Patent Number: 047045396
Section: summary

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a loading and/or unloading device for containers of irradiated fuel of a nuclear reactor or of a reprocessing unit of irradiated fuel, and it is more particularly concerned with the container transportation device, its positioning and sealing system underneath an unloading and/or loading pit, and to the traversing of the bottom of the pit of such a nuclear installation. In order to make clear the problems solved by the device according to this invention, reference is first made to FIGS. 1A through 1H which illustrate schematically the various steps of a container loading operation. In these Figures, one sees at 10 a cart carrying the container 12 provided with a tight plug 14, said cart being moved outside the installation by a locomotor 16. Inside the installation, it is self-propelled, which allows bringing it in succession underneath a system 18 providing the removal of plug 14 and underneath a penetration shaft 20 acting as a lock with a pit or cell 22. A loading operation includes the following steps: 1--bringing the container carrying cart to the removal station of plug 14 (FIG. 1B), after having previously passed through a preparation station; then PA0 2--moving the cart underneath penetration shaft 20 (FIG. 1C), in order to provide a path between pit 22 containing the irradiated fuel 24 and container 12, previously filled with water (FIG. 1D); PA0 3--the loading of container 12 with irradiated fuel 24 (FIG. 1E) is then carried out, then the container 12 is separated from pit 22, followed by the emptying of penetration shaft 20 (FIG. 1F); and finally PA0 4--the cart is transferred underneath the fitting and removal station of plug 14 (FIG. 1G), for resetting the sealing plug in position, followed by the carrying away of the loaded container (FIG. 1H). The invention proposes a number of improvements to the various means used in this installation. OBJECT AND SUMMARY OF THE INVENTION Therefore, the object of the invention is to provide an apparatus for transportation, positioning and sealing a container used for receiving irradiated fuel underneath a loading and/or unloading pit of a nuclear installation, of the type in which a container is disposed on a cart which is successively brought underneath a loading preparation station, underneath a removal station for removal of the plug from the container, and underneath a penetration shaft providing the connection between said loading and/or unloading pit and the hall beneath said pit where said cart travels, said apparatus being characterized in that said cart is made of a framework placed on a rolling platform via a sliding and/or rolling support, and guided by side rails between the cart and the hall, and in that said container is placed on said framework via a plate provided with means for adjusting the height and levelness of the upper face of said container, the positioning of the latter with respect to transverse and longitudinal axes taken in a plane passing through the framework and the container, being obtained with the assistance of a jig fixed on the container frame and cooperating with reference axes carried by the top of the cart, and in that armored protection plates are provided for reducing the radiations, during the container loading operations, and in that the fluid tightness between said loading and/or unloading pit and the container is maintained by a metallic bellows providing the continuity of the fluid tightness at the level of the bearing surface of the container on which the plug is received.