Abstract: The invention relates to a melting furnace for vitrifying highly radioactive waste, comprising a melting tank of refractory material and a furnace upper section enclosed by insulation and a steel container. The furnace contains electrodes of ceramic block material for direct heating which comprise part of the wall of the melting tank. Electrical conductors project from the electrodes through the top of the furnace. In order to avoid the danger of the melt flowing into the gaps between the electrodes and the surrounding tank wall and shorting the electrodes, the melt level is maintained below the top surface of the electrodes. In one form of the invention, the electrodes are recessed along the upper edge of the front side facing the melting tank, which recess accommodates a refractory block which is highly resistant to the corrosive effect of the waste at the melt level. The electrodes require no cooling, and are insulated on their back sides which avoids temperature differentials within the electrodes.
Abstract: A device for evacuating, filling and closing final storage containers for radioactive materials mixed with molten glass, comprising a suction pipe connected to the container, a meltable closure for said pipe and a closable evacuation connection fitting mounted in said meltable closure. The container is evacuated through the fitting whereupon the fitting is sealed closed to preserve the vacuum. When the suction pipe is dipped into the molten glass to fill the container, the closure melts and with the glass is sucked into the container.In another form the device also includes a protective sleeve surrounding the fitting, closed at its outer end with a meltable plate which also serves as a heat radiation shield. The shield prevents premature melting of the meltable closure, i.e. melting from the heat in the glass furnace prior to immersion of the suction pipe in the molten glass.
Abstract: Apparatus for treating radioactive comminuted fuel elements with hot nitric acid comprising an endless conveyor which carries the fuel fragments through a U-shaped jacketed tube counter to the flow of acid. The conveyor travels in a conduit which connects to the ends of the U-shaped tube to form a continuous loop. Downstream of the U-shaped tube associated with the conduit is a washing unit, a drying unit, and a discharge unit. Upstream of the U-shaped tube is a feed unit which joins the conduit. A radioactive fission material sensor is located just ahead of the discharge unit and serves to actuate a switch to recycle treated fragments that may still be radioactive. Drive apparatus for the conveyor comprises permanent magnets mounted at spaced intervals on the conveyor and exciter windings surrounding said U-shaped tube to direct forward movement.
Abstract: An apparatus is disclosed for carrying out repair, maintenance or testing of apparatus, components and the like in hot cells, more particularly hot cells of reprocessing plants for spent nuclear fuels. The position of damage zones is detected and ascertained with the use of coordinates. Replacement parts and tools are moved into the maintenance and work position in dependence upon the coordinate data, and the repair of maintenance work is automatically carried out under computer control, with remote operation and remote monitoring. For carrying out the work, computer-controlled handling machines and manipulators are used which are adapted to travel in controllable manner in the hot cell. The monitoring and detecting, using coordinates, of damage zones and defects may be carried out with the use of cameras and/or leak detectors.
Abstract: Accurate, contact-free measurement, outside the processing area, of the quantity of solid material in a centrifuge cylinder used in reprocessing nuclear fuel solutions. A mechanical vibration system consisting of the centrifuge cylinder and of a supplemental mass attached to the cylinder produces torsional vibrations by, for example, increasing or decreasing the speed of the cylinder drive shaft. The frequency of the vibrations reflect the quantity of solid material in the cylinder. A sensor senses the frequency of the vibrations and sends signals to a means for computing the quantity of the load from the frequency.