Kernforschungsanlage Julich Gesellschaft MIT Beschrankter Haftung

Kernforschungsanlage Julich

Helmut Ringel

Erich Zimmer

Hans Langen

Nabil Abdelmonem

Paul Naefe

Kurt Hein

Martin Messler

Wolfgang Frommelt

A process for heat-treating refuse comprising the steps of decomposing in a combustion furnace a quantity of refuse into slag, emitted gas and fly dust. The fly dust is separated into a fine dust fraction and a coarse dust fraction. The coarse dust fraction is fed back to the combustion chamber, and the fine dust fraction is treated for removal of desired constituents.

Process for heat-treating refuse and equipment to carry out the process

A process and installation for the adsorptive separation, in an adsorption olumn, of krypton from a gas mixture containing, in particular, nitrogen in addition to the krypton. The adsorption column is filled with an adsorption medium which adsorbs krypton and nitrogen over a length L extending in the direction of the inflowing gas mixture. After the adsorption of the gas components in the adsorptive column, the adsorption medium is desorbed in the following process step through the intermediary of a gaseous scavenging medium. The scavenging medium flows through the adsorption column in the same direction in which the gas mixture was introduced into the adsorption column during the first process step. The adsorption medium is charged with krypton commencing from the gas inlet of the adsorption column over only such a partial length L.sub.O of the entire column length L, that during the desorption of the adsorption column with the scavenging medium there is separately removable from each other at the gas discharge of the adsorption column, initially only nitrogen, and later on krypton.

Process and installation for the adsorptive separation of krypton from a

A process for the separation of krypton from a radioactive waste gas mixt which is released during the chemical dissolution of burned-down nuclear fuel particles, and which in a carrier gas such as air, in addition to krypton, also contains xenon, argon, nitrous oxide and residual gas components. The waste gas mixture flowing out from a resolver has xenon removed therefrom after purifying the waste gas of nitrous oxides and radioactive residual gas components, such as aerosols, iodine, tritium and carbon(C-14) dioxide; and wherein krypton is finally withdrawn from the residual gas mixture and then stored. The invention also relates to an arrangement for the implementation of the inventive process. Subsequent to the purifying of the waste gas mixture from nitrous oxides and radioactive residual gas components, such as aerosols and iodine, a portion of the waste gas mixture is reconveyed into the resolver, and wherein the remaining portion of the waste gas mixture is purified of tritium and carbon(C-14) dioxide, and after an adsorptive removal of xenon discontinuously flows through a preparative gas chromatograph in which the krypton is separated from the residual gas. The remaining portion of the waste gas mixture is thereafter purified of tritium and carbon(C-14), which are removed in the form of HTO or, in essence, 14CO.sub.2, and thereafter adsorptively freed from xenon. The remaining waste gas mixture containing krypton is discontinously conveyed to a preparative gas chromatograph in which the krypton is separated from the residual gas.

Process for the separation of krypton from a radioactive waste gas

A process for the separation of krypton from a radioactive waste gas mixt which is released during the chemical dissolution of burned-down nuclear fuel particles, and which in a carrier gas such as air, in addition to krypton, also contains xenon, argon, nitrous oxide and residual gas components. The waste gas mixture flowing out from a resolver has xenon removed therefrom after purifying the waste gas of nitrous oxides and radioactive residual gas components, such as aerosols, iodine, tritium and carbon(C-14) dioxide; and wherein krypton is finally withdrawn from the residual gas mixture and then stored. The invention also relates to an arrangement for the implementation of the inventive process. Subsequent to the purifying of the waste gas mixture from nitrous oxides and radioactive residual gas components, such as aerosols and iodine, a portion of the waste gas mixture is reconveyed into the resolver, and wherein the remaining portion of the waste gas mixture is purified of tritium and carbon(C-14) dioxide, and after an adsorptive removal of xenon discontinuously flows through a preparative gas chromatograph in which the krypton is separated from the residual gas. The remaining portion of the waste gas mixture is thereafter purified of tritium and carbon(C-14), which are removed in the form of HTO or, in essence, 14CO.sub.2, and thereafter adsorptively freed from xenon. The remaining waste gas mixture containing krypton is discontinuously conveyed to a preparative gas chromatograph in which the krypton is separated from the residual gas.

For the separation and recycling of NO.sub.x gas constituents through adstion and desorption on a molecular sieve the molecular sieve is passed through in sequential, alternating process steps. Initially, the NO.sub.x is retained up to saturation of the molecular sieve. Thereafter the molecular sieve is regenerated through the introduction of gas. In order to reduce the demands during scavenging of the molecular sieve, and then to facilitate the provision of a closed separating and recycling system, the molecular sieve for regeneration is heated to a temperature for desorbing the adsorbed NO.sub.x and scavenged with a portion of the waste gas containing the NO.sub.x which is to be cleaned. The scavenging gas flow is recycled after passing through the molecular sieve.

Process for the separation and recycling of NO.sub.x gas constituents

An apparatus charges weakly acidic cationic ion exchange resin particles with uranyl ions by contacting the particles stepwise with aqueous uranyl nitrate solution at higher uranium concentrations from stage to stage. An alkaline medium is added to the uranyl nitrate solution in each stage to increase the successive pH values of the uranyl nitrate solution contacting the particles in dependance upon the uranium concentration effective for maximum charging of the particles with uranyl ions.

Apparatus for producing ion exchange particles charged with uranyl ions

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

Weakly acidic cationic ion exchange resin particles are charged with uranyl ions by contacting the particles step wise with aqueous uranyl nitrate solution at higher uranium concentrations from stage to stage. An alkaline medium is added to the uranyl nitrate solution in each stage to increase the successive pH values of the uranyl nitrate solution contacting the particles in dependence upon the uranium concentration effective for maximum charging of the particles with uranyl ions.

Method of producing weakly acidic cation exchange resin particles

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 separating in a continuous process particles such as heavy ml particles consisting of fuel and/or breeder materials for core reactors, from a first liquid and introducing the separated particles into a second liquid. The device comprises a screen in the form of a movable endless belt or drum over which ends a feeding line conveying the first liquid containing the particles to be separated onto the endless screen. While the particles are retained on the surface of the moving screen journalled in a housing, the first liquid passes through the screen into a catching funnel and from there to a discharge, the catching funnel being arranged in the housing. In the lower portion of the housing and in contact with the outer screen surfaces is a second liquid which takes off from the outside of the screen the particles deposited onto the screen.

Growing community of inventors

Niederzier-Hambach, Germany

Helmut Ringel