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Sample records for enrichment processes enrichissement

  1. Transformations of highly enriched uranium into metal or oxide; Etudes des procedes de transformation des composes d'uranium a fort enrichissement isotopique

    Energy Technology Data Exchange (ETDEWEB)

    Nollet, P; Sarrat, P [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1964-07-01

    The enriched uranium workshops in Cadarache have a double purpose on the one hand to convert uranium hexafluoride into metal or oxide, and on the other hand to recover the uranium contained in scrap materials produced in the different metallurgical transformations. The principles that have been adopted for the design and safety of these workshops are reported. The nuclear safety is based on the geometrical limitations of the processing vessels. To establish the processes and the technology of these workshops, many studies have been made since 1960, some of which have led to original achievements. The uranium hexafluoride of high isotopic enrichment is converted either by injection of the gas into ammonia or by an original process of direct hydrogen reduction to uranium tetrafluoride. The uranium contained m uranium-zirconium metal scrap can be recovered by combustion with hydrogen chloride followed treatment of the uranium chloride by fluorine in order to obtain the uranium in the hexafluoride state. Recovery of the uranium contained m various scrap materials is obtained by a conventional refining process combustion of metallic scrap, nitric acid dissolution of the oxide, solvent purification by tributyl phosphate, ammonium diuranate precipitation, calcining, reduction and hydro fluorination into uranium tetrafluoride, bomb reduction by calcium and slag treatment. Two separate workshops operate along these lines one takes care of the uranium with an isotopic enrichment of up to 3 p. 100, the other handles the high enrichments. The handling of each step of this process, bearing in mind the necessity for nuclear safety, has raised some special technological problems and has led to the conception of new apparatus, in particular the roasting furnace for metal turnings, the nitric acid dissolution unit, the continuous precipitator and ever safe filter and dryer for ammonium diuranate, the reduction and hydro fluorination furnace and the slag recovery apparatus These are

  2. An experimental stack for the control of uranium enrichment; Empilement pour le controle de l'enrichissement de l'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Bailly du Bois, B; Raievski, V; Tretiakoff, O [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1957-07-01

    An apparatus is described for controlling the enrichment of the uranium in a fuel element at all stages in its fabrication. The apparatus consists of a stack of graphite surrounded by cadmium, in which a thermal neutron density is maintained by a Ra-Be source placed in the stack. The fuel element to be controlled is placed in the stack at 16 cm from the cadmium wall and at 70 cm from the source. The fast neutrons produced in this fuel element are slowed down and detected by a BF{sub 3} counter placed in a second graphite stack adjacent to the first. The enrichment is obtained by comparing the counting rate measured with the element to be controlled, with that of a geometrically similar standard element, previously calibrated. (author) [French] On decrit un dispositif permettant de controler l'enrichissement de l'uranium contenu dans un element de combustible a tous les stades de sa fabrication. Le dispositif est constitue par un empilement de graphite entoure de cadnium dans lequel regne une densite de neutrons thermiques entretenus par une source de Ra-Be placee dans l'empilement. L'element de combustible a contr er est place dans cet empilement a 16 cm de la paroi de cadmium et a 70 cm de la source. Les neutrons rapides produits dans cet element de combustible sont ralentis et detectes par un compteur a BF{sub 3} place dans un deuxieme empilement de graphite contigu au premier. L'enrichissement est obtenu en comparant les taux de comptage mesures arec l'element a controler et un element standard geometriquement semblable, prealablement etalonne. (auteur)

  3. Uranium enrichment. Enrichment processes

    International Nuclear Information System (INIS)

    Alexandre, M.; Quaegebeur, J.P.

    2009-01-01

    Despite the remarkable progresses made in the diversity and the efficiency of the different uranium enrichment processes, only two industrial processes remain today which satisfy all of enriched uranium needs: the gaseous diffusion and the centrifugation. This article describes both processes and some others still at the demonstration or at the laboratory stage of development: 1 - general considerations; 2 - gaseous diffusion: physical principles, implementation, utilisation in the world; 3 - centrifugation: principles, elementary separation factor, flows inside a centrifuge, modeling of separation efficiencies, mechanical design, types of industrial centrifuges, realisation of cascades, main characteristics of the centrifugation process; 4 - aerodynamic processes: vortex process, nozzle process; 5 - chemical exchange separation processes: Japanese ASAHI process, French CHEMEX process; 6 - laser-based processes: SILVA process, SILMO process; 7 - electromagnetic and ionic processes: mass spectrometer and calutron, ion cyclotron resonance, rotating plasmas; 8 - thermal diffusion; 9 - conclusion. (J.S.)

  4. Tritium enrichment by thermal diffusion. I. Calculation of an installation for measuring natural tritium; Enrichissement du tritium par diffusion thermique. - I. Calcul d'une installation destinee a la mesure du tritium naturel

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, M.; Ravoire, J. [Commissariat a l' Energie Atomique, Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)

    1966-07-01

    The natural content of tritium is so low that its measurement generally requires a preliminary enrichment. The thermal diffusion on hydrogen is studied as an enrichment method. The installation studied comprises two stages of columns of the hot-wire type, together with a device for transferring the tritium from the water sample into the hydrogen in the columns using catalytic exchange. A complete mathematical treatment for the operation of such a unit has been made and programmed for the IBM 7094 computer. An optimization has been effected by means of this program. It is shown that for similar performances, less hydrogen is retained in the case of hot-wire type columns than in the case of columns composed of concentric tubes. (authors) [French] La teneur naturelle du tritium est si faible que sa mesure demande generalement un enrichissement prealable. On etudie la diffusion thermique sur l'hydrogene comme moyen d'enrichissement. L'installation que l'on etudie comprend deux etages de colonnes du type fil chaud, et un dispositif de transfert du tritium de l'echantillon d'eau dans l'hydrogene des colonnes par echange catalytique. Un traitement mathematique complet du fonctionnement d'un tel ensemble a ete etabli et programme sur machine IBM 7094. Une optimisation a ete faite a l'aide du programme. On montre egalement qu'a performances egales, la retenue d'hydrogene est plus faible dans le cas des colonnes du type fil chaud que dans le cas des colonnes du type tubes concentriques. (auteurs)

  5. Tritium enrichment by thermal diffusion. I. Calculation of an installation for measuring natural tritium; Enrichissement du tritium par diffusion thermique. - I. Calcul d'une installation destinee a la mesure du tritium naturel

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, M; Ravoire, J [Commissariat a l' Energie Atomique, Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)

    1966-07-01

    The natural content of tritium is so low that its measurement generally requires a preliminary enrichment. The thermal diffusion on hydrogen is studied as an enrichment method. The installation studied comprises two stages of columns of the hot-wire type, together with a device for transferring the tritium from the water sample into the hydrogen in the columns using catalytic exchange. A complete mathematical treatment for the operation of such a unit has been made and programmed for the IBM 7094 computer. An optimization has been effected by means of this program. It is shown that for similar performances, less hydrogen is retained in the case of hot-wire type columns than in the case of columns composed of concentric tubes. (authors) [French] La teneur naturelle du tritium est si faible que sa mesure demande generalement un enrichissement prealable. On etudie la diffusion thermique sur l'hydrogene comme moyen d'enrichissement. L'installation que l'on etudie comprend deux etages de colonnes du type fil chaud, et un dispositif de transfert du tritium de l'echantillon d'eau dans l'hydrogene des colonnes par echange catalytique. Un traitement mathematique complet du fonctionnement d'un tel ensemble a ete etabli et programme sur machine IBM 7094. Une optimisation a ete faite a l'aide du programme. On montre egalement qu'a performances egales, la retenue d'hydrogene est plus faible dans le cas des colonnes du type fil chaud que dans le cas des colonnes du type tubes concentriques. (auteurs)

  6. Enrichments in authigenic uranium in glacial sediments of the Southern Ocean; Enrichissement en uranium authigene dans les sediments glaciaires de l'ocean Austral

    Energy Technology Data Exchange (ETDEWEB)

    Dezileau, L. [Universidad de Conception, Programa Regional de Oceanografia Fisica y Climat PROFC, Y Centro de Investigacion Oceanografica (Chile); Bareille, G. [Pau Univ., Lab. de Chimie Analytique Bio-Inorganique et Environnement, EP-CNRS 132, 64 (France); Reyss, J.L. [CEA Saclay, Direction des Sciences de la Matiere, Lab. des Sciences du Climat et de L' environnement, Lab. Mixte CEA-CNRS, 91 - Gif-sur-Yvette (France)

    2002-11-01

    Four sediment cores from the Polar frontal zone and the Antarctic zone in the Indian sector of the Southern Ocean present an increase of authigenic uranium during glacial periods. We show that this increase in uranium is due to a combination of (i) an increase in the lateral transport of organic matter, (ii) a decrease in the oxygen in deep waters, and (iii) a process of diagenesis. It appears that uranium concentration cannot be used as a proxy of paleo-productivity in the Southern Ocean, as previously suggested by Kumar et al. in 1995. (authors)

  7. Advanced uranium enrichment processes

    International Nuclear Information System (INIS)

    Clerc, M.; Plurien, P.

    1986-01-01

    Three advanced Uranium enrichment processes are dealt with in the report: AVLIS (Atomic Vapour LASER Isotope Separation), MLIS (Molecular LASER Isotope Separation) and PSP (Plasma Separation Process). The description of the physical and technical features of the processes constitutes a major part of the report. If further presents comparisons with existing industrially used enrichment technologies, gives information on actual development programmes and budgets and ends with a chapter on perspectives and conclusions. An extensive bibliography of the relevant open literature is added to the different subjects discussed. The report was drawn up by the nuclear research Centre (CEA) Saclay on behalf of the Commission of the European Communities

  8. Progress towards phosphorus-33 production: studies on the enrichment of sulphur-33 by means of anion exchangers; Mise au point d'une methode de production du phosphore-33: etudes sur l'enrichissement du soufre-33 au moyen d'echangeurs anioniques; Uspekhi v poluchenii fosfora-33: izuchenie obogashcheniya sery-33 pri pomoshchi anionnykh obmennikov; Progresos on la produccion de fosforo-33: estudios realizados sobre el enriquecimiento del azufre-33 por medio de intercambiadores anionicos

    Energy Technology Data Exchange (ETDEWEB)

    Forberg, S; Westermark, T [Division of Physical Chemistry, Kungl. Tekniska Hogskolan, Stockholm 70 (Sweden)

    1962-01-15

    Enrichment of S{sup 33} by chemical exchange between HSO{sub 3}{sup -} and H{sub 2}SO{sub 3} was selected as the most promising means for P{sup 33} production. HCl displacement of HSO{sub 3}{sup -} from anion exchangers was found to be a convenient method for obtaining counter-current and bulk reflux conditions for this system. Some inherent drawbacks concerning the very high reflux requirements are pointed out. In this institute a plant has been constructed for this process, and the obtained parameters, operation experiences and results are presented. Due to a 'tail' formation of H{sub 2}SO{sub 3} in the displacing HCl, a considerably smaller enrichment than had been calculated from laboratory runs was obtained. Investigations on this problem have been carried out, and a possible way out seems to be the introduction of organic solvents instead of aqueous solutions. (author) [French] L'enrichissement du {sup 33}S par echange chimique entre HSO{sub 3}{sup -} et H{sub 2}SO{sub 3} a ete choisi comme etant le moyen le plus interessant de produire du {sup 33}P. On a constate que l'elution par le HCl du HSO{sub 3}{sup -} fixe par les echangeurs anioniques constituait une methode tres pratique pour realiser les contre-courants et reflux necessaires a cet enrichissement. Les auteurs indiquent quelques inconvenients inherents a la necessite d'obtenir des reflux tres intenses. Une installation speciale a ete construite a l'institut pour realiser ce processus; les auteurs indiquent les parametres observes, les experiences effectuees et les resultats obtenus. Par suite d'une formation de H{sub 2}SO{sub 3} residuairo dans l'eluant HCl, l'enrichissement obtenu etait beaucoup plus faible qu'on ne l'avait calcule d'apres les essais en laboratoire. Les auteurs ont fait des recherches sur ce probleme; il semble possible de remedier a la difficulte en remplacant les solutions aqueuses par des solvants organiques. (author) [Spanish] Los autores han optado por el enriquecimiento del

  9. Enrichment: centrifuge process

    International Nuclear Information System (INIS)

    Soubbaramayer.

    1989-01-01

    This short course is divided into three sections devoted respectively to the physics of the process, some practical problems raised by the design of a centrifuge and the present situation of centrifugation in the World. 31 figs., 18 refs

  10. Advances in uranium enrichment processes

    International Nuclear Information System (INIS)

    Rae, H.K.; Melvin, J.G.; Slater, J.B.

    1986-05-01

    Advances in gas centrifuges and development of the atomic vapour laser isotope separation process promise substantial reductions in the cost of enriched uranium. The resulting reduction in LWR fuel costs could seriously erode the economic advantage of CANDU, and in combination with LWR design improvements, shortened construction times and increased operational reliability could allow the LWR to overtake CANDU. CANDU's traditional advantages of neutron economy and high reliability may no longer be sufficient - this is the challenge. The responses include: combining neutron economy and dollar economy by optimizing CANDU for slightly enriched uranium fuel; developing cost-reducing improvements in design, manufacture and construction; and reducing the cost of heavy water. Technology is a renewable resource which must be continually applied to a product for it to remain competitive in the decades to come. Such innovation is a prerequisite to Canada increasing her share of the international market for nuclear power stations. The higher burn-up achievable with enriched fuel in CANDU can reduce the fuel cycle costs by 20 to 40 percent for a likely range of costs for yellowcake and separative work. Alternatively, some of the benefits of a higher fissile content can take the form of a cheaper reactor core containing fewer fuel channels and less heavy water, and needing only a single fuelling machine. An opportunity that is linked to this need to introduce an enriched uranium fuel cycle into CANDU is to build an enrichment business in Canada. This could offer greater value added to our uranium exports, security of supply for enriched CANDUs, technological growth in Canada and new employment opportunities. AECL has a study in progress to define this opportunity

  11. Process for recovering water enriched with deuterium

    International Nuclear Information System (INIS)

    Mandel, H.

    1975-01-01

    By the process proposed herewith, enrichment of deuterium in water by cooling water recirculation through series-connection of several cooling ciruits in the form of columns is obtained. With this method, conventional, open-type cooling towers without special installations can be applied, which is an important advantage as compared with a formerly proposed single-stage process with specially designed, complicated cooling towers. Series-connection of the cooling towers is carried out in such a way that the circulating water of a certain cooling circuit, which has a corresponding output value of deuterium enrichment, is conveyed to a succeeding circuit where further enrichment is achieved. The water enriched with deuterium is removed from the last cooling circuit of the series while an amount of fresch water equivalent to the water removed or evaporated altogether is fed to the first circuit of the series. (RB) [de

  12. Enriching the Web Processing Service

    Science.gov (United States)

    Wosniok, Christoph; Bensmann, Felix; Wössner, Roman; Kohlus, Jörn; Roosmann, Rainer; Heidmann, Carsten; Lehfeldt, Rainer

    2014-05-01

    The OGC Web Processing Service (WPS) provides a standard for implementing geospatial processes in service-oriented networks. In its current version 1.0.0 it allocates the operations GetCapabilities, DescribeProcess and Execute, which can be used to offer custom processes based on single or multiple sub-processes. A large range of ready to use fine granular, fundamental geospatial processes have been developed by the GIS-community in the past. However, modern use cases or whole workflow processes demand specifications of lifecycle management and service orchestration. Orchestrating smaller sub-processes is a task towards interoperability; a comprehensive documentation by using appropriate metadata is also required. Though different approaches were tested in the past, developing complex WPS applications still requires programming skills, knowledge about software libraries in use and a lot of effort for integration. Our toolset RichWPS aims at providing a better overall experience by setting up two major components. The RichWPS ModelBuilder enables the graphics-aided design of workflow processes based on existing local and distributed processes and geospatial services. Once tested by the RichWPS Server, a composition can be deployed for production use on the RichWPS Server. The ModelBuilder obtains necessary processes and services from a directory service, the RichWPS semantic proxy. It manages the lifecycle and is able to visualize results and debugging-information. One aim will be to generate reproducible results; the workflow should be documented by metadata that can be integrated in Spatial Data Infrastructures. The RichWPS Server provides a set of interfaces to the ModelBuilder for, among others, testing composed workflow sequences, estimating their performance and to publish them as common processes. Therefore the server is oriented towards the upcoming WPS 2.0 standard and its ability to transactionally deploy and undeploy processes making use of a WPS

  13. Novel Membranes and Processes for Oxygen Enrichment

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Haiqing

    2011-11-15

    The overall goal of this project is to develop a membrane process that produces air containing 25-35% oxygen, at a cost of $25-40/ton of equivalent pure oxygen (EPO2). Oxygen-enriched air at such a low cost will allow existing air-fueled furnaces to be converted economically to oxygen-enriched furnaces, which in turn will improve the economic and energy efficiency of combustion processes significantly, and reduce the cost of CO{sub 2} capture and sequestration from flue gases throughout the U.S. manufacturing industries. During the 12-month Concept Definition project: We identified a series of perfluoropolymers (PFPs) with promising oxygen/nitrogen separation properties, which were successfully made into thin film composite membranes. The membranes showed oxygen permeance as high as 1,200 gpu and oxygen/nitrogen selectivity of 3.0, and the permeance and selectivity were stable over the time period tested (60 days). We successfully scaled up the production of high-flux PFP-based membranes, using MTR's commercial coaters. Two bench-scale spiral-wound modules with countercurrent designs were made and parametric tests were performed to understand the effect of feed flow rate and pressure, permeate pressure and sweep flow rate on the membrane module separation properties. At various operating conditions that modeled potential industrial operating conditions, the module separation properties were similar to the pure-gas separation properties in the membrane stamps. We also identified and synthesized new polymers [including polymers of intrinsic microporosity (PIMs) and polyimides] with higher oxygen/nitrogen selectivity (3.5-5.0) than the PFPs, and made these polymers into thin film composite membranes. However, these membranes were susceptible to severe aging; pure-gas permeance decreased nearly six-fold within two weeks, making them impractical for industrial applications of oxygen enrichment. We tested the effect of oxygen-enriched air on NO{sub x} emissions

  14. Developments on uranium enrichment processes in France

    International Nuclear Information System (INIS)

    Frejacques, C.; Gelee, M.; Massignon, D.; Plurien, P.

    1977-01-01

    Gaseous diffusion has so far been the main source of supply for enriched uranium and it is only recently that the gas centrifuge came into the picture. Numerous other isotope separation processes have been considered or are being assessed, and there is nothing to exclude the future use of a new process. Developments on likely new processes have been carried out by many organizations both governmental and private. The French Commissariat a l'energie atomique, besides their very extensive endeavours already devoted to gaseous diffusion, have studied and developed the gas centrifuge, chemical exchange, aerodynamic and selective photoexcitation processes. The gaseous diffusion process, selected by Eurodif for the Tricastin plant, and which will also be used by Coredif, is discussed in another paper in these Proceedings. This process is the technico-economic yardstick on which our comparisons are based. Within the limits of their development level, processes are compared on the basis of the separative work cost components: specific investment, specific power consumption and power cost, and specific operating and maintenance costs. (author)

  15. Uranium enrichment by the gaseous diffusion process

    International Nuclear Information System (INIS)

    Petit, J.F.

    1977-01-01

    After a brief description of the process and technology (principle, stage constitution, cascade constitution, and description of a plant), the author gives the history of gaseous diffusion and describes the existing facilities. Among the different enrichment processes contemplated in the USA during and after the last world war, gaseous diffusion has been the only one to be developed industrially on a wide scale in the USA, then in the UK, in the USSR and in France. The large existing capacities in the USA provided the country with a good starting base for the development of a light-water nuclear power plant programme, the success of which led to a shortfall in production means. France and the USA, possessing the necessary know-how, have been able to undertake the realization of two industrial programmes: the CIP-CUP programme in the USA and the Eurodif project in France. Current plans still call for the construction of several plants by 1990. Can the gaseous diffusion process meet this challenge. Technically, there is no doubt about it. Economically, this process is mainly characterized by large energy consumption and the necessity to build large plants. This leads to a large investment, at least for the first plant. Other processes have been developed with a view to reducing both energy and capital needs. However, in spite of continuous studies and technological progress, no process has yet proved competitive. Large increments in capacities are still expected to come from gaseous diffusion, and several projects taking into account the improvements in flexibility, automatization, reliability and reduced investment, are analysed in the paper. Combining new facilities with existing plants has already proved to be of great interest. This situation explains why gaseous diffusion is being further investigated and new processes are being studied. (author)

  16. Aerodynamic isotope separation processes for uranium enrichment: process requirements

    International Nuclear Information System (INIS)

    Malling, G.F.; Von Halle, E.

    1976-01-01

    The pressing need for enriched uranium to fuel nuclear power reactors, requiring that as many as ten large uranium isotope separation plants be built during the next twenty years, has inspired an increase of interest in isotope separation processes for uranium enrichment. Aerodynamic isotope separation processes have been prominently mentioned along with the gas centrifuge process and the laser isotope separation methods as alternatives to the gaseous diffusion process, currently in use, for these future plants. Commonly included in the category of aerodynamic isotope separation processes are: (a) the separation nozzle process; (b) opposed gas jets; (c) the gas vortex; (d) the separation probes; (e) interacting molecular beams; (f) jet penetration processes; and (g) time of flight separation processes. A number of these aerodynamic isotope separation processes depend, as does the gas centrifuge process, on pressure diffusion associated with curved streamlines for the basic separation effect. Much can be deduced about the process characteristics and the economic potential of such processes from a simple and elementary process model. In particular, the benefit to be gained from a light carrier gas added to the uranium feed is clearly demonstrated. The model also illustrates the importance of transient effects in this class of processes

  17. Factors that predict consumer acceptance of enriched processed meats

    OpenAIRE

    Shan, Liran Christine; Henchion, Maeve; De Brún, Aoife; Murrin, Celine; Wall, Patrick G.; Monahan, Frank J.

    2017-01-01

    The study aimed to understand predictors of consumers' purchase intention towards processed meat based functional foods (i.e. enriched processed meat). A cross-sectional survey was conducted with 486 processed meat consumers in spring 2016. Results showed that processed meats were perceived differently in healthiness, with sausage-type products perceived less healthy than cured meat products. Consumers were in general more uncertain than positive about enriched processed meat but differences ...

  18. Device and method to enrich and process heavy water

    International Nuclear Information System (INIS)

    Hammerli, M.M.; Butler, J.P.

    1979-01-01

    A device to process and enrich heavy water is proposed which is based on a combined electrolysis catalyst exchange system in which a D 2 O enrichment of more than 99.8% is achieved in the end stage. Water partly enriched with D 2 -containing hydrogen gas from an electrolysis cell is brought into contact in a catalyst column. The water is further enriched here with deuterium. It is then fed to the electrolysis cell. Details of the apparatus are closely described. (UWI) [de

  19. The uranium enrichment industry and the SILEX process

    International Nuclear Information System (INIS)

    Goldsworthy, M.

    1999-01-01

    Silex Systems Limited has been developing a new laser isotope separation process since 1992. The principle application of the SILEX Technology is Uranium Enrichment, the key step in the production of fuel for nuclear power plants. The Uranium Enrichment industry, today worth ∼ US$3.5 Billion p.a., is dominated by four major players, the largest being USEC with almost 40% of the market. In 1996, an agreement was signed between Silex and USEC to develop SILEX Technology for potential application to Uranium Enrichment. The SILEX process is a low cost, energy efficient scheme which may provide significant commercial advantage over current technology and competing laser processes. Silex is also investigating possible application to the enrichment of Silicon, Carbon and other materials. Significant markets may develop for such materials, particularly in the semiconductor industry

  20. Minimally processed fruit salad enriched with Lactobacillus ...

    African Journals Online (AJOL)

    Minimal processing promotes browning of some vegetal tissues due to cell membrane disruption, which results in the release of oxidative enzymes. This study evaluated the efficiency of citric acid, ascorbic acid, sodium metabisulfite and L-cysteine hydrochloride to retard enzymatic browning of minimally processed fruit ...

  1. Root cause analysis with enriched process logs

    NARCIS (Netherlands)

    Suriadi, S.; Ouyang, C.; Aalst, van der W.M.P.; Hofstede, ter A.H.M.; La Rosa, M.; Soffer, P.

    2013-01-01

    n the field of process mining, the use of event logs for the purpose of root cause analysis is increasingly studied. In such an analysis, the availability of attributes/features that may explain the root cause of some phenomena is crucial. Currently, the process of obtaining these attributes from

  2. Minimally processed fruit salad enriched with Lactobacillus ...

    African Journals Online (AJOL)

    paula

    2015-06-17

    Jun 17, 2015 ... Minimal processing promotes browning of some vegetal tissues due to cell membrane disruption, which results in the release of oxidative enzymes. This study evaluated the efficiency of citric acid, ascorbic acid, sodium metabisulfite and L-cysteine hydrochloride to retard enzymatic browning of minimally.

  3. Logic-programming language enriches design processes

    Energy Technology Data Exchange (ETDEWEB)

    Kitson, B.; Ow-Wing, K.

    1984-03-22

    With the emergence of a set of high-level CAD tools for programmable logic devices, designers can translate logic into functional custom devices simply and efficiently. The core of the package is a blockstructured hardware description language called PLPL, for ''programmable-logic programming language.'' The cheif advantage of PLPL lies in its multiple input formats, which permit different design approaches for a variety of design problems. The higher the level of the approach, the closer PLPL will come to directly specifying the desired function. Intermediate steps in the design process can be eliminated, along with the errors that might have been generated during those steps.

  4. Factors that predict consumer acceptance of enriched processed meats.

    Science.gov (United States)

    Shan, Liran C; Henchion, Maeve; De Brún, Aoife; Murrin, Celine; Wall, Patrick G; Monahan, Frank J

    2017-11-01

    The study aimed to understand predictors of consumers' purchase intention towards processed meat based functional foods (i.e. enriched processed meat). A cross-sectional survey was conducted with 486 processed meat consumers in spring 2016. Results showed that processed meats were perceived differently in healthiness, with sausage-type products perceived less healthy than cured meat products. Consumers were in general more uncertain than positive about enriched processed meat but differences existed in terms of the attitudes and purchase intention. Following regression analysis, consumers' purchase intention towards enriched processed meat was primarily driven by their attitudes towards the product concept. Perceived healthiness of existing products and eating frequency of processed meat were also positively associated with the purchase intention. Other factors such as general food choice motives, socio-demographic characteristics, consumer health and the consumption of functional foods and dietary supplements in general, were not significant predictors of the purchase intention for enriched processed meat. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. The jet nozzle process for uranium 235 isotopic enrichment

    International Nuclear Information System (INIS)

    Jordan, I.; Umeda, K.; Brown, A.E.P.

    1979-01-01

    A general survey of the isotopic enrichment of Uranium - 235, principally by jet nozzle process, is made. Theoretical treatment of a single stage and cascade of separation stages of the above process with its development in Germany until 1976 is presented [pt

  6. The ``SILVA`` program; Le cycle du combustible (evolution des techniques d`enrichissement isotopique)

    Energy Technology Data Exchange (ETDEWEB)

    Jacob, M.

    1996-12-31

    The ``SILVA`` process (Uranium Atomic Vapor Laser Isotopic Separation) is an innovating system of enriched uranium (electronuclear reactors fuel) production. Its great interest comes from its selectivity. The aim is to divide by a factor of three the costs of production compared with those of the current plants. The stakes of this research program, its principle, the main research axis, the material means and the future prospects beyond 1997 are given as well as its technical advancement state. (O.M.).

  7. Numerical modelling of the jet nozzle enrichment process

    International Nuclear Information System (INIS)

    Vercelli, P.

    1983-01-01

    A numerical model was developed for the simulation of the isotopic enrichment produced by the jet nozzle process. The flow was considered stationary and under ideal gas conditions. The model calculates, for any position of the skimmer piece: (a) values of radial mass concentration profiles for each isotopic species and (b) values of elementary separation effect (Σ sub(A)) and uranium cut (theta). The comparison of the numerical results obtained with the experimental values given in the literature proves the validity of the present work as an initial step in the modelling of the process. (Author) [pt

  8. Uranium enrichment in Europe by the gas centrifuge process

    International Nuclear Information System (INIS)

    Severin, D.J.E.

    1975-01-01

    To begin with, this lesson gives an outline of the expected energy demand of the Western World and the concentration of the European companies participating in uranium enrichment by the gas centrifuge method. Next, a) the principles of the gas centrifuge method are outlined, b) its advantages over other industrial processes are stressed, and c) the characteristic data of complete plants are given. The existing German, Dutch, and British pilot plants are mentioned as examples for the perfected state of the process. The Capenhurst (UK) and Almedo (NL) demonstration plants, each with a capacity of 200 t SW/a, will have been extended to 2 x 1.000 t SW/a by 1982. Finally, economic data of the gas centrifuge process are given. The term 'separative work' is explained in an annex. (GG) [de

  9. Remote Handling Devices for Disposition of Enriched Uranium Reactor Fuel Using Melt-Dilute Process

    International Nuclear Information System (INIS)

    Heckendorn, F.M.

    2001-01-01

    Remote handling equipment is required to achieve the processing of highly radioactive, post reactor, fuel for the melt-dilute process, which will convert high enrichment uranium fuel elements into lower enrichment forms for subsequent disposal. The melt-dilute process combines highly radioactive enriched uranium fuel elements with deleted uranium and aluminum for inductive melting and inductive stirring steps that produce a stable aluminum/uranium ingot of low enrichment

  10. ON THE r -PROCESS ENRICHMENT OF DWARF SPHEROIDAL GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Bramante, Joseph [Department of Physics, 225 Nieuwland Science Hall, University of Notre Dame, Notre Dame, IN 46556 (United States); Linden, Tim [Center for Cosmology and AstroParticle Physics (CCAPP) and Department of Physics The Ohio State University, Columbus OH, 43210 (United States)

    2016-07-20

    Recent observations of Reticulum II have uncovered an overabundance of r -process elements compared to similar ultra-faint dwarf spheroidal galaxies (UFDs). Because the metallicity and star formation history of Reticulum II appear consistent with all known UFDs, the high r -process abundance of Reticulum II suggests enrichment through a single, rare event, such as a double neutron star (NS) merger. However, we note that this scenario is extremely unlikely, as binary stellar evolution models require significant supernova natal kicks to produce NS–NS or NS–black hole (BH) mergers, and these kicks would efficiently remove compact binary systems from the weak gravitational potentials of UFDs. We examine alternative mechanisms for the production of r -process elements in UFDs, including a novel mechanism wherein NSs in regions of high dark matter (DM) density implode after accumulating a BH-forming mass of DM. We find that r -process proto-material ejection by tidal forces, when a single NS implodes into a BH, can occur at a rate matching the r -process abundance of both Reticulum II and the Milky Way. Remarkably, DM models which collapse a single NS in observed UFDs also solve the missing pulsar problem in the Milky Way Galactic Center. We propose tests specific to DM r -process production which may uncover or rule out this model.

  11. Enrichment and purification process of astragalosides and their anti ...

    African Journals Online (AJOL)

    2014-03-01

    Mar 1, 2014 ... water until there was no smell of ethanol and set aside. Enrichment and .... Detection of the effect of astragelosides on cell proliferation by. MTT assay6-7 ... relatively large leakage starting from 10 BV; mass con- centration of ...

  12. A design pattern for event-based processing of security-enriched SOAP messages

    DEFF Research Database (Denmark)

    Gruschka, Nils; Jensen, Meiko; Lo Iacono, Luigi

    2010-01-01

    For Web Services in Cloud Computing contexts, the efficient processing of XML documents is a major topic of interest. Especially for WS-Security-enriched messages, processing performance nowadays tends to become a major issue. Streaming XML processing approaches lead to valuable optimization due ...

  13. Krypton-85 enrichment by adsorption-desorption process

    International Nuclear Information System (INIS)

    Khan, A.A.; Deshingkar, D.S.; Ramarathinam, K.

    1975-01-01

    The use of activated charcoal columns in conjunction with cryogenic distillation system for concentration of krypton-85 in fuel reprocessing process off-gas stream is reported. Dynamic adsorption of krypton on activated charcoals and its subsequent desorption by applying vacuum were studied. The possible reduction in the quantity of carrier gas to be liquified in the cryogenic system by utilising this process has been discussed on the basis of results of laboratory evaluations. The possibility of elimination of air and oxygen to avoid explosion hazards associated with radiolytic formation and concentration of ozone has also been considered. (author)

  14. Specificity in the licensing process of reduced enrichment in the Bulgarian research reactor

    International Nuclear Information System (INIS)

    Vitkova, Marietta; Gorinov, Ivan

    2005-01-01

    The presented paper considers some specific questions of the licensing process regarding the reconstruction of the Bulgarian IRT-2000 research reactor, which includes conversion to the low enriched fuel. This specificity has risen as a result of two facts. The design of the reactor reconstruction was made on the basis of the existing fresh 36% highly enriched fuel. But after finishing of the design process, this fresh highly enriched fuel was shipped back to Russia in the framework of the RERTR program. These facts have involved some changes in both - in the licensing and the design processes. Re-analysis of the neutronic and thermal-hydraulic calculations is required to be made on the base of the technical specifications of the new LEU fuel. To facilitate the licensing process the NRA has adopted regulatory acceptance criteria for approval of the reactor core design with LEU fuel. (author)

  15. Magnetic separation as a plutonium residue enrichment process

    International Nuclear Information System (INIS)

    Avens, L.R.; Gallegos, U.F.; McFarlan, J.T.

    1990-01-01

    Several plutonium contaminated residues have been subjected to Open Gradient Magnetic Separation (OGMS) on an experimental scale. OGMS experiments on graphite and bomb reduction residues resulted in a plutonium rich fraction and a plutonium lean fraction. Values for the bulk quantity rejected to the lean fraction varied between about 20% to 85% of the feed bulk. The plutonium content of the lean fraction can be reduced from about 2% in the feed to the 0.1% to 0.5% range dependent on the portion of the feed rejected to this lean fraction. These values are low enough in plutonium to meet economic discard limits and be considered for direct discard. Magnetic separation of pyrochemical salts gave less favorable results. While a fraction very rich in plutonium could be obtained, the lean fraction plutonium content was too high for direct discard. This may still have chemical processing applications. OGMS experiments at low magnetic field strength on incinerator ash did give two fractions but the plutonium content of each fraction was essentially identical. Thus, no chemical processing advantage was identified for magnetic separation of this residue. 6 refs., 1 fig., 9 tabs

  16. The separation nozzle process for uranium isotope enrichment

    International Nuclear Information System (INIS)

    Becker, E.W.

    1977-01-01

    In the separation nozzle 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 ration 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 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 were developed. However, promising results were 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 Center of Karlsruhe. Since 1970 the German company STEAG 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

  17. Huanglongbing impairs the rhizosphere-to-rhizoplane enrichment process of the citrus root-associated microbiome.

    Science.gov (United States)

    Zhang, Yunzeng; Xu, Jin; Riera, Nadia; Jin, Tao; Li, Jinyun; Wang, Nian

    2017-08-10

    Roots are the primary site for plant-microbe interactions. Among the three root-associated layers (i.e., rhizosphere, rhizoplane, and endorhiza), the rhizoplane is a key component serving a critical gating role that controls microbial entry into plant roots. The microbial communities colonizing the three layers are believed to be gradually enriched from the bulk soil inoculum. However, it is unknown how this enrichment process, particularly the rhizosphere to rhizoplane step, is affected by biotic stresses, such as disease. In this study, we address this question using the citrus root-associated microbiome as a model. We identified the rhizosphere-to-rhizoplane-enriched taxonomic and functional properties of the citrus root-associated microbiome and determined how they were affected by Huanglongbing (HLB), a severe systemic disease caused by Candidatus Liberibacter asiaticus, using metagenomic and metatranscriptomic approaches. Multiple rhizoplane-enriched genera were identified, with Bradyrhizobium and Burkholderia being the most dominant. Plant-derived carbon sources are an important driving force for the enrichment process. The enrichment of functional attributes, such as motility, chemotaxis, secretion systems, and lipopolysaccharide (LPS) synthesis, demonstrated more active microbe-plant interactions on the rhizoplane than the rhizosphere. We observed that HLB impaired the rhizosphere-to-rhizoplane enrichment process of the citrus root-associated microbiome in three ways: (1) by decreasing the relative abundance of most rhizoplane-enriched genera; (2) by reducing the relative abundance and/or expression activity of the functional attributes involved in microbe-plant interactions; and (3) by recruiting more functional features involved in autotrophic life cycle adaptation, such as carbon fixation and nitrogen nitrification in the HLB rhizoplane microbiome. Finally, our data showed that inoculation of Burkholderia strains isolated from the healthy citrus root

  18. Uranium enrichment measurement by X- and γ-ray spectrometry with the 'URADOS' process

    International Nuclear Information System (INIS)

    Morel, Jean; Etcheverry, Michel; Riazuelo, Gilles

    1998-01-01

    The methods used for the uranium enrichment measurement require in general prior instrument calibration with several standards. Thus, it is possible to avoid the constraints involved in calibration by considering the complex spectral region called XK α . This spectral region is sufficiently limited so that the variation of the detector efficiency response is small enough to facilitate a self-calibration. Processing this region is critical and requires taking into account 3 elemental images, one corresponding to 235 U, one to 238 U and one to the X-ray fluorescence induced in the sample by radiation above 100 keV. A process called 'URADOS' based on this principle has been developed. Six uranium oxide standards with different enrichments and infinite thicknesses were counted several times to test this process; other samples, some highly enriched, were also used. The results obtained are compared to the declared values. From these measurements, it has been possible to improve the photon emission probability values

  19. Enriched uranium processing with 7-1/2% TBP

    International Nuclear Information System (INIS)

    Orth, D.A.; Martin, W.H.; Pickett, C.E.

    1983-01-01

    The 7-1/2% TBP flowsheet gives adequate recovery of uranium and neptunium or plutonium, with reduced waste volume as compared to the prior aluminum-salted 3-1/2% TBP flowsheet. Decontamination from fission products is sensitive to numerous variables, including aluminum nitrate concentration in the feed, impeller speeds, and prior treatment of the fuel solution in head end operations. The impeller speed in the 1A bank also influences uranium losses as well as the fission product decontamination. The magnitudes of these effects suggest that stage efficiency is poor with this flowsheet in this mixer settler unit. The existing continuous solvent washers give evidence of low washing efficiency that limits permissible feed activity and that may be related to low contact time between the solvent and the carbonate wash solution. The most general conclusion is that satisfactory operation can be obtained with all projected domestic and foreign fuels under consideration for processing, by suitable adjustment of operating conditions. Also, possible flowsheet and equipment changes are known that could improve operations with these fuels further. 7 references

  20. Measurement system analysis (MSA) of the isotopic ratio for uranium isotope enrichment process control

    Energy Technology Data Exchange (ETDEWEB)

    Medeiros, Josue C. de; Barbosa, Rodrigo A.; Carnaval, Joao Paulo R., E-mail: josue@inb.gov.br, E-mail: rodrigobarbosa@inb.gov.br, E-mail: joaocarnaval@inb.gov.br [Industrias Nucleares do Brasil (INB), Rezende, RJ (Brazil)

    2013-07-01

    Currently, one of the stages in nuclear fuel cycle development is the process of uranium isotope enrichment, which will provide the amount of low enriched uranium for the nuclear fuel production to supply 100% Angra 1 and 20% Angra 2 demands. Determination of isotopic ration n({sup 235}U)/n({sup 238}U) in uranium hexafluoride (UF{sub 6} - used as process gas) is essential in order to control of enrichment process of isotopic separation by gaseous centrifugation cascades. The uranium hexafluoride process is performed by gas continuous feeding in separation unit which uses the centrifuge force principle, establishing a density gradient in a gas containing components of different molecular weights. The elemental separation effect occurs in a single ultracentrifuge that results in a partial separation of the feed in two fractions: an enriched on (product) and another depleted (waste) in the desired isotope ({sup 235}UF{sub 6}). Industrias Nucleares do Brasil (INB) has used quadrupole mass spectrometry (QMS) by electron impact (EI) to perform isotopic ratio n({sup 235}U)/n({sup 238}U) analysis in the process. The decision of adjustments and change te input variables are based on the results presented in these analysis. A study of stability, bias and linearity determination has been performed in order to evaluate the applied method, variations and systematic errors in the measurement system. The software used to analyze the techniques above was the Minitab 15. (author)

  1. An ideal cascade for uranium 235 enrichment by centrifuge jet nozzle process

    International Nuclear Information System (INIS)

    Santos, E.C. dos.

    1981-01-01

    The design of an ideal cascade for the process of isotope separation by centrifugation for the U 235 enrichment, is presented. A selection of building materials used in fabrication of isotope separation plants, showing the importance of aluminium, due the bauxite mines in Northern Brazil, is done. (M.C.K.) [pt

  2. An isotope-enrichment unit and a process for isotope separation

    International Nuclear Information System (INIS)

    1981-01-01

    A process and equipment for isotope enrichment using gas-centrifuge cascades are described. The method is described as applied to the separation of uranium isotopes, using natural-abundance uranium hexafluoride as the gaseous-mixture feedstock. (U.K.)

  3. Formulation and synthesis by melting process of titanate enriched glass-ceramics and ceramics

    International Nuclear Information System (INIS)

    Advocat, T.; Fillet, C.; Lacombe, J.; Bonnetier, A.; McGlinn, P.

    1999-01-01

    The main objective of this work is to provide containment for the separated radionuclides in stable oxide phases with proven resistance to leaching and irradiation damage and in consequence to obtain a glass ceramic or a ceramic material using a vitrification process. Sphene glass ceramic, zirconolite glass ceramic and zirconolite enriched ceramic have been fabricated and characterized by XRD, SEM/EDX and DTA

  4. Process of advective diffusive enrichment using differential gradients and the effects of variations in relaxation times

    International Nuclear Information System (INIS)

    Suarez Antola R.; Bernasconi, G.; Bertolotti, Angel

    1995-01-01

    A multicomponent solution is considered in advective diffusion chambers between two half-permeable barriers. A mathematical model is developed to calculate the concentration fields in the chamber. A new enrichment process is proposed and assessed using a digital simulation of space-time dynamics, based on the analytical solution of the model

  5. Candidate processes for diluting the 235U isotope in weapons-capable highly enriched uranium

    International Nuclear Information System (INIS)

    Snider, J.D.

    1996-02-01

    The United States Department of Energy (DOE) is evaluating options for rendering its surplus inventories of highly enriched uranium (HEU) incapable of being used to produce nuclear weapons. Weapons-capable HEU was earlier produced by enriching uranium in the fissile 235 U isotope from its natural occurring 0.71 percent isotopic concentration to at least 20 percent isotopic concentration. Now, by diluting its concentration of the fissile 235 U isotope in a uranium blending process, the weapons capability of HEU can be eliminated in a manner that is reversible only through isotope enrichment, and therefore, highly resistant to proliferation. To the extent that can be economically and technically justified, the down-blended uranium product will be made suitable for use as commercial reactor fuel. Such down-blended uranium product can also be disposed of as waste if chemical or isotopic impurities preclude its use as reactor fuel

  6. The advanced CECE process for enriching tritium by the chemical exchange method with a hydrophobic catalyst

    International Nuclear Information System (INIS)

    Kitamoto, Asashi; Shimizu, Masami; Masui, Takashi.

    1992-01-01

    The monothermal chemical exchange process with electrolysis, i.e., CECE process, was an effective method for enriching and removing tritium from tritiated water with low to middle level activity. The purpose of this study is to propose the theoretical background of the two-parameter evaluation method, which is based on a two-step isotope exchange reaction between hydrogen gas and liquid water, for improvement of the performance of a hydrophobic catalyst by a trickle bed-type column. Finally, a two-parameter method could attain the highest performance of isotope separation and the lowest liquid holdup for a trickle bed-type column. Therefore, this method will present some effective and practical procedures in scaling up a tritium enrichment process. The main aspect of the CECE process in engineering design and system evaluation was to develop the isotope exchange column with a high performance catalyst. (author)

  7. Chemical processes for the extreme enrichment of tellurium into marine ferromanganese oxides

    Science.gov (United States)

    Kashiwabara, Teruhiko; Oishi, Yasuko; Sakaguchi, Aya; Sugiyama, Toshiki; Usui, Akira; Takahashi, Yoshio

    2014-04-01

    Tellurium, an element of growing economic importance, is extremely enriched in marine ferromanganese oxides. We investigated the mechanism of this enrichment using a combination of spectroscopic analysis and adsorption/coprecipitation experiments. X-ray Absorption Near-Edge Structure (XANES) analysis showed that in adsorption/coprecipitation systems, Te(IV) was oxidized on δ-MnO2 and not oxidized on ferrihydrite. Extended X-ray Absorption Fine Structure (EXAFS) analysis showed that both Te(IV) and Te(VI) were adsorbed on the surface of δ-MnO2 and ferrihydrite via formation of inner-sphere complexes. In addition, Te(VI) can be structurally incorporated into the linkage of Fe octahedra through a coprecipitation process because of its molecular geometry that is similar to the Fe octahedron. The largest distribution coefficient obtained in the adsorption/coprecipitation experiments was for the Te(VI)/ferrihydrite coprecipitation system, and it was comparable to those calculated from the distribution between natural ferromanganese oxides and seawater. Our XAFS and micro-focused X-ray fluorescence (μ-XRF) mapping of natural ferromanganese oxides showed that Te was structurally incorporated as Te(VI) in Fe (oxyhydr)oxide phases. We conclude that the main process for the enrichment of Te in ferromanganese oxides is structural incorporation of Te(VI) into Fe (oxyhydr)oxide phases through coprecipitation. This mechanism can explain the unique degree of enrichment of Te compared with other oxyanions, which are mainly enriched via adsorption on the surface of the solid structures. In particular, the great contrast in the distributions of Te and Se is caused by their oxidized species: (i) the similar geometry of the Te(VI) molecule to Fe octahedron, and (ii) quite soluble nature of Se(VI). Coexisting Mn oxide phases may promote structural incorporation of Te(VI) by oxidation of Te(IV), although the surface oxidation itself may not work as the critical enrichment process as

  8. Development of industrial-scale fission {sup 99}Mo production process using low enriched uranium target

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Kon; Lee, Jun Sig [Radioisotope Research Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Beyer, Gerd J. [Grunicke Strasse 15, Leipzig (Germany)

    2016-06-15

    Molybdenum-99 ({sup 99}Mo) is the most important isotope because its daughter isotope, technetium-99m ({sup 99}mTc), has been the most widely used medical radioisotope for more than 50 years, accounting for > 80% of total nuclear diagnostics worldwide. In this review, radiochemical routes for the production of {sup 99}Mo, and the aspects for selecting a suitable process strategy are discussed from the historical viewpoint of {sup 99}Mo technology developments. Most of the industrial-scale {sup 99}Mo processes have been based on the fission of {sup 235}U. Recently, important issues have been raised for the conversion of fission {sup 99}Mo targets from highly enriched uranium to low enriched uranium (LEU). The development of new LEU targets with higher density was requested to compensate for the loss of {sup 99}Mo yield, caused by a significant reduction of {sup 235}U enrichment, from the conversion. As the dramatic increment of intermediate level liquid waste is also expected from the conversion, an effective strategy to reduce the waste generation from the fission {sup 99}Mo production is required. The mitigation of radioxenon emission from medical radioisotope production facilities is discussed in relation with the monitoring of nuclear explosions and comprehensive nuclear test ban. Lastly, the {sup 99}Mo production process paired with the Korea Atomic Energy Research Institute's own LEU target is proposed as one of the most suitable processes for the LEU target.

  9. Enrichment of {sup 15}N and {sup 10}B isotopes by chemical exchange process

    Energy Technology Data Exchange (ETDEWEB)

    D` Souza, A B; Sonwalkar, A S; Subrahmanyam, B V; Valladares, B A [Chemical Engineering Division, Bhabha Atomic Research Centre, Mumbai (India)

    1994-06-01

    Many processes are available for separation of stable isotopes like distillation, chemical exchange, thermal diffusion, gaseous diffusion, centrifuge etc. Chemical exchange process is eminently suitable for separation of isotopes of light elements. Work done on separation and enrichment of two of the stable isotopes viz. {sup 15}N and {sup 10}B in Chemical Engineering Division is presented. {sup 15}N is widely used as a tracer in agricultural research and {sup 10}B is used in nuclear industry as control rod material, soluble reactor poison, neutron detector etc. The work on {sup 15}N isotope resulted in a pilot plant, which was the only source of this material in the country for many years and later it was translated into a production plant as M/s. RCF Ltd. The work done on the ion-exchange process for enrichment of {sup 10}B isotope which is basically a chemical exchange process, is now being updated into a pilot plant to produce enriched {sup 10}B to be used as soluble reactor poison. (author). 5 refs., 2 figs., 3 tabs.

  10. Enrichment of 15N and 10B isotopes by chemical exchange process

    International Nuclear Information System (INIS)

    D'Souza, A.B.; Sonwalkar, A.S.; Subrahmanyam, B.V.; Valladares, B.A.

    1994-01-01

    Many processes are available for separation of stable isotopes like distillation, chemical exchange, thermal diffusion, gaseous diffusion, centrifuge etc. Chemical exchange process is eminently suitable for separation of isotopes of light elements. Work done on separation and enrichment of two of the stable isotopes viz. 15 N and 10 B in Chemical Engineering Division is presented. 15 N is widely used as a tracer in agricultural research and 10 B is used in nuclear industry as control rod material, soluble reactor poison, neutron detector etc. The work on 15 N isotope resulted in a pilot plant, which was the only source of this material in the country for many years and later it was translated into a production plant as M/s. RCF Ltd. The work done on the ion-exchange process for enrichment of 10 B isotope which is basically a chemical exchange process, is now being updated into a pilot plant to produce enriched 10 B to be used as soluble reactor poison. (author)

  11. Development of Industrial-Scale Fission 99Mo Production Process Using Low Enriched Uranium Target

    Directory of Open Access Journals (Sweden)

    Seung-Kon Lee

    2016-06-01

    Full Text Available Molybdenum-99 (99Mo is the most important isotope because its daughter isotope, technetium-99m (99mTc, has been the most widely used medical radioisotope for more than 50 years, accounting for > 80% of total nuclear diagnostics worldwide. In this review, radiochemical routes for the production of 99Mo, and the aspects for selecting a suitable process strategy are discussed from the historical viewpoint of 99Mo technology developments. Most of the industrial-scale 99Mo processes have been based on the fission of 235U. Recently, important issues have been raised for the conversion of fission 99Mo targets from highly enriched uranium to low enriched uranium (LEU. The development of new LEU targets with higher density was requested to compensate for the loss of 99Mo yield, caused by a significant reduction of 235U enrichment, from the conversion. As the dramatic increment of intermediate level liquid waste is also expected from the conversion, an effective strategy to reduce the waste generation from the fission 99Mo production is required. The mitigation of radioxenon emission from medical radioisotope production facilities is discussed in relation with the monitoring of nuclear explosions and comprehensive nuclear test ban. Lastly, the 99Mo production process paired with the Korea Atomic Energy Research Institute's own LEU target is proposed as one of the most suitable processes for the LEU target.

  12. Olive oil enriched in lycopene from tomato by-product through a co-milling process.

    Science.gov (United States)

    Bendini, Alessandra; Di Lecce, Giuseppe; Valli, Enrico; Barbieri, Sara; Tesini, Federica; Toschi, Tullia Gallina

    2015-01-01

    The aim of this investigation was to produce an olive oil (OO) naturally enriched with antioxidants, recovering carotenoids, in particular lycopene, using an industrial by-product of tomato seeds and skin. For this purpose, a technological process in a low-scale industrial plant to co-mill olives and tomato by-product in de-frosted or freeze-dried forms was applied and studied with respect to control samples. Preliminary results obtained from two different experiments were carried out by 40 kg of cultivar Correggiolo olives and 60 kg of olive blends from different cultivars. In both the experiments, the co-milling showed significant enrichment in carotenoids, especially in lycopene (mean values of 5.4 and 7.2 mg/kg oil from defrosted and freeze-dried by-products, respectively). The experimental results demonstrated the possibility to obtain a new functional food naturally enriched in antioxidant compounds, which might be marketed as "OO dressing enriched in lycopene" or "condiment produced using olives and tomato by-product".

  13. Biomass of Spirulina maxima enriched by biosorption process as a new feed supplement for swine.

    Science.gov (United States)

    Saeid, A; Chojnacka, K; Korczyński, M; Korniewicz, D; Dobrzański, Z

    2013-04-01

    This paper deals with the new mineral feed additives with Cu produced in a biosorption process from a semi-technical scale. The natural biomass of edible microalga Spirulina sp. was enriched with Cu(II) and then used as a mineral supplement in feeding experiments on swine to assess its nutrition properties. A total of 24 piglets divided into two groups (control and experimental) were used to determine the bioavailability of a new generation of mineral feed additives based on Spirulina maxima . The control group was feed using traditional inorganic supplements of microelements, while the experimental group was fed with the feed containing the biomass of S. maxima enriched with Cu by biosorption. The apparent absorption was 30 % ( P  maxima -is a promising alternative to currently used inorganic salts as the source of nutritionally important microelements.

  14. R-process enrichment from a single event in an ancient dwarf galaxy.

    Science.gov (United States)

    Ji, Alexander P; Frebel, Anna; Chiti, Anirudh; Simon, Joshua D

    2016-03-31

    Elements heavier than zinc are synthesized through the rapid (r) and slow (s) neutron-capture processes. The main site of production of the r-process elements (such as europium) has been debated for nearly 60 years. Initial studies of trends in chemical abundances in old Milky Way halo stars suggested that these elements are produced continually, in sites such as core-collapse supernovae. But evidence from the local Universe favours the idea that r-process production occurs mainly during rare events, such as neutron star mergers. The appearance of a plateau of europium abundance in some dwarf spheroidal galaxies has been suggested as evidence for rare r-process enrichment in the early Universe, but only under the assumption that no gas accretes into those dwarf galaxies; gas accretion favours continual r-process enrichment in these systems. Furthermore, the universal r-process pattern has not been cleanly identified in dwarf spheroidals. The smaller, chemically simpler, and more ancient ultrafaint dwarf galaxies assembled shortly after the first stars formed, and are ideal systems with which to study nucleosynthesis events such as the r-process. Reticulum II is one such galaxy. The abundances of non-neutron-capture elements in this galaxy (and others like it) are similar to those in other old stars. Here, we report that seven of the nine brightest stars in Reticulum II, observed with high-resolution spectroscopy, show strong enhancements in heavy neutron-capture elements, with abundances that follow the universal r-process pattern beyond barium. The enhancement seen in this 'r-process galaxy' is two to three orders of magnitude higher than that detected in any other ultrafaint dwarf galaxy. This implies that a single, rare event produced the r-process material in Reticulum II. The r-process yield and event rate are incompatible with the source being ordinary core-collapse supernovae, but consistent with other possible sources, such as neutron star mergers.

  15. Using Process Load Cell Information for IAEA Safeguards at Enrichment Plants

    International Nuclear Information System (INIS)

    Laughter, Mark D.; Whitaker, J. Michael; Howell, John

    2010-01-01

    Uranium enrichment service providers are expanding existing enrichment plants and constructing new facilities to meet demands resulting from the shutdown of gaseous diffusion plants, the completion of the U.S.-Russia highly enriched uranium downblending program, and the projected global renaissance in nuclear power. The International Atomic Energy Agency (IAEA) conducts verification inspections at safeguarded facilities to provide assurance that signatory States comply with their treaty obligations to use nuclear materials only for peaceful purposes. Continuous, unattended monitoring of load cells in UF 6 feed/withdrawal stations can provide safeguards-relevant process information to make existing safeguards approaches more efficient and effective and enable novel safeguards concepts such as information-driven inspections. The IAEA has indicated that process load cell monitoring will play a central role in future safeguards approaches for large-scale gas centrifuge enrichment plants. This presentation will discuss previous work and future plans related to continuous load cell monitoring, including: (1) algorithms for automated analysis of load cell data, including filtering methods to determine significant weights and eliminate irrelevant impulses; (2) development of metrics for declaration verification and off-normal operation detection ('cylinder counting,' near-real-time mass balancing, F/P/T ratios, etc.); (3) requirements to specify what potentially sensitive data is safeguards relevant, at what point the IAEA gains on-site custody of the data, and what portion of that data can be transmitted off-site; (4) authentication, secure on-site storage, and secure transmission of load cell data; (5) data processing and remote monitoring schemes to control access to sensitive and proprietary information; (6) integration of process load cell data in a layered safeguards approach with cross-check verification; (7) process mock-ups constructed to provide simulated load

  16. Processing of irradiated, enriched uranium fuels at the Savannah River Plant

    Energy Technology Data Exchange (ETDEWEB)

    Hyder, M L; Perkins, W C; Thompson, M C; Burney, G A; Russell, E R; Holcomb, H P; Landon, L F

    1979-04-01

    Uranium fuels containing /sup 235/U at enrichments from 1.1% to 94% are processed and recovered, along with neptunium and plutonium byproducts. The fuels to be processed are dissolved in nitric acid. Aluminum-clad fuels are disssolved using a mercury catalyst to give a solution rich in aluminum. Fuels clad in more resistant materials are dissolved in an electrolytic dissolver. The resulting solutions are subjected to head-end treatment, including clarification and adjustment of acid and uranium concentration before being fed to solvent extraction. Uranium, neptunium, and plutonium are separated from fission products and from one another by multistage countercurrent solvent extraction with dilute tri-n-butyl phosphate in kerosene. Nitric acid is used as the salting agent in addition to aluminum or other metal nitrates present in the feed solution. Nuclear safety is maintained through conservative process design and the use of monitoring devices as secondary controls. The enriched uranium is recovered as a dilute solution and shipped off-site for further processing. Neptunium is concentrated and sent to HB-Line for recovery from solution. The relatively small quantities of plutonium present are normally discarded in aqueous waste, unless the content of /sup 238/Pu is high enough to make its recovery desirable. Most of the /sup 238/Pu can be recovered by batch extraction of the waste solution, purified by counter-current solvent extraction, and converted to oxide in HB-Line. By modifying the flowsheet, /sup 239/Pu can be recovered from low-enriched uranium in the extraction cycle; neptunium is then not recovered. The solvent is subjected to an alkaline wash before reuse to remove degraded solvent and fission products. The aqueous waste is concentrated and partially deacidified by evaporation before being neutralized and sent to the waste tanks; nitric acid from the overheads is recovered for reuse.

  17. Processing of irradiated, enriched uranium fuels at the Savannah River Plant

    International Nuclear Information System (INIS)

    Hyder, M.L.; Perkins, W.C.; Thompson, M.C.; Burney, G.A.; Russell, E.R.; Holcomb, H.P.; Landon, L.F.

    1979-04-01

    Uranium fuels containing 235 U at enrichments from 1.1% to 94% are processed and recovered, along with neptunium and plutonium byproducts. The fuels to be processed are dissolved in nitric acid. Aluminum-clad fuels are disssolved using a mercury catalyst to give a solution rich in aluminum. Fuels clad in more resistant materials are dissolved in an electrolytic dissolver. The resulting solutions are subjected to head-end treatment, including clarification and adjustment of acid and uranium concentration before being fed to solvent extraction. Uranium, neptunium, and plutonium are separated from fission products and from one another by multistage countercurrent solvent extraction with dilute tri-n-butyl phosphate in kerosene. Nitric acid is used as the salting agent in addition to aluminum or other metal nitrates present in the feed solution. Nuclear safety is maintained through conservative process design and the use of monitoring devices as secondary controls. The enriched uranium is recovered as a dilute solution and shipped off-site for further processing. Neptunium is concentrated and sent to HB-Line for recovery from solution. The relatively small quantities of plutonium present are normally discarded in aqueous waste, unless the content of 238 Pu is high enough to make its recovery desirable. Most of the 238 Pu can be recovered by batch extraction of the waste solution, purified by counter-current solvent extraction, and converted to oxide in HB-Line. By modifying the flowsheet, 239 Pu can be recovered from low-enriched uranium in the extraction cycle; neptunium is then not recovered. The solvent is subjected to an alkaline wash before reuse to remove degraded solvent and fission products. The aqueous waste is concentrated and partially deacidified by evaporation before being neutralized and sent to the waste tanks; nitric acid from the overheads is recovered for reuse

  18. Reorganization in processing of spectral and temporal input in the rat posterior auditory field induced by environmental enrichment

    Science.gov (United States)

    Jakkamsetti, Vikram; Chang, Kevin Q.

    2012-01-01

    Environmental enrichment induces powerful changes in the adult cerebral cortex. Studies in primary sensory cortex have observed that environmental enrichment modulates neuronal response strength, selectivity, speed of response, and synchronization to rapid sensory input. Other reports suggest that nonprimary sensory fields are more plastic than primary sensory cortex. The consequences of environmental enrichment on information processing in nonprimary sensory cortex have yet to be studied. Here we examine physiological effects of enrichment in the posterior auditory field (PAF), a field distinguished from primary auditory cortex (A1) by wider receptive fields, slower response times, and a greater preference for slowly modulated sounds. Environmental enrichment induced a significant increase in spectral and temporal selectivity in PAF. PAF neurons exhibited narrower receptive fields and responded significantly faster and for a briefer period to sounds after enrichment. Enrichment increased time-locking to rapidly successive sensory input in PAF neurons. Compared with previous enrichment studies in A1, we observe a greater magnitude of reorganization in PAF after environmental enrichment. Along with other reports observing greater reorganization in nonprimary sensory cortex, our results in PAF suggest that nonprimary fields might have a greater capacity for reorganization compared with primary fields. PMID:22131375

  19. Development of the chemical decontamination process of uranium enrichment gas centrifuges

    International Nuclear Information System (INIS)

    Mita, Yutaka; Endo, Yuji; Yamanaka, Toshihiro; Oohashi, Yusuke

    2002-01-01

    In Ningyo-Toge Environmental Engineering Center, many of the centrifuges that were tested for uranium enrichment are kept in storage. In the future, it will be necessary to dispose of them properly. By categorizing these centrifuges as 'items that are not required to be treated as radioactive waste', chemical decontamination tests were conducted with the wet process (diluted sulfuric acid) to reduce the amount of such radioactive waste. As a result, concerning the rotors, the assumed radioactive level was attained as items that are not required to be treated as radioactive waste', but the effectiveness of the casings varied. As a future subject, in order to find the optimal decontamination process, the basic test shall be conducted continuously. By taking economical efficiency and the processing time into consideration, the decontamination process will be evaluated and a rational method examined. (author)

  20. Development and technical implementation of the separation nozzle process for enrichment of uranium 235

    International Nuclear Information System (INIS)

    Syllus Martins Pinto, C.; Voelcker, H.; Becker, E.W.

    1977-12-01

    The separation nozzle process for the enrichment of uranium-235 has been developed at the Karlsruhe Nuclear Research Center as an alternative to the gaseous diffusion and centrifuge process. The separation of uranium isotopes is achieved by the deflection of a jet of uranium hexafluoride mixed with hydrogen. Since 1970, the German company of STEAG, has been involved in the technological development and commercial implementation of the nozzle process. In 1975, the Brazilian company of NUCLEBRAS, and the German company of Interatom, joined the effort. The primary objective of the common activity is the construction of a separation nozzle demonstration plant with an annual capacity of about 200 000 SWU and the development of components of a commercial plant. The paper covers the most important steps in the development and the technical implementation of the process. (orig.) [de

  1. Examinations of the process of hard coal and biomass blend combustion in OEA (oxygen enriched atmosphere)

    International Nuclear Information System (INIS)

    Pawlak-Kruczek, Halina; Ostrycharczyk, Michał; Czerep, Michał; Baranowski, Marcin; Zgóra, Jacek

    2015-01-01

    The benefits of oxygen enrichment have been demonstrated in a variety of industrial combustion applications, but to date no implementation of oxygen enrichment in boilers has been reported, primarily due to their already high thermal efficiencies and a very large scale of such systems, which require significant amounts of oxygen. But recently, oxygen combustion in boilers has become one of the CCS technologies which can be an effective tool for reducing greenhouse gases emissions, and oxygen enriched combustion is suitable for low-calorific fuels, including biomass. This paper analyses the use of oxygen enrichment in a furnace for co-firing of different kinds of biomass with hard coal in terms of emission and burnout impact (LOI). As a part of this research, the effect of injection oxygen mode and total oxygen concentration on the flue gas emission (SO_2, NO_x) and burnout from co-firing of straw and wooden biomass in different proportions (20% and 40%) with hard coal were studied. The co-firing tests were carried out in an isothermal flow reactor. One of the benefits from the OEA (oxygen enriched atmosphere) technology is more effective separation of CO_2 owing to the higher CO_2 concentration in the flue gas. The additional advantage of the OEA combustion technology in comparison with oxy-fuel combustion is that the OEA process needs lower O_2 purities and therefore it is cost-effective. Experimental tests on co-firing of 20% straw-hard coal blend were conducted in oxygen enriched (up to 25 and 30%) atmospheres with three variants of O_2 injection modes. NO_x, SO_2 emissions and burnout for the various atmospheres in the combustion chamber were studied. Moreover, co-firing tests were performed with 40% share of wooden biomass to examine the effect of the biomass share and a type on emission of NO_x and SO_2 in OEA. The two O_2 injection modes were investigated. In each case, the emission of SO_2 increases alongside an increase of oxygen concentration in

  2. The s-process enrichment of the globular clusters M4 and M22

    Energy Technology Data Exchange (ETDEWEB)

    Shingles, Luke J.; Karakas, Amanda I.; Fishlock, Cherie K.; Yong, David; Da Costa, Gary S.; Marino, Anna F. [Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611 (Australia); Hirschi, Raphael, E-mail: luke.shingles@anu.edu.au [Institute for the Physics and Mathematics of the Universe (WPI), University of Tokyo, 5-1-5 Kashiwanoha, 277-8583 Kashiwa (Japan)

    2014-11-01

    We investigate the enrichment in elements produced by the slow neutron-capture process (s-process) in the globular clusters M4 (NGC 6121) and M22 (NGC 6656). Stars in M4 have homogeneous abundances of Fe and neutron-capture elements, but the entire cluster is enhanced in s-process elements (Sr, Y, Ba, Pb) relative to other clusters with a similar metallicity. In M22, two stellar groups exhibit different abundances of Fe and s-process elements. By subtracting the mean abundances of s-poor from s-rich stars, we derive s-process residuals or empirical s-process distributions for M4 and M22. We find that the s-process distribution in M22 is more weighted toward the heavy s-peak (Ba, La, Ce) and Pb than M4, which has been enriched mostly with light s-peak elements (Sr, Y, Zr). We construct simple chemical evolution models using yields from massive star models that include rotation, which dramatically increases s-process production at low metallicity. We show that our massive star models with rotation rates of up to 50% of the critical (break-up) velocity and changes to the preferred {sup 17}O(α, γ){sup 21}Ne rate produce insufficient heavy s-elements and Pb to match the empirical distributions. For models that incorporate asymptotic giant branch yields, we find that intermediate-mass yields (with a {sup 22}Ne neutron source) alone do not reproduce the light-to-heavy s-element ratios for M4 and M22, and that a small contribution from models with a {sup 13}C pocket is required. With our assumption that {sup 13}C pockets form for initial masses below a transition range between 3.0 and 3.5 M {sub ☉}, we match the light-to-heavy s-element ratio in the s-process residual of M22 and predict a minimum enrichment timescale of between 240 and 360 Myr. Our predicted value is consistent with the 300 Myr upper limit age difference between the two groups derived from isochrone fitting.

  3. Hydrogen enriched gas production in a multi-stage downdraft gasification process

    International Nuclear Information System (INIS)

    Dutta, A.; Jarungthammachote, S.

    2009-01-01

    To achieve hydrogen enriched and low-tar producer gas, multi-stage air-blown and air-steam gasification were studied in this research. Results showed that the tar content from multi-stage air-blown and air-steam gasification was lower compared to the average value of that from downdraft gasification. It was also seen that an air-steam gasification process could potentially increase the hydrogen concentration in the producer gas in the expense of carbon monoxide; however, the summation of hydrogen and carbon monoxide in the producer gas was increased. (author)

  4. Analysis of civilian processing programs in reduction of excess separated plutonium and high-enriched uranium

    International Nuclear Information System (INIS)

    Persiani, P.J.

    1995-01-01

    The purpose of this preliminary investigation is to explore alternatives and strategies aimed at the gradual reduction of the excess inventories of separated plutonium and high-enriched uranium (HEU) in the civilian nuclear power industry. The study attempts to establish a technical and economic basis to assist in the formation of alternative approaches consistent with nonproliferation and safeguards concerns. The analysis addresses several options in reducing the excess separated plutonium and HEU, and the consequences on nonproliferation and safeguards policy assessments resulting from the interacting synergistic effects between fuel cycle processes and isotopic signatures of nuclear materials

  5. Development of dissolution process for metal foil target containing low enriched uranium

    International Nuclear Information System (INIS)

    Srinivasan, B.; Hutter, J.C.; Johnson, G.K.; Vandegrift, G.F.

    1994-01-01

    About six times more low enriched uranium (LEU) metal is needed to produce the same quantity of 99 Mo as from a high enriched uranium (HEU) oxide target, under similar conditions of neutron irradiation. In view of this, the post-irradiation processing procedures of the LEU target are likely to be different from the Cintichem process procedures now in use for the HEU target. The authors have begun a systematic study to develop modified procedures for LEU target dissolution and 99 Mo separation. The dissolution studies include determination of the dissolution rate, chemical state of uranium in the solution, and the heat evolved in the dissolution reaction. From these results the authors conclude that a mixture of nitric and sulfuric acid is a suitable dissolver solution, albeit at higher concentration of nitric acid than in use for the HEU targets. Also, the dissolver vessel now in use for HEU targets is inadequate for the LEU target, since higher temperature and higher pressure will be encountered in the dissolution of LEU targets. The desire is to keep the modifications to the Cintichem process to a minimum, so that the switch from HEU to LEU can be achieved easily

  6. Multivariate analysis of the heterogeneous geochemical processes controlling arsenic enrichment in a shallow groundwater system.

    Science.gov (United States)

    Huang, Shuangbing; Liu, Changrong; Wang, Yanxin; Zhan, Hongbin

    2014-01-01

    The effects of various geochemical processes on arsenic enrichment in a high-arsenic aquifer at Jianghan Plain in Central China were investigated using multivariate models developed from combined adaptive neuro-fuzzy inference system (ANFIS) and multiple linear regression (MLR). The results indicated that the optimum variable group for the AFNIS model consisted of bicarbonate, ammonium, phosphorus, iron, manganese, fluorescence index, pH, and siderite saturation. These data suggest that reductive dissolution of iron/manganese oxides, phosphate-competitive adsorption, pH-dependent desorption, and siderite precipitation could integrally affect arsenic concentration. Analysis of the MLR models indicated that reductive dissolution of iron(III) was primarily responsible for arsenic mobilization in groundwaters with low arsenic concentration. By contrast, for groundwaters with high arsenic concentration (i.e., > 170 μg/L), reductive dissolution of iron oxides approached a dynamic equilibrium. The desorption effects from phosphate-competitive adsorption and the increase in pH exhibited arsenic enrichment superior to that caused by iron(III) reductive dissolution as the groundwater chemistry evolved. The inhibition effect of siderite precipitation on arsenic mobilization was expected to exist in groundwater that was highly saturated with siderite. The results suggest an evolutionary dominance of specific geochemical process over other factors controlling arsenic concentration, which presented a heterogeneous distribution in aquifers. Supplemental materials are available for this article. Go to the publisher's online edition of the Journal of Environmental Science and Health, Part A, to view the supplemental file.

  7. Uranium enrichment

    International Nuclear Information System (INIS)

    Mohrhauer, H.

    1982-01-01

    The separation of uranium isotopes in order to enrich the fuel for light water reactors with the light isotope U-235 is an important part of the nuclear fuel cycle. After the basic principals of isotope separation the gaseous diffusion and the centrifuge process are explained. Both these techniques are employed on an industrial scale. In addition a short review is given on other enrichment techniques which have been demonstrated at least on a laboratory scale. After some remarks on the present situation on the enrichment market the progress in the development and the industrial exploitation of the gas centrifuge process by the trinational Urenco-Centec organisation is presented. (orig.)

  8. A uranium enrichment facility safeguards technology based on the separation nozzle process

    International Nuclear Information System (INIS)

    Bahm, W.; Weppner, J.; Didier, H.J.

    1979-01-01

    Under the Trilateral Agreement between Brazil, the Federal Republic of Germany and the IAEA an enrichment plant operating on the basis of the separation nozzle process, will be safeguarded under INFCIRC/66/Rev.2. For nuclear materials balancing purposes the plant has been subdivided into 17 key measuring points to assess the nuclear material flow and the nuclear material inventory. Preliminary studies have indicated that the balancing accuracy required for safeguards purposes cannot be achieved by only using the foreseen in-plant measuring systems, since considerable quantities of enriched uranium cannot be covered in this way. This fraction will merely be estimated by the operator and thus cannot be verified by the inspection authorities. The plant components, whose inventories could not be verified in the first estimate of the balancing accuracy referred to above by means of the in-plant measuring systems, also include the low-temperature separators of the cascade shoulder and the product. Assessing and verifying the inventories of these key measuring points is particularly important because of the enrichment (some 3% 235 U for the product) and the relatively large inventory and, hence, the considerable contribution to the balancing inaccuracy. An estimate of the balancing inaccuracy on the basis of the measuring uncertainties to be expected in the light of the present status of technology indicated values between 0.2 and 0.3% relative to the feed flow with semi-annual inventory-taking. However, this is based on the condition that the experiments planned to determine the inventories of cryogenic separators confirm the measuring uncertainties underlying the calculation

  9. Research and economic evaluation on uranium enrichment by gaseous diffusion process in Japan

    International Nuclear Information System (INIS)

    Aochi, T.; Takahashi, S.

    1977-01-01

    Research and development works on uranium enrichment by gaseous diffusion process were carried out by JAERI, IPCR and industries since 1965. There are two important keys to reduce the uranium separation cost. One is the characteristics of the barrier and the other is financing and/or political planning. The technics to prepare the barrier with pore diameter of 40A have been developed with polytetrafluoroethylene, alumina and nickel. The experiment on corrosion behavior of PTFE barriers has shown better characteristics than the others. In the field of engineering research, the adiabatic efficiency of axial compressor for UF 6 was resulted to as high as 90% by long term operation tests. Based on these experimental data, techno-economic evaluation on a uranium enrichment plant was carried out with regard to the optimization of separation efficiency, numbers of step and operating conditions of the plant. Sensitivity in the separation cost were calculated as a function of pore diameter, uranium hexafluoride cost, plant capacity, electric power cost, and the plant annual expenditure. A financing plan must be such as to achieve 1. maximization of debt in a percentage of total capitalization 2. off-take contracts to utilities as security for financing 3. minimization of risks to equity and achievable cost of capital. Therefore the cash flow analysis and the schedule for construction and operation are very important for a economical feasibility of a uranium enrichment plant. To minimize the risk, not only economical but also political environment are important. The governmental supports and international agreements will be necessary

  10. CONCEPTUAL PROCESS DESCRIPTION FOR THE MANUFACTURE OF LOW-ENRICHED URANIUM-MOLYBDENUM FUEL

    Energy Technology Data Exchange (ETDEWEB)

    Daniel M. Wachs; Curtis R. Clark; Randall J. Dunavant

    2008-02-01

    The National Nuclear Security Agency Global Threat Reduction Initiative (GTRI) is tasked with minimizing the use of high-enriched uranium (HEU) worldwide. A key component of that effort is the conversion of research reactors from HEU to low-enriched uranium (LEU) fuels. The GTRI Convert Fuel Development program, previously known as the Reduced Enrichment for Research and Test Reactors program was initiated in 1978 by the United States Department of Energy to develop the nuclear fuels necessary to enable these conversions. The program cooperates with the research reactors’ operators to achieve this goal of HEU to LEU conversion without reduction in reactor performance. The programmatic mandate is to complete the conversion of all civilian domestic research reactors by 2014. These reactors include the five domestic high-performance research reactors (HPRR), namely: the High Flux Isotope Reactor at the Oak Ridge National Laboratory, the Advanced Test Reactor at the Idaho National Laboratory, the National Bureau of Standards Reactor at the National Institute of Standards and Technology, the Missouri University Research Reactor at the University of Missouri–Columbia, and the MIT Reactor-II at the Massachusetts Institute of Technology. Characteristics for each of the HPRRs are given in Appendix A. The GTRI Convert Fuel Development program is currently engaged in the development of a novel nuclear fuel that will enable these conversions. The fuel design is based on a monolithic fuel meat (made from a uranium-molybdenum alloy) clad in Al-6061 that has shown excellent performance in irradiation testing. The unique aspects of the fuel design, however, necessitate the development and implementation of new fabrication techniques and, thus, establishment of the infrastructure to ensure adequate fuel fabrication capability. A conceptual fabrication process description and rough estimates of the total facility throughput are described in this document as a basis for

  11. Marine sediment sample pre-processing for macroinvertebrates metabarcoding: mechanical enrichment and homogenization

    Directory of Open Access Journals (Sweden)

    Eva Aylagas

    2016-10-01

    Full Text Available Metabarcoding is an accurate and cost-effective technique that allows for simultaneous taxonomic identification of multiple environmental samples. Application of this technique to marine benthic macroinvertebrate biodiversity assessment for biomonitoring purposes requires standardization of laboratory and data analysis procedures. In this context, protocols for creation and sequencing of amplicon libraries and their related bioinformatics analysis have been recently published. However, a standardized protocol describing all previous steps (i.e. processing and manipulation of environmental samples for macroinvertebrate community characterization is lacking. Here, we provide detailed procedures for benthic environmental sample collection, processing, enrichment for macroinvertebrates, homogenization, and subsequent DNA extraction for metabarcoding analysis. Since this is the first protocol of this kind, it should be of use to any researcher in this field, having the potential for improvement.

  12. Vibration signature analysis of compressors in the gaseous diffusion process for uranium enrichment

    International Nuclear Information System (INIS)

    Harbarger, W.B.

    1975-01-01

    Continuous operation of several thousand axial-flow and centrifugal compressors is vital to the gaseous diffusion process for uranium enrichment. Vibration signature analysis using a minicomputer-based Fast Fourier Transform Analyzer is being applied to the evaluation and surveillance of compressor performance at the Portsmouth Gaseous Diffusion Plant. Three areas of application include: (1) new blade design and prototype compressor evaluation; (2) corrective and preventive maintenance of machinery components; and (3) evaluation of machinery health. The present system is being used to monitor signals from accelerometers mounted on the load-bearing housings of 16 on-line compressors. These signals are transmitted by hard-wire to the analyzer for daily monitoring. A program for expansion of this system to monitor more than a thousand compressors and automation of the signature comparison process is planned for all three gaseous diffusion plants operated for the United States Energy Research and Development Administration. (auth)

  13. Uranium enrichment

    International Nuclear Information System (INIS)

    Rae, H.K.; Melvin, J.G.

    1988-06-01

    Canada is the world's largest producer and exporter of uranium, most of which is enriched elsewhere for use as fuel in LWRs. The feasibility of a Canadian uranium-enrichment enterprise is therefore a perennial question. Recent developments in uranium-enrichment technology, and their likely impacts on separative work supply and demand, suggest an opportunity window for Canadian entry into this international market. The Canadian opportunity results from three particular impacts of the new technologies: 1) the bulk of the world's uranium-enrichment capacity is in gaseous diffusion plants which, because of their large requirements for electricity (more than 2000 kW·h per SWU), are vulnerable to competition from the new processes; 2) the decline in enrichment costs increases the economic incentive for the use of slightly-enriched uranium (SEU) fuel in CANDU reactors, thus creating a potential Canadian market; and 3) the new processes allow economic operation on a much smaller scale, which drastically reduces the investment required for market entry and is comparable with the potential Canadian SEU requirement. The opportunity is not open-ended. By the end of the century the enrichment supply industry will have adapted to the new processes and long-term customer/supplier relationships will have been established. In order to seize the opportunity, Canada must become a credible supplier during this century

  14. Property and process correlations for iron-enriched basalt waste forms

    International Nuclear Information System (INIS)

    Grandy, J.D.; Eddy, T.L.; Anderson, G.L.

    1993-02-01

    Correlations of thermodynamic properties and process parameters of high-temperature slag for a range of compositions of iron-enriched basalt are presented. The quantification of the properties of this complex mixture can assist in the design and monitoring of high-temperature melting systems for the treatment of radioactive and hazardous wastes at the Idaho National Engineering Laboratory. The buried and stored wastes at the INEL Radioactive Waste Management Complex have a similar composition to iron-enriched basalt after oxidation of organics. The properties correlated are the viscosity, electrical conductivity, refractory corrosion, and recrystallization temperature. The correlations are expressed as a function of input waste-soil mixture composition, alkali concentration, and slag temperature. An application to determine the effect of alkali flux on slag temperature, leach rate, and volume reduction is presented. Though the correlations are for mixtures of soil and waste with average transuranic-contaminated waste compositions, it appears that good approximations for other waste streams and glass-ceramic waste forms can be obtained because of similarities in composition

  15. Gene-ontology enrichment analysis in two independent family-based samples highlights biologically plausible processes for autism spectrum disorders.

    LENUS (Irish Health Repository)

    Anney, Richard J L

    2012-02-01

    Recent genome-wide association studies (GWAS) have implicated a range of genes from discrete biological pathways in the aetiology of autism. However, despite the strong influence of genetic factors, association studies have yet to identify statistically robust, replicated major effect genes or SNPs. We apply the principle of the SNP ratio test methodology described by O\\'Dushlaine et al to over 2100 families from the Autism Genome Project (AGP). Using a two-stage design we examine association enrichment in 5955 unique gene-ontology classifications across four groupings based on two phenotypic and two ancestral classifications. Based on estimates from simulation we identify excess of association enrichment across all analyses. We observe enrichment in association for sets of genes involved in diverse biological processes, including pyruvate metabolism, transcription factor activation, cell-signalling and cell-cycle regulation. Both genes and processes that show enrichment have previously been examined in autistic disorders and offer biologically plausibility to these findings.

  16. ENRICHMENT OF r-PROCESS ELEMENTS IN DWARF SPHEROIDAL GALAXIES IN CHEMO-DYNAMICAL EVOLUTION MODEL

    Energy Technology Data Exchange (ETDEWEB)

    Hirai, Yutaka; Kajino, Toshitaka [Department of Astronomy, Graduate School of Science, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Ishimaru, Yuhri [Department of Material Science,International Christian University, 3-10-2 Osawa, Mitaka, Tokyo 181-8585 (Japan); Saitoh, Takayuki R. [Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551 (Japan); Fujii, Michiko S.; Hidaka, Jun, E-mail: yutaka.hirai@nao.ac.jp [Division of Theoretical Astronomy, National Astronomical Observatory of Japan, 2-21-1 Osawa Mitaka, Tokyo 181-8588 (Japan)

    2015-11-20

    The rapid neutron-capture process (r-process) is a major process for the synthesis of elements heavier than iron-peak elements, but the astrophysical site(s) of the r-process has not yet been identified. Neutron star mergers (NSMs) are suggested to be a major r-process site according to nucleosynthesis studies. Previous chemical evolution studies, however, required unlikely short merger times of NSMs to reproduce the observed large star-to-star scatters in the abundance ratios of r-process elements to iron: the [Eu/Fe] of extremely metal-poor stars in the Milky Way (MW) halo. This problem can be solved by considering chemical evolution in dwarf spheroidal galaxies (dSphs), which would be building blocks of the MW and have lower star formation efficiencies than the MW halo. We demonstrate the enrichment of r-process elements in dSphs by NSMs using an N-body/smoothed particle hydrodynamics code. Our high-resolution model reproduces the observed [Eu/Fe] due to NSMs with a merger time of 100 Myr when the effect of metal mixing is taken into account. This is because metallicity is not correlated with time ∼300 Myr from the start of the simulation due to the low star formation efficiency in dSphs. We also confirm that this model is consistent with observed properties of dSphs such as radial profiles and metallicity distribution. The merger time and the Galactic rate of NSMs are suggested to be ≲300 Myr and ∼10{sup −4} year{sup −1}, respectively, which are consistent with the values suggested by population synthesis and nucleosynthesis studies. This study supports the argument that NSMs are the major astrophysical site of the r-process.

  17. Uranium enrichment by jet nozzle separation process in the German-Brazil cooperation program

    International Nuclear Information System (INIS)

    Becker, E.W.

    1991-01-01

    It presents a lecture on technical and commercial aspects of uranium isotopic enrichment by the Get Lozzle Method in Brazil. The analysis is presented regarding the context of bilateral agreement German-Brazil it discusses the technical problems of a demonstration plant design as well as the commercial exportation viability of enriched uranium produced in Brazil by the Jet Nozzle Method. (author)

  18. Process for the production of protein enriched fractions from vegetable materials

    NARCIS (Netherlands)

    Dijkink, B.H.; Willemsen, J.H.A.

    2006-01-01

    The present invention provides a method for the production of a protein enriched fraction and a fibre enriched fraction from a vegetable material, wherein the vegetable material comprises a total fat content of 0.1 to 22.0 % by dry weight of the total vegetable material and a total starch content of

  19. Plasma Extracellular Vesicles Enriched for Neuronal Origin: A Potential Window into Brain Pathologic Processes

    Directory of Open Access Journals (Sweden)

    Maja Mustapic

    2017-05-01

    Full Text Available Our team has been a pioneer in harvesting extracellular vesicles (EVs enriched for neuronal origin from peripheral blood and using them as a biomarker discovery platform for neurological disorders. This methodology has demonstrated excellent diagnostic and predictive performance for Alzheimer's and other neurodegenerative diseases in multiple studies, providing a strong proof of concept for this approach. Here, we describe our methodology in detail and offer further evidence that isolated EVs are enriched for neuronal origin. In addition, we present evidence that EVs enriched for neuronal origin represent a more sensitive and accurate base for biomarkers than plasma, serum, or non-enriched total plasma EVs. Finally, we proceed to investigate the protein content of EVs enriched for neuronal origin and compare it with other relevant enriched and non-enriched populations of plasma EVs. Neuronal-origin enriched plasma EVs contain higher levels of signaling molecules of great interest for cellular metabolism, survival, and repair, which may be useful as biomarkers and to follow response to therapeutic interventions in a mechanism-specific manner.

  20. Biotransformation of vegetable and fruit processing wastes into yeast biomass enriched with selenium

    Energy Technology Data Exchange (ETDEWEB)

    Stabnikova, O.; Jing Yuan Wang; Hong Bo Ding; Joo Hwa Tay [Nanyang Technological Univ., Singapore (Singapore). School of Civil and Environmental Engineering

    2005-04-01

    Water extracts of cabbage, watermelon, a mixture of residual biomass of green salads and tropical fruits were used for yeast cultivation. These extracts contained from 1420 to 8900 mg/l of dissolved organic matter, and from 600 to 1800 mg/l of nitrogen. pH of the extracts was in the range from 4.1 to 6.4. Biomass concentration of yeast, Saccharomyces cerevisiae CEE 12 grown at 30 {sup o}C for 96 h in the sterilized extracts without any nutrient supplements was from 6.4 to 8.2 g/l; content of protein was from 40% to 45% of dry biomass. The yield was comparable with the yield of yeast biomass grown in potato dextrose broth. The biomass can be considered as the protein source. Its feed value was enhanced by incorporation of selenium in biomass to the level of 150 {mu}g/g of dry biomass. Therefore, it was recommended to transform the extracts from vegetable and fruit processing wastes into the yeast biomass enriched with selenium. (Author)

  1. Process for the preparation of deuterium enriched water in the production of hydrogen

    International Nuclear Information System (INIS)

    Mandrin, Ch.

    1986-01-01

    A synthesis gas facility is operated for n consecutive periods. During the first period excess feed water is added to the facility. The effluent from the resulting mixture is fed to a storage container. During the following n-1 operating periods the stored effluent water is used as feed for the synthesis gas facility. The effluent from each operating period is stored in layers with corresponding deuterium concentration in the storage container. The effluent from the last operating period involving the highest deuterium concentration is fed to a second container and from there to a heavy water production unit. In order to recuperate the deuterium contained in the gas mixture leaving the condensor (consisting of hydrogen, vapour and residual compounds), the mixture is fed to an exchange stage. There the mixture is isotopically exchanged with additional water in a cross flow whereby this water gets enriched in deuterium and is fed to the synthesis gas facility. The process leads to an improved yield of heavy water in the heavy water production facility

  2. 77 FR 33253 - Regulatory Guide 8.24, Revision 2, Health Physics Surveys During Enriched Uranium-235 Processing...

    Science.gov (United States)

    2012-06-05

    ... NUCLEAR REGULATORY COMMISSION [NRC-2010-0115] Regulatory Guide 8.24, Revision 2, Health Physics..., ``Health Physics Surveys During Enriched Uranium-235 Processing and Fuel Fabrication'' was issued with a... specifically with the following aspects of an acceptable occupational health physics program that are closely...

  3. Converting targets and processes for fission-product molybdenum-99 from high- to low-enriched uranium

    International Nuclear Information System (INIS)

    Vandegrift, G.F.; Snelgrove, J.L.; Aase, S.

    1999-01-01

    Most of the world's supply of 99 Mo is produced by the fissioning of 235 U in high-enriched uranium targets (HEU, generally 93% 235 U). To reduce nuclear-proliferation concerns, the U.S. Reduced Enrichment for Research and Test Reactor Program is working to convert the current HEU targets to low-enriched uranium (LEU, 235 U). Switching to LEU targets also requires modifying the separation processes. Current HEU processes can be classified into two main groups based on whether the irradiated target is dissolved in acid or base. Our program has been working on both fronts, with development of targets for acid-side processes being the furthest along. However, using an LEU metal foil target may allow the facile replacement of HEU for both acid and basic dissolution processes. Demonstration of the irradiation and 99 Mo separation processes for the LEU metal-foil targets is being done in cooperation with researchers at the Indonesian PUSPIPTEK facility. We are also developing LEU UO 2 /Al dispersion plates as substitutes for HEU UA1 x /A1 dispersion plates for base-side processes. Results show that conversion to LEU is technically feasible; working with producers is essential to lowering any economic penalty associated with conversion. (author)

  4. Enriched ammonia-tolerant methanogenic cultures as bioaugmentation inocula in continuous biomethanation processes

    DEFF Research Database (Denmark)

    Fotidis, Ioannis; Treu, Laura; Angelidaki, Irini

    2017-01-01

    reactor (CSTR), resulted in up to 90% recovery of the methane production compared to the uninhibited production. However, cultivation of pure strains has practical difficulties due to the need of special growth media and sterile conditions. In contrast, acclimatized enriched cultures have minor sterility...... requirements. In the current study, an enriched ammonia-tolerant methanogenic culture was bioaugmented in a CSTR reactor operating under ammonia-induced, inhibited-steady-state. The results demonstrated that bioaugmentation, completely counteracted the ammonia toxicity effect. This indicates that a commercial...

  5. Enrichment Wastes' Processing of Manganiferous Ores with the Use of Mechanochemical Methods

    Science.gov (United States)

    Kubekova, Sholpan N.; Kapralova, Viktoria I.; Ibraimova, Gulnur T.; Batyrbayeva, Aigul A.

    2016-01-01

    The aim of the research is the study of the chemical and phase composition of enrichment wastes of manganiferous ore in Ushkatyn-III deposit and the synthesis of new materials by mechanochemical activation and subsequent heat treatment of the mechanical activation products. The use of XFA, infrared spectroscopy and electron probe microanalysis…

  6. The Effect of an Enrichment Reading Program on the Cognitive Processes and Neural Structures of Children Having Reading Difficulties

    Directory of Open Access Journals (Sweden)

    Hayriye Gül KURUYER

    2017-06-01

    Full Text Available The main purpose of the current study is to explain the effect of an enrichment reading program on the cognitive processes and neural structures of children experiencing reading difficulties. The current study was carried out in line with a single-subject research method and the between-subjects multiple probe design belonging to this method. This research focuses on a group of eight students with reading difficulties. Within the context of the study, memory capacities, attention spans, reading-related activation and white matter pathways of the students were determined before and after the application of the enrichment reading program. This determination process was carried out in two stages. Neuro-imaging was performed in the first stage and in the second stage the students’ cognitive processes and neural structures were investigated in terms of focusing attention and memory capacities by using the following tools: Stroop Test TBAG Form, Auditory Verbal Digit Span Test-Form B, Cancellation Test and Number Order Learning Test. The results obtained show that the enrichment reading program resulted in an improvement in the reading profiles of the students having reading difficulties in terms of their cognitive processes and neural structures.

  7. Rotational mixing in carbon-enhanced metal-poor stars with s-process enrichment

    Science.gov (United States)

    Matrozis, E.; Stancliffe, R. J.

    2017-10-01

    Carbon-enhanced metal-poor (CEMP) stars with s-process enrichment (CEMP-s) are believed to be the products of mass transfer from an asymptotic giant branch (AGB) companion, which has long since become a white dwarf. The surface abundances of CEMP-s stars are thus commonly assumed to reflect the nucleosynthesis output of the first AGB stars. We have previously shown that, for this to be the case, some physical mechanism must counter atomic diffusion (gravitational settling and radiative levitation) in these nearly fully radiative stars, which otherwise leads to surface abundance anomalies clearly inconsistent with observations. Here we take into account angular momentum accretion by these stars. We compute in detail the evolution of typical CEMP-s stars from the zero-age main sequence, through the mass accretion, and up the red giant branch for a wide range of specific angular momentum ja of the accreted material, corresponding to surface rotation velocities, vrot, between about 0.3 and 300 kms-1. We find that only for ja ≳ 1017 cm2s-1 (vrot > 20 kms-1, depending on mass accreted) angular momentum accretion directly causes chemical dilution of the accreted material. This could nevertheless be relevant to CEMP-s stars, which are observed to rotate more slowly, if they undergo continuous angular momentum loss akin to solar-like stars. In models with rotation velocities characteristic of CEMP-s stars, rotational mixing primarily serves to inhibit atomic diffusion, such that the maximal surface abundance variations (with respect to the composition of the accreted material) prior to first dredge-up remain within about 0.4 dex without thermohaline mixing or about 0.5-1.5 dex with thermohaline mixing. Even in models with the lowest rotation velocities (vrot ≲ 1 kms-1), rotational mixing is able to severely inhibit atomic diffusion, compared to non-rotating models. We thus conclude that it offers a natural solution to the problem posed by atomic diffusion and cannot be

  8. Development and modelling of a steel slag filter effluent neutralization process with CO2-enriched air from an upstream bioprocess.

    Science.gov (United States)

    Bove, Patricia; Claveau-Mallet, Dominique; Boutet, Étienne; Lida, Félix; Comeau, Yves

    2018-02-01

    The main objective of this project was to develop a steel slag filter effluent neutralization process by acidification with CO 2 -enriched air coming from a bioprocess. Sub-objectives were to evaluate the neutralization capacity of different configurations of neutralization units in lab-scale conditions and to propose a design model of steel slag effluent neutralization. Two lab-scale column neutralization units fed with two different types of influent were operated at hydraulic retention time of 10 h. Tested variables were mode of flow (saturated or percolating), type of media (none, gravel, Bionest and AnoxKaldnes K3), type of air (ambient or CO 2 -enriched) and airflow rate. One neutralization field test (saturated and no media, 2000-5000 ppm CO 2 , sequential feeding, hydraulic retention time of 7.8 h) was conducted for 7 days. Lab-scale and field-scale tests resulted in effluent pH of 7.5-9.5 when the aeration rate was sufficiently high. A model was implemented in the PHREEQC software and was based on the carbonate system, CO 2 transfer and calcite precipitation; and was calibrated on ambient air lab tests. The model was validated with CO 2 -enriched air lab and field tests, providing satisfactory validation results over a wide range of CO 2 concentrations. The flow mode had a major impact on CO 2 transfer and hydraulic efficiency, while the type of media had little influence. The flow mode also had a major impact on the calcite surface concentration in the reactor: it was constant in saturated mode and was increasing in percolating mode. Predictions could be made for different steel slag effluent pH and different operation conditions (hydraulic retention time, CO 2 concentration, media and mode of flow). The pH of the steel slag filter effluent and the CO 2 concentration of the enriched air were factors that influenced most the effluent pH of the neutralization process. An increased concentration in CO 2 in the enriched air reduced calcite precipitation

  9. Mathematical Modeling of the Sugar Cane Bagasse'Sprotein Enrichment Processes, in a Packed-Bed Bioreactor

    International Nuclear Information System (INIS)

    Julián-Ricardo, María Caridad; Ramos-Sánchez, Luís Beltrán; Gómez-Atanay, Angel Osvaldo

    2014-01-01

    The residues of the sugar industry have been used usually, natural or processed in the animal alimentation and have been developed a lot of investigations that are allowed obtain protein enrichment products by solid state fermentation (SSF). However, the technologies employed in the production have limitations that are restraining their commercialization. This investigation was directed to find solutions to the problems that are presented and was planted like objective: to obtain a mathematical model for the scale-up of the sugar cane bagasse´s protein enrichment process, using the Candida utilis yeast, in a packed-bed bioreactor. The experimental work was realized in a pilot plant that have an installation for the air accommodation that is supply for the bioreactor, with a temperature of 30 ºC and more than 95 % of relative humidity. Was used a mathematical model compose by a pseudohomogenous energy balance and the mass balances for the biomass overgrowth and the substrate consumption. The validation studies, was realized by the temperatures comparisons axially measure in 10 L and 100 L bioreactor and the temperatures calculated by simulation. The statistic treatment demonstrate that doesn´t exist big differences between the middle temperatures, for a confidence level of 95 %. The analysis realized to characterize the obtained product, allowed establish that it is accord to quality specifications of the protein enrichment feed. (author)

  10. Uranium enrichment

    International Nuclear Information System (INIS)

    1991-08-01

    This paper reports that in 1990 the Department of Energy began a two-year project to illustrate the technical and economic feasibility of a new uranium enrichment technology-the atomic vapor laser isotope separation (AVLIS) process. GAO believes that completing the AVLIS demonstration project will provide valuable information about the technical viability and cost of building an AVLIS plant and will keep future plant construction options open. However, Congress should be aware that DOE still needs to adequately demonstrate AVLIS with full-scale equipment and develop convincing cost projects. Program activities, such as the plant-licensing process, that must be completed before a plant is built, could take many years. Further, an updated and expanded uranium enrichment analysis will be needed before any decision is made about building an AVLIS plant. GAO, which has long supported legislation that would restructure DOE's uranium enrichment program as a government corporation, encourages DOE's goal of transferring AVLIS to the corporation. This could reduce the government's financial risk and help ensure that the decision to build an AVLIS plant is based on commercial concerns. DOE, however, has no alternative plans should the government corporation not be formed. Further, by curtailing a planned public access program, which would have given private firms an opportunity to learn about the technology during the demonstration project, DOE may limit its ability to transfer AVLIS to the private sector

  11. Hammond Postulate Mirroring Enables Enantiomeric Enrichment of Phosphorus Compounds via Two Thermodynamically Interconnected Sequential Stereoselective Processes.

    Science.gov (United States)

    Rajendran, Kamalraj V; Nikitin, Kirill V; Gilheany, Declan G

    2015-07-29

    The dynamic resolution of tertiary phosphines and phosphine oxides was monitored by NMR spectroscopy. It was found that the stereoselectivity is set during the formation of the diastereomeric alkoxyphosphonium salts (DAPS), such that their initial diastereomeric excess (de) limits the final enantiomeric excess (ee) of any phosphorus products derived from them. However, (31)P NMR monitoring of the spontaneous thermal decomposition of the DAPS shows consistent diastereomeric self-enrichment, indicating a higher rate constant for decomposition of the minor diastereomer. This crucial observation was confirmed by reductive trapping of the unreacted enriched DAPS with lithium tri-sec-butylborohydride (commercially distributed as L-Selectride reagent) at different time intervals after the start of reaction, which gives progressively higher ee of the phosphine product with time. It is proposed that the Hammond postulate operates for both formation and decomposition of DAPS intermediate so that the lower rate of formation and faster subsequent collapse of the minor isomer are thermodynamically linked. This kinetic enhancement of kinetic resolution furnishes up to 97% ee product.

  12. REE enrichment in granite-derived regolith deposits of the southeast United States: Prospective source rocks and accumulation processes

    Science.gov (United States)

    Foley, Nora K.; Ayuso, Robert A.; Simandl, G.J.; Neetz, M.

    2015-01-01

    The Southeastern United States contains numerous anorogenic, or A-type, granites, which constitute promising source rocks for REE-enriched ion adsorption clay deposits due to their inherently high concentrations of REE. These granites have undergone a long history of chemical weathering, resulting in thick granite-derived regoliths, akin to those of South China, which supply virtually all heavy REE and Y, and a significant portion of light REE to global markets. Detailed comparisons of granite regolith profiles formed on the Stewartsville and Striped Rock plutons, and the Robertson River batholith (Virginia) indicate that REE are mobile and can attain grades comparable to those of deposits currently mined in China. A REE-enriched parent, either A-type or I-type (highly fractionated igneous type) granite, is thought to be critical for generating the high concentrations of REE in regolith profiles. One prominent feature we recognize in many granites and mineralized regoliths is the tetrad behaviour displayed in REE chondrite-normalized patterns. Tetrad patterns in granite and regolith result from processes that promote the redistribution, enrichment, and fractionation of REE, such as late- to post- magmatic alteration of granite and silicate hydrolysis in the regolith. Thus, REE patterns showing tetrad effects may be a key for discriminating highly prospective source rocks and regoliths with potential for REE ion adsorption clay deposits.

  13. Vacuum Exhaust Process in Pilot-Scale Vacuum Pressure Swing Adsorption for Coal Mine Ventilation Air Methane Enrichment

    Directory of Open Access Journals (Sweden)

    Xiong Yang

    2018-04-01

    Full Text Available Recovery and treatment of methane from coal mine ventilation air methane (VAM with cost-effective technologies have been an ongoing challenge due to low methane concentrations. In this study, a type of coconut shell-based active carbon was employed to enrich VAM with a three-bed vacuum pressure swing adsorption unit. A new vacuum exhaust step for the VPSA process was introduced. The results show that the vacuum exhaust step can increase the methane concentration of the product without changing adsorption and desorption pressure. Under laboratory conditions, the concentration of product increased from 0.4% to 0.69% as the vacuum exhaust ratio increased from 0 to 3.1 when the feed gas concentration was 0.2%. A 500 m³/h pilot-scale test system for VAM enrichment was built rendering good correlation with the laboratory results in terms of the vacuum exhaust step. By using a two-stage three-bed separation unit, the VAM was enriched from 0.2% to over 1.2%.

  14. 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

  15. Uranium enrichment: an overview

    International Nuclear Information System (INIS)

    Cazalet, J.

    1995-01-01

    This paper is a general presentation of uranium enrichment processes and assessments of the prevailing commercial and industrial situations. It gives first some theoretical aspects of enrichment in general and explains the differences between statistical and selective processes in particular. Then a review of the different processes is made with a comparison between them. Finally, some general remarks concerning applications are given and the risks of proliferation related to enrichment are mentioned. (J.S.). 4 refs., 5 figs., 8 tabs

  16. Enrichment of tropical peat with micronutrients for agricultural applications: evaluation of adsorption and desorption processes

    Energy Technology Data Exchange (ETDEWEB)

    Melo, Camila de A.; Oliveira, Lilian K. de; Fraceto, Leonardo F.; Rosa, Andre H., E-mail: ahrosa@sorocaba.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Sorocaba, SP (Brazil). Dept. de Engenharia Ambiental; Goveia, Danielle [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Araraquara, SP (Brazil). Inst. de Quimica

    2014-01-15

    The objective of this work was to evaluate the adsorption and desorption of micronutrients in tropical peats, from the perspective of potential agricultural applications. Adsorption experiments were performed at different pH values, using solutions containing individual and multiple metal ions. Maximum adsorption capacity occurred at pH 6.0, and the order of affinity was Cu > Fe > Co > Ni > Zn = Mn. Release of the micronutrients was evaluated at different pH values, using an aqueous medium as well as soil and plants. Release of the micronutrients was most efficient at pH 6.0, and followed the order: Fe > Zn > Mn > Co = Ni > Cu. Micronutrient release to the soil was accompanied by uptake by the plant. The use of tropical peat enriched with micronutrients could contribute to improved agricultural productivity, since the release profile of the micronutrients can effectively stimulate plant growth. (author)

  17. Conceptual Process for the Manufacture of Low-Enriched Uranium/Molybdenum Fuel for the High Flux Isotope Reactor

    International Nuclear Information System (INIS)

    Sease, J.D.; Primm, R.T. III; Miller, J.H.

    2007-01-01

    The U.S. nonproliferation policy 'to minimize, and to the extent possible, eliminate the use of HEU in civil nuclear programs throughout the world' has resulted in the conversion (or scheduled conversion) of many of the U.S. research reactors from high-enriched uranium (HEU) to low-enriched uranium (LEU). A foil fuel appears to offer the best option for using a LEU fuel in the High Flux Isotope Reactor (HFIR) without degrading the performance of the reactor. The purpose of this document is to outline a proposed conceptual fabrication process flow sheet for a new, foil-type, 19.75%-enriched fuel for HFIR. The preparation of the flow sheet allows a better understanding of the costs of infrastructure modifications, operating costs, and implementation schedule issues associated with the fabrication of LEU fuel for HFIR. Preparation of a reference flow sheet is one of the first planning steps needed in the development of a new manufacturing capacity for low enriched fuels for U.S. research and test reactors. The flow sheet can be used to develop a work breakdown structure (WBS), a critical path schedule, and identify development needs. The reference flow sheet presented in this report is specifically for production of LEU foil fuel for the HFIR. The need for an overall reference flow sheet for production of fuel for all High Performance Research Reactors (HPRR) has been identified by the national program office. This report could provide a starting point for the development of such a reference flow sheet for a foil-based fuel for all HPRRs. The reference flow sheet presented is based on processes currently being developed by the national program for the LEU foil fuel when available, processes used historically in the manufacture of other nuclear fuels and materials, and processes used in other manufacturing industries producing a product configuration similar to the form required in manufacturing a foil fuel. The processes in the reference flow sheet are within the

  18. Conceptual Process for the Manufacture of Low-Enriched Uranium/Molybdenum Fuel for the High Flux Isotope Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Sease, J.D.; Primm, R.T. III; Miller, J.H.

    2007-09-30

    The U.S. nonproliferation policy 'to minimize, and to the extent possible, eliminate the use of HEU in civil nuclear programs throughout the world' has resulted in the conversion (or scheduled conversion) of many of the U.S. research reactors from high-enriched uranium (HEU) to low-enriched uranium (LEU). A foil fuel appears to offer the best option for using a LEU fuel in the High Flux Isotope Reactor (HFIR) without degrading the performance of the reactor. The purpose of this document is to outline a proposed conceptual fabrication process flow sheet for a new, foil-type, 19.75%-enriched fuel for HFIR. The preparation of the flow sheet allows a better understanding of the costs of infrastructure modifications, operating costs, and implementation schedule issues associated with the fabrication of LEU fuel for HFIR. Preparation of a reference flow sheet is one of the first planning steps needed in the development of a new manufacturing capacity for low enriched fuels for U.S. research and test reactors. The flow sheet can be used to develop a work breakdown structure (WBS), a critical path schedule, and identify development needs. The reference flow sheet presented in this report is specifically for production of LEU foil fuel for the HFIR. The need for an overall reference flow sheet for production of fuel for all High Performance Research Reactors (HPRR) has been identified by the national program office. This report could provide a starting point for the development of such a reference flow sheet for a foil-based fuel for all HPRRs. The reference flow sheet presented is based on processes currently being developed by the national program for the LEU foil fuel when available, processes used historically in the manufacture of other nuclear fuels and materials, and processes used in other manufacturing industries producing a product configuration similar to the form required in manufacturing a foil fuel. The processes in the reference flow sheet are

  19. Real-time image processing for label-free enrichment of Actinobacteria cultivated in picolitre droplets.

    Science.gov (United States)

    Zang, Emerson; Brandes, Susanne; Tovar, Miguel; Martin, Karin; Mech, Franziska; Horbert, Peter; Henkel, Thomas; Figge, Marc Thilo; Roth, Martin

    2013-09-21

    The majority of today's antimicrobial therapeutics is derived from secondary metabolites produced by Actinobacteria. While it is generally assumed that less than 1% of Actinobacteria species from soil habitats have been cultivated so far, classic screening approaches fail to supply new substances, often due to limited throughput and frequent rediscovery of already known strains. To overcome these restrictions, we implement high-throughput cultivation of soil-derived Actinobacteria in microfluidic pL-droplets by generating more than 600,000 pure cultures per hour from a spore suspension that can subsequently be incubated for days to weeks. Moreover, we introduce triggered imaging with real-time image-based droplet classification as a novel universal method for pL-droplet sorting. Growth-dependent droplet sorting at frequencies above 100 Hz is performed for label-free enrichment and extraction of microcultures. The combination of both cultivation of Actinobacteria in pL-droplets and real-time detection of growing Actinobacteria has great potential in screening for yet unknown species as well as their undiscovered natural products.

  20. Enrichment of the metallic components from waste printed circuit boards by a mechanical separation process using a stamp mill

    International Nuclear Information System (INIS)

    Yoo, Jae-Min; Jeong, Jinki; Yoo, Kyoungkeun; Lee, Jae-chun; Kim, Wonbaek

    2009-01-01

    Printed circuit boards incorporated in most electrical and electronic equipment contain valuable metals such as Cu, Ni, Au, Ag, Pd, Fe, Sn, and Pb. In order to employ a hydrometallurgical route for the recycling of valuable metals from printed circuit boards, a mechanical pre-treatment step is needed. In this study, the metallic components from waste printed circuit boards have been enriched using a mechanical separation process. Waste printed circuit boards shredded to 5.0 mm. The fractions of milled printed circuit boards of size 5.0 mm fraction and the heavy fraction were subjected to two-step magnetic separation. Through the first magnetic separation at 700 Gauss, 83% of the nickel and iron, based on the whole printed circuit boards, was recovered in the magnetic fraction, and 92% of the copper was recovered in the non-magnetic fraction. The cumulative recovery of nickel-iron concentrate was increased by a second magnetic separation at 3000 Gauss, but the grade of the concentrate decreased remarkably from 76% to 56%. The cumulative recovery of copper concentrate decreased, but the grade increased slightly from 71.6% to 75.4%. This study has demonstrated the feasibility of the mechanical separation process consisting of milling/size classification/gravity separation/two-step magnetic separation for enriching metallic components such as Cu, Ni, Al, and Fe from waste printed circuit boards

  1. Study of the first section of an enrichment plant of heavy water by the Girdler sulfide process

    International Nuclear Information System (INIS)

    Chavez T, R.H.

    1985-01-01

    The present paper describes the behaviour of the capital and operating cost with driving forces for a design. It is referred from the first stage of enrichment for heavy water production by the Girdler Sulfide process. A most useful procedure for analyzing a process or control system is by means of the Second Law of Thermodynamics. Determining where the irreversibilities of a process or control systems are generally indicated is where the greatest improvements can be made, particularly as they relate to operating cost. Thermodynamic analyses based on the concepts of irreversible entropy increases have frequently been suggested as pointers to sources of inefficiency in chemical processes. Optimization of chemical processes coupled with appropriate control systems is one of the areas where industry is presently making significant advances in conserving energy. The process was considered as a black box with incoming and outgoing energy flows at different levels. Furthermore, a generalized discussion of the cost with respect to the optimization parameters is done, where the irreversibilities of the process are place and a generalized discussion from the successful application of the approach in this study are shown. (Author)

  2. Process optimization for the enrichment of α-linolenic acid from ...

    African Journals Online (AJOL)

    USER

    2010-05-17

    May 17, 2010 ... medicine, food and cosmetic industries. Extraction technology of crude .... Crude MFAs in desilked silkworm pupae determined by HPLC-UV. On the .... process of urea clathration reaction lead to a low purity of. ALA. Therefore ...

  3. Enriching psychological assessment using a person-specific analysis of interpersonal processes in daily life.

    Science.gov (United States)

    Roche, Michael J; Pincus, Aaron L; Rebar, Amanda L; Conroy, David E; Ram, Nilam

    2014-10-01

    We present a series of methods and approaches for clinicians interested in tracking their individual patients over time and in the natural settings of their daily lives. The application of person-specific analyses to intensive repeated measurement data can assess some aspects of persons that are distinct from the valuable results obtained from single-occasion assessments. Guided by interpersonal theory, we assess a psychotherapy patient's interpersonal processes as they unfold in his daily life. We highlight specific contexts that change these processes, use an informant report to examine discrepancies in his reported interpersonal processes, and examine how his interpersonal processes differ as a function of varying levels of self-esteem and anger. We advocate for this approach to complement existing psychological assessments and provide a scoring program to facilitate initial implementation. © The Author(s) 2014.

  4. “Marine eutrophication is the process of enrich- ment of marine ...

    African Journals Online (AJOL)

    spamer

    into a protected shallow water environment (Fig. 1) which is ... cent discharge of nitrogen from pelagic fish processing waste. It is suggested .... from deep eastern Pacific Ocean). Published ... temporal variability signal to be defined. Second ...

  5. Minor isotope safeguards techniques (MIST): Analysis and visualization of gas centrifuge enrichment plant process data using the MSTAR model

    Science.gov (United States)

    Shephard, Adam M.; Thomas, Benjamin R.; Coble, Jamie B.; Wood, Houston G.

    2018-05-01

    This paper presents a development related to the use of minor isotope safeguards techniques (MIST) and the MSTAR cascade model as it relates to the application of international nuclear safeguards at gas centrifuge enrichment plants (GCEPs). The product of this paper is a derivation of the universal and dimensionless MSTAR cascade model. The new model can be used to calculate the minor uranium isotope concentrations in GCEP product and tails streams or to analyze, visualize, and interpret GCEP process data as part of MIST. Applications of the new model include the detection of undeclared feed and withdrawal streams at GCEPs when used in conjunction with UF6 sampling and/or other isotopic measurement techniques.

  6. Galactic r-process enrichment by neutron star mergers in cosmological simulations of a Milky Way-mass galaxy

    Science.gov (United States)

    van de Voort, Freeke; Quataert, Eliot; Hopkins, Philip F.; Kereš, Dušan; Faucher-Giguère, Claude-André

    2015-02-01

    We quantify the stellar abundances of neutron-rich r-process nuclei in cosmological zoom-in simulations of a Milky Way-mass galaxy from the Feedback In Realistic Environments project. The galaxy is enriched with r-process elements by binary neutron star (NS) mergers and with iron and other metals by supernovae. These calculations include key hydrodynamic mixing processes not present in standard semi-analytic chemical evolution models, such as galactic winds and hydrodynamic flows associated with structure formation. We explore a range of models for the rate and delay time of NS mergers, intended to roughly bracket the wide range of models consistent with current observational constraints. We show that NS mergers can produce [r-process/Fe] abundance ratios and scatter that appear reasonably consistent with observational constraints. At low metallicity, [Fe/H] ≲ -2, we predict there is a wide range of stellar r-process abundance ratios, with both supersolar and subsolar abundances. Low-metallicity stars or stars that are outliers in their r-process abundance ratios are, on average, formed at high redshift and located at large galactocentric radius. Because NS mergers are rare, our results are not fully converged with respect to resolution, particularly at low metallicity. However, the uncertain rate and delay time distribution of NS mergers introduce an uncertainty in the r-process abundances comparable to that due to finite numerical resolution. Overall, our results are consistent with NS mergers being the source of most of the r-process nuclei in the Universe.

  7. Enrichment of r-Process Elements by Neutron Star Mergers through the Sub-Halo Clustering

    Science.gov (United States)

    Ishimaru, Yuhri; Ojima, Takuya; Wanajo, Shinya; Prantzos, Nikos

    Neutron star mergers (NSMs) are suggested to be the most plausible site of r-process by nucleosynthesis studies, while previous chemical evolution models pointed out that the long lifetimes of NS binaries are in conflict with the observed [r/Fe] of the Galactic halo stars. We attempt to solve this problem, assuming the Galactic halo was formed from merging sub-halos. We find that [r/Fe] start increasing at [Fe/H] < -3, if the star formation efficiencies are smaller for less massive sub-halos. We also show that small numbers of NSMs for least massive sub-halos could cause the large enhancement of [r/Fe]. Our results support NSMs as the major site of r-process.

  8. Method for processing coal-enrichment waste with solid and volatile fuel inclusions

    Science.gov (United States)

    Khasanova, A. V.; Zhirgalova, T. B.; Osintsev, K. V.

    2017-10-01

    The method relates to the field of industrial heat and power engineering. It can be used in coal preparation plants for processing coal waste. This new way is realized to produce a loose ash residue directed to the production of silicate products and fuel gas in rotary kilns. The proposed method is associated with industrial processing of brown coal beneficiation waste. Waste is obtained by flotation separation of rock particles up to 13 mm in size from coal particles. They have in their composition both solid and volatile fuel inclusions (components). Due to the high humidity and significant rock content, low heat of combustion, these wastes are not used on energy boilers, they are stored in dumps polluting the environment.

  9. Possible processes for origin of life and living matter in deuterium enriched hot mineral water

    OpenAIRE

    Ignatov, Ignat; Mosin, Oleg

    2013-01-01

    In the present paper the isotopic composition of water and its temperature in the process of evolution of life is analysed. It was proposed an assumption, that under conditions of the primary O 2 free atmosphere, under influence of short-wave solar radiation, geothermal energy and powerful spark discharges, deuterium in form of HDO could be collected in hydrosphere, which physical-chemical properties differ from those of H 2O. There were obtained adapted to the maximal concentration D 2O cell...

  10. Advanced enrichment techniques

    International Nuclear Information System (INIS)

    Johnson, A.

    1988-01-01

    BNFL is in a unique position in that it has commercial experience of diffusion enrichment, and of centrifuge enrichment through its associate company Urenco. In addition BNFL is developing laser enrichment techniques as part of a UK development programme in this area. The paper describes the development programme which led to the introduction of competitive centrifuge enrichment technology by Urenco and discusses the areas where improvements have and will continue to be made in the centrifuge process. It also describes the laser development programme currently being undertaken in the UK. The paper concludes by discussing the relative merits of the various methods of uranium enrichment, with particular reference to the enrichment market likely to obtain over the rest of the century

  11. Advanced enrichment techniques

    International Nuclear Information System (INIS)

    Johnson, A.

    1987-01-01

    BNFL is in a unique position in that it has commercial experience of diffusion enrichment, and of centrifuge enrichment through its associate company Urenco. In addition BNFL is developing laser enrichment techniques as part of a UK development programme in this area. The paper describes the development programme which led to the introduction of competitive centrifuge enrichment technology by Urenco and discusses the areas where improvements have and will continue to be made in the centrifuge process. It also describes the laser development programme currently being undertaken in the UK. The paper concludes by discussing the relative merits of the various methods of uranium enrichment, with particular reference to the enrichment market likely to obtain over the rest of the century. (author)

  12. Ion enrichment of snowmelt water by processes within a podzolic soil

    International Nuclear Information System (INIS)

    Hazlett, P.W.; Foster, N.W.; English, M.C.

    1992-01-01

    Ion concentrations in snowmelt runoff, forest-floor percolate and mineral-soil percolate collected in a tolerant hardwood forest at the Turkey Lakes Watershed, ON, were determined during the spring snowmelt of 1986. The results were examined to assess the modification of snowmelt water after contact with the forest soil. Concentrations of NO 3 - increased from 17 to 201 μmol c L -1 and SO 4 2- increased from 25 to 107 μmol c L -1 as meltwater passed through the organic layers and the upper mineral-soil horizons. Mineralization of organic N and S, and desorption of So 4 2- from the soil, provide sources of these ions for leaching during the snowmelt period. Ion-exchange reactions in the forest floor and upper mineral soil resulted in a decrease in H + and an increase in Ca 2+ concentration is solution. In the steep topography of this forested basin, the altered snowmelt solutions are rapidly transported downslope towards the aquatic system by lateral flow. Processes within the forest soil may therefore play an important role in determining the effects of snowmelt water on surface water chemistry in the spring

  13. Effects of Diets Enriched in Omega-9 or Omega-6 Fatty Acids on Reproductive Process

    Directory of Open Access Journals (Sweden)

    Seyedeh Neda Mousavi

    2016-08-01

    Full Text Available Objective: Maternal type and amounts of dietary fatty acids affect on reproductive process in the mice. The present study investigated the effects of maternal supplementation with different amounts of omega-6 or omega-9 during pregnancy on the number of offspring, sex-ratio and duration of gestation.Materials and methods: Eight-week-old female C57BL/6 mice were randomly assigned into four dietary groups including low omega-6 (16%; LO6, low omega-9 (16%; LO9, high omega-6 (45%; HO6 and high omega-9 (45%; HO9 during gestation. Number of offspring, sex-ratio and duration of pregnancy were compared among four dietary groups.Results: There was significant difference between LO6 and HO6 (p < 0.0001, LO9 and HO9 (p < 0.0001 groups in total number of pups. The number of female and male offspring were significantly different between LO6 and LO9 (p = 0.009 and p = 0.001, respectively, LO9 and HO9 (p = 0.01 and p = 0.025 groups. Duration of pregnancy was significantly higher in low fat diet than high fat diet groups (< 0.001.Conclusion: High fat diet reduced number of pups, gestation duration and lead to early labor. Omega-9 fatty acids shifted sex of offspring to females.

  14. Phenolic-enriched foods: sources and processing for enhanced health benefits.

    Science.gov (United States)

    McDougall, Gordon J

    2017-05-01

    Polyphenols are ubiquitous secondary products present in many plant foods. Their intake has been associated with health benefits ranging from reduced incidence of CVD, diabetes and cancers to improved neurodegenerative outcomes. Major dietary sources include beverages such as coffee, teas and foods such as chocolate. Fruits are also major sources and berries in particular are a palatable source of a diverse range of polyphenol components. There are a number of ways that polyphenol uptake could be increased and healthier polyphenol-rich foods could be produced with specific compositions to target-specific health effects. Firstly, we could exploit the genetic diversity of plants (with a focus on berries) to select varieties that have enhanced levels of specific polyphenols implicated in disease mitigation (e.g. anthocyanins, tannins or flavonols). Working with variation induced by environmental and agronomic factors, modern molecular breeding techniques could exploit natural variation and beneficially alter polyphenol content and composition, although this could be relatively long term. Alternatively, we could employ a synthetic biology approach and design new plants that overexpress certain genes or re-deploy more metabolic effort into specific polyphenols. However, such 'polyphenol-plus' fruit could prove unpalatable as polyphenols contribute to sensorial properties (e.g. astringency of tannins). However, if the aim was to produce a polyphenol as a pharmaceutical then 'lifting' biosynthetic pathways from plants and expressing them in microbial vectors may be a feasible option. Secondly, we could design processing methods to enhance the polyphenolic composition or content of foods. Fermentation of teas, cocoa beans and grapes, or roasting of cocoa and coffee beans has long been used and can massively influence polyphenol composition and potential bioactivity. Simple methods such as milling, heat treatment, pasteurisation or juicing (v. pureeing) can have notable

  15. Isotope enrichment

    International Nuclear Information System (INIS)

    Lydtin, H-J.; Wilden, R.J.; Severin, P.J.W.

    1978-01-01

    The isotope enrichment method described is based on the recognition that, owing to mass diffusion and thermal diffusion in the conversion of substances at a heated substrate while depositing an element or compound onto the substrate, enrichment of the element, or a compound of the element, with a lighter isotope will occur. The cycle is repeated for as many times as is necessary to obtain the degree of enrichment required

  16. Uranium enrichment

    International Nuclear Information System (INIS)

    1990-01-01

    This report looks at the following issues: How much Soviet uranium ore and enriched uranium are imported into the United States and what is the extent to which utilities flag swap to disguise these purchases? What are the U.S.S.R.'s enriched uranium trading practices? To what extent are utilities required to return used fuel to the Soviet Union as part of the enriched uranium sales agreement? Why have U.S. utilities ended their contracts to buy enrichment services from DOE?

  17. Uranium enrichment

    International Nuclear Information System (INIS)

    1989-01-01

    GAO was asked to address several questions concerning a number of proposed uranium enrichment bills introduced during the 100th Congress. The bill would have restructured the Department of Energy's uranium enrichment program as a government corporation to allow it to compete more effectively in the domestic and international markets. Some of GAO's findings discussed are: uranium market experts believe and existing market models show that the proposed DOE purchase of a $750 million of uranium from domestic producers may not significantly increase production because of large producer-held inventories; excess uranium enrichment production capacity exists throughout the world; therefore, foreign producers are expected to compete heavily in the United States throughout the 1990s as utilities' contracts with DOE expire; and according to a 1988 agreement between DOE's Offices of Nuclear Energy and Defense Programs, enrichment decommissioning costs, estimated to total $3.6 billion for planning purposes, will be shared by the commercial enrichment program and the government

  18. Expansion and functional properties of extruded snacks enriched with nutrition sources from food processing by-products.

    Science.gov (United States)

    Korkerd, Sopida; Wanlapa, Sorada; Puttanlek, Chureerat; Uttapap, Dudsadee; Rungsardthong, Vilai

    2016-01-01

    Rich sources of protein and dietary fiber from food processing by-products, defatted soybean meal, germinated brown rice meal, and mango peel fiber, were added to corn grit at 20 % (w/w) to produce fortified extruded snacks. Increase of total dietary fiber from 4.82 % (wb) to 5.92-17.80 % (wb) and protein from 5.03 % (wb) to 5.46-13.34 % were observed. The product indicated high expansion and good acceptance tested by sensory panels. There were 22.33-33.53 and 5.30-11.53 fold increase in the phenolics and antioxidant activity in the enriched snack products. The effects of feed moisture content, screw speed, and barrel temperature on expansion and nutritional properties of the extruded products were investigated by using response surface methodology. Regression equations describing the effect of each variable on the product responses were obtained. The snacks extruded with feed moisture 13-15 % (wb) and extrusion temperature at 160-180 °C indicated the products with high preference in terms of expansion ratio between insoluble dietary fiber and soluble dietary fiber balance. The results showed that the by-products could be successfully used for nutritional supplemented expanded snacks.

  19. Promotion of uranium enrichment business

    International Nuclear Information System (INIS)

    Kurushima, Morihiro

    1981-01-01

    The Committee on Nuclear Power has studied on the basic nuclear power policy, establishing its five subcommittees, entrusted by the Ministry of Nternational Trade and Industry. The results of examination by the subcommittee on uranium enrichment business are given along with a report in this connection by the Committee. In order to establish the nuclear fuel cycle, the aspect of uranium enrichment is essential. The uranium enrichment by centrifugal process has proceeded steadily in Power Reactor and Nuclear Fuel Development Corporation. The following matters are described: the need for domestic uranium enrichment, the outlook for overseas enrichment services and the schedule for establishing domestic enrichment business, the current state of technology development, the position of the prototype enrichment plant, the course to be taken to establish enrichment business the main organization operating the prototype and commercial plants, the system of supplying centrifuges, the domestic conversion of natural uranium the subsidies for uranium enrichment business. (J.P.N.)

  20. Contribution to the study of the flow of adsorbed phases. Enrichment of binary Gaseous mixtures; Contribution a l'etude de l'ecoulement des phases absorbees. Enrichissement des melanges gazeux binaires

    Energy Technology Data Exchange (ETDEWEB)

    Sapet, J C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1962-12-15

    The research which makes up this thesis is concerned both with the problems of adsorption an chromatographic columns and of catalysis, which involve the surface properties of these solids, and with problems of isotope separation by gaseous diffusion. In this latter case, the flow in the two-dimensional adsorbed phase is a secondary phenomenon but it is nevertheless necessary to know its influence on the separation factor. Up to the present time very little work has been published on this subject, the importance of which needs no stressing. The author has devised very sensitive techniques making it possible to study the flow of two-dimensional phases in micro-porous bodies. He has demonstrated not only the role of the relative pressure and of the nature of the components (gas and solid) but also the relationship between the mobility of the adsorbate and the thermodynamic characteristics of the adsorption. The author has treated numerous examples involving the diffusion either of pure gases (n-butane, n-pentane, isopentane), or of binary mixtures, and has shown on the one hand that the separative effect of the two-dimensional flow at the interface is a maximum in the neighbourhood of the monolayer, and on the other hand that the mass effect is of the second order with respect to the structural factor of the diffusing molecule. The problem considered is of importance both from a fundamental point of view and from that of its industrial applications. (author) [French] Le sujet de travail de cette these interesse aussi bien les problemes d'adsorption sur colonne de chromatographie et de catalyse, qui font intervenir directement les proprietes superficielles des solides, que ceux concernant la separation isotopique par diffusion gazeuse. Dans ce dernier cas l'ecoulement en phase adsorbee bidimensiormelle est un phenomene secondaire dont i1 faut cependant connaitre l'effet sur le facteur de separation. Pratiquement aucun travail fondamental n'a encore ete publie sur ce sujet dont il n'est pas besoin de souligner l'importance. L'auteur a imagine des techniques tres sensibles permettant d'etudier l'ecoulement des phases bidimensionnelles a travers des corps microporeux. Il a mis en evidence non seulement le role de la pression relative et de la nature des constituants (gaz et substrat) mais encore la relation entre la mobilite de l'adsorbat et les caracteristiques thermodynamiques de l'adsorption. L'auteur a traite de nombreux exemples concernant la diffusion soit de corps purs (n-butane, n-pentane, isopentane), soit de melanges binaires, et a montre d'une part que l'effet separatif de l'ecoulement tridimensionnel d'interface est maximum au voisinage de la monocouche, d'autre part que l'effet de masse est du second ordre par rapport au facteur structural de la molecule diffusante. Le probleme traite est important aussi bien sur le plan fondamental que sur celui des applications industrielles. (auteur)

  1. Effects of future climate change, CO2 enrichment, and vegetation structure variation on hydrological processes in China

    Science.gov (United States)

    Zhu, Qiuan; Jiang, Hong; Peng, Changhui; Liu, Jinxun; Fang, Xiuqin; Wei, Xiaohua; Liu, Shirong; Zhou, Guomo

    2012-01-01

    Investigating the relationship between factors (climate change, atmospheric CO2 concentrations enrichment, and vegetation structure) and hydrological processes is important for understanding and predicting the interaction between the hydrosphere and biosphere. The Integrated Biosphere Simulator (IBIS) was used to evaluate the effects of climate change, rising CO2, and vegetation structure on hydrological processes in China at the end of the 21st century. Seven simulations were implemented using the assemblage of the IPCC climate and CO2 concentration scenarios, SRES A2 and SRES B1. Analysis results suggest that (1) climate change will have increasing effects on runoff, evapotranspiration (ET), transpiration (T), and transpiration ratio (transpiration/evapotranspiration, T/E) in most hydrological regions of China except in the southernmost regions; (2) elevated CO2 concentrations will have increasing effects on runoff at the national scale, but at the hydrological region scale, the physiology effects induced by elevated CO2 concentration will depend on the vegetation types, climate conditions, and geographical background information with noticeable decreasing effects shown in the arid Inland region of China; (3) leaf area index (LAI) compensation effect and stomatal closure effect are the dominant factors on runoff in the arid Inland region and southern moist hydrological regions, respectively; (4) the magnitudes of climate change (especially the changing precipitation pattern) effects on the water cycle are much larger than those of the elevated CO2 concentration effects; however, increasing CO2 concentration will be one of the most important modifiers to the water cycle; (5) the water resource condition will be improved in northern China but depressed in southernmost China under the IPCC climate change scenarios, SRES A2 and SRES B1.

  2. Literature review on production process to obtain extra virgin olive oil enriched in bioactive compounds. Potential use of byproducts as alternative sources of polyphenols.

    Science.gov (United States)

    Frankel, Edwin; Bakhouche, Abdelhakim; Lozano-Sánchez, Jesús; Segura-Carretero, Antonio; Fernández-Gutiérrez, Alberto

    2013-06-05

    This review describes the olive oil production process to obtain extra virgin olive oil (EVOO) enriched in polyphenol and byproducts generated as sources of antioxidants. EVOO is obtained exclusively by mechanical and physical processes including collecting, washing, and crushing of olives, malaxation of olive paste, centrifugation, storage, and filtration. The effect of each step is discussed to minimize losses of polyphenols from large quantities of wastes. Phenolic compounds including phenolic acids, alcohols, secoiridoids, lignans, and flavonoids are characterized in olive oil mill wastewater, olive pomace, storage byproducts, and filter cake. Different industrial pilot plant processes are developed to recover phenolic compounds from olive oil byproducts with antioxidant and bioactive properties. The technological information compiled in this review will help olive oil producers to improve EVOO quality and establish new processes to obtain valuable extracts enriched in polyphenols from byproducts with food ingredient applications.

  3. Developments in uranium enrichment

    International Nuclear Information System (INIS)

    Mohrhauer, H.

    1995-01-01

    The enrichment services market is still characterized by overcapacities. While consumption worldwide will rise by some 15% to 39,000 t SWU/a over the next ten years, capacities amount to nearly 50,000 t SWU/a. The price for enrichment services probably has reached its all time low. Prices below U.S. $ 100/kg SWU are not likely to cover costs even of the economically most advanced enrichment processes. Urenco has prepared for the difficult enrichment business in the years to come by streamlining and cost cutting measures. The company intends to hold and increase its share of more than 10% in the world market. The uranium enrichment plant of Gronau will be expanded further. Expansion beyond 1000 t is subject to another permit being granted under the Atomic Energy Act, an application for which was filed in December 1994. Centrifuge technology is the superior enrichment technology, i.e., there is still considerable potential for further development. Construction of enrichment plants employing the centrifuge technology in the United States and in France is being pursued in various phases, from feasibility studies to licensing procedures. Before these plants could be implemented, however, considerable problems of organization would have to be solved, and the market would have to change greatly, respectively. The laser process, at the present time, does not seem to be able to develop into a major industrial competitor. (orig.) [de

  4. Enriching distinctive microbial communities from marine sediments via an electrochemical-sulfide-oxidizing process on carbon electrodes

    Directory of Open Access Journals (Sweden)

    Shiue-Lin eLi

    2015-02-01

    Full Text Available Sulfide is a common product of marine anaerobic respiration, and a potent reactant biologically and geochemically. Here we demonstrate the impact on microbial communities with the removal of sulfide via electrochemical methods. The use of differential pulse voltammetry revealed that the oxidation of soluble sulfide was seen at + mV (vs. SHE at all pH ranges tested (from pH = 4 to 8, while non-ionized sulfide, which dominated at pH = 4 was poorly oxidized via this process. Two mixed cultures (CAT and LA were enriched from two different marine sediments (from Catalina Island, CAT; from the Port of Los Angeles, LA in serum bottles using a seawater medium supplemented with lactate, sulfate, and yeast extract, to obtain abundant biomass. Both CAT and LA cultures were inoculated in electrochemical cells (using yeast-extract-free seawater medium as an electrolyte equipped with carbon-felt electrodes. In both cases, when potentials of +630 or 130 mV (vs. SHE were applied, currents were consistently higher at +630 then at 0 mV, indicating more sulfide being oxidized at the higher potential. In addition, higher organic-acid and sulfate conversion rates were found at +630 mV with CAT, while no significant differences were found with LA at different potentials. The results of microbial-community analyses revealed a decrease in diversity for both CAT and LA after electrochemical incubation. In addition, some bacteria (e.g., Clostridium and Arcobacter not well known to be capable of extracellular electron transfer, were found to be dominant in the electrochemical cells. Thus, even though the different mixed cultures have different tolerances for sulfide, electrochemical-sulfide removal can lead to major population changes.

  5. Uranium enrichment by gas centrifuge

    International Nuclear Information System (INIS)

    Heriot, I.D.

    1988-01-01

    After recalling the physical principles and the techniques of centrifuge enrichment the report describes the centrifuge enrichment programmes of the various countries concerned and compares this technology with other enrichment technologies like gaseous diffusion, laser, aerodynamic devices and chemical processes. The centrifuge enrichment process is said to be able to replace with advantage the existing enrichment facilities in the short and medium term. Future prospects of the process are also described, like recycled uranium enrichment and economic improvements; research and development needs to achieve the economic prospects are also indicated. Finally the report takes note of the positive aspect of centrifuge enrichment as far as safeguards and nuclear safety are concerned. 27 figs, 113 refs

  6. New Measurements of s-Process Enrichments in Planetary Nebulae from High-Resolution Near-Infrared Spectra

    Science.gov (United States)

    Dinerstein, Harriet L.; Karakas, Amanda; Sterling, Nicholas C.; Kaplan, Kyle

    2017-06-01

    We present preliminary results from a high-spectral resolution survey of near-infrared emission lines of neutron-capture elements in planetary nebulae using the Immersion Grating Infrared Spectrometer, IGRINS (Park et al. 2014, SPIE. 9147, 1), which spans the H- and K-bands at spectral resolving power R ≈ 45,000. Both the [Kr III] and [Se IV] lines identified by Dinerstein (2001, ApJL, 550, L223) are seen in nearly all of an initial sample of ≈ 15 nebulae, with improved accuracy over earlier studies based on lower-resolution data (Sterling & Dinerstein 2008, ApJS, 174, 158; Sterling, Porter, & Dinerstein 2015, ApJS, 218, 25). Several new detections of the [Rb IV], [Cd IV], and [Ge VI] lines identified by Sterling et al. (2016, ApJL, 819, 9), as well as a [Br V] line, were made. About half the objects in this sample descend from stars with [Fe/H] = -0.7 ± 0.2 dex, while the remainder have -0.3 ≤ [Fe/H] ≤ 0. We compare the measured enhancements of Se, Kr, Rb, and Cd with predictions of their production by slow-neutron captures (the s-process) during the AGB from theoretical evolutionary models for the corresponding metallicities and various initial masses. New nucleosynthesis calculations were carried out for [Fe/H] = -0.7 for initial masses between 1.1 and 3 M⊙ using the Monash stellar evolution and post-processing codes described in Karakas & Lugaro (2016, ApJ, 825, 26), which provides the nucleosynthesis predictions for the metal-rich end of our sample. The Monash models predict enrichments larger by factors of two or more than those from FRUITY (Cristallo et al. 2015, ApJS, 219, 40) and NuGRID (Pignatari et al. 2016, ApJS, 225, 24) models for the same masses and metallicities. We find that the Monash models are in substantially better agreement than the others with the abundances derived from the IGRINS observations.This work is based on data taken at the McDonald Observatory of the University of Texas at Austin. IGRINS was developed with support from

  7. Process and device for step by step enrichment of deuterium and/or tritium by isotope exchange

    International Nuclear Information System (INIS)

    Iniotakis, N.; Decken, C.B. von der.

    1984-01-01

    Deuterium and/or tritium are bound to steam by isotope exchange after permeation through an exchange wall. Primary and secondary flows are guided by the counterflow principle. The secondary side has a metal oxide as oxidation catalyst. The plant can consist of several enrichment stages. The various flows and parts of the plant are described. (PW) [de

  8. Isotope enrichment

    International Nuclear Information System (INIS)

    Garbuny, M.

    1979-01-01

    The invention discloses a method for deriving, from a starting material including an element having a plurality of isotopes, derived material enriched in one isotope of the element. The starting material is deposited on a substrate at less than a critical submonatomic surface density, typically less than 10 16 atoms per square centimeter. The deposit is then selectively irradiated by a laser (maser or electronic oscillator) beam with monochromatic coherent radiation resonant with the one isotope causing the material including the one istope to escape from the substrate. The escaping enriched material is then collected. Where the element has two isotopes, one of which is to be collected, the deposit may be irradiated with radiation resonant with the other isotope and the residual material enriched in the one isotope may be evaporated from the substrate and collected

  9. Radiometric enrichment of nonradioactive ores

    International Nuclear Information System (INIS)

    Mokrousov, V.A.; Lileev, V.A.

    1979-01-01

    Considered are the methods of mineral enrichment based on the use of the radioation of various types. The physical essence of enrichment processes is presented, their classification is given. Described are the ore properties influencing the efficiency of radiometric enrichment, methods of the properties study and estimation of ore enrichment. New possibilities opened by radiometric enrichment in the technology of primary processing of mineral raw materials are elucidated. A considerable attention is paid to the main and auxiliary equipment for radiometric enrichment. The foundations of the safety engineering are presented in a brief form. Presented are also results of investigations and practical works in the field of enrichment of ores of non-ferrous, ferrous and non-metallic minerals with the help of radiometric methods

  10. Enrichment of Rare Earth Elements during magmatic and post-magmatic processes: a case study from the Loch Loyal Syenite Complex, northern Scotland

    Science.gov (United States)

    Walters, A. S.; Goodenough, K. M.; Hughes, H. S. R.; Roberts, N. M. W.; Gunn, A. G.; Rushton, J.; Lacinska, A.

    2013-10-01

    Concern about security of supply of critical elements used in new technologies, such as the Rare Earth Elements (REE), means that it is increasingly important to understand the processes by which they are enriched in crustal settings. High REE contents are found in syenite-dominated alkaline complexes intruded along the Moine Thrust Zone, a major collisional zone in north-west Scotland. The most northerly of these is the Loch Loyal Syenite Complex, which comprises three separate intrusions. One of these, the Cnoc nan Cuilean intrusion, contains two mappable zones: a Mixed Syenite Zone in which mafic melasyenite is mixed and mingled with leucosyenite and a Massive Leucosyenite Zone. Within the Mixed Syenite Zone, hydrothermal activity is evident in the form of narrow altered veins dominated by biotite and magnetite; these are poorly exposed and their lateral extent is uncertain. The REE mineral allanite is relatively abundant in the melasyenite and is extremely enriched in the biotite-magnetite veins, which have up to 2 % total rare earth oxides in bulk rock analyses. An overall model for development of this intrusion can be divided into three episodes: (1) generation of a Light Rare Earth Element (LREE)-enriched parental magma due to enrichment of the mantle source by subduction of pelagic carbonates; (2) early crystallisation of allanite in melasyenite, due to the saturation of the magma in the LREE; and (3) hydrothermal alteration, in three different episodes identified by petrography and mineral chemistry, generating the intense enrichment of REE in the biotite-magnetite veins. Dating of allanite and titanite in the biotite-magnetite veins gives ages of c. 426 Ma, overlapping with previously published crystallisation ages for zircon in the syenite.

  11. In-Situ Measurements of Low Enrichment Uranium Holdup Process Gas Piping at K-25 - Paper for Waste Management Symposia 2010 East Tennessee Technology Park Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    Rasmussen, B.

    2010-01-01

    This document is the final version of a paper submitted to the Waste Management Symposia, Phoenix, 2010, abstract BJC/OR-3280. The primary document from which this paper was condensed is In-Situ Measurement of Low Enrichment Uranium Holdup in Process Gas Piping at K-25 Using NaI/HMS4 Gamma Detection Systems, BJC/OR-3355. This work explores the sufficiency and limitations of the Holdup Measurement System 4 (HJVIS4) software algorithms applied to measurements of low enriched uranium holdup in gaseous diffusion process gas piping. HMS4 has been used extensively during the decommissioning and demolition project of the K-25 building for U-235 holdup quantification. The HMS4 software is an integral part of one of the primary nondestructive assay (NDA) systems which was successfully tested and qualified for holdup deposit quantification in the process gas piping of the K-25 building. The initial qualification focused on the measurement of highly enriched UO 2 F 2 deposits. The purpose of this work was to determine if that qualification could be extended to include the quantification of holdup in UO 2 F 2 deposits of lower enrichment. Sample field data are presented to provide evidence in support of the theoretical foundation. The HMS4 algorithms were investigated in detail and found to sufficiently compensate for UO 2 F 2 source self-attenuation effects, over the range of expected enrichment (4-40%), in the North and East Wings of the K-25 building. The limitations of the HMS4 algorithms were explored for a described set of conditions with respect to area source measurements of low enriched UO 2 F 2 deposits when used in conjunction with a 1 inch by 1/2 inch sodium iodide (NaI) scintillation detector. The theoretical limitations of HMS4, based on the expected conditions in the process gas system of the K-25 building, are related back to the required data quality objectives (DQO) for the NBA measurement system established for the K-25 demolition project. The combined

  12. Nitrogen source effects on the denitrifying anaerobic methane oxidation culture and anaerobic ammonium oxidation bacteria enrichment process.

    Science.gov (United States)

    Fu, Liang; Ding, Jing; Lu, Yong-Ze; Ding, Zhao-Wei; Zeng, Raymond J

    2017-05-01

    The co-culture system of denitrifying anaerobic methane oxidation (DAMO) and anaerobic ammonium oxidation (Anammox) has a potential application in wastewater treatment plant. This study explored the effects of permutation and combination of nitrate, nitrite, and ammonium on the culture enrichment from freshwater sediments. The co-existence of NO 3 - , NO 2 - , and NH 4 + shortened the enrichment time from 75 to 30 days and achieved a total nitrogen removal rate of 106.5 mg/L/day on day 132. Even though ammonium addition led to Anammox bacteria increase and a higher nitrogen removal rate, DAMO bacteria still dominated in different reactors with the highest proportion of 64.7% and the maximum abundance was 3.07 ± 0.25 × 10 8 copies/L (increased by five orders of magnitude) in the nitrite reactor. DAMO bacteria showed greater diversity in the nitrate reactor, and one was similar to M. oxyfera; DAMO bacteria in the nitrite reactor were relatively unified and similar to M. sinica. Interestingly, no DAMO archaea were found in the nitrate reactor. This study will improve the understanding of the impact of nitrogen source on DAMO and Anammox co-culture enrichment.

  13. Modular enrichment measurement system for in-situ enrichment assay

    International Nuclear Information System (INIS)

    Stewart, J.P.

    1976-01-01

    A modular enrichment measurement system has been designed and is in operation within General Electric's Nuclear Fuel Fabrication Facility for the in-situ enrichment assay of uranium-bearing materials in process containers. This enrichment assay system, which is based on the ''enrichment meter'' concept, is an integral part of the site's enrichment control program and is used in the in-situ assay of the enrichment of uranium dioxide (UO 2 ) powder in process containers (five gallon pails). The assay system utilizes a commercially available modular counting system and a collimnator designed for compatability with process container transport lines and ease of operator access. The system has been upgraded to include a microprocessor-based controller to perform system operation functions and to provide data acquisition and processing functions. Standards have been fabricated and qualified for the enrichment assay of several types of uranium-bearing materials, including UO 2 powders. The assay system has performed in excess of 20,000 enrichment verification measurements annually and has significantly contributed to the facility's enrichment control program

  14. Industrial aspects in uranium enrichment

    International Nuclear Information System (INIS)

    Mezin, M.

    1982-05-01

    Characteristics of isotope separation processes in operation and under development are discussed. These include the number of stages in series, the number of components, the component unit capacity and enery requirements. The implementation of an enrichment process and the question of an enrichment plant in Australia are also considered

  15. Measurement of Soot Volume Fraction and Temperature for Oxygen-Enriched Ethylene Combustion Based on Flame Image Processing

    Directory of Open Access Journals (Sweden)

    Weijie Yan

    2017-05-01

    Full Text Available A method for simultaneously visualizing the two-dimensional distributions of temperature and soot volume fraction in an ethylene flame was presented. A single-color charge-coupled device (CCD camera was used to capture the flame image in the visible spectrum considering the broad-response spectrum of the R and G bands of the camera. The directional emissive power of the R and G bands were calibrated and used for measurement. Slightly increased temperatures and reduced soot concentration were predicted in the central flame without self-absorption effects considered, an iterative algorithm was used for eliminating the effect of self-absorption. Nine different cases were presented in the experiment to demonstrate the effects of fuel mass flow rate and oxygen concentration on temperature and soot concentration in three different atmospheres. For ethylene combustion in pure-air atmosphere, as the fuel mass flow rate increased, the maximum temperature slightly decreased, and the maximum soot volume fraction slightly increased. For oxygen fractions of 30%, 40%, and 50% combustion in O2/N2 oxygen-enhanced atmospheres, the maximum flame temperatures were 2276, 2451, and 2678 K, whereas combustion in O2/CO2 atmospheres were 1916, 2322, and 2535 K. The maximum soot volume fractions were 4.5, 7.0, and 9.5 ppm in oxygen-enriched O2/N2 atmosphere and 13.6, 15.3, and 14.8 ppm in oxygen-enriched O2/CO2 atmosphere. Compared with the O2/CO2 atmosphere, combustion in the oxygen-enriched O2/N2 atmosphere produced higher flame temperature and larger soot volume fraction. Preliminary results indicated that this technique is reliable and can be used for combustion diagnosis.

  16. Isotopic analysis of uranium hexafluoride highly enriched in U-235; Analyse isotopique de l'hexafluorure d'uranium fortement enrichi en U 235

    Energy Technology Data Exchange (ETDEWEB)

    Chaussy, L; Boyer, R [Commissariat a l' Energie Atomique, Pierrelatte (France). Centre d' Etudes Nucleaires

    1968-07-01

    Isotopic analysis of uranium in the form of the hexafluoride by mass-spectrometry gives gross results which are not very accurate. Using a linear interpolation method applied to two standards it is possible to correct for this inaccuracy as long as the isotopic concentrations are less than about 10 per cent in U-235. Above this level, the interpolations formula overestimates the results, especially if the enrichment of the analyzed samples is higher than 1.3 with respect to the standards. A formula is proposed for correcting the interpolation equation and for the extending its field of application to high values of the enrichment ({approx_equal}2) and of the concentration. It is shown that by using this correction the results obtained have an accuracy which depends practically only on that of the standards, taking into account the dispersion in the measurements. (authors) [French] L'analyse isotopique de l'uranium sous forme d'hexafluorure, par spectrometrie de masse, fournit des resultats bruts entaches d'inexactitude. Une methode d'interpolation lineaire entre deux etalons permet de corriger cette inexactitude, tant que les concentrations isotopiques sont inferieures a 10 pour cent en U-235 environ. Au-dessus de cette valeur, la formule d'interpolation surestime les resultats, notamment si l'enrichissement des echantillons analyses par rapport aux etalons est superieur a 1,3. On propose une formule de correction de l'equation d'interpolation qui etend son domaine d'application jusqu'a des valeurs elevees d'enrichissement ({approx_equal}2) et de concentration. On montre experimentalement que par cette correction, les resultats atteignent, a la precision des mesures, une exactitude qui ne depend pratiquement plus que de celles des etalons. (auteurs)

  17. The processing of enriched germanium for the MAJORANA DEMONSTRATOR and R&D for a next generation double-beta decay experiment

    Science.gov (United States)

    Abgrall, N.; Arnquist, I. J.; Avignone, F. T., III; Barabash, A. S.; Bertrand, F. E.; Bradley, A. W.; Brudanin, V.; Busch, M.; Buuck, M.; Caja, J.; Caja, M.; Caldwell, T. S.; Christofferson, C. D.; Chu, P.-H.; Cuesta, C.; Detwiler, J. A.; Dunagan, C.; Dunstan, D. T.; Efremenko, Yu.; Ejiri, H.; Elliott, S. R.; Gilliss, T.; Giovanetti, G. K.; Goett, J.; Green, M. P.; Gruszko, J.; Guinn, I. S.; Guiseppe, V. E.; Haufe, C. R. S.; Henning, R.; Hoppe, E. W.; Jasinski, B. R.; Kidd, M. F.; Konovalov, S. I.; Kouzes, R. T.; Lopez, A. M.; MacMullin, J.; Martin, R. D.; Massarczyk, R.; Meijer, S. J.; Mertens, S.; Meyer, J. H.; Myslik, J.; O'Shaughnessy, C.; Poon, A. W. P.; Radford, D. C.; Rager, J.; Reine, A. L.; Reising, J. A.; Rielage, K.; Robertson, R. G. H.; Shanks, B.; Shirchenko, M.; Suriano, A. M.; Tedeschi, D.; Toth, L. M.; Trimble, J. E.; Varner, R. L.; Vasilyev, S.; Vetter, K.; Vorren, K.; White, B. R.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Yu, C.-H.; Yumatov, V.; Zhitnikov, I.; Zhu, B. X.

    2018-01-01

    The MAJORANA DEMONSTRATOR is an array of point-contact Ge detectors fabricated from Ge isotopically enriched to 88% in 76 Ge to search for neutrinoless double beta decay. The processing of Ge for germanium detectors is a well-known technology. However, because of the high cost of Ge enriched in 76 Ge special procedures were required to maximize the yield of detector mass and to minimize exposure to cosmic rays. These procedures include careful accounting for the material; shielding it to reduce cosmogenic generation of radioactive isotopes; and development of special reprocessing techniques for contaminated solid germanium, shavings, grindings, acid etchant and cutting fluids from detector fabrication. Processing procedures were developed that resulted in a total yield in detector mass of 70%. However, none of the acid-etch solution and only 50% of the cutting fluids from detector fabrication were reprocessed. Had they been processed, the projections for the recovery yield would be between 80% and 85%. Maximizing yield is critical to justify a possible future ton-scale experiment. A process for recovery of germanium from the acid-etch solution was developed with yield of about 90%. All material was shielded or stored underground whenever possible to minimize the formation of 68Ge by cosmic rays, which contributes background in the double-beta decay region of interest and cannot be removed by zone refinement and crystal growth. Formation of 68Ge was reduced by a significant factor over that in natural abundance detectors not protected from cosmic rays.

  18. Centrifuge enrichment program

    International Nuclear Information System (INIS)

    Astley, E.R.

    1976-01-01

    Exxon Nuclear has been active in privately funded research and development of centrifuge enrichment technology since 1972. In October of 1975, Exxon Nuclear submitted a proposal to design, construct, and operate a 3000-MT SWU/yr centrifuge enrichment plant, under the provisions of the proposed Nuclear Fuel Assurance Act of 1975. The U.S. Energy Research and Development Administration (ERDA) accepted the proposal as a basis for negotiation. It was proposed to build a 1000-MT SWU/yr demonstration increment to be operational in 1982; and after successful operation for about one year, expand the facilities into a 3000-MT SWU/yr plant. As part of the overall centrifuge enrichment plant, a dedicated centrifuge manufacturing plant would be constructed; sized to support the full 3000-MT SWU/yr plant. The selection of the centrifuge process by Exxon Nuclear was based on an extremely thorough evaluation of current and projected enrichment technology; results show that the technology is mature and the process will be cost effective. The substantial savings in energy (about 93%) from utilization of the centrifuge option rather than gaseous diffusion is a compelling argument. As part of this program, Exxon Nuclear has a large hardware R and D program, plus a prototype centrifuge manufacturing capability in Malta, New York. To provide a full-scale machine and limited cascade test capability, Exxon Nuclear is constructing a $4,000,000 Centrifuge Test Facility in Richland, Washington. This facility was to initiate operations in the Fall of 1976. Exxon Nuclear is convinced that the centrifuge enrichment process is the rational selection for emergence of a commercial enrichment industry

  19. Results from a 'Proof-of-Concept' Demonstration of RF-Based Tracking of UF6 Cylinders during a Processing Operation at a Uranium Enrichment Plant

    International Nuclear Information System (INIS)

    Pickett, Chris A; Kovacic, Donald N; Whitaker, J Michael; Younkin, James R; Hines, Jairus B; Laughter, Mark D; Morgan, Jim; Carrick, Bernie; Boyer, Brian; Whittle, K.

    2008-01-01

    Approved industry-standard cylinders are used globally for processing, storing, and transporting uranium hexafluoride (UF 6 ) at uranium enrichment plants. To ensure that cylinder movements at enrichment facilities occur as declared, the International Atomic Energy Agency (IAEA) must conduct time-consuming periodic physical inspections to validate facility records, cylinder identity, and containment. By using a robust system design that includes the capability for real-time unattended monitoring (of cylinder movements), site-specific rules-based event detection algorithms, and the capability to integrate with other types of monitoring technologies, one can build a system that will improve overall inspector effectiveness. This type of monitoring system can provide timely detection of safeguard events that could be used to ensure more timely and appropriate responses by the IAEA. It also could reduce reliance on facility records and have the additional benefit of enhancing domestic safeguards at the installed facilities. This paper will discuss the installation and evaluation of a radio-frequency- (RF-) based cylinder tracking system that was installed at a United States Enrichment Corporation Centrifuge Facility. This system was installed primarily to evaluate the feasibility of using RF technology at a site and the operational durability of the components under harsh processing conditions. The installation included a basic system that is designed to support layering with other safeguard system technologies and that applies fundamental rules-based event processing methodologies. This paper will discuss the fundamental elements of the system design, the results from this site installation, and future efforts needed to make this technology ready for IAEA consideration

  20. Enrichment plants. A survey of major new uranium enriching projects

    International Nuclear Information System (INIS)

    Kovan, D.

    1976-01-01

    The work enrichment situation is reported. The development of enrichment in the U.S. and in Europe is outlined. A brief description is given of the technology of separation by diffusion and by centrifugation and the advantages and disadvantages of the two processes are compared. Finally the supply and demand situation is briefly considered. (U.K.)

  1. AEC determines uranium enrichment policy

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    The Advisory Committee on Uranium Enrichment of the Atomic Energy Commission (AEC) has submitted a report to AEC chairman concerning the promotion of the introduction of advanced material, high performance centrifuges to replace conventional metallic drum centrifuges, and the development of next generation advanced centrifuges. The report also called for the postponement until around 1997 of the decision whether the development should be continued or not on atomic vapor laser isotope separation (AVLIS) and molecular laser isotope separation (MLIS) processes, as well as the virtual freezing of the construction of a chemical process demonstration plant. The report was approved by the AEC chairman in August. The uranium enrichment service market in the world will continue to be characterized by oversupply. The domestic situation of uranium enrichment supply-demand trend, progress of the expansion of Rokkasho enrichment plant, the trend in the development of gas centrifuge process and the basic philosophy of commercializing domestic uranium enrichment are reported. (K.I.)

  2. Uranium enrichment

    International Nuclear Information System (INIS)

    1991-11-01

    This paper analyzes under four different scenarios the adequacy of a $500 million annual deposit into a fund to pay for the cost of cleaning up the Department of Energy's (DOE) three aging uranium enrichment plants. These plants are located in Oak Ridge, Tennessee; Paducah, Kentucky; and Portsmouth, Ohio. In summary the following was found: A fixed annual $500 million deposit made into a cleanup fund would not be adequate to cover total expected cleanup costs, nor would it be adequate to cover expected decontamination and decommissioning (D and D) costs. A $500 million annual deposit indexed to an inflation rate would likely be adequate to pay for all expected cleanup costs, including D and D costs, remedial action, and depleted uranium costs

  3. Application of a novel calcium looping process for production of heat and carbon dioxide enrichment of greenhouses

    International Nuclear Information System (INIS)

    Ramezani, Mohammad; Shah, Kalpit; Doroodchi, Elham; Moghtaderi, Behdad

    2015-01-01

    Highlights: • The greenhouse calcium looping process was developed by ASPEN Plus simulator. • In this process, the carbonation reaction provides required heat during night time. • The calcination reaction provides required carbon dioxide during day time. • This novel process saves up to 72% energy compared to the fossil fuel burners. • The process thermodynamically attributes to zero emission of carbon dioxide. - Abstract: Greenhouses typically employ conventional burner systems to suffice heat and carbon dioxide required for plant growth. The energy requirement and carbon dioxide emissions from fossil fuel burner are generally high. As an alternative, this paper describes a novel greenhouse calcium looping process which is expected to decrease the energy requirements and associated carbon dioxide emissions. The conceptual design of greenhouse calcium looping process is carried out in the ASPEN Plus v 7.3 simulator. In a greenhouse calcium looping process, the calcination reaction is considered to take place during day time in order to provide the required optimum carbon dioxide between 1000 and 2000 ppm, while the carbonation reaction is occurred during night time to provide required heat. The process simulations carried out in ASPEN indicates that greenhouse calcium looping process theoretically attributes to zero emission of carbon dioxide. Moreover, in a scenario modelling study compared to the conventional natural gas burner system, the heat duty requirements in the greenhouse calcium looping process were found to reduce by as high as 72%

  4. 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

  5. An experimental investigation of the combustion process of a heavy-duty diesel engine enriched with H{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Liew, C.; Li, H.; Nuszkowski, J.; Liu, S.; Gatts, T.; Atkinson, R.; Clark, N. [Department of Mechanical and Aerospace Engineering, West Virginia University, Morgantown, WV 26506-6106 (United States)

    2010-10-15

    This paper investigated the effect of hydrogen (H{sub 2}) addition on the combustion process of a heavy-duty diesel engine. The addition of a small amount of H{sub 2} was shown to have a mild effect on the cylinder pressure and combustion process. When operated at high load, the addition of a relatively large amount of H{sub 2} substantially increased the peak cylinder pressure and the peak heat release rate. Compared to the two-stage combustion process of diesel engines, a featured three-stage combustion process of the H{sub 2}-diesel dual fuel engine was observed. The extremely high peak heat release rate represented a combination of diesel diffusion combustion and the premixed combustion of H{sub 2} consumed by multiple turbulent flames, which substantially enhanced the combustion process of H{sub 2}-diesel dual fuel engine. However, the addition of a relatively large amount of H{sub 2} at low load did not change the two-stage heat release process pattern. The premixed combustion was dramatically inhibited while the diffusion combustion was slightly enhanced and elongated. The substantially reduced peak cylinder pressure at low load was due to the deteriorated premixed combustion. (author)

  6. South Australia, uranium enrichment

    International Nuclear Information System (INIS)

    1976-02-01

    The Report sets out the salient data relating to the establishment of a uranium processing centre at Redcliff in South Australia. It is conceived as a major development project for the Commonwealth, the South Australian Government and Australian Industry comprising the refining and enrichment of uranium produced from Australian mines. Using the data currently available in respect of markets, demand, technology and possible financial return from overseas sales, the project could be initiated immediately with hexafluoride production, followed rapidly in stages by enrichment production using the centrifuge process. A conceptual development plan is presented, involving a growth pattern that would be closely synchronised with the mining and production of yellowcake. The proposed development is presented in the form of an eight-and-half-year programme. Costs in this Report are based on 1975 values, unless otherwise stated. (Author)

  7. Effects of carbon sources on the enrichment of halophilic polyhydroxyalkanoate-storing mixed microbial culture in an aerobic dynamic feeding process

    Science.gov (United States)

    Cui, You-Wei; Zhang, Hong-Yu; Lu, Peng-Fei; Peng, Yong-Zhen

    2016-08-01

    Microbial polyhydroxyalkanoate (PHA) production serves as a substitute for petroleum-based plastics. Enriching mixed microbial cultures (MMCs) with the capacity to store PHA is a key precursor for low-cost PHA production. This study investigated the impact of carbon types on enrichment outcomes. Three MMCs were separately fed by acetate sodium, glucose, and starch as an enriching carbon source, and were exposed to long-term aerobic dynamic feeding (ADF) periods. The PHA production capacity, kinetics and stoichiometry of the enrichments, the PHA composition, and the microbial diversity and community composition were explored to determine carbon and enrichment correlations. After 350-cycle enriching periods under feast-famine (F-F) regimes, the MMCs enriched by acetate sodium and glucose contained a maximum PHA content of 64.7% and 60.5% cell dry weight (CDW). The starch-enriched MMC only had 27.3% CDW of PHA. High-throughput sequencing revealed that non-PHA bacteria survived alongside PHA storing bacteria, even under severe F-F selective pressure. Genus of Pseudomonas and Stappia were the possible PHA accumulating bacteria in acetate-enriched MMC. Genus of Oceanicella, Piscicoccus and Vibrio were found as PHA accumulating bacteria in glucose-enriched MMC. Vibrio genus was the only PHA accumulating bacteria in starch-enriched MMC. The community diversity and composition were regulated by the substrate types.

  8. 31 CFR 540.316 - Uranium enrichment.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Uranium enrichment. 540.316 Section 540.316 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... REGULATIONS General Definitions § 540.316 Uranium enrichment. The term uranium enrichment means the process of...

  9. Characterization of recharge processes in shallow and deeper aquifers using isotopic signatures and geochemical behavior of groundwater in an arsenic-enriched part of the Ganga Plain

    International Nuclear Information System (INIS)

    Saha, Dipankar; Sinha, U.K.; Dwivedi, S.N.

    2011-01-01

    Research highlights: → Sub-regional scale aquifers delineated in arsenic-enriched belt in the Ganga Plain. Isotopic fingerprint of the groundwater, from arsenic-enriched and arsenic-safe aquifers established for the first time in the Ganga Plain. → Recharge processes and the water provenances of vertically separated Quaternary aquifers have been established. → Mean residence time of groundwater in the deeper aquifers has been worked out using C-14 isotope. → Water from the deeper aquifer has been correlated with the paleoclimatic model of the Middle Ganga Plain (Mid-Ganga Basin) for 6-2 ka. - Abstract: Arsenic concentrations in groundwater extracted from shallow aquifers in some areas of the Ganga Plain in the states of Bihar and Uttar Pradesh, exceed 50 μg L -1 and locally reach levels in the 400 μg L -1 range. The study covered 535 km 2 of active flood plain of the River Ganga, in Bihar where a two-tier aquifer system has been delineated in a multi-cyclic sequence of Quaternary sand, clay, sandy clay and silty clay all ≤∼250 m below ground surface. The research used isotopic signatures (δ 18 O, δ 2 Η, 3 H, 14 C) and major chemical constituents (HCO 3 - ,SO 4 2- ,NO 3 - ,Cl - ,Ca 2+ ,Mg 2+ ,Na + ,K + ,As total ) of groundwater to understand the recharge processes and groundwater circulation in the aquifers. Values of δ 18 O and δ 2 Η combined with 3 H data indicate that the recharge to the As-enriched top 40 m of the deposits is modern ( -1 ) is hydrologically isolated from the upper aquifer and is characterized by lower 14 C concentration and lower (more negative) δ 18 O values. Groundwater in the lower aquifer is ∼3 ka old, occurs under semi-confined to confined conditions, with hydrostatic head at 1.10 m above the head of the upper aquifer during the pre-monsoon. The recharge areas of the lower aquifer lies in Pleistocene deposits in basin margin areas with the exposed Vindhyan System, at about 55 km south of the area.

  10. Availability of enrichment services

    International Nuclear Information System (INIS)

    Svenke, E.

    1977-01-01

    The report summarizes major uncertainties which are likely to influence future demands for uranium isotopic enrichment. Since for the next decade the development of nuclear power will be largely concerned with the increment in demand the timely need for enrichment capacity will be particularly sensitive to assumptions about growth rates. Existing worldwide capacity together with capacities under construction will be sufficient well into the 1980's. However, long decision and construction leadtime, uncertainty as to future demand as well as other factors, specifically high capital need, all of which entail financial risks, create hindrances to a timely development of increment. The adequacy of current technology is well demonstrated in plant operation and new technology is under way. Technology is, however, not freely available on a purely commercial basis. Commercial willingness, which anticipates a limited degree of financial risk, is requesting both long term back-up from the utilities that would parallel their firm decisions on the acquisition of nuclear power units, and a protective government umbrella. This situation depends on the symbiotic relationship that exists between the nuclear power generating organizations, the enrichment undertakings and the governments involved. The report accordingly stresses the need for a more cooperative approach and this, moreover, at the multinational level. There is otherwise a risk that proper resources and financing means will not be allocated to the enrichment sector. Export limitations that request the highest degree of industrial processing of nuclear fuel, i.e. the compulsory enrichment of natural uranium, do not serve the interests of overall industrial efficiency

  11. KARAKTERISTIK MIKROKAPSUL MINYAK KAYA ASAM LEMAK OMEGA-3 DARI HASIL SAMPING PENEPUNGAN LEMURU [Characteristics of Microcapsule of omega-3 Fatty Acids Enriched Oil from Lemuru Meal Processing

    Directory of Open Access Journals (Sweden)

    Teti Estiasih 1

    2008-12-01

    Full Text Available Omega-3 fatty acids enriched fish oil from lemuru fishmeal processing met the quality standard of food grade fish oil, but it was susceptible to oxidation. Microencapsulation by spray drying was one method that could protect this oil against oxidation and the microcapsule could be applied more widely and easier to handle. The important factor that affected microencapsulation process by spray drying method was encapsulant to core ratio. The objective of research was to elucidate the effect of encapsulant to core ratio (2:1; 3:1; 4:1; 5:1; and 6:1 (w/w on characteristics of omega-3 fatty acids enriched fish oil microcapsule. The increase of microencapsulation efficiency and the decrease of surface oil proportion were related to better emulsion stability prior to spray drying and film forming ability around oil globule as the sodium caseinate proportion increased. Emulsification and heating during spray drying could induce hydrolysis of triglycerides in fish oil. Therefore, the quantity of free fatty acids relatively unchanged although the proportion of encapsulated oil decreased. The decrease of oxidation degree is caused by better protective effect of sodium caseinate during emulsification and spray drying due to better film forming ability as proportion of encapsulant increased. However, it was followed by the decrease of omega-3 fatty acids content that related to decreasing proportion of fish oil. This phenomenon was supported by unchanging omega-3 fatty acids retention that showed protective effect of sodium caseinate on oxidation during microencapsulation. Different encapsulant to core ratio did not change yield of microcapsule. Different proportion of surface oil did not affect microcapsule recovery.

  12. Effect of composition and processing conditions on selected characteristics of extruded corn instant gruels enriched with fruits addition

    Directory of Open Access Journals (Sweden)

    Kręcisz Magdalena

    2018-01-01

    Full Text Available Cranberries and goji berries were used as natural supplements in extruded instant corn gruels. The effects of additive type and level, as well as extrusion-cooking screw speed on selected properties of extrudates were tested. Corn grit was used as the base raw materials and dry and ground goji berries and cranberries were added at 1, 2, 3, 4 and 5%. Extrusion-cooking of blends was performed with a single screw extruder at temperature ranged 125-135°C using various screw speed during processing. Extrudates were ground below 1 mm for instant gruels. Water absorption, water solubility, as well as colour profile were tested. The results showed that the highest water absorption was evaluated for instant gruels consist the highest amount of goji berries extruded at the highest screw speed during processing, while cranberries addition have no significant effect on water absorption. Increasing amount of dry cranberries and goji berries in the recipe affected on lowering the water solubility of the extrudates. Significant effect of fruits on color coordinates was observed. Increasing amount of dry berries lowered lightness L* and yellowness of instant gruels, especially when goji berries were used in the recipe. Increasing the screw speed during processing decreased intensity b* values.

  13. Process and device for the excitation and selective dissociation by absorption of a laser light and application to isotopic enrichment

    International Nuclear Information System (INIS)

    Rigny, Paul.

    1975-01-01

    The description is given of a process for the excitation and selective dissociation by absorption of the monochromatic light emitted by a high power laser. The laser light at frequency ν 1 is beamed on to an isotopic mixture of gaseous molecules, some of these molecules presenting transitions, between two vibration levels corresponding to a given isotope, separated by an energy interval ΔE 1 =2h ν 1 , and the molecules of a given isotopic species are thus preferentially dissociated into several component parts [fr

  14. Innovative Process to Enrich Carbon Content of EFB-Derived Biochar as an Alternative Energy Source in Ironmaking

    Directory of Open Access Journals (Sweden)

    Hadi Purwanto

    2018-01-01

    Full Text Available This paper describes the mechanism of a developed process—an integrated pyrolysis-tar decomposition process—to produce oil palm empty fruit bunch- (EFB- derived biochar with additional solid carbon within the biochar bodies, produced by decomposition of tar vapor on its pore surface, using the chemical vapor infiltration (CVI method. The product, carbon-infiltrated biochar, was characterized to investigate the possibility to be used as partial coke breeze replacement in ironmaking. Carbon-infiltrated biochar is proposed to be utilized for a sintering process that could reduce the consumption of coke and CO2 emission in iron-steel industry.

  15. Expansion and functional properties of extruded snacks enriched with nutrition sources from food processing by-products

    OpenAIRE

    Korkerd, Sopida; Wanlapa, Sorada; Puttanlek, Chureerat; Uttapap, Dudsadee; Rungsardthong, Vilai

    2015-01-01

    Rich sources of protein and dietary fiber from food processing by-products, defatted soybean meal, germinated brown rice meal, and mango peel fiber, were added to corn grit at 20 % (w/w) to produce fortified extruded snacks. Increase of total dietary fiber from 4.82 % (wb) to 5.92–17.80 % (wb) and protein from 5.03 % (wb) to 5.46–13.34 % were observed. The product indicated high expansion and good acceptance tested by sensory panels. There were 22.33–33.53 and 5.30–11.53 fold increase in the ...

  16. Juvenile psittacine environmental enrichment.

    Science.gov (United States)

    Simone-Freilicher, Elisabeth; Rupley, Agnes E

    2015-05-01

    Environmental enrichment is of great import to the emotional, intellectual, and physical development of the juvenile psittacine and their success in the human home environment. Five major types of enrichment include social, occupational, physical, sensory, and nutritional. Occupational enrichment includes exercise and psychological enrichment. Physical enrichment includes the cage and accessories and the external home environment. Sensory enrichment may be visual, auditory, tactile, olfactory, or taste oriented. Nutritional enrichment includes variations in appearance, type, and frequency of diet, and treats, novelty, and foraging. Two phases of the preadult period deserve special enrichment considerations: the development of autonomy and puberty. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Evaluation of processes controlling the geochemical constituents in deep groundwater in Bangladesh: Spatial variability on arsenic and boron enrichment

    International Nuclear Information System (INIS)

    Halim, M.A.; Majumder, R.K.; Nessa, S.A.; Hiroshiro, Y.; Sasaki, K.; Saha, B.B.; Saepuloh, A.; Jinno, K.

    2010-01-01

    Forty-six deep groundwater samples from highly arsenic affected areas in Bangladesh were analyzed in order to evaluate the processes controlling geochemical constituents in the deep aquifer system. Spatial trends of solutes, geochemical modeling and principal component analysis indicate that carbonate dissolution, silicate weathering and ion exchange control the major-ion chemistry. The groundwater is dominantly of Na-Cl type brackish water. Approximately 17% of the examined groundwaters exhibit As concentrations higher than the maximum acceptable limit of 10 μg/L for drinking water. Strong correlation (R 2 = 0.67) of Fe with dissolved organic carbon (DOC) and positive saturation index of siderite suggests that the reductive dissolution of Fe-oxyhydroxide in presence of organic matter is considered to be the dominant process to release high content of Fe (median 0.31 mg/L) in the deep aquifer. In contrast, As is not correlated with Fe and DOC. Boron concentration in the 26% samples exceeds the standard limit of 500 μg/L, for water intended for human consumption. Negative relationships of B/Cl ratio with Cl and boron with Na/Ca ratio demonstrate the boron in deep groundwater is accompanied by brackish water and cation exchange within the clayey sediments.

  18. Progress in developing processes for converting 99Mo production from high- to low-enriched uranium--1998

    International Nuclear Information System (INIS)

    Conner, C.

    1998-01-01

    During 1998, the emphasis of our activities was focused mainly on target fabrication. Successful conversion requires a reliable irradiation target; the target being developed uses thin foils of uranium metal, which can be removed from the target hardware for dissolution and processing. This paper describes successes in (1) improving our method for heat-treating the uranium foil to produce a random-small grain structure, (2) improving electrodeposition of zinc and nickel fission-fragment barriers onto the foil, and (3) showing that these fission fragment barriers should be stable during transport of the targets following irradiation. A method was also developed for quantitatively electrodepositing uranium and plutonium contaminants in the 99 Mo. Progress was also made in broadening international cooperation in our development activities

  19. Single screw extrusion of apple pomace-enriched blends: Extrudate characteristics and determination of optimum processing conditions.

    Science.gov (United States)

    Singha, Poonam; Muthukumarappan, Kasiviswanathan

    2018-07-01

    Response surface methodology was used to investigate the single screw extrusion of apple pomace-defatted soy flour-corn grits blends and the product properties. Five different blends at a level of 0-20% w/w apple pomace were extrusion cooked with varied barrel and die temperature (100-140℃), screw speed (100-200 rpm), and feed moisture content (14-20% wet basis). Increasing apple pomace content in the blends significantly ( P extrudates. The expansion ratio increased with pomace inclusion level of 5% but decreased significantly ( P extruded snack products were at 140℃ barrel and die temperature, 20% feed moisture content, and 200 rpm screw speed. The results indicated active interaction between apple pomace and starch during expansion process.

  20. Quantification of Listeria monocytogenes in minimally processed leafy vegetables using a combined method based on enrichment and 16S rRNA real-time PCR.

    Science.gov (United States)

    Aparecida de Oliveira, Maria; Abeid Ribeiro, Eliana Guimarães; Morato Bergamini, Alzira Maria; Pereira De Martinis, Elaine Cristina

    2010-02-01

    Modern lifestyle markedly changed eating habits worldwide, with an increasing demand for ready-to-eat foods, such as minimally processed fruits and leafy greens. Packaging and storage conditions of those products may favor the growth of psychrotrophic bacteria, including the pathogen Listeria monocytogenes. In this work, minimally processed leafy vegetables samples (n = 162) from retail market from Ribeirão Preto, São Paulo, Brazil, were tested for the presence or absence of Listeria spp. by the immunoassay Listeria Rapid Test, Oxoid. Two L. monocytogenes positive and six artificially contaminated samples of minimally processed leafy vegetables were evaluated by the Most Probable Number (MPN) with detection by classical culture method and also culture method combined with real-time PCR (RTi-PCR) for 16S rRNA genes of L. monocytogenes. Positive MPN enrichment tubes were analyzed by RTi-PCR with primers specific for L. monocytogenes using the commercial preparation ABSOLUTE QPCR SYBR Green Mix (ABgene, UK). Real-time PCR assay presented good exclusivity and inclusivity results and no statistical significant difference was found in comparison with the conventional culture method (p < 0.05). Moreover, RTi-PCR was fast and easy to perform, with MPN results obtained in ca. 48 h for RTi-PCR in comparison to 7 days for conventional method.

  1. High-performance thin-film-transistors based on semiconducting-enriched single-walled carbon nanotubes processed by electrical-breakdown strategy

    Energy Technology Data Exchange (ETDEWEB)

    Aïssa, B., E-mail: aissab@emt.inrs.ca [Centre Énergie, Matériaux et Télécommunications, INRS, 1650, boulevard Lionel-Boulet, Varennes, Quebec J3X 1S2 (Canada); Qatar Environment and Energy Research Institute (QEERI), Qatar Foundation, P.O. Box 5825, Doha (Qatar); Nedil, M. [Telebec Wireless Underground Communication Laboratory, UQAT, 675, 1" è" r" e Avenue, Val d’Or, Québec J9P 1Y3 (Canada); Habib, M.A. [Computer Sciences and Engineering Department, Yanbu University College, P.O. Box 30031 (Saudi Arabia); Abdul-Hafidh, E.H. [High Energy Physics Department, Yanbu University College, P.O. Box 30031 (Saudi Arabia); Rosei, F. [Centre Énergie, Matériaux et Télécommunications, INRS, 1650, boulevard Lionel-Boulet, Varennes, Quebec J3X 1S2 (Canada)

    2015-02-15

    Highlights: • We selectively burn metallic single wall carbon nanotubes (SWCNT) by electrical breakdown. • We successfully achieve a semiconducting enriched-SWCNT in TFT configuration. • High performance, like On/Off of 10{sup 5} and a subthreshold swing of 165 mV/decades were obtained. • After PMMA coating, the SWCNT–TFTs were found stables for more than 4 months. - Abstract: Over the past two decades, among remarkable variety of nanomaterials, single-walled carbon nanotubes (SWCNTs) remain the most intriguing and uniquely well suited materials for applications in high-performance electronics. The most advanced technologies require the ability to form purely semiconducting SWCNTs. Here, we report on our strategy based on the well known progressive electrical breakdown process that offer this capability and serves as highly efficient means for selectively removing metallic carbon nanotubes from electronically heterogeneous random networks, deposited on silicon substrates in a thin film transistor (TFT) configuration. We demonstrate the successful achievement of semiconducting enriched-SWCNT networks in TFT scheme that reach On/Off switching ratios of ∼100,000, on-conductance of 20 μS, and a subthreshold swing of less than 165 mV/decades. The obtained TFT devices were then protected with thin film poly(methyl methacrylate) (PMMA) to keep the percolation level of the SWCNTs network spatially and temporally stable, while protecting it from atmosphere exchanges. TFT devices were found to be air-stable and maintained their excellent characteristics in ambient atmosphere for more than 4 months. This approach could work as a platform for future nanotube-based nanoelectronics.

  2. New generation enrichment monitoring technology for gas centrifuge enrichment plants

    International Nuclear Information System (INIS)

    Ianakiev, Kiril D.; Alexandrov, Boian S.; Boyer, Brian D.; Hill, Thomas R.; Macarthur, Duncan W.; Marks, Thomas; Moss, Calvin E.; Sheppard, Gregory A.; Swinhoe, Martyn T.

    2008-01-01

    The continuous enrichment monitor, developed and fielded in the 1990s by the International Atomic Energy Agency, provided a go-no-go capability to distinguish between UF 6 containing low enriched (approximately 4% 235 U) and highly enriched (above 20% 235 U) uranium. This instrument used the 22-keV line from a 109 Cd source as a transmission source to achieve a high sensitivity to the UF 6 gas absorption. The 1.27-yr half-life required that the source be periodically replaced and the instrument recalibrated. The instrument's functionality and accuracy were limited by the fact that measured gas density and gas pressure were treated as confidential facility information. The modern safeguarding of a gas centrifuge enrichment plant producing low-enriched UF 6 product aims toward a more quantitative flow and enrichment monitoring concept that sets new standards for accuracy stability, and confidence. An instrument must be accurate enough to detect the diversion of a significant quantity of material, have virtually zero false alarms, and protect the operator's proprietary process information. We discuss a new concept for advanced gas enrichment assay measurement technology. This design concept eliminates the need for the periodic replacement of a radioactive source as well as the need for maintenance by experts. Some initial experimental results will be presented.

  3. Working by projects: A way to enrich critical thinking and the writing process in a third grade eflclassroom

    Directory of Open Access Journals (Sweden)

    Sandra Dolores Ruiz

    2014-01-01

    Full Text Available This document presents the result of a qualitative action research developed with thirty-three third grade students at a public school in Bogota. This action research aimed at describing and analyzing the role of project work in the development of critical thinking in third grade efl students and to describe and document the way in which those students developed their writing skills through this methodology. The participants developed different inquiries related to topics they were interested in exploring and related to the recycling project of the school. The data were collected during eleven sessions carried out along eight months through field notes, artifacts, and audio recordings. The results show that through project work the students enhanced their emerging critical thinking skills and their writing process; improved their interactions with their classmates, discovered that learning English was something useful for their lives, and therefore they acquired more confidence in writing and speaking in English. Additionally, they became more reflective, organized and critical about what they think, what they say, and about what happens around them.

  4. Other enrichment related contracts

    International Nuclear Information System (INIS)

    Hall, J.C.

    1978-01-01

    In addition to long-term enrichment contracts, DOE has other types of contracts: (1) short-term, fixed-commitment enrichment contract; (2) emergency sales agreement for enriched uranium; (3) feed material lease agreement; (4) enriched uranium storage agreement; and (5) feed material usage agreement

  5. Uranium enrichment. Technology, economics, capacity

    International Nuclear Information System (INIS)

    Voigt, W.R. Jr.; Saire, D.E.; Gestson, D.K.; Peske, S.E.; Vanstrum, P.R.

    1983-01-01

    Large-scale enrichment of uranium has now been carried out for 40 years. While the gaseous diffusion process was the original choice of several countries and continues today to provide the major component of the world production of separative work, the last two decades have witnessed the development of a number of alternative processes for enrichment. These processes, which are being studied and deployed around the world, offer a wide range of technical and economic characteristics which will be useful in assuring adequate capacity to meet projected reactor fuel market needs through the rest of this century at competitive prices. With present uncertainties in future enriched uranium needs, it is apparent that flexibility in the deployment and operation of any enrichment process will be one of the prime considerations for the future. More economical production of separative work not only can have a beneficial impact on reactor fuel costs, but also tends to conserve natural uranium resources. This paper reviews the world scene in the enrichment component of the fuel cycle, including existing or planned commercial-scale facilities and announced R+D efforts on various processes. (author)

  6. Uranium enrichment: technology, economics, capacity

    Energy Technology Data Exchange (ETDEWEB)

    Voigt, Jr., W. R.; Vanstrum, P. R.; Saire, D. E.; Gestson, D. K.; Peske, S. E.

    1982-08-01

    Large-scale enrichment of uranium has now been carried out for 40 years. While the gaseous diffusion process was the original choice of several countries and continues today to provide the major component of the world production of separative work, the last two decades have witnessed the development of a number of alternative processes for enrichment. These processes, which are being studied and deployed around the world, offer a wide range of technical and economic characteristics which will be useful in assuring adequate capacity to meet projected reactor fuel market needs through the rest of this century at competitive prices. With present uncertainties in future enriched uranium needs, it is apparent that flexibility in the deployment and operation of any enrichment process will be one of the prime considerations for the future. More economical production of separative work not only can have a beneficial impact on reactor fuel costs, but also tends to conserve natural uranium resources. This paper reviews the world scene in the enrichment component of the fuel cycle, including existing or planned commercial-scale facilities and announced R and D efforts on various processes.

  7. Uranium enrichment: technology, economics, capacity

    International Nuclear Information System (INIS)

    Voigt, W.R. Jr.; Vanstrum, P.R.; Saire, D.E.; Gestson, D.K.; Peske, S.E.

    1982-01-01

    Large-scale enrichment of uranium has now been carried out for 40 years. While the gaseous diffusion process was the original choice of several countries and continues today to provide the major component of the world production of separative work, the last two decades have witnessed the development of a number of alternative processes for enrichment. These processes, which are being studied and deployed around the world, offer a wide range of technical and economic characteristics which will be useful in assuring adequate capacity to meet projected reactor fuel market needs through the rest of this century at competitive prices. With present uncertainties in future enriched uranium needs, it is apparent that flexibility in the deployment and operation of any enrichment process will be one of the prime considerations for the future. More economical production of separative work not only can have a beneficial impact on reactor fuel costs, but also tends to conserve natural uranium resources. This paper reviews the world scene in the enrichment component of the fuel cycle, including existing or planned commercial-scale facilities and announced R and D efforts on various processes

  8. Uranium enrichment. 1980 annual report

    International Nuclear Information System (INIS)

    1981-05-01

    This report contains data and related information on the production of enriched uranium at the gaseous diffusion plants and an update on the construction and project control center for the gas centrifuge plant. Power usage at the gaseous diffusion plants is illustrated. The report contains several glossy color pictures of the plants and processes described. In addition to gaseous diffusion and the centrifuge process, three advanced isotope separation process are now being developed. The business operation of the enrichment plants is described; charts on revenue, balance sheets, and income statements are included

  9. Novel process of fermenting black soybean [Glycine max (L.) Merrill] yogurt with dramatically reduced flatulence-causing oligosaccharides but enriched soy phytoalexins.

    Science.gov (United States)

    Feng, Shengbao; Saw, Chin Lee; Lee, Yuan Kun; Huang, Dejian

    2008-11-12

    Black soybeans [Glycine max (L.) Merrill] were germinated under fungal stress with food grade R. oligosporus for 3 days and were homogenized and fermented with lactic acid bacteria (LAB) to produce soy yogurt. Fungal stress led to the generation of oxylipins [oxooctadecadienoic acids (KODES) isomers and their respective glyceryl esters] and glyceollins--a type of phytoalexins unique to soybeans. In soy yogurt, the concentrations of total KODES and total glyceollins were 0.678 mg/g (dry matter) and 0.953 mg/g, respectively. The concentrations of other isoflavones (mainly genistein and daidzein and their derivatives) in soy yogurt remained largely unchanged after the processes compared with the control soy yogurt. Germination of black soybean under fungal stress for 3 days was sufficient to reduce stachyose and raffinose (which cause flatulence) by 92 and 80%, respectively. With a pH value of 4.42, a lactic acid content of 0.262%, and a maximum viable cell count of 2.1 x 10 (8) CFU/mL in the final soy yogurt, soy milk from germinated soybeans under fungal stress was concluded to be a suitable medium for yogurt-making. The resulting soy yogurt had significantly altered micronutrient profiles with significantly reduced oligosaccharides and enriched glyceollins.

  10. Synthesis of 15N-enriched urea (CO(15NH22 from 15NH3, CO, and S in a discontinuous process

    Directory of Open Access Journals (Sweden)

    C. R. Sant Ana Filho

    2012-12-01

    Full Text Available CO(15NH22 enriched with the stable isotope 15N was synthesized based on a reaction involving CO, 15NH3, and S in the presence of CH3OH. The method differs from the industrial method; a stainless steel reactor internally lined with polytetrafluoroethylene (PTFE was used in a discontinuous process under low pressure and temperature. The yield of the synthesis was evaluated as a function of the parameters: the amount of reagents, reaction time, addition of H2S, liquid solution and reaction temperature. The results showed that under optimum conditions (1.36, 4.01, and 4.48 g of 15NH3, CO, and S, respectively, 40 ml CH3OH, 40 mg H2S, 100 ºC and 120 min of reaction 1.82 g (yield 76.5% of the compound was obtained per batch. The synthesized CO(15NH22 contained 46.2% N, 0.55% biuret, melting point of 132.55 ºC and did not exhibit isotopic fractionation. The production cost of CO(15NH22 with 90.0 at. % 15N was US$ 238.60 per gram.

  11. Influence of fine process particles enriched with metals and metalloids on Lactuca sativa L. leaf fatty acid composition following air and/or soil-plant field exposure

    International Nuclear Information System (INIS)

    Schreck, Eva; Laplanche, Christophe; Le Guédard, Marina; Bessoule, Jean-Jacques; Austruy, Annabelle; Xiong, Tiantian; Foucault, Yann; Dumat, Camille

    2013-01-01

    We investigate the effect of both foliar and root uptake of a mixture of metal(loid)s on the fatty acid composition of plant leaves. Our objectives are to determine whether both contamination pathways have a similar effect and whether they interact. Lactuca sativa L. were exposed to fine process particles enriched with metal(loid)s in an industrial area. Data from a first experiment were used to conduct an exploratory statistical analysis which findings were successfully cross-validated by using the data from a second one. Both foliar and root pathways impact plant leaf fatty acid composition and do not interact. Z index (dimensionless quantity), weighted product of fatty acid concentration ratios was built up from the statistical analyses. It provides new insights on the mechanisms involved in metal uptake and phytotoxicity. Plant leaf fatty acid composition is a robust and fruitful approach to detect and understand the effects of metal(loid) contamination on plants. -- Highlights: •The study compares foliar and root transfers of metal(loid)s and their effects on plants. •Field experiments are performed combining ecotoxicological and statistical analyses. •The use of leaf fatty acid composition is a relevant indicator of exposure pathway. •The uptake pathways are independent, with an additive effect in terms of phytotoxicity. -- Metal uptake via both foliar and root pathways alters in a distinctive manner the fatty acid composition of lettuce leaves

  12. Influence of fine process particles enriched with metals and metalloids on Lactuca sativa L. leaf fatty acid composition following air and/or soil-plant field exposure.

    Science.gov (United States)

    Schreck, Eva; Laplanche, Christophe; Le Guédard, Marina; Bessoule, Jean-Jacques; Austruy, Annabelle; Xiong, Tiantian; Foucault, Yann; Dumat, Camille

    2013-08-01

    We investigate the effect of both foliar and root uptake of a mixture of metal(loid)s on the fatty acid composition of plant leaves. Our objectives are to determine whether both contamination pathways have a similar effect and whether they interact. Lactuca sativa L. were exposed to fine process particles enriched with metal(loid)s in an industrial area. Data from a first experiment were used to conduct an exploratory statistical analysis which findings were successfully cross-validated by using the data from a second one. Both foliar and root pathways impact plant leaf fatty acid composition and do not interact. Z index (dimensionless quantity), weighted product of fatty acid concentration ratios was built up from the statistical analyses. It provides new insights on the mechanisms involved in metal uptake and phytotoxicity. Plant leaf fatty acid composition is a robust and fruitful approach to detect and understand the effects of metal(loid) contamination on plants. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Development of batch electrolytic enrichment cells with 100-fold volume reduction, control electronic units and neutralization/distillation unit, to enable better sensitivity to be achieved in low-level tritium measurements when liquid scintillation counting follows the enrichment process

    International Nuclear Information System (INIS)

    Taylor, C.B.

    1980-06-01

    Full details of the batch-cell tritium enrichment system design are provided including electronic control circuits specially developed for these cells. The system incorporates a new type of concentric electrode cell (outer cathode of mild steel, anode of stainless steel, inner cathode of mild steel) with volume reduction capability 1 l to ca 9 ml. Electrolysis of 20 cells is performed in 2 steps. Down to sample volume ca 20 ml, the cells are series connected at constant currents up to 14.5 A, in the 2nd step, each cell is connected to its own individual current supply (2A) and control circuit. Automatic shut-off at the desired final volume is achieved by sensing the drop in current through the inner cathode as the electrolyte level falls below a PTFE insulator. The large electrode surface area and careful dimensioning at the foot of the cell allow operation with low starting electrolyte concentration 1.5 g Na 2 O 2 .l -1 . After electrolysis, quantitative recovery as distilled water of all hydrogen from the enriched residue is achieved by CO 2 -neutralisation and vacuum distillation at 100 0 C in a distillation unit which handles 20 cells simultaneously

  14. Environmental Development Plan: uranium enrichment

    International Nuclear Information System (INIS)

    1979-09-01

    This Environmental Development Plan identifies and examines the environmental, health, safety, and socioeconomic concerns and corresponding requirements associated with the DOE research, development, demonstration, and operation of the Uranium Enrichment program, including the gaseous diffusion process, the centrifuge process, centrifuge rotor fabrication, and related research and development activities

  15. High-EPA Biomass from Nannochloropsis salina Cultivated in a Flat-Panel Photo-Bioreactor on a Process Water-Enriched Growth Medium

    Directory of Open Access Journals (Sweden)

    Hamed Safafar

    2016-07-01

    Full Text Available Nannochloropsis salina was grown on a mixture of standard growth media and pre-gasified industrial process water representing effluent from a local biogas plant. The study aimed to investigate the effects of enriched growth media and cultivation time on nutritional composition of Nannochloropsis salina biomass, with a focus on eicosapentaenoic acid (EPA. Variations in fatty acid composition, lipids, protein, amino acids, tocopherols and pigments were studied and results compared to algae cultivated on F/2 media as reference. Mixed growth media and process water enhanced the nutritional quality of Nannochloropsis salina in laboratory scale when compared to algae cultivated in standard F/2 medium. Data from laboratory scale translated to the large scale using a 4000 L flat panel photo-bioreactor system. The algae growth rate in winter conditions in Denmark was slow, but results revealed that large-scale cultivation of Nannochloropsis salina at these conditions could improve the nutritional properties such as EPA, tocopherol, protein and carotenoids compared to laboratory-scale cultivated microalgae. EPA reached 44.2% ± 2.30% of total fatty acids, and α-tocopherol reached 431 ± 28 µg/g of biomass dry weight after 21 days of cultivation. Variations in chemical compositions of Nannochloropsis salina were studied during the course of cultivation. Nannochloropsis salina can be presented as a good candidate for winter time cultivation in Denmark. The resulting biomass is a rich source of EPA and also a good source of protein (amino acids, tocopherols and carotenoids for potential use in aquaculture feed industry.

  16. A Mock UF6 Feed and Withdrawal System for Testing Safeguards Monitoring Systems and Strategies Intended for Nuclear Fuel Enrichment and Processing Plants

    International Nuclear Information System (INIS)

    Krichinsky, Alan M.; Bates, Bruce E.; Chesser, Joel B.; Koo, Sinsze; Whitaker, J. Michael

    2009-01-01

    plant operating conditions. The ultimate use of technologies tested on the engineering-scale test bed is to work with safeguards agencies to install them in operating plants (e.g., enrichment and fuel processing plants), thereby promoting new safeguards measures with minimal impact to operating plants. In addition, this system is useful in identifying features for new plants that can be incorporated as part of 'safeguards by design,' in which load cells and other monitoring technologies are specified to provide outputs for automated monitoring and inspector evaluation.

  17. Uranium enriched granites in Sweden

    International Nuclear Information System (INIS)

    Wilson, M.R.; Aakerblom, G.

    1980-01-01

    Granites with uranium contents higher than normal occur in a variety of geological settings in the Swedish Precambrian, and represent a variety of granite types and ages. They may have been generated by (1) the anatexis of continental crust (2) processes occurring at a much greater depth. They commonly show enrichement in F, Sn, W and/or Mo. Only in one case is an important uranium mineralization thought to be directly related to a uranium-enriched granite, while the majority of epigenetic uranium mineralizations with economic potential are related to hydrothermal processes in areas where the bedrock is regionally uranium-enhanced. (Authors)

  18. Derived enriched uranium market

    International Nuclear Information System (INIS)

    Rutkowski, E.

    1996-01-01

    The potential impact on the uranium market of highly enriched uranium from nuclear weapons dismantling in the Russian Federation and the USA is analyzed. Uranium supply, conversion, and enrichment factors are outlined for each country; inventories are also listed. The enrichment component and conversion components are expected to cause little disruption to uranium markets. The uranium component of Russian derived enriched uranium hexafluoride is unresolved; US legislation places constraints on its introduction into the US market

  19. Uranium enrichment plans

    International Nuclear Information System (INIS)

    Thomas, D.C.; Gagne, R.W.

    1978-01-01

    The following topics are covered: the status of the Government's existing uranium enrichment services contracts, natural uranium requirements based on the latest contract information, uncertainty in predicting natural uranium requirements based on uranium enrichment contracts, and domestic and foreign demand assumed in enrichment planning

  20. Organizational work-family resources as predictors of job performance and attitudes: the process of work-family conflict and enrichment.

    Science.gov (United States)

    Odle-Dusseau, Heather N; Britt, Thomas W; Greene-Shortridge, Tiffany M

    2012-01-01

    The goal of the current study was to test a model where organizational resources (aimed at managing work and family responsibilities) predict job attitudes and supervisor ratings of performance through the mechanisms of work-family conflict and work-family enrichment. Employees (n = 174) at a large metropolitan hospital were surveyed at two time periods regarding perceptions of family supportive supervisor behaviors (FSSB), family supportive organizational perceptions (FSOP), bidirectional work-family conflict, bidirectional work-family enrichment, and job attitudes. Supervisors were also asked to provide performance ratings at Time 2. Results revealed FSSB at Time 1 predicted job satisfaction, organizational commitment and intention to leave, as well as supervisor ratings of performance, at Time 2. In addition, both work-family enrichment and family-work enrichment were found to mediate relationships between FSSB and various organizational outcomes, while work-family conflict was not a significant mediator. Results support further testing of supervisor behaviors specific to family support, as well models that include bidirectional work-family enrichment as the mechanism by which work-family resources predict employee and organizational outcomes.

  1. EURODIF: the uranium enrichment by gaseous diffusion

    International Nuclear Information System (INIS)

    Rougeau, J.P.

    1981-01-01

    During the seventies the nuclear power programme had an extremely rapid growth rate which entailed to increase the world uranium enrichment capacity. EURODIF is the largest undertaking in this field. This multinational joint venture built and now operates and enrichment plant using the gaseous diffusion process at Tricastin (France). This plant is delivering low enriched uranium since two years and has contracted about 110 million SWU's till 1990. Description, current activity and prospects are given in the paper. (Author) [pt

  2. A diet enriched with Mugil cephalus processed roes modulates the tissue lipid profile in healthy rats: a biochemical and chemometric assessment.

    Science.gov (United States)

    Rosa, A; Atzeri, A; Putzu, D; Scano, P

    2016-01-01

    The effect of a diet enriched with mullet bottarga on the lipid profile (total lipids, total cholesterol, unsaturated fatty acids, α-tocopherol, and hydroperoxides) of plasma, liver, kidney, brain, and perirenal adipose tissues of healthy rats was investigated. Rats fed a 10% bottarga enriched-diet for 5 days showed body weights and tissue total lipid and cholesterol levels similar to those of animals fed control diet. Univariate and multivariate results showed that bottarga enriched-diet modified the fatty acid profile in all tissues, except brain. Significant increases of n-3 PUFA, particularly EPA, were observed together with a 20:4 n-6 decrease in plasma, liver, and kidney. Perirenal adipose tissue showed a fat accumulation that reflected the diet composition. The overall data suggest that mullet bottarga may be considered as a natural bioavailable source of n-3 PUFA and qualify it as a traditional food product with functional properties and a potential functional ingredient for preparation of n-3 PUFA enriched foods.

  3. Gaseous diffusion -- the enrichment workhorse

    International Nuclear Information System (INIS)

    Shoemaker, J.E. Jr.

    1984-01-01

    Construction of the first large-scale gaseous diffusion facility was started as part of the Manhattan Project in Oak Ridge, Tennessee, in 1943. This facility, code named ''K-25,'' began operation in January 1945 and was fully on stream by September 1945. Four additional process buildings were later added in Oak Ridge as the demand for enriched uranium escalated. New gaseous diffusion plants were constructed at Paducah, Kentucky, and Portsmouth, Ohio, during this period. The three gaseous diffusion plants were the ''workhorses'' which provided the entire enriched uranium demand for the United States during the 1950s and 1960s. As the demand for enriched uranium for military purposes decreased during the early 1960s, power to the diffusion plants was curtailed to reduce production. During the 1960s, as plans for the nuclear power industry were formulated, the role of the diffusion plants gradually changed from providing highly-enriched uranium for the military to providing low-enriched uranium for power reactors

  4. Enrichment of light hydrocarbon mixture

    Science.gov (United States)

    Yang,; Dali, [Los Alamos, NM; Devlin, David [Santa Fe, NM; Barbero, Robert S [Santa Cruz, NM; Carrera, Martin E [Naperville, IL; Colling, Craig W [Warrenville, IL

    2010-08-10

    Light hydrocarbon enrichment is accomplished using a vertically oriented distillation column having a plurality of vertically oriented, nonselective micro/mesoporous hollow fibers. Vapor having, for example, both propylene and propane is sent upward through the distillation column in between the hollow fibers. Vapor exits neat the top of the column and is condensed to form a liquid phase that is directed back downward through the lumen of the hollow fibers. As vapor continues to ascend and liquid continues to countercurrently descend, the liquid at the bottom of the column becomes enriched in a higher boiling point, light hydrocarbon (propane, for example) and the vapor at the top becomes enriched in a lower boiling point light hydrocarbon (propylene, for example). The hollow fiber becomes wetted with liquid during the process.

  5. Report of the Subcommittee on Domestic Uranium Enrichment

    International Nuclear Information System (INIS)

    1981-01-01

    A report by the Subcommittee on Domestic Uranium Enrichment to the Atomic Energy Commission is described; which covers the procedure of the domestic uranium enrichment by centrifugal process up to the commercial production, reviewing the current situation in this field. Domestic uranium enrichment is important in the aspects of securing stable enrichment service, establishing sound fuel cycle, and others. As the future target, the production around the year 2000 is set at 3,000 tons SWU per year at least. The business of uranium enrichment, which is now developed in the Power Reactor and Nuclear Fuel Development Corporation, is to be carried out by private enterprise. The contents are as follows: demand and supply balance of uranium enrichment service, significance of domestic uranium enrichment, evaluation of centrifugal uranium enrichment technology, the target of domestic uranium enrichment, the policy of domestic uranium enrichment promotion. (J.P.N.)

  6. Perspectives for the uranium enrichment in Brazil

    International Nuclear Information System (INIS)

    Senna, J.G.S.M.

    1991-01-01

    Through an analysis of the electrical energy future in Brazil, the needs for enriched uranium are discussed, and therefore the importance of developing local capability for self-production. A description of the production processes that are well established is given first, then the analysis itself is performed and finally a visualization of the International Market for enriched uranium is shown. (author)

  7. Uranium enrichment : global view and Brazilian perspectives

    International Nuclear Information System (INIS)

    Zouain, D.M.; Sakamoto, L.H.

    1981-12-01

    A global view of isotope enrichment involving a general description of process (technical-economical aspects and policy) and status in developing countries is done. An enrichment demand in function of the Brazilian Nuclear Program is evaluated, analyzing a probable market and a low market. The perspectives to attend this demand, are studied. (E.G.) [pt

  8. A novel approach using metabolomics coupled with hematological and biochemical parameters to explain the enriching-blood effect and mechanism of unprocessed Angelica sinensis and its 4 kinds of processed products.

    Science.gov (United States)

    Ji, Peng; Wei, Yanming; Hua, Yongli; Zhang, Xiaosong; Yao, Wanling; Ma, Qi; Yuan, Ziwen; Wen, Yanqiao; Yang, Chaoxue

    2018-01-30

    Angelica sinensis (AS), root of Angelica sinensis (Oliv.) Diels, an important kind of Chinese traditional herbal medicine, has been used for women to enrich the blood for thousands of years. It is mainly distributed in Gansu province of China. According to Traditional Chinese medicine usage, unprocessed AS (UAS) and its 4 kinds of processed products (ASs) are all used to treat different diseases or syndromes. The difference among the enriching-blood effects of ASs is unclear. And their exact mechanisms of enriching the blood are not fully understood. In this study, our aim is to compare the enriching-blood effect and explain the related mechanism of ASs, to lay the foundation for the blood deficiency diagnosis and the rational use of ASs in the clinic. ASs were used to intervene the blood deficiency syndrome model mice induced by acetyl phenylhydrazine (APH) and cyclophosphamide (CTX). A novel approach using metabolomics coupled with hematological and biochemical parameters to explain the enriching-blood effect and mechanism of ASs was established. The blood routine examination, ATPase, glucose-6-phosphate dehydrogenase, methemoglobin, glutathion peroxidase, glutathione reductase, and erythropoietin were measured. Two biofluids (plasma and urine) obtained from mice were analyzed with GC-MS. Distinct changes in metabolite patterns of the two biofluids after mice were induced by APH and CTX, and mice were intervened with ASs were analyzed using partial least squares-discriminant analysis. Potential biomarkers were found using a novel method including variable importance in the projection (VIP) >1.0, volcano plot analysis, and significance analysis of microarray. The results of hematological, biochemical parameters and the integrated metabolomics all showed the blood deficiency syndrome model was built successfully, ASs exhibited different degree of enriching-blood effect, and AS pached with alcohol (AAS) exhibited the best enriching-blood effect. 16 metabolites in

  9. The enrichment secondary market

    International Nuclear Information System (INIS)

    Einbund, D.R.

    1986-01-01

    This paper will addresses two topics: the background to the present status of the enrichment secondary market and the future outlook of the secondary market in enrichment services, and the viability of the nuclear fuel brokerage industry. These two topics are inevitably connected, as most secondary market activity, not only in enrichment but also in natural uranium, has traditionally been conducted with the participation of brokers. Therefore, the author interrelates these topics

  10. Principles and techniques of uranium enrichment

    International Nuclear Information System (INIS)

    Frejacques, Claude; Mezin, Michel

    1975-01-01

    The main separation processes already used industrially or likely to be used before the end of century (gas diffusion, ultracentrifugation, laser, the nozzle process, a process developed in South Africa) are presented. Some data on the costs of the enrichment are clarified. The main characteristics of the enrichment market in which the Eurodif plant is called upon, on the expiration of five years, to take a foremost place are reported [fr

  11. Implementation of the ICRP 66 respiratory tract model: example of occupational exposure to uranium oxides formed in a new laser enrichment process

    International Nuclear Information System (INIS)

    Ansoborlo, E.; Henge-Napoli, M.H.; Hodgson, A.; Stradling, G.N.; Birchall, A.

    1996-01-01

    A new uranium enrichment facility using laser isotopic separation generates aerosols consisting of U metal + UO 2 : with traces of UPON. Results of lung absorption to blood showed that the U metal + UO 2 transportability was appreciably greater than for other industrial forms of UO 2 . Taking into account the new ICRP human respiratory tract model, the data were used as a basis for assessing the dose coefficient, for the dust sampled at the workplace. (author)

  12. Determination of enrichment processes and radon concentration in underground mines of fluorite and coal in Santa Catarina state: criteria for radiation risk assessment

    International Nuclear Information System (INIS)

    Santos, Carlos Eduardo Lima dos

    2008-01-01

    The inhalation of radon present in underground mines can imply in the deposition of its descendants in the lungs, which may cause harm to the lungs tissues and induce cancer. Concentration of radon not greater than 500 Bq/m 3 in the environment of underground mines is considered to be acceptable internationally and concentrations above 1500 Bq/m 3 require protective measures for the miners. The objectives of this research work are to determine the enrichment processes and the concentrations of radon in air, as well as the resulting doses due to the presence of this radionuclide in three underground mines of fluorite and three underground mines of coal in the State of Santa Catarina. The concentration of radon was measured employing two types of detectors of nuclear tracks (SSNTD), the LEXAN and the CR-39. This detection method consists in counting, with the help of a microscope, tracks resulting from the interaction of alpha particles with the film, due to the penetration of Rn-222 in the interior of the detector chamber and its decaying process. Contents of radium in collected samples of rocks, minerals and underground water were determined and compared with the corresponding radon concentration found in the underground air. It was observed that the coal mines showed low concentrations of radon, which can be explained by the low concentration of radium in rocks (sandstones and siltites in the foot wall and hang wall) and in the coal that composes the mining environment or, yet still, due to the good ventilation system. The average dose to the workers of the coal mines was estimated as 0.7 mSv/a, value inferior to the limit of 1 mSv/a established by the Brazilian Nuclear Energy Commission (CNEN) for members of the public, and corresponding to a risk of fatal cancer after 50 years of work under this condition of 0.2%. On the other hand, the fluorite mines showed much higher concentrations of radon and superior to 1000 Bq/m 3 . The inefficiency of the ventilation

  13. Determination of enrichment processes and the concentrations of radon in underground mines of fluorite and coal in Santa Catarina state: criteria for evaluation of radiological risks

    International Nuclear Information System (INIS)

    Santos, Carlos Eduardo Lima dos

    2008-01-01

    The inhalation of radon present in underground mines can imply in the deposition of its descendent in the lungs, which may cause harm to the lungs tissues and induce cancer. Concentration of radon not greater than 500 Bq/m3 in the environment of underground mines is considered to be acceptable internationally and concentrations above 1500 Bq/m3 require protective measures for the miners. The objectives of this research work are to determine the enrichment processes and the concentrations of radon in air, as well as the resulting doses due to the presence of this radionuclide in three underground mines of fluorite and three underground mines of coal in the State of Santa Catarina. The concentration of radon was measured employing two types of detectors of nuclear tracks (SSNTD), the LEXAN and the CR-39. This detection method consists in counting, with the help of a microscope, tracks resulting from the interaction of alpha particles with the film, due to the penetration of Rn-222 in the interior of the detector chamber and its decaying process. Contents of radium in collected samples of rocks, minerals and underground water were determined and compared with the corresponding radon concentration found in the underground air. It was observed that the coal mines showed low concentrations of radon, which can be explained by the low concentration of radium in rocks (sandstones and siltites in the footwall and hang wall) and in the coal that composes the mining environment or, yet still, due to the good ventilation system. The average dose to the workers of the coal mines was estimated as 0.7 mSv/a, value inferior to the limit of 1 mSv/a established by the Brazilian Nuclear Energy Commission (CNEN) for members of the public, and corresponding to a risk of fatal cancer after 50 years of work under this condition of 0.2%. On the other hand, the fluorite mines showed much higher concentrations of radon and superior to 1000 Bq/m3. The inefficiency of the ventilation system

  14. Uranium enrichment capacity: public versus private ownership

    International Nuclear Information System (INIS)

    Fraser, J.T.

    1977-01-01

    Continual growth of conventional nuclear capacity requires an assured supply of enriched uranium and, hence, potential expansion of domestic uranium enrichment capacity. The question of ownership of new enrichment capacity, i.e., public or private, entails not only the social-opportunity costs of alternative investments but also technical parameters of uranium utilization and advanced reactor development. Inclusion of risk preferences in both the public and private sectors produces interesting results in terms of optimal investment strategies with respect to choice of technology and scale of investment. Utilization of a nuclear fuel cycle requirements process model allows explicit specification of production technology. Integration of process model output with a least-cost investment model permits flexibility in parametric analysis. Results indicate minimum incentive for Government subsidy of a private enrichment sector through 2000 given moderate to low nuclear growth assumptions. The long-run scenario, to 2020, exhibits potentially greater incentives for private enrichment investment

  15. Uranium enrichment plans

    International Nuclear Information System (INIS)

    Gagne, R.W.; Thomas, D.C.

    1977-01-01

    The status of existing uranium enrichment contracts in the US is reviewed and expected natural uranium requirements for existing domestic uranium enrichment contracts are evaluated. Uncertainty in natural uranium requirements associated with requirements-type and fixed-commitment type contracts is discussed along with implementation of variable tails assay

  16. Boron isotopic enrichment by displacement chromatography

    International Nuclear Information System (INIS)

    Mohapatra, K.K.; Bose, Arun

    2014-01-01

    10 B enriched boron is used in applications requiring high volumetric neutron absorption (absorption cross section- 3837 barn for thermal and 1 barn for 1 MeV fast neutron). It is used in fast breeder reactor (as control rod material), in neutron counter, in Boron Neutron Capture Therapy etc. Owing to very small separation factor, boron isotopic enrichment is a complex process requiring large number of separation stages. Heavy Water Board has ventured in industrial scale production of 10 B enriched boron using Exchange Distillation Process as well as Ion Displacement Chromatography Process. Ion Displacement Chromatography process is used in Boron Enrichment Plant at HWP, Manuguru. It is based on isotopic exchange between borate ions (B(OH) 4 - ) on anion exchange resin and boric acid passing through resin. The isotopic exchange takes place due to difference in zero point energy of 10 B and 11 B

  17. Magma Differentiation Processes That Develop an "Enriched" Signature in the Izu Bonin Rear Arc: Evidence from Drilling at IODP Site U1437

    Science.gov (United States)

    Heywood, L. J.; DeBari, S. M.; Schindlbeck, J. C.; Escobar-Burciaga, R. D.

    2015-12-01

    The Izu Bonin rear arc represents a unique laboratory to study the development of continental crust precursors at an intraoceanic subduction zone., Volcanic output in the Izu Bonin rear arc is compositionally distinct from the Izu Bonin main volcanic front, with med- to high-K and LREE-enrichment similar to the average composition of the continental crust. Drilling at IODP Expedition 350 Site U1437 in the Izu Bonin rear arc obtained volcaniclastic material that was deposited from at least 13.5 Ma to present. IODP Expedition 350 represents the first drilling mission in the Izu Bonin rear arc region. This study presents fresh glass and mineral compositions (obtained via EMP and LA-ICP-MS) from unaltered tephra layers in mud/mudstone (Lithostratigraphic Unit I) and lapillistone (Lithostratigraphic Unit II) <4.5 Ma to examine the geochemical signature of Izu Bonin rear arc magmas. Unit II samples are coarse-grained tephras that are mainly rhyolitic in composition (72.1-77.5 wt. % SiO2, 3.2-3.9 wt. % K2O and average Mg# 24) and LREE-enriched. These rear-arc rhyolites have an average La/Sm of 2.6 with flat HREEs, average Th/La of 0.15, and Zr/Y of 4.86. Rear-arc rhyolite trace element signature is distinct from felsic eruptive products from the Izu Bonin main volcanic front, which have lower La/Sm and Th/La as well as significantly lower incompatible element concentrations. Rear arc rhyolites have similar trace element ratios to rhyolites from the adjacent but younger backarc knolls and actively-extending rift regions, but the latter is typified by lower K2O, as well as a smaller degree of enrichment in incompatible elements. Given these unique characteristics, we explore models for felsic magma formation and intracrustal differentiation in the Izu Bonin rear arc.

  18. Process and device for stage by stage enrichment of deuterium and/or tritium in a material suitable for isotope exchange of deuterium and tritium with hydrogen

    International Nuclear Information System (INIS)

    Iniotakis, N.; Decken, C.B. von der.

    1983-01-01

    Water containing deuterium and/or tritium is first introduced into a carrier gas flow and reduced for the stage by stage enrichment of deuterium and/or tritium. A hydrogen partial pressure of a maximum of 100 millibar is set in the carrier gas flow. The carrier gas flow is taken along the primary side of an exchange wall suitable for the permeation of hydrogen, and a further carrier gas flow flows on its secondary side, which contains water or hydrogen. Reaction products formed after isotope exchange of deuterium and/or tritium with hydrogen are removed by the secondary carrier gas flow. (orig./HP) [de

  19. TRIGA low enrichment fuel

    International Nuclear Information System (INIS)

    Gietzen, A.

    1993-01-01

    Sixty TRIGA reactors have been sold and the earliest of these are now passing twenty years of operation. All of these reactors use the uranium zirconium hydride fuel (UZrH) which provides certain unique advantages arising out of its large prompt negative temperature coefficient, very low fission product release, and high temperature capability. Eleven of these Sixty reactors are conversions from plate fuel to TRIGA fuel which were made as a result of these advantages. With only a few exceptions, TRIGA reactors have always used low-enriched uranium (LEU) fuel with an enrichment of 19.9%. The exceptions have either been converted from the standard low-enriched fuel to the 70% enriched FLIP fuel in order to achieve extended lifetime, or are higher powered reactors which were designed for long life using 93%-enriched uranium during the time when the use and export of highly enriched uranium (HEU) was not restricted. The advent of international policies focusing attention on nonproliferation and safeguards made the HEU fuels obsolete. General Atomic immediately undertook a development effort (nearly two years ago) in order to be in a position to comply with these policies for all future export sales and also to provide a low-enriched alternative to fully enriched plate-type fuels. This important work was subsequently partially supported by the U.S. Department of Energy. The laboratory and production tests have shown that higher uranium densities can be achieved to compensate for reducing the enrichment to 20%, and that the fuels maintain the characteristics of the very thoroughly proven standard TRIGA fuels. In May of 1978, General Atomic announced that these fuels were available for TRIGA reactors and for plate-type reactors with power levels up to 15 MW with General Atomic's standard commercial warranty

  20. TRIGA low enrichment fuel

    International Nuclear Information System (INIS)

    Gietzen, A.

    1993-01-01

    Sixty TRIGA reactors have been sold and the earliest of these are now passing twenty years of operation. All of these reactors use the uranium-zirconium hydride fuel (UZrH) which provides certain unique advantages arising out of its large prompt negative temperature coefficient, very low fission product release, and high temperature capability. Eleven of these Sixty reactors are conversions from plate fuel to TRIGA fuel which were made as a result of these advantages. With only a few exceptions, TRIGA reactors have always used low-enriched-uranium (LEU) fuel with an enrichment of 19.9%. The exceptions have either been converted from the standard low-enriched fuel to the 70% enriched FLIP fuel in order to achieve extended lifetime, or are higher powered reactors which were designed for long life using 93%-enriched uranium during the time when the use and export of highly enriched uranium (HEU) was not restricted. The advent of international policies focusing attention on nonproliferation and safeguards made the HEU fuels obsolete. General Atomic immediately undertook a development effort (nearly two years ago) in order to be in a position to comply with these policies for all future export sales and also to provide a low-enriched alternative to fully enriched plate-type fuels. This important work was subsequently partially supported by the U.S. Department of Energy. The laboratory and production tests have shown that higher uranium densities can be achieved to compensate for reducing the enrichment to 20%, and that the fuels maintain the characteristics of the very thoroughly proven standard TRIGA fuels. In May of 1978, General Atomic announced that these fuels were available for TRIGA reactors and for plate-type reactors with power levels up to 15 MW with GA's standard commercial warranty

  1. The Cladophora glomerata Enriched by Biosorption Process in Cr(III Improves Viability, and Reduces Oxidative Stress and Apoptosis in Equine Metabolic Syndrome Derived Adipose Mesenchymal Stromal Stem Cells (ASCs and Their Extracellular Vesicles (MV’s

    Directory of Open Access Journals (Sweden)

    Krzysztof Marycz

    2017-12-01

    Full Text Available This study investigated in vitro effects of freshwater alga Cladophora glomerata water extract enriched during a biosorption process in Cr(III trivalent chromium and chromium picolinate on adipose-derived mesenchymal stromal stem cells (ASCs and extracellular microvesicles (MVs in equine metabolic syndrome-affected horses. Chemical characterisation of natural Cladophora glomerata was performed with special emphasis on: vitamin C, vitamin E, total phenols, fatty acids, free and protein-bound amino acids as well as measured Cr in algal biomass. To examine the influence of Cladophora glomerata water extracts, in vitro viability, oxidative stress factor accumulation, apoptosis, inflammatory response, biogenesis of mitochondria, autophagy in ASCs of EMS and secretory activity manifested by MV release were investigated. For this purpose, various methods of molecular biology and microscopic observations (i.e., immunofluorescence staining, SEM, TEM, FIB observations, mRNA and microRNA expression by RT-qPCR were applied. The extract of Cladophora glomerata enriched with Cr(III ions reduced apoptosis and inflammation in ASCs of EMS horses through improvement of mitochondrial dynamics, decreasing of PDK4 expression and reduction of endoplastic reticulum stress. Moreover, it was found, that Cladophora glomerata and Cr(III induce antioxidative protection coming from enhanced SOD activity Therefore, Cladophora glomerata enriched with Cr(III ions might become an interesting future therapeutic agent in the pharmacological treatment of EMS horses.

  2. The Cladophora glomerata Enriched by Biosorption Process in Cr(III) Improves Viability, and Reduces Oxidative Stress and Apoptosis in Equine Metabolic Syndrome Derived Adipose Mesenchymal Stromal Stem Cells (ASCs) and Their Extracellular Vesicles (MV's).

    Science.gov (United States)

    Marycz, Krzysztof; Michalak, Izabela; Kocherova, Ievgeniia; Marędziak, Monika; Weiss, Christine

    2017-12-08

    This study investigated in vitro effects of freshwater alga Cladophora glomerata water extract enriched during a biosorption process in Cr(III) trivalent chromium and chromium picolinate on adipose-derived mesenchymal stromal stem cells (ASCs) and extracellular microvesicles (MVs) in equine metabolic syndrome-affected horses. Chemical characterisation of natural Cladophora glomerata was performed with special emphasis on: vitamin C, vitamin E, total phenols, fatty acids, free and protein-bound amino acids as well as measured Cr in algal biomass. To examine the influence of Cladophora glomerata water extracts, in vitro viability, oxidative stress factor accumulation, apoptosis, inflammatory response, biogenesis of mitochondria, autophagy in ASCs of EMS and secretory activity manifested by MV release were investigated. For this purpose, various methods of molecular biology and microscopic observations (i.e., immunofluorescence staining, SEM, TEM, FIB observations, mRNA and microRNA expression by RT-qPCR) were applied. The extract of Cladophora glomerata enriched with Cr(III) ions reduced apoptosis and inflammation in ASCs of EMS horses through improvement of mitochondrial dynamics, decreasing of PDK4 expression and reduction of endoplastic reticulum stress. Moreover, it was found, that Cladophora glomerata and Cr(III) induce antioxidative protection coming from enhanced SOD activity Therefore, Cladophora glomerata enriched with Cr(III) ions might become an interesting future therapeutic agent in the pharmacological treatment of EMS horses.

  3. The Cladophora glomerata Enriched by Biosorption Process in Cr(III) Improves Viability, and Reduces Oxidative Stress and Apoptosis in Equine Metabolic Syndrome Derived Adipose Mesenchymal Stromal Stem Cells (ASCs) and Their Extracellular Vesicles (MV’s)

    Science.gov (United States)

    Marycz, Krzysztof; Marędziak, Monika; Weiss, Christine

    2017-01-01

    This study investigated in vitro effects of freshwater alga Cladophora glomerata water extract enriched during a biosorption process in Cr(III) trivalent chromium and chromium picolinate on adipose-derived mesenchymal stromal stem cells (ASCs) and extracellular microvesicles (MVs) in equine metabolic syndrome-affected horses. Chemical characterisation of natural Cladophora glomerata was performed with special emphasis on: vitamin C, vitamin E, total phenols, fatty acids, free and protein-bound amino acids as well as measured Cr in algal biomass. To examine the influence of Cladophora glomerata water extracts, in vitro viability, oxidative stress factor accumulation, apoptosis, inflammatory response, biogenesis of mitochondria, autophagy in ASCs of EMS and secretory activity manifested by MV release were investigated. For this purpose, various methods of molecular biology and microscopic observations (i.e., immunofluorescence staining, SEM, TEM, FIB observations, mRNA and microRNA expression by RT-qPCR) were applied. The extract of Cladophora glomerata enriched with Cr(III) ions reduced apoptosis and inflammation in ASCs of EMS horses through improvement of mitochondrial dynamics, decreasing of PDK4 expression and reduction of endoplastic reticulum stress. Moreover, it was found, that Cladophora glomerata and Cr(III) induce antioxidative protection coming from enhanced SOD activity Therefore, Cladophora glomerata enriched with Cr(III) ions might become an interesting future therapeutic agent in the pharmacological treatment of EMS horses. PMID:29292726

  4. Enrichment situation outside the United States

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    Different enrichment technologies are briefly characterized which include gaseous diffusion, which is presently the production mainstay of the United States and France; the gaseous centrifuge which is the production plant for Urenco and the technology for future United States enrichment expansion; the aero-dynamic processes which include the jet nozzle (also known as the Becker process) and the fixed-wall centrifuge (also known as the Helikon process); chemical processes; laser isotope separation processes (also referred to in the literature as LIS); and plasma technology

  5. 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

  6. Uranium enrichment plans and policies

    International Nuclear Information System (INIS)

    Schwennesen, J.L.

    1981-01-01

    Significant progress has been made in US efforts to expand its enrichment capacity. The Cascade Improvement Program (CIP) and Cascade Upgrading Program (CUP) are now complete at Oak Ridge and Paducah and almost complete at Portsmouth. Considerable progress has also been made in constructing the Gas Centrifuge Enrichment Plant (GCEP), and physical construction of the first process building is well under way. Current plans are to have two process buildings on-line by 1989 with the remaining six buildings to be added sequentially as needed to meet demand. The status of DOE enrichment services contracts is essentially unchanged from that reported at last year's seminar. The OUEA latest forecast of nuclear power growth, however, is considerably lower than reported last year, although a leveling trend is becoming apparent. The Variable Tails Assay Option (VTAO) of the AFC contract was made available for the third time for FY 1983. The DOE inventories of natural uranium still remain high. The Department of Energy will dispose of this material by using it for Government programs and for enrichment plant operations. It appears that Government inventories of uranium are adequate through at least the mid-1990s. It remains DOE policy not to dispose of its natural uranium stocks through direct sales in the marketplace, except for very small quantities or if an emergency situation would exist and all reasonable attempts had been made, without success, to obtain natural uranium from commercial sources. Finally, with regard to DOE plans on future transaction tails assays, it still appears likely that the current 0.20 percent uranium-235 reference tails assay will be maintained until well into the 1990s, at which time it might be increased up to 0.25 percent uranium-235

  7. Civilian inventories of plutonium and highly enriched uranium

    International Nuclear Information System (INIS)

    Albright, D.

    1987-01-01

    In the future, commercial laser isotope enrichment technologies, currently under development, could make it easier for national to produce highly enriched uranium secretly. The head of a US firm that is developing a laser enrichment process predicts that in twenty years, major utilities and small countries will have relatively small, on-site, laser-based uranium enrichment facilities. Although these plants will be designed for the production of low enriched uranium, they could be modified to produce highly enriched uranium, an option that raises the possibility of countries producing highly enriched uranium in small, easily hidden facilities. Against this background, most of this report describes the current and future quantities of plutonium and highly enriched uranium in the world, their forms, the facilities in which they are produced, stored, and used, and the extent to which they are transported. 5 figures, 10 tables

  8. The competitive enrichment market

    International Nuclear Information System (INIS)

    Parks, J.W.; Huffman, F.C.

    1984-01-01

    With the enactment of the ''Private Ownership of Special Nuclear Materials Act'' in 1964, the U.S. Government made provisions to enter into the uranium enrichment services business. Since nuclear power was in its infancy and the Government was promoting its growth as well as trying to help U.S. industry sell reactors overseas, the initial contracts (Requirements Contracts) for enrichment services placed most of the risks associated with the supplying of the services on the Government. Projections of nuclear power additions continued to grow and in 1972 the Atomic Energy Commission (AEC) stopped contracting under Requirements Contracts in order to study which mode of contracting best suited the commercial development of the industry. In mid-1973, the AEC introduced the Long-Term Fixed Commitment (LTFC) contract which shifted the risk to the customer. By mid-1974, AEC had contracts which completely used the enrichment capacity of its complex and refused to accept requests for additional contracts. This action further convinced European nations that they should continue to develop their own enrichment capacity and resulted in the EURODIF and URENCO projects. Before this time the U.S. supplied 100% of the world market for enriching services

  9. Enrichment: Dealing with overcapacity

    International Nuclear Information System (INIS)

    Peterson, C.H.

    1989-01-01

    Today's surplus of enrichment capacity will continue until at least the end of this century. This will challenge the ingenuity of the separative work unit (SWU) suppliers as they attempt to keep market share and remain profitable in a very competitive marketplace. The utilities will be faced with attractive choices, but making the best choice will require careful analysis and increased attention to market factors. Current demand projections will probably prove too high to the extent that more reactors are canceled or delayed. The DOE has the vast majority of the unused capacity, so it will feel the most immediate impact of this large surplus in productive capacity. The DOE has responded to these market challenges by planning another reorganization of its enriching operations. Without a major agreement among the governments affected by the current surplus in enrichment capacity, the future will see lower prices, more competitive terms, and the gradual substitution of centrifuge or laser enrichment for the gaseous diffusion plants. The competition that is forcing the gaseous diffusion prices down to marginal cost will provide the long-term price basis for the enrichment industry

  10. Uranium enrichment: heading for a cliff

    International Nuclear Information System (INIS)

    Norman, C.

    1987-01-01

    Thanks to drastic cost cutting in the past 2 years, US enrichment plants now have the lowest cost production in the world, but US prices are still higher than those of overseas competitors because the business is paying for past mistakes. The most serious difficulty is that the Department of Energy (DOE), which owns and operates the US enrichment enterprise, is paying more than $500 million a year to the Tennessee Valley Authority (TVA) for electricity it once thought it would need but no longer requires. Another is that billions of dollars were spent in the 1970s and early 1980s to build new capacity that is now not needed. As a result, the enrichment enterprise has accumulated a debt to the US Treasury that the General Accounting Office (GAO) estimates at $8.8 billion. This paper presents the background and current debate in Congress about the difficulties facing the enrichment industry. In the midst of this debate over the future of the enterprise, the development of the next generation of enrichment technology is being placed in jeopardy. Known as atomic vapor laser isotope separation, or AVLIS, the process was viewed as the key to the long-term competitiveness of US enrichment. As the federal deficit mounted, however, funding for the AVLIS program was cut back and the timetable was stretched out. The US enrichment program has reached the point at which Congress will be forced to make some politically difficult decisions

  11. Laser and gas centrifuge enrichment

    Energy Technology Data Exchange (ETDEWEB)

    Heinonen, Olli [Senior Fellow, Belfer Center for Science and International Affairs, Harvard Kennedy School, Cambridge, Massachusetts (United States)

    2014-05-09

    Principles of uranium isotope enrichment using various laser and gas centrifuge techniques are briefly discussed. Examples on production of high enriched uranium are given. Concerns regarding the possibility of using low end technologies to produce weapons grade uranium are explained. Based on current assessments commercial enrichment services are able to cover the global needs of enriched uranium in the foreseeable future.

  12. Oxygen enrichment incineration

    International Nuclear Information System (INIS)

    Kim, Jeong Guk; Yang, Hee Chul; Park, Geun Il; Kim, Joon Hyung

    2000-10-01

    Oxygen enriched combustion technology has recently been used in waste incineration. To apply the oxygen enrichment on alpha-bearing waste incineration, which is being developed, a state-of-an-art review has been performed. The use of oxygen or oxygen-enriched air instead of air in incineration would result in increase of combustion efficiency and capacity, and reduction of off-gas product. Especially, the off-gas could be reduced below a quarter, which might reduce off-gas treatment facilities, and also increase an efficiency of off-gas treatment. However, the use of oxygen might also lead to local overheating and high nitrogen oxides (NOx) formation. To overcome these problems, an application of low NOx oxy-fuel burner and recycling of a part of off-gas to combustion chamber have been suggested

  13. Oxygen enrichment incineration

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeong Guk; Yang, Hee Chul; Park, Geun Il; Kim, Joon Hyung

    2000-10-01

    Oxygen enriched combustion technology has recently been used in waste incineration. To apply the oxygen enrichment on alpha-bearing waste incineration, which is being developed, a state-of-an-art review has been performed. The use of oxygen or oxygen-enriched air instead of air in incineration would result in increase of combustion efficiency and capacity, and reduction of off-gas product. Especially, the off-gas could be reduced below a quarter, which might reduce off-gas treatment facilities, and also increase an efficiency of off-gas treatment. However, the use of oxygen might also lead to local overheating and high nitrogen oxides (NOx) formation. To overcome these problems, an application of low NOx oxy-fuel burner and recycling of a part of off-gas to combustion chamber have been suggested.

  14. NMR spectroscopy of lactate in the skeleton muscle: visibility, quantification and measurement of carbon 13 enrichment by double quantum edition; Spectroscopie RMN du lactate dans le muscle squeletique: visibilite, quantification et mesure de l'enrichissement au carbone 13 par edition a double quantum

    Energy Technology Data Exchange (ETDEWEB)

    Jouvensal, L

    1997-12-18

    The metabolism of skeleton muscles gave rise to numerous research works since the beginning of the century in order to make some reply about the muscle physiology with the will to improve the sport performances or the understanding of muscles diseases. This metabolism is complex and the lactate has an importance place; the purpose of this work is to answer these questions with some strategy studies by nuclear magnetic resonance spectroscopy. (N.C.)

  15. US enrichment reduction studies

    International Nuclear Information System (INIS)

    1979-06-01

    A major national program, the Reduced Enrichment Research and Test Reactor (RERTR) Program, is currently under way in the U.S., centered at the Argonne National Laboratory (ANL), to reduce the potential of research and test reactor fuels for increasing the proliferation of nuclear explosive devices. The main objective of the program is to provide the technical means by which the uranium enrichment to be used in these reactors can be reduced to less than 20% without significant economic and performance penalties. The criteria, basis and goals of the program are consistent with the results of a number of case studies which have been performed as part of the program

  16. Uranium Conversion & Enrichment

    Energy Technology Data Exchange (ETDEWEB)

    Karpius, Peter Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-02-06

    The isotopes of uranium that are found in nature, and hence in ‘fresh’ Yellowcake’, are not in relative proportions that are suitable for power or weapons applications. The goal of conversion then is to transform the U3O8 yellowcake into UF6. Conversion and enrichment of uranium is usually required to obtain material with enough 235U to be usable as fuel in a reactor or weapon. The cost, size, and complexity of practical conversion and enrichment facilities aid in nonproliferation by design.

  17. Safety aspects of gas centrifuge enrichment plants

    International Nuclear Information System (INIS)

    Hansen, A.H.

    1987-01-01

    Uranium enrichment by gas centrifuge is a commercially proven, viable technology. Gas centrifuge enrichment plant operations pose hazards that are also found in other industries as well as unique hazards as a result of processing and handling uranium hexafluoride and the handling of enriched uranium. Hazards also found in other industries included those posed by the use of high-speed rotating equipment and equipment handling by use of heavy-duty cranes. Hazards from high-speed rotating equipment are associated with the operation of the gas centrifuges themselves and with the operation of the uranium hexafluoride compressors in the tail withdrawal system. These and related hazards are discussed. It is included that commercial gas centrifuge enrichment plants have been designed to operate safely

  18. Oak Ridge National Laboratory's isotope enrichment program

    International Nuclear Information System (INIS)

    Tracy, J.G.; Aaron, W.C.

    1997-01-01

    The Isotope Enrichment Program (IEP) at Oak Ridge National Laboratory (ORNL) is responsible for the production and distribution of ∼225 enriched stable isotopes from 50 multi-isotopic elements. In addition, ORNL distributes enriched actinide isotopes and provides extensive physical- and chemical-form processing of enriched isotopes to meet customer requirements. For more than 50 yr, ORNL has been a major provider of enriched isotopes and isotope-related services to research, medical, and industrial institutions throughout the world. Consolidation of the Isotope Distribution Office (IDO), the Isotope Research Materials Laboratory (IRML), and the stable isotope inventories in the Isotope Enrichment Facility (IEF) have improved operational efficiencies and customer services. Recent changes in the IEP have included adopting policies for long-term contracts, which offer program stability and pricing advantages for the customer, and prorated service charges, which greatly improve pricing to the small research users. The former U.S. Department of Energy (DOE) Loan Program has been converted to a lease program, which makes large-quantity or very expensive isotopes available for nondestructive research at a nominal cost. Current efforts are being pursued to improve and expand the isotope separation capabilities as well as the extensive chemical- and physical-form processing that now exists. The IEF's quality management system is ISO 9002 registered and accredited in the United States, Canada, and Europe

  19. Development of on-line uranium enrichment monitor of gaseous UF6 for uranium enrichment plant

    International Nuclear Information System (INIS)

    Lu Xuesheng; Liu Guorong; Jin Huimin; Zhao Yonggang; Li Jinghuai; Hao Xueyuan; Ying Bin; Yu Zhaofei

    2013-01-01

    An on-line enrichment monitor was developed to measure the enrichment of UF 6 , flowing through the processing pipes in uranium enrichment plant. A Nal (Tl) detector was used to measure the count rates of the 185.7 keV γ-ray emitted from 235 U, and the total quantity of uranium was determined from thermodynamic characteristics of gaseous uranium hexafluoride. The results show that the maximum relative standard deviation is less than 1% when the measurement time is 120 s or more and the pressure is more than 2 kPa in the measurement chamber. Uranium enrichment of gaseous uranium hexafluoride in the output end of cascade can be monitored continuously by using the device. It should be effective for nuclear materials accountability verifications and materials balance verification at uranium enrichment plant. (authors)

  20. An Enriching Community.

    Science.gov (United States)

    Holland, Nancy A.; Burroughs, Jean

    2001-01-01

    Successful school-community partnerships in Volusia (Florida) Public Schools are the results of marketing creatively, meeting community members' needs, and bringing the right people together. The 3-year old program now offers students of all ages an expanding list of enrichment classes on many subjects for a nominal fee. (MLH)

  1. Uranium enrichment techniques

    International Nuclear Information System (INIS)

    Hamdoun, N.A.

    2007-01-01

    This article includes an introduction about the isotopes of natural uranium, their existence and the difficulty of the separation between them. Then it goes to the details of a number of methods used to enrich uranium: Gaseous Diffusion method, Electromagnetic method, Jet method, Centrifugal method, Chemical method, Laser method and Plasma method.

  2. Requirements for enrichment tools

    NARCIS (Netherlands)

    Boer, A.; Winkels, R.; Trompper, M.

    2016-01-01

    This report gives a high level overview of requirements for Enrichment tools in the Openlaws.eu project. Openlaws.eu aims to initiate a platform and develop a vision for Big Open Legal Data (BOLD): an open framework for legislation, case law, and legal literature from across Europe.

  3. Enriching the Catalog

    Science.gov (United States)

    Tennant, Roy

    2004-01-01

    After decades of costly and time-consuming effort, nearly all libraries have completed the retrospective conversion of their card catalogs to electronic form. However, bibliographic systems still are really not much more than card catalogs on wheels. Enriched content that Amazon.com takes for granted--such as digitized tables of contents, cover…

  4. NRC licensing of uranium enrichment plants

    International Nuclear Information System (INIS)

    Moran, B.W.

    1991-01-01

    The US Nuclear Regulatory Commission (NRC) is preparing a rule making that establishes the licensing requirements for low-enriched uranium enrichment plants. Although implementation of this rule making is timed to correspond with receipt of a license application for the Louisiana Energy Services centrifuge enrichment plant, the rule making is applicable to all uranium enrichment technologies. If ownership of the US gaseous diffusion plants and/or atomic vapor laser isotope separation is transferred to a private or government corporation, these plants also would be licensable under the new rule making. The Safeguards Studies Department was tasked by the NRC to provide technical assistance in support of the rule making and guidance preparation process. The initial and primary effort of this task involved the characterization of the potential safeguards concerns associated with a commercial enrichment plant, and the licensing issues associated with these concerns. The primary safeguards considerations were identified as detection of the loss of special nuclear material, detection of unauthorized production of material of low strategic significance, and detection of production of uranium enriched to >10% 235 U. The primary safeguards concerns identified were (1) large absolute limit of error associated with the material balance closing, (2) the inability to shutdown some technologies to perform a cleanout inventory of the process system, and (3) the flexibility of some technologies to produce higher enrichments. Unauthorized production scenarios were identified for some technologies that could prevent conventional material control and accounting programs from detecting the production and removal of 5 kg 235 U as highly enriched uranium. Safeguards techniques were identified to mitigate these concerns

  5. United States uranium enrichment policies

    International Nuclear Information System (INIS)

    Roberts, R.W.

    1977-01-01

    ERDA's uranium enrichment program policies governing the manner in which ERDA's enrichment complex is being operated and expanded to meet customer requirements for separative work, research and development activities directed at providing technology alternatives for future enrichment capacity, and establishing the framework for additional domestic uranium enrichment capacity to meet the domestic and foreign nuclear industry's growing demand for enrichment services are considered. The ERDA enrichment complex consists of three gaseous diffusion plants located in Oak Ridge, Tennessee; Paducah, Kentucky; and Portsmouth, Ohio. Today, these plants provide uranium enrichment services for commercial nuclear power generation. These enrichment services are provided under contracts between the Government and the utility customers. ERDA's program involves a major pilot plant cascade, and pursues an advanced isotope separation technique for the late 1980's. That the United States must develop additional domestic uranium enrichment capacity is discussed

  6. Profile of World Uranium Enrichment Programs - 2007

    International Nuclear Information System (INIS)

    Laughter, Mark D.

    2007-01-01

    It is generally agreed that the most difficult step in building a nuclear weapon is acquiring weapons grade fissile material, either plutonium or highly enriched uranium (HEU). Plutonium is produced in a nuclear reactor, while HEU is produced using a uranium enrichment process. Enrichment is also an important step in the civil nuclear fuel cycle, in producing low enriched uranium (LEU) for use in fuel for nuclear reactors. However, the same equipment used to produce LEU for nuclear fuel can also be used to produce HEU for weapons. Safeguards at an enrichment plant are the array of assurances and verification techniques that ensure uranium is only enriched to LEU, no undeclared LEU is produced, and no uranium is enriched to HEU or secretly diverted. There are several techniques for enriching uranium. The two most prevalent are gaseous diffusion, which uses older technology and requires a lot of energy, and gas centrifuge separation, which uses more advanced technology and is more energy efficient. Gaseous diffusion plants (GDPs) provide about 40% of current world enrichment capacity, but are being phased out as newer gas centrifuge enrichment plants (GCEPs) are constructed. Estimates of current and future enrichment capacity are always approximate, due to the constant upgrades, expansions, and shutdowns occurring at enrichment plants, largely determined by economic interests. Currently, the world enrichment capacity is approximately 53 million kg-separative work units (SWU) per year, with 22 million in gaseous diffusion and 31 million in gas centrifuge plants. Another 23 million SWU/year of capacity are under construction or planned for the near future, almost entirely using gas centrifuge separation. Other less-efficient techniques have also been used in the past, including electromagnetic and aerodynamic separations, but these are considered obsolete, at least from a commercial perspective. Laser isotope separation shows promise as a possible enrichment technique

  7. Centrifuge enrichment plants. (Latest citations from the NTIS bibliographic database). Published Search

    International Nuclear Information System (INIS)

    1993-09-01

    The bibliography contains citations concerning the design, control, monitoring, and safety of centrifuge enrichment plants. Power supplies, enrichment plant safeguards, facility design, cascade heater test loops to monitor the enrichment process, inspection strategies, and the socioeconomic effects of centrifuge enrichment plants are examined. Radioactive waste disposal problems are considered. (Contains a minimum of 171 citations and includes a subject term index and title list.)

  8. The Helikon technique for isotope enrichment

    International Nuclear Information System (INIS)

    Haarhoff, P.C.

    1976-11-01

    The separating element employed in the UCOR process for uranium enrichment has an enriched stream which is much smaller than the depleted stream. To deal with this small cut and to exploit the full potential of the process, a new cascade technique has been developed, the so-called helikon technique. It is based on the principle that an axial flow compressor can simultaneously compress a number of streams of different isotopic composition, which flow through it in parallel, without any significant mixing between them. The technique makes it possible to achieve the desired enrichment with a relatively small number of separating units, by making the best use of the high enrichment factor available. A further feature of the helikon technique is that a module yields an enrichment factor which is not constant, but can vary. In this way a cascade can be built up from modules of a fixed size, which is a great advantage when compared to conventional cascade arrangements where several unit sizes are required. A general theoretical treatment of the helikon technique is given and the similarity between helikon and conventional cascades is pointed out. Practical helikon cascades are subsequently discussed on the basis of the UCOR process

  9. U.S. forms uranium enrichment corporation

    International Nuclear Information System (INIS)

    Seltzer, R.

    1993-01-01

    After almost 40 years of operation, the federal government is withdrawing from the uranium enrichment business. On July 1, the Department of Energy turned over to a new government-owned entity--the US Enrichment Corp. (USEC)--both the DOE enrichment plants at Paducah, Ky., and Portsmouth, Ohio, and domestic and international marketing of enriched uranium from them. Pushed by the inability of DOE's enrichment operations to meet foreign competition, Congress established USEC under the National Energy Policy Act of 1992, envisioning the new corporation as the first step to full privatization. With gross revenues of $1.5 billion in fiscal 1992, USEC would rank 275th on the Fortune 500 list of top US companies. USEC will lease from DOE the Paducah and Portsmouth facilities, built in the early 1950s, which use the gaseous diffusion process for uranium enrichment. USEC's stock is held by the US Treasury, to which it will pay annual dividends. Martin Marietta Energy Systems, which has operated Paducah since 1984 and Portsmouth since 1986 for DOE, will continue to operate both plants for USEC. Closing one of the two facilities will be studied, especially in light of a 40% world surplus of capacity over demand. USEC also will consider other nuclear-fuel-related ventures. USEC will produce only low-enriched uranium, not weapons-grade material. Indeed, USEC will implement a contract now being completed under which the US will purchase weapons-grade uranium from dismantled Russian nuclear weapons and convert it into low-enriched uranium for power reactor fuel

  10. Uranium-enriched granites in Sweden

    International Nuclear Information System (INIS)

    Wilson, M.R.; Aakerblom, G.

    1980-01-01

    Granites with uranium contents higher than normal occur in a variety of geological settings in the Swedish Precambrian, and represent a variety of granite types and ages. They may have been generated by the anatexis of continental crust or processes occurring at a much greater depth. They commonly show enrichment in F, Sn, W and/or Mo. Only in one case is an important uranium mineralization thought to be directly related to a uranium-enriched granite, while the majority of epigenetic uranium mineralizations with economic potential are related to hydrothermal processes in areas where the bedrock is regionally uranium-enhanced. (author)

  11. Future of uranium enrichment

    International Nuclear Information System (INIS)

    Hosmer, C.

    1981-01-01

    The increasing amount of separative work being done in government facilities to produce low-enriched uranium fuel for nuclear utilities again raises the question: should this business-type, industrial function be burned over the private industry. The idea is being looked at by the Reagan administration, but faces problems of national security as well as from the unique nature of the business. This article suggests that a joint government-private venture combining enriching, reprocessing, and waste disposal could be the answer. Further, a separate entity using advanced laser technology to deplete existing uranium tails and lease them for fertile blankets in breeder reactors might earn substantial revenues to help reduce the national debt

  12. Low-resolution gamma-ray measurements of uranium enrichment

    International Nuclear Information System (INIS)

    Sprinkle, J.K. Jr.; Christiansen, A.; Cole, R.; Collins, M.L.

    1996-01-01

    Facilities that process special nuclear material perform periodic inventories. In bulk facilities that process low-enriched uranium, these inventories and their audits are based primarily on weight and enrichment measurements. Enrichment measurements determine the 211 U weight fraction of the uranium compound from the passive gamma-ray emissions of the sample. Both international inspectors and facility operators rely on the capability to make in-field gamma-ray measurements of uranium enrichment. These users require rapid, portable measurement capability. Some in-field measurements have been biased, forcing the inspectors to resort to high-resolution measurements or mass spectrometry to accomplish their goals

  13. Uranium enrichment in South Africa

    International Nuclear Information System (INIS)

    Roux, A.J.A.; Grant, W.L.

    1976-01-01

    It is stated that the South African process is of an aerodynamic type, the separating element being in effect a high performance stationary-walled centrifuge using UF 6 in hydrogen as process fluid. Some details of the very low uranium inventory and high separation factor achievable are given. A new cascade technique is described, based on the principle that an axial flow compressor can simultaneously transmit several streams of different isotopic composition without there being significant mixing between them. The research and development programme is discussed. It is expected that an enrichment plant of 5000 t/a SW capacity, with provision for expansion up to 10,000 t/a SW capacity, will come into operation by 1984. (U.K.)

  14. High-EPA Biomass from Nannochloropsis salina Cultivated in a Flat-Panel Photo-Bioreactor on a Process Water-Enriched Growth Medium

    DEFF Research Database (Denmark)

    Safafar, Hamed; Hass, Michael Z.; Møller, Per

    2016-01-01

    salina biomass, with a focus on eicosapentaenoic acid (EPA). Variations in fatty acid composition, lipids, protein, amino acids, tocopherols and pigments were studied and results compared to algae cultivated on F/2 media as reference. Mixed growth media and process water enhanced the nutritional quality...... of Nannochloropsis salina in laboratory scale when compared to algae cultivated in standard F/2 medium. Data from laboratory scale translated to the large scaleusing a 4000 L flat panel photo-bioreactor system. The algae growth rate in winter conditions in Denmark was slow, but results revealed that large...... after 21 days of cultivation. Variations in chemical compositions of Nannochloropsis salina were studied during the course of cultivation. Nannochloropsis salina can be presented as a good candidate for winter time cultivation in Denmark.The resulting biomass is a rich source of EPA and also a good...

  15. Development of low enriched uranium target plates by thermo-mechanical processing of UAl2–Al matrix for production of 99Mo in Pakistan

    International Nuclear Information System (INIS)

    Ali, Kanwar Liaqat; Khan, Akhlaque Ahmad; Mushtaq, Ahmad; Imtiaz, Farhan; Ziai, Maratab Ali; Gulzar, Amir; Farooq, Muhammad; Hussain, Nazar; Ahmed, Nisar; Pervez, Shahid; Zaidi, Jamshed Hussain

    2013-01-01

    Uranium aluminide predominated with UAl 2 phase was prepared by arc-melting procedures and comminuted to required particle size. UAl 2 and Al powders were blended and compacted to achieve LEU fuel density of 2.17 g/cm 3 . The picture-frame technique was used to clad the dispersions (UAl 2 –Al) with aluminum. A few target plates were fabricated by thermo-mechanical processing (hot rolling and annealing) of UAl 2 –Al matrix contained in roll billet of Al. The fabricated plates were characterized by destructive and some of non-destructive testing techniques and then annealed to achieve required phase of uranium aluminide for proper dissolution in basic media

  16. Beta activity of enriched uranium

    International Nuclear Information System (INIS)

    Nambiar, P.P.V.J.; Ramachandran, V.

    1975-01-01

    Use of enriched uranium as reactor fuel necessitates its handling in various forms. For purposes of planning and organising radiation protection measures in enriched uranium handling facilities, it is necessary to have a basic knowledge of the radiation status of enriched uranium systems. The theoretical variations in beta activity and energy with U 235 enrichment are presented. Depletion is considered separately. Beta activity build up is also studied for two specific enrichments, in respect of which experimental values for specific alpha activity are available. (author)

  17. S.210: A Bill to establish the United States Enrichment Corporation to operate the Federal uranium enrichment program on a profitable and efficient basis in order to maximize the long term economic value to the United States, to provide assistance to the domestic uranium industry and to provide a Federal contribution for the reclamation of mill tailings generated pursuant to Federal defense contracts at active uranium and thorium processing sites, introduced in the Senate of the United States, One Hundred Second Congress, First Session, January 15, 1991

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    The bill would amend the Atomic Energy Act of 1954 to establish the US Enrichment Corporation to operate the Federal uranium enrichment program on a profitable and efficient basis in order to maximize the long term economic value to the US, would provide a Federal contribution for the reclamation of mill tailings generated as a result of Federal defense contracts at active uranium and thorium processing sites, and would provide assistance to the domestic uranium industry

  18. Blueprint for domestic uranium enrichment

    International Nuclear Information System (INIS)

    1981-01-01

    The AEC advisory committee on domestic production of uranium enrichment has studied for more than a year how to achieve the domestic enrichment of uranium by the construction and operation of a commercial enriching plant using centrifugal separation method, and the report was submitted to the Atomic Energy Commission on August 18, 1980. Japan has depended wholly on overseas services for her uranium enrichment needs, but the development of domestic enrichment has been carried on in parallel. The AEC decided to construct a uranium enrichment pilot plant using centrifuges, and it has been forwarded as a national project. The plant is operated by the Power Reactor and Nuclear Fuel Development Corp. since 1979. The capacity of the plant will be raised to approximately 75 ton SWU a year. The centrifuges already operated have provided the first delivery of fuel of about 1 ton for the ATR ''Fugen''. The demand-supply balance of uranium enrichment service, the significance of the domestic enrichment of uranium, the evaluation of uranium enrichment technology, the target for domestic enrichment plan, the measures to promote domestic uranium enrichment, and the promotion of the construction of a demonstration plant are reported. (Kako, I.)

  19. Drama in English: An Enriching Experience.

    Science.gov (United States)

    Geffen, Mitzi

    1998-01-01

    Examines the rationale behind using musical drama in English-as-a-Second-Language classes, explaining that it is an enjoyable experience that enriches students' English while they are relaxed, working as a team, and having fun with their imaginations. The article explains the process of putting on a play and evaluates the effect such a project had…

  20. Challenges when developing omega-3 enriched foods

    DEFF Research Database (Denmark)

    Jacobsen, Charlotte

    2010-01-01

    the influence of important factors such as oil quality, delivery systems for omega-3 fatty acids, processing conditions, composition of the food matrix on lipid oxidation in different omega-3 enriched foods (milk, yoghurt, mayonnaise and mayonnaise-based salads, dressing, energy bar and fish paté). Moreover...

  1. Enriched lithium collection from lithium plasma flow

    International Nuclear Information System (INIS)

    Karchevsky, A.I.; Laz'ko, V.S.; Muromkin, Y.A.; Pashkovsky, V.G.; Ustinov, A.L.; Dolgolenko, D.A.

    1994-01-01

    In order to understand the physical processes concerned with the selective heating by ion cyclotron resonance and with the subsequent collection of heated particles, experiments were carried out with the extraction of lithium samples, enriched with 6 Li isotopes. Probe and integral extractors allow to collect enriched Li at the end of the selective heating region. Surface density distribution on the collector and local isotopic content of lithium are measured, as a function of the screen height and the retarding potential. Dependence of the collected amount of lithium and of its isotopic content on the value of the magnetic field is also measured. 4 figs., 2 tabs., 5 refs

  2. The world enrichment market

    International Nuclear Information System (INIS)

    Gunter, L.; McCants, C.; Rutkowski, E.

    1991-01-01

    The enrichment market can be divided into two periods: the near-term market (1991 to 1995) and the long-term market (1995 and beyond). The near-term market is characterized by limited unfilled requirements of 4% per year, to be supplied by national stockpiles and excess inventories. This low-cost material will be drawn down by about 1993, causing a subsequent price rise. As the price rises, primary supplier activity is expected to increase. In the near-term, two contracting activities are apparent: spot; and intermediate-term. The current spot market is expected to last until available low cost inventories are drawn down. Recently, in attempts to gain market share, suppliers have offered attractively priced intermediate-term (3 year) contracts for 1996 to 1998. While a small spot market will continue after 1995, it is anticipated that utilities will prefer a mix of medium- and long-term (5 to 10 year) contracts from primary suppliers for most of their enrichment requirements. As national stockpiles and utility inventories are consumed, low-cost supply available to the spot market is expected to diminish. Consequently, with little low-cost supply available, the only apparent source of material will be from primary suppliers, and the resulting competition over market share is expected to be intense. (author)

  3. Motif enrichment tool.

    Science.gov (United States)

    Blatti, Charles; Sinha, Saurabh

    2014-07-01

    The Motif Enrichment Tool (MET) provides an online interface that enables users to find major transcriptional regulators of their gene sets of interest. MET searches the appropriate regulatory region around each gene and identifies which transcription factor DNA-binding specificities (motifs) are statistically overrepresented. Motif enrichment analysis is currently available for many metazoan species including human, mouse, fruit fly, planaria and flowering plants. MET also leverages high-throughput experimental data such as ChIP-seq and DNase-seq from ENCODE and ModENCODE to identify the regulatory targets of a transcription factor with greater precision. The results from MET are produced in real time and are linked to a genome browser for easy follow-up analysis. Use of the web tool is free and open to all, and there is no login requirement. ADDRESS: http://veda.cs.uiuc.edu/MET/. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

  4. A consideration on laser enrichment module

    International Nuclear Information System (INIS)

    Arisawa, Takashi; Shiba, Koreyuki

    1983-09-01

    Several problems are discussed for designing a simplified enrichment module based on Atomic Laser Isotope Separation Method, which involve the vaporization of metal, laser excitation, laser ionization and ion recovery. The conditions at which the consumed energy has the minimum value are obtained by calculating the specific energy consumption for producing unit amount of enriched products. It is found that there should be an appropriate relationship between the processing atomic density and the electrode gap in order to avoid the enrichment loss caused by the charge exchange during the ion recovery. Moreover it is also found that this relation depends on the electrode length measured along both the atomic beam direction and the laser beam direction. (author)

  5. Energy consumption of chemical uranium enrichment

    International Nuclear Information System (INIS)

    Miyake, T.; Takeda, K.; Obanawa, H.

    1987-01-01

    A quantitative study of chemical separation energy for enriching uranium-235 by the redox chromatography was conducted. Isotope exchange reactions between U 4+ -UO 2 2+ ions in the enrichment column are maintained by the redox reactions. The chemical separation energy is ultimately supplied by hydrogen and oxygen gas for regenerating redox agents. The redox energy for the isotope separation is theoretically predicted as a function of the dynamic enrichment factor observed in the chromatographic development of uranium adsorption band. Thermodynamic treatments of the equilibrium reactions implies and inverse redox reaction which can be enhanced by the chemical potential of the ion-exchange reaction of oxidant. Experimental results showed 30 to 90% recovery of the redox energy by the inverse reaction. These results will devise a simplified redox chromatography process where a number of columns in one module is reduced

  6. Method of deuterium isotope separation and enrichment

    International Nuclear Information System (INIS)

    Benson, S.W.

    1980-01-01

    A method of deuterium isotope separation and enrichment using infrared laser technology in combination with chemical processes for treating and recycling the unreacted and deuterium-depleted starting materials is described. Organic molecules of the formula RX (where R is an ethyl, isopropyl, t-butyl, or cyclopentenyl group and X is F, Cl, Br or OH) containing a normal abundance of hydrogen and deuterium are exposed to intense laser infrared radiation. An olefin containing deuterium (olefin D) will be formed, along with HX. The enriched olefin D can be stripped from the depleted stream of RX and HX, and can be burned to form enriched water or pyrolyzed to produce hydrogen gas with elevated deuterium content. The depleted RX is decomposed to olefins and RX, catalytically exchanged with normal water to restore the deuterium content to natural levels, and recombined to form RX which can be recycled. (LL)

  7. 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

  8. Axial blanket enrichment optimization of the NPP Krsko fuel

    International Nuclear Information System (INIS)

    Kromar, M.; Kurincic, B.

    2001-01-01

    In this paper optimal axial blanket enrichment of the NPP Krsko fuel is investigated. Since the optimization is dictated by economic categories that can significantly vary in time, two step approach is applied. In the first step simple relationship between the equivalent change in enrichment of axial blankets and central fuel region is established. The relationship is afterwards processed with economic criteria and constraints to obtain optimal axial blanket enrichment. In the analysis realistic NPP Krsko conditions are considered. Except for the fuel enrichment all other fuel characteristics are the same as in the fuel used in the few most recent cycles. A typical reload cycle after the plant power uprate is examined. Analysis has shown that the current blanket enrichment is close to the optimal. Blanket enrichment reduction results in an approximately 100 000 US$ savings per fuel cycle.(author)

  9. Uranium enrichment by centrifuge in Japan

    International Nuclear Information System (INIS)

    Watanabe, T.; Murase, T.

    1977-01-01

    The demand for enriched uranium is on the increase with nuclear power capacity in which the LWR predominates and is estimated to exceed the supply from the present facilities in the world in less than ten years. Therefore, the basic strategy for enriched uranium is investigated on the following three-point long-range program in Japan: 1. To continue negotiations to extend the current allocation by the long-term contract; 2. To seek active participation in international enrichment projects; and 3. To make efforts to develop uranium enrichment technology and to construct inland facilities. On this basis, a vigorous development program of gas centrigue process for industrialization was launched out in 1972 as a national project. Ever since substantial progress in this field has been made and development works have been increased year after year. At present, a concrete plan of a pilot plant is taking shape. Up to now, several types of centrifuges were developed, of which some were completed as prototype models, and subjected to life tests and also to extensive earthquake-resistivity tests for the characteristics of Japanese geological condition. An enrichment plant is composed of so many centrifuges that the installation and piping system of centrifuges is an important factor which has an effect on plant economy and reliability. Two types of the experimental cascade were constructed in Japan. One has been in operation since 1973, and the other since 1975. Valuable empirical data have been accumulated on cascade characteristics, maintenance scheme and so on. It will be important for the coming plants to have a flexibility to escalation of labor and energy cost, or to variation of the separative work requirement and further. An economic prospect of centrifuge enrichment process is presented

  10. Adoption of Enriched Local Complementary Food in Osun State ...

    African Journals Online (AJOL)

    Locally processed complementary foods, appropriately enriched can complement breast milk and traditional foods during the nutritionally vulnerable periods of a child life. The study therefore examines the adoption of enriched local complementary foods in Osun State Nigeria. Structured interview schedule was used to ...

  11. Enrichment of boron 10

    International Nuclear Information System (INIS)

    Coutinho, C.M.M.; Rodrigues Filho, J.S.R.; Umeda, K.; Echternacht, M.V.

    1990-01-01

    A isotopic separation pilot plant with five ion exchange columns interconnected in series were designed and built in the IEN. The columns are charged with a strong anionic resin in its alkaline form. The boric acid solution is introduced in the separation columns until it reaches a absorbing zone length which is sufficient to obtain the desired boron-10 isotopic concentration. The boric acid absorbing zone movement is provided by the injection of a diluted hydrochloric acid solution, which replace the boric acid throughout the columns. The absorbing zone equilibrium length is proportional to its total length. The enriched boron-10 and the depleted boron are located in the final boundary and in the initial position of the absorbing zones, respectively. (author)

  12. Thermal breeder fuel enrichment zoning

    International Nuclear Information System (INIS)

    Capossela, H.J.; Dwyer, J.R.; Luce, R.G.; McCoy, D.F.; Merriman, F.C.

    1992-01-01

    A method and apparatus for improving the performance of a thermal breeder reactor having regions of higher than average moderator concentration are disclosed. The fuel modules of the reactor core contain at least two different types of fuel elements, a high enrichment fuel element and a low enrichment fuel element. The two types of fuel elements are arranged in the fuel module with the low enrichment fuel elements located between the high moderator regions and the high enrichment fuel elements. Preferably, shim rods made of a fertile material are provided in selective regions for controlling the reactivity of the reactor by movement of the shim rods into and out of the reactor core. The moderation of neutrons adjacent the high enrichment fuel elements is preferably minimized as by reducing the spacing of the high enrichment fuel elements and/or using a moderator having a reduced moderating effect. 1 figure

  13. Advanced Neutron Source enrichment study

    International Nuclear Information System (INIS)

    Bari, R.A.; Ludewig, H.; Weeks, J.R.

    1996-01-01

    A study has been performed of the impact on performance of using low-enriched uranium (20% 235 U) or medium-enriched uranium (35% 235 U) as an alternative fuel for the Advanced Neutron Source, which was initially designed to use uranium enriched to 93% 235 U. Higher fuel densities and larger volume cores were evaluated at the lower enrichments in terms of impact on neutron flux, safety, safeguards, technical feasibility, and cost. The feasibility of fabricating uranium silicide fuel at increasing material density was specifically addressed by a panel of international experts on research reactor fuels. The most viable alternative designs for the reactor at lower enrichments were identified and discussed. Several sensitivity analyses were performed to gain an understanding of the performance of the reactor at parametric values of power, fuel density, core volume, and enrichment that were interpolations between the boundary values imposed on the study or extrapolations from known technology

  14. Process for enriching uranium from seawater

    International Nuclear Information System (INIS)

    Heitkamp, D.; Inden, P.

    1982-01-01

    In selective elutriation of uranium deposited on titanium oxide hydrate by carbonate solution, only uranium should be dissolved from the absorption material forming carbonate compounds, without the deposited ballast ions, above all of magnesium, calcium and sodium being elutriated. The uranium elutriation according to the invention is therefore carried out in the presence of these ballast ions in the same concentrations as those in seawater. The carbonate concentration can only be raised as far as the solubility product of the basic magnesium carbonate permits, so that magnesium remains in the solution, as well as carbonate, in the concentration present in seawater. One must accept the absence of calcium ions in the elutriation solution, as their solubility product with carbonate is considerably less than that for magnesium. (orig./PW) [de

  15. Unattended safeguards instrumentation at centrifuge enrichment plants

    International Nuclear Information System (INIS)

    Smith, L. Eric; Lebrun, Alain R.; Labella, Rocco

    2014-01-01

    As global uranium enrichment capacity under international safeguards expands, the International Atomic Energy Agency (IAEA) is challenged to develop effective safeguards approaches at gaseous centrifuge enrichment plants, particularly high‑capacity plants, while working within budgetary constraints. New safeguards approaches should meet the high‑level verification objectives for such facilities (i.e., timely detection of: diversion of declared material, excess production beyond declared amounts, and production of enrichment levels higher than declared), but should also strive for efficiency advantages in implementation, for both the IAEA and operators. Under the Agency’s State- level approach to safeguards implementation, the Agency needs a flexible toolbox of technologies, allowing tailoring of safeguards measures for each individual enrichment facility. In this paper, the potential roles and development status for three different types of unattended measurement instrumentation are discussed. On‑Line Enrichment Monitors (OLEM) could provide continuous enrichment measurement for 100% of the declared gas flowing through unit header pipes. Unattended Cylinder Verification Stations (UCVS) could provide unattended verification of the declared uranium mass and enrichment of 100% of the cylinders moving through the plant, but also apply and verify an ‘NDA Fingerprint’ to preserve verification knowledge on the contents of each cylinder throughout its life in the facility. Sharing of the operator’s load cell signals from feed and withdrawal stations could count all cylinders introduced to the process and provide periodic monitoring of the uranium mass balance for in‑process material. The integration of load cell, OLEM and UCVS data streams offers the possibility for 100% verification of declared cylinder flow, and enables the periodic verification of the declared 235 U mass balance in the plant. These new capabilities would enhance the IAEA

  16. Status report on uranium enrichment associates

    International Nuclear Information System (INIS)

    Langley, R.A. Jr.; O'Donnell, A.J.; Garrett, G.A.

    1977-01-01

    Uranium Enrichment Associates (UEA) had as its priority project financing, an approach in which the total project is financially self-liquidating. UEA worked with financial institutions to define the combination of assurances and guarantees required by lenders in order to provide the required debt funding. UEA's assets against which the debt liability for the plant would be balanced would be the facilities under construction and the equipment on order. On the customer side, there was major concern on the part of the utilities of whether private industry would be able to complete and operate the plant owing to many of the same possibilities which concerned financial institutions. The disparity between the conditions under which financing could be obtained and the terms acceptable to utilities was a significant element in EUA's choice of process to use for its enrichment plants. UEA's technical staff then began to parallel conceptual designs of gaseous diffusion and gas cenrifuge plants. UEA negotiated with ERDA on the terms of a Cooperative Arrangement, within the provisions of the NFAA, providing the minimum conditions necessary to obtain financing and contracts with utilities for enrichment sources. The UEA plant has several features different from the ERDA plants. The UEA plant used only two basic stage sizes. The UEA design employed four main process buildings. The partners in UEA have mutually agreed to follow the private uranium enrichment project to a logical conclusion. 6 figures

  17. Stable isotope enrichment by thermal diffusion

    International Nuclear Information System (INIS)

    Vasaru, Gheorghe

    2003-01-01

    Thermal diffusion (TD) in both gaseous and liquid phase has been the subject of extensive experimental and theoretical investigations, especially after the invention by K. Clusius and G. Dickel of the thermal diffusion column, sixty years ago. This paper gives a brief overview of the most important applications and developments of this transport phenomenon for enrichment of 13 C and of some noble gases isotopes in our institute. The results of calculations of the transport coefficients H and K for a concentric tube type TD column, operated with methane as process gas, are presented. Static separation factor at equilibrium vs gas pressure has been calculated for various molecular models. The experimental separation factors for different gas pressure were found to be consistent with those calculated for the inverse power repulsion model and the Lennard-Jones model. The most important characteristics of a seven-stage cascade consisting of 19 TD columns of concentric tube type are given. This system has been constructed and successfully operated at a temperature of 673 K and produces an enrichment of methane of natural isotopic 13 C abundance, up to the concentration of 25% 13 CH 4 . Enrichment of the noble gases isotopes implies: - a . Enrichment of 20 Ne and 22 Ne in a eight-stage cascade consisting of 8 TD columns; - b. enrichment of 46 Ar in a seven-stage cascade consisting of TD columns and finally; - c. enrichment of 78 Kr and 86 Kr in a fifteen-stage cascade, consisting of 35 TD columns. For all these installations we have adopted TD columns of hot wire type (4 m in length), operated at a temperature of 1073 K. (author)

  18. Profile of World Uranium Enrichment Programs-2009

    International Nuclear Information System (INIS)

    Laughter, Mark D.

    2009-01-01

    It is generally agreed that the most difficult step in building a nuclear weapon is acquiring fissile material, either plutonium or highly enriched uranium (HEU). Plutonium is produced in a nuclear reactor, whereas HEU is produced using a uranium enrichment process. Enrichment is also an important step in the civil nuclear fuel cycle, in producing low enriched uranium (LEU) for use as fuel for nuclear reactors to generate electricity. However, the same equipment used to produce LEU for nuclear reactor fuel can also be used to produce HEU for weapons. Safeguards at an enrichment plant are the array of assurances and verification techniques that ensure uranium is not diverted or enriched to HEU. There are several techniques for enriching uranium. The two most prevalent are gaseous diffusion, which uses older technology and requires a lot of energy, and gas centrifuge separation, which uses more advanced technology and is more energy efficient. Gaseous diffusion plants (GDPs) provide about 40% of current world enrichment capacity but are being phased out as newer gas centrifuge enrichment plants (GCEPs) are constructed. Estimates of current and future enrichment capacity are always approximate, due to the constant upgrades, expansions, and shutdowns occurring at enrichment plants, largely determined by economic interests. Currently, the world enrichment capacity is approximately 56 million kilogram separative work units (SWU) per year, with 22.5 million in gaseous diffusion and more than 33 million in gas centrifuge plants. Another 34 million SWU/year of capacity is under construction or planned for the near future, almost entirely using gas centrifuge separation. Other less-efficient techniques have also been used in the past, including electromagnetic and aerodynamic separations, but these are considered obsolete, at least from a commercial perspective. Laser isotope separation shows promise as a possible enrichment technique of the future but has yet to be

  19. City model enrichment

    Science.gov (United States)

    Smart, Philip D.; Quinn, Jonathan A.; Jones, Christopher B.

    The combination of mobile communication technology with location and orientation aware digital cameras has introduced increasing interest in the exploitation of 3D city models for applications such as augmented reality and automated image captioning. The effectiveness of such applications is, at present, severely limited by the often poor quality of semantic annotation of the 3D models. In this paper, we show how freely available sources of georeferenced Web 2.0 information can be used for automated enrichment of 3D city models. Point referenced names of prominent buildings and landmarks mined from Wikipedia articles and from the OpenStreetMaps digital map and Geonames gazetteer have been matched to the 2D ground plan geometry of a 3D city model. In order to address the ambiguities that arise in the associations between these sources and the city model, we present procedures to merge potentially related buildings and implement fuzzy matching between reference points and building polygons. An experimental evaluation demonstrates the effectiveness of the presented methods.

  20. Parasite and nutrient enrichment effects on Daphnia interspecific competition

    NARCIS (Netherlands)

    Decaestecker, Ellen; Verreydt, Dino; De Meester, Luc; Declerck, Steven A.J.

    2015-01-01

    Increased productivity due to nutrient enrichment is hypothesized to affect density-dependent processes, such as transmission success of horizontally transmitting parasites. Changes in nutrient availability can also modify the stoichiometry and condition of individual hosts, which may affect their

  1. Enriching stable isotopes: Alternative use for Urenco technology

    International Nuclear Information System (INIS)

    Rakhorst, H.; de Jong, P.G.T.; Dawson, P.D.

    1996-01-01

    The International Urenco Group utilizes a technologically advanced centrifuge process to enrich uranium in the fissionable isotope 235 U. The group operates plants in the United Kingdom, the Netherlands, and Germany and currently holds a 10% share of the multibillion dollar world enrichment market. In the early 1990s, Urenco embarked on a strategy of building on the company's uniquely advanced centrifuge process and laser isotope separation (LIS) experience to enrich nonradioactive isotopes colloquially known as stable isotopes. This paper summarizes the present status of Urenco's stable isotopes business

  2. Low enrichment of uranium in the light of the nuclear weapon problem

    International Nuclear Information System (INIS)

    Barstad, G.

    1979-09-01

    A difficult problem in the immediate future will be to direct civil nuclear technology in such a way that the ability to produce nuclear weapons by additional countries is prevented. There are two main problems. First, enrichment plants can be used to produce high enriched uranium, which can be used in nuclear weapons, as well as low enriched reactor fuel. Second, plutonium produced during reactor operation can be used as nuclear weapon material, as well as for nuclear fuel. The problem discussed here is particularly the development of an enrichment process which is economic for low enriched reactor fuel, but which may not easily be adapted to produce high enriched uranium. (JIW)

  3. Hydrogen-enriched fuels

    Energy Technology Data Exchange (ETDEWEB)

    Roser, R. [NRG Technologies, Inc., Reno, NV (United States)

    1998-08-01

    NRG Technologies, Inc. is attempting to develop hardware and infrastructure that will allow mixtures of hydrogen and conventional fuels to become viable alternatives to conventional fuels alone. This commercialization can be successful if the authors are able to achieve exhaust emission levels of less than 0.03 g/kw-hr NOx and CO; and 0.15 g/kw-hr NMHC at full engine power without the use of exhaust catalysts. The major barriers to achieving these goals are that the lean burn regimes required to meet exhaust emissions goals reduce engine output substantially and tend to exhibit higher-than-normal total hydrocarbon emissions. Also, hydrogen addition to conventional fuels increases fuel cost, and reduces both vehicle range and engine output power. Maintaining low emissions during transient driving cycles has not been demonstrated. A three year test plan has been developed to perform the investigations into the issues described above. During this initial year of funding research has progressed in the following areas: (a) a cost effective single-cylinder research platform was constructed; (b) exhaust gas speciation was performed to characterize the nature of hydrocarbon emissions from hydrogen-enriched natural gas fuels; (c) three H{sub 2}/CH{sub 4} fuel compositions were analyzed using spark timing and equivalence ratio sweeping procedures and finally; (d) a full size pick-up truck platform was converted to run on HCNG fuels. The testing performed in year one of the three year plan represents a baseline from which to assess options for overcoming the stated barriers to success.

  4. Automated Information Enrichment for a Better Search

    OpenAIRE

    José Luis Preza

    2016-01-01

    The process of adding the Metadata when uploading a digital object onto a repository is usually manual. This means that the user has to have already at hand the keywords and all the other information about the asset. This paper addresses the possibility of enriching the “manual metadata” by generating automated metadata using the cognitive services provided by technologies like IBM Watson platform. The cognitive computing services offered by IBM Watson automatically generate Semantic Data (in...

  5. Uranium enrichment export control guide: Gaseous diffusion

    Energy Technology Data Exchange (ETDEWEB)

    1989-09-01

    This document was prepared to serve as a guide for export control officials in their interpretation, understanding, and implementation of export laws that relate to the Zangger International Trigger List for gaseous diffusion uranium enrichment process components, equipment, and materials. Particular emphasis is focused on items that are especially designed or prepared since export controls are required for these by States that are party to the International Nuclear Nonproliferation Treaty.

  6. Ningyo Toge uranium enrichment pilot plant comes into full

    International Nuclear Information System (INIS)

    1982-01-01

    The uranium enrichment pilot plant of the Power Reactor and Nuclear Fuel Development Corporation at Ningyo Toge went into full operation on March 26, 1982. This signifies that the front end of the nuclear fuel cycle in Japan, from uranium ore to enrichment, is only a step away from commercialization. On the same day, the pilot plant of uranium processing and conversion to UF 6 , the direct purification of uranium ore into uranium hexafluoride, began batch operation at the same works. The construction of the uranium enrichment pilot plant has been advanced in three stages: i.e. OP-1A with 1000 centrifuges, OP-1B with 3000 centrifuges and OP-2 with 3000 centrifuges. With a total of 7000 centrifuges, the pilot plant, the first enrichment plant in Japan, has now a capacity of supplying enriched uranium for six months operation of a 1,000 MW nuclear power plant. (J.P.N.)

  7. History of enrichment research at the CEA

    International Nuclear Information System (INIS)

    Camarcat, N.

    1996-01-01

    French researches about uranium enrichment have been carried out at the CEA for about 40 years. In the beginning, these researches were considered as marginal and were carried out by a small team from the Powders Central Laboratory. They became intensive since 1955 and culminated in 1967 with the conception of Pierrelatte's factory. Several processes were studied: the gaseous diffusion, the chemical treatments, the centrifugation, the laser and electromagnetic separation processes on atomic and molecular vapors. Only a few of them were fully developed. This paper summarizes the development of these different processes in their historical context. (J.S.). 1 fig

  8. France makes steady progress with lasers [enrichment

    International Nuclear Information System (INIS)

    Coates, J.-H.; Clerc, M.; Plurien, P.

    1988-01-01

    With the CHEMEX process now a commercially available technology, the French Commissariat a l'Energie (CEA) is focussing its R and D activity on two enrichment processes: gaseous diffusion, and atomic vapour laser isotope separation (AVLIS or SILVA). The SILVA process is being developed, with particular attention being paid to test campaigns undertaken on the pilot unit installed at Saclay. A core of technical know-how is being maintained in gaseous diffusion in order to study the behaviour of, and possible improvements to, the newly named George Besse plant at the Tricastin site. (U.K.)

  9. High enrichment to low enrichment core's conversion. Technical securities

    International Nuclear Information System (INIS)

    Abbate, P.; Madariaga, M.R.

    1990-01-01

    This work presents the fulfillment of the technical securities subscribed by INVAP S.E. for the conversion of a high enriched uranium core. The reactor (of 5 thermal Mw), built in the 50's and 60's, is of the 'swimming pool' type, with light water and fuel elements of the curve plates MTR type, enriched at 93.15 %. These are neutronic and thermohydraulic securities. (Author) [es

  10. Safety of uranium enrichment plant

    International Nuclear Information System (INIS)

    Yonekawa, Shigeru; Morikami, Yoshio; Morita, Minoru; Takahashi, Tsukasa; Tokuyasu, Takashi.

    1991-01-01

    With respect to safety evaluation of the gas centrifuge enrichment facility, several characteristic problems are described as follows. Criticality safety in the cascade equipments can be obtained to maintain the enrichment of UF 6 below 5 %. External radiation dose equivalent rate of the 30B cylinder is low enough, the shield is not necessary. Penetration ratio of the two-stage HEPA filters for UF 6 aerosol is estimated at 10 -9 . From the experimental investigation, vacuum tightness is not damaged by destruction of gas centrifuge rotor. Carbon steel can be used for uranium enrichment equipments under the condition below 100degC. (author)

  11. Environmental enrichment for aquatic animals.

    Science.gov (United States)

    Corcoran, Mike

    2015-05-01

    Aquatic animals are the most popular pets in the United States based on the number of owned pets. They are popular display animals and are increasingly used in research settings. Enrichment of captive animals is an important element of zoo and laboratory medicine. The importance of enrichment for aquatic animals has been slower in implementation. For a long time, there was debate over whether or not fish were able to experience pain or form long-term memories. As that debate has reduced and the consciousness of more aquatic animals is accepted, the need to discuss enrichment for these animals has increased. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. World enrichment requirements to 2005

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    The primary enrichment suppliers-Eurodif, Techsnabexport, Urenco, and the US DOE - are positioning themselves to take advantage of the post - 1995 market. Overall, unfilled requirements represent about 40 percent of world requirements in the year 2000. The USA will be the primary market, as US utilities' unfilled enrichment requirements account for over 60 percent of the world's total unfilled requirements. The enrichment market is moving toward more global competition, as each supplier tries to maintain its current regional market base and then to capture additional market share in other regions

  13. OPTIMASI PEMADATAM CEPAT PADA PENGAYAAN MINYAK IKAN HASIL SAMPING PENGALENGAN LEMURU DENGAN ASAM LEMAK w-3 MENGGUNAKAN METODE PERMUKAAN RESPON [Optimization of Rapid Solidification to Enrich Fish Oil from by-Product of Lemuru Canning Processing with w-3 batty Acids by Response Surface Method

    Directory of Open Access Journals (Sweden)

    Teti Estiasih1

    2005-12-01

    Full Text Available Oil from by-product of lemuru canning processing was a source of w-3 fatty acid but its characteristics had out been known. The content of w-3 fatty acids of this oil had to be increased. Various methods are available to enhance w-3 fatty acids concentration Rapid solidification was one of limited methods to enrich fish oil by w-3 fatty acids containing triglycerides.This research was conducted to optimize rapid solidification condition to enrich fish oil from by product of lemuru canning processing with w-3 fatty acids and characterize the enriched oil compared by International Association of Fish Meal and Oil Manufacturers standard. In optimization process, the content of EPA+OHA and yield .was maximized. A two-factors central composite design in Response Surface Method was used to study the effect of solvent-to-oil ratio (X1 and extraction time (X2. The response (Y is the multiplication of EPA+DHA content by yield.The results showed that under optimum conditions the maximum response were obtained at a solvent-to-oil ratio of 3,95:1(vw and extraction time of 24,93 hours. The w-3 fatty acids enriched fish oil had EPA+DHA content of 33,33% and yield of 9.40% (w/w.The produced w-3 fatty acids enriched fish oil had good quality based on food grade fish oil standard, unless Fe and Cu content. Chelation could reduce these oxidizing metals.

  14. Centar's gas centrifuge enrichment project

    International Nuclear Information System (INIS)

    Abajian, V.V.; Fishman, A.M.

    1976-01-01

    Plans for the building and operating of Centar Associates gas centrifuge uranium enrichment plant are described. Operating costs and machine manufacture are considered. Commitments with the utilities are summarised. (U.K.)

  15. Extraosseus enrichments in bone scintigraphy

    International Nuclear Information System (INIS)

    Jochens, R.; Schumacher, T.; Amthauer, H.; Wolter, M.; Stock, W.; Stroszczynski, C.; Moersler, J.P.; Eichstaedt, H.

    1996-01-01

    Extraosseus enrichments are common findings in bone scintigraphy. Main causes are artifacts by skin or cloth contamination, paravenous and subcutaneous injection. Physical examination, removal of cloths, skin cleaning or further images in differing projections lead to the correct diagnosis artefact or extraosseous enrichments. Further on, extraosseous enrichments are seen in physiological variants. In different diseases extraosseous enrichments are common, especially in urinary tract, liver and extremities. Further diagnostics, e.g. conventional radiologic procedures, sonography and CT scans, have to be performed. In individual cases side results in bone scintigraphy lead to formerly unknown diagnosis, further diagnostic procedure is influenced decisively. Own cases show for example a cerebral apoplectic insult, formerly unknown liver metastasis or metastasis in extraosseous Ewings's sarcoma. (orig.) [de

  16. Uranium enrichment: an evolving market

    International Nuclear Information System (INIS)

    Longenecker, J.; Witzel, R.

    1997-01-01

    With over half of the world uranium enrichment market uncommitted to any supplier early in the next century, competition is certain to be fierce. In the meantime the outlood remains unclear, with the market dominated by a number of developments -privatisation of the United States Enrichment Corp (USEC), increasing availability of Russian and US military inventories, the deployment of advanced technology and the closure of nuclear power plants due to deregulation. (author)

  17. Unjust enrichment in business law

    OpenAIRE

    Vydrová, Zuzana

    2016-01-01

    This thesis analyses the concept of unjust enrichment under the business law. First of all the thesis explains the term of business law. Business law is a complex of legal rules concerning the contractual relationships between entrepreneurs arising from their business activities. Business law is a comprehensive field of law which extends into many other fields of law, both private and public law. Equally the regulation of unjust enrichment within the business law expands into many other laws ...

  18. Technical status study of heavy water enrichment

    International Nuclear Information System (INIS)

    Sukarsono; Imam Dahroni; Didik Herhady

    2007-01-01

    Technical status study of heavy water enrichment in Indonesia and also in the world has been done. Heavy water enrichment processes have been investigated were water distillation, hydrogen distillation, laser enrichment, electrolysis and isotop exchange. For the isotop exchange, the chemical pair can be used were water-hydrogen sulphite, ammonium-hydrogen, aminomethane-hydrogen, and water-hydrogen. For the isotope exchange, there was carried out by mono thermal or bi thermal. The highest producer of heavy water is Canada, and the other producer is USA, Norwegian and India. The processes be used in the world are isotope exchange Girdler Sulphide (GS), distillation and electrolysis. Research of heavy water carried out in Batan Yogyakarta, has a purpose to know the characteristic of heavy water purification. Several apparatus which has erected were 3 distillation column: Pyrex glass of 2 m tall, stainless steel column of 3 m tall and steel of 6 m tall. Electrolysis apparatus is 50 cell electrolysis and an isotope exchange unit which has catalyst: Ni- Cr 2 O 3 and Pt-Carbon. These apparatus were not ready to operate. (author)

  19. Market implications of advanced enrichment techniques

    International Nuclear Information System (INIS)

    Rougeau, J.-P.

    1987-01-01

    The only commercial outlet for uranium is for nuclear reactors and the uranium market will be closely linked to the nuclear power market for the forseeable future. Any production cost saving in the uranium cycle clearly, therefore, increases the chances for world-wide expansion of the nuclear industry. Thus, although there is overcapacity in enrichment, development of cheaper, new or more efficient established techniques, is important. The atomic vapour laser isotope separation process is considered and discussed against this background. Separative work units are explained for this technique. The problems of integrating laser isotope separation into the fuel cycle are discussed. The effects on the amount of natural uranium required for different recycling strategies, and for different laser tails assay and time schedules are illustrated. Over the next twenty years laser-based enrichment will have an important effect on the fuel cycle industry. COGEMA is expected to play a part in developing these new techniques. (U.K.)

  20. Uranium enrichment activities: the SILVA program

    International Nuclear Information System (INIS)

    Guyot, J.; Cazalet, J.; Camarcat, N.; Figuet, J.

    1994-01-01

    Through its commitment to a nuclear electricity generation policy, France holds today a specific position in the uranium enrichment market thanks to the modern multinational EURODIF gaseous diffusion plant. France has, altogether, a long-term goal in developing SILVA, a laser uranium enrichment process, based on the selective photo-ionization of U-235. After reviewing the fundamentals of SILVA (the laser system with copper vapor lasers and dye lasers and the separator system), a description of the general organization of the R and D program is provided going through basic research, subsystems assessment, production demonstrations and simulations (with the LACAN code), plant design and economics. The general schedule of SILVA is outlined, leading to the possible construction of a commercial plant. 7 figs., 11 refs

  1. The uranium enrichment market and long-term technological options

    International Nuclear Information System (INIS)

    Schneider-Maunoury, A.

    1992-01-01

    The world enrichment market situation is clearly delineated up to the year 2000. Including the East European countries, worldwide enriched uranium requirements should reach 40 million separative work units (SWUs) a year and production capacity should reach 44 millions SWUs. Two-thirds of this capacity will be supplied by the gaseous diffusion process and one-third by the centrifuge process. The enrichment processes currently considered are: (i) the gaseous diffusion process, (ii) the centrifuge process, (iii) the chemical treatment process and (iv) the laser processes, long-term assessment of the enrichment market up to the year 2015. Two scenarios may be envisioned for the (i) Public opinion will continue to block the development of nuclear power, and requirements will level off at 40 million SWUs. (ii) Changing attitudes will favor a reasonable approach enabling a revival of nuclear power expansion around 1995. Requirements should then increase starting in 2005 and would readily attain 60 million SWUs a year by 2015. Depending on market conditions, enrichment process options will be influenced either entirely by cost considerations, without allowance for the time factor, or by need to meet demand. Demonstrations of the industrial validity of laser processes are expected by 1992 - 1995 and, if interest in nuclear power makes a comeback, decisions should be made between 1995 and 2000 to build new large-capacity enrichment plants. The gaseous diffusion process may still be used for a long time if nuclear power is judiciously employed. The centrifuge process will be fully mature by the year 2000. The uranium vapor laser processes offer the most promise and should ultimately prevail. the chemical processes, though outsiders, deserve watching. (author)

  2. Research on aerodynamic means of isotope enrichment

    International Nuclear Information System (INIS)

    Cattolica, R.J.; Gallagher, R.J.; Talbot, L.; Willis, D.R.; Hurlbut, F.C.; Fiszdon, W.; Anderson, J.B.

    1978-03-01

    The results of a research program directed toward the understanding of the fundamental gas dynamics involved in aerodynamic isotope enrichment are summarized. The specific aerodynamic isotope enrichment method which was examined in this research is based on a velocity slip phenomenon which occurs in the rarefied hypersonic expansion of a heavy molecular weight gas and a light carrier gas in a nozzle or free jet. This particular aerodynamic method was chosen for study because it contains the fundamental molecular physics of other more complex techniques within the context of a one-dimensional flow without boundary effects. From both an experimental and theoretical modeling perspective this provides an excellent basis for testing the experimental and numerical tools with which to investigate more complex aerodynamic isotope enrichment processes. This report consists of three separate parts. Part I contains a theoretical analysis of the velocity slip effect in free jet expansions of binary and ternary gas mixtures. The analysis, based on a source flow model and using moment equations is derived from the Boltzmann equation using the hypersonic approximation. Part II contains the experimental measurements of velocity slip. The numerical simulation of the slip process was carried out by using a Monte-Carlo numerical technique. In addition, comparisons between the theoretical analysis of Part I and the experiments are presented. Part III describes impact pressure measurements of free jet expansions from slot shaped two dimensional nozzles. At least two methods of aerodynamic isotope enrichment (opposed jet and velocity slip) would depend on the use of this type of two dimensional expansion. Flow surveys of single free jet and the interferene of crossed free jets are presented

  3. Enrichment by diffusion

    International Nuclear Information System (INIS)

    Mezin, M.

    1976-01-01

    The report presents an introduction to general basic principles of the gaseous diffusion process for the separation of uranium isotopes. Dealt with are: a) theoretical background and basic considerations of separation work and production costs, b) construction of a single separation stage and a multistage plant, c) the components of a plant and the optimization factors, d) cost factors. The text is illustrated by instructive diagrammes and flow charts. (RB) [de

  4. Experimental Validation of a Permeability Model for Enrichment Membranes

    International Nuclear Information System (INIS)

    Orellano, Pablo; Brasnarof, Daniel; Florido Pablo

    2003-01-01

    An experimental loop with a real scale diffuser, in a single enrichment-stage configuration, was operated with air at different process conditions, in order to characterize the membrane permeability.Using these experimental data, an analytical geometric-and-morphologic-based model was validated.It is conclude that a new set of independent measurements, i.e. enrichment, is necessary in order to fully characterize diffusers, because of its internal parameters are not univocally determinated with permeability experimental data only

  5. PWR fuel of high enrichment with erbia and enriched gadolinia

    International Nuclear Information System (INIS)

    Bejmer, Klaes-Håkan; Malm, Christian

    2011-01-01

    Today standard PWR fuel is licensed for operation up to 65-70 MWd/kgU, which in most cases corresponds to an enrichment of more than 5 w/o "2"3"5U. Due to criticality safety reason of storage and transportation, only fuel up to 5 w/o "2"3"5U enrichment is so far used. New fuel storage installations and transportation casks are necessary investments before the reactivity level of the fresh fuel can be significantly increased. These investments and corresponding licensing work takes time, and in the meantime a solution that requires burnable poisons in all pellets of the fresh high-enriched fuel might be used. By using very small amounts of burnable absorber in every pellet the initial reactivity can be reduced to today's levels. This study presents core calculations with fuel assemblies enriched to almost 6 w/o "2"3"5U mixed with a small amount of erbia. Some of the assemblies also contain gadolinia. The results are compared to a reference case containing assemblies with 4.95 w/o "2"3"5U without erbia, utilizing only gadolinia as burnable poison. The comparison shows that the number of fresh fuel assemblies can be reduced by 21% (which increases the batch burnup by 24%) by utilizing the erbia fuel concept. However, increased cost of uranium due to higher enrichment is not fully compensated for by the cost gain due to the reduction of the number assemblies. Hence, the fuel cycle cost becomes slightly higher for the high enrichment erbia case than for the reference case. (author)

  6. High enrichment to low enrichment core's conversion. Accidents analysis

    International Nuclear Information System (INIS)

    Abbate, P.; Rubio, R.; Doval, A.; Lovotti, O.

    1990-01-01

    This work analyzes the different accidents that may occur in the reactor's facility after the 20% high-enriched uranium core's conversion. The reactor (of 5 thermal Mw), built in the 50's and 60's, is of the 'swimming pool' type, with light water and fuel elements of the curve plates MTR type, enriched at 93.15 %. This analysis includes: a) accidents by reactivity insertion; b) accidents by coolant loss; c) analysis by flow loss and d) fission products release. (Author) [es

  7. 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.)

  8. R and D on laser uranium enrichment

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    An AEC Advisory Committee on Uranium Enrichment has completed investigations into the actual condition of laser isotope separation. The working group set up for the purpose has issued a report on the series of investigations made on its development and measures for promoting it. The report says that the development of the process in Japan is at a fundamental stage. Noting that further efforts are needed before its future can be predicted, the report proposes a cource of research and development for the immediate future. For the atomic vapor laser isotope separation (AVLIS), government organizations are engaged in data base buildup and conducting basis engineering tests, and Japan Atomic Energy Research Institute will consider the re-enrichment of uranium recovered from reprocessing. Non-governmental unions of researchers will promote the combination of copper-vapor laser and dye laser. For the molecular laser isotope separation (MLIS), the Institute of Physical and Chemical Research will take up studies with the cooperation of the Power Reactor and Nuclear Fuel Development Corporation. In chapters covering the philosophy of laser uranium enrichment technology development, the report deals with its significance, actual conditions and tasks, and goals and measures for its promotion. (Nogami, K.)

  9. A Systematic Approach to Marital Enrichment.

    Science.gov (United States)

    Dinkmeyer, Don; Carlson, Jon

    1986-01-01

    Presents a systematic approach to enriching marital relationships. The history and current status of marital enrichment is reviewed. An Adlerian approach to marital enrichment is described. Applications of the program in enrichment groups, marriage therapy and couple groups are included. (Author)

  10. PC based uranium enrichment analyser

    International Nuclear Information System (INIS)

    Madan, V.K.; Gopalakrishana, K.R.; Bairi, B.R.

    1991-01-01

    It is important to measure enrichment of unirradiated nuclear fuel elements during production as a quality control measure. An IBM PC based system has recently been tested for enrichment measurements for Nuclear Fuel Complex (NFC), Hyderabad. As required by NFC, the system has ease of calibration. It is easy to switch the system from measuring enrichment of fuel elements to pellets and also automatically store the data and the results. The system uses an IBM PC plug in card to acquire data. The card incorporates programmable interval timers (8253-5). The counter/timer devices are executed by I/O mapped I/O's. A novel algorithm has been incorporated to make the system more reliable. The application software has been written in BASIC. (author). 9 refs., 1 fig

  11. Prospects and problems of uranium enrichment

    International Nuclear Information System (INIS)

    Imai, Ryukichi

    1974-01-01

    The problem of uranium enrichment now concerns principally peaceful nuclear power generation. With the current oil crisis, energy resources assume unprecedented importance. However, the requirements for enriched uranium vary with the vicissitude of the world situation in nuclear power generation; the enterprise of uranium enrichment is related to economic aspect. The following matters are described: dimension of enrichment problem, political factors, changes in requirements, projects in each country, and strategy of enrichment in Japan. (Mori, K.)

  12. Uranium enrichment in the United States

    International Nuclear Information System (INIS)

    Hill, J.H.; Parks, J.W.

    1975-01-01

    History, improvement programs, status of electrical power availability, demands for uranium enrichment, operating plan for the U. S. enriching facilities, working inventory of enriched uranium, possible factors affecting deviations in the operating plan, status of gaseous diffusion technology, status of U. S. gas centrifuge advances, transfer of enrichment technology, gaseous diffusion--gas centrifuge comparison, new enrichment capacity, U. S. separative work pricing, and investment in nuclear energy are discussed. (LK)

  13. The design of an automated electrolytic enrichment apparatus for tritium

    Energy Technology Data Exchange (ETDEWEB)

    Myers, J.L.

    1994-12-01

    The Radiation Analytical Sciences Section at Laboratory at Lawrence Livermore National Laboratory performs analysis of low-level tritium concentrations in various natural water samples from the Tri-Valley Area, DOE Nevada Test Site, Site 300 in Tracy, CA, and other various places around the world. Low levels of tritium, a radioactive isotope of hydrogen, which is pre-concentrated in the RAS laboratory using an electrolytic enrichment apparatus. Later these enriched waters are analyzed by liquid scintillation counting to determine the activity of tritium. The enrichment procedure and the subsequent purification process by vacuum distillation are currently undertaken manually, hence being highly labor-intensive. The whole process typically takes about 2 to 3 weeks to complete a batch of 30 samples, with a dedicated personnel operating the process. The goal is to automate the entire process, specifically having the operation PC-LabVIEW{trademark} controlled with real-time monitoring capability. My involvement was in the design and fabrication of a prototypical automated electrolytic enrichment cell. Work will be done on optimizing the electrolytic process by assessing the different parameters of the enrichment procedure. Hardware and software development have also been an integral component of this project.

  14. 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)

  15. Improved verification methods for safeguards verifications at enrichment plants

    Energy Technology Data Exchange (ETDEWEB)

    Lebrun, A.; Kane, S. C.; Bourva, L.; Poirier, S.; Loghin, N. E.; Langlands, D. [Department of Safeguards, International Atomic Energy Agency, Wagramer Strasse 5, A1400 Vienna (Austria)

    2009-07-01

    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{sub 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)

  16. Material control and accounting requirements for uranium enrichment facilities

    International Nuclear Information System (INIS)

    Ting, P.

    1991-01-01

    This paper reports that the U.S. Nuclear Regulatory Commission has defined material control and accounting (MC and A) requirement for low-enriched uranium enrichment plants licensed under 10 CFR parts 40 and 70. Following detailed assessment of potential safeguards issues relevant to these facilities, a new MC and A rule was developed. The primary safeguards considerations are detection of the loss of special nuclear material, detection of clandestine production of special nuclear material of low strategic significance for unauthorized use or distribution, and detection of unauthorized production of uranium enriched to ≥10 wt % U-235. The primary safeguards concerns identified were the large absolute limit of error associated with the material balance closing, the inability to shutdown some uranium enrichment technologies to perform a cleanout inventory of the process system, and the flexibility of some of these technologies to produce higher enrichments. Unauthorized production scenarios were identified for some technologies that could circumvent the detection of the production and removal of 5 kilograms of U-235 as high-enriched uranium through conventional material control and accounting programs. Safeguards techniques, including the use of production and process control information, measurements, and technical surveillance, were identified to compensate for these concerns

  17. Conversion and Blending Facility highly enriched uranium to low enriched uranium as metal. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-05

    The mission of this Conversion and Blending Facility (CBF) will be to blend surplus HEU metal and alloy with depleted uranium metal to produce an LEU product. The primary emphasis of this blending operation will 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 blended LEU will be produced as a waste suitable for storage or disposal.

  18. Conversion and Blending Facility highly enriched uranium to low enriched uranium as metal. Revision 1

    International Nuclear Information System (INIS)

    1995-01-01

    The mission of this Conversion and Blending Facility (CBF) will be to blend surplus HEU metal and alloy with depleted uranium metal to produce an LEU product. The primary emphasis of this blending operation will 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 blended LEU will be produced as a waste suitable for storage or disposal

  19. Mathematical Modeling of the Sugar Cane Bagasse'Sprotein Enrichment Processes, in a Packed-Bed Bioreactor; Modelación matemática del proceso de enriquecimiento proteico del bagazo de caña de azúcar en un biorreactor de lecho fijo

    Energy Technology Data Exchange (ETDEWEB)

    Julián-Ricardo, María Caridad; Ramos-Sánchez, Luís Beltrán, E-mail: maria.julian@reduc.edu.cu [Departamento de Ingeniería Química, Universidad de Camagüey, Camagüey (Cuba); Gómez-Atanay, Angel Osvaldo [Departamento Comercial, SOMEC-Camagüey (Cuba)

    2014-07-01

    The residues of the sugar industry have been used usually, natural or processed in the animal alimentation and have been developed a lot of investigations that are allowed obtain protein enrichment products by solid state fermentation (SSF). However, the technologies employed in the production have limitations that are restraining their commercialization. This investigation was directed to find solutions to the problems that are presented and was planted like objective: to obtain a mathematical model for the scale-up of the sugar cane bagasse´s protein enrichment process, using the Candida utilis yeast, in a packed-bed bioreactor. The experimental work was realized in a pilot plant that have an installation for the air accommodation that is supply for the bioreactor, with a temperature of 30 ºC and more than 95 % of relative humidity. Was used a mathematical model compose by a pseudohomogenous energy balance and the mass balances for the biomass overgrowth and the substrate consumption. The validation studies, was realized by the temperatures comparisons axially measure in 10 L and 100 L bioreactor and the temperatures calculated by simulation. The statistic treatment demonstrate that doesn´t exist big differences between the middle temperatures, for a confidence level of 95 %. The analysis realized to characterize the obtained product, allowed establish that it is accord to quality specifications of the protein enrichment feed. (author)

  20. Enriched uranium recovery flowsheet improvements

    International Nuclear Information System (INIS)

    Holt, D.L.

    1986-01-01

    Savannah River uses 7.5% TBP to recover and purify enriched uranium. Adequate decontamination from fission products is necessary to reduce personnel exposure and to ensure that the enriched uranium product meets specifications. Initial decontamination of the enriched uranium from the fission products is carried out in the 1A bank, 16 stages of mixer-settlers. Separation of the enriched uranium from the fission product, 95 Zr, has been adequate, but excessive solvent degradation caused by the long phase contact times in the mixer-settlers has limited the 95 Zr decontamination factor (DF). An experimental program is investigating the replacement of the current 1A bank with either centrifugal contactors or a combination of centrifugal contactors and mixer-settlers. Experimental work completed has compared laboratory-scale centrifugal contactors and mixer-settlers for 95 Zr removal efficiencies. Feed solutions spiked with actual plant solutions were used. The 95 Zr DF was significantly better in the mixer-settlers than in the centrifugal contactors. As a result of this experimental study, a hybrid equipment flowsheet has been proposed for plant use. The hybrid equipment flowsheet combines the advantages of both types of solvent extraction equipment. Centrifugal contactors would be utilized in the extraction and initial scrub sections, followed by additional scrub stages of mixer-settlers

  1. Enrichment plant management and safeguards

    International Nuclear Information System (INIS)

    Hurt, N.H.

    1978-01-01

    The next increment of enrichment at Portsmouth will be gas centrifuge. The safeguards program at Portsmouth is discussed, including the DYMCAS system, the computerization, and the detectors. Control of the material access areas is discussed. The licensee material surveillance and verification program is also described

  2. The changing face of enrichment

    International Nuclear Information System (INIS)

    Dunckel, E.

    1981-01-01

    The AIS techniques considered are atomic vapour laser isotope separation, molecular laser isotope separation and plasma separation. The future of the AIS technique and their advantages over the gas centrifuge method are discussed in terms of economics, power consideration, and possible enrichment contracts. (U.K.)

  3. The commercial role for centrifuge enrichment

    International Nuclear Information System (INIS)

    Readle, P.H.; Wilcox, P.

    1987-01-01

    The enrichment market is extremely competitive and capacity greatly exceeds demand. BNFL [British Nuclear Fuels Ltd.] is in a unique position in having commercial experience of the two enrichment technologies currently used industrially: diffusion, and centrifuge enrichment through its associate company Urenco. In addition, BNFL is developing laser enrichment techniques as part of a UK development programme. The paper describes the enrichment market, briefly discusses the relative merits of the various methods of uranium enrichment and concludes that the gas centrifuge will be best able to respond to market needs for at least the remainder of the century. (author)

  4. Enrichment into the 21st century

    International Nuclear Information System (INIS)

    Rutkowski, E.

    1995-01-01

    This article discusses the future of the enrichment services market into the next century. It is estimated that demand for enrichment services will reach 31 million SWU by the end of the century and remain constant for the following 10 years. The current world enrichment capacity is 44 million SWU, or some 50% ahead of the demand. This oversupply is projected to continue into the next century, but in spite of this, several suppliers are planning new enrichment facilities. HEU as a source of enriched uranium is examined. Overall, long-term prices for enrichment services are expected to decline in the coming decade

  5. Surface enrichment with chrome and nitriding of IF steel under an abnormal glow discharge

    International Nuclear Information System (INIS)

    Meira, S.R.; Borges, P.C.; Bernardelli, E.A.

    2014-01-01

    The objective of this work is to evaluate the influence of surface enrichment of IF steel with chrome, and nitriding, the formation of the nitrided layer. Thus, IF steel samples were subjected to surface enrichment process, using 409 stainless steel as a target for sputtering, followed by plasma nitriding, both under a dc abnormal glow discharge. The enrichment treatment was operated at 1200 ° C for 3h. The nitriding treatment was operated at 510 ° C for 2 h. The influence of the treatments on the layers formed was studied through optical microscopy (OM), scan electron microscopy (SEM), X-ray diffraction (XRD) and Vickers microindentation. The results show that the enrichment is effective to enrich the IF surface, furthermore, improves the characteristics of nitriding, comparing nitriding samples to nitriding and enriched, was observed needles of nitrides, as well as a higher hardness, which is associated with the nitrides of chrome, on the nitriding and enriched samples. (author)

  6. Standard specification for uranium metal enriched to more than 15 % and less Than 20 % 235U

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2000-01-01

    1.1 This specification covers nuclear grade uranium metal that has either been processed through an enrichment plant, or has been produced by the blending of highly enriched uranium with other uranium, to obtain uranium of any 235U concentration below 20 % (and greater than 15 %) and that is intended for research reactor fuel fabrication. The scope of this specification includes specifications for enriched uranium metal derived from commercial natural uranium, recovered uranium, or highly enriched uranium. Commercial natural uranium, recovered uranium and highly enriched uranium are defined in Section 3. The objectives of this specification are to define the impurity and uranium isotope limits for commercial grade enriched uranium metal. 1.2 This specification is intended to provide the nuclear industry with a standard for enriched uranium metal which is to be used in the production of research reactor fuel. In addition to this specification, the parties concerned may agree to other appropriate conditions. ...

  7. Experience with environmental sampling at gas centrifuge enrichment plants

    International Nuclear Information System (INIS)

    Ekenstam, G. af; Bush, W.; Janov, J.; Kuhn, E.; Ryjinski, M.

    2001-01-01

    Environmental sampling has been used routinely by the IAEA since 1996 after the IAEA Board of Governors approved it in March 1995 as a new technique to strengthen safeguards and improve efficiency. In enrichment plants it is used to confirm that there has been no production of highly enriched uranium (HEU), or production of uranium at above the declared enrichment. The use of environmental sampling is based on the assumption that every process, no matter how leak tight, will release small amounts of process material to the environment. Even though these releases of nuclear material are extremely small in gas centrifuge enrichment plants, and well below levels of concern from a health physics and safety standpoint, they are detectable and their analysis provides an indication of the enrichment of the material that has been processed in the plant. The environmental samples at enrichment plants are collected by swiping selected areas of the plant with squares of cotton cloth (10x10 cm) from sampling kits prepared in ultra clean condition. The squares of cotton cloth sealed in plastic bags are sent for analysis to the Network Analytical Laboratories. The analysis includes the measurement of the uranium isotopic composition in uranium-containing particles by Thermal lonization Mass Spectroscopy (TIMS) or Secondary ION Mass Spectroscopy (SIMS). Since the implementation of environmental sampling, swipes have been collected from 240 sampling points at three gas centrifuge plants of URENCO, which have a total throughput of more than 8,000 tonnes of uranium per year. The particle analysis results generally reflected the known operational history of the plants and confirmed that they had only been operated to produce uranium with enrichment less than 5% 235 U. The information about the content of the minor isotopes 234 U and 236 U also indicates that depleted and recycled uranium were sometimes used as feed materials in some plants. An example is given of the TIMS particle

  8. Georges Besse 2. A new era for enrichment

    International Nuclear Information System (INIS)

    2009-01-01

    Since 1978, AREVA group subsidiary EURODIF's Georges Besse plant has been using gaseous diffusion to enrich uranium and meet the requirements of electricity utilities. Georges Besse II plant, which will use far less electricity, will replace George Besse not so long. The Georges Besse II plant is located on the Tricastin nuclear site in southern France. AREVA ensure delivery of uranium enrichment services in accordance with customer expectations. AREVA obtained the right to use URENCO's centrifugation technology on July 3, 2006. This is the process to be used at Georges Besse II. The new uranium enrichment plant will comprise two enrichment units, with a total production capacity of 7.5 million separative work units, which can be extended to 11 million if needed. Each enrichment unit will include: a Centrifuge Assembly Building (CAB), a Centrifuge Utility Building (CUB) with offices and control room, annexes for purification, supply and extraction of uranium hexafluoride (UF 6 ), modules containing the halls that house the centrifuge cascades. The modular design of the Georges Besse II plant will allow production in the first cascade where as the others cascades are build. The first cascade should be operational in the first half of 2009. At an overall cost of 3 billion euros, this project is one of the largest investments of the decade in France On November 24, 2003, AREVA and URENCO signed an agreement under which AREVA would buy 50% of the shares in the Enrichment Technology Company (ETC), which designs and manufactures centrifuges

  9. Selective adsorption-desorption method for the enrichment of krypton

    International Nuclear Information System (INIS)

    Yuasa, Y.; Ohta, M.; Watanabe, A.; Tani, A.; Takashima, N.

    1975-01-01

    Selective adsorption-desorption method has been developed as an effective means of enriching krypton and xenon gases. A seriesof laboratory-scale tests were performed to provide some basic data of the method when applied to off-gas streams of nuclear power plants. For the first step of the enrichment process of the experiments, krypton was adsorbed on solid adsorbents from dilute mixtures with air at temperatures ranging from -50 0 C to -170 0 C. After the complete breakthrough was obtained, the adsorption bed was evacuated at low temperature by a vacuum pump. By combining these two steps krypton was highly enriched on the adsorbents, and the enrichment factor for krypton was calculated as the product of individual enrichment factors of each step. Two types of adsorbents, coconut charcoal and molecular sieves 5A, were used. Experimental results showed that the present method gave the greater enrichment factor than the conventional method which used selective adsorption step only. (U.S.)

  10. Enriching Students’ Vocabulary Mastery Using Graphic Organizers

    Directory of Open Access Journals (Sweden)

    Syaifudin Latif Darmawan

    2017-04-01

    Full Text Available This action research is carried out to (1 identify whether graphic organizers enrich student’s vocabulary mastery; and (2 to describe the classroom situation when graphic organizers are employed in instructional process of vocabulary. The research is conducted in two cycles from March to May 2016/2017 in the eight years of SMP Muhammadiyah Sekampung, East lampung. The procedure of the research consists of identifying the problem, planning the action, implementing the action, observing the action, and reflecting the result of the research. Qualitative data are collected through interview, observation, questionnaire, and research diary. Quantitative data are collected through test. To analyze qualitative data, the researcher used constant comparative method. It consists of four steps: (1 comparing incidents applicable to each category; (2 Integrating categories and their properties; (3 delimiting the theory; (4 Writing the theory. Meanwhile, to analyze quantitative data, the researcher employed descriptive statistic.    The result of the research shows that using graphic organizers can enrich students’ vocabulary mastery and classroom situation. The improvement on students’ vocabulary included; a the students are able to speak English; b the students are able to understand the meaning of the text as they have a lot of vocabularies. The improvement of the classroom situation; (a students come on time in the class (b students are more motivated to join the class (c Students pay more attention in the instructional process (d students’ participation in responding the questions are high.

  11. DOE hands over uranium enrichment duties to government corporation

    International Nuclear Information System (INIS)

    Simpson, J.

    1993-01-01

    In an effort to renew the United States' competitiveness in the world market for uranium enrichment services, the Department of Energy (DOE) is turning over control of its Paducah, KY, and Portsmouth, OH, enrichment facilities to a for-profit organization, the United States Enrichment Corp. (USEC), which was created by last year's Energy Policy Act. William H. Timbers, Jr., a former investment banker who was appointed acting CEO in March, said the Act's mandate will mean more competitive prices for enriched reactor fuel and greater responsiveness to utility customers. As a government corporation, USEC, with current annual revenues estimated at $1.5 billion, will no longer be part of the federal budget appropriations process, but will use business management techniques, set market-based prices for enriched uranium, and pay annual dividends to the US Treasury-its sole stockholder-from earnings. The goal is to finish privatizing the corporation within two years, and to sell its stock to investors for an estimated $1 to $3 billion. USEC's success will depend in part on developing short- and long-term marketing plants to help stanch the flow of enriched-uranium customers to foreign suppliers. (DOE already has received notice from a number of US utilities that they want to be let out of their long-term enrichment contracts as they expire over the next several years).USEC's plans likely will include exploring new joint ventures with other businesses in the nuclear fuel cycle-such as suppliers, fabricators, and converters-and offering a broader range of enrichment services than DOE provided. The corporation will have to be responsive to utilities on an individual basis

  12. Conversion and Blending Facility highly enriched uranium to low enriched uranium as oxide. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-05

    This Conversion and Blending Facility (CBF) will have two missions: (1) convert HEU materials into pure HEU oxide and (2) blend the pure HEU oxide with depleted and natural uranium oxide to produce an LWR grade LEU product. The primary emphasis of this blending operation will 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. To the extent practical, the chemical and isotopic concentrations of blended LEU product will be held within the specifications required for LWR fuel. Such blended LEU product will be offered to the United States Enrichment Corporation (USEC) to be sold as feed material to the commercial nuclear industry. Otherwise, blended LEU will be produced as a waste suitable for storage or disposal.

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-05

    This report describes the Conversion and Blending Facility (CBF) which will have two missions: (1) convert surplus HEU materials to pure HEU UF{sub 6} and a (2) blend the pure HEU UF{sub 6} with diluent UF{sub 6} to produce LWR grade LEU-UF{sub 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.

  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. Searching for self-enrichment in Cygnus OB2

    Science.gov (United States)

    Berlanas, Sara R.; Herrero, Artemio; Comerón, Fernando; Pasquali, Anna; Simón-Díaz, Sergio

    2017-11-01

    Cygnus OB2 is a rich and relatively close (d~1.4 kpc) OB association in our Galaxy. It represents an ideal testbed for our theories about self-enrichment processes produced by pollution of the interstellar medium by successive generations of massive stars. Comerón & Pasquali (2012, A&A, 543, A101) found a correlation between the age of young stellar groups in Cygnus OB2 and their Galactic longitude. If is associated with a chemical composition gradient, it could support these self-enrichment processes.

  16. Enrichment demand boosts SWU prices

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    The enrichment market is picking up significantly on very brisk demand. US utilities, which normally purchase material nine months to a year ahead of time, are already hitting the market to fill their 1996 requirements. In June, two non-US utilities, one European entity and a US utility bought SWUs, the entity in an off-market deal. But that doesn't tell the whole story. Three other US utilities entered the market during the month. Meanwhile, we count 13 more utilities getting ready to hit the market for more than 4 million SWUs. Why the surge in demand? Utilities, uncertain of the role to be played by the new US Enrichment Corp. and seeking to take advantage of low interest rates, are implementing buy and hold strategies. As a result, the upper end of NUKEM's SWU price range inched up to $78. The lower end dipped to $67 based on the European deal

  17. Enrichment techniques employed in phosphoproteomics

    Czech Academy of Sciences Publication Activity Database

    Fíla, Jan; Honys, David

    2012-01-01

    Roč. 43, č. 3 (2012), s. 1025-1047 ISSN 0939-4451 R&D Projects: GA ČR(CZ) GAP501/11/1462; GA ČR GA522/09/0858; GA ČR GA525/09/0994; GA MŠk OC08011 Institutional research plan: CEZ:AV0Z50380511 Keywords : Phosphoproteomics * Enrichment * IMAC Subject RIV: ED - Physiology Impact factor: 3.914, year: 2012

  18. Safeguards for reprocessing and enrichment plants

    International Nuclear Information System (INIS)

    1977-01-01

    Agency safeguards are entering a new phase with the coming under active safeguards for the first time of reprocessing plants in several regions of the world. This is taking place at a time when not only the safeguards aspect itself is coming under international scrutiny, but also at a time when the necessity of reprocessing plants is being called into question. Attracting less attention at the moment, but potentially of equal significance, are the enrichment plants that soon will be coming under Agency safeguards. It is not unreasonable in view of the present controversies to ask what is the significance of these reprocessing and enrichment plants, what are the problems concerning safeguards that appear to have given rise to the controversies, and how these problems are to be solved. The question of significance is an easy one to answer. The output of these plants is material which some people consider can be used directly for military purposes, whereas the output from other plants, for instance, reactors, would require long and extensive processing before it could be used for military purposes. Like most short answers, this one is an over-simplification which requires some elaboration to make it strictly accurate. For example, the material output of a power reactor is in the form of irradiate assemblies containing plutonium which is potentially of military use if the irradiation had been within a certain range. However, to utilize this plutonium under clandestine conditions, the highly radioactive material would have to be secretly transported to a reprocessing plant and there would have to be simultaneous falsification of the reactor material accounts and the plant records. Such falsification would be difficult to conceal. The total time required to obtain usable plutonium would be many months. Diversion of material from a uranium fabrication plant making fuel for power reactors would be easier physically but strategically it would be of little value. The

  19. Selenium Enrichment of Horticultural Crops.

    Science.gov (United States)

    Puccinelli, Martina; Malorgio, Fernando; Pezzarossa, Beatrice

    2017-06-04

    The ability of some crops to accumulate selenium (Se) is crucial for human nutrition and health. Selenium has been identified as a cofactor of the enzyme glutathione peroxidase, which is a catalyzer in the reduction of peroxides that can damage cells and tissues, and can act as an antioxidant. Plants are the first link in the food chain, which ends with humans. Increasing the Se quantity in plant products, including leafy and fruity vegetables, and fruit crops, without exceeding the toxic threshold, is thus a good way to increase animal and human Se intake, with positive effects on long-term health. In many Se-enriched plants, most Se is in its major organic form. Given that this form is more available to humans and more efficient in increasing the selenium content than inorganic forms, the consumption of Se-enriched plants appears to be beneficial. An antioxidant effect of Se has been detected in Se-enriched vegetables and fruit crops due to an improved antioxidative status and to a reduced biosynthesis of ethylene, which is the hormone with a primary role in plant senescence and fruit ripening. This thus highlights the possible positive effect of Se in preserving a longer shelf-life and longer-lasting quality.

  20. Selenium Enrichment of Horticultural Crops

    Directory of Open Access Journals (Sweden)

    Martina Puccinelli

    2017-06-01

    Full Text Available The ability of some crops to accumulate selenium (Se is crucial for human nutrition and health. Selenium has been identified as a cofactor of the enzyme glutathione peroxidase, which is a catalyzer in the reduction of peroxides that can damage cells and tissues, and can act as an antioxidant. Plants are the first link in the food chain, which ends with humans. Increasing the Se quantity in plant products, including leafy and fruity vegetables, and fruit crops, without exceeding the toxic threshold, is thus a good way to increase animal and human Se intake, with positive effects on long-term health. In many Se-enriched plants, most Se is in its major organic form. Given that this form is more available to humans and more efficient in increasing the selenium content than inorganic forms, the consumption of Se-enriched plants appears to be beneficial. An antioxidant effect of Se has been detected in Se-enriched vegetables and fruit crops due to an improved antioxidative status and to a reduced biosynthesis of ethylene, which is the hormone with a primary role in plant senescence and fruit ripening. This thus highlights the possible positive effect of Se in preserving a longer shelf-life and longer-lasting quality.

  1. Preliminary study of the economics of enriching PWR fuel with a fusion hybrid reactor

    International Nuclear Information System (INIS)

    Kelly, J.L.

    1978-09-01

    This study is a comparison of the economics of enriching uranium oxide for pressurized water reactor (PWR) power plant fuel using a fusion hybrid reactor versus the present isotopic enrichment process. The conclusion is that privately owned hybrid fusion reactors, which simultaneously produce electrical power and enrich fuel, are competitive with the gaseous diffusion enrichment process if spent PWR fuel rods are reenriched without refabrication. Analysis of irradiation damage effects should be performed to determine if the fuel rod cladding can withstand the additional irradiation in the hybrid and second PWR power cycle. The cost competitiveness shown by this initial study clearly justifies further investigations

  2. The isotopic enrichment of uranium in 1979

    International Nuclear Information System (INIS)

    Baron, M.

    1979-01-01

    The Eurodif uranium enrichment plant built on the Tricastin site is described. The uranium isotope separation plants in service abroad are presented. The main characteristics of the international enrichment market are defined [fr

  3. Uranium enrichment (a strategy analysis overview)

    International Nuclear Information System (INIS)

    Blahnik, C.

    1979-08-01

    An analysis of available information on enrichment technology, separative work supply and demand, and SWU cost is presented. Estimates of present and future enrichment costs are provided for use in strategy analyses of alternate nuclear fuel cycles and systems. (auth)

  4. Curriculum enrichment through indigenous Zulu games | Roux ...

    African Journals Online (AJOL)

    Curriculum enrichment through indigenous Zulu games. ... 1997). The aim of the study was to document and analyze indigenous Zulu games for possible curriculum enrichment of physical ... AJOL African Journals Online. HOW TO USE AJOL.

  5. Nitrogen enrichment regulates calcium sources in forests

    Science.gov (United States)

    Hynicka, Justin D.; Pett-Ridge, Julie C.; Perakis, Steven

    2016-01-01

    Nitrogen (N) is a key nutrient that shapes cycles of other essential elements in forests, including calcium (Ca). When N availability exceeds ecosystem demands, excess N can stimulate Ca leaching and deplete Ca from soils. Over the long term, these processes may alter the proportion of available Ca that is derived from atmospheric deposition vs. bedrock weathering, which has fundamental consequences for ecosystem properties and nutrient supply. We evaluated how landscape variation in soil N, reflecting long-term legacies of biological N fixation, influenced plant and soil Ca availability and ecosystem Ca sources across 22 temperate forests in Oregon. We also examined interactions between soil N and bedrock Ca using soil N gradients on contrasting basaltic vs. sedimentary bedrock that differed 17-fold in underlying Ca content. We found that low-N forests on Ca-rich basaltic bedrock relied strongly on Ca from weathering, but that soil N enrichment depleted readily weatherable mineral Ca and shifted forest reliance toward atmospheric Ca. Forests on Ca-poor sedimentary bedrock relied more consistently on atmospheric Ca across all levels of soil N enrichment. The broad importance of atmospheric Ca was unexpected given active regional uplift and erosion that are thought to rejuvenate weathering supply of soil minerals. Despite different Ca sources to forests on basaltic vs. sedimentary bedrock, we observed consistent declines in plant and soil Ca availability with increasing N, regardless of the Ca content of underlying bedrock. Thus, traditional measures of Ca availability in foliage and soil exchangeable pools may poorly reflect long-term Ca sources that sustain soil fertility. We conclude that long-term soil N enrichment can deplete available Ca and cause forests to rely increasingly on Ca from atmospheric deposition, which may limit ecosystem Ca supply in an increasingly N-rich world.

  6. Modeling of ELM events and their effect on impurity enrichment

    International Nuclear Information System (INIS)

    Hogan, J.; Colchin, R.; Coster, D.; Baylor, L.; Fenstermacher, M.; Groth, M.; Wade, M.

    2003-01-01

    Modeling of transient impurity transport during large ELMs is used to explore basic processes which may determine ELM-averaged enrichment. The b2-Eirene code (solps4), used for DIII-D geometry, suggests that a complex sequence can occur during an ELM cycle in which a transiently detached phase, with relatively low enrichment, can occur even under nominally attached conditions. A slower recovery phase then follows, in which the effect of induced scrape-off layer flows can increase in importance. The model results are compared with available fast time-scale measurements. The observed increased enrichment with higher Z is similar to trends in basic particle reflection properties. Neon recycling processes may thus introduce a significant history effect, as illustrated by analysis of continuous, unforced neon accumulation in a DIII-D discharge with a well-characterized operational history

  7. Experimental study on enriching 12C by centrifuge method

    International Nuclear Information System (INIS)

    Xiao Huaxian

    1994-07-01

    The diamond made from the highly enriched 12 C, whose thermal conductivity and electric insulativity are much better than that of natural diamond, has widely uses in new and high technology. In many enriching 12 C methods, the gas centrifuge method is superior to others. After selecting the appropriate process gas and solving key problems, such as feed and extract, the separation experiments are performed by a single stage of centrifuge. To increase the separation capacity of single machine, various parameters in the centrifugal separation are optimized, and appropriate mechanical drive, thermal drive, hold-up and process parameters are selected. The optimal operating condition of single machine is also obtained in the cascade. Thus, highly enriched 12 C is produced in the centrifuge cascade

  8. Production of Mo-99 using low-enriched uranium silicide

    International Nuclear Information System (INIS)

    Hutter, J.C.; Srinivasan, B.; Vicek, M.; Vandegrift, G.F.

    1994-01-01

    Over the last several years, uranium silicide fuels have been under development as low-enriched uranium (LEU) targets for Mo-99. The use of LEU silicide is aimed at replacing the UAl x alloy in the highly-enriched uranium dissolution process. A process to recover Mo-99 from low-enriched uranium silicide is being developed at Argonne National Laboratory. The uranium silicide is dissolved in alkaline hydrogen peroxide. Experiments performed to determine the optimum dissolution procedure are discussed, and the results of dissolving a portion of a high-burnup (>40%) U 3 Si 2 miniplate are presented. Future work related to Mo-99 separation and waste disposal are also discussed

  9. Network-based functional enrichment

    Directory of Open Access Journals (Sweden)

    Poirel Christopher L

    2011-11-01

    Full Text Available Abstract Background Many methods have been developed to infer and reason about molecular interaction networks. These approaches often yield networks with hundreds or thousands of nodes and up to an order of magnitude more edges. It is often desirable to summarize the biological information in such networks. A very common approach is to use gene function enrichment analysis for this task. A major drawback of this method is that it ignores information about the edges in the network being analyzed, i.e., it treats the network simply as a set of genes. In this paper, we introduce a novel method for functional enrichment that explicitly takes network interactions into account. Results Our approach naturally generalizes Fisher’s exact test, a gene set-based technique. Given a function of interest, we compute the subgraph of the network induced by genes annotated to this function. We use the sequence of sizes of the connected components of this sub-network to estimate its connectivity. We estimate the statistical significance of the connectivity empirically by a permutation test. We present three applications of our method: i determine which functions are enriched in a given network, ii given a network and an interesting sub-network of genes within that network, determine which functions are enriched in the sub-network, and iii given two networks, determine the functions for which the connectivity improves when we merge the second network into the first. Through these applications, we show that our approach is a natural alternative to network clustering algorithms. Conclusions We presented a novel approach to functional enrichment that takes into account the pairwise relationships among genes annotated by a particular function. Each of the three applications discovers highly relevant functions. We used our methods to study biological data from three different organisms. Our results demonstrate the wide applicability of our methods. Our algorithms are

  10. Enriched uranium sales: effect on supply industry

    International Nuclear Information System (INIS)

    Andersen, R.K.

    1985-01-01

    The subject is covered in sections: introduction (combined effect of low-enriched uranium (LEU) inventory sales and utility services enrichment contract terms); enrichment market overview; enrichment market dynamics; the reaction of the US Department of Energy; elimination of artificial demand; draw down of inventories; purchase and sale of LEU inventories; tails assay option; unfulfilled requirements for U 3 O 8 ; conclusions. (U.K.)

  11. An automated solution enrichment system for uranium analysis

    International Nuclear Information System (INIS)

    Jones, S.A.; Sparks, R.; Sampson, T.; Parker, J.; Horley, E.; Kelly, T.

    1993-01-01

    An automated Solution Enrichment system (SES) for analysis of Uranium and U-235 isotopes in process samples has been developed through a joint effort between Los Alamos National Laboratory and Martin Marietta Energy systems, Portsmouth Gaseous Diffusion Plant. This device features an advanced robotics system which in conjuction with stabilized passive gamma-ray and X-ray fluorescence detectors provides for rapid, non-destructive analyses of process samples for improved special nuclear material accountability and process control

  12. 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

  13. 76 FR 11523 - Atomic Safety and Licensing Board; AREVA Enrichment Services, LLC (Eagle Rock Enrichment Facility...

    Science.gov (United States)

    2011-03-02

    ... and Licensing Board; AREVA Enrichment Services, LLC (Eagle Rock Enrichment Facility); Notice of... Governmental Entities Regarding Environmental Portion of Enrichment Facility Licensing Proceeding February 24.... White. In this 10 CFR part 70 proceeding regarding the request of applicant AREVA Enrichment Services...

  14. Enriching Orphans’ Potentials through Interpersonal and Intrapersonal Intelligence Enrichment Activities

    Directory of Open Access Journals (Sweden)

    Nurulwahida Hj Azid

    2016-01-01

    Full Text Available Orphans are considered a minority and they should be given a greater emphasis so that they do not feel left out and can build their own lives without a sense of humility. This does not mean that the orphans should be pampered instead they should be given the confidence and motivation to strive for success in later life. Humility among orphans can be associated with interpersonal and intrapersonal intelligences. This study aims to evaluate the impact of problem-solving activity treatment based on the interpersonal and intrapersonal intelligences. 46 students from two orphanages were involved as the treatment group. The research design used was a one-group pretest-posttest design applied through a combination of quantitative and qualitative approaches. Enrichment activities that provided interpersonal and intrapersonal skills as evidenced in this study should be carried out regularly at orphanages. Our study has proven that orphans‟ rights to learn cannot be neglected and „no child left behind „policy needs to be carried through by everybody involved with orphans‟ well-being. Teachers and carers need to be trained to use these enrichment activities at their orphanages to help maximize the orphans‟ potentials.

  15. The reduced enrichment program for JRR-4

    International Nuclear Information System (INIS)

    Takayanagi, M.

    1992-01-01

    Japan Research Reactor No. 4(JRR-4) with the rated power of 3.5 MW, swimming pool type research reactor, 93 % enriched uranium ETR-type fuel used, light water moderated and cooled. The first criticality reached on 28th January, 1965. The reactor has operated for about 26 years. However, it was planed to the reduced enrichment of the fuels to low enrichment according to the International Reduced Enrichment for Research and Test Reactors (RERTR) program. This paper describes the program for conversion of the enrichment of fuel from 93 % to less than 20 %. (author)

  16. Enrichment planting without soil treatment

    Energy Technology Data Exchange (ETDEWEB)

    Hagner, Mats

    1998-12-31

    Where enrichment planting had been carried out with either of the two species Picea abies and Pinus contorta, the survival of the planted seedlings was at least as good as after planting in a normal clear cut area treated with soil scarification. This was in spite of the fact that the seedlings were placed shallow in the humus layer without any soil treatment. However, they were sheltered from insects by treatment before planting. Where enrichment planting was carried out with Pinus sylvestris the survival in dense forest was poor, but in open forest the survival was good. The growth of planted seedlings was enhanced by traditional clearing and soil treatment. However, this was for Pinus sylvestris not enough to compensate for the loss of time, 1-2 years, caused by arrangement of soil scarification. The growth of seedlings planted under crown cover was directly related to basal area of retained trees. However, the variation in height growth among individual seedlings was very big, which meant that some seedlings grow well also under a fairly dense forest cover. The pioneer species Pinus sylvestris reacted more strongly to basal area of retained trees than did the shade tolerant species Picea abies. Enrichment planting seems to be a necessary tool for preserving volume productivity, at places where fairly intensive harvest of mature trees has been carried out in stands of ordinary forest type in central Sweden. If double seedlings, with one Picea abies and one Pinus sylvestris, are used, the probability for long term establishment is enhanced 13 refs, 20 figs, 4 tabs

  17. [Hydroxylamine conversion by anammox enrichment].

    Science.gov (United States)

    Hu, Anhui; Zheng, Ping; Lu, Huifeng; Ding, Shuang; Wang, Caihua

    2010-04-01

    Hydroxylamine is an important intermediate product of anammox. This study was focused on the characteristics of hydroxylamine and nitrite conversions by anammox enrichment. The changes of nitrogenous substrates and related products with time were measured using batch tests with anammox enrichment as inoculum. Since hydroxylamine didn't react with nitrite in uninoculated control culture, these two compounds were chemically stable. Both of them decreased with time in anammox enrichment inoculated cultures, in which ammonia as intermediate product would be produced and converted with the maximum concentration being 0.338 mg/L. The total nitrogen concentration decreased from 4.694 mmol/L to 0.812 mmol/L with conversion rate 82.7% in the end. When hydroxylamine and nitrite concentrations were about 2.5 mmol/L respectively, the maximum specific sludge conversion rates of hydroxylamine was 0.535 mmol/(gVSS.h), which was 1.81 times bigger than that of ammonia in ammonia reaction system; the maximum specific sludge rate of total nitrogen was slightly higher than that in ammonia reaction system. When hydroxylamine concentration increased to 5.0 mmol/L, the hydroxylamine and nitrite conversion rates promoted by 26.7% and 120.7% respectively; and the maximum ammonia accumulated was 1.810 mmol/L. When nitrite concentration increased to 5.0 mmol/L, the hydroxylamine and nitrite conversion rates promoted by 6.9% and 9.0% respectively; and the maximum ammonia accumulated was 0.795 mmol/L. Anammox enrichment was capable of converting hydroxylamine and nitrite simultaneously and had the higher conversion rate of hydroxylamine than ammonia conversion rate. Hydroxylamine and nitrite conversion rates were less affected by increase in nitrite concentration, but more significantly influenced by increase in hydroxylamine. The maximum ammonia concentration accumulated would rise as the result of increasing both hydroxylamine and nitrite. The result of experiment was consistent with pathway

  18. Boron enrichment in martian clay.

    Directory of Open Access Journals (Sweden)

    James D Stephenson

    Full Text Available We have detected a concentration of boron in martian clay far in excess of that in any previously reported extra-terrestrial object. This enrichment indicates that the chemistry necessary for the formation of ribose, a key component of RNA, could have existed on Mars since the formation of early clay deposits, contemporary to the emergence of life on Earth. Given the greater similarity of Earth and Mars early in their geological history, and the extensive disruption of Earth's earliest mineralogy by plate tectonics, we suggest that the conditions for prebiotic ribose synthesis may be better understood by further Mars exploration.

  19. Producing deuterium-enriched products

    International Nuclear Information System (INIS)

    1980-01-01

    A method of producing an enriched deuterium product from a gaseous feed stream of mixed hydrogen and deuterium, comprises: (a) combining the feed stream with gaseous bromine to form a mixture of the feed stream and bromine and exposing the mixture to an electrical discharge effective to form deuterium bromide and hydrogen bromide with a ratio of D/H greater than the ratio of D/H in the feed stream; and (b) separating at least a portion of the hydrogen bromide and deuterium bromide from the mixture. (author)

  20. Implementing Enrichment Clusters in Elementary Schools: Lessons Learned

    Science.gov (United States)

    Fiddyment, Gail E.

    2014-01-01

    Enrichment clusters offer a way for schools to encourage a high level of learning as students and adults work together to develop a product, service, or performance by applying advanced knowledge and authentic processes to real-world problems. This study utilized a qualitative research design to examine the perceptions and experiences of two…

  1. IR laser enrichment of light elements isotopes - challenges and prospects

    International Nuclear Information System (INIS)

    Parthasarathy, V.

    2002-01-01

    Full text: Infra-red multiple photon dissociation (IR MPD) of poly-atomic molecules has made considerable progress since its discovery in the early seventies. Since the process was found to be isotopically selective; the possibility of laser isotope separation (LIS) created a lot of initial excitement. While the early investigations were concerned with the fundamental dynamics and potential applications of the phenomenon, serious efforts for the isotope enrichment process have been made only during the last decade. These efforts focussed on aspects to improve both the enrichment factor and throughput in various systems. Many research groups have achieved a good measure of success for scaling up the process for various light elements like carbon, oxygen, silicon and sulphur whose isotopes are quite important in medicine and technology. Significant results have been reported especially for the separation of carbon isotopes wherein macroscopic operating scales have been already realised. This talk will give-a summary of our work carried out at BARC and highlight the current efforts for scaling up the process for carbon isotopes enrichment. This would include the design aspects of a large photochemical reactor with multi-pass, refocusing optics for efficient photon utilization. It will also cover the development of a cryogenic distillation set up and a preparative gas chromatograph for a large scale separation and collection of the isotopically enriched photoproduct in the post irradiation stage. Based on the experience gained and infra structure developed, plans are afoot to separate oxygen and sulphur isotopes using a similar approach

  2. The method of water enrichment in oxygen-18

    International Nuclear Information System (INIS)

    Chmielewski, A.G.; Zakrzewska-Trznadel, G.; Van Hook, A.; Milievic, N.R.

    1996-01-01

    The process of membrane distillation has been used for water enrichment in oxygen-18. The hydrophobic PTFE membranes has been used as a boundary for liquids being at different temperatures on the each side of membrane. Example of obtained results have been shown

  3. Feasibility of nondestructive assay measurements in uranium enrichment plants

    Energy Technology Data Exchange (ETDEWEB)

    Walton, R.B.

    1978-04-01

    enrichment processes.

  4. Availability of enriched stable isotopes: present status and future prospects

    International Nuclear Information System (INIS)

    Hoff, R.W.

    1986-01-01

    The Electromagnetic Isotope Enrichment Facility (EMIEF) is currently used to produce 225 enriched stable isotopes of 50 elements. Among these are included most of the known elements with stable isotopes except for the noble gases, certain light elements, monisotopic elements, etc. The EMIEF can also be used to produce enriched samples of radioactive species, most notably the isotopes of uranium and plutonium. These enriched materials are placed in either the Sales Inventory of in the Research Materials Collection (RMC). The materials in the Sales Inventory are for sale to anyone on a first come, first served basis. Prices in the most recent catalog range from $0.05/mg for 99.8% 140 Ce to $1,267/mg for 98.5% 176 Lu. The materials in the RMC are made available to US researchers (or groups that include a US investigator) on a loan basis for use in non-destructive experiments and applications. In addition, certain samples have been provided to European investigators for cross-section studies through the auspices of EURATOM and the European-American Nuclear Data Committee. The status of the enriched isotopes included in the Sales Inventory is tabulated where isotopes are listed that are either not available or are in insufficient quantity or quality to meet current requests, as of 6/30/86. These can be summarized in the following subcategories: isotopes with zero inventory (22), Isotopes of insufficient quantity (17), and isotopes with insufficient enrichment quality (10). Of these 49 species, the supplies of 10 will be replenished by the scheduled FY86 enrichments in process (isotopes of bromine, calcium, nickel, potassium, rubidium, and strontium). In Table 3 are listed isotopes where the current inventory is less than the average annual sales level for the past five years. There are 47 isotopes listed, representing 25 different elements. Thus, there exists considerable potential for a substantial increase in the number of isotopes with zero inventory

  5. Development of Solvent Extraction Approach to Recycle Enriched Molybdenum Material

    Energy Technology Data Exchange (ETDEWEB)

    Tkac, Peter [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Brown, M. Alex [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Sen, Sujat [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division; Bowers, Delbert L. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Wardle, Kent [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Copple, Jacqueline M. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Pupek, Krzysztof Z. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Dzwiniel, Trevor L. [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division; Pereira, Candido [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Krumdick, Gregory K. [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division; Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division

    2016-06-01

    Argonne National Laboratory, in cooperation with Oak Ridge National Laboratory and NorthStar Medical Technologies, LLC, is developing a recycling process for a solution containing valuable Mo-100 or Mo-98 enriched material. Previously, Argonne had developed a recycle process using a precipitation technique. However, this process is labor intensive and can lead to production of large volumes of highly corrosive waste. This report discusses an alternative process to recover enriched Mo in the form of ammonium heptamolybdate by using solvent extraction. Small-scale experiments determined the optimal conditions for effective extraction of high Mo concentrations. Methods were developed for removal of ammonium chloride from the molybdenum product of the solvent extraction process. In large-scale experiments, very good purification from potassium and other elements was observed with very high recovery yields (~98%).

  6. Assay of low-enriched uranium using spontaneous fission neutrons

    International Nuclear Information System (INIS)

    Zucker, M.S.; Fainberg, A.

    1980-01-01

    Low-enriched uranium oxide in bulk containers can be assayed for safeguards purposes, using the neutrons from spontaneous fission of 238 U as a signature, to complement enrichment and mass measurement. The penetrability of the fast fission neutrons allows the inner portion of bulk samples to register. The measurement may also be useful for measuring moisture content, of significance in process control. The apparatus used can be the same as for neutron correlation counting for Pu assay. The neutron multiplication observed in 238 U is of intrinsic interest

  7. Development of empirical relation for isotope of uranium in enriched uranium matrix

    International Nuclear Information System (INIS)

    Srivastava, S.K.; Vidyasagar, D.; Jha, S.K.; Tripathi, R.M.

    2018-01-01

    Uranium enriched in 235 U is required in commercial light water reactors to produce a controlled nuclear reaction. Enrichment allows the 235 U isotopes to be increased from 0.71% to a range between 2% to 5% depending upon requirement. The enriched uranium in the form of sintered UO 2 pellet is used for any commercially operating boiling light water reactors. The enriched uranium fuel bundle surface swipes sample is being analysed to assess the tramp uranium as a quality control parameter. It is known that the 234 U isotope also enriched along with 235 U isotope in conventional gaseous diffusion enrichment process. The information about enrichment percentage of 234 U helps to characterize isotopic properties of enriched uranium. A few reports provide the empirical equation and graphs for finding out the specific activity, activity percentage, activity ratio of 234 U isotopes for enriched uranium. Most of them have not provided the reference for the data used and their source. An attempt has been made to model the relationship between 234 U and 235 U as a function of uranium enrichment at low level

  8. Involvement of glycosphingolipid-enriched lipid rafts in inflammatory responses.

    Science.gov (United States)

    Iwabuchi, Kazuhisa

    2015-01-01

    Glycosphingolipids (GSLs) are membrane components consisting of hydrophobic ceramide and hydrophilic sugar moieties. GSLs cluster with cholesterol in cell membranes to form GSL-enriched lipid rafts. Biochemical analyses have demonstrated that GSL-enriched lipid rafts contain several kinds of transducer molecules, including Src family kinases. Among the GSLs, lactosylceramide (LacCer, CDw17) can bind to various microorganisms, is highly expressed on the plasma membranes of human phagocytes, and forms lipid rafts containing the Src family tyrosine kinase Lyn. LacCer-enriched lipid rafts mediate immunological and inflammatory reactions, including superoxide generation, chemotaxis, and non-opsonic phagocytosis. Therefore, LacCer-enriched membrane microdomains are thought to function as pattern recognition receptors (PRRs), which recognize pathogen-associated molecular patterns (PAMPs) expressed on microorganisms. LacCer also serves as a signal transduction molecule for functions mediated by CD11b/CD18-integrin (αM/β2-integrin, CR3, Mac-1), as well as being associated with several key cellular processes. LacCer recruits PCKα/ε and phospholipase A2 to stimulate PECAM-1 expression in human monocytes and their adhesion to endothelial cells, as well as regulating β1-integrin clustering and endocytosis on cell surfaces. This review describes the organizational and inflammation-related functions of LacCer-enriched lipid rafts.

  9. Oxygen enriched air using membrane for palm oil wastewater treatment

    Directory of Open Access Journals (Sweden)

    Ramlah Mohd Tajuddin

    2002-11-01

    Full Text Available A research aimed to explore new method of aeration using oxygen enriched air performance on BOD reduction of palm oil wastewater was conducted. The oxygen enriched air was obtained from an Oxygen Enriched System (OES developed using asymmetric polysulfone hollow fiber membrane with composition consisting of PSF: 22%, DMAc: 31.8%, THF: 31.8%, EtOH: 14.4%. Palm oil wastewater samples were taken from facultative pond effluent. These samples were tested for its initial biochemical oxygen demand (BOD, total suspended solids (TSS, pH, conductivity, turbidity, dissolved oxygen (DO, suspended solids (SS, and total dissolved solids (TDS before being subjected to two modes of aeration system, that is diffused air and oxygen enriched air. These water quality concentrations were tested for every 20 minutes for two-hour period during the aeration process. Results of BOD, TSS, pH, conductivity, DO, SS and TDS concentrations against time of samples from the two modes of aeration were then compared. It was found that DO concentration achieved in oxygen enriched air aeration was better than aeration using diffused air system. Aeration using OES improve the DO concentration in the wastewater and thus improve the BOD reduction and also influence other physical characteristics of wastewater. This phenomenon indicates the advantage of using air with higher oxygen concentration for wastewater aeration instead of diffused air system.

  10. Development of an On-Line Uranium Enrichment Monitor

    International Nuclear Information System (INIS)

    Xuesheng, L.; Guorong, L.; Yonggang, Z.; Xueyuan, H. X.-Y.

    2015-01-01

    An on-line enrichment monitor was developed to measure the enrichment of UF6 flowing through the processing pipes in centrifuge uranium enrichment plant. A NaI(Tl) detector was used to measure the count rates of the 186 keV gamma ray emitted from 235U, and the total quantity of uranium was determined from thermodynamic characteristics of gaseous uranium hexafluoride. The results show that the maximum relative standard deviation is less than 1% when the measurement time is 120 s or more and the pressure is more than 2 kPa in the measurement chamber. There are two working models for the monitor. The monitor works normally in the continuous model, When the gas's pressure in the pipe fluctuates greatly, it can work in the intermittent model, and the measurement result is very well. The background of the monitor can be measured automatically periodically. It can control automatically electromagnetic valves open and close, so as to change the gas's quantity in the chamber. It is a kind of unattended and remote monitor, all of data can be transfer to central control room. It should be effective for nuclear materials accountability verifications and materials balance verification at uranium enrichment plant by using the monitor to monitor Uranium enrichment of gaseous uranium hexafluoride in the output end of cascade continuously. (author)

  11. A new era in U.S. uranium enrichment

    International Nuclear Information System (INIS)

    Longenecker, J.R.

    1984-01-01

    Complex market conditions, including lower than anticipated electrical growth rates, creation of a large spot market of enriched uranium, fluctuations in currency exchange rates, and certain political considerations, have created an unstable market for all primary producers, including the United States. In response to these conditions, the Department of Energy made significant changes to the U.S. program including the issuance of the Utility Services contract on January 18, 1984. Other major changes include redirecting research and development efforts on the advanced gas centrifuge and atomic vapor laser isotope separation processes, rescoping of the Gas Centrifuge Enrichment Plant project, and reevaluation of the operational mode of the three gaseous diffusion plants. Taken together, we believe these actions will retain the U.S. position of leadership in uranium enrichment. In summary, we plan to compete--through introduction of the world's most advanced, lowest cost technology and through responsiveness to our customers' needs

  12. Glycoprotein Enrichment Analytical Techniques: Advantages and Disadvantages.

    Science.gov (United States)

    Zhu, R; Zacharias, L; Wooding, K M; Peng, W; Mechref, Y

    2017-01-01

    Protein glycosylation is one of the most important posttranslational modifications. Numerous biological functions are related to protein glycosylation. However, analytical challenges remain in the glycoprotein analysis. To overcome the challenges associated with glycoprotein analysis, many analytical techniques were developed in recent years. Enrichment methods were used to improve the sensitivity of detection, while HPLC and mass spectrometry methods were developed to facilitate the separation of glycopeptides/proteins and enhance detection, respectively. Fragmentation techniques applied in modern mass spectrometers allow the structural interpretation of glycopeptides/proteins, while automated software tools started replacing manual processing to improve the reliability and throughput of the analysis. In this chapter, the current methodologies of glycoprotein analysis were discussed. Multiple analytical techniques are compared, and advantages and disadvantages of each technique are highlighted. © 2017 Elsevier Inc. All rights reserved.

  13. Chemical uranium enrichment with ion exchanger

    International Nuclear Information System (INIS)

    Takeda, Kunihiko; Onitsuka, Hatsuki; Obanawa, Heiichiro

    1991-01-01

    The uranium enrichment by using ion-exchange has been studied and developed since 1972. The ion-exchange rate has been improved approx. 3000 times and the electron exchange reaction, which occurs with ion-exchange reaction, was also accelerated with catalyst. Flow disturbance in a ion-exchange column has been fully studied and the value of turbulence has been reduced to 150μm. These results allowed us to design a very fine separation column, in which about 10000 stages can be obtained even when the column is more than 1 m in diameter. In the course of the development, a self-regenerating reaction between the redox agents was discovered and incorporated into the process, and has resulted in a reduction of 70 % in the separation energy requirement. (author)

  14. Dimensional enrichment of statistical linked open data

    DEFF Research Database (Denmark)

    Varga, Jovan; Vaisman, Alejandro; Romero, Oscar

    2016-01-01

    On-Line Analytical Processing (OLAP) is a data analysis technique typically used for local and well-prepared data. However, initiatives like Open Data and Open Government bring new and publicly available data on the web that are to be analyzed in the same way. The use of semantic web technologies...... for this context is especially encouraged by the Linked Data initiative. There is already a considerable amount of statistical linked open data sets published using the RDF Data Cube Vocabulary (QB) which is designed for these purposes. However, QB lacks some essential schema constructs (e.g., dimension levels......) to support OLAP. Thus, the QB4OLAP vocabulary has been proposed to extend QB with the necessary constructs and be fully compliant with OLAP. In this paper, we focus on the enrichment of an existing QB data set with QB4OLAP semantics. We first thoroughly compare the two vocabularies and outline the benefits...

  15. Present state of development of uranium enrichment

    International Nuclear Information System (INIS)

    1979-01-01

    The pilot plant for uranium enrichment started the operation on September 12, 1979. The pilot plant has been constructed by the Power Reactor and Nuclear Fuel Development Corp. in Ningyo Pass, Okayama Prefecture. 7000 centrifugal separators will be installed by mid 1981, and yearly production of 70 t SWU is expected. The Uranium Enrichment Committee of Japan Atomic Industrial Forum has made the proposal on the method of forwarding the development of uranium enrichment in Japan to Atomic Energy Commission and related government offices in December, 1978. This survey summarized the trends of uranium enrichment in Japan and foreign countries and the problems about nuclear non-proliferation, and provides with the reference materials. The demand and supply of uranium enrichment in the world, the present states and plans in USA, Europe, USSR and others, the demand and supply of uranium enrichment and the measures for securing it in Japan, the present state and future plan of uranium enrichment project in Japan, the international regulation of uranium enrichment, the recent policy of USA and INFCE, and the trend of the regulation of utilizing enriched uranium are described. Moreover, the concept of separation works in uranium enrichment and the various technologies of separation are explained. (Kako, I.)

  16. Laboratory studies of 235U enrichment by chemical separation methods

    International Nuclear Information System (INIS)

    Daloisi, P.J.; Orlett, M.J.; Tracy, J.W.; Saraceno, A.J.

    1976-01-01

    Laboratory experiments on 235 U enrichment processes based on column redox ion exchange, electrodialysis, and gas exchange chromatography performed from August 1972 to September 1974 are summarized. Effluent from a 50 to 50 weight mixture of U +4 and U +6 (as UO 2 2+ ), at a total uranium concentration of 5 mg U per ml in 0.25N H 2 SO 4 -0.03N NaF solution, passing through a 100 cm length cation exchange column at 0.5 ml/min flow rates, was enriched in 235 U by 1.00090 +- .00012. The enriched fraction was mostly in the +6 valence form while the depleted fraction was U +4 retained on the resin. At flow rates of 2 ml/min, the enrichment factor decreases to 1.00033 +- .00003. In the electrodialysis experiments, the fraction of uranium diffusing through the membranes (mostly as +6 valence state) in 4.2 hours is enriched in 235 U by 1.00096 +- .00012. Gas exchange chromatography tests involved dynamic and static exposure of UF 6 over NaF. In dynamic tests, no significant change in isotopic abundance occurred in the initial one-half weight cut of UF 6 . The measured relative 235 U/ 238 U mole ratios were 1.00004 +- .00004 for these runs. In static runs, enrichment became evident. For the NaF(UF 6 )/sub x/-UF 6 system, there is 235 U depletion in the gas phase, with a single-stage factor of 1.00033 at 100 0 C and 1.00025 at 25 0 C after 10 days of equilibration. The single-stage or unit holdup time is impractically long for all three chemical processes

  17. Industrial plants for production of highly enriched nitrogen-15

    International Nuclear Information System (INIS)

    Krell, E.; Jonas, C.

    1977-01-01

    A discussion is presented of the present stage of development of large-scale enrichment of 15 N. The most important processes utilized to separate nitrogen isotopes, namely chemical exchange in the NO/NO 2 /HNO 3 system and low-temperature distillation of NO at -151 0 C, are compared, especially with respect to their economics and use of energy. As examples, chemical exchange plants in the GDR are discussed, and the research activities necessary to optimize the process, especially to solve aerodynamic, hydrodynamic, interface and processing problems, are reviewed. Good results were obtained by the choice of an optimum location and the design of a plant for pre-enrichment to 10 at.% 15 N and an automatically operating two-section cascade for the high enrichment of 15 N to more than 99 at.%. The chemical industry has taken over operation of the plant with the consequence that the raw materials are all available without additional transport. All by-products (nitrous gases and sulphuric acid) are returned for use elsewhere within the industry. The technology of the plant has been chosen so that the quantity of highly enriched product can be varied within a wide range. The final product is used to synthesize more than 250 different 15 N-labelled compounds which are also produced on an industrial scale. (author)

  18. Review of Membrane Oxygen Enrichment for Efficient Combustion

    Science.gov (United States)

    Ariono, Danu; Kusuma Wardani, Anita

    2017-07-01

    Oxygen enrichment from air is a simple way of increasing the efficiency of combustion process, as in oxy-combustion. Oxy-combustion has become one of the most attracting combustion technologies because of its potential to address both pollutant reduction and CO2 capture. In oxy-combustion, the fuel and recycled flue gas are combusted with oxygen enriched air (OEA). By using OEA, many benefits can be obtained, such as increasing available heat, improving ignition characteristics, flue gas reduction, increasing productivity, energy efficiency, turndown ratio, and flame stability. Membrane-based gas separation for OEA production becomes an attractive technology over the conventional technology due to the some advantages, including low capital cost, low energy consumption, compact size, and modularity. A single pass through membrane usually can enrich O2 concentration in the air up to 35% and a 50% concentration can be achieved with a double pass of membrane. The use of OEA in the combustion process eliminates the presence of nitrogen in the flue gas. Hence, the flue gas is mainly composed of CO2 and condensable water that can be easily separated. This paper gives an overview of oxy-combustion with membrane technology for oxygen enrichment process. Special attention is given to OEA production and the effect of OEA to the efficiency of combustion.

  19. The development and application of solid polymer electrolysis enrichment device of tritium in water

    International Nuclear Information System (INIS)

    Wen Xuelian; Yang Hailan Wu Bin; Yang Huaiyuan

    2003-01-01

    This paper briefly describes the working principle of solid polymer electrolysis enrichment device of tritium in water, presents experiments and works in development of SPE tritium automatic electrolysis enrichment device by CIRP, with which the water samples had been processed for TRIC2000, and the measurement results are satisfied

  20. 78 FR 17942 - Request To Amend a License To Export High-Enriched Uranium

    Science.gov (United States)

    2013-03-25

    ... NUCLEAR REGULATORY COMMISSION Request To Amend a License To Export High-Enriched Uranium Pursuant... Administration. Enriched Uranium contained in 99.7 Reactor in the be processed for March 6, 2013 (93.35%)) kilograms Czech Republic to medical isotope March 11, 2013 uranium) the list of production at the XSNM3622...

  1. Super enrichment of Fe-group nuclei in solar flares and their association with large 3He enrichments

    International Nuclear Information System (INIS)

    Anglin, J.D.; Dietrich, W.F.; Simpson, J.A.

    1977-01-01

    ''Fe''/He ratios at approximately 2 MeV/n have been measured in 60 solar flares and periods of enhanced fluxes during the interval 1972-1976. The observed ditribution of ratios is extremely wide with values ranging from approximately 1 to more than 1000 times the solar abundance ratio. In constrast, most of the CHO/He ratios for the same flares lie within a factor 2 of the observed mean value of 2 x 10 -2 . While experimental limitations prevent a complete correlation study of Fe-group and 3 He abundances, comparison of flares with large Fe enrichments with flares with large 3 He enrichments for the period 1969-1976 shows that a 3 He-rich flare is also likely to be rich in iron. We feel that the association of 3 He and Fe enrichments may be explained by a two-stage process in which a preliminary enrichment of heavy nuclei precedes the preferential acceleration of ambient 3 He. Nuclear interactions are ruled out as the principal source of the enriched 3 He. (author)

  2. Computational fluid mechanics in R and D on uranium enrichment

    International Nuclear Information System (INIS)

    Soubbaramayer, O.

    1988-01-01

    Uranium enrichment represents an essential link in the cycle of nuclear fuels for power production. There are many processes of uranium enrichment, but three of them dominate the nuclear history as well in the past (Gaseous diffusion and centrifugation) as in the present (Laser process). The important role played by the Numerical Fluid Mechanics in the three processes is pointed out. The type of problem raised by Gaseous Diffusion is Channel Flow with wall suction, by Centrifugation, flow of a Compressible gas in a strongly rotating cylinder (Stewartson and Ekman layers) and by Laser process, Thermocapillary-buoyancy flow of a molten metal in an evaporation crucible. The methods and results in these problems are reviewed. 18 refs, 11 figs

  3. Gasket for uranium enrichment plant

    Energy Technology Data Exchange (ETDEWEB)

    Kishi, S; Aiyoshi, H

    1977-02-08

    A gasket to be inserted between flange joints in the equipments and pipe lines of an uranium enrichment plant having neither permeability nor adsorptivity to water while maintaining mechanical, physical and chemical properties of an elastomer gasket is described. A gasket made of an elastomeric material such as a polymer is integratedly formed at its surface with anti-slip projections. The gasket is further surrounded at its upper and lower peripheral sides, as well as outer circumferential portion with a U-sectioned cover (enclosure) made of fluoro-plastics. In this arrangement, the gasket main body shows a gas-tightness for uranium hexafluoride gas and the cover exhibits a gas-tightness for other component gases such as moisture to thereby prevent degradation of the gasket due to absorption and permeation of the moisture.

  4. Historical review of CEA researches on uranium enrichment

    International Nuclear Information System (INIS)

    Camarcat, N.

    1997-01-01

    The various uranium enrichment processes that have been studied at the CEA since 1953 are briefly reviewed: gaseous diffusion (which led to the construction of EURODIF plant), chemical treatments (which were abandoned in 1988 for cost reasons), gaseous ultracentrifugation, electromagnetic processes, laser techniques (since 1980) and especially the SILVA technique (atomic vapour laser isotopic separation) which could take the place of the gaseous diffusion technique when the EURODIF plant will need to be renewed before 2010

  5. Methanogenic degradation of acetone by an enrichment culture

    OpenAIRE

    Platen, Harald; Schink, Bernhard

    1987-01-01

    An anaerobic enrichment culture degraded 1 mol of acetone to 2 tool of methane and 1 tool of carbon dioxide. Two microorganisms were involved in this process, a filament-forming rod similar to Methanothrix sp. and an unknown rod with round to slightly pointed ends. Both organisms formed aggregates up to 300 gm in diameter. No fluorescing bacteria were observed indicating that hydrogen or formate-utilizing methanogens are not involved in this process. Acetate was utilized in this culture by th...

  6. Stable isotope enrichment: Current and future potential

    International Nuclear Information System (INIS)

    Tracy, J.G.; Aaron, W.S.

    1992-01-01

    Oak Ridge National Laboratory (ORNL) operates the Isotope Enrichment Facility for the purpose of providing enriched stable isotopes, selected radioactive isotopes (including the actinides), and isotope-related materials and services for use in various research applications. ORNL is responsible for isotope enrichment and the distribution of approximately 225 nongaseous stable isotopes from 50 multi-isotopic elements. Many enriched isotope products are of prime importance in the fabrication of nuclear targets and the subsequent production of special radionuclides. State-of-the-art techniques to achieve special isotopic, chemical, and physical requirements are performed at ORNL This report describes the status and capabilities of the Isotope Enrichment Facility and the Isotope Research Materials Laboratory as well as emphasizing potential advancements in enrichment capabilities

  7. Considering the post-1995 enrichment market

    International Nuclear Information System (INIS)

    Gunter, L.

    1994-01-01

    World demand for uranium enrichment services is likely to grow only a little over the next decade, from the current 28 million separative work units (SWU) per year to 33 MSWU per year. Much of the growth will come from Asia where nuclear generating capacity is still increasing. The current situation of the primary enrichment companies is summarized. The primary Western suppliers, Cogema, United States Enrichment Corporation and Urenco, are competing for increased market share in the USA, Europe and Asia as utilities purchase their post-1995 requirements. Entry of the Russian enrichment company, Tenex, into Western markets has been limited by trade restrictions. As a consequence of disarmament, blended weapons material has resulted in a surplus of low-enriched uranium. Together with over-capacity amongst the primary enrichers this has led to an expectation that reduced prices will be negotiable in the medium term. (3 figures). (UK)

  8. Noble gas enrichment studies at JET

    International Nuclear Information System (INIS)

    Groth, M.; Andrew, P.; Fundamenski, W.; Guo, H.Y.; Hillis, D.L.; Hogan, J.T.; Horton, L.D.; Matthews, G.F.; Meigs, A.G.; Morgan, P.M.; Stamp, M.F.; Hellermann, M. von

    2001-01-01

    Adequate helium exhaust has been achieved in reactor-relevant ELMy H-mode plasmas in JET performed in the MKII AP and MKII GB divertor geometry. The divertor-characteristic quantities of noble gas compression and enrichment have been experimentally inferred from Charge Exchange Recombination Spectroscopy measurements in the core plasma, and from spectroscopic analysis of a Penning gauge discharge in the exhaust gas. The retention of helium was found to be satisfactory for a next-step device, with enrichment factors exceeding 0.1. The helium enrichment decreases with increasing core plasma density, while the neon enrichment has the opposite behaviour. Analytic and numerical analyses of these plasmas using the divertor impurity code package DIVIMP/NIMBUS support the explanation that the enrichment of noble gases depends significantly on the penetration depth of the impurity neutrals with respect to the fuel atoms. Changes of the divertor plasma configuration and divertor geometry have no effect on the enrichment

  9. Stable isotope enrichment - current and future potential

    International Nuclear Information System (INIS)

    Tracy, J.G.; Aaron, W.S.

    1993-01-01

    Oak Ridge National Laboratory (ORNL) operates the Isotope Enrichment Facility for the purpose of providing enriched stable isotopes, selected radioactive isotopes (including the actinides), and isotope-related materials and services for use in various research applications. ORNL is responsible for isotope enrichment and the distribution of approximately 225 nongaseous stable isotopes from 50 multi-isotopic elements. Many enriched isotope products are of prime importance in the fabrication of nuclear targets and the subsequent production of special radionuclides. State-of-the-art techniques to achieve special isotopic, chemical, and physical requirements are performed at ORNL. This report describes the status and capabilities of the Isotope Enrichment Facility and the Isotope Research Materials Laboratory as well as emphasizing potential advancements in enrichment capabilities. (orig.)

  10. Turkey's regulatory plans for high enriched to low enriched conversion of TR-2 reactor core

    International Nuclear Information System (INIS)

    Guelol Oezdere, Oya

    2003-01-01

    Turkey is a developing country and has three nuclear facilities two of which are research reactors and one pilot fuel production plant. One of the two research reactors is TR-2 which is located in Cekmece site in Istanbul. TR-2 Reactor's core is composed of both high enriched and low enriched fuel and from high enriched to low enriched core conversion project will take place in year 2005. This paper presents the plans for drafting regulations on the safety analysis report updates for high enriched to low enriched core conversion of TR-2 reactor, the present regulatory structure of Turkey and licensing activities of nuclear facilities. (author)

  11. The future cost of uranium enrichment

    International Nuclear Information System (INIS)

    Pouris, A.

    1986-01-01

    The cost of uranium enrichment is the most important factor determining the fuel cost of nuclear energy. This paper attempts to forecast the future direction of the price of separative work by examining the forces that determine it. It is argued that the interplay among the characteristics of enrichment technologies, the structure of the international market, and the balance of supply and demand determine the enrichment price. The analysis indicates that all forces point towards a price much lower than the current one. It is predicted that, depending on the technological advances, the price of separative work unit for uranium enrichment will range between $40 and $90 by the year 2000. (author)

  12. Inventory control through gamma spectrometry at the enriched uranium laboratory

    International Nuclear Information System (INIS)

    Vicens, H.E.; Korob, R.O.; Goldschmidt, A.E.

    1987-01-01

    The enriched uranium laboratory processes alternatively uranium 90% and 20% enriched in U-235. The control of the isotopic composition of lots is made through mass spectrometry. In the laboratory operation wastes of both enrichments are generated and the recovery is performed with a time delay. To strengthen the administrative controls, avoid errors related to personnel replacement and/or deferred operations, it seemed suitable to adjust the gamma spectrometry as a fast, simple and available method to determine the enrichment. The laboratory work includes a wet and a dry process. The waste recovery necessarily involves the handling of liquid samples. For this reason, it was decided to determine the calibration curve for uranyl nitrate samples of fixed concentration and geometry. The samples were prepared from material purified through double precipitation of uranium peroxide and subsequent ignition to U 3 O 8 in platinum crucible, in tubular oven during 8 hours at 720 deg C. The preparation of samples, the measurement description, the discussion of results and the analysis of errors due to the presence of insoluble material and concentration changes are included. (Author)

  13. Solvent-Detergent Treatment of IgM-Enriched Immunoglobulin

    Directory of Open Access Journals (Sweden)

    Mojgan Pourmokhtar

    2003-08-01

    Full Text Available Viral safety of human plasma products plays a key role in their safe uses. Solvent- detergent (SD virus-inactivation method has gained widespread popularity in the manufacture of biological products. This treatment which inactivates lipid-enveloped viruses effectively consists of incubation of a plasma protein solution in the presence of a non-volatile organic solvent and a detergent. In this study, IgM-enriched immunoglobulin was incubated at 24 °C for 6 h under slow stirring in the presence of tri(n-butyl phosphate (0.3% w/w as solvent and tween 80 (1% w/w as detergent. After completion of the inactivation process and removal of the solvent-detergent, the ability of SD-treatment to remove Infectious Bovine Rhinotracheitis (IBR virus (a lipid-enveloped virus and Foot-and-Mouth Disease virus (a non-enveloped virus were evaluated by "virus spiking studies" using a scaled down process. Reduction factor of 4 log was obtained for the SD-treatment of IgM-enriched immunoglobulin spiked with IBR virus. No virus inactivation was observed in the SD-treated IgM-enriched immunoglobulin, spiked with Foot-and-Mouth Disease virus. It was concluded that treatment of IgM-enriched immunoglobulin with TNBP-TWEEN 80 may be considered as an efficient lipid-enveloped virus inactivation step in the manufacture of this product.

  14. Ultrahigh thermal conductivity of isotopically enriched silicon

    Science.gov (United States)

    Inyushkin, Alexander V.; Taldenkov, Alexander N.; Ager, Joel W.; Haller, Eugene E.; Riemann, Helge; Abrosimov, Nikolay V.; Pohl, Hans-Joachim; Becker, Peter

    2018-03-01

    Most of the stable elements have two and more stable isotopes. The physical properties of materials composed of such elements depend on the isotopic abundance to some extent. A remarkably strong isotope effect is observed in the phonon thermal conductivity, the principal mechanism of heat conduction in nonmetallic crystals. An isotopic disorder due to random distribution of the isotopes in the crystal lattice sites results in a rather strong phonon scattering and, consequently, in a reduction of thermal conductivity. In this paper, we present new results of accurate and precise measurements of thermal conductivity κ(T) for silicon single crystals having three different isotopic compositions at temperatures T from 2.4 to 420 K. The highly enriched crystal containing 99.995% of 28Si, which is one of the most perfect crystals ever synthesized, demonstrates a thermal conductivity of about 450 ± 10 W cm-1 K-1 at 24 K, the highest measured value among bulk dielectrics, which is ten times greater than the one for its counterpart natSi with the natural isotopic constitution. For highly enriched crystal 28Si and crystal natSi, the measurements were performed for two orientations [001] and [011], a magnitude of the phonon focusing effect on thermal conductivity was determined accurately at low temperatures. The anisotropy of thermal conductivity disappears above 31 K. The influence of the boundary scattering on thermal conductivity persists sizable up to much higher temperatures (˜80 K). The κ(T) measured in this work gives the most accurate approximation of the intrinsic thermal conductivity of single crystal silicon which is determined solely by the anharmonic phonon processes and diffusive boundary scattering over a wide temperature range.

  15. Hybrid Enrichment Verification Array: Module Characterization Studies

    Energy Technology Data Exchange (ETDEWEB)

    Zalavadia, Mital A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Smith, Leon E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McDonald, Benjamin S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kulisek, Jonathan A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mace, Emily K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Deshmukh, Nikhil S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-03-01

    The work presented in this report is focused on the characterization and refinement of the Hybrid Enrichment Verification Array (HEVA) approach, which combines the traditional 186-keV 235U signature with high-energy prompt gamma rays from neutron capture in the detector and surrounding collimator material, to determine the relative enrichment and 235U mass of the cylinder. The design of the HEVA modules (hardware and software) deployed in the current field trial builds on over seven years of study and evolution by PNNL, and consists of a ø3''×3'' NaI(Tl) scintillator coupled to an Osprey digital multi-channel analyzer tube base from Canberra. The core of the HEVA methodology, the high-energy prompt gamma-ray signature, serves as an indirect method for the measurement of total neutron emission from the cylinder. A method for measuring the intrinsic efficiency of this “non-traditional” neutron signature and the results from a benchmark experiment are presented. Also discussed are potential perturbing effects on the non-traditional signature, including short-lived activation of materials in the HEVA module. Modeling and empirical results are presented to demonstrate that such effects are expected to be negligible for the envisioned implementation scenario. In comparison to previous versions, the new design boosts the high-energy prompt gamma-ray signature, provides more flexible and effective collimation, and improves count-rate management via commercially available pulse-processing electronics with a special modification prompted by PNNL.

  16. CENTAR gas centrifuge enrichment project: economics and engineering considerations

    International Nuclear Information System (INIS)

    Fishman, A.M.

    1977-01-01

    Description of some economic and engineering considerations of the CENTAR Associates' 3000000 SWU/yr gas centrifuge uranium enrichment plant project. The need for uranium enrichment facilities is discussed, and the advantages of using the centrifuge process rather than the presently used gaseous diffusion process are reviewed. A description of the CENTAR plant is given, highlighting the major features of the facility. Since the centiruges to be used in the plant account for approximately 50% of the capital cost of the project, the philosophy of their manufacture and procurement is discussed. Various design considerations which bear upon process economics are presented to give the reader an appreciation of the subtleties of the technology and the flexibility possible in plant design. Special attention is given to meeting the needs of the utility customer at the lowest possible cost

  17. Response of the brain to enrichment

    Directory of Open Access Journals (Sweden)

    MARIAN C. DIAMOND

    2001-06-01

    Full Text Available Before 1960, the brain was considered by scientists to be immutable, subject only to genetic control. In the early sixties, however, investigators were seriously speculating that environmental influences might be capable of altering brain structure. By 1964, two research laboratories proved that the morphology and chemistry or physiology of the brain could be experientially altered (Bennett et al. 1964, Hubel and Wiesel 1965. Since then, the capacity of the brain to respond to environmental input, specifically "enrichment,'' has become an accepted fact among neuroscientists, educators and others. In fact, the demonstration that environmental enrichment can modify structural components of the rat brain at any age altered prevailing presumptions about the brain's plasticity (Diamond et al. 1964, Diamond 1988. The cerebral cortex, the area associated with higher cognitive processing, is more receptive than other parts of the brain to environmental enrichment. The message is clear: Although the brain possesses a relatively constant macrostructural organization, the ever-changing cerebral cortex, with its complex microarchitecture of unknown potential, is powerfully shaped by experiences before birth, during youth and, in fact, throughout life. It is essential to note that enrichment effects on the brain have consequences on behavior. Parents, educators, policy makers, and individuals can all benefit from such knowledge.Antes de 1960, os cientistas consideravam o encéfalo como imutável, sujeito apenas ao controle genético. Entretanto, no início dos anos 60, alguns pesquisadores especulavam seriamente que influências ambientais podiam ser capazes de alterar a estrutura cerebral. Por volta de 1964, dois laboratórios de pesquisa demonstraram que a morfologia e a química ou a fisiologia do cérebro poderia ser modificada pela experiência (Bennett et al. 1964, Hubel e Wiesel 1965. Desde então, a capacidade do cérebro a responder para responder a

  18. 76 FR 387 - Atomic Safety and Licensing Board; AREVA Enrichment Services, LLC (Eagle Rock Enrichment Facility)

    Science.gov (United States)

    2011-01-04

    ... and Licensing Board; AREVA Enrichment Services, LLC (Eagle Rock Enrichment Facility) December 17, 2010... construction and operation of a gas centrifuge uranium enrichment facility--denoted as the Eagle Rock... site at http://www.nrc.gov/materials/fuel-cycle-fac/arevanc.html . These and other documents relating...

  19. Study on the radiotoxicology of enriched uranium

    International Nuclear Information System (INIS)

    Zhu Shoupeng; Zheng Siying; Wang Guolin; Wang Chongdao; Cao Genfa

    1987-12-01

    A study on the retentive peculiarity of soluble enriched uranium UO 2 F 2 were observed after iv once or consecutive ip qd x 3d to Wistar male rats. The dynamic retention of radioactivity in the body showed that the enriched uranium UO 2 F 2 was chiefly localized in kidney, and then in skeleton and liver. The radioactivity of the enriched uranium UO 2 F 2 in skeleton rose steadily while the concentratoin in kidney and liver droped. When enriched uranium UO 2 F 2 was accumulated in organism, it caused chromosome aberrations on bone marrow cells. Results indicated that the chromosome aberration rates were elevated when the dose of the enriched uranium UO 2 F 2 was increased, at the same time, the cell division was depressed. Accumulation of insoluble enriched uranium U 3 O 8 in gastrointestinal tract was well described by a two exponential expression. Values of retention estimate for fast component, T 1 = 0.34 d, and for relatively long term component, T 2 = 4.05 d. The deposition of UO 2 F 2 in the intact skin was only 0.16 to 0.18% of the total contaminated UO 2 F 2 . Penetration of the enriched uranium UO 2 F 2 was dominantly increased in abraded skin. This value is about 25 to 32 times as compaired with that in intact skin. Retention of the enriched uranium UO 2 F 2 through abraded skins was dominantly localized in kidney and skeleton

  20. Uranium enrichment: a vital new industry

    International Nuclear Information System (INIS)

    1975-10-01

    The energy problem facing the nation and the need for nuclear power are pointed out. Uranium enrichment and the demand for it are discussed. Reasons for, and obstacles to, private enrichment are outlined. The President's plan (including the Nuclear Fuel Assurance Act) is summarized

  1. Inoculation stress hypothesis of environmental enrichment.

    Science.gov (United States)

    Crofton, Elizabeth J; Zhang, Yafang; Green, Thomas A

    2015-02-01

    One hallmark of psychiatric conditions is the vast continuum of individual differences in susceptibility vs. resilience resulting from the interaction of genetic and environmental factors. The environmental enrichment paradigm is an animal model that is useful for studying a range of psychiatric conditions, including protective phenotypes in addiction and depression models. The major question is how environmental enrichment, a non-drug and non-surgical manipulation, can produce such robust individual differences in such a wide range of behaviors. This paper draws from a variety of published sources to outline a coherent hypothesis of inoculation stress as a factor producing the protective enrichment phenotypes. The basic tenet suggests that chronic mild stress from living in a complex environment and interacting non-aggressively with conspecifics can inoculate enriched rats against subsequent stressors and/or drugs of abuse. This paper reviews the enrichment phenotypes, mulls the fundamental nature of environmental enrichment vs. isolation, discusses the most appropriate control for environmental enrichment, and challenges the idea that cortisol/corticosterone equals stress. The intent of the inoculation stress hypothesis of environmental enrichment is to provide a scaffold with which to build testable hypotheses for the elucidation of the molecular mechanisms underlying these protective phenotypes and thus provide new therapeutic targets to treat psychiatric/neurological conditions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. 21 CFR 137.350 - Enriched rice.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Enriched rice. 137.350 Section 137.350 Food and... Related Products § 137.350 Enriched rice. (a) The foods for which definitions and standards of identity are prescribed by this section are forms of milled rice (except rice coated with talc and glucose and...

  3. Providing incentives to buy US enrichment

    International Nuclear Information System (INIS)

    Steyn, J.

    1985-01-01

    The U.S. Department of Energy is making a series of commercial and technological decisions crucial to its future as an enriching enterprise. The state of US enrichment, as revealed in this years AIF Fuel Cycle conference, is reported. (U.K.)

  4. Enrichment technology. Dependable vendor of gas centrifuges

    International Nuclear Information System (INIS)

    Anon.

    2011-01-01

    Enrichment Technology is an innovative, high-tech company that develops, manufactures and installs gas centrifuges for enriching uranium. In addition, Enrichment Technology designs enrichment plants that use gas centrifuge technology. This technology offers the most efficient and cost-effective method for enriching uranium yet: high-performance, safe technology that dominates the market with a global share of 45 percent. A determining factor in Enrichment Technology's success is its mission: supplying its customers with safe, reliable technology. Production of the centrifuges requires versatile know-how and collaboration between different departments as well as interdisciplinary teams at the various sites. More than 2000 operators at 8 sites in 5 countries contribute their individual knowledge and personal skills in order to produce this exceptional technology. The head office is in Beaconsfield near London and the operational headquarters are in Almelo in the Netherlands. There are other sites in Germany (Juelich und Gronau), Great Britain (Capenhurst) as well as project sites in the USA and France. Capenhurst is where experienced engineers design new enrichment plants and organise their construction. Centrifuge components are manufactured in Almelo and Juelich, while the pipework needed to connect up the centrifuges is produced at the site in Gronau. In Juelich, highly qualified scientists in interdisciplinary teams are continuously researching ways of improving the current centrifuges. Communication between specialists in the fields of chemistry, physics and engineering forms the basis for the company's success and the key to extending this leading position in the global enrichment market. (orig.)

  5. Student science enrichment training program

    Energy Technology Data Exchange (ETDEWEB)

    Sandhu, S.S.

    1994-08-01

    This is a report on the Student Science Enrichment Training Program, with special emphasis on chemical and computer science fields. The residential summer session was held at the campus of Claflin College, Orangeburg, SC, for six weeks during 1993 summer, to run concomitantly with the college`s summer school. Fifty participants selected for this program, included high school sophomores, juniors and seniors. The students came from rural South Carolina and adjoining states which, presently, have limited science and computer science facilities. The program focused on high ability minority students, with high potential for science engineering and mathematical careers. The major objective was to increase the pool of well qualified college entering minority students who would elect to go into science, engineering and mathematical careers. The Division of Natural Sciences and Mathematics and engineering at Claflin College received major benefits from this program as it helped them to expand the Departments of Chemistry, Engineering, Mathematics and Computer Science as a result of additional enrollment. It also established an expanded pool of well qualified minority science and mathematics graduates, which were recruited by the federal agencies and private corporations, visiting Claflin College Campus. Department of Energy`s relationship with Claflin College increased the public awareness of energy related job opportunities in the public and private sectors.

  6. Technical and economic aspects of new gaseous diffusion uranium enrichment capacity

    International Nuclear Information System (INIS)

    Langley, R.A. Jr.; O'Donnell, A.J.

    1977-01-01

    Work is well advanced on design and construction of the next major increment of U.S. uranium enrichment capacity. The plant will use the gaseous diffusion process to provide the required capacity and reliability at a competitive enrichment services cost. Gaseous diffusion technology is the base against which other processes are compared in order to assess their commercial viability. While it has generally been described as a mature technology with limited future development potential, work on design of the new U.S. plant has resulted in major improvement in plant design with corresponding decreases in plant capacity and operating costs. The paper describes major technological advances incorporated into the new plant design and their impact on enrichment costs. These include the effects of: - advanced barrier technology; - tandem compressor drive systems; - optimization of number of equipment sizes; - single level plant design; - development of rapid power level change capability; - electrical system simplification; - plant arrangement and layout. Resulting capital costs and projected enrichment costs are summarized. Enrichment costs are placed in the context of total nuclear fuel cycle costs. Trade-offs between uranium feed material quantities and enrichment plant tails assays are described, and optimization of this aspect of the nuclear fuel cycle is discussed. The effect on enrichment plant characteristics is described. Flexibility and capability of the new U.S. enrichment plant to meet these changing optimization conditions are described

  7. Enriching an effect calculus with linear types

    DEFF Research Database (Denmark)

    Egger, Jeff; Møgelberg, Rasmus Ejlers; Simpson, Alex

    2009-01-01

    We define an ``enriched effect calculus'' by conservatively extending  a type theory for computational effects with primitives from linear logic. By doing so, we obtain a generalisation of linear type theory, intended as a formalism for expressing linear aspects of effects. As a worked example, we...... formulate  linearly-used continuations in the enriched effect calculus. These are captured by a fundamental translation of the enriched effect calculus into itself, which extends existing call-by-value and call-by-name linearly-used CPS translations. We show that our translation is involutive. Full...... completeness results for the various linearly-used CPS translations  follow. Our main results, the conservativity of enriching the effect calculus with linear primitives, and the involution property of the fundamental translation, are proved using a category-theoretic semantics for the enriched effect calculus...

  8. Review of environmental enrichment for broiler chickens

    DEFF Research Database (Denmark)

    Riber, Anja Brinch; Van de Weerd, H.A.; de Jong, I.C.

    2018-01-01

    to improvements of the biological function. This definition has been broadened to include practical and economic aspects, as any enrichment strategy that adversely affects the health of animals or that has too many economic or practical constraints will never be implemented on commercial farms and thus never...... benefit animals. Environmental enrichment for broilers often has the purpose of satisfying behavioral needs and/or stimulating the broilers to an increased level of activity, which among others will reduce the occurrence of leg problems. Potentially successful environmental enrichments for broiler...... chickens are elevated resting-places, panels, barriers, and bales of straw (“point-source enrichment”), as well as covered verandas and outdoor ranges (“complex enriched environments”). Many of the ideas for environmental enrichment for broilers need to be further developed and studied, preferably...

  9. Current perspective of the uranium enrichment market

    International Nuclear Information System (INIS)

    Laughon, K.O.

    1986-01-01

    Over the past several years, developments in the uranium enrichment market have required the Department of Energy (DOE) to make a number of changes in the U.S. enrichment enterprise. These changes have been made to allow DOE to conduct our enrichment business so as to be more responsive to changing market forces. Needless to say, some of these changes have been difficult, but they have been necessary if they are to conduct a healthy and competitive uranium enrichment business in the United States. This paper discusses several topics, including: The Uranium Enrichment Market, Utility Services (US) Contracts, Reduced Prices, Incentive Pricing, Better Customer Services, and Advanced Technology. In addition to these topics, information is provided on the recent court action regarding the US Contracts and the viability finding on the uranium mining industry

  10. The low-enrichment fuel development program

    International Nuclear Information System (INIS)

    Stahl, D.

    1993-01-01

    In the 1950s and 1960s, low-power research reactors were built around the world utilized MTR-type fuel elements containing 20% enriched uranium. However, the demand for higher specific power created a need for greater uranium-235 concentrations. Early difficulties in increasing uranium content led to the substitution of highly enriched uranium in place of the 20% enriched fuel previously utilized. The highly enriched material also yielded other benefits including longer core residence time, higher specific reactivity, and somewhat lower cost. Highly enriched material then became readily available and was used for high-power reactors as well as in low-power reactors where 20% enriched material would have sufficed. The trend toward higher and higher specific power also led to the development of the dispersion-type fuels which utilized highly enriched uranium at a concentration of about 40 wt%. In the 1970's, however, concerns were raised about the proliferation resistance of fuels and fuel cycles. As a consequence, the U.S. Department of State has recently prohibited the foreign shipment of highly enriched material, except where prior contractual obligation or special merit exists. This will impact on the availability and utilization of highly enriched uranium for research and test reactor fuel. It has also stimulated development programs on fuels with higher uranium content which would allow the use of uranium of lower enrichment. The purpose of this report is to briefly describe the overall fuel-development program which is coordinated by Argonne National Laboratory for the Department of Energy, and to indicate the current and potential uranium loadings. Other reports will address the individual fuel-development activities in greater detail

  11. Multi-detector system approach for unattended uranium enrichment monitoring at gas centrifuge enrichment plants

    Science.gov (United States)

    Favalli, A.; Lombardi, M.; MacArthur, D. W.; McCluskey, C.; Moss, C. E.; Paffett, M. T.; Ianakiev, K. D.

    2018-01-01

    Improving the quality of safeguards measurements at Gas Centrifuge Enrichment Plants while reducing the inspection effort is an important objective given the number of existing and new plants that need to be safeguarded. A useful tool in many safeguards approaches is the on-line monitoring of enrichment in process pipes. One requirement of such a monitor is a simple, reliable and precise passive measurement of the 186-keV line from 235U. The other information required is the amount of gas in the pipe, which can be obtained by a transmission or pressure measurement. We describe our research to develop such a passive measurement system. Unfortunately, a complication arises in the interpretation of the gamma measurements, from the contribution of uranium deposits on the wall of the pipe to the 186-keV peak. A multi-detector approach to address this complication is presented where two measurements, one with signal primarily from gas and one with signal primarily from deposits, are performed simultaneously with different detectors and geometries. This allows a correction to be made to the 186-keV peak for the contribution from the deposit. We present the design of the multi-detector system and the results of the experimental calibration of the proof-of-principle prototype built at LANL.

  12. Multi-detector system approach for unattended uranium enrichment monitoring at gas centrifuge enrichment plants

    International Nuclear Information System (INIS)

    Favalli, A.; Lombardi, M.; MacArthur, D. W.; McCluskey, C.; Moss, C. E.

    2017-01-01

    Improving the quality of safeguards measurements at Gas Centrifuge Enrichment Plants while reducing the inspection effort is an important objective given the number of existing and new plants that need to be safeguarded. A useful tool in many safeguards approaches is the on-line monitoring of enrichment in process pipes. One requirement of such a monitor is a simple, reliable and precise passive measurement of the 186-keV line from 235 U. The other information required is the amount of gas in the pipe, which can be obtained by a transmission or pressure measurement. Here, we describe our research to develop such a passive measurement system. Unfortunately, a complication arises in the interpretation of the gamma measurements, from the contribution of uranium deposits on the wall of the pipe to the 186-keV peak. A multi-detector approach to address this complication is presented where two measurements, one with signal primarily from gas and one with signal primarily from deposits, are performed simultaneously with different detectors and geometries. This allows a correction to be made to the 186-keV peak for the contribution from the deposit. Finally, we present the design of the multi-detector system and the results of the experimental calibration of the proof-of-principle prototype built at LANL.

  13. Energies and media nr 32. Conditions for the nuclear sector. Uranium and its enrichment for EDF. The role of Russia

    International Nuclear Information System (INIS)

    2010-07-01

    After some comments on recent events in the nuclear sector in different countries (international conference, agreement between Rosatom and the IAEA, energy policy and projects in India, Turkey, Vietnam, France, Finland, UK, Sweden, USA, Germany), this publication discusses the uranium enrichment issue for EDF and the role of Russia. It refers to a report by the French High committee for transparency and information on nuclear safety (HCTISN) and to a hearing by the French Parliament. Different aspects are discussed: the national and international legal contexts and their relationship, the EDF reactor supply (enriched uranium of MOX, fixed elements in enrichment contracts, supply security), enrichment processes and installations (in France, natural uranium enrichment, use of reprocessed or recycle uranium, use of depleted uranium as a by-product of enrichment), how EDF and AREVA are working with Russia (enrichment of recycled uranium, use of depleted uranium)

  14. Enrichment Assay Methods Development for the Integrated Cylinder Verification System

    International Nuclear Information System (INIS)

    Smith, Leon E.; Misner, Alex C.; Hatchell, Brian K.; Curtis, Michael M.

    2009-01-01

    International Atomic Energy Agency (IAEA) inspectors currently perform periodic inspections at uranium enrichment plants to verify UF6 cylinder enrichment declarations. Measurements are typically performed with handheld high-resolution sensors on a sampling of cylinders taken to be representative of the facility's entire product-cylinder inventory. Pacific Northwest National Laboratory (PNNL) is developing a concept to automate the verification of enrichment plant cylinders to enable 100 percent product-cylinder verification and potentially, mass-balance calculations on the facility as a whole (by also measuring feed and tails cylinders). The Integrated Cylinder Verification System (ICVS) could be located at key measurement points to positively identify each cylinder, measure its mass and enrichment, store the collected data in a secure database, and maintain continuity of knowledge on measured cylinders until IAEA inspector arrival. The three main objectives of this FY09 project are summarized here and described in more detail in the report: (1) Develop a preliminary design for a prototype NDA system, (2) Refine PNNL's MCNP models of the NDA system, and (3) Procure and test key pulse-processing components. Progress against these tasks to date, and next steps, are discussed.

  15. Automated assay of uranium solution concentration and enrichment

    International Nuclear Information System (INIS)

    Horley, E.C.; Gainer, K.; Hansen, W.J.; Kelley, T.A.; Parker, J.L.; Sampson, T.E.; Walton, G.; Jones, S.A.

    1992-01-01

    For the first time, the concentration and enrichment of uranium solutions can be measured in one step. We have developed a new instrument to automatically measure the concentration and enrichment of uranium solutions through the adaptation of a commercial robot. Two identical solution enrichment systems are being installed in the Portsmouth Gaseous Diffusion Plant. These automated systems will reduce radiation exposure to personnel and increase the reliability and repeatability of the measurements. Each robotic system can process up to 40 batch and 8 priority samples in an unattended mode. Both passive gamma-ray and x-ray fluorescence (XRF) analyses are performed to determine total uranium concentration and 235 U enrichment. Coded samples are read by a bar-code reader to determine measurement requirements, then assayed by either or both of the gamma-ray and XRF instruments. The robot moves the sample containers and operates all shield doors and shutters, reducing hardware complexity. If the robots is out of service, an operator can manually perform all operations

  16. Enrichment Assay Methods Development for the Integrated Cylinder Verification System

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Leon E.; Misner, Alex C.; Hatchell, Brian K.; Curtis, Michael M.

    2009-10-22

    International Atomic Energy Agency (IAEA) inspectors currently perform periodic inspections at uranium enrichment plants to verify UF6 cylinder enrichment declarations. Measurements are typically performed with handheld high-resolution sensors on a sampling of cylinders taken to be representative of the facility's entire product-cylinder inventory. Pacific Northwest National Laboratory (PNNL) is developing a concept to automate the verification of enrichment plant cylinders to enable 100 percent product-cylinder verification and potentially, mass-balance calculations on the facility as a whole (by also measuring feed and tails cylinders). The Integrated Cylinder Verification System (ICVS) could be located at key measurement points to positively identify each cylinder, measure its mass and enrichment, store the collected data in a secure database, and maintain continuity of knowledge on measured cylinders until IAEA inspector arrival. The three main objectives of this FY09 project are summarized here and described in more detail in the report: (1) Develop a preliminary design for a prototype NDA system, (2) Refine PNNL's MCNP models of the NDA system, and (3) Procure and test key pulse-processing components. Progress against these tasks to date, and next steps, are discussed.

  17. Nuclear fuel cycle, nuclear fuel makes the rounds: choosing a closed fuel cycle, nuclear fuel cycle processes, front-end of the fuel cycle: from crude ore to enriched uranium, back-end of the fuel cycle: the second life of nuclear fuel, and tomorrow: multiple recycling while generating increasingly less waste

    International Nuclear Information System (INIS)

    Philippon, Patrick

    2016-01-01

    France has opted for a policy of processing and recycling spent fuel. This option has already been deployed commercially since the 1990's, but will reach its full potential with the fourth generation. The CEA developed the processes in use today, and is pursuing research to improve, extend, and adapt these technologies to tomorrow's challenges. France has opted for a 'closed cycle' to recycle the reusable materials in spent fuel (uranium and plutonium) and optimise ultimate waste management. France has opted for a 'closed' nuclear fuel cycle. Spent fuel is processed to recover the reusable materials: uranium and plutonium. The remaining components (fission products and minor actinides) are the ultimate waste. This info-graphic shows the main steps in the fuel cycle currently implemented commercially in France. From the mine to the reactor, a vast industrial system ensures the conversion of uranium contained in the ore to obtain uranium oxide (UOX) fuel pellets. Selective extraction, purification, enrichment - key scientific and technical challenges for the teams in the Nuclear Energy Division (DEN). The back-end stages of the fuel cycle for recycling the reusable materials in spent fuel and conditioning the final waste-forms have reached maturity. CEA teams are pursuing their research in support of industry to optimise these processes. Multi-recycle plutonium, make even better use of uranium resources and, over the longer term, explore the possibility of transmuting the most highly radioactive waste: these are the challenges facing future nuclear systems. (authors)

  18. Comparative Study of Green Sub- and Supercritical Processes to Obtain Carnosic Acid and Carnosol-Enriched Rosemary Extracts with in Vitro Anti-Proliferative Activity on Colon Cancer Cells

    Directory of Open Access Journals (Sweden)

    Andrea del Pilar Sánchez-Camargo

    2016-12-01

    Full Text Available In the present work, four green processes have been compared to evaluate their potential to obtain rosemary extracts with in vitro anti-proliferative activity against two colon cancer cell lines (HT-29 and HCT116. The processes, carried out under optimal conditions, were: (1 pressurized liquid extraction (PLE, using an hydroalcoholic mixture as solvent at lab-scale; (2 Single-step supercritical fluid extraction (SFE at pilot scale; (3 Intensified two-step sequential SFE at pilot scale; (4 Integrated PLE plus supercritical antisolvent fractionation (SAF at pilot scale. Although higher extraction yields were achieved by using PLE (38.46% dry weight, this extract provided the lowest anti-proliferative activity with no observed cytotoxic effects at the assayed concentrations. On the other hand, extracts obtained using the PLE + SAF process provided the most active rosemary extracts against both colon cancer cell lines, with LC50 ranging from 11.2 to 12.4 µg/mL and from 21.8 to 31.9 µg/mL for HCT116 and HT-29, respectively. In general, active rosemary extracts were characterized by containing carnosic acid (CA and carnosol (CS at concentrations above 263.7 and 33.9 mg/g extract, respectively. Some distinct compounds have been identified in the SAF extracts (rosmaridiphenol and safficinolide, suggesting their possible role as additional contributors to the observed strong anti-proliferative activity of CA and CS in SAF extracts.

  19. How can computers support, enrich, and transform collaborative creativity

    DEFF Research Database (Denmark)

    Dalsgaard, Peter; Inie, Nanna; Hansen, Nicolai Brodersen

    2017-01-01

    The aim of the workshop is to examine and discuss how computers can support, enrich, and transform collaborative creative processes. By exploring and combining methodological, theoretical, and design- oriented perspectives, we wish to examine the implications, potentials, and limitations of diffe......The aim of the workshop is to examine and discuss how computers can support, enrich, and transform collaborative creative processes. By exploring and combining methodological, theoretical, and design- oriented perspectives, we wish to examine the implications, potentials, and limitations...... of different approaches to providing digital support for collaborative creativity. Participation in the workshop requires participants to actively document and identify salient themes in one or more examples of computer- supported collaborative creativity, and the resulting material will serve as the empirical...

  20. Comments on applications of reduced enrichment fuels

    International Nuclear Information System (INIS)

    Winkler, M.H.

    1983-01-01

    Full text: I will briefly describe the experience gained using different fuels in the SAPHIR reactor in Switzerland. The SAPHIR has been operating since 1957 and was the first swimming pool reactor built outside of the United States, which was originally known as the Geneva Conference Reactor. The first core was loaded with 20 percent enriched high density UO 2 fuel with a density of about 2.5 grams per cc, fabricated in 1955 by Oak Ridge National Laboratory. After a few years of operation at a power level of one MW, more than one batch of the elements released small amounts of fission products mainly Xe and Kr. When these releases were discovered, high enriched fuel was becoming available so that the fuel fabricators began to produce the lower density high enriched fuels. During this transition from fabrication of low to high enriched fuels no one could foresee that the stone age of nuclear fuel fabrication would come back again. Therefore, we did not investigate the reasons for the fission product release from the high density low enriched UO 2 fuel. The second fuel type used in the SAPHIR was the 90 percent enriched low density U 3 O 8 fuel fabricated by NUKEM. This high enriched fuel has performed satisfactorily over the years. Since 1968, the core has been using improved 23 plate fuel elements with a loading of 280 grams of uranium. The reactor power has been recently increased to five MW. An additional increase in the power level to 10 MW is planned at the end of next year so that heavier loaded elements will be needed. In order to follow the recommendations of the INFCE working group 8C and in cooperation with the reduced enrichment program, we intend to initially reduce the fuel enrichment to 45 percent. Last year we ordered five fuel elements with a loading of 320 grams 235 U/element and 45 percent enrichment for full power tests. Unfortunately, the delivery of the necessary enriched fuel uranium has been delayed and it is not available at this time. If

  1. Enrichment of gadolinium-157 and gadolinium-155 by laser method

    International Nuclear Information System (INIS)

    Xinjun, Su; Xiaowei, Zhang; Zhiquan, Li

    2008-01-01

    Laser isotope separation experiments of gadolinium by atomic vapor method have been performed. Gadolinium-157 and gadolinium-155 were selectively photoionized by means of three linearly polarized dye lasers, the excitation process of which is based on the polarization selection rules. Gramme-magnitude of enriched gadolinium was obtained and the total abundance of gadolinium-157 and gadolinium-155 was in excess of 80%, and the product rating exceeded 200 mg/h. (author)

  2. Multinational uranium enrichment in the Middle East

    International Nuclear Information System (INIS)

    Ahmad, Ali; Salahieh, Sidra; Snyder, Ryan

    2017-01-01

    The Joint Comprehensive Plan of Action (JCPOA) agreed to by Iran and the P5+1 in July 2015 placed restrictions on Iran’s nuclear program while other Middle Eastern countries– Egypt, Jordan, Saudi Arabia, Turkey, and the United Arab Emirates–are planning to build their own nuclear power plants to meet increasing electricity demands. Although the JCPOA restricts Iran's uranium enrichment program for 10–15 years, Iran's neighbors may choose to develop their own national enrichment programs giving them a potential nuclear weapons capability. This paper argues that converting Iran's national enrichment program to a more proliferation-resistant multinational arrangement could offer significant economic benefits–reduced capital and operational costs–due to economies of scale and the utilization of more efficient enrichment technologies. In addition, the paper examines policy aspects related to financing, governance, and how multinational enrichment could fit into the political and security context of the Middle East. A multinational enrichment facility managed by regional and international partners would provide more assurance that it remains peaceful and could help build confidence between Iran and its neighbors to cooperate in managing other regional security challenges. - Highlights: • Freezing Iran's nuclear program is an opportunity to launch joint initiatives in ME. • A joint uranium enrichment program in the Middle East offers economic benefits. • Other benefits include improved nuclear security and transparency in the region.

  3. Enrichment of Acinetobacter spp. from food samples.

    Science.gov (United States)

    Carvalheira, Ana; Ferreira, Vânia; Silva, Joana; Teixeira, Paula

    2016-05-01

    Relatively little is known about the role of foods in the chain of transmission of acinetobacters and the occurrence of different Acinetobacter spp. in foods. Currently, there is no standard procedure to recover acinetobacters from food in order to gain insight into the food-related ecology and epidemiology of acinetobacters. This study aimed to assess whether enrichment in Dijkshoorn enrichment medium followed by plating in CHROMagar™ Acinetobacter medium is a useful method for the isolation of Acinetobacter spp. from foods. Recovery of six Acinetobacter species from food spiked with these organisms was compared for two selective enrichment media (Baumann's enrichment and Dijkshoorn's enrichment). Significantly (p enrichment. Next, the Dijkshoorn's enrichment followed by direct plating on CHROMagar™ Acinetobacter was applied to detect Acinetobacter spp. in different foods. Fourteen different presumptive acinetobacters were recovered and assumed to represent nine different strains on the basis of REP-PCR typing. Eight of these strains were identified by rpoB gene analysis as belonging to the species Acinetobacter johnsonii, Acinetobacter calcoaceticus, Acinetobacter guillouiae and Acinetobacter gandensis. It was not possible to identify the species level of one strain which may suggests that it represents a distinct species. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Review of environmental enrichment for broiler chickens.

    Science.gov (United States)

    Riber, A B; van de Weerd, H A; de Jong, I C; Steenfeldt, S

    2018-02-01

    Welfare problems are commonly found in both conventional and organic production of broiler chickens. In order to reduce the extent of welfare problems, it has been suggested to provide stimulating, enriched environments. The aim of the present paper is to provide a review of the effect on behavior and welfare of the different kinds of environmental enrichments in the production of broilers that have been described in the scientific literature. Environmental enrichment is defined as an improvement of the environment of captive animals, which increases the behavioral opportunities of the animal and leads to improvements of the biological function. This definition has been broadened to include practical and economic aspects, as any enrichment strategy that adversely affects the health of animals or that has too many economic or practical constraints will never be implemented on commercial farms and thus never benefit animals. Environmental enrichment for broilers often has the purpose of satisfying behavioral needs and/or stimulating the broilers to an increased level of activity, which among others will reduce the occurrence of leg problems. Potentially successful environmental enrichments for broiler chickens are elevated resting-places, panels, barriers, and bales of straw ("point-source enrichment"), as well as covered verandas and outdoor ranges ("complex enriched environments"). Many of the ideas for environmental enrichment for broilers need to be further developed and studied, preferably in commercial trials, with respect to the use, the effect on behavior and on other welfare aspects such as leg health, and the interaction with genotype, production system, stocking density, light, and flock size. In addition, information on the practical application and the economics of the production system is often lacking, although it is important for application in practice. © 2017 Poultry Science Association Inc.

  5. Enrichment behavior and transport mechanism of soil-bound PAHs during rainfall-runoff events

    International Nuclear Information System (INIS)

    Zheng Yi; Luo Xiaolin; Zhang Wei; Wu Bin; Han Feng; Lin Zhongrong; Wang Xuejun

    2012-01-01

    Polycyclic Aromatic Hydrocarbons (PAHs) transported by surface runoff result in nonpoint source pollution and jeopardize aquatic ecosystems. The transport mechanism of PAHs during rainfall-runoff events has been rarely studied regarding pervious areas. An experimental system was setup to simulate the runoff pollution process on PAHs-contaminated soil. The enrichment behavior of soil-bound PAHs was investigated. The results show that soil organic matters (SOM), rather than clay particles, seem to be the main carrier of PAHs. The enrichment is highly conditioned on runoff and erosion processes, and its magnitude varies among PAH compounds. It is not feasible to build a simple and universal relationship between enrichment ratio and sediment discharge following the traditional enrichment theory. To estimate the flux of PAHs from pervious areas, soil erosion process has to be clearly understood, and both organic carbon content and composition of SOM should be factored into the calculation. - Highlights: ► Significant enrichment of particle-bound PAHs during rainfall-runoff events. ► Organic matters as the direct carrier of PAHs in runoff from contaminated soil. ► The traditional enrichment theory is not fully valid for PAHs. - The traditional enrichment theory is not fully valid for PAHs, and soil organic matters have a significant impact on the transport of PAHs during rainfall-runoff events.

  6. Low enrichment Mo-99 target development program at ANSTO

    International Nuclear Information System (INIS)

    Donlevy, Therese M.; Anderson, Peter J.; Beattie, David; Braddock, Ben; Fulton, Scott; Godfrey, Robert; Law, Russell; McNiven, Scott; Sirkka, Pertti; Storr, Greg; Wassink, David; Wong, Alan; Yeoh, Guan

    2002-01-01

    The Australian Nuclear Science and Technology Organisation (ANSTO, formerly AAEC) has been producing fission product Mo-99 in HIFAR, from the irradiation of Low Enrichment Uranium (LEU) UO 2 targets, for nearly thirty years. Over this period, the U-235 enrichment has been increased in stages, from natural to 1.8% to 2.2%. The decision to provide Australia with a replacement research reactor (RRR) for HIFAR has created an ideal opportunity to review and improve the current Mo-99 production process from target design through to chemical processing and waste management options. ANSTO has entered into a collaboration with Argonne National Laboratory (RERTR) to develop a target using uranium metal foil with U-235 enrichment of less than 20% The initial focus has been to demonstrate use of LEU foil targets in HIFAR, using existing irradiation methodology. The current effort focussed on designing a target assembly with optimised thermohydraulic characteristics to accommodate larger LEU foils to meet Mo-99 production needs. The ultimate goal is to produce an LEU target suitable for use in the Replacement Research Reactor when it is commissioned in 2005. This paper reports our activities on: - The regulatory approval processes required in order to undertake irradiation of this new target; -Supporting calculations (neutronics, computational fluid dynamics) for safety submission; - Design challenges and changes to prototype irradiation; - Trial irradiation of LEU foil target in HIFAR; - Future target and rig development program at ANSTO. (author)

  7. Safeguarding uranium enrichment facilities. Review and analysis of the status of safeguards technology for uranium enrichment facilities

    International Nuclear Information System (INIS)

    1977-09-01

    The objective of this paper is to examine critically the diversion potential at uranium enrichment facilities and to outline a basic safeguards strategy which counters all identified hazards as completely as possible yet with a minimum of non-essential redundancy. Where existing technology does not appear to be adequate for effective safeguards, the limitations are examined, and suggestions for further R and D effort are made. Parts of this report are generally applicable to all currently known enrichment processes, while other parts are specifically directed toward facilities based on the gas centrifuge process. It is hoped that additional sections discussing a safeguards strategy for gas diffusion facilities can be added later. It should be emphasized that this is a technical report, and does not reflect any legal positions. The safeguards strategy and subsequent inspection procedures are intended as guidelines, not as negotiating positions

  8. Device for the enrichment of uranium isotopes according to the nozzle enrichment process

    International Nuclear Information System (INIS)

    Wenzel, W.

    1979-01-01

    The individual units consisting of separating elements are combined each with their heat exchangers, forming a cascade stage. These cascade stages on the other hand form sections, bounded by diametrically running partition walls in a cylindrical vessel. Below the vessel there are the compressors. The horizontal vessel is carried at the ends by shield or shell-type supports. The cooling performed by means of the heat exchangers is constructionally simplified in such a way that there are applied straight tubes passing through all of the sections, i.e. through the partitions, too. This is why there may be worked with only one single distributing chamber and one single accumulator. (DG) [de

  9. Development of low enriched uranium target plates by thermo-mechanical processing of UAl{sub 2}–Al matrix for production of {sup 99}Mo in Pakistan

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Kanwar Liaqat; Khan, Akhlaque Ahmad [Pakistan Institute of Nuclear Science and Technology (PINSTECH) P.O Nilore, Islamabad (Pakistan); Mushtaq, Ahmad, E-mail: amushtaq1@hotmail.com [Pakistan Institute of Nuclear Science and Technology (PINSTECH) P.O Nilore, Islamabad (Pakistan); Imtiaz, Farhan; Ziai, Maratab Ali; Gulzar, Amir; Farooq, Muhammad; Hussain, Nazar; Ahmed, Nisar; Pervez, Shahid; Zaidi, Jamshed Hussain [Pakistan Institute of Nuclear Science and Technology (PINSTECH) P.O Nilore, Islamabad (Pakistan)

    2013-02-15

    Uranium aluminide predominated with UAl{sub 2} phase was prepared by arc-melting procedures and comminuted to required particle size. UAl{sub 2} and Al powders were blended and compacted to achieve LEU fuel density of 2.17 g/cm{sup 3}. The picture-frame technique was used to clad the dispersions (UAl{sub 2}–Al) with aluminum. A few target plates were fabricated by thermo-mechanical processing (hot rolling and annealing) of UAl{sub 2}–Al matrix contained in roll billet of Al. The fabricated plates were characterized by destructive and some of non-destructive testing techniques and then annealed to achieve required phase of uranium aluminide for proper dissolution in basic media.

  10. Status of stable isotope enrichment, products, and services at the Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Aaron, W.S.; Tracy, J.G.; Collins, E.D.

    1997-01-01

    The Oak Ridge national laboratory (ORNL) has been supplying enriched stable and radioactive isotopes to the research, medical, and industrial communities for over 50 y. Very significant changes have occurred in this effort over the past several years, and, while many of these changes have had a negative impact on the availability of enriched isotopes, more recent developments are actually improving the situation for both the users and the producers of enriched isotopes. ORNL is still a major producer and distributor of radioisotopes, but future isotope enrichment operations to be conducted at the isotope enrichment facility (IEF)fwill be limited to stable isotopes. Among the positive changes in the enriched stable isotope area are a well-functioning, long-term contract program, which offers stability and pricing advantages; the resumption of calutron operations; the adoption of prorated conversion charges, which greatly improves the pricing of isotopes to small users; ISO 9002 registration of the IEF's quality management system; and a much more customer-oriented business philosophy. Efforts are also being made to restore and improve upon the extensive chemical and physical form processing capablities that once existed in the enriched stable isotope program. Innovative ideas are being pursued in both technical and administrative areas to encourage the beneficial use of enriched stable isotopes and the development of related technologies. (orig.)

  11. Status of stable isotope enrichment, products, and services at the Oak Ridge National Laboratory

    Science.gov (United States)

    Scott Aaron, W.; Tracy, Joe G.; Collins, Emory D.

    1997-02-01

    The Oak Ridge National Laboratory (ORNL) has been supplying enriched stable and radioactive isotopes to the research, medical, and industrial communities for over 50 y. Very significant changes have occurred in this effort over the past several years, and, while many of these changes have had a negative impact on the availability of enriched isotopes, more recent developments are actually improving the situation for both the users and the producers of enriched isotopes. ORNL is still a major producer and distributor of radioisotopes, but future isotope enrichment operations to be conducted at the Isotope Enrichment Facility (IEF) will be limited to stable isotopes. Among the positive changes in the enriched stable isotope area are a well-functioning, long-term contract program, which offers stability and pricing advantages; the resumption of calutron operations; the adoption of prorated conversion charges, which greatly improves the pricing of isotopes to small users; ISO 9002 registration of the IEF's quality management system; and a much more customer-oriented business philosophy. Efforts are also being made to restore and improve upon the extensive chemical and physical form processing capablities that once existed in the enriched stable isotope program. Innovative ideas are being pursued in both technical and administrative areas to encourage the beneficial use of enriched stable isotopes and the development of related technologies.

  12. Study on behaviors and performances of universal N-glycopeptide enrichment methods.

    Science.gov (United States)

    Xue, Yu; Xie, Juanjuan; Fang, Pan; Yao, Jun; Yan, Guoquan; Shen, Huali; Yang, Pengyuan

    2018-04-16

    Glycosylation is a crucial process in protein biosynthesis. However, the analysis of glycopeptides through MS remains challenging due to the microheterogeneity and macroheterogeneity of the glycoprotein. Selective enrichment of glycopeptides from complex samples prior to MS analysis is essential for successful glycoproteome research. In this work, we systematically investigated the behaviors and performances of boronic acid chemistry, ZIC-HILIC, and PGC of glycopeptide enrichment to promote understanding of these methods. We also optimized boronic acid chemistry and ZIC-HILIC enrichment methods and applied them to enrich glycopeptides from mouse liver. The intact N-glycopeptides were interpreted using the in-house analysis software pGlyco 2.0. We found that boronic acid chemistry in this study preferred to capture glycopeptides with high mannose glycans, ZIC-HILIC enriched most N-glycopeptides and did not show significant preference during enrichment and PGC was not suitable for separating glycopeptides with a long amino acid sequence. We performed a detailed study on the behaviors and performances of boronic acid chemistry, ZIC-HILIC, and PGC enrichment methods and provide a better understanding of enrichment methods for further glycoproteomics research.

  13. Status of stable isotope enrichment, products, and services at the Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Aaron, W.S.; Tracy, J.G.; Collins, E.D.

    1996-01-01

    The Oak Ridge National Laboratory (ORNL) has been supplying enriched stable and radioactive isotopes to the research, medical, and industrial communities for over 50 years. Very significant changes have occurred in this effort over the past several years, and, while many of these changes have had a negative impact on the availability of enriched isotopes, more recent developments are actually improving the situation for both the users and the producers of enriched isotopes. ORNL is still a major producer and distributor of radioisotopes, but future isotope enrichment operations conducted at the Isotope Enrichment Facility (IEF) will be limited to stable isotopes. Among the positive changes in the enriched stable isotope area are a well-functioning, long-term contract program, which offers stability and pricing advantages; the resumption of calutron operations; the adoption of prorated conversion charges, which greatly improves the pricing of isotopes to small users; SIO 9002 registration of the IEF's quality management system; and a much more customer-oriented business philosophy. Efforts are also being made to restore and improve upon the extensive chemical and physical form processing capabilities that once existed in the enriched stable isotope program. Innovative ideas are being pursued in both technical and administrative areas to encourage the beneficial use of enriched stable isotopes and the development of related technologies

  14. Enrichment behavior and transport mechanism of soil-bound PAHs during rainfall-runoff events.

    Science.gov (United States)

    Zheng, Yi; Luo, Xiaolin; Zhang, Wei; Wu, Bin; Han, Feng; Lin, Zhongrong; Wang, Xuejun

    2012-12-01

    Polycyclic Aromatic Hydrocarbons (PAHs) transported by surface runoff result in nonpoint source pollution and jeopardize aquatic ecosystems. The transport mechanism of PAHs during rainfall-runoff events has been rarely studied regarding pervious areas. An experimental system was setup to simulate the runoff pollution process on PAHs-contaminated soil. The enrichment behavior of soil-bound PAHs was investigated. The results show that soil organic matters (SOM), rather than clay particles, seem to be the main carrier of PAHs. The enrichment is highly conditioned on runoff and erosion processes, and its magnitude varies among PAH compounds. It is not feasible to build a simple and universal relationship between enrichment ratio and sediment discharge following the traditional enrichment theory. To estimate the flux of PAHs from pervious areas, soil erosion process has to be clearly understood, and both organic carbon content and composition of SOM should be factored into the calculation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Centrifugation. A theoretical study of oxygen enrichment by centrifugation

    Energy Technology Data Exchange (ETDEWEB)

    Kierkegaard, P.; Raetz, E.

    1998-12-01

    In the present paper we first investigate what happens if we fill a cylinder with air, close it and rotate it. The results show that no matter which peripheral speed is used, it is not possible by means of the radial separation effect alone, to enrich the oxygen concentration from the previous 21% to more then 23.3%, which is of no practical value. In case of a too low enrichment in one centrifuge, the wanted material from this centrifuge can be used as an input for a second centrifuge and so on, in this way forming a cascade of centrifuges. Oxygen will be enriched in each step, until the desired concentration is reached. Cascading was the technology in the very beginning by enrichment plants for uraniumhexaflouride, used for atomic weapons and nuclear power plants. In this study we try to avoid cascading by aiming for higher separation factors. Therefore, we next investigate the possibilities of using a countercurrent centrifuge where in principle the enriched gas is subjected to several centrifugation in the same centrifuge. The calculations show, that in this way it is possible to produce nearly a 100% pure oxygen (polluted with some heavier molecules like argon) in one machine. Our third step was to calculate the amount of oxygen produced per hour. Using a countercurrent centrifuge of the Zippe type, 100 cm high and 20 cm in diameter, it is or will be possible in the near future to produce 17 g enriched air per hour enriched to 50% oxygen. That corresponds to processing 1 m{sup 3} atmospherical air in the period of approximately 24 hours. This is not very impressive. Our fourth step was to estimate the amount of power used for producing this amount of oxygen. A rough, but complicated, estimate shows that the power consumption at the production level will be about the double of the consumption used today. The overall conclusion is, that centrifugation as a production method for oxygen (or nitrogen) will not be competitive with the currently used method in the

  16. Laser Isotope Enrichment for Medical and Industrial Applications

    Energy Technology Data Exchange (ETDEWEB)

    Leonard Bond

    2006-07-01

    repression. In this scheme a gas, of the selected isotopes for enrichment, is irradiated with a laser at a particular wavelength that would excite only one of the isotopes. The entire gas is subject to low temperatures sufficient to cause condensation on a cold surface. Those molecules in the gas that the laser excited are not as likely to condense as are the unexcited molecules. Hence the gas drawn out of the system will be enriched in the isotope that was excited by the laser. We have evaluated the relative energy required in this process if applied on a commercial scale. We estimate the energy required for laser isotope enrichment is about 20% of that required in centrifuge separations, and 2% of that required by use of "calutrons".

  17. Laser Isotope Enrichment for Medical and Industrial Applications

    International Nuclear Information System (INIS)

    Leonard Bond

    2006-01-01

    repression. In this scheme a gas, of the selected isotopes for enrichment, is irradiated with a laser at a particular wavelength that would excite only one of the isotopes. The entire gas is subject to low temperatures sufficient to cause condensation on a cold surface. Those molecules in the gas that the laser excited are not as likely to condense as are the unexcited molecules. Hence the gas drawn out of the system will be enriched in the isotope that was excited by the laser. We have evaluated the relative energy required in this process if applied on a commercial scale. We estimate the energy required for laser isotope enrichment is about 20% of that required in centrifuge separations, and 2% of that required by use of ''calutrons''

  18. Calculated NWIS signatures for enriched uranium metal

    International Nuclear Information System (INIS)

    Valentine, T.E.; Mihalczo, J.T.; Koehler, P.E.

    1995-01-01

    Nuclear Weapons Identification System (NWIS) signatures have been calculated using a Monte Carlo transport code for measurement configurations of a 252 Cf source, detectors, and a uranium metal casting. NWIS signatures consist of a wide variety of time-and frequency-analysis signatures such as the time distribution of neutrons after californium fission, the time distribution of counts in a detector after a previous count, the number of times n pulses occur in a time interval, and various frequency-analysis signatures, such as auto-power and cross-power spectral densities, coherences, and a ratio of spectral densities. This ratio is independent of detection efficiency. The analysis presented here, using the MCNP-DSP code, evaluates the applicability of this method for measurement of the 235 U content of 19-kg castings of depleted uranium and uranium with enrichments of 20, 40, 60, 80, 90, and 93.2 wt % 235 U. The dependence of the wide variety of NWIS signatures on 235 U content and possible configurations of a measurement system are presented. These preliminary calculations indicate short measurement times. Additional calculations are being performed to optimize the source-detector-moderator-casting configuration for the shortest measurement time. Although the NWIS method was developed for nuclear weapons identification, the development of a small processor now allows it to be also applied in a practical way to subcriticality measurements, nuclear fuel process monitoring and qualitative nondestructive assay of special nuclear material

  19. 76 FR 34103 - In the Matter of Areva Enrichment Services, LLC (Eagle Rock Enrichment Facility); Notice of...

    Science.gov (United States)

    2011-06-10

    .... 10-899-02-ML-BD01] In the Matter of Areva Enrichment Services, LLC (Eagle Rock Enrichment Facility...'' portion of this proceeding regarding the December 2008 application by AREVA Enrichment Services, LLC (AES... gas centrifuge uranium enrichment facility--denoted as the Eagle Rock Enrichment Facility (EREF)--in...

  20. A Guide to Job Enrichment and Redesign.

    Science.gov (United States)

    Cunningham, J. Barton; Eberle, Ted

    1990-01-01

    Describes job design alternatives--job enrichment, the job characteristics model, Japanese style management, and quality-of-worklife approaches. Focuses on the problems that human resources professionals may encounter when attempting to implement these approaches. (Author/JOW)

  1. Mercury enrichment in sediments of Amba estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Ram, A.; Rokade, M.A.; Zingde, M.D.

    of anthropogenic metal to the estuary. Geoaccumulation index and enrichment factor support Hg contamination of the estuarine sediment to a varying degree. Hg is not significantly correlated with TOC, Al, Fe and Mn in these sediments...

  2. Safety criteria of uranium enrichment plants

    International Nuclear Information System (INIS)

    Nardocci, A.C.; Oliveira Neto, J.M. de

    1994-01-01

    The applicability of nuclear reactor safety criteria applied to uranium enrichment plants is discussed, and a new criterion based on the soluble uranium compounds and hexafluoride chemical toxicities is presented. (L.C.J.A.). 21 refs, 4 tabs

  3. Management's Ecstasy and Disparity Over Job Enrichment

    Science.gov (United States)

    King, Albert S.

    1976-01-01

    A case study analyzing job enrichment schemes and manager expectations of increased productivity is presented. It was found that it was the managers' expectations of increased productivity, not the reorganization of work, that led to higher productivity. (EC)

  4. (+)- 10-camphorsulfonic acid and enrichment of enantiomeric

    Indian Academy of Sciences (India)

    WINTEC

    . The partially resolved enriched sample of (S,S)-(–)-2,3-diphenylpiperazine with 73% ee was purified to obtain samples of 97% ee using different achiral acids via the preparation of either homochiral or heterochiral hydrogen bonded.

  5. Unattended Monitoring of HEU Production in Gaseous Centrifuge Enrichment Plants using Automated Aerosol Collection and Laser-based Enrichment Assay

    International Nuclear Information System (INIS)

    Anheier, Norman C.; Bushaw, Bruce A.

    2010-01-01

    Nuclear power is enjoying rapid growth as government energy policies and public demand shift toward low carbon energy production. Pivotal to the global nuclear power renaissance is the development and deployment of robust safeguards instrumentation that allows the limited resources of the IAEA to keep pace with the expansion of the nuclear fuel cycle. Undeclared production of highly enriched uranium (HEU) remains a primary proliferation concern for modern gaseous centrifuge enrichment plants (GCEPs), due to their massive separative work unit (SWU) processing power and comparably short cascade equilibrium timescale. The Pacific Northwest National Laboratory is developing an unattended safeguards instrument, combining continuous aerosol particulate collection with uranium isotope assay, to provide timely detection of HEU production within a GCEP. This approach is based on laser vaporization of aerosol particulates, followed by laser spectroscopy to characterize the uranium enrichment level. Our prior investigation demonstrated single-shot detection sensitivity approaching the femtogram range and relative isotope ratio uncertainty better than 10% using gadolinium as a surrogate for uranium. In this paper we present measurement results on standard samples containing traces of depleted, natural, and low enriched uranium, as well as measurements on aerodynamic size uranium particles mixed in background materials (e.g., dust, minerals, soils). Improvements and optimizations in the detection electronics, signal timing, calibration, and laser alignment have lead to significant improvements in detection sensitivity and enrichment accuracy, contributing to an overall reduction in the false alarm probability. The sample substrate media was also found to play a significant role in facilitating laser-induced vaporization and the production of energetic plasma conditions, resulting in ablation optimization and further improvements in the isotope abundance sensitivity.

  6. Comparative proteomic assessment of matrisome enrichment methodologies

    Science.gov (United States)

    Krasny, Lukas; Paul, Angela; Wai, Patty; Howard, Beatrice A.; Natrajan, Rachael C.; Huang, Paul H.

    2016-01-01

    The matrisome is a complex and heterogeneous collection of extracellular matrix (ECM) and ECM-associated proteins that play important roles in tissue development and homeostasis. While several strategies for matrisome enrichment have been developed, it is currently unknown how the performance of these different methodologies compares in the proteomic identification of matrisome components across multiple tissue types. In the present study, we perform a comparative proteomic assessment of two widely used decellularisation protocols and two extraction methods to characterise the matrisome in four murine organs (heart, mammary gland, lung and liver). We undertook a systematic evaluation of the performance of the individual methods on protein yield, matrisome enrichment capability and the ability to isolate core matrisome and matrisome-associated components. Our data find that sodium dodecyl sulphate (SDS) decellularisation leads to the highest matrisome enrichment efficiency, while the extraction protocol that comprises chemical and trypsin digestion of the ECM fraction consistently identifies the highest number of matrisomal proteins across all types of tissue examined. Matrisome enrichment had a clear benefit over non-enriched tissue for the comprehensive identification of matrisomal components in murine liver and heart. Strikingly, we find that all four matrisome enrichment methods led to significant losses in the soluble matrisome-associated proteins across all organs. Our findings highlight the multiple factors (including tissue type, matrisome class of interest and desired enrichment purity) that influence the choice of enrichment methodology, and we anticipate that these data will serve as a useful guide for the design of future proteomic studies of the matrisome. PMID:27589945

  7. Modeling of Transients in an Enrichment Circuit

    International Nuclear Information System (INIS)

    Fernandino, Maria; Delmastro, Dario; Brasnarof, Daniel

    2003-01-01

    In the present work a mathematical model is presented in order to describe the dynamic behavior inside a closed enrichment loop, the latter representing a single stage of an uranium gaseous diffusion enrichment cascade.The analytical model is turned into a numerical model, and implemented through a computational code.Transients of two species separation were numerically analyzed, including setting times of each magnitude, behavior of each one of them during different transients, and redistribution of concentrations along the closed loop

  8. A Resolution of the Paradox of Enrichment

    OpenAIRE

    Feng, Z. C.; Li, Y. Charles

    2011-01-01

    The paradox of enrichment was observed by M. Rosenzweig in a class of predator-prey models. Two of the parameters in the models are crucial for the paradox. These two parameters are the prey's carrying capacity and prey's half-saturation for predation. Intuitively, increasing the carrying capacity due to enrichment of the prey's environment should lead to a more stable predator-prey system. Analytically, it turns out that increasing the carrying capacity always leads to an unstable predator-p...

  9. Reducing enrichment of fuel for research reactors

    International Nuclear Information System (INIS)

    Kanda, Keiji; Matsuura, Shojiro.

    1980-01-01

    In research reactors, highly enriched uranium (HEU) is used as fuel for their purposes of operation. However, the United States strongly required in 1977 that these HEU should be replaced by low enrichment uranium (LEU) of 20% or less, or even in unavoidable cases, it should be replaced by medium enrichment uranium (MEU). INFCE (International Nuclear Fuel Cycle Evaluation) which started its activity just at that time decided to discuss this problem in the research reactor group of No. 8 sectional committee. Japan has been able to forward the work, taking a leading part in the international opinion because she has taken the countermeasures quickly. INFCE investigated the problem along the lines of policy that the possibility of reducing the degree of enrichment should be limited to the degree in which the core structures and equipments of research reactors will be modified as little as possible, and the change of fuel element geometry will be done within the permissible thermohydrodynamic capacity, and concluded that it might be possible in near future to reduce the degree of enrichment to about 45% MEU, while the reduction to 20% LEU might require considerable research, development and verification. On the other hand, the joint researches by Kyoto University and ANL (Argonne National Laboratory) and by Japan Atomic Energy Research Institute and ANL are being continued. IAEA has edited the guidebook (IAEA-TECDOC-233) for reducing the degree of enrichment for developing countries. (Wakatsuki, Y.)

  10. Environmental enrichment choices of shelter cats.

    Science.gov (United States)

    Ellis, J J; Stryhn, H; Spears, J; Cockram, M S

    2017-08-01

    Choices made by cats between different types of environmental enrichment may help shelters to prioritize how to most effectively enrich cat housing, especially when limited by space or funds. This study investigates the environmental enrichment use of cats in a choice test. Twenty-six shelter cats were kept singularly in choice chambers for 10days. Each chamber had a central area and four centrally-linked compartments containing different types of environmental enrichment: 1) an empty control, 2) a prey-simulating toy, 3) a perching opportunity, and 4) a hiding opportunity. Cat movement between compartments was quantitatively recorded using a data-logger. Enriched compartments were visited significantly more frequently during the light period than during the dark period. Cats spent a significantly greater percentage of time in the hiding compartment (median=55%, IQR=46) than in the toy compartment (median=2%, IQR=9), or in the empty control compartment (median=4%, IQR=4). These results provide additional evidence to support the value of a hiding box to cats housed in a novel environment, in that they choose hiding relative to other types of environmental enrichment. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Toward a predictive theory for environmental enrichment.

    Science.gov (United States)

    Watters, Jason V

    2009-11-01

    There have been many applications of and successes with environmental enrichment for captive animals. The theoretical spine upon which much enrichment work hangs largely describes why enrichment should work. Yet, there remains no clear understanding of how enrichment should be applied to achieve the most beneficial results. This lack of understanding may stem in part from the assumptions that underlie the application of enrichment by practitioners. These assumptions are derived from an understanding that giving animals choice and control in their environment stimulates their motivation to perform behaviors that may indicate a heightened state of well-being. Learning theory provides a means to question the manner in which these constructs are routinely applied, and converting learning theory's findings to optimality predictions suggests a particularly vexing paradox-that motivation to perform appears to be maintained best when acquiring a payoff for expressing the behavior is uncertain. This effect occurs even when the actual value of the payoff is the same for all schedules of certainty of payoff acquisition. The paradox can be resolved by invoking rewards of an alternative type, such as cognitive rewards, or through an understanding of how the average payoff changes with changes in the probability of reward. This model, with measures of the average change of the payoff, suggests testable scenarios by which practitioners can measure the quality of environmental uncertainty in enrichment programs.

  12. Enriching text with images and colored light

    Science.gov (United States)

    Sekulovski, Dragan; Geleijnse, Gijs; Kater, Bram; Korst, Jan; Pauws, Steffen; Clout, Ramon

    2008-01-01

    We present an unsupervised method to enrich textual applications with relevant images and colors. The images are collected by querying large image repositories and subsequently the colors are computed using image processing. A prototype system based on this method is presented where the method is applied to song lyrics. In combination with a lyrics synchronization algorithm the system produces a rich multimedia experience. In order to identify terms within the text that may be associated with images and colors, we select noun phrases using a part of speech tagger. Large image repositories are queried with these terms. Per term representative colors are extracted using the collected images. Hereto, we either use a histogram-based or a mean shift-based algorithm. The representative color extraction uses the non-uniform distribution of the colors found in the large repositories. The images that are ranked best by the search engine are displayed on a screen, while the extracted representative colors are rendered on controllable lighting devices in the living room. We evaluate our method by comparing the computed colors to standard color representations of a set of English color terms. A second evaluation focuses on the distance in color between a queried term in English and its translation in a foreign language. Based on results from three sets of terms, a measure of suitability of a term for color extraction based on KL Divergence is proposed. Finally, we compare the performance of the algorithm using either the automatically indexed repository of Google Images and the manually annotated Flickr.com. Based on the results of these experiments, we conclude that using the presented method we can compute the relevant color for a term using a large image repository and image processing.

  13. Techno-Economic Analysis of a 600 MW Oxy-Enrich Pulverized Coal-Fired Boiler

    Directory of Open Access Journals (Sweden)

    Ming Lei

    2018-03-01

    Full Text Available Oxy-fuel combustion is one of the most promising methods for CO2 capture and storage (CCS but the operating costs—mainly due to the need for oxygen production—usually lead to an obvious decrease in power generation efficiency. An “oxy-enrich combustion” process was proposed in this study to improve the efficiency of the oxy-fuel combustion process. The oxidizer for oxy-enrich combustion was composed of pure oxygen, air and recycled flue gas. Thus, the CO2 concentration in the flue gas decreased to 30–40%. The PSA (pressure swing adsorption, which has been widely used for CO2 removal from the shifting gases of ammonia synthesis in China, was applied to capture CO2 during oxy-enrich combustion. The technological economics of oxy-enrich combustion with PSA was calculated and compared to that of oxy-fuel combustion. The results indicated that, compared with oxy-fuel combustion: (1 the oxy-enrich combustion has fewer capital and operating costs for the ASU (air separation unit and the recycle fan; (2 there were fewer changes in the components of the flue gas in a furnace for oxy-enrich combustion between dry and wet flue gas circulation; and (3 as the volume ratio of air and oxygen was 2 or 3, the economics of oxy-enrich combustion with PSA were more advantageous.

  14. Standard specification for uranium hexafluoride enriched to less than 5 % 235U

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This specification covers nuclear grade uranium hexafluoride (UF6) that either has been processed through an enrichment plant, or has been produced by the blending of Highly Enriched Uranium with other uranium to obtain uranium of any 235U concentration below 5 % and that is intended for fuel fabrication. The objectives of this specification are twofold: (1) To define the impurity and uranium isotope limits for Enriched Commercial Grade UF6 so that, with respect to fuel design and manufacture, it is essentially equivalent to enriched uranium made from natural UF6; and (2) To define limits for Enriched Reprocessed UF6 to be expected if Reprocessed UF6 is to be enriched without dilution with Commercial Natural UF6. For such UF6, special provisions, not defined herein, may be needed to ensure fuel performance and to protect the work force, process equipment, and the environment. 1.2 This specification is intended to provide the nuclear industry with a standard for enriched UF6 that is to be used in the pro...

  15. The Metal-Enriched Environments of Galaxies Near Reionization

    Science.gov (United States)

    Becker, George

    2016-10-01

    The relationship between galaxies and extended metal-enriched gas offers a powerful diagnostic of the feedback processes that shape galaxy growth. Over 0 6; to date, however, little work on the galaxy-absorber connection at these redshifts has been done due to the high cost of identifying the galaxies. To overcome this obstacle, we propose to obtain deep ACS and WFC3 imaging-building on archival data-in the field of a single z=7 quasar whose spectrum contains an unusually high number of intervening absorbers over 5.5 systems systems simultaneously, offering a high multiplexing advantage for follow-up spectroscopy. The extent to which z 6 galaxies are (or are not) associated with these metal lines, and the relationship between absorber and galaxy properties will deliver much needed insights into the mechanisms that drive galaxy growth and metal enrichment during the reionization epoch.

  16. Comments on proposed legislation to restructure DOE's uranium enrichment program

    International Nuclear Information System (INIS)

    1991-04-01

    This book focuses on H.R.145, H.R.788, and S.210. Each of the proposed bills would restructure DOE's enrichment program as a government corporation with private financing and would encourage the eventual sale of the corporation to the private sector. In doing so, the bills would, among other things, allow the corporation to set prices to maximize long-term returns; establish a fund to meet the costs of decontamination, decommissioning, and other environmental cleanup costs associated with uranium enrichment activities; transfer interest in DOE's new atomic vapor laser isotope separation (AVLIS) process to the new corporation; and, except for H.R. 145, require the government to pay its share of the costs to clean up mill tailings (mining wastes) generated under government contracts

  17. Chromium Enrichment on P11 Ferritic Steel by Pack Cementation

    Directory of Open Access Journals (Sweden)

    Fauzi F. A.

    2016-01-01

    Full Text Available The future thermal power plant is expected to operate at higher temperature to improve its efficiency and to reduce greenhouse gas emission. This target requires better corrosion properties of ferritic steels, which commonly used as materials for superheater and reheater of boiler tubes. In this work, chromium enrichment on the surface of ferritic steel is studied. The deposited chromium is expected to become a reservoir for the formation of chromia protective layer. Chromium was deposited on the substrate of steel by pack cementation process for two hours at the temperature of 850ºC, 950ºC and 1050ºC, respectively. XRD analysis indicated that chromium was successfully deposited at all temperatures. Somehow, SEM cross sectional image showed that continuous layer of chromium was not continuously formed at 850oC. Therefore, this research clarify that chromium enrichment by pack cementation may be conducted at the temperature above 950°C.

  18. Study of Transients in an Enrichment Closed Loop

    International Nuclear Information System (INIS)

    Fernandino, M.

    2002-06-01

    In the present thesis a mathematic model is presented in order to describe the dynamic behavior inside a closed enrichment loop, the latter representing a single stage of an uranium gaseous diffusion enrichment cascade.The analytical model is turned into a numerical model, and implemented through a computational code.For the verification of the model, measurements were taken in an experimental circuit using air as the process fluid.This circuit was instrumented so as to register its characteristic thermohydraulic variables.The measured transients were simulated, comparing the numerical results with the experimental measurements.A good agreement between the characteristic setting times and the thermohydraulic parameters evolution was observed.Besides, other transients of two species separation were numerically analyzed, including setting times of each magnitude, behavior of each one of them during different transients, and redistribution of concentrations

  19. Enrichment of 15N by ion exchange chromatography

    International Nuclear Information System (INIS)

    Ohwaki, Masao; Ohtsuka, Haruhisa; Nomura, Masao; Okamoto, Makoto; Fujii, Yasuhiko

    1996-01-01

    15 N isotope separation was studied using cation exchange resins which consist of functional groups: sulfonic acid, carboxylic acid and phenol at various concentration of the eluent LiOH. The isotope separation coefficients for these ion exchange resins were observed to be nearly equal, in spite of the large difference in ion exchange characteristics. The effect of flow rate on 15 N isotope separation was also studied, and the results indicate that the operation at high flow rate would be preferable for the industrial process of 15 N enrichment. Based on the preliminary investigations, a continuous operation using a series of ion exchange columns has been carried out in order to achieve high enrichment of 15 N. (author)

  20. Sixty-fold electrolytic batch enrichment for the assay of environmental tritium

    International Nuclear Information System (INIS)

    Gugelmann, A.A.; Brenninkmeijer, C.A.M.; Jalil, A.

    1977-01-01

    In Part 1 the general principles for the evaluation of low-level counting systems are outlined. Part 2 reviews current practices and experiences in tritium enrichment and counting systems. Part 3 describes a new approach to achieve high enrichment factors in a simple batch process. Sixty-fold tritium enrichment is achieved with an eighty-fold volume reduction. Specially designed large surface electrolysis cells are operated initially in series at 13A constant current, then for the final rundown at a constant voltage at 3.5V the cells are connected in parallel. (auth.)

  1. INVESTIGATION OF IRRIGATION INFLUENCE MADE BY FOAMED MOTHER SOLUTION ON EFFICIENCY OF SECONDARY ENRICHMENT

    Directory of Open Access Journals (Sweden)

    M. Scherbakova

    2013-01-01

    Full Text Available The secondary enrichment of a flotation concentrate in  the bubble column is considered as the easiest way to increase efficiency and quality of a mineral flotation process and reduce energy consumption for its implementation. The secondary enrichment of the mineral froth in a flotation concentrate is done by its washing-out  with  preliminary foamed  mother solution and applying an even layer of the obtained froth on the concentrate surface directly in the chamber of a flotation cell. The developed method of the secondary enrichment is simple in realization and does not require any additional reagents or expensive equipment. 

  2. An integrated multicriteria decision-making approach for evaluating nuclear fuel cycle systems for long-term sustainability on the basis of an equilibrium model: Technique for order of preference by similarity to ideal solution, preference ranking organization method for enrichment evaluation, and multiattribute utility theory combined with analytic hierarchy process

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Sae Rom [Dept of Quantum Energy Chemical Engineering, Korea University of Science and Technology (KUST), Daejeon (Korea, Republic of); Choi, Sung Yeol [Ulsan National Institute of Science and Technology, Ulju (Korea, Republic of); Ko, Wonil [Nonproliferation System Development Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2017-02-15

    The focus on the issues surrounding spent nuclear fuel and lifetime extension of old nuclear power plants continues to grow nowadays. A transparent decision-making process to identify the best suitable nuclear fuel cycle (NFC) is considered to be the key task in the current situation. Through this study, an attempt is made to develop an equilibrium model for the NFC to calculate the material flows based on 1 TWh of electricity production, and to perform integrated multicriteria decision-making method analyses via the analytic hierarchy process technique for order of preference by similarity to ideal solution, preference ranking organization method for enrichment evaluation, and multiattribute utility theory methods. This comparative study is aimed at screening and ranking the three selected NFC options against five aspects: sustainability, environmental friendliness, economics, proliferation resistance, and technical feasibility. The selected fuel cycle options include pressurized water reactor (PWR) once-through cycle, PWR mixed oxide cycle, or pyroprocessing sodium-cooled fast reactor cycle. A sensitivity analysis was performed to prove the robustness of the results and explore the influence of criteria on the obtained ranking. As a result of the comparative analysis, the pyroprocessing sodium-cooled fast reactor cycle is determined to be the most competitive option among the NFC scenarios.

  3. An integrated multicriteria decision-making approach for evaluating nuclear fuel cycle systems for long-term sustainability on the basis of an equilibrium model: Technique for order of preference by similarity to ideal solution, preference ranking organization method for enrichment evaluation, and multiattribute utility theory combined with analytic hierarchy process

    International Nuclear Information System (INIS)

    Yoon, Sae Rom; Choi, Sung Yeol; Ko, Wonil

    2017-01-01

    The focus on the issues surrounding spent nuclear fuel and lifetime extension of old nuclear power plants continues to grow nowadays. A transparent decision-making process to identify the best suitable nuclear fuel cycle (NFC) is considered to be the key task in the current situation. Through this study, an attempt is made to develop an equilibrium model for the NFC to calculate the material flows based on 1 TWh of electricity production, and to perform integrated multicriteria decision-making method analyses via the analytic hierarchy process technique for order of preference by similarity to ideal solution, preference ranking organization method for enrichment evaluation, and multiattribute utility theory methods. This comparative study is aimed at screening and ranking the three selected NFC options against five aspects: sustainability, environmental friendliness, economics, proliferation resistance, and technical feasibility. The selected fuel cycle options include pressurized water reactor (PWR) once-through cycle, PWR mixed oxide cycle, or pyroprocessing sodium-cooled fast reactor cycle. A sensitivity analysis was performed to prove the robustness of the results and explore the influence of criteria on the obtained ranking. As a result of the comparative analysis, the pyroprocessing sodium-cooled fast reactor cycle is determined to be the most competitive option among the NFC scenarios

  4. An Integrated Multicriteria Decision-Making Approach for Evaluating Nuclear Fuel Cycle Systems for Long-term Sustainability on the Basis of an Equilibrium Model: Technique for Order of Preference by Similarity to Ideal Solution, Preference Ranking Organization Method for Enrichment Evaluation, and Multiattribute Utility Theory Combined with Analytic Hierarchy Process

    Directory of Open Access Journals (Sweden)

    Saerom Yoon

    2017-02-01

    Full Text Available The focus on the issues surrounding spent nuclear fuel and lifetime extension of old nuclear power plants continues to grow nowadays. A transparent decision-making process to identify the best suitable nuclear fuel cycle (NFC is considered to be the key task in the current situation. Through this study, an attempt is made to develop an equilibrium model for the NFC to calculate the material flows based on 1 TWh of electricity production, and to perform integrated multicriteria decision-making method analyses via the analytic hierarchy process technique for order of preference by similarity to ideal solution, preference ranking organization method for enrichment evaluation, and multiattribute utility theory methods. This comparative study is aimed at screening and ranking the three selected NFC options against five aspects: sustainability, environmental friendliness, economics, proliferation resistance, and technical feasibility. The selected fuel cycle options include pressurized water reactor (PWR once-through cycle, PWR mixed oxide cycle, or pyroprocessing sodium-cooled fast reactor cycle. A sensitivity analysis was performed to prove the robustness of the results and explore the influence of criteria on the obtained ranking. As a result of the comparative analysis, the pyroprocessing sodium-cooled fast reactor cycle is determined to be the most competitive option among the NFC scenarios.

  5. The Fractionation and Enrichment of La Content by Precipitation

    International Nuclear Information System (INIS)

    Suyanti; Purwani, MV

    2007-01-01

    The fractionation and enrichment of La content by precipitation have been done. The feed was La hydroxide by product of monazite sand. La hydroxide was diluted in HNO 3 and was precipitated with ammonia. For to obtain La, diluent was precipitated at pH 8 and the filtrate was precipitated with oxalic acid. The precipitant of La concentrated was more rich than the feed. This process was done continue and fractionally. The best yield of enrichment of La was obtained at dilution of 25 gram La Hydroxide in 20 ml HNO 3 . The efficient degree of fractionation was XV. The average weight of La concentrate was obtained at every fraction was 1 gram. The total sum weight from fraction I until fraction XV 13.5 grams. The average of La content was 48%, average fractionation efficiency of La for every step of fractionation was 48 %. Total efficiency all process was 100%. The average ratio of La/Nd was 2 and the ratio of La/Ce almost infinite. Before processed La/Ce was 7.86, and after process increase to 26.92 - to approach ∞. Before processed ratio of La/Nd was 2.79, after processed increased to 4.4 - to approach ∞. (author)

  6. Uranium enrichment by laser: a technology for the future

    International Nuclear Information System (INIS)

    Cazalet, J.

    1999-01-01

    The SILVA (Isotopic Separation by Laser on atomic Vapor of uranium) process, developed by CEA and COGEMA, is an innovative system of production of enriched uranium, to be used as the fuel of nuclear reactors. It is a sound research program, calling on advanced technologies that are quickly changing. The goal is to cut drastically the production cost in comparison with the operating cost of the present plants based on gaseous diffusion. its industrialization is forecast for the beginning of next century. The SILVA process consists in putting a vapor of uranium through a beam of photons emitted by finely tuned lasers capable of ionising selectively the isotopes 235. The ionised isotopes are attracted on plates by an electric field, they are condensed and collected on these plates. The very high selectivity of enrichment technologies by laser, which are quite new, pave the way for compact and modular plants, which will consume little energy. Accordingly their production cost will be very low. So a new process could take a significant part of the uranium enrichment market after 2010. Even if the multinational EURODIF gaseous diffusion plant is modern and performing, it will be necessary to strengthen the French industry of uranium enrichment to maintain or improve its competitive position on the world market. This could be achieved by smoothly replacing EURODIF by a high performance laser plant. This is the common goal of CEA and COGEMA: all the efforts are concentrated on SILVA, the qualities of which (high selectivity, separation in one single step) have been demonstrated in the facilities of Saclay and Pierrelatte. 400 researchers and technicians are involved, as well as many industrial firms. The budget is equally by CEA and COGEMA through a cooperation agreement. The program includes: a phase of scientific and technical research, which has been highlighted in 1997-1998 by a demonstration of feasibility of the process; a phase of technological development, with

  7. Magnesium enriched lactic acid bacteria as a carrier for probiotic ice cream production.

    Science.gov (United States)

    Góral, Małgorzata; Kozłowicz, Katarzyna; Pankiewicz, Urszula; Góral, Dariusz

    2018-01-15

    The following strains of bacteria: Lactobacillus rhamnosus B 442, Lactobacillus rhamnosus 1937, and Lactococcus lactis JBB 500 were enriched with magnesium ions using Pulsed Electric Fields. The potentially probiotic strains were added to the mixture in the DVS process and applied for the production of ice cream which were then analyzed physicochemically and microbiologically. Results showed that addition of bacteria enriched with magnesium did not change chemical parameters of the ice cream and did not affect the freezing process, meltability, and hardness. No significant differences were noted in colour of the samples. The ice cream with addition of bacteria enriched with magnesium had higher adhesiveness. The results of viability determination showed that the total number of microorganisms in the ice cream was higher than in the starter cultures. Viability of the bacteria enriched with magnesium in the obtained ice cream was lower in comparison to the control samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Conversion and Blending Facility highly enriched uranium to low enriched uranium as uranyl nitrate hexahydrate. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-05

    This Conversion and Blending Facility (CBF) will have two missions: (1) convert HEU materials to pure HEU uranyl nitrate (UNH) and (2) blend pure HEU UNH with depleted and natural UNH to produce HEU UNH crystals. The primary emphasis of this blending operation will 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. To the extent practical, the chemical and isotopic concentrations of blended LEU product will be held within the specifications required for LWR fuel. Such blended LEU product will be offered to the United States Enrichment Corporation (USEC) to be sold as feed material to the commercial nuclear industry. Otherwise, blended LEU Will be produced as a waste suitable for storage or disposal.

  9. Use of enriched uranium in Canada's power reactors

    International Nuclear Information System (INIS)

    Dormuth, K.W.; Jackson, D.P.

    2011-01-01

    Recent trends in Canadian nuclear power reactor design and proposed development of nuclear power in Canada have indicated the possibility that Canada will break with its tradition of natural uranium fuelled systems, designed for superior neutron economy and, hence, superior uranium utilization. For instance, the Darlington B new reactor project procurement process included three reactor designs, all employing enriched fuel, although a natural uranium reactor design was included at a late stage in the ensuing environmental assessment for the project as an alternative technology. An evaluation of the alternative designs should include an assessment of the environmental implications through the entire fuel cycle, which unfortunately is not required by the environmental assessment process. Examples of comparative environmental implications of the reactor designs throughout the fuel cycle indicate the importance of these considerations when making a design selection. As Canada does not have enrichment capability, a move toward the use of enriched fuel would mean that Canada would be exporting natural uranium and buying back enriched uranium with value added. From a waste management perspective, Canada would need to deal with mill, refinery, and conversion tailings, as well as with the used fuel from its own reactors, while the enrichment supplier would retain depleted uranium with some commercial value. On the basis of reasoned estimates based on publicly available information, it is expected that enrichment in Canada is likely to be more profitable than exporting natural uranium and buying back enriched uranium. Further, on the basis of environmental assessments for enrichment facilities in other countries, it is expected that an environmental assessment of a properly sited enrichment facility would result in approval. (author)

  10. Study on atmospheric hydrogen enrichment by cryopump method and isotope separation by gas chromatography

    International Nuclear Information System (INIS)

    Taniyama, Yuki; Momoshima, Noriyuki

    2001-01-01

    To obtain the information of source of atmospheric hydrogen tritium an analysis of tritium isotopes is thought to be effective. So an atmospheric hydrogen enrichment apparatus and a cryogenic gas chromatographic column were made. Experiments were carried out to study the performance of cryopump to enrich atmospheric hydrogen and the column to separate hydrogen isotopes that obtained by cryopump method. The cryopump was able to process about 1000 1 atmosphere and the column was able to separate hydrogen isotopes with good resolution. (author)

  11. Cascades for natural water enrichment in deuterium and oxygen-18 using membrane permeation

    International Nuclear Information System (INIS)

    Chmielewski, A.G.; Matuszak, A.; Zakrzewska-Trznadel, G.; Van Hook, A.

    1991-01-01

    The enrichment of water in heavy isotopes by permeation through a hydrophobic membrane is described. Simple counter - current cascades are of no practical interest because of their high energy demand. A better solution is to employ a double counter - current cascade re-utilizing part of the heat of condensation. Currently employed methods of natural water enrichment in heavy isotopes are compared to the proposed membrane process. (author). 18 refs, 14 tabs, 21 figs

  12. IPAD: the Integrated Pathway Analysis Database for Systematic Enrichment Analysis.

    Science.gov (United States)

    Zhang, Fan; Drabier, Renee

    2012-01-01

    Next-Generation Sequencing (NGS) technologies and Genome-Wide Association Studies (GWAS) generate millions of reads and hundreds of datasets, and there is an urgent need for a better way to accurately interpret and distill such large amounts of data. Extensive pathway and network analysis allow for the discovery of highly significant pathways from a set of disease vs. healthy samples in the NGS and GWAS. Knowledge of activation of these processes will lead to elucidation of the complex biological pathways affected by drug treatment, to patient stratification studies of new and existing drug treatments, and to understanding the underlying anti-cancer drug effects. There are approximately 141 biological human pathway resources as of Jan 2012 according to the Pathguide database. However, most currently available resources do not contain disease, drug or organ specificity information such as disease-pathway, drug-pathway, and organ-pathway associations. Systematically integrating pathway, disease, drug and organ specificity together becomes increasingly crucial for understanding the interrelationships between signaling, metabolic and regulatory pathway, drug action, disease susceptibility, and organ specificity from high-throughput omics data (genomics, transcriptomics, proteomics and metabolomics). We designed the Integrated Pathway Analysis Database for Systematic Enrichment Analysis (IPAD, http://bioinfo.hsc.unt.edu/ipad), defining inter-association between pathway, disease, drug and organ specificity, based on six criteria: 1) comprehensive pathway coverage; 2) gene/protein to pathway/disease/drug/organ association; 3) inter-association between pathway, disease, drug, and organ; 4) multiple and quantitative measurement of enrichment and inter-association; 5) assessment of enrichment and inter-association analysis with the context of the existing biological knowledge and a "gold standard" constructed from reputable and reliable sources; and 6) cross-linking of

  13. On-Line Enrichment Monitor for UF{sub 6} Gas Centrifuge Enrichment Plant

    Energy Technology Data Exchange (ETDEWEB)

    Ianakiev, K. D.; Boyer, B.; Favalli, A.; Goda, J. M.; Hill, T.; Keller, C.; Lombardi, M.; Paffett, M.; MacArthur, D. W.; McCluskey, C.; Moss, C. E.; Parker, R.; Smith, M. K.; Swinhoe, M. T. [Los Alamos National Laboratory, Los Alamos (United States)

    2012-06-15

    This paper is a continuation of the Advanced Enrichment Monitoring Technology for UF{sub 6} Gas Centrifuge Enrichment Plant (GCEP) work, presented in the 2010 IAEA Safeguards Symposium. Here we will present the system architecture for a planned side-by-side field trial test of passive (186-keV line spectroscopy and pressure-based correction for UF{sub 6} gas density) and active (186-keV line spectroscopy and transmission measurement based correction for UF{sub 6} gas density) enrichment monitoring systems in URENCO's enrichment plant in Capenhurst. Because the pressure and transmission measurements of UF{sub 6} are complementary, additional information on the importance of the presence of light gases and the UF{sub 6} gas temperature can be obtained by cross-correlation between simultaneous measurements of transmission, pressure and 186-keV intensity. We will discuss the calibration issues and performance in the context of accurate, on-line enrichment measurement. It is hoped that a simple and accurate on-line enrichment monitor can be built using the UF{sub 6} gas pressure provided by the Operator, based on online mass spectrometer calibration, assuming a negligible (a small fraction of percent) contribution of wall deposits. Unaccounted-for wall deposits present at the initial calibration will lead to unwanted sensitivity to changes in theUF{sub 6} gas pressure and thus to error in the enrichment results. Because the accumulated deposits in the cascade header pipe have been identified as an issue for Go/No Go measurements with the Cascade Header Enrichment Monitor (CHEM) and Continuous Enrichment Monitor (CEMO), it is important to explore their effect. Therefore we present the expected uncertainty on enrichment measurements obtained by propagating the errors introduced by deposits, gas density, etc. and will discuss the options for a deposit correction during initial calibration of an On-Line Enrichment Monitor (OLEM).

  14. The enriched chromium neutrino source for GALLEX

    International Nuclear Information System (INIS)

    Hartmann, F.X.; Hahn, R.L.

    1991-01-01

    The preparation and study of an intense source of neutrinos in the form of neutron irradiated materials which are enriched in Cr-50 for use in the GALLEX solar neutrino experiment are discussed. Chromyl fluoride gas is enriched in the Cr-50 isotope by gas centrifugation and subsequently converted to a very stable form of chromium oxide. The results of neutron activation analyses of such chromium samples indicate low levels of any long-lived activities, but show that short-lived activities, in particular Na-24, may be of concern. These results show that irradiating chromium oxide enriched in Cr-50 is preferable to irradiating either natural chromium or argon gas as a means of producing a neutrino source to calibrate the GALLEX detector. These results of the impurity level analysis of the enriched chromyl fluoride gas and its conversion to the oxide are also of interest to work in progress by other members of the Collaboration investigating an alternative conversion of the enriched gas to chromium metal. 35 refs., 12 figs., 5 tabs

  15. How is uranium supply affecting enrichment?

    International Nuclear Information System (INIS)

    Steve Kidd

    2007-01-01

    As a result of the enlivened uranium market, momentum has in turn picked up in the enrichment sector. What are the consequences of higher uranium prices? There is, of course, a link between uranium and enrichment supply to the extent that they are at least partial substitutes. On the enrichment supply side, the most obvious feature is the gradual replacement of the old gas diffusion facilities of Usec in the USA and EURODIF in France with more modern and economical centrifuge plants. Assuming Usec can overcome the financing and technical issues surrounding its plans, the last gas diffusion capacity should disappear around 2015 and the entire enrichment market should then be using centrifuges. On the commercial side, the key anticipated developments are mostly in Russia. Although there should still continue to be substantial quantities of surplus Russian HEU available for down blending in the period beyond 2013, it is now reasonable to expect that it will be mostly consumed by internal needs, to fuel Russian-origin reactors both at home and in export markets such as China and India. Finally, as a key sensitive area for the non-proliferation of nuclear weapons, the enrichment sector is likely to be a central point of the new international arrangements which must be developed to support a buoyant nuclear sector throughout this century.

  16. Linking nutrient enrichment, sediment erodibility and biofilms

    Science.gov (United States)

    Conrad, B.; Mahon, R.; Sojka, S. L.

    2014-12-01

    Sediment movement in coastal lagoons affects nutrient flux and primary producer growth. Previous research has shown that sediment erodibility is affected by biofilm concentration and that growth of benthic organisms, which produce biofilm, is affected by nutrient enrichment. However, researchers have not examined possible links between nutrient addition and sediment erodibility. We manipulated nutrient levels in the water column of 16 microcosms filled with homogenized sediment from a shallow coastal lagoon and artificial seawater to determine the effects on biofilm growth, measured through chlorophyll a and colloidal carbohydrate concentrations. Erosion tests using a Gust microcosm were conducted to determine the relationship between sediment erodibility and biofilm concentration. Results show that carbohydrate levels decreased with increasing nutrient enrichment and were unrelated to chlorophyll concentrations and erodibility. The nutrient levels did not predictably affect the chlorophyll levels, with lower chlorophyll concentrations in the control and medium enrichment treatments than the low and high enrichment treatments. Controls on biofilm growth are still unclear and the assumed relationship between carbohydrates and erodibility may be invalid. Understanding how biofilms respond to nutrient enrichment and subsequent effects on sediment erodibility is essential for protecting and restoring shallow coastal systems.

  17. Disposal of wastes from uranium conversion and enrichment processes

    International Nuclear Information System (INIS)

    Costello, J.M.

    1981-11-01

    This paper reviews the general principles and objectives in radioactive waste management, and shows how these are applied in options for management and disposal of wastes from uranium upgrading operations. Some estimates of radiological dose commitments and health effects from LWR nuclear power and its fuel cycle have been made for US conditions

  18. Clinical-scale elutriation as a means of enriching antigen-presenting cells and manipulating alloreactivity.

    Science.gov (United States)

    Micklethwaite, Kenneth P; Garvin, Frances M; Kariotis, Melina R; Yee, Leng L; Hansen, Anna M; Antonenas, Vicki; Sartor, Mary M; Turtle, Cameron J; Gottlieb, David J

    2009-01-01

    Clinical-scale elutriation using the Elutra(c) has been shown to enrich monocytes reliably for immunotherapy protocols. Until now, a detailed assessment of the four (F1-F4) non-monocyte fractions derived from this process has not been performed. Using fluorescence-activated cell sorting (FACS), we performed phenotypic analyses to investigate the possible enrichment of T, B, natural killer (NK) and dendritic cells (DC) or their subsets in one or more Elutra fractions. Blood DC were enriched up to 10-fold in some fractions (F3 and F4) compared with the pre-elutriation apheresis product. This increased the number of DC that could be isolated from a given cell number by immunomagnetic separation. It was also found that CD62L(-) effector memory CD4(+) T cells were enriched in later fractions. In four of five cases tested, cells from F3 demonstrated decreased alloreactive proliferation in a mixed lymphocyte reaction compared with cells from the apheresis product. B cells were enriched in F1 compared with the apheresis product. In addition to providing enrichment of monocytes for the generation of DC, the Elutra enriches cell subsets that may be incorporated into and enhance existing immunotherapy and stem cell transplantation protocols.

  19. Community-aware user profile enrichment in folksonomy.

    Science.gov (United States)

    Xie, Haoran; Li, Qing; Mao, Xudong; Li, Xiaodong; Cai, Yi; Rao, Yanghui

    2014-10-01

    In the era of big data, collaborative tagging (a.k.a. folksonomy) systems have proliferated as a consequence of the growth of Web 2.0 communities. Constructing user profiles from folksonomy systems is useful for many applications such as personalized search and recommender systems. The identification of latent user communities is one way to better understand and meet user needs. The behavior of users is highly influenced by the behavior of their neighbors or community members, and this can be utilized in constructing user profiles. However, conventional user profiling techniques often encounter data sparsity problems as data from a single user is insufficient to build a powerful profile. Hence, in this paper we propose a method of enriching user profiles based on latent user communities in folksonomy data. Specifically, the proposed approach contains four sub-processes: (i) tag-based user profiles are extracted from a folksonomy tripartite graph; (ii) a multi-faceted folksonomy graph is constructed by integrating tag and image affinity subgraphs with the folksonomy tripartite graph; (iii) random walk distance is used to unify various relationships and measure user similarities; (iv) a novel prototype-based clustering method based on user similarities is used to identify user communities, which are further used to enrich the extracted user profiles. To evaluate the proposed method, we conducted experiments using a public dataset, the results of which show that our approach outperforms previous ones in user profile enrichment. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Development for analysis system of rods enrichment of nuclear fuels

    International Nuclear Information System (INIS)

    Rojas C, E.L.

    1998-01-01

    Nuclear industry is strongly regulated all over the world and quality assurance is important in every nuclear installation or process related with it. Nuclear fuel manufacture is not the exception. ININ was committed to manufacture four nuclear fuel bundles for the CFE nucleo electric station at Laguna Verde, Veracruz, under General Electric specifications and fulfilling all the requirements of this industry. One of the quality control requisites in nuclear fuel manufacture deals with the enrichment of the pellets inside the fuel bundle rods. To achieve the quality demanded in this aspect, the system described in this work was developed. With this system, developed at ININ it is possible to detect enrichment spikes since 0.4 % in a column of pellets with a 95 % confidence interval and to identify enrichment differences greater than 0.2 % e between homogeneous segments, also with a 95 % confidence interval. ININ delivered the four nuclear fuel bundles to CFE and these were introduced in the core of the nuclear reactor of Unit 1 in the fifth cycle. Nowadays they are producing energy and have shown a correct mechanical performance and neutronic behavior. (Author)

  1. Environmental Enrichment Therapy for Autism: Outcomes with Increased Access

    Directory of Open Access Journals (Sweden)

    Eyal Aronoff

    2016-01-01

    Full Text Available We have previously shown in two randomized clinical trials that environmental enrichment is capable of ameliorating symptoms of autism spectrum disorder (ASD, and in the present study, we determined whether this therapy could be effective under real-world circumstances. 1,002 children were given daily Sensory Enrichment Therapy, by their parents, using personalized therapy instructions given over the Internet. Parents were asked to assess the symptoms of their child every 2 weeks for up to 7 months. An intention-to-treat analysis showed significant overall gains for a wide range of symptoms in these children, including learning, memory, anxiety, attention span, motor skills, eating, sleeping, sensory processing, self-awareness, communication, social skills, and mood/autism behaviors. The children of compliant caregivers were more likely to experience a significant improvement in their symptoms. The treatment was effective across a wide age range and there was equal progress reported for males and females, for USA and international subjects, for those who paid and those who did not pay for the therapy, and for individuals at all levels of initial symptom severity. Environmental enrichment, delivered via an online system, therefore appears to be an effective, low-cost means of treating the symptoms of ASD.

  2. 31 CFR 540.308 - Low Enriched Uranium (LEU).

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Low Enriched Uranium (LEU). 540.308... OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.308 Low Enriched Uranium (LEU). The term low enriched...

  3. Uranium enrichment management review: summary of analysis

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    In May 1980, the Assistant Secretary for Resource Applications within the Department of Energy requested that a group of experienced business executives be assembled to review the operation, financing, and management of the uranium enrichment enterprise as a basis for advising the Secretary of Energy. After extensive investigation, analysis, and discussion, the review group presented its findings and recommendations in a report on December 2, 1980. The following pages contain background material on which that final report was based. This report is arranged in chapters that parallel those of the uranium enrichment management review final report - chapters that contain summaries of the review group's discussion and analyses in six areas: management of operations and construction; long-range planning; marketing of enrichment services; financial management; research and development; and general management. Further information, in-depth analysis, and discussion of suggested alternative management practices are provided in five appendices.

  4. Uranium enrichment management review: summary of analysis

    International Nuclear Information System (INIS)

    1981-01-01

    In May 1980, the Assistant Secretary for Resource Applications within the Department of Energy requested that a group of experienced business executives be assembled to review the operation, financing, and management of the uranium enrichment enterprise as a basis for advising the Secretary of Energy. After extensive investigation, analysis, and discussion, the review group presented its findings and recommendations in a report on December 2, 1980. The following pages contain background material on which that final report was based. This report is arranged in chapters that parallel those of the uranium enrichment management review final report - chapters that contain summaries of the review group's discussion and analyses in six areas: management of operations and construction; long-range planning; marketing of enrichment services; financial management; research and development; and general management. Further information, in-depth analysis, and discussion of suggested alternative management practices are provided in five appendices

  5. Method of deuterium isotope separation and enrichment

    International Nuclear Information System (INIS)

    Benson, S.W.

    1979-01-01

    A method is described for separating and enriching deuterium containing molecules comprising the steps of: providing a source of organic molecules containing a normal abundance of deuterium atoms, the organic molecules having a structural formula RX, in which R is an organic radical selected from ethyl, isopropyl, t-butyl and 3-cyclopentenyl, and in which X is selected from F, Cl, Br and OH, and wherein R represents 3-cyclopentenyl, X may additionally represent H; exposing the molecules to the radiation of at least one pulsed infrared laser source which has been specifically tuned and focussed to selectively decompose RX molecules containing deuterium to form an enriched olefin specie containing deuterium, and HX; and separating the deuterium enriched olefin specie from the undecomposed deuterium depleted RX molecules and HX. (author)

  6. Method of deuterium isotope separation and enrichment

    International Nuclear Information System (INIS)

    Benson, S.W.

    1978-01-01

    A method of separating deuterium, i.e., heavy hydrogen, from certain naturally occurring sources using tuned infrared lasers to selectively decompose specified classes of organic molecules (i.e., RX) into enriched molecular products containing deuterium atoms is described. The deuterium containing molecules are easily separated from the starting material by absorption, distillation or other simple chemical separation techniques and methods. After evaporation such deuterium containing molecules can be burned to form water with an enriched deuterium content or pyrolyzed to form hydrogen gas with an enriched deuterium content. The undecomposed molecules and the other reaction products which are depleted of their deuterium containing species can be catalytically treated, preferably using normal water, to restore the natural abundance of deuterium and such restored molecules can then be recycled

  7. The evolution of the enriched uranium markets

    International Nuclear Information System (INIS)

    Arnaiz, J.; Moleres, C.; Tarin, F.

    2004-01-01

    This paper deals with the evolution of the enriched uranium component markets (uranium concentrates, conversion and enrichment), starting with the situation of historically low prices that occurred during 2000. The situation that has been reached as on December 2003, when the concentrates and conversion markets were 44% and 70% (current US$) respectively, and the enrichment prices 30%, higher, is analysed. Finally, the negative impact of the 90's depressed prices, due to abundant alternative sources of uranium components, on the primary production of all three components and, as a conclusion, the impact of the new situation on the transport logistics, and the need of appropriate economic conditions to make the future primary production sustainable, is commented. (Author)

  8. Nutrient enrichment increases mortality of mangroves.

    Directory of Open Access Journals (Sweden)

    Catherine E Lovelock

    Full Text Available Nutrient enrichment of the coastal zone places intense pressure on marine communities. Previous studies have shown that growth of intertidal mangrove forests is accelerated with enhanced nutrient availability. However, nutrient enrichment favours growth of shoots relative to roots, thus enhancing growth rates but increasing vulnerability to environmental stresses that adversely affect plant water relations. Two such stresses are high salinity and low humidity, both of which require greater investment in roots to meet the demands for water by the shoots. Here we present data from a global network of sites that documents enhanced mortality of mangroves with experimental nutrient enrichment at sites where high sediment salinity was coincident with low rainfall and low humidity. Thus the benefits of increased mangrove growth in response to coastal eutrophication is offset by the costs of decreased resilience due to mortality during drought, with mortality increasing with soil water salinity along climatic gradients.

  9. L'enrichissement des sols et des semences permet d'améliorer la ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    6 juin 2016 ... Grâce à des sols en meilleure santé et à l'utilisation de variétés améliorées, les agriculteurs du sud de l'Éthiopie ont multiplié par deux le rendement du pois chiche. L'amélioration des méthodes de transformation et de préparation de cet aliment, conjuguée à des programmes d'éducation, s'est traduite par ...

  10. Phosphopeptide enrichment by immobilized metal affinity chromatography

    DEFF Research Database (Denmark)

    Thingholm, Tine E.; Larsen, Martin R.

    2016-01-01

    Immobilized metal affinity chromatography (IMAC) has been the method of choice for phosphopeptide enrichment prior to mass spectrometric analysis for many years and it is still used extensively in many laboratories. Using the affinity of negatively charged phosphate groups towards positively...... charged metal ions such as Fe3+, Ga3+, Al3+, Zr4+, and Ti4+ has made it possible to enrich phosphorylated peptides from peptide samples. However, the selectivity of most of the metal ions is limited, when working with highly complex samples, e.g., whole-cell extracts, resulting in contamination from...

  11. Isotopic enrichment in a plasma centrifuge

    International Nuclear Information System (INIS)

    Del Bosco, E.; Dallaqua, R.S.; Ludwig, G.O.; Bittencourt, J.A.

    1986-05-01

    A rotating fully ionized plasma column was produced in a vacuum-arc centrifuge. The apparatus is described and new results for the rotational velocity and isotope enrichment of carbon and metal plasmas are shown. The ion rotation velocity is derived from electrostatic probes measurents and from the azimuthal displacement of the material deposited behind of a narrow slit. The isotope enrichment is measured with a modified quadrupole mass spectrometer, which determines, in situ, the relative abundance of the isotopes at the end of the plasm column at various radil positions. (Author) [pt

  12. Enrichment and Preservation of Architectural Knowledge

    DEFF Research Database (Denmark)

    Beetz, Jakob; Blümel, Ina; Dietze, Stefan

    2016-01-01

    In the context of the EU FP7 DURAARK project (2013–2016), inter-disciplinary methods, technologies and tools have been researched and developed, that support the Long Term Preservation of semantically enriched digital representations of built structures. The results of the research efforts include...... approaches of semi-automatically deriving building models from point cloud data sets acquired from laser scans and the integration and overlay of such representations with explicit Building Information Models (BIM). We introduce novel ways for the further semantic enrichment of such hybrid building models...

  13. Uranium enrichment: heading for the abyss

    International Nuclear Information System (INIS)

    Norman, C.

    1983-01-01

    This article discusses the federal government's $2.3 billion a year business enriching uranium for nuclear power plants which is heading toward a major crisis. Due to miscalculations by the Department of Energy, it is caught with billions of dollars of construction in progress just as projected demand for enriched uranium is decreasing. At the center of the controversy is the Gas Centrifuge Plant at Portsmouth, Ohio - estimated to cost $10 billion dollars. A review of how DOE got into this situation and how they plan to solve it is presented

  14. Slightly enriched uranium fuel for a PHWR

    International Nuclear Information System (INIS)

    Notari, C.; Marajofsky, A.

    1997-01-01

    An improved fuel element design for a PHWR using slightly enriched uranium fuel is presented. It maintains the general geometric disposition of the currently used in the argentine NPP's reactors, replacing the outer ring of rods by rods containing annular pellets. Power density reduction is achieved with modest burnup losses and the void volume in the pellets can be used to balance these two opposite effects. The results show that with this new design, the fuel can be operated at higher powers without violating thermohydraulic limits and this means an improvement in fuel management flexibility, particularly in the transition from natural uranium to slightly enriched uranium cycle. (author)

  15. Uranium enrichment services in the United States

    International Nuclear Information System (INIS)

    Jelinek, P.; Lenders, M.

    1994-01-01

    The United States of America is the world's largest market for uranium enrichment services. After the disintegration of the Soviet Union, Russian uranium is entering the world market on an increasing scale. The U.S. tries to protect its market and, in this connection, also the European market from excessive price drops by taking anti-dumping measures. In order to become more competitive, American companies have adapted modern enrichment techniques from Europe. European - U.S. joint ventures are to help, also technically and economically, to integrate military uranium, accumulating as a consequence of worldwide disarmament, into the commercial fuel cycle for the peaceful use of nuclear power. (orig.) [de

  16. Uranium enrichment. Industrial and commercial aspect

    International Nuclear Information System (INIS)

    Lamorlette, G.

    1983-01-01

    The uranium enrichment, a key stage in the fuel cycle of light-water nuclear power stations, applies sophisticated and protected techniques in installations on a very large scale. This article shows how there was a sudden change from a monopoly position in production to a severe competition in a market which is depressed today but offers good prospects for the future. It indicates how the enrichment industrialist have adapted themselves to the fluctuations of the demand, while safeguarding the reliability of the rendered service and the necessary security of supplies for the proper development of the nuclear electric power [fr

  17. Transformations of highly enriched uranium into metal or oxide

    International Nuclear Information System (INIS)

    Nollet, P.; Sarrat, P.

    1964-01-01

    The enriched uranium workshops in Cadarache have a double purpose on the one hand to convert uranium hexafluoride into metal or oxide, and on the other hand to recover the uranium contained in scrap materials produced in the different metallurgical transformations. The principles that have been adopted for the design and safety of these workshops are reported. The nuclear safety is based on the geometrical limitations of the processing vessels. To establish the processes and the technology of these workshops, many studies have been made since 1960, some of which have led to original achievements. The uranium hexafluoride of high isotopic enrichment is converted either by injection of the gas into ammonia or by an original process of direct hydrogen reduction to uranium tetrafluoride. The uranium contained m uranium-zirconium metal scrap can be recovered by combustion with hydrogen chloride followed treatment of the uranium chloride by fluorine in order to obtain the uranium in the hexafluoride state. Recovery of the uranium contained m various scrap materials is obtained by a conventional refining process combustion of metallic scrap, nitric acid dissolution of the oxide, solvent purification by tributyl phosphate, ammonium diuranate precipitation, calcining, reduction and hydro fluorination into uranium tetrafluoride, bomb reduction by calcium and slag treatment. Two separate workshops operate along these lines one takes care of the uranium with an isotopic enrichment of up to 3 p. 100, the other handles the high enrichments. The handling of each step of this process, bearing in mind the necessity for nuclear safety, has raised some special technological problems and has led to the conception of new apparatus, in particular the roasting furnace for metal turnings, the nitric acid dissolution unit, the continuous precipitator and ever safe filter and dryer for ammonium diuranate, the reduction and hydro fluorination furnace and the slag recovery apparatus These are

  18. Application of ICPMS for performance evaluation of boron enrichment plant at HWP, Manuguru

    International Nuclear Information System (INIS)

    Murthy, P.K.; Mohapatra, C.; Vithal, G.K.

    2011-01-01

    10 B enriched compounds are used in neutron control rod in Fast Breeder Reactors (FBR), Neutron Detector, Neutron Capture Therapy, and Neutron Shielding. Heavy Water Board (HWB) is given a mandate to produce enriched elemental boron which is being produced using Ion exchange chromatography and BF 3 - ether complex distillation methods. Ion Exchange Chromatography based Boron Enrichment Plant is operating at HWP, Manuguru. Ion Exchange Chromatography based process depends, besides other process parameters, on column run time and movement of band length. For effective process and quality control, it is necessary to analyze 10 B/ 11 B ratio in feed, process stream, waste and the product. 10 B/ 11 B ratio measurements are possible by Thermal Ionization Mass Spectrometer (TIMS) and Inductively Coupled Plasma Mass Spectrometer (ICPMS), the former offers better accuracy but takes longer analysis time whereas the later offers quick analysis of isotopic ratios and as well as trace metal impurities in the Boric acid

  19. High Efficient Enrichment and Activated Dissolution of Refractory Low Grade Rh-containing Material

    Institute of Scientific and Technical Information of China (English)

    WU Xiaofeng; DONG Haigang; TONG Weifeng; ZHAO Jiachun; ZENG Rui

    2012-01-01

    Aiming to the low-grade rhodium-containing waste materials,a new process was proposed to enrich and activate rhodium by smelting using iron oxide as a trapping agent and activator.A rhodium concentrate was obtained by the separation of base metals and precious metals.The concentrate was reacted with dilute aqua regia to obtain rhodium solution.The factors influencing the enrichment and activation effects were discussed in this paper.The results showed that the dissolution rate is greater than 99% under the optimum conditions.In this process,the activation of rhodium was finished in the enrichment process.The iron oxide is both a trapping agent and activator,which simplifies the process and reduce the cost.

  20. 75 FR 10525 - In the Matter of: AREVA Enrichment Services, LLC (Eagle Rock Enrichment Facility) and All Other...

    Science.gov (United States)

    2010-03-08

    ...: AREVA Enrichment Services, LLC (Eagle Rock Enrichment Facility) and All Other Persons Who Seek or Obtain... for the Implementation of a Safeguards Information Program (Effective Immediately) I AREVA Enrichment... it to construct and operate a uranium enrichment facility in Bonneville County, Idaho. AES submitted...

  1. 77 FR 14838 - General Electric-Hitachi Global Laser Enrichment LLC, Commercial Laser-Based Uranium Enrichment...

    Science.gov (United States)

    2012-03-13

    ... Laser Enrichment LLC, Commercial Laser-Based Uranium Enrichment Facility, Wilmington, North Carolina... a license to General Electric-Hitachi Global Laser Enrichment LLC (GLE or the applicant) to authorize construction of a laser-based uranium enrichment facility and possession and use of byproduct...

  2. SIGMA: the novel approach of a new non-proliferating uranium enrichment technology

    International Nuclear Information System (INIS)

    Rivarola, M.; Florido, P.; Brasnarof, D.; Bergallo, E.

    2000-01-01

    The SIGMA concept, under development by Argentina, represents the evolution of the Uranium Enrichment Gaseous Diffusion technology, updated to face the challenge of the new economic-based and competitive world frame. The Enrichment technology has been historically considered as a highly proliferating activity in the nuclear field, and central countries limited the access of the developing countries to this technology. The SIGMA concept incorporates innovative proliferation resistant criteria at the beginning of the design process, and inherits all the non-proliferation features of the gaseous diffusion plants (GDPs). The radical new proliferation resistance approach of the SIGMA technology suggests a new kind of global control of the uranium enrichment market, where some developing countries might access an Enrichment plant without access to the technology itself. In this paper, we investigate the economy of the SIGMA plants, and the implications of this technology on the Uranium Global Market. (authors)

  3. Effect of spermidine in PC12 cells on the cell apoptosis induced by enriched uranium

    International Nuclear Information System (INIS)

    Gu Guixiong; Zhu Shoupeng; Wang Liuyi; Yang Shuqin; Zhu Lingli

    2003-01-01

    This is a study on injurious effects of cellular spermidine to PC12 cells irradiated by enriched uranium. PC12 cells were cultured in DMEM/F12 medium with enriched uranium, and the exposure doses were calculated. The contents of free spermidine PC12 cells were examined with Dansyl-chloride reaction and thin-layer chromatography. Viability of the cells treated with enriched uranium reduced rapidly and DNA strand break increased significantly with increasing time of the irradiation. Autoradiographic tracks showed that the radionuclide located in the nucleus predominantly. The content of free spermidine in PC12 cells could markedly decrease as the irradiation time increased. The results suggested that PC12 cells exposured to enriched uranium were apoptotic and the free spermidine in cells might play some role in this process

  4. Attempt to enrich of a new spontaneous fissioning nuclide by evaporation of natural brine

    International Nuclear Information System (INIS)

    Adamek, A.; Zhuravleva, E.L.; Constantinescu, M.; Constantinescu, o.; Chuburkov, Yu.T.

    1983-01-01

    The enrichment of the new spontaneous fissioning nuclide discovered in the Cheleken brine, was made by evaporation. The purpose of this work was the comparison of behaviour of the new spontaneous fissioning nuclide with that of the known elements in the formation processes of the high concentration brines. Spontaneous fission of the nuclide was measured by means of the counters for multiple emission of neutrons. It is shown that the new spontaneous fissioning nuclide was enriched as well as other trace elements (Hg, Tl, Bi and Pb) in a solution remained after the evaporation of the initial solution. The conclusion is drawn that from the sea water brines could be obtained by evaporation which are enriched in trace elements with an enrichment degree higher than the natural brines

  5. SIGMA, the novel approach of a new non-proliferating uranium enrichment technology

    International Nuclear Information System (INIS)

    Rivarola, M.; Florido, P.; Brasnarof, D.; Bergallo, J.

    2001-01-01

    The SIGMA concept, under development by Argentina, represents the evolution of the Uranium Enrichment Gaseous Diffusion technology, updated to face the challenge of the new economic-based and competitive world frame. The Enrichment technology has been historically considered as a highly proliferating activity in the nuclear field, and central countries have limited the access of the developing countries to this technology. The SIGMA concept incorporates innovative proliferation resistant criteria at the beginning of the design process, and inherits all the non-proliferation features of the Gaseous Diffusion Plants (GDPs). The radical new proliferation resistant approach of the SIGMA technology, suggest a new kind of global control of the Uranium Enrichment Market, were some developing countries might access to an Enrichment plant without accessing to the technology itself. In this paper, we analyse the economy of the SIGMA plants, and the implications of this technology on the Uranium Global Market. (authors)

  6. Low-enriched fuel particle performance review

    International Nuclear Information System (INIS)

    Homan, F.; Nabielek, H.; Yang, L.

    1978-08-01

    The available data on low-enriched (LEU) fuel particles were reviewed under the United States-Federal Republic of Germany Agreement. The most influential factors controlling the irradiation performance of LEU fuel particles were found to be plutonium transport, fission product transport, fuel particle mechanical performance and fuel particle chemical performande. (orig.) [de

  7. Low-enriched fuel particle performance review

    International Nuclear Information System (INIS)

    Homan, F.; Nabielek, H.; Yang, L.

    1978-08-01

    The available data on low-enriched uranium (LEU) fuel particles were reviewed under the United States-Federal Republic of Germany Agreement. The most influential factors controlling the irradiation performance of LEU fuel particles were found to be plutonium transport, fission product transport, fuel particle mechanical performance, and fuel particle chemical performance

  8. GRAN SASSO: Enriched germanium in action

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1991-12-15

    Two large crystals of carefully enriched germanium, one weighing 1 kilogram and the other 2.9 kilograms, and worth many millions of dollars, are being carefully monitored in the Italian Gran Sasso Laboratory in the continuing search for neutrinoless double beta decay.

  9. Isotope enrichment by photolysis on ordered surfaces

    International Nuclear Information System (INIS)

    Epling, G.A.; Florio, E.

    1981-01-01

    A surface was prepared as a micelle model which could be altered, by reacting trichlorododecylsilane with silica gel. Adsorption of dibenzyl ketone onto this surface followed by irradiation resulted in a recovered dibenzyl ketone enriched in 13 C. The plot of log S vs -log (1-f) had a slope of 1.66

  10. Isotope enrichment by photolysis on ordered surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Epling, G.A.; Florio, E.

    1981-03-11

    A surface was prepared as a micelle model which could be altered, by reacting trichlorododecylsilane with silica gel. Adsorption of dibenzyl ketone onto this surface followed by irradiation resulted in a recovered dibenzyl ketone enriched in /sup 13/C. The plot of log S vs -log (1-f) had a slope of 1.66. (DLC)

  11. Isotopic enrichment in a plasma centrifuge

    International Nuclear Information System (INIS)

    Del Bosco, E.; Dallaqua, R.S.; Ludwig, G.O.; Bittencourt, J.A.

    1987-01-01

    High rotational velocity and centrifugal isotopic separation of carbon in a vacuum-arc plasma centrifuge are presented. Enrichments of up to 390% for 13 C are measured at 6 cm radius with angular rotation frequencies in excess of 1.0 x 10 5 rad/s in an axial magnetic field of 0.12 T

  12. GRAN SASSO: Enriched germanium in action

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    Two large crystals of carefully enriched germanium, one weighing 1 kilogram and the other 2.9 kilograms, and worth many millions of dollars, are being carefully monitored in the Italian Gran Sasso Laboratory in the continuing search for neutrinoless double beta decay

  13. Genetic enrichment of cardiomyocytes derived from mouse ...

    African Journals Online (AJOL)

    Genetic enrichment of cardiomyocytes derived from mouse embryonic stem cells. WJ He, SC Li, LL Ye, H Liu, QW Wang, WD Han, XB Fu, ZL Chen. Abstract. Pluripotent embryonic stem cells (ESC) have the ability to differentiate into a variety of cell lineages in vitro, including cardiomyocytes. Successful applications of ...

  14. Recommendations based on semantically enriched museum collections

    NARCIS (Netherlands)

    Wang, Y.; Stash, N.; Aroyo, L.M.; Gorgels, P.; Rutledge, L.W.; Schreiber, G.

    2008-01-01

    This article presents the CHIP demonstrator1 for providing personalized access to digital museum collections. It consists of three main components: Art Recommender, Tour Wizard, and Mobile Tour Guide. Based on the semantically enriched Rijksmuseum Amsterdam2 collection, we show how Semantic Web

  15. Review of environmental enrichment for broiler chickens

    NARCIS (Netherlands)

    Riber, A.B.; De Weerd, Van H.A.; Jong, De I.C.; Steenfeldt, S.

    2018-01-01

    Welfare problems are commonly found in both conventional and organic production of broiler chickens. In order to reduce the extent of welfare problems, it has been suggested to provide stimulating, enriched environments. The aim of the present paper is to provide a review of the effect on behavior

  16. Feasibility of uranium enrichment in Australia

    International Nuclear Information System (INIS)

    1979-10-01

    The Council considered that provided the balance between costs and markets was found to be acceptable, there was no valid reason against the Government proceeding with a study on the feasibility of, and perhaps participating in the establishment of a commercial uranium enrichment industry in Australia. Areas covered include technical expertise and industrial structure in Australia, environmental aspects and safeguards

  17. 21 CFR 137.165 - Enriched flour.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Enriched flour. 137.165 Section 137.165 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... riboflavin, 24 milligrams of niacin, 0.7 milligrams of folic acid, and 20 milligrams of iron. (b) It may...

  18. Gas Enrichment at Liquid-Wall Interfaces

    NARCIS (Netherlands)

    Dammer, S.M.; Lohse, Detlef

    2006-01-01

    Molecular dynamics simulations of Lennard-Jones systems are performed to study the effects of dissolved gas on liquid-wall and liquid-gas interfaces. Gas enrichment at walls, which for hydrophobic walls can exceed more than 2 orders of magnitude when compared to the gas density in the bulk liquid,

  19. Metacognitive Enrichment for Community College Students

    Science.gov (United States)

    Wyre, Steven H.

    2012-01-01

    Recent research was conducted to explore how introducing metacognitive enrichment into courses containing implicit or explicit critical thinking goals would affect the students' personal epistemological maturity. At the beginning of a fall semester at a moderate sized community college in the southeastern United States, 733 students were divided…

  20. PROTEIN ENRICHMENT OF SPENT SORGHUM RESIDUE USING ...

    African Journals Online (AJOL)

    BSN

    The optimum concentration of spent sorghum for protein enrichment with S. cerevisiae was 7.Sg/100 ml. Th.: protein ... production of single sell protein using Candida utilis and cassava starch effluem as substrate. ... wastes as substrates, Kluyveromyces fragilis and milk whey coconut water as substrate (Rahmat et al.,. 1995 ...