9.2-Nuclear Energy
Nuclear Fission:
When a large nucleus splits into smaller nucleii releasing a large
amounts of energy, it is called nuclear 6ission.
During 6ission, a small amount of mass is converted into a tremendous
amount of thermal energy.
Nuclear power plants convert nuclear energy into electrical energy.
Nuclear Fusion:
Nuclear Fusion occurs when smaller atomic nuclei combine to make a
larger nucleus at very high temperartures.
In this process a small amount of mass is transformed into a large amount
of energy.The sun is a giant nuclear reactor in the sky.
Fusion occurs at millions of degrees celsius and so it is not practical on
earth.
Nuclear Reactors:
The fuel that is used in a nuclear reactor is usually
uranium dioxide. Naturally occuring Uranium
contains the isotope U-235,which has nuclei that can
split apart.
Nuclear Chain Reaction:
When a U-235 nuclei absorbs a neutron,it splits into
two smaller nuclei and two or three free neutrons
as shown in the Aigure.
Every Uranium atom that splits apart releases free
neutrons that cause other uranium atoms to split
apart,this process is called a nuclear chain reaction.
If the process is not controlled,the chain reaction
could release a tremendous amount of energy in the
form of an explosion.
Benefits of nuclear power
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Nuclear power plants do not produce air pollutants.
Nuclear power plants do not relaease carbon dioxide into the atmosphere.
Risks of nuclear power
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Nuclear power plants are very expensive to build.
The building process can take 10 or more years to complete.
Nuclear power plants produce radioactive waste that can be harmful to living organisms and
environment.