Control system for a nuclear reactor

Guide distortions are accomodated and jamming of absorber elements in the guide are prevented with the control rod system for a nuclear reactor core in which fast neutrons are used for the chain reactions. The absorber elements are hung on a central rotating support. When introducing in a downwards direction, the absorber rods are moved in such a manner that the minimum distance from the side between the absorber rods and the inner wall of the guide is increased. The group of absorber rods is thus attached in such a way that it compresses with this downward movement. Supporting arms can be used for this which are rotationally mounted on the support. They spread out sideways and are flexibly fixed. A T-piece ball-and-socket joint or a shackle toggle joint is used as attachment. In the upward motion, the absorber rods return by themselves to their starting position. (DG/LH)