Reactor Theory (Nuclear Parameters)
DOE-HDBK-1019/2-93
CONTROL RODS
Integral and Differential Control Rod Worth
The exact effect of control rods on reactivity can be determined experimentally. For example,
a control rod can be withdrawn in small increments, such as 0.5 inch, and the change in
reactivity can be determined following each increment of withdrawal. By plotting the resulting
reactivity versus the rod position, a graph similar to Figure 9 is obtained. The graph depicts
integral control rod worth over the full range of withdrawal. The integral control rod worth is
the total reactivity worth of the rod at that particular degree of withdrawal and is usually defined
to be the greatest when the rod is fully withdrawn.
Figure 9 Integral Control Rod Worth
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