Iran told the IAEA that the fire was quickly extinguished and that there had been no nuclear material or other radioactive material in the building. Iran said the cause was not yet known, adding there were no injuries or radioactive contamination.
The Natanz site is under IAEA safeguards, including verification and monitoring under the Joint Comprehensive Plan of Action, an agreement reached in Vienna in 2015, between Iran and the P5+1 (China, France, Russia, the UK, the US plus Germany).
The JCPOA was a far-reaching 25-year settlement that constrained Iran’s nuclear capacity in exchange for sanctions relief. Iran agreed to remove about two-thirds of Natanz’s centrifuges, limit uranium enrichment to 3.67%, and down-blend or sell most of its LEU stockpile. Iran is also required to provide the IAEA daily access to Natanz for continuous monitoring of enrichment activities and centrifuge production.
The IAEA said there were no IAEA safeguards inspectors at the Natanz facility at the time, and that the location where the incident occurred does not contain nuclear materials.
The IAEA said it has been in contact with Iranian authorities to confirm there will be no impact on its safeguards verification activities, which are expected to continue as before. IAEA inspectors are present on a regular basis at Natanz.
According to the US-based Nuclear Threat Initiative, Natanz is Iran’s primary enrichment facility and houses both the commercial fuel enrichment plant and the pilot fuel enrichment plant. The facility consists of three underground buildings, two of which are designed to hold 50,000 centrifuges, and six above ground buildings. Two of the above ground buildings are 2,500-metre halls used for gas centrifuge assemblies.
Iran has a Russia-supplied commercial nuclear reactor in operation at Bushehr and another, also being supplied by Russia, under construction at the same site.