Project Y: the Los Alamos Story - David Hawkins
David Hawkins - Project Y: the Los Alamos Story, pp.218-19.
Beta-stage enriched uranium from the Oak Ridge Y-12 plant generally was received as a purified fluoride and reduced directly to metal. For hydride experiments, the metal was converted to hydride and formed by plastic bonding. When hydride or metal experiments were completed, the material was returned for recovery, as were crucibles, liners, and other containers used in fabrication. Recovered solutions were converted to hexanitrate, extracted with ether, and precipitated as reduced oxalate. The oxalate was ignited to oxide and converted back to the original tetrafluoride.
The essential purification step was the ether extraction method (Chap. 8), also applied by the radiochemists to decontamination of Water Boiler solutions and used by the Recovery Group in experiments on test-shot recovery methods. In April 1945, uranium recovery and purification were done by a new group (CM-16). Before that time, extensive investigations were made to determine the best reagents and ion concentrations for the extraction.
The dry purification step (reduction of U02 to UF4) was developed to give fluoride yields as high as 99.9%. Fluorination of the trioxide and oxalate also was investigated. Studies of recovery from liners and slag showed that complete dissolution of these materials was necessary before recovery. Ether extraction was then used. The Recovery Group designed and built continuous extraction apparatus capable of extracting a large volume of solution per hour and giving recovery yields of better than 99.9%. The average uranium remaining in stripped solutions was not more than 60 microgram/liter.
Beta-stage enriched uranium from the Oak Ridge Y-12 plant generally was received as a purified fluoride and reduced directly to metal. For hydride experiments, the metal was converted to hydride and formed by plastic bonding. When hydride or metal experiments were completed, the material was returned for recovery, as were crucibles, liners, and other containers used in fabrication. Recovered solutions were converted to hexanitrate, extracted with ether, and precipitated as reduced oxalate. The oxalate was ignited to oxide and converted back to the original tetrafluoride.
The essential purification step was the ether extraction method (Chap. 8), also applied by the radiochemists to decontamination of Water Boiler solutions and used by the Recovery Group in experiments on test-shot recovery methods. In April 1945, uranium recovery and purification were done by a new group (CM-16). Before that time, extensive investigations were made to determine the best reagents and ion concentrations for the extraction.
The dry purification step (reduction of U02 to UF4) was developed to give fluoride yields as high as 99.9%. Fluorination of the trioxide and oxalate also was investigated. Studies of recovery from liners and slag showed that complete dissolution of these materials was necessary before recovery. Ether extraction was then used. The Recovery Group designed and built continuous extraction apparatus capable of extracting a large volume of solution per hour and giving recovery yields of better than 99.9%. The average uranium remaining in stripped solutions was not more than 60 microgram/liter.