A fire broke out early Thursday at a building above Iran’s underground Natanz nuclear enrichment facility, though officials said it did not affect its centrifuge operation or cause any release of radiation.
The Atomic Energy Organization of Iran sought to downplay the fire, calling it an “incident” that only affected an “industrial shed” under construction, spokesman Behrouz Kamalvandi said. However, both Kamalvandi and Iranian nuclear chief Ali Akbar Salehi rushed after the fire to Natanz, which has been targeted in sabotage campaigns in the past.
Kamalvandi did not identify what damaged the building, though Natanz governor Ramazanali Ferdowsi said a “fire” struck the site, according to a report by the semiofficial Tasnim news agency.
A photograph later released by the atomic energy agency showed a brick building with scorch marks and its roof apparently destroyed. It wasn’t clear if that was the “shed” to which Kamalvandi referred. Debris on the ground and a door that looked blown off its hinges suggested an explosion accompanied the blaze.
Data collected by a US National Oceanic and Atmospheric Administration satellite suggested the fire broke out around 2 a.m. local time in the northwest corner of the Natanz compound. Flames from the blaze were bright enough to be detected by the satellite from space.
“There are physical and financial damages and we are investigating to assess,” Kamalvandi told Iranian state television. “Furthermore, there has been no interruption in the work of the enrichment site. Thank God, the site is continuing its work as before.”
There was no previously announced construction work at Natanz, a uranium enrichment center some 250 kilometers (155 miles) south of the capital, Tehran. Natanz includes underground facilities buried under some 7.6 meters (25 feet) of concrete, which offers protection from airstrikes.
Natanz, also known as the Pilot Fuel Enrichment Plant, is among the sites now monitored by the International Atomic Energy Agency after Iran’s 2015 nuclear deal with world powers.
The IAEA said in a statement it was aware of reports of the fire. “We currently anticipate no impact on the IAEA’s safeguards verification activities,” the Vienna-based agency said.
Located in Iran’s central Isfahan province, Natanz hosts the country’s main uranium enrichment facility. There, centrifuges rapidly spin uranium hexafluoride gas to enrich uranium. Currently, the IAEA says Iran enriches uranium to about 4.5% purity, above the terms of the nuclear deal, but far below weapons-grade levels of 90%. It also has conducted tests on advanced centrifuges, according to the IAEA.
The US under President Donald Trump unilaterally withdrew from the nuclear deal in May 2018, setting up months of tensions between Tehran and Washington. Iran now is breaking all the production limits set by the deal, but still allows IAEA inspectors and cameras to watch its nuclear sites.
However, Natanz did become a point of controversy last year as Iranian officials refused to allow an IAEA inspector into the facility in October after allegedly testing positive for suspected traces of explosive nitrates. Nitrates are a common fertilizer. However, when mixed with proper amounts of fuel, the material can become an explosive as powerful as TNT. Swab tests, common at airports and other secure facilities, can detect its presence on the skin or objects.
Natanz also remains of particular concern to Tehran as it has been targeted for sabotage before. The Stuxnet computer virus, widely believed to be an American and Israeli creation, disrupted and destroyed centrifuges at Natanz amid the height of Western concerns over Iran’s nuclear program.
Thursday’s incident came days after another mysterious explosion near Tehran.
An unnamed former Iranian nuclear official told Reuters that sabotage was a possibility. “Considering that this so-called incident happened just a few days after the explosion near the Parchin military base, the possibility of a sabotage cannot be ruled out,” this source said. “Also Natanz enrichment facility has been targeted in the past by a computer virus,” he added, referring to Stuxnet.
The explosion near Parchin, which rattled Iran’s capital on Friday, came from an area in its eastern mountains that analysts believe hides an underground tunnel system and missile production sites, satellite photographs showed Saturday.
Satellite photos of the area, some 20 kilometers (12.5 miles) east of downtown Tehran, showed hundreds of meters of charred scrubland not seen in images of the area taken in the weeks ahead of the incident. The building near the char marks resembled the facility seen in the state TV footage.
The area sits near what analysts describe as Iran’s Khojir missile facility. The explosion appears to have struck a facility for the Shahid Bakeri Industrial Group, which makes solid-propellant rockets, said Fabian Hinz, a researcher at the James Martin Center for Nonproliferation Studies at the Middlebury Institute of International Studies in Monterey, California.
The Washington-based Center for Strategic and International Studies identified Khojir as the “site of numerous tunnels, some suspected of use for arms assembly.” Large industrial buildings at the site visible from satellite photographs also suggest missile assembly being conducted there.
The US Defense Intelligence Agency says Iran overall has the largest underground facility program in the Middle East.
Iranian officials themselves also identified the site as being in Parchin, home to a military base where the International Atomic Energy Agency previously said it suspects Iran conducted tests of explosive triggers that could be used in nuclear weapons. Iranian authorities blamed the blast on a gas leak.
Western concerns over the Iranian atomic program led to sanctions and eventually to Tehran’s 2015 nuclear deal with world powers. The US under President Donald Trump unilaterally withdrew from the accord in May 2018, leading to a series of escalating attacks between Iran and the US, and to Tehran abandoning the deal’s production limits.
Separately, Iranian media reported Tuesday evening that an explosion from a gas leak in a medical clinic in northern Tehran had killed at least 19 people and injured several others. The ensuing fire broke out at Sina Athar Medical Center in Iran’s capital and state TV said firefighters battled and extinguished the blaze.