Abstract: A nuclear reactor fuel assembly includes an elongated fuel channel having opposite channel sides. Fuel rods containing nuclear fuel are mutually spaced apart in the fuel channel and parallel to the longitudinal direction of the fuel channel. A water tube inside the fuel channel has an outer surface and is parallel to the fuel rods. The water tube has a lower end with an inlet opening and an upper end with an outlet opening for liquid water. A longitudinal rib inside the fuel channel is secured to and interconnects two of the opposite channel sides and is spaced apart from the others of the channel sides. The longitudinal rib is longitudinally divided into two partial ribs each being secured to the outer surface of the water tube.

Abstract: A nuclear reactor fuel assembly includes an elongated fuel channel with a square cross section and channel walls, the fuel channel having an imaginary lattice disposed therein with a box-shaped cross section having mesh openings and sides parallel to the channel walls, fuel rods containing nuclear fuel being mutually spaced apart in the mesh openings, and a prismatic water pipe spaced apart from the fuel channel by a given spacing and having a cross section spanning more than one of the mesh openings of the imaginary lattice, the given spacing being completely filled with the mesh openings of the imaginary lattice and the fuel rods disposed therein.