Abstract: A control rod position indication system is for a nuclear reactor with a reactor core and at least one control rod which is movable along a linear path of movement for controlling reactivity of the core. The system includes a permanent magnet mounted on the control rod or a corresponding drive rod, and a number of reed switches arranged around the path of movement in order to be switched by a magnetic field generated by the permanent magnet when passing by. The permanent magnet has a north-south axis whose orientation is constant during movement, and the respective reed switch has a number of reed contacts which are aligned along a longitudinal axis. The longitudinal axis of at least one reed switch is inclined relative to the north-south axis of the permanent magnet, and the angle of inclination has an absolute value within a range from 15 to 65 degrees.

Abstract: A control rod position indication system (2) is for a nuclear reactor (4) with a reactor core (8) and at least one control rod (6) which is movable along a linear path of movement for controlling the reactivity of the reactor core (8). The control rod position indication system (2) includes a permanent magnet (16) mounted on the control rod (6) or a corresponding drive rod (12), and a number of reed switches (20) arranged around the path of movement in order to be switched by a magnetic field generated by the permanent magnet (16) when passing by. The permanent magnet (16) has a north-south axis (18) whose orientation is constant during movement, and the respective reed switch (20) has a number of reed contacts (22) which are aligned along a longitudinal axis (24). The longitudinal axis (24) of at least one of the reed switches (20) is inclined relative to the north-south axis (18) of the permanent magnet (16), and the angle of inclination (W) has an absolute value within a range from 15 to 65 degrees.

Abstract: A securing device for a control rod in a nuclear plant contains a control rod drive and a drive housing, which encloses the control rod drive and which is configured to be fed through a reactor pressure wall. The aim of the securing device is to prevent, in the most reliable manner possible, the control rod from being extended in an uncontrolled manner. Furthermore, the securing device should be as inexpensive as possible and should pose the slightest obstacle possible to installation work. For this purpose, the drive housing has at least one coupling element for forming a force-locked and/or form-fit connection of the drive housing to the reactor pressure wall.