fast reactor

A nuclear reactor operates on the principle of nuclear fission, where heavy atomic nuclei split, releasing neutrons and energy. These neutrons can trigger further fissions, creating a self-sustaining chain reaction. In a reactor, this chain reaction is controlled to produce energy, unlike in an atomic bomb where it escalates rapidly.

Reactors are classified by the energy of the neutrons causing fission:
* Thermal reactors use slow neutrons that have reached thermal equilibrium with the reactor, requiring a moderator to slow them down.
* Fast reactors use high-energy neutrons and do not use a moderator. They require higher concentrations of fissile material but are more efficient at converting fertile material into fissile material. Some fast reactors are designed as breeder reactors, producing more fissionable material than they consume.123