Recent military actions targeting Iran’s nuclear facilities have brought the unsettling science behind these operations and their profound global geopolitical implications into sharp focus. Following President Donald Trump’s announcement on Truth Social about U.S. strikes on sites like Fordow, Natanz, and Isfahan, concerns have heightened.
These strikes followed multiple Israeli air attacks on Iranian nuclear facilities since June 13, targeting research reactors, enrichment plants, and other key sites. Satellite imagery reveals significant damage, raising serious concerns about Iran’s nuclear program and the potential for radiological and chemical releases into the environment.
Speaking at the UN Security Council, Rafael Grossi, the director-general of the International Atomic Energy Agency (IAEA), addressed the immediate aftermath. He stated that “no radiological release has affected the public,” which provided some initial reassurance regarding off-site contamination. However, he added a crucial caveat, noting that “[Israel’s] attacks on Iranian nuclear sites have caused a sharp degradation in nuclear safety and security.”
Since June 13, several key Iranian nuclear sites, including the Natanz enrichment facilities, four buildings at Isfahan, and a research reactor at Khondab, have sustained damage. While the IAEA confirmed no external radiation increase, there’s a risk of toxic chemicals and radiological contaminants dispersing internally, particularly at the underground Natanz enrichment plant.
A critical concern is Iran’s estimated 9,250 kilograms of enriched uranium as of May 17, according to the IAEA. This inventory includes 8,400 kilograms of uranium hexafluoride gas, 620 kilograms of uranium oxide, 71 kilograms of uranium metal, 4 kilograms of uranium in targets, and about 140 kilograms of uranium scrap, which is essentially radioactive waste.
Notably, the IAEA estimates over 400 kilograms of uranium hexafluoride gas has been enriched to 60 percent, a level considered highly enriched uranium and a significant step toward weapons-grade material, though not yet there. Non-proliferation expert Ian Stewart points out that this 60-percent enriched material is outside international oversight and could be sufficient for approximately 10 nuclear weapons, posing an immediate proliferation risk.
A troubling unknown factor is the current location of Iran’s highly enriched uranium stockpile. It is not publicly known precisely where this material is stored. There is speculation that it could potentially already be under the control of Iran’s Islamic Revolutionary Guard Corps (IRGC) and moved to one of several secret facilities. Adding weight to this concern, a senior IRGC official reportedly stated on Thursday that all the enriched uranium had been preventively transferred to hidden locations.
Furthermore, Iran might possess undisclosed centrifuges at alleged secret sites, which could accelerate the enrichment of its 60-percent uranium stockpile toward weapons-grade material. Experts suggest these advanced centrifuges might already be operational, potentially shortening the timeline for Iran to reach a weapons capability.
Mined uranium naturally contains less than 1 percent of the fissile isotope uranium 235, the material capable of sustaining nuclear chain reactions. The process of enriching uranium from this natural concentration to 60 percent uranium 235 is considerably more time-consuming than the final step of further purifying 60-percent uranium 235 to a 90-percent concentration. The 90-percent level is widely recognized as the standard for “weapons grade” material.
Experts estimate that, starting from 60-percent enriched uranium, it could take Iran as little as five to six days to complete this final step and enrich enough uranium for a single nuclear weapon. While the prospect of Iran weaponizing this material is an extremely urgent and rightly focused concern, it is not the sole potential risk stemming from the country’s nuclear stockpile, especially in the context of military strikes.
Even if the enriched uranium isn’t being actively processed for weapons, its sheer presence and storage conditions pose inherent risks of contamination or radiation exposure, irrespective of external attacks or accidental incidents. The exact whereabouts and storage conditions of this material remain largely unknown, amplifying the potential danger.
Storing a large quantity of enriched uranium hexafluoride gas in tanks within confined areas presents a significant chemical risk, especially if these storage facilities were targeted. The lack of precise information about the exact quantities and storage conditions further intensifies this potential hazard, making it difficult to assess the full scope of the threat.
Hurried transport or improper storage conditions for nuclear materials could also substantially increase the risk of exposure to toxic chemicals. Uranium hexafluoride gas, while not directly fissile itself, undergoes a dangerous reaction if moisture comes into contact with transport or storage cylinders. When water is present, uranium, especially enriched uranium, becomes more reactive, potentially creating conditions conducive to a nuclear fission chain reaction.
A chemical reaction could escalate, potentially causing an explosion of the cylinders and leading to a widespread dispersion of uranium hexafluoride gas both within the facility and into the surrounding environment. This scenario, resulting in substantial contamination, could occur even without an external military attack due to unsafe handling or storage practices.
To better understand the potential for radiological contamination from the Israel-Iran conflict, experts have analyzed risks based on pre-attack public information about Iran’s nuclear sites. However, a truly accurate assessment requires complete and current knowledge of the nuclear material inventories’ chemical properties, quantities, and storage conditions, information that is currently unavailable.
