No sign of breach detected at Iran's key nuclear enrichment site in Natanz

By Jonathan Tirone

  The United Nations atomic watchdog said there’s no indication of increased radiation levels at Iran’s main uranium-enrichment site, an early sign that Israel’s strikes haven’t penetrated the containment layers protecting the Islamic Republic’s nuclear stockpile. 

Iranian authorities told the International Atomic Energy Agency they haven’t observed higher radiation doses at the Natanz facility, located about 300 kilometers (186 miles) south of Tehran. No radiological or chemical contamination has spread beyond the site, according to an IAEA statement.  

“Radiation levels outside the Natanz facility remained unchanged,” IAEA Director General Rafael Mariano Grossi wrote on X. “The type of radioactive contamination present inside the facility, mainly alpha particles, can be managed with appropriate protective measures.” 

Israel hasn’t carried out raids against Iran’s Bushehr nuclear power plant on the shore of the Persian Gulf, the authorities said. Neither Iran’s heavily-protected enrichment site at Fordow, 200 kilometers south of Tehran, or its uranium-conversion facility, 400 kilometers south of the capital, were hit, Gross wrote earlier.   

Israel’s Prime Minister Benjamin Netanyahu has said the attacks “will continue for as many days as it takes to remove this threat.” 

The Israeli Air Force said in a statement that the Natanz strike hit an underground multistory chamber with centrifuges, electrical rooms and other infrastructure. Targets included equipment key to the site functioning, it said. 

Only the strongest conventional munitions are capable of penetrating Iran’s enrichment sites. The Natanz facility was built more than 40 meters (131 feet) underground and is protected by a steel and concrete shell, which researchers estimate to be some 8 meters thick. Similarly in Fordow, the enrichment hall is built into the side of a mountain. After a recent visit, Grossi estimated the hall is a half kilometer below the surface. 

Addressing the agency’s board of governors in Vienna, which convened this week to discuss Iran’s nuclear work, Grossi said he’s “deeply concerned” by Israel’s military action. The attack breaches international legal norms, Grossi said, urging “maximum restraint” by both countries.  

“Nuclear facilities must never be attacked, regardless of the context or circumstances, as it could harm both people and the environment,” Grossi told the IAEA’s board of governors on Friday, in his first detailed assessment of the attacks. “Such attacks have serious implications for nuclear safety, security and safeguards, as well as regional and international peace and security.”   

There are still plentiful above-ground targets including power lines, transformers, labs and testing facilities. Choking off the flow of electricity is likely to have already forced Iran to begin the procedure of bringing centrifuges to a halt — that process to stop the machines, which spin at supersonic speeds to separate uranium isotopes, can take days. 

The IAEA said in a statement that its inspectors are still in the country, and it’s in touch with Iranian authorities about potential radiation releases. Iran warned the agency in a May 22 diplomatic note that it would take “special measures” to protect its stockpile of nuclear material in the event of an Israeli strike.  

Last year, the agency conducted more than 400 inspections in Iran, keeping track of the Islamic Republic’s uranium stockpile to gram levels.