GENERAL KNOWLEDGE

Detailed explanation-1: -The fast breeder reactors: They are so called because they use fast neutrons for sustaining the chain reaction, hence no moderator is needed and, besides generating power, they also breed more fissile species (plutonium) than they consume.

Detailed explanation-2: -No moderator is used in the breeder reactor since fast neutrons are more efficient in transmuting U-238 to Pu-239. At this concentration of U-235, the cross-section for fission with fast neutrons is sufficient to sustain the chain-reaction.

Detailed explanation-3: -Graphite is used as a moderator in nuclear reactors. Name the moderator used in a nuclear reactor.

Detailed explanation-4: -The fast reactor has no moderator and relies on fast neutrons alone to cause fission, which for uranium is less efficient than using slow neutrons. Hence a fast reactor usually uses plutonium as its basic fuel, since it fissions sufficiently with fast neutrons to keep going.

Detailed explanation-5: -It works by using highly enriched uranium, between 15-20% uranium-235 content, surrounded or “blanketed” by natural uranium-238 in the reactor core. No moderator is used to slow down the neutrons, because fast neutrons transmute uranium-238 much more efficiently than slow neutrons.