A control rod is a rod made of chemical elements capable of absorbing many neutrons without fissioning themselves. They are used in nuclear reactors to control the rate of fission of uranium and plutonium. Because these elements have different capture cross sections for neutrons of varying energies, the compositions of the control rods must be designed for the neutron spectrum of the reactor it is supposed to control. Light water reactors (BWR, PWR) and heavy water reactors (HWR) operate with "thermal" neutrons, whereas breeder reactors operate with "fast" neutrons.
Read more about Control Rod: Operation Principle, Materials Used, Safety
Famous quotes containing the words control and/or rod:
“There is one thing you and I as parents cannot do, not do we want to do if we really think about it, and that’s control our children’s will—that spirit that lets them be themselves apart from you and me. They are not ours to possess, control, manipulate, or even to make mind.”
—Barbara Coloroso (20th century)
“The tracks of moose, more or less recent, to speak literally, covered every square rod on the sides of the mountain; and these animals are probably more numerous there now than ever before, being driven into this wilderness, from all sides, by the settlements.”
—Henry David Thoreau (1817–1862)