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Nuclear Energy. By: Vivek Tanna , Evyn Sewing, Dominic Genna , Jordan Beck. What is it?. Fission: Splitting of nuclei to release residual strong force energy Radioactive elements from Actinide series used; Uranium Provides energy in power plants, some naval ships, bombs Fusion:
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Nuclear Energy By: VivekTanna, Evyn Sewing, Dominic Genna, Jordan Beck
What is it? • Fission: • Splitting of nuclei to release residual strong force energy • Radioactive elements from Actinide series used; Uranium • Provides energy in power plants, some naval ships, bombs • Fusion: • Joining of nuclei in which extra mass is multiplied by speed of light squared and converted to energy—E=mc2 • Not expected to be used by humans before 2050 as no material can contain it; happens in the sun • Both: • Exothermal processes: thermal energy like fossil fuels
How it Happens—Uranium • Uranium-235 is naturally occurring and constantly decays alpha particles (two protons, two neutrons) • Uranium originated in stars that formed planet earth • Non-renewable because Uranium can run out • Firing one neutron at the nucleus makes it unstable and causes it to split, sending off more neutrons • Gamma radiation (energetic photons) caused by the split, beta radiation (electrons) by resultant pieces • In the Uranium used by power plants, 2-3% is U-235; weapons-grade Uranium is at least 90% U-235 • The fission of one U-235 releases 200 MeV (million electron Volts); one pound could replace one million gallons of gas
Power Plants • As Uranium fissions, more neutrons are sent—chain reaction • Uranium fissions in a reactor with water, which is heated • Steam of water turns turbines to generate electricity • Put simply, steam goes to cooling tower and the cycle repeats • There are sometimes secondary cooling cycles • Neutron-absorbing control rods can be placed nearer or farther from U to increase or decrease thermal energy production • Thick concrete and steel layers line the reactor core to prevent leaking radiation • Radioactive waste must be stored mixed with glass in cooled concrete structures
Who Uses It • Supplies: • 76.2% of Lithuania’s energy • 75.2% of France’s energy • 20% of the USA’s energy • 140 naval vessels are run on nuclear propulsion • Some countries with nuclear weapons: • U.K., France, United States • Asia: China,India, Pakistan, Russia, Israel, North Korea
Pros • Organizations: • World Nuclear Association • IAEA • Environmentalists for Nuclear Energy • Points: • 2 billion metric tons less CO2 emitted per year • Less radioactivity than fossil fuels when used properly • Less fluctuating prices • Million times more energy produced per unit weight
Cons • Organizations: • Greenpeace international • NIRS • Points: • Radioactive waste emits heat & radiation and is expensive to store mixed with glass in cool concrete structures • Accidents cause deaths and require city evacuations, but more deaths are caused by fossil fuel pollution (per energy) • Uranium mining, enrichment, and shipping is dirty • Expensive plants & risks of catastrophe • Disasters: Japan 2011, Chernobyl (Ukraine) 1986