Patent Number: 044144750
Section: description

Referring now to the figures of the drawing and first particularly to FIGS. 1-3 thereof, it is seen that in a nuclear power plant, especially with a pressurized water reactor, provisions are made for at least temporary storage of the weak to medially active waste which results, for example, from the purification of the cooling medium, in a storage chamber 1 which is bounded by walls 2 in a protected building of the nuclear power plant. The walls 2 form a mostly even, flat inner surface 3. From the surface 3, projections 4 extend into the chamber 1, and recesses 5 are formed along side of the projections 4. Because of the uneven conditions formed by this configuration, shielding containers 7 which are densely stacked in the storage chamber 1 are secured in four layers on top of each other, as particularly shown in FIG. 2. The stacking extends, if possible, as far as the construction will allow up under the ceiling 8 of the chamber 1, where a hoist 9 is disposed so as to be movable on a rail 10. The shielding containers 7 are formed of concrete or another readily available and inexpensively manufactured material with good shielding properties, such as cast iron. As especially clearly shown in FIG. 4, the containers have a mostly square cross section with flat side surfaces 13, 14, 15 and 16. Only the corners 18, 19, 20 and 21 deviate from this square cross section. In this way the diagonally opposed corners 18 and 20 are provided with projections 23 and 24, which extend beyond the square cross section, while the other corners 19 and 21 are flattened or chamfered so that the edge regions 25 and 26 form an angle 27 in FIG. 4, and thereby form recesses with respect to the square cross section. The angle 27 matches an angle 28 of the projections 23 and 24, as shown at the corner 18. This causes the shielding containers 7 to interlock with each other and with the projections 4 and recesses 5 of the wall surface 3 due to the dense stacking as shown in FIGS. 1 and 2. The result is a solid stack 29 shown in FIG. 2, which, however, can still be taken apart in spite of its earthquake-resisting configuration, because it is based on an interlocking connection and not a permanently fixed connection. The shielding containers 7 have a cylindrical clearance 30, having centers 31 that coincide with the centerpoint of the square cross section. In this cylindrical clearance, which extends through the total height H of the shielding container 7, as shown in FIG. 5, a storage barrel which is indicated at reference numeral 33 with dot-dash lines can be inserted. Thus, the barrel is mechanically well secured and shielded in the stack 29 of shielding containers 7, without having a fixed connection of its own with the shielding containers 7 or the walls 2. Therefore, the barrel 33 can be inserted after the shielding containers have been stacked, and it can also be removed again before breaking up the stack 29. In order to reinforce the connection when stacking several layers on top of each other, projections 36 are provided at the bottom surface 35 of the shielding containers 7 at all four corners 18, 19, 20 and 21, in such a way that the side of the projections 36 facing the through-clearance 30 is formed by diagonally-oriented slopes 37, 38, 39 and 40. The top surface 42 on top of the shielding container 7 is provided with corresponding recesses 41, so that the middle region 43 between the corners 18 and 21 and the clearance 30 is raised. The height H.sub.1 of the raised portions at the top surface 42 is the same as the height H.sub.2 of the projections 36 at the bottom surface 35. FIG. 5 shows that at the top surface 42, undercuts 44 are provided for attaching gripper-tools 47, 48 shown in FIG. 2, the undercuts being lined with an anchoring sheeting 45. The anchoring extends into the side-wall 46 of the shielding container. The anchoring 45 is formed of metal, so that the forces induced by the gripper tool into the concrete are well distributed into the concrete. As shown in FIG. 4, in the illustrated embodiment there are four undercuts 44 symmetrically formed at the square cross section. However, for actual transport it may be sufficient if the hoist or lifting tool 9 is only attached to the shielding container 7 with two oppositely-disposed jaws 47 and 48.