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Differential spectrophotometric determination of plutonium using the Cary Model 16 spectrophotometer

Description: ABS>The application of a high-precision Cary Model 16 spectrophotometer to the differential spectrophotometric determination of plutonium(III) was investigated. The absorbances of plutonium(III) solutions were measured against colored glass filters at 560 nanometers. Selection of various instrument parameters and the determination of the best reference filter for the highest precision are discussed. Two sets of calibration points were analyzed, The absorbance for each set was measured once a day for three days. A statistical comparison between the three readings, the three least squares curves, and the two sets of calibration points are discussed. The standard deviation of the average reading about the line was plus or minus 0.0028 g/liter plutonium in the 11 to 15 g/liter plutonium range. Detailed procedures for standard preparation from plutonium nitrate and for operation of the Cary Model 16 are included. The advantages and disadvantages of the equipment and method are discussed and further experiments suggested. (auth)
Date: August 1, 1973
Creator: Winters, W.I.
Partner: UNT Libraries Government Documents Department

Sulfur isotope relative ratios determined by mass spectrometry

Description: BS>The ratio of the sulfur isotope ratio, /sup 34/S/(/sup 32/S + /sup 32/ S), in a sample of sulfur hexafluoride to that in an isotopically different sample (relative ratio) is determined to plus or minus 0.00003 (standard deviation) at relative ratios of 1.003-1.007 and near-natural isotopic abundances. (auth)
Date: December 1, 1973
Creator: Howard, O.H.
Partner: UNT Libraries Government Documents Department

ALLCAL: an interactive BASIC program for spectrochemical calculations

Description: An interactive program, ALLCAL, has been developed at Los Alamos Scientific Laboratory (LASL) to calculate the results of spectrochemical measurements of impurities in production samples. The program generates a working curve from input data of standard samples to calculate the impurity concentrations. ALLCAL permits use by individuals with minimal programming experience/ it is truly interactive in providing periodic means to edit, modify, and change incorrect data that might have been introduced through various human error factors affecting any computer program, without the need to terminate and reinitialize after such editing. The program can be used as a research tool to manipulate data with minimum effort and eliminates repetitive input data from its operation. It also provides the spectroscopist a comparison mode to evaluate the effect of the use or nonuse of a given internal standard. ALLCAL accepts either optical density or percent transmittance data from photographic plates and films. The program is written in BASIC language for a minicomputer with 28,000 octal words of core memory and has been shown to be adaptable to another computer system with slight modifications. (auth)
Date: June 1, 1975
Creator: Apel, C.T.
Partner: UNT Libraries Government Documents Department

Continued studies of calorimeter performance at the Lawrence Livermore Laboratory

Description: Calibrations of two calorimeters used for tritium and plutonium assays were made. Data from three new standards of about 0.5, 1, and 5 W were added to the results of a previous report and analyzed together. The accuracies of both calorimeters appear to fall within the specified 0.5 percent, although the data now available for the large calorimeter is insufficient to permit a more definite conclusion. An expression of the bias correction for each calorimeter with respect to the sample power cannot be determined. The bias of the medium thermopile-type calorimeter tends to be positive, however, and that of the large resistance-bridge design appears to be negative. (auth)
Date: November 17, 1975
Creator: Steward, S.A. & Tsugawa, R.T.
Partner: UNT Libraries Government Documents Department

Determination of trace noble gases in air and natural gas

Description: From symposium on noble gases; Las Vegas, Nevada, USA (24 Sep 1973). A method was developed for the analysis of air and natural gas samples containing trace amounts of noble gases. The gas samples are preconcentrated by reaction with calcium at 900 to 1000 deg C and analyzed by mass spectrometry on an automated instrument. Methods of relating the concentrated sample to the original sample and the preparation of gas standards are given. The accuracy of the technique at the 25 ppM level was determined. The precision of the method and requirements for improving the technique are also discussed. (auth)
Date: September 1, 1973
Creator: Newton, J.C.; Stephens, F.B. & Stump, R.K.
Partner: UNT Libraries Government Documents Department

Detector system for in-situ spectrometric analysis of $sup 241$Am and Pu in soil

Description: This system for quantitative analysis of Pu in soil via $sup 241$Am has four 2.5-mm high-purity Ge detectors of 33 cm$sup 2$ total detecting surface area. These detectors are paralleled by gating circuitry to avoid the degradation of energy resolution associated with electronic output summing. In field tests the system was approximately three times as sensitive as a 70-cm$sup 3$ Ge(Li) detector and approximately an order of magnitude more sensitive than the FIDLER system. (auth)
Date: January 1, 1975
Creator: Kirby, J.A.; Anspaugh, L.R.; Phelps, P.L.; Amantrout, G.A. & Sawyer, D.
Partner: UNT Libraries Government Documents Department

Automated spectrophotometer for plutonium and uranium determination

Description: The automated spectrophotometer described is the first in a planned series of automated instruments for determining plutonium and uranium in nuclear fuel cycle materials. It has a throughput rate of 5 min per sample and uses a highly specific method of analysis for these elements. The range of plutonium and uranium measured is 0.5 to 14 mg and 1 to 14 mg, respectively, in 0.5 ml or less of solution with an option to pre-evaporate larger volumes. The precision of the measurements is about 0.02 mg standard deviation over the range corresponding to about 2 rel percent at the 1-mg level and 0.2 rel percent at the 10-mg level. The method of analysis involves the extraction of tetrapropylammonium plutonyl and uranyl trinitrate complexes into 2-nitropropane and the measurement of the optical absorbances in the organic phase at unique peak wavelengths. Various aspects of the chemistry associated with the method are presented. The automated spectrophotometer features a turntable that rotates as many as 24 samples in tubes to a series of stations for the sequential chemical operations of reagent addition and phase mixing to effect extraction, and then to a station for the absorbance measurement. With this system, the complications of sample transfers and flow-through cells are avoided. The absorbance measurement system features highly stable interference filters and a microcomputer that controls the timing sequence and operation of the system components. Output is a paper tape printout of three numbers: a four-digit number proportional to the quantity of plutonium or uranium, a two-digit number that designates the position of the tube in the turntable, and a one-digit number that designates whether plutonium or uranium was determined. Details of the mechanical and electrical components of the instrument and of the hardware and software aspects of the computerized control system are provided.
Date: September 1, 1975
Creator: Jackson, D.D.; Hodgkins, D.J.; Hollen, R.M. & Rein, J.E.
Partner: UNT Libraries Government Documents Department

Accurate determination of impurity concentrations in plutonium metals by statistical evaluation of analytical data

Description: Analytical data from a plutonium-metal exchange program conducted by six ERDA laboratories are statistically evaluated. The objective is an accurate determination of five metal impurities (aluminum, chromium, iron, nickel, silicon) in each of three plutonium metals by using data from four analytical methods. The statistical evaluation yields the weighted mean and its standard deviation for each method, plutonium metal, and impurity, using a procedure that minimizes the effect of outliers by assigning zero weights to the most extreme values and variable weights to the remaining data. Where possible, weighted means from the various analytical methods are pooled. (auth)
Date: July 1975
Creator: Martell, C. J.; Tietjen, G. L. & Horita, M. M.
Partner: UNT Libraries Government Documents Department