P2 - Nuclear Fission And Fusion Flashcards
What happens in a nuclear reactor?
A controlled chain reaction occurs where atomic nuclei split up and release heat energy.
What happens to the heat energy released in a nuclear reactor?
The heat is used to heat water, which drives a steam turbine connected to an electricity generator.
What fuel is split in a nuclear reactor?
Uranium-235 or plutonium-239.
What must occur for nuclear fission to happen?
A slow moving neutron must be absorbed into a fuel nucleus.
This additional neutron causes the nucleus to become unstable and split.
What happens when a uranium/plutonium nucleus splits up in a nuclear reactor?
It spits out 2 or 3 neutrons which hit another nucleus, causing that to split, keeping the reaction going.
Why is nuclear fission better than chemical processes?
They give out more energy.
What is the main problem with nuclear fission?
The waste products are radioactive - difficult and expensive to dispose of safely.
Discuss the costs of nuclear fission [2].
Fuel is cheap.
Cost of power plant and decommissioning is high.
What other risk do nuclear power plants carry?
Radiation leaks like Chernobyl.
What is nuclear fusion?
The joining of two small atomic nuclei.
What are the advantages of nuclear fusion? [3].
1) releases more energy than fission.
2) doesn’t leave behind radioactive waste.
3) lots of hydrogen to use as fuel.
What are the problems with nuclear fusion? [2].
1) only happens at high temperatures (10,000,000c).
2) need strong magnetic field to hold hydrogen at correct temperature and pressure.
3) current takes more power than produces.
What is nuclear fission?
The splitting up of big atomic nuclei.
