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Physical characterization of radioactive sludges in selected Melton Valley and evaporator facility storage tanks

Description: Physical measurements were performed on typical radioactive sludge samples from selected Melton Valley Storage Tanks (MVSTs) and evaporator facility storage tanks at ORNL. These measurements included viscosity, particle size, density, sedimentation rate, and solids content. The techniques developed during this project are simple and use inexpensive apparatus to assay the range of physical properties spanned by the sample set. The report provides data in support of the design of the proposed Waste Handling and Packaging Plant, and research and development activities in developing waste management alternatives. 5 refs., 11 figs., 6 tabs.
Date: October 1, 1990
Creator: Ceo, R.N.; Sears, M.B. & Shor, J.T.
Partner: UNT Libraries Government Documents Department

Analysis of active neutron multiplicity data for Y-12 skull oxide samples

Description: Previous work on active neutron multiplicity measurements and analyses is summarized. New active multiplicity measurements are described for samples of Y-12 skull oxide using an Active Well Coincidence Counter and MSR4 multiplicity electronics. Neutron multiplication values for the samples were determined from triples/doubles ratios. Neutron multiplication values were also obtained from Monte Carlo calculations using the MCNP code and the results compared with the experimental values. A calibration curve of AmLi source-sample coupling vs neutron multiplication was determined and used for active multiplicity assay of the skull oxides. The results are compared with those obtained from assay with the conventional calibration-curve technique, where the doubles rate is calibrated vs the {sup 235}U mass. The coupling-multiplication relationship determined for the skull oxides is compared with that determined earlier for pure high-enrichment uranium metal and pure uranium oxide. Conclusions are drawn about the application of active multiplicity techniques to uranium assay. Additional active multiplicity measurements and calculations are recommended.
Date: September 1996
Creator: Krick, M. S.; Ensslin, N.; Ceo, R. N. & May, P. K.
Partner: UNT Libraries Government Documents Department

Low-enriched uranium holdup measurements in Kazakhstan

Description: Quantification of the residual nuclear material remaining in process equipment has long been a challenge to those who work with nuclear material accounting systems. Fortunately, nuclear material has spontaneous radiation emissions that can be measured. If gamma-ray measurements can be made, it is easy to determine what isotope a deposit contains. Unfortunately, it can be quite difficult to relate this measured signal to an estimate of the mass of the nuclear deposit. Typically, the measurement expert must work with incomplete or inadequate information to determine a quantitative result. Simplified analysis models, the distribution of the nuclear material, any intervening attenuation, background(s), and the source-to-detector distance(s) can have significant impacts on the quantitative result. This presentation discusses the application of a generalized-geometry holdup model to the low-enriched uranium fuel pellet fabrication plant in Ust-Kamenogorsk, Kazakhstan. Preliminary results will be presented. Software tools have been developed to assist the facility operators in performing and documenting the measurements. Operator feedback has been used to improve the user interfaces.
Date: December 31, 1998
Creator: Barham, M.A.; Ceo, R.N. & Smith, S.E.
Partner: UNT Libraries Government Documents Department

Well coincidence counting and analysis

Description: In several recent papers a physical/mathematical model was developed to describe the nuclear multiplicative processes in samples containing fissile material from a general statistical viewpoint, starting with the basic underlying physical phenomena. The results of this model agreed with the established picture used in ``standard`` HLNCC (High Level Neutron Coincidence Counter) measurements, but considerably extended them, and allowed a more detailed interpretation of the underlying physical mechanisms and of the higher moments of the neutron counts. The present paper examines some recent measurements made at Y-12 (Oak Ridge) using the AWCC, in the light of this model. The results show internal consistency under a variety of conditions, and give good agreement between experiment and theory.
Date: March 1, 1994
Creator: Lu, Ming-Shih; Teichmann, T.; Ceo, R. N. & Collins, L. L.
Partner: UNT Libraries Government Documents Department

A Generalized Finite Source Calibration Factor: A Natural Improvement to the Finite Source Correction Factor for Uranium Holdup Measurements

Description: This paper proposes refinements to the finite source correction factor used in holdup measurements. Specifically it focuses on a more general method to estimate the average detector response for a finite source. This proposed method for the average detector response is based directly on the Generalized Geometry Holdup (GGH) assay method. First, the finite source correction factor as originally proposed is reviewed in this paper. Following this review the GGH assay method is described. Lastly, a new finite area calibration factor based on GGH is then proposed for finite point and line sources. As an alternative to the direct use of the finite arca calibration factor, finite source correction factors are also derived from this calibration factor. This new correction factor can be used in a manner similar to the finite source correction factor as currently implemented.
Date: January 28, 2003
Creator: Gunn, C.A.; Oberer, R.B.; chiang, L.G. & Ceo, R.N.
Partner: UNT Libraries Government Documents Department

Sampling and analysis of radioactive liquid wastes and sludges in the Melton Valley and evaporator facility storage tanks at ORNL

Description: The sampling and analysis of the radioactive liquid wastes and sludges in the Melton Valley Storage Tanks (MVSTs), as well as two of the evaporator service facility storage tanks at ORNL, are described. Aqueous samples of the supernatant liquid and composite samples of the sludges were analyzed for major constituents, radionuclides, total organic carbon, and metals listed as hazardous under the Resource Conservation and Recovery Act (RCRA). Liquid samples from five tanks and sludge samples from three tanks were analyzed for organic compounds on the Environmental Protection Agency (EPA) Target Compound List. Estimates were made of the inventory of liquid and sludge phases in the tanks. Descriptions of the sampling and analytical activities and tabulations of the results are included. The report provides data in support of the design of the proposed Waste Handling and Packaging Plant, the Liquid Low-Level Waste Solidification Project, and research and development activities (R D) activities in developing waste management alternatives. 7 refs., 8 figs., 16 tabs.
Date: September 1, 1990
Creator: Sears, M.B.; Botts, J.L.; Ceo, R.N.; Ferrada, J.J.; Griest, W.H.; Keller, J.M. et al.
Partner: UNT Libraries Government Documents Department