Annual Progress Report for the Period July 1961 Through June 1962

Technical Report · Sat Dec 01 00:00:00 EST 1962

DOI:https://doi.org/10.2172/4772643· OSTI ID:4772643

Rodden, C. J. ^[1]

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1. New Brunswick Laboratory (NBL), New Brunswick, NJ (United States)

*Spectrophotometric Determination of Silicon in Thorium Dioxide* The procedure of Menis and Manning for the determination of silicon in thorium dioxide has been modified so that very refractory samples can he analyzed. *Spectrophotometric Determination of Zirconium in Thorium-Zirconium Alloys* A summary is given of a procedure developed for the determination of zirconium in thorium-zirconium alloys involving the precipitation of the zirconium-p(p-dimethylaminophenylazo)-benzenearsonic acid complex, dissolution of the complex in acid fluoride solution to release the free dye, and spectrophotometric determination of the red dye color. *Determination of Tungsten in Reactor Materials-Extraction and Spectrophotometric Determination with 8-Quinolinol* A summary is given of a procedure developed for the determination of tungsten in zirconium, Zircaloy, uranium, beryllium, and stainless steel involving the extraction and spectrophotometric determination with 8-quinolinol. *Neutron Activation Analysis of U²³⁵ with Improved Precision and Accuracy* The changes made in the method for the determination of uranium-235 by the neutron activation method, which increase the activation count sufficiently so that the precision in the 15 to 93% uranium-235 range is ± 0.1 wt. % uranium-235, and in the 0.4 to 15% uranium-235 range, ± 1% relative, are noted and evaluated. *Determination of Total Uranium in Flat Fuel Elements by Gamma-Ray Absorptiometry* A method for the determination of total uranium in metal-clad uranium fuel elements by measuring the attenuation of the 0.34 m.e.v. gamma ray of europim-152,154 has been demonstrated. The method uses a gamma-ray spectrometer to discriminate against the uranium-235 gamma rays and uses an equation to correct for the absorption of the cladding metal absorption. The precision and accuracy is of the order of one per cent. *Limitations of the Method for the Determination of Uranium-235 by Gamma-Ray Spectrometry in Flat Fuel. Elements* A limitation has been noted and measured in the method used to determine the total uranium-235 in flat fuel elements, when the absorption correction for cladding metals, such as zirconium and stainless steel, becomes appreciable. Extensive data is presented. *The Calibration of an Americium-241 Alpha Source by Alpha-Gamma Coincidence Counting* The absolute disintegration rate of an americium-241 alpha source, for use in calibration of alpha counting equipment, has been determined by means of the alpha-gamma coincidence method with a precision of 0.6$ and a probable accuracy of 1-2%. *Cation-Exchange Separation and Spectrographic Determination of Silicon in Plutonium* A cation-exchange separation of silicon from plutonium is made prior to spectrographic determination. Plutonium(lll) in dilute nitric acid is adsorbed on Dowex-50 cation resin while silicon passes un adsorbed into the effluent. The effluent is evaporated to dryness and the residue is fused with sodium carbonate. The fused residue is dissolved, aliquots are dried on graphite electrodes, capped with "boiler caps", and the electrodes are excited in a D.C. arc. "Boiler caps" in conjunction with a sodium carbonate buffer double the sensitivity normally obtained without caps in the same direct current arc methods. The lower limit of detection is 1 p.p.m. with an overall coefficient of variation of ± 9%. *Spectrochemical Determination of Boron in 8n Nitric Acid Solutions* In the spectrographic analysis of boron in plutonium about half of the boron is lost when 8N nitric acid solutions are evaporated to dryness on graphite electrodes. An investigation of the use of mannitol to complex boron and prevent volatilization during evaporation was extended to higher nitric acid concentrations not previously reported. Quantitative retention of boron in 8N nitric acid was obtained only at 6000 to 1 mannitol to boron mole ratios. At all other lower mannitol concentrations excessive degradation by the nitric acid resulted in boron recoveries of less than 90%. *The Purity 'of Plutonium Sulfate Tetrahydrate Obtained by Recrystallization and by Ion-Exchange Purification* Plutonium sulfate tetrahydrate, Pu(S0₄)₂.4H₂0, 99.99% pure, studied as an analytical standard for several years, has been prepared from high purity metal (99.97%). A material of at least 99.995% purity was prepared by recrystallization, or by ion-exchange purification of this compound. Preparation of the tetrahydrate from impure waste solutions (<90$ purity) provides material of 98.2, 99.72, and 99.92% purity with three successive recrystallizations. *A Study of the Gravimetric Determination of Plutonium as Anhydrous Plutonium Sulfate* The use of anhydrous plutonium sulfate, Pu(S04)2, as a gravimetric weighing form for plutonium has been studied. When plutonium sulfate tetrahydrate is ignited at 525°C for 48 hours a stoichiometric compound results, but present tests show that heating slurries or solutions of the tetrahydrate in concentrated or 1-2N sulfuric acid does not produce the anhydrous sulfate even after 100 hours at the above temperature. Igniting the tetrahydrate dissolved in 0.1N sulfuric acid for periods up to 8l days produced a variegated material of constant but non stoichiometric weight. *Separation and Determination of Plutonium in Plutonium-Uranium Fuel Elements* Plutonium is separated from uranium in plutonium-uranium oxide and plutonium-uranium carbide reactor fuel elements by cation exchange. Initially the refractory oxide or carbide is dissolved by refluxing in concentrated nitric acid-6N hydrofluoric acid solution. After separation, plutonium is determined by potentiometric titration with potassium dichromate; uranium may be determined similarly. At least 99.9% recovery of both plutonium and uranium was obtained. *Stability of Dicesium Plutonium Hexachloride* The evaluation of dicesium plutonium hexachloride as a primary plutonium standard was continued. Current investigations of the stability of Cs₂PuCl₆ indicate continuing instability as the material consistently loses weight and evolves acid vapors while in storage. Hydrolysis of the compound is suspected as the cause of instability. *Preparation of Plutonium Alpha Counting Standards* The uncertainty in the experimental value obtained for the efficiency factor of an alpha proportional counter was determined by calibration with prepared plutonium standards using ordinary techniques. A value of 49.91 ± 0.57% (95% confidence level) indicated the need for more refined calibration methods for highest accuracy in plutonium assay. *Anion-Exchange Separation and Spectrographic Determination of Impurities in Plutonium* The study of the spectrographic determination of trace impurities in high-purity plutonium following the anion-exchange separation from plutonium in 8n nitric acid has been continued. Additional procedures have been developed for the estimation of potassium, cesium, rubidium, and for the analysis of plutonium sulfates using a hydriodic acid treatment for sulfuric acid removal from the ion-exchange effluent. The use of "boiler cap" electrodes and various photographic emulsions to increase the sensitivity of the method was investigated. The loss in sensitivity caused by modification of the spectrograph for gloved box operation is 50%. Twenty-two elements (Fe, Mn, Mg, pb, Cr, Ni, Al, Ag, Zn, Mo, Cu, Be, B, Cd, K, Na, Cs, Rb, Ba, Li, Pu, Am) can be determined by the method. The sensitivity of the method for plutonium was determined. *Additional Plutonium Sulfate Tetrahydrate Stability Tests* Additional data on the stability of plutonium sulfate tetrahydrate under study for use as an analytical plutonium standard has been obtained. Current tests indicate the continuing stability of the compound for periods of at least 26-28 months. *A Chemical Uranium Bias Check Program* A chemical uranium bias check program carried out in the reactor field is presented. It includes data pertaining to the preparation of synthetic known solutions similar in composition to the fuel element in question, as well as the analytical steps employed for the purpose of verifying the uranium content. The program is an example of the cooperation existing between commercial facilities and government in dealing with the accountability of SS material. *Determination of Boron in Plastic Tape Impregnated with Boron Carbide* A volumetric procedure for determining boron in plastic tape impregnated with boron carbide is described. The ash residue from a sodium carbonate treated specimen is decomposed by fusion and interfering elements removed by filtration after adjusting the test solution to pH 5.0-5-5. Boric acid is titrated with standard 0.1N sodium hydroxide in the presence of mannitol. *Evaluation of the Accuracy of Surface Ionization Mass Spectrometric Data* A ratio method of uranium isotopic analysis previously described was evaluated for accuracy by analyzing National Bureau of Standards (NBS) certified standards and New Brunswick Laboratory gravimetrically prepared materials. A systematic procedure is presented to permit the reporting of an isotopic measurement with an accuracy within that certified by NBS of the same level. Also, it is shown that gravimetrically prepared materials may be useful in determining the accuracy of small concentrations of U²³⁴ and U²³⁶. *The Determination of Impurities in Beryllium Metal by X-Ray Fluorescence* A rapid method is described for determining various impurities in beryllium metal by X-ray fluorescence using the characteristic radiation of the tungsten peak as a built-in internal standard. *The Determination of Enriched Uranium in U0₂-Stainless Steel Solutions by X-Ray Fluorescence* X-ray analysis is described as a rapid technique for the analysis of uranium in UO₂-stainless steel materials within 5% of the uranium content.

• Research Organization: New Brunswick Laboratory (NBL), New Brunswick, NJ (United States)
• Sponsoring Organization: US Atomic Energy Commission (AEC)
• NSA Number: NSA-17-012182
• OSTI ID: 4772643
• Report Number(s): NBL-188
• Resource Relation: Other Information: Orig. Receipt Date: 31-DEC-63
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
ABSORPTION
ALPHA DECAY
ALPHA DETECTION
ALUMINUM
AMERICIUM
AMERICIUM 241
BARIUM
BERYLLIUM
BORON
CADMIUM
CESIUM
CESIUM CHLORIDES
CHROMATES
CHROMIUM
COINCIDENCE METHODS
COPPER
EFFICIENCY
ELECTRIC POTENTIAL
ELECTRODES
EQUATIONS
EUROPIUM 152
EUROPIUM 154
EVAPORATION
FUEL CANS
FUEL ELEMENTS
GAMMA RADIATION
GAMMA SPECTROMETERS
HYDROFLUORIC ACID
HYDROLYSIS
IMPURITIES
ION EXCHANGE
IRON
LEAD
LITHIUM
MAGNESIUM
MANGANESE
MEASURED VALUES
METALS
MOCKUP
MOLYBDENUM
NICKEL
NITRIC ACID
NUCLEAR EMULSIONS
PLUTONIUM
PLUTONIUM CHLORIDES
PLUTONIUM SULFATES
POTASSIUM
POTASSIUM COMPOUNDS
PREPARATION
PROPORTIONAL COUNTE