Energy sources fit into three main buckets–fossil fuels (coal, oil and natural gas), renewable (e.g. wind, solar, hydroelectric, geothermal, etc.) and nuclear.  Nuclear energy is a nonrenewable energy resource because it relies on Earth’s uranium deposits.

Nuclear energy is derived from the splitting of atoms. The nucleus of an atom contains protons and neutrons held together by the strong force, one of the four fundamental forces of nature. When the strong force is overcome and protons or neutrons are able to escape the nucleus, nuclear potential energy escapes, too. This process is called a fission reaction.



Click on the text boxes above to learn how nuclear reactors work.

Humans first harnessed the power of fission reactions in the form of nuclear bombs. Not long after, scientists learned to how to create fission reactions in a much more controlled way inside nuclear reactors.

Nuclear reactors at nuclear power plants are fueled mostly by U-235, an isotope of uranium. The process of splitting the nuclei of the U-235 isotopes releases large amounts of energy. That energy is used to heat water and create steam to turn turbines and generate electricity.

Once people understood how to harness nuclear energy in a controlled way in properly designed reactors, nuclear energy quickly caught on as a means of generating electricity. Today, nuclear reactors generate almost 15 percent of the world’s electricity.


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Examine the science of energy, from what it is to where it comes from.

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How Nuclear Reactors Work 18 December,2015QUEST Staff

  • Paxus Calta

    Nuclear reactor construction did not take off because “people understood how to harness nuclear energy in a controlled way in properly designed reactors” Nuclear power took off because nuclear reactor sales persons 1) lied or 2) were incompetent in estimating the costs of reactors. Once utilities had sunk a billion or two into reactor projects they could not go backwards. Most of Japan does not want reactors restarted (about 60%) still the Abe government wants to re-open reactors.

    Nuclear power is heavily subsidized, Wall Street has no interest in it without government loans and guarantees. As the Economist Magazine says “Originally billed as too cheap to matter, nuclear power is now too expensive to matter.” http://funologist.org/2012/11/27/what-a-really-poor-investment-looks-like/

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QUEST Staff

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