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