Vorrichtung zum Festlegen des Fusses eines Brennstoffelementes in dem Haltegitter eines Kernreaktors

1,025,939. Reactors. COMMISSARIAT A L'ENERGIE ATOMIQUE. Nov. 5, 1963 [Nov. 5, 1962], No. 43645/63. Heading G6C. The lower end of a fuel element is secured in an aperture in a support grid within a reactor by a deformable sleeve located within the aperture, the deformation of the sleeve being controllable so it may be made to grasp the fuel element. As shown, Fig. 2, a support grid 2 has an aperture 21 provided with an annular seating 23 receiving an elastomer sleeve 4, this sleeve forming an annular space 5 and being sealed at its ends by flanges 41 to the grid. Fluid pressure is admitted to the space 5 via a pipe 24 to cause deformation of the sleeve 4 to secure the foot of a fuel element (not shown). Preferably, a flexible metal ring 6 having slots 61 is interposed between the sleeve 4 and the fuel element. In a modification (Figs. 4, 5, not shown) the ring 6 is omitted and the sleeve 4 has metal inserts. In a further modification, Fig. 6, the sleeve comprises a toric chamber having inner and outer walls 71, 72 and connected to a fluid pressure source through the pipe 24, the chamber being of elastomer. In a modification of Fig. 6 (Figs. 8, 9, not shown the chamber is of metal. The inner wall of the chamber may be rendered more flexible by longitudinal grooving (Figs. 10, 11, not shown). A slotted metal ring may be interposed between the chamber and fuel element (Figs. 12, 13, not shown). In a final modification the chamber does not extend through a complete circle but has a small longitudinal gap (Figs. 14, 15, not shown). The pressure fluid may be air, nitrogen, argon, steam, demineralized water or molten sodium.