IAEA raises alarm over Iran nuclear program's renewed activity and HEU stockpiles

International Atomic Energy Agency (IAEA) Director General Rafael Mariano Grossi reported on  Wednesday that Iran did not appear to be actively enriching uranium. However, he warned that renewed movement has been detected at the country’s nuclear sites, and that while inspectors remain in Iran, the level of cooperation is not what it should be.

The concerns stem from critical developments following the 12-day war with Israel in June. Iran immediately suspended all co-operation with the IAEA, and inspectors have been unable to gain full access to its nuclear sites. Grossi stressed the urgency of returning to key locations to  verify that existing stocks of highly enriched uranium (HEU) have not been diverted.

A major point of alarm for the IAEA is Iran’s stockpile of HEU enriched to 60 per cent, currently held within its borders. According to the agency, the quantity could, under certain conditions,  be sufficient to build up to 10 nuclear bombs should Iran decide to weaponise its programme. Grossi emphasised the importance of site visits in order to confirm that the material is still present and has not been moved.

Just as the IAEA was poised to be granted access to a third enrichment site near Isfahan, the June war and Iran’s subsequent withholding of cooperation caused a setback of years in the agency’s progress. The re-imposition of United Nations sanctions, triggered by the so-called “snap-back” mechanism, has further complicated the already fragile relationship between the IAEA and Tehran.

There are also growing concerns about Iran’s ballistic missile ambitions. Despite the reinstated UN sanctions banning arms sales to Iran and ballistic-missile activity, Iranian efforts to rebuild its depleted missile stocks appear to be intensifying. European intelligence sources confirm that Tehran is engaged in a determined campaign to restore its missile capabilities, which were significantly damaged during the June conflict.

Key to these efforts is the import of sodium perchlorate—a principal precursor for the solid propellant used in mid-range conventional missiles. Since the sanctions were reapplied at the end of September, several shipments totalling around 2 000 tons of sodium perchlorate have arrived at the Iranian port of Bandar Abbas from Chinese suppliers. Intelligence analyses estimate this quantity would be sufficient to manufacture roughly 500 missiles. The deliveries appear to have used vessels already sanctioned by the United States and employed front companies in an opaque logistics chain designed to keep material flowing to Iran despite the sanctions regime.

China, which opposed the re-imposition of the UN sanctions, is navigating what it regards as a legal grey area. Although the UN resolutions prohibit the provision of materials that could contribute to Iran’s development of a nuclear-weapon delivery system, sodium perchlorate is not explicitly named in the documents. China may therefore argue that it is not formally in breach of any UN ban even though the substance is a direct precursor of a listed oxidiser, ammonium perchlorate, used in ballistic missiles. Beijing has also publicly criticised the “snap-back” mechanism as “unconstructive” and a “serious setback”.

Satellite imagery analysed by the Center for Strategic and International Studies (CSIS) confirms that the US and Israeli military strikes in June successfully destroyed key areas of Iran’s nuclear programme. Imagery from the sites at Fordow, Natanz, and Isfahan shows virtually zero activity or only attempts to rehabilitate the facilities following the strikes.

Yet the analysis indicates emerging risks as Iran appears to be shifting its programme toward strategic opacity. Notably, satellite imagery detects intensified construction at a deeply-buried facility just one mile south of the Natanz enrichment site, known as “Pickaxe Mountain”. Construction began in 2020 to build a modern centrifuge assembly hall “in the heart of the mountain”. Since the June strikes, Iran has notably stepped up construction, including extending tunnels and erecting a security wall. CSIS analysts suggest three possible explanations for the activity: acceleration of the planned centrifuge assembly facility, expansion to include metallurgical operations destroyed at Isfahan, or a move to build a truly clandestine uranium-enrichment facility. The fact that Iran still holds roughly 400 kg of 60 per cent enriched HEU and refuses full access to the site compounds concerns.

In addition to physical infrastructure damage, Israel reports that it killed at least 14 leading Iranian nuclear scientists during the June strikes. The loss of these highly skilled individuals and the tacit knowledge they embodied is expected to hamper Iran’s ability to sustain and advance a future nuclear-weapons programme. In the wake of these failures—including earlier sabotage and assassinations—Tehran launched a fierce internal crackdown, arresting over 700 Iranians accused of spying for Israel and executing more than a thousand this year, the highest number in three decades. This campaign is believed to have fostered a culture of fear and distrust within Iran’s nuclear and military organisations.

On October 18, the international nuclear agreement known as the Joint Comprehensive Plan of Action (JCPOA) officially ended. Iran’s Ministry of Foreign Affairs formally announced that all of the accord’s provisions—including nuclear-programme restrictions and related mechanisms—were “considered terminated”. Although the deal had been in practical disarray since the US withdrawal in 2018, and more recently disrupted by summer strikes and Iran’s withholding of cooperation with the IAEA, the official termination date was largely formal.

Iran’s Supreme Leader, Ayatollah Ali Khamenei, publicly dismissed assertions by US President Donald Trump that Washington had bombed and destroyed Iran’s nuclear programme. Speaking during a meeting a few days ago with Iranian sports and science champions, Khamenei called the comments “nonsense spoken to console disheartened Israeli officials after an unexpected defeat in the 12-day war”. “The US President proudly says they bombed and destroyed Iran’s nuclear industry. Very well, keep dreaming,” he added. “The United States is in no position to determine what countries should or should not possess nuclear capabilities. Our youth-built missiles have already penetrated and destroyed sensitive Israeli facilities. These missiles are ours, built by our youth, not borrowed or bought from anyone. They remain ready and will be used again if necessary.”

 

Middle East