Energy - Fission and Fusion
major form of energy is nuclear energy, the energy that is trapped
atom. One of the laws of the universe is that matter and energy can't
created nor destroyed. But they can be changed in form.
can be changed into energy. The famous scientist Albert Einstein
created the mathematical formula that explains this. It is:
E = mc2
This equation says:
E [energy] equals m [mass]
[c stands for the speed of
light. c2 means c times c, or the
speed of light raised to
the second power -- or c-squared.]
used Einstein's famous equation as the key to unlock atomic
energy and also create atomic bombs.
ancient Greeks said the smallest part of nature is an atom. But
they did not know 2,000 years ago about nature's even smaller parts.
are made up of smaller particles -- a nucleus of protons and
neutrons, surrounded by electrons which swirl around the nucleus much
earth revolves around the sun.
atom's nucleus can be split apart. When this is done, a tremendous
amount of energy is released. The energy is both heat and light energy.
energy, when let out slowly, can be harnessed to generate electricity.
is let out all at once, it makes a tremendous explosion in an atomic
word fission means to split apart.
A nuclear power plant (like Diablo Canyon Nuclear Plant shown on the
uses uranium as a "fuel." Uranium is an element that is dug out of
the ground many places around the world. It is processed into tiny
are loaded into very long rods that are put into the power plant's
the reactor of an atomic power plant, uranium atoms are split
apart in a controlled chain reaction.
chain reaction, particles released by the splitting of the atom go
off and strike other uranium atoms splitting those. Those particles
split still other atoms in a chain reaction. In nuclear power plants,
rods are used to keep the splitting regulated so it doesn't go too
reaction is not controlled, you could have an atomic bomb. But
in atomic bombs, almost pure pieces of the element Uranium-235 or
a precise mass and shape, must be brought together and held together,
great force. These conditions are not present in a nuclear reactor.
reaction also creates radioactive material. This material could
hurt people if released, so it is kept in a solid form. The very strong
concrete dome in the picture is designed to keep this material inside
chain reaction gives off heat energy. This heat energy is used to
boil water in the core of the reactor. So, instead of burning a fuel,
power plants use the chain reaction of atoms splitting to change the
atoms into heat energy.
water from around the nuclear core is sent to another section of
the power plant. Here it heats another set of pipes filled with water
steam. The steam in this second set of pipes powers a turbine to
more about nuclear fission by visiting other web sites:
form of nuclear energy is called fusion. Fusion means joining
smaller nuclei (the plural of nucleus) to make a larger nucleus. The
nuclear fusion of hydrogen atoms into helium atoms. This gives off heat
light and other radiation.
picture to the right, two types of hydrogen atoms, deuterium and
tritium, combine to make a helium atom and an extra particle called a
given off in this fusion reaction is energy! Thanks to the
University of California,
Berkeley for the picture.
have been working on controlling nuclear fusion for a long
time, trying to make a fusion reactor to produce electricity. But they
been having trouble learning how to control the reaction in a contained
better about nuclear fusion is that it creates less radioactive
material than fission, and its supply of fuel can last longer than the
Here's What We Learned
fission means splitting an atom apart.
an atom releases heat and light
a nuclear power plant, an atomic chain
reaction is controlled to produce heat to boil water. That water boils
pipes to make steam to turn a turbine and a generator to make
fusion means combines atomic nuclei to
make a larger nucleus.
sun uses nuclear fusion of hydrogen into
helium to make light and heat energy.
are trying to create nuclear fusion
to make a cleaner source of power.