One of a number of rods of a material, such as boron or cadmium, that absorbs neutrons. Control rods can be moved into or out of the core of a nuclear reactor to control the rate of the reaction taking place within it.
Chemical Engineering
A neutron-absorbing rod that is used to control the reactivity variations of a nuclear reactor. Cadmium and boron are neutron-absorbing materials used for control rods.