Grid structure for fuel rod consolidation canister

摘要

A grid structure (42) is mounted within the upper portion (24) of a tapered canister (24), for receiving a relatively loosely packed rectangular array of rods (22) and rearranging the rods into a relatively tightly packed rectangular array at the lower end of the grid. The grid structure comprises a multiplicity of flat, vertically oriented trapezoidal segments (78, 80) interconnected to form a plurality of vertically overlapping grid layers (74, 76). The layers alternate between a row orientation and a column orientation, and thus form a substantially continuous honeycomb of longitudinal cells (64) for guiding individual rods. The cross-sectional area of each cell decreases from the uppermost layer (74a) to the lowermost layer (74i) such that the rods are funneled by the cells to form the tightly packed array.