Power control device of reactor

Object: To control the reactor power to an intended value by operating a plurality of control rods automatically up to a goal position while maintaining a predetermined difference in inserting position. Structure: A plurality of control rods are separately driven through a ball screw by means of a stepping motor. Meanwhile, the difference between the output of the reactor power detector and the preset value is detected, and this output signal and the output of the control rod position detector are used to select and operate the control rods. At this time, depending upon the polarity of the difference, the control rod inserted to the greatest extent is actuated when the reactor power is insufficient, while the control rod withdrawn to the greatest extent is actuated when the reactor power is excessive. (Yoshino, Y.)