GEO- EXAM 3 REVIEW - Lecture 12 1 Nuclear power generates...

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Lecture 12 1. Nuclear power: generates electricity a. France generates 77% of electricity from NP after oil prices went up. 2. 1951 first reactor in the US; costly to build, no new ones since the 70s. 3. Nuclear fission: nuclear reaction; nucleus of an atom splits into smaller parts, producing free neutrons, lighter nuclei and energy (heat). a. To artificially induce, strike 235U nuclei with slow moving neutrons. a.i. Sets off chain reaction where more neutrons are generated. (releases heat) b. 235U and 238U, 235 is isotope that is fissionable. c. Uranium is a solid, during diffusion the lighter ones get through. 4. Nuclear reactors: 4 main parts a. Fuel: pellets of enriched uranium dioxide in 12 foot long fuel rods. b. Control rods: contain material that absorbs neutrons and regulates rate of chain reaction or turn off. c. Coolant: usually water, pumped through the reactor to carry away heat produced by fission, creates electricity. d. Moderator: slows down the speed at which neutrons travel. d.i. Fast don’t interact w/ Uranium, so no reaction occurs. 5. Pressurized water reactors: most common—66% a. Encased in cement and steel lining for safety. b. Reactor core generates heat. c. Pressurized the H20 carries heat to steam generator. d. Inside generator heat produces steam. e. Steam turns turbine which produces electricity. f. Unused steam is exhausted to condenser, where it is condensed into water. g. Water pumped out condenser, reheated and pumped back to the steam generator. 6. Fast Breeder Reactors: turn usable 238 to 239Pu a. Uses plutonium, not uranium b. Pu surrounded by rods of 238U, which absorb neutrons and are transmitted into 239pu. c. As the plutonium in core depletes it ‘breeds’ more pu from the U around it. d. Extreme temperature surround reactor require liquid sodium as coolant. 7. Differences: breeder doesn’t use moderator and has higher temperatures. 8. Uranium life cycle: a. Uranium (geological processes) ORE (mining processing) ”yellowcake” (concentrated uranium) enrichment fuel rods reactor 9. Advantages to nuclear power: there is a lot of energy just in a little bit of 235U. a. One pellet=3 barrels of oil, I ton of coal, 1700 cubic ft of natural gas, 1 cord of wood. (separately) b. Secures imports, cheaper. Reduces pollution, no CO2 emissions from the plants. b.i. Much less than any other plant used to create energy electricity power. c. Eventually become more economic.
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Lecture 13 1. Three Mile Island: civilian nuclear power plant. In Pennsylvania. a. One of the 2 pressurized water reactors suffered a partial meltdown due to a cooling system malfunction. a.i. Loss of coolant released radioactivity into the environment.
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GEO- EXAM 3 REVIEW - Lecture 12 1 Nuclear power generates...

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