JP2807960B

PURPOSE:To allow long bar like foreign matter such as a wire piece to be caught in a lower nozzle by inclining the boring angle of each water flow hole of the adapter. CONSTITUTION:In a fuel assembly, a supporting lattice 3' at the lowest part is placed close onto the adapter plate 8 of a lower nozzle 6 with numerous water flow holes 7. Each hole 7 is formed in such a way that the boring angle 7a is inclined at an angle of about 30 deg. (in a range of 20-40 deg. although different according to the length of foreign matter T and the thickness of the plate 8) to the direction 10a of passages 10 formed by the lattice plate 9 of the lattice 3'. In addition to the holes 7, small diameter holes are occasionally formed at part of the plate 8, but there is also a case of not forming the small diameter holes in the inclined state like the holes 7. In the case of the long bar like foreign matter T going to pass through the hole 7, a path formed of the hole 7 and lattice 3' can be bent in dogleg shape, so that the foreign matter T can be caught being clogged in the bent path.