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US 2,698,290 (The Isotope of Curium Having a Mass Number of 238) G.T. Seaborg, K. Street Jr.; Dec 28, 1954.
A method of producing Cm238 by bombarding Pu239 with 80-Mev alpha particles from a cyclotron and chemically separating the curium from the complex mixture of products including several curium isotopes, the original target material, and a variety of rare earth fission products are described. The Cm238 is identified by means of an alpha particle pulse analysis.
US 2,776,185 (Method of Concentrating Fissionable Material) G.T. Seaborg, L.B. Werner, B.A. Fries; Jan 1, 1957.
A process is described for concentrating dilute solutions of Pu. The process consists of alternately using La salt precipitate and Nb2O5 precipitates as carriers for the Pu, and of redissolving each precipitate in a substantially smaller volume of solvent than it was precipitated from. This cycle is repeated a sufficient number of times to obtain the desired degree of concentration.
US 2,785,951 (Bismuth Phosphate Process for the Separation of Plutonium from Aqueous Solutions) G.T. Seaborg, S.G. Thompson; Mar 19, 1957.
A method is given for separating Pu from fission products arising with it in the irradiated U. The method makes use of the fact that Pu6+ forms a soluble phosphate while lower valent plutonium forms an insoluble phosphate. The irradiated U is dissolved, Bi ion is added to serve as a carrier, and while the Pu is being maintained in its lower valent state, PO4 is added, causing the precipitation of the Pu and any fission products which form insoluble phosphate. This precipitate is filtered out and then redissolved in an aqueous acid solution. The Pu is then oxidized to the higher valent state causing it to remain in solution when phosphate ion is added to precipitate out the phosphate insoluble fission products which accompanied the plutonium in the first precipitation.
US 2,799,553 (Phosphate Method for Separation of Radioactive Elements) G.T. Seaborg, S.G. Thompson; Jul 16, 1957.
A method is given separating Pu from U, certain fission products and Np. Neutron irradiated U containing Pu, U, Np and fission products is treated with HNO3 to obtain an aqueous solution which is adjusted to have a UNH concentration of about 22%. Sulfuric acid is added to the solution to give an acidity of about 0.85 to 1.24N based on sulfuric and nitric acids present. A soluble Bi compound is added to the Bi ion concentration of about 1 to 2.5 grams per liter of solution. The addition of a soluble phosphate then precipitates BiPO4 carrying substantially all the Pu and leaving the bulk of the U, Np and fission products in solution.
US 2,811,415 (Extraction Method for Separating Uranium, Plutonium, and Fission Products from Compositions Containing Same) G.T. Seaborg; Oct 29, 1957.
Methods for separating plutonium from the fission products present in masses of neutron irradiated uranium are reported. The neutron irradiated uranium is first dissolved in an aqueous solution of nitric acid. The plutonium in this solution is present as plutonous nitrate. The aqueous solution is then agitated with an organic solvent, which is not miscible with water, such as diethyl ether. The ether extracts 90% of the uranyl nitrate, leaving substantially all of the plutonium in the aqueous phase. The aqueous solution of plutonous nitrate is then oxidized to the hexavalent state, and agitated with diethyl ether again. In the ether phase there is then obtained 90% of plutonium as a solution of plutonyl nitrate. The ether solution of plutonyl nitrate is then agitated with water containing a reducing agent such as sulfur dioxide, and the plutonium dissolves in the water and is reduced to the plutonous state. The uranyl nitrate remains in the ether. The plutonous nitrate in the water may be recovered by precipitation.
US 2,819,144 (Separation of Plutonium from Uranium and Fission Products by Adsorption) G.T. Seaborg, J.E. Willard; Jan 7, 1958.
A method is presented for the separation of plutonium from solutions containing that element in a valence state not higher than 4+ together with uranium ions and fission products. This separation is accomplished by contacting the solutions with diatomaceous earth which preferentially adsorbs the plutonium present. Also mentioned as effective for this adsorbtive separation are silica gel, fuller's earth and alumina.
US 2,831,750 (Separating Protoactinium with Manganese Dioxide) G.T. Seaborg, J.W. Gofman, R.W. Stoughton; Apr 22, 1958.
The preparation of U235 and an improved method for isolating Pa 233 from foreign products present in neutronirradiated thorium is described. The method comprises forming a solution of neutron-irradiated thorium together with a manganous salt, then adding potassium permanganate to precipitate the manganese as manganese dioxide whereby protoactinium is carried down with the manganese dioxide dissolving the precipitate, adding a soluble zirconium salt, and adding phosphate ion to precipitate zirconium phosphate whereby protoactinium is then carried down with the zirconium phosphate to effect a further concentration.
US 2,833,617 (Fluorine Process for Separation of Materials) G.T. Seaborg, H.S. Brown; May 6, 1958.
A process is described for separating plutonium from neutron-irradiated uranium, which consists of reacting the irradiated uranium mass with HF to form the tetrafluorides of U, Pu, and Np, and then reacting this mixture of tetrafluorides with fluorine at temperature between 140 and 315 d C. This causes volatile hexafluorides of U and Np to form while at the temperature employed the Pu tetrafluoride is unaffected and remains as a residue.
US 2,845,544 (Neutron Measuring Method and Apparatus) G.T. Seaborg, G. Friedlander, J.W. Gofman; Jul 29, 1958.
A fast neutron fission detecting apparatus is described consisting of a source of fast neutrons, an ion chamber containing air, two electrodes within the ion chamber in confronting spaced relationship, a high voltage potential placed across the electrodes, a shield placed about the source, and a suitable pulse amplifier and recording system in the electrode circuit to record the impulse due to fissions in a sample material. The sample material is coated onto the active surface of the disc electrode and shielding means of a material having high neutron capture capabilities for thermal neutrons are provided in the vicinity of the electrodes and about the ion chamber so as to absorb slow neutrons of thermal energy to effectively prevent their diffusing back to the sample and causing an error in the measurement of fast neutron fissions.
US 2,852,336 (Peroxide Process for Separation of Radioactive Materials) G.T. Seaborg, I. Perlman; Sep 16, 1958.
A method is described of separating plutonium, in the reduced state, from hexavalent uranium. It consists in treating an aqueous solution containing such uranium and plutonium ions with sulfate ions in order to form a soluble uranium sulfate complex and then treating the solution with a soluble thorium compound and a soluble peroxide compound in order to form a thorium peroxide carrier precipitate which carries down with it the plutonium peroxide present. During this treatment the pH of the solution must be maintained between 2 and 3.
US 2,861,866 (Wet Fluoride Separation Method) G.T. Seaborg, J.W. Gofman, R.W. Stoughton; Nov 25, 1958.
The separation of U233 from thorium, protactinium, and fission products present in neutron-irradiated thorium is accomplished by dissolving the irradiated materials in aqueous nitric acid, adding either a soluble fluoride, iodate, phosphate, or oxalate to precipltate the thorium, separating the precipltate from the solution, and then precipitating uranium and protactinium by alkalizing the solution. The uranium and protactinium precipitate is removed from the solution and dissolved in nitric acid. The uranyl nitrate may then be extracted from the acid solution by means of ether, and the protactinium recovered from the aqueous phase.
US 2,865,703 (Process of Purifying Uranium) G.T. Seaborg, E.F. Orlemann, L.H. Jensen; Dec 23, 1958.
A method of obtaining substantially pure uranium from a uranium composition contaminated with light element impurities such as sodium, magnesium, beryllium, and the like is described. An acidic aqueous solution containing tetravalent uranium is treated with a soluble molybdate to form insoluble uranous molybdate which is removed. This material after washing is dissolved in concentrated nitric acid to obtain a uranyl nitrate solution from which highly purified uranium is obtained by extraction with ether.
US 2,865,704 (Method of Separating Uranium, Plutonium and Fission Products by Bromination and Distillation) G.T. Seaborg, A.H. Jaffey; Dec 23, 1958.
The method for separation of plutonium from uranium and radioactive fission products obtained by neutron irradiation of uranium consists of reacting the irradiated material with either bromine, hydrogen bromide, aluminum bromide, or sulfur and bromine at an elevated temperature to form the bromides of all the elements, then recovering substantially pure plutonium bromide by distillation in combination with selective condensation at prescribed temperature and pressure.
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