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 having fuel rods containing nuclear fuel, includes a fuel assembly box in which the fuel rods are disposed, a head plate in the box having feedthroughs formed therein in which fuel rods are guided, at least some of the fuel rods being fastened to the head plate in the feedthroughs, a corner bolt disposed on top of the head plate, a cross piece disposed on the corner bolt at an upper inside corner of the box, an angular part disposed on two outer surfaces of the box, two leaf springs each extended in longitudinal direction of the box on a respective one of the two outer surfaces, a screw bolt connecting the box and the angular part to the corner bolt, the screw bolt having an expansion shank formed therein with a reduced diameter at the corner bolt, the screw bolt having a screw head with two ends, the screw head having a constriction formed therein between the ends thereof defining a coaxial screw head shank with a reduced diameter disposed in a hole formed in the angular part,

Abstract: A nuclear reactor fuel assembly includes a fuel assembly box. A head plate is disposed in the fuel assembly box. Fuel rods containing nuclear fuel are disposed in the fuel assembly box and guided in leadthroughs formed in the head plate, at least some of the fuel rods being secured in the head plate. A corner bolt stands on top of the head plate. A cross bar is disposed inside one of the corners at the upper end of the fuel assembly box on the corner bolt. An angle element is adapted to the fuel assembly box. Each of two leaf springs are disposed on an outer surface of the angle element at a respective one of the sides of the fuel assembly box and extend in longitudinal direction of the fuel assembly box.

Abstract: Method of loading or unloading or both loading and unloading a nuclear reactor, wherein control rods of cruciform cross section are at least partly withdrawn, each of the control rods being associated with a respective group of four fuel assemblies respectively having elongated duct tubes of rectangular cross section and being disposed in respective corners of a rectangular mesh of a transverse support grid, the duct tubes forming therebetween a gap-shaped intermediate space of cruciform cross section for accommodating a respective one of the control rods of cruciform cross section, which includes, prior to withdrawing a respective control rod associated with the respective group of four fuel assemblies, unloading from the nuclear reactor at least one of the four fuel assemblies of the group thereof, and inserting a support member into the respective mesh so as to fix in the respective corners of the mesh the ends of two diagonally opposed fuel assemblies of the group remaining in the nuclear reactor; and sup

Abstract: An assembly fixture for cross-shaped control rods of boiling-water nuclear reactors with an upper core grid mesh for holding a core cell formed of four fuel assemblies having a gap therebetween and means disposed beneath the reactor core for driving the control rods in the gap, including a frame having corners formed therein, the frame being substantially the size of a core cell and being disposable on the core grid, templates diagonally oppositely disposed on the frame and extending into the core cell for lateral guidance of the control rods, stops for the control rods disposed on the templates, and a carrying handle having a first portion thereof being pivotable at one of the corners of the frame and a second portion thereof being locked to an opposite corner of the frame in a disassembled condition and swung out of the locked condition in an assembled condition.

Abstract: Fuel assembly for boiling water reactors formed of a cluster of fuel rods held by a head piece and a base, respectively, at opposite ends thereof and surrounded by a coolant-flow guiding casing with the aid of a fastening angle includes leaf springs carried by the fastening angle for mutually spacing the fuel assembly from and mutually clamping it with a multiplicity of other fuel assemblies combinable therewith into a reactor core, the leaf springs extending in axial direction of the fuel assembly and having both ends thereof in contact with the fastening angle, one of the ends being rigidly held by the fastening angle, and the other of the ends being slidingly held on the fastening angle.