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Sample records for struktury molekuly uf6

  1. Corrosion of breached UF6 storage cylinders

    International Nuclear Information System (INIS)

    Barber, E.J.; Taylor, M.S.; DeVan, J.H.

    1993-01-01

    This paper describes the corrosion processes that occurred following the mechanical failure of two steel 14-ton storage cylinders containing depleted UF 6 . The failures both were traced to small mechanical tears that occurred during stacking of the cylinders. Although subsequent corrosion processes greatly extended the openings in the wall. the reaction products formed were quite protective and prevented any significant environmental insult or loss of uranium. The relative sizes of the two holes correlated with the relative exposure times that had elapsed from the time of stacking. From the sizes and geometries of the two holes, together with analyses of the reaction products, it was possible to determine the chemical reactions that controlled the corrosion process and to develop a scenario for predicting the rate of hydrolysis of UF 6 , the loss rate of HF, and chemical attack of a breached UF 6 storage cylinder

  2. Depleted UF6 programmatic environmental impact statement

    International Nuclear Information System (INIS)

    1997-01-01

    The US Department of Energy has developed a program for long-term management and use of depleted uranium hexafluoride, a product of the uranium enrichment process. As part of this effort, DOE is preparing a Programmatic Environmental Impact Statement (PEIS) for the depleted UF 6 management program. This report duplicates the information available at the web site (http://www.ead.anl.gov/web/newduf6) set up as a repository for the PEIS. Options for the web site include: reviewing recent additions or changes to the web site; learning more about depleted UF 6 and the PEIS; browsing the PEIS and related documents, or submitting official comments on the PEIS; downloading all or part of the PEIS documents; and adding or deleting one's name from the depleted UF 6 mailing list

  3. UF6 cylinder lifting equipment enhancements

    International Nuclear Information System (INIS)

    Hortel, J.M.

    1991-01-01

    This paper presents numerous enhancements that have been made to the Portsmouth lifting equipment to ensure the safe handling of cylinders containing liquid uranium hexafluoride (UF 6 ). The basic approach has been to provide redundancy to all components of the lift path so that any one component failure would not cause the load to drop or cause any undesirable movement. 4 figs

  4. Thermal plasma reduction of UF6

    International Nuclear Information System (INIS)

    Fincke, J.R.; Swank, W.D.; Haggard, D.C.

    1995-01-01

    This paper describes the experimental demonstration of a process for the direct plasma reduction of depleted uranium hexafluoride to uranium metal. The process exploits the large departures from equilibrium that can be achieved in the rapid supersonic expansion of a totally dissociated and partially ionized mixture of UF 6 , Ar, He, and H 2 . The process is based on the rapid condensation of subcooled uranium vapor and the relatively slow rate of back reaction between metallic uranium and HF to F 2 to reform stable fluorides. The high translational velocities and rapid cooling result in an overpopulation of atomic hydrogen which persists throughout the expansion process. Atomic hydrogen shifts the equilibrium composition by inhibiting the reformation of uranium-fluorine compounds. This process has the potential to reduce the cost of reducing UF 6 to uranium metal with the added benefit of being a virtually waste free process. The dry HF produced is a commodity which has industrial value

  5. New regulatory aspects of UF6 transport

    International Nuclear Information System (INIS)

    Biaggio, A.L.; Lee Gonzales, H.M.; Lopez Vietri, J.R.; Novo, R.G.

    1987-01-01

    In nuclear industry, a great amount of uranium is transformed from a chemical form to another. When the fuel cycle requires enrichment, uranium hexafluoride (UF 6) is handled, stored and transported in great quantities. To analyze the risks involved in possible accidents associated with UF 6 , radiological and chemical aspects must be considered. So far, the international practice was based on the adoption of regulations from a particular country (ANSI No. 14.1-1982.U.S.A.). In this way, the adoption of these norms at international level is difficult. For that reason, the International Atomic Energy Agency has attempted to consider the chemical risks associated with UF 6 in order to establish a more universal basis ('Recommendations for Providing Protection during the Transport of Uranium Hexafluoride' IAEA-TECDOC-423, Vienna, June 1987 - Austria). A critical analysis of these recommendations is presented in this work. The coherence and the degree of completion of the new recommendations are evaluated and the safety level is compared with that of the accepted regulations for toxic or corrosive substances and for radioactive materials transport. (Author)

  6. Fracture mechanics performance of UF6 containers

    International Nuclear Information System (INIS)

    Gonzalez, M.E.; Iorio, A.F.; Crespi, J.C.

    1993-01-01

    The main purpose of this work was to determine the fracture mechanics performance of UF 6 transport cylinders type ANSI N14.1.30B, which was made from ASTM A 516 Grade 70 steel. It was assumed an internal surface axial crack subjected to stresses due to service, proof and transport accident loads. The KUMAR-GERMAN-SHIH elastoplastic methodology gave adequate results for crack depth estimation. The results validate the leak-before-break criteria for service and proof conditions but not for accident ones. In the last case a non-destructive examination must be done in order to assure the absence of defects larger than one third of the cylinder wall thickness. (Author)

  7. Technical documentation of HGSYSTEM/UF6 model

    International Nuclear Information System (INIS)

    Hanna, S.R.; Chang, J.C.; Zhang, J.X.

    1996-01-01

    MMES has been directed to upgrade the safety analyses for the gaseous diffusion plants at Paducah KY and Piketon OH. These will require assessment of consequences of accidental releases of UF 6 to the atmosphere at these plants. The HGSYSTEM model has been chosen as the basis for evaluating UF 6 releases; it includes dispersion algorithms for dense gases and treats the chemistry and thermodynamics of HF, a major product of the reaction of UF 6 with water vapor in air. Objective of this project was to incorporate additional capability into HGSYSTEM: UF 6 chemistry and thermodynamics, plume lift-off algorithms, and wet and dry deposition. The HGSYSTEM modules are discussed. The hybrid HGSYSTEM/UF 6 model has been evaluated in three ways

  8. Results of ultrasonic testing evaluations on UF6 storage cylinders

    International Nuclear Information System (INIS)

    Lykins, M.L.

    1997-02-01

    The three site cylinder management program is responsible for the safe storage of the DOE owned UF 6 storage cylinders at PORTS, PGDP and at the K-25 site. To ensure the safe storage of the UF 6 in the cylinders, the structural integrity of the cylinders must be evaluated. This report represents the latest cylinder integrity investigation that utilized wall thickness evaluations to identify thinning due to atmospheric exposure

  9. Investigation of the UF6 aerosol behavior in air, (4)

    International Nuclear Information System (INIS)

    Ishida, Junichiro; Sakamoto, Genji; Takeda, Seiichi; Kato, Jinzo

    1979-01-01

    When gaseous uranium hexafluoride (UF 6 ) is released into air, it hydrolizes with moisture in air to produce HF gas and particulate UO 2 F 2 which is visible. The lowest visible concentration in air is about 5 x 10 -8 μCi/cm 3 in case of releasing UF 6 and about 10 -9 μCi/cm 3 in case of released UF 6 cloud. By watching the occurrence of released UF 6 cloud, it is possible to take necessary action without delay. But in the case that there is no one to watch or that the concentration is not high enough to be visible, an alarm monitor system has to be relied on. Therefore the characteristics of the alarm monitors which can detect UF 6 promptly were examined. As UF 6 is hydrolized into gaseous HF and particulate UO 2 F 2 , three monitoring methods are considered; (1) to detect the alpha radiation of uranium, (2) to detect HF gas and (3) to detect airborne particles (aerosol). Performance tests were conducted on an alpha dust monitor, an electrochemical HF monitor, a thin film electrolyte HF monitor and an ionized smoke detector. The relationship between radioactivity concentration and HF concentration was investigated especially regarding with the conditions of released UF 6 amount and the distance from a release point to the observation point. The experimental facilities containing a large glove-box made of SUS and acrylic resin walls, a dust monitor, an HF monitor, a smoke detector and a filter, and the experimental procedure are explained. As the experimental results, the response characteristics of the dust monitor and HF monitor, the relationship of radioactivity concentration to HF concentration in air and the relation of the distance from the release point to the concentration of U and HF are presented. (Nakai, Y.)

  10. Review of potential models for UF6 dispersion

    International Nuclear Information System (INIS)

    Sykes, R.I.; Lewellen, W.S.

    1992-07-01

    A survey of existing atmospheric dispersion models has been conducted to determine the most appropriate basis for the development of a model for predicting the consequences of an accidental UF 6 release. The model is required for safety analysis studies and should therefore be computationally efficient. The release of UF 6 involves a number of physical phenomena which make the situation more complicated than passive dispersion of a trace gas. The safety analysis must consider the density variations in the UF 6 cloud, which can be heavier or lighter than the ambient air. The release also involves rapid chemical reactions and associated heat release, which must be modeled. Other Department of Energy storage facilities require a dense gas prediction capability, so the model must be sufficiently general for use with a variety of release scenarios. The special problems associated with UF 6 make it unique, so there are very few models with existing capability for the problem. There are, however, a large number of dense gas dispersion models, some with relevant chemical reaction modeling, that could potentially form the basis of an advanced UF 6 model. We have examined a large selection of possible candidates, and selected 5 models for detailed consideration

  11. Anisotropy of the fluorine chemical shift tensor in UF6

    International Nuclear Information System (INIS)

    Rigny, P.

    1965-04-01

    An 19 F magnetic resonance study of polycrystalline UF 6 is presented. The low temperature complex line can be analyzed as the superposition of two distinct lines, which is attributed to a distortion of the UF 6 octahedron in the solid. The shape of the two components is studied. Their width is much larger than the theoretical dipolar width, and must be explained by large anisotropies of the fluorine chemical shift tensors. The resulting shape functions of the powder spectra are determined. The values of the parameters of the chemical shift tensors yield estimates of the characters of the U-F bonds, and this gives some information on the ground state electronic wave function of the UF 6 molecule in the solid. (author) [fr

  12. HEU to LEU Conversion and Blending Facility: UF6 blending alternative to produce LEU UF6 for commercial use

    International Nuclear Information System (INIS)

    1995-09-01

    US DOE is examining options for disposing of surplus weapons-usable fissile materials and storage of all weapons-usable fissile materials; the nuclear material will be converted to a form more proliferation- resistant than the original form. Examining options for increasing the proliferation resistance of highly enriched uranium (HEU) is part of this effort. Five technologies for blending HEU will be assessed; blending as UF 6 to produce a UF 6 product for commercial use is one of them. This document provides data to be used in the environmental impact analysis for the UF 6 blending HEU disposition option. Resource needs, employment needs, waste and emissions from plant, hazards, accident scenarios, and intersite transportation are discussed

  13. Conversion of U3O8 to UF6

    International Nuclear Information System (INIS)

    Bodu, R.L.

    1975-01-01

    Three main processes for the production of UF 6 from the uranium ores (yellow cake) is described. The economic aspects of the conversion - capital cost, operating costs and conversion market and the future of conversion - capacity and prices - are discussed. (HPH) [de

  14. Development of AN Active 238UF6 Gas Target

    Science.gov (United States)

    Eckardt, C.; Enders, J.; Freudenberger, M.; Göök, A.; von Neumann-Cosel, P.; Oberstedt, A.; Oberstedt, S.

    2014-09-01

    Detailed studies of the fission process, e.g., the search for parity nonconservation (PNC) effects, the energy dependence of fission modes or the population of fission isomers, depend on high quality data, therefore requiring high luminosities. An active gas target containing uranium may overcome the deterioration of energy and angular resolution caused by large solid target thicknesses. A single Frisch-grid ionization chamber has been built to test a mixture of standard counting gases (e.g., argon) with depleted uranium hexafluoride (238UF6), utilizing a triple alpha source to evaluate signal quality and drift velocity. For mass fractions of up to 4 percent of 238U the drift velocity increases with rising UF6 content, while a good signal quality and energy resolution is preserved.

  15. Two-frequency multiphoton absorption in UF6

    International Nuclear Information System (INIS)

    Koren, G.

    1983-01-01

    The multiphoton absorption of 9.3-μm CO 2 laser radiation induced by multiphoton absorption of 16-μm CF 4 laser radiation in UF 6 is reported. An average vibrational energy deposition in the range of 1 to 2.8 eV per molecule is found, which is sufficient to cause the observed dissociation either by collision-assisted or unimolecular decomposition processes

  16. Application of the HGSYSTEM/UF6 model to simulate atmospheric dispersion of UF6 releases from uranium enrichment plants

    International Nuclear Information System (INIS)

    Goode, W.D. Jr.; Bloom, S.G.; Keith, K.D. Jr.

    1995-01-01

    Uranium hexafluoride is a dense, reactive gas used in Gaseous Diffusion Plants (GDPs) to make uranium enriched in the 235 U isotope. Large quantities of UF 6 exist at the GDPs in the form of in-process gas and as a solid in storage cylinders; smaller amounts exist as hot liquid during transfer operations. If liquid UF 6 is released to the environment, it immediately flashes to a solid and a dense gas that reacts rapidly with water vapor in the air to form solid particles of uranyl fluoride and hydrogen fluoride gas. Preliminary analyses were done on various accidental release scenarios to determine which scenarios must be considered in the safety analyses for the GDPS. These scenarios included gas releases due to failure of process equipment and liquid/gas releases resulting from a breach of transfer piping from a cylinder. A major goal of the calculations was to estimate the response time for mitigating actions in order to limit potential off-site consequences of these postulated releases. The HGSYSTEM/UF 6 code was used to assess the consequences of these release scenarios. Inputs were developed from release calculations which included two-phase, choked flow followed by expansion to atmospheric pressure. Adjustments were made to account for variable release rates and multiple release points. Superpositioning of outputs and adjustments for exposure time were required to evaluate consequences based on health effects due to exposures to uranium and HF at a specific location

  17. Radiation-Triggered Surveillance for UF6 Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Curtis, Michael M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-12-01

    This paper recommends the use of radiation detectors, singly or in sets, to trigger surveillance cameras. Ideally, the cameras will monitor cylinders transiting the process area as well as the process area itself. The general process area will be surveyed to record how many cylinders have been attached and detached to the process between inspections. Rad-triggered cameras can dramatically reduce the quantity of recorded images, because the movement of personnel and equipment not involving UF6 cylinders will not generate a surveillance review file.

  18. Potential detection systems for monitoring UF6 releases

    International Nuclear Information System (INIS)

    Beck, D.E.; Bostick, W.D.; Armstrong, D.P.; McNeely, J.R.; Stockdale, J.A.D.

    1994-09-01

    In the near future, the Nuclear Regulatory Commission (NRC) will begin to regulate the gaseous diffusion plants. Them is a concern that the smoke detectors currently used for uranium hexafluoride (UF 6 ) release detection will not meet NRC safety system requirements such as high reliability and rapid response. The NRC's position is that licensees should utilize state-of-the-art equipment such as hydrogen fluoride (HF) detectors that would provide more dependable detection of a UF 6 release. A survey of the literature and current vendor information was undertaken to define the state-of-the-art and commercial availability of HF (or other appropriate) detection systems. For the purpose of this report, classification of the available HF detection systems is made on the basis of detection principle (e.g., calorimetric, electrochemical, separational, or optical). Emphasis is also placed on whether the device is primarily sensitive to response from a point source (e.g., outleakage in the immediate vicinity of a specific set of components), or whether the device is potentially applicable to remote sensing over a larger area. Traditional HF point source monitoring typically uses gas sampling tubes or coated paper tapes with color developing indicator, portable and small area HF monitors are often based upon electrochemical or extractive/separational systems; and remote sensing by optical systems holds promise for indoor and outdoor large area monitoring (including plant boundary/ambient air monitoring)

  19. Transport of natural UF6 in a challenging environment

    International Nuclear Information System (INIS)

    Chollet, P.; Presta, A.

    2004-01-01

    At the entrance of the nuclear fuel cycle, the front-end material transportation takes a major and specific place. After years of stability the landscape of front-end industry is going toward significant changes regarding capacity, implementation of new technologies, imbalance of conversion capacity between geographical areas with increasing volumes of natural UF6 to transport and transport issues such as new regulations and denial of shipments by liners and ports. Facing this evolution the front end-industry is re-organizing its environment to increase robustness of the logistical chain: by being active in industrial organizations such as WNTI and WNA to share technical views and develop licensed standard transport equipment usable worldwide by developing other safe and reliable comprehensive logistics solutions as an alternative to conventional transport means. Our paper will describe the solutions under review to meet nuclear fuel cycle companies expectations: qualification of several robust logistics systems chartered vessels for maritime transport of UF6 specific 20' flat racks for safer handling of 48Y cylinders with future thermal protections

  20. Transport of natural UF6 in a challenging environment

    Energy Technology Data Exchange (ETDEWEB)

    Chollet, P.; Presta, A. [COGEMA Logistics (AREVA Group) (France)

    2004-07-01

    At the entrance of the nuclear fuel cycle, the front-end material transportation takes a major and specific place. After years of stability the landscape of front-end industry is going toward significant changes regarding capacity, implementation of new technologies, imbalance of conversion capacity between geographical areas with increasing volumes of natural UF6 to transport and transport issues such as new regulations and denial of shipments by liners and ports. Facing this evolution the front end-industry is re-organizing its environment to increase robustness of the logistical chain: by being active in industrial organizations such as WNTI and WNA to share technical views and develop licensed standard transport equipment usable worldwide by developing other safe and reliable comprehensive logistics solutions as an alternative to conventional transport means. Our paper will describe the solutions under review to meet nuclear fuel cycle companies expectations: qualification of several robust logistics systems chartered vessels for maritime transport of UF6 specific 20' flat racks for safer handling of 48Y cylinders with future thermal protections.

  1. Uranium isotope fractionation resulting from UF6 vapor distillation from containers

    International Nuclear Information System (INIS)

    Hedge, W.D.; Turner, C.M.

    1985-01-01

    This empirical study for possible isotopic fractionation due to UF 6 vapor distillation from valved containers was performed to determine the effects of repeated vapor sampling. Four different experiments were performed, each of which varied by the method of measuring the isotopic contents and/or by the difference in temperature gradients as follows: The ratio of the parent UF 6 to the desublimed UF 6 collected at liquid nitrogen temperature and homogenized was measured by sampling the containers. The ratio of the parent UF 6 to the desublimed UF 6 collected at liquid nitrogen temperature and homogenized was measured by direct comparison to each other without subsampling. The ratio of the parent UF 6 to the desublimed UF 6 collected at liquid nitrogen and ice-water temperatures and homogenized was measured by indirect comparison to a common UF 6 reference material without subsampling. The ratio of the parent UF 6 to the desublimed UF 6 collected at liquid nitrogen temperature without homogenizing was measured by indirect comparison to a common UF 6 reference. Gas-phase, relative mass spectrometry was used for all isotopic measurements. Results of the study indicate that fractionation does occur. The U-235 isotope becomes more enriched in the parent container as the UF 6 is vaporized from it and desublimed into the receiving cylinder; i.e., the vaporized fraction is enriched in the U-238 isotope. The degree of fractionation indicates that the separation is due to the U-238 isotope of UF 6 having a higher vapor pressure than the U-235 isotope of UF 6 . 3 refs., 4 figs., 4 tabs

  2. UF6 breeder reactor power plants for electric power generation

    International Nuclear Information System (INIS)

    Rust, J.H.; Clement, J.D.; Hohl, F.

    1976-01-01

    The reactor concept analyzed is a 233 UF 6 core surrounded by a molten salt (Li 7 F, BeF 2 , ThF 4 ) blanket. Nuclear survey calculations were carried out for both spherical and cylindrical geometries. A maximum breeding ratio of 1.22 was found. Thermodynamic cycle calculations were performed for a variety of Rankine cycles. Optimization of a Rankine cycle for a gas core breeder reactor employing an intermediate heat exchanger gave a maximum efficiency of 37 percent. A conceptual design is presented along with a system layout for a 1000 MW stationary power plant. The advantages of the GCBR are as follows: (1) high efficiency, (2) simplified on-line reprocessing, (3) inherent safety considerations, (4) high breeding ratio, (5) possibility of burning all or most of the long-lived nuclear waste actinides, and (6) possibility of extrapolating the technology to higher temperatures and MHD direct conversion

  3. Perekayasaan Heat Exchanger Sebagai Pemanas Umpan Uf 6 Dalam Pabrik Elemen Bakar Nuklir

    OpenAIRE

    Zacharias, Petrus; Pancoko, Marliyadi

    2011-01-01

    DESIGN OF HEAT EXCHANGER FOR HEATING UF6 FEED IN NUCLEAR FUEL ELEMENT PLANT. The process of conversion of UF6 to UO through Integrated Dry Route (IDR) i s done in a rotary kiln reactor. There are two stages of initi al treatment / conditioni ng before inserting the UF 6 in to the reactor : changing UF6 2 solid into the gas phase at a temperature of 60°C in an evaporator, and then, raising the temperature of UF C to 2900 C i n a Heat Exchanger (HE). Therefore it i s necessary to desi gn...

  4. TENERIFE program: high temperature experiments on A 4 tons UF6 container

    International Nuclear Information System (INIS)

    Casselman, C.; Duret, B.; Seiler, J.M.; Ringot, C.; Warniez, P.; Wataru, M.; Shiomi, S.; Ozaki, S.; Yamakawa, H.

    1993-01-01

    To know the input of the future thermo-mechanical code, we have to get a better understanding of the thermo-physical evolution of the UF 6 which pressurizes the container. This evolution is function of: a) the heat transfer rate from the fire to the container b) the UF 6 behaviour in the container. These tests are essentially analytical at simulated fire temperatures of between 800 and 1000degC. They use a representative mass of UF 6 (around 4 tons). The tests will not seek to rupture the test container which has a diameter equal to the 48Y container, but shorter length. These tests carried out in realistic conditions (typical thermal gradient at the wall, characteristic period for UF 6 internal mass transfer) should make possible to improve knowledge of two fundamental phenomena: 1) vaporization of UF 6 on contact with the heated wall (around 400degC), a phenomenon which controls the container internal pressurization kinetic, 2) the equivalent conductivity of solid UF 6 , a phenomenon which is linked to the heat transfer by UF 6 vaporization-condensation through the solid's porosities and which depends on the diameter of the container. In addition, they will allow the influence of other parameters to be studied, such as UF 6 container filling mode or the mechanical characteristics of the container material. A UF 6 container fitted with instruments (wall temperature, UF 6 temperature, pressure) is heated by a rapid heat transient in a radiating furnace where the temperature and thermal power supplied can be measured. The test continues until pre-established thresholds have been reached: 1) strain threshold measured on the container surface (strain gauges positioned on the outside), 2) maximum temperature threshold of UF 6 , 3) container internal pressure threshold. (J.P.N.)

  5. Gas-phase UF6 enrichment monitor for enrichment plant safeguards

    International Nuclear Information System (INIS)

    Strittmatter, R.B.; Tape, J.W.

    1980-03-01

    An in-line enrichment monitor is being developed to provide real-time enrichment data for the gas-phase UF 6 feed stream of an enrichment plant. The nondestructive gamma-ray assay method can be used to determine the enrichment of natural UF 6 with a relative precision of better than 1% for a wide range of pressures

  6. Synthesis and characterization of a new uranium(V) compound: H3O+UF6-

    International Nuclear Information System (INIS)

    Masson, J.P.; Desmoulin, J.P.; Charpin, P.; Bougon, R.

    1976-01-01

    The reaction of equimolar amounts of UF 5 and H 2 O in hydrogen fluoride results in the partial dissolution of UF 5 , yielding a blue-green solution from which the new salt oxonium hexafluorouranate(V)(H 3 O + UF 6 - ) could be isolated as a green crystalline solid. Calorimetric measurements showed H 3 O + UF 6 - to decompose at about 68 0 C and its heat of formation to be equal to -628 +- 2 kcal mol. Its ionic nature in the solid state and in HF solutions was demonstrated from vibrational and electronic spectra. The electronic spectrum is closely similar to those of LiUF 6 , NaUF 6 , and CsUF 6 and differs from those of RbUF 6 and KUF 6 . This adduct shows a strong ESR signal, with g = -0.78 +- 0.10, characteristic of UF 6 - salts. Based on its x-ray powder diffraction pattern, H 3 O + UF 6 - is cubic with a = 5.2229 +- 0.0005 A

  7. 2D modelling of a UF6 container in a fire

    International Nuclear Information System (INIS)

    Duret, B.; Seiler, J.M.

    1993-01-01

    We present some results on 2D thermal modelisation of the behaviour of UF6 in a fire. A cylindrical container is engulfed by a high temperature space where the heat transfer is expected to occur by radiation only. During the first minutes, we assume that the thermal resistance is between the external wall and the UF6 solid, the heat transfer can be split up into three kinds: 1) conduction to solid UF6 through a contact surface. 2) radiative transfer. 3) gas layer with a small heat conductance. This thermal resistance is initially determined by the UF6 filling type, shape and also is time dependant by thermal dilatation effects. On the onset of liquifying the heat transfer increases because of the larger liquid exchange. The liquid and boiling heat flow is then calculated by a model on the basis of classical correlations in vertical cavities. Numerical evaluations have been performed with a finite element model using: ANSYS. With a realistic hypothesis, the effect of the following parameters is estimated: thermal conductivity of UF6 solid, contact surface fraction, UF6 emissivity, gas gap thickness, liquid UF6 wall exchange, solid liquid transition criteria, non condensation factor k. (J.P.N.)

  8. Reimiep 87. An interlaboratory U-235 enrichment determination by gamma measurement on solid UF6 sample

    International Nuclear Information System (INIS)

    Aparo, M.; Cresti, P.

    1988-01-01

    Gamma spectroscopy technique, based on the measurement of U 235 186 KeV flux, is now currently used for the determination of Uranium enrichment in different material of nuclear fuel cycle, namely: Uranium metallic, UO 2 pellets, UF 6 liquid or solid. The present paper describes the use of such a technique and the obtained results in determining the U 235 /U atomic isotopic abundance on a certified UF 6 solid sample. The measurements have been carried out in the frame work of the partecipation to the ''UF 6 Interlaboratory Measurements Evaluation Programme'' organized by CBNM/Geel with the support of the ESARDA (European Safeguards Research and Development Association)

  9. The electron spectrum of UF6 recorded in the gas phase

    Science.gov (United States)

    Mârtensson, N.; Malmquist, P.-Å.; Svensson, S.; Johansson, B.

    1984-06-01

    Gas phase core and valence electron spectra from UF6, excited by AlKα monochromatized x rays, in the binding energy range 0-1000 eV are presented. It is shown that the AlKα excited valence electron spectrum can be used to reassign the highest occupied molecular orbital (HOMO) in UF6. Many-body effects on the core levels are discussed and core level lifetimes are determined. The shift between solid phase and gas phase electron binding energies for core lines is used to discuss the U5 f population in UF6.

  10. Dynamics of UF6 Desublimation with the Influence of Tank Geometry for Various Coolant Temperature

    Directory of Open Access Journals (Sweden)

    Orlov Аleksey А.

    2016-01-01

    Full Text Available Mathematical model of UF6 desublimation in a vertical immersion tank is presented in the article. Results of calculations of the filling dynamics of the tanks with 1m3 volume at various coolant temperatures, with and without ellipticity of the end walls are given. It is shown that allowance for the ellipticity of the end walls of the tanks leads to a significant increase in the time of desublimation of UF6.

  11. Dynamics of UF6 Desublimation with the Influence of Tank Geometry for Various Coolant Temperature

    OpenAIRE

    Orlov Аleksey А.; Tsimbalyuk Alexandr F.; Malyugin Roman V.; Glazunov Anatolij A.

    2016-01-01

    Mathematical model of UF[6] desublimation in a vertical immersion tank is presented in the article. Results of calculations of the filling dynamics of the tanks with 1m3 volume at various coolant temperatures, with and without ellipticity of the end walls are given. It is shown that allowance for the ellipticity of the end walls of the tanks leads to a significant increase in the time of desublimation of UF[6].

  12. Presentation and interpretation of field experiments of gaseous UF6 releases in the atmosphere

    International Nuclear Information System (INIS)

    Crabol, B.; Boulaud, D.; Deville-Cavelin, G.

    1992-01-01

    An experimental programme concerning the behaviour of UF 6 released in gaseous phase in the atmosphere has been conducted in the years 1986-1989 by the french Atomic Energy Commission and Eurodif. Three field tests have been performed on the CEA/CESTA experimental site. These experiments permitted to get informations about the kinetics of the hydrolysis reaction of the UF 6 , the behaviour of the hydrolysis products in the atmosphere and the granulometry of the solid particles

  13. Review of models used for determining consequences of UF6 release: Model evaluation report. Volume 2

    International Nuclear Information System (INIS)

    Nair, S.K.; Chambers, D.B.; Park, S.H.; Radonjic, Z.R.; Coutts, P.T.; Lewis, C.J.; Hammonds, J.S.; Hoffman, F.O.

    1997-11-01

    Three uranium hexafluoride-(UF 6 -) specific models--HGSYSTEM/UF 6 , Science Application International Corporation, and RTM-96; three dense-gas models--DEGADIS, SLAB, and the Chlorine Institute methodology; and one toxic chemical model--AFTOX--are evaluated on their capabilities to simulate the chemical reactions, thermodynamics, and atmospheric dispersion of UF 6 released from accidents at nuclear fuel-cycle facilities, to support Integrated Safety Analysis, Emergency Response Planning, and Post-Accident Analysis. These models are also evaluated for user-friendliness and for quality assurance and quality control features, to ensure the validity and credibility of the results. Model performance evaluations are conducted for the three UF 6 -specific models, using field data on releases of UF 6 and other heavy gases. Predictions from the HGSYSTEM/UF 6 and SAIC models are within an order of magnitude of the field data, but the SAIC model overpredicts beyond an order of magnitude for a few UF 6 -specific data points. The RTM-96 model provides overpredictions within a factor of 3 for all data points beyond 400 m from the source. For one data set, however, the RTM-96 model severely underpredicts the observations within 200 m of the source. Outputs of the models are most sensitive to the meteorological parameters at large distances from the source and to certain source-specific and meteorological parameters at distances close to the source. Specific recommendations are being made to improve the applicability and usefulness of the three models and to choose a specific model to support the intended analyses. Guidance is also provided on the choice of input parameters for initial dilution, building wake effects, and distance to completion of UF 6 reaction with water

  14. Evaluation of tecniques for controlling UF6 release clouds in the GAT environmental chamber

    International Nuclear Information System (INIS)

    Lux, C.J.

    1982-01-01

    Studies designed to characterize the reaction between UF 6 and atmospheric moisture, evaluate environmental variables of UF 6 cloud formation and ultimate cloud fate, and UF 6 release cloud control procedure have been conducted in the 1200 cu. ft. GAT environmental chamber. In earlier chamber experiments, 30 separate UF 6 release tests indicated that variations of atmospheric conditions and sample sizes had no significant effect on UO 2 F 2 particle size distribution, release cloud formation, or cloud settling rates. During the past year, numerous procedures have been evaluated for accelerating UF 6 cloud knockdown in a series of 37 environmental chamber releases. Knockdown procedures included: coarse water spray; air jet; steam spray (electrostatically charged and uncharged); carbon dioxide; Freon-12; fine water mist (uncharged); boric acid mist (charged and uncharged); and an ionized dry air stream. UF 6 hydrolysis cloud settling rates monitored by a laser/powermeter densitometer, indicated the relative effectiveness of various cloud knockdown techniques. Electrostatically charged boric acid/water mist, and electrostatically ionized dry air were both found to be very effective, knocking down the UO 2 F 2 release cloud particles in two to five minutes. Work to adapt these knockdown techniques for use under field conditions is continuing, taking into account recovery of the released uranium as well as nuclear criticality constraints

  15. Criticality safety review of 2 1/2-, 10-, and 14-ton UF6 cylinders

    International Nuclear Information System (INIS)

    Broadhead, B.L.

    1991-10-01

    Currently, UF 6 cylinders designed to contain 2 1/2 tons of UF 6 are classified as Fissile Class 2 packages with a transport index (TI) of 5 for the purpose of transportation. The 10-ton UF 6 cylinders are classified as Fissile Class 1 with no TI assigned for transportation. The 14-ton cylinders, although not certified for transport with enrichments greater than 1 wt % because they have no approved overpack, can be used in on-site operations for enrichments greater than 1 wt %. The maximum 235 U enrichments for these cylinders are 5.0 wt % for the 2 1/2-ton cylinder and 4.5 wt % for the 10- and 14-ton cylinders. This work reviews the suitability for reclassification of the 2 1/2-ton UF 6 packages as Fissile Class 1 with a maximum 235 U enrichment of 5 wt %. Additionally, the 10- and 14-ton cylinders are reviewed to address a change in maximum 235 U enrichment from 4.5 to 5 wt %. Based on this evaluation, the 2 1/2-ton UF 6 cylinders meet the 10 CFR.71 criteria for Fissile Class 1 packages, and no TI is needed for criticality safety purposes; however, a TI may be required based on radiation from the packages. Similarly, the 10- and 14-ton UF 6 packages appear acceptable for a maximum enrichment rating change to 5 wt % 235 U. 11 refs., 13 figs., 7 tabs

  16. Scenarios and analytical methods for UF6 releases at NRC-licensed fuel cycle facilities

    International Nuclear Information System (INIS)

    Siman-Tov, M.; Dykstra, J.; Holt, D.D.; Huxtable, W.P.; Just, R.A.; Williams, W.R.

    1984-06-01

    This report identifies and discusses potential scenarios for the accidental release of UF 6 at NRC-licensed UF 6 production and fuel fabrication facilities based on a literature review, site visits, and DOE enrichment plant experience. Analytical tools needed for evaluating source terms for such releases are discussed, and the applicability of existing methods is reviewed. Accident scenarios are discussed under the broad headings of cylinder failures, UF 6 process system failures, nuclear criticality events, and operator errors and are categorized by location, release source, phase of UF 6 prior to release, release flow characteristics, release causes, initiating events, and UF 6 inventory at risk. At least three types of releases are identified for further examination: (1) a release from a liquid-filled cylinder outdoors, (2) a release from a pigtail or cylinder in a steam chest, (3) an indoor release from either (a) a pigtail or liquid-filled cylinder or (b) other indoor source depending on facility design and operating procedures. Indoor release phenomena may be analyzed to determine input terms for a ventilation model by using a time-dependent homogeneous compartment model or a more complex hydrodynamic model if time-dependent, spatial variations in concentrations, temperature, and pressure are important. Analytical tools for modeling directed jets and explosive releases are discussed as well as some of the complex phenomena to be considered in analyzing UF 6 releases both indoors and outdoors

  17. Conceptual Ideas for New Nondestructive UF6 Cylinder Assay Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Karen A. [Los Alamos National Laboratory

    2012-05-02

    Nondestructive assay (NDA) measurements of uranium cylinders play an important role in helping the International Atomic Energy Agency (IAEA) safeguard uranium enrichment plants. Traditionally, these measurements have consisted of a scale or load cell to determine the mass of UF{sub 6} in the cylinder combined with a gamma-ray measurement of the 186 keV peak from {sup 235}U to determine enrichment. More recently, Los Alamos National Laboratory (LANL) and Pacific Northwest National Laboratory (PNNL) have developed systems that exploit the passive neutron signal from UF{sub 6} to determine uranium mass and/or enrichment. These include the Uranium Cylinder Assay System (UCAS), the Passive Neutron Enrichment Meter (PNEM), and the Hybrid Enrichment Verification Array (HEVA). The purpose of this report is to provide the IAEA with new ideas on technologies that may or may not be under active development but could be useful for UF{sub 6} cylinder assay. To begin, we have included two feasibility studies of active interrogation techniques. There is a long history of active interrogation in the field of nuclear safeguards, especially for uranium assay. Both of the active techniques provide a direct measure of {sup 235}U content. The first is an active neutron method based on the existing PNEM design that uses a correlated {sup 252}Cf interrogation source. This technique shows great promise for UF{sub 6} cylinder assay and is based on advanced technology that could be implemented in the field in the near term. The second active technique is nuclear resonance fluorescence (NRF). In the NRF technique, a bremsstrahlung photon beam could be used to illuminate the cylinder, and high-resolution gamma-ray detectors would detect the characteristic de-excitation photons. The results of the feasibility study show that under certain measurement geometries, NRF is impractical for UF6 cylinder assay, but the 'grazing transmission' and 'secant transmission' geometries

  18. Analyses of postulated accidental releases of UF6 inside process buildings

    International Nuclear Information System (INIS)

    Oliveira Neto, Jose Messias de; Nunes, Beatriz Guimaraes; Dias, Cristiane

    2009-01-01

    Uranium Hexafluoride is a material used in the various processes which comprise the front end of the nuclear fuel cycle (conversion, enrichment and fuel fabrication). Confinement of UF 6 is a very important safety requirement since this material is highly reactive and presents safety hazards to humans. The present paper discusses the safety relevant aspects of accidental releases of UF 6 inside process confinement buildings. Postulated accidental scenarios are analyzed and their consequences evaluated. Implant releases rates are estimated using computer code predictions. A time dependent homogeneous compartment model is used to predict concentrations of UF 6 , hydrogen fluoride and uranyl fluoride inside a confinement building, as well as to evaluate source terms released to the atmosphere. These source terms can be used as input to atmospheric dispersion models to evaluate consequences to the environment. The results can also be used to define adequate protective measures for emergency situations. (author)

  19. Handling of UF6 in U.S. gaseous diffusion plants

    International Nuclear Information System (INIS)

    Legeay, A.J.

    1978-01-01

    A comprehensive systems analysis of UF 6 handling has been made in the three U.S. gaseous diffusion plants and has resulted in a significant impact on the equipment design and the operating procedures of these facilities. The equipment, facilities, and industrial practices in UF 6 handling operations as they existed in the early 1970's are reviewed with particular emphasis placed on the changes which have been implemented. The changes were applied to the systems and operating methods which evolved from the design, startup, and operation of the Oak Ridge Gaseous Diffusion Plant in 1945

  20. Nuclear criticality safety aspects of gaseous uranium hexafluoride (UF6) in the diffusion cascade

    International Nuclear Information System (INIS)

    Huffer, J.E.

    1997-04-01

    This paper determines the nuclear safety of gaseous UF 6 in the current Gaseous Diffusion Cascade and auxiliary systems. The actual plant safety system settings for pressure trip points are used to determine the maximum amount of HF moderation in the process gas, as well as the corresponding atomic number densities. These inputs are used in KENO V.a criticality safety models which are sized to the actual plant equipment. The ENO V.a calculation results confirm nuclear safety of gaseous UF 6 in plant operations

  1. HGSYSTEMUF6, Simulating Dispersion Due to Atmospheric Release of Uranium Hexafluoride (UF6)

    International Nuclear Information System (INIS)

    Hanna, G; Chang, J.C.; Zhang, J.X.; Bloom, S.G.; Goode, W.D. Jr; Lombardi, D.A.; Yambert, M.W.

    2001-01-01

    1 - Description of program or function: HGSYSTEMUF6 is a suite of models designed for use in estimating consequences associated with accidental, atmospheric release of Uranium Hexafluoride (UF 6 ) and its reaction products, namely Hydrogen Fluoride (HF), and other non-reactive contaminants which are either negatively, neutrally, or positively buoyant. It is based on HGSYSTEM Version 3.0 of Shell Research LTD., and contains specific algorithms for the treatment of UF 6 chemistry and thermodynamics. HGSYSTEMUF6 contains algorithms for the treatment of dense gases, dry and wet deposition, effects due to the presence of buildings (canyon and wake), plume lift-off, and the effects of complex terrain. The models components of the suite include (1) AEROPLUME/RK, used to model near-field dispersion from pressurized two-phase jet releases of UF6 and its reaction products, (2) HEGADAS/UF6 for simulating dense, ground based release of UF 6 , (3) PGPLUME for simulation of passive, neutrally buoyant plumes (4) UF6Mixer for modeling warm, potentially reactive, ground-level releases of UF 6 from buildings, and (5) WAKE, used to model elevated and ground-level releases into building wake cavities of non-reactive plumes that are either neutrally or positively buoyant. 2 - Methods: The atmospheric release and transport of UF 6 is a complicated process involving the interaction between dispersion, chemical and thermodynamic processes. This process is characterized by four separate stages (flash, sublimation, chemical reaction entrainment and passive dispersion) in which one or more of these processes dominate. The various models contained in the suite are applicable to one or more of these stages. For example, for modeling reactive, multiphase releases of UF 6 , the AEROPLUME/RK component employs a process-splitting scheme which numerically integrates the differential equations governing dispersion, UF 6 chemistry, and thermodynamics. This algorithm is based on the assumption that

  2. Neutron measurements of 234U isotopic abundance in UF6 samples

    International Nuclear Information System (INIS)

    Stieff, L.R.; Walton, R.B.; Reilly, T.D.; Fields, L.W.; Walker, R.L.; Mullins, W.T.; Thoms, J.I.

    1975-01-01

    Neutrons produced from the (α,n) reaction on fluorine were used to measure the 234 U isotopic abundance in UF 6 samples. A 4PI detector consisting of 14 3 He counters embedded in a polyethylene anulus was specifically designed to receive standard 1S (high-enriched) and 2S (low-enriched) UF 6 sample cylinders. The 235 U isotopic abundances of the 19 2S and 5 1S samples studied range from 0.30 to 4.0 percent (wt) and 80.0 to 97.7 percent (wt) respectively. A typical net weight for the UF 6 in the 1S cylinders is 800 g and in 2S cylinders is 1700 g. For counting times of 10 3 sec and for 234 U concentrations over a range of 0.001 to 1.0 percent (wt), the neutron method will achieve accuracies better than 2.5 percent (1 sigma) for the depleted and low-enriched UF 6 and approximately 0.5 percent (1 sigma) for the high-enriched UF 6 when compared with the 234 U isotopic abundances obtained using a high precision, two-stage mass spectrometer. Extension of the 234 U neutron assay method to samples containing 232 U is now being investigated. From these preliminary results it appears that the isotope separation plant operator and the safeguards inspector should be able to use this new nondestructive assay technique for precision measurements of the isotopic abundance of 234 U. In addition, the method could be useful as an indirect field method for 235 U assay where gamma techniques give inconclusive results and where the 235 U/ 234 U ratio can be assumed or has been previously established either by measurement or calculation. (U.S.)

  3. Transport of UF6 in compliance with TS-R-1

    International Nuclear Information System (INIS)

    Dekker, B.G.

    2004-01-01

    The IAEA Regulations TS-R-1 (ST-1, Revised) 1996 Edition include requirements for packages containing uranium hexafluoride (UF6); these are the first and only substance-specific requirements in the IAEA regulations. These requirements have already particularly affected, and will further affect, the transport of non-fissile and fissile excepted UF 6 and the packages used for these transports. Non-fissile and fissile excepted UF6 (ASTM C 787) has been transported worldwide for decades in a safe and reliable manner, using internationally standardised packages. Under the auspices of the World Nuclear Transport Institute (WNTI), an industry working group has been evaluating the existing packages against the requirements in TS-R-1. As new requirements came into effect, there were new challenges for the use of these standard packages, including the free drop test and the thermal requirements. In close cooperation with the WNTI HEXT Industry Working Group, a consortium of UF6 producers/users has worked together on the design and development, testing and certification of technical solutions for modification and optimisation of the existing packages to comply with TS-R-1. This paper reviews the existing standard packages against the requirements in TS-R-1. An update is also given describing the enhancements to the standard packages that have been designed and developed recently. The paper also describes how these solutions have been tested and certified, as well as the status of implementation. Finally, a review is made of the options that are available internationally to transport UF6 in compliance with TS-R-1. (author)

  4. Modeling and analyses of postulated UF6 release accidents in gaseous diffusion plant

    International Nuclear Information System (INIS)

    Kim, S.H.; Taleyarkhan, R.P.; Keith, K.D.; Schmidt, R.W.; Carter, J.C.; Dyer, R.H.

    1995-10-01

    Computer models have been developed to simulate the transient behavior of aerosols and vapors as a result of a postulated accident involving the release of uranium hexafluoride (UF 6 ) into the process building of a gaseous diffusion plant. UF 6 undergoes an exothermic chemical reaction with moisture (H 2 O) in the air to form hydrogen fluoride (HF) and radioactive uranyl fluoride (UO 2 F 2 ). As part of a facility-wide safety evaluation, this study evaluated source terms consisting of UO 2 F 2 as well as HF during a postulated UF 6 release accident in a process building. In the postulated accident scenario, ∼7900 kg (17,500 lb) of hot UF 6 vapor is released over a 5 min period from the process piping into the atmosphere of a large process building. UO 2 F 2 mainly remains as airborne-solid particles (aerosols), and HF is in a vapor form. Some UO 2 F 2 aerosols are removed from the air flow due to gravitational settling. The HF and the remaining UO 2 F 2 are mixed with air and exhausted through the building ventilation system. The MELCOR computer code was selected for simulating aerosols and vapor transport in the process building. MELCOR model was first used to develop a single volume representation of a process building and its results were compared with those from past lumped parameter models specifically developed for studying UF 6 release accidents. Preliminary results indicate that MELCOR predicted results (using a lumped formulation) are comparable with those from previously developed models

  5. Long-term evaluation of fluoroelastomer O-rings in UF6

    International Nuclear Information System (INIS)

    Russell, R.G.; Otey, M.G.; Dippo, G.L.

    1986-01-01

    A major component in the gaseous centrifuge enrichment plant (GCEP) was fluoroelastomer O-rings, which were used to seal the uranium hexafluoride (UF 6 ) gas system. A program utilizing accelerated test conditions was used to help identify the best material out of four selected candidates and to predict the service life of these materials at GCEP conditions. The tests included accelerated temperatures, mechanical stress, and UF 6 exposure. Data were evaluated using the Newman--Keuls 1 ranking system to identify the best material and a zero-order reaction rate equation to help predict service life. This presentation includes a description of the test facility, the materials tested, the types of tests, objectives of the study, service life predictions, and conclusions. The O-rings are predicted to last approx. 30 years, and a high-molecular-weight polymer had the best performance ranking

  6. Releases of UF6 to the atmosphere after a potential fire in a cylinder storage yard

    International Nuclear Information System (INIS)

    Lombardi, D.A.; Williams, W.R.; Anderson, J.C.

    1997-01-01

    Uranium hexafluoride (UF 6 ), a toxic material, is stored in just over 6200 cylinders at the K-25 site in Oak Ridge, Tennessee. The safety analysis report (SAR) for cylinder yard storage operations at the plant required the development of accident scenarios for the potential release of UF 6 to the atmosphere. In accordance with DOE standards and guidance, the general approach taken in this SAR was to examine the functions and contents of the cylinder storage yards to determine whether safety-significant hazards were present for workers in the immediate vicinity, workers on-site, the general public off-site, or the environment. and to evaluate the significance of any hazards that were found. A detailed accident analysis was performed to determine a set of limiting accidents that have potential for off-site consequences. One of the limiting accidents identified in the SAR was the rupture of a cylinder engulfed in a fire

  7. Sampling and characterization of aerosols formed in the atmospheric hydrolysis of UF6

    International Nuclear Information System (INIS)

    Bostick, W.D.; McCulla, W.H.; Pickrell, P.W.; Branam, D.A.

    1983-01-01

    When gaseous UF 6 is released into the atmosphere, it rapidly reacts with ambient moisture to form an aerosol of uranyl fluoride and HF. As part of our Safety Analysis program, we have performed several experimental releases of UF 6 (from natural uranium) in contained volumes in order to investigate techniques for sampling and characterizing the aerosol materials. The aggregrate particle morphology and size distribution have been found to be dependent upon several conditions, including the relative humidity at the time of the release and the elapse time after the release. Aerosol composition and settling rate have been investigated using isokinetic samplers for the separate collection of UO 2 F 2 and HF, and via laser spectroscopic remote sensing (Mie scatter and infrared spectroscopy). 8 references

  8. Calculational criticality analyses of 10- and 20-MW UF6 freezer/sublimer vessels

    International Nuclear Information System (INIS)

    Jordan, W.C.

    1993-02-01

    Calculational criticality analyses have been performed for 10- and 20-MW UF 6 freezer/sublimer vessels. The freezer/sublimers have been analyzed over a range of conditions that encompass normal operation and abnormal conditions. The effects of HF moderation of the UF 6 in each vessel have been considered for uranium enriched between 2 and 5 wt % 235 U. The results indicate that the nuclearly safe enrichments originally established for the operation of a 10-MW freezer/sublimer, based on a hydrogen-to-uranium moderation ratio of 0.33, are acceptable. If strict moderation control can be demonstrated for hydrogen-to-uranium moderation ratios that are less than 0.33, then the enrichment limits for the 10-MW freezer/sublimer may be increased slightly. The calculations performed also allow safe enrichment limits to be established for a 20-NM freezer/sublimer under moderation control

  9. Modelling of the behaviour of a UF6 container in a fire

    International Nuclear Information System (INIS)

    Pinton, Eric

    1996-01-01

    This thesis is justified by the safety needs about storage and transport of UF 6 containers. To define their behaviour under fire conditions, a modelling was developed. Before tackling the numerical modelling, a phenomenological interpretation with experimental results of containers inside a furnace (800 C) during a fixed period was carried out. The internal heat transfers were considerably improved with these results. The 2D elaborated model takes into account most of the physical phenomena encountered in this type of situation (boiling, evaporation, condensation, radiant heat transfers through an absorbing gas, convection, pressurisation, thermal contact resistance, UF 6 expansion, solid core sinking in the liquid, elastic and plastic deformations of the steel container). This model was successfully confronted with experiments. (author) [fr

  10. The regulations and the problems of their implementation in UF6 transport

    International Nuclear Information System (INIS)

    Devillers, C.; Grenier, M.; Ringot, C.; Warniez, P.

    1988-12-01

    UF 6 is currently transported in packagings which were developed in the sixties - standardized and used all over the world, these packagings perform their duty adequately. Nevertheless, the growing amounts of UF 6 and the changes in the regulations now raises the problem of compliance of these packagings with the latter. The problems which deserve special attention are: selection of the packaging type in terms of the origin and the enrichment, design of valve covers, behaviour at low temperatures, regulatory requirements in handling, tying down cleaning and unloading, allowable dose rate increase in case of minor mishaps, behaviour in fire, taking into account the toxicity, identification of special features required in the case of controlled moderation of fissile packages, transport conditions of empty packagings containing heels. In this paper are reviewed the results of this analysis, which is limited to the case of transport using cylinders of 48Y and 30B

  11. Computer-optimized γ-NDA geometries for uranium enrichment verification of gaseous UF6

    International Nuclear Information System (INIS)

    Wichers, V.A.; Aaldijk, J.K.; Betue, P.A.C. de; Harry, R.J.S.

    1993-05-01

    An improved collimator pair of novel design tailored for deposit independent enrichment verification of gaseous UF 6 at low pressures in cascade-to-header pipes of small diameters in centrifuge enrichment plants is presented. The designs are adapted for use in a dual-geometry arrangement for simultaneous measurements with both detection geometries. The average measurement time with the dual-geometry arrangement is approximately half an hour for deposit-to-gas activity ratios as high as 20. (orig.)

  12. Materials considerations for UF6 gas-core reactor. Interim report for preliminary design study

    International Nuclear Information System (INIS)

    Wagner, P.

    1977-04-01

    The limiting materials problem in a high-temperature UF 6 core reactor is the corrosion of the core containment vessel. The UF 6 , the lower fluorides of uranium, and the fluorine that exist at the anticipated reactor operating conditions (1000 K and about one atmosphere UF 6 ) are all corrosive. Because of this, the materials evaluation effort for this reactor design study has concentrated on the identification of a viable system for the containment vessel that meets both the materials and neutronic requirements. A study of the literature has revealed that the most promising corrosion-resistant candidates are Ni or Ni-Al alloys. One of the conclusions of this work is that the containment vessel use a nickel liner or clad since the use of Ni as a structural member is precluded by its relative blackness to thermal neutrons. Estimates of corrosion rates of Ni and Ni-Al alloys, the effects of the pressure and temperature of F 2 on the corrosion rates, calculated equilibrium gas compositions at reactor core operating conditions, suggested methods of fabrication, and recommendations for future research and development are included

  13. Photochemical removal of NpF6 and PuF6 from UF6 gas streams

    International Nuclear Information System (INIS)

    Beitz, J.V.; Williams, C.W.

    1990-01-01

    A novel photochemical method of removing reactive fluorides from UF 6 gas has been discovered. This method reduces generated waste to little more than the volume of the removed impurities, minimizes loss of UF 6 , and can produce a recyclable by-product, fluorine gas. In our new method, impure UF 6 , is exposed to ultraviolet light which dissociates the UF 6 to UF 5 and fluorine atom. Impurities which chemically react with UF 5 are reduced and form solid compounds easily removed from the gas while UF 5 is converted back to UF 6 . Proof-of-concept testing involved UF 6 containing NpF 6 and PuF 6 with CO added as a fluorine atom scavenger. In a single photolysis step, greater than 5000-fold reduction of PuF 6 was demonstrated while reducing NpF 6 by more than 40-fold. This process is likely to remove corrosion and fission product fluorides that are more reactive than UF 6 and has been demonstrated without an added fluorine atom scavenger by periodically removing photogenerated fluorine gas. 44 refs., 3 figs., 2 tabs

  14. Evaluation of a dry process for conversion of U-AVLIS product to UF6. Milestone U361

    International Nuclear Information System (INIS)

    1992-05-01

    A technical and engineering evaluation has been completed for a dry UF 6 production system to convert the product of an initial two-line U-AVLIS plant. The objective of the study has been to develop a better understanding of process design requirements, capital and operating costs, and demonstration requirements for this alternate process. This report summarizes the results of the study and presents various comparisons between the baseline and alternate processes, building on the information contained in UF 6 Product Alternatives Review Committee -- Final Report. It also provides additional information on flowsheet variations for the dry route which may warrant further consideration. The information developed by this study and conceptual design information for the baseline process will be combined with information to be developed by the U-AVLIS program and by industrial participants over the next twelve months to permit a further comparison of the baseline and alternate processes in terms of cost, risk, and compatibility with U-AVLIS deployment schedules and strategies. This comparative information will be used to make a final process flowsheet selection for the initial U-AVLIS plant by March 1993. The process studied is the alternate UF 6 production flowsheet. Process steps are (1) electron-beam distillation to reduce enriched product iron content from about 10 wt % or less, (2) hydrofluorination of the metal to UF 4 , (3) fluorination of UF 4 to UF 6 , (4) cold trap collection of the UF 6 product, (5) UF 6 purification by distillation, and (6) final blending and packaging of the purified UF 6 in cylinders. A preliminary system design has been prepared for the dry UF 6 production process based on currently available technical information. For some process steps, such information is quite limited. Comparisons have been made between this alternate process and the baseline plant process for UF 6 production

  15. Thermal properties evaluation of insulation in overpack containers for UF6 transport

    International Nuclear Information System (INIS)

    Frazier, J.L.

    1989-01-01

    Two types of insulation are currently in use in overpacks utilized to protect UF 6 during transport. Phenolic foam has been used in the family of UF 6 overpacks under US Department of Transportation Specifications. Recently new generation overpacks have been developed which utilize polyurethane foam. A comparative analysis was made of the thermal characteristics of the phenolic foam with that of polyurethane in two different densities. Thermal properties of materials vary with temperature with the relationship being a complex interaction of basic materials properties, processing variables, and environmental conditions. Typically, the thermal conductivity of a material increases with increasing temperature, and adequate thermal models of materials systems or structures require temperature dependent thermal properties such as conductivity. In the event of an overpack container exposed to a fire as a heat source, the thermal properties of the materials of construction will vary with temperature which varies with time. Environmental interactions will result in material properties changes which will be reflected in changes in thermal properties. The need to incorporate temperature dependent thermal properties into analytical finite element codes led to an experimental program to measure thermal properties, principally thermal conductivity, for the 21PF-1 overpack phenolic foam. The thermal conductivity-temperature relationship for this insulator has been measured from room temperature to over 1000F. An alternate UF 6 product cylinder overpack container has recently entered service; an overpack design incorporating polyurethane as the primary thermal resistance in place of the phenolic foam in a 2 1/2 ton cylinder overpack. Elevated temperature thermal properties measurements for the polyurethane material system are presented

  16. Scoping study to expedite development of a field deployable and portable instrument for UF6 enrichment assay

    OpenAIRE

    Chan, CYG; Valentine, JD; Russo, RE

    2017-01-01

    The primary objective of the present study is to identity the most promising, viable technologies that are likely to culminate in an expedited development of the next-generation, field-deployable instrument for providing rapid, accurate, and precise enrichment assay of uranium hexafluoride (UF6). UF6 is typically involved, and is arguably the most important uranium compound, in uranium enrichment processes. As the first line of defense against proliferation, accurate analytical techniques t...

  17. Process for decontamination of surfaces in an facility of natural uranium hexafluoride production (UF6)

    International Nuclear Information System (INIS)

    Almeida, Claudio C. de; Silva, Teresinha M.; Rodrigues, Demerval L.; Carneiro, Janete C.G.G.

    2017-01-01

    The experience acquired in the actions taken during the decontamination process of an IPEN-CNEN / SP Nuclear and Energy Research Institute facility, for the purpose of making the site unrestricted, is reported. The steps of this operation involved: planning, training of facility operators, workplace analysis and radiometric measurements. The facility had several types of equipment from the natural uranium hexafluoride (UF 6 ) production tower and other facility materials. Rules for the transportation of radioactive materials were established, both inside and outside the facility and release of materials and installation

  18. Finite element modelling of fire situations in UF6 transport containers

    International Nuclear Information System (INIS)

    Basombrio, F.G.

    1996-01-01

    In this report we describe some runs made with the code FASES2. They concern different situations associated to fires originated by accidents in the transport of containers filled with UF6. Such situations have been inspired in cases taken from the current literature, and related to numerical modelling or experiments. We aim to consign the most relevant aspects of such runs, with the future purpose of comparing them with the predictions made with simpler lumped models. In such a way, it will be possible to calibrate the simple models with the results coming from detailed models. (author). 6 refs., 12 figs

  19. Method of absorbing UF6 from gaseous mixtures in alkamine absorbents

    International Nuclear Information System (INIS)

    Lafferty, R.H.; Smiley, S.H.; Radimer, K.J.

    1976-01-01

    A method is described for recovering UF 6 from gaseous mixtures by absorption in a liquid. The liquid absorbent must have a relatively low viscosity and at least one component of the absorbent is an alkamine having less than 3 carbon atoms bonded to the amino nitrogen, less than 2 of the carbon atoms other than those bonded to the amino nitrogen are free of the hydroxy radical and precipitate the absorbed uranium from the absorbent. At least one component of the absorbent is chosen from the group consisting of ethanolamine, diethanolamine, and 3-methyl-3-amino-propane-diol-1,2

  20. Evaluation of coverage of enriched UF6 cylinder storage lots by existing criticality accident alarms

    International Nuclear Information System (INIS)

    Lee, B.L. Jr.; Dobelbower, M.C.; Woollard, J.E.; Sutherland, P.J.; Tayloe, R.W. Jr.

    1995-03-01

    The Portsmouth Gaseous Diffusion Plant (PORTS) is leased from the US Department of Energy (DOE) by the United States Enrichment Corporation (USEC), a government corporation formed in 1993. PORTS is in transition from regulation by DOE to regulation by the Nuclear Regulatory Commission (NRC). One regulation is 10 CFR Part 76.89, which requires that criticality alarm systems be provided for the site. PORTS originally installed criticality accident alarm systems in all building for which nuclear criticality accidents were credible. Currently, however, alarm systems are not installed in the enriched uranium hexafluoride (UF 6 ) cylinder storage lots. This report analyzes and documents the extent to which enriched UF 6 cylinder storage lots at PORTS are covered by criticality detectors and alarms currently installed in adjacent buildings. Monte Carlo calculations are performed on simplified models of the cylinder storage lots and adjacent buildings. The storage lots modelled are X-745B, X-745C, X745D, X-745E, and X-745F. The criticality detectors modelled are located in building X-343, the building X-344A/X-342A complex, and portions of building X-330 (see Figures 1 and 2). These criticality detectors are those located closest to the cylinder storage lots. Results of this analysis indicate that the existing criticality detectors currently installed at PORTS are largely ineffective in detecting neutron radiation from criticality accidents in most of the cylinder storage lots at PORTS, except sometimes along portions of their peripheries

  1. Hydraulic breakage of tanks for the transport of uranium hexafluoride (UF6)

    International Nuclear Information System (INIS)

    Biaggio, A.L.; Lee Gonzales, H.M.; Lopez Vietri, J.R.; Novo, R.G.

    1987-01-01

    To begin with, the tank models that are proposed by the international norms for the transport and storage of hexafluoride of uranium (UF 6 ) are briefly described. The operations related to the transport in its different forms are also described, particularly those that can produce the hydraulic breakage of tanks during its course or in later stages, when incorrectly performed. With reference to those operations, the most important physicochemical properties of UF 6 as for safety are analyzed. A quantitative evaluation of the deviations of parameters that are controlled during the heating of tanks, comparing them with the normative nominal values, is performed. Adopting some simplifying hypothesis, a general study, applicable to all tank models proposed by norms, is carried out to determine the temperature at which the hydraulic breakage takes place when they are heated in closed-valve conditions. A curve is obtained by plotting the hydraulic breakage temperature against the filling degree. To conclude, the values obtained are compared with the results of other theoretical studies on this subject. (Author)

  2. Review of models used for determining consequences of UF6 release: Development of model evaluation criteria. Volume 1

    International Nuclear Information System (INIS)

    Nair, S.K.; Chambers, D.B.; Park, S.H.; Hoffman, F.O.

    1997-11-01

    The objective of this study is to examine the usefulness and effectiveness of currently existing models that simulate the release of uranium hexafluoride from UF 6 -handling facilities, subsequent reactions of UF 6 with atmospheric moisture, and the dispersion of UF 6 and reaction products in the atmosphere. The study evaluates screening-level and detailed public-domain models that were specifically developed for UF 6 and models that were originally developed for the treatment of dense gases but are applicable to UF 6 release, reaction, and dispersion. The model evaluation process is divided into three specific tasks: model-component evaluation; applicability evaluation; and user interface and quality assurance and quality control (QA/QC) evaluation. Within the model-component evaluation process, a model's treatment of source term, thermodynamics, and atmospheric dispersion are considered and model predictions are compared with actual observations. Within the applicability evaluation process, a model's applicability to Integrated Safety Analysis, Emergency Response Planning, and Post-Accident Analysis, and to site-specific considerations are assessed. Finally, within the user interface and QA/QC evaluation process, a model's user-friendliness, presence and clarity of documentation, ease of use, etc. are assessed, along with its handling of QA/QC. This document presents the complete methodology used in the evaluation process

  3. Measurement of 235U content and flow of UF6 using delayed neutrons or gamma rays following induced fission

    International Nuclear Information System (INIS)

    Stromswold, D.C.; Peurrung, A.J.; Reeder, P.L.; Perkins, R.W.

    1996-06-01

    Feasibility experiments conducted at Pacific Northwest National Laboratory demonstrate that either delayed neutrons or energetic gamma rays from short-lived fission products can be used to monitor the blending of UF 6 gas streams. A 252 Cf neutron source was used to induce 235 U fission in a sample, and delayed neutrons and gamma rays were measured after the sample moved open-quotes down-stream.close quotes The experiments used a UO 2 powder that was transported down the pipe to simulate the flowing UF 6 gas. Computer modeling and analytic calculation extended the test results to a flowing UF 6 gas system. Neutron or gamma-ray measurements made at two downstream positions can be used to indicate both the 235 U content and UF 6 flow rate. Both the neutron and gamma-ray techniques have the benefits of simplicity and long-term reliability, combined with adequate sensitivity for low-intrusion monitoring of the blending process. Alternatively, measuring the neutron emission rate from (a, n) reactions in the UF 6 provides an approximate measure of the 235 U content without using a neutron source to induce fission

  4. Uniform deposition of uranium hexafluoride (UF6): Standardized mass deposits and controlled isotopic ratios using a thermal fluorination method

    Energy Technology Data Exchange (ETDEWEB)

    McNamara, Bruce K.; O’Hara, Matthew J.; Casella, Andrew M.; Carter, Jennifer C.; Addleman, R. Shane; MacFarlan, Paul J.

    2016-07-01

    Abstract: We report a convenient method for the generation of volatile uranium hexafluoride (UF6) from solid uranium oxides and other uranium compounds, followed by uniform deposition of low levels of UF6 onto sampling coupons. Under laminar flow conditions, UF6 is shown to interact with surfaces within the chamber to a highly predictable degree. We demonstrate the preparation of uranium deposits that range between ~0.01 and 470±34 ng∙cm-2. The data suggest the method can be extended to creating depositions at the sub-picogram∙cm-2 level. Additionally, the isotopic composition of the deposits can be customized by selection of the uranium source materials. We demonstrate a layering technique whereby two uranium solids, each with a different isotopic composition, are employed to form successive layers of UF6 on a surface. The result is an ultra-thin deposit of UF6 that bears an isotopic signature that is a composite of the two uranium sources. The reported deposition method has direct application to the development of unique analytical standards for nuclear safeguards and forensics.

  5. Theoretical study of relativistic effects in the electronic structure and chemical bonding of UF6

    International Nuclear Information System (INIS)

    Onoe, Jun; Takeuchi, Kazuo; Sekine, Rika; Nakamatsu, Hirohide; Mukoyama, Takeshi; Adachi, Hirohiko.

    1992-01-01

    We have performed the relativistic molecular orbital calculation for the ground state of UF 6 , using the discrete-variational Dirac-Slater method (DV-DS), in order to elucidate the relativistic effects in the electronic structure and chemical bonding. Compared with the electronic structure calculated by the non-relativistic Hartree-Fock-Slater (DV-X α )MO method, not only the direct relativistic effects (spin-orbit splitting etc), but also the indirect effect due to the change in screening core potential charge are shown to be important in the MO level structure. From the U-F bond overlap population analysis, we found that the U-F bond formation can be explained only by the DV-DS, not by the DV-X α . The calculated electronic structure in valence energy region (-20-OeV) and excitation energies in UV region are in agreement with experiments. (author)

  6. Optimization of air plasma reconversion of UF6 to UO2 based on thermodynamic calculations

    Science.gov (United States)

    Tundeshev, Nikolay; Karengin, Alexander; Shamanin, Igor

    2018-03-01

    The possibility of plasma-chemical conversion of depleted uranium-235 hexafluoride (DUHF) in air plasma in the form of gas-air mixtures with hydrogen is considered in the paper. Calculation of burning parameters of gas-air mixtures is carried out and the compositions of mixtures obtained via energy-efficient conversion of DUHF in air plasma are determined. With the help of plasma-chemical conversion, thermodynamic modeling optimal composition of UF6-H2-Air mixtures and its burning parameters, the modes for production of uranium dioxide in the condensed phase are determined. The results of the conducted researches can be used for creation of technology for plasma-chemical conversion of DUHF in the form of air-gas mixtures with hydrogen.

  7. Evaluation of environmental-control technologies for commercial nuclear fuel-conversion (UF6) facilities

    International Nuclear Information System (INIS)

    Perkins, B.L.

    1982-10-01

    At present in the United States, there are two commercial conversion facilities. These facilities process uranium concentrate into UF 6 for shipment to the enrichment facilities. One conversion facility uses a dry hydrofluor process, whereas the other facility uses a process known as the wet solvent extraction-fluorination process. Because of the different processes used in the two plants, waste characteristics, quantities, and treatment practices differ at each facility. Wastes and effluent streams contain impurities found in the concentrate (such as uranium daughters, vanadium, molybdenum, selenium, arsenic, and ammonia) and process chemicals used in the circuit (including fluorine, nitrogen, and hydrogen), as well as small quantities of uranium. Studies of suitable disposal options for the solid wastes and sludges generated at the facilities and the long-term effects of emissions to the ambient environment are needed. 30 figures, 34 tables

  8. Determination of the isotopic ratio 235U/238U in UF6 using quadrupole mass spectrometry

    International Nuclear Information System (INIS)

    Kusahara, Helena Sueco

    1979-01-01

    In this work measurements of isotope ratios 235 U / 23 '8U in uranium hexafluoride are carried out using a quadrupole mass spectrometer. The operational parameters, which affect the final precision of the results, are standardized. Optimized procedures for the preparation of uranium hexafluoride samples by fluorination of uranium oxides using cobalt trifluoride method are established. Careful attention is given to the process of purification of uranium hexafluoride samples by fractional distillation. Adequate statistical methods for analysing the results obtained for single ratio measurements as well as the ratio ' of isotopic ratios of sample and standard ar.e developed. A precision of about 10 -4 for single ratio measurements and accuracy of about 0,3% for the ratio of sample and standard ratios are obtained. These results agree with the values which have been obtained using magnetic mass spectrometers. The procedures and methods established in this work can be employed in the systematic uranium isotope analysis in UF 6 form. (author)

  9. Fission product range effects on HEU fissile gas monitoring for UF6 gas

    International Nuclear Information System (INIS)

    Munro, J.K. Jr.; Valentine, T.E.; Perez, R.B.

    1997-01-01

    The amount of 235 U in UF 6 flowing in a pipe can be monitored by counting gamma rays emitted from fission fragments carried along by the flowing gas. Neutron sources are mounted in an annular sleeve that is filled with moderator material and surrounds the pipe. This provides a source of thermal neutrons to produce the fission fragments. Those fragments that remain in the gas stream following fission are carried past a gamma detector. A typical fragment will be quite unstable, giving up energy as it decays to a more stable isotope with a significant amount of this energy being emitted in the form of gamma rays. A given fragment can emit several gamma rays over its lifetime. The gamma ray emission activity level of a distribution of fission fragments decreases with time. The monitoring system software uses models of these processes to interpret the gamma radiation counting data measured by the gamma detectors

  10. High frequency titration in non-aqueous solvents. Application to HF and UF6

    International Nuclear Information System (INIS)

    Neveu, Claude

    1965-01-01

    In this research thesis, the author first presents the main theoretical notions regarding high frequency titration, notably by studying characteristic curves, i.e. the titration meter indication with respect to conductibility. He reports the use of this method for the study of various reactions in non-aqueous medium: reaction of AlCl 3 with pyridine in acetonitrile, of AlCl 3 with HCl in tetrachloroethane and in nitromethane. He also reports the attempt of application of this method to the titration of HF in presence of UF 6 in CCl 4 as solvent, or by using F acceptors like BF 3 , PF 5 or ClF 3 as reactants [fr

  11. 235U enrichment determination on UF6 cylinders with CZT detectors

    Science.gov (United States)

    Berndt, Reinhard; Mortreau, Patricia

    2018-04-01

    Measurements of uranium enrichment in UF6 transit cylinders are an important nuclear safeguards verification task, which is performed using a non-destructive assay method, the traditional enrichment meter, which involves measuring the count rate of the 186 keV gamma ray. This provides a direct measure of the 235U enrichment. Measurements are typically performed using either high-resolution detectors (Germanium) with e-cooling and battery operation, or portable devices equipped with low resolution detectors (NaI). Despite good results being achieved when measuring Low Enriched Uranium in 30B type cylinders and natural uranium in 48Y type containers using both detector systems, there are situations, which preclude the use of one or both of these systems. The focus of this work is to address some of the recognized limitations in relation to the current use of the above detector systems by considering the feasibility of an inspection instrument for 235U enrichment measurements on UF6 cylinders using the compact and light Cadmium Zinc Telluride (CZT) detectors. In the present work, test measurements were carried out, under field conditions and on full-size objects, with different CZT detectors, in particular for situations where existing systems cannot be used e.g. for stacks of 48Y type containers with depleted uranium. The main result of this study shows that the CZT detectors, actually a cluster of four μCZT1500 micro spectrometers provide as good results as the germanium detector in the ORTEC Micro-trans SPEC HPGe Portable spectrometer, and most importantly in particular for natural and depleted uranium in 48Y cylinders.

  12. Field testing of UF6 cylinder gamma-ray measuring equipment for international safeguards

    International Nuclear Information System (INIS)

    Fields, L.W.; Ricci, E.

    1982-01-01

    Two portable intrinsiIAEA (high-purity) Germanium (HP Ge) detectors, a Davidson portable multichannel analyzer (MCA), and accessory equipment were field-tested on product and feed UF 6 cylinders at the Oak Ridge Gaseous Diffusion Plant. These latter two instruments were not available to UCC-ND at the time of the field tests were designed to assess the usefulness of the above equipment for safeguards; specifically, each cylinder's average 235 U assay was determined by gamma spectrometry and the results were compared statistically with assays obtained previously by mass spectrometry for the same cylinders. This comparison was pivotal to show that the HP Ge detectors can produce results acceptable statistically, and that they can be used with confidence in field measurements. The portable HP Ge detectors are rugged for field use and are most useful in determining 235 U enrichment in UF 6 cylinders during international safeguards inspections at enrichment plants. Aside from their high resolution and light weight, they can be stored and transported at ambient temperatures. The latter results in a reduction of storage and handling costs for the IAEA inspector, in comparison with the use of high resolution lithium-drifted Ge detectors. The MCA and the accessory equipment also performed reliably. It is concluded that, although the Davidson portable MCA performed reliably, a higher degree of portability and electronic versatility would be desirable to assist the IAEA inspector in the field. Equipment such as the compact MCA recently developed by Los Alamos National Laboratory and/or the B-SAM developed by Brookhaven National Laboratory do have these features and, as such, would be more useful to the IAEC during field measurements. These field tests, but prototypes are being tried and evaluated by the IAEA inspectorate. At this writing the first commercialunits are being marketed in the US

  13. Release of UF6 from a ruptured model 48Y cylinder at Sequoyah Fuels Corporation Facility: lessons-learned report

    International Nuclear Information System (INIS)

    1986-08-01

    The uranium hexafluoride (UF 6 ) release of January 4, 1986, at the Sequoyah Fuels Corporation facility has been reviewed by a NRC Lessons-Learned Group. A Model 48Y cylinder containing UF 6 ruptured upon being heated after it was grossly overfilled. The UF 6 released upon rupture of the cylinder reacted with airborne moisture to produce hydrofluoric acid (HF) and uranyl fluoride (UO 2 F 2 ). One individual died from exposure to airborne HF and several others were injured. There were no significant immediate effects from exposure to uranyl fluoride. This supplement report contains NRC's response to the recommendations made in NUREG-1198 by the Lessons Learned Group. In developing a response to each of the recommendations, the staff considered actions that should be taken: (1) for the restart of the Sequoyah Fuels Facility; (2) to make near-term improvement; and (3) to improve the regulatory framework

  14. Thermodynamic properties of a high pressure subcritical UF6He gas volume (irradiated by an external source)

    International Nuclear Information System (INIS)

    Sterritt, D.E.; Lalos, G.T.; Schneider, R.T.

    1976-12-01

    A computer simulation study concerning a compressed fissioning UF 6 gas is presented. The compression is to be achieved by a ballistic piston compressor. Data on UF 6 obtained with this compressor were incorporated in the simulation study. As a neutron source to create the fission events in the compressed gas, a fast burst reactor was considered. The conclusion is that it takes a neutron flux in excess of 10 15 n/cm 2 -s to produce measurable increases in pressure and temperature, while a flux in excess of 10 19 n/cm 2 -s would probably damage the compressor

  15. Scoping study to expedite development of a field deployable and portable instrument for UF6 enrichment assay

    Energy Technology Data Exchange (ETDEWEB)

    Chan, George; Valentine, John D.; Russo, Richard E.

    2017-09-14

    The primary objective of the present study is to identity the most promising, viable technologies that are likely to culminate in an expedited development of the next-generation, field-deployable instrument for providing rapid, accurate, and precise enrichment assay of uranium hexafluoride (UF6). UF6 is typically involved, and is arguably the most important uranium compound, in uranium enrichment processes. As the first line of defense against proliferation, accurate analytical techniques to determine the uranium isotopic distribution in UF6 are critical for materials verification, accounting, and safeguards at enrichment plants. As nuclear fuel cycle technology becomes more prevalent around the world, international nuclear safeguards and interest in UF6 enrichment assay has been growing. At present, laboratory-based mass spectrometry (MS), which offers the highest attainable analytical accuracy and precision, is the technique of choice for the analysis of stable and long-lived isotopes. Currently, the International Atomic Energy Agency (IAEA) monitors the production of enriched UF6 at declared facilities by collecting a small amount (between 1 to 10 g) of gaseous UF6 into a sample bottle, which is then shipped under chain of custody to a central laboratory (IAEA’s Nuclear Materials Analysis Laboratory) for high-precision isotopic assay by MS. The logistics are cumbersome and new shipping regulations are making it more difficult to transport UF6. Furthermore, the analysis is costly, and results are not available for some time after sample collection. Hence, the IAEA is challenged to develop effective safeguards approaches at enrichment plants. In-field isotopic analysis of UF6 has the potential to substantially reduce the time, logistics and expense of sample handling. However, current laboratory-based MS techniques require too much infrastructure and operator expertise for field deployment and operation. As outlined in the IAEA Department of Safeguards Long

  16. Heat transfer characteristics of UF6 in a container heated from outer surface. Pt. 1. Thermal hydraulic analysis method taking account of phase change and volume expansion

    International Nuclear Information System (INIS)

    Wataru, Masumi; Gomi, Yoshio; Yamakawa, Hidetsugu; Tsumune, Daisuke

    1995-01-01

    Natural UF6 is transported in a steel container from foreign countries to the enrichment plant in Japan. If the container meets fire accident, it is heated by fire (800degC) and rupture of the container may occur. For the safety point of view, it is necessary to know whether rupture occurs or not. Because UF6 has a radiological and chemical hazards, it is difficult to perform a demonstration test with UF6. So thermal calculation method has to be developed. The rupture is caused by UF6 gaseous pressure or volume expansion of liquid UF6. To know time history of internal pressure and temperature distribution in the container, it is important to evaluate thermal phenomena of UF6. When UF6 is heated, it changes from solid to liquid or gas at low temperature (64degC) and then its volume expands little by little. In this study, thermal calculation method has been developed taking phase change and thermal expansion of UF6 into account. In the calculation, a two-dimensional model is adopted and natural convection of liquid UF6 is analyzed. As a result of this study, numerical solutions have been obtained taking phase change and volume expansion into account. (author)

  17. Nuclear criticality safety study for increased enrichment limit in 2 1/2-ton (30B) UF6 cylinders

    International Nuclear Information System (INIS)

    Tayloe, R.W. Jr.; Davis, T.C.; Lindenschmidt, D.J.; Fentiman, A.W.

    1992-10-01

    The current U 235 enrichment limit for 30B 2 1/2-ton UF 6 cylinders is 5.0 percent. This feasibility study examined the nuclear criticality safety issues associated with increasing the U 235 enrichment limit in 2 1/2-ton cylinders to 10.0 percent. Operations affected include cylinder cleaning, filling, storage, sampling, and transfer

  18. Uniform deposition of uranium hexafluoride (UF6): Standardized mass deposits and controlled isotopic ratios using a thermal fluorination method.

    Science.gov (United States)

    McNamara, Bruce K; O'Hara, Matthew J; Casella, Andrew M; Carter, Jennifer C; Addleman, R Shane; MacFarlan, Paul J

    2016-07-01

    We report a convenient method for the generation of volatile uranium hexafluoride (UF6) from solid uranium oxides and other U compounds, followed by uniform deposition of low levels of UF6 onto sampling coupons. Under laminar flow conditions, UF6 is shown to interact with surfaces within a fixed reactor geometry to a highly predictable degree. We demonstrate the preparation of U deposits that range between approximately 0.01 and 500ngcm(-2). The data suggest the method can be extended to creating depositions at the sub-picogramcm(-2) level. The isotopic composition of the deposits can be customized by selection of the U source materials and we demonstrate a layering technique whereby two U solids, each with a different isotopic composition, are employed to form successive layers of UF6 on a surface. The result is an ultra-thin deposit that bears an isotopic signature that is a composite of the two U sources. The reported deposition method has direct application to the development of unique analytical standards for nuclear safeguards and forensics. Further, the method allows access to very low atomic or molecular coverages of surfaces. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Measurement of 235U enrichment in UF6 by passive gamma spectrometry

    International Nuclear Information System (INIS)

    Sawai, Hideo; Ochiai, Ken-ichi; Kaya, Akira

    1979-01-01

    For the assay of UF 6 , a single-channel analyzer (SCA) system of a passive gamma spectrometer has been developed. Basic measuring conditions were studied: such as the effects of sample density and heterogeneity and the effects of cylinder material and wall thickness. Called ''enrichment analyzer'', the system is operated to carry out the measurement and calculation of 235 U enrichment by a directive of the program in a calculator. The resulting data are available in real time output. Measurements were carried out in two modes: ''all way'' mode which measured in the rotation of the cylinder and the up-and-down motion of the detector, and ''spot'' mode which measured at one point on the cylinder. The average accuracy was about 1.8% in case of the former, and 3.2% in case of the latter. It was shown that the ''all way'' mode is preferable, but the ''spot'' mode is also necessary for the assay of large cylinders such as 30 A type. (J.P.N.)

  20. Neutron methods for measuring 235U content in UF6 gas

    International Nuclear Information System (INIS)

    Stromswold, D.C.; Peurrung, A.J.; Reeder, P.L.; Pappas, R.A.; Sunberg, D.S.

    1996-10-01

    In the United States and Russia, UF 6 gas streams of highly enriched uranium and lower enrichment uranium am being blended to reduce the stockpile of the highly enriched material. The resultant uranium is no longer useful for weapons, but is suitable as fuel for nuclear reactors. A method to verify the blending of high- and low-enrichment uranium was developed at Pacific Northwest National Laboratory (PNNL) for the U.S. Department of Energy, Office of Research and Development (NN-20). In the United States, blending occurs at the U.S. Department of Energy's Portsmouth Gaseous Diffusion Plant located near Portsmouth, Ohio. In Russia, the blending takes place at Novouralsk. The United States is purchasing the blended product produced in Russia in a program to reduce the availability of enriched uranium that can be used for weapons production. Monitoring the 235 U mass flux of the input stream having the highly enriched uranium will provide confidence that high-enrichment uranium is being consumed in the blending process, and monitoring the output stream will provide an on-line measure of the 235 U in the mixed product. The Portsmouth plant is a potential test facility for non-destructive technology to monitor blending. In addition, monitoring the blending at Portsmouth can support International Atomic Energy Agency activities on controlling and reducing enriched uranium stockpiles

  1. Application of a Kalman filter to UF6 gaseous diffusion plant freezer/sublimer systems

    International Nuclear Information System (INIS)

    Ruppel, F.R.

    1992-03-01

    A signal is required to control the flow of UF 6 in gaseous diffusion plant freezer/sublimer systems. The original strategy envisioned for deriving a flow signal was to take the derivative of the freezer/sublimer weigh cell signal. However, the derivative of the digitized weight signal is noisy, preventing good control. In addition, a bias is introduced into the weight derivative signal because a refrigerant is circulated through a shell-and-tube heat exchanger inside the freezer/sublimer. The weight of the refrigerant is included in the weight measured by the weigh cell. If the circulation rate of the refrigerent is not steady state, a bias exists. Measurements of upstream pressure, vessel pressure, and output to the system control valve are available to the control system. Thus, if the flow through the control valve is characterized properly by the measurements, a Kalman filter can be used in conjunction with these auxiliary inputs and the weigh cell input to overcome the noise and bias problem and provide an improve estimate of flow rate. A discussion of the development and the current status of a Kalman filter used for this application is given. 5 refs

  2. The COMURHEX 2 project. Investing in UF6 long-term security of supply

    International Nuclear Information System (INIS)

    Bouzon, Pierre; Lacombe, Philippe; Durante, Pierre; Teyssier, Patrick

    2008-01-01

    The front-end nuclear fuel supply chain for LWRs encompasses four major industrial stages that are mining and concentration, conversion, enrichment, and eventually fuel fabrication. The different stages involve uranium in different chemical and physical forms. Enrichment of the 235-U fissile isotope requires gaseous UF6. As the standard output of mine is U3O8, referred to as ''yellow cake'', a purely chemical stage is therefore needed to fluorinate U3O8 and turn it into UFe: this is the conversion stage. U3O8 inventories management is thus performed at the conversion sites.Purification of the mining concentrates is also needed prior to actual conversion into UFe. This step is important because the front-end supply chain facilities have strict specifications concerning impurities. The conversion stage may involve intermediary products, namely UO3 and/or UF4, depending on the industrial scheme implemented. With the Comurhex 2 project, AREVA is not only shaping the future of conversion market and contributing to the security of supply of its customers, but it is also developing innovative techniques and reorganizing the conversion process steps. Providing such guaranteed and valuable conversion supply with a brand new plant is our strong commitment to a sustainable nuclear fuel cycle. And AREVA is the first that has launched such a project, looking further ahead. The three main axes of sustainable development, economical, social, and environmental, are truly taken into account in the development of the new project.

  3. Optimalizace organizační struktury

    OpenAIRE

    Marquardt, Petr

    2010-01-01

    Cílem této diplomové práce „Optimalizace organizační struktury“ je analýza organizačního uspořádání společnosti Bosch Rexroth, s. r. o. zaměřená na soulad organizační struktury s firemními procesy a strategickým zaměřením a návrh nové optimální organizační struktury na základě literární analýzy zásad pro vytváření optimálních organizačních struktur. The aim of this diploma thesis “Optimalization of organization structure” is the analysis of the current organization form of the company Bosc...

  4. Technology Assessment for Proof-of-Concept UF6 Cylinder Unique Identification Task 3.1.2 Report – Survey and Assessment of Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Wylie, Joann; Hockert, John

    2014-04-24

    The National Nuclear Security Administration (NNSA) Office of Nonproliferation and International Security’s (NA-24) Next Generation Safeguards Initiative (NGSI) and the nuclear industry have begun to develop approaches to identify and monitor uranium hexafluoride (UF6) cylinders. The NA-24 interest in a global monitoring system for UF6 cylinders relates to its interest in supporting the International Atomic Energy Agency (IAEA) in deterring and detecting diversion of UF6 (e.g., loss of cylinder in transit) and undeclared excess production at conversion and enrichment facilities. The industry interest in a global monitoring system for UF6 cylinders relates to the improvements in operational efficiencies that such a system would provide. This task is part of an effort to survey and assess technologies for a UF6 cylinder to identify candidate technologies for a proof-of-concept demonstration and evaluation for the Cylinder Identification System (CIS).

  5. Direct fissile assay of highly enriched UF6 using random self-interrogation and neutron coincidence response

    International Nuclear Information System (INIS)

    Stewart, J.E.; Menlove, H.O.

    1983-01-01

    A new nondestructive method for direct assay of 235 U mass contained in Model 5A uranium hexafluoride (UF 6 ) product storage cylinders has been successfully tested in the laboratory and under field conditions. The technique employs passive neutron self-interrogation and uses the ratio of coincidences-to-totals counts as a measure of bulk fissile mass. The accuracy of the method is 6.8% (1 sigma) based on field measurements of 44 Model 5A cylinders, 11 of which were either only partially filled or contained reactor return material. The cylinders contained UF 6 with enrichments from 5.96% to 97.6%. Count times were 3 to 6 min depending on 235 U mass. Samples ranged from below 1 kg to over 16 kg of 235 U. Because the method relies primarily on fast neutron self-interrogation, complete sampling of the UF 6 takes place. This feature alleviates inhomogeneity problems and offers increased assurance of the presence of stated amounts of bulk fissile material as compared with current verification methods

  6. Release of UF6 from a ruptured Model 48Y cylinder at Sequoyah Fuels Corporation Facility: lessons-learned report

    International Nuclear Information System (INIS)

    1986-06-01

    The uranium hexafluoride (UF 6 ) release of January 4, 1986, at the Sequoyah Fuels Corporation facility has been reviewed by a NRC Lessons-Learned Group. A Model 48Y cylinder containing UF 6 ruptured upon being heated after it was grossly overfilled. The Uf 6 released upon rupture of the cylinder reacted with airborne moisture to produce hydrofluoric acid (HF) and uranyl fluoride (UO 2 F 2 ). One individual died from exposure to airborne HF and several others were injured. There were no significant immediate effects from exposure to uranyl fluoride. This report of the Lessons-Learned Group presents discussions and recommendations on the process, operation and design of the facility, as well as on the responses of the licensee, NRC, and other local, state and federal agencies to the incident. It also provides recommendations in the areas of NRC licensing and inspection of fuel facility and certain other NMSS licensees. The implementation of some recommendations will depend on decisions to be made regarding the scope of NRC responsibilities with respect to those aspects of the design and operation of such facilities that are not directly related to radiological safety

  7. Characterization of the solid, airborne materials created when UF6 reacts with moist air flowing in single-pass mode

    International Nuclear Information System (INIS)

    Pickrell, P.W.

    1985-10-01

    A series of experiments has been performed in which UF 6 was released into flowing air in order to characterize the solid particulate material produced under non-static conditions. In two of the experiments, the aerosol was allowed to stagnate in a static chamber after release and examined further but in the other experiments characterization was done only on material collected a few seconds after release. Transmission electron microscopy and mass measurement by cascaded impactor were used to characterize the aerosol particles which were usually single spheroids with little agglomeration in evidence. The goal of the work is to determine the chemistry and physics of the UF 6 -atmospheric moisture reaction under a variety of conditions so that information about resulting species and product morphologies is available for containment and removal (knockdown) studies as well as for dispersion plume modeling and toxicology studies. This report completes the milestone for reporting the information obtained from releases of UF 6 into flowing rather than static air. 26 figs., 3 tabs

  8. Viability Study for an Unattended UF6 Cylinder Verification Station: Phase I Final Report

    International Nuclear Information System (INIS)

    Smith, Leon E.; Miller, Karen A.; Garner, James R.; Branney, Sean; McDonald, Benjamin S.; Webster, Jennifer B.; Zalavadia, Mital A.; Todd, Lindsay C.; Kulisek, Jonathan A.; Nordquist, Heather; Deshmukh, Nikhil S.; Stewart, Scott

    2016-01-01

    In recent years, the International Atomic Energy Agency (IAEA) has pursued innovative techniques and an integrated suite of safeguards measures to address the verification challenges posed by the front end of the nuclear fuel cycle. Among the unattended instruments currently being explored by the IAEA is an Unattended Cylinder Verification Station (UCVS) that could provide automated, independent verification of the declared relative enrichment, 235 U mass, total uranium mass and identification for all declared UF 6 cylinders in a facility (e.g., uranium enrichment plants and fuel fabrication plants). Under the auspices of the United States and European Commission Support Programs to the IAEA, a project was undertaken to assess the technical and practical viability of the UCVS concept. The US Support Program team consisted of Pacific Northwest National Laboratory (PNNL, lead), Los Alamos National Laboratory (LANL), Oak Ridge National Laboratory (ORNL) and Savanah River National Laboratory (SRNL). At the core of the viability study is a long-term field trial of a prototype UCVS system at a Westinghouse fuel fabrication facility. A key outcome of the study is a quantitative performance evaluation of two nondestructive assay (NDA) methods being considered for inclusion in a UCVS: Hybrid Enrichment Verification Array (HEVA), and Passive Neutron Enrichment Meter (PNEM). This report provides context for the UCVS concept and the field trial: potential UCVS implementation concepts at an enrichment facility; an overview of UCVS prototype design; field trial objectives and activities. Field trial results and interpretation are presented, with a focus on the performance of PNEM and HEVA for the assay of over 200 ''typical'' Type 30B cylinders, and the viability of an ''NDA Fingerprint'' concept as a high-fidelity means to periodically verify that the contents of a given cylinder are consistent with previous scans. A modeling study

  9. Emergency preparedness and response in case of a fire accident with (UF6) packages tracking Suez Canal

    International Nuclear Information System (INIS)

    Salama, M.

    2004-01-01

    Egypt has a unique problem - the Suez Canal. Radioactive cargo passing regularly through the canal carrying new and spent reactor fuel. Moreover there are also about 1000 metric tons of uranium hexaflouride (UF6) passing through the canal every year. In spite of all precautions taken in the transportation, accidents with packages containing (UF 6 ) and shipped through the Suez Canal, accidents may arise even though the probability is minimal. These accidents, may be accompanied by injuries or death of persons and damage to property. Due to the radiation and criticality hazards of (UF 6 ) and its high risk of chemical toxicity. The probability of a fire accident with a cargo carrying (UF 6 ) during its crossing the Suez Canal can cause serious chemical toxic and radiological hazards, particularly if the accident occurred close or near to one of the three densely populated cities (Port-Said, Ismailia, and Suez), which are located along the Suez Canal, west bank. The government of Egypt has elaborated a national radiological emergency plan inorder to face probable radiological accidents, which may be arised inside the country. Arrangements have been also elaborated for the medical care of any persons who, might be injured or contaminated, or who, have been exposed to severe radiation doses. The motivation of the present paper was undertaken to visualize a fire accident scenario occurring in industrial packages containing UF6 on board of a Cargo crossing the Suez Canal near Port-Said City. The accident scenario and emergency response actions taken during the different phases of the accident are going to be presented and discussed. The proposed emergency response actions taken to face the accident are going to be also presented. The work presented had revealed the importance of public awareness will be needed for populations located in densely populated areas along Suez Canal bank inorder to react timely and effectively to avoid the toxic and radiological hazards

  10. Laboratory and pilot-plant studies on the conversion of uranyl nitrate hexahydrate to UF6 by fluidized-bed processes

    International Nuclear Information System (INIS)

    Youngblood, E.L.; Urza, I.J.; Cathers, G.I.

    1977-06-01

    This report describes laboratory and pilot-plant studies on the conversion of uranyl nitrate hexahydrate (UNH) to UF 6 and on purification of the UF 6 . Experimental laboratory studies on the removal of residual nitrate from uranium trioxide (UO 3 ) calcine and the fluorination of technetium and subsequent sorption on MgF 2 were conducted to support the pilot-plant work. Two engineering-scale pilot plants utilizing fluidized-bed processes were constructed for equipment and process testing of the calcination of UNH to UO 3 and the direct fluorination of UO 3 to UF 6

  11. Rupture of Model 48Y UF6 cylinder and release of uranium hexafluoride, Sequoyah Fuels Facility, Gore, Oklahoma, January 4, 1986. Volume 1

    International Nuclear Information System (INIS)

    1986-02-01

    At 11:30 a.m. on January 4, 1986, a Model 48Y UF 6 cylinder filled with uranium hexafluoride (UF 6 ) ruptured while it was being heated in a steam chest at the Sequoyah Fuels Conversion Facility near Gore, Oklahoma. One worker died because he inhaled hydrogen fluoride fumes, a reaction product of UF 6 and airborne moisture. Several other workers were injured by the fumes, but none seriously. Much of the facility complex and some offsite areas to the south were contaminated with hydrogen fluoride and a second reaction product, uranyl fluoride. The interval of release was approximately 40 minutes. The cylinder, which had been overfilled, ruptured while it was being heated because of the expansion of UF 6 as it changed from the solid to the liquid phase. The maximum safe capacity for the cylinder is 27,560 pounds of product. Evidence indicates that it was filled with an amount exceeding this limit. 18 figs

  12. An optimized device for UF6 laser isotopic photochemistry using an optical parametric oscillator and a down converter

    International Nuclear Information System (INIS)

    Kupecek, P.; Weulersse, J.M.; Isnard, P.; Alexandre, M.; Clerc, M.

    1983-01-01

    We developped a tunable coherent source near 16 μm for selective photochemistry studies on UF 6 . The device uses a YAG:Nd 3+ pumped lithium niobate optical parametric oscillator coupled with a cadmium selenide frequency down converter. The components and physical parameters have been optimized leading to an overall optical conversion efficiency of about 6.10 -3 , that is a quantum yield of 0.1. The main characteristics such as beam quality and spectral width have been measured, the last one beeing 60 mK at 16 μm, for 1.5mJ pulses [fr

  13. Extremely low temperature behaviour of the thermodynamical properties of gaseous UF6 under an exact quantum approach

    International Nuclear Information System (INIS)

    Amarante, J.A.A. do.

    1979-10-01

    The thermodynamic functions of molecules of type XF 6 are calculated under an exact quantum-mechanical approach, which also yields general expressions valid for other types of molecules. The formalism is used to analyse the behavior of gaseous UF 6 at very low temperatures (around and below 1 0 K), where symmetry effects due to Pauli principle lead to results which are very markedly different from those obtained with the semi-classical approximation. It is shown that this approximation becomes sufficiently accurate only for temperatures about ten times the rotational temperature. (Author) [pt

  14. Progress in the dry route conversion process of UF-6 to UO-2: new equipment and theoretical approach

    International Nuclear Information System (INIS)

    Perrais, C.; Ablitzer, C.

    1999-01-01

    The dry route conversion process of UF 6 to UO 2 is used on a large scale to produce powder for UO 2 fuel pellets. However, this powder is not very suitable for other kinds of fuels, such as for instance, Mixed Oxide (Mox) fuel. Thus, CEA and COGEMA have developed a programme to study and model the process in order to identify the parameters which lead to a better quality powder. For this purpose, specific equipment was built at the CEA/Cadarache. The first results of experiments and modelling have shown parameters which clearly modify the powder quality. (authors)

  15. An Operator Perspective from a Facility Evaluation of an RFID-Based UF6 Cylinder Accounting and Tracking System

    International Nuclear Information System (INIS)

    Martyn, Rose; Fitzgerald, Peter; Stehle, Nicholas D.; Rowe, Nathan C.; Younkin, James R.

    2011-01-01

    An operational field test of a Radio-Frequency Identification (RFID) system for tracking and accounting UF6 cylinders was conducted at the Global Nuclear Fuel Americas (GNF) fuel fabrication plant in 2009. The Cylinder Accountability and Tracking System (CATS) was designed and deployed by Oak Ridge National Laboratory (ORNL) and evaluated in cooperation with GNF. The system required that passive RFID be attached to several UF6 30B cylinders as they were received at the site; then the cylinders were tracked as they proceeded to interim storage, to processing in an autoclave, and eventually to disposition from the site. This CATS deployment also provided a direct integration of scale data from the site accountability scales. The integration of this information into the tracking data provided an attribute for additional safeguards for evaluation. The field test provided insight into the advantages and challenges of using RFID at an operating nuclear facility. The RFID system allowed operators to interact with the technology and demonstrated the survivability of the tags and reader equipment in the process environment. This paper will provide the operator perspective on utilizing RFID technology for locating cylinders within the facility, thereby tracking the cylinders for process and for Material Control and Accounting functions. The paper also will present the operator viewpoint on RFID implemented as an independent safeguards system.

  16. Load-cell-based weighing system for weighing 9.1- and 12.7-tonne UF6 cylinders

    International Nuclear Information System (INIS)

    McAuley, W.A.; Kane, W.R.

    1986-01-01

    For the independent verification of UF 6 cylinder masses by the International Atomic Energy Agency (IAEA) at uranium enrichment facilities, an 18-tonne capacity Load-Cell-Based Weighing System (LCBWS) has been developed. The system was developed at Brookhaven National Laboratory and the Oak Ridge Gaseous Diffusion Plant and calibrated at the US National Bureau of Standards. The principal components of the LCBWS are two load cells, with readout and ancillary equipment, and a lifting fixture that couples the load cells to a cylinder. Initial experience with the system demonstrates that it has the advantages of transportability, ease of application, stability, and an attainable accuracy of 2 kg or better for a full cylinder

  17. Standard test method for determination of bromine and chlorine in UF6 and uranyl nitrate by X-Ray fluorescence (XRF) spectroscopy

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2001-01-01

    1.1 This method covers the determination of bromine (Br) and chlorine (Cl) in uranium hexafluoride (UF6) and uranyl nitrate solution. The method as written covers the determination of bromine in UF6 over the concentration range of 0.2 to 8 μg/g, uranium basis. The chlorine in UF6 can be determined over the range of 4 to 160 μg/g, uranium basis. Higher concentrations may be covered by appropriate dilutions. The detection limit for Br is 0.2 μg/g uranium basis and for Cl is 4 μg/g uranium basis. 1.2 This standard may involve hazardous materials, operations and equipment. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  18. Estimation of time to rupture in a fire using 6FIRE, a lumped parameter UF6 cylinder transient heat transfer/stress analysis model

    International Nuclear Information System (INIS)

    Williams, W.R.; Anderson, J.C.

    1995-01-01

    The transportation of UF 6 is subject to regulations requiring the evaluation of packaging under a sequence of hypothetical accident conditions including exposure to a 30-min 800 degree C (1475 degree F) fire [10 CFR 71.73(c)(3)]. An issue of continuing interest is whether bare cylinders can withstand such a fire without rupturing. To address this issue, a lumped parameter heat transfer/stress analysis model (6FIRE) has been developed to simulate heating to the point of rupture of a cylinder containing UF 6 when it is exposed to a fire. The model is described, then estimates of time to rupture are presented for various cylinder types, fire temperatures, and fill conditions. An assessment of the quantity of UF 6 released from containment after rupture is also presented. Further documentation of the model is referenced

  19. Monitoring the mass of UF6 gas and uranium deposits in aluminium pipes using X-ray fluorescence and X-ray transmission gauges

    International Nuclear Information System (INIS)

    Packer, T.W.; Smith, S.M.

    1984-12-01

    In order to determine the enrichment of UF 6 gas in centrifuge plant pipework it is necessary to measure the mass of the gas (pressure) and the mass per unit area of any uranium deposited on the pipe. This paper shows that it is possible to determine the pressure of the UF 6 gas in pipes 120 mm in diameter using an energy-dispersive X-ray fluorescence spectrometer. Results are also given of transmission measurements made using a low power X-ray generator operated at two different applied voltages. A method of using the two measurements to determine the mass per unit area of deposited uranium is described. (author)

  20. Qualification for Safeguards Purposes of UF6 Sampling using Alumina – Results of the Evaluation Campaign of ABACC-Cristallini Method

    OpenAIRE

    ESTAEBAN ADOLFO; GAUTIER EDUARDO; MACHADO DA SILVA LUIS; FERNANDEZ MORENO SONIA; RENHA JR GERALDO; DIAS FABIO; PEREIRA DE OLIVEIRA JUNIOR OLIVIO; AMMARAGGI DAVID; MASON PETER; SORIANO MICHAEL; CROATTO PAUL; ZULEGER EVELYN; GIAQUINTO JOSEPH; HEXEL COLE; VERCOUTER THOMAS

    2017-01-01

    The procedure currently used to sample material from process lines in uranium enrichment plants consists of collecting the uranium hexafluoride (UF6) in gaseous phase by desublimation inside a metal sampling cylinder cooled with liquid nitrogen or in certain facilities in a fluorothene P-10 tube type. The ABACC-Cristallini method (A-C method) has been proposed to collect the UF6 (gas) by adsorption in alumina (Al2O3) in the form of uranyl fluoride (UO2F2) (solid). This method uses a fluor...

  1. HGSYSTEM/UF6 model enhancements for plume rise and dispersion around buildings, lift-off of buoyant plumes, and robustness of numerical solver

    International Nuclear Information System (INIS)

    Hanna, S.R.; Chang, J.C.

    1997-01-01

    The HGSYSTEM/UF 6 model was developed for use in preparing Safety Analysis Reports (SARs) by estimating the consequences of possible accidental releases of UF 6 to the atmosphere at the gaseous diffusion plants (GDPs) located in Portsmouth, Ohio, and Paducah, Kentucky. Although the latter report carries a 1996 date, the work that is described was completed in late 1994. When that report was written, the primary release scenarios of interest were thought to be gas pipeline and liquid tank ruptures over open terrain away from the influence of buildings. However, upon further analysis of possible release scenarios, the developers of the SARs decided it was necessary to also consider accidental releases within buildings. Consequently, during the fall and winter of 1995-96, modules were added to HGSYSTEM/UF 6 to account for flow and dispersion around buildings. The original HGSYSTEM/UF 6 model also contained a preliminary method for accounting for the possible lift-off of ground-based buoyant plumes. An improved model and a new set of wind tunnel data for buoyant plumes trapped in building recirculation cavities have become available that appear to be useful for revising the lift-off algorithm and modifying it for use in recirculation cavities. This improved lift-off model has been incorporated in the updated modules for dispersion around buildings

  2. RESULTS FROM A DEMONSTRATION OF RF-BASED UF6 CYLINDER ACCOUNTING AND TRACKING SYSTEM INSTALLED AT A USEC FACILITY

    Energy Technology Data Exchange (ETDEWEB)

    Pickett, Chris A [ORNL; Kovacic, Donald N [ORNL; Morgan, Jim [Innovative Solutions; Younkin, James R [ORNL; Carrick, Bernie [USEC, Inc.; Ken, Whittle [USEC, Inc.; Johns, R E [Pacific Northwest National Laboratory (PNNL)

    2008-09-01

    Approved industry-standard cylinders are used globally for storing and transporting uranium hexafluoride (UF{sub 6}) at uranium enrichment plants and processing facilities. To verify that no diversion or undeclared production of nuclear material involving UF{sub 6} cylinders at the facility has occurred, the International Atomic Energy Agency (IAEA) conducts periodic, labor-intensive physical inspections to validate facility records, cylinder identities, and cylinder weights. A reliable cylinder monitoring system that would improve overall inspector effectiveness would be a significant improvement to the current international safeguards inspection regime. Such a system could include real-time unattended monitoring of cylinder movements, situation-specific rules-based event detection algorithms, and the capability to integrate with other types of safeguards technologies. This type of system could provide timely detection of abnormal operational activities that may be used to ensure more appropriate and efficient responses by the IAEA. A system of this type can reduce the reliance on paper records and have the additional benefit of facilitating domestic safeguards at the facilities at which it is installed. A radio-frequency (RF)-based system designed to track uranium hexafluoride (UF{sub 6}) cylinders during processing operations was designed, assembled, and tested at the United States Enrichment Corporation (USEC) facility in Portsmouth, Ohio, to determine the operational feasibility and durability of RF technology. The overall objective of the effort was to validate the robustness of RF technology for potential use as a future international safeguards tool for tracking UF6 cylinders at uranium-processing facilities. The results to date indicate that RF tags represent a feasible technique for tracking UF{sub 6} cylinders in operating facilities. Additional work will be needed to improve the operational robustness of the tags for repeated autoclave processing and to

  3. Washing water treatment process for UF6 cylinder by adjusting evaporation technology in a low temperature and low pressure

    International Nuclear Information System (INIS)

    Kim, Ki-tae; Ju, Young-jong; Cho, Nam-chan; Kim, Yun-kwan; Jin, Chang-suk

    2016-01-01

    The liquid waste is treated in this procedure; 1) Add NaOH to the liquid waste and filter the mixture with a screen. 2) Screened residue is dried and then stored in a uranium storage. 3) liquid part is moved to a storage tank and radioactivity is measured in the liquid. 5) If the concentration of radioactivity is lower than corresponding regulation limit, the liquid moved to a reaction tank and evaporated with additional low concentration HF in 105℃. 6) Radioactivity of distillate is measured and the value is lower than regulation, it is treated with a thermal decomposition process and discharged to the atmosphere in gas state. 7) Solid waste produced in the evaporation step is managed as solid nuclear waste. The treatment procedure mentioned above has disadvantageous points, producing large amount of solid waste as well as, high energy and chemical consumption. In this study, liquid waste from a real scaled cylinder wash process is applied to evaporation system to confirm feasibility of the application of evaporation and, to reduce waste production and energy consumption. Liquid radioactive wastewater from a real scaled UF6 cylinder wash process was applied to evaporation treatment system. Radioactive concentration in gross alpha was removed 99.9% in the evaporation system. And the concentration in distillate was lower than the discharge regulation. Removal of U-235 was 99.9% in the process. And 15 other kinds of radionuclides in the raw wastewater were removed completely. Secondary waste production of the evaporation system is 15g/L

  4. Analysis of risk and dose when using thermal protection on non-fissile and fissile-excepted UF6 48-inch cylinder packages

    International Nuclear Information System (INIS)

    Chambers, D.B.; Lowe, L.M.; Elizabeth Darrough, M.; Jones, R.H.

    2004-01-01

    An industry consortium of owners of large (i.e., the 48-inch or 48X and 48Y) cylinders commissioned an independent study to evaluate the safety of using thermal protective covers on the cylinders and the likelihood that the cylinders would experience the regulations' hypothetical thermal accident. The study examined the demonstrable risks of the protective covers, i.e., increased dose to workers and the potential for accidents associated with the extra handling, vs. the theoretical risk of the UF 6 cylinders' encountering the hypothetical fire, to evaluate the appropriateness of using the thermal protective covers

  5. Correlation of radioactive waste treatment costs and the environmental impact of waste effluents in the nuclear fuel cycle: conversion of recycle uranium to UF6

    International Nuclear Information System (INIS)

    Roddy, J.W.; Blanco, R.E.; Finney, B.C.; Hill, G.S.; Moore, R.E.; Witherspoon, J.P.

    1977-04-01

    A cost/benefit study was made to determine the cost and effectiveness of various radioactive waste (radwaste) treatment systems for decreasing the amount of radioactive materials released from a model recycle uranium conversion and uranium hexafluoride (UF 6 ) production plant and to determine the radiological impact (dose commitment) of the released radioactive materials on the environment. This study is designed to assist the US NRC in defining the term ''as low as reasonably achievable'' as it applies to these nuclear facilities. The base case model plant is representative of a licensable UF 6 production plant and has an annual capacity of 1500 metric tons of uranium. Additional radwaste treatment systems are added to the base case plant in a series of case studies to decrease the amounts of radioactive materials released and to reduce the radiological dose commitment to the population in the surrounding area. The cost for the added waste treatment operations and the corresponding dose commitments is calculated for each case. In the final analysis, radiological dose is plotted vs the annual cost for treatment of the radwastes. The status of the radwaste treatment methods used in the case studies is discussed. The methodology used in estimating the costs is presented

  6. Evaluation of natural radionuclide occurrence (Rn-222) in a nuclear facility that processes UF6 for the UO2 powder and pellet productions

    International Nuclear Information System (INIS)

    Mouco, Charles Dickens do Carmo Lacerda; Matta, Luiz Ernesto Santos Carvalho

    2001-01-01

    This paper presents the early data from the concentration evaluation of Rn-222 in a nuclear facility that processes UF 6 for the UO 2 powder and tablet productions. Measurements were accomplished in the same points and under the same climatic conditions with the factory working and not working. The results showed that no significant alteration was detected in the obtained values in both situations. The average value was 15 and 18 Bq/m3 for operating and not operating respectively. There is no significant difference between data. The concentrations values of Rn-222 are lower than the internationally established limits for this radionuclide. The Rn-222 concentration values obtained, are probably originated from the building material, and the Rn-222 concentration levels are due to the great air exchange inside the factory. (author)

  7. Cost-effectiveness of safety measures to reduce public risk associated with the transportation of UF6 by truck and trains

    International Nuclear Information System (INIS)

    Hubert, Philippe; Pages, Pierre

    1989-01-01

    The present case study deals with the problem of uranium hexafluoride transportation by truck and train. It consists of a probabilistic risk assessment of the potential hazards to the public that can arise from the traffic that will take place in France in 1990. The specificity of UF 6 is that it presents both chemical and radiological hazards. But, whatever the transported material, road traffic entails a risk of its own. Thus three kinds of risks are assessed for natural, depleted and enriched uranium hexafluoride. These assessments are the basis of a cost-effectiveness analysis which deals with such safety measures as using a protective overpack, avoiding populated areas and escorting the trucks

  8. Thermal reactions of uranium metal, UO 2, U 3O 8, UF 4, and UO 2F 2 with NF 3 to produce UF 6

    Science.gov (United States)

    McNamara, Bruce; Scheele, Randall; Kozelisky, Anne; Edwards, Matthew

    2009-11-01

    This paper demonstrates that NF 3 fluorinates uranium metal, UO 2, UF 4, UO 3, U 3O 8, and UO 2F 2·2H 2O to produce the volatile UF 6 at temperatures between 100 and 550 °C. Thermogravimetric and differential thermal analysis reaction profiles are described that reflect changes in the uranium fluorination/oxidation state, physiochemical effects, and instances of discrete chemical speciation. Large differences in the onset temperatures for each system investigated implicate changes in mode of the NF 3 gas-solid surface interaction. These studies also demonstrate that NF 3 is a potential replacement fluorinating agent in the existing nuclear fuel cycle and in actinide volatility reprocessing.

  9. Semiportable load-cell-based weighing system prototype of 18.14-metric-ton (20-ton) capacity for UF6 cylinder weight verifications: description and testing procedure

    International Nuclear Information System (INIS)

    McAuley, W.A.

    1984-01-01

    The 18.14-metric-ton-capacity (20-ton) Load-Cell-Based Weighing System (LCBWS) prototype tested at the Oak Ridge (Tennessee) Gaseous Diffusion Plant March 20-30, 1984, is semiportable and has the potential for being highly accurate. Designed by Brookhaven National Laboratory, it can be moved to cylinders for weighing as opposed to the widely used operating philosophy of most enrichment facilities of moving cylinders to stationary accountability scales. Composed mainly of commercially available, off-the-shelf hardware, the system's principal elements are two load cells that sense the weight (i.e., force) of a uranium hexafluoride (UF 6 ) cylinder suspended from the LCBWS while the cylinder is in the process of being weighed. Portability is achieved by its attachment to a double-hook, overhead-bridge crane. The LCBWS prototype is designed to weigh 9.07- and 12.70-metric ton (10- and 14-ton) UF 6 cylinders. A detailed description of the LCBWS is given, design information and criteria are supplied, a testing procedure is outlined, and initial test results are reported. A major objective of the testing is to determine the reliability and accuracy of the system. Other testing objectives include the identification of (1) potential areas for system improvements and (2) procedural modifications that will reflect an improved and more efficient system. The testing procedure described includes, but is not limited to, methods that account for temperature sensitivity of the instrumentation, the local variation in the acceleration due to gravity, and buoyance effects. Operational and safety considerations are noted. A preliminary evaluation of the March test data indicates that the LCBWS prototype has the potential to have an accuracy in the vicinity of 1 kg

  10. Correlation study among the International Atomic Energy Agency standards and market standards on management system applicable to a UF6 conversion plant operation

    International Nuclear Information System (INIS)

    Oliveira, Dirceu Paulo de

    2008-01-01

    The Agency - International Atomic Energy Agency (IAEA), following the market trend of the management system integration, has decided to revise the quality assurance standards - IAEA 50-C/SG-Q publishing, in 2006, the standard on Management System (MS). IAEA GS-R-3 and its IAEA GS-G-3.1 guide. Also, the IAEA is about to publish a supplementary guide - IAEA DS349, which consider the integration of several functions involved in management of nuclear facilities, such as: safety, health, environmental and quality, ensuring that nuclear safety is not compromised. Conversion plants of 'Yellowcake' in UF 6 use and process radioactive materials, as well as other substances normally found in the chemical conventional industry, inserting themselves in the organization profile that require a high pattern of definition, implementation and continuous improvement of their MS and, therefore, should consider an approach of management integrated system (MIS). Taking a UF 6 conversion plant as focus, the correlation was performed among the Agency MS standards and those of the market - ISO 9001, ISO 14001 and OHSAS 18001, as well as with the Agency drafts standards on safety (DS316 and DS344), concluding that, in structuring an MIS, in compliance with the Agency MS standards, except for some adjustments, the ISO 9001, ISO 14001, and OHSAS 18001 are going to be met. On the other hand, the structuring of MIS should identify other requirements on safety, health and environmental, which also consider the conventional chemical and industrial characteristics that are out of the scope (ionizing radiation) of the safety standards of the Agency. The research proposes a documental procedure for a MIS applicable to this plant, providing elements for rationalization and contents of the identified documentation, for the promotion of the integration of the considered MS functions. (author)

  11. Assessment of the Public Health impact from the accidental release of UF6 at the Sequoyah Fuels Corporation Facility at Gore, Oklahoma (Docket No. 40-8027). Volume 2

    International Nuclear Information System (INIS)

    1986-03-01

    Following the accidental release of UF 6 from the Sequoyah Fuels Facility on January 4, 1986, an Ad Hoc Interagency Public Health Assessment Task Force was established. The Task Force consists of technical staff members from various agencies who have prepared this assessment of the public health impact associated with the accidental release. Volume 2 of the report contains Appendices which provide more detailed information used in the assessment and support the discussion in Volume 1

  12. Surface decontamination in the old storage shed number 99 of the General Plan of IPEN/CNEN-SP, containing production equipment of natural uranium hexafluoride (UF6), aiming at its decommissioning

    International Nuclear Information System (INIS)

    Almeida, Claudio C. de; Cambises, Paulo B.S.; Paiva, Julio E. de; Paiva, Julio E. de; Silva, Teresina M.; Rodrigues, Demerval L.

    2013-01-01

    This paper presents the steps adopted in the operation planned for the decontamination of surfaces in the old storage shed number 99 the general layout of the Energy Research and Nuclear IPEN-CNEN/SP, Brazil, and contained various types of equipment originating from production hexafluoride natural uranium (UF6). This operation involved the planning, training of operators of the facility, analysis of workplaces and radiometric surveys for monitoring of external radiation and surface contamination. The training involved the procedures for decontamination of surfaces, segregation of materials and practical procedures for individual monitoring of contamination outside of the body. Were also established rules for the transport of radioactive materials in the internal and external facility and release of material and sites already decontaminated

  13. Assessment of the public health impact from the accidental release of UF6 at the Sequoyah Fuels Corporation Facility at Gore, Oklahoma (Docket No. 40-8027, License No. SUB-1010). Main report. Volume 1

    International Nuclear Information System (INIS)

    1986-03-01

    Following the accidental release of UF 6 from the Sequoyah Fuels Facility on January 4, 1986, an Ad Hoc Interagency Public Health Assessment Task Force was established. The Task Force consists of technical staff members from various agencies who have prepared this assessment of the public health impact associated with the accidental release. The assessment consists of two volumes and is based on data from the accident available as of February 14, 1986. Volume 1 of the report describes the effects from the intake of uranium and fluoride and summarizes the findings and recommendations of the Task Force. Volume 2 of the report contains Appendices which provide more detailed information used in the assessment and support the discussion in Volume 1. 57 refs., 26 figs., 12 tabs

  14. Assessment of UF6 Equation of State

    Energy Technology Data Exchange (ETDEWEB)

    Brady, P; Chand, K; Warren, D; Vandersall, J

    2009-02-11

    A common assumption in the mathematical analysis of flows of compressible fluids is to treat the fluid as a perfect gas. This is an approximation, as no real fluid obeys the perfect gas relationships over all temperature and pressure conditions. An assessment of the validity of treating the UF{sub 6} gas flow field within a gas centrifuge with perfect gas relationships has been conducted. The definition of a perfect gas is commonly stated in two parts: (1) the gas obeys the thermal equation of state, p = {rho}RT (thermally perfect), and, (2) the gas specific heats are constant (calorically perfect). Analysis indicates the thermally perfect assumption is valid for all flow conditions within the gas centrifuge, including shock fields. The low operating gas pressure is the primary factor in the suitability of the thermally perfect equation of state for gas centrifuge computations. UF{sub 6} is not calorically perfect, as the specific heats vary as a function of temperature. This effect is insignificant within the bulk of the centrifuge gas field, as gas temperatures vary over a narrow range. The exception is in the vicinity of shock fields, where temperature, pressure, and density gradients are large, and the variation of specific heats with temperature should be included in the technically detailed analyses. Results from a normal shock analysis incorporating variable specific heats is included herein, presented in the conventional form of shock parameters as a function of inlet Mach Number. The error introduced by assuming constant specific heats is small for a nominal UF{sub 6} shock field, such that calorically perfect shock relationships can be used for scaling and initial analyses. The more rigorous imperfect gas analysis should be used for detailed analyses.

  15. Przyczynek do postrzegania struktury współczesnego systemu rachunkowości

    Directory of Open Access Journals (Sweden)

    Irena Sobańska

    2018-03-01

    Full Text Available Głównym celem artykułu jest objaśnienie procesu ewoluowania elementów systemu rachunkowości organizacji gospodarczej pod wpływem zmian zachodzących w różnicach informacji oczekiwanych przez odbiorców wewnętrznych i zewnętrznych. Dla zrealizowania tego celu przedstawiono zamęt regu- lacyjny w obszarze rachunkowości i jego skutki dla rozwoju systemów rachunkowości w praktyce w Polsce oraz przeanalizowano zmiany w potrzebach informacyjnych interesariuszy w kontekście wprowadzanych zmian w sprawozdaniach finansowych, zintegrowanych raportach biznesowych i zmian w stosowanych metodach rachunkowości zarządczej w organizacjach społecznie odpowiedzialnych. Następnie przedsta- wiona została autorska propozycja nowej struktury systemu rachunkowości odpowiadająca jego współczesnej funkcjonalności w warunkach obecnego poziomu rozwoju globalizacji, zmierzającego w kierun- ku zrównoważonej gospodarki oraz szereg wniosków ogólnych wynikających z przedstawionych rozwa- żań. W propozycji nowej struktury przyjęto, że system rachunkowości organizacji społecznie odpowie- dzialnej powinien być zbudowany z podsystemu rachunkowości biznesowej, emitującego zintegrowany raport biznesowy (sprawozdanie finansowe + raporty niefinansowe i wewnętrzne raporty dla zarządu oraz podsystemu rachunkowości podatkowej, emitującego informacje dla agend podatkowych. W opra- cowaniu artykułu zastosowano analizę treści i opinii autorów wybranych publikacji, metodę analizy dokumentów oraz wiedzę uzyskaną metodą obserwacji bezpośredniej i wyniki badań empirycznych innych autorów. The main goal of the article is to explain the process of evolution of the organization's accounting system elements as a result of changes taking place in information expected by internal and external users. To achieve this goal, regulatory uncertainties in the area of accounting and their consequences for the devel- opment of accounting systems in

  16. Struktury, historia i praxis. O sporze Sartre’a z Levi-Straussem z dzisiejszej perspektywy

    Directory of Open Access Journals (Sweden)

    Małgorzata Kowalska

    2016-12-01

    Full Text Available W artykule zostaje przypomniany historyczny spór między Sartrem i Lévi-Straussem dotyczący rozumienia dialektyki (relacji między rozumem dialektycznym i rozumem analitycznym, który był zarazem sporem o pojęcia historii i struktury, status świadomej podmiotowości i rolę swobodnego działania, „sporem o człowieka” i sposób uprawiania antropologii, w tym o stosunek filozofii do nauki/nauk empirycznych. Zamiast prostego przeciwstawienia stanowisk Sartre’a i Lévi-Straussa autorka stara się wydobyć dość złożoną, dialektyczną grę między nimi, podkreślając jednak ich ostateczną opozycyjność, którą wiąże z nieusuwalnym napięciem między biegunami całej nowoczesnej filozofii i kultury, przede wszystkim biegunami subiektywizmu i obiektywizmu. To napięcie ujawnia się w różnych sposobach pojmowania i badania człowieka w ogóle (jako przede wszystkim podmiotu i projektu lub, przeciwnie, przedmiotu i uwarunkowanego elementu znacznie szerszego uniwersum, ale także w relacji między kulturą i naturą oraz – wreszcie – relacji między różnymi kulturami. Celem artykułu jest nie tylko rekonstrukcja historycznego sporu, ale również jego aktualizacja, tj. odniesienie go do całkowicie współczesnych dyskusji o charakterze teoretycznym i praktycznym, moralno-politycznym, dotyczących takich zagadnień jak status umysłu i świadomości, a także kwestii ekologicznych i pytań o możliwe i pożądane relacje między światem zachodu oraz innymi kulturami. W świetle artykułu napięcie między stanowiskami à la Sartre i à la Lévi-Strauss jawi się we współczesnych dyskusjach jako obecne i żywe.

  17. UF6 overfilling prevention at Eurodif production Georges Besse plant

    Energy Technology Data Exchange (ETDEWEB)

    Reneaud, J.M. [Eurodif Production, Pierrelatte (France)

    1991-12-31

    Risk of overfilling exists on different equipments of Georges BESSE Plant: cylinders, desublimers and intermediate tanks. The preventive measures are composed of technical devices: desublimers weighing, load monitoring alarms, automatic controls ... and procedures, training, safety organization. In thirteen years of operation, some incidents have occurred but none of them has caused any personal injuries. They are related and discussed. The main factors involved in the Sequoyah fuel facility accident on 1/4/1986 have been analyzed and taken into account.

  18. Testing and evaluation of used UF6 shipping packages

    International Nuclear Information System (INIS)

    Barlow, C.R.; Ziehlke, K.T.; Pryor, W.A.; Housholder, W.R.

    1986-01-01

    Damage to shipping packages and their components, whether due to normal environmental exposure or because of unforeseen accidents, requires occasional reevaluation and requalification to assure the suitability of the packages for continued service. Pressure tests have been conducted on used 30B cylinders that were involved in a warehouse fire to assess the possible damaging effects of the exposure. Deteriorated and mechanically damaged overpacks which had absorbed large quantities of water in service were subjected to drying tests, foam properties were evaluated, and a rehabilitation procedure was developed to allow return of such packages to service. Protective shipping packages show deterioration with extended service, principally structural damage from rough handling and rust damage from exposure to weather and from storage practices which may promote absorption of water by the insulating foam. The structural and thermal properties of the phenolic foam insulation from used shipping packages were found to be not adversely affected by absorbed water, and they were not degraded by the drying process. In order to slow or avoid continuing rust damage in renovated packages, however, a process was developed for drying the foam in commercial facilities prior to restoration work on used or damaged containers. Two 2-1/2-ton steel transport cylinders, type 30B, were involved in a warehouse fire where portions of the cylinders were estimated to have reached a temperature of 1600 0 F. The cylinders were empty at the time of the fire and thus were not in the protective packages in which full product cylinders are handled while in transit. Hydrostatic burst tests showed that the integrity of the cylinders was not degraded by the fire exposure. They withstood test pressures in excess of 10 times the design pressure, and showed a volume expansion of 30% above the original capacity before rupturing in a completely ductile fashion

  19. pVT-Second Virial Coefficients B(T ), Viscosity η(T ), and Self-Diffusion ρD(T) of the Gases: BF3, CF4, SiF4, CCl4, SiCl4, SF6, MoF6, WF6, UF6, C(CH3)4, and Si(CH3)4 Determined by Means of an Isotropic Temperature-Dependent Potential

    Science.gov (United States)

    Zarkova, L.; Hohm, U.

    2002-03-01

    We present results on self-consistent calculations of second pVT-virial coefficients B(T), viscosity data η(T), and diffusion coefficients ρD(T) for eleven heavy globular gases: boron trifluoride (BF3), carbon tetrafluoride (CF4), silicon tetrafluoride (SiF4), carbon tetrachloride (CCl4), silicon tetrachloride (SiCl4), sulfur hexafluoride (SF6), molybdenum hexafluoride (MoF6), tungsten hexafluoride (WF6), uranium hexafluoride (UF6), tetramethyl methane (C(CH3)4, TMM), and tetramethyl silane (Si(CH3)4, TMS). The calculations are performed mainly in the temperature range between 200 and 900 K by means of isotropic n-6 potentials with temperature-dependent separation rm(T) and potential well depth ɛ(T). The potential parameters at T=0 K (ɛ, rm, n) and the enlargement of the first level radii δ are obtained solving an ill-posed problem of minimizing the squared deviations between experimental and calculated values normalized to their relative experimental error. The temperature dependence of the potential is obtained as a result of the influence of vibrational excitation on binary interactions. This concept of the isotropic temperature-dependent potential (ITDP) is presented in detail where gaseous SF6 will serve as an example. The ITDP is subsequently applied to all other gases. This approach and the main part of the results presented here have already been published during 1996-2000. However, in some cases the data are upgraded due to the recently improved software (CF4, SF6) and newly found experimental data (CF4, SiF4, CCl4, SF6).

  20. Model Podejmowania Decyzji w Oparciu o Wartości Służący Ocenie Wariantów Systemu Monitorowania Stanu Technicznego Struktury Statków Powietrznych z Punktu Widzenia Wymagań Użytkownika Wojskowego

    Directory of Open Access Journals (Sweden)

    Klimaszewski Sławomir

    2016-12-01

    Full Text Available Niniejszy artykuł opisuje model podejmowania decyzji w oparciu o wartości (ang. Value-Focused Thinking - VFT opracowany w celu oceny różnych wariantów wdrożenia systemu monitorowania stanu technicznego struktury (ang. Structural Health Monitoring - SHM wojskowego statku powietrznego. Rozpatruje się cztery warianty wspomnianego systemu (SHM oparte na: kontroli wzrokowej (aktualne podejście, czujnikach piezoelektrycznych (PZT, czujnikach światłowodowych z siatką Bragga (FBG i czujnikach próżniowych (Comparative Vacuum Monitoring - CVM. Przedstawiono przykład numeryczny w celu zilustrowania możliwości modelu. Analizy wrażliwości są wykonane dla takich wartości jak koszt, wydajność, dostępność statku powietrznego oraz poziom gotowości technologicznej (Technology Readiness Level - TRL, aby zbadać wpływ tych parametrów na całkowitą wartość informacji z zakresu stanu technicznego struktury dostarczanych przez określony wariant systemu SHM.

  1. Assessment of Reusing 14-Ton, Thin-Wall, Depleted UF6 Cylinders as LLW Disposal Containers

    International Nuclear Information System (INIS)

    O'Connor, D.G.; Poole, A.B.; Shelton, J.H.

    2000-01-01

    Approximately 700,000 MT of DUF 6 is stored, or will be produced under a current agreement with the USEC, at the Paducah site in Kentucky, Portsmouth site in Ohio, and ETTP site in Tennessee. On July 21, 1998, the 105th Congress approved Public Law 105-204, which directed that facilities be built at the Kentucky and Ohio sites to convert DUF 6 to a stable form for disposition. On July 6, 1999, the Department of Energy (DOE) issued the ''Final Plan for the Conversion of Depleted Uranium Hexafluoride as Required by Public Law 105-204'', in which DOE committed to develop a ''Depleted Uranium Hexafluoride Materials Use Roadmap''. On September 1,2000, DOE issued the ''Draft Depleted Uranium Hexafluoride Materials Use Roadmap'' (Roadmap), which provides alternate paths for the long-term storage, beneficial use, and eventual disposition of each product form and material that will result from the DUF 6 conversion activity. One of the paths being considered for DUF 6 cylinders is to reuse the empty cylinders as containers to transport and dispose of LLW, including the converted DU. The Roadmap provides results of the many alternate uses and disposal paths for conversion products and the empty DUF 6 storage cylinders. As a part of the Roadmap, evaluations were conducted of cost savings, technical maturity, barriers to implementation, and other impacts. Results of these evaluations indicate that using the DUF 6 j storage cylinders as LLW disposal containers could provide moderate cost savings due to the avoided cost of purchasing LLW packages and the avoided cost of disposing of the cylinders. No significant technical or institutional .issues were identified that.would make using cylinders as LLW packages less effective than other disposition paths. Over 58,000 cylinders have been used, or will be used, to store DUF 6 . Over 5 1,000 of those cylinders are 14TTW cylinders with a nominal wall thickness of 5/16-m (0.79 cm). These- 14TTW cylinders, which have a nominal diameter of 48 inches and nominally contain 14 tons (12.7 MT) of DUF 6 , were originally designed and fabricated for temporary storage of DUF 6 . They were fabricated from pressure-vessel-grade steels according to the provisions of the ASME Boiler and Pressure Vessel Code. Cylinders are stored in open yards at the three sites and, due to historical storage techniques, were subject to corrosion. Roughly 10,000 of the 14TTW cylinders are considered substandard due to corrosion and other structural anomalies caused by mishandling. This means that approximately 40,000 14TTW cylinders could be made available as containers for LLW disposal In order to demonstrate the use of 14TTW cylinders as LLW disposal containers, several qualifying tasks need to be performed. Two demonstrations are being considered using 14TTW cylinders--one demonstration using contaminated soil and one demonstration using U 3 O 8 . The objective of this report are to determine how much information is known that could be used to support the demonstrations, and how much additional work will need to be done in order to conduct the demonstrations. Information associated with the following four qualifying tasks are evaluated in this report

  2. West Valley UF6 Facility. Environmental report and safety evaluation, supplement 1

    International Nuclear Information System (INIS)

    1975-01-01

    Revised pages are provided for the Environmental Report and the Safety Evaluation Report which reflect design changes and more detailed information on the items requested in the USAEC letter to NFS dated September 6, 1974

  3. An unattended verification station for UF6 cylinders: Field trial findings

    Science.gov (United States)

    Smith, L. E.; Miller, K. A.; McDonald, B. S.; Webster, J. B.; Zalavadia, M. A.; Garner, J. R.; Stewart, S. L.; Branney, S. J.; Todd, L. C.; Deshmukh, N. S.; Nordquist, H. A.; Kulisek, J. A.; Swinhoe, M. T.

    2017-12-01

    In recent years, the International Atomic Energy Agency (IAEA) has pursued innovative techniques and an integrated suite of safeguards measures to address the verification challenges posed by the front end of the nuclear fuel cycle. Among the unattended instruments currently being explored by the IAEA is an Unattended Cylinder Verification Station (UCVS), which could provide automated, independent verification of the declared relative enrichment, 235U mass, total uranium mass, and identification for all declared uranium hexafluoride cylinders in a facility (e.g., uranium enrichment plants and fuel fabrication plants). Under the auspices of the United States and European Commission Support Programs to the IAEA, a project was undertaken to assess the technical and practical viability of the UCVS concept. The first phase of the UCVS viability study was centered on a long-term field trial of a prototype UCVS system at a fuel fabrication facility. A key outcome of the study was a quantitative performance evaluation of two nondestructive assay (NDA) methods being considered for inclusion in a UCVS: Hybrid Enrichment Verification Array (HEVA), and Passive Neutron Enrichment Meter (PNEM). This paper provides a description of the UCVS prototype design and an overview of the long-term field trial. Analysis results and interpretation are presented with a focus on the performance of PNEM and HEVA for the assay of over 200 "typical" Type 30B cylinders, and the viability of an "NDA Fingerprint" concept as a high-fidelity means to periodically verify that material diversion has not occurred.

  4. A Radiation-Triggered Surveillance System for UF6 Cylinder Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Curtis, Michael M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Myjak, Mitchell J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-09-23

    This report provides background information and representative scenarios for testing a prototype radiation-triggered surveillance system at an operating facility that handles uranium hexafluoride (UF6) cylinders. The safeguards objective is to trigger cameras using radiation, or radiation and motion, rather than motion alone, to reduce significantly the number of image files generated by a motion-triggered system. The authors recommend the use of radiation-triggered surveillance at all facilities where cylinder paths are heavily traversed by personnel. The International Atomic Energy Agency (IAEA) has begun using surveillance cameras in the feed and withdrawal areas of gas centrifuge enrichment plants (GCEPs). The cameras generate imagery using elapsed time or motion, but this creates problems in areas occupied 24/7 by personnel. Either motion-or-interval-based triggering generates thousands of review files over the course of a month. Since inspectors must review the files to verify operator material-flow-declarations, a plethora of files significantly extends the review process. The primary advantage of radiation-triggered surveillance is the opportunity to obtain full-time cylinder throughput verification versus what presently amounts to part-time verification. Cost savings should be substantial, as the IAEA presently uses frequent unannounced inspections to verify cylinder-throughput declarations. The use of radiation-triggered surveillance allows the IAEA to implement less frequent unannounced inspections for the purpose of flow verification, but its principal advantage is significantly shorter and more effective inspector video reviews.

  5. Effects of fire exposure on integrity of UF6 shipping cylinders

    International Nuclear Information System (INIS)

    Barlow, C.R.; Ziehlke, K.T.; Pryor, W.A.

    1985-01-01

    Two 2-1/2-ton steel cylinders for the transport of uranium hexafluoride within the United States nuclear fuel enrichment cycle were involved in a warehouse fire where portions of the cylinders were estimated to have reached a temperature of 1600 0 F (870 0 C). The cylinders were empty at the time of the fire and therefore were not in protective overpacks in which full product cylinders are handled while in transit. Hydrostatic tests to failure showed that the integrity of the cylinders was not degraded by exposure to the temperatures generated by the fire. They withstood test pressures in excess of 10 times the design pressure, and showed a volume expansion of 30% above the original capacity before rupture in a completely ductile fashion. Reference CAPE-323. 9 figs

  6. The development of thermal models for a UF6 transport container in a fully engulfing fire

    International Nuclear Information System (INIS)

    Lomas, J.; Clayton, D.G.

    1993-01-01

    This paper describes the recent development work on a lumped-parameter model known as BURST3 created by BNFL to examine the physics of the heating problem. The predictions of this model were compared with the results obtained by Mallett in 1965, in which small (3.5, 5 and 8 inch diameter) cylinders were exposed to a fire. In general, the comparison is good; however there are some differences - particularly on the speed of response of the wall temperature to the heating from the fire. The model was further modified to allow conditions of partial and full insulation to be investigated. The partially insulated condition simulates the Japanese proposal to insulate the ends of the container only, leaving the cylinder bare between the stiffening rings. The results obtained with our modified model support the predictions of Abe et al that the partially-insulated cylinder will survive the fire test. The analysis of a completely insulated container has indicated that a minimal thickness of insulation provides sufficient protection to allow survival in the fire test. A discussion of additional improvements to the lumped-parameter model are presented. (J.P.N.)

  7. Ultra-low field NMR for detection and characterization of 235 UF6

    Energy Technology Data Exchange (ETDEWEB)

    Espy, Michelle A [Los Alamos National Laboratory; Magnelind, Per E [Los Alamos National Laboratory; Matlashov, Andrei N [Los Alamos National Laboratory; Urbaitis, Algis V [Los Alamos National Laboratory; Volegov, Petr L [Los Alamos National Laboratory

    2009-01-01

    We have demonstrated the first ultra-low field (ULF) nuclear magnetic resonance measurements of uranium hexafluoride (UF{sub 6}), both depleted and 70% enriched, which is used in the uranium enrichment process. A sensitive non-invasive detection system would have an important role in non-proliferation surveillance. A two-frequency technique was employed to remove the transients induced by rapidly switching off the 50 mT pre-polarization field. A mean transverse relaxation time T{sub 2} of 24 ms was estimated for the un-enriched UF{sub 6} sample measured at a mean temperature of 80 C. Nuclear magnetic resonance at ULF has several advantages including the ability to measure through metal, such as pipes, and simple magnetic field generation hardware. We present here recent data and discuss the potential for non-proliferation monitoring of enrichment and flow velocity.

  8. High temperature experiments on a 4 tons UF6 container TENERIFE program

    Energy Technology Data Exchange (ETDEWEB)

    Casselman, C.; Duret, B.; Seiler, J.M.; Ringot, C.; Warniez, P.

    1991-12-31

    The paper presents an experimental program (called TENERIFE) whose aim is to investigate the behaviour of a cylinder containing UF{sub 6} when exposed to a high temperature fire for model validation. Taking into account the experiments performed in the past, the modelization needs further information in order to be able to predict the behaviour of a real size cylinder when engulfed in a 800{degrees}C fire, as specified in the regulation. The main unknowns are related to (1) the UF{sub 6} behaviour beyond the critical point, (2) the relationship between temperature field and internal pressure and (3) the equivalent conductivity of the solid UF{sub 6}. In order to investigate these phenomena in a representative way it is foreseen to perform experiments with a cylinder of real diameter, but reduced length, containing 4 tons of UF{sub 6}. This cylinder will be placed in an electrically heated furnace. A confinement vessel prevents any dispersion of UF{sub 6}. The heat flux delivered by the furnace will be calibrated by specific tests. The cylinder will be changed for each test.

  9. Next Generation Safeguards Initiative: Overview and Policy Context of UF6 Cylinder Tracking Program

    Energy Technology Data Exchange (ETDEWEB)

    Boyer, Brian D [Los Alamos National Laboratory; Whitaker, J. Michael [ORNL; White-Horton, Jessica L. [ORNL; Durbin, Karyn R. [NNSA

    2012-07-12

    Thousands of cylinders containing uranium hexafluoride (UF{sub 6}) move around the world from conversion plants to enrichment plants to fuel fabrication plants, and their contents could be very useful to a country intent on diverting uranium for clandestine use. Each of these large cylinders can contain close to a significant quantity of natural uranium (48Y cylinder) or low-enriched uranium (LEU) (30B cylinder) defined as 75 kg {sup 235}U which can be further clandestinely enriched to produce 1.5 to 2 significant quantities of high enriched uranium (HEU) within weeks or months depending on the scale of the clandestine facility. The National Nuclear Security Administration (NNSA) Next Generation Safeguards Initiative (NGSI) kicked off a 5-year plan in April 2011 to investigate the concept of a unique identification system for UF{sub 6} cylinders and potentially to develop a cylinder tracking system that could be used by facility operators and the International Atomic Energy Agency (IAEA). The goal is to design an integrated solution beneficial to both industry and inspectorates that would improve cylinder operations at the facilities and provide enhanced capabilities to deter and detect both diversion of low-enriched uranium and undeclared enriched uranium production. The 5-year plan consists of six separate incremental tasks: (1) define the problem and establish the requirements for a unique identification (UID) and monitoring system; (2) develop a concept of operations for the identification and monitoring system; (3) determine cylinder monitoring devices and technology; (4) develop a registry database to support proof-of-concept demonstration; (5) integrate that system for the demonstration; and (6) demonstrate proof-of-concept. Throughout NNSA's performance of the tasks outlined in this program, the multi-laboratory team emphasizes that extensive engagement with industry stakeholders, regulatory authorities and inspectorates is essential to its success.

  10. Methods and results for stress analyses on 14-ton, thin-wall depleted UF6 cylinders

    International Nuclear Information System (INIS)

    Kirkpatrick, J.R.; Chung, C.K.; Frazier, J.L.; Kelley, D.K.

    1996-10-01

    Uranium enrichment operations at the three US gaseous diffusion plants produce depleted uranium hexafluoride (DUF 6 ) as a residential product. At the present time, the inventory of DUF 6 in this country is more than half a million tons. The inventory of DUF 6 is contained in metal storage cylinders, most of which are located at the gaseous diffusion plants. The principal objective of the project is to ensure the integrity of the cylinders to prevent causing an environmental hazard by releasing the contents of the cylinders into the atmosphere. Another objective is to maintain the cylinders in such a manner that the DUF 6 may eventually be converted to a less hazardous material for final disposition. An important task in the DUF 6 cylinders management project is determining how much corrosion of the walls can be tolerated before the cylinders are in danger of being damaged during routine handling and shipping operations. Another task is determining how to handle cylinders that have already been damaged in a manner that will minimize the chance that a breach will occur or that the size of an existing breach will be significantly increased. A number of finite element stress analysis (FESA) calculations have been done to analyze the stresses for three conditions: (1) while the cylinder is being lifted, (2) when a cylinder is resting on two cylinders under it in the customary two-tier stacking array, and (3) when a cylinder is resting on tis chocks on the ground. Various documents describe some of the results and discuss some of the methods whereby they have been obtained. The objective of the present report is to document as many of the FESA cases done at Oak Ridge for 14-ton thin-wall cylinders as possible, giving results and a description of the calculations in some detail

  11. Advanced fuel cycle for the LWR on a basis of UF6 pyrohydrolysis up to UO2 and vibropack technology

    International Nuclear Information System (INIS)

    Ivanov, V.B.; Mayorshin, A.A.; Sokolovsky, Y.S.; Skiba, O.V.; Porodnov, P.T.; Rybin, D.G.; Chernyshov, V.A.

    1997-01-01

    The traditional circuit of a fuel cycle for thermal neutrons reactors provides conversion of enriched uranium hexafluoride in a press-powder uranium dioxide, using it for manufacturing pellet fuel and subsequently pins. It is known that, each of these stages contains rather plenty of technological and control operations. In SSC RF RIAR the large cycle of studies for improving and simplifying fuel cycle of power reactors is executed. One of studies is devoted to the development of one-stage way of granulated uranium dioxide obtaining by hexafluoride pyrohydrolysis in UO 2 particles boiling layer in a combination with vibropack technology for pins manufacture of fast and thermal neutrons reactors. Reduction of time that conversion of uranium hexafluoride into uranium dioxide takes in a combination with potential advantages of vibropacking: 1) minimum quantity of technological and control operations; 2) possibility of introducing various component (getter, burning out absorber) at a stage of preparation of fuel portion; 3) possibility of using fuel on the basis of mechanical mixes and, if it is necessary, distribution of components profiled along length of the fuel column. (J.P.N.)

  12. TRP receptory jako transdukční molekuly nociceptivních podnětů

    Czech Academy of Sciences Publication Activity Database

    Boukalová, Štěpánka; Vlachová, Viktorie

    2008-01-01

    Roč. 11, č. 4 (2008), s. 194-206 ISSN 1212-0634 R&D Projects: GA MŠk(CZ) 1M0517; GA MŠk(CZ) LC554; GA ČR(CZ) GA305/06/0319 Institutional research plan: CEZ:AV0Z50110509 Keywords : termo-TRP receptory * nociceptory Subject RIV: ED - Physiology

  13. AKTIVNO ELEKTRONSKO BREME ZASNOVANO NA MULTIFAZNI STRUKTURI PRETVORNIKA NAVZGOR

    OpenAIRE

    Marjanovič, Sašo

    2010-01-01

    V diplomski nalogi je predstavljena regulacija aktivnega elektronskega bremena s PI regulatorjem in pred-krmiljenjem. Opisane so posamezne komponente ter sestava simulacijskega in aplikacijskega modela. Predstavljeno je delovanje več-faznega pretvornika navzgor, dimenzioniranje dušilk in programiranje vgrajenega mikro-krmilnika. Delovanje več-faznega pretvornika je bilo najprej preverjeno s simulacijo v MATLAB Simulink okolju in nato verificirano z laboratorijskim eksperimentom.

  14. Nanovlákenné struktury pro filtraci vody

    Czech Academy of Sciences Publication Activity Database

    Lev, J.; Holba, Marek; Kimmer, D.; Došek, M.; Kalhotka, L.; Mikula, Přemysl

    2013-01-01

    Roč. 63, č. 12 (2013), s. 409-413 ISSN 1211-0760 R&D Projects: GA TA ČR TA01010356 Institutional support: RVO:67985939 Keywords : electrospinning * nanofibres * filtration Subject RIV: EF - Botanics

  15. Vývoj struktury devizového trhu

    OpenAIRE

    Hakobyan, Ani

    2011-01-01

    This thesis describes the instruments of the foreign exchange market and analyses the trend of its single elements over the past 15 years. The work is divided into two parts. The first part includes the description of the global foreign exchange market,its history, geografical concentration, participants and financial instruments. The second part analyses the foreign exchange market in the Czech Republic and its comparison with transition economies such as Poland, Hungary and The Slovak Repub...

  16. Prototype Tests for the Recovery and Conversion of UF6 Chemisorbed in NaF Traps for the Molten Salt Reactor Remediation Project

    International Nuclear Information System (INIS)

    Del Cul, G.D.; Icenhour, A.S.; Simmons, D.W.

    2000-01-01

    The remediation of the Molten Salt Reactor Experiment (MSRE) site includes the removal of about 37 kg of uranium. Of that inventory, about 23 kg have already been removed from the piping system and chemisorbed in 25 NaF traps. This material is being stored in Building 3019. The planned recovery of -11 kg of uranium from the fuel salt will generate another 15 to 19 NaF traps. The remaining 2 to 3 kg of uranium are present in activated charcoal beds, which are also scheduled to be removed from the reactor site. Since all of these materials (NaF traps and the uranium-laden charcoal) are not suitable for long-term storage, they will be converted to a chemical form (uranium oxide), which is suitable for long-term storage. This document describes the process that will be used to recover and convert the uranium in the NaF traps into a stable oxide for long-term storage. Included are a description of the process, equipment, test results, and lessons learned. The process was developed for remote operation in a hot cell. Lessons learned from the prototype testing were incorporated into the process design

  17. Prototype Tests for the Recovery and Conversion of UF6 Chemisorbed in NaF Traps for the Molten Salt Reactor Remediation Project

    Energy Technology Data Exchange (ETDEWEB)

    Del Cul, G.D.; Icenhour, A.S.; Simmons, D.W.

    2000-04-01

    The remediation of the Molten Salt Reactor Experiment (MSRE) site includes the removal of about 37 kg of uranium. Of that inventory, about 23 kg have already been removed from the piping system and chemisorbed in 25 NaF traps. This material is being stored in Building 3019. The planned recovery of -11 kg of uranium from the fuel salt will generate another 15 to 19 NaF traps. The remaining 2 to 3 kg of uranium are present in activated charcoal beds, which are also scheduled to be removed from the reactor site. Since all of these materials (NaF traps and the uranium-laden charcoal) are not suitable for long-term storage, they will be converted to a chemical form [uranium oxide], which is suitable for long-term storage. This document describes the process that will be used to recover and convert the uranium in the NaF traps into a stable oxide for long-term storage. Included are a description of the process, equipment, test results, and lessons learned. The process was developed for remote operation in a hot cell. Lessons learned from the prototype testing were incorporated into the process design.

  18. Enrichment Meter Dataset from High-Resolution Gamma Spectroscopy Measurements of U3O8 Enrichment Standards and UF6 Cylinder Wall Equivalents

    Energy Technology Data Exchange (ETDEWEB)

    Nicholson, Andrew D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Croft, Stephen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shephard, Adam M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-12-01

    The Enrichment Meter Principle (EMP) is the basis for a commonly used standard test method for the non-destructive assay of 235U enrichment in bulk compounds [1]. The technique involves determining the net count rate in the direct 186 keV peak using medium or high energy gamma-ray spectrometry in a fixed geometry. With suitable correction for wall attenuation, compound type, rate loss (live time), and peaked background (if significant), the atom fraction of 235U may be obtained from the counting rate from a linear relationship through the origin. The widespread use of this method for field verification of enrichment [2,3] together with the fact that the response function rests on fundamental physics considerations (i.e., is not represented by a convenient but arbitrary form) makes it an interesting example of uncertainty quantification, one in which one can expect a valid measurement model can be applied. When applied using NaI(Tl) and region of interest analysis, the technique is susceptible to both interference error and bias [2-4]. When implemented using high-resolution gamma-ray spectroscopy, the spectrum interpretation is considerable simplified and more robust [5]. However, a practical challenge to studying the uncertainty budget of the EMP method (for example, to test linearity, extract wall corrections and so forth using modern methods) is the availability of quality experimental data that can be referenced and shared. To fill this gap, the research team undertook an experimental campaign [6]. A measurement campaign was conducted to produce high-resolution gamma spectroscopy enrichment meter data comparable to UF6 cylinder measurements. The purpose of this report is to provide both an introduction to and quality assurance (QA) of the raw data produced. This report is intended for the analyst or researcher who uses the raw data. Unfortunately, the raw data (i.e., the spectra files) are too voluminous to include in this report but can be requested from Steven Croft of the Safeguards & Security Technology Group (scroft@ornl.gov 865-241-2834). The complete processed data are tabulated in Appendix A. The analysis techniques used to produce the QA data presented in this report [e.g., three regions-ofinterest (ROI) peak extraction and batch analysis processes] are not the most sophisticated techniques available; analysts are encouraged to reanalyze the raw data using more sensitive techniques and to improve upon the results presented here. With that being said, the analysis techniques used here are more than adequate to present and inspect the quality of the data.

  19. Feeding the nuclear fuel cycle with a long term view; AREVA's front-end business units, uranium mining, UF6 conversion and isotopic enrichment

    International Nuclear Information System (INIS)

    Capus, G.A.P.; Autegert, R.

    2005-01-01

    As a leading provider of technological solutions for nuclear power generation and electricity transmission, the AREVA group has the unique capability of offering a fully integrated fuel supply, when requested by its customers. At the core of the AREVA group, COGEMA Front End Division is an essential part of the overall fuel supply chain. Composed of three Business Units and gathering several subsidiaries and joint 'ventures, this division enjoys several leading positions as shown by its market shares and historical production records. Current Uranium market evolutions put the natural uranium supply under focus. The uranium conversion segment also recently revealed some concerning evolutions. And no doubt, the market pressure will soon be directed also at the enrichment segment. Looking towards the long term, AREVA strongly believes that a nuclear power renewal is needed, especially to help limiting green house effect gas release. Therefore, to address future supplies needed to fuel the existing fleet of nuclear power plants, but also new ones, the AREVA group is planning very significant investments to build new facilities in all the three front-end market segments. As far as uranium mining is concerned, these new mines will be based upon uranium reserves of outstanding quality. As for uranium conversion and enrichment, two large projects will be based on the most advanced technologies. This paper is aimed at recalling COGEMA Front End Division experience, the current status of its plants and operating entities and will provide a detailed overview of its major projects. (authors)

  20. Phase equilibrium liquid-vapor in three-component system UF6-IF5-BrF3 at complete mutual components solubility

    OpenAIRE

    Zherin, Ivan Ignatyevich; Usov, V. F.; Ostvald, R. V.; Shagalov, V. V.; Gayday, I. V.; Tyulyubaev, Z. M.

    2007-01-01

    The results of studying phase equilibrium liquid-vapor at 353,15 K in the system of uranium hexafluoride, iodine pentafluoride, bromine trifluoride have been presented. The dependences of saturated vapor pressure on condensed phase composition, the results of analysis of studied system deviation from error-free behavior, the data on equilibrium vapor phase are given

  1. Molekuly a ionty v pohybu: Počítačové simulace biochemických a biofyzikálních procesů

    Czech Academy of Sciences Publication Activity Database

    Jungwirth, Pavel

    2014-01-01

    Roč. 108, č. 4 (2014), s. 278-284 ISSN 0009-2770 R&D Projects: GA ČR GBP208/12/G016 Institutional support: RVO:61388963 Keywords : molecular dynamics * proteins * ions * membranes Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.272, year: 2014

  2. Architektura organizační struktury ve vybraném podniku

    OpenAIRE

    JAREŠOVÁ, Jana

    2009-01-01

    The theoretical part is intent on organization, organizational structure and types of organizational structure. The practical part contains analysis of organization structure of the pharmaceutical wholesale trade. According to the realized analyse, propose improvements.

  3. Struktury významu. Karel Kosík a problém kultury

    Czech Academy of Sciences Publication Activity Database

    Landa, Ivan

    2017-01-01

    Roč. 14, č. 1 (2017), s. 7-42 ISSN 1214-7249 R&D Projects: GA ČR(CZ) GA16-26686S Institutional support: RVO:67985955 Keywords : Kosík * Lukács * Marx * Goldmann * Materialism * Politics * Culture Subject RIV: AA - Philosophy ; Religion OBOR OECD: Philosophy, History and Philosophy of science and technology

  4. Analýza struktury trhu práce: MAJOR LEAGUE SOCCER

    OpenAIRE

    Hrdina, Martin

    2013-01-01

    This thesis deals with the determination of the player labour market for the American professional sports league Major League Soccer (MLS). In the theoretical part I focus on the description of the league's development along with the salary politics rules. Using the two stages least square method in the empirical part I then provide the model for the estimation of player's marginal productivity (MRP). In the first step I explain the correlation between the percentages of obtained points by te...

  5. Moderní teoretické metody analýzy elektronové struktury molekul.

    Czech Academy of Sciences Publication Activity Database

    Ponec, Robert

    2016-01-01

    Roč. 10, č. 5 (2016), s. 323-329 ISSN 0009-2770 Institutional support: RVO:67985858 Keywords : molecular structure * chemical bond * pair population analysis Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.387, year: 2016

  6. Životní cyklus podniku a vliv na volbu finanční struktury

    Directory of Open Access Journals (Sweden)

    Zdeněk Konečný

    2013-11-01

    Full Text Available Purpose of the article: Companies during their existence pass through the phases of their life cycle. Every phase is among others characterized by different availability of financial sources and this fact will significantly influence the financial structure of a company. Previous researches were aimed mostly on availability and usability of external financial sources during the life cycle of a company. The financial structure in context of the life cycle of a company was so far most researched by Marc Reiners. This author viewed the financial structure only in accordance with the legal status of the investors and he did´nt consider other important criterions like origin, usable life and bribability of financial sources. According to all these criterions is the financial structure in context of the life cycle of a company considered in this article. Scientific aim: The companies are classified into three groups into companies that are in phases of growth, stabilisation and decline. The financial structure is separately within these groups under review. Financial sources are divided always according to the criterion, which is selected to consider the financial structure. Methodology/methods: To implementing the research is used the method of analysing the secondary data that are extracted from the financial reports of surveyed firms. Phases of the life cycle of a company are identified on the basis of the growth indicator, developed by Marc Reiners. All the selected companies are from the Czech automotive industry, they are small or middle, and they have some history, because for companies in the phase of foundation isn´t this growth indicator usable. Findings: In the financial structure of all selected companies, regardless of the phase of their life cycle, dominate long-dated and bribable financial sources. The companies in phase of stabilisation are at least indebted and have the highest share of internal sources. Conclusions: (limits, implications etc It can be said, that the fact, that especially companies in phase of stabilisation have most available external sources and they can most indebt, wasn´t approved oneself on financial structure of these companies. The limitation of this finding is that only few companies are in the phase of stabilisation according to the used growth indicator.

  7. Analýza spokojenosti a motivační struktury společnosti

    OpenAIRE

    BRŮŽKOVÁ, Simona

    2013-01-01

    The main object of the diploma thesis is to analysis work satisfaction and motivation structure in selected company. The theoretical part deals with components of motivation structures, theoretical backgrounds of work motivation, and its relationship to job. The subject of the practical part is questionnaire survey and analysis of the current state of satisfaction and motivation of employees in selected company. Based on the obtained data will be defined aspects of the problem and proposed me...

  8. Vliv organizační struktury na ekonomickou strukturu podniku

    OpenAIRE

    Vaníková, Lucie

    2017-01-01

    The goal of the diploma thesis is to analyse the influence of an organizational structure on an economic structure of an organization. The theoretical part summarises basic features of responsibility accounting and tries to find out whether the economic structure is determined only by the organizational structure or by more features. The case of a change of the particular company´s organizational structure proves the influence of the organizational structure on the economic structure in pract...

  9. Experimentální zkoumání struktury zkušenosti

    Czech Academy of Sciences Publication Activity Database

    Koubová, Alice

    2013-01-01

    Roč. 68, č. 5 (2013), s. 393-401 ISSN 0046-385X R&D Projects: GA ČR(CZ) GAP401/10/1164 Grant - others:AV ČR(CZ) M300091203 Institutional support: RVO:67985955 Keywords : resentment * self-relationship * dialogical acting * (inter)acting with the inner partner * topology * phenomenology Subject RIV: AA - Philosophy ; Religion

  10. Severokorejská kulturní krajina II. Struktury a vztahy v krajině

    Czech Academy of Sciences Publication Activity Database

    Sádlo, Jiří; Kolbek, Jiří

    2006-01-01

    Roč. 54, č. 2 (2006), s. 70-72 ISSN 0044-4812 R&D Projects: GA ČR GA206/05/0119 Institutional research plan: CEZ:AV0Z60050516 Keywords : plant communities * management * landscape Subject RIV: EF - Botanics

  11. Mapování struktury 1-fluor-1-lithioalk-1-enů v roztoku

    Czech Academy of Sciences Publication Activity Database

    Czernek, Jiří; Kvíčala, J.; Hrabal, R.; Böhm, S.; Paleta, O.

    2000-01-01

    Roč. 94, č. 11 (2000), s. 1042 ISSN 0009-2770. [Pokroky v organické, bioorganické a farmaceutické chemii /35./. 13.11.2000-15.11.2000, Liblice] R&D Projects: GA AV ČR KSK2055603 Subject RIV: CC - Organic Chemistry

  12. Vliv věkové struktury na míru kriminalityv České republice

    OpenAIRE

    Pražský, Přemysl

    2014-01-01

    I establish 2 main hypotheses explaining the relationship of age structure and crime rate: Limited number of crime opportunities will lead to lower crime participation rates of strong age groups, second: crowding effects due to strong age groups will lead to less favorable social outcomes such as less legal income opportunities and therefore to the increase of crime participation rate. I evaluate these hypotheses on Czech criminal and demographic data during 1996-2013. By using Oaxaca decompo...

  13. Využití komputačních metod při studiu struktury

    Czech Academy of Sciences Publication Activity Database

    Drahokoupil, Jan

    2013-01-01

    Roč. 20, č. 2 (2013), s. 85-86 ISSN 1211-5894. [Struktura 2013 - Kolokvium Krystalografické společnosti. 09.09.2013-13.09.2013, Češkovice (Blansko)] Institutional research plan: CEZ:AV0Z10100520 Keywords : X-ray * structure * computer simulation Subject RIV: BM - Solid Matter Physics ; Magnetism

  14. Vliv změny majetkové struktury na ekonomické výsledky podniku

    OpenAIRE

    ČAPKOVÁ, Hana

    2011-01-01

    The aim of this thesis was to classify the proprietary structure of the selected company in the South Bohemian Region. Furthermore to evaluate the sources of funding individual components of assets and quantify the impacts of the extensity of the long-term assets on the economic results of the company.

  15. Kvantifikace vlivu struktury ekonomiky na strukturu středního školství v Praze

    Czech Academy of Sciences Publication Activity Database

    Benáček, Vladimír; Brzobohatý, F.

    2008-01-01

    Roč. 6, č. 9 (2008), s. 3-5 ISSN 1214-1720 R&D Projects: GA AV ČR(CZ) IAA700280803 Institutional research plan: CEZ:AV0Z70280505 Keywords : structure of production * education * productivity Subject RIV: AO - Sociology, Demography http://www.socioweb.cz

  16. Analysis of structure of the biathlon runs Analýza struktury biathlonového běhu

    Directory of Open Access Journals (Sweden)

    Adam Zając

    2005-02-01

    Full Text Available The biathlon is an Olympic sport discipline, which is a combination of two events, Nordic skiing and precision shooting. Combining events of such different psychophysical background creates great demands on the athlete and coach. The main objective of this paper was to determine which of these events has a greater impact on the final result considering the distance and sports level. The results of the World Cup and the Olympic Games in the 2001/02 season were analyzed statistically. The data indicates that the results of the run influence the final result to a higher degree than shooting does. This is especially true in the sprint and in relation to biathletes of higher sports level. At long distances, the level of shooting and the time of the run influence the final result to the same extent. The influence of the time of shooting on the final result is dependent on the distance of the run. Biathlon je olympijská disciplína spojující v sobě vlastně dvě sportovní disciplíny: lyžařský běh a střelbu ze sportovní pušky. Spojení těchto odlišných sportovních disciplín o různých psychofyzických požadavcích klade na závodníky i trenéry velmi vysoké požadavky. V práci se autoři snažili najít odpověď na otázku: která složka je důležitější pro dosažení konečného výsledku v závislosti na proběhnuté vzdálenosti, jakož i sportovní úrovni závodníků. Statistické analýze byly podrobeny výsledky vybraných závodů Světového poháru i olympijských her v sezóně 2001/02 v kategorii mužů. Analýze byl podroben čas běhu, přesnost střelby, čas střílení i sportovní výsledek. Na základě výsledků získaných z předmětné analýzy byl zjištěn větší význam běhové přípravy v sprintérském běhu u závodníků na vyšší sportovní úrovni vzhledem k vysoké vyrovnané úrovni střelby. V běhu na dlouhých tratích byl zjištěn přibližně stejný význam přesnosti střelby a času běhu. Vliv času střelby na konečný výsledek závisí na délce proběhnuté vzdálenosti.

  17. Paralelní robotické struktury a moderní metody jejich řízení

    Czech Academy of Sciences Publication Activity Database

    Belda, Květoslav

    2009-01-01

    Roč. 52, č. 5 (2009), s. 296-300 ISSN 0005-125X Institutional research plan: CEZ:AV0Z10750506 Keywords : Parallel robotic structures * industrial robotics * predictive control * real-time control Subject RIV: BC - Control Systems Theory http://library.utia.cas.cz/separaty/historie/belda-0325559.pdf

  18. Rol' rasčetov elektronnoj struktury iz pervych principov v sovremennom materialovedenii, časť I.

    Czech Academy of Sciences Publication Activity Database

    Šob, Mojmír; Friák, Martin; Wang, L. G.; Kuriplach, J.; Vitek, V.

    2007-01-01

    Roč. 1, č. 10 (2007), s. 363-367 ISSN 1994-6279 R&D Projects: GA ČR GA202/03/1351; GA AV ČR IAA1041302; GA MŠk OC 147 Institutional research plan: CEZ:AV0Z20410507 Keywords : multiscale modelling * electronic structure * ab initio calculations Subject RIV: BM - Solid Matter Physics ; Magnetism

  19. Rol' rasčetov elektronnoj struktury iz pervych principov v sovremennom materialovedenii, časť II.

    Czech Academy of Sciences Publication Activity Database

    Šob, Mojmír; Friák, Martin; Wang, L. G.; Kuriplach, J.; Vitek, V.

    2007-01-01

    Roč. 1, č. 11 (2007), s. 408-419 ISSN 1994-6279 R&D Projects: GA ČR GA202/03/1351; GA AV ČR IAA1041302; GA MŠk OC 147 Institutional research plan: CEZ:AV0Z20410507 Keywords : multiscale modelling * electronic structure * ab initio calculations Subject RIV: BM - Solid Matter Physics ; Magnetism

  20. Mechanical design

    Science.gov (United States)

    1976-01-01

    Design concepts for a 1000 mw thermal stationary power plant employing the UF6 fueled gas core breeder reactor are examined. Three design combinations-gaseous UF6 core with a solid matrix blanket, gaseous UF6 core with a liquid blanket, and gaseous UF6 core with a circulating blanket were considered. Results show the gaseous UF6 core with a circulating blanket was best suited to the power plant concept.

  1. Progress in the dry route conversion process of UF-6 to UO-2: new equipment and theoretical approach; Progres dans la conversion ''voie seche' de l'hexafluorure d'uranium en poudre d'oxyde d'uranium: nouveaux moyens experimentaux et approche theorique

    Energy Technology Data Exchange (ETDEWEB)

    Perrais, C.; Ablitzer, C. [CEA Cadarache, Dept. d' Etudes des Combustibles (DEC/SPUA) 13 - Saint-Paul-lez-Durance (France)

    1999-07-01

    The dry route conversion process of UF{sub 6} to UO{sub 2} is used on a large scale to produce powder for UO{sub 2} fuel pellets. However, this powder is not very suitable for other kinds of fuels, such as for instance, Mixed Oxide (Mox) fuel. Thus, CEA and COGEMA have developed a programme to study and model the process in order to identify the parameters which lead to a better quality powder. For this purpose, specific equipment was built at the CEA/Cadarache. The first results of experiments and modelling have shown parameters which clearly modify the powder quality. (authors)

  2. Vývoj struktury osobnosti od adolescence do stáří: předběžné výsledky

    Czech Academy of Sciences Publication Activity Database

    Hřebíčková, Martina; Čermák, Ivo; Osecká, Lída

    2000-01-01

    Roč. 42, č. 3 (2000), s. 163-166 ISSN 0039-3320 R&D Projects: GA ČR GA406/99/1155 Institutional research plan: CEZ:AV0Z7025918 Keywords : five -factor model of personality * NEO-FFI * developmental trends of Big Five Subject RIV: AN - Psychology Impact factor: 0.292, year: 2000

  3. Modeling the structure of the overall training facilities and training of skilled boxers [Modelirovanie struktury trenirovochnykh sredstv obshchej i special'noj podgotovki kvalificirovannykh bokserov

    Directory of Open Access Journals (Sweden)

    Gaskov A.V.

    2011-11-01

    Full Text Available Discussed ways of improving the technical and tactical skills in long-term preparation of athletes. Focuses on the overall level of physical fitness and training. In the experiment 28 participants qualified boxers. It is noted that the factor structure of physical preparation and training of skilled boxer does not change depending on the stage of learning. It is established that at each stage of the test selected factors are independent of each other. These factors represent some of the general physical and specialized training. We recommend the allocation of training load evenly dispense their attitude to all allocations factors.

  4. Dopady vlastnické struktury, firemních charakteristik a krize na efektivitu českých podniků

    Czech Academy of Sciences Publication Activity Database

    Hanousek, Jan; Kočenda, E.

    2017-01-01

    Roč. 65, č. 1 (2017), s. 3-25 ISSN 0032-3233 R&D Projects: GA ČR(CZ) GA15-15927S Institutional support: Progres-Q24 Keywords : global financial crisis * efficiency * ownership structure Subject RIV: AH - Economics OBOR OECD: Finance Impact factor: 0.589, year: 2016

  5. Podnikové organizační a řídící struktury na rozcestí

    Directory of Open Access Journals (Sweden)

    Petra Pártlová

    2017-06-01

    Full Text Available In the system concept of the enterprise, organization and management and their structures are its functional, spatial integrating elements that create relations and links of corporate architecture. The paper focuses on organizational and management structures in the current market economy conditions of the Czech Republic. The theoretical basis of the issue is defined as the theory of organizing with organizational behaviour. It contains important definitions of the terms, including the basic configuration of organizational structures. Based on a large sample of mostly South Bohemian enterprises, the current level of organizational and management structures is analysed, basic comparisons according to the size categories of enterprises with sectoral differentiation is carried out. The outputs of the analysis revealed that there is a decline of classical management structures such as the divisional and combined structure at the expense of unit structures with the trend being the most intense in the largest enterprises. Such transformation provably relates to business orientation, and the industrial sector is more pronounced. In terms of the number of management levels, there was no causal relation to the focus of the enterprise, unlike its size. At the same time, the results revealed a significant lack of knowledge of organizational and managerial skills of business managers, particularly in micro and small enterprises. The overriding opinion of all the executives in the sample should be a requirement for the gradual reorganization of the existing organizational and management structures with an individual approach for each enterprise. The conclusion of the paper summarizes the results achieved and indicates the expected trend of the corporate architecture.

  6. Magnetic fields of AIC-144S isochronous cyclotron measuring system and their structure analysis; System pomiarowy pol magnetycznych oraz analiza ich struktury dla izochronicznego cyklotronu AIC -144S

    Energy Technology Data Exchange (ETDEWEB)

    Potempa, J.; Potempa, M.; Schwabe, J. [Dept. of Research and Development of Cyclic Accelerator Techniques, The H. Niewodniczanski Inst. of Nuclear Physics, Cracow (Poland)

    1997-06-01

    The method and apparatus for fast measuring of the magnetic field structure in symmetry plane of the AIC-144S isochronous cyclotron is presented. The measuring system is controlled by a computer code. The processed data allow one to control the cyclotron beam dynamics

  7. Studium struktury a růstu nizkoteplotního protokrystalického křemíku pomocí AFM mikroskopu

    Czech Academy of Sciences Publication Activity Database

    Mates, Tomáš; Fejfar, Antonín; Drbohlav, Ivo; Rezek, Bohuslav; Fojtík, Petr; Luterová, Kateřina; Pelant, Ivan; Kočka, Jan

    2003-01-01

    Roč. 53, - (2003), s. 93-96 ISSN 0009-0700 R&D Projects: GA AV ČR IAA1010809; GA AV ČR IAB2949101 Institutional research plan: CEZ:AV0Z1010914 Keywords : PECVD * microcrystalline silicon * AFM Subject RIV: BM - Solid Matter Physics ; Magnetism

  8. Dopady vlastnické struktury, firemních charakteristik a krize na efektivitu českých podniků

    Czech Academy of Sciences Publication Activity Database

    Hanousek, J.; Kočenda, Evžen

    2017-01-01

    Roč. 65, č. 1 (2017), s. 3-25 ISSN 0032-3233 Institutional support: RVO:67985556 Keywords : global financial crisis * efficiency * ownership structure * firms * panel data * stochastic frontier * Czech Republic Subject RIV: AH - Economics OBOR OECD: Finance Impact factor: 0.589, year: 2016 http://library.utia.cas.cz/separaty/2017/E/kocenda-0472597.pdf

  9. Proměny organizační struktury Ústavu pro jazyk český (1946-1989)

    Czech Academy of Sciences Publication Activity Database

    Dvořáčková, Věra

    2011-01-01

    Roč. 3, č. 1 (2011), s. 37-52 ISSN 1803-9448 Institutional research plan: CEZ:AV0Z90610521 Keywords : The Institute of the Czech Language, organisational structure * organisational structure * Czechoslovak Academy of Sciences Subject RIV: AI - Linguistics

  10. Konsolidace obecní struktury v České republice: Mezi slučováním a meziobecní spoluprací

    Directory of Open Access Journals (Sweden)

    Jiří Ježek

    2017-10-01

    Full Text Available Alongside France, Italy and Slovakia the Czech Republic belongs to the countries with the most fragmented municipal structure. The aim of this paper is to analyze the attitudes of representatives of the Czech municipalities to two ideal forms of consolidation of the structure: amalgamation of the municipalities and inter-municipal cooperation. It is based on the survey results, which took place in the summer of 2015, which was attended by 573 municipalities and towns. The research has shown that the representatives of the Czech municipalities significantly prefer inter-municipal cooperation. In the case of amalgamation of the municipalities they are primarily afraid of loss of identity of the merging municipalities. As shown by foreign experience, to encourage inter-municipal cooperation it is necessary to access conceptually (model, with respect to its objectives and tasks, financing method, the territorial reach and organizational and legal structures.

  11. Návrh optimální organizační struktury sociálního podniku

    OpenAIRE

    Socha, Jan

    2015-01-01

    Social entrepreneurship is an innovative solution to increasing social problems related to unemployment and its inseparable social impact, such as social exclusion of persons that are disadvantaged in terms of labour market access. In spite of the fact that the law of the Czech Republic lacks a legal framework of social entrepreneurship (the term of social enterprise as such is not legally based nor defined), there are many local activists who make effort to change this state of inequality, u...

  12. Reactions of uranium hexafluoride photolysis products

    Science.gov (United States)

    Lyman, John L.; Laguna, Glenn; Greiner, N. R.

    1985-01-01

    This paper confirms that the ultraviolet photolysis reactions of UF6 in the B band spectral region is simple bond cleavage to UF5 and F. The photolysis products may either recombine to UF6 or the UF5 may dimerize, and ultimately polymerize, to solid UF5 particles. We use four methods to set an upper limit for the rate constant for recombination of krUF6 and UF5 after laser photolysis of the UF6 gas sample.

  13. TLÜ teadlased andsid panuse avastusse, mis tõotab läbimurret Alzheimeri ravis

    Index Scriptorium Estoniae

    2015-01-01

    Tallinna ülikooli teadlased professor Jan Johansson ja dr Jenny Presto teevad koostööd kolleegidega Karolinska instituudist, Cambridge’ist ja Lundi ülikoolist. Uurimisrühm leidis Alzheimeri tõbe käivitava molekuli ning seda on õpitud blokeerima

  14. Väikesel RNA-l suur roll rinnavähis

    Index Scriptorium Estoniae

    2007-01-01

    Massachusettsi tehnoloogiainstituudi Cambridge'i Whiteheadi instituudi teadlased eesotsas Robert Weinbergiga tuvastasid mikro-RNA molekuli, mis näib juhtivat rinnavähi rakkude võimet levida üle kogu patsiendi keha ning tekitada seal uusi vähikoldeid

  15. 10 CFR Appendix F to Part 110 - Illustrative List of Laser-Based Enrichment Plant Equipment and Components Under NRC Export...

    Science.gov (United States)

    2010-01-01

    ... for fluorinating UF5 (solid) to UF6 (gas). These systems are designed to fluorinate the collected UF5... compressing and converting UF6 to a liquid or solid; and (iv) “Product” or “tails” stations used to transfer... contact with the uranium or UF6 are wholly made of or protected by corrosion-resistant materials. For...

  16. 10 CFR Appendix D to Part 110 - Illustrative List of Aerodynamic Enrichment Plant Equipment and Components Under NRC Export...

    Science.gov (United States)

    2010-01-01

    ... enrichment process by compressing and converting UF6 to a liquid or solid form; and (iv) “Product” or “tails... Export Licensing Authority Note—In aerodynamic enrichment processes, a mixture of gaseous UF6 and light... quantities can provide an important indication of end use. Because aerodynamic processes use UF6, all...

  17. 10 CFR Appendix B to Part 110 - Illustrative List of Gas Centrifuge Enrichment Plant Components Under NRC's Export Licensing...

    Science.gov (United States)

    2010-01-01

    ... the centrifuges or to control the plant. Normally UF6 is evaporated from the solid using heated... disc-shaped baffle(s) and a stationary tube arrangement for feeding and extracting UF6 gas and... main separation chamber and, in some cases, to assist the UF6 gas circulation within the main...

  18. Uranium hexafluoride - chemistry and technology of a raw material of the nuclear fuel cycle

    International Nuclear Information System (INIS)

    Bacher, W.; Jacob, E.

    1986-01-01

    Uranium hexafluoride exhibits an unusual combination of properties: UF 6 is both a large-scale industrial product, and also one of the most reactive compounds known. Its industrial application arises from the need to use enriched uranium with up to 4% 235 U as fuel in light water reactors. Enrichment is performed in isotope separation plants with UF 6 as the working gas. Its volatility and thermal stability make UF 6 suitable for this application. UF 6 handling is difficult because of its high reactivity and its radioactivity, and special experience and equipment are required which are not commonly available in laboratories or industrial facilities. The chemical reactions of UF 6 are characterized by its marked fluorination efficiency which is similar to that of F 2 . Of special importance in connection with the handling of UF 6 is its extreme sensitivity to hydrolysis. Because they all use UF 6 , the isotope separation processes currently in use (gas diffusion, gas centrifuge, separation nozzle process) have a number of common features. For instance, they are all beset by the problem of formation of solid UF 6 decomposition products, e.g. by radiolysis of UF 6 molecules induced by its own radiation. Reconversion of UF 6 into UO 2 is achieved by three well-known methods (ADU, AUC, IDP-process). To produce uranium metal, UF 6 is first reduced to UF 4 , which is subsequently reduced by Ca 6 or Mg metal. 158 refs

  19. Manual on safe production, transport, handling and storage of uranium hexafluoride

    International Nuclear Information System (INIS)

    1994-11-01

    This document includes a description of the physical, chemical and radiological properties of UF 6 and related products, including information concerning their production, handling, storage and transportation and the management of the wastes which result. All the operations of UF 6 management are considered form a safety point of view. The IAEA organized a series of meetings to consider the hazards of UF 6 transport since considerable quantities of depleted, natural and enriched UF 6 are transported between nuclear fuel sites. Storage of depleted UF 6 is another important issue. Factors affecting long term storage are presented, especially site choice and cylinder corrosion. Other topics such as waste management, quality assurance and emergency preparedness which contribute to the overall safety of UF 6 handling, are included. The intention of this document is to provide analysis of the safety implications of all stages of UF 6 operations and to draw attention to specific features and properties of importance. 38 refs, figs, tabs

  20. The solubility of uranium hexafluoride in perfluoroethers

    International Nuclear Information System (INIS)

    Barber, E.J.

    1984-01-01

    The polyperfluoroethers are compatible with uranium hexafluoride (UF 6 ) and are suitable for use in diffusion pumps and in mechanical vacuum pumps which rely on oil as both the lubricant and the seal. The UF 6 is soluble in all fluids with which it is compatible. Because a number of vacuum pumps in the BOP facilities of the GCEP plant employ these perfluoroether oils as the working fluid and have oil chambers which are large, questions have been raised as to the relationships governing the solubility of UF 6 in these materials and the maximum quantities of UF 6 which could be dissolved in these oils under credible accident conditions. This report summarizes these solubility relations and the interaction of the UF 6 solubility and the pumping capability of this type of vacuum pump. It will be shown that, whereas the solubility of UF 6 in Fomblin Y25 fluoroether fluid under a UF 6 pressure of 760 torr and at the pump operating temperature of 160 0 F is about 500 g of UF 6 per liter of oil, the system controls are such as to isolate the system from the pumps before the quantity of UF 6 dissolved in the perfluoroether exceeds about 10 g of UF 6 per liter of oil. 13 refs., 7 figs

  1. Process gas solidification system

    International Nuclear Information System (INIS)

    1980-01-01

    A process for withdrawing gaseous UF 6 from a first system and directing same into a second system for converting the gas to liquid UF 6 at an elevated temperature, additionally including the step of withdrawing the resulting liquid UF 6 from the second system, subjecting it to a specified sequence of flash-evaporation, cooling and solidification operations, and storing it as a solid in a plurality of storage vessels. (author)

  2. Reaction of uranium hexafluoride with fluoroelastomers

    International Nuclear Information System (INIS)

    Bacher, W.; Bier, W.; Guber, A.

    1986-03-01

    All investigations were made in a stainless steel reaction vessel which was designed to serve also as a gas cell. By infrared spectroscopy of the gas phase it can be shown that traces of hydrogen fluoride present in technical grade UF 6 penetrate into the fluoroelastomer material where they react with the metallic compounds forming water. This water diffuses through the sealing material and causes subsequently a hydrolysis process of UF 6 in the gas phase. Gaseous HF is produced and acts as a fluorine transmitter between UF 6 and the metallic compounds. These solid products formed by UF 6 hydrolysis are deposited in the vicinity of the fluoroelastomers. (orig./PW) [de

  3. Isotope separation process

    International Nuclear Information System (INIS)

    Lyon, R.K.; Kaldor, A.

    1977-01-01

    In a method for the separation of isotopes of uranium in UF 6 , the UF 6 is subjected to ir radiation at a predetermined wavelength or set of wavelengths for less than 10 -3 sec in such a manner that at least 0.1% of the 235 UF 6 molecules absorb an energy of more than 2000 cm -1 . The excited UF 6 is then reacted with a gaseous reagent, F 2 , Cl 2 , or Br 2 , to produce a product which is then recovered by means known in the art

  4. Uranium isotope separation using IR-lasers

    International Nuclear Information System (INIS)

    Jetter, H.; Guers, K.; Dibbert, H.J.

    1976-01-01

    A method of uranium isotope separation based on selective excitation of UF 6 is described. By optically exciting certain molecular vibrations, the activation energy for the rate of a chemical reaction is reduced, resulting in an increase in reaction rate. Isotope separation can therefore be reduced to a simple chemical process. Experiments and results are described for selective excitation of UF 6 gas using a tunable C0 laser. It is shown that isotopically selective excitation of UF 6 combination bands is not feasible in a simple manner, but the excitation of UF 6 in the ν 3 fundamental is much more promising. (U.K.)

  5. Dálkový průzkum a GIS při hodnocení vztahů krajinné struktury a koncentrace živin v povodí Lipna

    Czech Academy of Sciences Publication Activity Database

    Žaloudík, Jiří; Hejzlar, Josef; Rohlík, V.

    - (2004), s. 77-80 ISSN 1212-4311 R&D Projects: GA AV ČR IBS6017004; GA ČR GA103/98/0281 Institutional research plan: CEZ:AV0Z6087904; CEZ:AV0Z6017912 Keywords : water quality * remote sensing * GIS Subject RIV: DJ - Water Pollution ; Quality

  6. Více-kvantová NMR spektroskopie pevného stavu: způsob, jak nahlédnout do struktury anorganických materiálů

    Czech Academy of Sciences Publication Activity Database

    Kobera, Libor; Urbanová, Martina; Brus, Jiří

    2012-01-01

    Roč. 106, č. 9 (2012), s. 802-808 ISSN 0009-2770 R&D Projects: GA ČR GAP108/10/1980 Institutional research plan: CEZ:AV0Z40500505 Keywords : NMR spectroscopy * structural analysis * NMR crystalography Subject RIV: JI - Composite Materials Impact factor: 0.453, year: 2012 http://www.chemicke-listy.cz/docs/full/2012_09_802-808.pdf

  7. BIOTECHNOLOGICKÉ ASPEKTY SVĚTLEM INICIOVANÉHO SÍŤOVÁNÍ – PIXL (Z ANGL. PHOTO INDUCED CROSS LINKING): NOVÉ ALTERNATIVNÍ TECHNIKY PRO STUDIUM 3D STRUKTURY PROTEINŮ ČI VZÁJEMNÝCH INTERAKCÍ

    Czech Academy of Sciences Publication Activity Database

    Šulc, Miroslav; Ptáčková, Renata

    2016-01-01

    Roč. 26, č. 4 (2016), s. 79-83 ISSN 1210-1737 R&D Projects: GA MŠk(CZ) LO1509 Institutional support: RVO:61388971 Keywords : Photo Induced Cross Linking * photo methionine * photo methionine, diazirines Subject RIV: EE - Microbiology, Virology

  8. Dvě zprávy o raně křesťanské liturgii. Pokus o analýzu narativní struktury

    Czech Academy of Sciences Publication Activity Database

    Fialová, Radka

    -, č. 24 (2014), s. 83-111 ISSN 1805-2762 R&D Projects: GA ČR(CZ) GBP401/12/G168 Institutional support: RVO:67985955 Keywords : Early Christian liturgy * baptism and Eucharist in the 2nd Century * Didache * Justin Martyr's Apology Subject RIV: AA - Philosophy ; Religion https://www.etf.cuni.cz/ sat /2014-1.html

  9. A.W., Nowak, K.Abriszewski, M.Wróblewski, Czyje lęki? Czyja nauka? Struktury wiedzy wobec kontrowersji naukowo-społecznych, Poznań 2016, s.233.

    OpenAIRE

    Nowak, Andrzej W.; Abriszewski, Krzysztof; Wróblewski, Michał

    2016-01-01

    Książka wpisuje się w popularne ostatnio zainteresowanie humanistyki i nauk społecznych kwestiami związanymi z techniką oraz postępem. Podejmuje wątki obecne we współczesnej socjologii wiedzy i filozofii nauki, odnosząc je jednocześnie do wielu palących problemów dzisiejszego świata społecznego. Idąc śladem Urlicha Becka i jego tezy o społeczeństwie ryzyka, autorzy twierdzą, że dzisiejsza nauka rzuca nam dwojakiego rodzaju wyzwanie. Z jednej strony generuje ona na niespotykaną wcześniej sk...

  10. Od fyzikálních základů studia struktury pevných látek k monokrystalům superslitin pro plynové turbíny

    Czech Academy of Sciences Publication Activity Database

    Lukáš, Petr; Kunz, Ludvík; Svoboda, Milan

    2008-01-01

    Roč. 58, č. 2 (2008), s. 81-83 ISSN 0009-0700 Institutional research plan: CEZ:AV0Z20410507 Keywords : solid state physics * superalloy single crystals Subject RIV: BM - Solid Matter Physics ; Magnetism

  11. Udjel mlijeka i mliječnih proizvoda u strukturi društveno organiziranog obroka u učeničkim domovima na području grada Zagreba

    OpenAIRE

    Gajdoš, Jasenka; Kurtanjek, Želimir

    1999-01-01

    Zbog velikog udjela proteina, minerala i vitamina, mlijeko spada u skupinu vrlo važnih namirnica tijekom rasta i razvoja mladih. Osobito su važne prehrambene navike pojedinaca. Kako bi se dobio što bolji uvid u prehrambeni status izabrane skupine (djevojke i mladići od 14-18 godina) obavljena je analiza obroka u učeničkim domovima. Iz analiziranih obroka razvidno je što se može poboljšati u obrocima društvene prehrane. Analizom obroka te anketom, utvrđeno je da 62% djevojaka i 66% mladića kon...

  12. Фазовое равновесие жидкость пар в трёхкомпонентной системе UF6-IF5-BrF3 при полной взаимной растворимости компонентов

    OpenAIRE

    Жерин, И.; Усов, В.; Оствальд, Р.; Шагалов, В.; Гайдай, И.; Тюлюбаев, З.

    2007-01-01

    Представлены результаты исследования фазового равновесия жидкость пар при 353,15 К в системе гексафторид урана, пентафторид йода, трифторид брома. Приведены зависимости давления насыщенного пара от состава конденсированной фазы, результаты анализа отклонения изучаемой системы от идеального поведения, данные о равновесной паровой фазе....

  13. Circulation system for flowing uranium hexafluoride cavity reactor experiments

    International Nuclear Information System (INIS)

    Jaminet, J.F.; Kendall, J.S.

    1976-01-01

    Accomplishment of the UF 6 critical cavity experiments, currently in progress, and planned confined flowing UF 6 initial experiments requires development of reliable techniques for handling heated UF 6 throughout extended ranges of temperature, pressure, and flow rate. The development of three laboratory-scale flow systems for handling gaseous UF 6 at temperatures up to 500 K, pressures up to approximately 40 atm, and continuous flow rates up to approximately 50 g/s is presented. A UF 6 handling system fabricated for static critical tests currently being conducted at Los Alamos Scientific Laboratory (LASL) is described. The system was designed to supply UF 6 to a double-walled aluminum core canister assembly at temperatures between 300 K and 400 K and pressures up to 4 atm. A second UF 6 handling system designed to provide a circulating flow of up to 50 g/s of gaseous UF 6 in a closed-loop through a double-walled aluminum core canister with controlled temperature and pressure is described

  14. 49 CFR 173.417 - Authorized fissile materials packages.

    Science.gov (United States)

    2010-10-01

    ... for export and import shipments. (2) A residual “heel” of enriched solid uranium hexafluoride may be... made in accordance with Table 2, as follows: Table 2—Allowable Content of Uranium Hexafluoride (UF6... Liters Cubic feet Maximum Uranium 235-enrichment (weight)percent Maximum “Heel” weight per cylinder UF6...

  15. Device for controlling gas recovery

    International Nuclear Information System (INIS)

    Ichioka, Atsushi.

    1976-01-01

    Purpose: To provide a controlling device for UF 6 gas recovery device, which can increase working efficiency and to discriminate normality and abnormality of the recovery device. Constitution: The gas recovery device comprises a plurality of traps, which are connected in series. The UF 6 gas is introduced into the first trap where adsorbing work is taken place to accumulate UF 6 gases, and the UF 6 gases partly flow into the succeeding trap. Even in this trap, when the adsorbing work begins, the succeeding trap is operated in series fashion. In this manner, two traps are continuously operated to recover the gases while performing the steps of adsorbing, waiting and regenerating in that order. The switching operation of the aforesaid steps is accomplished on the basis of concentration of the UF 6 detected between two traps, which are continuously driven. (Kamimura, M.)

  16. Parametric analyses of planned flowing uranium hexafluoride critical experiments

    Science.gov (United States)

    Rodgers, R. J.; Latham, T. S.

    1976-01-01

    Analytical investigations were conducted to determine preliminary design and operating characteristics of flowing uranium hexafluoride (UF6) gaseous nuclear reactor experiments in which a hybrid core configuration comprised of UF6 gas and a region of solid fuel will be employed. The investigations are part of a planned program to perform a series of experiments of increasing performance, culminating in an approximately 5 MW fissioning uranium plasma experiment. A preliminary design is described for an argon buffer gas confined, UF6 flow loop system for future use in flowing critical experiments. Initial calculations to estimate the operating characteristics of the gaseous fissioning UF6 in a confined flow test at a pressure of 4 atm, indicate temperature increases of approximately 100 and 1000 K in the UF6 may be obtained for total test power levels of 100 kW and 1 MW for test times of 320 and 32 sec, respectively.

  17. Freezer-sublimer for gaseous diffusion plant

    International Nuclear Information System (INIS)

    Reti, G.R.

    1978-01-01

    A method and apparatus is disclosed for freezing and subliming uranium hexafluoride (UF 6 ) as part of a gaseous diffusion plant from which a quantity of the UF 6 inventory is intermittently withdrawn and frozen to solidify it. A plurality of upright heat pipes holds a coolant and is arranged in a two compartment vessel, the lower compartment is exposed to UF 6 , the higher one serves for condensing the evaporated coolant by means of cooling water. In one embodiment, each pipe has a quantity of coolant such as freon, hermetically sealded therein. In the other embodiment, each pipe is sealed only at the lower end while the upper end communicates with a common vapor or cooling chamber which contains a water cooled condenser. The cooling water has a sufficiently low temperature to condense the evaporated coolant. The liquid coolant flows gravitationally downward to the lower end portion of the pipe. UF 6 gas is flowed into the tank where it contacts the finned outside surface of the heat pipes. Heat from the gas evaporates the coolant and the gas in turn is solidified on the exterior of the heat pipe sections in the tank. To recover UF 6 gas from the tank, the solidified UF 6 is sublimed by passing compressed UF 6 gas over the frozen UF 6 gas on the pipes or by externally heating the lower ends of the pipes sufficiently to evaporate the coolant therein above the subliming temperature of the UF 6 . The subliming UF 6 gas then condenses the coolant in the vertical heat pipes, so that it can gravitationally flow back to the lower end portions

  18. Uranium hexafluoride: A manual of good handling practices. Revision 7

    International Nuclear Information System (INIS)

    1995-01-01

    The United States Enrichment Corporation (USEC) is continuing the policy of the US Department of Energy (DOE) and its predecessor agencies in sharing with the nuclear industry their experience in the area of uranium hexafluoride (UF 6 ) shipping containers and handling procedures. The USEC has reviewed Revision 6 or ORO-651 and is issuing this new edition to assure that the document includes the most recent information on UF 6 handling procedures and reflects the policies of the USEC. This manual updates the material contained in earlier issues. It covers the essential aspects of UF 6 handling, cylinder filling and emptying, general principles of weighing and sampling, shipping, and the use of protective overpacks. The physical and chemical properties of UF 6 are also described. The procedures and systems described for safe handling of UF 6 presented in this document have been developed and evaluated during more than 40 years of handling vast quantities of UF 6 . With proper consideration for its nuclear properties, UF 6 may be safely handled in essentially the same manner as any other corrosive and/or toxic chemical

  19. Interim guidance on the safe transport of uranium hexafluoride

    International Nuclear Information System (INIS)

    1991-06-01

    Uranium hexafluoride (UF 6 ) is a radioactive material that has significant non-radiological hazardous properties. In conformity with international regulatory practice for dangerous goods transport, these properties are classed as ''subsidiary risks'', although they predominate in the cases of depleted and natural UF 6 . UF 6 is transported as a solid material below atmospheric pressure. The IAEA Regulations for the Safe Transport of Radioactive Material, 1985 Edition, Safety Series No. 6, make recommendations that aimed to provide an adequate level of safety against radiological and criticality hazards. The basis for these is that the stringency of package performance requirements, operational procedures and approval and administrative procedures is graded relative to the severity of the hazard. The cylinders used for transporting UF 6 are also used in the production, storage and use of the material and that the fraction of their life cycle in which transport is involved is small. Consideration must also be given to the large number of existing cylinders (estimated to be between 60,000 and 70,000). Specific recommendations provided for UF 6 transport, listed in Section II, are additional to the requirements of the Regulations. The intent of these additional recommendations is to restrict contamination and to provide protection to workers and to the general public against the chemical hazard possibly resulting from a severe accident involving the transport of UF 6 , and in addition against the consequences of explosive rupture of small bare cylinders of UF 6 . 20 refs, figs and tabs

  20. NMR shielding calculations across the periodic table: diamagnetic uranium compounds. 2. Ligand and metal NMR.

    Science.gov (United States)

    Schreckenbach, Georg

    2002-12-16

    In this and a previous article (J. Phys. Chem. A 2000, 104, 8244), the range of application for relativistic density functional theory (DFT) is extended to the calculation of nuclear magnetic resonance (NMR) shieldings and chemical shifts in diamagnetic actinide compounds. Two relativistic DFT methods are used, ZORA ("zeroth-order regular approximation") and the quasirelativistic (QR) method. In the given second paper, NMR shieldings and chemical shifts are calculated and discussed for a wide range of compounds. The molecules studied comprise uranyl complexes, [UO(2)L(n)](+/-)(q); UF(6); inorganic UF(6) derivatives, UF(6-n)Cl(n), n = 0-6; and organometallic UF(6) derivatives, UF(6-n)(OCH(3))(n), n = 0-5. Uranyl complexes include [UO(2)F(4)](2-), [UO(2)Cl(4)](2-), [UO(2)(OH)(4)](2-), [UO(2)(CO(3))(3)](4-), and [UO(2)(H(2)O)(5)](2+). For the ligand NMR, moderate (e.g., (19)F NMR chemical shifts in UF(6-n)Cl(n)) to excellent agreement [e.g., (19)F chemical shift tensor in UF(6) or (1)H NMR in UF(6-n)(OCH(3))(n)] has been found between theory and experiment. The methods have been used to calculate the experimentally unknown (235)U NMR chemical shifts. A large chemical shift range of at least 21,000 ppm has been predicted for the (235)U nucleus. ZORA spin-orbit appears to be the most accurate method for predicting actinide metal chemical shifts. Trends in the (235)U NMR chemical shifts of UF(6-n)L(n) molecules are analyzed and explained in terms of the calculated electronic structure. It is argued that the energy separation and interaction between occupied and virtual orbitals with f-character are the determining factors.

  1. Draft Programmatic Environmental Impact Statement for alternative strategies for the long-term management and use of depleted uranium hexafluoride. Volume 2: Appendices

    International Nuclear Information System (INIS)

    1997-12-01

    This PEIS assesses the potential impacts of alternative management of alternative management strategies for depleted uranium hexafluoride (UF 6 ) currently stored at three DOE sites: Paducah site near Paducah, Kentucky; Portsmouth site near Portsmouth, Ohio; and K-25 site on the Oak Ridge Reservation, Oak Ridge, Tennessee. The alternatives analyzed in the PEIS include no action, long-term storage as UF 6 , long-term storage as uranium oxide, use as uranium oxide, use as uranium metal, and disposal. The preferred alternative for the long-term management of depleted UF 6 is to use the entire inventory of material. This volume contains the appendices to volume I

  2. Draft Programmatic Environmental Impact Statement for alternative strategies for the long-term management and use of depleted uranium hexafluoride. Volume 1: Main text

    International Nuclear Information System (INIS)

    1997-12-01

    This PEIS assesses the potential impacts of alternative management of alternative management strategies for depleted uranium hexafluoride (UF 6 ) currently stored at three DOE sites: Paducah site near Paducah, Kentucky; Portsmouth site near Portsmouth, Ohio; and K-25 site on the Oak Ridge Reservation, Oak Ridge, Tennessee. The alternatives analyzed in the PEIS include no action, long-term storage as UF 6 , long-term storage as uranium oxide, use as uranium oxide, use as uranium metal, and disposal. The preferred alternative for the long-term management of depleted UF 6 is to use the entire inventory of material

  3. Method to separate off hydrogen fluoride from a uranium hexafluoride-hydrogen fluoride mixture

    International Nuclear Information System (INIS)

    Pfistermeister, M.; Jokar, J.

    1979-01-01

    There have been sofar difficulties involved in separating off HF when purifying UF 6 . According to the invention, this can be achieved without great expenditure if one adds a perfluorated amine or derivative of it to the UF 6 -HF mixture. The UF 6 can be separated by simple distillation or sublimation from the hardly-volatile formed tri-(perfluoro-butyl) ammonium fluoride. The adduct formed can be easily split again with NaOH so that the amine can be recycled without loss. (UWI) [de

  4. Fuel Fabrication and Nuclear Reactors

    International Nuclear Information System (INIS)

    Karpius, Peter Joseph

    2017-01-01

    The uranium from the enrichment plant is still in the form of UF 6 . UF 6 is not suitable for use in a reactor due to its highly corrosive chemistry as well as its phase diagram. UF 6 is converted into UO 2 fuel pellets, which are in turn placed in fuel rods and assemblies. Reactor designs are variable in moderators, coolants, fuel, performance etc.The dream of energy ''too-cheap to meter'' is no more, and now the nuclear power industry is pushing ahead with advanced reactor designs.

  5. Emission characteristics of uranium hexafluoride at high temperatures

    International Nuclear Information System (INIS)

    Krascella, N.L.

    1976-01-01

    An experimental study was conducted to ascertain the spectral characteristics of uranium hexafluoride (UF 6 ) and possible UF 6 thermal decomposition products as a function of temperature and pressure. Relative emission measurements were made for UF 6 /Argon mixtures heated in a plasma torch over a range of temperatures from 800 to about 3600 0 K over a wavelength range from 80 to 600 nm. Total pressures were varied from 1 to approximately 1.7 atm. Similarly absorption measurements were carried out in the visible region from 420 to 580 nm over a temperature range from about 1000 to 1800 0 K. Total pressure for these measurements was 1.0 atm

  6. Environmental impact appraisal for renewal of source material license No. SUB-526 (Docket No. 40-3392)

    International Nuclear Information System (INIS)

    1984-05-01

    Allied Chemical Company operates a privately owned UF 6 production facility at Metropolis, Illinois, At this facility, uranium ore concentrates are converted into uranium hexafluoride (UF 6 ). The UF 6 product from this facility is shipped to Department of Energy (DOE) gaseous diffusion plants for enrichment of the 235 U isotope. This assessment: (1) reviews the operation of the facility during the recent license period by comparing the plant effluent releases or environmental monitoring data with permissible levels of contaminants; and (2) determines the impact on the environment from continued operation of the facility in its current configuration. 10 figures, 44 tables

  7. Transport of Powders through Rotary Kilns: Experimental Study and Modelling

    OpenAIRE

    Debacq , Marie; Hartmann , Didier; Houzelot , Jean-Leon; Ablitzer , Denis

    1999-01-01

    International audience; During the nuclear fuel cycle, uranium as hexafluoride is enriched by means of gaseous-diffusion process. The depleted UF6 resulting from the isotope separation stage is converted into U3O8 to enable its safe storage (conversion carried out by COGEMA). The UF6 -> UO2 conversion is performed in four identical plants : UF6 is hydrolysed in the gaseous phase through a vertical reactor, then the UO2F2 powder formed is pyrohydrolysed into U3O8 powder through a lightly incli...

  8. Study and production of a lubricating emulsion based on poly-trifluoro-monochloroethylene inert to chemical agents

    International Nuclear Information System (INIS)

    Marquet-Ellis, Hubert

    1964-01-01

    This report addresses the study of the chemical behaviour of some polymers of (CF 2 - CFCl) x with respect to UF 6 and ClF 3 . The author first reports the study of the physical-chemical properties of the different chloro-fluorinated polymers, and then the study of the reaction of UF 6 on chloro-fluorinated oils, of the reaction of gaseous ClF 3 on these oils, the solubility of UF 6 at 20 C in a chloro-fluorinated oil (Voltalef 10), and the production and chloro-fluorinated synthetic greases

  9. The reduction of uranium hexafluoride by carbon tetrachloride in the gaseous phase

    International Nuclear Information System (INIS)

    Xu Heqing; Qiu Lufu

    1987-01-01

    The reduction of UF 6 to UF 4 by CCl 4 in a 0.08 m diameter vertical glass reactor has been studied. In the tests, UF 6 and CCl 4 , preheated to about 350 deg C, were fed into the reactor and the tower walls were held at about 500 deg C, the reaction was taking place almost completely in the gaseous phase. A high temperature flames can be visually observed by increasing in the reactant feed rates, and the brightness of the flame changes with the reactant feed rates. The conversion of UF 6 is essentially complete if a CCl 4 excess is maintained. The method is considered to be an effective process to meet continuous conversion of slightly enriched UF 6

  10. The action of uranium hexafluoride on some metallic fluorides (1962)

    International Nuclear Information System (INIS)

    Michallet, M.

    1961-12-01

    A metallic difluoride is inert to UF 6 unless the metal can exist in a higher valency state. In this case, UF 6 acts as an oxidising agent and is transformed into UF 4 . The fluorides of tri- and tetra-valent metals give rise to new compounds when they are maintained at a high temperature (500 deg. C) in the presence of uranium hexachloride vapour. The products obtained are characterized by their X-ray diffraction diagrams. The distributions of the lines of the powder diagrams are very similar to that of U 4 F 17 . Assuming that this resemblance is due to a stacking of identical fluorine atoms, it can be calculated that the corresponding structure is given by the theoretical formulae: MeF 3 , 0,562 UF 6 ; MeF 4 , 0,396 UF 6 which are in good agreement with chemical measurements. (author) [fr

  11. Initial conceptual design study of self-critical nuclear pumped laser systems

    Science.gov (United States)

    Rodgers, R. J.

    1979-01-01

    An analytical study of self-critical nuclear pumped laser system concepts was performed. Primary emphasis was placed on reactor concepts employing gaseous uranium hexafluoride (UF6) as the fissionable material. Relationships were developed between the key reactor design parameters including reactor power level, critical mass, neutron flux level, reactor size, operating pressure, and UF6 optical properties. The results were used to select a reference conceptual laser system configuration. In the reference configuration, the 3.2 m cubed lasing volume is surrounded by a graphite internal moderator and a region of heavy water. Results of neutronics calculations yield a critical mass of 4.9 U(235) in the form (235)UF6. The configuration appears capable of operating in a continuous steady-state mode. The average gas temperature in the core is 600 K and the UF6 partial pressure within the lasing volume is 0.34 atm.

  12. University of Illinois nuclear pumped laser program. [experiments with a TRIGA pulsed reactor with a broad pulse and a low peak flux

    Science.gov (United States)

    Miley, G. H.

    1979-01-01

    The development of nuclear pumped lasers with improved efficiency, energy storage capability, and UF6 volume pumping is reviewed. Results of nuclear pumped laser experiments using a TRIGA-type pulsed reactor are outlined.

  13. Transport of RAM in tanks: how to fit into the IAEA safety philosophy

    International Nuclear Information System (INIS)

    Schulz-Forberg, B.; Ulrich, A.

    1983-01-01

    The transport of radioactive materials (RAM) in tanks will become a field of increasing interest. Especially for substances with low radioactive hazard but may be with subsidary risks which can overrule the RAM-philosophy. The IAEA should pay attention to the problem whether to take over a more active part in the non-nuclear field of transport regulations by influencing and using the outcome of RAM transport conditions or to incorporate some or all provisions for tank transport in their own regulations. The necessity to solve the problems of shipments of substances with low radioactive hazards but high chemical hazards is highlighted by the requirements for UF 6 -cylinders. Up to now UF 6 is listed in class 7 only, but the IAEA requirements for large UF 6 cylinders don't come up to the level of requirements needed for the toxic and corrosive nature of UF 6 . 5 references

  14. Conversion and Blending Facility Highly enriched uranium to low enriched uranium as uranium hexafluoride. Revision 1

    International Nuclear Information System (INIS)

    1995-01-01

    This report describes the Conversion and Blending Facility (CBF) which will have two missions: (1) convert surplus HEU materials to pure HEU UF 6 and a (2) blend the pure HEU UF 6 with diluent UF 6 to produce LWR grade LEU-UF 6 . The primary emphasis of this blending be to destroy the weapons capability of large, surplus stockpiles of HEU. The blended LEU product can only be made weapons capable again by the uranium enrichment process. The chemical and isotopic concentrations of the blended LEU product will be held within the specifications required for LWR fuel. The blended LEU product will be offered to the United States Enrichment Corporation (USEC) to be sold as feed material to the commercial nuclear industry

  15. Uranium fluoride chemistry. Part 1. The gas phase reaction of uranium hexafluoride with alcohols

    International Nuclear Information System (INIS)

    Schnautz, N.G.; Venter, P.J.

    1992-01-01

    The reaction between uranium hexafluoride (UF 6 ) and simple alcohols in the gas phase was observed to proceed by way of three possible reaction pathways involving dehydration, deoxygenative fluorination, and ether formation. These reactions can best be explained by assuming that alcohols first react with UF 6 to afford the alkoxy uranium pentafluoride intermediate ROUF 5 , which reacts further to give the dehydration, deoxygenative fluorination, and ether products. In each of the above three reaction pathways, UF 6 is transformed to UOF 4 , which being as reactive toward alcohols as UF 6 , reacts further with the alcohol in question to finally afford the unreactive uranyl fluoride (UO 2 F 2 ). 6 refs., 2 tabs

  16. Isotopic separation

    International Nuclear Information System (INIS)

    Castle, P.M.

    1979-01-01

    This invention relates to molecular and atomic isotope separation and is particularly applicable to the separation of 235 U from other uranium isotopes including 238 U. In the method described a desired isotope is separated mechanically from an atomic or molecular beam formed from an isotope mixture utilising the isotropic recoil momenta resulting from selective excitation of the desired isotope species by radiation, followed by ionization or dissociation by radiation or electron attachment. By forming a matrix of UF 6 molecules in HBr molecules so as to collapse the V 3 vibrational mode of the UF 6 molecule the 235 UF 6 molecules are selectively excited to promote reduction of UF 6 molecules containing 235 U and facilitate separation. (UK)

  17. Thermodynamic data for uranium fluorides

    International Nuclear Information System (INIS)

    Leitnaker, J.M.

    1983-03-01

    Self-consistent thermodynamic data have been tabulated for uranium fluorides between UF 4 and UF 6 , including UF 4 (solid and gas), U 4 F 17 (solid), U 2 F 9 (solid), UF 5 (solid and gas), U 2 F 10 (gas), and UF 6 (solid, liquid, and gas). Included are thermal function - the heat capacity, enthalpy, and free energy function, heats of formation, and vaporization behavior

  18. Procedures for handling and analysis of uranium hexafluoride. Volume 2. Analysis

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    1972-04-01

    Volume 2 of this report contains analytical procedures - which. may be used by AEC customers and UF6 processors to determine conformance to the Federal Register specifications and other properties for UF6. The procedures presented are typical of those currently in use at the AEC-owned gaseous diffusion plants. Other procedures may be used provided analytical results of comparable precision and accuracy are obtained.

  19. Uranium hexafluoride: A manual of good handling practices

    International Nuclear Information System (INIS)

    1991-10-01

    For many years, the US Department of Energy (DOE) and its predecessor agencies have shared with the nuclear industry their experience in the area of uranium hexafluoride (UF 6 ) shipping containers and handling procedures. The information contained in this manual updates information contained in earlier issues. It covers the essential aspects of UF 6 handling, cylinder filling and emptying, general principles of weighing and sampling, shipping, and the use of protective overpacks. The physical and chemical properties of UF 6 are also described and tabulated. The nuclear industry is responsible for furnishing its own shipping cylinders and suitable protective overpacks. A substantial effort has been made by the industry to standardize UF 6 cylinders, samples, and overpacks. The quality of feed materials is important to the safe and efficient operation of the enriching facilities, and the UF 6 product purity from the enriching facilities is equally important to the fuel fabricator, the utilities, the operators of research reactors, and other users. The requirements have been the impetus for an aggressive effort by DOE and its contractors to develop accurate techniques for sampling and for chemical and isotopic analysis. A quality control program is maintained within the DOE enriching facilities to ensure that the proper degree of accuracy and precision are obtained for all the required measurements. The procedures and systems described for safe handling of UF 6 presented in this document have been developed and evaluated in DOE facilities during more than 40 years of handling vast quantities of UF 6 . With proper consideration for its nuclear properties, UF 6 may be safely handled in essentially the same manner as any other corrosive and/or toxic chemical

  20. COGEMA's UMF [Uranium Management Facility

    International Nuclear Information System (INIS)

    Lamorlette, G.; Bertrand, J.P.

    1988-01-01

    The French government-owned corporation, COGEMA, is responsible for the nuclear fuel cycle. This paper describes the activities at COGEMA's Pierrelatte facility, especially its Uranium Management Facility. UF6 handling and storage is described for natural, enriched, depleted, and reprocessed uranium. UF6 quality control specifications, sampling, and analysis (halocarbon and volatile fluorides, isotopic analysis, uranium assay, and impurities) are described. In addition, the paper discusses the filling and cleaning of containers and security at UMF

  1. Regulatory and performance tests of packages for transporting radioactive materials

    International Nuclear Information System (INIS)

    Itoh, Chihiro

    2003-01-01

    This is a summary of nuclear tests conducted in our institute, including (1) fireproof and pressure tests of an enriched UF 6 transport package, (2) drop, thermal, and pressure tests of a natural UF 6 transport package, (3) drop, thermal, submerge tests of a spent fuel transport cask, and (4) drop, thermal, and submerge tests of a returned high level vitrified waste transport cask. These tests proved that the transport packages meet IAEA's transport requirements with sufficient margins for the safety. (author)

  2. Математическое моделирование процесса десублимации гексафторида урана

    OpenAIRE

    Малюгин, Р. В.; Цимбалюк, Александр Федорович

    2015-01-01

    A non-stationary mathematical model of desublimation UF6 in vertical tanks considers the movement of gaseous uranium hexafluoride contains in the article. Results of calculation of time dependence of the linear velocity desublimation, the thickness of the resulting layer of the solid phase, the temperature distribution in the tank wall - desublimation layer, filling dynamics of vertical tank B-12 by solid UF6 are presented. Calculations have shown that the 70% of B-12 tank is filled by desubl...

  3. High mass isotope separation arrangement

    International Nuclear Information System (INIS)

    Eerkens, J.W.

    1980-01-01

    This invention relates to the isotope separation art and, more particularly, to a selectively photon-induced energy level transition of an isotopic molecule containing the isotope to be separated and a chemical reaction with a chemically reactive agent to provide a chemical compound containing atoms of the isotope desired. In particular a description is given of a method of laser isotope separation applied to the separation of 235 UF 6 from 238 UF 6 . (U.K.)

  4. Modeling of a rotative kiln for the conversion of uranium hexafluoride into uranium dioxide

    International Nuclear Information System (INIS)

    Lacombe, S.; Perrais, C.; Michaille, P.; Lisbonne, P.; Bernardin, M.

    1993-01-01

    In the framework of the study of the conversion process of UF 6 into UO 2 , the FLUOX code (FLUoride/OXide conversion) was developed for modeling the industrial reactor. A first model on the pyrohydrolysis of UO 2 F 2 into UO 2 was partially validated. The reactor for hydrolysis of UF 6 into UO 2 is also taken into account for a global model of the process

  5. Změny struktury a fázového složení intermetalické sloučeniny Ni3Al vlivem okolní atmosféry při zvýšených teplotách

    Czech Academy of Sciences Publication Activity Database

    Pizúrová, Naděžda; Schneeweiss, Oldřich

    2001-01-01

    Roč. 39, č. 2 (2001), s. 121-131 ISSN 0023-432X R&D Projects: GA ČR GA106/97/1044; GA ČR GA106/99/0183 Institutional research plan: CEZ:AV0Z2041904 Keywords : electrical resistivity * intermetallics * corrosion Subject RIV: JG - Metallurgy Impact factor: 0.343, year: 2001

  6. Využití piezoelektrických kompozitních aktuátorů k potlačování přenášeného hluku skrz tenkostěnné plošné struktury

    Czech Academy of Sciences Publication Activity Database

    Nováková, K.; Mokrý, P.; Václavík, Jan

    2012-01-01

    Roč. 57, 11-12 (2012), s. 300-307 ISSN 0447-6441. [OaM 2012 International Conference on Optics and Measurement. Liberec, 16.10.2012-18.10.2012] R&D Projects: GA MŠk(CZ) ED2.1.00/03.0079 Institutional research plan: CEZ:AV0Z20430508 Keywords : piezoelectric composites * reduction of the noise transmission * control their elastic Subject RIV: BI - Acoustics

  7. Nepříliš harmonická realita. Rodičovské kombinace práce a péče v mezích genderové struktury současné české společnosti

    Czech Academy of Sciences Publication Activity Database

    Křížková, Alena

    2007-01-01

    Roč. 8, č. 2 (2007), s. 60-67 ISSN 1213-0028 R&D Projects: GA ČR GA403/05/2474 Institutional research plan: CEZ:AV0Z70280505 Keywords : work / life balance * gender inequalities * labour market Subject RIV: AO - Sociology, Demography www.genderonline.cz

  8. Vývoj osídlení a struktury pravěké krajiny na středním Labi. Pokus o přímé srovnání archeologické a pyloanalytické evidence

    Czech Academy of Sciences Publication Activity Database

    Dreslerová, Dagmar; Pokorný, Petr

    2005-01-01

    Roč. 56, č. 4 (2005), s. 739-762 ISSN 0323-1267 Institutional research plan: CEZ:AV0Z8002910 Keywords : environment * pollen analyses * settlement pattern Subject RIV: AC - Archeology, Anthropology, Ethnology

  9. Posouzení vztahu mezi zaváděním procesního řízení a zplošťováním organizační struktury malých a středních podniků

    Directory of Open Access Journals (Sweden)

    Jana Kubecová

    2014-10-01

    Full Text Available Purpose of the article: Business process management is a topical theme in the field of corporate. The introduction of business process management has a huge impact on business organization and dramatically changes ingrained principles, procedures and methods. One of the changes associated with the introduction of business process management is company´s direction to horizontal organization. The purpose of this article is to verify the assumption flattening of organizational structures as a result of the increasing rate of introduction of business process management. Methodology/methods: The issue is solved on small and medium-sized enterprises. The analyzed sample contains 187 small and medium-sized enterprises from South Bohemia. Business process management in enterprises, respectively the rate of implementation of the principles of business process management, is measured by indicator Degree of Business Process Management Principles Implementation. The flattening of the organizational structure is based on the number of managers who, because of the three levels of managers converted to points. The relationship and its intensity are analyzed using statistical methods Spearman correlation coefficient. Scientific aim: The aim of the paper is to verify the assumption of horizontal organization in connection with the implementation of business process management. Findings: For analyzed micro enterprises were able to demonstrate moderate positive correlation between the degree of business process management implementation and the number of managers. Based on the analyzed micro enterprises therefore cannot confirm the assumption of business process management, which is company approaching to the horizontal organization. Based on statistical methods were found in small and medium-sized enterprises exactly the same results as for micro enterprises. Conclusions: Statistical analysis was able to demonstrate a positive dependence with a significant relationship between the degree of business process management implementation and the number of managers. This means that with the increasing degree of business process management implementation grows the number of managers. Based on the analyzed data, with increasing degree of business process management implementation organization not come close to horizontal organization.

  10. Skutečná kupní síla v krajích České republiky: zohlednění regionální cenové hladiny a struktury pracovní síly

    Czech Academy of Sciences Publication Activity Database

    Bajgar, Matěj; Janský, Petr

    2015-01-01

    Roč. 63, č. 7 (2015), s. 860-876 ISSN 0032-3233 R&D Projects: GA TA ČR(CZ) TD020188 Institutional support: RVO:67985998 Keywords : price levels * regional price levels * regional price differentials Subject RIV: AH - Economics Impact factor: 0.904, year: 2015

  11. Učení a paměť v dynamickém světě: od percepce času, přes mozkové struktury a buňky až po neuropsychiatrická onemocnění

    Czech Academy of Sciences Publication Activity Database

    Stuchlík, Aleš; Valeš, Karel; Kubík, Štěpán; Vlček, Kamil

    2014-01-01

    Roč. 18, č. 2 (2014), s. 69-76 ISSN 1211-7579 R&D Projects: GA MŠk(CZ) LH14053; GA MZd(CZ) NT13386; GA ČR(CZ) GA14-03627S Grant - others:Rada Programu interní podpory projektů mezinárodní spolupráce AV ČR(CZ) M200111204 Institutional support: RVO:67985823 Keywords : learning * timing * pharmacology * neurogenesis * human tests Subject RIV: FH - Neurology

  12. Dislocation structures, effective and internal stresses of cyclic stained ferritic stainless steel

    Czech Academy of Sciences Publication Activity Database

    Petrenec, Martin; Polák, Jaroslav

    2001-01-01

    Roč. 72, č. 279 (2001), s. 129-133 ISSN 1429-6055. [Medzynarodowe Sympozjum - Metody oceny struktury oraz wlasnosci materialów i wyrobów /16./. Komorní Lhotka, 11.12.2001-13.12.2001] Institutional research plan: CEZ:AV0Z2041904 Keywords : dislocation * cyclicling * stresses Subject RIV: JL - Materials Fatigue, Friction Mechanics

  13. Życie wirtualnych dzikich

    OpenAIRE

    Jemielniak, Dariusz

    2013-01-01

    Jemielniak, Dariusz (2013) Życie wirtualnych dzikich. Netnografia Wikipedii, największego projektu współtworzonego przez ludzi, Warszawa: Poltext Analiza etnograficzna Wikipedii, badająca relacje władzy, biurokrację, zaufanie, przywództwo, oraz struktury WIkipedii.

  14. Tallinna Keskraamatukogu vahetuspraktikate kogemusi / Kaie Holm

    Index Scriptorium Estoniae

    Holm, Kaie, 1967-

    2011-01-01

    2009. aastal käivitas Tallinna Keskraamatukogu töötajate vahetuse projekti, töötajad vahetasid omavahel töökohad, töötades lühikest aega teises sama strukturiüksuse raamatukogus või osakonnas

  15. Gas core reactors for actinide transmutation and breeder applications

    Science.gov (United States)

    Clement, J. D.; Rust, J. H.

    1978-01-01

    This work consists of design power plant studies for four types of reactor systems: uranium plasma core breeder, uranium plasma core actinide transmuter, UF6 breeder and UF6 actinide transmuter. The plasma core systems can be coupled to MHD generators to obtain high efficiency electrical power generation. A 1074 MWt UF6 breeder reactor was designed with a breeding ratio of 1.002 to guard against diversion of fuel. Using molten salt technology and a superheated steam cycle, an efficiency of 39.2% was obtained for the plant and the U233 inventory in the core and heat exchangers was limited to 105 Kg. It was found that the UF6 reactor can produce high fluxes (10 to the 14th power n/sq cm-sec) necessary for efficient burnup of actinide. However, the buildup of fissile isotopes posed severe heat transfer problems. Therefore, the flux in the actinide region must be decreased with time. Consequently, only beginning-of-life conditions were considered for the power plant design. A 577 MWt UF6 actinide transmutation reactor power plant was designed to operate with 39.3% efficiency and 102 Kg of U233 in the core and heat exchanger for beginning-of-life conditions.

  16. Uranium hexafluoride: Handling procedures and container descriptions

    International Nuclear Information System (INIS)

    1987-09-01

    The US Department of Energy (DOE) guidelines for packaging, measuring, and transferring uranium hexafluoride (UF 6 ) have been undergoing continual review and revision for several years to keep them in phase with developing agreements for the supply of enriched uranium. Initially, K-1323 ''A Brief Guide to UF 6 Handling,'' was issued in 1957. This was superceded by ORO-651, first issued in 1966, and reissued in 1967 to make editorial changes and to provide minor revisions in procedural information. In 1968 and 1972, Revisions 2 and 3, respectively, were issued as part of the continuing effort to present updated information. Revision 4 issued in 1977 included revisions to UF 6 cylinders, valves, and methods to use. Revision 5 adds information dealing with pigtails, overfilled cylinders, definitions and handling precautions, and cylinder heel reduction procedures. Weighing standards previously presented in ORO-671, Vol. 1 (Procedures for Handling and Analysis of UF 6 ) have also been included. This revision, therefore, supercedes ORO-671-1 as well as all prior issues of this report. These guidelines will normally apply in all transactions involving receipt or shipment of UF 6 by DOE, unless stipulated otherwise by contracts or agreements with DOE or by notices published in the Federal Register. Any questions or requests for additional information on the subject matter covered herein should be directed to the United States Department of Energy, P.O. Box E, Oak Ridge, Tennessee 37831, Attention: Director, Uranium Enrichment Operations Division. 33 figs., 12 tabs

  17. Gas core reactors for actinide transmutation and breeder applications. Annual report

    International Nuclear Information System (INIS)

    Clement, J.D.; Rust, J.H.

    1978-01-01

    This work consists of design power plant studies for four types of reactor systems: uranium plasma core breeder, uranium plasma core actinide transmuter, UF6 breeder and UF6 actinide transmuter. The plasma core systems can be coupled to MHD generators to obtain high efficiency electrical power generation. A 1074 MWt UF6 breeder reactor was designed with a breeding ratio of 1.002 to guard against diversion of fuel. Using molten salt technology and a superheated steam cycle, an efficiency of 39.2% was obtained for the plant and the U233 inventory in the core and heat exchangers was limited to 105 Kg. It was found that the UF6 reactor can produce high fluxes (10 to the 14th power n/sq cm-sec) necessary for efficient burnup of actinide. However, the buildup of fissile isotopes posed severe heat transfer problems. Therefore, the flux in the actinide region must be decreased with time. Consequently, only beginning-of-life conditions were considered for the power plant design. A 577 MWt UF6 actinide transmutation reactor power plant was designed to operate with 39.3% efficiency and 102 Kg of U233 in the core and heat exchanger for beginning-of-life conditions

  18. Criticality analysis in uranium enrichment plant

    International Nuclear Information System (INIS)

    Okamoto, Tsuyoshi; Kiyose, Ryohei

    1977-01-01

    In a large scale uranium enrichment plant, uranium inventory in cascade rooms is not very large in quantity, but the facilities dealing with the largest quantity of uranium in that process are the UF 6 gas supply system and the blending system for controlling the product concentration. When UF 6 spills out of these systems, the enriched uranium is accumulated, and the danger of criticality accident is feared. If a NaF trap is placed at the forestage of waste gas treatment system, plenty of UF 6 and HF are adsorbed together in the NaF trap. Thus, here is the necessity of checking the safety against criticality. Various assumptions were made to perform the computation surveying the criticality of the system composed of UF 6 and HF adsorbed on NaF traps with WIMS code (transport analysis). The minimum critical radius resulted in about 53 cm in case of 3.5% enriched fuel for light water reactors. The optimum volume ratio of fissile material in the double salt UF 6 .2NaF and NaF.HF is about 40 vol. %. While, criticality survey computation was also made for the annular NaF trap having the central cooling tube, and it was found that the effect of cooling tube radius did not decrease the multiplication factor up to the cooling tube radius of about 5 cm. (Wakatsuki, Y.)

  19. March market review

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    The spot market price for uranium in unrestricted markets weakened further during March, and at month end, the NUEXCO Exchange Value had fallen $0.15, to $7.45 per pound U3O8. The Restricted American Market Penalty (RAMP) for concentrates increased $0.15, to $2.55 per pound U3O8. Ample UF6 supplies and limited demand led to a $0.50 decrease in the UF6 Value, to $25.00 per kgU as UF6, while the RAMP for UF6 increased $0.75, to $5.25 per kgU. Nine near-term uranium transactions were reported, totalling almost 3.3 million pounds equivalent U3O8. This is the largest monthly spot market volume since October 1992, and is double the volume reported in January and February. The March 31 Conversion Value was $4.25 per kgU as UF6. Beginning with the March 31 Value, NUEXCO now reports its Conversion Value in US dollars per kilogram of uranium (US$/kgU), reflecting current industry practice. The March loan market was inactive with no transactions reported. The Loan Rate remained unchanged at 3.0 percent per annum. Low demand and increased competition among sellers led to a one-dollar decrease in the SWU Value, to $65 per SWU, and the RAMP for SWU declined one dollar, to $9 per SWU

  20. Material surveillance and verification program at a uranium enriching plant

    International Nuclear Information System (INIS)

    DeVito, V.J.

    1975-01-01

    A license for a nuclear facility in the United States is approved only after a licensee demonstrates by procedure or practice that an adequate material control system exists. A license can specify acceptable material control practices. Therefore, processors in the United States receiving uranium hexafluoride (UF 6 ) from a U. S. Government-owned enriching plant can accept shipper's values for nuclear material accounting purposes if: there is surveillance during withdrawal of the UF 6 , an independent sample is obtained, and certain measurement verification is subsequently performed by the receiver or the receiver's agent. Because of the high equipment and operating costs, essentially all UF 6 processors have adopted a surveillance and verification program. A resident observer is employed to perform surveillance, obtain samples, and tamper-safe the shipping cylinders. Samples are analyzed by the receiver or by an independent laboratory. The observer determines by surveillance that withdrawals, or transfers of material, weighings, and sampling are accomplished in accordance with accepted procedures. Surveillance of the withdrawals includes observing the transfer of UF 6 from the enriching plant cylinder to the shipping cylinder(s) and the withdrawal of samples. In addition, it inclu []es observing the weighing of all cylinders associated with a sample lot of UF 6 . Following the surveillance of withdrawals, weighings, and sampling, the cylinders are made tamper-safe by the application of tamper-indicating devices. Statistics for the verification program have shown shipper and receiver measurements to be within the limits acceptable for adequate material control. (auth)

  1. Final programmatic environmental impact statement for alternative strategies for the long-term management and use of depleted uranium hexafluoride. Volume 2: Appendices

    International Nuclear Information System (INIS)

    1999-04-01

    This PEIS assesses the potential impacts of alternative management strategies for depleted uranium hexafluoride (UF 6 ) currently stored at three DOE sites: Paducah site near Paducah, Kentucky, Portsmouth site near Portsmouth, Ohio; and K-25 site on the Oak Ridge Reservation, Oak Ridge, Tennessee. The alternatives analyzed in the PEIS include no action, long-term storage as UF 6 , long-term storage as uranium oxide, use as uranium oxide, use as uranium metal, and disposal. DOE's preferred alternative is to begin conversion of the depleted UF 6 inventory as soon as possible, either to uranium oxide, uranium metal, or a combination of both, while allowing for use of as much of this inventory as possible. This volume contains Appendices A--O

  2. Properties of radio-frequency heated argon confined uranium plasmas

    International Nuclear Information System (INIS)

    Roman, W.C.

    1976-01-01

    An experimental investigation was performed to aid in determining the characteristics of uranium plasma core reactors. Pure uranium hexafluoride (UF 6 ) was injected into an argon-confined, steady-state, rf-heated plasma, within a fused-silica peripheral wall test chamber. Exploratory tests conducted using an 80 kW rf facility and different test chamber flow configurations permitted selection of the configuration demonstrating the best confinement characteristics and minimum uranium compound wall coating. The test chamber selected was 10-cm-long and 5.7-cm-inside diameter; operating pressures were up to 12 atm. A UF 6 handling and feeder system to provide a controlled and steady flow of heated UF 6 at temperatures up to 500 0 K and mass flow rates up to 0.21 g/s was employed

  3. Model plant key measurement points

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    The key measurement points for the model low enriched fuel fabrication plant are described as well as the measurement methods. These are the measurement points and methods that are used to complete the plant's formal material balance. The purpose of the session is to enable participants to: (1) understand the basis for each key measurement; and (2) understand the importance of each measurement to the overall plant material balance. The feed to the model low enriched uranium fuel fabrication plant is UF 6 and the product is finished light water reactor fuel assemblies. The waste discards are solid and liquid wastes. The plant inventory consists of unopened UF 6 cylinders, UF 6 heels, fuel assemblies, fuel rods, fuel pellets, UO 2 powder, U 3 O 8 powder, and various scrap materials. At the key measurement points the total plant material balance (flow and inventory) is measured. The two types of key measurement points-flow and inventory are described

  4. Final programmatic environmental impact statement for alternative strategies for the long-term management and use of depleted uranium hexafluoride. Volume 1: Main text

    International Nuclear Information System (INIS)

    1999-04-01

    This PEIS assesses the potential impacts of alternative management strategies for depleted uranium hexafluoride (UF 6 ) currently stored at three DOE sites: Paducah site near Paducah, Kentucky, Portsmouth site near Portsmouth, Ohio; and K-25 site on the Oak Ridge Reservation, Oak Ridge, Tennessee. The alternatives analyzed in the PEIS include no action, long-term storage as UF 6 , long-term storage as uranium oxide, use as uranium oxide, use as uranium metal, and disposal. DOE's preferred alternative is to begin conversion of the depleted UF 6 inventory as soon as possible, either to uranium oxide, uranium metal, or a combination of both, while allowing for use of as much of this inventory as possible

  5. Depleted uranium plasma reduction system study

    International Nuclear Information System (INIS)

    Rekemeyer, P.; Feizollahi, F.; Quapp, W.J.; Brown, B.W.

    1994-12-01

    A system life-cycle cost study was conducted of a preliminary design concept for a plasma reduction process for converting depleted uranium to uranium metal and anhydrous HF. The plasma-based process is expected to offer significant economic and environmental advantages over present technology. Depleted Uranium is currently stored in the form of solid UF 6 , of which approximately 575,000 metric tons is stored at three locations in the U.S. The proposed system is preconceptual in nature, but includes all necessary processing equipment and facilities to perform the process. The study has identified total processing cost of approximately $3.00/kg of UF 6 processed. Based on the results of this study, the development of a laboratory-scale system (1 kg/h throughput of UF6) is warranted. Further scaling of the process to pilot scale will be determined after laboratory testing is complete

  6. Environmental assessment for renewal of special nuclear material, License No. SUB-1010 (Docket No. 40-8027)

    International Nuclear Information System (INIS)

    1985-08-01

    The proposed action is the renewal of the license necessary for continued operation of the SFC production plant at Gore, Oklahoma. The plant has been in operation with authority to use source material for the production of UF 6 since February 1970. In addition to facilities for production of UF 6 the site also includes: (1) a storage area for drums of uranium ore concentrates received from uranium mills, (2) a uranium sampling facility, (3) bulk storage of hazardous chemicals such as hydrofluoric (HF), nitric (HNO 3 ), and sulfuric (H 2 SO 4 ) acids and tributyl phosphate-hexane solvent, (4) a facility for electrolytic production of fluorine from HF, (5) separate treatment systems and storage ponds for radiological and nonradiological liquid wastes, and (6) a program for disposal of raffinate from a solvent extraction system in the UF 6 production as fertilizer on land owned by SFC. 13 figs., 30 tabs

  7. Market values summary/October market review/current market data

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    This article is the October uranium market summary. During this period, volume increased to 2.2 Mlb U3O8 on the spot concentrates market. The unrestricted and restricted exchange values remained steady at $7.00 and $9.05 per pound U3O8 respectively. There were two UF6 deals during this period, and with supply more than adequate to meet the demand, the restricted UF6 price remained unchanged at $29.00 per kgU as UF6. The unrestricted value increased slightly to $24.50. The conversion value was unchanged, and the enrichment services market/prices weakened. Both active supply and demand decreased during this period

  8. Distribution of uranium supply and enrichment

    International Nuclear Information System (INIS)

    Bamford, F.W.

    1982-01-01

    Uranium supply and demand is examined from the perspective of companies in the uranium hexafluoride (UF6) conversion business whose main interest is their sources of uranium supply and UF6 destinations because of transportation costs. Because of the variations in yellowcake transport, charges for conversion, and UF6 transport costs, most converters don't have standard prices. Companies try to look ahead to determine patterns of supplies and delivery points when they analyze the market and estimate future prices. Market analyses must take into account the purchasing policies of utilities around the world. The presentation shows North America supplying about 40% of world uranium, with about 13% of the enrichment done elsewhere. It also shows North American converters getting 53% of the business, but that will require importing uranium from outside North America. 6 tables

  9. Final programmatic environmental impact statement for alternative strategies for the long-term management and use of depleted uranium hexafluoride. Summary

    International Nuclear Information System (INIS)

    1999-04-01

    This PEIS assesses the potential impacts of alternative management strategies for depleted uranium hexafluoride (UF 6 ) currently stored at three DOE sites: Paducah site near Paducah, Kentucky, Portsmouth site near Portsmouth, Ohio; and K-25 site on the Oak Ridge Reservation, Oak Ridge, Tennessee. The alternatives analyzed in the PEIS include no action, long-term storage as UF 6 , long-term storage as uranium oxide, use as uranium oxide, use as uranium metal, and disposal. DOE's preferred alternative is to begin conversion of the depleted UF 6 inventory as soon as possible, either to uranium oxide, uranium metal, or a combination of both, while allowing for use of as much of this inventory as possible

  10. Lessons learned from recent safety related incidents at A Canadian uranium conversion facility

    International Nuclear Information System (INIS)

    Jaferi, Jafir

    2013-01-01

    This paper presents the Canadian Nuclear Safety Commission's (CNSC) regulatory requirements for nuclear fuel facility licensees to report any situation or incident that results or is likely to result in a hazard to the health or safety of any person or the environment and to submit its incident investigation report with cause(s) of the incident and corrective actions taken or planned. In addition, the paper presents two recent safety-related incidents that occurred at a uranium conversion facility in Canada along with their consequences, causes, corrective actions and any lessons learned. The first incident resulted in a release of uranium hexafluoride (UF6) inside the UF6 cylinder filling station and the second one resulted in a spill of uranium tetrafluoride (UF 4 ) slurry inside the UF6 plant. Both incidents had no impact on the workers or the environment. (authors)

  11. Study of the molecular structure of uranium hexafluoride

    International Nuclear Information System (INIS)

    Bougon, R.

    1967-06-01

    The vibrational spectrum of uranium hexafluoride has been studied in both the gaseous and solid states. The study of gaseous UF 6 confirms the regular octahedral structure of the fluorine atoms around the central U atom and makes it possible to evaluate some of the vibrational frequencies. From these, some new force constants have been determined. A tetragonal distortion is observed on solid UF 6 ; this distortion has only observed up till now by means of X-ray diffraction and nuclear magnetic resonance techniques. (author) [fr

  12. Market values summary/April market review/current market data

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    This article is the April 1995 uranium market summary. Overall market activity during this period was low, with five deals in the concentrates market, two deals in the long-term natural uranium market, and three deals in the spot enrichment market. There were no spot trades in the UF6 or conversion market. The restricted and unrestricted exchange values were $11.60 and $7.35 respectively. The restricted and unrestricted UF6 values were $36.00 and $25.50, and the restricted and unrestricted transaction values were $10.30 and $7.25. Active uranium supply rose, and active demand fell

  13. Development of the CARS method for measurement of pressure and temperature gradients in centrifuges

    International Nuclear Information System (INIS)

    Zeltmann, A.H.; Valentini, J.J.

    1983-12-01

    These experiments evaluated the feasibility of applying the CARS technique to the measurement of UF 6 concentrations and pressure gradients in a gas centrifuge. The resultant CARS signals were properly related to system parameters as suggested by theory. The results have been used to guide design of an apparatus for making CARS measurements in a UF 6 gas centrifuge. Ease of measurement is expected for pressures as low as 0.1 torr. Temperature gradients can be measured by this technique with changes in the data acquisition method. 16 references, 8 figures, 2 tables

  14. Go-no go monitors

    International Nuclear Information System (INIS)

    Baxter, P.; Boldeman, J.W.; Delaney, I.

    1985-01-01

    The IAEA have discussed the need for an NDA instrument to verify that UF 6 production is within the range of declared enrichment at gas centrifuge plants. The instrument must be capable of making a go-nogo decision on whether the enrichment is greater than or less than 20%. It must also be capable of being used during a limited frequency unannounced access inspection of cascade areas. The Go-No Go detector presently being developed uses X-ray spectroscopy to determine the enrichment of the UF 6 gas in the pipework based on the number of the 185.72 KeV gamma rays emitted from the gas

  15. Recent measurements concerning uranium hexafluoride-electron collision processes

    International Nuclear Information System (INIS)

    Trajmar, S.; Chutjian, A.; Srivastava, S.; Williams, W.; Cartwright, D.C.

    1976-01-01

    Scattering of electrons by UF 6 molecule was studied at impact energies ranging from 5 to 100 eV and momentum transfer, elastic and inelastic scattering cross sections were determined. The measurements also yielded spectroscopic information which made possible to extend the optical absorption cross sections from 2000 to 435A. It was found that UF 6 is a very strong absorber in the vacuum UV region. No transitions were found to lie below the onset of the optically detected 3.0 eV feature

  16. Method to separate hydrogen fluoride from an uranium hexafluoride-hydrogen fluoride mixture

    International Nuclear Information System (INIS)

    Pfistermeister, M.; Jokar, J.

    1978-01-01

    It is difficult to separate off HF in the purification of UF 6 from additional compounds. According to the invention, it is possible without too greater effort to form the hardly volatile tri-(perfluorobutyl)-ammonium fluoride by adding a perfluorate amine or a derivate of it, and then to separate off the UF 6 from the adduct by simple distillation or sublimation. The adduct can be easily split again with NaOH, so that the amine can be used again without loss. (RW) [de

  17. Process for separating U isotopes by infrared excitation

    International Nuclear Information System (INIS)

    Lyon, R.K.; Kaldor, Andrew.

    1976-01-01

    This invention concerns a process for separating a substance into at least two parts in which the isotopic abundances of a given element differ from those of the isotopes of the substance prior to separation. Specifically, the invention concerns a process for the selective excitation of the isotopes of a gaseous phase UF 6 by absorption of infra-red photons, then by selective reaction of UF 6 excited with atomics chlorine, bromine or iodine, forming a product that may be separated by a standard method. The preference criteria of the atomic chlorine, bromine and iodine are related to the thermal dilution problem [fr

  18. Synthetic methods and reactions. XVII. Uranium hexafluoride, a convenient new oxidizing agent for organic synthesis

    International Nuclear Information System (INIS)

    Olah, G.A.; Welch, J.; Ho, T.L.

    1976-01-01

    A study was made of reactions of the highly covalent UF 6 with organic compounds. Oxidative cleavage was observed for ethers and hydrazones; oxidation or oxidative fluorination for alcohols and aldehydes; and oxidation for carboxylic acid hydrazides and N,N-dimethylalkyl(cycloalkly)amines. Reaction products and yields were tabulated for several organic compounds. The limited fluorinating ability of UF 6 did not interfere with most reactions; and inter alia, ketone, ester, amide, nitrile, and nitro groups were unaffected under the given reaction conditions

  19. Outlooks for the development of ozone-safe refrigerant production at the Minatom facilities

    International Nuclear Information System (INIS)

    Shatalov, V.V.; Orekhov, V.T.; Dedov, A.S.; Zakharov, V.Yu.; Golubev, A.N.; Tsarev, V.A.

    2001-01-01

    Results of activities undertaken at the All-Russian Research Institute of Chemical Technology since 1988, which were aimed at search of new methods of synthesis of ozone-safe refrigerants, using depleted uranium hexafluoride waste formed at gas-diffusion plants as fluorinating agent, are considered. It is pointed out that major advantages of the flowsheets making use of UF 6 versus traditional method consist in the fact that the processes are conducted in gas phase under normal pressure and moderate temperatures with UF 6 transfer into a more environmentally friendly form. Outlooks for expansion of production of ozone-safe refrigerants by the method described are discussed [ru

  20. Annual report, 1978

    International Nuclear Information System (INIS)

    A financial report for 1978 is presented. Net earnings were $17,618,000. The Beaverlodge mine produced 307,000 tons of ore, and the mill 1,283,000 lb. of concentrate. The Port Hope refinery produced 1,283,000 lb of UF 6 and 2.1 million lb. of U0 2 . The construction of a new UF 6 refinery near Port Granby, Ontario was turned down by the federal government on environmental grounds. The search for a new site is continuing. Exploration is underway in seven provinces and two territories; a share in the Key Lake joint venture was acquired. (LL)

  1. Uranium Enrichment Safeguards

    Energy Technology Data Exchange (ETDEWEB)

    Demuth, Scott F. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Trahan, Alexis Chanel [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-06-26

    DIV of facility layout, material flows, and other information provided in the DIQ. Material accountancy through an annual PIV and a number of interim inventory verifications, including UF6 cylinder identification and counting, NDA of cylinders, and DA on a sample collection of UF6. Application of C/S technologies utilizing seals and tamper-indicating devices (TIDs) on cylinders, containers, storage rooms, and IAEA instrumentation to provide continuity of knowledge between inspection. Verification of the absence of undeclared material and operations, especially HEU production, through SNRIs, LFUA of cascade halls, and environmental swipe sampling

  2. Market review - Market values summary/August market review/current market data

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    This article is the August 1995 uranium market review. During this reporting period, there were three transactions in the long-term concentrates sector, no transactions in the UF6 market, and limited activity in the spot conversion market and the enrichment services market. Active supply rose, as did active demand. Prices were stable to slightly increasing

  3. Measurements of uranium mass confined in high density plasmas

    International Nuclear Information System (INIS)

    Stoeffler, R.C.

    1976-01-01

    An x-ray absorption method for measuring the amount of uranium confined in high-density, rf-heated uranium plasmas is described. Preliminary tests were conducted to calibrate the measurement system using argon, uranium hexafluoride (UF 6 ), and mixtures of argon and UF 6 at room temperature. A comparison of measured absorption of 8 keV x-rays with absorption calculated using Beer's Law indicated the method could be used to measure uranium densities from 3 x 10 16 atoms/cm 3 to 3 x 10 18 atoms/cm 3 . Tests were conducted to measure the density of uranium in an rf-heated argon plasma with UF 6 injection and with the power to maintain the discharge supplied by the United Technologies Research Center (UTRC) 1.2-MW rf induction heater facility. The uranium density was measured as the UF 6 flow rate through the test chamber was varied. A maximum uranium density of 3.85 x 10 17 atoms/cm 3 was measured

  4. Semi-annual report of the chemical process division of CDTN - July to December 1988

    International Nuclear Information System (INIS)

    Lima Soares, M.L. de.

    1989-01-01

    The main activities developed by the Chemical Process Division of CDTN are described, including the reconversion of UF 6 to UO 2 , the separation and purification of rare earths and the solvent extraction with pulse column. (C.G.C.) [pt

  5. Long-term disposal of enrichment plant tails

    International Nuclear Information System (INIS)

    1979-08-01

    Approximately 97% of the uranium fed to the isotope separation plants is recovered as tails containing nominally 0.2 wt percent U-235. Essentially all this tails material produced in the past, as well as that currently being generated, is stored as solidified UF 6 in steel cylinders. This report describes a stand-alone, 10 tU/day facility for converting the UF 6 to a stable uranium oxide powder amenable to long-term storage in steel drums. The conversion is accomplished in a two-step process in which the UF 6 is first reduced to UF 4 with hydrogen in a tower reactor and then the UF 4 is pyrohydrolyzed to UO 2 with steam in a three-stage screw reactor. One reduction reactor supplies the feed for three pyrohydrolysis reactor lines. Included in the process flow sheets and reactor design details are descriptions of the major auxiliary components for vaporizing and feeding the UF 6 , a dissociator for ammonia used as a hydrogen source, a system for recovering anhydrous hydrogen fluoride, and a reactor system for the disposal of hydrous hydrogen fluoride. Two of the nominal 10 tU/day plants would be required to handle the tails produced in isotope separation plants supplying enriched uranium to a nuclear power industry with a generation capacity of 50 GWe per year

  6. PATRAM '83: 7th international symposium on packaging and transportation of radioactive materials. Proceedings. Volume 1

    International Nuclear Information System (INIS)

    1983-12-01

    Volume 1 contains the papers from the following sessions: Plenary session; international regulations; fracture toughness of ferritic steels; monolithic cast iron casks; risk analysis techniques; storage in packagings; packaging design considerations; risk analysis; facility/transportation system interface; research and development programs; UF 6 packagings; national regulations; transportation operations and traffic; containment, seals, and leakage; and radiation risk experiences

  7. High-pressure continuously tunable CO2 lasers and molecular laser ...

    Indian Academy of Sciences (India)

    2014-01-05

    Jan 5, 2014 ... The acronym MLIS (molecular laser isotope separation) defines the laser process whereby the isotopes of uranium can be separated by mid-infrared laser/s when the molecule employed is UF6. The theoretical and spectroscopical data to configure and enable experiments and demonstrations in the ...

  8. Safety analysis report on the ''Paducah Tiger'' protective overpack for 10-ton cylinders of uranium hexafluoride

    International Nuclear Information System (INIS)

    Stitt, D.H.

    1975-01-01

    The ''Paducah Tiger'' is a protective overpack used in shipment of 10-ton cylinders of enriched UF 6 . The calculations and tests are described which made and which indicate that the overpack is in compliance with the type B packaging requirements of ERDA Manual Chapter 0529 and Title 10 Code Federal Regulations Part 71. (U.S.)

  9. Evaluation of safety in the transportation of natural uranium hexafluoride

    International Nuclear Information System (INIS)

    Maitre, P.; Meslin, T.; Pages, P.

    A general model developed for the safety of transporting radioactive materials is applied to UF 6 . Results given concern only the container contents during an accident; harmful consequences to the environment are not considered. It is shown that railroad transport is safer than road transport, particularly with regard to fire. 13 figs., 12 tables

  10. FY16 Safeguards Technology Cart-Portable Mass Spectrometer Project Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Cyril V. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Whitten, William B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-02-01

    The Oak Ridge National Laboratory project for the Next Generation Safeguards Initiative Safeguards Technology Development Subprogram has been involved in the development of a cart portable mass spectrometer based on a Thermo ITQ ion trap mass spectrometer (referred to simply as the ITQ) for the field analysis of 235U/238U ratios in UF6. A recent discovery of the project was that combining CO2 with UF6 and introducing the mixture to the mass spectrometer (MS) appeared to increase the ionization efficiency and, thus, reduce the amount of UF6 needed for an analysis while also reducing the corrosive effects of the sample. However, initial experimentation indicated that mixing parameters should be closely controlled to ensure reproducible results. To this end, a sample manifold (SM) that would ensure the precise mixing of UF6 and CO2 was designed and constructed. A number of experiments were outlined and conducted to determine optimum MS and SM conditions which would provide the most stable isotope ratio analysis. The principal objective of the project was to provide a retrofit ITQ mass spectrometer operating with a SM capable of achieving a variation in precision of less than 1% over 1 hour of sampling. This goal was achieved by project end with a variation in precision of 0.5 to 0.8% over 1 hour of sampling.

  11. System and method of plasma particle separation

    International Nuclear Information System (INIS)

    Schmidt, G.; Halpern, G.M.; Thomas, W.R.L.

    1975-01-01

    Several examples of the design are described to ionize flowing uranium or UF 6 vapour through laser beam and to conduct the thus produced flowing plasma into the region of a magnetic field gradient separating the isotopes. (GG/LH) [de

  12. A study of UF4 preparations

    International Nuclear Information System (INIS)

    Chang, I.S.; Doh, J.B.; Choi, Y.D.

    1985-05-01

    Uranium tetrafluoride (UF 4 ), green salt, is very important intermediate in the production of metallic uranium and uranium hexafluoride (UF 6 ) for enrichment. The hydrofluorination of uranium dioxide (UO 2 ) with anhydrous hydrogen fluoride (HF), produced from ADU (ammonium diuranate) process or AUC (ammonium uranyl carbonate) process, are commercially used for the production of uranium tetrafluoride. At present, a new approach such as direct UF 4 preparation at the mine-site without further precipitation, filteration and drying of yellow cake from leaching solution has been studied. The single step continous reduction of uranium hexafluoride to uranium tetrafluoride is one of the most interesting process being applied for the commercial use of a large amount of depleted UF 6 which is produced in tail after enrichment. The direct conversion of UF 6 and UF 4 with hydrogen and fluorine gases using cold wall reactor has a certain advantage over various wet process such as AUD and AUC processes in which hydrolysis of UF 6 and various kind of chemicals are required, including liquid waste treatment. This report reviews and analyzes the theory and processes being used commercially or under study. (Author)

  13. Nuclear fuel manufacture at PJSC NCCP. Technology development and quality assurance

    International Nuclear Information System (INIS)

    Goncharov, Yu.; Enin, A.; Kustov, L.; Mokshin, I.; Pluzhnikov, D.

    2015-01-01

    This report presents the PJSC NCCP fuel performance results and measures for improvement of FA and component manufacturing technique. Also it is demonstrated the process capacities, starting from UF6 procurement, its processing, and actual production of finished fuel assemblies as well as FA mounting and modifications of TVSA design

  14. Annual report, 1976

    International Nuclear Information System (INIS)

    A financial report for 1976 is presented. A boom in uranium sales is tempered by the necessity for safeguards agreements and setbacks in reactor construction schedules. The company is active in Saskatchewan, anticipating additional uranium discoveries in the Athabasca region. A uranium refinery designed around UF 6 production is planned for Port Granby, Ont. Exploration is proceeding throughout Canada. (E.C.B.)

  15. Expansion cooled CO nuclear pumped laser

    Science.gov (United States)

    Davis, J. F.; Bird, P. F.; Mansfield, C. R.; Helmick, H. H.

    1979-01-01

    The paper describes a series of experiments designed to investigate the performance of a fission fragment excited CO laser with gasdynamic cooling. The experiments use a wall source of fission fragments to provide excitation of CO or CO gas mixtures. A separate investigation examines the effects on vibrational excitation distribution of CO or CO gas mixtures with the addition of UF6.

  16. The calculation of the deflection angle in a collision process between an atom of rare gas and a complex molecule of Xsub(n)Ysub(m) type

    International Nuclear Information System (INIS)

    Trisca, I.; Vasiu, M.; Vasaru, G.

    1987-01-01

    We report a classical method for the calculation of the angle of deflection in a nonresonant collision in Xsub(n)Ysub(m)-Z physical active systems. The classical turning point versus temperature, for UF 6 -Ar system was calculated. For small temperature has been pointed out the association interaction. (authors)

  17. 75 FR 12738 - Proposed Subsequent Arrangement

    Science.gov (United States)

    2010-03-17

    ... the retransfer of 302,188 kg of U.S.-origin natural uranium trioxide (UO3) (82.73% U), 250,000 kg of which is uranium, from Cameco in Saskatoon, Saskatchewan, Canada to Springfields Fuels Ltd. in... transferred to Springfields Fuels Ltd. for conversion to uranium hexafluoride (UF6) for ultimate end use in a...

  18. NF ISO 7097-1. Nuclear fuel technology - Uranium dosimetry in solutions, in uranium hexafluoride and in solids - Part 1: reduction with iron (II) / oxidation with potassium bi-chromate / titration method

    International Nuclear Information System (INIS)

    2002-04-01

    This standard document describes the mode of operation of three different methods for the quantitative dosimetry of uranium in solutions, in UF 6 and in solids: reduction by iron (II), oxidation by potassium bi-chromate and titration. (J.S.)

  19. Generic report on health effects for the US Gaseous Diffusion Plants. Sect. 8, Pt. 1

    International Nuclear Information System (INIS)

    Just, R.A.; Emler, V.S.

    1984-06-01

    Toxic substances present in uranium enrichment plants include uranium hexafluoride (UF 6 ), hydrogen fluoride (HF), uranyl fluoride (UO 2 F 2 ), chlorine (Cl 2 ), chlorine trifluoride (ClF 3 ), fluorine (F 2 ), uranium tetrafluoride (UF 4 ), and technetium (Tc). The current knowledge of the expected health effects of acute exposures to these substances is described. 10 references, 2 figures, 6 tables

  20. Vliv povrchové vrstvy Al-Si na nízkocyklovou únavu superslitiny in 713LC pri teplotě 800°C

    Czech Academy of Sciences Publication Activity Database

    Juliš, M.; Obrtlík, Karel; Podrábský, T.

    2008-01-01

    Roč. 327, - (2008), s. 197-202 ISSN 1429-6055. [Metody oceny struktury oraz wlasności materiálow i wyrobow. Svratka, 01.10.2008-03.10.2008] R&D Projects: GA AV ČR 1QS200410502; GA ČR GA106/07/1507 Institutional research plan: CEZ:AV0Z20410507 Keywords : low cycle fatigue * Inconel 713LC * surface treatment Subject RIV: JL - Materials Fatigue, Friction Mechanics

  1. CYCLIC STRAIN LOCALIZATION IN CAST NICKEL BASED SUPERALLOY INCONEL 792-5A AT ROOM TEMPERATURE

    Czech Academy of Sciences Publication Activity Database

    Petrenec, Martin; Man, Jiří; Obrtlík, Karel; Polák, Jaroslav

    308/2005, č. 86 (2005), s. 269-274 ISSN 1429-6055. [Metody oceny struktury oraz wlasności materialów i wyrobów. Ustroń-Jaszowiec, 07.12.2005-09.12.2005] Institutional research plan: CEZ:AV0Z20410507 Keywords : low cycle fatigue * superalloy * cyclic strain localization Subject RIV: JL - Materials Fatigue, Friction Mechanics

  2. Algoritmus detekující změny průběhu experimentálních dat

    Czech Academy of Sciences Publication Activity Database

    Zezulka, Petr

    2001-01-01

    Roč. 72, č. 279 (2001), s. 97-100 ISSN 1429-6055. [Międzynarodowe Sympozjum - Metody oceny struktury oraz własnosci materiałow i wyroboów /16./. Komorní Lhotka, 11.12.2001-13.12.2001] Institutional research plan: CEZ:AV0Z2041904 Keywords : algorithm Subject RIV: BA - General Mathematics

  3. Global Monitoring Of Uranium Hexifloride Cylinders Next Steps In Development Of An Action Plan

    International Nuclear Information System (INIS)

    Hanks, D.

    2010-01-01

    Over 40 industrial facilities world-wide use standardized uranium hexafluoride (UF 6 ) cylinders for transport, storage and in-process receiving in support of uranium conversion, enrichment and fuel fabrication processes. UF 6 is processed and stored in the cylinders, with over 50,000 tU of UF 6 transported each year in these International Organization for Standardization (ISO) qualified containers. Although each cylinder is manufactured to an ISO standard that calls for a nameplate with the manufacturer's identification number (ID) and the owner's serial number engraved on it, these can be quite small and difficult to read. Recognizing that each facility seems to use a different ID, a cylinder can have several different numbers recorded on it by means of metal plates, sticky labels, paint or even marker pen as it travels among facilities around the world. The idea of monitoring movements of UF 6 cylinders throughout the global uranium fuel cycle has become a significant issue among industrial and safeguarding stakeholders. Global monitoring would provide the locations, movements, and uses of cylinders in commercial nuclear transport around the world, improving the efficiency of industrial operations while increasing the assurance that growing nuclear commerce does not result in the loss or misuse of cylinders. It should be noted that a unique ID (UID) attached to a cylinder in a verifiable manner is necessary for safeguarding needs and ensuring positive ID, but not sufficient for an effective global monitoring system. Modern technologies for tracking and inventory control can pair the UID with sensors and secure data storage for content information and complete continuity of knowledge over the cylinder. This paper will describe how the next steps in development of an action plan for employing a global UF 6 cylinder monitoring network could be cultivated using four primary UID functions - identification, tracking, controlling, and accounting.

  4. FIREPLUME model for plume dispersion from fires: Application to uranium hexafluoride cylinder fires

    International Nuclear Information System (INIS)

    Brown, D.F.; Dunn, W.E.

    1997-06-01

    This report provides basic documentation of the FIREPLUME model and discusses its application to the prediction of health impacts resulting from releases of uranium hexafluoride (UF 6 ) in fires. The model application outlined in this report was conducted for the Draft Programmatic Environmental Impact Statement for Alternative Strategies for the Long-Term Management and Use of Depleted UF 6 . The FIREPLUME model is an advanced stochastic model for atmospheric plume dispersion that predicts the downwind consequences of a release of toxic materials from an explosion or a fire. The model is based on the nonbuoyant atmospheric dispersion model MCLDM (Monte Carlo Lagrangian Dispersion Model), which has been shown to be consistent with available laboratory and field data. The inclusion of buoyancy and the addition of a postprocessor to evaluate time-varying concentrations lead to the current model. The FIREPLUME model, as applied to fire-related UF 6 cylinder releases, accounts for three phases of release and dispersion. The first phase of release involves the hydraulic rupture of the cylinder due to heating of the UF 6 in the fire. The second phase involves the emission of material into the burning fire, and the third phase involves the emission of material after the fire has died during the cool-down period. The model predicts the downwind concentration of the material as a function of time at any point downwind at or above the ground. All together, five fire-related release scenarios are examined in this report. For each scenario, downwind concentrations of the UF 6 reaction products, uranyl fluoride and hydrogen fluoride, are provided for two meteorological conditions: (1) D stability with a 4-m/s wind speed, and (2) F stability with a 1-m/s wind speed

  5. Production of uranium dioxide

    International Nuclear Information System (INIS)

    Knudsen, I.E.

    1977-01-01

    A three stage fluidized bed process is described for converting uranium hexafluoride (UF 6 ) to a ceramic-grade uranium dioxide (UO 2 ) powder by first, reacting hydrogen and steam with UF 6 in a first fluidized bed in a temperature range of from about 475 to 600 0 C to form solid intermediate products UO 2 F 2 and U 3 O 8 ; second, reacting hydrogen and steam with the intermediate products in a second fluidized bed at a temperature ranging from about 575 to about 675 0 C to produce a second group of intermediate products including UO 2 F 2 , U 3 O 8 , and UO 2 ; and, third, reacting hydrogen and steam with the second group of intermediate products in a third fluidized bed as a temperature of 575 to 675 0 C to produce ceramic grade UO 2 powder having low residual content of fluorides and other foreign materials. 9 claims, 1 figure

  6. A concept of a nonfissile uranium hexafluoride overpack for storage, transport, and processing of corroded cylinders

    International Nuclear Information System (INIS)

    Pope, R.B.; Cash, J.M.; Singletary, B.H.

    1996-01-01

    There is a need to develop a means of safely transporting breached 48-in. cylinders containing depleted uranium hexafluoride (UF 6 ) from current storage locations to locations where the contents can be safely removed. There is also a need to provide a method of safely and easily transporting degraded cylinders that no longer meet the US Department of Transportation (DOT) and American National Standards Institute, Inc., (ANSI) requirements for shipments of depleted UF 6 . A study has shown that an overpack can be designed and fabricated to satisfy these needs. The envisioned overpack will handle cylinder models 48G, 48X, and 48Y and will also comply with the ANSI N14.1 and the American Society of Mechanical Engineers (ASME) Sect. 8 requirements

  7. Serving the fuel cycle: preparing tomorrow's packagings

    International Nuclear Information System (INIS)

    Roland, V.

    2001-01-01

    The main fleet of transport packagings serving today the fuel cycle was born more than 20 years ago. Or was it they? The present paper will show that serving the fuel cycle by preparing tomorrow's logistics is actually an on-going process, rather than a rupture. We shall review the great packagings of the fuel cycle: In the front end, the major actors are the UF 4 , UF 6 , enriched UF 6 , UO 2 powders, fresh fuel packagings. In the back end of the fuel cycle, we find the dry transport casks of the TN-12, TN-17, TN-13, family and also the Excellox wet flasks. In the waste management, a whole fleet of containers, culminating in the TN Gemini, are available or being created. (author)

  8. Recommendations for providing protection during the transport of uranium hexafluoride

    International Nuclear Information System (INIS)

    1987-06-01

    In July 1986 a group of consultants was convened by the IAEA to provide initial guidance on the transport of UF 6 and the regulations for it considering the hazards posed by this material. A Technical Committee meeting was held in November 1986 to finalize the development of the recommendations for providing protection during the transport of UF 6 . This report provides the recommendations resulting from the meetings of these experts. The IAEA recommends that national competent authorities and other relevant national regulatory and standards-related organizations, and appropriate international organizations seriously consider all of the information provided in this report especially the additional requirements set forth in Section III.3 concerning design, manufacturing and testing requirements, design approval requirements, requirements on loading for transport, and requirements for quality assurance and maintenance. This report also deals with United Nations' Recommendations of the Transport of Dangerous Goods, International Modal Regulatory Documents, ANSIN14.1-1982 and ISO/DIS/7195 Standards

  9. The fabrication of nuclear fuel

    International Nuclear Information System (INIS)

    D'Amore, Mead

    1987-01-01

    The chronology of fuel product and core management development over the past 25 years in the USA is explained. Nuclear fuel for Westinghouse reactors is made by converting enriched uranium hexafluoride (UF 6 ) into uranium dioxide (UO 2 ) powder. The powder is pressed into pellets which are loaded into zircalloy fuel tubes (typically over 14 million pellets in 50,952 rods). The fuel rods are arranged in fuel assemblies which are shipped to the reactor site (typically 193 fuel assemblies are needed for one 1000MWe reactor). Each stage of the fuel fabrication cycle (cladding manufacture, chemical conversion UF 6 - UO 2 , pellet production, fuel rod fabrication, grid assembly, skeleton assembly, fuel assembly) is described, with particular reference to the Westinghouse process and plant. (UK)

  10. Specialized equipment needs for the transportation of radioactive material

    International Nuclear Information System (INIS)

    Condrey, D.; Lambert, M.

    1998-01-01

    To ensure the safe and reliable transportation of radioactive materials and components, from both the front and back-end of the nuclear fuel cycle, a transport management company needs three key elements: specialized knowledge, training and specialized equipment. These three elements result, in part, from national and international regulations which require specialized handling of all radioactive shipments. While the reasons behind the first two elements are readily apparent, the role of specialized equipment is often not considered until too late shipment process even though it plays an integral part of any radioactive material transport. This paper will describe the specialized equipment needed to transport three of the major commodities comprising the bulk of international nuclear transports: natural uranium (UF6), low enriched uranium (UF6) and fresh nuclear fuel. (authors)

  11. Market values summary/March market review/current market data

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    This article is the March 1993 uranium market summary. In the natural uranium and concentrates market, there were eight transactions. Both the restricted and unrestricted values were unchanged at $9.45 and $7.00 per pound of U3O8 respectively. In the UF6 market, there were three deals. Both restricted and unrestricted values were also unchanged at $30.00 and $24.50 per kgU as UF6 respectively. The restricted transaction value dropped slightly to $9.45, and the unrestricted value dropped to $7.05. In the enrichment services market, there were six deals reported, with the restricted SWU value rising to $87.00 and the unrestricted SWU value dropping to $67.00. Active uranium demand decreased considerably, while active supply increased

  12. Compliance assessment of an uranium hexafluoride package 30B with overpack to the IAEA standards

    International Nuclear Information System (INIS)

    Andreuccetti, P.; Aquaro, D.; Forasassi, G.; Beone, G.; Eletti, G.; Orsini, A.

    1988-01-01

    At the Dipartimento di Costruzioni Meccaniche e Nucleari (DCMN) of the Pisa University a research program was carried out in order to assess the compliance to the updated IAEA standards of the UF6 30B container, complete with its sandwich phenolic foam filled external overpack. The research program, performed in collaboration with ENEA and several interested Italian firms, included 9 mt free drop, perforation, thermal and leaktightness tests, on two complete packages with dummy load. The heat transfer conditions, with the UF6 real contents, were simulated by means of numerical analyses with the TRUMP computer code and calculation procedures set up using the available experimental data. The attained results seem to be useful from the point of view of the foreseen purposes

  13. Isotope separation method and apparatus

    International Nuclear Information System (INIS)

    Lyon, R.K.; Eisner, P.N.; Thomas, W.R.L.

    1980-01-01

    A method and apparatus are specified for separating a mixture of isotopes present in a compound, preferably a gaseous compound, into two or more parts in each of which the abundances of the isotopes differ from the natural abundances of the isotopes in the compound. The invention particularly relates to carrying out a laser induced, isotopically selective conversion of gaseous molecules in such a manner as to achieve more than one stage of isotope separation along the length of the laser beam. As an example, the invention is applied to the separation of the isotopes of uranium in UF 6 , in which either the U-235 or U-238 isotope is selectively excited by means of irradiation from an infrared laser, and the selectively excited isotope converted into a product that can be recovered from UF 6 by one of a variety of methods that are described. (U.K.)

  14. Uranium hexafluoride purification

    International Nuclear Information System (INIS)

    Araujo, Eneas F. de

    1986-01-01

    Uranium hexafluoride might contain a large amount of impurities after manufacturing or handling. Three usual methods of purification of uranium hexafluoride were presented: selective sorption, sublimation, and distillation. Since uranium hexafluoride usually is contaminated with hydrogen fluoride, a theoretical study of the phase equilibrium properties was performed for the binary system UF 6 -HF. A large deviation from the ideal solution behaviour was observed. A purification unity based on a constant reflux batch distillation process was developed. A procedure was established in order to design the re boiler, condenser and packed columns for the UF 6 -HF mixture separation. A bench scale facility for fractional distillation of uranium hexafluoride was described. Basic operations for that facility and results extracted from several batches were discussed. (author)

  15. Market values summary/December market review/current market data

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    This article is the December 1993 uranium market summary. During this period, there were six deals in the restricted concentrates market and none in the unrestricted market. The restricted value dropped slightly to $9.85 per pound U3O8, while the unrestricted market rose slightly to $7.00. The UF6 market was also slow, with a slight decrease in the restricted UF6 value to $31.00 and no change in the unrestricted value ($24.00). The unrestricted transaction value was $7.15 per pound U3O8, and the restricted value was $10.25. In the enrichment services market, the unrestricted SWU value remained fixed at $68.00 per SWU, while the unrestricted value increased by a dollar to $84.00 per SWU. Active uranium supply decreased, while active demand increased

  16. Standard test methods for chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of uranium hexafluoride

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 These test methods cover procedures for subsampling and for chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of uranium hexafluoride UF6. Most of these test methods are in routine use to determine conformance to UF6 specifications in the Enrichment and Conversion Facilities. 1.2 The analytical procedures in this document appear in the following order: Note 1—Subcommittee C26.05 will confer with C26.02 concerning the renumbered section in Test Methods C761 to determine how concerns with renumbering these sections, as analytical methods are replaced with stand-alone analytical methods, are best addressed in subsequent publications. Sections Subsampling of Uranium Hexafluoride 7 - 10 Gravimetric Determination of Uranium 11 - 19 Titrimetric Determination of Uranium 20 Preparation of High-Purity U3O 8 21 Isotopic Analysis 22 Isotopic Analysis by Double-Standard Mass-Spectrometer Method 23 - 29 Determination of Hydrocarbons, Chlorocarbons, and Partially Substitut...

  17. The ten stages pilot plant: its utilization in the research of the dynamic behavior and regullating process of a jet nozzle cascade for uranium enrichment

    International Nuclear Information System (INIS)

    Yadoya, R.; Camara, A.S.; Consiglio, R.V.; Bley, P.; Hein, H.; Linder, G.

    1986-01-01

    A ten stage pilot plant to study experimentally dynamic behavior of a uranium enrichment plant based on separation nozzle process was developed and constructed at Karlsruhe Nuclear Research Center. This installation was transfered to the Development Center of Nuclear Technology (CDTN) of Nuclebras in Belo Horizonte, Brazil. The separation elements installed have a new design with higher efficiency, Known as double-deflections system. The power plant has been used to improve the control method and to prove the stability of separation nozzle cascade under pertubations produced artificially. The stabilization process of UF 6 quantity in cascade by UF 6 inventory regulation at bottom stage will have practication in the First Cascade, in Rezende, RJ, Brazil and may be uded i emonstration plant. The experimental results have shown to be comparable with those obtained by computer simulation. (Author) [pt

  18. Influence of vibrations of gas molecules on neutron reaction cross sections

    Science.gov (United States)

    Bowman, C. D.; Schrack, R. A.

    1980-01-01

    The change in molecular vibrational energy upon absorption of a neutron by a nucleus bound in a free molecule can influence resonance shape and other aspects of neutron reaction cross sections. A formalism is developed for centrosymmetric molecules such as UF6 and applied to the shape of the 6.67 eV resonance in 238U. The ratio of the resonance shape for 238UF6 gas and for solid 238U3O8 has been measured and compared with the calculation. Reasonable agreement is obtained indicating the validity of the calculation and the necessity to include vibration effects to avoid large errors in measurements and calculations on gascontaining systems. NUCLEAR REACTIONS 238U(n,γ) measured at 6.67 eV resonance; Effect of molecular vibrations studied experimentally and theoretically.

  19. Orientational ordering and site structure of SiF4 trapped in rare gas solids

    Science.gov (United States)

    Jones, Llewellyn H.; Swanson, Basil I.; Ekberg, Scott A.

    1984-12-01

    The infrared spectrum of the ν3 mode of SiF4 shows only one site with marked site-symmetry splitting accompanied by pronounced (>95%) orientational ordering. The results indicate a site symmetry of C3v with the SiF4 molecule occupying a four-atom substitutional site with a cubic-close-packed environment. In krypton and xenon matrices, however, SiF4 occupies a three-atom substitutional site. The fact that SiF4 shows only one dominant site when present in argon matrices of UF6 indicates that one of the two UF6 sites has a local hexagonal close packed environment induced by short range stacking faults.

  20. Study of secular equilibrium reinstatement on UO2 pellets manufactured by AUC route

    International Nuclear Information System (INIS)

    Carnaval, João Paulo R.; Beltran, Dalton J.M.C.; Oliveira, Carlos A.

    2017-01-01

    The fuel assemblies manufactured by INB for Angra-1 power plant has axial blanket fuel rods which must be inspected due the columns formed by different enrichment pellets. The equipment used for inspection is built with a group of BGO scintillators detectors which measurement principle is based on the absorption of gamma rays emitted from Uranium decay. The commercial grade UF 6 used by INB is stored into cylinders type 30B. The uranium inside these cylinders is in secular equilibrium before the processing. It has been found that the AUC route causes the loss of that equilibrium because the UF 6 is volatilized from the cylinder and the uranium daughters remain in the container. As AUC is converted to powder and pellets, the secular equilibrium is restored through time. The purpose of this work is to present a study of the secular equilibrium reinstatement on UO 2 pellets manufactured by AUC route before being inspected on Rod Scanner. (author)

  1. New approach for safeguarding enriched uranium hexafluoride bulk transfers

    International Nuclear Information System (INIS)

    Doeher, L.W.; Pontius, P.E.; Whetstone, J.R.

    1978-01-01

    The unique concepts of American National Standard ANSI N15.18-1975 ''Mass Calibration Techniques for Nuclear Material Control'' are discussed in regard to the establishment and maintenance of control of mass measurement of Uranium Hexafluoride (UF 6 ) both within and between facilities. Emphasis is placed on the role of control of the measurements between facilities, and thus establish decision points for detection of measurement problems and making safeguards judgments. The unique concepts include the use of artifacts of UF 6 packaging cylinders, calibrated by a central authority, to introduce the mass unit into all of the industries' weighing processes. These are called Replicate Mass Standards (RMS). This feat is accomplished by comparing the RMS to each facility's In-House Standards (IHS), also artifacts, and thence the usage of these IHS to quantify the systematic and random errors of each UF 6 mass measurement process. A recent demonstration, which exchanged UF 6 cylinders between two facilities, who used ANSI N15.18-1975 concepts and procedures is discussed. The discussion includes methodology and treatment of data for use in detection of measurement and safeguards problems. The discussion incorporates the methodology for data treatment and judgments concerning (1) the common base, (2) measurement process off-sets, (3) measurement process precision, and (4) shipper-receiver bulk measurement differences. From the evidence gained in the demonstration, conclusions are reached as to the usefulness of the realistic criteria for detection of mass measurement problems upon acceptance of the concepts of ANSI N15.18-1975

  2. Adaptation of the continuous cold trap system of fluidized-bed to the fluoride volatility process

    International Nuclear Information System (INIS)

    1976-02-01

    A continuous cold trap system consisting of fluidized condenser and stripper has been evaluated with a view to adapt it to the Fluoride Volatility Process in establishing the continuous purification process without radiation decomposition of PuF 6 . Its feasibility is shown by the test with UF 6 -air. Necessary conditions for the cold trap, and performance of the two inch-dia. fluidized bed cold trap system are presented, and also a model of mist formation in the condenser. (auth.)

  3. Cascade plant control by timer method

    International Nuclear Information System (INIS)

    Kiguchi, Takashi; Inoue, Kotaro; Kawai, Toshio; Senoo, Makoto.

    1970-01-01

    The present invention relates to a method of controlling uranium flow rate through a cascaded centrifuge plant for the purpose of enriching uranium 235. Such a cascade includes multiple gas separation stage each of which consists of a plurality of centrifuges. The product gas usually includes a large amount of He gas, and a cold trap is used to eliminate the He from UF 6 . The cold trap is operated periodically in such a way that the mixed gas of He and UF 6 is cooled to solidify only UF 6 and then warmed to obtain UF 6 by gasification. In order to operate the plant continuously, parallel multiple cold traps are operated alternatively. The operating conditions in such a complex cascade system are difficult to alter by conventional control methods. The present invention provides a rapid method of controlling the system when a certain percentage of the centrifuges in one stage malfunction. The control system consists of timers which are provided one for each cold trap to control the operational period of the trap. For example, if 20% of the centrifuges in a particular stage malfunction, the timer period of the cold traps attached to the normally operating centrifuge within the stage is maintained, and the period of all the other centrifuges are changed to 10/8 times that of the initial value. In this way the flow volume through all centrifuges except that in the particular stage is reduced to 80% of the initial value and the operation of the system can be continued with reduced efficiency. (Masui, R.)

  4. Investigation into the mechanism and the kinetics of the reaction of uranium hexafluoride with hydrogen and steam in a fluidized bed

    International Nuclear Information System (INIS)

    Veryatin, U.D.; Yakhonin, I.F.

    1976-01-01

    A fluidized bed of UO 2 nuclei is formed in the pyrohydrolysis of UF 6 ; the nuclei grow in the course of the process and lead to a granulated end product in a single process step. The mechanism of the reactions taking place here in the temperature region of 650-700 0 C, as well as the kinetics of the defluorination at 700 0 -800 0 C were investigated. (RB/LH) [de

  5. Investigation of gas-phase decontamination of internally radioactively contaminated gaseous diffusion process equipment and piping

    International Nuclear Information System (INIS)

    Bundy, R.D.; Munday, E.B.

    1991-01-01

    Construction of the gaseous diffusion plants (GDPs) was begun during World War 2 to produce enriched uranium for defense purposes. These plants, which utilized UF 6 gas, were used primarily for this purpose through 1964. From 1959 through 1968, production shifted primarily to uranium enrichment to supply the nuclear power industry. Additional UF 6 -handling facilities were built in feed and fuel-processing plants associated with the uranium enrichment process. Two of the five process buildings at Oak ridge were shut down in 1964. Uranium enrichment activities at Oak Ridge were discontinued altogether in 1985. In 1987, the Department of Energy (DOE) decided to proceed with a permanent shutdown of the Oak Ridge Gaseous Diffusion Plant (ORGDP). DOE intends to begin decommissioning and decontamination (D ampersand D) of ORGDP early in the next century. The remaining two GDPs are expected to be shut down during the next 10 to 40 years and will also require D ampersand D, as will the other UF 6 -handling facilities. This paper presents an investigation of gas- phase decontamination of internally radioactively contaminated gaseous diffusion process equipment and piping using powerful fluorinating reagents that convert nonvolatile uranium compounds to volatile UF 6 . These reagents include ClF 3 , F 2 , and other compounds. The scope of D ampersand D at the GDPs, previous work of gas-phase decontamination, four concepts for using gas-phase decontamination, plans for further study of gas-phase decontamination, and the current status of this work are discussed. 13 refs., 15 figs

  6. Qualification of national fluoroelastomers for using in installations that work with uranium hexafluoride

    International Nuclear Information System (INIS)

    Abreu Mendonca Schvartzman, M.M. de; Vasconcelos, M.C.R.L. de; Fraga, R.R.

    1990-01-01

    This paper describes the techniques utilized for testing and qualifying national fluororelastomers, also known as 'Vitons', to be employed as sealing material in UF 6 handling equipments of the Centro de Desenvolvimento da Tecnologia Nuclear - CDTN in Belo Horizonte. Comparisons are made between the results obtained with nacional Vitons and the imported Viton previously qualified by the Germans for use in an enrichment plant. (author) [pt

  7. Market review: Market values summary/May market review/current market data

    International Nuclear Information System (INIS)

    Anon.

    1996-01-01

    This article is the May 1996 Uranium transactions summary. Data on Uranium supply and demand is included, as is data on conversion services and separative work units supply and demand. The spot market was active during this period, with 3.6 million pounds U3O8 changing hands in nine transactions. This brought a strengthing of prices. There were also five deals in the long-term market and three deals for natural UF6

  8. Annual report, 1977

    International Nuclear Information System (INIS)

    A financial report for 1977 is presented. Net earnings were $6,933,172. The Beaverlodge operations produced 255,622 tons of ore and 1,184,961 lb. of concentrate. The Port Hope refinery produced 8.5 million lb. of UF 6 and 1.8 million lb. of UO 2 . Sales to Japan and some other countries were held up pending ratification by these countries of the non-proliferation treaty. (LL)

  9. Comparison of cost effectiveness of risk reduction among different energy systems: French case studies. Final report of the co-ordinated research programme

    International Nuclear Information System (INIS)

    Lochard, Jacques

    1989-08-01

    This report presents the three French case studies performed in the framework of the coordinated research program on 'Comparison of Cost-effectiveness of Risk Reduction among different Energy Systems': Cost effectiveness of robotics and remote tooling for occupational risk reduction at a nuclear fuel fabrication facility; Cost-effectiveness of protection actions to reduce occupational exposures in underground uranium mines; Cost-effectiveness of safety measures to reduce public risk associated with the transportation of UF 6 by truck and trains

  10. Criticality concerns in cleaning large uranium hexafluoride cylinders

    International Nuclear Information System (INIS)

    Sheaffer, M.K.; Keeton, S.C.; Lutz, H.F.

    1995-06-01

    Cleaning large cylinders used to transport low-enriched uranium hexafluoride (UF 6 ) presents several challenges to nuclear criticality safety. This paper presents a brief overview of the cleaning process, the criticality controls typically employed and their bases. Potential shortfalls in implementing these controls are highlighted, and a simple example to illustrate the difficulties in complying with the Double Contingency Principle is discussed. Finally, a summary of recommended criticality controls for large cylinder cleaning operations is presented

  11. Cyclic process for re-use of waste water generated during the production of UO2

    International Nuclear Information System (INIS)

    Crossley, T.J.

    1976-01-01

    The process is described whereby waste water produced during the hydrolysis and ammonium hydroxide treatment of UF 6 to produce ammonium diuranate is recycled for reuse. The solution containing large amounts of ammonia and fluorides and trace amounts of uranium is first treated with lime to precipitate the fluoride. The ammonia is distilled off and recycled to UO 2 F 2 treatment vessel. The CaF 2 precipitate is separated by centrifugation and the aqueous portion is passed through cationic exchange beds

  12. A quadrupole mass spectrometer system for nuclear safeguards applications

    International Nuclear Information System (INIS)

    Evans, P.J.

    1987-12-01

    An on-line enrichment monitor for nuclear safeguards-related surveillance of a pilot-scale gas centrifuge plant is described. This monitor utilises a quadrupole mass spectrometer to measure the isotopic composition of UF 6 in the feed and product gas streams. Details of the design and construction are given, and several difficulties are identified and discussed. Finally, the performance of this system is illustrated with typical results

  13. Joint ANSI-INMM 8.1: Nuclear Regulatory Commission study of uranium hexafluoride cylinder material accountability bulk measurements

    International Nuclear Information System (INIS)

    Pontius, P.E.; Doher, L.W.

    1977-01-01

    This paper reports the progress to date in a demonstration of the procedures in ANSI N15.18-1975, ''Mass Calibration Techniques for Nuclear Material Control,'' sponsored and funded by the Nuclear Regulatory Commission (NRC). The philosophy of mass measurement as a production process, as promulgated in ANSI N15.18-1975, is reviewed. Special emphasis is placed on the use of artifact Reference Mass Standards (RMS) as references for uranium hexafluoride (UF 6 ) calibration and bulk measurement processes. The history of the creation of the artifact concept and its adoption by ANSI N15.18-1975 and the Nuclear Regulatory Commission is narrated. The program now under way is specifically described; including descriptions of the RMS, their calibration, and the assignment of uncertainties to them by the National Bureau of Standards (NBS). Instrument tests, in-house standards (IHS), and assignment of values relative to the RMS-NBS values at nuclear facilities which measure UF 6 cylinders are described. Comparisons and the data base are detailed to provide realistic measurement process parameters associated with accountable transfer of UF 6 . The as yet uncompleted part of the demonstration is described, that is, to further close the measurement loop by verification both between and within facilities

  14. Contribution to the study of interactions between uranium hexafluoride and alkali fluorides

    International Nuclear Information System (INIS)

    Paillet, Alain

    1972-01-01

    The author describes the complexation of UF 6 with alkaline fluorides by various ways: a preliminary chemical study of the synthesis, a spectrographic study (diffraction of X-rays, Raman-laser spectroscopy, I.R. spectroscopy), a calorimetric study, at last a study of kinetics by thermogravimetry. The complexes present the formula MF, UF 6 or 2MF, UF 6 whatever is M (including Rb and Cs). The X ray diffraction study, made for analytical purposes, enabled to describe the spectra of NaUF 7 , Na 2 UF 8 , KUF 7 , RbUF 7 , CsUF 7 . For KUF 7 , RbUF 7 , CsUF 7 the tri-periodic array of the uranium atoms is cubic. The thermodynamical study shows that the initial stage of germination evolves, at room temperature, 40 or CO Kcal/mole for a reaction rate, lower than 5%, for all the complexes; then, approximately 16 Kcal/mole. For the ulterior stages, the activation energy for the inter-crystalline diffusion is about 6 Kcal/mole. Various types of original apparatus, working in fluorinating atmosphere, are described: particularly a miniaturized microcalorimeter, especially designed to gain a great sensitivity. (author) [fr

  15. Some Investigations of the Reaction of Activated Charcoal with Fluorine and Uranium Hexafluoride

    International Nuclear Information System (INIS)

    Del Cul, G.D.; Fiedor, J.N.; Simmons, D.W.; Toth, L.M.; Trowbridge, L.D.; Williams

    1998-01-01

    The Molten Salt Reactor Experiment (MSRE) at Oak Ridge National Laboratory has been shut down since 1969, when the fuel salt was drained from the core into two Hastelloy N drain tanks at the reactor site. Over time, fluorine (F 2 ) and uranium hexafluoride (UF 6 ) moved from the salt through the gas piping to a charcoal bed, where they reacted with the activated charcoal. Some of the immediate concerns related to the migration of F 2 and UF 6 to the charcoal bed were the possibility of explosive reactions between the charcoal and F 2 , the existence of conditions that could induce a criticality accident, and the removal and recovery of the fissile uranium from the charcoal. This report addresses the reactions and reactivity of species produced by the reaction of fluorine and activated charcoal and between charcoal and F 2 -UF 6 gas mixtures in order to support remediation of the MSRE auxiliary charcoal bed (ACB) and the recovery of the fissile uranium. The chemical identity, stoichiometry, thermochemistry, and potential for explosive decomposition of the primary reaction product, fluorinated charcoal, was determined

  16. Standard test method for isotopic analysis of uranium hexafluoride by double standard single-collector gas mass spectrometer method

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This is a quantitative test method applicable to determining the mass percent of uranium isotopes in uranium hexafluoride (UF6) samples with 235U concentrations between 0.1 and 5.0 mass %. 1.2 This test method may be applicable for the entire range of 235U concentrations for which adequate standards are available. 1.3 This test method is for analysis by a gas magnetic sector mass spectrometer with a single collector using interpolation to determine the isotopic concentration of an unknown sample between two characterized UF6 standards. 1.4 This test method is to replace the existing test method currently published in Test Methods C761 and is used in the nuclear fuel cycle for UF6 isotopic analyses. 1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro...

  17. Uranium hexafluoride packaging tiedown systems overview at Portsmouth Gaseous Diffusion Plant, Piketon, Ohio

    International Nuclear Information System (INIS)

    Becker, D.L.; Green, D.J.; Lindquist, M.R.

    1993-07-01

    The Portsmouth Gaseous Diffusion Plant (PORTS) in Piketon, Ohio, is operated by Martin Marietta Energy Systems, Inc., through the US Department of Energy-Oak Ridge Operations Office (DOE-ORO) for the US Department of Energy-Headquarters, Office of Nuclear Energy. The PORTS conducts those operations that are necessary for the production, packaging, and shipment of uranium hexafluoride (UF 6 ). Uranium hexafluoride enriched uranium than 1.0 wt percent 235 U shall be packaged in accordance with the US Department of Transportation (DOT) regulations of Title 49 CFR Parts 173 (Reference 1) and 178 (Reference 2), or in US Nuclear Regulatory Commission (NRC) or US Department of Energy (DOE) certified package designs. Concerns have been expressed regarding the various tiedown methods and condition of the trailers being used by some shippers/carriers for international transport of the UF 6 cylinders/overpacks. Because of the concerns about international shipments, the US Department of Energy-Headquarters (DOE-HQ) Office of Nuclear Energy, through DOE-HQ Transportation Management Division, requested Westinghouse Hanford Company (Westinghouse Hanford) to review UF 6 packaging tiedown and shipping practices used by PORTS, and where possible and appropriate, provide recommendations for enhancing these practices. Consequently, a team of two individuals from Westinghouse Hanford visited PORTS on March 5 and 6, 1990, for the purpose of conducting this review. The paper provides a brief discussion of the review activities and a summary of the resulting findings and recommendations. A detailed reporting of the is documented in Reference 4

  18. Geometry and electronic structure of an impurity-trapped exciton in the Cs2GeF6 crystal doped with U4+. The 5f17s1 manifold

    International Nuclear Information System (INIS)

    Ordejon, B.; Seijo, L.; Barandiaran, Z.

    2007-01-01

    Complete text of publication follows: Excitons trapped at impurity centres in highly ionic crystals were first described by McClure and Pedrini [Phys. Rev. B 32, 8465 (1985)] as excited states consisting of a bound electron-hole pair with the hole localized on the impurity and the electron on nearby lattice sites, and a very short impurity-ligand bond length. In this work we present a detailed microscopic characterization of an impurity - trapped exciton in Cs 2 GeF 6 doped with U 4+ . Its electronic structure has been studied by means of CASSCF/CASPT2/SOCI relativistic ab initio model potential (AIMP) embedded-cluster calculations on (UF 6 ) 2- and (UF 6 Cs 8 ) 6+ clusters embedded in Cs 2 GeF 6 . The local geometry of the impurity-trapped exciton, the potential energy curves, and the multi electronic wavefunctions, have been obtained as direct, non-empirical results of the methods. The calculated excited states appear to be significantly delocalized outside the UF 6 volume and their U-F bond length turns out to be very short, closer to that of a pentavalent uranium defect than to that of a tetravalent uranium defect. The wavefunctions of these excited states show a dominant U 5f 1 7s 1 configuration character. This result has never been anticipated by simpler models and reveals the unprecedented ability of diffuse orbitals of f-element impurities to act as electron traps in ionic crystals

  19. Prediction of external corrosion for steel cylinders

    International Nuclear Information System (INIS)

    Lyon, B.F.

    1997-02-01

    The US Department of Energy (DOE) currently manages the UF 6 Cylinder Program (the program). The program was formed to address the depleted-uranium hexafluoride (UF 6 ) stored in approximately 50,000 carbon steel cylinders. The cylinders are located at three DOE sites: the K-25 site (K-25) at Oak Ridge, Tennessee; the Paducah Gaseous Diffusion Plant (PGDP) in Paducah, Kentucky, and the Portsmouth Gaseous Diffusion Plant (PORTS) in Portsmouth, Ohio. The System Requirements Document (SRD) (LMES 1996a) delineates the requirements of the program. The appropriate actions needed to fulfill these requirements are then specified within the System Engineering Management Plan (SEMP) (LMES 1996b). The report presented herein documents activities that in whole or in part satisfy specific requirements and actions stated in the UF 6 Cylinder Program SRD and SEMP with respect to forecasting cylinder conditions. The wall thickness projections made in this report are based on the assumption that the corrosion trends noted will continue. Some activities planned may substantially reduce the rate of corrosion, in which case the results presented here are conservative. The results presented here are intended to supersede those presented previously, as the quality of several of the datasets has improved

  20. Refurbishment of uranium hexafluoride cylinder storage yards C-745-K, L, M, N, and P and construction of a new uranium hexafluoride cylinder storage yard (C-745-T) at the Paducah Gaseous Diffusion Plant, Paducah, Kentucky

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-07-01

    The Paducah Gaseous Diffusion Plant (PGDP) is a uranium enrichment facility owned by the US Department of Energy (DOE). A residual of the uranium enrichment process is depleted uranium hexafluoride (UF6). Depleted UF6, a solid at ambient temperature, is stored in 32,200 steel cylinders that hold a maximum of 14 tons each. Storage conditions are suboptimal and have resulted in accelerated corrosion of cylinders, increasing the potential for a release of hazardous substances. Consequently, the DOE is proposing refurbishment of certain existing yards and construction of a new storage yard. This environmental assessment (EA) evaluates the impacts of the proposed action and no action and considers alternate sites for the proposed new storage yard. The proposed action includes (1) renovating five existing cylinder yards; (2) constructing a new UF6 storage yard; handling and onsite transport of cylinders among existing yards to accommodate construction; and (4) after refurbishment and construction, restacking of cylinders to meet spacing and inspection requirements. Based on the results of the analysis reported in the EA, DOE has determined that the proposed action is not a major Federal action that would significantly affect the quality of the human environment within the context of the National Environmental Policy Act of 1969. Therefore, DOE is issuing a Finding of No Significant Impact. Additionally, it is reported in this EA that the loss of less than one acre of wetlands at the proposed project site would not be a significant adverse impact.

  1. Final programmatic environmental impact statement for alternative strategies for the long-term management and use of depleted uranium hexafluoride. Volume 3: Responses to public comments

    International Nuclear Information System (INIS)

    1999-04-01

    This PEIS assesses the potential impacts of alternative management strategies for depleted uranium hexafluoride (UF 6 ) currently stored at three DOE sites: Paducah site near Paducah, Kentucky, Portsmouth site near Portsmouth, Ohio; and K-25 site on the Oak Ridge Reservation, Oak Ridge, Tennessee. The alternatives analyzed in the PEIS include no action, long-term storage as UF 6 , long-term storage as uranium oxide, use as uranium oxide, use as uranium metal, and disposal. DOE's preferred alternative is to begin conversion of the depleted UF 6 inventory as soon as possible, either to uranium oxide, uranium metal, or a combination of both, while allowing for use of as much of this inventory as possible. This volume of the Final PEIS contains the comments and DOE's responses to comments received during the comment period. Chapter 2 contains photocopies of written submissions received by DOE on the Draft PEIS; DOE's responses to those comments are listed in Chapter 3. Chapter 4 provides the oral comments received at the public hearings and DOE's responses. Chapter 5 provides indices to comments and responses arranged by commentor name and by comment number

  2. Mass spectrometric determination of enthalpies of dissociation of gaseous complex fluorides into neutral and charged particles. Pt. 3

    International Nuclear Information System (INIS)

    Sidorov, L.N.; Skokan, E.V.; Nikitin, M.I.; Sorokin, I.D.

    1980-01-01

    Mass spectrometry is used to study ion-molecule equilibria in the saturated vapours of the two-component systems MF-UF 4 (where M is Na or K), containing the negative ions F - , UF - 5 and UF - 6 . The electron affinities of UF 5 and UF 6 are determined as 3.3 +- 0.16 eV and 4.89 +- 0.25 eV and the heats of the following reactions are: F - + UF 4 → UF - 5 ΔH 0 1100 = -98,0 +- 0.3 kcal mol -1 (-410.0 +- 1.3 kJ mol -1 ), AlF 3 + UF - 5 → AlF - 4 + UF 4 ΔH 0 1100 = -22.3 +- 0.3 kcal mol -1 (-93.3 +- 1.3 kJ mol -1 ), UF 5 + UF - 5 → UF 4 + UF - 6 ΔH 0 1087 = -3.4 +- 0.2 kcal mol -1 (-14.2 +- 0.8 kJ mol -1 ). These data and literature values are used to calculate the heat of formation of the UF - 5 ion and the heats of dissociation of the alkali metal fluorouranates into neutral and charged particles. (orig.)

  3. Refurbishment of uranium hexafluoride cylinder storage yards C-745-K, L, M, N, and P and construction of a new uranium hexafluoride cylinder storage yard (C-745-T) at the Paducah Gaseous Diffusion Plant, Paducah, Kentucky

    International Nuclear Information System (INIS)

    1996-07-01

    The Paducah Gaseous Diffusion Plant (PGDP) is a uranium enrichment facility owned by the US Department of Energy (DOE). A residual of the uranium enrichment process is depleted uranium hexafluoride (UF6). Depleted UF6, a solid at ambient temperature, is stored in 32,200 steel cylinders that hold a maximum of 14 tons each. Storage conditions are suboptimal and have resulted in accelerated corrosion of cylinders, increasing the potential for a release of hazardous substances. Consequently, the DOE is proposing refurbishment of certain existing yards and construction of a new storage yard. This environmental assessment (EA) evaluates the impacts of the proposed action and no action and considers alternate sites for the proposed new storage yard. The proposed action includes (1) renovating five existing cylinder yards; (2) constructing a new UF6 storage yard; handling and onsite transport of cylinders among existing yards to accommodate construction; and (4) after refurbishment and construction, restacking of cylinders to meet spacing and inspection requirements. Based on the results of the analysis reported in the EA, DOE has determined that the proposed action is not a major Federal action that would significantly affect the quality of the human environment within the context of the National Environmental Policy Act of 1969. Therefore, DOE is issuing a Finding of No Significant Impact. Additionally, it is reported in this EA that the loss of less than one acre of wetlands at the proposed project site would not be a significant adverse impact

  4. Safety Evaluation Report for the Claiborne Enrichment Center, Homer, Louisiana (Docket No. 70-3070)

    International Nuclear Information System (INIS)

    1994-01-01

    This report documents the US Nuclear Regulatory Commission (NRC) staff review and safety evaluation of the Louisiana Energy Services, L.P. (LES, the applicant) application for a license to possess and use byproduct, source, and special nuclear material and to enrich natural uranium to a maximum of 5 percent U-235 by the gas centrifuge process. The plant, to be known as the Claiborne Enrichment Center (CEC), would be constructed near the town of Homer in Claiborne Parish, Louisiana. At full production in a given year, the plant will receive approximately 4,700 tonnes of feed UF 6 and produce 870 tonnes of low-enriched UF 6 , and 3,830 tonnes of depleted UF 6 tails. Facility construction, operation, and decommissioning are expected to last 5, 30, and 7 years, respectively. The objective of the review is to evaluate the potential adverse impacts of operation of the facility on worker and public health and safety under both normal operating and accident conditions. The review also considers the management organization, administrative programs, and financial qualifications provided to assure safe design and operation of the facility. The NRC staff concludes that the applicant's descriptions, specifications, and analyses provide an adequate basis for safety review of facility operations and that construction and operation of the facility does not pose an undue risk to public health and safety

  5. A kinematically complete, interdisciplinary, and co-institutional measurement of the 19F(α,n) cross section for nuclear safeguards science

    International Nuclear Information System (INIS)

    Peters, W. A.; Smith, M. S.; Pittman, S.; Thompson, S. J.; Clement, R. R. C.; Cizewski, J. A.; Pain, S. D.; Febbraro, M.; Chipps, K. A.; Burcher, S.; Manning, B.; Reingold, C.; Avetisyan, R.; Battaglia, A.; Chen, Y.; Long, A.; Lyons, S.; Marley, S. T.; Seymour, C.; Siegl, K. T.; Smith, M. K.; Strauss, S.; Talwar, R.; Bardayan, D. W.; Gyurjinyan, A.; Smith, K.; Thornsberry, C.; Thompson, P.; Madurga, M.; Stech, E.; Tan, W. P.; Wiescher, M.; Ilyushkin, S.; Tully, Z.; Grinder, M. M.

    2016-01-01

    Alpha particles emitted from the decay of uranium in a UF 6 matrix can interact with fluorine and generate neutrons via the 19 F(α,n) 22 Na reaction. These neutrons can be used to determine the uranium content in a UF 6 storage cylinder. The accuracy of this self-interrogating, non-destructive assay (NDA) technique is, however, limited by the uncertainty of the 19 F(α,n) 22 Na cross section. We have performed complementary measurements of the 19 F(α,n) 22 Na reaction with both 4 He and 19 F beams to improve the precision of the 19 F(α,n) 22 Na cross section over the alpha energy range that encompasses common actinide alpha decay needed for NDA studies. We have determined an absolute cross section for the 19 F(α,n) 22 Na reaction to an average precision of 7.6% over the alpha energy range of 3.9 - 6.7 MeV. We utilized this cross section in a simulation of a 100 g spherical UF 6 assembly and obtained a change in neutron emission rate values of approximately 10-12%, and a significant (factor of 3.6) decrease in the neutron emission rate uncertainty (from 50-51% to 13-14%), compared to simulations using the old cross section. Our new absolute cross section enables improved interpretations of NDAs of containers of arbitrary size and configuration.

  6. Spent nuclear fuel recycling with plasma reduction and etching

    Science.gov (United States)

    Kim, Yong Ho

    2012-06-05

    A method of extracting uranium from spent nuclear fuel (SNF) particles is disclosed. Spent nuclear fuel (SNF) (containing oxides of uranium, oxides of fission products (FP) and oxides of transuranic (TRU) elements (including plutonium)) are subjected to a hydrogen plasma and a fluorine plasma. The hydrogen plasma reduces the uranium and plutonium oxides from their oxide state. The fluorine plasma etches the SNF metals to form UF6 and PuF4. During subjection of the SNF particles to the fluorine plasma, the temperature is maintained in the range of 1200-2000 deg K to: a) allow any PuF6 (gas) that is formed to decompose back to PuF4 (solid), and b) to maintain stability of the UF6. Uranium (in the form of gaseous UF6) is easily extracted and separated from the plutonium (in the form of solid PuF4). The use of plasmas instead of high temperature reactors or flames mitigates the high temperature corrosive atmosphere and the production of PuF6 (as a final product). Use of plasmas provide faster reaction rates, greater control over the individual electron and ion temperatures, and allow the use of CF4 or NF3 as the fluorine sources instead of F2 or HF.

  7. Production of uranium hexafluoride by the catalysed fluorox process: pilot plant and supporting bench-scale studies

    International Nuclear Information System (INIS)

    Janov, J.; Charlton, B.G.; LePage, A.H.; Vilkaitis, V.K.

    1982-04-01

    The feasibility of producing UF 6 by the catalysed reaction of UF 4 with oxygen (the Fluorox process) was investigated in a 150 mm diameter fluidised bed reactor and in supporting bench-scale experiments. The rate of the Fluorox reaction in batch experiments was increased by an order of magnitude with 1 to 5 per cent catalyst (containing 3 to 4 per cent platinum on alumina). The maximum UF 6 production rate at 650 deg. C was 0.9 kg h -1 . However, the platinum catalyst was completely poisoned after production of only 1 and 20 kg UF 6 per kg of catalyst when using respectively French and British UF 4 . Regeneration of the catalyst was demonstrated to be technically feasible by washing with water or ammonium oxalate solution or treating with hydrogen and hydrogen fluoride at 350-650 deg. C. However, since the very fast rate of poisoning would necessitate higher catalyst concentrations and/or frequent regeneration, the catalysed Fluorox process in unlikely to be economically competitive with the direct fluorination of UF 4

  8. Laser-based data acquisition in gas centrifuge environments using optical fibers

    International Nuclear Information System (INIS)

    Cates, M.R.; Allison, S.W.; Marshall, B.; Davies, T.J.; Franks, L.A.; Nelson, M.A.; Noel, B.W.

    1984-01-01

    The operating environment of gas centrifuges poses three basic experimental problems: rotating reference frame, corrosive effects of UF 6 gas, and vacuum coupling. Diagnostic experiments in this environment effectively use fiber optics as laser transport systems and data extraction channels. Access to the interior of rotating centrifuges is only from a central nonrotating column assembly. Optical paths are often long and difficult to measure in static conditions with precision necessary in operating conditions. Residual traces of HF gas, from UF 6 , damage exposed optical components over time. Diagnostic measurements requiring pulsed laser sources and analysis of fluorescence emissions, both from UF 6 gas and from temperature-sensitive phosphor are described, with emphasis on optical fiber components and experimental design configurations. The studies were done at Oak Ridge Gaseous Diffusion Plant through the Centrifuge Physics Department of the Centrifuge Division. The advantages of fiber optics methods include: optical path flexibility, small and adaptable size of components, utility in connection with moveable assemblies, and relative ease of vacuum isolation. 3 references, 6 figures

  9. Gas-phase thermal dissociation of uranium hexafluoride: Investigation by the technique of laser-powered homogeneous pyrolysis

    International Nuclear Information System (INIS)

    Bostick, W.D.; McCulla, W.H.; Trowbridge, L.D.

    1987-04-01

    In the gas-phase, uranium hexafluoride decomposes thermally in a quasi-unimolecular reaction to yield uranium pentafluoride and atomic fluorine. We have investigated this reaction using the relatively new technique of laser-powered homogeneous pyrolysis, in which a megawatt infrared laser is used to generate short pulses of high gas temperatures under strictly homogeneous conditions. In our investigation, SiF 4 is used as the sensitizer to absorb energy from a pulsed CO 2 laser and to transfer this energy by collisions with the reactant gas. Ethyl chloride is used as an external standard ''thermometer'' gas to permit estimation of the unimolecular reaction rate constants by a relative rate approach. When UF 6 is the reactant, CF 3 Cl is used as reagent to trap atomic fluorine reaction product, forming CF 4 as a stable indicator which is easily detected by infrared spectroscopy. Using these techniques, we estimate the UF 6 unimolecular reaction rate constant near the high-pressure limit. In the Appendix, we describe a computer program, written for the IBM PC, which predicts unimolecular rate constants based on the Rice-Ramsperger-Kassel theory. Parameterization of the theoretical model is discussed, and recommendations are made for ''appropriate'' input parameters for use in predicting the gas-phase unimolecular reaction rate for UF 6 as a function of temperature and gas composition and total pressure. 85 refs., 17 figs., 14 tabs

  10. Příspěvek k modelování teplotní závislosti difuzních koeficientů ve svarovém spoji ocelí

    Czech Academy of Sciences Publication Activity Database

    Řeháčková, L.; Million, Bořivoj; Dobrovská, J.; Stránský, K.

    2004-01-01

    Roč. 78, č. 298 (2004), s. 119-124 ISSN 1429-6055. [Metody hodnocení struktury a vlastností materiálů /19./. Rožnov pod Radhoštěm, 30.11.2004-02.12.2004] R&D Projects: GA ČR(CZ) GA106/04/0949; GA ČR(CZ) GA106/04/1006 Institutional research plan: CEZ:AV0Z2041904 Keywords : carbon diffusion coefficient * steel weldments Subject RIV: JG - Metallurgy

  11. Sustav obrazovanja kadrova za hotelijersko-turističko gospodarstvo

    OpenAIRE

    Peršić, Milena

    1995-01-01

    Kadrovi su osnovni društveni i gospodarski resurs razvoja svake djelatnosti, pa tako i pojedinih segmenata u strukturi hotelijersko-turističkog gospodarstva. Iz te spoznaje proizlazi potreba ustroja takvog obrazovnog sustava koji će postojećim i potencijalnim djelatnicima pružiti odgovarajuća znanja za što kvalitetnije uključivanje u sve segmente izvođačkog, informacijskog i upravljačkog sustava hotelskog poduzeća. Neusklađenost nastavnih planova, programa i obrazovnih profila sa stvarnim zah...

  12. Spanje dojenčkov

    OpenAIRE

    Matjaž, Mojca

    2017-01-01

    IZVLEČEK Uvod: Spanje je pomembno za vse ljudi, zlasti za dojenčka, saj v spanju raste in se mu razvijajo možgani. V prvih mesecih dojenčkovega življenja potekajo velike spremembe v vzpostavljanju ritma in trajanja spanja, vzorcih spanja in budnosti ter v strukturi spanja. Namen: Predstaviti spanje dojenčkov in dejavnike, ki vplivajo na spanje dojenčkov. Cilj diplomske naloge je odgovoriti na raziskovalna vprašanja: o razlikah v spanju med dojenimi in nedojenimi dojenčki, povezavi med spal...

  13. Reallocation of organic functions on the example of domestic subsidiary - a case study

    Directory of Open Access Journals (Sweden)

    Sobotkiewicz Dariusz

    2014-12-01

    Full Text Available W opracowaniu poruszono problem funkcji organicznych w kontekście zmian ich lokalizacji na przykładzie krajowej spółki zależnej będącej częścią holdingu. W części teoretycznej opracowania wykazano, iż ewolucja struktury organizacyjnej oraz zmiana w postrzeganiu roli jednostek zależnych w całym holdingu wpływa na realokację funkcji organicznych. W części empirycznej natomiast podjęto próbę identyfi kacji zmian jakie zaszły w rozmieszczeniu funkcji na poziomie spółki zależnej oraz rozpoznano jak te zmiany wpłynęły na przekształcenia struktury organizacyjnej. Opracowanie kończy podsumowanie, w którym wyartykułowane główne wnioski z badań

  14. Depleted uranium: A DOE management guide

    International Nuclear Information System (INIS)

    1995-10-01

    The U.S. Department of Energy (DOE) has a management challenge and financial liability in the form of 50,000 cylinders containing 555,000 metric tons of depleted uranium hexafluoride (UF 6 ) that are stored at the gaseous diffusion plants. The annual storage and maintenance cost is approximately $10 million. This report summarizes several studies undertaken by the DOE Office of Technology Development (OTD) to evaluate options for long-term depleted uranium management. Based on studies conducted to date, the most likely use of the depleted uranium is for shielding of spent nuclear fuel (SNF) or vitrified high-level waste (HLW) containers. The alternative to finding a use for the depleted uranium is disposal as a radioactive waste. Estimated disposal costs, utilizing existing technologies, range between $3.8 and $11.3 billion, depending on factors such as applicability of the Resource Conservation and Recovery Act (RCRA) and the location of the disposal site. The cost of recycling the depleted uranium in a concrete based shielding in SNF/HLW containers, although substantial, is comparable to or less than the cost of disposal. Consequently, the case can be made that if DOE invests in developing depleted uranium shielded containers instead of disposal, a long-term solution to the UF 6 problem is attained at comparable or lower cost than disposal as a waste. Two concepts for depleted uranium storage casks were considered in these studies. The first is based on standard fabrication concepts previously developed for depleted uranium metal. The second converts the UF 6 to an oxide aggregate that is used in concrete to make dry storage casks

  15. Uranium milling and conversion at Ningyo-toge Works

    International Nuclear Information System (INIS)

    Takada, Shingo

    1981-01-01

    Based on these experimental results, the refining and conversion pilot plant (annual pro duction capacity 200 t-U) is now under construction, in order to promote further industrialization and to supply UF 6 to the enrichment pilot plant in Ningyotoge works. The new plant has two systems of solvent extraction using tri-n-octylamine, one of which treats the pregnant liquor from the section of heap leach and ion exchange, and the other treats the uranyl sulphate solution in which yellow cake is dissolved. Both of the pregnant solvents are stripped with hydrochloric acid to obtain high grade pregnant eluates (100 g-U). Uranyl sulphate solution from the stripping circuit is reduced to uranous sulphate solution by electrolytic method. In a reduction cell, uranyl sulphate solution and dilute sulphuric acid are used respectively as catholyte and anolyte, and a cation exchange membrane is used to prevent re-oxidation of the uranous sulphate. In this case, reduction power consumption is about 1.5 kWh/kg-U and the reduction rate is over 99.5%. The uranous sulphate solution is then heated to 90 0 C, and UF 4 1 -- 1.2H 2 O (particle size of 50 -- 100 μ) is precipitated continuously with hydrofluoric acid by a new type eouipment which has made it possible to simplify the procedures of liquid-solid separation, drying and granulation. Then the crystal water in uranium tetrafluoride is dehydrated by heating to 350 0 C in an inert gas flow. The conversion of UF 4 to UF 6 is accomplished by a fluidized-bed reactor and high fluorine efficiencies over 99.9% (less than 0.1% of fluorine unreacted) is attained at about 400 0 C with the complete conversion of UF 4 to UF 6 . (J.P.N.)

  16. On the applicability of the critical safety function concept to a uranium hexafluoride conversion unit

    International Nuclear Information System (INIS)

    Santos, F.C.; Goncalves, J.S.; Melo, P.F. Frutuoso e; Medeiros, J.A.C.C.

    2013-01-01

    This paper presents a discussion on the applicability on the critical safety function (CSF) concept as a design criterion for the new UF 6 conversion plant of Industrias Nucleares do Brazil (INB). This discussion is in the context of accident management, under the safety function oriented management. Safety functions may be understood as those whose loss may lead to releases of radioactive material or highly toxic chemicals, having possible radiological and/or occupational consequences for workers, the public or the environment. They should be designed to prevent criticality and to ensure adequate process confinement, thus preventing radioactive material releases that might lead to internal or external exposure and highly toxic chemical releases and exposure. The main hazards is the potential release of chemicals, especially HF and UF 6 . A criticality hazard exists only if the conversion facility processes uranium with a 235 U concentration greater than 1% Industrial activities for UF 6 production include handling and processing explosive, toxic and lethal chemicals, such as HF, H 2 and elemental F 2 , besides intermediate compounds containing uranium. State trees and definition of logical arrangements to construct an annunciation system are the next development stages, resulting form the establishment of applicable CSFs as representative of the next development stages, resulting from the establishment of applicable CSFs as representative of the various systems that make up the conversion plant. Discussed also in the biggest challenge of the development of this innovation, that is, the uncertainties related to the impact of human factors (not subject to monitoring by sensors or process conventional instrumentation). (author)

  17. Assessment of the risk of transporting uranium hexafluoride by truck and train

    International Nuclear Information System (INIS)

    Geffen, C.A.; Johnson, J.F.; Davis, D.K.; Friley, J.R.; Ross, B.A.

    1978-08-01

    This report is the fifth in a series of studies of the risk of transporting potentially hazardous energy materials. The report presents an assessment of the risk of shipping uranium hexafluoride (UF 6 ) by truck and rail. The general risk assessment methodology, summarized in Section 3, used in this study is that developed for the first study in this series. The assessment includes the risks from release of uranium hexafluoride during truck or rail transport due to transportation accidents. The contribution to the risk of deteriorated or faulty packaging during normal transport was also considered. The report is sectioned to correspond to the specific analysis steps of the risk assessment model. The transportation system and accident environment are described in Sections 4 and 5. Calculation of the response of the shipping system to forces produced in transportation accidents are presented in Section 6 and the results of a survey to determine the condition of the package during transport are presented in Section 7. Sequences of events that could lead to a release of radioactive material from the shipping cask during transportation are postulated in Section 8 using fault tree analysis. These release sequences are evaluated in Sections 9 through 11, to determine both the likelihood and the possible consequences of each release. Supportive data and analyses are given in the appendices. The results of the risk assessment have been related to the year 1985, when it is projected that 100 GW of electric power will be generated annually by nuclear power plants. It was estimated that approximately 46,000 metric tons (MT) of natural UF 6 and 14,600 MT of enriched UF 6 would be shipped in the reference year

  18. Pollution and wet cleaning of separation nozzle systems for enrichment of uranium-235

    International Nuclear Information System (INIS)

    Bacher, W.; Bier, W.; Linder, N.

    1980-06-01

    Operational defects in separation nozzle plants resulting in air leaking into the system may cause permanent pollution of the narrow slits of the separation elements by products of the hydrolysis of UF 6 . The deposits may deteriorate the separation performance of the separation elements to such an extent that their further use for uranium enrichment is no longer feasible. Tests performed on commercial-scale separation element tubes indicated that the deposits can be removed by a wet chemical process effectively enough to restore the full separative power of the elements. The aspects of the technical application of the cleanup process are discussed. (orig.) [de

  19. The conditions of ADU two steps precipitation

    International Nuclear Information System (INIS)

    Li Chaoduan; Gong Xingyuan; Tang Anyuan; Duan Dezhi; Zhang Weiye

    1999-11-01

    The two steps precipitation process of ADU powder from UF 6 hydrolyzates to high active and sinterable UO 2 powder is studied. The optimized precipitation is obtained. The results indicate that the prepared ADU powder has such advantages as fine particle and active surface with higher SSA (24-30 m 2 /g) by the first step of pH value 3.0-4.0, temperature 30-40 degree C, PAM concentration 0.05 g/L. The UO 2 powder produced by such ADU has higher activity, sinterability and matrix density (≥ 96.5% T.D.)

  20. Disposition of highly enriched uranium obtained from the Republic of Kazakhstan. Environmental assessment

    International Nuclear Information System (INIS)

    1995-05-01

    This EA assesses the potential environmental impacts associated with DOE's proposal to transport 600 kg of Kazakhstand-origin HEU from Y-12 to a blending site (B ampersand W Lynchburg or NFS Erwin), transport low-enriched UF6 blending stock from a gaseous diffusion plant to GE Wilmington and U oxide blending stock to the blending site, blending the HEU and uranium oxide blending stock to produce LEU in the form of uranyl nitrate, and transport the uranyl nitrate from the blending site to USEC Portsmouth

  1. Development of F2 two-step fluorination process for non-aqueous reprocessing

    International Nuclear Information System (INIS)

    1976-02-01

    To establish the F 2 two-step fluorination for stable and high recoveries of plutonium, the fluorination process has been studied with the simulated fuel to a FBR containing UO 2 - PuO 2 and non-radioactive fission products in the 2''phi fluid-bed. The process principle was demonstrated and the effect of FPs on fluorination of U and Pu and the possibility of reducing the Pu loss could be clarified. The feasibility of separating PuF 6 from UF 6 onto UO 2 F 2 by adsorption, was also indicated. (auth.)

  2. Nuclear materials transport in France

    International Nuclear Information System (INIS)

    Korycanek, J.

    1990-01-01

    About 1.5 million tons of uranium ore, 8000 tons of uranium concentrate, 1000 tons of UF 6 , 340 spent fuel containers, and 30 000 m 3 of nuclear wastes are transported annually by trucks, trains and ships in France. Annual costs of this transportation amount to 500-600 million FRF, and about 200 employees are engaged in this activity. Transportation of spent fuel to the La Hague and Marcoule fuel reprocessing plants, and the transport of plutonium are dealt with in detail. (Z.M.). 5 figs., 1 ref

  3. Technology of the light water reactor fuel cycle

    International Nuclear Information System (INIS)

    Wymer, R.G.

    1979-01-01

    This essay presents elements of the processes used in the fuel cycle steps and gives an indication of the types of equipment used. The amounts of radioactivity released in normal operation of the processes are indicated and related to radiation doses. Types and costs of equipment or processes required to lower these radioactivity releases are in some cases suggested. Mining and milling, conversion of uranium concentrate to UF 6 , uranium isotope separation, LWR fuel fabrication, fuel reprocessing, transportation, and waste management are covered in this essay. 40 figures, 34 tables

  4. Flowsheets and source terms for radioactive waste projections

    International Nuclear Information System (INIS)

    Forsberg, C.W.

    1985-03-01

    Flowsheets and source terms used to generate radioactive waste projections in the Integrated Data Base (IDB) Program are given. Volumes of each waste type generated per unit product throughput have been determined for the following facilities: uranium mining, UF 6 conversion, uranium enrichment, fuel fabrication, boiling-water reactors (BWRs), pressurized-water reactors (PWRs), and fuel reprocessing. Source terms for DOE/defense wastes have been developed. Expected wastes from typical decommissioning operations for each facility type have been determined. All wastes are also characterized by isotopic composition at time of generation and by general chemical composition. 70 references, 21 figures, 53 tables

  5. Technology for the storage of radioactive materials packagings during maritime transport. Phase 1

    International Nuclear Information System (INIS)

    Ringot, C.; Chevalier, G.; Tomachevski, E.G.

    1989-01-01

    Following the accident of the M/S Mont Louis on August 25, 1984 carrying UF 6 cylinders, this report is a preliminary study of bibliographic data to help to define recommendations on packaging stowing for sea transport. Data on acceleration to take into account for normal or accidental transport conditions, safe areas on board that should be reserved for radioactive materials and accidents statistics are collected. Main information concerns: number of serious casualities or total losses to ships in European waters, accident causes, collision probability in function of mean distance between ships in the British Channel, selection of 8 reference accidents for future studies

  6. The Oklo fossil reactor

    International Nuclear Information System (INIS)

    Roth, Etienne.

    1975-01-01

    From the observation of anomalous 235 U content of a UF 6 cylinder in Pierrelatte, it was possible to trace back this anomaly to minerals coming from the Oklo quarry in Gabon. Large variations in 235 U content such as were observed could only come from very specific processes, one of them being induced fission. To investigate this hypothesis it was looked for the fission rare earths and their isotopic composition, and these unequivocally assigned the phenomenon to a reaction of fission of 235 U [fr

  7. Activity report on research and development work 1980 of the institute for Nuclear Process Technology

    International Nuclear Information System (INIS)

    1981-02-01

    Within the framework of guaranteeing supplies of nuclear fuel for the generation of nuclear energy, the KfK developed the separation nozzle method for the enrichment of U-235. It is based on partial separation of this uranium isotope by a deflected jet from a mixture of UF 6 /hydrogen. This method is now being applied on a technical scale for the first time in Brazil within the framework of an agreement concluded between the Federal Republic of Germany and Brazil and approved by the International Atomic Energy Agency. (orig./EF) [de

  8. Prediction of External Corrosion for Steel Cylinders--2004 Report

    International Nuclear Information System (INIS)

    Schmoyer, RLS

    2004-01-01

    Depleted uranium hexafluoride (UF 6 ) is stored in over 60,000 steel cylinders at the East Tennessee Technology Park (ETTP) in Oak Ridge, Tennessee, at the Paducah Gaseous Diffusion Plant (PGDP) in Paducah, Kentucky, and at the Portsmouth Gaseous Diffusion Plant (PORTS) in Portsmouth, Ohio. The cylinders range in age from 4 to 53 years. Although when new the cylinders had wall thicknesses specified to within manufacturing tolerances, over the years corrosion has reduced their actual wall thicknesses. The UF 6 Cylinder Project is managed by the United States Department of Energy (DOE) to safely maintain the UF 6 and the cylinders containing it. This report documents activities that address UF 6 Cylinder Project requirements and actions involving forecasting cylinder wall thicknesses. These requirements are delineated in the System Requirements Document (LMES 1997a), and the actions needed to fulfill them are specified in the System Engineering Management Plan (LMES 1997b). The report documents cylinder wall thickness projections based on models fit to ultrasonic thickness (UT) measurement data. UT data is collected at various locations on randomly sampled cylinders. For each cylinder sampled, the minimum UT measurement approximates the actual minimum thickness of the cylinder. Projections of numbers of cylinders expected to fail various thickness criteria are computed from corrosion models relating minimum wall thickness to cylinder age, initial thickness estimates, and cylinder subpopulations defined in terms of plant site, yard, top or bottom storage positions, nominal thickness, etc. In this report, UT data collected during FY03 is combined with UT data collected in earlier years (FY94-FY02), and all of the data is inventoried chronologically and by various subpopulations. The UT data is used to fit models of maximum pit depth and minimum thickness, and the fitted models are used to extrapolate minimum thickness estimates into the future and in turn to compute

  9. Disposition of highly enriched uranium obtained from the Republic of Kazakhstan. Environmental assessment

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-05-01

    This EA assesses the potential environmental impacts associated with DOE`s proposal to transport 600 kg of Kazakhstand-origin HEU from Y-12 to a blending site (B&W Lynchburg or NFS Erwin), transport low-enriched UF6 blending stock from a gaseous diffusion plant to GE Wilmington and U oxide blending stock to the blending site, blending the HEU and uranium oxide blending stock to produce LEU in the form of uranyl nitrate, and transport the uranyl nitrate from the blending site to USEC Portsmouth.

  10. Minimum critical masses for uranium at the Portsmouth Gaseous Diffusion Plant

    International Nuclear Information System (INIS)

    Tayloe, R.W. Jr.; Davis, T.C.

    1994-06-01

    This report presents a tabulation of safe masses and minimum critical masses for uranium (U). These minimum critical mass and safe mass tables were obtained by interpolating between the values reported in the literature to obtain values as a function of enrichment within the 1.5 percent to 100 percent range. Equivalent mass values for uranium-235 (U 235 ), uranium hexafluoride (UF 6 ), and uranyl fluoride (UO 2 F 2 ) have been generated from the safe mass and minimum critical masses for uranium

  11. Depleted uranium hexafluoride: Waste or resource?

    International Nuclear Information System (INIS)

    Schwertz, N.; Zoller, J.; Rosen, R.; Patton, S.; Bradley, C.; Murray, A.

    1995-07-01

    The US Department of Energy is evaluating technologies for the storage, disposal, or re-use of depleted uranium hexafluoride (UF 6 ). This paper discusses the following options, and provides a technology assessment for each one: (1) conversion to UO 2 for use as mixed oxide duel, (2) conversion to UO 2 to make DUCRETE for a multi-purpose storage container, (3) conversion to depleted uranium metal for use as shielding, (4) conversion to uranium carbide for use as high-temperature gas-cooled reactor (HTGR) fuel. In addition, conversion to U 3 O 8 as an option for long-term storage is discussed

  12. PATRAM '83: 7th international symposium on packaging and transportation of radioactive materials

    International Nuclear Information System (INIS)

    1983-01-01

    Papers were presented at the following sessions: international regulations; materials, fracture toughness of ferritic steels; risk analysis techniques; storage in packagings; packaging design considerations; monolithic cast iron casks; risk analysis; facility/transportation system interface; research and development programs; UF 6 packagings; national regulations; transportation operations and traffic; containment, seals, and leakage; radiation risk experience; emergency response; structural modeling and testing; transportation system planning; institutional issues and public response; packaging systems; thermal analysis and testing; systems analysis; structural analyses; quality assurance; packaging and transportation systems; physical protection; criticality and shielding; transportation operations and experience; standards; shock absorber technology; and information and training for regulatory compliance. Individual summaries are title listed

  13. Electrodeposition of nickel onto steel using a soluble mobile anode

    International Nuclear Information System (INIS)

    Petit, G.S.; Wright, R.R.

    1978-04-01

    During the Cascade Improvement Program (CIP), a number of component parts that have been in service for many years will be reused. Many of these parts will have exposed steel from loss of nickel plate or mechanical damage. A good method is needed to patch small areas of exposed steel with electroplated nickel to inhibit the corrosive attack of uranium hexafluoride (UF 6 ) on the steel. A method to patch bare plate steel with nickel, using a mobile soluble anode, has been developed by the K-25 Technical Services Division. This report describes the method and presents test results of coupons plated by the method

  14. A suggested periodic table up to Z≤ 172, based on Dirac-Fock calculations on atoms and ions.

    Science.gov (United States)

    Pyykkö, Pekka

    2011-01-07

    Extended Average Level (EAL) Dirac-Fock calculations on atoms and ions agree with earlier work in that a rough shell-filling order for the elements 119-172 is 8s Periodic Table develops further that of Fricke, Greiner and Waber [Theor. Chim. Acta 1971, 21, 235] by formally assigning the elements 121-164 to (nlj) slots on the basis of the electron configurations of their ions. Simple estimates are made for likely maximum oxidation states, i, of these elements M in their MX(i) compounds, such as i = 6 for UF(6). Particularly high i are predicted for the 6f elements.

  15. CFD-simulation of uranium hexafluoride during phase change

    International Nuclear Information System (INIS)

    Pakarinen, Tomi

    2014-01-01

    A model for simulating the behavior of uranium hexafluoride during melting and solidification cycles has been developed. First goal was to create a user-defined material of uranium hexafluoride for commercial computational fluid dynamics software (FLUENT). The results of the thermo physical properties are presented in this paper. The material properties were used to create a model that is able to simulate melting, solidification, evaporation and condensation. The model was used to obtain knowledge of UF 6 s behaviour when melting and solidifying the matter in a two-dimensional cylinder. The results were compared to the results of an analytical solution. The calculation results are consistent with the simulation. (authors)

  16. Model of the coercion uranium hexafluoride on a human body

    International Nuclear Information System (INIS)

    Babenko, S.P.

    2007-01-01

    A method for calculating certain quantities characterizing the effect of uranium hexafluoride (UF 6 ) on the human body under industrial conditions in uranium enrichment plants is described. It is assumed that the effect is determined by uranium and fluorine inhaled together with the products of hydrolysis of uranium hexafluoride. The proposed complex model consists of three models, the first of which describes the contamination of the industrial environment and the second and third describe inhalation and percutaneous intake. A relation is obtained between uranium and fluorine intake and the uranium hexafluoride concentration in air at the moment the compound is discharged [ru

  17. Thermodynamic properties of UF sub 6 measured with a ballistic piston compressor

    Science.gov (United States)

    Sterritt, D. E.; Lalos, G. T.; Schneider, R. T.

    1973-01-01

    From experiments performed with a ballistic piston compressor, certain thermodynamic properties of uranium hexafluoride were investigated. Difficulties presented by the nonideal processes encountered in ballistic compressors are discussed and a computer code BCCC (Ballistic Compressor Computer Code) is developed to analyze the experimental data. The BCCC unfolds the thermodynamic properties of uranium hexafluoride from the helium-uranium hexafluoride mixture used as the test gas in the ballistic compressor. The thermodynamic properties deduced include the specific heat at constant volume, the ratio of specific heats for UF6, and the viscous coupling constant of helium-uranium hexafluoride mixtures.

  18. Adaptation of the continuous cold-trap system of fluidized-bed to the fluoride volatility process

    International Nuclear Information System (INIS)

    1976-01-01

    A continuous cold-trap system consisting of fluidized condensor and stripper has been evaluated with a view to adapt it to the Fluoride Volatility Process in establishing the continuous purification process without radiation decomposition of PuF 6 . Its feasibility is shown by the test with UF 6 -air. Necessary conditions for the cold trap, and performance of the 2-in.-dia. fluidized-bed cold-trap system are presented, and also a model of mist formation in the condensor

  19. University of Florida nuclear pumped laser program. [excitation of laser gaseous

    Science.gov (United States)

    Schneider, R. T.

    1979-01-01

    The mechanism of excitation of laser gases by fast ions (triton, proton, or fission fragments) and especially any role UF6 might play in radiative deexcitation of these gases were investigated. Population densities of excited important for laser action were obtained. Nuclear pumped CW-laser systems, especially He-Ne and CO2, were studied using steady state reactors. It was demonstrated that He-Ne lases in a CW-mode with nuclear pumping at both the red and the infrared transition. The infrared transition was observed to be superradiant.

  20. Comparison of cost effectiveness of risk reduction among different energy systems: French case studies. Final report for the period 1 May 1982 - 20 February 1988

    International Nuclear Information System (INIS)

    Lochard, J.

    1989-08-01

    The report presents the three French case studies performed in the framework of the co-ordinated research programme on ''Comparison of Cost-Effectiveness of Risk Reduction Among Different Energy Systems'': cost-effectiveness of robotics and remote tooling for occupational risk reduction at a nuclear fuel fabrication facility; cost-effectiveness of protection actions to reduce occupational exposure in underground uranium mines; cost effectiveness of safety measures to reduce public risk associated with the transportation of UF 6 by truck and trains. Figs and tabs

  1. LEU fuel element produced by the Egyptian fuel manufacturing pilot plant

    International Nuclear Information System (INIS)

    Zidan, W.I.

    2000-01-01

    The Egyptian Fuel Manufacturing Pilot Plant, FMPP, is a Material Testing Reactor type (MTR) fuel element facility, for producing the specified fuel elements required for the Egyptian Second Research Reactor, ETRR-2. The plant uses uranium hexafluoride (UF 6 , 19.75% U 235 by wt) as a raw material which is processed through a series of the manufacturing, inspection and test plan to produce the final specified fuel elements. Radiological safety aspects during design, construction, operation, and all reasonably accepted steps should be taken to prevent or reduce the chance of accidents occurrence. (author)

  2. Automation of the Process to Obtain U F4 Powders

    International Nuclear Information System (INIS)

    Fenocchio, A.D

    2001-01-01

    Here is exposed the preliminary analysis of the control system to be implemented in the Production Plant of UF 4 Powders.The work has been done in the electronic laboratory.This implies, the setting of devices (PLC, Temperature Controllers, etc.) and the setting of the communications using the proper protocol.Also is shown a study about the logic for the first part of the conversion process of UF 6 : the evaporation.This study is used to define the methodology to follow in a future PLC program

  3. Separation of a multicomponent mixture by gaseous diffusion: modelization of the enrichment in a capillary - application to a pilot cascade

    International Nuclear Information System (INIS)

    Doneddu, F.

    1982-01-01

    Starting from the modelization of gaseous flow in a porous medium (flow in a capillary), we generalize the law of enrichment in an infinite cylindrical capillary, established for an isotropic linear mixture, to a multicomponent mixture. A generalization is given of the notion of separation yields and characteristic pressure classically used for separations of isotropic linear mixtures. We present formulas for diagonalizing the diffusion operator, modelization of a multistage, gaseous diffusion cascade and comparison with the experimental results of a drain cascade (N 2 -SF 6 -UF 6 mixture). [fr

  4. Development of ammonium uranyl carbonate reduction to uranium dioxide using fluidized bed

    International Nuclear Information System (INIS)

    Gomes, R.P.; Riella, H.G.

    1988-01-01

    Laboratory development of Ammonium Uranyl Carbonate (AUC) reduction to uranium dioxide (UO 2 ) using fluidized bed furnace technique is described. The reaction is carried out at 500-550 0 C using hydrogen, liberated from cracking of ammonia, as a reducing agent. As the AUC used is obtained from uranium hexafluoride (UF 6 ) it contains considerable amounts of fluoride ( - 500μgF - /gTCAU) as contaminant. The presence of fluoride leads to high corrosion rates and hence the fluoride concentrations is reduced by pyrohydrolisis of UO 2 . Physical and Chemical proterties of the final product (UO 2 ) obtained were characterized. (author) [pt

  5. Study of reactions for the production of uranium titrafluoride and uranium hexafluoride

    International Nuclear Information System (INIS)

    Guzella, M.F.R.

    1985-01-01

    The main production processes of uranium hexafluoride in pilot plants and industrial facilities are described. The known reactions confirmed in laboratory experiments that lead to Uf 6 or other intermediate fluorides are discussed. For the purpose of determining a thermodinamically feasible reaction involving the sulfur hexafluoride as fluorinating agent, a mock-up facility was designed and constructed as a part of the R and D work planned at the CDTN (Nuclebras Center for Nuclear Technology Development). IN the uranium tatrafluoride synthesis employing U 3 O 8 and SF 6 several experimental parameters are studied. The reaction time, gasflow, temperature and stoechiometic relations among reagents are described in detail. (Author) [pt

  6. PATRAM '83: 7th International Symposium on Packaging and Transportation of Radioactive Materials, summaries

    Science.gov (United States)

    Papers were presented at the following sessions: international regulations; materials, fracture toughness of ferritic steels; risk analysis techniques; storage in packagings; packaging design considerations; monolithic cast iron casks; risk analysis; facility/transportation system interface; research and development programs; UF6 packagings; national regulations; transportation operations and traffic; containment, seals, and leakage; radiation risk experience; emergency response; structural modeling and testing; transportation system planning; institutional issues and public response; packaging systems; thermal analysis and testing; systems analysis; structural analyses; quality assurance; packaging and transportation systems; physical protection; criticality and shielding; transportation operations and experience; standards; shock absorber technology; and information and training for regulatory compliance. Individual summaries are title listed.

  7. South Korea's nuclear fuel industry

    International Nuclear Information System (INIS)

    Clark, R.G.

    1990-01-01

    March 1990 marked a major milestone for South Korea's nuclear power program, as the country became self-sufficient in nuclear fuel fabrication. The reconversion line (UF 6 to UO 2 ) came into full operation at the Korea Nuclear Fuel Company's fabrication plant, as the last step in South Korea's program, initiated in the mid-1970s, to localize fuel fabrication. Thus, South Korea now has the capability to produce both CANDU and pressurized water reactor (PWR) fuel assemblies. This article covers the nuclear fuel industry in South Korea-how it is structures, its current capabilities, and its outlook for the future

  8. Isotope separation using lasers

    International Nuclear Information System (INIS)

    Guers, K.

    1976-01-01

    In laser isotope separation atoms or molecules of a specific isotopic species are selectively excited in a gaseous mixture by means of laser light and then separated from the mixture by physical or chemical methods. The methods of excitation and separation are described and compared in terms of their effectiveness. The use of molecules is investigated by analysing the possibility of the selective excitation of UF 6 . Finally, developments in this field are discussed together with the cost of research incurred in the United States and the economic benefit expected from this research. (author)

  9. Overview of the recovery and processing of 233U from the Oak Ridge molten salt reactor experiment (MSRE) remediation activities

    International Nuclear Information System (INIS)

    Del Cul, G.D.; Icenhour, A.S.; Simmons, D.W.; Trowbridge, L.D.; Williams, D.F.; Toth, L.M.; Dai, S.

    2001-01-01

    The Molten Salt Reactor Experiment (MSRE) was operated at Oak Ridge National Laboratory (ORNL) from 1965 to 1969 to test the concept of a high-temperature, homogeneous, fluid-fueled reactor. The discovery that UF 6 and F 2 migrated from the storage tanks into distant pipes and a charcoal bed resulted in significant activities to remove and recover the 233 U and to decommission the reactor. The recovered fissile uranium will be converted into uranium oxide (U 3 O 8 ), which is a suitable form for long-term storage. This publication reports the research and several new developments that were needed to carry out these unique activities. (author)

  10. Current status of MLIS program in PNC

    International Nuclear Information System (INIS)

    Suto, Osamu; Yamaguchi, Hiromi; Tashiro, Kiyoshi; Kawakami, Shigeaki; Shimazaki, Yoshihiro

    1995-01-01

    According to the Atomic Energy Long-Term Program revised by the Japan Atomic Commission in 1987, PNC has started R and D on Molecular Laser Isotope Separation (MLIS) since 1988. The main target of our program is to attain a high enrichment factor under engineering conditions that has been already achieved under experimental conditions by the Institute of Physical and Chemical Research. The test facility for enrichment tests under engineering conditions which consists of 100Hz laser systems at 16μm and a UF 6 handling system has been developed and several tens of tests have been successfully carried out. (author)

  11. Synthèse et caractérisation de composés fluorés pour le piégeage de fluorures gazeux

    OpenAIRE

    Clarenc , Romain Pierre

    2010-01-01

    This work deals with the synthesis and characterization of alkali, alkali-earth and rare earthbased fluorides and the reactivity of the latter with ReF6 for UF6 purification. In a first part,we focused our attention on the synthesis of KMgF3, MgF2 and CaF2 high surface area metalfluorides coupling both microwave assisted solvothermal process and a fluorination step withelemental fluorine (F2). The higher the surface area, the higher the oxygen rate. Thesenanofluorides exhibit Lewis basic char...

  12. Synthesis, Microstructure and the Crystalline Structure of the Barium Titanate Ceramics Doped with Lanthanum

    Directory of Open Access Journals (Sweden)

    Wodecka-Duś B.

    2013-12-01

    Full Text Available W prezentowanej pracy przeprowadzono badania ceramiki BaTiO3 i Ba1-xLąxTi1-x/4O3 (BLT dla koncentracji z prze- działu 0,001< x <0,004 (0,l-0,4mol.% La. Ceramikę BLT wytworzono z mieszaniny prostych tlenków La203, TiOi i BaCOj (wszystkie o czystości 99,9+%, Aldrich Chemical Co. Proszki ceramiczne otrzymano metodą konwencjonalną w stanie stałym (metodą MOM i poddano badaniu mikrostruktury i struktury krystalicznej. Mieszaniny proszków poddano analizie termicznej. Wyniki analizy termicznej określiły optymalną temperaturę syntezy oraz procesy zachodzące podczas ogrzewania proszków. Następnie proszki formowano w dyski pod ciśnieniem 300MPa w matrycach ze stali nierdzewnej o średnicy 10 mm. Syntezę przeprowadzono w Ts =950°C t =2godz. Ostatnim krokiem technologii było bezciśnieniowe spiekanie metodą swobodnego spiekania w T = 1350^ przez / =2 godziny. Morfologię otrzymanego materiału ceramicznego obserwowano metodą skaningowej mikroskopii elektronowej. Ceramikę BLT badano również pod względem składu chemicznego metodą EDS. Analizę strukturalną przeprowadzono metodą dyfrakcji rentgenowskiej. Badania mikrostruktury i struktury krystalicznej ceramiki przeprowadzono w temperaturze pokojowej. Badania EDS potwierdziły zachowanie stechiometrii otrzymanych próbek według wzoru chemicznego. Rentgenowska analiza dyfrakcyjna potwierdziły wytworzenie pożądanej struktury krystalicznej zarówno czystej ceramiki BaTiOj jak i z domieszką Lau. Otrzymana ceramika wykazuje strukturę typu perowskitu A BO? o symetrii tetragonalnej P4 mm. Stwierdzono, że wraz ze wzrostem stężenia La3* w BaTiOj następuje zmniejszenie wielkości ziam krystalicznych, zmniejszenie średniego wymiaru krystalitów, zmniejszenie objętości komórki elementarnej oraz wzrost obliczonej rentgenowskiej gęstości.

  13. Uranium enrichment by the separation nozzle process

    International Nuclear Information System (INIS)

    Becker, E.W.; Bier, W.; Ehrfeld, W.; Schubert, K.; Schuette, R.; Seidel, D.

    1975-11-01

    The separation nozzle process for the enrichment of the light uranium isotope U-235 has been developed at the Karlsruhe Nuclear Research Center as an alternative to the gaseous diffusion and centrifuge processes. Since 1970 the STEAG company, Essen, has been involved in the commercial implementation of the nozzle process. A first separation nozzle process. A first separation nozzle demonstration plant with a separative capacity of 180 t SWU/a shall be erected in Brazil with the participation of the Brazilian company NUCLEBRAS and the German companies STEAG and INTERATOM. Methods for the mass production of separation elements were developed by industry and extensive performance tests were carried out on commercially fabricated separation elements. Two prototype separative stages were successfully tested in Karlsruhe. Besides further plant components, a prototype of a UF 6 recycle facility was developed which serves the purpose of stripping the UF 6 from the light auxiliary gas to be recycled in a separation nozzle cascade. The performance level achieved to date characterizes the separation nozzle process as reliable and feasible economically. Therefore, the erection of a separation nozzle demonstration plant can be recognized as the implementation of an enrichment process which combines a reliable and comparatively simple technology with a high potential for further improvements. (orig.) [de

  14. Research on plasma core reactors

    International Nuclear Information System (INIS)

    Jarvis, G.A.; Barton, D.M.; Helmick, H.H.; Bernard, W.; White, R.H.

    1976-01-01

    Experiments and theoretical studies are being conducted for NASA on critical assemblies with one-meter diameter by one-meter long low-density cores surrounded by a thick beryllium reflector. These assemblies make extensive use of existing nuclear propulsion reactor components, facilities, and instrumentation. Due to excessive porosity in the reflector, the initial critical mass was 19 kg U(93.2). Addition of a 17-cm-thick by 89-cm-diameter beryllium flux trap in the cavity reduced the critical mass to 7 kg when all the uranium was in the zone just outside the flux trap. A mockup aluminum UF 6 container was placed inside the flux trap and fueled with uranium-graphite elements. Fission distributions and reactivity worths of fuel and structural materials were measured. Finally, an 85,000 cm 3 aluminum canister in the central region was fueled with UF 6 gas and fission density distributions determined. These results will be used to guide the design of a prototype plasma core reactor which will test energy removal by optical radiation

  15. Compton DIV: Using a Compton-Based Gamma-Ray Imager for Design Information Verification of Uranium Enrichment Plants

    International Nuclear Information System (INIS)

    Burks, M.; Verbeke, J.; Dougan, A.; Wang, T.; Decman, D.

    2009-01-01

    A feasibility study has been performed to determine the potential usefulness of Compton imaging as a tool for design information verification (DIV) of uranium enrichment plants. Compton imaging is a method of gamma-ray imaging capable of imaging with a 360-degree field of view over a broad range of energies. These systems can image a room (with a time span on the order of one hour) and return a picture of the distribution and composition of radioactive material in that room. The effectiveness of Compton imaging depends on the sensitivity and resolution of the instrument as well the strength and energy of the radioactive material to be imaged. This study combined measurements and simulations to examine the specific issue of UF 6 gas flow in pipes, at various enrichment levels, as well as hold-up resulting from the accumulation of enriched material in those pipes. It was found that current generation imagers could image pipes carrying UF 6 in less than one hour at moderate to high enrichment. Pipes with low enriched gas would require more time. It was also found that hold-up was more amenable to this technique and could be imaged in gram quantities in a fraction of an hour. another questions arises regarding the ability to separately image two pipes spaced closely together. This depends on the capabilities of the instrument in question. These results are described in detail. In addition, suggestions are given as to how to develop Compton imaging as a tool for DIV

  16. Technology development for nuclear material accountability

    International Nuclear Information System (INIS)

    Hong, Jong Sook; Lee, Byung Doo; Cha, Hong Ryul; Choi, Hyoung Nae; Park, Ho Jun.

    1990-01-01

    Neutron yields from 19 F(α,n) 22 Na reaction of uranium neutron interaction with uranium-bass materials, and the characteristics of shielded neutron assay probe have been studied. On the basis of the above examination, U-235 enrichment in UF 6 cylinders like model 30B and model 48Y was measured by the reaction and U-235 contents in the containers by non-destructive total passive neutron assay method. Total measurement efficiency as a result was found to be 6.44 x 10 -4 and 1.25 x 10 -4 for model 30B and model 40Y UF 6 cylinder, respectively. The uncertainty of measured enrichment as compared to Tag value obtained from chemical analysis approached about 5 % of relative error at 95 % confidence interval. In the follow-up action for the previously developed (1988) computer system of nuclear material accounting the error searching and treatment routine in accordance with code 10, of IAEA and respective facility attachment has been added to easing the burden of manual error correction by operator. In addition, the procedure for LEMUF calculation has been prepared to help bulk facility operators evaluating MUF in the period of material balance. (author)

  17. The separation nozzle process for uranium isotope enrichment

    International Nuclear Information System (INIS)

    Becker, E.W.

    1977-01-01

    The paper covers the most important steps in the technological development and the future prospects of the separation nozzle process. In this process uranium isotope separation is brought about by the mass dependence of the centrifugal forces in a curved flow of a UF 6 /H 2 mixture. Due to the large excess in hydrogen, the high ratio of UF 6 flow velocity to thermal velocity required for an effective isotope separation is obtained at relatively low expansion ratios and, accordingly, with relatively low gas-dynamic losses. As the optimum Reynolds number of the curved jet is comparatively low, and as a high absolute pressure is essential for economic reasons, the characteristic dimensions of the nozzle systems are made as small as possible. For commercial application in the near future, systems involving mechanical jet deflection have been developed. Promising results were, however, also obtained with separation nozzle systems generating a streamline curvature by the interaction of opposed jets. Most of the development work has been done at the Nuclear Research Centre, Karlsruhe. Since 1970 the STEAG company (FRG) has been involved in the commercial implementation of the process. Two industrial-scale separative stages were tested successfully. This work constitutes the basis of planning of a separation nozzle demonstration plant to be built in Brazil. (author)

  18. Preliminary Concept of Operations for a Global Cylinder Identification and Monitoring System

    Energy Technology Data Exchange (ETDEWEB)

    Whitaker, J. M. [ORNL; White-Horton, J. L. [ORNL; Morgan, J. B. [InSolves Associates

    2013-08-01

    This report describes a preliminary concept of operations for a Global Cylinder Identification and Monitoring System that could improve the efficiency of the International Atomic Energy Agency (IAEA) in conducting its current inspection activities and could provide a capability to substantially increase its ability to detect credible diversion scenarios and undeclared production pathways involving UF6 cylinders. There exist concerns that a proliferant State with access to enrichment technology could obtain a cylinder containing natural or low-enriched uranium hexafluoride (UF6) and produce a significant quantity (SQ)1 of highly enriched uranium in as little as 30 days. The National Nuclear Security Administration (NNSA) through the Next Generation Safeguards Initiative sponsored a multi-laboratory team to develop an integrated system that provides for detecting scenarios involving 1) diverting an entire declared cylinder for enrichment at a clandestine facility, 2) misusing a declared cylinder at a safeguarded facility, and 3) using an undeclared cylinder at a safeguarded facility. An important objective in developing this integrated system was to improve the timeliness for detecting the cylinder diversion and undeclared production scenarios. Developing this preliminary concept required in-depth analyses of current operational and safeguards practices at conversion, enrichment, and fuel fabrication facilities. The analyses evaluated the processing, movement, and storage of cylinders at the facilities; the movement of cylinders between facilities (including cylinder fabrication); and the misuse of safeguarded facilities.

  19. Isotope separation by photoselective dissociative electron

    International Nuclear Information System (INIS)

    Stevens, C.G.

    1978-01-01

    A method of separating isotopes based on photoselective electron capture dissociation of molecules having an electron capture cross section dependence on the vibrational state of the molecule is described. A molecular isotope source material is irradiated to selectively excite those molecules containing a desired isotope to a predetermined vibrational state having associated therewith an electron capture energy region substantially non-overlapping with the electron capture energy ranges associated with the lowest vibration states of the molecules. The isotope source is also subjected to electrons having an energy corresponding to the non-overlapping electron capture region whereby the selectively excited molecules preferentially capture electrons and dissociate into negative ions and neutrals. The desired isotope may be in the negative ion product or in the neutral product depending upon the mechanism of dissociation of the particular isotope source used. The dissociation product enriched in the desired isotope is then separated from the reaction system by conventional means. Specifically, 235 UF 6 is separated from a UF 6 mixture by selective excitation followed by dissociative electron capture into 235 UF 5 - and F

  20. Nuclear piston engine and pulsed gaseous core reactor power systems

    International Nuclear Information System (INIS)

    Dugan, E.T.

    1976-01-01

    The investigated nuclear piston engines consist of a pulsed, gaseous core reactor enclosed by a moderating-reflecting cylinder and piston assembly and operate on a thermodynamic cycle similar to the internal combustion engine. The primary working fluid is a mixture of uranium hexafluoride, UF 6 , and helium, He, gases. Highly enriched UF 6 gas is the reactor fuel. The helium is added to enhance the thermodynamic and heat transfer characteristics of the primary working fluid and also to provide a neutron flux flattening effect in the cylindrical core. Two and four-stroke engines have been studied in which a neutron source is the counterpart of the sparkplug in the internal combustion engine. The piston motions which have been investigated include pure simple harmonic, simple harmonic with dwell periods, and simple harmonic in combination with non-simple harmonic motion. The results of the conducted investigations indicate good performance potential for the nuclear piston engine with overall efficiencies of as high as 50 percent for nuclear piston engine power generating units of from 10 to 50 Mw(e) capacity. Larger plants can be conceptually designed by increasing the number of pistons, with the mechanical complexity and physical size as the probable limiting factors. The primary uses for such power systems would be for small mobile and fixed ground-based power generation (especially for peaking units for electrical utilities) and also for nautical propulsion and ship power

  1. Japan-IAEA sefeguards demonstration programme in the gas centrifuge uranium enrichment facility

    International Nuclear Information System (INIS)

    Akiba, Mitsunori; Iwamoto, Tomonori; Omae, Masayoshi

    1985-01-01

    The Hexa-partite Safequard Project was started for the purpose of examining the effective techniques of safeguards for gas centrifuge uranium enrichment facilities. By the proposal of respective participating countries, it was decided to carry out the verifying test of various safeguard techniques at the actual plants. Japan carried out the verifying test of safeguard techniques at the Ningyotoge uranium enrichment pilot plant in June, 1982, and from November, 1983, to August, 1984. The contents of this test is reported. In Japan, this verifying test was positioned as a part of JASPAS (Japanese project of supporting IAEA safeguards). The verifying test of realtime and in-operation inventories, the verifying test of IAEA load cell type weighing machines for UF 6 cylinders, the verifying test of the measurement of the degree of enrichment in UF 6 cylinders by nondestructive test, the verifying test of confinement/watch system, and the verifying test of IAEA gas phase uranium enrichment monitors were carried out. The results were presented as the data for examination in the HSP, and evaluated as useful, informative and well compiled. It is necessary to pursue more cost-effective approaches. (Kako, I.)

  2. Implementation of the Fissile Mass Flow Monitor Source Verification and Confirmation

    International Nuclear Information System (INIS)

    Uckan, Taner; March-Leuba, Jose A.; Powell, Danny H.; Nelson, Dennis; Radev, Radoslav

    2007-01-01

    This report presents the verification procedure for neutron sources installed in U.S. Department of Energy equipment used to measure fissile material flow. The Fissile Mass Flow Monitor (FMFM) equipment determines the 235 U fissile mass flow of UF 6 gas streams by using 252 Cf neutron sources for fission activation of the UF 6 gas and by measuring the fission products in the flow. The 252 Cf sources in each FMFM are typically replaced every 2 to 3 years due to their relatively short half-life (∼ 2.65 years). During installation of the new FMFM sources, the source identity and neutronic characteristics provided by the manufacturer are verified with the following equipment: (1) a remote-control video television (RCTV) camera monitoring system is used to confirm the source identity, and (2) a neutron detection system (NDS) is used for source-strength confirmation. Use of the RCTV and NDS permits remote monitoring of the source replacement process and eliminates unnecessary radiation exposure. The RCTV, NDS, and the confirmation process are described in detail in this report.

  3. DOE enrichment plants-safeguards means business

    International Nuclear Information System (INIS)

    Donnelly, R.

    1987-01-01

    The Portsmouth Gaseous Diffusion Plant, owned by the US Department of Energy (DOE) and operated by Martin Marietta Energy Systems, Inc., is a full service enrichment plant. Its long enriching cascade can process uranium hexafluoride (UF 6 ) feeds at almost any 235 U level and can produce UF 6 over the complete spectrum from depleted to very highly enriched uranium. The DOE uranium enrichment program is a government-owned enterprise operating as a business. The operating concerns of the DOE uranium enrichment plants and their safeguards programs have evolved together over the past three decades, and that evolution will likely continue. As the risk associated with possession, processing, and shipment of strategic nuclear material increased, the protection and control of it increased; as the value of the product grew with time, better ways were found to measure and conserve it. In each of these areas, safeguards objectives and the business requirements of the plant are complementary, and the progress made in one area has been reflected by progress in the other. The plant's material control and accountability program has become crucial to such business requirements as quantifying the enriched uranium (separative work units) produced in each monthly period and convincing financial auditors that the multibillion dollar enriched uranium assets located at the Portsmouth plant are properly stated

  4. Standard test methods for arsenic in uranium hexafluoride

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2005-01-01

    1.1 These test methods are applicable to the determination of total arsenic in uranium hexafluoride (UF6) by atomic absorption spectrometry. Two test methods are given: Test Method A—Arsine Generation-Atomic Absorption (Sections 5-10), and Test Method B—Graphite Furnace Atomic Absorption (Appendix X1). 1.2 The test methods are equivalent. The limit of detection for each test method is 0.1 μg As/g U when using a sample containing 0.5 to 1.0 g U. Test Method B does not have the complete collection details for precision and bias data thus the method appears as an appendix. 1.3 Test Method A covers the measurement of arsenic in uranyl fluoride (UO2F2) solutions by converting arsenic to arsine and measuring the arsine vapor by flame atomic absorption spectrometry. 1.4 Test Method B utilizes a solvent extraction to remove the uranium from the UO2F2 solution prior to measurement of the arsenic by graphite furnace atomic absorption spectrometry. 1.5 Both insoluble and soluble arsenic are measured when UF6 is...

  5. Basic tests on integrity evaluation for natural hexafluoride transporting container

    International Nuclear Information System (INIS)

    Gomi, Yoshio; Yamakawa, Hidetsugu; Kato, Osamu; Kobayashi, Seiichi

    1990-01-01

    In this study, the affected factors that needed to integrity evaluation for UF 6 transporting 48Y cylinder, were confirmed by basic tests and preliminary analysis. The factors were the sealing parts and external surface emissivity that ruled both the behavior under fire accident condition and the fire resistance capability of the cylinder, and the external pressure resistance capability at the sunk accident. The results obtained as follows. (1) Confirming tests for fire resistance of cylinder valve and plug, seat leakage of the valve caused at 150 degrees C. by unequal thermal expansion between the valve body and the stem. The tin-lead solder coating the tapered thread of valve and plug, melted at 200 degrees C., then the sealing boundary broke. (2) An external emissivity influence to radiation heat transfer measured with test pieces heated by electric oven. The covered paints of the specimen burned and separated, the emissivity changed 0.4 to 0.6, dependent on the surrounding temperature. Type 48Y cylinder filled with 12.5 tons of UF 6 and the measured emissivity was used the computer code analysis. The hydraulic breaking did not happen under the fire accident condition at 800 degrees C., for 30 minutes. (3) The external pressure test of the valve endured the hydrostatic pressure at 3000 meters, which corresponded to about five times the cylinder body buckling strength. (author)

  6. Optimization of public protection in the case of transportation of radioactive materials

    International Nuclear Information System (INIS)

    Pages, P.; Hubert, P.

    1986-09-01

    The initial purpose of the study was to assess risk to the public associated with UF 6 transportation in France as projected for the years to come. In a first stage a particular risk assessment methodology has been developed at the CEPN in the field of radioactive material transportation, through this first example and some others. Then a number of questions were raised as to the opportunity of given safety measures, associated for example with possible changes in the regulations. One such measure could be to adopt an overpack for natural uranium hexafluoride containers. This particular action and others bearing on either natural or enriched uranium hexafluoride transportation in both truck and rail modes were envisaged. The case study presented here deals with the comparison of a set of such alternative options aiming at reducing the risk to the public in the transportation of natural UF 6 by truck in France. Risk from the transportation only itself is taken into account, risk is assessed for accident situations only, health detriment is evaluated only for the consequences of the release itself

  7. Integration of the AVLIS [atomic vapor laser isotopic separation] process into the nuclear fuel cycle

    International Nuclear Information System (INIS)

    Hargrove, R.S.; Knighton, J.B.; Eby, R.S.; Pashley, J.H.; Norman, R.E.

    1986-08-01

    AVLIS RD and D efforts are currently proceeding toward full-scale integrated enrichment demonstrations in the late 1980's and potential plant deployment in the mid 1990's. Since AVLIS requires a uranium metal feed and produces an enriched uranium metal product, some change in current uranium processing practices are necessitated. AVLIS could operate with a UF 6 -in UF 6 -out interface with little effect to the remainder of the fuel cycle. This path, however, does not allow electric utility customers to realize the full potential of low cost AVLIS enrichment. Several alternative processing methods have been identified and evaluated which appear to provide opportunities to make substantial cost savings in the overall fuel cycle. These alternatives involve varying levels of RD and D resources, calendar time, and technical risk to implement and provide these cost reduction opportunities. Both feed conversion contracts and fuel fabricator contracts are long-term entities. Because of these factors, it is not too early to start planning and making decisions on the most advantageous options so that AVLIS can be integrated cost effectively into the fuel cycle. This should offer economic opportunity to all parties involved including DOE, utilities, feed converters, and fuel fabricators. 10 refs., 11 figs., 2 tabs

  8. New method for conversion of uranium hexafluoride to uranium dioxide

    International Nuclear Information System (INIS)

    Nakabayashi, S.; Suzuki, M.; Tanaka, H.

    1987-01-01

    Five different methods for conversion of UF 6 to ceramic-grade UO 2 powder have been developed to industrial scale. Two of them, the ammonium diuranate (ADU) and AUC processes, are based on precipitation of uranium compounds from aqueous solutions. The other three follow a dry route in which UF 6 is hydrolyzed and reduced by steam and hydrogen using fluidized bed techniques, rotating kilns, or flame chemistry methods. The ADU process has the advantage of flexible product powder characteristics, while disadvantages include a large quantity of waste, low powder fluidity, and a complicated process. On the other hand, the dry process using fluidized-bed techniques has the advantages of hydrofluoric acid recovery, a free-flowing powder, and process simplicity, but the disadvantages of poorer ceramic properties for the product. The new method developed at Mitsubishi Metal Corp. is a semidry process, which has well-balanced merits over the ADU process and the dry process using fluidized-bed techniques. This process is very attractive from powder characteristics, process simplicity, and waste reduction

  9. Obtention of uranium tetrafluoride from effluents generated in the hexafluoride conversion process

    International Nuclear Information System (INIS)

    Silva Neto, J.B.; Urano de Carvalho, E.F.; Durazzo, M.; Riella, H.G.

    2009-01-01

    Full text: The uranium silicide (U3Si2) fuel is produced from uranium hexafluoride (UF6) as the primary raw material. The uranium tetrafluoride (UF4) and metallic uranium are the two subsequent steps. There are two conventional routes for UF4 production: the first one reduces the uranium from the UF6 hydrolysis solution by adding stannous chloride (SnCl2). The second one is based on the hydrofluorination of solid uranium dioxide (UO2) produced from the ammonium uranyl carbonate (AUC). This work introduces a third route, a dry way route which utilizes the recovering of uranium from liquid effluents generated in the uranium hexafluoride reconversion process adopted at IPEN/CNEN-SP. Working in the liquid phase, this route comprises the recovery of ammonium fluoride by NH4HF2 precipitation. The crystallized bifluoride is added to the solid UO2 to get UF4, which returns to the metallic uranium production process and, finally, to the U3Si2 powder production. The UF4 produced by this new route was chemically and physically characterized and will be able to be used as raw material for metallic uranium production by magnesiothermic reduction. (author)

  10. Molecular dynamics simulation of uranium compound adsorption on solid surface

    International Nuclear Information System (INIS)

    Omori, Yuki; Takizawa, Yuji; Okamoto, Tsuyoshi

    2010-01-01

    Particles mixed in the UF6 gas have the property of accumulating on the inside of piping or units. This type of accumulation will cause material unaccounted for (MUF) in the UF6 gas processing facilities. Development of a calculation model for estimating the accumulation rate of uranium compounds has been expected. And predicting possible part of the units where uranium compounds adsorb will contribute to design an effective detection system. The purpose of this study is to take the basic knowledge of the particle's adsorption mechanism from the microscopic point of view. In simulation analysis, UF5 model particle is produced, then two types of solid surfaces are prepared; one is a solid surface at rest and the other is a moving solid surface. The result obtained by the code 'PABS' showed that when the solid surface moves at a lower velocity, the particle's adsorption process dominates over the particle's breakup one. Besides the velocity of the solid surface, other principal factors affecting an adsorption ratio were also discussed. (author)

  11. Environmental assessment for the purchase of Russian low enriched uranium derived from the dismantlement of nuclear weapons in the countries of the former Soviet Union

    International Nuclear Information System (INIS)

    1994-01-01

    The United States is proposing to purchase from the Russian Federation low enriched uranium (LEU) derived from highly enriched uranium (HEU) resulting from the dismantlement of nuclear weapons in the countries of the former Soviet Union. The purchase would be accomplished through a proposed contract requiring the United States to purchase 15,250 metric tons (tonnes) of LEU (or 22,550 tonnes of UF 6 ) derived from blending 500 metric tones uranium (MTU) of HEU from nuclear warheads. The LEU would be in the form of uranium hexafluoride (UF 6 ) and would be converted from HEU in Russia. The United States Enrichment Corporation (USEC) is the entity proposing to undertake the contract for purchase, sale, and delivery of the LEU from the Russian Federation. The US Department of Energy (DOE) is negotiating the procedure for gaining confidence that the LEU is derived from HEU that is derived from dismantled nuclear weapons (referred to as ''transparency),'' and would administer the transparency measures for the contract. There are six environments that could potentially be affected by the proposed action; marine (ocean); US ports of entry; truck or rail transportation corridors; the Portsmouth GDP; the electric power industry; and the nuclear fuel cycle industry. These environmental impacts are discussed

  12. Vlastnosti svarů při vysokovýkonných metodách svařování

    OpenAIRE

    Tresová, Vendula

    2008-01-01

    Vlastnosti svarů při vysokovýkonných metodách svařování. Popis MIG/MAG svařování, LaserHybrid, Time Twin Digital. Charakteristika vysokopevností oceli IMEX 700/DILLIMAX 690 a vysokopevnostních plechů HARDOX a WELDOX. Zhodnocení svarů metodou Time Twin Digital. Vyhodnocení tahové, ohybové zkoušky, zkoušky tvrdosti a struktury svarového povrchu. Properties of weld at the high-powered welding methods. Description of MIG/MAG welding, LaserHybrid, Time Twin Digital. Steel Characteristic IMEX 70...

  13. Hra s roboty

    OpenAIRE

    Sasýn, Radek

    2011-01-01

    Tato bakalářská práce se zabývá vytvořením počítačové hry, ve které v aréně bojují roboti. Chování robotů definují uživatelé pomocí speciálního programovacího jazyka. Definice robotů a její zpracování je implementováno pomocí fuzzy logiky. Práce popisuje teoretické poznatky z fuzzy logiky a hry Robocode, dále návrh programovacího jazyka a struktury aplikace a~nakonec popis implementace jednotlivých částí aplikace. This thesis deals with creating a computer game in which robots are fighting...

  14. Struktura przestrzenna nowych inwestycji budowlanych w małych miastach województwa łódzkiego

    OpenAIRE

    Turczyn, Marcin

    2015-01-01

    Tematem rozprawy doktorskiej jest „Struktura przestrzenna nowych inwestycji budowlanych w małych miastach województwa łódzkiego”. Całość składa się ze wstępu oraz 5 rozdziałów i liczy niemal 300 stron. W pracy wyznaczono 3 cele główne: analiza struktury przestrzennej nowych inwestycji budowlanych pod względem rodzaju, okresu realizacji, własności inwestycji oraz pochodzenia inwestorów; określenie czynników determinujących powstanie nowych inwestycji budowlanych; określenie miejsca nowych inwe...

  15. Różnorodność ekologiczna krajobrazu w dolinie rzeki Zgłowiączki

    OpenAIRE

    Warot, Lucyna; Załuski, Tomasz; Piernik, Agnieszka; Nienartowicz, Andrzej; Pisarek, Regina; Grzelka, Joanna; Grabowska, Jadwiga; Kunz, Mieczysław

    2001-01-01

    Przedmiotem badań były zależności pomiędzy różnorodnością ekologiczną a gradientami wilgotności, zasolenia podłoża i gospodarczej działalności człowieka w wybranym fragmencie doliny rzeki Zgłowiączki na Kujawach. Analizę struktury krajobrazu przeprowadzono w oparciu o numeryczną mapę roślinności w skali 1:10 000 oraz badania fitosocjologiczne. Fragment badanej doliny obejmował rzekę, słone źródło i różne typy zbiorowisk roślinnych. Największą powierzchnię zajmowały niehalofilne zbiorowiska łą...

  16. Rachunek dochodów i wydatków budżetu jednostki samorządu terytorialnego na przykładzie gminy Chełmiec w latach 2011-2013

    OpenAIRE

    Rodak, Anna

    2015-01-01

    Przedłożona praca ma na celu wskazanie źródeł i struktury dochodów budżetowych oraz charakteru wydatkowania środków budżetowych gminy Chełmiec, a także dokonanie rzetelnej oceny sytuacji finansowej wymienionej powyżej jednostki. Analiza budżetu obejmuje zakres czasowy od 2011 do 2013 roku. Szczegółowe pytania, na które starano się w niniejszej pracy odpowiedzieć są następujące: Czy gmina Chełmiec jest gospodarna w wykorzystywaniu środków budżetowych? oraz jak gmina Chełmiec mając do dyspozycj...

  17. Performances’ Estimation by Tests of Composite Material Structures With Respect to the Lay-Up Configuration and Mixing the Position of Tape and Fabric Laminae

    Directory of Open Access Journals (Sweden)

    Di Leo R.

    2015-12-01

    Full Text Available W artykule przedstawiono estymację, na podstawie testów, właściwości użytkowych struktur z materiałów kompozytowych. W celu oceny różnych wpływów na zachowanie się struktury wykonano testy przy zmiennej procentowej zawartości włókien o orientacji 0, 45 i 90° i przy zamianie pozycji warstwy jednokierunkowej i warstwy tkaniny. Przy ustalonej konfiguracji prelaminatu i takiej samej sekwencji ułożenia warstw, analizowano dwie topologie struktury, z których pierwsza miała tylko warstwy jednokierunkowe, a w drugiej była warstwa z tkaniny (splot płócienny 0/90 w miejscu warstw jednokierunkowych, górnej i dolnej. Na podstawie testu wyznaczono wytrzymałość na ściskanie próbki z otwartym otworem i wytrzymałość na rozciąganie oraz moduły przy wypełnionym otworze. W ramach badań doświadczalnych testowano ogółem 72 próbki. By prawidłowo porównać wyniki testów wprowadzono wagowy indeks osiągów (Performance Weight Index, PWI, pozwalający normalizować wytrzymałość każdego laminatu względem jego wagi na jednostkę powierzchni. Przedyskutowano i oceniono wyniki badań i zachowanie się różnych laminatów.

  18. COMURHEX II, a 610 million euro investment to meet tomorrow's nuclear power needs

    International Nuclear Information System (INIS)

    2007-01-01

    The worldwide development of nuclear power will lead to increasing demands for uranium. To meet its customers' growing requirements, AREVA has chosen to invest in COMURHEX II to renew and modernize its industrial conversion tool. An entirely new plant is to be built on the Tricastin site to the north of the existing COMURHEX plant. The plant, together with other large-scale investment projects such as the future Georges Besse II enrichment plant - also located on the Tricastin site - and the modernization of the FBFC fuel fabrication facilities in the south of France, will enable AREVA to strengthen its position as a long-standing and fully integrated player at the Front End of the nuclear fuel cycle. These major investments confirm the group's strong commitment to the global development of nuclear power. Converting uranium ore into uranium hexafluoride (UF 6 ) is a key stage before the enrichment and fabrication of nuclear fuel. AREVA is gearing up for market changes, increasing its uranium production from 15,000 tons per year to 21,000 tons per year to match market needs. Today the conversion units of the different industrial operators are showing their age. They will need replacing in the medium term to increase production capacity and keep abreast of the economic, regulatory and environmental conditions of tomorrow's market. Its euros 610 million investment in the Narbonne and Pierrelatte sites in southern France will make AREVA the first uranium converter to overhaul its industrial tool. Thus indicating the group's intention of remaining world leader in UF 6 conversion. The COMURHEX II project will involve the modernization and upgrading of our installations on the basis of tried-and-tested processes and techniques, while incorporating technological innovations that will improve the production performance, reinforce nuclear safety in the facilities, while further reducing the environmental impact of their activities. The first industrial production on the

  19. Process and system for isotope separation using the selective vibrational excitation of molecules

    International Nuclear Information System (INIS)

    Woodroffe, J.A.; Keck, J.C.

    1976-01-01

    This invention concerns the separation of isotopes by using the isotopically selective vibrational excitation and the vibration-translation reactions of the excited particles. UF 6 molecular mixed with a carrier gas, such as argon, are directed through a refrigerated chamber lighted by a laser radiation tuned to excite vibrationally the uranium hexafluoride molecules of a particular uranium isotope. The density of the carrier gas is preferably maintained above the density of the uranium hexafluoride to allow a greater collision probability of the vibrationally excited molecules with a carried molecule. In such a case, the vibrationally excited uranium hexafluoride will collide with a carrier gas molecule provoking the conversion of the excitation energy into a translation of the excited molecule, resulting in thermal energy or greater diffusibility than that of the other uranium hexafluoride molecules [fr

  20. Development of fluoric compound treatment system in conversion for recycle in metal industry

    International Nuclear Information System (INIS)

    Kim, P.O.; Cho, N.C.

    1998-01-01

    Korea Nuclear Fuel Company (KNFC) has been operating AUC conversion process from UF 6 to UO 2 from 1990. In 1997, KNFC constructed another conversion line called dry conversion to meet the increasing demand for nuclear fuel fabrication. In the dry conversion, two kinds of hydrofluoric acid (HF) are produced as a by-product. The first one is 50% concentration HF and the other one is diluted HF ranging from 10% to 49%. The high concentration HF can be used in metal industry, but there is no use for diluted one. The diluted HF should be disposed of as liquid waste after some treatment. To solve this problem we have developed the process to convert the diluted hydrofluoric acid to the sodium fluoride, which is readily used in the metal industry. By developing the process we could make a contribution to the environment as well as cost reduction in manufacturing nuclear fuel. (author)

  1. Welcome to Romans. FBFC and CERCA

    International Nuclear Information System (INIS)

    1999-01-01

    The Franco-Belge de Fabrication de Combustibles (FBFC) and the Compagnie pour l'Etude et la Realisation de Combustibles Atomiques (CERCA) are companies located in the site of Romans sur Isere (France) and involved in the manufacturing of nuclear fuels and fuel elements for PWR and research reactors. Framatome is the industrial operator of both companies which have the same shareholders. This booklet presents the activities of both companies: the role of FBFC in the fuel cycle (UF 6 -UO 2 conversion, recycling, pelletizing, loading of fuel rods, assembly, machining, manufacturing of mixing grids and rod cluster control assemblies), and the activities of CERCA (manufacturing of the Triga fuel for research reactors, manufacturing of superconducting cavities, neutron multidetectors and radiation sources). (J.S.)

  2. Origin and characteristics of low-level nontransuranic waste from the nuclear fuel cycle

    International Nuclear Information System (INIS)

    Alexander, C.W.; Blomeke, J.O.

    1977-01-01

    Low-level nontransuranic wastes are generated in all nuclear fuel cycle operations. While the activity levels and radiotoxicities of these effluents are generally of a lower magnitude than other fuel cycle wastes, their large volumes and their appearance throughout the fuel cycle make their management a very real concern regardless of the fuel cycle option being considered. Low-level nontransuranic wastes are defined here as wastes that contain less than about 10 nCi of long-lived alpha radiation per gram and have gamma radiations low enough to require only minimal biological shielding and remote handling. Wastes from uranium mining and milling, UF 6 conversion, enrichment, fuel fabrication, and fuel reprocessing are examined with respect to their radionuclide content, volume, and chemical composition. Projections of total quantities through the end of this century are also presented. Fuel cycles based on recycling only uranium, and on recycling both uranium and plutonium, are considered

  3. Improved verification methods for safeguards verifications at enrichment plants

    International Nuclear Information System (INIS)

    Lebrun, A.; Kane, S. C.; Bourva, L.; Poirier, S.; Loghin, N. E.; Langlands, D.

    2009-01-01

    The International Atomic Energy Agency (IAEA) has initiated a coordinated research and development programme to improve its verification methods and equipment applicable to enrichment plants. The programme entails several individual projects to meet the objectives of the IAEA Safeguards Model Approach for Gas Centrifuge Enrichment Plants updated in 2006. Upgrades of verification methods to confirm the absence of HEU (highly enriched uranium) production have been initiated and, in particular, the Cascade Header Enrichment Monitor (CHEM) has been redesigned to reduce its weight and incorporate an electrically cooled germanium detector. Such detectors are also introduced to improve the attended verification of UF 6 cylinders for the verification of the material balance. Data sharing of authenticated operator weighing systems such as accountancy scales and process load cells is also investigated as a cost efficient and an effective safeguards measure combined with unannounced inspections, surveillance and non-destructive assay (NDA) measurement. (authors)

  4. Measurement of the enrichment of uranium in the pipework of a gas centrifuge enrichment plant

    International Nuclear Information System (INIS)

    Packer, T.W.; Lees, E.W.; Close, D.; Nixon, K.V.; Pratt, J.C.; Strittmatter, R.

    1985-01-01

    The US and UK have been separately working on the development of a NDA instrument to determine the enrichment of gaseous UF 6 at low pressures in cascade header pipework in line with the conclusions of the Hexapartite Safeguards Project viz. the instrument is capable of making a ''go/no go'' decision of whether the enrichment is less than/greater than 20%. Recently, there has been a series of very useful technical exchanges of ideas and information between the two countries. This has led to a technical formulation for such an instrumentation based on γ-ray spectrometry which, although plant-specific in certain features, nevertheless is based on the same physical principles. Experimental results from commercially operating enrichment plants are very encouraging and indicate that a complete measurement including set up time on the pipe should be attainable in about 30 minutes when measuring pipes of diameter around 110 mm. 5 refs., 4 figs

  5. I/asterisk/ /6s 4P/ collisional quenching - Application to the IF 491-nm laser

    Science.gov (United States)

    Hutchison, S. B.; Verdeyen, J. T.; Eden, J. G.

    1981-01-01

    Measurements of the rate constants for quenching of the excited I (6s 4P) states by Ar, Xe, CF39I, UF6, and NF3 are described. Each rate constant is determined by recording the exponential time decay of the excited IF or excited I2 (342 nm) fluorescence in the afterglow of the e-beam-excited plasmas containing Ar, CF3I, NF3, and the desired quenching gas. In addition, further experimental evidence in support of neutral channel formation of excited IF in e-beam-pumped Ar/CF3I/NF3 mixtures is presented. Details of the experimental apparatus and gas handling procedures are given, and the kinetics model developed to interpret the experimental data is described.

  6. Evaluation of environmental control technologies for commercial uranium nuclear fuel fabrication facilities

    International Nuclear Information System (INIS)

    Perkins, B.L.

    1983-01-01

    At present in the United States, there are seven commercial light-water reactor uranium fuel fabrication facilities. Effluent wastes from these facilities include uranium, nitrogen, fluorine, and organic-containing compounds. These effluents may be either discharged to the ambient environment, treated and recycled internally, stored or disposed of on-site, sent off-site for treatment and/or recovery, or sent off-site for disposal (including disposal in low-level waste burial sites). Quantities of waste generated and treatment techniques vary greatly depending on the facility and circuits used internally at the facility, though in general all the fluorine entering the facility as UF 6 is discharged as waste. Further studies to determine techniques and procedures that might minimize dose (ALARA) and to give data on possible long-term effects of effluent discharge and waste disposal are needed

  7. Reduction of uranium hexafluoride to uranium tetrafluoride

    International Nuclear Information System (INIS)

    Chang, I.S.; Do, J.B.; Choi, Y.D.; Park, M.H.; Yun, H.H.; Kim, E.H.; Kim, Y.W.

    1982-01-01

    The single step continuous reduction of uranium hexafluoride (UF 6 ) to uranium tetrafluoride (UF 4 ) has been investigated. Heat required to initiate and maintain the reaction in the reactor is supplied by the highly exothermic reaction of hydrogen with a small amount of elemental fluorine which is added to the uranium hexafluoride stream. When gases uranium hexafluoride and hydrogen react in a vertical monel pipe reactor, the green product, UF 4 has 2.5g/cc in bulk density and is partly contaminated by incomplete reduction products (UF 5 ,U 2 F 9 ) and the corrosion product, presumably, of monel pipe of the reactor itself, but its assay (93% of UF 4 ) is acceptable for the preparation of uranium metal with magnesium metal. Remaining problems are the handling of uranium hexafluoride, which is easily clogging the flowmeter and gas feeding lines because of extreme sensitivity toward moisture, and a development of gas nozzel for free flow of uranium hexafluoride gas. (Author)

  8. Over all separation factors for stable isotopes by gas centrifuge

    International Nuclear Information System (INIS)

    Chuntong Ying; Nie Yuguang; Zeng Shi; Shang Xiuyong; Wood, Houston G.

    1999-01-01

    The separation factor for the elements with molar wight differences, γ 0 , is an important characteristic parameter for separation of varied isotopes. Besides the dependence on construction parameters of the gas centrifuge it depends on many variables. Some of them are operation conditions, such as feeding flow rate F, pressure at wall p w , temperature T 0 and distribution temperature on the wall and others. Separation factor γ 0 depends on physical properties, such as molar weight M, viscosity μ, product of ρD, where ρ is density of working media and D is its diffusion coefficient. It was taken four examples: UF 6 , WF 6 , OsO 4 and Xe [ru

  9. Standard Test Method for Isotopic Analysis of Uranium Hexafluoride by Single-Standard Gas Source Multiple Collector Mass Spectrometer Method

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 This test method is applicable to the isotopic analysis of uranium hexafluoride (UF6) with 235U concentrations less than or equal to 5 % and 234U, 236U concentrations of 0.0002 to 0.1 %. 1.2 This test method may be applicable to the analysis of the entire range of 235U isotopic compositions providing that adequate Certified Reference Materials (CRMs or traceable standards) are available. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety health practices and determine the applicability of regulatory limitations prior to use.

  10. Market values summary/September market review/current market data

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    This article is the September 1994 uranium market summary. In the concentrates and conversion market, there were four deals. The unrestricted value decreased slightly to $7.00, and the restricted value decreased to $9.05. In the UF6 market, there was a single transaction. Both the restricted and the unrestricted values decreased ($29.00 and $24.25 respectively). The restricted transaction value was unchanged at $9.15, while the unrestricted value decreased to $7.10. In the enrichment services market, long-term contracting picked up and there were two deals in the spot market. Restricted values dropped to $84.00 per SWU, while the unrestricted value remained constant at $67.00 per SWU. Active uranium supply increased, while active uranium demand decreased

  11. Status report on the cost and availability of enriched uranium for research reactors

    International Nuclear Information System (INIS)

    Mueller, Hans; Laucht, Juergen

    2005-01-01

    Availability and price development of enriched uranium contained in fuel elements for research reactors plays an important role with regard to reliability and economic and planning reasons. The leading price factors of LEU (19.75% enriched uranium metal), are the contained natural uranium equivalent in the form of UF6 (feed component), the separative work of the enrichment (SWU), conversion of the enriched uranium into metal form and associated services, such as transportation. World market price of feed material for enrichment was more or less stable in the last decades. After very moderate feed price increases between 2001 and mid-2003, the price gained momentum and almost doubled in the short period between the 2nd half of 2003 and year-end 2004. (author)

  12. Export regulation

    International Nuclear Information System (INIS)

    Gates, D.J.

    1978-01-01

    Australia is a major uranium supplier. Uranium is exported under conditions laid down to avoid any nuclear proliferation. On 24 May 1977 the Prime Minister had stated the main elements of Australian policy: the strengthening of the system of international safeguards and the selection of importing countries. (Non-nuclear weapon states must be Contracting Parties to the NPT. Nuclear weapon states must undertake not to use Australian uranium for this purpose). Australia retains property of the uranium up to the UF 6 stage (uranium hexafluoride) in the fuel cycle; it reserves the right to stop any export if the importing country no longer complies with AIEA Safeguards. Any transfer to a third country, any irradiated fuel reprocessing, requires Australia's prior agreement. Finally, importing countries must satisfy physical protection conditions. (NEA) [fr

  13. Nuclear-fuel-cycle risk assessment: descriptions of representative non-reactor facilities, Sections 15-19

    International Nuclear Information System (INIS)

    Schneider, K.J.

    1982-09-01

    Information is presented under the following section headings: fuel reprocessing; spent fuel and high-level and transuranic waste storage; spent fuel and high-level and transuranic waste disposal; low-level and intermediate-level waste disposal; and, transportation of radioactive materials in the nuclear fuel cycle. In each of the first three sections a description is given on the mainline process, effluent processing and waste management systems, plant layout, and alternative process schemes. Safety information and a summary are also included in each. The section on transport of radioactive materials includes information on the transportation of uranium ore, uranium ore concentrate, UF 6 , PuO 2 powder, unirradiated uranium and mixed-oxide fuel assemblies, spent fuel, solidified high-level waste, contact-handled transuranic waste, remote-handled transuranic waste, and low and intermediate level nontransuranic waste. A glossary is included

  14. Summarizing annual report 1989, on R and D work performed by the KfK Institute for Microstructural Engineering, IMT

    International Nuclear Information System (INIS)

    1990-03-01

    The main activities of the institute in the year under review continued the work with the separation nozzle method for U-235 enrichment, the testing of separation nozzle elements and the related methods for UF 6 production, and the design and testing of components for separation systems. In another working area, activities centered on microstructural techniques, as e.g. the production of masking blanks or structural masks for the deep-etch synchrotron radiation lithography, on the development of synchrotron radiation sources, or the design of irradiation facilities or wet chemical processes for microstructural techniques. The latter include molding of metals or plastics, surface etching and thin-film deposition. Experiments were carried out for microstructural process development, and product control and analyses for the purpose of quality assurance of microstructures. (HK) [de

  15. PWR burnable absorber evaluation

    International Nuclear Information System (INIS)

    Cacciapouti, R.J.; Weader, R.J.; Malone, J.P.

    1995-01-01

    The purpose of the study was to evaluate the relative neurotic efficiency and fuel cycle cost benefits of PWR burnable absorbers. Establishment of reference low-leakage equilibrium in-core fuel management plans for 12-, 18- and 24-month cycles. Review of the fuel management impact of the integral fuel burnable absorber (IFBA), erbium and gadolinium. Calculation of the U 3 O 8 , UF 6 , SWU, fuel fabrication, and burnable absorber requirements for the defined fuel management plans. Estimation of fuel cycle costs of each fuel management plan at spot market and long-term market fuel prices. Estimation of the comparative savings of the different burnable absorbers in dollar equivalent per kgU of fabricated fuel. (author)

  16. Preliminary 1990 market review

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    The uranium market began 1990 with prices at record low levels, large supplies, and relatively modest demand. Though market prices were extremely voltaile during the year - sinking to new record lows and achieving record increases, the market situation is now almost exactly the same as the end of 1989. The underlying near-term oversupply of natural uranium remains unchanged. Natural uranium concentrates are selling between nine and ten dollars per pound U3O8 and natural UF6 is selling between 28 and 29 dollars per kgU. Discretionary demand emerges near eight dollars per pound U3O8, but tends to subside above ten dollars per pound. Supply remains abundant for both near- and intermediate-term sale

  17. Detection of uranium enrichment activities using environmental monitoring techniques

    International Nuclear Information System (INIS)

    Belew, W.L.; Carter, J.A.; Smith, D.H.; Walker, R.L.

    1993-01-01

    Uranium enrichment processes have the capability of producing weapons-grade material in the form of highly enriched uranium. Thus, detection of undeclared uranium enrichment activities is an international safeguards concern. The uranium separation technologies currently in use employ UF 6 gas as a separation medium, and trace quantities of enriched uranium are inevitably released to the environment from these facilities. The isotopic content of uranium in the vegetation, soil, and water near the plant site will be altered by these releases and can provide a signature for detecting the presence of enriched uranium activities. This paper discusses environmental sampling and analytical procedures that have been used for the detection of uranium enrichment facilities and possible safeguards applications of these techniques

  18. Mechanical evaluation of a 48Y cylinder during the IAEA fire test

    International Nuclear Information System (INIS)

    Duret, B.; Pinton, E.; Sert, G.

    1998-01-01

    From the TENERIFE results and using the DIBONA model we predict the thermal behavior and the inner pressure of an UF 6 container engulfed in a fire recommended as by IAEA. Following this approach, the mechanical phenomena has been represented by elastic then plastic mechanisms. The experimental stress/strain curves have been implemented from CRIEPI tensile tests interpretation from ambient temperature up to 900 deg. C. The evolution of these previous curves according to the temperature, has been considered and extrapolated in term of minimal and maximal value. For every case of steel type and thickness value, we discuss and evaluate whether rupture occurs. Finally, our tool seems acceptable for predicting mechanical behaviour, but a rupture criterion has to be implemented into the model in order to predict the rupture time for every case. (authors)

  19. EURODIF company - Tricastin gaseous diffusion plant. Requests following the safety re-evaluation of the facility after 20 years of operation

    International Nuclear Information System (INIS)

    2000-01-01

    This decision from the French authority of nuclear safety (ASN) concerns the safety reevaluation of the EURODIF plant ('Georges Besse plant') of the Tricastin site at Pierrelatte (France) which uses the gaseous diffusion process to separate the uranium isotopes. Since the last safety reevaluation in 1988, several points have been improved: reduction of the frequency and importance of uranium hexafluoride leaks (control of the pitting corrosion in the exchangers), no incident linked with exo-thermal reactions or explosions, a mastery of the exposure to ionizing radiations etc.. On the other hand, several points need improvement: the prevention of criticality risks, the earthquake resistance of some structures, and the integration of some accident scenarios (aircraft crash, UF 6 leak) in the emergency plan to avoid the fast release of toxic materials in the environment. These points are detailed in the document. (J.S.)

  20. Sensitivity analysis of the Two Geometry Method

    International Nuclear Information System (INIS)

    Wichers, V.A.

    1993-09-01

    The Two Geometry Method (TGM) was designed specifically for the verification of the uranium enrichment of low enriched UF 6 gas in the presence of uranium deposits on the pipe walls. Complications can arise if the TGM is applied under extreme conditions, such as deposits larger than several times the gas activity, small pipe diameters less than 40 mm and low pressures less than 150 Pa. This report presents a comprehensive sensitivity analysis of the TGM. The impact of the various sources of uncertainty on the performance of the method is discussed. The application to a practical case is based on worst case conditions with regards to the measurement conditions, and on realistic conditions with respect to the false alarm probability and the non detection probability. Monte Carlo calculations were used to evaluate the sensitivity for sources of uncertainty which are experimentally inaccessible. (orig.)

  1. On-Line Enrichment Monitor (OLEM) Phase II Final Report Techniques and Equipment for Safeguards at Gas Centrifuge Enrichment Plants

    Energy Technology Data Exchange (ETDEWEB)

    Younkin, James R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Garner, James R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-04-01

    Over the last five years, OLEM has been a collaborative development effort involving the IAEA, LANL, ORNL, URENCO, and the NNSA. The collective team has completed the following: design and modelling, software development, hardware integration, testing with the ORNL UF6 Flow Loop, a field trial at the Urenco facility in Almelo, the Netherlands, and a Demonstration at the Urenco USA facility in Eunice, New Mexico. This combined effort culminated in the deployment of several OLEM collection nodes in Iran. These OLEM units are one unattended monitoring system component of the Joint Comprehensive Plan of Action allowing the International Atomic Energy Agency to verify Iran’s compliance with the enrichment production aspects of the agreement.

  2. Characterization of an enriched uranyl fluoride deposit in a valve and pipe intersection using time-of-flight transmission measurements with 252Cf

    International Nuclear Information System (INIS)

    Wyatt, M.S.; Hannon, T.F.

    1998-01-01

    A method was developed and successfully applied to characterize large uranyl fluoride (UO 2 F 2 ) deposits at the former Oak Ridge Gaseous Diffusion Plant. These deposits were formed by a wet air in-leakage into the UF 6 process gas lines over a period of years. The resulting UO 2 F 2 is hygroscopic, readily absorbing moisture from the air to form hydrates as UO 2 F 2 -nH 2 O. The ratio of hydrogen to uranium can vary from 0--16, and has significant nuclear criticality safety impacts for large deposits. In order to properly formulate the required course of action, a non-intrusive characterization of the distribution of the fissile material within the pipe, its total mass, and amount of hydration was necessary. The Nuclear Weapons Identification System (NWIS) previously developed at the Oak Ridge Y-12 Plant for identification of uranium weapons components in storage containers was used to successfully characterize these deposits

  3. Market Review: Market values summary; March market review; Current market data

    International Nuclear Information System (INIS)

    Anon.

    1996-01-01

    This article is the March 1996 uranium market summary. In this reporting period, there were two deals in the natural uranium spot market and four deals in the long-term market. The unrestricted value moved upward to $13.50 per pound U3O8, and the long-term price indicator was $16.50. In the UF6 market, there was but a single deal. Both the restricted and the unrestricted values moved upward, to $47.00 and $41.25 respectively. The restricted and the unrestricted transaction values moved upward, to $13.35 and $8.40 respectively. In the enrichment services market, there were no transactions. Both the restricted and the unrestricted SWU values remained constant at $97 and $90 respectively. Active uranium supply rose, while active demand decreased sharply

  4. KWL annual report 1983

    International Nuclear Information System (INIS)

    1983-01-01

    The application for decommissioning comprises the shutdown of the plant, methods for safe shielding of the nuclear section, and a modification in the utilization of the conventional plant sections. The planning documents are worked out by the Nuklear-Ingenieur-Service GmbH, Hanau. The activities for the Euratom research programmes have been completed by KWL. The final report on the determination of the activation of the biological shield is available. The processing of the enriched uranium originating from unirradiated FE as well as the conversion to UF 6 has been terminated. All spent fuel elements have been transported to BNFL. The joint works management of KWL and the VEW-power plant Emsland has been rearranged. (DG) [de

  5. Market values summary/January market review/current market data

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    This article is the January 1994 uranium market summary. In the natural uranium and concentrates market, there were only three deals reported. The restricted value dropped to $9.50, while the unrestricted value remained steady at $7.00. There was only one UF6 trade reported, and both the restricted and unrestricted values decreased (to $30.15 and $24.50 respectively). The restricted transaction value remained at $7.15, and the unrestricted value declined to $10.00. In the enrichment services market, only one deal was concluded. In this market, the restricted value increased to $85.00 per SWU, and the unrestricted value remained unchanged at $68.00 per SWU. Both active uranium supply and active uranium demand decreased slightly during this period

  6. Radiochemical procedure specific for the determination of protactinium-231

    International Nuclear Information System (INIS)

    Walker, C.R.; Short, B.W.

    1979-01-01

    Protactinium-231, a daughter product of uranium-235, can be present at the Portsmouth Gaseous Diffusion Plant in detectable amounts in such sources as uranium oxide fluorination filter ash and UF 6 cylinder residues. Since its detection is important for health physics considerations, a method for its analysis was required. To improve on lengthy existing procedures, a simple procedure specific for protactinium-231 was developed: Protactinium is first extracted from a sulfate-chloride medium into amyl acetate. It is then back-extracted into a chloride-fluoride medium, complexed with cupferron, and re-extracted into amyl acetate. A portion of the amyl acetate is evaporated on a planchet, and protactinium-231, the only alpha-emitting nuclide carried through the process, is determined by alpha activity measurement on a proportional counter

  7. The nuclear fuel cycle

    International Nuclear Information System (INIS)

    Vernaz, Etienne

    2015-10-01

    The author proposes an overview of the different steps of the nuclear fuel cycle: uranium mining (applied processes, formation of Yellow Cake), conversion into uranium hexafluoride (UF 6 ) for enrichment purposes, enrichment (physical methods and plants), nuclear fuel fabrication (description of a fuel assembly), physical, chemical and radiological evolution of the nuclear fuel in the reactor, spent fuel warehousing, spent fuel processing (dissolution, methods of liquid/liquid extraction, output products), effluents and by-products, recycling of valuable materials (URE, MOX, RNR and others), waste containment for the different waste types regarding their radioactivity level and lifetime (vitrification, shell compacting, cementation, and other processes). The author also presents the French policy and choices regarding spent fuel processing and waste management

  8. Recent advances in fuel fabrication techniques and prospects for the nineties

    International Nuclear Information System (INIS)

    Frain, R.G.; Caudill, H.L.; Faulhaber, R.

    1987-01-01

    Advanced Nuclear Fuels Corporation's approach and experience with the application of a flexible, just-in-time manufacturing philosophy to the production of customized nuclear fuel is described. Automation approaches to improve productivity are described. The transfer of technology across product lines is discussed as well as the challenges presented by a multiple product fabrication facility which produces a wide variety of BWR and PWR designs. This paper also describes the method of managing vendor quality control programs in support of standardization and clarity of documentation. Process simplification and the ensuing experience are discussed. Prospects for fabrication process advancements in the nineties are given with emphasis on the benefits of dry conversion of UF 6 to UO 2 powder, and increased use of automated and computerized inspection techniques. (author)

  9. Measurements of uranium mass confined in high density plasmas

    Science.gov (United States)

    Stoeffler, R. C.

    1976-01-01

    An X-ray absorption method for measuring the amount of uranium confined in high density, rf-heated uranium plasmas is described. A comparison of measured absorption of 8 keV X-rays with absorption calculated using Beer Law indicated that the method could be used to measure uranium densities from 3 times 10 to the 16th power atoms/cu cm to 5 times 10 to the 18th power atoms/cu cm. Tests were conducted to measure the density of uranium in an rf-heated argon plasma with UF6 infection and with the power to maintain the discharge supplied by a 1.2 MW rf induction heater facility. The uranium density was measured as the flow rate through the test chamber was varied. A maximum uranium density of 3.85 times 10 to the 17th power atoms/cu cm was measured.

  10. Thermal behaviour of the type 30 B cylinder equipped with the 21 PF.1 overpack and study of protective covers for the 48 Y cylinder valve

    International Nuclear Information System (INIS)

    Warniez, P.; Ringot, C.; Bernard, H.

    1988-12-01

    This paper describes the tests which have been performed in France: first to verify the behaviour of 30B cylinders with their 21 PF.1 protective overpack, secondly to develop a better mechanical protection of the valve. The thermal tests have been performed on real packagings filled with UF 6 , after the mechanical AIEA tests (free drop 9 m and 1 m on a pitch). The results were very satisfactory, the maximal temperatures which were measured on the external overpack of the 30B cylinder being much lower than the filling temperature. In the Mont Louis wreckage, some of the valves of 48Y cylinders were damaged. A new valve protector was designed and was tested under impact situations. The tests have demonstrated that the new design which has the same weight as the original one and which may be used without any modifications of the cylinder, has a better behaviour, increasing the safety during transport

  11. ConverDyn and the new conversion market

    International Nuclear Information System (INIS)

    Fuller, D.M.

    1993-01-01

    In November 1992, AlliedSignal (Allied) and General Atomics (GA) formed a conversion marketing partnership, known as ConverDyn. The venture was formed to market UF 6 conversion services following the closure of the Gore, Oklahoma, conversion facility operated by GA's wholly owned subsidiary, Sequoyah Fuels Corporation (SFC). The closure of the Gore facility occurred after an extended period of regulatory snarls that resulted in production outages and substantial expense. The loss of SFC's capacity (9,100 MTU nameplate) brings conversion supply and demand more into balance after many years of significant oversupply. In the past two months, spot prices have increased more than 30 percent, yet prices in the USA still lag those observed in Europe. However, the conversion market is still fraught with uncertainty in the face of weapons dismantlement, the availability of low-enriched uranium (LEU) products, and the potential for increased capacity from other countries

  12. Uranium Enrichment, an overview

    International Nuclear Information System (INIS)

    Coates, J.H.

    1994-01-01

    This general presentation on uranium enrichment will be followed by lectures on more specific topics including descriptions of enrichment processes and assessments of the prevailing commercial and industrial situations. I shall therefore avoid as much as possible duplications with these other lectures, and rather dwell on: some theoretical aspects of enrichment in general, underlying the differences between statistical and selective processes, a review and comparison between enrichment processes, remarks of general order regarding applications, the proliferation potential of enrichment. It is noteworthy that enrichment: may occur twice in the LWR fuel cycle: first by enriching natural uranium, second by reenriching uranium recovered from reprocessing, must meet LWR requirements, and in particular higher assays required by high burn up fuel elements, bears on the structure of the entire front part of the fuel cycle, namely in the conversion/reconversion steps only involving UF 6 for the moment. (author). tabs., figs., 4 refs

  13. Standard test method for isotopic abundance analysis of uranium hexafluoride and uranyl nitrate solutions by multi-collector, inductively coupled plasma-mass spectrometry

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2014-01-01

    1.1 This test method covers the isotopic abundance analysis of 234U, 235U, 236U and 238U in samples of hydrolysed uranium hexafluoride (UF6) by inductively coupled plasma source, multicollector, mass spectrometry (ICP-MC-MS). The method applies to material with 235U abundance in the range of 0.2 to 6 % mass. This test method is also described in ASTM STP 1344. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  14. Study of reducing pyrohydrolysis of uranyl fluoride into uranium dioxide

    International Nuclear Information System (INIS)

    Favre, P.

    1977-06-01

    The dry process studied in this paper for the preparation of UO 2 (for sintering) from UF 6 presents the following advantages on other wet or dry processes (fluidized beds or discontinuous processes): it is completely continuous, one chemical reactor only is required for the successive reactions hydrolysis, pyrolysis and reduction, it is possible to obtain various densities after sintering and particularly high densities. Safety, environmental, economical and technical aspects are also improved. Pyrohydrolysis and reduction reactions of UO 2 F 2 into UO 2 are studied because kinetics are not well known although they have been used for several years. Reaction temperature and pressure are examined for optimization. Influence of the gaseous mixture hydrogen and inert gas on reaction inhibition could lead to rate, in particular nitrogen flow should be reduced. Operation and product quality should be both improved. 68 refs [fr

  15. Enriched-uranium feed costs for the High-Temperature Gas-Cooled reactor: trends and comparison with other reactor concepts

    International Nuclear Information System (INIS)

    Thomas, W.E.

    1976-04-01

    This report discusses each of the components that affect the unit cost for enriched uranium; that is, ore costs, U 3 O 8 to UF 6 conversion cost, costs for enriching services, and changes in transaction tails assay. Historical trends and announced changes are included. Unit costs for highly enriched uranium (93.15 percent 235 U) and for low-enrichment uranium (3.0, 3.2, and 3.5 percent 235 U) are displayed as a function of changes in the above components and compared. It is demonstrated that the trends in these cost components will probably result in significantly less cost increase for highly enriched uranium than for low-enrichment uranium--hence favoring the High-Temperature Gas-Cooled Reactor

  16. Uranyl fluoride luminescence in acidic aqueous solutions

    International Nuclear Information System (INIS)

    Beitz, J.V.; Williams, C.W.

    1996-01-01

    Luminescence emission spectra and decay rates are reported for uranyl species in acidic aqueous solutions containing HF or added NaF. The longest luminescence lifetime, 0.269 ± 0.006 ms, was observed from uranyl in 1 M HF + 1 M HClO 4 at 296 K and decreased with increasing temperature. Based on a luminescence dynamics model that assumes equilibrium among electronically excited uranyl fluoride species and free fluoride ion, this long lived uranyl luminescence in aqueous solution is attributed primarily to UO 2 F 2 . Studies on the effect of added LiNO 3 or Na 2 WO 4 ·2H 2 O showed relatively weak quenching of uranyl fluoride luminescence which suggests that high sensitivity determination of the UF 6 content of WF 6 gas should be feasible via uranyl luminescence analysis of hydrolyzed gas samples of impure WF 6

  17. The Determination of Uranium and Trace Metal Impurities in Yellow Cake Sample by Chemical Method

    International Nuclear Information System (INIS)

    Busamongkol, Arporn; Rodthongkom, Chouvana

    1999-01-01

    The purity of uranium cake is very critical in nuclear-grade uranium (UO 2 ) and uranium hexafluoride (UF 6 ) production. The major element in yellow cake is uranium and trace metal impurities. The objective of this study is to determine uranium and 25 trace metal impurities; Aluminum, Barium, Bismuth, Calcium, Cadmium, Cobalt, Chromium, Copper, Iron, Potassium, Iithium, Magnesium, Manganese, Molybdenum, Sodium, Niobium, Nickel, Lead, Antimony, Tin, Strontium, Titanium, Vanadium, Zinc and Zirconium, Uranium is determined by Potassium dichromate titration, after solvent extraction with Cupferon in Chloroform, Trace metal impurities are determined by solvent extraction with Tributyl Phosphate in Carbon-tetrachloride ( for first 23 elements) and N-Benzoyl-N-Phenylhydroxylamine in Chloroform ( for last 2 elements), then analyzed by Atomic Absorption Spectrophotometer (AAS) compared with Inductively Couple Plasma Spectrophotometers (ICP). The accuracy and precision are studied with standard uranium octaoxide

  18. US-ROK Action Sheet 34: Safeguards Application of a Hand-held Mechanically Cooled Germanium Spectrometer

    International Nuclear Information System (INIS)

    Dreyer, J.; Burks, M.; Ham, Y.; Kwak, S.

    2015-01-01

    This report summarizes results of Action Sheet 34 - for the cooperative efforts on the field testing and evaluation of a high-resolution, hand-held, gamma-ray spectrometer, known as SPG (Spectroscopic Planar Germanium), for safeguards application such as short notice inspections, UF6 analysis, enrichment determination, and other potential applications. The Spectroscopic Planar Germanium (SPG) has been demonstrated IAEA Physical Inventory Verification (PIV) in South Korea. This field test was a success and the feedback provided by KINAC, IAEA, and national laboratory staff was used to direct efforts to improve the instrument this year. Key points in this report include measurement results from PIV, analysis of spectra with commercially available Ortec U235 and PC-FRAM, and completion of tripod and tungsten collimator and integration of user feedback.

  19. New liquid waste control with tannin adsorbent

    International Nuclear Information System (INIS)

    Nakamura, Yoshinobu; Shirato, Wataru; Nakamura, Yasuo

    1998-01-01

    Since 1971, the Mitsubishi Nuclear Fuel Co., Ltd. (MNF) has been fabricating PWR fuels and developing related technology and processes. In the UF 6 reconversion lines of MNF, the ammonium diuranate (ADU) process has been operating and the newly developed process of liquid waste treatment was installed last year. The characteristic of this process is to use insoluble tannin adsorbent which has been developed by MNF. The tannin adsorbent is not only an effective means to adsorb heavy metals such as uranium and plutonium but is also easy to incinerate at low temperature. Control of radioactive liquid waste from nuclear facilities is generally implemented by co-precipitation. However, it produces secondary wastes such as noncombustible materials which include radionuclides and it is anticipated that the storage and disposal of those wastes will be at high cost. Those are the reasons why tannin adsorbent has an advantage, and why MNF develops it. (author)

  20. General description and production lines of the Egyptian fuel manufacturing pilot plant

    International Nuclear Information System (INIS)

    Zidan, W.I.; Elseaidy, I.M.

    1999-01-01

    The Egyptian Fuel Manufacturing Pilot Plant, FMPP, is a new facility, producing an MTR-type fuel elements required for the Egyptian Second Research Reactor, ETRR-2, as well as other plates or elements for an external clients with the same type and enrichment percent or lower, (LEU). General description is presented. The production lines in FMPP, which begin from uranium hexaflouride (UF 6 , 19.7±0.2 % U 235 by wt), aluminum powder, and nuclear grade 6061 aluminium alloy in sheets, bars, and rods with the different heat treatments and dimensions as a raw materials, are processed through a series of the manufacturing, inspection, and quality control plan to produce the final specified MTR-type fuel elements. All these processes and the product control in each step are presented. The specifications of the final product are presented. (author)

  1. Study of reactions for the obtention of uranium tetrafluoride and hexafluoride

    International Nuclear Information System (INIS)

    Guzella, M.F.R.

    1984-01-01

    Based on an exhaustive bibliographical review, the main production processes of uranium hexafluoride in pilot plants and industrial facilities are described. The known reactions, confirmed in laboratory experiments, that lead to UF 6 or other intermediate fluorides, are presented and discussed. In order to determine a new thermodinamically feasible reaction involving the sulfur hexafluoride as fluorinating agent, a mock-up facility was designed and constructed as part of the R and D work planned at CDTN (NUCLEBRAS Center for Nuclear Technology Development, MG - Brazil). For the UF 4 synthesis employing U 3 O 8 and SF 6 , several experimental parameters were studied. The reaction time, gas flow, temperature and stoichiometric relations among reagents are described in detail. Suggestions for further investigations regarding this new reagent are made. (Author) [pt

  2. Environmental impact appraisal for renewal of Special Nuclear Material License No. SNM-1097 (Docket No. 70-1113)

    International Nuclear Information System (INIS)

    1984-06-01

    The proposed action, the full 5-year renewal of License SNM-1097, is necessary for GE to continue producing fuel used in light-water nuclear reactors. The fuel manufacturing operation principally involves converting UF 6 to UO 2 powder, pressing the UO 2 powder into pellets, sintering and grinding the pellets, loading the pellets into Zircaloy tubes, and then assembling the loaded tubes into fuel bundles. A variety of radiological and nonradiological gaseous, liquid, and solid wastes are generated. After treatment, some of the wastes are released to the environment. In addition to the nuclear fuel fabrication operation, there are other operations performed at GE which do not require NRC licensing (e.g., zirconium metal processing, production of fuel bundle and mechanical reactor components, and the manufacture of aircraft engine parts) and are not associated with the proposed action. 28 references, 15 figures, 21 tables

  3. Safety analysis report on the ''Paducah Tiger'' overpack for 10-ton cylinder of uranium hexafluoride

    International Nuclear Information System (INIS)

    Stitt, D.H.

    1978-01-01

    A summary of analysis performed to assess the puncture resistance of the Paducah Tiger under a particularly severe (worst case) orientation of the external puncture pin is presented. The six-inch diameter cylindrical puncture pin has been oriented to place its impact location immediately opposite the valve body mounted to the dished head of the uranium hexafluoride cylinder. The valve body is assumed to have a one-inch clearance relative to the inner wall of the overpack. Analysis indicates that significant residual kinetic energy remains in the system at the instant of overpack inner wall contact with the valve body. Thus, there is strong evidence suggesting that the valve body can be damaged, or sheared from the dished head of the UF 6 , under the assumed worst case impact orientation

  4. Energy distributions and radiation transport in uranium plasmas

    International Nuclear Information System (INIS)

    Miley, G.; Bathke, C.; Maceda, E.; Choi, C.

    1976-01-01

    Electron energy distribution functions have been calculated in a 235 U-plasma at 1 atmosphere for various plasma temperatures (5000 to 8000 0 K) and neutron fluxes (2 x 10 12 to 2 x 10 16 neutrons/(cm 2 -sec)). Two sources of energetic electrons are included; namely fission-fragment and electron-impact ionization, resulting in a high-energy tail superimposed on the thermalized electron distribution. Consequential derivations from equilibrium collision rates are of interest relative to direct pumping of lasers and radiation emission. Results suggest that non-equilibrium excitation can best be achieved with an additive gas such as helium or in lower temperature plasmas requiring UF 6 . An approximate analytic model, based on continuous electron slowing, has been used for survey calculations. Where more accuracy is required, a Monte Carlo technique is used which combines an analytic representation of Coulombic collisions with a random-walk treatment of inelastic collisions

  5. Eldorado Nuclear Limited annual report 1979

    International Nuclear Information System (INIS)

    1980-01-01

    In the fiscal year ending Dec. 31, 1979 Eldorado Nuclear had gross revenues totalling $111 498 000. Net earnings were $398 000. Progress was made towards the completion of capital projects leading to the development of the key Lake deposit and the construction of a new UF 6 plant. Studies on a new conversion plant to be located in Saskatchewan are being carried out. Eldorado's mining and processing capacity is to be more than doubled in the early 1980's. The company participated in 28 exploration projects in eight provinces and both territories in 1979. The Beaverlodge mine produced more than 312 000 tons of ore, and 1 006 000 pounds of U 3 O 8 were recovered. Uranium hexafluoride production was 9 890 000 pounds U, and UO 2 production accounted for 2 919 000 pounds U. (LL)

  6. The fabrication process of ceramic grade UO2 powder via fluorid system AUC and the treatment on AUC precipitation filtrate

    International Nuclear Information System (INIS)

    Liu Jinhong; Xu Kui; Li Zhiwan; Yi Wei; Tang Yueming; Li Guangrong; Lei Maolin; Cui Chuanjiang

    2006-10-01

    It is described about the technology of fabricating AUC powder by Circum-fluence Precipitation Reactor with Gas (CPRG) from UF 6 hydrolyzed liquid, manufacturing nuclear pure ceramic grade UO 2 powder via fluorid system AUC process with fluidized bed method, recovering U(VI) with ion exchange resin, depositing fluorin in an outflow of effusion wastewater from the ion exchange using calces. The primary control parameters on the fabricating AUC powder is study, it is discussed to character difference of AUC powder between fluorid system and nitrate. Result show that the composing the manufacture AUC powder is invariable by CORG, and that the AUC quality is consistent, and that by decomposition and reduction of AUC and stabilization of UO 2 powder with fluidized bed, through optimum technological parameters, the excellent UO 2 powder is obtained on the quality. (authors)

  7. Competitiveness in Canada's nuclear industry

    International Nuclear Information System (INIS)

    Mirwald, R.

    1997-01-01

    Cameco, now a publicly traded company, mines and processes uranium. The mines are mostly in northern Saskatchewan. In 1996, Cameco increased its market share to about 15% of the western world's U 3 O 8 , and more than 20% of conversion to UF 6 . Cameco is the only commercial converter of uranium for Candu reactors. In 1996, sales were C$591 million. Net earnings last year were C$137.5 million - a fourfold increase over six years earlier - and long-term debt had been reduced to C$200 million. Cameco's position is secured by its substantial ownership position in Cigar Lake and McArthur River, the richest uranium deposits in the world. To answer questions by investors, Cameco has had to provide good public information about uranium and nuclear power

  8. Development of a portable mass spectrometric system for determination of isotopic composition of solid uranium samples using fluorine volatilization. Final report

    International Nuclear Information System (INIS)

    Loge, G.

    1994-01-01

    Using hardware and materials supplied by LANL, a prototype quadrupole mass spectrometer system designed for portable field analysis of isotopic composition of solid uranium samples was assembled and tested. The system contained the capability for fluorine volatilization of solid uranium samples with gas introduction, which was successfully tested and demonstrated using 100 mg samples of U 3 O 8 . Determination of precision and accuracy for measuring isotopic composition was performed using isotopic standards. Use with soil samples containing uranium were also attempted. Silicates in the soil forming SiF 4 were found to be a kinetic bottleneck to the formation of UF 6 . This could be avoided by performing some sort of chemical separation as a pre-treatment step, which was demonstrated using nitric acid

  9. Development of Halide and Oxy-Halides for Isotopic Separations

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Leigh R. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Johnson, Aaron T. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Pfeiffer, Jana [Idaho National Lab. (INL), Idaho Falls, ID (United States); Finck, Martha R. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-10-01

    The goal of this project was to synthesize a volatile form of Np for introduction into mass spectrometers at INL. Volatile solids of the 5f elements are typically those of the halides (e.g. UF6), however fluorine is highly corrosive to the sensitive internal components of the mass separator, and the other volatile halides exist as several different stable isotopes in nature. However, iodide is both mono-isotopic and volatile, and as such presents an avenue for creation of a form of Np suitable for introduction into the mass separator. To accomplish this goal, the technical work in the project sought to establish a novel synthetic route for the conversion NpO2+ (dissolved in nitric acid) to NpI3 and NpI4.

  10. Uranium hexaflouride freezer/sublimer process simulator/trainer

    International Nuclear Information System (INIS)

    Carnal, C.L.; Belcher, J.D.; Tapp, P.A.; Ruppel, F.R.; Wells, J.C.

    1991-01-01

    This paper describes a software and hardware simulation of a freezer/sublimer unit used in gaseous diffusion processing of uranium hexafluoride (UF 6 ). The objective of the project was to build a plant simulator that reads control signals and produces plant signals to mimic the behavior of an actual plant. The model is based on physical principles and process data. Advanced Continuous Simulation Language (ACSL) was used to develop the model. Once the simulation was validated with actual plant process data, the ACSL model was translated into Advanced Communication and Control Oriented Language (ACCOL). A Bristol Babcock Distributed Process Controller (DPC) Model 3330 was the hardware platform used to host the ACCOL model and process the real world signals. The DPC will be used as a surrogate plant to debug control system hardware/software and to train operators to use the new distributed control system without disturbing the process. 2 refs., 4 figs

  11. Development of a portable mass spectrometric system for determination of isotopic composition of solid uranium samples using fluorine volatilization

    Science.gov (United States)

    Loge, G.

    1994-09-01

    Using hardware and materials supplied by LANL, a prototype quadrupole mass spectrometer system designed for portable field analysis of isotopic composition of solid uranium samples was assembled and tested. The system contained the capability for fluorine volatilization of solid uranium samples with gas introduction, which was successfully tested and demonstrated using 100 mg samples of U3O8. Determination of precision and accuracy for measuring isotopic composition was performed using isotopic standards. Use with soil samples containing uranium were also attempted. Silicates in the soil forming SiF4 were found to be a kinetic bottleneck to the formation of UF6. This could be avoided by performing some sort of chemical separation as a pre-treatment step, which was demonstrated using nitric acid.

  12. An historical collection of papers on nuclear thermal propulsion

    Science.gov (United States)

    The present volume of historical papers on nuclear thermal propulsion (NTP) encompasses NTP technology development regarding solid-core NTP technology, advanced concepts from the early years of NTP research, and recent activities in the field. Specific issues addressed include NERVA rocket-engine technology, the development of nuclear rocket propulsion at Los Alamos, fuel-element development, reactor testing for the Rover program, and an overview of NTP concepts and research emphasizing two decades of NASA research. Also addressed are the development of the 'nuclear light bulb' closed-cycle gas core and a demonstration of a fissioning UF6 gas in an argon vortex. The recent developments reviewed include the application of NTP to NASA's Lunar Space Transportation System, the use of NTP for the Space Exploration Initiative, and the development of nuclear rocket engines in the former Soviet Union.

  13. DRY URANIUM TETRAFLUORIDE PROCESS PREPARATION USING THE URANIUM HEXAFLUORIDE RECONVERSION PROCESS EFFLUENTS.

    OpenAIRE

    João Batista da Silva Neto

    2008-01-01

    O processamento químico a partir do hexafluoreto de urânio (UF6), permite uma flexibilidade na produção de combustíveis à base de siliceto de urânio (U3Si2) e octóxido de urânio (U3O8). Atualmente no IPEN-CNEN/SP desenvolvem-se trabalhos visando o processamento de combustíveis com alta concentração de urânio, por meio da substituição do U3O8 por U3Si2. Para a obtenção de U3Si2, duas possibilidades podem ser consideradas na preparação da matéria-prima utilizada, que é o tetrafluoreto de urânio...

  14. Production of sized particles of uranium oxides and uranium oxyfluorides

    International Nuclear Information System (INIS)

    Knudsen, I.E.; Randall, C.C.

    1976-01-01

    A process is claimed for converting uranium hexafluoride (UF 6 ) to uranium dioxide (UO 2 ) of a relatively large particle size in a fluidized bed reactor by mixing uranium hexafluoride with a mixture of steam and hydrogen and by preliminary reacting in an ejector gaseous uranium hexafluoride with steam and hydrogen to form a mixture of uranium and oxide and uranium oxyfluoride seed particles of varying sizes, separating the larger particles from the smaller particles in a cyclone separator, recycling the smaller seed particles through the ejector to increase their size, and introducing the larger seed particles from the cyclone separator into a fluidized bed reactor where the seed particles serve as nuclei on which coarser particles of uranium dioxide are formed. 9 claims, 2 drawing figures

  15. The Mailbox Computer System for the IAEA verification experiment on HEU downblending at the Portsmouth Gaseous Diffusion Plant

    International Nuclear Information System (INIS)

    Aronson, A.L.; Gordon, D.M.

    2000-01-01

    IN APRIL 1996, THE UNITED STATES (US) ADDED THE PORTSMOUTH GASEOUS DIFFUSION PLANT TO THE LIST OF FACILITIES ELIGIBLE FOR THE APPLICATION OF INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA) SAFEGUARDS. AT THAT TIME, THE US PROPOSED THAT THE IAEA CARRY OUT A ''VERIFICATION EXPERIMENT'' AT THE PLANT WITH RESPECT TO DOOWNBLENDING OF ABOUT 13 METRIC TONS OF HIGHLY ENRICHED URANIUM (HEU) IN THE FORM OF URANIUM HEXAFLUROIDE (UF6). DURING THE PERIOD DECEMBER 1997 THROUGH JULY 1998, THE IAEA CARRIED OUT THE REQUESTED VERIFICATION EXPERIMENT. THE VERIFICATION APPROACH USED FOR THIS EXPERIMENT INCLUDED, AMONG OTHER MEASURES, THE ENTRY OF PROCESS-OPERATIONAL DATA BY THE FACILITY OPERATOR ON A NEAR-REAL-TIME BASIS INTO A ''MAILBOX'' COMPUTER LOCATED WITHIN A TAMPER-INDICATING ENCLOSURE SEALED BY THE IAEA

  16. Scientific report 1999

    International Nuclear Information System (INIS)

    1999-01-01

    The aim of this report is to outline the main developments of the 'Departement des Reacteurs Nucleaires' (DRN) during the year 1999. DRN is one of the CEA Institutions. This report is divided in three main parts: the DRN scientific programs, the scientific and technical publications (with abstracts in English) and economic data on staff, budget and communication. Main results of the Department for the year 1999 are presented giving information on the simulation of low mach number compressible flow, experimental irradiation of multi-materials, progress in the dry route conversion process of UF 6 to UO 2 , the neutronics, the CASCADE installation, the corium, the BWR type reactor cores technology, the reactor safety, the transmutation of americium and fuel cell flow studies, the crack propagation, the hybrid systems and the CEA sites improvement. (A.L.B.)

  17. New Prototype Safeguards Technology Offers Improved Confidence and Automation for Uranium Enrichment Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Brim, Cornelia P.

    2013-04-01

    An important requirement for the international safeguards community is the ability to determine the enrichment level of uranium in gas centrifuge enrichment plants and nuclear fuel fabrication facilities. This is essential to ensure that countries with nuclear nonproliferation commitments, such as States Party to the Nuclear Nonproliferation Treaty, are adhering to their obligations. However, current technologies to verify the uranium enrichment level in gas centrifuge enrichment plants or nuclear fuel fabrication facilities are technically challenging and resource-intensive. NNSA’s Office of Nonproliferation and International Security (NIS) supports the development, testing, and evaluation of future systems that will strengthen and sustain U.S. safeguards and security capabilities—in this case, by automating the monitoring of uranium enrichment in the entire inventory of a fuel fabrication facility. One such system is HEVA—hybrid enrichment verification array. This prototype was developed to provide an automated, nondestructive assay verification technology for uranium hexafluoride (UF6) cylinders at enrichment plants.

  18. Study of extraction-spectrophotometric micro-determination of boron with methylene blue and its application

    International Nuclear Information System (INIS)

    Zhu Daohong

    1990-08-01

    A sensitive extraction-spectrophotometric method for microdetermination of boron with methylene blue was investigated. The method was based on the extraction of a BF 4 - -methylene blue complex into dichloroethane. Boron was determined directly by measuring the absorbance at 658 nm. The calibration graph was linear over the range of 2.5 x 10 -9 to 8 x 10 -8 g/mL. The blank, mechanism of the reactions, interference of other ions and some optimum conditions of the method were studied in detail. The main source of the blank resulted from methylene blue and the complex of F - -methylene blue. In order to reduce the blank, the amounts of methylene blue, H 2 SO 4 and HF were used as less as possible. Only one to one complex BF 4 - -methylene blue was formed in the medium of H 2 SO 4 . About 90% of methylene blue and F - -methylene blue complex was removre with 5 ml of water and only a little amount of BF 4 -methylene blue complex was decomposed. The extraction-spectrophotometric method with methylene blue was first applied to the microdetermination of boron in sodium metal and UF 6 . The sample of sodium metal was taken and weighed in the glovebox filled with argon. Then sodium metal was oxidized, hydrolyzed, netralized and fluorizated with H 2 O, H 2 SO 4 and HF, respectively. The 0.5 ppm of boron in sodium metal was determined with a relative error about ±4%. This method can be applied to the determination of boron in sodium metal, sodium sulfate and sodium hydroxide at diffeent grades. The species of boron in the hydrolysate of UF 6 is BF 4 - anion, so the sample can be directly analyzed. Boron contents in the range of 0.1 to 0.5 ppm was determined with a relative error about ±3%. Six samples could be analysed in 2h

  19. Laboratory tests in support of the MSRE reactive gas removal system

    International Nuclear Information System (INIS)

    Rudolph, J.C.; Del Cul, G.D.; Caja, J.; Toth, L.M.; Williams, D.F.; Thomas, K.S.; Clark, D.E.

    1997-07-01

    The Molten Salt Reactor Experiment (MSRE) at Oak Ridge National Laboratory has been shut down since December 1969, at which time the molten salt mixture of LiF-BeF 2 -ZrF 4 - 233 UF 4 (64.5-30.3-5.0-0.13 mol%) was transferred to fuel salt drain tanks for storage. In the late 1980s, increased radiation in one of the gas lines from the drain tank was attributed to 233 UF 6 . In 1994 two gas samples were withdraw (from a gas line in the Vent House connecting to the drain tanks) and analyzed. Surprisingly, 350 mm Hg of F 2 , 70 mm Hg of UF 6 , and smaller amounts of other gases were found in both of the samples. To remote this gas from above the drain tanks and all of the associated piping, the reactive gas removal system (RGRS) was designed. This report details the laboratory testing of the RGRS, using natural uranium, prior to its implementation at the MSRE facility. The testing was performed to ensure that the equipment functioned properly and was sufficient to perform the task while minimizing exposure to personnel. In addition, the laboratory work provided the research and development effort necessary to maximize the performance of the system. Throughout this work technicians and staff who were to be involved in RGRS operation at the MSRE site worked directly with the research staff in completing the laboratory testing phase. Consequently, at the end of the laboratory work, the personnel who were to be involved in the actual operations had acquired all of the training and experience necessary to continue with the process of reactive gas removal

  20. Regulatory analysis on emergency preparedness for fuel cycle and other radioactive material licensees. Draft report for comment

    International Nuclear Information System (INIS)

    McGuire, S.A.

    1985-06-01

    Potential accidents for 15 types of fuel cycle and other radioactive material licensees were analyzed. The most potentially hazardous accident, by a large margin, was determined to be the sudden rupture of a heated multi-ton cylinder of UF 6 . Acute fatalities offsite are probably not credible. Acute permanent injuries may be possible for many hundreds of meters, and clinically observable transient effects of unknown long term consequences may be possible for distances up to a few miles. These effects would be caused by the chemical toxicity of the UF 6 . Radiation doses would not be significant. The most potentially hazardous accident due to radiation exposure was determined to be a large fire at certain facilities handling large quantities of alpha-emitting radionuclides (i.e., Po-210, Pu-238, Pu-239, Am-241, Cm-242, Cm-244) or radioiodines (I-125 and I-131). However, acute fatalities or injuries to people offsite due to accidental releases of these materials do not seem plausible. The only other significant accident was identified as a long-term pulsating criticality at fuel cycle facilities handling high-enriched uranium or plutonium. An important feature of the most serious accidents is that releases are likely to start without prior warning. The releases would usually end within about half an hour. Thus protective actions would have to be taken quickly to be effective. There is not likely to be enough time for dose projections, complicated decisionmaking during the accident, or the participation of personnel not in the immediate vicinity of the site. The appropriate response by the facility is to immediately notify local fire, police, and other emergency personnel and give them a brief predetermined message recommending protective actions. Emergency personnel are generally well qualified to respond effectively to small accidents of these types

  1. Guidelines for implementation of an environmental management system in the nuclear fuel cycle: a case study of USEXA-CEA; Diretrizes para implantacao de um sistema de gestao ambiental no ciclo do combustivel nuclear: estudo de caso da USEXA-CEA

    Energy Technology Data Exchange (ETDEWEB)

    Mattiolo, Sandra Regina

    2012-07-01

    The environmental management standards are intended to provide to the organizations the elements needed for the implementation of an Environmental Management System (EMS) that can be effectively integrated to another management requirements and assist them to achieve their environmental and economic goals. The Uranium Hexafluoride Production Unit - USEXA, located at the Navy Technological Center in Sao Paulo, will be the first Brazilian industrial plant responsible for the conversion stage in the nuclear fuel cycle (production of uranium hexafluoride - UF6), allowing added-value to the uranium ore. The EMS proposed to USEXA in this project allows to regulate its interfaces with the environment, since the Standards of CNEN - National Commission of Nuclear Energy and of the IAEA - International Atomic Energy Agency for Nuclear Installations, aim, mostly, to attend the security criteria for the population and the environment, concerning ionizing radiation. This model of EMS fills the gaps in standards of IAEA and CNEN, since it takes into account the environmental impacts from the use of chemicals in the manufacturing process of UF6, and general aspects of sustainability. It can be considered an original contribution within the complex activities that includes the uranium processing in the nuclear fuel cycle. This research proposes, as result, the use of a filter of significance to evaluate the environmental impacts depending on the installation location. It is also presented the Management System Manual for USEXA and models for training in personnel management are suggested, such as coaching and neuro linguistic programing, which can be applied to any Management System. The training can be considered a preventive action as they considerably decreased incidents related to equipment maintenance and thus the occurrence of environmental impacts. (author)

  2. Selection of a management strategy for depleted uranium hexafluoride

    International Nuclear Information System (INIS)

    Patton, S.E.; Hanrahan, E.J.; Bradley, C.E.

    1995-01-01

    A consequence of the uranium enrichment process used in the United States (US) is the accumulation of a significant amount of depleted uranium hexafluoride (UF 6 ). Currently, approximately 560,000 metric tons of the material are stored at three different sites. The US Department of Energy (DOE) has recently initiated a program to consider alternative strategies for the cost-effective and environmentally safe long-term management of this inventory of depleted UF 6 . The program involves a technology and engineering assessment of proposed management options (use/reuse, conversion, storage, or disposal) and an analysis of the potential environmental impacts and life-cycle costs of alternative management strategies. The information obtained from the studies will be used by the DOE to select a preferred long-term management strategy. The selection and implementation of a management strategy will involve consideration of a number of important issues such as environmental, health, and safety effects; the balancing of risks versus costs in a context of reduced government spending; socioeconomic implications, including effects on the domestic and international uranium industry; the technical status of proposed uses or technologies; and public involvement in the decision making process. Because of its provisions for considering a wide range of relevant issues and involving the public, this program has become a model for future DOE materials disposition programs. This paper presents an overview of the Depleted Uranium Hexafluoride Management Program. Technical findings of the program to date are presented, and major issues involved in selecting and implementing a management strategy are discussed

  3. Pharmacokinetic models relevant to toxicity and metabolism for uranium in humans and animals

    International Nuclear Information System (INIS)

    Wrenn, M.E.

    1989-01-01

    Models to predict short and long term accumulation of uranium in the human kidney are reviewed and summarised. These are generally first order linear compartmental models or pseudo-pharmacokinetic models such as the retention model of the ICRP. Pharmacokinetic models account not only for transfer from blood to organs, but also recirculation from the organ to blood. The most recent information on mammalian and human metabolism of uranium is used to establish a revised model. The model is applied to the short term accumulation of uranium in the human kidney after a single rapid dosage to the blood, such as that obtained by inhaling UF6 or its hydrolysis products. It is shown that the maximum accumulation in the kidney under these conditions is less than the fraction of the material distributed from the blood to kidney if a true pharmacokinetic model is used. The best coefficients applicable to man in the authors' view are summarised in model V. For a half-time of two days in the mammalian kidney, the maximum concentration in kidney is 75% of that predicted by a retention model such as that used by the ICRP following a single acute intake. We conclude that one must use true pharmacokinetic models, which incorporate recirculation from the organs to the blood, in order to realistically predict time dependent uptake in the kidneys and other organs. Information is presented showing that the half-time for urinary excretion of soluble uranium in man after inhalation of UF6 is about one quarter of a day. (author)

  4. Comparison of experimental results of a Quad-CZT array detector, a NaI(Tl), a LaBr3(Ce), and a HPGe for safeguards applications

    Science.gov (United States)

    Kwak, S.-W.; Choi, J.; Park, S. S.; Ahn, S. H.; Park, J. S.; Chung, H.

    2017-11-01

    A compound semiconductor detector, CdTe (or CdZnTe), has been used in various areas including nuclear safeguards applications. To address its critical drawback, low detection efficiency, which leads to a long measurement time, a Quad-CZT array-based gamma-ray spectrometer in our previous study has been developed by combining four individual CZT detectors. We have re-designed the developed Quad-CZT array system to make it more simple and compact for a hand-held gamma-ray detector. The objective of this paper aims to compare the improved Quad-CZT array system with the traditional gamma-ray spectrometers (NaI(Tl), LaBr3(Ce), HPGe); these detectors currently have been the most commonly used for verification of nuclear materials. Nuclear materials in different physical forms in a nuclear facility of Korea were measured by the Quad-CZT array system and the existing gamma-ray detectors. For measurements of UO2 pellets and powders, and fresh fuel rods, the Quad-CZT array system turned out to be superior to the NaI(Tl) and LaBr3(Ce). For measurements of UF6 cylinders with a thick wall, the Quad-CZT array system and HPGe gave similar accuracy under the same measurement time. From the results of the field tests conducted, we can conclude that the improved Quad-CZT array system would be used as an alternative to HPGes and scintillation detectors for the purpose of increasing effectivenss and efficiency of safeguards applications. This is the first paper employing a multi-element CZT array detector for measurement of nuclear materials—particularly uranium in a UF6 cylinder—in a real nuclear facility. The present work also suggests that the multi-CZT array system described in this study would be one promising method to address a serious weakness of CZT-based radiation detection.

  5. Guidelines for implementation of an environmental management system in the nuclear fuel cycle: a case study of USEXA-CEA

    International Nuclear Information System (INIS)

    Mattiolo, Sandra Regina

    2012-01-01

    The environmental management standards are intended to provide to the organizations the elements needed for the implementation of an Environmental Management System (EMS) that can be effectively integrated to another management requirements and assist them to achieve their environmental and economic goals. The Uranium Hexafluoride Production Unit - USEXA, located at the Navy Technological Center in São Paulo, will be the first Brazilian industrial plant responsible for the conversion stage in the nuclear fuel cycle (production of uranium hexafluoride - UF6), allowing added-value to the uranium ore. The EMS proposed to USEXA in this project allows to regulate its interfaces with the environment, since the Standards of CNEN - National Commission of Nuclear Energy and of the IAEA - International Atomic Energy Agency for Nuclear Installations, aim, mostly, to attend the security criteria for the population and the environment, concerning ionizing radiation. This model of EMS fills the gaps in standards of IAEA and CNEN, since it takes into account the environmental impacts from the use of chemicals in the manufacturing process of UF6, and general aspects of sustainability. It can be considered an original contribution within the complex activities that includes the uranium processing in the nuclear fuel cycle. This research proposes, as result, the use of a filter of significance to evaluate the environmental impacts depending on the installation location. It is also presented the Management System Manual for USEXA and models for training in personnel management are suggested, such as coaching and neuro linguistic programing, which can be applied to any Management System. The training can be considered a preventive action as they considerably decreased incidents related to equipment maintenance and thus the occurrence of environmental impacts. (author)

  6. Uranyl Nitrate Flow Loop

    International Nuclear Information System (INIS)

    Ladd-Lively, Jennifer L

    2008-01-01

    The objectives of the work discussed in this report were to: (1) develop a flow loop that would simulate the purified uranium-bearing aqueous stream exiting the solvent extraction process in a natural uranium conversion plant (NUCP); (2) develop a test plan that would simulate normal operation and disturbances that could be anticipated in an NUCP; (3) use the flow loop to test commercially available flowmeters for use as safeguards monitors; and (4) recommend a flowmeter for production-scale testing at an NUCP. There has been interest in safeguarding conversion plants because the intermediate products [uranium dioxide (UO 2 ), uranium tetrafluoride (UF 4 ), and uranium hexafluoride (UF 6 )] are all suitable uranium feedstocks for producing special nuclear materials. Furthermore, if safeguards are not applied virtually any nuclear weapons program can obtain these feedstocks without detection by the International Atomic Energy Agency (IAEA). Historically, IAEA had not implemented safeguards until the purified UF 6 product was declared as feedstock for enrichment plants. H. A. Elayat et al. provide a basic definition of a safeguards system: 'The function of a safeguards system on a chemical conversion plant is in general terms to verify that no useful nuclear material is being diverted to use in a nuclear weapons program'. The IAEA now considers all highly purified uranium compounds as candidates for safeguarding. DOE is currently interested in 'developing instruments, tools, strategies, and methods that could be of use to the IAEA in the application of safeguards' for materials found in the front end of the nuclear fuel cycle-prior to the production of the uranium hexafluoride or oxides that have been the traditional starting point for IAEA safeguards. Several national laboratories, including Oak Ridge, Los Alamos, Lawrence Livermore, and Brookhaven, have been involved in developing tools or techniques for safeguarding conversion plants. This study was sponsored by

  7. Safeguards approaches for conversion and gas centrifuge enrichment plants

    International Nuclear Information System (INIS)

    Stanuch, C.; Whitaker, M.; Lockwood, D.; Boyer, B.

    2013-01-01

    This paper describes recent studies and investigations of new safeguards measures and inspection tools to strengthen international safeguards at GCEPs (Gas Centrifuge Enrichment Plants) and conversion plants. The IAEA has indicated that continuous, unattended process monitoring should play a central role in future safeguards approaches for conversion plants and GCEPs. Monitoring safeguards relevant information from accountancy scales, process load cells, and unit header pipes can make existing safeguards approaches more efficient by replacing repetitive, routine, labor-intensive inspection activities with automated systems. These systems can make the safeguards approach more effective by addressing more completely the safeguards objectives at these facilities. Automated collection and analysis of the data can further enable the IAEA to move towards a fully-information driven inspection regime with randomized (from the operator's perspective), short-notice inspections. The reduction in repetitive on-site inspection activities would also be beneficial to plant operators, but only if sensitive and proprietary information can be protected and the new systems prove to be reliable. New facilities that incorporate Safeguards by Design into the earliest design stages can facilitate the effective DIV (Design Information Verification) of the plant to allow the inspectors to analyze the capacity of the plant, to project maximum production from the plant, and to provide a focus on the areas in the plant where credible diversion scenarios could be attempted. Facilitating efficient nuclear material accountancy by simplifying process pipework and making flow measurement points more accessible can allow for easier estimation of plant holdup and a potential reduction in the number of person-days of inspection. Lastly, a universal monitoring standard that tracks the location, movement, and use of UF 6 cylinders may enhance the efficiency of operations at industry sites and would

  8. Containment and storage of uranium hexafluoride at US Department of Energy uranium enrichment plants

    International Nuclear Information System (INIS)

    Barlow, C.R.; Alderson, J.H.; Blue, S.C.; Boelens, R.A.; Conkel, M.E.; Dorning, R.E.; Ecklund, C.D.; Halicks, W.G.; Henson, H.M.; Newman, V.S.; Philpot, H.E.; Taylor, M.S.; Vournazos, J.P.; Pryor, W.A.; Ziehlke, K.T.

    1992-07-01

    Isotopically depleted UF 6 (uranium hexafluoride) accumulates at a rate five to ten times greater than the enriched product and is stored in steel vessels at the enrichment plant sites. There are approximately 55,000 large cylinders now in storage at Paducah, Kentucky; Portsmouth, Ohio; and Oak Ridge, Tennessee. Most of them contain a nominal 14 tons of depleted UF 6 . Some of these cylinders have been in the unprotected outdoor storage environment for periods approaching 40 years. Storage experience, supplemented by limited corrosion data, suggests a service life of about 70 years under optimum conditions for the 48-in. diameter, 5/16-in.-wall pressure vessels (100 psi working pressure), using a conservative industry-established 1/4-in.-wall thickness as the service limit. In the past few years, however, factors other than atmospheric corrosion have become apparent that adversely affect the serviceability of small numbers of the storage containers and that indicate the need for a managed program to ensure maintenance ofcontainment integrity for all the cylinders in storage. The program includes periodic visual inspections of cylinders and storage yards with documentation for comparison with other inspections, a group of corrosion test programs to permit cylinder life forecasts, and identification of (and scheduling for remedial action) situations in which defects, due to handling damage or accelerated corrosion, can seriously shorten the storage life or compromise the containment integrity of individual cylinders. The program also includes rupture testing to assess the effects of certain classes of damage on overall cylinder strength, aswell as ongoing reviews of specifications, procedures, practices, and inspection results to effect improvements in handling safety, containment integrity, and storage life

  9. The Stability of CI02 as a Product of Gas Phase Decontamination Treatments

    International Nuclear Information System (INIS)

    Simmons, D. W.

    1994-01-01

    The gas phase decontamination project is investigating the use of chlorine trifluoride (ClF 3 ) to fluorinate nonvolatile uranium deposits to produce uranium hexafluoride (UF 6 ) gas. The potential existence of chlorine dioxide (ClO 2 ) during gas phase decontamination with ClF 3 has been the subject of recent safety discussions. Some of the laboratory data collected during feasibility studies of the gas phase process has been evaluated for the presence of ClO 2 in the product gas stream. The preliminary evidence to date can be summarized as follows: (1) ClO 2 was not detected in the flow loop in the absence of ClF 3 ; (2) ClO 2 was not detected in the static reactors in the absence of both ClF 3 and ClF; and (3) ClO 2 was detected in a static reactor in the absence of all fluorinating gases. The experimental evidence suggests that ClO 2 will not exist in the presence of ClF 3 , ClF, or UF 6 . The data analyzed to date is insufficient to determine the stability of ClO 2 in the presence of ClO 2 F. Thermodynamic calculations of the ClF 3 + H 2 O system support the experimental evidence, and suggest that ClO 2 will not exist in the presence of ClO 2 F. Additional experimental efforts are needed to provide a better understanding of the gas phase ClF 3 treatments and the product gases. However, preliminary evidence to date suggests that ClO 2 should not be present as a product during the normal operations of the gas phase decontamination project

  10. Study of production of fuel pellets for a reactor

    International Nuclear Information System (INIS)

    Mendes, Luiz F.F.; Conti, Thadeu N.

    2017-01-01

    Nowadays the electrical energy was been used much on society. A method for getting electricity is through nuclear power plants, this power plant uses fission that occurs inside the UO 2 pellets to generate thermal energy that will be transform into electric. The pellets production was made from enriched UF 6 uses some techniques of reprocessing UF 6 gas to UO 2 powder. This reprocessing process done by wet route (Ammonium Diuranate ADU or Ammonium Uranium Carbonate AUC) or by dry route (Fluidized bed or GECO). With getting of UO 2 powder is forwarded to metallurgy where this powder is compacted in cylindrical matrix so that powder take the desired shape, this green pellets are full of the empty spaces (porosity) for this it is sent to the sintering. The sintering consists of a joint of these particles of powders by means of the heating of this green pellets, coming arrive the melting temperature, the UO 2 molecules melting each other so decrease the porosity and increase the density. For the production of fuel pellets the process all most used is wed route by means the AUC ,this process arrive created for replace the ADU because the AUC is a process where less rework for the pore geometry is required compared to DUA. The fluidized bed process is more used in small samples however, for a large amount it becomes unfeasible, moreover the dry route process require more robust materials because of the generation of HF that is highly corrosive and cannot used the UNH (uranyl nitrate hexahydrate) used for recycle materials discarded in manufacturing. (author)

  11. Czasowniki mentalne i czasowniki emocji w opisie semantyczno-syntaktycznym

    Directory of Open Access Journals (Sweden)

    Małgorzata Korytkowska

    2017-12-01

    Full Text Available Mental and emotional verbs in semantic and syntactic description The main issue of this article concerns relations between the semantic plane of the sentence, which is presented by means of notions of predicate argument structure, and the plane of formal realisation of this structure. The existing attitudes to the studied verb classes are presented. Then rules governing the model of description used are specified (the article has been written within an elaborate scientific grant concerning Bulgarian, Polish and Russian. Obligatory semantic features of both classes are pointed out, followed by an elaboration on the scope of analysis of semantic and syntactic phenomena. This scope is determined by basic semantic sentence categories on which comparative, including contrastive, research is based. Drawing on examples of particular units studied, I then discuss the effectiveness of the analysis which enables comparing differences between sets of sentence structures allowable for each class studied. Those differences stem from semantic differences typical of those classes.   Czasowniki mentalne i czasowniki emocji w opisie semantyczno-syntaktycznym Tematyka artykułu dotyczy relacji między płaszczyzną semantyczną zdania, ujętą w terminach struktury predykatowo-argumentowej, a płaszczyzną realizacji formalnej tej struktury. Zarysowane zostały dotychczasowe podejścia do opisu badanych klas czasowników oraz sprecyzowano ustalenia dotyczące zastosowanego w artykule modelu opisu (artykuł powstał w związku z realizacją obszernego grantu dotyczącego języka bułgarskiego, polskiego i rosyjskiego. Wskazano obligatoryjne dla obu klas cechy semantyczne oraz scharakteryzowano zakres analizy zjawisk semantyczno-składniowych. Zakres ten wyznaczają podstawowe semantyczne kategorie zdaniowe, których badanie stanowi podstawę dla porównań, także porównań konfrontatywnych. Zaprezentowane zostały przykłady opracowania wybranych jednostek oraz

  12. Projekt datového centra - strukturovaná kabeláž

    OpenAIRE

    Hejtmánek, Ondřej

    2012-01-01

    Tato diplomová práce se zabývá rozborem kabeláže a kabelážních systémů v datových centrech a následným projektováním. Část práce se věnuje měření parametrů metalických kabelů používaných v datových centrech při působícím rušení. První část práce je zaměřena na rozbor struktury datového centra a kabeláže v něm využívané. Struktura datového centra vychází z modelu TIA-942 a skládá se ze vstupní místnosti, hlavní distribuční oblasti MDA, horizontální distribuční oblasti HDA, zóny distribuční obl...

  13. Imaginaria pracy kreatywnej: ciało i władza w serialu Mad Men

    Directory of Open Access Journals (Sweden)

    Artur Szarecki

    2015-12-01

    Full Text Available Mad Men to wielokrotnie nagradzany serial telewizyjny, którego akcja rozgrywa się w latach sześćdziesiątych, ukazując codzienne życie pracowników fikcyjnej agencji reklamowej Sterling Cooper, ulokowanej na nowojorskiej Madison Avenue. Środowisko to przechodziło wówczas radykalną transformację, która położyła fundamenty pod kapitalistyczną mitologię kreatywności. Oryginalność Mad Men polega jednak na tym, że serial unika powielania większości klisz składających się na obraz pracy kreatywnej, zamiast tego ukazując ją jako nieodzownie uwikłaną w cielesne doświadczenie – doznania, afekty i formy więzi społecznej, oraz instytucjonalne struktury władzy – podziały, hierarchie i formy wyzysku. Perspektywa ta umożliwia wyprowadzenie krytycznej analizy pracy kreatywnej, wskazując, że rzekomo minione formy eksploatacji są we współczesnym kapitalizmie wciąż obecne, ale zarazem podatne na zmiany.

  14. Moderní metody hodnocení polymerů

    OpenAIRE

    Ropek, Lukáš

    2012-01-01

    Práce tvoří přehled současných moderních metod hodnocení polymerů. První část se zabývá historickým vývojem, jednotlivými druhy a přípravou samotných polymerů. Dále je práce zaměřena na samotnou strukturu polymerů, popis moderních přístupů tvorby vzorků a metod studia struktury polymerů. Poté jsou v práci diskutovány mechanické vlastnosti polymerů a metody jejich zkoušení. Závěrem je pak práce zaměřena na konkrétní testy odolnosti trubkových polymerních materiálů používaných v současné praxi....

  15. Prostředí, organizace a řízení sportovního klubu HC Kometa Brno

    OpenAIRE

    Dufek, Robin

    2015-01-01

    Cílem předkládané bakalářské práce je analyzovat vybraný hokejový klub z hlediska řízení a organizační struktury. Práce je rozdělena do tří částí, přičemž v první, teoretické části, se zaobírám organizační strukturou, jejími typy v tomto druhu společností a sportovních organizací. Dále se zabývám vymezením ekonomických pojmů a metod, které byly použity při zpracování mé bakalářské práce. V praktické části je rozebrána především organizační struktura a činnost profesionálního aparátu, ekonomic...

  16. A Study of the Impact of Power Supply Parameters on Metal Flow Velocity in the Channel of a Device for Washing out Precious Metals from of the Automotive Catalytic Converters

    Directory of Open Access Journals (Sweden)

    Fornalczyk A.

    2014-06-01

    Full Text Available Czas życia katalizatorów samochodowych jest ograniczony. Dzisiejsze przepisy środowiskowe wymagają aby były one poddawane procesowi recyklingu jako cenne źródło platynowców, AI2O3 i złomu stalowego. Metale szlachetne stosowane w tych urządzeniach pełnią funkcje katalityczne, naniesione są na ceramiczny lub metalowy nośnik. Artykuł ten dotyczy procesu odzyskiwania metali szlachetnych ze zużytych katalizatorów samochodowych przy wykorzystaniu metody metalu-zbieracza. W celu przyspieszenia procesu wymywania metali szlachetnych ze struktury kapilarnej katalizatora, przepływ ciekłego metalu-zbieracza zmuszony został przez pole elektromagnetyczne. W pracy przedstawiono wyniki modelowania mające na celu poprawę skuteczności przepływu ciekłego metalu przez nośniki katalizatora za pomocą urządzenia z podwójnym uzwojeniem. Przeanalizowano także różne sposoby zasilania urządzenia. Eksperyment obliczeniowy został zrealizowany jako słabosprzężona analiza pola elektromagnetycznego i pola przepływu.

  17. Zakurzone białe kruki – niemieckie roczniki oficerskie (Ranglisty w zbiorach Książnicy Kopernikańskiej

    Directory of Open Access Journals (Sweden)

    Barbara Centek

    2013-12-01

    Full Text Available Od początku istnienia Prus armia cieszyła się w tym kraju wielkim poważaniem wśród obywateli, a kolejni władcy dbali o to, by jej wartość bojowa wciąż rosła. Jedną z charakterystycznych cech wojskowości pruskiej jest wydawanie co roku wykazu oficerów wszystkich oddziałów wraz z informacjami na temat struktury czy dyslokacji wojska. Przy każdym oficerze znajdowała się nie tylko informacja o jego aktualnym stopniu czy przydziale służbowym, ale także o dacie otrzymania patentu czy posiadanych odznaczeniach.Niniejszy artykuł przybliża specyfikę i dzieje pruskich roczników oficerskich, a także analizuje treść oraz cechy formalne tych woluminów, które znalazły się w posiadaniu Książnicy Kopernikańskiej. Nacisk położono przy tym na ukazanie ich wartości źródłowej dla historyka. Ustalono również drogi, którymi roczniki oficerskie trafiły do zbiorów biblioteki.

  18. „Biblioteka ucząca się” – zmiany w organizacji i systemie zarządzania w Bibliotece Uniwersytetu Finlandii Wschodniej

    Directory of Open Access Journals (Sweden)

    Hanna Grabowska

    2012-01-01

    Full Text Available Zmieniające się, dynamiczne i wymagające otoczenie współczesnej biblioteki naukowej wywiera nacisk na procesy innowacyjne związane ze zmianami modelu zarządzania. Tematem artykułu są zmiany w organizacji i systemie zarządzania w Bibliotece Uniwersytetu Finlandii Wschodniej przeprowadzone w związku z fuzją poszczególnych jednostek bibliotecznych. W artykule opisano przeobrażenia na poziomie struktury organizacyjnej, polityki gromadzenia, przechowywania i udostępniania zbiorów oraz w zakresie zarządzania zasobami ludzkimi w kontekście koncepcji organizacji uczącej się, która potrafi funkcjonować w niestabilnym otoczeniu, dostosowuje się do zmian, ale także poszukuje alternatywy zapewniającej ciągłość i rozwój organizacji.

  19. Structural Optimization of Box Wing Aircraft

    Directory of Open Access Journals (Sweden)

    Kalinowski Miłosz J.

    2015-03-01

    Full Text Available Układ zamkniętych skrzydeł to niekonwencjonalne rozwiązanie połączenia powierzchni nośnych, które coraz częściej konstruktorzy starają się stosować w prototypach nowych konstrukcji. Ten artykuł prezentuje przykładowy sposób realizacji optymalizacji strukturalnej struktury nośnej skrzydeł w rozpatrywanym układzie, który może być użyteczny w trakcie projektowania wstępnego samolotu. Na wstępie zaprezentowano metody oraz teorię wykorzystane do stworzenia algorytmu optymalizacji. Struktura analizowana jest przy użyciu belkowego modelu MES. Optymalizacja została przeprowadzona z wykorzystaniem połączenia metod iteracji prostych i gradientowych. Wyniki działania algorytmu przedstawione są na prostym przypadku obliczeniowym.

  20. Premature Cracking of Dies for Aluminium Alloy Die-Casting

    Directory of Open Access Journals (Sweden)

    Pawłowski B.

    2013-12-01

    Full Text Available Dwie identyczne matryce do ciśnieniowego odlewania stopów aluminium zostały przedwcześnie wycofane z eksploatacji z powodu wystąpienia na ich powierzchniach roboczych szeregu równoległych pęknięć. Kierunek propagacji pęknięć pokry w ał się z kierunkiem pasmowości mikrostrukturalnej a samo tworzenie się pęknięć było skutkiem niewłaściwej obróbki cieplnej matryc. Stwierdzono nieprawidłową orientację geometryczną matrycy wrzględem kierunku włókien struktury pierwotnej. Badania przy użyciu skaningowego mikroskopu elektronowego z wykorzystaniem techniki EDS wykazały, że przyczyną powstawania pęknięć matryc była nieprawidłową przeprowadzona obróbki cieplna matryc.

  1. Porovnání měřených okamžitých rychlostí a modelovaného proudění v míchané nádobě

    OpenAIRE

    Kysela, B. (Bohuš); Pešava, V.; Konfršt, J. (Jiří); Chára, Z. (Zdeněk); Kotek, M.

    2013-01-01

    Proces míchání je řízen změnami rychlostního pole a tvorbou vírových struktur v průběhu pracovního cyklu. V této studii porovnáváme výsledky CFD výpočtů s výsledky měření střední prostorově průměrované rychlosti, a také polohově závislé rychlosti odpovídající otáčivému pohybu míchadla, při kterém vznikají vírové struktury. Experimentální data časových řad dvourozměrných vektorových map rychlostí byly získány pomocí TR PIV měření v oblasti míchadla. Pro získání hodnot okamžitých rychlostí a ví...

  2. Numerical Analysis of Test Embankment on Soft Ground Using Multi-Laminate Type Model with Destructuration / Analiza Numeryczna Nasypu Drogowego Posadowionego Na Gruncie Słabonosnym Z Zastosowaniem Modelu Wielopłaszczyznowego Z Destrukturyzacja

    Directory of Open Access Journals (Sweden)

    Cundi M.

    2011-03-01

    Full Text Available W artykule przedstawiono model wielopłaszczyznowy (multi-laminate uwzgledniajacy anizotropie struktury słabonosnych gruntów drobnoziarnistych. Anizotropia indukowana naprezeniem, która otrzymuje sie przy zastosowaniu modeli wielopłaszczyznowych, jest dodatkowo wzmocniona poprzez wprowadzene prekonsolidacji zaleznej od orientacji przestrzennej. Model przedstawiono w wersji sprezysto-plastycznej, w której mozliwa jest symulacja anizotropii wytrzymałosci słabonosnych gruntów drobnoziarnistych oraz zjawiska destrukturyzacji. Działanie modelu pokazano w symulacjach numerycznych wybranych badan elementarnych oraz przy zastosowaniu w modelowaniu numerycznym odkształcenia słabonosnego podłoza gruntowego pod próbnym nasypem drogowym w Haarajoki, Finlandia. Symulacje numeryczna przeprowadzono przy uzyciu komercyjnego programu metody elementów skonczonych pozwalajacego na analize sprzezonych zagadnien brzegowych statyki i konsolidacji. Omówiono zagadnienia zwiazane z przyjeciem warunków poczatkowych stanu naprezenia in situ oraz warunków prekonsolidacji, jak równiez przedstawiono problemy zwiazane z przyjeciem parametrów modelu. Pomimo przyjecia prostych zasad dotyczacych warunków poczatkowych oraz przy pominieciu efektów lepkosci w modelu konstytutywnym, otrzymane wyniki pozwoliły na osiagniecie wystarczajacej w praktyce geotechnicznej dokładnosci w stosunku do wartosci pomierzonych.

  3. Personální rozvoj firmy ASUS Computer Czech Republic s.r.o.

    OpenAIRE

    Kubrichtová, Lenka

    2007-01-01

    Práce pojednává o personálním rozvoji firmy v závislosti na firemních cílech, které si společnost určila pro období 2-3 let. Výsledkem je - na základě analýzy výsledků empirického šetření zaměřeného na zjištění cílů společnosti, popisů pracovních míst a reálné náplně práce - identifikace rozvojových potřeb zaměstnanců, navržení individuálních plánů rozvoje a návrh struktury náboru a výběru nového zaměstnance, kterého firma potřebuje.

  4. Dependability issues in designing warehouse facilities and their functional areas / Zagadnienia niezawodności w projektowaniu magazynów i ich obszarów funkcjonalnych magazynów

    Directory of Open Access Journals (Sweden)

    Lewczuk Konrad

    2016-10-01

    Full Text Available Niezawodność obiektu magazynowego wynika z niezawodności jego obszarów funkcjonalnych i wpływa na niezawodność całego łańcucha dostaw. Aspekty niezawodnościowe pracy magazynu powinny być uwzględniane na etapie projektu, jednakże jest to trudne ze względu na złożoność tych systemów oraz zmienność struktury jakościowej i ilościowej strumieni materiałów na wejściach. Aktualnie stosowane procedury projektowania obiektów magazynowych uwzględniają klasyczne miary niezawodności jako kryterium oceny rozwiązania jedynie w dużym uproszczeniu. W artykule podjęto próbę usystematyzowania podstawowych zagadnień badawczych związanych z niezawodnością magazynów będących elementami łańcuchów dostaw, a jednocześnie obiektami technicznymi. Na tej podstawie możliwe będzie wyspecyfikowanie miar niezawodności możliwych do określenia w oparciu o typowe parametry obiektu magazynowego. Pozwoli to na uogólnienie modelu do oceny niezawodności procesu magazynowego.

  5. Etching of uranium dioxide in nitrogen trifluoride RF plasma glow discharge

    Science.gov (United States)

    Veilleux, John Mark

    1999-10-01

    A series of room temperature, low pressure (10.8 to 40 Pa), low power (25 to 210 W) RF plasma glow discharge experiments with UO2 were conducted to demonstrate that plasma treatment is a viable method for decontaminating UO2 from stainless steel substrates. Experiments were conducted using NF3 gas to decontaminate depleted uranium dioxide from stainless-steel substrates. Results demonstrated that UO2 can be completely removed from stainless-steel substrates after several minutes processing at under 200 W. At 180 W and 32.7 Pa gas pressure, over 99% of all UO2 in the samples was removed in just 17 minutes. The initial etch rate in the experiments ranged from 0.2 to 7.4 mum/min. Etching increased with the plasma absorbed power and feed gas pressure in the range of 10.8 to 40 Pa. A different pressure effect on UO2 etching was also noted below 50 W in which etching increased up to a maximum pressure, ˜23 Pa, then decreased with further increases in pressure. A computer simulation, CHEMKIN, was applied to predict the NF3 plasma species in the experiments. The code was validated first by comparing its predictions of the NF3 plasma species with mass spectroscopy etching experiments of silicon. The code predictions were within +/-5% of the measured species concentrations. The F atom radicals were identified as the primary etchant species, diffusing from the bulk plasma to the UO2 surface and reacting to form a volatile UF6, which desorbed into the gas phase to be pumped away. Ions created in the plasma were too low in concentration to have a major effect on etching, but can enhance the etch rate by removing non-volatile reaction products blocking the reaction of F with UO2. The composition of these non-volatile products were determined based on thermodynamic analysis and the electronic structure of uranium. Analysis identified possible non-volatile products as the uranium fluorides, UF2-5, and certain uranium oxyfluorides UO2F, UO2F2, UOF3, and UOF 4 which form over the

  6. Study of mass and momentum transfer and their effect on the direct fluorination of uranium oxide

    International Nuclear Information System (INIS)

    Cross, P.E.

    1983-01-01

    The mechanism for the fluorination of solid U 3 O 8 to gaseous UF 6 was found to be a two-step process with solid UO 2 F 2 as an intermediate. The highest particle temperatures were found to be associated with the initial reaction step to UO 2 F 2 ; it was recommended that these temperatures be maintained below 1700 0 F. The chemical equilibrium constant for the fluorination of PuF 4 to PuF 6 was found to be unexpectedly low at typical flame tower temperatures. Although not confirmed, there is an indication in the literature that a similar equilibrium constant is associated with the fluorination of NpF 4 and other transuranic molecules. It was recommended that uranium oxides which are significantly contaminated with transuranics should not be processed through a direct fluorination reactor such as the UF 6 flame tower. Reaction rate equations were developed for the fluorination of U 3 O 8 , UF 4 , PuF 4 and NpF 4 . During the course of the development, a significant discrepancy was found in the literature for the activation energy of the fluorination of U 3 O 8 . Equations were developed for both a high and low limit rate constant for the fluorination of U 3 O 8 . A variey of momentum, heat and mass transfer equations were developed for both oxide particles and the gas phase within the flame tower. Equations were developed to estimate the physical and transport properties of each gaseous component and the gas mixture as a whole. These properties and the transport equations were used to estimate the reaction time and distance for oxide particles with both the low and high limit reaction rate constant. The procedures used to perform these calculations is limited to constant temperature and an oxide feed comprised of a single particle size. The results indicate that above 1000 0 F the mass transfer of reactants and products becomes increasingly important to the overall rate of the reaction

  7. Emergency preparedness and response in case of a fire accident with (UF{sub 6}) packages tracking Suez Canal

    Energy Technology Data Exchange (ETDEWEB)

    Salama, M. [National Center for Nuclear Safety and Radiation Control (NCNSRC), Nasr City, Cairo (Egypt)

    2004-07-01

    Egypt has a unique problem - the Suez Canal. Radioactive cargo passing regularly through the canal carrying new and spent reactor fuel. Moreover there are also about 1000 metric tons of uranium hexaflouride (UF6) passing through the canal every year. In spite of all precautions taken in the transportation, accidents with packages containing (UF{sub 6}) and shipped through the Suez Canal, accidents may arise even though the probability is minimal. These accidents, may be accompanied by injuries or death of persons and damage to property. Due to the radiation and criticality hazards of (UF{sub 6}) and its high risk of chemical toxicity. The probability of a fire accident with a cargo carrying (UF{sub 6}) during its crossing the Suez Canal can cause serious chemical toxic and radiological hazards, particularly if the accident occurred close or near to one of the three densely populated cities (Port-Said, Ismailia, and Suez), which are located along the Suez Canal, west bank. The government of Egypt has elaborated a national radiological emergency plan inorder to face probable radiological accidents, which may be arised inside the country. Arrangements have been also elaborated for the medical care of any persons who, might be injured or contaminated, or who, have been exposed to severe radiation doses. The motivation of the present paper was undertaken to visualize a fire accident scenario occurring in industrial packages containing UF6 on board of a Cargo crossing the Suez Canal near Port-Said City. The accident scenario and emergency response actions taken during the different phases of the accident are going to be presented and discussed. The proposed emergency response actions taken to face the accident are going to be also presented. The work presented had revealed the importance of public awareness will be needed for populations located in densely populated areas along Suez Canal bank inorder to react timely and effectively to avoid the toxic and radiological

  8. Synthesis of uranium fluorides from uranium dioxide with ammonium bifluoride and ammonolysis of uranium fluorides to uranium nitrides

    Science.gov (United States)

    Yeamans, Charles Burnett

    This work presents the chemical conversion of uranium oxides to uranium fluorides, and their subsequent conversion to uranium nitrides. Uranium dioxide reacts with ammonium bifluoride at 20°C to form compound in the ammonium-uranium fluoride chemical system. This reaction occurs between solid uranium dioxide at the surface of the particles and ammonium fluoride vapor. A shrinking-sphere model demonstrated surface reaction kinetics, not mass transport by diffusion through the product layer, limit the reaction rate when the starting material consists of 100 mum uranium dioxide particles. Powder x-ray diffraction showed the reaction to be complete within 8 hours, with (NH4) 4UF8 the reaction product. High-resolution electron microcopy revealed the product is largely amorphous on a micrometer-scale, but contains well-formed crystal domains on the order of 10x10 nm. X-ray diffraction showed the reaction progresses though beta-NH4UF5, delta-(NH 4)2UF6, and gamma-(NH4)2UF6 intermediate phases before finally forming (NH4)4UF 8. Modeling the system as a series of first-order reaction suggested a fourth intermediate, possibly UF4, is likely to occur. The reaction of (NH4)4UF8 with ammonia gas at 800°C forms alpha-U2N3/UN2 solid solution products with a composition of UN1.83. The x-ray powder diffraction pattern of this product is the fcc pattern commonly referenced as that of UN2 and the lattice parameter was 0.53050 nm. Surface area increased by a factor of ten during ammonolysis, consistent with the action of a hydriding agent. The alpha-U2N 3/UN2 solid solution system formed contained 1 wt% UO 2 as an impurity. Upon subsequent heating to 1150°C for 4.5 hours under argon, the nitride sample formed UN with a UO2 impurity of 9 wt%. Based on the HRTEM images, oxidation in the UN product appears to be limited to within 20 nm of particle surfaces and grain boundaries.

  9. Hydrothermal preparation of nickel(II)/uranium(IV) fluorides with one-, two-, and three-dimensional topologies.

    Science.gov (United States)

    Bean, Amanda C; Sullens, Tyler A; Runde, Wolfgang; Albrecht-Schmitt, Thomas E

    2003-04-21

    A modified compositional diagram for the reactions of Ni(C(2)H(3)O(2))(2).4H(2)O with UO(2)(C(2)H(3)O(2))(2).2H(2)O and HF in aqueous media under mild hydrothermal conditions (200 degrees C) has been completed to yield three Ni(II)/U(IV) fluorides, Ni(H(2)O)(4)UF(6).1.5H(2)O (1), Ni(2)(H(2)O)(6)U(3)F(16).3H(2)O (2), and Ni(H(2)O)(2)UF(6)(H(2)O) (3). The structure of 1 consists of one-dimensional columns constructed from two parallel chains of edge-sharing dodecahedral [UF(8)] units. The sides of the columns are terminated by octahedral Ni(II) units that occur as cis-[Ni(H(2)O)(4)F(2)] polyhedra. In contrast, the crystal structure of 2 reveals a two-dimensional Ni(II)/U(IV) architecture built from edge-sharing tricapped trigonal prismatic [UF(9)] units. The top and bottom of the sheets are capped by fac-[Ni(H(2)O)(3)F(3)] octahedra. The structure of 3 is formed from [UF(8)(H(2)O)] tricapped trigonal prisms that edge share with one another to form one-dimensional chains. These chains are then joined together into a three-dimensional network by corner sharing with trans-[Ni(H(2)O)(2)F(4)] octahedra. Crystallographic data: 1, orthorhombic, space group Cmcm, a = 14.3383(8) A, b = 15.6867(8) A, c = 8.0282(4) A, Z = 8; 2, hexagonal, space group P6(3)/mmc, a = 7.9863(5) A, c = 16.566(1) A, Z = 2; 3, monoclinic, space group C2/c, a = 12.059(1) A, b = 6.8895(6) A, c = 7.9351(7) A, beta = 92.833(2) degrees, Z = 4.

  10. Integrated safety analysis to operate while constructing Urenco USA

    International Nuclear Information System (INIS)

    Kohrt, Rick; Su, Shiaw-Der; Lehman, Richard

    2013-01-01

    The URENCO USA (UUSA) site in Lea County, New Mexico, USA is authorized by the U.S. Nuclear Regulatory Commission (NRC) for construction and operation of a uranium enrichment facility under 10 CFR 70 (Ref 1). The facility employs the gas centrifuge process to separate natural uranium hexafluoride (UF 6 ) feed material into a product stream enriched up to 5% U-235 and a depleted UF 6 stream containing approximately 0.2 to 0.34% U-235. Initial plant operations, with a limited number of cascades on line, commenced in the second half of 2010. Construction activities continue as each subsequent cascade is commissioned and placed into service. UUSA performed an Integrated Safety Analysis (ISA) to allow the facility to operate while constructing the remainder of the facility. The ISA Team selected the What-If/Checklist method based on guidance in NUREG-1513 (Ref 2) and AIChE Guidelines (Ref 3). Of the three methods recommended for high risk events HAZOP, What-If/Checklist, or Failure Modes and Effects Analysis (FMEA), the What-If/Checklist lends itself best to construction activities. It combines the structure of a checklist with an unstructured 'brainstorming' approach to create a list of specific accident events that could produce an undesirable consequence. The What-If/Checklist for Operate While Constructing divides the UUSA site into seven areas and creates what-if questions for sixteen different construction activities, such as site preparation, external construction cranes, and internal construction lifts. The result is a total of 112 nodes, for which the Operate While Constructing ISA Team created hundreds of what-if questions. For each what-if question the team determined the likelihood, consequences, safeguards, and acceptability of risk. What-if questions with unacceptable risk are the accident sequences and their selected safeguards are the Items Relied on For Safety (IROFS). The final ISA identified four (4) new accident sequences that, unless

  11. Alpha spectrometry enriched uranium urinalysis results from IPEN

    International Nuclear Information System (INIS)

    Lima, Marina Ferreira

    2008-01-01

    Full text: IPEN (Instituto de Pesquisas Energeticas e Nucleares) manufactures the nuclear fuel to its research reactor, the IEA-R1. The CCN (Centro do Ciclo do Combustivel) facility produces the fuel cermets from UF 6 (uranium hexafluoride) enriched to 19.75% in 235 U. The production involves the transformation of the gaseous form in oxides and silicates by ceramic and metallurgical processing. The workers act in more than one step that involves exposition to types F, S and M compounds of uranium. Until 2003, only fluorimetric analysis was carried out by the LRT (Laboratorio de Radiotoxicologia - IPEN) in order to evaluate the intake of uranium, in spite of the sub estimation of the 234 U contribution to the internal doses. Isotopic uranium determination in urine by alpha spectrometry is the current method to monitoring the contribution of 234 U, 235 U and 238 U. Alpha spectrometry data of 164 samples from 84 individuals separate in three categories of workers: routinely work group; special operation group and control group - were analyzed how the isotopic composition excreted by urinary tract corresponds with the level of enrichment and isotopic composition of the plant products. Results show that is hard to estimate these intakes of 234 U and 235 U since these isotopes alpha activities are below the limit of detection or minimum detectable activity (MAD) of this method in the most part of the samples. Only in 22 samples it was possibly to measure the three radionuclides. Not expected high contribution of 234 U activity was found in samples of the control group. No one result over the 234 U and 235 U MAD was found in the samples from the special operation group. Only in 5 samples from the routinely group the levels of 235 U was higher than the levels of others groups. In a complementary study, 3 solid samples of UF 6 , U 2 O 8 and U 3 Si 2 from CCN plant were analyzed to determinate the isotopic uranium composition in these salts, since this composition varies

  12. The regulation of uranium refineries and conversion facilities in Canada

    International Nuclear Information System (INIS)

    Didyk, J.P.

    1986-04-01

    The nuclear regulatory process as it applies to uranium refineries and conversion facilities in Canada is reviewed. In the early 1980s, Eldorado Resources Limited proposed to construct and operate new facilities for refining yellowcake and for the production of uranium hexafluoride (UF 6 ). These projects were subject to regulation by the Atomic Energy Control Board (AECB). A description of the AECB's comprehensive licensing process covering all stages of siting, construction, operation and eventual decommissioning of nuclear facilities is traced as it was applied to the Eldorado projects. The AECB's concern with occupational health and safety, with public health and safety and with the protection of the environment in so far as it affects public health and safety is emphasized. Some regulatory difficulties encountered during the project's development which led to opening up the licensing process to public input and closer coordination of regulatory activities with other provincial and federal regulatory agencies are described. The Board's regulatory operational compliance program for uranium refineries and conversion facilities is summarized

  13. IAEA verification experiment at the Portsmouth Gaseous Diffusion Plant

    International Nuclear Information System (INIS)

    Gordon, D.M.; Subudhi, M.; Calvert, O.L.; Bonner, T.N.; Cherry, R.C.; Whiting, N.E.

    1998-01-01

    In April 1996, the United States (US) added the Portsmouth Gaseous Diffusion Plant to the list of facilities eligible for the application of International Atomic Energy Agency (IAEA) safeguards. At that time, the US proposed that the IAEA carry out a Verification Experiment at the plant with respect to the downblending of about 13 metric tons of highly enriched uranium (HEU) in the form of UF 6 . This material is part of the 226 metric tons of fissile material that President Clinton has declared to be excess to US national-security needs and which will be permanently withdrawn from the US nuclear stockpile. In September 1997, the IAEA agreed to carry out this experiment, and during the first three weeks of December 1997, the IAEA verified the design information concerning the downblending process. The plant has been subject to short-notice random inspections since December 17, 1997. This paper provides an overview of the Verification Experiment, the monitoring technologies used in the verification approach, and some of the experience gained to date

  14. Improved mass-measurement accuracy using a PNB Load Cell Scale

    International Nuclear Information System (INIS)

    Suda, S.; Pontius, P.; Schoonover, R.

    1981-08-01

    The PNB Load Cell Scale is a Preloaded, Narrow-Band calibration mass comparator. It consists of (1) a frame and servo-mechanism that maintains a preload tension on the load cell until the load, an unknown mass, is sensed, and (2) a null-balance digital instrument that suppresses the cell response associated with the preload, thereby improving the precision and accuracy of the measurements. Ideally, the objects used to set the preload should be replica mass standards that closely approximate the density and mass of the unknowns. The advantages of the PNB scale are an expanded output signal over the range of interest which increases both the sensitivity and resolution, and minimizes the transient effects associated with loading of load cells. An area of immediate and practical application of this technique to nuclear material safeguards is the weighing of UF 6 cyliners where in-house mass standards are currently available and where the mass values are typically assigned on the basis of comparison weighings. Several prototypical versions of the PNB scale have been assembled at the US National Bureau of Standards. A description of the instrumentation, principles of measurements, and applications are presented in this paper

  15. Potential National Security Applications of Nuclear Resonance Fluorescence Methods

    International Nuclear Information System (INIS)

    Warren, Glen A.; Peplowski, Patrick N.; Caggiano, Joseph A.

    2009-01-01

    The objective of this report is to document the initial investigation into the possible research issues related to the development of NRF-based national security applications. The report discusses several potential applications ranging from measuring uranium enrichment in UF6 canisters to characterization of gas samples. While these applications are varied, there are only a few research issues that need to be addressed to understand the limitation of NRF in solving these problems. These research issues range from source and detector development to measuring small samples. The next effort is to determine how best to answer the research issues, followed by a prioritization of those questions to ensure that the most important are addressed. These issues will be addressed through either analytical calculations, computer simulations, analysis of previous data or collection of new measurements. It will also be beneficial to conduct a thorough examination of a couple of the more promising applications in order to develop concrete examples of how NRF may be applied in specific situations. The goals are to develop an understanding of whether the application of NRF is limited by technology or physics in addressing national security applications, to gain a motivation to explore those possible applications, and to develop a research roadmap so that those possibilities may be made reality.

  16. Nuclear light bulb

    Science.gov (United States)

    Latham, Tom

    1991-01-01

    The nuclear light bulb engine is a closed cycle concept. The nuclear light bulb concept provides containment by keeping the nuclear fuel fluid mechanically suspended in a cylindrical geometry. Thermal heat passes through an internally cooled, fused-silica, transparent wall and heats hydrogen propellant. The seeded hydrogen propellant absorbs radiant energy and is expanded through a nozzle. Internal moderation was used in the configuration which resulted in a reduced critical density requirement. This result was supported by criticality experiments. A reference engine was designed that had seven cells and was sized to fit in what was then predicted to be the shuttle bay mass and volume limitations. There were studies done of nozzle throat cooling schemes to remove the radiant heat. Elements of the nuclear light bulb program included closed loop critical assembly tests done at Los Alamos with UF6 confined by argon buffer gas. It was shown that the fuel region could be seeded with constituents that would block UV radiation from the uranium plasma. A combination of calculations and experiments showed that internal moderation produced a critical mass reduction. Other aspects of the research are presented.

  17. Canada's nuclear fuel industry: An overview. Background paper

    International Nuclear Information System (INIS)

    Nixon, A.

    1993-11-01

    Canada was among the first countries to mine and process uranium-bearing ores. Such ores contain trace amounts of radium, which was in great demand for medical treatment and for use by research laboratories in the early part of the century. For the last half century, the same basic processes have been used to extract uranium from its ores and convert it to a form suitable for use in nuclear reactors. The process described here is that currently in use in Canada. Mining can take a variety of forms, from open-pit to deep, hard-rock. Mining is typically the most costly step in the process, particularly for lower-grade ores. The ore is crushed and ground in the mill to the consistency of fine sand from which the uranium is extracted chemically to produce the impure concentrate known as yellowcake. In the next step, the impure uranium concentrate is chemically refined into highly purified, nuclear-grade, uranium trioxide (UO 3 ). Uranium trioxide is then converted, in two separate chemical processes, into uranium dioxide (UO 2 ) which is destined for domestic consumption and uranium hexafluoride (UF 6 ) which is exported. In Canada, fabrication is the final step of the fuel production process. Uranium dioxide powder is compressed and sintered into very dense ceramic pellets which are then sealed in zirconium tubes and assembled into fuel bundles for Candu reactors. This background paper will review the Canadian nuclear fuels industry. 1 fig

  18. Physics design of fissile mass-flow monitoring system

    International Nuclear Information System (INIS)

    Mattingly, J.K.; March-Leuba, J.; Valentine, T.E.; Mihalczo, J.T.; Uckan, T.

    1997-01-01

    The system measures the flow rate and uranium-235 content in liquid or gas streams; it does not penetrate the process piping. A moderated fission neutron source is used to periodicially introduce a burst of thermal neutrons into the fluid stream to induce fission; delayed gamma emissions from the resulting fission fragments are detected by high-efficiency scintillators downstream of the neutron source. The fluid flow rate is measure from the time between initiation of the thermal neutron burst and detection of the fission product gamma emissions, and the U-235 content is inferred from the intensity of the gamma burst detected. Design of the fissile mass flow monitor requires satisfaction of several competing constraints. Efficient operation of the monitor requires that source-induced fission rate and detection efficiency be maximized while the source-induced background rate is simultaneoulsy minimized. Near optical nuclear design of the system was achieved using numerous Monte Carlo calculations and measurements. This paper addresses calculational aspects of the physics design for the system applied to UF 6 gas

  19. Preconceptual design of the gas-phase decontamination demonstration cart

    International Nuclear Information System (INIS)

    Munday, E.B.

    1993-12-01

    Removal of uranium deposits from the interior surfaces of gaseous diffusion equipment will be a major portion of the overall multibillion dollar effort to decontaminate and decommission the gaseous diffusion plants. Long-term low-temperature (LTLT) gas-phase decontamination is being developed at the K-25 Site as an in situ decontamination process that is expected to significantly lower the decontamination costs, reduce worker exposure to radioactive materials, and reduce safeguard concerns. This report documents the preconceptual design of the process equipment that is necessary to conduct a full-scale demonstration of the LTLT method in accordance with the process steps listed above. The process equipment and method proposed in this report are not intended to represent a full-scale production campaign design and operation, since the gas evacuation, gas charging, and off-gas handling systems that would be cost effective in a production campaign are not cost effective for a first-time demonstration. However, the design presented here is expected to be applicable to special decontamination projects beyond the demonstration, which could include the Deposit Recovery Program. The equipment will therefore be sized to a 200 ft size 1 converter (plus a substantial conservative design margin), which is the largest item of interest for gas phase decontamination in the Deposit Recovery Program. The decontamination equipment will allow recovery of the UF 6 , which is generated from the reaction of ClF 3 with the uranium deposits, by use of NaF traps

  20. Observation of inner surface of flame-tower type reactor for uranium conversion

    International Nuclear Information System (INIS)

    Amamoto, Ippei; Terai, Takayuki; Umetsu, Hiroshi

    2003-01-01

    A fluorination reactor, which has been used to convert uranium tetrafluoride (UF 4 ) into uranium hexafluoride (UF 6 ), was completed after approximately 6000 hours operation at the uranium conversion facility in Japan. The observation of its inner surface was carried out to understand its corrosive condition and mechanism. The main wall of the reactor is made of Monel Alloy and its operational temperature is approximately 450degC at external surface under gaseous fluorine atmosphere. A sampling was undertaken from the most corrosive part of the reactor wall, and its analysis was carried out to obtain the data for the condition of appearance, thickness, macro and micro structure, etc. The results of observation are as follows: (1) The thickness decreased evenly (average 3.9 mm/year); (2) The chemical composition of corrosive products as coating was mainly nickel fluoride (NiF 2 ), which suggested that the corrosion mechanism could have been caused by the high temperature gas corrosion; (3) The total amount of coating was lower than that of a loss in thickness. For some reason, some of coating would seem to become extinct on the surface of the wall. The deterioration of coating, which formed a protector on the wall due to excess heating of the wall, the sand erosion effect by UF 4 , etc. have contributed to this state of condition. (author)