Fission and fusion

# Fission and fusion

## Fission and fusion

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##### Presentation Transcript

1. 30 May 2012 Fission and fusion U-235 binding energy Nuclear power plants Advantages and disadvantages Nuclear disasters 11 Physics

2. U-235 binding energy per nucleon Calculate the binding energy per nucleon where the mass of a U-235 nucleus is 235.0439299 u. Image: http://en.wikipedia.org/wiki/Uranium-235

3. Binding energy per nucleon

4. Nuclear fusion

5. Nuclear fission The sun

6. Nuclear power plant • Thermal power plant • Uses a nuclear chain reaction Image: http://en.wikipedia.org/wiki/Nuclear_power_plant

7. Uranium fuel • Natural uranium ore (pitchblende, uranium oxide) is a mix of isotopes: • 99.3% U-238 • 0.7% U-235 (Plutonium-239 can also be used as fuel) not enough U-235 for a chain reaction Image:http://en.wikipedia.org/wiki/Uranium_ore

8. Critical mass: minimum size for a nuclear chain reaction to occur • 11kg Pu-239 • 52kg U-235 Mk-54 SADM (Special Atomic Demolition Munition). The bare warhead package was an 28 cm by 41 cm cylinder that weighed 23kg. Image: http://en.wikipedia.org/wiki/Suitcase_nuke image: http://en.wikipedia.org/wiki/Critical_mass

9. PhETsim • Artificial transmutation: 10n + 23592U  23692U • Nuclear chain reaction with U-235, eg: 23692U 13755Cs + 9637Br + 3 10n • Isotopic enrichment to 5% U-235 • Containment vessel • Control rods

10. Nuclear power plant Image: http://en.wikipedia.org/wiki/Nuclear_power_plant Moderator Control rods Reactor vessel Heat exchanger Turbine Generator

11. Advantages and disadvantages • high energy density • large uranium reserves in Australia, Canada, Kazahkstan • does not depend on weather, time of day, etc. • Radioactive waste • Accident (thermal meltdown) • Terrorist target • Non-renewable • Mining and transport of fuel difficult and expensive • Expensive to builld plant • Nuclear technology proliferation • Pu-239 created as waste product- could be used for weapons

12. Nuclear accidents: Chernobyl 1986 power surge  containment vessel rupture  graphite moderator exposed to air  fire 31 workers died from acute radiation sickness thousands (?) of extra cancer deaths, particularly from thyroid cancer Image: en.wikipedia.org/wiki/Chernobyl_disaster

13. Nuclear accident: Fukushima 2011 tsunami  flooding of control rooms  coolant systems not working  meltdown  build up of hydrogen gas  explosion 0workers died from acute radiation sickness (though some were drowned in tsunami) dozens (?) of extra cancer deaths (not from thyroid cancer) Image: http://en.wikipedia.org/wiki/Fukushima_I_nuclear_accidents

14. Nuclear power plant Short (3 slide max, 4 min) presentation including information about: cooling system, fuel, moderator, control rods, waste, safety systems diagrams and nuclear equations references AGR, PWR BWR, fast breeder