Liquid Metal Cooled Fast Breeder Reactor liquid metal cooled fast breeder reactor

Fast Breeder Reactors

In a fast breeder reactor, also known as a liquid metal fast breeder reactor (LMFBR), splitting atoms generates more fissionable material (fissile) than it consumes. Breeders use mixed oxide fuels (MOX) primarily composed of 238U and other minor actinides. The typical design of the fast breeder begins with the center of the reactor core coated with impoverished uranium (238U).

The initial fuel, 235U, harnesses the fast neutrons emitted by the impoverished 238U and becomes 239Pu. Active isotope production rods get replaced approximately every week, and 239Pu extracted is used once more in the same or another power plant.

Coolant in an LMFBR (commonly liquid sodium) operates at a temperature of approximately 600 ºC, with the reactor enclosed in a concrete protection shield. The liquid metal coolant does not limit the neutron energy from 235U. Unlike a pressurized water reactor (PWR) or boiling water reactor (BWR), which uses water as a moderator, the neutrons emitted by the fission of active nuclei are not slowed down.

Despite its advantages, the LMFBR has gained limited interest due to its shorter fuel life, higher operating cost and a plentiful supply of uranium fuel. Overall, there is little use of ion exchange resins in LMFBR.