Nuclear Energy

Everyday energy sources -- fossil fuels such as coal, petroleum and natural gas, along with firewood -- release energy through CHEMICAL reactions, typically involving only a few electron-volts (eV) of energy per individual reaction; these fuels also take millions of years to form naturally, so their supply, though currently large, is fundamentally limited and will eventually run out if consumption continues at present rates. This has driven the search for, and adoption of, alternative energy sources such as hydroelectric, solar, wind and nuclear power -- of which nuclear energy is, by far, the largest-scale alternative currently in use.

Nuclear energy is released when nuclei undergo a NUCLEAR reaction -- some interaction or transformation that changes their internal structure -- and the energy released per reaction is typically of order MeV, roughly a MILLION times larger than the eV-scale energy of a typical chemical reaction. Weight for weight, then, nuclear fuel can release roughly a million times more energy than an equivalent mass of chemical fuel -- though harnessing that energy safely is also a far more complex, expensive, and potentially hazardous undertaking than burning a conventional fuel. …