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How does the energy released by fissioning uranium-235 compare with burning coal?

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A color-coded periodic table of the elements displays each element's symbol and atomic number, with categories such as alkali metals, noble gases, halogens, transition metals, and actinoid elements distinguished by different background colors. — actinoid element Modern version of the periodic table of the elements (printable).

The energy density of uranium-235 is vastly superior to that of coal. While coal releases thermal energy through chemical combustion, uranium-235 releases an enormous amount of energy through the process of nuclear fission, where the nucleus of an atom is split.12

The disparity in energy content is significant:
* A single uranium pellet, roughly the size of a gummy bear, possesses an energy-production capacity comparable to one ton of coal.3
* When completely fissioned, 1 kilogram (2.2 pounds) of uranium-235 releases energy equivalent to 17,000 tons of TNT.1

This immense energy density is why nuclear fuel costs are substantially lower than fossil fuel costs per kilowatt-hour of electricity generated, despite the higher complexity and regulatory requirements associated with operating nuclear power plants. Consequently, nuclear power plants can maintain a much higher capacity factor—the ability to run consistently at maximum output—compared to coal-fired plants.43