GB1222238A - Nuclear reactor fuel rod spacer - Google Patents

Abstract

1,222,238. Fuel elements. GENERAL ELECTRIC CO. 24 May, 1968 [26 June, 1967], No. 25016/68. Heading G6C. A spacer grid for supporting and spacing the fuel rods of a nuclear reactor fuel bundle comprises a peripheral support band, a plurality of divider means forming a plurality of separate fuel rod passages of square cross-section, one for each of the fuel rods, and a plurality of spring assemblies providing a spring member extending diagonally into each fuel rod passage for resiliently restraining lateral movement of the fuel rods, the divider means including protuberances of limited area extending into the fuel rod passages to limit the area of contact between the fuel rods and the divider means, In one embodiment, a first group of spaced divider members 21 formed of sheet metal is rigidly supported between opposite sides 20(1), 20(3) of a peripheral support band 20 and a second group is rigidly supported between opposite sides 20(2), 20(4), the divider members of the two groups intersecting at right angles and being appropriately slotted to interlock at the intersections. In addition, divider wires 2 are arranged in vertically spaced pairs with a first group supported between sides 20(1), 20(3) and a second group between sides 20(2), 20(4). Each of the divider wires 22 is crimped along its length to form a series of S-shaped curves centered along the sides of the fuel rod passages. Supported at each intersection of the divider members 21 is a four-sided spring assembly 23 slotted along each side edge and with each side curved outwardly to form outwardly extending spring members supported between upper and lower end portions. The intersecting divider members 21 pass through the edge slots of the spring assembly 23. A fuel rod 12 is shown in Fig. 4 in a fuel rod passage 40 of the spacer grid of Fig. 2. A spring member 23(1) of spring assembly 23 exerts a lateral force on the fuel rod 12 along a diagonal of the passage 40 forcing the fuel rod into contact with the S-curves of the upper divider wires at points 41(1), 41(2) and with the S-curves of the lower divider wires at points 42(1), 42(2).