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:
“Our culture still holds mothers almost exclusively responsible when things go wrong with the kids. Sensing this ultimate accountability, women are understandably reluctant to give up control or veto power. If the finger of blame was eventually going to point in your direction, wouldn’t you be?”
—Ron Taffel (20th century)
“For the first fourteen years for a rod they do whine,
For the next as a pearl in the world they do shine,
For the next trim beauty beginneth to swerve,
For the next matrons or drudges they serve,
For the next doth crave a staff for a stay,
For the next a bier to fetch them away.”
—Thomas Tusser (c. 1520–1580)