Patent Number: 
Section: claims

1. A method of operating a pressurized water reactor that has a core of a plurality of fuel assemblies and at least a first bank of control rods that are primarily moved into and out of selected fuel assemblies in the core to adjust the axial flux difference to substantially maintain or restore the axial flux difference within a first target band and at least a second bank of control rods that are primarily moved into and out of other selected fuel assemblies in the core to adjust the average temperature of the core to substantially maintain or return the average temperature to within a second target band, wherein the first bank of control rods and second bank of control rods are not moved together, comprising the steps of:giving the second bank of control rods priority of movement when the first bank of control rods and the second bank of control rods receive at the same time a demand signal to move in different directions; andgiving the first bank of control rods priority of movement when the first bank of control rods and the second bank of control rods receive at the same time a demand signal to move in the same direction. 2. The method of claim 1 wherein when the first bank of control rods is moving and the second bank of control rods gets a signal instructing the second bank of control rods to move in a different direction, the first bank of control rods will stop moving and the second bank will take over movement as it was instructed. 3. The method of claim 1 wherein when the first bank of control rods has priority of movement and moves to alter the axial flux difference to within a first preselected deadband at which the first bank of control rods stops movement, the second bank of control rods will start movement if the average temperature is not within a second preselected deadband.