Nuclear fuel assembly debris resistant bottom nozzle

A debris resistant bottom nozzle useful in a fuel assembly for a nuclear reactor is described, the bottom nozzle comprising: (a) support means adapted to rest on a lower core plate of a nuclear reactor; and (b) a plate fixed on the support means and being of a substantial solid configuration with a plurality of spaced cut-out regions therein adapted to align directly above inlet holes in the lower core plate; and (c) a plurality of open separate criss-cross structures, each of the criss-cross structures fixed to the plate and extending across one of the cut-out regions therein, the criss-cross structures defining individual openings small enough in cross-sectional size to filter out debris of damage-inducing size larger than 0.190 inch in width otherwise collects in unoccupied spaces of a lowermost grid of the fuel assembly, but large enough in size to let pass debris of nondamage-inducing size which otherwise passes through the unoccupied spaced of the lowermost grid