III. Nuclear Power

A. Reactions and Sources 1. Uses energy released by nuclear fission- the splitting of the nucleus of an atom 2. Nucleus is hit with neutron which breaks it releasing heat, radiation, and free neutrons a. Neutrons move to cause other atoms to break b. If not controlled causes chain reaction

3. Usually use enriched Uranium, specifically U 235 a. U 235 emits more neutrons than U 238 but us rarer b. Most mined Uranium must be processed into U 235 c. This is compressed into UO 2 pellets which are formed in to fuel rods

B. Reactors 1. Use same theory as a coal power plant a. Heat generated by decay is used to boil water which turns a turbine that spins a generator to produce electricity

2. Problems are with radiation and containment a. Radiation must be completely contained b. Reaction takes place in lead-lined core and all parts must be sealed from outside 1. in core are control rods- can be raised or lowered to control reaction rate a. Blocks neutrons c. Steam, coolant, rods are all radioactive and must be treated carefully

3. Breeder reactors create fuel as they produce energy a. Bombard U 238 which decays into Plutonium which triggers new U 238 to react b. High risk of explosion because reaction occurs in liquid sodium

C. Benefits/risks 1. High energy output 2. zero emissions 3. Less stressing mining procedure 4. Produce waste materials that remain dangerous for 100’s of years

5. When accidents do occur, can be terrible a. 3-mile Island had a near meltdown but no contamination b. Chernobyl released radioactive steam cloud c. Only major accidents and both from mhuman error