Grid structure for nuclear reactor fuel assembly

Claim 2

IN A GRID STRUCTURE FOR A NUCLEAR REACTOR FUEL ASSEMBLY, A PLURALITY OF SLOTTED MEMBERS INTERCONNECTED TO EACH OTHER TO FORM AN EGG-CRATE ASSEMBLY HAVING OPENINGS THROUGH WHICH ELONGATED FUEL ELEMENTS EXTEND, EACH OF SAID OPENINGS BEING BOUNDED BY CORNERS FORMED FROM VERTICAL PORTIONS, AND AT LEAST TWO CROSS STRAPS AT EACH SIDE OF EACH OF SAID OPENINGS, SAID CROSS STRAPS INTERCONNECTING SAID VERTICAL PORTIONS AND BEING DISPOSED AT AN ACUTE ANGLE WITH RESPECT TO THE VERTICAL AXES OF SAID VERTICAL PORTIONS WHERBY THE FLEXIBILITY OF SAID CROSS STRAPS IS INCREASED FOR A GIVEN FUEL ELEMENT DIAMETER, EACH CROSS STRAP EXTENDING FROM THE TOP OF ONE VERTICAL PORTION TO THE BOTTOM OF AN ADJACENT VERTICAL PORTION IN A SLOTTED MEMBER.

Claim 3

The grid structure of claim 1 wherein said cross straps are provided with dimpled portions which engage an elongated fuel element disposed within said egg-crate assembly.

Claim 4

The grid structure of claim 1 wherein there are two cross straps interconnecting one of said vertical portions to the next successive vertical portion.

Claim 5

The grid structure of claim 3 wherein each of said cross straps interconnecting adjacent vertical portions is provided with a centrally disposed dimple, said dimples in the respective cross straps facing in opposite directions.

Claim 6

The grid structure of claim 4 wherein said cross straps cross each other in a criss-cross configuration.

Claim 7

The grid structure of claim 4 wherein said cross straps are parallel to each other.

Claim 8

The grid structure of claim 5 wherein one of said cross straps is integral with said vertical portions and the other of said cross straps is a separate element secured to said vertical portions.

Claim 9

The grid structure of claim 6 wherein both of said cross straps are integral with said vertical portions.

Claim 10

In a nuclear reactor fuel element assembly including a plurality of fuel containing tubes forming a bundle, said tubes being closed and spaced from each other at each end of said bundle, and means intermediate the ends of said tubes for holding said tubes against lateral displacement; the improvement in said means for holding the tubes against Lateral displacement comprising: a plurality of interconnected bands forming an egg-crate assembly having openings through which said tubes extend, the bands having pairs of oppositely-facing rigid dimples embossed therein at spaced locations along their lengths, the oppositely-facing rigid dimples engaging sides of adjacent tubes in said bundle to provide lateral support therefor, a portion of the band between the dimples in each oppositely-facing pair of dimples being cut away, and cut-away portions in said band on the sides of each pair of dimples opposite the cut-away portion between the dimples, edges of said cut-away portions being at an oblique angle with respect to the axes of said tubes.

Claim 11

In a nuclear reactor fuel element assembly including a plurality of fuel containing tubes forming a bundle, said tubes being closed and spaced from each other at each end of said bundle, and means intermediate the ends of said tubes for holding said tubes against lateral displacement; the improvement in said means for holding the tubes against Lateral displacement comprising: a plurality of interconnected bands forming an egg-crate assembly having openings through which said tubes extend, the bands having pairs of oppositely-facing rigid dimples embossed therein at spaced locations along their lengths, the oppositely-facing rigid dimples engaging sides of adjacent tubes in said bundle to provide lateral support therefor, a portion of the band between the dimples in each oppositely-facing pair of dimples being cut away, and cut-away portions in said band on the sides of each pair of dimples opposite the cut-away portion between the dimples, edges of said cut-away portions being at an oblique angle with respect to the axes of said tubes.

Claim 12

The assembly of claim 9 wherein said cut-away portions are all in the form of slots, one slot being between the dimples and the other two slots being on the sides of the dimples opposite said one slot.