Uranium provides commerce to the city that works it. Among all tile resources, Uranium is exceptional in that it does not add any bonus yield to its tile, unless improved with a Mine. It is required for the production of many of the late-game military units and nuclear weapons and doubles the production speed of the Manhattan Project.
One of the most valuable metals in the world, uranium's use has dramatically changed since its discovery in 1789. Originally used in the production of steel alloys, uranium improved the strength and elasticity of steel without making it brittle. Since 1939, however, it has rarely been used for anything besides atomic energy. This heavy, white metal's greatest contribution to civilization lies in the process of nuclear fission. Radioactive manipulation of uranium atoms can eject neutrons, which travel at speeds up to 12,000 miles per second. If such a neutron impacts the nucleus of a neighboring atom, the target atom can fragment. Not only is the resulting energy released immense, but the shattered atom can also potentially collide with additional atoms. This chain reaction is the phenomenon underlying all nuclear fission applications, including nuclear weapons and power.