In a heterogeneous or solid-fuel reactor, the fuel is mixed in a regular pattern within moderator.
Slow or thermal neutrons have energy of the order or 0.025 eV
Fast neutrons have energies above 1000 eV
Fast reactor uses moderator
electron-volt
electron-ampere
curie
MeV
operate at extremely high power densities.
are liquid-metal cooled
produce more fuel than they consume
use water as coolant.
as basic raw material
by neutron irradiation of Uz
by neutron irradiation of thorium
artificially
by neutron irradiation of IT*