Patent Number: 055747590
Section: description

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is seen a sub-region of a reactor pressure vessel 1 with a particularly bulky part of pressure-vessel fittings 2. The method according to the invention is to be described with reference to this bulky part, which is formed of upper and lower core grids 3, 4 and a core shroud 5. As a rule, between the core grids 3, 4 and the core shroud 5 there is a screw connection which is released as early as during removal from the reactor pressure vessel, so that three individual parts are available for dismantling. However, the method can also be employed when, for example, a welded structure is present and the core grids 3, 4 and the core shroud 5 form a single part. After being removed from the reactor pressure vessel 1, the core grids 3 and 4 and the core shroud 5 are set down on a bottom 6 of a water tank 7, as is indicated by the core shroud 5 in dot-dash lines in FIGS. 2 to 4. According to FIG. 2, a bottom part 8a of a dismantling container 8 is set down on the bottom 6 and one of the core grids 3, 4 is laid onto the bottom part 8 a. A casing 8 b of the dismantling container which is set down on a tank edge 9 is moved into the water tank 7 through the use of a non-illustrated lifting appliance and is connected to the bottom part 8a to form the dismantling container 8, as is also seen in FIGS. 3 and 4. A receiving container 11 for receiving parts obtained during subsequent dismantling is disposed on the core grid. A dismantling manipulator 12 that is likewise set down on the tank edge 9 is set down on a flange 13 of the dismantling container 8 through the use of the non-illustrated lifting appliance or through a likewise non-illustrated rail connection and is fixed relative to the dismantling container, as is shown in FIG. 4. When this phase for dismantling a core grid 3, 4 according to FIG. 2 is reached, a separation of the core grid into transportable parts is carried out by the dismantling manipulator, for example by plasma cutting, with the parts being deposited in the receiving container 11 through the use of an auxiliary lifting appliance 14 that is seen in FIG. 4 and is assigned to the dismantling manipulator 12. After the receiving container 11 is filled, the dismantling manipulator 12 is brought into its set-down position on the tank edge 9. According to FIG. 3, a shielding container 15 is introduced into the water tank 7, its bottom part 15 a is removed, the receiving container 11 is drawn into the shielding container 15 and the bottom part 15 a is reattached. The shielding container 15 that is loaded with the receiving container 11 is brought to a transfer station 16 stationed on a tank edge 9 a. A transport container 17, which is constructed as an ultimate-storage container and has a cover 18 that is removed, is already disposed there. The shielding container 15 is set down on the transport container 17 in alignment in the axial direction, and its bottom part 15 a is moved away laterally, so that the receiving container 11 is lowered into the transport container 17 by a lifting device 20. The shielding container 15 is closed through the use of its bottom part 15 a and is set down at a suitable point until it is next used. After the receiving container 11 has been loaded several times, as soon as the core grids 3, 4 are dismantled, extracted and stored in a radiation-proof manner, the dismantling of the core shroud 5 is dealt with according to FIG. 4. In this case as well, the procedure according to FIG. 2 is carried out analogously, with the core-container shroud 5 and a receiving container 11a being set down on the bottom part 8a after the bottom part 8a has been put in place. The dismantling-container casing 8 b is then lowered in a sleeve-like manner over the core shroud 5 and is connected to the bottom part 8a to form the dismantling container 8. The dismantling manipulator is then supported on the flange of the dismantling container 8 and the dismantling of the core shroud 5 commences according to FIG. 4. Segments which are detached in each case during this dismantling are inserted into the container 11 a through the use of the auxiliary lifting appliance. After the container 11 a is filled, the dismantling manipulator is brought to its set-down point on the tank edge 9 and the load of the receiving container 11 a is transferred to a transport container 17 correspondingly to FIG. 3. In another embodiment, the receiving container 11 a, together with its load, can also be placed directly into a transport container. The water of the dismantling container 8 is purified through the use of a circulating system 21.