Background
On October 25, 2024, Israel launched an attack on Iran that destroyed multiple buildings within the Parchin Military Complex. Three out of four attacked buildings were directly associated with solid rocket motor propellant mixing for ballistic missile production. However, one target stood out-a building used for nuclear weapons development purposes under Iran's Amad Plan in the early 2000s. Named after the high explosive test chamber the building housed, it was labeled "Taleghan 2" in many documents in the Israeli captured Iran Nuclear Archive. Although available evidence supports that the high explosive chamber and associated flash x-ray were removed from the building during a multi-year Iranian sanitization of the site, which also included the co-located Taleghan 1 building, Israel indicated that Taleghan 2 had in the last few years a nuclear weapons connection. Moreover, after the strike, Axios reported that the site was "active" recently and contained nuclear weapons related equipment at the time of the strike. Subsequently, Israel's Prime Minister Netanyahu stated about the strike: "It's not a secret - it's published. There is a certain element of their nuclear program that was damaged in this attack. But still the program itself, its ability to operate here, has not yet been thwarted."
Figure 1. A before and after satellite image of Taleghan 2, which was destroyed during Israel's strike on Iran on October 25.
Findings
- High resolution satellite imagery shows that the Taleghan 2 building was thoroughly destroyed in the strikes (see Figure 1).
- According to an Israeli government source, Taleghan 2 was attacked for multiple reasons, and sending a message was one of them.
- The Institute was able to confirm with a Western government that there is evidence that nuclear weapons related activities recently took place at Taleghan 2.
- The exact type of nuclear weapons related activities recently taking place at Taleghan 2 requires further clarification.
- Based on Axios reporting and the Institute's understanding, it appears likely that Taleghan 2 contained equipment to make high purity PETN plastic explosives. These explosives, which are moldable, were used during the Amad Plan in the channels of the shock wave generators, a type of multipoint initiation system used to detonate the main high explosive charge in a nuclear weapon.
- Whether the reported activities included making such plastic explosives, or one step further, using them to produce multi-point initiation systems, needs further clarification. Both activities have non-nuclear military applications, however, it is the context and intention that need to be taken into account to differentiate between actual non-nuclear military activities versus using a cover story. In the case of Iran, the facts at hand point to the latter, making the activities nuclear-related even if no nuclear material was being used.
- Commercial satellite imagery shows renewed activity at the Taleghan 2 site over the last few years.
- Post-strike imagery analysis does indicate that unidentified equipment was present inside Taleghan 2, and Iran evidently took steps to hide its cleanup activities from both overhead reconnaissance and nearby ground observation.
- Post-strike cleanup efforts conducted by Iran and visible in satellite imagery include rapidly covering the building remnants with a makeshift structure, separating debris piles and erecting visual security screens, all indicative of efforts to hide the removal of remnants of sensitive equipment from the ruins.
- It remains unclear if the strike damaged plastic explosive manufacturing equipment and/or finished explosives. They may in part be difficult to replace for Iran as the production of high purity PETN involves sensitive production and analytical equipment, best made by Western and allied suppliers and typically requiring export authorization for a destination like Iran. PETN, while otherwise easy to make, needs to be of very high purity to be used in a shock wave generator where detonation velocity needs to be controlled at the nanosecond level.
- The Taleghan 2 building also provided intrinsic value - the orientation of the long axis of the building backstopped into the hillside was advantageous for activities involving high explosives or projectile impact/shock physics studies.
- Based on Taleghan 2's use during the Amad Plan, additional equipment, including a high explosive test chamber and a flash x-ray were once inside the building, however, it is judged as unlikely that this equipment remained inside the building following extensive, multi-year cleanup efforts at Parchin starting in 2011.
- If either of these materials or equipment remained inside the building, the attack would have dealt a serious blow to Iran's ability to peer deeply into a high explosive experiment, necessary for nuclear weapons development, as Iran is assessed to only have had one such flash x-ray and this type of diagnostic equipment is tightly controlled due to its military applications.
- To this day, Iran has not addressed the questions the IAEA raised about the Taleghan sites. With this recent strike, there are now new questions about Iran's ongoing work on nuclear weapons. The number of questions have also likely multiplied with the many new revelations in the nuclear archive concerning Taleghan 1 and 2's former nuclear weapons activities. It is long past time for the IAEA to reopen its discussions with Iran on this particular site.
- At the November 2024 IAEA Board of Governors meeting, the board passed a resolution requesting the IAEA to submit a comprehensive report on the "possible presence or use of undeclared nuclear material in connection with past and present outstanding issues regarding Iran's nuclear programme." The board did not define "comprehensive." Based on considering the sum of knowledge about Iran's undeclared nuclear materials and nuclear weapon-related activities, now including activities at Parchin, a comprehensive report should connect the IAEA's findings from before 2016, before implementation of the Joint Comprehensive Plan of Action, to those from 2018 onwards, after the revelation of the nuclear archive documents beyond the IAEA's findings about additional undeclared nuclear material or undeclared nuclear-related activities at four IAEA specified sites.
Visible Recent Activity at Taleghan 2
Commercial satellite imagery shows renewed activity at the Taleghan 2 site over the last few years. Following the extensive cleanup of Taleghan 1 and 2 in the period from 2011 to 2015 (see Annex, section, IAEA and Parchin) the site appeared abandoned for several years. However, in more recent imagery, there is a white vehicle parked next to the building on the south side or under the entrance cover from time to time (see Figure 2). Further, in recent years, new equipment or materials appeared along the south side of the building. One image taken on October 22, 2021, shows new unidentified equipment or materials stacked along the south side of the building that was not present in an earlier October 2021 image. Some of the equipment or materials newly added over the last few years remained outside of the building and were still visible in imagery taken shortly before the strike (see Figure 3).
Figure 2. A white vehicle was present at Taleghan 2 from time to time, such as in these images taken September 2021 and November 2022.
Figure 3. Unidentified equipment and materials appeared along the south side of the building in recent years, most notably in October 2021 (top image). A few days before the strike, unknown equipment or materials added in the past few years were still visibly present at the site (bottom image).
