Abstract The invention relates to a nuclear reactor fuel element assembly which is in the form of a bundle of parallel fuel pins extending between top and bottom end fittings in the assembly. The top and bottom end fittings are held together by a number of lifting pins which are screwed into the bottom end fitting and have spigots extending through the top end fitting and fitted with retaining nuts. A fuel pin locking member consists of a U-shaped split pin having its legs extending through transverse drillings in the retaining units and spigots of two adjacent pins. Thus the retaining nut of each pin is locked to the spigot and the locking member prevents relative rotation between the pins and hence prevents unscrewing of the pins from the bottom end fitting.
A fuel pin locking member for a nuclear reactor fuel element assembly of the kind comprising a plurality of transversely spaced elongated fuel pins with the fuel pins extending between upper and lower end fittings in the assembly, an adjacent pair of fuel pins having their ends screwed into the end fitting at one end of the assembly and the other ends of the pair of fuel pins extending through apertures in the second end fitting at the other end of the assembly, said other ends being in screw threaded engagement with nuts, said fuel pin locking member being in the form of a U-shaped split pin having bifurcated arms extending through corresponding transverse drillings in each of the nuts and the ends of the fuel pins within the nuts thereby to prevent both unscrewing of the nuts from the ends of the fuel pins and the rotation of the fuel pins relative to one another.
Claim 2
Dependent Claim
156 words
A fuel pin locking member for a nuclear reactor fuel element assembly of the kind comprising a plurality of transversely spaced elongated fuel pins with the fuel pins extending between upper and lower end fittings in the assembly, an adjacent pair of fuel pins having their ends screwed into the end fitting at one end of the assembly and the other ends of the pair of fuel pins extending through apertures in the second end fitting at the other end of the assembly, said other ends being in screw threaded engagement with nuts, said fuel pin locking member being in the form of a U-shaped split pin having bifurcated arms extending through corresponding transverse drillings in each of the nuts and the ends of the fuel pins within the nuts thereby to prevent both unscrewing of the nuts from the ends of the fuel pins and the rotation of the fuel pins relative to one another.