NPT safeguards fundamentals

Kian Sharifi, RFE/RL, reported on July 16 that Ali Vaez, director of Iran program at International Crisis Group, says the E3’s “ultimatum [on snapback] is very serious.” He [said] the West is becoming increasingly more confident that the mechanism is “leverage that should not be lost” in order to compel Iran to, at the very least, allow international inspectors to visit its nuclear sites and, at most, strike a deal with the United States. 

It continues to surprise me how little the experts on Iran understand about how inspections by the IAEA work. “Compel Iran to, at the very least, allow international inspectors to visit its nuclear sites”?? Sorry Ali and Kian, that ain’t the way it works. 

NPT safeguards fundamentals: Determined by safeguards agreement between State and IAEA based on IAEA document INFCIRC/153; State submits declarations of its nuclear material in standard documents giving locations, types, amounts, based on State’s measurements; IAEA visits locations under agreed procedures for the purpose of carrying out verification of the State’s measurements of declared nuclear material. That’s about it, under NPT. 

Under NPT, IAEA does not need nor receive information about nuclear equipment beyond what is necessary for the verification of nuclear material. Relevant example: at an enrichment facility, the nuclear material is verified in the form of uranium hexafluoride (UF6) in cylinders by weighing and measurement of uranium enrichment externally and by samplng. IAEA therefore gets access to the UF6 cylinders. It does not need to know anything much about the enrichment process equipment, i.e., the centrifuges. 

Prior to the Israeli strikes on Natanz and Isfahan, and the U.S. strikes on Fordow, Natanz and Isfahan, IAEA was regularly verifying the 60%, 20% and 2-5% uranium in UF6 cylinders at those locations. The last published results were for May 17, 2025. Following the strikes, the IAEA should return to the locations for the sole purpose of verifying material declared by Iran to IAEA to be in UF6 cylinders. The first step, at each facility, will be for Iran to reestablish and remeasure its inventory of uranium in UF6 cylinders. Next, Iran should submit documentation to IAEA on the current uranium inventories. Then, IAEA inspectors will return to the facilities to verify the new declarations. 

Let’s make up an example. At location X, on May 17, 2025, IAEA verified 100 kg of 60 % uranium in UF6 cylinders. After reconstituting the inventory at location X, Iran submits a declaration to IAEA with 25 kg 60% uranium and declares 75 kg as lost. IAEA will go to location X and verify the 25 kg and confirm the declaration. IAEA will certainly ask questions about the lost 75 kg, and Iran will provide answers. IAEA may or may not be satisfied with Iran’s answers.

Now, back to “allow international inspectors to visit its nuclear sites.” Under Iran’s NPT safeguards agreement, the obligation and mandate of IAEA is to detect the diversion of declared nuclear material and confirm that it remains in peaceful use. The above paragraphs explain the conditions on which IAEA inspectors visit nuclear sites for that purpose. They do not visit sites to determine damage to a facility or the state of equipment in the facility, or to count centrifuges. 

Yes, there is a real question of whether Iran removed material from the sites before or during the 12-day war. If so, Iran is obligated under its NPT safeguards agreement to report the relocation of the nuclear material to IAEA. That part of this story has not yet unfolded.