Military plans for striking Iranian nuclear sites, including the Pickaxe Mountain facility near Natanz, explicitly include options for deploying the GBU-43/B MOAB bomb.

From the article'Mother of all bombs': US potential Iran strike plans include largest non-nuclear weapon - reportAlso in The US is considering using the "mother of all bombs" against Iran - CNN | УНН, What is the ‘Mother of All Bombs’ US may use in Iran?, What is the ‘Mother of All Bombs’? Why the US is considering its massive MOAB weapon for potential strikes on Iran, US considering using ‘Mother of All Bombs’ against Iran, sources say | CNN Politics