Hydrosol droplet casting process for production of nuclear fuel and breeder material granules

US4193953A · kind A · utility

Assignee

• Kernforschungsanlage Lulich Gesellschaft mit beschrankter Haftung · DE

Inventors

• Hans Langen · Frechen, DE
• Helmut Ringel · Niederzier, DE
• Erich Zimmer · Jülich, DE

Key dates

• Filing date: Jul 19, 1978
• Grant date: Mar 18, 1980
• Expiry date: Jul 19, 1998

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02E30/30
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

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 redu…