Abstract:
L'invention concerne un dispositif de préhension d'éléments combustibles, dont la structure permet d'être poussée en position horizontale et d'être désaccouplée du système de manutention en cas de défaillance, le désaccouplement permettant de libérer la charge constituée par les éléments combustibles et leur support agrippée et de le mettre en situation sûre. L'invention concerne également un système de manutention, un procédé de manutention d'éléments combustibles en cas de défaillance et une pince de préhension associés.
Abstract:
L'installation comprend une caméra (9) suspendue à un pont roulant (6) en même temps qu'un palan (7) porteur de l'élément de combustible (8) à descendre ou monter. Elle indique la position du pont roulant (6) par rapport à l'alvéole (2) à occuper, et un mouvement déterminé du pont roulant (6) place l'élément de combustible (8) au-dessus de l'alvéole. Un avaloir (10) à l'entrée de l'alvéole (2), porteur d'une paire de caméras (13, 14), effectue une seconde mesure de la position de l'élément de combustible (8) en même temps qu'un guidage sans frottement. Application au chargement ou au déchargement d'éléments de combustible nucléaire dans des emballages de transport.
Abstract:
Conductive fins (107) are welded to the opposite sides of a band-like member (105a) with some of opposite end edges of the member left exposed to the outside to form a unit (105c). This unit (105c) is welded to a trunk body (101) from the outside at conductive fins (107). Next, a band-like member (105b) is allowed to span between adjacent band-like members (105a, 105a) and they are welded together from the outside. Welding permitted all from the outside eliminates the need of welding in a small, long space and facilitates a cask assembling work.
Abstract:
A container for nuclear fuel transportation comprises first and second cylindrical bodies of carbon steel (or stainless steel). The first cylindrical body encloses a plurality of spent fuel assemblies. The second cylindrical body encloses the first cylindrical body. Between the first and second cylindrical bodies is provided a first neutron shield composed of a material (for example, W, Gd or Mn) whose inelastic scattering cross section is greater than those of the cylindrical bodies. A second neutron shield containing hydrogen surrounds the second cylindrical body inside an outer cylindrical body. The first neutron shield effectively shields the neutrons of 10 -10 eV energy, and it helps decrease the weight of the container for nuclear fuel transportation.
Abstract:
The invention concerns a storage container for radioactive materials, comprising a tube bundle (10), interconnected by an assembling structure (14), so as to constitute a uniform array of cells (16). Cross braces (12) are fixed between the tubes (10), so as to define, around each cell (16), a substantially continuous second wall enclosing the first wall consisting of the tubes (10) and at least in partial contact therewith. Thus, containers comprising cells with any type of cross-section, and in particular, square, rectangular, hexagonal or circular, are produced easily and inexpensively.
Abstract:
A device (10) for storage of hazardous material, especially heat-producing hazardous material, such as radioactive spent nuclear reactor fuel, comprises a substantially cylindrical reinforced concrete body (12) and has an axially elongate storage space (18) for the hazardous material. A prestressed reinforcement (17) having reinforcing members (28, 29) extending helically about the storage space (18) is provided in the concrete body (12) adjacent to the outer side thereof. Preferably, the reinforcing members (28, 29) are divided into two groups, one inside the other, the hand of the reinforcing members (28) of one of the groups being opposite to the hand of the reinforcing members (29) of the other group. Also preferably, the ends of the concrete body are provided with end covers (15, 16) in which the reinforcing members (28, 29) are anchored.
Abstract:
Resin (106) for shielding neutrons is provided on the outer periphery of a main body (101) for shielding gamma -rays. A basket (130) comprises a plurality of square pipes (132) having a neutron absorbing power. The inside of a cavity (102) of the main body (101) is worked into a shape in conformity with the outer shape of the basket (130), and the square pipes (132) are inserted so as to contact the inner surface thereof. Spend nuclear fuel assemblies are placed and stored in lattice-form cells (131) consisting of square pipes (132). Decay heat generated from spent nuclear fuel assemblies can be handled with an improved heat-conducting efficiency because the outer surfaces of the square pipes (132) are in direct contact with the inner surface of the cavity (102).
Abstract:
A casing for the protection of an article contained within the casing is described, the protective casing comprising: at least two casing members which are assemblable to constitute a casing having an internal volume to receive the article, each of said at least two casing members comprising: an outer skin of fibre reinforced plastics material having a plurality of layers of reinforcing fibres in a plastics material matrix; an inner skin of fibre reinforced plastics material having a plurality of layers of reinforcing fibres in a plastics material matrix; a filling of a low density core material in a space between the outer and inner skin members; sealing means disposed in the joint face between said at least two casing members; and fastener means to hold said at least two members together.
Abstract:
Apparatus for the containment of a radioactive object or material comprises an outer sealed vessel (3), and an inner sealed vessel (5) for containing the radioactive object, the inner vessel being located within the outer sealed vessel and separated therefrom by a gap (9) which is filled with an inert fluid such as helium, wherein the apparatus is self contained and thus more easily transportable, and is arranged for circulation of the inert fluid in the gap by natural convection only.