Forager: Production Master
Forager
Production Master (BRONZE)
Own 100 nuclear structures at once #PlayStationTrophy
Craft 100 Nuclear Machinery and then add them to the to a building.
Add them to a building by placing them on the toolbar and then using the action button with the machinery selected while standing at a particular building.
Furnaces, Forges, Power Plants, Factories, and Ballistas all seemed upgradeable.
Personally, I did this at the end so I wouldn't have to feed them the fuel for them to continue working.