Dr Ian J Stewart, 21 June 2025
On the 13th June, Israel took the dramatic step of launching a wave of airstrikes on Iranian nuclear, missile and military facilities and undertook covert operations aimed at assassinating key Iranian nuclear figures. The US then struck Fordow, Natanz and Esfahan on 21 June. The unprecedented action comes in the context of Iran's buildup of significant quantities of close-to-weapons grade fissile material, a report from the International Atomic Energy Agency about mostly historical non-compliance with Iran's safeguards obligations, and looming deadlines related to the Joint Comprehensive Plan of Action (JCPOA). This page contains a comprehensive situation briefing on the status of Iran's nuclear program that will be updated regularly based on new developments.
Headline Assessment
At the time of Israel's action, Iran had accumulated more than 400kgs of Highly Enriched Uranium enriched to 60% - a sufficient quantity to produce around 10 nuclear weapons. This material would likely require further enrichment to 90% and conversion to metal for use in a nuclear weapon. While Israel’s and the US strike destroyed key infrastructure and reportedly killed scientists, the overall setback to Iran’s weaponization timeline remains uncertain due to the possibility of clandestine efforts and uncertainties around the damage to Fordow. The 60% HEU is currently out of international verification as a result of the bombing campaign, with there being unconfirmed reports that Iran has moved the material. This material must be tracked, verified, and disposed of to effectively increase Iran's breakout timeline even with the questions around the status of Iran's nuclear facilities.
Status of Facilities
Israel struck the nuclear fuel cycle facilities at Esfahan, the enrichment facilities at Natanz, the past weaponization facilities at Parchin and the non-operational heavy water reactor at Arak. Israel has not struck the Bushehr power reactor or the Fordow enrichment facility. The US struck Esfahan, Natanz and most importantly Fordow.
Israel should not strike Bushehr. The reactor is not relevant to Iran's potential development of nuclear weapons and such a strike would carry a significant radiological risk. Such a strike would also probably be illegal under international law.
At the time of the US action, Fordow was the most challenging issue. There were 7 installed centrifuge cascades at Fordow that could further enrich the HEU in a matter of days. If all seven cascades were converted to enrich to 90%, I calculate that less than 3 days would be required to enrich the first 25kgs of HEU to 90%, which is the level generally assumed to be required for nuclear weapons. Further, while the quantities are not publicly known, at least some of Iran's 60% HEU will already be located at Fordow given that it is one of the two sites that produce the 60% material (with the other being Natanz). The US action on 21 June may have destroyed Fordow, but an assessment of the damage to the site is necessary before drawing conclusions.
| Type | Name | Status | Radiological Risk | Weapons Relevance |
| Enrichment | Fordow | Unclear | Low/Trivial | High |
| Enrichment | Natanz | Not operational | Low/Trivial | High |
| Conversion, Fuel Manufacture, Metal Manufacture | Esfahan | Not operational | Low | High |
| Nuclear Reactor | Bushehr | Operational | Significant | Low |
| Nuclear Reactor | Arak | Not operational | Nil | Medium |
| Past weaponization | Parchin | Not operational | Low/Trivial | High (historical) |
Related Documents
This section contains a list of relevant documents contained elsewhere on this site that are relevant to the content of this page.
Description
The IAEA Director General’s report GOV/2025/24, issued to the Board of Governors and the UN Security Council, assesses Iran’s implementation of its nuclear-related commitments under the Joint Comprehensive Plan of Action (JCPOA) and Security Council Resolution 2231. The report highlights that, since Iran ceased implementation of the JCPOA and removed all IAEA monitoring equipment, the Agency has lost continuity of knowledge regarding key aspects of Iran’s nuclear program, including centrifuge production and enriched uranium stockpiles. As of May 2025, Iran has accumulated over 400 kg of uranium enriched to 60%—a level of significant proliferation concern—and its total enriched uranium stockpile exceeds 9,200 kg. The IAEA cannot verify the peaceful nature of Iran’s program and warns of the serious implications of Iran's continued lack of transparency.
The IAEA Director General’s report GOV/2025/24, issued to the Board of Governors and the UN Security Council, assesses Iran’s implementation of its nuclear-related commitments under the Joint Comprehensive Plan of Action (JCPOA) and Security Council Resolution 2231. The report highlights that, since Iran ceased implementation of the JCPOA and removed all IAEA monitoring equipment, the Agency has lost continuity of knowledge regarding key aspects of Iran’s nuclear program, including centrifuge production and enriched uranium stockpiles.
Description
The IAEA Board of Governors adopted a resolution on June 12, 2025, expressing deep regret and concern over Iran's continued failure to cooperate fully with the Agency regarding its NPT Safeguards Agreement. The resolution highlights Iran's lack of technically credible explanations for uranium particles found at undeclared locations, its failure to provide information on the whereabouts of nuclear material and contaminated equipment, and its non-compliance with legal obligations such as implementing modified Code 3.1. The Board found that Iran's actions constitute non-compliance with its Safeguards Agreement and that the Agency is unable to verify that there has been no diversion of nuclear material, raising serious questions about the exclusively peaceful nature of Iran's nuclear program and its implications for international peace and security. The resolution strongly supports the Director General's efforts and calls upon Iran to urgently remedy its non-compliance and provide necessary cooperation to resolve all outstanding Safeguards issues.
Description
The IAEA Board of Governors adopted a report from the Director General on May 31, 2025, detailing ongoing concerns regarding Iran's NPT Safeguards Agreement. The report, a comprehensive assessment requested by the Board in November 2024, highlights Iran's continued failure to provide technically credible explanations for the presence of undeclared nuclear material and activities at three locations: Lavisan-Shian, Varamin, and Turquzabad. These locations are assessed to have been part of an undeclared structured nuclear program until the early 2000s. The report emphasizes that Iran's lack of cooperation, including the sanitization of sites and the withdrawal of experienced inspectors, significantly obstructs the Agency's ability to verify the exclusively peaceful nature of Iran's nuclear program. Furthermore, Iran's refusal to implement modified Code 3.1, a legal obligation, prevents the Agency from obtaining early design information for new nuclear facilities, further impeding safeguards implementation. Despite numerous high-level meetings and joint statements, the Director General regrets that no significant progress has been made in resolving these long-standing issues, noting that Iran is the only non-nuclear-weapon state producing and accumulating uranium enriched to 60%, which presents serious proliferation concerns.
