I wonder if the bunker buster was used. It has a somewhat indirect lineage to the ww2 grand slam designed by Barnes Wallis.
Iran has massive earthquake risks. For reasons unassociated with nuclear bunkers they do a lot of research into (fibre, and other) strengthened cement construction. With obvious applications to their nuclear industry of course.
Another unrelated point, a significant number of Iranian civil engineering graduates are women. A somewhat dichotomous economy, when you consider the theocratic restrictions on costume and behaviour.
Iran has massive earthquake risks. For reasons unassociated with nuclear bunkers they do a lot of research into (fibre, and other) strengthened cement construction. With obvious applications to their nuclear industry of course.
Another unrelated point, a significant number of Iranian civil engineering graduates are women. A somewhat dichotomous economy, when you consider the theocratic restrictions on costume and behaviour.