11.3. Nuclear Energy http://www.ck12.org
Using Energy from Nuclear Fission
If a nuclear chain reaction is uncontrolled, it produces a lot of energy all at once. This is what happens in an atomic
bomb. If a nuclear chain reaction is controlled, it produces energy more slowly. This is what occurs in a nuclear
power plant. The reaction may be controlled by inserting rods of material that do not undergo fission into the core
of fissioning material (seeFigure11.14). The radiation from the controlled fission is used to heat water and turn it
to steam. The steam is under pressure and causes a turbine to spin. The spinning turbine runs a generator, which
produces electricity.
FIGURE 11.14
This diagram shows the main parts of a nuclear power plant.Pros and Cons of Nuclear Fission
In the U.S., the majority of electricity is produced by burning coal or other fossil fuels. This causes air pollution,
acid rain, and global warming. Fossil fuels are also limited and may eventually run out. Like fossil fuels, radioactive
elements are limited. In fact, they are relatively rare, so they could run out sooner rather than later. On the other
hand, nuclear fission does not release air pollution or cause the other environmental problems associated with burning
fossil fuels. This is the major advantage of using nuclear fission as a source of energy.
The main concern over the use of nuclear fission is the risk of radiation. Accidents at nuclear power plants can
release harmful radiation that endangers people and other living things. Even without accidents, the used fuel that is
left after nuclear fission reactions is still radioactive and very dangerous. It takes thousands of years for it to decay
until it no longer releases harmful radiation. Therefore, used fuel must be stored securely to people and other living
things. You can learn more about the problem of radioactive waste at this URL: http://www.youtube.com/watch
?v=OPQ97LVRuuM.