Patent Number: 044329423
Section: summary

BACKGROUND OF THE INVENTION This invention relates to the filling of a container, for the purpose of storage, with radioactive wastes, particularly, miscellaneous incombustible solid wastes, arising from atomic power plants or other establishments for handling radioactive materials. Since in such radioactive wastes, the radioactive rays emitted therefrom exert a great influence upon living things in the natural world including humankind, the wastes need be stored until the final disposal (for example, such as dumping into the seas or burying under the ground) has been done. In this case, it involves a problem that the wastes as described above are generally so bulky that a very large storing space must be provided if the wastes are stored without modification. In order to eliminate the aforesaid problem, it has been conceived to reduce the wastes into small pieces so as to fill a container with thus reduced wastes. However, even in such a case, clearances are formed between these reduced pieces within the container, resulting in a limited reduction in the quantity capable of being filled. The present inventor has also conceived an apparatus in which such wastes are melted in a crucible of a high frequency induction furnace or an arc furnace, the furnace body being tilted to transfer the molten wastes into a solidifying container for solidification, and the solidified wastes being transferred into a storing container for storage. However, this requires much labor during the operation. OBJECTS OF THE INVENTION An object of this invention is to provide an apparatus for reducing the volume of bulky radioactive wastes having various shapes so that the wastes can be stored in a convenient manner. Another object of this invention is to provide an apparatus for reducing the volume of wastes and providing the whole of the wastes with a predetermined or uniform shape in a simultaneous manner, i.e. to pack wastes having different shapes to the full into a container having a uniform shape and solidify the wastes in the fully-packed condition. The wastes melted and solidified in the container are reduced in volume, and a predetermined shape is simultaneously given to the whole of the wastes since the container has a uniform shape. This feature of the invention provides many advantages, such as ease in storing the solidified waste and the like. A further object of this invention is to provide an apparatus which is adapted to prevent any environmental pollution when and if melted radioactive wastes are scattered during the melting of the wastes in a container, i.e. the apparatus herein is such that wastes are put into a container, for storing the wastes, in advance, and the wastes are melted by plasma arcs in this condition, i.e., surrounded by the walls of the container. Therefore, when any portion of the melted wastes is scattered, most of it is prevented from going out of the container by the walls thereof so that environmental pollution due to a scatter of the radioactive wastes can be minimized. A further object of this invention is to provide an apparatus which makes it possible to melt radioactive wastes with a higher thermal efficiency by positioning the wastes and a plasma torch, for heating the wastes, to each other in a melting-efficient manner whether the wastes in the container happen to be located nearer to the bottom of the container or to the top of the container. The apparatus herein employs a plasma torch, i.e., a device capable of heating wastes in a local and concentrated manner by emitting highly linear plasma arcs, as a means for heating wastes. The plasma torch can be moved in a vertical direction, and has a lower end adapted to come into a container, so that the wastes, regardless of their vertical position in the container, can be irradiated by the plasma torch by moving the torch in a vertical direction. Therefore, the wastes can be melted with a higher thermal efficiency in any case. A still further object of this invention is to provide an apparatus which makes it possible to use a container having a simple construction, prevent the container from being melted when wastes are melted therein, and employ a simple means for protecting the container against heat. Having the above-mentioned construction, the apparatus according to the invention can melt wastes in a container in a concentrated manner. Therefore, wastes can be melted with a minimum danger of melting of the container. The container can be filled in its required space with the radioactive wastes with high density and in all parts thereof closely. The radioactive wastes are heated to be molten, and the melt is introduced into the container in orderly fashion from the bottom thereof and accordingly, the container is filled in its required space with the wastes with little clearance. The radioactive wastes can be decreased in volume through that portion. Consequently, in the event after the container has been filled, the radioactive wastes filled in the container are stored, a small site required for the storage thereof will suffice. Further, the radioactive wastes can be filled into the container in its required space with little clearance, and so, even if a given quantity of radioactive wastes are required to be filled in that required space, it is possible to easily meet the requirement. The container can be filled for storing the radioactive wastes with the radioactive wastes in a state of high density as described above, merely by the operation of principally melting the radioactive wastes. The operation of melting the radioactive wastes is all that is required to minimize bulking thereof, and as a consequence, the operation of filling the container for storing the radioactive wastes with the wastes with high density can be simultaneously effected without requiring much labor. Other objects and advantages of the invention will become apparent during the following discussion of the accompanying drawings.