Patent Number: 039403092
Section: claims

1. An electromagnet coupling for supporting a safety rod and a control-and-safety rod in a nuclear reactor which coupling comprises a plurality of electromagnet means acting in parallel on a single armature common to all of them each of said electromagnet means being provided with an energizing winding adapted for being fed separately from the other; in which coupling a fraction only of the total number of electromagnet means is necessary for holding the suspended rod. 2. In a safety system for a nuclear reactor with vertical safety rods said system comprising three n sensing means of n variable quantities such as for example coolant temperature, fuel temperature and ratio of reactor power to coolant flow rate of the reactor operation, three n measuring means of said variable quantities each provided with limiting threshold 3, logic circuits to each of which one of the output signals from said three n measuring means is supplied, three amplifying means which are separately supplied with the three output signals from said logic circuits, a coupling means for releasably supporting each safety rod in the reactor which coupling means comprises six identical electromagnets with vertical axes arranged in pairs in a circular row at regular distances from one another around the rod axis, the electromagnets of each pair being disposed at diametrically opposed positions with respect to said axis and a single annular armature attached to said rod and located beneath said six electromagnets to contact the lower ends thereof; the windings of each pair of electromagnets being supplied in parallel by one of said amplifying means; said electromagnets being so dimensioned that two pairs of them are capable of holding the supported load comprising the rod while a single pair of electromagnets is not capable of holding the rod.