Abstract: A nuclear fuel rod assembly storage rack comprises a rigid structure delimiting vacant spaces of square, cross-section and neutron-absorbing units also having a square cross-section prearranged before introduction into all or part of the vacant spaces between the shroud tubes. Each neutron-absorbing unit is made up of four flat plates of neutron-absorbing material, surrounded by at least two support grids. The support grids may comprise two units assembled together, for example by welding.

Abstract: A storage rack for nuclear fuel assemblies and its manufacturing process.A storage rack for nuclear fuel assemblies is formed by assembling main plates (12), spacer plates (14), two end plates (16) and a base plate (18), preferably by welding. Once a first main plate (12(1)), a first end plate (16(1)) and the base plate (18) have been mounted on a tooling, a first series of housings (10) is formed by securing a first row of spacer plates (14(1)) to the first main plate (12(1)), and then mounting a second main plate (12(2)). The other rows of housings (10) are obtained in the same manner. The rack is completed by mounting the second end plate.

Abstract: Process for the renovation of a nuclear fuel assembly storage rack.For the renovation of a nuclear fuel assembly storage rack, whereof the bulkheads (10) incorporate a neutrophage material sheet held between the partition (16) and a plate (18) welded to said partition, the plate (18) is cut, the sheet extracted and is replaced by a new neutrophage material sheet. This process obviates the need for replacing the rack when the sheets have dissolved in the water of the pool containing the rack.

Abstract: An installation, designed to stock both nuclear fuel assemblies of square section and control bars of cruciform shape taken from a boiling water nuclear reactor, comprises vertical housings of square section, each able to accommodate a control bar and four assemblies. The housings are formed in and between encasing tubes (22) which rest upon a lower plate (10). After placing a control bar in the housing, a removable unit (30) is inserted which comprises a baseplate (34) surrounding the tip of the bar, four holders (32) resting on this baseplate, and spacer wedges (36) separating the holders. One assembly is then placed in each holder (32).

Abstract: A device for treating cerebral lesions by gamma radiation, comprising an approximately semi-spherical source-collimator assembly having a large number of gamma ray sources associated with channels directed to the same focal point. Each gamma ray source is associated with a group of channels arranged in the manner of a cone, the apex of which is at the focal point.