Page 160 - Dynamics and Control of Nuclear Reactors

12.9 Control rod operating band and control rod operation 157

FIG. 12.11
Reactivity controller and control rod speed program used in a typical Westinghouse PWR.
Adapted from the U.S. Nuclear Regulatory Commission (Westinghouse Electric Company, The Westinghouse
Pressurized Water Reactor Nuclear Power Plant, Westinghouse Electric Company, Water Reactor Division,
Pittsburgh, 1984.). SPM: steps per minute.

The rod controller receives the temperature error signal and responds as shown in
Fig. 12.11. This is similar to reactivity control in a Westinghouse PWR. During load-
following maneuver, the total error signal may also include a rate of change of power
mismatch, converted to an equivalent temperature value. During a load-following
maneuver, the total error signal may also include a rate of change of power mismatch,
converted to an equivalent temperature value. Thus, the total error is a sum of
T-average error and power mismatch error [2].
The full-length rod control cluster (RCC) assemblies are operated by a magnetic
jack mechanism. The rod motion has a dead-band of 1.5°F. The rod motion goes to