Alkem Gmbh

Wolfgang Stoll

Wolf-Gunther Druckenbrodt

Volker Schneider

Friedrich-Wilhelm Ledebrink

Dieter Schafer

Christian Ost

Ralf Guldner

Siegfried Baumann

Karl Ennerst

Roland Krause

Wilhelm Ledebrink

Friedrich-Wilheim Ledebrink

Wolfgang Rosenkranz

Method for treating plutonium and/or uranyl nitrate by superheating and concentrating a nitric acid starting solution, characterized by the feature that nitric acid starting solution is concentrated to form a Pu(VI)-and/or U(VI)-containing nitrate melt, is poured into a mold, is solidified by cooling down, and is transported and/or stored as a solidified solid body until further processing.

Method of processing plutonium and/or uranyl nitrate

Container, especially for radioactive substances such as radioactive liquids, with an inner container for receiving these substances and an outer container, in which the inner container and thermal insulation between the inner and outer container are located. The inner container is associated with a cooling tube within the outer container which tube contains a coolant that can be circulated. A heat discharge tube likewise containing the coolant that can be circulated is arranged at the outer container. The cooling tube and the heat discharge tube are in communication with each other via connecting lines at both tube ends.

Container, especially for radioactive substances

A method for manufacturing Pu.sub.2 -containing crystals by oxidizing plutonium in a heavily contaminated nitric acid starting solution to Pu.sup.6+, precipitating ammonium plutonyl carbonate containing crystals by reaction with ammonium- and carbonate ions and subsequent separating and calcining of these crystals. The nitric acid solution with the oxidized Pu.sup.6+ as well as carbonate and/or acetate ions and NH.sub.3 are dosed into an aqueous starting solution of ammonium carbonate or ammonium acetate in a concentration such that the mol ratio of carbonate and/or acetate ions to the Pu.sup.6+ -ions in the solution is at least 4:1 and plutonium containing carbonato- or acetato complex compounds which remain dissolved in the receiver solution, are formed, while difficult-to-dissolve metal hydroxide compounds are precipitated. Thereupon NH.sub.3 and carbonate ions are added to precipitate the ammonium plutonyl carbonate containing crystals.

Method for the manufacture of PuO.sub.2 -containing crystals

Method for dissolving hard-to-dissolve thorium and/or plutonium oxides, especially dioxides such as ThO.sub.2, PuO.sub.2 or (U/Pu)O.sub.2 mixed oxides by heating the oxides in a hermetically sealed vessel in fluoride-free nitric acid. The use of a gas atmosphere containing oxygen in the sealed vessel is advantageous.

Method for dissolving hard-to-dissolve thorium and/or plutonium oxides

Reprocessing a nuclear reactor fuel rod which contains nuclear fuel in a cladding tube, by removing the cladding tube from the nuclear fuel. The cladding tube is uniformly heated in hermetically sealed condition together with the nuclear fuel contained thereon to permanently expand the diameter of the cladding tube without the formation of cracks in the cladding tube, increasing the distance between the nuclear fuel and the cladding tube. Subsequently the expanded cladding tube is opened at one end. The nuclear fuel is removed from the opened cladding tube and is processed further, separate from the cladding tube.

Method for reprocessing a nuclear reactor fuel rod

Dissolving hard-to-dissolve nuclear fuels such as ThO.sub.2 and PuO.sub.2 in a nitric acid fission material solution which contains nitric acid and a Pu-fluoride complex to provide free fluorine ions in a small catalytically active amount due to small dissociation of fluoride ions from the Pu-fluoride complex. This permits dissolving hard-to-dissolve nuclear fuels in normal metallic dissolving vessels and also eliminates need for using polytetrafluoroethylene.

Method for dissolving hard-to dissolve nuclear fuels

Recovering fission material from solid raw wastes and producing a space-saving product which can be committed to ultimate storage by the following steps:

Method of processing radioactive wastes

Manufacture of uranium/plutonium oxide mixed crystals soluble in nitric acid in which a solution of uranium nitrate and plutonium nitrate are oxidized to cause the plutonium to reach valence VI. The oxidized solution is admixed with ammonium carbonate, oxalate or carbamate and the pH adjusted to 8.1 to 8.5 to precipitate an ammonium uranyl plutonyl carbonate, oxalate or carbamate. The precipitate is calcined to uranium/plutonium oxide.

Growing community of inventors

Hanau, Germany

Wolfgang Stoll