Background and Report Content

• This report summarizes and assesses information in the International Atomic Energy Agency’s (IAEA) quarterly report, dated September 3, 2025: Verification and monitoring in the Islamic Republic of Iran in light of United Nations Security Council resolution 2231 (2015), including Iran’s compliance with the Joint Comprehensive Plan of Action (JCPOA), as well as new findings in the IAEA’s companion report, NPT Safeguards Agreement with the Islamic Republic of Iran.  Context and commentary are added on aspects omitted from these reports.
• The reports are the first quarterly reports since the 12-Day War in June, when Israel and the United States attacked Iran’s nuclear facilities, causing substantial damage and destruction to Iran’s sensitive nuclear sites.  During the war, the IAEA temporarily “stopped all in-field verification and monitoring activities in Iran for safety reasons.”  The IAEA reports that “by the end of June 2025, the Agency had decided to withdraw all of its inspectors from Iran for safety reasons.”  According to media reporting, these safety reasons included threats from the regime.^[1]  Iran formally suspended IAEA cooperation in July.  Iran subsequently allowed two inspectors to observe refueling of the Bushehr nuclear power plant, but the inspectors reportedly had to leave Iran afterward. Iran has refused to allow inspectors access to all other sites, including to a new enrichment facility at Esfahan, aka Isfahan, that was under construction prior to the war, and to provide updates on the location of its enriched uranium stockpiles.
• Iran’s enriched uranium stockpiles in the form of uranium hexafluoride on the eve of the start of the war included 440.9 kg (U mass) of uranium enriched up to 60 percent U-235, 184.1 kg (U mass) of uranium enriched up to 20 percent U-235, 6024.4 kg (U mass) of uranium enriched up to 5 percent U-235 and 2391.1 kg (U mass) of uranium enriched up to 2 percent U-235.
• A priority is knowing the location and status of the 60 percent enriched uranium, which is highly enriched uranium (HEU) and directly usable in a nuclear explosive.  The IAEA states that under the comprehensive safeguards agreement, HEU stockpiles need to be verified once a month, or every 30 days. The IAEA emphasizes that “Iran’s inventory of HEU, the only NPT non-nuclear weapon State to have produced such nuclear material, is a matter of serious concern.  The Agency has not had access to verify this specific nuclear material in Iran for over two and a half months, which means that its verification – according to standard safeguards practice – is overdue.”
• The IAEA reports that since June 13, the day the bombing began, it has little to no information about Iran’s nuclear material stockpiles or nuclear sites.  It has “not received nuclear material accountancy reports and updated design information questionnaires (DIQs) and has not had access to any safeguarded nuclear facilities in Iran, with the exception of the Bushehr Nuclear Power Plant (BNPP).”  The IAEA calls for “full resumption of Agency inspections […] without delay” a request that Iran refuses.  The IAEA notes that while the withdrawal of inspectors during the war was necessary, Iran’s subsequent actions to suspend cooperation with the IAEA are “deeply regrettable.”
• To partly compensate for the lack of on-ground inspections, the IAEA is using commercial satellite imagery and other reporting to determine the status of nuclear sites and nuclear material, although the inadequacy of these approaches is evident in the reports.
• The IAEA reports on its efforts to restore access with Iran since the war.  Per media reports, IAEA Director General Rafael Grossi said the status quo is “not something that can go on for months on end” and has refused as contrary to Iran’s legal safeguards obligations its requests to implement safeguards “a la carte.”^[2]
• To further discussions on resuming inspections, Grossi indicated his willingness to meet Iran “in Vienna or elsewhere,” notably omitting an offer to travel to Iran.  This omission may be related to recent media reporting that Grossi requires round-the-clock security from Austrian security services due to ongoing threats from the Iranian regime.^[3]

Overall Institute Assessment

Highlights

• The military attacks destroyed or made inoperative all of Iran’s installed centrifuges—almost 22,000 gas centrifuges—at Iran’s three enrichment sites.  They destroyed Iran’s ability to make gas centrifuges, severely degraded its capabilities to research and develop them, and destroyed Iran’s ability to make uranium hexafluoride.  In essence, the attacks destroyed Iran’s gas centrifuge enrichment program.
• With the massive destruction of its gas centrifuge program and installed centrifuge cascades, for the first time in over 15 years, Iran has no identifiable route to produce weapon-grade uranium (WGU) in its centrifuge plants.  In addition, the attacks caused immense destruction to Iran’s ability to make the nuclear weapon itself.  For the first time in over 15 years, no breakout estimate to WGU is included in the Institute reporting on the IAEA reports, since to do so would require unsubstantiated speculation about the existence and operability of centrifuges that were not destroyed in the war, such as centrifuges already made but not yet deployed, as well as about the availability of enriched uranium stocks, whether near five percent, near 20 percent, or 60 percent enriched uranium.
• Iran’s stock of 60 percent enriched uranium can be used directly in a nuclear explosive.  Practically, 40 kg are sufficient for an implosion-type nuclear weapon and double that amount, or 80 kg, is sufficient for a gun-type nuclear explosive device.[4]  Iran’s ability to develop and make nuclear explosives has been severely degraded by the war.  Thus, estimates of the time it would take Iran to turn the HEU into a nuclear explosive are fraught with uncertainty.
• The IAEA reports that Iran intended to establish a new enrichment plant, named the “Isfahan Fuel Enrichment Plant” (IFEP) at the Nuclear Reactors Fuel Company (NRFC) site, although the IAEA reports do not provide its location.  The authors assess that it is in the mountain complex at the main Esfahan nuclear site.  The IAEA language implies that portions of the facility had already been built, although centrifuges were unlikely to have been installed.  U.S. attacks destroyed the three tunnel entrances to this site, which included ventilation equipment servicing the tunnel complex.  Iran subsequently gained access to at least one of three tunnel entrances, but visible damage remains, and the plant does not appear to be ready for operations.
• Iran held enriched uranium at all three main nuclear sites: Natanz, Fordow, and Esfahan.  There are no indications that Iran moved stocks outside of these three sites, but the exact location and amounts of enriched uranium within facilities at the sites is unknown.
• Iran likely stored most of its lower enriched uranium stocks at Natanz.  Fordow and Natanz also made HEU and held stocks of HEU there, with Fordow holding the far larger amount.  However, it is well known that Iran had moved significant portions of its 20 and 60 percent stockpiles to the Esfahan site, and portions of these stocks, along with lower enriched uranium stocks, were in buildings subsequently destroyed or damaged. Fearing an attack, Iran likely moved portions of its enriched uranium stocks, particularly its HEU stock at Esfahan, into the Esfahan tunnel complex associated with the nuclear site.  When it was building the tunnel complex two decades ago, Iran declared it as a potential storage site for nuclear material in the event of military strikes and the IAEA has confirmed that the tunnel complex is used for the storage of enriched material.
• The IAEA reports that it “lost continuity of knowledge in relation to the current inventories of nuclear material in Iran, including low enriched uranium (LEU) and high enriched uranium (HEU), which urgently needs to be addressed.”  It adds that it had “already lost continuity of knowledge in relation to the production and current inventory of centrifuges, rotors and bellows, heavy water and UOC [uranium ore concentrate], which it will not be able to restore.”
• The IAEA reports no new progress and no engagements with Iran regarding unresolved safeguards issues that the agency has been investigating since 2018.

Damage Assessments

The IAEA reports list many of the main Iranian facilities attacked by Israel and the United States during the 12-Day War. The following summarizes the main activities and sites affected.  Because the IAEA provides little information about the extent of damage or any satellite imagery showing the damage, additional information is added to clarify the IAEA reporting. 

In most cases, more information about the attacks on particular sites is available publicly, such as on the Institute website or its social media posts during the war. 

In an omission, the IAEA does not list sites reportedly linked to Iranian nuclear weaponization work that were attacked. Assessments of the known weaponization sites can be found on the Institute website.^[5] 

Sites Containing Nuclear Material: The IAEA reports that the facilities known to have contained nuclear material and affected by the military attacks were the Fordow Fuel Enrichment Plant (FFEP); the Fuel Enrichment Plant (FEP) at Natanz; the Pilot Fuel Enrichment Plant (PFEP) at Natanz; the Uranium Conversion facility (UCF) at Esfahan which makes all the natural uranium hexafluoride and natural uranium metal; the Fuel Manufacturing Plant (FMP) at Esfahan which makes low enriched uranium fuel; the Fuel Plate Fabrication Plant (FPFP) at Esfahan which makes fuel and targets for the Tehran Research Reactor and enriched uranium metal; and the Enriched UO₂ Powder Plant (EUPP) at Esfahan, also associated with making low enriched uranium fuel. Although the tunnel complex at Esfahan is officially declared by Iran to be part of the Esfahan nuclear site, the IAEA report does not explicitly mention it above.  Likewise, it does not mention any other facilities storing enriched uranium at Esfahan, such as site-wide shipping and receiving buildings, which are listed in past IAEA publications as slated to hold enriched uranium stocks.   

Enriched Uranium Stockpiles: The IAEA estimates that as of June 13, 2025, the day on which military attacks began, Iran had an estimated stockpile of 9040.5 kg (U mass) in the form of uranium hexafluoride, and 834.4 kg (U mass) of enriched uranium in forms other than UF₆.  The enriched uranium stockpile in the form of uranium hexafluoride included 440.9 kg (U mass) of uranium enriched up to 60 percent U-235, 184.1 kg (U mass) of uranium enriched up to 20 percent U-235, 6024.4 kg (U mass) of uranium enriched up to 5 percent U-235 and 2391.1 kg (U mass) of uranium enriched up to 2 percent U-235.  The report notes that this represents an increase in the 60 percent HEU stock by 32.3 kg (U mass) since May 17, the date of the previous quarterly stockpile reporting.  It also represents a decrease of 90.4 kg (U mass) in the stock of near 20 percent enriched uranium, an increase of 515.6 kg (U mass) in the 5 percent enriched uranium stock, and an increase of 169.7 kg (U mass) in the up to 2 percent enriched uranium stock.  This appears consistent with previous monthly average production rates.  The IAEA previously reported that of the enriched uranium stock in forms other than UF₆, 60.6 kg are up to 20 percent enriched uranium and 2 kg are up to 60 percent HEU. 

Enriched Uranium Status: The IAEA reports that on June 13, it received a letter from Iranian Foreign Minister Abbas Araghchi indicating Iran would “adopt special measures to protect our nuclear equipment and materials.” The Director-General replied the same day that “any transfers of nuclear material from a safeguarded facility to another location in Iran must be declared to the Agency, as required under Iran’s NPT Safeguards Agreement and expressed his readiness to work with Iran on the matter.” 

Most reports indicate the enriched uranium stockpiles remain at their original sites.  For example, on August 27, Director-General Grossi stated to the press that “satellite imagery show no evidence that nuclear material has been moved.”^[6] Thus, it does not appear that Iran has moved enriched uranium away from the declared nuclear sites.  This means that the vast bulk of the material that was less than five percent enriched is still at Natanz and Fordow.  Significant amounts of near 20 percent enriched uranium and near 60 percent HEU are also at Fordow and Natanz, but also at Esfahan.  However, Iran may have moved the enriched uranium stocks within the Esfahan site, in a declared or undeclared manner, including significant amounts of the HEU.  Overall, a significant amount of highly enriched uranium may now be in the Esfahan mountain complex and buried in the Fordow site. 

Enrichment activities: The IAEA notes that prior to the attacks, there were “125 full-sized cascades installed in Iran’s three previously declared enrichment facilities, containing a total of over 20,000 centrifuges (of the types IR-1, IR-2[m], IR-4, and IR-6).”  The Institute estimates, based on previous IAEA reporting, that Iran had close to 22,000 centrifuges installed, of which 14,700 were advanced centrifuge types. 

• FFEP: The IAEA reports that “based on the analysis of commercially available satellite imagery…FFEP is expected to have suffered very significant damage.” The Institute assesses that all six cascades of IR-1 centrifuges, or about 1040 centrifuges, and all ten cascades of IR-6 centrifuges, or about 1740 centrifuges, installed at the FFEP were likely destroyed in the U.S. attack on the Fordow facility.  The IAEA reports that Iran intended to replace the six IR-1 cascades with IR-6 cascades after June 12, 2025, adding about 1000 additional IR-6 centrifuges to the underground enrichment plant.  Given that military attacks started on June 13, 2025, it is unlikely that Iran proceeded with the installation.  These IR-6 centrifuges may still be inside Fordow.  If not delivered to Fordow, and already manufactured, their whereabouts are unknown to the IAEA.  There are indications that Iran moved equipment or material into the Fordow facility for protection following the start of the war; if this included newly manufactured centrifuges, they are also assessed to be destroyed.  Based on satellite imagery since the war ended, Iran has made efforts to establish limited access to the site for damage assessment but has made no visible efforts to enter the Fordow site to remove anything.
• FEP:  The IAEA reports that based on satellite imagery, “FEP has been extensively damaged, including indications of direct impacts on the underground enrichment halls.”  The IAEA previously reported that Iran had installed at the Natanz FEP 36 cascades of IR-1 centrifuges, 39 cascades of IR-2m centrifuges, 23 cascades of IR-4 centrifuges, and three cascades of IR-6 centrifuges in Hall A1000. This meant there was a total of about 11,200 advanced centrifuges installed at the FEP, as well as about 6100 IR-1 centrifuges.  The Institute assesses that all of these were destroyed or rendered inoperable in the combined attacks by Israel and the United States on the underground site.   More than two months after the attacks, the visible activities at the Natanz FEP remain minimal but indicate that the plant remains inoperational and that Iran is not planning to resume operations in the near future.
• PFEP: The above-ground PFEP experienced complete destruction early during the 12-Day war.  The Institute assesses that all previously reported centrifuges present, which include one full cascade of IR-6 centrifuges and two full cascades of IR-4 cascades, as well as a number of small and intermediate cascades, have been destroyed.  The below-ground PFEP area also held multiple centrifuge cascades, which Iran set up in the same main enrichment hall as the regular FEP centrifuges.  The IAEA reports that based on satellite imagery, “the underground part of the PFEP has been extensively damaged, including indications of direct impacts.”  This portion of the PFEP included four full cascades of 174 IR-6 centrifuges each, one full cascade of IR-2m centrifuges, and additional smaller cascades of up to 55 centrifuges.  The Institute assesses that these centrifuges were also destroyed.
• Overall assessment: The Institute assesses that Iran lost any and all enrichment capabilities represented by these installed centrifuge cascades, which notably includes a cascade arrangement of two IR-6 cascades at Fordow that was easily modifiable for the production of weapon-grade uranium. 

Centrifuge Component Manufacturing: The IAEA report lists three facilities that were involved in centrifuge manufacturing and previously monitored by the IAEA under the JCPOA.  It reports that, during the 12-Day war and according to the IAEA’s analysis of satellite imagery, “one building was hit” at the Tehran Research Center, where “advanced centrifuge rotors were manufactured and tested,” “two buildings were destroyed” at the Karaj workshop, where “different centrifuge components were manufactured,” and a “workshop was hit” at Esfahan, where “centrifuge manufacturing” took place.  The location of the Karaj workshop has been publicly known, and the destruction is visible, as is the destruction of a building at the Esfahan complex labeled by the Israeli Defense Force (IDF) as involving centrifuge manufacturing. The location of the building at the Tehran Research Center remains publicly unknown. 

Centrifuge Research and Development: The IAEA report is silent on Israeli revelations that it attacked and destroyed the Damavand advanced centrifuge research and development facility.  This site appears to be more commonly known as the Kalaye Electric advanced centrifuge research and development facility on Damavand Road in Tehran.  It has functioned as an important research and development site for a variety of centrifuge types and as a location to conduct quality assurance and mechanical testing of advanced centrifuges. 

Isfahan Fuel Enrichment Plant

The IAEA reports that just prior to the start of the 12-Day War, Iran was in the process of declaring a new enrichment facility at Esfahan at the NRFC site, called the IFEP.[7]  According to Iran’s Foreign Minister Abbas Araghchi, this facility was to be “activated” in response to censure by the IAEA Board of Governors in June 2025 which found Iran in non-compliance with its safeguards agreement.^[8]  Araghchi added that this facility was attacked but was not active by then.  The exact status of the construction was not discussed in the IAEA reports, but the IFEP apparently had been under construction for some time.^[9]  The Wall Street Journal reported that the head of Iran’s Atomic Energy Organization, Mohammad Eslami, had said, “Iran was starting the process of readying and installing centrifuges in the new site and would start producing fissile material there as soon as it was ready.”  Eslami’s comment implies that centrifuges had not been installed, but preliminary piping work may have commenced. Overall, the reporting indicates that centrifuges had not yet been installed by the start of the war, but this requires further verification.

The available information strongly indicates that the IFEP was located within the Esfahan tunnel complex, just north of the destroyed above-ground facilities at the Esfahan nuclear complex.  This was indirectly confirmed by a Western government source.  In addition, Eslami stated the site was “located in a secure and invulnerable place,” consistent with it being in the Esfahan mountain complex.^[10] 

On June 12, the IAEA reports that Iran notified the IAEA about the IFEP in a letter and noted “the related DIQ was available for examination by the Agency at the facility.”  The IAEA replied the same day that it would conduct a design information verification (DIV) at the site on June 13 but canceled the inspection due to the military conflict.  It should be noted that Iran was required to inform the IAEA as soon as it made a decision to build this enrichment plant, and the fact that it did not is a clear violation of the comprehensive safeguards agreement (CSA), modified code 3.1. In addition, a DIV is undertaken to determine that the “as-built" portion matches the provided plant design.  This confirms that at least a portion of the enrichment plant was built. 

NRFC is also known as Sureh or Sooreh and has been tied to uranium metal production at the Esfahan site, among other functions, with locations at the Esfahan site but also outside it.  According to the U.S. Treasury Department’s Office of Foreign Assets Control, NRFC is an AEOI entity under U.S. sanctions.^[11] 

The United States attacked the tunnel complex with Tomahawk missiles and destroyed its entrances, as well as a ventilation building outside the southernmost tunnel entrance and likely ventilation-related equipment at the northernmost tunnel entrance.  In recent weeks, Iran has been working to restore access to the tunnel complex, but the southernmost portal remains inaccessible.  Thus, the current status of the enrichment plant or other assets within the tunnels, which may include stocks of enriched uranium, in particular HEU, is unknown.  A forthcoming Institute report will provide additional details on Sureh and the Esfahan tunnel complex. 

Heavy water and reprocessing activities: The IAEA reports the well-known fact that “key buildings at the Heavy Water Production Plant (HWPP) were damaged.” Likewise, the Khondab Heavy Water Research Reactor’s (KHRR) containment dome was breached and reactor internals destroyed.  The Institute assesses that damage is sufficient to have likely made further construction work on the KHRR infeasible.

Monitoring and Verification and Iran’s Safeguards Violations

JCPOA Monitoring and Additional Protocol

The IAEA repeats its finding since Iran stopped adhering to the Additional Protocol (AP) and JCPOA monitoring measures in 2021, that in addition to its lack of continuity of knowledge of LEU and HEU stocks, the agency still has had no insight into Iran’s production and inventory of centrifuges, rotors and bellows, heavy water, and uranium ore concentrate.  It also lacks monitoring and surveillance equipment at such sites.  However, apart from uranium mining and milling facilities, relevant sites sustained heavy damage or were completely destroyed.  Since Iran’s suspension of the AP, Iran has not provided updated declarations, and the agency has not been able to conduct complementary accesses to any sites and locations in Iran. 

De-designation of inspectors over Fordow security incident

The IAEA reports that Iran used an incident in May as a pretext to remove the credentials of an additional two experienced inspectors.  It previously de-designated several inspectors following IAEA board censure in 2023.  Following an inspection at the FFEP on May 14, the two inspectors mistakenly brought DIQ pages used during the inspection to the IAEA’s headquarters in Vienna “instead of returning them to the Agency’s working place at the facility.”  The pages “contained some description of the interior of the facility,” but did not compromise its security.  The IAEA informed Iran of the mistake on May 27 and promptly returned the pages.  However, on August 14, Iran withdrew the designation of the inspectors for breach of the CSA.  The IAEA laments the decision as unjustified. 

No progress on IAEA investigation

The IAEA reports no new progress and no engagements with Iran regarding unresolved safeguards issues that the agency has been investigating since 2018.  These and other issues were discussed in detail in a previous, comprehensive IAEA report dated May 31, 2025.  This report was followed soon afterwards by an IAEA Board of Governors resolution stating that Iran was in violation of its safeguards obligations.