Patent Number: 042740070
Section: description

SPECIFIC DESCRIPTION The radiation shielding transport and storage vessel 1 shown in the drawing is intended primarily to receive radioactive waste, especially nuclear-reactor fuel elements. The vessel comprises an upright wall structure 2 and a bottom 3 which is unitarily cast in one piece with the wall structure out of cast iron, especially spherolytic cast iron, cast steel or the like. The container, which has a central cavity or chamber 1a to receive the radioactive material, is closed at its upper end with a shielding cover 4 of a plug configuration. The cover has a downwardly convergent frustoconical portion 5 which is received in a downwardly tapered recess. The outwardly extending flange 6 of the plug-like cover rests upon the shoulder 7 at the mouth of the vessel. As is especially clear from FIG. 2, in the outer regions of the vertical wall 2 passages 9 are provided and receive a moderating material which is designed especially to capture neutrons which may be emitted from the stored radioactive material. These passages 9, filled with water, heavy water, paraffin or the like, are closed by a safety cover 8 which can be bolted to the wall 2, outwardly of the passage 6, which it overhangs. The wall 2 of the vessel is provided with unitary cast cooling or heat-dissipating ribs 10, as described in connection with applications 940,856 and 966,951, the ribs, having cut out or being erupted at 11 so that extension and contraction of individual rib sections is possible. Between the conical surface of the plug portion 5 and the conical face of the surrounding recess 13, sealing rings 14 and 15 are provided. Each of these sealing rings is an O-ring, which is partly trapped in an annular groove 16, which is of trapezoidal cross section. As shown in FIGS. 1 and 3, two such rings are provided in axial-spaced relation along the frustoconical portion of the cover, a further ring 15 between the flange 6 and the shoulder 7 and still another O-ring 18 between the shoulder 17 and an end face 4a of the cover. The interior of the vessel, after filling, receives a control gas which normally is excluded from the compartments 21 formed between the seals. The flange 6 is overhung by a peripheral portion 19 of the cover 8. This peripheral portion having another annular groove, receives an O-ring 20 which rests upon a shoulder 19a, flush with the top of the plug 6. Another control compartment 21 is provided between the O-rings 15 and 20. Passages 22 in the container wall run from a quick connect fitting 22a to the individual compartments 21 and can be coupled by the fitting to a gas closure 23 which monitors the security of the seal. Naturally, each of the compartments 21 can be connected by separate passage 22 to a separate fitting 22a, with the fittings monitored successively from the inner compartments to the outermost to ascertain whether any of the seals has leaked. In place of the O-ring between the flange 6 and the wall 2 and especially between the peripheral portion 19 and the shoulder 19a, a lip tight seal can be provided with welds 30 and 40, sealing the lips 31 and 32 and 41 and 42, which are set off by annular grooves. The advantages described in Ser. No. 966,951 are thereby gained here as well.