DEBRIS FILTERING ARRANGEMENT FOR NUCLEAR FUEL ASSEMBLY BOTTOM NOZZLE AND BOTTOM NOZZLE INCLUDING SAME
A filtering arrangement for use in a bottom nozzle of a fuel assembly in a nuclear reactor includes a top surface, a bottom surface, a plurality of vertical wall portions arranged in a generally squared grid-like pattern which extend between the bottom surface and the top surface and define a plurality of non-circular passages extending between the bottom surface and the top surface through the arrangement, and a plurality of first debris filters which are each positioned between the top surface and the bottom surface to generally span across a respective one of the plurality of passages.
1 . A filtering arrangement for use in a bottom nozzle of a fuel assembly in a nuclear reactor, the filtering arrangement comprising:
a top surface;
a bottom surface;
a plurality of vertical wall portions arranged in a generally squared grid-like pattern which extend between the bottom surface and the top surface and define a plurality of non-circular passages extending between the bottom surface and the top surface through the arrangement; and
a plurality of first debris filters, each debris filter being positioned between the top surface and the bottom surface to generally span across a respective one of the plurality of passages.
2 . The filtering arrangement of claim 1 , wherein each first debris filter comprises a hollow pyramid or hollow cone-like structure formed from a lattice structure which is sized and configured to minimize resistance in regard to coolant flow through the lattice structure.
3 . The filtering arrangement of claim 2 , wherein when viewed from directly above the filtering arrangement or directly below the filtering arrangement the lattice structure of each first debris filter is arranged so as to form a first squared grid-like pattern.
4 . The filtering arrangement of claim 2 , wherein at least one first debris filter narrows from bottom to top.
5 . The filtering arrangement of claim 2 , wherein at least one first debris filter narrows from top to bottom.
6 . The filtering arrangement of claim 1 , further comprising a plurality of second debris filters which are each positioned between the top surface and the first debris filter to generally span across a respective one of the plurality of passages.
7 . The filtering arrangement of claim 6 , wherein each first debris filter comprises a hollow pyramid or hollow cone-like structure formed from a lattice structure which is sized and configured to minimize resistance in regard to coolant flow through the lattice structure, and
wherein each second debris filter comprises a hollow pyramid or hollow cone-like structure formed from a lattice structure which is sized and configured to minimize resistance in regard to coolant flow through the lattice structure.
8 . The filtering arrangement of claim 7 , wherein when viewed from directly above the filtering arrangement or directly below the filtering arrangement the lattice structure of each second debris filter is arranged so as to form a second squared grid-like pattern.
9 . The filtering arrangement of claim 8 , when viewed from above, the second squared grid-like pattern is offset a distance from the first squared grid-like pattern.
10 . The filtering arrangement of claim 7 , wherein at least one first debris filter narrows from bottom to top and wherein at least one second debris filter narrows from bottom to top.
11 . The filtering arrangement of claim 7 , wherein at least one first debris filter narrows from top to bottom and wherein at least one second debris filter narrows from top to bottom.
12 . A bottom nozzle assembly for use in a fuel assembly in a nuclear reactor, the bottom nozzle assembly comprising:
a generally rectangular skirt portion; and
a filtering arrangement as recited in claim 1 coupled to the generally rectangular base portion.
13 . A bottom nozzle assembly for use in a fuel assembly in a nuclear reactor, the bottom nozzle assembly comprising:
a generally rectangular skirt portion; and
a filtering arrangement as recited in claim 6 coupled to the generally rectangular base portion.