How do fast breeder reactors work?
Fast breeder reactors When a plutonium nucleus absorbs one such free neutron, it splits into two fission fragments. This fissioning releases heat as well as neutrons, which in turn split other plutonium nuclei, freeing still more neutrons.
Why moderator is not used in fast breeder reactor?
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.
Do fast reactors produce waste?
Fast reactors are capable of destroying the longest-lived nuclear waste, transforming it to waste that decays to harmlessness in centuries rather than hundreds of millennia. Fast reactors typically use liquid metal coolants rather than water.
Why water is not used as coolant in fast breeder?
 Light water is a good coolant for thermal reactors but not for fast breeders; pressurized water also moderates (slows down) the neutrons because hydrogen-1 (H-1), which comprises much of water, has a scattering cross section of σ = 82.03 barns, far larger than any other atom.
Why don’t we use breeder reactors?
Another is that, to extract the plutonium, the fuel must be reprocessed, creating radioactive waste and potentially high radiation exposures. For these reasons, in the U.S., President Carter halted such spent fuel reprocessing, making the use of breeder reactors problematic.
Which fuel is used in fast breeder reactor?
Fast reactors more deliberately use the uranium-238 as well as the fissile U-235 isotope used in most reactors. If they are designed to produce more plutonium than the uranium and plutonium they consume, they are called fast breeder reactors (FBRs).
How fast does reactor work?
Whereas traditional reactors contain moderators to slow down neutrons after they’re emitted, fast reactors keep their neutrons moving quickly. An average slow neutron moves around at about 2200 m/s while a fast neutron might be cruising well above 9 million m/s, which is about 3% of the speed of light.