Abstract: The present invention provides a method and apparatus for fuel handling in a nuclear reactor. The nuclear reactor has a reactor vessel comprising a reactor core with a plurality of fuel assemblies and control rods. A fuel pool is arranged adjacent to the reactor vessel. A group comprising at least a plurality of fuel assemblies is simultaneously lifted out of or into the reactor vessel with a single gripper, the gripper having a plurality of gripping devices. The group is transported between the reactor vessel and the fuel pool by means of the gripper.

Abstract: The present invention relates to a method and a device for correction of the movements of a suspension device and positioning thereof in a fluid. The suspension device is provided with a first and a second end, and the first end is suspended from a point (S). A correction device is arranged at the second end of the suspension device and adapted to generate a force which provides an acceleration in the fluid so that the position of the second end of the suspension device is corrected.

Abstract: The present invention is used in fuel handling for lifting of fuel assemblies and/or control rods out of/into a reactor vessel in a nuclear reactor. The reactor vessel comprises a reactor core with a plurality of fuel assemblies and control rods. A fuel pool is arranged adjacent the reactor vessel. A cassette comprising a plurality of storage positions for fuel assemblies and/or control rods is arranged near the reactor core, whereupon fuel assemblies and/or control rods are lifted out of the reactor core and arranged in the cassette. The cassette is then transported to the fuel pool for temporary storage.

Abstract: During local cleaning of metallic surfaces (15, 24) on parts included in the primary circuit of a nuclear reactor, which surfaces are coated with corrosion products, in connection with inspection of the surfaces, the coated surface, while being located below the surface of the reactor water (13) in the reactor vessel (10) or reactor pool (12) of the nuclear reactor, is arranged in contact with an electrolytically permeable spacer (16) of an electrically insulating material which, at a distance from the coated surface, is arranged in contact with a body (170 of electrically conductive material. An electrolyte (21) is supplied to the spacer and an electrical potential difference is maintained between the coated metallic surface and the body of conductive material by connecting the surface to the positive pole (18) and the body to the negative pole (19) of a voltage source (20).

Abstract: A method of treating a sheathing tube or fuel channel of a spent fuel box of a fuel assembly of a nuclear reactor comprises containing and reducing the volume of the sheathing tube prior to its disposal. The sheathing tube, after separation from a bottom piece of the fuel box, is placed in a protective tube. The protective tube and sheathing tube contained therein are then flattened and shaped into a convoluted form. Typically the flattening and shaping are performed in a single operation in a rolling mill, the protective tube and sheathing tube being rolled into a coil.

Abstract: In a nuclear reactor of the BWR type having finger control rods mounted in guide tubes and having a member movable upwardly to push the control rods into the guide tubes, the control rods are connected to this member by a joint such as a bayonet joint releasable by turning of the control rods about their longitudinal axis. On the upper ends of each control rod is slidably mounted a sleeve which is spring-pressed downwardly. This sleeve is non-rotatable with respect to the control rod. The sleeve has either a square lower end slidable within a square tube or has projections at its lower end in a round tube having ribs running longitudinally thereof. The arrangement is such that when the support is in its uppermost position the control rods project above the fuel assembly and the sleeve can be raised against the spring action out of the upper ends of the tubes so as to permit turning of the rods to release them for removal.