Explore More Energy
help teacher resources contact us
web sites glossary careers explore more
profiles uses issues viewpoints

Fossil Fuels
   • History
   • How it Works
   • Benefits
   • Limitations
   • Geography
   • Sources


Nuclear energy uses the power of a uranium atom to produce electricity. An atom is broken apart, resulting in heat. This heat is absorbed by water. The hot water or steam runs a generator, which produces electricity.

nuclear power plantNuclear energy is one of the most recent achievements in the long history of harnessing energy, and one of the most controversial. A result of research originally done to produce the atomic bomb, nuclear energy takes advantage of the incredible potential energy within the atom in a productive instead of destructive way. Explore more about this powerful but potentially dangerous form of energy.
Image courtesy Dept. of Commerce/NOAA

Nuclear plants first came on-line during the late 1950s. In the 1970's, plants popped up across the United States as a solution to our reliance on foreign sources of energy. Tightly regulated by the federal government, plants were issued operating licenses lasting approximately 40 years. Many of those licenses are about to expire and again our nation is questioning our dependence on foreign energy resources.

How it Works
fuel rodHere’s how it works.

  • Uranium is mined from the earth.
  • The uranium is formed into small pellets, and placed in long rods.
  • Bundles of these rods are housed in a strictly contained environment called a reactor, where the nuclear reaction unfolds.
  • The reaction begins when nuclei of the uranium atoms are bombarded with neutrons, causing the nuclei to split apart. This process is called fission.
  • When the nuclei split apart, some of the energy takes the form of heat, the rest results in radiation
  • The heat is put to work, turning water into steam
  • The steam drives a turbine, which spins a generator, producing electricity.

Due to the dangers of radiation, the fission process is conducted under strictly controlled conditions. The primary use of nuclear energy is to produce electricity, and the extremely efficient process contributes a steady supply of power to our overall energy mix. Just one pound of uranium produces as much energy as 3 million pounds of coal.


  • Environmental–Nuclear energy's environmental impact is minimal. It does not contribute to air pollution. Nuclear power contributes no emissions at all to the atmosphere. Compare that to fossil fuels whose emissions, known as greenhouse gases, are blamed for everything from global climate change to ozone problems and acid rain.
  • Cost–Another benefit is the cost of producing the power. When compared to other energy types, nuclear is relatively cheap. The cost of the raw fuel, uranium, is less than natural gas, oil, or coal. The costs of running the actual plant are similar to those of running a coal or gas plant. Those lower costs combine to give consumers cheap electricity.
  • Reliability–Nuclear energy power plants produce a consistently large amount of power.

The most serious limitations of nuclear energy are disposal/storage of the nuclear waste, and radiation. After a period of time in the reactor, the bundles of rods lose their ability to produce heat effectively. These "spent" rods remain radioactive, posing a disastrous threat if that radiation were released. Since it takes hundreds of thousands of years for the radiation to extinguish, nuclear waste has to be disposed of in a way that will contain the radioactivity and protect people.

Disposal/Storage of Spent Fuel
Where do we store a material that is radioactive? After all, we can't just leave radioactive waste lying around. We don't want terrorists to have access to the nuclear waste and use it for weapons. And we can't put it in a landfill without seriously damaging our environment. The Federal Government has decided to create a national repository for nuclear waste in Nevada. Yucca Mountain will be the long-term storage site for all nuclear waste in the US This means transporting the waste over long distances in order to dispose of it, a plan which concerns many Americans. Industry officials counter those concerns by stressing the safety precautions they take. The waste is in a solid form, and carried in extremely durable containers, making a "spill" highly unlikely. But, no one can say with certainty how safe a place Yucca Mountain is or how long storage containers could last. And they will need to last for 40,000 years.

Radioactivity happens when an atom degrades, shooting off neutrons. It is very dangerous for all animal life when it isn't controlled. Your body's DNA can be damaged by too much radiation. Radioactivity is spread by wind, affecting large areas. And radioactivity remains in an area long after a reactor melts down. The radioactivity will stay in an environment for years.

Geographical Considerations
Nuclear power can be generated almost anywhere. It’s dependent only on a supply of uranium and the physical space needed for the plant. However, the potential dangers of nuclear power make it a tough sell to get communities to allow plants to be built. The nuclear industry points to good-paying jobs, contributions to the community’s tax base, and to their safety record as incentives for communities to let nuclear plants locate there. For example, pebble bed reactors , a new design of nuclear energy plants, may allow smaller communities to use nuclear energy.

What do you think?
Weigh the benefits and the limitations of nuclear power. Should this resource have a bigger piece of our "energy pie?" Would you want a nuclear reactor in your community? Would you want nuclear waste stored near your community?


  1. CNN. "Chernobyl's Deadly Legacy." (Online) http://www.cnn.com/2001/WORLD/europe/04/25/ukraine.chernobyl/index.html. June 2001.
  2. Energy Information Administration. "World Nuclear Generation of Electricity." (Online) http://www.eia.doe.gov/cneaf/nuclear/page/nuc_generation/gensum2.html. August 2001.
  3. Energy Information Administration. "U.S. Nuclear Generation of Electricity." (Online) http://www.eia.doe.gov/cneaf/nuclear/page/nuc_generation/gensum.html. August 2001.
  4. Nuclear Energy Institute. "Nuclear Energy in Iowa." (Online) http://www.nei.org/documents/maps/statebystate/iowa.html. September 2001.
  5. Pebble Bed Modular Reactor Ltd. "The Advantages of a Pebble Bed Reactor." (Online) http://www.pbmr.co.za/2_about_the_pbmr/2_5advantages_of_pbmr.htm. June 2001.
  6. World Nuclear Association. "Chernobyl." (Online) http://www.world-nuclear.org/info/chernobyl/inf07.htm. June 2001.



A New Design for Nuclear Plants: The Pebble Bed Reactor
New nuclear power reactor designs could help ease concerns over the safety of nuclear power generation. One new design called the "pebble bed reactor" differs in several ways from the current generation of reactors.

Nuclear Accidents
There have been three major nuclear accidents, one in the United States at the Three Mile Island Nuclear Facility in Pennsylvania, one in Chernobyl, Russia...

PBS NewsHour Links

Will 2,000 new nuclear plants be built over the next 20 years?

The Pros and Cons of Nuclear Power and Trying to Cope with Nuclear Fear

A report on underground storage tanks leaking nuclear waste.

Interested in how nuclear waste will be stored in Yucca Mountain? NewsHour Extra looks into the sticky situation of storing our nuclear waste.

After researching and debating for twenty years, the US government supports the Yucca Mountain plan to store tons of radioactive waste in a Nevada mountain.

Web Links
Who makes sure Nuclear Power is safe?
The Nuclear Regulatory Commission regulates U.S. commercial nuclear power plants and the civilian use of nuclear materials