Uranium

Uranium is the third and second to last resource obtainable, and can be mined with the Uranium Mine, which costs $250M to buy. The Uranium Mine is unlocked with the discovery of the Nuclear Cell. Uranium is required in order to power a Nuclear Cell, Thermonuclear Cell, and Fusion Cell. Uranium is mined most effectively on the Donutville map, which consumes 300k power and produces 1.5 uranium, however you can produce Uranium on any map.