Describe how the control rods in a nuclear reactor are used to regulate nuclear fission in a nuclear reactor.

A control rod is a device that can be used to absorb neutrons released from nuclear fission. They can be used to slow down or completely stop a reaction by lowering them or raising them into the reactor chamber . They are useful as nuclear fission on average releases 2.5 neutron per reaction where the process only needs one to continue the chain reaction. The control rods absorb these extra neutrons adjusting the power output of the nuclear reactor to a satisfactory level to be sure the reactor does not overheat which would lead to failure.