Abstract A perimeter strip for a nuclear reactor fuel assembly support grid. The perimeter strip forms the outer edge of an egg-cratetype fuel-rod-spacing grid and is rigidly welded to the strips passing intermediate the fuel rods. It comprises a central portion parallel to the fuel rods and spaced therefrom as well as upper and lower portions parallel to the fuel rods at a location inwardly of the central portion. Sloping portions of the strip join the central portion and the upper and lower portions, with the distance between the outer surface of the outer fuel rods and the outer surface of the upper and lower portions being less than the distance between the outer surface of the central portion. The upper and lower portions are arched inwardly slightly to contact alternate fuel rods, while the and portion is formed to make resilient spring contact with the intermediate fuel rods. The sloped portion has holes therethrough adjacent the arches where rigid contact is made with the fuel rods. The egg crate structure is welded to the perimeter strip intermediate the arches and springs only at the upper and lower portions.
A perimeter strip as in claim 1 wherein the openings in said sloped portion are immediately adjacent the rigid contact points of said upper and lower portions.
Claim 2
Dependent Claim
38 words
A perimeter strip as in claim 1 wherein said upper and lower portions have arches extending the height of the respective portions having an axis parallel to the fuel rods whereby said arches form said rigid contact points.
Claim 3
Dependent Claim
33 words
A perimeter strip as in claim 2 having also an elastic spring portion extending from said central portion and being in resilient contact with at least a portion of the outer fuel rods.
Claim 4
Dependent Claim
35 words
A perimeter strip as in claim 4 wherein alternate outer fuel rods are in rigid contact with the peripheral strip and the intermediate outer fuel rods are in resilient contact with said elastic spring portions.
Claim 5
Dependent Claim
59 words
A perimeter strip as in claim 2 wherEin said central portion has a flat portion extending between the corresponding openings in said upper and lower sloped portions, said support grid being of an egg crate construction; each of the support grid strips passing intermediate the fuel rods welded to said perimeter strip only at the upper and lower portions.
Claim 6
Dependent Claim
45 words
A perimeter strip as in claim 2 wherein the distance from the outer surface of the outer fuel rods to the outer surface of the central portion of the perimeter strip is equal to one-half the spacing between the fuel rods of the fuel assembly.
Claim 7
Dependent Claim
42 words
A perimeter strip as in claim 2, said central portion having openings therein throughout its entire height at locations adjacent said rigid contact points, whereby a single opening extends throughout the central portion as well as the upper and lower sloped portions.
Claim 8
Dependent Claim
32 words
A perimeter strip as in claim 8 wherein the width of said openings in said central portion is less than the width of the material remaining in said central portion between openings.