Westinghouse Electric Corporation

Wyoming Mineral Corporation

Minatome Corp.

Uranerz U.s.a. Inc

Erich W Tiepel

Arnold S Kitzes

Regis R Stana

Peter T Chiang

Pang K Lee

Christopher K Wu

Donald L Grover

Parameschwaran S Sundar

An apparatus for the volume reduction of radioactive liquid waste solutions such as evaporator waste bottoms containing boric acid or sodium sulfate and trace quantities of radioactivity through a vacuum evaporative cooling crystallization process or an evaporative crystallization process. A crystallization unit has an internal baffle which separates the center portion of the unit into a quiescent zone where crystallization can be effected and an inner chamber into which the liquid waste is tangentially introduced. The waste is circulated from the bottom of the crystallization unit through a heat exchanger which adjusts the temperature of the liquid waste and maintains the temperature within a predetermined range. The vacuum draws off a portion of the solvent in the solution. Upon the crystallization of the liquid waste solution to a degree which renders a solid-liquid slurry, the slurry is removed from the apparatus for further treatment.

Process and apparatus for the volume reduction of PWR liquid wastes

A continuous process is disclosed for precipitating uranium from an aqueous solution formed by the hydrolysis of uranium hexafluoride gas. Undersized ammonium diuranate particles are formed in a first container by mixing the aqueous solution and an ammonium hydroxide solution containing about 10 to about 30% by weight ammonium. The ratio of the two solutions should be such that there are about 20 to about 30 moles of ammonium per mole of uranium. The temperature is maintained at about 30.degree. to about 50.degree. C. and the residence time in the first container is about 14 to about 57 seconds. The slurry is then transported to a second container for further particle growth where it is agitated at a temperature of about 20.degree. to 40.degree. C. for a residence time of about 2 to about 9 minutes. The resulting ammonium diuranate precipitate has a surface area of about 10 to about 20 meters squared per gram. The precipitate can then be calcined and pressed into pellets.

Process for making high quality nuclear fuel grade ammonium diuranate

A method for concentrating and recovering uranium material from a solution containing uranium, comprises passing the solution through at least one semipermeable membrane system capable of concentrating uranium, to provide a uranium rich product.

Recovery of uranium from enriched solution by a membrane separation

A method is disclosed for restoring a clay rich aquifer which has been solution mined with ammonium ions. Calcium carbonate is precipitated from a solution pumped through the aquifer by the addition of calcium oxide, calcium hydroxide, or a mixture thereof in quantities sufficient to raise the pH to at least about 9.5. The precipitated calcium carbonate is separated from the solution and the ammonium ion is then removed from the solution by standard techniques. The solution is recycled through the aquifer and these steps are repeated until the bicarbonate ion concentration has been reduced to such an extent that the addition of at least one soluble salt of calcium, magnesium, or potassium to the solution does not result in precipitation of calcite underground, plugging the aquifer. Recycling with the addition of the soluble salt is continued until the ammonium ion concentration is reduced to a desired level. Finally, residual amounts of the salt are removed from the aquifer using standard techniques.

Method of aquifer restoration

A process for reducing the volume of spent organic radioactive ion-exchange material which has been used for conditioning water circulated through a nuclear reactor. The spent radioactive ion-exchange material is removed from the reactor system and inserted into a dryer, where the residual free water and some of the intrinsic water in the ion-exchange material is removed so that the ion-exchange material has a moisture content less than 50% by weight. The dried ion-exchange material is then inserted into a fluid bed reactor, a carrier gas is inserted into the reactor and fluidizes the ion-exchange material, and the ion-exchange material is heated. The heating thermally decomposes the ion-exchange material, producing an effluent gas, which contains the volatile decomposition products. The carrier gas and the effluent gas are removed from the fluid bed reactor. After the thermal decomposition, or pyrolysis, is completed, the insertion of the carrier gas into the reactor is stopped and an oxygen-containing gas is inserted into the reactor. The remaining ion-exchange material is burned with the oxygen-containing gas, and a volume reduction of approximately 20:1, depending on the inorganic species loading, is obtained from the original settled bed volume of ion-exchange material to the end product.

Volume reduction of spent radioactive ion-exchange material

A process for reducing the volume of spent radioactive ion exchange resins which have been used for conditioning water circulated through a nuclear reactor. The spent resins are discharged from the reactor system as radioactive wastes to a spent resin storage tank in the form of a slurry. The slurry is first vacuum dewatered to remove the free water and then the intrinsic water in the wet resin beads is removed by drying in a vacuum fluidized bed chamber utilizing superheated steam which also acts to fluidize the bed. Further drying is accomplished by spraying the partially dried resin and superheated steam through a steam injected two-fluid nozzle for further extraction of intrinsic water from the resins. The steam is discharged to a condenser and the dried resins to an evacuated disposal drum. Approximate 4:1 volume reductions from the resin-water slurry to the dried resin is obtainable by practicing the process.

Growing community of inventors

Littleton, CO, United States of America

Erich W Tiepel