Uranium
235
The fuel most widely used by nuclear power
plants is uranium.
Uranium
Uranium is a mineral buried in the ground.
It has energy in it.
Uranium
Once uranium is mined, a certain kind of
uranium, U-235, is extracted.
The U-235 is processed at a nuclear power plant.
Uranium
Uranium atoms are
split during a process
called fission.
The energy released
is used to generate
electricity.
Nuclear energy is energy in the
nucleus (core) of an atom.
Atoms are tiny particles that make up every object in
the universe.
There is enormous energy in the bonds that hold
atoms together.
Nuclear energy is energy in the
nucleus (core) of an atom.
An atom has two main parts: a very tiny nucleus and the electrons
that surround it.
A very common picture that is often shown looks like this:
Nuclear energy is energy in the
nucleus (core) of an atom.
electron
proton
neutron
&
=
nucleus
Nuclear energy is energy in the
nucleus (core) of an atom.
 This diagram of an atom is
partially true, since it shows that
electrons “orbit” around the
nucleus.
 However, it is misleading, since it
gives you the idea that electrons
move in circular paths.
 In fact, electrons do not move in nice orderly circles!
Nuclear energy is energy in the
nucleus (core) of an atom.
An electron should be thought of more as a fuzzy
"cloud" that is able to fill the whole space around a
nucleus, kind of like the picture below:
Nuclear energy is energy in the
nucleus (core) of an atom.
 The energy stored in the nucleus of an atom is
called nuclear energy.
 It holds the atoms together.
 In order to use this energy, we have to set it
free!
There are two ways to free the
energy in atoms:
• One way is to combine
atoms to make a new atom.
• This is called fusion.
• The energy from the sun is from fusion!
Fusion
There are two ways to free the
energy in atoms:
Another way to free the energy in atoms is to
split them apart.
We can split one atom into two smaller atoms.
This is called fission.
Nuclear Fission
During nuclear fission, a small particle called a neutron hits
the uranium atom and it splits, releasing a great amount of
energy as heat and radiation.
Nuclear Fission
More neutrons are also released. These neutrons go on to
bombard other uranium atoms, and the process repeats itself
over and over again.
This is called a chain reaction.
Uranium
The fuel most widely used by
nuclear plants for nuclear fission is
uranium.
235
Uranium is Non-Renewable
We can’t make more! It is a
common metal, though, found
in rocks all over the world.
Nuclear plants use a certain
kind of uranium, U-235, as fuel
because its atoms are easily
split apart.
So how does Uranium go
from…
to
?
Uranium ore
Electricity
Uranium Fuel Cycle
1. Uranium ore is mined.
2. The mined uranium
ore is turned into
yellowcake.
Uranium Fuel Cycle
3. Yellowcake is turned into a gas –
Uranium Hexafluoride
Uranium Fuel Cycle
5. U-235 is made into
ceramic fuel pellets.
4. Gas is filtered to increase
the amount of U-235.
Ceramic Pellets
The uranium fuel is formed into ceramic
pellets.
=
1
150 gallons
The pellets are about the size of your fingertip,
but each one produces the same amount of
energy as 150 gallons of oil!
Uranium Fuel Cycle
6. These energy-rich pellets are stacked end-to-end
in 12-foot metal fuel rods. A bundle of fuel rods
is called a fuel assembly.
Most power plants burn fuel to
produce electricity, but not nuclear
power plants!
Instead, nuclear plants use the heat
given off during fission as fuel.
Atoms of uranium are
split into two smaller
atoms.
The extra energy is
released as heat.
The heat is used to boil
water into steam.
The steam turns huge
turbine blades
The turbines generate
electricity.
Nuclear Power is Clean!
Since no fuel is
burned, nuclear power
plants don’t release
pollution into the air!
Nuclear Power is Cheap!
Right now, about 20%
of our electricity comes
from nuclear power
plants.
Nuclear Power Plants in the
United States
Unfortunately, nuclear
power creates problems!
During fission, heat isn’t the only energy that is
released!
Rays of energy, like x-rays, are also given off.
These rays of energy, called radiation, can be
dangerous!
Radiation
Radiation is everywhere!
It comes from the sun.
It comes from TV sets.
Small amounts of radiation are harmless.
Radiation
Large amounts of
radiation, however, can
kill our cells and poison
our food and water.
Power plants are very
careful to keep radiation
from escaping!
Radiation
The fuel from nuclear power plants
produces radiation for a long time.
Radiation
After the fuel is used, it is still
radioactive- it gives off radiation.
It can’t be put into a landfill.
It must be carefully stored away from people.
Storing Nuclear Waste
Spent fuel is
stored at the
power plant
or
buried in an
underground
repository.
The Nuclear Energy Debate
Some people don’t think we should use
nuclear energy.
They think the radiation is too
dangerous.
Other people think nuclear energy is a
clean, safe way to make electricity.
Discussion Questions
1. Do you think we should use nuclear
power? Why or why not?
2. Are the benefits of using nuclear
power greater than the consequences?
3. Would you want a nuclear power
plant in your neighborhood? Why or
why not?