Vienna-based analysts said spiraling tensions around Iran’s crackdown on protests and broader U.S.-Iran hostility raise concerns about possible nuclear risks, including the protection of Iran’s highly enriched uranium stockpile and the security of nuclear facilities.
The concerns come as U.S.-Iran relations remain tense. The report said U.S. President Donald Trump, reacting to comments from Supreme Leader Ayatollah Ali Khamenei, called Saturday for an end to Khamenei’s nearly 40-year reign. It said Khamenei had branded Trump a “criminal” for supporting protesters in Iran and blamed demonstrators for causing thousands of deaths.
The analysis also referenced regional military movements. The Associated Press reported that a U.S. aircraft carrier that days earlier had been in the South China Sea passed Singapore overnight to enter the Strait of Malacca, putting it on a route that could bring it to the Middle East.
Against that backdrop, analysts warned that internal upheaval in Iran could undermine safeguards for nuclear assets. David Albright, a former nuclear weapons inspector in Iraq and founder of the nonprofit Institute for Science and International Security in Washington, said that in a scenario of internal chaos Iran’s government could “lose the ability to protect its nuclear assets.” He said Iran’s highly enriched uranium stockpile “would be the most worrisome” and suggested there is a possibility someone could steal some of the material.
The report noted that similar dangers have existed before. It said that after the Soviet Union’s collapse in 1991, highly enriched uranium and plutonium suitable for building nuclear bombs went missing amid eroded security and weakened protection. It added that Iran had maintained control of its sites so far, including after the U.S. bombed them during a 12-day war in June launched by Israel against the Islamic Republic.
The Associated Press cited the International Atomic Energy Agency as describing a 60%-purity stockpile figure for Iran. It said Iran has a stockpile of 440.9 kilograms (972 pounds) of uranium enriched up to 60% purity, described by the Vienna-based IAEA as a short, technical step away from weapons-grade levels of 90% purity. The report said the agency has not been able to verify the status and location of that stockpile since the June war and said it lost “continuity of knowledge in relation to the previously declared inventories of nuclear material in Iran” at facilities affected by the war.
A diplomat close to the IAEA confirmed the ongoing verification gap, the report said, adding that the agency had still not received information from Iran on the status or whereabouts of the highly enriched uranium stockpile. The diplomat spoke on condition of anonymity in line with diplomatic protocol.
Albright also described how the stockpile could be handled if security faltered. He said the highly enriched uranium stockpile would fit in around 18 to 20 cylinders designed for transport, weighing around 50 kilograms (110 pounds) each when full, and he said “Two people can easily carry it” for each container.
Kelsey Davenport, director for nonproliferation policy at the Washington-based Arms Control Association, said the risk includes diversion or theft. She said the stockpile “could be diverted either to a covert program or stolen by a faction of the government or the military that wanted to retain the option of weaponization,” and she said the risk increases as the Iranian government feels threatened or becomes destabilized. Davenport also said some nuclear material could be smuggled out of Iran or sold to non-state actors if Iran experienced internal chaos or a potential government collapse. She stressed that “The risk is real but it is difficult to assess, given the unknowns regarding the status of the materials and the whereabouts.”
Beyond diversion, the analysts discussed the theoretical possibility of building a nuclear device with 60%-enriched uranium, while emphasizing the practical challenges. Eric Brewer, a former U.S. intelligence analyst and now deputy vice president at the Nuclear Threat Initiative, said the possibility should not be “totally dismissed” but that most information suggests the highly enriched uranium “remains buried in a tunnel as a result of the U.S. strikes.” He said the material is probably not easily accessible to the regime without major risk of detection and another strike by the U.S. or Israel, and he added that recent events “have also shown that the Supreme Leader has a very high bar for any decision to weaponize.”
Brewer said a weapon made directly from 60% enriched uranium would require more material than a device built from 90% purity, and he said it would be “much bigger and bulkier and probably not well suited to delivery” on a missile. He said such a device could still be “blown up in the desert,” for example.
The report also raised the possibility of sabotage aimed at disrupting Iran’s nuclear operations. Albright said that in internal chaos, Iran’s nuclear power reactor in Bushehr could be sabotaged or targeted to cause havoc or make a political point. It said Bushehr is Iran’s only commercial nuclear power plant, about 750 kilometers (465 miles) south of Tehran, and that it is fueled by uranium produced in Russia, not Iran.
Albright told the report there has been no sign of Iran losing command and control of its security forces. He pointed to an attack by the African National Congress’s armed wing on South Africa’s Koeberg Nuclear Power Station near Cape Town in 1982, saying the sabotage caused significant damage but resulted in no nuclear fallout. He also warned: “If the Bushehr reactor has a major accident, the winds would carry the fallout within 12 to 15 hours to the United Arab Emirates, Saudi Arabia and Oman.”