Radioactivity 6

HideShow resource information
  • Created by: Rianne B
  • Created on: 23-04-13 22:34

The fission reaction

A slow neutron is fired at a uranium nucleus.

    n +        U ------->           U

The new nucleus formed is unstable.  Fission occurs.  The nucleus breaks into 2 smaller nuclei, called daughter nuclei, gamma radiation and 3 neutrons.

           U ----------->           Ba +         Kr + 3 x    n + gamma

Barium and Krypton

Chain reaction

Each neutron will then carry on to cause the fission of 3 more uranium nuclei nad each of these products more neutrons and the number of fission reactions increases very rapidly.


  • Fuel rods - enriched uranium, where the fission reaction takes place.
  • Moderator - graphite, to absorb some of the kinetic energy of the neutrons to slow them down.  need to cause fission.
  • Control rods - cadium or boron, to stop neutrons completely.  can be lowered or raised to control the amount of fission.
  • shield or chamber - concrete, to absobrb


No comments have yet been made

Similar Physics resources:

See all Physics resources »See all Radioactivity resources »