Patent Number: 047023910
Section: description

DESCRIPTION OF THE PREFERRED EMBODIMENT A container 1 enclosing solidified melted material with highly radioactive content is disposed in a hollow circular containment cylinder 2 which is closed at its bottom by a bottom plug structure 4 and at its top by a top plug structure 3. Together these parts form a containment. Both plugs 3 and 4 are mounted to the cylinder 2 by means of threads 9 and 10. The top plug structure 3 consists of a lid 5 and a cover plate 6; the bottom plug structure 4 consists of a bottom 7 and a bottom plate 8, the bottom plate 8 and the cover plate 6 having a diameter slightly larger than the bottom 7 and the lid 5, so that they both project slightly radially outwardly. Lid 5 and cover plate 6, as well as bottom 7 and bottom plate 8, are mounted together in a special way as shown in FIG. 2. The containment cylinder 2, the lid 5, the cover plate 6, the bottom 7 and the bottom plate 8 all consist of fine-grain construction steel. The cover plate 6 has a gripping cavity 11 formed therein for engagement thereof by a lifting mechanism. The containment cylinder 2 has disposed therein around the body 1 a heat conductive centering sleeve 12 adapted to improve the heat transfer from the body 1 to the containment cylinder walls. The containment cylinder 2 is provided, by explosion plating, with a liner 13, for example, of titanium-palladium alloy, providing a corrosion protective barrier which extends axially beyond its bottom and top ends such that it forms axial projections 14 of a length about equal the thickness thereof. This projection 14 serves as a centering means for the top and bottom plug structures 3 and 4. The bottom 7 and the lid 5 are also provided, by explosion plating, with liners of the titanium-palladium alloy. The liners 15, 16 have about the same thickness as the liner 13. They project radially slightly beyond the bottom 7 or the cover 5 and have a diameter essentially corresponding to the inner diameter of the liner 13. When the bottom and top plug structures are mounted, the liners' 15 and 16 circumferential faces 17 are disposed adjacent the inner circumference of the projections 14 of the cylinder's outer liner 13. Additional titanium-palladium layers 18, 19 of the same thickness are explosion welded onto the inner sides of the cover plate 6 and the bottom plate 8. As may be seen from FIG. 2, where the layer 18 of the bottom plate 8 is shown in greater detail, the radius of this layer 18 is larger than that of the liner 15 of the bottom 7 by about a layer's thickness. The projection 20 so formed is disposed adjacent the projection 14 of the cylinder liner 13 and is flush therewith when the bottom plug is mounted. The arrangement at the top end of the containment is essentially the same, that is, the layer arrangement is identical and so is the welding procedure for the layers to be described below. The bottom plate 8 and the bottom 7 and also the cover plate 6 and the lid 5 are welded together before the bottom and top plug structures are threaded into the containment cylinder 2. For this purpose bottom plate 8 and bottom 7 and also cover plate 6 and lid 5 are placed together such that liner 15 and layer 18 and also liner 16 and layer 19 are disposed adjacent one another. They are then welded together at the separating seam 21 by a circumferential weld 22, which is formed by electron beam welding and which extends between the plating liners and layers to a depth of up to 15 mm. When the top and bottom plugs 3, 4 are now threaded into the containment cylinder 2, the liner 13 with its projection 14 overlaps the liner 15 and abuts the layer 18 and forms an additional seam 23 between the projections 14 and 20. This seam 23 is now also welded by means of a circumferential weld 24 which is formed as a smooth cosmetic weld such that the lid 5, the bottom 7 and the containment cylinder 2 are completely surrounded by explosion welded layers and liners of the titanium-palladium alloy with sections of normal steel such as the bottom plate 8 and the cover plate 6 being disposed adjacent the corrosion protection layers below the bottom 7 and above the lid 5. The corrosion protection liners and layers 13, 15, 16, 18, 19 therefore completely surround the containment 2, 3, 4. At the top and bottom end faces there are the cover plates 6 and 8 which consist of a material different from that of which the corrosion protection liners and layers consist and which have a diameter slightly larger than that of the containment cylinder 2. The bottom and cover plates consist of the same fine-grain construction steel as the containment cylinder walls 2, the bottom 7 and the lid 5 onto which the corrosion protection liners and layers are explosion welded. At the separating seam 21 the corrosion protection liners and layers 15, 18 and 16, 19 of the lid 5 and cover plate 6 and of the bottom 7 and the bottom plate 8, respectively, are welded together radially from the circumference thereof. The explosion welded layers 18, 19 of the bottom and cover plates 8, 6 have a larger diameter than the explosion welded liners 15, 16 of the bottom 7 and the lid 5; the liner 13 which is explosion welded onto the containment cylinder 2 has projecting end portions 14 which overlap the liners 15, 16 of the bottom 7 and the lid 5 and which are tightly welded from the outside, that is, circumferentially to the larger diameter layers 18, 19 of the bottom and cover plates 8, 6. For the manufacture of the sealed containment according to the invention, the manufacturing steps are as follows: (a) Explosion plating of the outer surfaces of the containment cylinder 2 and of the outer surfaces of the lid 5 and the bottom 7 with liners or layers of a corrosion inhibiting material such as a titanium-palladium alloy, PA1 (b) Explosion plating of the inner surfaces of the bottom and cover plates 8, 6 with layers 18, 19 of the same material, PA1 (c) Fitting together of the bottom 7 and the bottom plate 8 and also of the lid 5 and cover plate 6 by placing the explosion welded liners and layers 15 and 18 and also 16 and 19 adjacent one another and welding along the separation seam at the circumference thereof, PA1 (d) Threading the bottom plate structure 4 into the lower end of the containment cylinder 2, PA1 (e) Welding the two explosion welded liner 15 and layer 18 between the bottom 78 and the bottom plate 8 along their circumference together with the projection 14 of the explosion welded liner 13 protruding at the lower end of the containment cylinder 2, PA1 (f) Installing a heat conductive centering sleeve 12 into the containment cylinder 2, PA1 (g) Inserting the radioactive body 1 into the centering sleeve 12, PA1 (h) Threading the top plug structure 3 consisting of lid 5 and cover plate 6 from the top into the containment cylinder 2, and PA1 (i) Welding the outer edges of the explosion welded liner 16 and layer 19 between the lid 5 and cover plate 6 to the upwardly projecting end of the explosion welded liner 13 of the containment cylinder 2. LISTING OF REFERENCE NUMERALS 1--Container with radioactive content PA0 2--Container cylinder PA0 3--Top plug structure PA0 4--Bottom plug structure PA0 5--Lid PA0 6--Cover plate PA0 7--Bottom PA0 8--Bottom plate PA0 9--Thread PA0 10--Thread PA0 11--Grapping cavity PA0 12--Heat conductive centering sleeve PA0 13--Titanium-palladium liner PA0 14--Projection PA0 15--Titanium-palladium liner PA0 16--Titanium-palladium liner PA0 17--Circumferential faces PA0 18--Titanium-palladium layer PA0 19--Titanium-palladium layer PA0 20--Projection PA0 21--Separating seam PA0 22--Circumferential weld PA0 23--Seam PA0 24--Circumferential weld