Patent Number: 053234340
Section: abstract

A fuel assembly for a boiling water nuclear reactor contains a plurality of vertical fuel rods, which are arranged between a bottom-tie plate and a top-tie plate (12) in a surrounding vertical casing part. The fuel rods extend through a number of spacers which are arranged in a spaced relationship in the vertical direction and which together with the bottom-tie plate and the top-tie plate retain the fuel rods in a spaced relationship in the lateral direction. The fuel assembly is designed for conducting water in through the bottom-tie plate, through the space between the fuel rods in the vertical casing part, and out through the top-tie plate. To counteract unfavourable temperatures caused by dryout, each fuel rod, in at least a majority of the fuel rods, is adapted to give off a considerably lower power in those parts of the fuel rod which are located immediately below the spacers in at least the uppermost one-third of the active length of the fuel rod than in the remaining parts of the active length of the fuel rod.