Kernforschungsanlage Julich Gesellschaft MIT Beschrankter Haftung

Kernforschungsanlage Julich

Hans Langen

Helmut Ringel

Erich Zimmer

Paul Naefe

Kurt Scharf

A process for the embedding or containment of waste materials, especially of radioactive waste materials, by embedding in a ceramic matrix through the intermediary of the chemical precipitation of a hydrosol of the matrix, which is formed through the reaction of a nitrate with ammonia or ammonium hydroxide. In this process, the hydrosol is trickled in a pouring column into a precipitation bath, subsequent to the introduction of the material which is to be embedded, in which the hydrosol particles which are formed during the trickling gelatinize into gel particles. The gel particles are removed from the precipitation bath, washed, dried and finally sintered.

Process for the containment of materials in a ceramic matrix through the

An operating process for the formation of a steady particle stream of particles which are conveyed within a flow conduit through the intermediary of a flow medium, and which are introduced into the medium flow under the effect of gravity through an infeed conduit discharging into the flow conduit. The invention also includes an arrangement for the effectuation of the process. A partial flow of the flow medium from the flow conduit is introduced into the infeed conduit in a direction counter to the flow direction of the particles, and is regulated in the manner so as to set the desired particle flow. The volumetric flow of the flow medium which streams counter to the particles in the infeed conduit can, in an advantageous manner, be regulated externally of the infeed conduit whereby no regulating devices will be located in the flow path of the particles.

Operating process for the formation of a steady particle stream of

A vibrating nozzle produces a stream of drops of a nitrate solution that attain spherical drop shape before entering an ammonia gas phase where gas supply nozzles direct streams of ammonia gas obliquely against the drop stream with a component of motion in the direction of movement of the droplet stream, the incidence of the gas streams on the droplet stream being offset a few millimeters from each other along the path of the droplet stream. The flow of gas is at a speed 10 to 20 times that of the velocity of the drops of solution that are uniformly hardened on the surface in their spherical shape so that there is no deformation upon entering the aqueous solution of ammonia in the lower part of the container that confines the ammonia gas phase. The ammonia solution completes the conversion of the nitrate to the corresponding oxide, producing highly uniform spheres such are required for subsequent sintering in the production of nuclear fuel or breeder elements.

Method and apparatus for producing spherical particles of uniform size

A hydrosol containing, in nitrate form, a fuel or fuel-and-breeder material which is projected horizontally in the form of droplets into a gas phase containing gaseous ammonia and allowed to fall in a drip-casting column into a precipitation bath containing ammonium hydroxide. In the gas phase, the droplets are hardened just enough to prevent their deformation upon penetrating into the precipitation bath where the hardening is completed. A falling height of 5 cm is suitable. The granules are washed free of ammonium nitrate, then dried, and then sintered. The heavy metal content in the hydrosol is between 1.5 and 3 moles per liter, and the pH value of the precipitation bath is between 8 and 9. The hydrosol contains the heavy metal in oxide form and the process can be used with a thorium oxide hydrosol or a hydrosol that, in addition to thorium oxide, contains the oxide of hexavalent uranium, in the latter case the hexavalent uranium being present in a proportion up to 25% by weight of the total heavy metal. The process is also applicable to producing kernels of mixed thorium and plutonium oxides. In the case of uranium-containing granules, the sintering step is carried out in a reducing atmosphere to convert the uranium to the tetravalent state.

Hydrosol droplet casting process for production of nuclear fuel and

A device for making ball-shaped metal oxide and metal carbide particles, ecially particles of fuel or breeder substances for nuclear reactors such as oxidic or carbide cores of uranium or the like. The device comprises a container for the ammonia and organic phase, and an injection tube leading into the top of the container. The injection tube is surrounded by a mantle passage of which the cross section is widened in the region of the mouth of the injection tube. The injection tube leads into the container at a distance of from 0.5 to 2 mm. ahead of the end of the mantle passage. The injection tube has an outward diameter which steadily decreases toward the mouth of the injection tube.

Growing community of inventors

Julich, Germany

Hans Langen