Iran fortifies nuclear sites under concrete as U.S. bombers approach

Satellite imagery released by commercial providers showed Iran pouring fresh concrete at tunnel entrances at the Natanz enrichment complex and hardening structures at the Fordow fuel enrichment plant, which is buried under 80 meters of rock. At the Parchin military complex, engineers covered the Taleghan-2 site's concrete shell with earth to camouflage it. Analysts at the Institute for Science and International Security warned the fortifications were designed to limit damage from U.S. GBU-57 bunker-buster bombs, whose penetration depth is estimated at 60 meters through rock.