DEVICE FOR SUPPORTING A CLUSTER OF FUEL OR NEUTRON ABSORBENT PINS WITHIN THE WRAPPER OF A NUCLEAR REACTOR ASSEMBLY

摘要

1474321 Fuel elements; control elements COMMISSARIAT A L'ENERGIE ATOMIQUE 6 March 1975 [28 March 1974] 9394/75 Heading G6C A device for supporting a cluster of fuel or neutron-absorbent pins 11 within the casing 2 of a fuel or control assembly comprises, at the lower end of the vertically disposed casing 2, a supporting member 4 for a series of parallel rails 15 with ribs 14 on their upper extremities which are slidably engaged in grooves 12 of the end caps 13 of the pins 11. The supporting member 4 has a lateral groove 9 open towards its periphery and co-operating with fastening lugs 16 forming lateral extensions of the rails 15, each lug 16 having a re-entrant portion 17 which engages in the groove 9. The rails 15 each carry one row of pins 11 and the spring of the pins 11 in each row is ensured by means of wires 11a helically wound on the external surfaces of the pins. Locking of the rails 15 may be effected by means of two combs 18 engaged in two grooves 9a, 9b machined in an upper tubular portion 8 of the supporting member 4, the teeth 19 of the combs being inserted between the rails 15. Alternatively, each rail 15 is welded or brazed to a lateral block which is placed within the space formed between two adjacent rails (Fig. 3, not shown), or the re-entrant portion 17 of each rail 15 is provided with a transverse tongue which serves as a distance-piece between two adjacent rails (Fig. 4, not shown).