: Neutrons from a fissioning core are absorbed by a "blanket" of fertile material (e.g., U-238), transforming it into fissile isotopes (e.g., Pu-239).
: They often use liquid metals like sodium because of their excellent heat transfer properties and high boiling points. Major Types The rise and demise of the Clinch River Breeder Reactor breeder reactor
: Most breeders are "fast" reactors that do not use a moderator (like water) to slow down neutrons, allowing for more efficient conversion of fertile material. : Neutrons from a fissioning core are absorbed