Key Iran Nuclear Enrichment Site of Natanz Shows No Sign of Breach 

(Bloomberg) -- The United Nations’ atomic watchdog said there are no indications of increased radiation levels at Iran’s main uranium-enrichment site, an early sign that Israel’s strikes have not 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. Israel hasn’t carried out any 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, have been hit by Israel, IAEA Director General Rafael Mariano Grossi said in a statement. He’s expected to address the agency’s board of governors later Friday in Vienna, which convened this week to discuss Iran’s nuclear work. 

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

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, IAEA Director General Rafael Mariano Grossi estimated the enrichment hall is a half kilometer below the surface.

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 Vienna-based IAEA said in a statement that its inspectors are still in the country, and that 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 IAEA conducted more than 400 inspections in Iran, keeping track of the Islamic Republic’s uranium stockpile to gram levels.

(Updates with additional nuclear site details in the third paragraph)

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