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Development of resin-bead isotope-dilution mass spectrometric techniques for Tc-99 analysis

Description: An isotope dilution mass spectrometric method was developed for the analysis of Tc-99 after isolating it onto anion exchange resin beads. A single resin bead containing Tc-99 and Tc-97 spike is loaded onto a rhenium V-shaped filament for thermal emission mass spectrometry. The application of this technique requires the use of a mass spectrometer of high abundance sensitivity and pulse counting capability for the necessary ion detection sensitivity. This paper discusses the development of the technique, including the mass spectrometer, choice of filament material, scanning modes, interferences, and present achievable sample sensitivities.
Date: January 1, 1979
Creator: Walker, R.L.
Partner: UNT Libraries Government Documents Department

Analysis of plutonium and uranium by the resin bead-mass spectrometric method

Description: The development of the resin bead method and the techniques employed in its application to isotopic analysis of Pu and U in highly radioactive solutions of spent reactor fuel will be described. The method, developed primarily for safeguards analyses, may also be applied to isotopic measurement for assessing nuclear fuel cycle technology. Satisfactory analyses of both elements can be obtained from a single resin bead when the initial dissolver solution has a U/Pu ratio in the range of 50 to 300. Optimum bead loadings are 1 to 3 ng Pu and U; these loadings are obtained if the concentration of the solution is adjusted to about 1 ..mu..g U per bead before the beads are introduced. Isotopic composition measurements of NBS standards using this technique indicate a precision of +- 0.5% for minor isotopes in the 1% concentration range and +- 0.1% for major isotopes in the 50% range. Analyses of a synthetic dissolver solution give an accuracy for the isotope dilution measurement of Pu and U of less than or equal to 0.5% with an internal precision of 0.9% and 0.6% for Pu and U, respectively.
Date: January 1, 1979
Creator: Walker, R.L. & Smith, D.H.
Partner: UNT Libraries Government Documents Department

A SUMMARY OF SHIELDING CONSTANTS FOR CONCRETE

Description: The present knowledge of the shielding constants of concrete is summarized. The densities, elemental compositions, and mixes, where available, are given for a wide range of concretes. From these data, various constants useful for shielding calculations were computed. These constants include the removal cross sections, total cross sections, average thermal neutron absorption cross sections, thermal neutron diffusion coefficients, reciprocal thermal neutron diffusion lengths, total gamma-ray linear attenuation coefficients, gamma-ray energy absorption linear attenuation coefficients, the effective atomic numbers for the determination of buildup factors, and the capture gamma-ray spectra. Experimental results are included where available. (auth)
Date: November 1, 1961
Creator: Walker, R.L. & Grotenhuis, M.
Partner: UNT Libraries Government Documents Department

Resin bead methodology as applied to fuel burn-up and fissile inventories

Description: A new technique has been developed that allows acquisition of samples from matrices difficult to access. While the examples given in this paper are from the nuclear field, the technique is readily modified to address other areas. The technique involves obtaining samples on resin beads; each bead then comprises a sample for mass spectrometric analysis. Through the application of isotope dilution, concentrations of the target elements can be obtained in addition to their isotopic compositions. Examples of application of this technique are given for U, Pu, and Nd. 19 refs., 3 figs., 3 tabs.
Date: January 1, 1986
Creator: Smith, D.H.; Walker, R.L. & Carter, J.A.
Partner: UNT Libraries Government Documents Department

Mass-spectrometric measurements for nuclear safeguards

Description: The need of an on-site inspection device to provide isotopic ratio measurements led to the development of a quadrupole mass spectrometer mounted in a van. This mobile laboratory has the ability, through the use of the resin bead technique, to acquire, prepare, and analyze samples of interest to nuclear safeguards. Precision of the measurements is about 1 to 2%.
Date: January 1, 1982
Creator: Carter, J.A.; Smith, D.H. & Walker, R.L.
Partner: UNT Libraries Government Documents Department

Summary report of TASTEX Task J: resin beam mass spectrometry for safeguards

Description: Our involvement with the TASTEX program is described in Task J; progress on this task during FY-1978 is described. This task involves collaboration with the Japanese at the Tokai reprocessing facility to evolve a sampling scheme suitable for use by International Atomic Energy Agency inspectors. The samples would be taken on resin beads and shipped in that form; because of the small quantities of material involved in this sampling technique, health hazards during transport are eliminated and costs minimized. During a conference at Tokai, the Japanese familiarized us with their reprocessing procedure, and consultations with them led to a sampling protocol that would inconvenience them very little. At Japanese request, we have made measurements and calculations of the amount of radiation from typical beads, and present recommendations as to the number of beads that can safely be handled in a single shipment. Tables of our results are included.
Date: October 1, 1978
Creator: Carter, J. A.; Smith, D. H. & Walker, R. L.
Partner: UNT Libraries Government Documents Department

Simplified method for the preparation of micro samples for the simultaneous isotopic analysis of uranium and plutonium

Description: A basic anion resin is employed to selectively adsorb plutonium and uranium from 8 M HNO$sub 3$ solutions containing dissolved spent reactor fuels. After a few beads of the resin are equilibrated with the solution, a single bead is used for establishing the isotopic composition of plutonium and uranium. The resin bead separation essentially removes all possible isobaric interference from such elements as americium and curium and at the same time eliminates most fission product contamination in the mass spectrometer. Small aliquots of dissolver solution that contain 10$sup -6$g of U and 10$sup -8$ g of Pu are adequate for preparing about ten resin beads. By employing a single-focusing, tandem-magnet-type mass spectrometer, equipped with pulse counting for ion detection, simultaneous plutonium and uranium assays are obtained. The quantity of each element per bead may be as low as 10$sup -9$ to 10$sup -10$g. The technique of isotope dilution can be coupled with the ion exchange bead separation and used effectively for measuring the total quantity of U and Pu. The technique possesses advantages such as: reduced radiation hazards from the infinitely smaller samples, thus less shielding and transport cost for sample handling; greatly simplified chemical preparations that eliminate fission products and actinide isobaric interferences; and the minor isotopes are more precisely established. (auth)
Date: January 1, 1974
Creator: Carter, J.A.; Walker, R.L.; Eby, R.E. & Pritchard, C.A.
Partner: UNT Libraries Government Documents Department

Development of the NBS beryllium isotopic standard reference material

Description: The National Bureau of Standards, in conjunction with the Oak Ridge National Laboratory and the Accelerator Mass Spectrometry community, is in the process of developing a beryllium isotopic solution Standard Reference Material. The master /sup 10/Be//sup 9/Be solution was characterized isotopically by resonance-ionization and secondary-ion mass-spectrometric-based techniques, and radioactivity measurements were by liquid scintillation counting. The master solution was gravimetrically diluted with /sup 9/Be to a final /sup 10/Be//sup 9/Be atomic ratio of 3 x 10/sup -11/. The preliminary data indicate a half life for /sup 10/Be of 1.3 million years, and AMS measurements are within 10% of the known beryllium isotopic ratio.
Date: January 1, 1987
Creator: Inn, K.G.W; Fassett, J.D.; Coursey, B.M.; Walker, R.L. & Raman, S.
Partner: UNT Libraries Government Documents Department

Resin bead U and PU analysis of WAK input solutions: a statistical summary of experiment No. 1

Description: A statistical analysis of the resin bead experimental data was made to identify sources of variations among the measurements of isotopic atom ratios and elemental concentrations of plutonium and uranium. Comparisons among treatment means of the analytical laboratory and the resin bead preparation methods are tabulated using Duncan's multiple range test.
Date: June 1, 1980
Creator: Bayne, C.K.; Carter, J.A.; Smith, D.H. & Walker, R.L.
Partner: UNT Libraries Government Documents Department

The US/UK Actinides Experiment at the Dounreay PFR

Description: The United States and the United Kingdom have been engaged in a joint research program in which samples of higher actinides were irradiated in the 600-MW Dounreay Prototype Fast Reactor in Scotland. Analytical results using mass spectrometry and radiometry for actinides and fission products are now available for the samples in Fuel Pins 1 and 2, which were irradiated for 63 full-power days, and for the samples in Fuel Pin 4, which were irradiated for 492 full-power days. Results from these three fuel pins are providing estimates of integral cross sections and fission yields.
Date: November 1, 1997
Creator: Raman, S., Walker, R.L., Dickens, J.K., Murphy, B.D.
Partner: UNT Libraries Government Documents Department

Reactor production of sup 252 Cf and transcurium isotopes

Description: Berkelium, californium, einsteinium, and fermium are currently produced in the High Flux Isotope Reactor (HFIR) and recovered in the Radiochemical Engineering Development Center (REDC) at the Oak Ridge National Laboratory (ORNL). All the isotopes are used for research. In addition, {sup 252}Cf, {sup 253}Es, and {sup 255}Fm have been considered or are used for industrial or medical applications. ORNL is the sole producer of these transcurium isotopes in the western world. A wide range of actinide samples were irradiated in special test assemblies at the Fast Flux Test Facility (FFTF) at Hanford, Washington. The purpose of the experiments was to evaluate the usefulness of the two-group flux model for transmutations in the special assemblies with an eventual goal of determining the feasibility of producing macro amounts of transcurium isotopes in the FFTF. Preliminary results from the production of {sup 254g}Es from {sup 252}Cf will be discussed. 14 refs., 5 tabs.
Date: January 1, 1990
Creator: Alexander, C.W.; Halperin, J.; Walker, R.L. & Bigelow, J.E.
Partner: UNT Libraries Government Documents Department

Analysis of U and Pu resin bead samples with a single stage mass spectrometer

Description: Resin bead sampling enables the shipment of nanogram U and Pu quantities for analysis. Application of this sampling technique to safeguards was investigated with a single-stage mass spectrometer. Standards gave results in good agreement with NBS certified values. External precisions of +-0.5% were obtained on isotopic ratios of approx. 0.01; precisions on quantitative measurements are +-1.0%. (DLC)
Date: January 1, 1979
Creator: Smith, D.H.; Walker, R.L.; Bertram, L.K. & Carter, J.A.
Partner: UNT Libraries Government Documents Department

Development of the NBS /sup 10/Be//sup 9/Be isotopic standard reference material

Description: The National Bureau of Standards (NBS), in conjunction with the Oak Ridge National Laboratory (ORNL) and the Accelerator Mass Spectrometry (AMS) community, is in the process of developing a /sup 10/Be//sup 9/Be isotopic solution Standard Reference Material (SRM). The starting /sup 10/Be//sup 9/Be solution was provided by the ORNL after Secondary Ionization Mass Spectrometric characterization for isotopic concentration. The radioactivity purity of the ORNL Master solution was confirmed by gamma-ray spectrometry, then diluted at NBS with solutions made from zone-refined single-crystal beryllium metal and sub-boiling double-distilled hydrochloric acid. Four serial dilutions were necessary to achieve a final /sup 10/Be//sup 9/Be isotopic composition of approximately 3 x 10/sup -11/ (g/g). The accuracy of the dilutions was confirmed by liquid scintillation and AMS measurements. The isotopic composition of the ORNL Master solution was also confirmed at NBS by Resonant Ionization Mass Spectrometry. The isotopic composition of the final solution is being affirmed at the present time through international laboratory AMS measurements.
Date: April 1, 1987
Creator: Inn, K.G.W.; Raman, S.; Coursey, B.M.; Fassett, J.D. & Walker, R.L.
Partner: UNT Libraries Government Documents Department

Characterization of actinide physics specimens for the US/UK joint experiment in the Dounreay Prototype Fast Reactor

Description: The United States and the United Kingdom are engaged in a joint research program in which samples of the higher actinides are irradiated in the Dounreay Prototype Fast Reactor in Scotland. The purpose of the porogram is (1) to study the materials behavior of selected higher actinide fuels and (2) to determine the integral cross sections of a wide variety of the higher actinide isotopes. Samples of the actinides are incorporated in fuel pins inserted in the core. For the fuel study, the actinides selected are /sup 241/Am and /sup 244/Cm in the form of Am/sub 2/O/sub 3/, Cm/sub 2/O/sub 3/, and Am/sub 6/Cm(RE)/sub 7/O/sub 21/, where (RE) represents a mixture of lanthanides. For the cross-section determinations, the samples are milligram quantities of actinide oxides of /sup 248/Cm, /sup 246/Cm, /sup 244/Cm, /sup 243/Cm, /sup 243/Am, /sup 241/Am, /sup 244/Pu, /sup 242/Pu, /sup 241/Pu, /sup 240/Pu, /sup 239/Pu, /sup 238/Pu, /sup 237/Np, /sup 238/U, /sup 236/U, /sup 235/U, /sup 234/U, /sup 233/U, /sup 232/Th, /sup 230/Th, and /sup 231/Pa encapsulated in vanadium. Coincident with the irradiations, neutron flux and energy spectral measurements are made with vanadium-encapsulated dosimeter materials located within the same fuel pins.
Date: October 1, 1983
Creator: Walker, R.L.; Botts, J.L.; Cooper, J.H.; Adair, H.L.; Bigelow, J.E. & Raman, S.
Partner: UNT Libraries Government Documents Department

Analyses of physics specimens in fuel pins 1 and 2 irradiated in the Dounreay Prototype Fast Reactor

Description: The United States and the United Kingdom have been engaged in a joint research program in which samples of fissile and fertile actinides have been incorporated into three separate fuel pins and irradiated in the Dounreay Prototype Fast Reactor in Scotland. The actinides in the second fuel pin were studied for fission-product decay, specifically to obtain absolute yields of {sup 137}Cs. Comparisons with calculated yields result in ratios of measured to calculated between 0.67 ({plus minus}0.05) and 1.09 ({plus minus}0.18). Plotting of experimental versus calculated values of {sup 137}Cs indicated that the assumed flux levels were some 5 to 20% overestimated. This flux level information will be useful in the forthcoming analysis of the last fuel pin, FP-4.
Date: January 1, 1992
Creator: Raman, S.; Broadhead, B.L.; Dickens, J.K.; Walker, R.L. & Botts, J.L.
Partner: UNT Libraries Government Documents Department

Experimental and calculational analyses of actinide samples irradiated in EBR-II

Description: Higher actinides influence the characteristics of spent and recycled fuel and dominate the long-term hazards of the reactor waste. Reactor irradiation experiments provide useful benchmarks for testing the evaluated nuclear data for these actinides. During 1967 to 1970, several actinide samples were irradiated in the Idaho EBR-II fast reactor. These samples have now been analyzed, employing mass and alpha spectrometry, to determine the heavy element products. A simple spherical model for the EBR-II core and a recent version of the ORIGEN code with ENDF/B-V data were employed to calculate the exposure products. A detailed comparison between the experimental and calculated results has been made. For samples irradiated at locations near the core center, agreement within 10% was obtained for the major isotopes and their first daughters, and within 20% for the nuclides up the chain. A sensitivity analysis showed that the assumed flux should be increased by 10%.
Date: October 1, 1982
Creator: Gilai, D.; Williams, M.L.; Cooper, J.H.; Laing, W.R.; Walker, R.L.; Raman, S. et al.
Partner: UNT Libraries Government Documents Department

Experimental and calculational results of an irradiation experiment in EBR-II

Description: During the period from 1967 to 1970, several actinide samples were irradiated by ANL in the fast reactor EBR-II for approximately 10/sup 23/ nvt. In 1978, ORNL began an experimental determination of the exposure products in the irradiated samples, and to date, 12 of the samples have already been analyzed. In a previous paper preliminary experimental results for /sup 239/Pu sample were compared with the exposure products predicted by calculations. In this paper, the comparison is extended to samples of /sup 238/U, /sup 233/U, /sup 232/Th, /sup 240/Pu, /sup 237/Np, and a second /sup 239/Pu sample, with the calculations utilizing the recently released ENDF/B-V data and improved modeling approximations. The experimental results presented in this paper represent a fairly comprehensive set of measurements of actinide burnup in a fast reactor spectrum.
Date: January 1, 1981
Creator: Gilai, D.; Cooper, J.H.; Laing, W.R.; Raman, S.; Stelson, P.H.; Walker, R.L. et al.
Partner: UNT Libraries Government Documents Department

Analyses of physics specimens in fuel pins 1 and 2 irradiated in the Dounreay Prototype Fast Reactor

Description: The United States and the United Kingdom have been engaged in a joint research program in which samples of fissile and fertile actinides have been incorporated into three separate fuel pins and irradiated in the Dounreay Prototype Fast Reactor in Scotland. The actinides in the second fuel pin were studied for fission-product decay, specifically to obtain absolute yields of {sup 137}Cs. Comparisons with calculated yields result in ratios of measured to calculated between 0.67 ({plus_minus}0.05) and 1.09 ({plus_minus}0.18). Plotting of experimental versus calculated values of {sup 137}Cs indicated that the assumed flux levels were some 5 to 20% overestimated. This flux level information will be useful in the forthcoming analysis of the last fuel pin, FP-4.
Date: January 1, 1992
Creator: Raman, S.; Broadhead, B. L.; Dickens, J. K.; Walker, R. L. & Botts, J. L.
Partner: UNT Libraries Government Documents Department