Patent Number: 059498390
Section: abstract

A fuel assembly for a boiling water reactor where the fuel assembly during operation is arranged vertically in the core of the reactor. The fuel assembly comprises a plurality of vertical fuel rods (22) arranged in one or more fuel bundles, wherein at least the majority of the fuel rods comprise a stack of fuel pellets (7) surrounded by a cladding tube (8b) and a plenum tube (23) which is connected to the upper part of the cladding tube (8b), the plenum tube having a cross-section area which is smaller than the cross-section area of the cladding tube. Further, the fuel assembly comprises a bottom tie plate (15) which retains and supports the lower part of the fuel bundle, a number of spacers (13) which retain and position the fuel rods in spaced relationship and are arranged axially separated along the fuel rods, a top spacer (21) which retains and supports the upper part of the fuel bundle and is arranged above and at a distance from the stacks of fuel pellets, and a fuel channel (2) which surrounds the fuel bundle or the fuel bundles.