How does a Breeder Reactor Work?
Breeder reactors work like regular nuclear fission reactors with the difference being that the fissionable material, such as enriched Uranium, is supplemented with a material that can be made fissionable usually by neutron capture. The supplemented material is usually Thorium or Plutonium. Thorium makes Uranium-233 while the Plutonium merely converts from a non-fissionable isotope to one that is fissionable.