Light water reactor reactivity control

This Paper reviews reactivity control in light water reactor designs, concentrating on the major reactivity control devices, the control rods and burnable absorbers. An overview of the physics requirements is presented. The use of control rods and burnable absorbers in controlling reactivity depletion and reactor power changes is reviewed and discussed. The bases for selecting materials are reviewed and the relative advantages and disadvantages of the various materials in use are compared. Finally, the performance and operating experience of LWR control rods and burnable absorbers are summarized. (author)