VIENNA — IAEA Director General Rafael Grossi confirmed that inspectors verified approximately 73 tonnes of natural uranium metal at a previously undeclared nuclear site in Syria. The discovery revealed that the Assad-era government constructed a reactor configured to produce fissile material for possible use in nuclear weapons.

During the inspection, officials confirmed that uncovered cooling infrastructure at the Deir el-Zour site is consistent with that of a nuclear reactor. Inspectors had to tear down walls and navigate difficult, narrow passages to reach hidden nuclear material at the undeclared site. They found boxes scattered throughout the area and installed cameras at the location to safeguard the nuclear material.

Grossi stated that the decision on whether the nuclear material remains in Syria or is removed rests with the Syrian government. "For us what’s important is that we know all the time where this [material] is until the last gram," he said. The nuclear reactor in Deir el-Zour was built by North Korea, according to agency reports.

Logan Mintz, director for nuclear materials security at the Nuclear Threat Initiative, stated that natural uranium metal is not directly usable for a nuclear weapon. However, he noted that the material could be "diverted to a covert weapons program that further processes it into plutonium for a nuclear weapon." Mintz added that once deemed safe, the material could be transported in certified containers to a third country for disposition into a more chemically stable form for potential use in nuclear power plants. Mintz stated that transporting nuclear material requires robust security against theft or sabotage. The new Syrian government agreed to give IAEA inspectors access to suspected former nuclear sites following the ouster of Bashar al-Assad in December 2024.

Timeline

US officials accused Syria of seeking to build a secret nuclear reactor in 2008. Israel admitted in 2018 to carrying out an air raid on the Deir ez-Zor site in 2007. Bashar al-Assad was ousted in December 2024.

Syria notified the IAEA of a previously undeclared site's existence in a letter dated July 17, 2026. On the same date, Syria invited the IAEA to cooperate with Syrian authorities in the inspection and verification of the site and any nuclear material found there. IAEA inspectors visited a previously undeclared site in Syria identified by Syrian authorities in August 2026.

During that month, the IAEA verified the presence of approximately 73 tonnes of natural uranium metal in the form of fuel rods with cladding at the undeclared site.

What's New

Grossi described the IAEA's investigation into secret nuclear activities under the Assad family's rule as a "historic breakthrough." He welcomed Syria's transparency and cooperation with the agency. Grossi stated in a speech to the IAEA board that the agency has been able to clarify and resolve questions concerning outstanding safeguards issues related to Syria's past nuclear activities.

Grossi stated it was "obvious that the previous government was pursuing a number of clandestine" activities. Regarding the previous government, he said, "They didn’t want the world to know what they were doing." He stated that building the reactor was a "very important step."

Why It Matters

The verification of 73 tonnes of natural uranium metal at an undeclared site confirms long-standing suspicions about Syria's nuclear ambitions. The Assad-era government constructed a reactor configured to produce fissile material, a capability that represents a serious proliferation concern according to the IAEA. The material's presence shows the extent of clandestine activities pursued by the previous regime, which sought to keep its nuclear program hidden from international oversight.

The disposition of the uranium remains uncertain, as the decision to keep or remove the material rests with the Syrian government. Logan Mintz stated that while natural uranium is not directly weapons-usable, it can be processed into plutonium for nuclear weapons if diverted to a covert program. Safe transport and disposal require robust security measures to prevent theft or sabotage, posing logistical and security challenges for the current administration and international partners.