Abstract: A method for preparing a built-in part for disposal including the steps of mounting a supporting element such that it can be displaced in an axially elastic manner by a spring on a head of the built-in part and being used for support on the grid plate of the head frame of a fuel element. The supporting element is fixed in a pushed-back position against the action of the spring, enabling a common disposal of the built-in part with the fuel element.

Abstract: A method for testing whether fuel rods of fuel assemblies resting on a working base and under water, of a nuclear reactor are leaking is disclosed. The method includes heating at least one first fuel assembly of a first division of fuel assemblies for driving radioactive fission products out of a defective fuel rod contained in the first fuel assembly. The first fuel assembly is continuously tested by extracting samples of water and continuously degassing the water removed from an area around the first fuel assembly even during the heating resulting in gas. A radioactivity of gaseous fission products released in the gas is continuously recorded. A fuel assembly belonging to a second division of fuel assemblies is heated only if the first fuel assembly belonging to the first division of fuel assemblies has been tested. An apparatus for implementing the method is also disclosed.

Abstract: A method for testing whether fuel rods of fuel assemblies resting on a working base and under water, of a nuclear reactor are leaking is disclosed. The method includes heating at least one first fuel assembly of a first division of fuel assemblies for driving radioactive fission products out of a defective fuel rod contained in the first fuel assembly. The first fuel assembly is continuously tested by extracting samples of water and continuously degassing the water removed from an area around the first fuel assembly even during the heating resulting in gas. A radioactivity of gaseous fission products released in the gas is continuously recorded. A fuel assembly belonging to a second division of fuel assemblies is heated only if the first fuel assembly belonging to the first division of fuel assemblies has been tested. An apparatus for implementing the method is also disclosed.

Abstract: A method for packaging, compacting or storing spent control and absorber elements of light-water reactors for waste disposal, a device for preparing an elongated component of a spent control element, a light-water-cooled reactor and a coil of an originally elongated component are provided for storing absorber fingers or absorber sheets of spent control elements in storage containers in pressurized-water reactors or boiling-water reactors. The absorber fingers or absorber sheets are separated from the control elements. They are not cut into pieces (in which process large amounts of radioactive substances would be released), but instead they are only deformed, namely wound into coils which can be stacked in a space-saving manner in the storage containers.

Abstract: A method for shredding and packing used structural elements of nuclear reactors, such as fuel assembly cases, comprises the steps of shredding structural elements to scrap pieces; flushing the scrap pieces in a transport container and flushing away highly radioactive particles of foreign matter and collecting the particles in the interior of the transport container; packing the flushed scrap pieces around the particles of foreign matter collected in the interior; and inserting the packed transport container into a sealable disposal container.

Abstract: An apparatus for storing nuclear reactor fuel assemblies in a water pit, includes means for holding an end of a fuel assembly and for transporting the fuel assembly through the water pit, a vessel disposed in the water pit having a closed bottom and an open top in communication with a water space in the water pit forming a vertically elongated well in the vessel for at least partly receiving a fuel assembly, a suction connection in communicaton with the well through the closed bottom of the vessel, a suction pump connected to the suction connection, a shielding container, and a filter disposed in the shielding container and connected to the pump for collecting deposits suctioned from the well.

Abstract: In a nuclear reactor fuel assembly having a fuel rod filled with nuclear fuel retained in a gap formed in a lattice-like spacer by a spring disposed in the gap, the fuel assembly is repaired by replacing the fuel rod with a replacement rod and the replacement rod is retained in the gap of the spacer with a retaining spring.

Abstract: A method of repairing under water a boiling water reactor-fuel assembly having a fuel assembly channel and an upper grid plate by means of a channel stripping machine, disassembling the upper grid plate, determining a damaged fuel rod and exchanging the damaged fuel rod for another fuel rod by means of a fuel rod exchanging device, which includes, after stripping off the fuel assembly channel and disassembling the upper grid plate at the location thereof in the channel stripping machine, placing on the fuel assembly a guide box with which the fuel rods of the fuel assembly are centered, then placing thereon an indicator plate and determining the varying growth of the fuel rods, and replacing the indicator plate by a centering plate to which the fuel rod-exchanging device is coupled and a device for carrying out the method.

Abstract: Alignment tool for the remotely controlled recalibration of resilient protruding contact dimples or springs in substantially square spacer grid meshes of nuclear reactor fuel assemblies, including an outer centering tube adapted to the cross section of a spacer mesh and rigid and resilient contact dimples protruding into the interior of the mesh in given directions, the outer centering tube having a window formed therein in the vicinity of the contact dimple, a gripper-actuating tube being concentrically surrounded by and axially movable within the outer centering tube, a pendulum rod having a free end and being disposed in the interior of the gripper-actuating tube and being axially fixed relative to the gripper-actuating tube and able to oscillate in the given protrusion direction of the resilient contact dimple to be recalibrated, a gripper attached to the free end of the pendulum rod, a restoring spring for exerting pressure on the gripper, and a run-on incline formed on the pendulum rod being engageable

Abstract: A method of repairing partly burnt-off fuel elements in a fuel-element pit of a pressurized-water reactor which includes placing a fuel element previously detected as being defective into a holding cage in substantially upright position with the aid of remotely controlled tools, and tipping it over through 180.degree.; removing the then upwardly disposed fuel-element foot from the fuel element so as to expose the ends of the fuel rods received in the fuel element; inspecting the fuel rods, the ends of which are then freely accessible for defects; removing with a fuel-rod exchanging tool those fuel rods at least which are determined to be defective and depositing them in a storage container; and raising replacement rods with the fuel-rod exchanging tool and inserting them into the fuel element without bending stress in exchange for the removed fuel rods.