General

Created by

Shekinah Obare

Cards (16)

Nuclear fission 
The splitting of large, unstable nuclei to form smaller more stable nuclei (+the emission of spare neutrons)
Fissionable isotope
Uranium - 235
What usually needs to happen to induce fission
1. The unstable nuclei must absorb a neutron
2. Spontaneous fission (where no neutron absorption occurs) is rare
What is emitted in a fission reaction
Two or three neutrons
Gamma rays
Energy
Fission products
Kinetic energy
What takes place during a chain reaction in a nuclear reactor
1. An unstable nucleus absorbs a neutron
2. The nucleus undergoes fission and releases 2 or 3 further neutrons
3. These induce more fission, which results in a chain reaction
Consequence of an uncontrolled chain reaction 
The rate of fission events becomes to high and results in the production of too much energy
This can lead to a nuclear explosion
Main components of the core a nuclear reactor
Fuel rods
Control rods
Moderator
Role of the moderator in a nuclear reactor
To slow down the neutrons so they are travelling at speeds which allow them to be absorbed by fissile nuclei and cause fission
How the chain reaction in a fission reactor is kept under control
1. Control rods are positioned in between the fuel rods
2. The rate of fission is controlled by moving these rods up and down
3. The lower the rods are inserted, the slower the rate of fission
Fissile nuclei 
Nuclei in which fission can be induced through the absorption of slow neutrons
Nuclear fusion
The joining of two light nuclei to produce a heavier nuclei and release energy
Isotopes of hydrogen commonly used in nuclear fusion
Deuterium and Tritium
Nuclear fusion releases more energy than nuclear fission
Difficulty of generating energy through nuclear fusion
Fusion requires very high temperatures which in itself requires large quantities of energy and also requires casing which can withstand them
Nuclear fusion is currently not a viable way to produce energy on Earth