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Nuclear Energy. Power Plants. Chernobyl. Fuel. Uranium-235 an isotope of naturally occurring uranium-238 Uranium is mined-common mineral is urananite. Uranium-238 is enriched so more of the isotope U-235 is present.
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Nuclear Energy Power Plants
Fuel • Uranium-235 • an isotope of naturally occurring uranium-238 • Uranium is mined-common mineral is urananite. • Uranium-238 is enriched so more of the isotope U-235 is present. • Enriched from about 0.7% in naturally occurring uranium to 5% for use in reactors
Fuel Rods in the Reactor Core • The fuel rods in a reactor are about a finger width in diameter. • They are 12 feet long • 100 fuel rods make up a fuel rod assembly (fra) • There are 100 fra in a reactor core
Chain Reaction What happens in the Reactor?
Chain Reactions in Fission Nuclear Reactors • Our present day Nuclear Power plants are fission power plants. • What does fission mean? The atom is split apart to produce energy. • A controlled chain reaction takes place within the reactor core.
Can a reactor become a Nuclear Bomb? • No, the uranium used in a nuclear bomb must be U-235 enriched to 95%.
Can a reactor sustain damage that results in the release of radiation? • Yes Two examples: Three Mile Island (1979) and Chernobyl (1986) • In both cases radiation was released into the atmosphere. • Both were caused by human error
How is a chain reaction controlled? • Control Rods-made of cadmium and boron. • They absorb neutrons to help control a reaction. If we drop more control rods into the reactor core, what will happen to the reaction rate? SLOW IT DOWN!
What else helps to control the reaction? • Water present in the reactor core slows down the movement of the neutrons in the chain reaction. • It also absorbs heat energy.
Containment Domes- Building that encloses the reactor and helps to contain any radiation leaks should they occur. Four (4) foot thick wall of cement. Safety
Reactors in the United StatesHistory • First active reactor in the Unites States to produce electricity 1957 • As of 1990 there are 111 operating units producing about 20% of the total electricity generated in the United States.
Minnesota Nuclear Power Plants How many are there in Minnesota Answer: 2 Where are they located? Answer: Monticello and Prairie Island What kind of reactor are they? Answer: Monticello is a BWR and Prairie Island is a PWR