Patent ID: 6167105
Filing Date: 2000-12-26
Classification: G21C,Y02E

Abstract:
A spacer grid for use in a nuclear reactor fuel assembly, comprising two sets of intersectional grid strips arranged in sets at an angle to each other prior to being encircled by a plurality of perimeter strips, thus forming a plurality of four-walled cells individually placing and supporting an elongated fuel rod therein, further comprising;a plurality of regularly spaced openings formed on each of said grid strips and perimeter strips at portions corresponding to the cells;an H-shaped spring set in each of said openings; thus elastically supporting a fuel rod placed in each of said cells; andtwo positioning dimples provided on each of said strips at positions above and below each of said openings, thus cooperating with the H-spring in order to support a fuel rod within each of said cells,said H-shaped spring comprising;two bowed arms set along opposite longitudinal sides of each of said openings, thus extending along the axes of the fuel rods; anda specifically curved rib extending between said two arms, thus integrating the two bowed arms into a single structured, H-shaped spring, said rib having no additional structural member extending upwardly or downwardly therefrom so as to allow for free flow of coolant through the opposed openings defined by the rib and two bowed arms without interference from an additional structural member, said rib being curved so as to have the same radius of curvature as that of each of said fuel rods, thus being brought into surface contact with each of said fuel rods,each of said positioning dimples being curved so as to have the same radius of curvature as that of each of said fuel rods, thus being brought into surface contact with each of said fuel rods,said specifically curved rib of the H-shaped spring and each of said positioning dimples being individually curved so as to be brought into conformal surface contact with each of said fuel rods and individually made of a curved, thin plate, thus forming a passage between each of said strips and each of said rib and dimples and thereby allowing coolant to smoothly pass through the spacer grid without being interfered with the rib or the dimples.