Figure 7.5 shows the refueling route for a large pool-type fast breeder reactor. The objective in this refueling process is to keep the used fuel permanently under sodium, which acts as a heat sink for the decay heat. The fuel is extracted by a grab attached to a rotating plate above the reactor. It is extracted from the core and, still under sodium, is passed into an intermediate buffer store, from which it is transferred through a sloping transfer line (also sodium-filled) to a sodium-cooled spent fuel store, where it is kept for 100-200 days before being transferred to the reprocessing plant.