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.