Patent Number: 042347980
Section: description

SPECIFIC DESCRIPTION The shielding transport and storage container illustrated in the drawing and represented generally at 1 is formed with a vertically elongated compartment 1a adapted to receive irradiated nuclear fuel elements. Naturally, the chamber can also receive other radioactive wastes as may be required. Basically, the container or receptacle comprises a container wall or shell 2, a bottom 3 and a cover as will be described in greater detail below. According to the invention, the wall 2 laterally surrounding the chamber 1a, and the bottom 3 of the container are cast in one piece from cast iron, especially spherolytic cast iron, cast steel or the like. The receptacle is generally prismatic and of the configuration of a rectangle parallele-pipedon with rounded edges, i.e. has vertical faces 2a and 2b which are parallel to one another and vertical faces 2c and 2d which are also parallel to one another but are perpendicular to the faces 2a and 2b. The upper and lower end faces of the receptacle are also flat. The chamber 1a for receiving the radioactive waste, is formed with a shoulder 1b at its upper end upon which rests a lateral flange 4a of a shielding cover 4. Surrounded by this flange is a block 4b of shielding material which plugs the upper end of the chamber 1a, the cover 4 being recessed in the body formed by the wall 2 and the bottom 3 so that its upper surface 4c lies flush with an end face 2e of this body. According to the invention, the vessel wall 2 is provided in situ, i.e. during the casting process, with a tubular passage 5 which communicates between the low point 5a of the chamber 1a and the face 2e of the body 2, 3. To close this passage 5 at its upper end, which can be formed with an internally threaded formation 5b for connection to a pipe, the receptacle 1 is provided with a passage cover which is generally represented at 6. The latter is wholly received in a recess 2f formed at the upper end of the container. In the embodiment illustrated, the cover 6 not only closes the passage 5b, 5, but also overlies the cover 4. Bolts or screws 6a are threaded into the body 2, 3 and screws 4d passing through the flange 4a secure the cover 6 and 4 in place. In the bestmode embodiment of the invention, a further tubular passage 7 is cast in situ within the body 2, 3, the passage 7 communicating at 7a with the chamber 1a at its upper end, i.e. just below the plug 4b. At its opposite end, the passage 7 opens into a compartment 8 recessed in this body and terminates flush with the bottom 8a of this compartment. A valve 9 can have a flange 9a which is screwed to the body so as to sealingly couple this valve with the passage 9. The valve 9 is wholly received in the compartment 8 which, in turn, is closed by the cover 6. Thus the cover 6 is screwed to the body 2, 3 outwardly of the regions in which the passages 5 and 7 open at the surface 2e of the body. The valve 9 may be a fluid control valve or a pressure relief or safety valve which can be vented, e.g. through an additional tube. As is apparent from FIGS. 1 and 2, the passages 5 and 7 lie within the inner half of the thickness T of the wall 2. This permits the outer half of the wall thickness to receive passages 10 which, as shown in FIG. 2, are of oval cross section and extend the full length of the vessel. These passages receive radiation shielding material 10a, e.g. graphite or some other neutron moderator or a heavy metal such as lead. The additional moderator 10a is especially advantageous when the radioactive wastes have a high neutron emission. The channels 10 can also be closeable by the cover 6. Of course, the cover 4, 6 can be connected together e.g. by screws. The outer periphery of the receptacle is provided with cooling ribs 11 which are cast in situ and in one piece with the body 2, 3. The ribs 11 are shown to extend along generatrices of the body and to have gaps or cutouts 12 which facilitate expansion and contraction. Naturally, the ribs may also lie in horizontal planes as desired.