The site, located within the Parchin military complex southeast of Tehran, was hit in an Israeli airstrike on October 25, 2024, but was not struck during the June conflict.
The Institute for Science and International Security (ISIS) said rebuilding at the site—identified as Taleghan 2—began before the country’s 12-day war with Israel in June and continued afterward.
“The purpose of the new construction at this location cannot be discerned from the imagery; a multitude of other non-nuclear purposes are also possible,” the report said.
“It is deeply concerning that construction is occurring at a former AMAD Plan nuclear weapons development site, raising considerable questions as to the true purpose of the facilities there.”
AMAD was a secret scientific project allegedly aimed at developing nuclear weapons. It began in 1989 and ended in 2003, according to the International Atomic Energy Agency (IAEA).
Satellite imagery from May 20, 2025, showed a black temporary cover hastily installed over the destroyed building, the report said.
By June 12, groundwork and foundations had been laid, and by late August, a new arch-roofed structure about 45 by 17 meters was under construction over the temporary cover, with two smaller buildings nearby.
ISIS said imagery from September 27 showed a third arched structure and further progress on the others. It added that the smaller side buildings appeared to include “blast traps” if later bunkered with earth.
A support facility about 200 meters east of the main complex was also identified, with construction first noted in May and still ongoing.
The institute said that although there is no current evidence to support any nuclear-weapons-related purpose, efforts should be made to determine whether Iran is attempting to reconstitute either the high-explosive test chamber facilities originally part of the AMAD program or the more recently reported PETN plastic-explosive manufacturing capability.
It added that the structures’ arched roofs could later be covered with earth to enhance survivability in the event of future airstrikes and said it will continue to monitor developments at the site.
It added that the structures’ arched roofs could later be covered with earth to enhance survivability in the event of future airstrikes and said it will continue to monitor changes at the site.