Fast Breeder Reactors (FBRs) are a type of nuclear reactor designed to generate more fissile material than they consume. They use fast neutrons to sustain the nuclear fission process, allowing them to convert non-fissile isotopes, like uranium-238, into fissile isotopes, such as plutonium-239. This makes FBRs efficient in utilizing nuclear fuel and helps extend the availability of nuclear resources. FBRs operate without a moderator, which distinguishes them from traditional reactors that slow down neutrons. By recycling spent fuel, FBRs can significantly reduce nuclear waste and enhance sustainability in nuclear energy production. This technology is considered vital for the future of nuclear power.