Iranian authorities are reporting no signs of off-site radiation or contamination in the wake of U.S. attacks on three of the country’s nuclear sites. […] That’s according to a statement put out by the International Atomic Energy Agency on Sunday. Rafael Mariano Grossi, the agency’s Director General, said that “as of this time, we don’t expect that there will be any health consequences for people or the environment outside the targeted sites.”
It won’t spread very far due to its density though. I wouldn’t like to be in the enrichment room itself if the bombing did rupture some active centrafuges but outside should be fine.
They often keep that shit in tanks outside, particularly depleted(figuring out what to do with depleted uranium hexafluoride is often a challenge and the US has a truly staggering amount of full tanks just sitting around waiting to leak). Once it hits air you get hydrofluoric acid gas which will spread thanks to the explosion and will kill you in small concentrations(as low as 30 ppm). It’s awful and blowing it up to spread it everywhere is even more awful. The only thing worse would be bombing a purex plutonium reprocessing plant. That is just as toxic in different ways but you can make the tanks go prompt critical thanks to changing it’s geometry and it has actual fission products you can spread around. Those reprocessing plants were a main plank in how north Korea got their bomb.