A Civilization advance.
Nuclear fission is the process by which two atomic nuclei combine to form one heavier atomic nucleus, giving off tremendous energy as a by-product. Thermonuclear fusion reactions require very high temperatures to initiate and some system of fuel containment to sustain. Nuclear fusion offers great promise as a source of electric power, because safe fuel is available in large quantities and the process does not create the radioactive wastes that plague nuclear fission.
Prerequisites: Nuclear Power and Superconductor
Allows for: none.