Patent Number: 
Section: claims

1. A basket apparatus for supporting a plurality of spent nuclear fuel rods within a containment structure comprising:a disk-like grate having a ring-like structure encompassing and supporting a gridwork of horizontal beams;the gridwork of beams comprising a first series of parallel beams, a second series of parallel beams and a third series of parallel beams;each of the first, second, and third series of parallel beams having a first end engaged with the ring-like structure and an opposite second end engaged with the ring-like structure;wherein the first, second and third series of parallel beams are arranged in the ring-like structure so as to intersect and form a plurality of cells of at least two different shapes. 2. The basket apparatus of claim 1 wherein the first, second and third series of parallel beams are arranged in the ring-like structure form a first set of cells of a first size having a first shape and a second set of cells of a second size smaller than the first size having a second shape. 3. The basket apparatus of claim 2 wherein the first set of cells are hexagonal shaped and the second set of shells are triangular shaped. 4. The basket apparatus of claim 1 wherein the first, second and third series of parallel beams are arranged in the ring-like structure so that: (i) the first and second series of parallel beams intersect with one another; (ii) the first and third series of parallel beams intersect with one another; and (iii) the third and second series of parallel beams intersect with one another. 5. The basket apparatus of claim 1 further comprising:a plurality of the disk-like grates arranged in a stacked and spaced orientation;spacers located between the disk-like grates, the spacers maintaining separation between the disk-like structures. 6. The basket apparatus of claim 1, wherein the first and second series of parallel beams are oriented perpendicularly to each other and the third series of parallel beams are oriented obliquely to the first and second series of parallel beams. 7. The basket apparatus of claim 1, wherein the first and second series of parallel beams intersect at a plurality of first intersection points, and the third series of parallel beams intersect the first and second series of parallel beams at a plurality of second intersection points which do not coincide with the first intersection points. 8. A basket apparatus for supporting a plurality of spent nuclear fuel rods within a containment structure comprising:a disk-like grate having a circular ring-like structure encompassing and supporting a gridwork of intersecting horizontal beams; andthe gridwork of beams forming a first set of cells having a first shape and a second set of cells having a second shape, wherein the first set of cells are larger than the second set of cells;wherein the second set of cells are interspersed between the first set of cells in interior portions of the gridwork. 9. The basket apparatus of claim 8 wherein the first set of cells are hexagonal shaped and the second set of cells are triangular shaped. 10. The basket apparatus of claim 9, further comprising a vertically elongated fuel tube positioned in each cell of the first set of hexagonal shaped cells and a vertically elongated poison rod positioned in each cell of the second set of triangular shaped cells. 11. The basket apparatus of claim 8, wherein:the gridwork of beams includes a first series of parallel beams, a second series of parallel beams, and a third series of parallel beams; andthe first and second series of parallel beams are oriented perpendicularly to each other and the third series of parallel beams are oriented obliquely to the first and second series of parallel beams. 12. The basket apparatus of claim 11, wherein the first and second series of parallel beams intersect at a plurality of first intersection points, and the third series of parallel beams intersect the first and second series of parallel beams at a plurality of second intersection points which do not coincide with the first intersection points. 13. A basket apparatus for supporting a plurality of spent nuclear fuel rods within a containment structure comprising:a plurality of vertically spaced part disk-like grates each having a circular structural ring defining a central opening and supporting a gridwork of intersecting horizontal beams each spanning across the opening;the gridwork of beams comprising a first series of parallel beams having a first angular orientation, a second series of parallel beams having a second angular orientation, and a third series of parallel beams having a third angular orientation, wherein the first, second, and third angular orientations are each different than the other;wherein the first, second and third series of parallel beams in each structural ring are arranged to intersect and form a first array of open cells having a first shape and first size, and a second array of open cells having a second shape and second size different than the first shape and first size of the open cells of the first array. 14. The basket apparatus of claim 13, wherein the first and second series of parallel beams are oriented perpendicularly to each other and the third series of parallel beams are oriented obliquely to the first and second series of parallel beams. 15. The basket apparatus of claim 14, wherein the first and second series of parallel beams intersect at a plurality of first intersection points, and the third series of parallel beams intersect the first and second series of parallel beams at a plurality of second intersection points which do not coincide with the first intersection points. 16. The basket apparatus of claim 13, wherein the first array of cells are hexagonal shaped and the second array of cells are triangular shaped. 17. The basket apparatus of claim 13, wherein the second array of cells are interspersed between the first array of cells in interior portions of the gridwork.