelsIran’s Highly Enriched Uranium Likely Still at Isfahan: GrossiRussia participates in negotiations on a plan to remove uranium from IranThe HillForeign Policy

In June 2025 Israel launched a 12-day war that included U.S. strikes on three Iranian nuclear sites, after which IAEA inspectors were barred from Isfahan. Subsequent U.S.–Israeli operations this year caused only limited additional damage. Iran’s nuclear facilities at Natanz and Fordow also remain inaccessible to inspectors.

Times of IsraelTimes of IsraelThe IndependentForeign PolicyGrossi Claims Bulk of Iran’s Uranium Stockpile is Hidden in Isfahan TunnelsIran’s Highly Enriched Uranium Likely Still at Isfahan: GrossiWION

The IAEA reports that Iran possesses 440.9 kg (972 lb) of uranium enriched to 60 % purity, a short step from weapons-grade (90 %). Grossi estimates roughly 200 kg (about 440 lb) of this material is stored in Isfahan’s underground tunnels. He has warned that the total stockpile could theoretically support up to ten nuclear weapons. A separate source claims an “11-ton” stockpile, creating a notable discrepancy.

Times of Israel

If the HEU can be retrieved, Iran could “access its stockpile of near weapons-grade uranium,” raising proliferation concerns for the United States, Israel, and the broader Middle East. The material also underpins the diplomatic stalemate over the Strait of Hormuz, a key conduit for global oil and gas flows that remains constrained by the eight-week war.

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

• IAEA: Grossi emphasized that removal or dilution of the material is essential, stating “what’s going to be important is that material leaves Iran” and that any deal without verification “is an illusion.” The agency is in talks with Russia and other partners about a possible extraction, and it participated in U.S.–Iran nuclear talks in February but not in recent cease-fire negotiations.

Times of Israel

• United States: President Donald Trump asserted that the war’s primary purpose was to deny Iran a nuclear weapon, rejected Iran’s proposal to reopen the Strait of Hormuz in exchange for lifting the blockade, and downplayed Russia’s offer to assist, saying he would rather see Putin “be involved with ending the war with Ukraine.”

Times of Israel

• Russia: President Vladimir Putin reiterated an offer to help the United States manage Iran’s enriched uranium, a proposal the U.S. has not embraced.

Russia participates in negotiations on a plan to remove uranium from Iran

• Iran: Tehran maintains its nuclear program is peaceful and has offered to reopen the Strait of Hormuz if the U.S. ends its naval blockade, while postponing more complex nuclear negotiations.

Bloomberg

Experts cited by *Scientific American* argue that a unilateral removal operation would be “unlike any mission the U.S. military has tried before,” requiring heavy earth-moving equipment, prolonged security perimeters, and cooperation from Iranian scientists—factors that make the plan highly risky without Iranian consent.

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

• Quantity Discrepancy: IAEA figures (440.9 kg total, ~200 kg at Isfahan) contrast with a WION report describing an “11-ton” stockpile.

Times of Israel

• Location Uncertainty: No on-site inspections have occurred since June 2025, leaving the exact status of seals, containers, and possible leakage unverified.

Times of Israel

• Verification Gap: The IAEA’s inability to confirm the material’s presence hampers confidence in any removal or dilution plan.

The Hill

• “we continue to get information.” — Rafael Grossi, IAEA Director General

Times of Israel

• “An agreement without verification is an illusion.” — Rafael Grossi

Bloomberg

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

Times of Israel

• “what’s going to be important is that that material leaves Iran” — Rafael Grossi

Times of Israel

• “They don’t know how to sign a nonnuclear deal. They better get smart soon!” — Donald Trump, Truth Social post

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, phone call with Vladimir Putin

The Hill

The IAEA plans to resume inspections at Isfahan, Natanz, and Fordow once security conditions allow. Ongoing diplomatic talks involve the United States, Russia, and Iran about either extracting the HEU or blending it to lower enrichment levels. Grossi stressed that “political will” from Tehran is required for any agreement, and the agency will continue to monitor satellite data while seeking a verification framework that could end the current impasse.

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