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Nuclear Fusion. Fusion – perfect, but difficult small nuclei combine to create larger atoms 2 H + 3 H 4 He + 1 n + 1 1 2 0 Occurs in the sun and other stars. Energy. Nuclear Fusion. “Hot” fusion -- difficult to contain 100million Kelvins
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Nuclear Fusion Fusion – perfect, but difficult small nuclei combine to create larger atoms 2H + 3H4He + 1n + 1 1 2 0 Occurs in the sun and other stars Energy
Nuclear Fusion • “Hot” fusion -- difficult to contain 100million Kelvins • At this temperature a Plasma is formed (charged ions as a gas) • Nuclear Physicists use Magnets to contain the hot plasma and force the plasma together
Nuclear Fission • Nuclear fission can be induced by bombarding atoms with neutrons. • The nuclei of the atoms then split into 2 parts. • Induced fission decays are also accompanied by the release of neutrons and LOTS of energy
Each time a fission occurs, large amounts of energy are released Under certain conditions a chain reaction is started that creates a HUGE amount of energy to be released very quickly!
When this source of energy was discovered in the last century, it was first used as a massive weapon.
Fission Bombs Called “atomic bombs” or “A-bombs” Critical mass = need enough U-235 to start an uncontrollable fissioning chain reaction! Strength of up to 500,000 TONS of TNT
Little Boy dropped on Hiroshima: August 6, 1945 Uranium bomb Gun-type assembly (15 kTons)
Fat Man dropped on Nagasaki: August 9, 1945 Plutonium made at Hanford in Washington State Implosion bomb (21 kTons)
Fusion Bombs • “H-bombs” or Thermonuclear Bombs • Developed after WWII • Mixture of Fission and Fusion • Fission first to get energy up • Then fusion started • Then more fission once reaction gets going!
They have found a way to tap the energy in nuclear reactions in a controlled way. Link to Animation http://www.msnbc.msn.com/id/42029294/ns/technology_and_science-science/t/how-nuclear-plant-works/
Infamous Powerplant 3 Mile Island March 1979 Pennsylvania Core meltdown in reactor: human error and valve issue Most significant nuclear accident in US history 1-2 cancer deaths due to accident
Infamous Powerplant CHERNOBYL April 1986 Ukraine Reactor vessel rupture and explosions atmosphere 32 immediate deaths; 100,000s of cancer-related deaths since 19 mile evacuation zone still in place today
Infamous Powerplant FUKUSHIMA March 2011 Japan Earthquake and tsunami knocked out central power and generator power, so the reactions couldn’t be controlled 37 with physical injuries, 2 workers hospitalized and 1 death (from a heart attack)
Nuclear Fission & POWER • Currently about 103 nuclear power plants in the U.S. and about 434 worldwide. • 17% of the world’s energy comes from nuclear.
Anything Else? What questions do you still have that I can answer next time?
Homework Reading on Nuclear Powerplants Answer the questions at the end