(I've read about the scientists/technicians.)
There are some questions whether the GBU-54 MOP would be able to take out the most-hardened facilities (or able to do so quickly):
Iran has many scientists with nuclear expertise and has stored its most critical facilities in bunkers that may be beyond the reach of Israel's bombs.
www.businessinsider.com
June 13, 2025
...However, military and nuclear experts say firepower alone won't be enough to completely wipe out Iran's nuclear program....[Iran] has stored its most critical facilities in bunkers buried deep underground.
This makes the facilities particularly challenging targets that, from the air, can only be reached by the largest bunker busters, which Israel lacks, or repeated strikes in the same spots.
Natanz, home to Iran's largest uranium enrichment site, is located several floors underground in the center of the country. The Israel Defense Forces said its airstrikes damaged an underground area of the facility that contains an enrichment hall with centrifuges, electrical rooms, and additional infrastructure.
Satellite imagery captured on Friday revealed what appears to be significant damage at Natanz, but only on the surface.
Iran's other main enrichment site, Fordow, is buried even deeper in the side of a mountain and is the country's most "hardened" facility, said Darya Dolzikova, a senior research fellow for proliferation and nuclear policy at the UK-based Royal United Services Institute think tank.
In comments shared with Business Insider, Dolzikova said Fordow has not been affected by the Israeli strikes, nor have other locations. "Should Iran make a decision to produce a nuclear weapon, it would likely do that at hardened and potentially still secret sites," she said....
The likely best weapon for the job is the US military's GBU-57 Massive Ordnance Penetrator, one of the most powerful non-nuclear bombs and the largest bunker buster in America's arsenal at 15 tons. These munitions can only be carried by the B-2 Spirit stealth bomber and the B-21 Raider in development.
Israel doesn't have bomber aircraft capable of carrying the largest bunker-buster munitions. The IDF shared footage showing its fighter jets — F-35s, F-16s, and F-15s — taking off and landing during the strikes. Weapons experts pointed out that some of the aircraft appear to be carrying 2,000-pound guided bombs. Israel's F-15I, though, can carry 4,000-pound anti-bunker bombs.
Military analysts with RUSI estimated in March that the Fordow site could be as deep as 260 feet underground, likely beyond the reach of even America's MOP. Damaging it would almost certainly require repeated strikes, likely over days or weeks....