nonrenewable energy nuclear energy. nuclear energy- released by a nuclear fission or fusion...
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Nonrenewable Energy
Nuclear Energy
Nuclear Energy
• Nuclear energy- released by a nuclear fission or fusion reaction.– Nuclear force 1,000,000 times stronger than
chemical bonds between atoms– Uranium atoms used as fuel in nuclear power
plants
Nuclear Fission
• Splitting of the nucleus into two or more fragments– Chain reaction
Nuclear Fission
How it Works
• Heat energy is released
• Closed loop of water heats another water source
• Water boils producing steam
• Steam drives a turbine which in turn produces electricity
How it Works
• Reactor contained in a thick pressure vessel that’s filled with cooling fluid
• Surrounded by concrete
• Metal fuel rods contain Uranium pellets which are bombarded with neutrons
• Control rods, made of Boron and Cadmium, lower to slow or stop the chain reaction
Nuclear Power Plant
Pros and Cons of Nuclear Energy
• Advantages:– Very concentrated
energy source
– No air pollution
– Release less radioactivity than coal
– Can rely on when fossil fuels are limited
• Disadvantages:– Safe reactors-expensive– Expense not competitive– Investors hard to predict– Storage of waste must be
stable for 1,000’s of years
– Fission can be dangerous if not controlled
Nuclear Accidents
• Chernobyl of the Ukraine, 1986– Unauthorized tests
unsafe– Explosions destroyed
plant and released large amounts of radioactivity
– 100’s died from radiation exposure
– Areas still radioactive
• Three Mile Island nuclear power plant in Pennsylvania, 1979– Human error
– Blocked valves
– Broken pumps
– Small amount of radiation released
Future of Nuclear Power
• Safer nuclear power plants
• Researching transmutation, recycling of radioactive waste into nuclear fuel
• U.S. Nuclear Regulatory Commission- 300 safety regulation improvements
Nuclear Fusion
• Combination of smaller nuclei into larger nuclei
• Large amounts of energy
• Less dangerous radioactive byproducts
• Same reactions that comprise stars, including our sun
Disadvantages of Nuclear Fusion
• Technically difficult
• Three things must occur simultaneously:– Extremely high temperatures (100,000,000 C
or 180,000,000 F)– Nuclei must be concentrated– Nuclei must be properly confined
Nuclear Fusion
Chernobyl Radiation Results
Hiroshima
Radiation Results