Lower end fitting debris collector
AssigneeCombustion Engineering, Inc.
InventorsWilliam J. Bryan, Harold V. Lichtenberger
Life of this patent
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Abstract
A fuel assembly (10) has a lower end fitting debris collector (40) assembled in the form of a welded assembly of an "eggcrate" grid (21) and cast base (40) with hollow legs (42). Fastener seats (46) in hollow legs (42) permit guide tubes (14) with internally threaded ends to be joined to the upper surface of the lower end fitting debris collector (40) by means of slotted fasteners (50). Bevels (62) and notches (64) in the grid bars (26 and 24a, respectively), provide an embodiment with contoured seats for fuel rod end caps (22). Otherwise, end caps (22) rest on grid (21) at the intersection of slottedly interlocked bars (24 and 26). Thin strips (30) mounted in slots between bars (24) and bars (26) provide small debris catching openings in grid (21).
Claims9
A lower end fitting debris collector for capturing and retaining deleterious debris carried by reactor coolant flow before the debris enters the active region of a fuel assembly and creates fuel rod cladding damage, comprising in combination:
- a polygonal perimeter member,
- a plurality of debris trapping compartments defined by a plurality of parallel first slotted bars and parallel second slotted bars intersecting and slottedly interlocked with said first bass in a grid-forming arrangement in which the bars ar attached to said perimeter member and to each other,
- a first plurality of parallel strips mounted on said second bars and between said first bar on a first side of said grid,
- a second plurality of parallel strips mounted on said first bars and between said second bars on the side thereof opposite said first side of said grid in an orientation normal to said first plurality of parallel strips,
- and means for fastening the ends of guide tubes to said grid formed by said bars.
Dependencies are inferred from the claim text.