Commenting on the US attack on Iranian nuclear sites, International Atomic Energy Agency director Rafael Grossi said the surface facility at Natanz had been “completely destroyed.” But just outside the perimeter of the uranium enrichment plant, which is located about 225 km south of Tehran, the regime has reportedly built another one, buried dozens of meters deep in the belly of a mountain. The official announcement was made on June 12 by the head of the Atomic Energy Organization of Iran Mohammad Eslami, a few hours after the IAEA approved the resolution used by Israel as a pretext to start the war. The Islamic Republic, the official said, quoted by the semi-official Mehr News agency, has built a third uranium enrichment plant in addition to those at Fordow and Natanz:"The new site has been completed and is in a safe and invulnerable location. As soon as the installation and configuration of the centrifuges are completed, enrichment will begin."
The new facility, consisting of a complex system of tunnels and an advanced centrifuge assembly plant, has been on the radar of American and Israeli intelligence services for years and is said to be located in the bowels of Mount Kuh-e Kolang Gaz La. Its construction began after the Iran Centrifuge Assembly Center, the surface structure of the main Natanz site, was heavily damaged by an Israeli attack in July 2020 and the following November 27th Mohsen Fakhrizadeh, the brains of the nuclear program, was killed in an attack along with his wife and the agents of his escort. At the time, Washington intelligence believed that Tehran wanted to use it to build centrifuges, rebuilding the plants that Tel Aviv had destroyed. Israeli intelligence, however, leaked the belief that its purpose was to enrich uranium on a large scale.
Satellite photographs taken in April 2023 by Planet Labs PBC and analyzed by Associated Press show that the new complex would be located just beyond the southern fence of the Natanz site. Other images analyzed by the James Martin Center for Nonproliferation Studies show that four entrances, each 6 meters deep and 8 meters high, had been cut into the mountainside, two to the east and two to the west. From this data, engineers at the center concluded that Iran was building a facility at a depth of 80 to 100 meters, like the one at Fordow.
According to the Institute for Science and International Security, however, the tunnel system could go even deeper. Mount Kuh-e Kolang Gaz La “is 1,608 meters above sea level,” says David Albright, president of the Washington-based anti-nuclear think tank that has long monitored Tehran’s nuclear operations, in a 2020 report. By comparison, the mountain that hosts the Fordow plant “is about 960 meters high,” which means the new Natanz facility is protected by an additional “armor” of rock 650 meters thick, “even more protection than any facility” in the country. “Fordow,” Albright added, “is already considered so deep that it would be difficult to destroy with an air strike. The new site could be even more difficult to destroy.”
It will take days, if not weeks, to assess the damage caused by the attack decided by Donald Trump. Today, speaking about Natanz, Grossi added that its underground corridors “ have suffered a lot ” due to the power cuts caused by the Israeli attacks in the past few hours. In the coming days, it will be clear whether the structures of the site whose existence was made official on June 12 by the Iranian authorities have also suffered damage.
