1. Section 3

2.  Inside the nucleus of the atom contains protons and neutrons.  Nuclear reactions involves tremendous amounts of energy.  Two types of nuclear reactions: 1. Fission 2. Fusion

3. Nuclear fission is the splitting of an atom’s nucleus into two smaller nuclei. The fuel is a large unstable atom such as Uranium-235. When the neutron hits the U-235 nucleus, the nucleus splits apart into two smaller nuclei and 2 or more neutrons.

5.  If a nuclear chain reaction is not controlled, the released energy causes a huge explosion. (atomic bomb)  If a nuclear chain reaction is controlled, the energy is released as heat, which can be used to generate electricity.

6.  Controlled nuclear fission. The heat released from the reactions is used to change water into steam. The steam then turns the blades of a turbine to generate the electricity.  Two main parts to the power plant:  Reactor Vessel  Heat Exchanger Nuclear power plants generate much of the worlds electricity.(20% in the U.S.)

8.  Meltdowns (Chernobyl, Ukraine) 1. Fuel rods produced too much heat, 2. Increase steam pressure, 3. Explosions occurred, 4. Radioactive materials escapes.  Radioactive waste disposal

9.  Nuclear Fusion is the combining of 2 atomic nuclei to produce a single larger nucleus.  Advantages: 1. It produces more energy per atom than nuclear fission. 2. It is readily available. 3. It is safer 4. Less polluting than nuclear fission.

11.  Disadvantages: 1. Scientists have not yet been able to control a large-scale fusion reaction. No material has been found that could serve as a reactor vessel under high pressure. Scientist believe one day they will succeed and produce a clean, cheap energy source.