FISSION or FUSION

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FISSION or FUSION?!?!?!?!
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FISSION!!!
MOVIE CLIP
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Nuclear Chain Reactions
Play Movie
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Little Boy
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Inside the little guy
Little Boy
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Hiroshima
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Fat Man
Fat Man
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Nagasaki
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Nuclear Power Plants

• Nuclear power plants use fission just like a
  nuclear or atomic bomb.
• But in a power plant, the chain reactions are
  somewhat controlled.
• How? Lets look at a diagram of a nuclear reactor
  in a power plant

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Diagram of a power plant
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In the reactor core, we have

• fuel rods that contain Uranium for a chain
  reaction
• plus control rods
• coolant and moderator
• and a cooling tower

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Fuel rods

• The uranium are first processed into small
  pellets about the size of a pencil eraser.
• Then the pellets are placed into rods.

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Control Rods

• The control rods are how we control the chain
  reaction (duh).
• The material that makes up the control rods
  absorb some of the neutrons that come from a
  nucleus being split.
• Since some of the neutrons are absorbed into the
  rod, these neutrons cannot travel on to split
  another nucleus.
• So, the chain reaction is controlled by the
  control rods.
• We can think of the control rods as neutron
  sponges.

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Coolant and Moderator

• In most reactors, the coolant is simply water.
• Coolant is there to help do what?
• Cool the reaction!
• The moderator in a reactor is also usually water,
  but its special water
• They use something called heavy water which is
  water made with a heavy hydrogen isotope.
• The heavy water helps to slow down the neutrons
  in a chain reaction.

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Cooling Towers

• A cooling tower is a tall, hollow cylinder that
  is pinched a little at the top (those towers they
  feature on The Simpsons with the steam coming
  out of it).
• The warm water from the reactor core must be
  cooled before releasing it to the environment to
  protect the wildlife.
• Some of the water evaporates in the cooling
  tower, but most of it is recycled to be used in
  the reactor core once it is cooled.

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Benefits of Nuclear Power

• The power from one kilogram of uranium is equal
  to the power of 100,000 kilograms of oil.
• No carbon dioxide emissions to contribute to the
  Greenhouse Effect
• No sulfur emission to contribute to acid rain.
• No need to use pipelines to transport gas and oil.

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How much of the U.S. uses nuclear power?
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Hydrogen Bomb
Hydrogen Bomb
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FUSION

• Joining nuclei of two atoms to form a heavier
  atom.
• Gives off MORE energy than fission
• Extremely HIGH temperatures.
• Hydrogen isotopes combine to form heavier
  elements and release energy.
• Electrostatic repulsion between atoms must be
  overcome in order for fusion to happen.

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