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Sample records for greater uf volume

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

    International Nuclear Information System (INIS)

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

    1995-01-01

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

  2. Rupture of Model 48Y UF6 cylinder and release of uranium hexafluoride. Cylinder overfill, March 12-13, 1986. Investigation of a failed UF6 shipping container. Volume 2

    International Nuclear Information System (INIS)

    1986-06-01

    NUREG-1179, Volume 1, reported on the rupture of a Model 48Y uranium hexafluoride (UF 6 ) cylinder and the subsequent release of UF 6 . At the time of publication, a detailed metallurgical examination of the damaged cylinder was under way and results were not available. Subsequent to the publication of Volume 1, a second incident occurred at the Sequoyah Fuels Corporation facility. On March 13, 1986, a Model 48X cylinder was overfilled during a special one-time draining procedure; however, no release of UF 6 occurred. An Augmented Investigation Team investigated this second incident. This report, NUREG-1179, Volume 2, presents the findings made by the Augmented Investigation Team of the March 13 incident and the report of the detailed metallurgical examination conducted by Battelle Columbus Division of the cylinder damaged on January 4, 1986

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

    International Nuclear Information System (INIS)

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

    1997-11-01

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

  4. Review of models used for determining consequences of UF{sub 6} release: Model evaluation report. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Nair, S.K.; Chambers, D.B.; Park, S.H.; Radonjic, Z.R.; Coutts, P.T.; Lewis, C.J.; Hammonds, J.S.; Hoffman, F.O. [Senes Oak Ridge, Inc., TN (United States). Center for Risk Analysis

    1997-11-01

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

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

    International Nuclear Information System (INIS)

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

    1990-01-01

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

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

    International Nuclear Information System (INIS)

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

    1997-11-01

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

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

    International Nuclear Information System (INIS)

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

    1976-12-01

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

  8. Disorganized Attachment in Infancy Predicts Greater Amygdala Volume in Adulthood

    Science.gov (United States)

    Lyons-Ruth, K.; Pechtel, P.; Yoon, S.A.; Anderson, C.M.; Teicher, M.H.

    2016-01-01

    Early life stress in rodents is associated with increased amygdala volume in adulthood. In humans, the amygdala develops rapidly during the first two years of life. Thus, disturbed care during this period may be particularly important to amygdala development. In the context of a 30-year longitudinal study of impoverished, highly stressed families, we assessed whether disorganization of the attachment relationship in infancy was related to amygdala volume in adulthood. Amygdala volumes were assessed among 18 low-income young adults (8M/10F, 29.33±0.49 years) first observed in infancy (8.5±5.6 months) and followed longitudinally to age 29. In infancy (18.58±1.02 mos), both disorganized infant attachment behavior and disrupted maternal communication were assessed in the standard Strange Situation Procedure (SSP). Increased left amygdala volume in adulthood was associated with both maternal and infant components of disorganized attachment interactions at 18 months of age (overall r = .679, p attachment disturbance in adolescence, were not significantly related to left amygdala volume. Left amygdala volume was further associated with dissociation and limbic irritability in adulthood. Finally, left amygdala volume mediated the prediction from attachment disturbance in infancy to limbic irritability in adulthood. Results point to the likely importance of quality of early care for amygdala development in human children as well as in rodents. The long-term prediction found here suggests that the first two years of life may be an early sensitive period for amygdala development during which clinical intervention could have particularly important consequences for later child outcomes. PMID:27060720

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

    International Nuclear Information System (INIS)

    1986-03-01

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

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

    International Nuclear Information System (INIS)

    1986-02-01

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

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

    International Nuclear Information System (INIS)

    1986-03-01

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

  12. Photoionization mass spectrometry of UF6

    International Nuclear Information System (INIS)

    Berkowitz, J.

    1979-01-01

    The photoionization mass spectrum of 238 UF 6 was obtained. At 600 A = 20.66 eV, the relative ionic abundances were as follows: UF 6 + , 1.4; UF 5 + , 100; UF + , 17; UF 3 + , approx. 0.7; UF 2 + , very weak; UF + , very weak; U + , essentially zero. The adiabatic ionization potential for UF 6 was 13.897 +- 0.005 eV. The production of UF 5 + begins at approx. 887 A = 13.98 eV, at which energy the UF 6 + partial cross section abruptly declines and then levels off. This behavior suggests the vague possibility of an isotope effect. The UF 4 + signal begins at approx. 725 A = 17.10 eV, at which energy the UF 5 + signal reaches a plateau value. The UF 5 + photoionization yield curve displays some autoionization structure from its threshold to approx. 750 A

  13. UF{sub 6} pressure excursions during cylinder heating

    Energy Technology Data Exchange (ETDEWEB)

    Brown, P.G. [Martin Marietta Energy Systems, Inc., Paducah, KY (United States)

    1991-12-31

    As liquid UF{sub 6} inside a cylinder changes from a liquid to a solid, it forms a porous solid which occupies approximately the same volume as that of the liquid before cooling. Simultaneously as the liquid cools, UF{sub 6} vapor in the cylinder ullage above the liquid desublimes on the upper region of the inner cylinder wall. This solid is a dense, glass-like material which can accumulate to a significant thickness. The thickness of the solid coating on the upper cylinder wall and directly behind the cylinder valve area will vary depending on the conditions during the cooling stage. The amount of time lapsed between UF{sub 6} solidification and UF{sub 6} liquefaction can also affect the UF{sub 6} coating. This is due to the daily ambient heat cycle causing the coating to sublime from the cylinder wall to cooler areas, thus decreasing the thickness. Structural weakening of the dense UF{sub 6} layer also occurs due to cylinder transport vibration and thermal expansion. During cylinder heating, the UF{sub 6} nearest the cylinder wall will liquefy first. As the solid coating behind the cylinder valve begins to liquefy, it results in increased pressure depending upon the available volume for expansion. At the Paducah Gaseous Diffusion Plant (PGDP) during the liquefaction of the UF{sub 6} in cylinders in the UF{sub 6} feed and sampling autoclaves, this pressure increase has resulted in the activation of the systems rupture discs which are rated at 100 pounds per square inch differential.

  14. Cognitively Engaging Activity is Associated with Greater Cortical and Subcortical Volumes

    Directory of Open Access Journals (Sweden)

    Talia R. Seider

    2016-05-01

    Full Text Available As the population ages and dementia becomes a growing healthcare concern, it is increasingly important to identify targets for intervention to delay or attenuate cognitive decline. Research has shown that the most successful interventions aim at altering lifestyle factors. Thus, this study examined how involvement in physical, cognitive, and social activity is related to brain structure in older adults. Sixty-five adults (mean age = 71.4 years, standard deviation = 8.9 received the Community Healthy Activities Model Program for Seniors (CHAMPS, a questionnaire that polls everyday activities in which older adults may be involved, and also underwent structural magnetic resonance imaging. Stepwise regression with backwards selection was used to predict weekly time spent in either social, cognitive, light physical, or heavy physical activity from the volume of one of the cortical or subcortical regions of interest (corrected by intracranial volume as well as age, education, and gender as control variables. Regressions revealed that more time spent in cognitive activity was associated with greater volumes of all brain regions studied: total cortex (β = .289, p = .014, frontal (β = .276, p = .019, parietal (β = .305, p = .009, temporal (β = .275, p = .020, and occipital (β = .256, p = .030 lobes, and thalamus (β = .310, p = .010, caudate (β = .233, p = .049, hippocampus (β = .286, p = .017, and amygdala (β = .336, p = .004. These effects remained even after accounting for the positive association between cognitive activity and education. No other activity variable was associated with brain volumes. Results indicate that time spent in cognitively engaging activity is associated with greater cortical and subcortical brain volume. Findings suggest that interventions aimed at increasing levels of cognitive activity may delay cognitive consequences of aging and decrease the risk of developing dementia.

  15. Monte carlo feasibility study of an active neutron assay technique for full-volume UF{sub 6} cylinder assay using a correlated interrogation source

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Karen A., E-mail: kamiller@lanl.gov [Los Alamos National Laboratory, Los Alamos, P.O. Box 1663 MS E540, NM 87545 (United States); Menlove, Howard O.; Swinhoe, Martyn T.; Marlow, Johnna B. [Los Alamos National Laboratory, Los Alamos, P.O. Box 1663 MS E540, NM 87545 (United States)

    2013-03-01

    Uranium cylinder assay plays an important role in the nuclear material accounting at gas centrifuge enrichment plants. The Passive Neutron Enrichment Meter (PNEM) was designed to determine uranium mass and enrichment in 30B and 48Y cylinders using total neutron and coincidence counting in the passive mode. 30B and 48Y cylinders are used to hold bulk UF{sub 6} feed, product, and tails at enrichment plants. In this paper, we report the results of a Monte-Carlo-based feasibility study for an active uranium cylinder assay system based on the PNEM design. There are many advantages of the active technique such as a shortened count time and a more direct measure of {sup 235}U content. The active system is based on a modified PNEM design and uses a {sup 252}Cf source as the correlated, active interrogation source. We show through comparison with a random AmLi source of equal strength how the use of a correlated driver significantly boosts the active signal and reduces the statistical uncertainty. We also discuss ways in which an active uranium cylinder assay system can be optimized to minimize background from {sup 238}U fast-neutron induced fission and direct counts from the interrogation source.

  16. Reactions UF4 - ClO2F and UF5 - ClO2F

    International Nuclear Information System (INIS)

    Benoit, Raymond; Besnard, Ginette; Hartmanshenn, Olivier; Luce, Michel; Mougin, Jacques; Pelissie, Jean

    1970-02-01

    The study of the reaction UF 4 - ClO 2 F between 0 deg. and 100 deg. C, by various techniques (micro-sublimation, isopiestic method, IR and UV spectrography, thermogravimetry and X-ray diffraction) shows that intermediate steps are possible before the production of UF 5 . The whole reaction may be schematised by two equations: (1) n UF 4 + ClO 2 F → n UF x + ClO 2 (4 4 + ClO 2 F → UF x + 1/2 Cl 2 + O 2 . The more the temperature rises, the more the second equation becomes experimentally verified. The reaction at 0 deg. C between UF 5 and ClO 2 F may be represented by: UF 5 + ClO 2 F → UF 6 ClO 2 . The reactions: UF 5 + ClO 2 F → UF 6 + ClO 2 , UF 5 + ClO 2 F → UF 6 + 1/2 Cl 2 + O 2 are verified, the first and the second at 25 deg. C., the second from 50 deg. to 150 deg. C. From the results of AGRON it is possible to predict the residual solids before complete volatilization as UF 6 . The IR spectra of ClO 2 F adsorbed on UF 4 and UF x at 60 deg. C have been compared with those of gaseous ClO 2 F and UF 6 adsorbed on UF 4 . (authors) [fr

  17. Analysis of accidental UF6 releases

    International Nuclear Information System (INIS)

    Fan Yumao; Tan Rui; Gao Qifa

    2012-01-01

    As interim substance in the nuclear fuel enrichment process, Uranium Hexafluoride (UF 6 ) is widely applied in nuclear processing, enrichment and fuel fabrication plants. Because of its vivid chemical characteristics and special radiological hazard and chemical toxicity, great attention must be paid to accident of UF 6 leakage. The chemical reactions involved in UF 6 release processes were introduced, therewith potential release styles, pathways and characteristics of diffusion were analyzed. The results indicated that the accidental release process of UF 6 is not a simple passive diffusion. So, specific atmospheric diffusion model related to UF 6 releases need be used in order to analyze and evaluate accurately the accidental consequences. (authors)

  18. Pilot plant UF6 to UF4 test operations report

    International Nuclear Information System (INIS)

    Bicha, W.J.; Fallings, M.; Gilbert, D.D.; Koch, G.E.; Levine, P.J.; McLaughlin, D.F.; Nuhfer, K.R.; Reese, J.C.

    1987-02-01

    The FMPC site includes a plant designed for the reduction of uranium hexafluoride (UF 6 ) to uranium tetrafluoride (UF 4 ). Limited operation of the upgraded reduction facility began in August 1984 and continued through January 19, 1986. A reaction vessel ruptured on that date causing the plant operation to be shut down. The DOE conducted a Class B investigation with the findings of the investigation board issued in preliminary form in May 1986 and as a final recommendation in July 1986. A two-phase restart of the plant was planned and implemented. Phase I included implementing safety system modifications, changing reaction vessel temperature control strategy, and operating the reduction plant under an 8-week controlled test. The results of the test period are the subject of this report. 41 figs., 11 tabs

  19. Risk for affective disorders is associated with greater prefrontal gray matter volumes: A prospective longitudinal study

    DEFF Research Database (Denmark)

    Macoveanu, Julian; Baaré, William; Madsen, Kristoffer Hougaard

    2017-01-01

    transmission. Methods: We used voxel based morphometry to investigate changes in regional GM brain volume, over a seven-year period, in 37 initially healthy individuals having a mono- or di-zygotic twin diagnosed with major depression or bipolar disorder (high-risk group; mean age 41.6 yrs.) as compared to 36...... anterior cingulate, inferior frontal gyrus and temporoparietal regions as compared to low-risk twins. Further, individuals who developed an affective disorder at follow-up (n=12), had relatively the largest GM volumes, both at baseline and follow-up, in the right dorsal anterior cingulate cortex and right...

  20. Rowing increases stroke volume and cardiac output to a greater extent than cycling

    Czech Academy of Sciences Publication Activity Database

    Horn, P.; Ošťádal, P.; Ošťádal, Bohuslav

    2015-01-01

    Roč. 64, č. 2 (2015), s. 203-207 ISSN 0862-8408 Institutional support: RVO:67985823 Keywords : cardiac output * cycling * heart rate * stroke volume Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 1.643, year: 2015

  1. Risk for affective disorders is associated with greater prefrontal gray matter volumes

    DEFF Research Database (Denmark)

    Macoveanu, Julian; Baaré, William Frans Christian; Madsen, Kristoffer H

    2018-01-01

    Background: Major depression and bipolar disorders aggregates in families and are linked with a wide range ofneurobiological abnormalities including cortical gray matter (GM) alterations. Prospective studies of individualsat familial risk may expose the neural mechanisms underlying risk...... inferior frontal cortex compared to high- and low-risk twins who remainedwell at follow-up.Conclusion: This pattern of apparently stable grater regional GM volume may constitute a neural marker of anincreased risk for developing an affective disorder in individuals at familial risk....... transmission.Methods: We used voxel based morphometry to investigate changes in regional GM brain volume, over a seven-year period, in 37 initially healthy individuals having a mono- or di-zygotic twin diagnosed with major de-pression or bipolar disorder (high-risk group; mean age 41.6 yrs.) as compared to 36...

  2. Properties of Sago Particleboards Resinated with UF and PF Resin

    Directory of Open Access Journals (Sweden)

    Chen Chiang Tay

    2016-01-01

    Full Text Available The sago processing industry in Mukah, Sarawak, had generated huge amount of sago waste after the milling process and scientists have employed the waste into composite material. In this work, sago residues were mixed with the Phenol Formaldehyde (PF and Urea Formaldehyde (UF for particleboard fabrication. The fabrication and testing methods are based on JIS A 5908 Standard. A single layer particleboard using sago particles was fabricated at targeted density of 600 kg/m3. Particles with weight fractions of 90%, 85%, and 80% with two different matrices were used in the fabrication. The results demonstrated that the samples with different weight fraction and matrix have great influence on the mechanical properties such as MOR, MOE, Young’s Modulus, tensile strength, impact strength, screw test, and internal bonding. The sago UF/PF particleboard only displays single stage decomposition. All the panels underwent physical tests which are water absorption and thickness swelling. The combination of sago particles with UF/PF can be utilized for general indoor application purposes such as furniture manufacturing. Sago particleboard made by UF/PF provided the advantages like optimized performance, minimized weight and volume, cost effectiveness, chemical resistance, and resistance to biodegradation.

  3. Greater-than-Class C low-level radioactive waste characterization: Estimated volumes, radionuclide activities, and other characteristics

    International Nuclear Information System (INIS)

    Hulse, R.A.

    1991-08-01

    Planning for storage or disposal of greater-than-Class C low-level radioactive waste (GTCC LLW) requires characterization of that waste to estimate volumes, radionuclide activities, and waste forms. Data from existing literature, disposal records, and original research were used to estimate the characteristics and project volumes and radionuclide activities to the year 2035. GTCC LLW is categorized as: nuclear utilities waste, sealed sources waste, DOE-held potential GTCC LLW; and, other generator waste. It has been determined that the largest volume of those wastes, approximately 57%, is generated by nuclear power plants. The Other Generator waste category contributes approximately 10% of the total GTCC LLW volume projected to the year 2035. Waste held by the Department of Energy, which is potential GTCC LLW, accounts for nearly 33% of all waste projected to the year 2035; however, no disposal determination has been made for that waste. Sealed sources are less than 0.2% of the total projected volume of GTCC LLW

  4. Greater-than-Class C low-level radioactive waste characterization: Estimated volumes, radionuclide activities, and other characteristics. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    1994-09-01

    The Department of Energy`s (DOE`s) planning for the disposal of greater-than-Class C low-level radioactive waste (GTCC LLW) requires characterization of the waste. This report estimates volumes, radionuclide activities, and waste forms of GTCC LLW to the year 2035. It groups the waste into four categories, representative of the type of generator or holder of the waste: Nuclear Utilities, Sealed Sources, DOE-Held, and Other Generator. GTCC LLW includes activated metals (activation hardware from reactor operation and decommissioning), process wastes (i.e., resins, filters, etc.), sealed sources, and other wastes routinely generated by users of radioactive material. Estimates reflect the possible effect that packaging and concentration averaging may have on the total volume of GTCC LLW. Possible GTCC mixed LLW is also addressed. Nuclear utilities will probably generate the largest future volume of GTCC LLW with 65--83% of the total volume. The other generators will generate 17--23% of the waste volume, while GTCC sealed sources are expected to contribute 1--12%. A legal review of DOE`s obligations indicates that the current DOE-Held wastes described in this report will not require management as GTCC LLW because of the contractual circumstances under which they were accepted for storage. This report concludes that the volume of GTCC LLW should not pose a significant management problem from a scientific or technical standpoint. The projected volume is small enough to indicate that a dedicated GTCC LLW disposal facility may not be justified. Instead, co-disposal with other waste types is being considered as an option.

  5. Greater-than-Class C low-level radioactive waste characterization: Estimated volumes, radionuclide activities, and other characteristics. Revision 1

    International Nuclear Information System (INIS)

    1994-09-01

    The Department of Energy's (DOE's) planning for the disposal of greater-than-Class C low-level radioactive waste (GTCC LLW) requires characterization of the waste. This report estimates volumes, radionuclide activities, and waste forms of GTCC LLW to the year 2035. It groups the waste into four categories, representative of the type of generator or holder of the waste: Nuclear Utilities, Sealed Sources, DOE-Held, and Other Generator. GTCC LLW includes activated metals (activation hardware from reactor operation and decommissioning), process wastes (i.e., resins, filters, etc.), sealed sources, and other wastes routinely generated by users of radioactive material. Estimates reflect the possible effect that packaging and concentration averaging may have on the total volume of GTCC LLW. Possible GTCC mixed LLW is also addressed. Nuclear utilities will probably generate the largest future volume of GTCC LLW with 65--83% of the total volume. The other generators will generate 17--23% of the waste volume, while GTCC sealed sources are expected to contribute 1--12%. A legal review of DOE's obligations indicates that the current DOE-Held wastes described in this report will not require management as GTCC LLW because of the contractual circumstances under which they were accepted for storage. This report concludes that the volume of GTCC LLW should not pose a significant management problem from a scientific or technical standpoint. The projected volume is small enough to indicate that a dedicated GTCC LLW disposal facility may not be justified. Instead, co-disposal with other waste types is being considered as an option

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

    International Nuclear Information System (INIS)

    Broadhead, B.L.

    1991-10-01

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

  7. A study of UF4 preparations

    International Nuclear Information System (INIS)

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

    1985-05-01

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

  8. Characterization of Greater-Than-Class C sealed sources. Volume 3, Sealed sources held by general licensees

    International Nuclear Information System (INIS)

    Harris, G.

    1994-09-01

    This is the third volume in a series of three volumes characterizing the population of sealed sources that may become greater-than-Class C low-level radioactive waste (GTCC LLW). In this volume, those sources possessed by general licensees are discussed. General-licensed devices may contain sealed sources with significant amounts of radioactive material. However, the devices are designed to be safe to use without special knowledge of radiological safety practices. Devices containing Am-241 or Cm-244 sources are most likely to become GTCC LLW after concentration averaging. This study estimates that there are about 16,000 GTCC devices held by general licensees; 15,000 of these contain Am-241 sources and 1,000 contain Cm-244 sources. Additionally, this study estimates that there are 1,600 GTCC devices sold to general licensees each year. However, due to a lack of available information on general licensees in Agreement States, these estimates are uncertain. This uncertainty is quantified in the low and high case estimates given in this report, which span approximately an order of magnitude

  9. Sensitivity of UF-R, UF-VCh, UF-VR films used for soft x-ray (lambda=2+10A) detection

    International Nuclear Information System (INIS)

    Aglitskij, E.V.; Bojko, V.A.; Kalinkina, T.A.

    1975-01-01

    The sensitometric characteristics of the following types of photographic film were measured in the range of wavelengths 2-10A: UF-R, UF-VCh, and UF-VR. It was demonstrated that UF-VR photographic film is four times as sensitive as UF-R film and 1.6 times as sensitive as UF-VCh film; it is also most suitable film for x-ray spectroscopy of multiply charged ions and for diagnosing high-temperature laser plasma

  10. Uranium isotope exchange between gaseous UF6 and solid UF5

    International Nuclear Information System (INIS)

    Yato, Yumio; Kishimoto, Yoichiro; Sasao, Nobuyuki; Suto, Osamu; Funasaka, Hideyuki

    1996-01-01

    Based on a collision model, a new rate equation is derived for uranium isotope exchange between gaseous UF 6 and solid UF 5 by considering the number of UF 5 molecules on the solid surface to be dependent on time. The reaction parameters included in the equation are determined from the experimental data and compared with the previous ones. A remarkable agreement is found between the particle sizes of UF 5 estimated from the reaction parameter and from the direct observation with an electron microscope. The rate equation given in this work fully satisfies the related mass conservation and furthermore includes explicitly the terms related to the UF 6 density and the mean size of UF 5 particles, both of which are considered to cause an important effect on the reaction. This remarkable feature facilitates the simulation studies on this reaction under various conditions. The long term behavior of a simulated exchange reaction is studied under the condition considered to be close to that in a recovery zone of the MLIS process. The result indicates that the reaction is virtually limited to the solid surface under this conditions and thus the depletion of 235 UF 5 concentration averaged over the whole UF 5 particles is not significant even after 200 h of the exchange reaction

  11. Chemical exchange between UF6 and UF6- ion in anhydrous hydrofluoric acid

    International Nuclear Information System (INIS)

    Chatelet, J.; Luce, M.; Plurien, P.; Rigny, P.

    1975-01-01

    The chemical exchange between UF 6 and the UF 6 - ion is of potential interest for the separation of U isotopes. In this paper, results concerning the value of the separation factor and the kinetics of the homogeneous exchange are given [fr

  12. Studies on (2UF4 + H2 = 2UF3 + 2HF) and vapour pressure of UF3

    International Nuclear Information System (INIS)

    Roy, K.N.; Prasad, R.; Venugopal, V.; Singh, Z.; Sood, D.D.

    1982-01-01

    Equilibrium constants for 2UF 4 (s) + H 2 (g) = 2UF 3 (s) + 2HF(g) have been measured in the temperature range 967 to 1120 K. An expression is given for the results. The results have been treated by second- and third-law methods to obtain ΔH 0 (298.15 K) and the values are given. The value of ΔS 0 (298.15 K) has been calculated by the second-law method. An expression is given for the vapour pressure of UF 3 (s), measured by the transpiration technique in the range 1229 to 1367 K. The standard enthalpy of vaporization ΔH 0 sub(v) (298.15 K) and the standard entropy of vaporization ΔS 0 sub(v) (298.15 K) have been calculated. The vaporization results have also been used for the calculation of ΔH 0 sub(f)(UF 3 , g, 298.15 K) and ΔS 0 sub(f)(UF 3 ,g, 298.15 K). (author)

  13. Preventive maintenance basis: Volume 10 -- High voltage electric motors (5 kV and greater). Final report

    International Nuclear Information System (INIS)

    Worledge, D.; Hinchcliffe, G.

    1997-07-01

    US nuclear plants are implementing preventive maintenance (PM) tasks with little documented basis beyond fundamental vendor information to support the tasks or their intervals. The Preventive Maintenance Basis project provides utilities with the technical basis for PM tasks and task intervals associated with 40 specific components such as valves, electric motors, pumps, and HVAC equipment. This report provides an overview of the PM Basis project and describes use of the PM Basis database. Volume 10 of the report provides a program of PM tasks suitable for application to high voltage (5kV and greater) electric motors in nuclear power plants. The PM tasks that are recommended provide a cost-effective way to intercept the causes and mechanisms that lead to degradation and failure. They can be used, in conjunction with material from other sources, to develop a complete PM program or to improve an existing program. Users of this information will be utility managers, supervisors, craft technicians, and training instructors responsible for developing, optimizing, or fine-tuning PM programs. Reactor Coolant Pumps motors (RCP's) are not excluded from this report in so far as good PM practices for motors of the appropriate class are concerned. However, the special auxiliary equipment normally associated with RCP's has not been included. Consequently, this report does not provide a complete PM program for RCP's. Industry and vendor programs for RCP's should be consulted for complete definition of RCP motor PM programs

  14. Depleted UF6 programmatic environmental impact statement

    International Nuclear Information System (INIS)

    1997-01-01

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

  15. Corrosion of breached UF6 storage cylinders

    International Nuclear Information System (INIS)

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

    1993-01-01

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

  16. Metamorphosis: Phases of UF{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Dyer, R.H. [Department of Energy, Oak Ridge, TN (United States)

    1991-12-31

    A 15-minute videotape is presented. The subject matter is 150 grams of UF{sub 6} sealed in a glass tube. Close-up views show the UF{sub 6} as phase changes are effected by the addition or removal of heat from the closed system. The solid-to-liquid transition is shown as heat is added, both slowly and rapidly. The solid phases which result from freezing and from desublimation are contrasted. In the solid state, uranium hexafluoride is a nearly-white, dense crystalline solid. The appearance of this solid depends on whether it is formed by freezing from the liquid or by desublimation from the vapor phase. If frozen from the liquid, the solid particles take the form of irregularly shaped coarse grains, while the solid product of desublimation tends to be a rather formless mass without individually distinguishable particles. The changes in state are presented in terms of the UF{sub 6} phase diagram.

  17. Reactions UF{sub 4} - ClF, UF{sub 4} - ClF{sub 3}, UF{sub 5} - ClF, UF{sub 5} - ClF{sub 3}; Reactions UF{sub 4} - ClF, UF{sub 4} - ClF{sub 3}, UF{sub 5} - ClF, UF{sub 5} - ClF{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Luce, M; Benoit, R; Hartmanshenn, O [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1968-07-01

    The reaction between ClF{sub 3} and UF{sub 4} is partially explained by the study of the reactions of the three systems: UF{sub 4}-ClF, UF{sub 5}-ClF and UF{sub 5}-ClF{sub 3}. The analytical techniques used are: the micro-sublimation, the infra-red spectroscopy and the thermogravimetry. The origin of the by-products is indicated. (authors) [French] La reaction entre ClF{sub 3} et UF{sub 4} est partiellement expliquee grace a l'etude des reactions des trois systemes UF{sub 4}-ClF, UF{sub 5}-ClF et UF{sub 5}-ClF{sub 3}. Les techniques analytiques utilisees sont: la micro-sublimation, la spectroscopie infrarouge et la thermogravimetrie. L'origine des sous-produits est indiquee. (auteurs)

  18. UF{sub 6} cylinder fire test

    Energy Technology Data Exchange (ETDEWEB)

    Park, S.H. [Oak Ridge K-25 Site, Oak Ridge, TN (United States)

    1991-12-31

    With the increasing number of nuclear reactors for power generation, there is a comparable increase in the amount of UF{sub 6} being transported. Likewise, the probability of having an accident involving UF{sub 6}-filled cylinders also increases. Accident scenarios which have been difficult to assess are those involving a filled UF{sub 6} cylinder subjected to fire. A study is underway at the Oak Ridge K-25 Site, as part of the US DOE Enrichment Program, to provide empirical data and a computer model that can be used to evaluate various cylinder-in-fire scenarios. It is expected that the results will provide information leading to better handling of possible fire accidents as well as show whether changes should be made to provide different physical protection during shipment. The computer model being developed will be capable of predicting the rupture of various cylinder sizes and designs as well as the amount of UF{sub 6}, its distribution in the cylinder, and the conditions of the fire.

  19. Greater-than-Class C low-level waste characterization. Appendix I: Impact of concentration averaging low-level radioactive waste volume projections

    International Nuclear Information System (INIS)

    Tuite, P.; Tuite, K.; O'Kelley, M.; Ely, P.

    1991-08-01

    This study provides a quantitative framework for bounding unpackaged greater-than-Class C low-level radioactive waste types as a function of concentration averaging. The study defines the three concentration averaging scenarios that lead to base, high, and low volumetric projections; identifies those waste types that could be greater-than-Class C under the high volume, or worst case, concentration averaging scenario; and quantifies the impact of these scenarios on identified waste types relative to the base case scenario. The base volume scenario was assumed to reflect current requirements at the disposal sites as well as the regulatory views. The high volume scenario was assumed to reflect the most conservative criteria as incorporated in some compact host state requirements. The low volume scenario was assumed to reflect the 10 CFR Part 61 criteria as applicable to both shallow land burial facilities and to practices that could be employed to reduce the generation of Class C waste types

  20. Transport of natural UF6 in a challenging environment

    International Nuclear Information System (INIS)

    Chollet, P.; Presta, A.

    2004-01-01

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

  1. Transport of natural UF6 in a challenging environment

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-07-01

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

  2. Novel 3D-CT evaluation of carotid stent volume: greater chronological expansion of stents in patients with vulnerable plaques.

    Science.gov (United States)

    Itami, Hisakazu; Tokunaga, Koji; Okuma, Yu; Hishikawa, Tomohito; Sugiu, Kenji; Ida, Kentaro; Date, Isao

    2013-09-01

    Although self-expanding carotid stents may dilate gradually, the degrees of residual stenosis have been quantified by the NASCET criteria, which is too simple to reflect the configuration of the stented artery. We measured the volumes of the stent lumens chronologically by 3D-CT in patients after carotid artery stenting (CAS), and analyzed the correlations between the volume change and medical factors. Fourteen patients with carotid artery stenosis were treated using self-expanding, open-cell stents. All patients underwent preoperative plaque MRI (magnetization-prepared rapid acquisition gradient-echo, MPRAGE) and chronological 3D-CT examinations of their stents immediately after their placement and 1 day, 1 week, and 1 month after the procedure. The volume of the stent lumen was measured using a 3D workstation. The correlations between stent volume and various factors including the presence of underlying diseases, plaque characteristics, and the results of the CAS procedure were analyzed. Stent volume gradually increased in each case and had increased by 1.04-1.55 (mean, 1.25)-fold at 1 postoperative month. The presence of underlying medical diseases, plaque length, the degree of residual stenosis immediately after CAS, and plaque calcification did not have an impact on the change in stent volume. On the other hand, the stent volume increase was significantly larger in the patients with vulnerable plaques that demonstrated high MPRAGE signal intensity (P stent volume. Self-expanding stents in carotid arteries containing vulnerable plaques expand significantly more than those without such plaques in a follow-up period.

  3. Thermal plasma reduction of UF6

    International Nuclear Information System (INIS)

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

    1995-01-01

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

  4. New regulatory aspects of UF6 transport

    International Nuclear Information System (INIS)

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

    1987-01-01

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

  5. The process research of drying UF4 by microwave

    International Nuclear Information System (INIS)

    Wen Guo; Wang Yunbo; Liu Long

    2010-01-01

    This paper make use of microwave to dry UF 4 filter cake, the aim is desorbed adsorption water. The research focus on such process conditions, boat material, thickness of filter cake, drying time, setting temperature, heating power and so on. the research of desorption crystal water of UF 4 that dried by microwave in fixed bed .When UF 4 drying by microwave and claiming by fixed bed, the qualified UF 4 powder is prepared. The research is shown that microwave can desorbs adsorption water which contain in UF 4 filter cake. There is a stable water contents in UF 4 after drying, and the sum of two members is less. After drying by microwave and claiming by fixed bed, the contents of water, UO 2 and UO 2 F 2 are all according to the quality standard. (authors)

  6. Characterization of Greater-Than-Class C sealed sources. Volume 2, Sealed source characterization and future production

    International Nuclear Information System (INIS)

    Harris, G.; Griffel, A.

    1994-09-01

    Sealed sources are small, relatively high-activity radioactive sources typically encapsulated in a metallic container. The activities can range from less than 1 mCi to over 1,000 Ci. They are used in a variety of industries and are commonly available. Many of the sources will be classified as Greater-Than-Class C low-level radioactive waste (GTCC LLW) for the purpose of waste disposal. The US Department of Energy is responsible for disposing of this class of low-level radioactive waste. The characterization of a sealed source is essentially a function of the type of radiation it emits, the principal use for which it is applied, and the activity it contains. The types of radiation of most interest to the GTCC LLW Program are gamma rays and neutrons, since these are emitted by the highest activity sources. The principal uses of most importance are gamma irradiators, medical teletherapy, well logging probes, and other general neutron applications. Current annual production rates of potential Greater-Than-Class C (PGTCC) sources sold to specific licensees were estimated based on data collected from device manufacturers. These estimates were then adjusted for current trends in the industry to estimate future annual production rates. It is expected that there will be approximately 8,000 PGTCC sealed sources produced annually for specific licensees

  7. Polarized training has greater impact on key endurance variables than threshold, high intensity or high volume training

    Directory of Open Access Journals (Sweden)

    Thomas eStöggl

    2014-02-01

    Full Text Available Endurance athletes integrate four conditioning concepts in their training programs: high-volume training (HVT, ‘threshold-training’ (THR, high-intensity interval training (HIIT and a combination of these aforementioned concepts known as polarized training (POL. The purpose of this study was to explore which of these four training concepts provides the greatest response on key components of endurance performance in well-trained endurance athletes. Methods: Forty eight runners, cyclists, triathletes and cross-country skiers (peak oxygen uptake: (VO2peak: 62.6±7.1 mL∙min-1∙kg-1 were randomly assigned to one of four groups performing over nine weeks. An incremental test, work economy and a VO2peak tests were performed. Training intensity was heart rate controlled. Results: POL demonstrated the greatest increase in VO2peak (+6.8 ml∙min∙kg-1 or 11.7%, P0.05. Conclusion: POL resulted in the greatest improvements in most key variables of endurance performance in well-trained endurance athletes. THR or HVT did not lead to further improvements in performance related variables.

  8. Assessment of UF6 Equation of State

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-02-11

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

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

    International Nuclear Information System (INIS)

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

    1995-10-01

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

  10. Optimizing UF Cleaning in UF-SWRO System Using Red Sea Water

    KAUST Repository

    Bahshwan, Mohanad

    2012-07-01

    Increasing demand for fresh water in arid and semi-arid areas, similar to the Middle East, pushed for the use of seawater desalination techniques to augment freshwater. Seawater Reverse Osmosis (SWRO) is one of the techniques that have been commonly used due to its cost effectiveness. Recently, the use of Ultrafiltration (UF) was recommended as an effective pretreatment for SWRO membranes, as opposed to conventional methods (i.e. sand filtration). During UF operation, intermittent cleaning is required to remove particles and contaminants from the membrane\\'s surface and pores. The different cleaning steps consume chemicals and portion of the product water, resulting in a decrease in the overall effectiveness of the process and hence an increase in the production cost. This research focused on increasing the plant\\'s efficiency through optimizing the cleaning protocol without jeopardizing the effectiveness of the cleaning process. For that purpose, the design of experiment (DOE) focused on testing different combinations of these cleaning steps while all other parameters (such as filtration flux or backwash flux) remained constant. The only chemical used was NaOCI during the end of each experiment to restore the trans-membrane pressure (TMP) to its original state. Two trains of Dow™ Ultrafiltration SFP-2880 were run in parallel for this study. The first train (named UF1) was kept at the manufacturer\\'s recommended cleaning steps and frequencies, while the second train (named UF2) was varied according to the DOE. The normalized final TMP was compared to the normalized initial TMP to measure the fouling rate of the membrane at the end of each experiment. The research was supported by laboratory analysis to investigate the cause of the error in the data by analyzing water samples collected at different locations. Visual inspection on the results from the control unit showed that the data cannot be reproduced with the current feed water quality. Statistical analysis

  11. Angle β of greater than 80° at the start of spirometry may identify high-quality flow volume curves.

    Science.gov (United States)

    Lian, Ningfang; Li, Li; Ren, Weiying; Jiang, Zhilong; Zhu, Lei

    2017-04-01

    The American Thoracic Society (ATS) and European Respiratory Society (ERS) emphasize a satisfactory start in maximal expiratory flow-volume (MEFV) curves and highlight subjective parameters: performance without hesitation and expiration with maximum force. We described a new parameter, angle β for characterization of the start to the MEFV curve. Subjects completed the MEFV curve at least three times and at least two curves met ATS/ERS quality. Subjects were divided into normal, restrictive and obstructive groups according to pulmonary function test results. The tangent line was drawn at the start of the MEFV curve's ascending limb to the x-axis and the angle β between the tangent line and x-axis was obtained. The relationships between tangent of β, pulmonary function parameters (PFPs) and anthropometric data were assessed. The MEFV curves with insufficient explosion at the start were considered as poor-quality MEFV curves. In 998 subjects with high-quality spirometry, although PFP varied in relation to the three aspects: the angle β and its tangent were similar (P > 0.05), the tangent of β did not correlate with PFP or anthropometric measurements (P > 0.05) and the lower limit of normal (LLN) of the angle β was 80° in the group with high-quality spirometry (P < 0.05). Angle β derived from poor-quality MEFV curves was smaller than that from good quality one (P < 0.05). Angle β may function as a parameter to assess the expiratory efforts, which can be used to assess the quality of the MEFV curve start. © 2016 Asian Pacific Society of Respirology.

  12. Low-dose external beam radiotherapy for greater trochanteric pain syndrome. Target volume definition and treatment outcome

    International Nuclear Information System (INIS)

    Kaltenborn, Alexander; Carl, Ulrich Martin; Hinsche, Tanja; Nitsche, Mirko; Hermann, Robert Michael

    2017-01-01

    Low-dose external beam radiotherapy (ED-EBRT) is frequently used in the therapy of refractory greater trochanteric pain syndrome (GTPS). As studies reporting treatment results are scarce, we retrospectively analyzed our own patient collectives. In all, 60 patients (74 hips) received LD-EBRT (6 x 0.5 Gy in 29 hips, 6 x 1 Gy in 45). The endpoint was the patient's reported subjective response to treatment. The influence of different patient and treatment characteristics on treatment outcome was investigated. At the end of LD-EBRT, 69% reported partial remission, 4% complete remission, no change 28%. A total of 3 months later (n = 52 hips), the results were 37, 33, and 30% and 18 months after LD-EBRT (n = 47) 21, 51, and 28%. In univariate analysis ''inclusion of the total femoral head into the PTV'' and ''night pain before LD-EBRT'' were correlated with symptom remission at the end of LD-EBRT, while ''initial increase in pain during LD-EBRT'' was significantly associated with treatment failure. In multivariable modeling ''initial increase in pain'' was identified as a risk factor for treatment failure (p = 0.007; odds ratio [OR] 0.209; 95% confidence interval [CI] 0.048-0.957), while ''night pain'' was an independent factor for remission (p = 0.038; OR 3.484; 95% CI 1.004-12.6). Three months after LD-EBRT ''night pain'' and ''inclusion of the complete femoral neck circumference into the PTV'' were predictive for remission. LD-EBRT represents a useful treatment option for patients suffering from GTPS. Three months after therapy two-thirds of the patients reported a partial or complete symptom remission. Especially patients who suffered from nocturnal pain seemed to benefit. Treatment appeared to be more effective when the entire circumference of the femoral neck was encompassed. (orig.) [de

  13. UV dissociation of vibrationally excited UF6

    International Nuclear Information System (INIS)

    Alexandre, M.; Clerc, M.; Gagnon, R.; Gilbert, M.; Isnard, P.; Nectoux, P.; Rigny, P.; Weulersse, J.M.

    1983-01-01

    Before application of laser photodissociation of UF 6 to the separation of uranium isotopes becomes practical, isotopic selectivity should be optimized. We present here results on the cross sections involved in the irradiation of UF 6 simultaneously with infrared and ultraviolet lasers, as a function of wavelengths, fluence and temperature (at 293 K and 105 K, in an adiabatic expansion). The experiment uses a Nd 3+ YAG pumped lithium niobate optical parametric oscillator as a tunable 16 μ light source. Energies of the order of 1 mJ can be obtained with linewidths smaller than 0.1 cm - . The UV source used is based on ND 3+ YAG pumped dye laser and various frequency mixing schemes. At low temperature the frequency variation of the absorbed infrared energy per molecule depends markedly on the IR fluence phisub(IR) with a maximum value varying as phisub(IR)sup(-1/2) and a frequency extension far beyond the low level absorption spectrum. The absorbed vibrational energy leads to a change in the UV cross section comparable with the effect of a rise in temperature. Using this a model is put forward to express the isotopic selectivity 235 U/ 238 U as a function of UV wavelength and IR irradiation conditions. Experimental results agree with this model, and yield to maximum selectivity close to two [fr

  14. Yoga Meditation Practitioners Exhibit Greater Gray Matter Volume and Fewer Reported Cognitive Failures: Results of a Preliminary Voxel-Based Morphometric Analysis

    Directory of Open Access Journals (Sweden)

    Brett Froeliger

    2012-01-01

    Full Text Available Hatha yoga techniques, including physical postures (asanas, breathing exercises (pranayama, and meditation, involve the practice of mindfulness. In turn, yoga meditation practices may induce the state of mindfulness, which, when evoked recurrently through repeated practice, may accrue into trait or dispositional mindfulness. Putatively, these changes may be mediated by experience-dependent neuroplastic changes. Though prior studies have identified differences in gray matter volume (GMV between long-term mindfulness practitioners and controls, no studies to date have reported on whether yoga meditation is associated with GMV differences. The present study investigated GMV differences between yoga meditation practitioners (YMP and a matched control group (CG. The YMP group exhibited greater GM volume in frontal, limbic, temporal, occipital, and cerebellar regions; whereas the CG had no greater regional greater GMV. In addition, the YMP group reported significantly fewer cognitive failures on the Cognitive Failures Questionnaire (CFQ, the magnitude of which was positively correlated with GMV in numerous regions identified in the primary analysis. Lastly, GMV was positively correlated with the duration of yoga practice. Results from this preliminary study suggest that hatha yoga practice may be associated with the promotion of neuroplastic changes in executive brain systems, which may confer therapeutic benefits that accrue with repeated practice.

  15. Low-dose external beam radiotherapy for greater trochanteric pain syndrome. Target volume definition and treatment outcome

    Energy Technology Data Exchange (ETDEWEB)

    Kaltenborn, Alexander [Federal Armed Forces Hospital Westerstede, Department of Orthopedic and Trauma Surgery, Westerstede (Germany); Hannover Medical School, Core Facility Quality Management and Health Technology Assessment in Transplantation, Integrated Research and Treatment Center Transplantation (IFB-Tx), Hannover (Germany); Carl, Ulrich Martin; Hinsche, Tanja [Center for Radiotherapy and Radiooncology Bremen and Westerstede, Westerstede (Germany); Nitsche, Mirko [Center for Radiotherapy and Radiooncology Bremen and Westerstede, Westerstede (Germany); University of Schleswig Holstein, Campus Kiel, Department of Radiotherapy, Karl-Lennert Cancer Center, Kiel (Germany); Hermann, Robert Michael [Center for Radiotherapy and Radiooncology Bremen and Westerstede, Westerstede (Germany); Hannover Medical School, Department of Radiotherapy and Special Oncology, Hannover (Germany)

    2017-04-15

    Low-dose external beam radiotherapy (ED-EBRT) is frequently used in the therapy of refractory greater trochanteric pain syndrome (GTPS). As studies reporting treatment results are scarce, we retrospectively analyzed our own patient collectives. In all, 60 patients (74 hips) received LD-EBRT (6 x 0.5 Gy in 29 hips, 6 x 1 Gy in 45). The endpoint was the patient's reported subjective response to treatment. The influence of different patient and treatment characteristics on treatment outcome was investigated. At the end of LD-EBRT, 69% reported partial remission, 4% complete remission, no change 28%. A total of 3 months later (n = 52 hips), the results were 37, 33, and 30% and 18 months after LD-EBRT (n = 47) 21, 51, and 28%. In univariate analysis ''inclusion of the total femoral head into the PTV'' and ''night pain before LD-EBRT'' were correlated with symptom remission at the end of LD-EBRT, while ''initial increase in pain during LD-EBRT'' was significantly associated with treatment failure. In multivariable modeling ''initial increase in pain'' was identified as a risk factor for treatment failure (p = 0.007; odds ratio [OR] 0.209; 95% confidence interval [CI] 0.048-0.957), while ''night pain'' was an independent factor for remission (p = 0.038; OR 3.484; 95% CI 1.004-12.6). Three months after LD-EBRT ''night pain'' and ''inclusion of the complete femoral neck circumference into the PTV'' were predictive for remission. LD-EBRT represents a useful treatment option for patients suffering from GTPS. Three months after therapy two-thirds of the patients reported a partial or complete symptom remission. Especially patients who suffered from nocturnal pain seemed to benefit. Treatment appeared to be more effective when the entire circumference of the femoral neck was encompassed. (orig.) [German] In der Behandlung des

  16. Technical documentation of HGSYSTEM/UF6 model

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  17. Method and apparatus for measuring enrichment of UF6

    Science.gov (United States)

    Hill, Thomas Roy [Santa Fe, NM; Ianakiev, Kiril Dimitrov [Los Alamos, NM

    2011-06-07

    A system and method are disclosed for determining the enrichment of .sup.235U in Uranium Hexafluoride (UF6) utilizing synthesized X-rays which are directed at a container test zone containing a sample of UF6. A detector placed behind the container test zone then detects and counts the X-rays which pass through the container and the UF6. In order to determine the portion of the attenuation due to the UF6 gas alone, this count rate may then be compared to a calibration count rate of X-rays passing through a calibration test zone which contains a vacuum, the test zone having experienced substantially similar environmental conditions as the actual test zone. Alternatively, X-rays of two differing energy levels may be alternately directed at the container, where either the container or the UF6 has a high sensitivity to the difference in the energy levels, and the other having a low sensitivity.

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

    International Nuclear Information System (INIS)

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

    1983-01-01

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

  19. Fracture mechanics performance of UF6 containers

    International Nuclear Information System (INIS)

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

    1993-01-01

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

  20. Investigation of UF6 behavior in a fire

    International Nuclear Information System (INIS)

    Williams, W.R.

    1988-01-01

    Reactions between UF 6 and combustible gases and the potential for UF 6 -filled cylinders to rupture when exposed to fire are addressed. Although the absence of kinetic data prevents specific identification and quantification of the chemical species formed, potential reaction products resulting from the release of UF 6 into a fire include UF 4 , UO 2 F 2 , HF, C, CF 4 ,COF 2 , and short chain, fluorinated or partially fluorinated hydrocarbons. Such a release adds energy to a fire relative to normal combustion reactions. Time intervals to an assumed point of rupture for UF 6 -filled cylinders exposed to fire are estimated conservatively. Several related studies are also summarized, including a test series in which small UF 6 -filled cylinders were immersed in fire resulting in valve failures and explosive ruptures. It is concluded that all sizes of UF 6 cylinders currently in use may rupture within 30 minutes when totally immersed in a fire. For cylinders adjacent to fires, rupture of the larger cylinders appears much less likely

  1. Habitual 'sleep credit' is associated with greater grey matter volume of the medial prefrontal cortex, higher emotional intelligence and better mental health.

    Science.gov (United States)

    Weber, Mareen; Webb, Christian A; Deldonno, Sophie R; Kipman, Maia; Schwab, Zachary J; Weiner, Melissa R; Killgore, William D S

    2013-10-01

    In modern society, people often fail to obtain the amount of sleep that experts recommend for good health and performance. Insufficient sleep can lead to degraded cognitive performance and alterations in emotional functioning. However, most people also acknowledge that on a regular basis they obtain more sleep than they subjectively perceive they need at a minimum to stave off performance decrements, a construct we describe as subjective 'sleep credit'. Few people would contest the notion that getting more sleep is better, but data on both behavioural and neuroanatomical correlates of 'sleep credit' are surprisingly limited. We conducted a voxel-based morphometric study to assess cerebral grey matter correlates of habitually sleeping more than one's subjective requirements. We further tested whether these structural correlates are associated with perceived emotional intelligence and indices of psychopathology while controlling for age, gender, and total intracranial volume. In a sample of 55 healthy adults aged 18-45 years (28 males, 27 females), whole-brain multiple regression showed that habitual subjective 'sleep credit' was correlated positively with grey matter volume within regions of the left medial prefrontal cortex and right orbitofrontal gyrus. Volumes were extracted and regressed against self-report emotion and psychopathology indices. Only grey matter volume of the medial prefrontal cortex cluster correlated with greater emotional intelligence and lower scores on several indices of psychopathology. Findings converge with previous evidence of the role of the medial prefrontal cortex in the relationship between sleep and emotional functioning, and suggest that behaviour and brain structure vary with habitual 'sleep credit'. © 2013 European Sleep Research Society.

  2. Adducts of UF5 with SbF5 and structure of UF5 . 2SbF5

    International Nuclear Information System (INIS)

    Sawodny, W.; Rediess, K.

    1980-01-01

    Both α-UF 5 and β-UF 5 form only a 1:2 compound UF 5 . 2SbF 5 reacting directly with SbF 5 , from which UF 5 . SbF 5 can be obtained by thermal decomposition. UF 5 . 2SbF 5 crystallizes in the monoclinic space group P2 1 /c with the following lattice constants a = 8.110(4), b = 14.129(6), c = 10.032(6) A and β = 96.97(5) 0 ; Z = 4. An X-ray study shows centrosymmetric four-membered rings of alternating UF 8 and SbF 6 polyhedra connected by other SbF 6 entities. This structure is similar to that of UOF 5 . 2SbF 5 , but the distorted pentagonal-bipyramidal coordination of the U atom found there is increased to a dodecahedral coordination by an additional U-F-Sb bridge, though with a somewaht larger UF distance. (author)

  3. Analysis of an indirect neutron signature for enhanced UF_6 cylinder verification

    International Nuclear Information System (INIS)

    Kulisek, J.A.; McDonald, B.S.; Smith, L.E.; Zalavadia, M.A.; Webster, J.B.

    2017-01-01

    The International Atomic Energy Agency (IAEA) currently uses handheld gamma-ray spectrometers combined with ultrasonic wall-thickness gauges to verify the declared enrichment of uranium hexafluoride (UF_6) cylinders. The current method provides relatively low accuracy for the assay of "2"3"5U enrichment, especially for natural and depleted UF_6. Furthermore, the current method provides no capability to assay the absolute mass of "2"3"5U in the cylinder due to the localized instrument geometry and limited penetration of the 186-keV gamma-ray signature from "2"3"5U. Also, the current verification process is a time-consuming component of on-site inspections at uranium enrichment plants. Toward the goal of a more-capable cylinder assay method, the Pacific Northwest National Laboratory has developed the hybrid enrichment verification array (HEVA). HEVA measures both the traditional 186-keV direct signature and a non-traditional, high-energy neutron-induced signature (HEVA_N_T). HEVA_N_T enables full-volume assay of UF_6 cylinders by exploiting the relatively larger mean free paths of the neutrons emitted from the UF_6. In this work, Monte Carlo modeling is used as the basis for characterizing HEVA_N_T in terms of the individual contributions to HEVA_N_T from nuclides and hardware components. Monte Carlo modeling is also used to quantify the intrinsic efficiency of HEVA for neutron detection in a cylinder-assay geometry. Modeling predictions are validated against neutron-induced gamma-ray spectra from laboratory measurements and a relatively large population of Type 30B cylinders spanning a range of enrichments. Implications of the analysis and findings on the viability of HEVA for cylinder verification are discussed, such as the resistance of the HEVA_N_T signature to manipulation by the nearby placement of neutron-conversion materials.

  4. Analysis of an indirect neutron signature for enhanced UF{sub 6} cylinder verification

    Energy Technology Data Exchange (ETDEWEB)

    Kulisek, J.A., E-mail: Jonathan.Kulisek@pnnl.gov; McDonald, B.S.; Smith, L.E.; Zalavadia, M.A.; Webster, J.B.

    2017-02-21

    The International Atomic Energy Agency (IAEA) currently uses handheld gamma-ray spectrometers combined with ultrasonic wall-thickness gauges to verify the declared enrichment of uranium hexafluoride (UF{sub 6}) cylinders. The current method provides relatively low accuracy for the assay of {sup 235}U enrichment, especially for natural and depleted UF{sub 6}. Furthermore, the current method provides no capability to assay the absolute mass of {sup 235}U in the cylinder due to the localized instrument geometry and limited penetration of the 186-keV gamma-ray signature from {sup 235}U. Also, the current verification process is a time-consuming component of on-site inspections at uranium enrichment plants. Toward the goal of a more-capable cylinder assay method, the Pacific Northwest National Laboratory has developed the hybrid enrichment verification array (HEVA). HEVA measures both the traditional 186-keV direct signature and a non-traditional, high-energy neutron-induced signature (HEVA{sub NT}). HEVA{sub NT} enables full-volume assay of UF{sub 6} cylinders by exploiting the relatively larger mean free paths of the neutrons emitted from the UF{sub 6}. In this work, Monte Carlo modeling is used as the basis for characterizing HEVA{sub NT} in terms of the individual contributions to HEVA{sub NT} from nuclides and hardware components. Monte Carlo modeling is also used to quantify the intrinsic efficiency of HEVA for neutron detection in a cylinder-assay geometry. Modeling predictions are validated against neutron-induced gamma-ray spectra from laboratory measurements and a relatively large population of Type 30B cylinders spanning a range of enrichments. Implications of the analysis and findings on the viability of HEVA for cylinder verification are discussed, such as the resistance of the HEVA{sub NT} signature to manipulation by the nearby placement of neutron-conversion materials.

  5. Anisotropy of the fluorine chemical shift tensor in UF6

    International Nuclear Information System (INIS)

    Rigny, P.

    1965-04-01

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

  6. Computational simulation studies of the reduction process of UF4 to metallic uranium

    International Nuclear Information System (INIS)

    Borges, Wesden de Almeida

    2011-01-01

    The production of metallic uranium is essential for production of fuel elements for using in nuclear reactors manufacturing of radioisotopes and radiopharmaceuticals. In IPEN, metallic uranium is produced by magnesiothermical reduction of UF 4 . This reaction is performed in a closed graphite crucible inserted in a sealed metal reactor and no contact with the outside environment. The set is gradually heated in an oven pit, until it reaches the ignition temperature of the reaction (between 600-650 degree C). The modeling of the heating profile of the system can be made using simulation programs by finite element method. Through the thermal profiles in the load, we can have a notion of heating period required for the reaction to occur, allowing the identification of the same group in a greater or smaller yield in metallic uranium production. Thermal properties of UF 4 are estimated, obtaining thermal conductivity and heat capacity using the Flash Laser Method, and for the load UF 4 + Mg, either. The results are compared to laboratory tests to simulate the primary production process. (author)

  7. Results of ultrasonic testing evaluations on UF6 storage cylinders

    International Nuclear Information System (INIS)

    Lykins, M.L.

    1997-02-01

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

  8. Tight ceramic UF membrane as RO pre-treatment: the role of electrostatic interactions on phosphate rejection.

    Science.gov (United States)

    Shang, Ran; Verliefde, Arne R D; Hu, Jingyi; Zeng, Zheyi; Lu, Jie; Kemperman, Antoine J B; Deng, Huiping; Nijmeijer, Kitty; Heijman, Sebastiaan G J; Rietveld, Luuk C

    2014-01-01

    Phosphate limitation has been reported as an effective approach to inhibit biofouling in reverse osmosis (RO) systems for water purification. The rejection of dissolved phosphate by negatively charged TiO2 tight ultrafiltration (UF) membranes (1 kDa and 3 kDa) was observed. These membranes can potentially be adopted as an effective process for RO pre-treatment in order to constrain biofouling by phosphate limitation. This paper focuses on electrostatic interactions during tight UF filtration. Despite the larger pore size, the 3 kDa ceramic membrane exhibited greater phosphate rejection than the 1 kDa membrane, because the 3 kDa membrane has a greater negative surface charge and thus greater electrostatic repulsion against phosphate. The increase of pH from 6 to 8.5 led to a substantial increase in phosphate rejection by both membranes due to increased electrostatic repulsion. At pH 8.5, the maximum phosphate rejections achieved by the 1 kDa and 3 kDa membrane were 75% and 86%, respectively. A Debye ratio (ratio of the Debye length to the pore radius) is introduced in order to evaluate double layer overlapping in tight UF membranes. Threshold Debye ratios were determined as 2 and 1 for the 1 kDa and 3 kDa membranes, respectively. A Debye ratio below the threshold Debye ratio leads to dramatically decreased phosphate rejection by tight UF membranes. The phosphate rejection by the tight UF, in combination with chemical phosphate removal by coagulation, might accomplish phosphate-limited conditions for biological growth and thus prevent biofouling in the RO systems. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Sensitometric characteristics of UF-4, UF-5, and UFSh-O films in the quantum-energy range of 5-30 keV

    International Nuclear Information System (INIS)

    Datsko, I.M.; Slabkovskaya, M.A.; Sokolov, A.S.; Uvarova, N.V.; Sheromov, M.A.

    1987-01-01

    The sensitivity, gamma, and transmission of UF-4, UF-5, and UFSh-O for quanta with energies of 5-30 keV extracted from a beam of synchrotron radiation are measured. UFSh-O photographic film is more sensitive by a factor of 1.5-2 than are the UF-4 and UF-5 films. The gamma of all the films is greatly dependent on the quantum energy

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

    Science.gov (United States)

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

    1973-01-01

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

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

    International Nuclear Information System (INIS)

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

    1979-01-01

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

  12. Investigation of technology for monitoring UF6 mass flow

    International Nuclear Information System (INIS)

    Cooley, J.N.; Moran, B.W.; Swindle, D.W. Jr.

    1987-06-01

    The applicability of gas flow meters, in-line enrichment monitors, and instruments for measuring uranium or UF 6 concentrations in process streams as a means for verifying declared plant throughput have been investigated. The study was performed to assist the International Atomic Energy Agency in the development of an effective international safeguards approach for aerodynamic uranium enrichment plants. Because the process gas in an aerodynamic enrichment facility is a mixture of UF 6 and H 2 , a mass flow measurement in conjunction with a measurement of the uranium (or UF 6 ) concentration in the process gas is required to quantify the amount of uranium being fed into, and withdrawn from, the cascades for nuclear materials accountability verification. In-line enrichment monitors developed for the US gas centrifuge enrichment plant are found to be applicable only to pure UF 6 streams. Of the five gas flow meters evaluated, the orifice meter and the pitot tube meter are judged the best choices for the proposed applications: the first is recommended for low-velocity gas, small diameter piping; the latter, for high-velocity gas, large diameter piping. Of the six procedures evaluated for measurement of uranium or UF 6 concentration in a mixed process stream, infrared-ultraviolet-visible spectrophotometry is judged to be the best procedure currently available to perform the required measurement. 4 refs., 3 figs., 3 tabs

  13. Review of potential models for UF6 dispersion

    International Nuclear Information System (INIS)

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

    1992-07-01

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

  14. Optimization of the isotopic analysis of UF6 by quadrupole mass spectrometry technique

    International Nuclear Information System (INIS)

    Porto, Peterson

    2006-01-01

    In the present work a procedure for determination of the isotopic ratio 238 U/ 235 U in UF 6 samples was established using a quadrupole mass spectrometer with ionization by electron impact and ion detection by Faraday cup or electron multiplier. For this, the following items were optimized in the spectrometer: the parameters in the ion source that provided the most intense peak, with good shape, for the corresponding mass of the most abundant isotope; the resolution that reduced the non linear effects and the number of analytic cycles that reduced the uncertainty in the results. The measurement process was characterized with respect to the effects of mass discrimination, linearity and memory effect. The mass discrimination showed to be linearly dependent of the sample pressure in the batch volume, for the pressure ranges from 0.15 to 0.30 mbar and from 0.30 to 0.40 mbar. The spectrometer was shown linear in the measurement of isotopic ratios between 0.005 and 0.045. The memory factor for the ion source and for the introduction system were, respectively, 1.000 ± 0.001 and 1.003 ± 0.003; the first one can be ignored, the second one can be eliminated by washing the batch volume with the new sample. A methodology for routine analysis of UF 6 samples and the determination of the uncertainties were set up in details as well. (author)

  15. UF{sub 6} cylinder inspections at PGDP

    Energy Technology Data Exchange (ETDEWEB)

    Lamb, G.W.; Whinnery, W.N. [Martin Marietta Energy Systems, Inc., Paducah, KY (United States)

    1991-12-31

    Routine inspections of all UF{sub 6} cylinders at the Paducah Gaseous Diffusion Plant have been mandated by the Department of Energy. A specific UF{sub 6} cylinder inspection procedure for what items to inspect and training for the operators prior to inspection duty are described. The layout of the cylinder yards and the forms used in the inspections are shown. The large number of cylinders (>30,000) to inspect and the schedule for completion on the mandated time table are discussed. Results of the inspections and the actions to correct the deficiencies are explained. Future inspections and movement of cylinders for relocation of certain cylinder yards are defined.

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

    International Nuclear Information System (INIS)

    1995-09-01

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

  17. Safety provisions for UF{sub 6} handling in the design of a new UF{sub 6} conversion plant

    Energy Technology Data Exchange (ETDEWEB)

    Bannister, S.P. [British Nuclear Fuels plc, Preston (United Kingdom)

    1991-12-31

    British Nuclear Fuels plc (BNFL) Fuel Division is currently undertaking the final design and construction of a new UF{sub 6} conversion plant at its production site at Springfields near Preston in the north of England. The Company has gained much experience in the handling of UF{sub 6} during operation of plants on site since 1961. The major hazard occurs during the liquefication cycle and the basis of the maximum credible incident scenario adopted for safety assessment and design purposes is discussed. This paper considers the design features which have been incorporated in the new plant to counter the hazards presented by the presence of UF{sub 6} in gaseous and liquid form and explains current thinking on operational procedures in areas of potential risk such as cylinder filling. The plant emergency response philosophy and systems are described and specific design provisions which have been included to satisfy the UK regulatory bodies are outlined in some detail.

  18. Kinetics of magnesiothermic reduction of UF4 by DTA

    International Nuclear Information System (INIS)

    Raina, Amulya; Agarwal, Renu

    2016-01-01

    Uranium metal production for nuclear fuel is usually carried out by magnesio-thermic reduction of UF 4 (s). This is a highly exothermic reaction: UF 4 +2Mg → 2MgF 2 + U, ΔH r 298.15 K = -349 kJ/mol. The process is carried out by loading 1:2 molar ratio of UF 4 and Mg mixture in a large stainless steel vessel lined with insulating MgF 2 . This bomb reactor is heated to ~1023 K, but the reaction is known to start at lower temperature. The furnace heat and reaction heat results in shooting mixture temperature to >1800 K. Attaining such high temperatures is desired for complete segregation of fluoride slag (T m MgF 2 =1538 K) and uranium melt (T m =1406 K) due to large difference in their densities, 3.4 gm/cc and 17.9 gm/cc, respectively. For efficient and economic magnesio-thermic reduction of UF 4 , it is desired to understand heat distribution in the reactor vessel, which requires kinetic parameters of this reaction: activation energy (E α ) and A. As this is a solid-solid reaction, studying this reaction kinetics can be approximated by nonisothermal DTA analysis using different heating rates. For non-isothermal conditions, the heating rate (ϕ) = dT/dt is related to rate of propagation of reaction

  19. Dynamic coating of mf/uf membranes for fouling mitigation

    KAUST Repository

    Tabatabai, S. Assiyeh Alizadeh; Leiknes, TorOve

    2017-01-01

    A membrane system including an anti-fouling layer and a method of applying an anti-fouling layer to a membrane surface are provided. In an embodiment, the surface is a microfiltration (MF) or an ultrafiltration (UF) membrane surface. The anti

  20. Conversion of U3O8 to UF6

    International Nuclear Information System (INIS)

    Bodu, R.L.

    1975-01-01

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

  1. UF6 Cylinder Imaging by Fast Neutron Transmission Tomography

    International Nuclear Information System (INIS)

    McElroy, R.; Hausladen, P.; Blackston, M.; Croft, S.

    2015-01-01

    The common use Non-Destructive Assay techniques for the determination of 235 U enrichment and mass of UF6 cylinders used in the production of nuclear reactor fuel require prior knowledge of the physical distribution of the UF6 within the cylinder. The measurement performance for these techniques is typically evaluated based on assumed bounding case distributions of the material. However, little direct data such as radiographic or tomographic images, regarding the distribution of the UF6 within the cylinder is available against which to judge these assumptions. We have developed and tested a prototype active neutron tomographic imaging system employing an Associated Particle Imaging (API) neutron generator and an array of pixelated neutron scintillation counters. This system has been successfully used to obtain the 3-dimensional map of the distribution of UF6 within a type 12B storage cylinder. Results from these measurements are presented and the potential performance and utility of this technique with larger 30B and 48Y cylinders is discussed. (author)

  2. Urenco`s experience of UF{sub 6} handling

    Energy Technology Data Exchange (ETDEWEB)

    Saelmans, F. [Urenco Almelo (Netherlands); Scane, C. [Urenco Capenhurst (United Kingdom); Christofzik, J. [Urenco Gronau (Germany)

    1991-12-31

    Urenco operates enrichment plants at three sites, Almelo (Netherlands), Capenhurst (United Kingdom) and Gronau (Germany). Current installed separative work capacity is 2,500 tSWpa. Since 1971, when the first pilot plants were built, enrichment production has totalled 18,000 tSW. During this last 20 years over 3,500 48 containers of UF{sub 6} have been fed to the plants, over 3,700 30 containers have been filled with product and delivered successfully to Urenco`s customers worldwide and over 3,000 48 containers of depleted tails have been filled and have either been returned to customers or retained for long term storage on site. The paper gives a brief outline of Urenco`s experience in handling UF{sub 6}: the equipment and methods used in receiving, feeding, filling, blending, liquid sampling, storing, moving on site and despatching of UF{sub 6} containers. Some of the difficulties experienced with UF{sub 6} containers are appended.

  3. Temporary patching of damaged UF{sub 6} cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Cardenas, A.L. [Martin Marietta Energy Systems, Inc., OH (United States)

    1991-12-31

    Patching techniques based on application of epoxy resins have been developed for temporarily repairing UF{sub 6} cylinders which have sustained relatively minor damage and must be safely emptied. The method is considerably faster and simpler than metallurgical weld repairs. Laboratory tests, detailed operational procedures, and case histories of experience at the Portsmouth Gaseous Diffusion Plant are described.

  4. UF{sub 6} cylinder lifting equipment enhancements

    Energy Technology Data Exchange (ETDEWEB)

    Hortel, J.M. [Martin Marietta Energy Systems, Inc., Piketon, OH (United States)

    1991-12-31

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

  5. Alternative method of retesting UF{sub 6} cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Christ, R. [Nuclear Crago + Service GmbH, Hanau (Germany)

    1991-12-31

    The paper describes an alternative method to perform the periodic inspection of UF{sub 6} cylinders. The hydraulic test is replaced by ultrasonic checking of wall thickness and by magnetic particle testing of all the weld seams. Information about the legal background, the air leak test and the qualification of inspectors is also given.

  6. Investigation of technology for the monitoring of UF6 mass flow in UF6 streams diluted with H2

    International Nuclear Information System (INIS)

    Baker, O.J.; Cooley, J.N.; Hewgley, W.A.; Moran, B.W.; Swindle, D.W. Jr.

    1986-12-01

    The applicability, availability, and effectiveness of gas flow meters are assessed as a means for verifying the mass flows of pure UF 6 streams diluted with a carrier gas. The initial survey identified the orifice, pitot tube, thermal, vortex shedding, and vortex precession (swirl) meters as promising for the intended use. Subsequent assessments of these flow meters revealed that two - the orifice meter and the pitot tube meter - are the best choices for the proposed applications: the first is recommended for low velocity gas, small diameter piping; the latter, for high velocity gas, large diameter piping. Final selection of the gas flow meters should be based on test loop evaluations in which the proposed meters are subjected to gas flows, temperatures, and pressures representative of those expected in service. Known instruments are evaluated that may be applicable to the measurement of uranium or UF 6 concentration in a UF 6 - H 2 process stream at an aerodynamic enrichment plant. Of the six procedures evaluated, four have been used for process monitoring in a UF 6 environment: gas mass spectrometry, infrared-ultraviolet-visible spectrophotometry, gas chromatography, and acoustic gas analysis. The remaining two procedures, laser fluorimetry and atomic absorption spectroscopy, would require significant development work before they could be used for process monitoring. Infrared-ultravioloet-visible spectrophotometry is judged to be the best procedure currently available to perform the required measurement

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

    OpenAIRE

    Zacharias, Petrus; Pancoko, Marliyadi

    2011-01-01

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

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

    International Nuclear Information System (INIS)

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

    1985-01-01

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

  9. Treatment of poultry slaughterhouse wastewater using a static granular bed reactor (SGBR) coupled with ultrafiltration (UF) membrane system.

    Science.gov (United States)

    Basitere, M; Rinquest, Z; Njoya, M; Sheldon, M S; Ntwampe, S K O

    2017-07-01

    The South African poultry industry has grown exponentially in recent years due to an increased demand for their products. As a result, poultry plants consume large volumes of high quality water to ensure that hygienically safe poultry products are produced. Furthermore, poultry industries generate high strength wastewater, which can be treated successfully at low cost using anaerobic digesters. In this study, the performance of a bench-scale mesophilic static granular bed reactor (SGBR) containing fully anaerobic granules coupled with an ultrafiltration (UF) membrane system, as a post-treatment system, was investigated. The poultry slaughterhouse wastewater was characterized by a chemical oxygen demand (COD) range between 1,223 and 9,695mg/L, average biological oxygen demand of 2,375mg/L and average fats, oil and grease (FOG) of 554mg/L. The SGBR anaerobic reactor was operated for 9 weeks at different hydraulic retention times (HRTs), i.e. 55 and 40 h, with an average organic loading rate (OLR) of 1.01 and 3.14g COD/L.day. The SGBR results showed an average COD, total suspended solids (TSS) and FOG removal of 93%, 95% and 90% respectively, for both OLR. The UF post-treatment results showed an average of COD, TSS and FOG removal of 64%, 88% and 48%, respectively. The overall COD, TSS and FOG removal of the system (SGBR and UF membrane) was 98%, 99.8%, and 92.4%, respectively. The results of the combined SGBR reactor coupled with the UF membrane showed a potential to ensure environmentally friendly treatment of poultry slaughterhouse wastewater.

  10. Experimental Determination of the Solubility of Industrial UF4 Particles

    International Nuclear Information System (INIS)

    Chazel, V.; Houpert, P.; Paquet, F.; Ansoborlo, E.; Henge-Napoli, M.H.

    2000-01-01

    The chemical solubility in cell culture medium and in Gamble's solution and the biokinetic behaviour on rats of an industrial UF 4 compound have been studied in order to predict experimentally absorption parameters (f r , s r , s s ) after inhalation and to provide data for interpreting bioassay data. According to these results, this compound has been found to have an intermediate type of absorption between Types F and M as designated by ICRP for the human respiratory tract. A dose coefficient of 1.4 μSv.Bq -1 has been calculated for an inhaled aerosol with an AMAD of 5.1 μm (σg 2.5), which corresponded to the mean value encountered at the fluorination workplace. Predictive urinary and faecal excretion and lung retention curves have also been deduced to calculate the incorporated activity and the received dose in case of an inhalation of UF 4 by workers. (author)

  11. Development of AN Active 238UF6 Gas Target

    Science.gov (United States)

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

    2014-09-01

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

  12. THERMOPHYSICAL PROPERTIES AND WATER ACTIVITY OF TRANSFERRED CHEESE (UF

    Directory of Open Access Journals (Sweden)

    Mohsen Dalvi Esfahan

    2015-06-01

    Full Text Available Few data are available on the thermophysical properties of cheese in the ripening process.The main objective of this work was to investigate the effects of brining and temperature on the thermophysical properties, i.e., thermal conductivity, specific heat, density and water activity of UF cheese and finally we measure surface heat transfer coefficient .Then we develop models for thermophysical properties based on physical and multiple regression concept .

  13. Radiation dose rates from UF{sub 6} cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Friend, P.J. [Urenco, Capenhurst (United Kingdom)

    1991-12-31

    This paper describes the results of many studies, both theoretical and experimental, which have been carried out by Urenco over the last 15 years into radiation dose rates from uranium hexafluoride (UF{sub 6}) cylinders. The contents of the cylinder, its history, and the geometry all affect the radiation dose rate. These factors are all examined in detail. Actual and predicted dose rates are compared with levels permitted by IAEA transport regulations.

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

    International Nuclear Information System (INIS)

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

    1976-01-01

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

  15. Integrating UF6 Cylinder RF Tracking With Continuous Load Cell Monitoring for Verifying Declared UF6 Feed and Withdrawal Operations Verifying Declared UF6 Feed and Withdrawal Operations

    International Nuclear Information System (INIS)

    Krichinsky, Alan M.; Miller, Paul; Pickett, Chris A.; Richardson, Dave; Rowe, Nathan C.; Whitaker, J. Michael; Younkin, James R.

    2009-01-01

    Oak Ridge National Laboratory is demonstrating the integration of UF6 cylinder tracking, using RF technology, with continuous load cell monitoring (CLCM) at mock UF6 feed and withdrawal (F and W) stations. CLCM and cylinder tracking are two of several continuous-monitoring technologies that show promise in providing integrated safeguards of F and W operations at enrichment plants. Integrating different monitoring technologies allows advanced, automated event processing to screen innocuous events thereby minimizing false alerts to independent inspectors. Traditionally, international inspectors rely on batch verification of material inputs and outputs derived from operator declarations and periodic on-site inspections at uranium enrichment plants or other nuclear processing facilities. Continuously monitoring F and W activities between inspections while providing filtered alerts of significant operational events will substantially increase the amount of valuable information available to inspectors thereby promising to enhance the effectiveness of safeguards and to improve efficiency in conducting on-site inspections especially at large plants for ensuring that all operations are declared.

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

    International Nuclear Information System (INIS)

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

    1995-01-01

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

  17. Epidemiologisk forskning om uførepensjon i Norden

    Directory of Open Access Journals (Sweden)

    Johan Håkon Bjørngaard

    2010-01-01

    Full Text Available En relativ stor andel av befolkningen i yrkesaktiv alder i de nordiske landene mottar uførepensjon, og i Norge er det en klar tendens til økning. Parallelt med dette har interessen for forskning rundt uførepensjon som fenomen økt. Vi har i denne studien beskrevet den epidemiologiske forskningen om uførepensjon i Norden. I en systematisk litteraturgjennomgang fant vi 118 aktuelle artikler. Alle de nordiske landene er godt representert. Kohortstudier med uførepensjon som endepunkt utgjorde hovedvekten av materialet, hvor 67 var populasjonsbaserte mens 29 tok utgangspunkt i selekterte pasientpopulasjoner. I alt seks kohortstudier benyttet uførepensjon som eksponering. Vi fant videre syv kasus-kontrollstudier og ni forsøk. Det er betydelig dokumentasjon på at ulike sykdommer og helseplager er assosiert med økt risiko for uførhet, i tillegg til at sosioøkonomiske og arbeidsrelaterte forhold er av betydning. Gjennomgangen viser at den epidemiologiske forskningen for det meste har rettet blikket mot individuelle årsaker til uførepensjonering. Selv om denne forskningen er viktig, kan den neppe forklare økningen vi har sett i det siste tiåret. Den videre forskningen bør utforske nærmere hvordan individuell sårbarhet ender i utstøtelse fra arbeidslivet. Med tanke på den omfattende forskningen om årsaker på dette feltet, bør man også i større grad gjennomføre forsøk for å bedre utsatte gruppers arbeidsdeltakelse.Bjørngaard JH, Krokstad S, Johnsen R, Karlsen AO, Pape K, Støver M, Sund E, Westin S. Epidemiological research on disability benefits in the Nordic countries. Nor J Epidemiol 2009; 19 (2: 103-114 ENGLISH SUMMARYA substantial part of the workforce in the Nordic countries receives a disability benefit, and in Norway this beneficiary rate is growing. As a result, disability benefit has been the subject of new interest and research. In this study we have reviewed the epidemiological research on disability benefit in the

  18. Testing of the Model 48-14 overpack for UF6 cylinders

    International Nuclear Information System (INIS)

    Stitt, D.H.

    1983-01-01

    Shipment of UF 6 enriched to 1.0% or greater assay 235 U currently is done in either the 30-B overpack or the Paducah tiger overpack. The former contains a 2-1/2 ton cylinder, 30 in. in diameter, while the latter contains a 10-ton cylinder, 48 in. in diameter. There are apparent economy and safety considerations associated with shipping in the larger containers due to the reduced number of shipments and connect and disconnect operations. Further reductions in connect and disconnect operations and shipping costs could be achieved through use of the 14-ton cylinder for shipment of enriched material. With this thought, a program was initiated in 1980 to develop a protective overpack for the Model 48Y cylinder. Two prototype overpacks of wood and stainless steel construction were fabricated. The results from the drop tests and the thermal exposure test are presented

  19. High Intensity Interval Training Leads to Greater Improvements in Acute Heart Rate Recovery and Anaerobic Power as High Volume Low Intensity Training

    Science.gov (United States)

    Stöggl, Thomas L.; Björklund, Glenn

    2017-01-01

    The purpose of the current study was to explore if training regimes utilizing diverse training intensity distributions result in different responses on neuromuscular status, anaerobic capacity/power and acute heart rate recovery (HRR) in well-trained endurance athletes. Methods: Thirty-six male (n = 33) and female (n = 3) runners, cyclists, triathletes and cross-country skiers [peak oxygen uptake: (VO2peak): 61.9 ± 8.0 mL·kg−1·min−1] were randomly assigned to one of three groups (blocked high intensity interval training HIIT; polarized training POL; high volume low intensity oriented control group CG/HVLIT applying no HIIT). A maximal anaerobic running/cycling test (MART/MACT) was performed prior to and following a 9-week training period. Results: Only the HIIT group achieved improvements in peak power/velocity (+6.4%, P 0.05). Acute HRR was improved in HIIT (11.2%, P = 0.002) and POL (7.9%, P = 0.023) with no change in the HVLIT oriented control group. Conclusion: Only a training regime that includes a significant amount of HIIT improves the neuromuscular status, anaerobic power and the acute HRR in well-trained endurance athletes. A training regime that followed more a low and moderate intensity oriented model (CG/HVLIT) had no effect on any performance or HRR outcomes. PMID:28824457

  20. High Intensity Interval Training Leads to Greater Improvements in Acute Heart Rate Recovery and Anaerobic Power as High Volume Low Intensity Training

    Directory of Open Access Journals (Sweden)

    Thomas L. Stöggl

    2017-08-01

    Full Text Available The purpose of the current study was to explore if training regimes utilizing diverse training intensity distributions result in different responses on neuromuscular status, anaerobic capacity/power and acute heart rate recovery (HRR in well-trained endurance athletes.Methods: Thirty-six male (n = 33 and female (n = 3 runners, cyclists, triathletes and cross-country skiers [peak oxygen uptake: (VO2peak: 61.9 ± 8.0 mL·kg−1·min−1] were randomly assigned to one of three groups (blocked high intensity interval training HIIT; polarized training POL; high volume low intensity oriented control group CG/HVLIT applying no HIIT. A maximal anaerobic running/cycling test (MART/MACT was performed prior to and following a 9-week training period.Results: Only the HIIT group achieved improvements in peak power/velocity (+6.4%, P < 0.001 and peak lactate (P = 0.001 during the MART/MACT, while, unexpectedly, in none of the groups the performance at the established lactate concentrations (4, 6, 10 mmol·L−1 was changed (P > 0.05. Acute HRR was improved in HIIT (11.2%, P = 0.002 and POL (7.9%, P = 0.023 with no change in the HVLIT oriented control group.Conclusion: Only a training regime that includes a significant amount of HIIT improves the neuromuscular status, anaerobic power and the acute HRR in well-trained endurance athletes. A training regime that followed more a low and moderate intensity oriented model (CG/HVLIT had no effect on any performance or HRR outcomes.

  1. Quality assurance in the transport of UF{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Ravenscroft, N.L. [Edlow International Company, Washington, DC (United States)

    1991-12-31

    Edlow International`s primary business is the international transportation of radioactive materials. Therefore, Edlow has the responsibility to ensure that shipments are performed in compliance with regulatory requirements. In this regard, Edlow maintains a Quality Assurance (QA) Program. A major part of this Program is the establishment and use of QA Procedures. This paper addresses QA procedural requirements and how they are applied to a routine international shipment of low enriched UF{sub 6}. Only the major requirements for scheduling shipments will be addressed.

  2. Storage and uses alternatives of depleted UF6

    International Nuclear Information System (INIS)

    Marques, S.; Dotto, R.M.

    1988-01-01

    The U-enrichment of the Angra-1 pellets (Brazil) have generated about 792 ton of depleted-U, which is nowadays beeing stored by URENCO. The possible sending of this compound to Brazil, added to the fact that in the future, NUCLEI (Nuclebras Enriquecimento Isotopico) itself will generate it, reopens the discussion of the destination of this compound. In this context, the necessity, interest and viability aspects of a reconvertion plant of UF 6 in Brazil are getting important and are, in what follows, breafly discussed. (author) [pt

  3. Radiation-Triggered Surveillance for UF6 Monitoring

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-12-01

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

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

    International Nuclear Information System (INIS)

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

    1993-01-01

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

  5. Conversion of non-nuclear grade feedstock to UF4

    International Nuclear Information System (INIS)

    Ponelis, A.A.; Slabber, M.N.; Zimmer, C.H.E.

    1987-01-01

    The South African Conversion route is based on the direct feed of ammonium di-uranate produced by any one of a number of different mines. The physical and chemical characteristics of the feedstock can thus vary considerably and influence the conversion rate as well as the final UF 6 product purity. The UF 4 conversion reactor is a Moving Bed Reactor (MBR) with countercurrent flow of the reacting gas phases. Initial problems to continuously operate the MBR were mostly concerned with the physical nature of the UO 3 feed particles. Different approaches to eventually obtain a successful MBR are discussed. Besides obtaining UO 3 feed particles with certain physical attributes, the chemical impurities also have an effect on the operability of the MBR. The influence of the feedstock variables on the reduction and hydrofluorination rates after calcining has largely been determined from laboratory and pilot studies. The effect of chemical impurities such as sodium and potassium on the sinterability of the reacting particles and therefore the optimum temperature range in the MBR is also discussed. Confirmation of the effect of sodium and potassium impurities on the conversion rate has been obtained from large scale reactor operation. (author)

  6. Potential detection systems for monitoring UF6 releases

    International Nuclear Information System (INIS)

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

    1994-09-01

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

  7. Treatment of car wash wastewater by UF membranes

    Science.gov (United States)

    Istirokhatun, Titik; Destianti, Puti; Hargianintya, Adenira; Oktiawan, Wiharyanto; Susanto, Heru

    2015-12-01

    The existence of car wash service facilitates car owners to remove dirt and grime from their vehicles. However, the dirt washed off vehicles as well as the cleaning materials themselves may be harmful to the environment if they are not properly managed and discharged. Many technologies have been proposed to treat car wash wastewater such as coagulation flocculation, tricking filter and flocculation-flotation. Nevertheless, these technologies have low efficiency to eliminate oil and small organic compounds. Ultrafiltration (UF) membranes were used in this study to treat car wash wastewater. This study investigated the performance of UF membranes under various pressures to remove COD, oil and grease, and also turbidity from car wash waste water. The membrane performance was examined by investigation of permeate flux and membrane rejection. The results meet the standard of environmental regulation and it is possible to be reused. The highest rejection was shown by PES10 (polyethersulfone 10 kDa) in 1 bar operation with complete rejection for both turbidity and oil and grace and 95% rejection for COD.

  8. Spectroscopic properties of K5Li2UF10

    International Nuclear Information System (INIS)

    Karbowiak, M.; Gajek, Z.; Drozdzynski, J.

    2005-01-01

    A new uranium (III) fluoro-complex of the formula K 5 Li 2 UF 10 has been synthesised and characterised by X-ray powder diffraction and electronic absorption spectra measurements. The compound crystallises in the orthorhombic system, space group Pnma, with a = 20.723, b = 7.809, c = 6.932 A, V = 1121.89 A 3 , Z = 4 and is isostructural with its K 5 Li 2 NdF 10 and K 5 Li 2 LaF 10 analogous. The absorption spectrum of a polycrystalline sample of K 5 Li 2 UF 10 was recorded at 4.2 K in the 3500-45,000 cm -1 range and is discussed. The observed crystal-field levels were assigned and fitted to parameters of the simplified angular overlap model (AOM) and next to those of a semi-empirical Hamiltonian, which was representing the combined atomic and one-electron crystal-field interactions. The starting values of the AOM parameters were obtained from ab initio calculations. The analysis of the spectra enabled the assignment of 71 crystal-field levels of U 3+ with a relatively small r.m.s. deviation of 37 cm -1 . The total splitting of 714 cm -1 was calculated for the 4 I 9/2 ground multiplet

  9. Spectroscopic properties of K 5Li 2UF 10

    Science.gov (United States)

    Karbowiak, M.; Gajek, Z.; Drożdżyński, J.

    2005-04-01

    A new uranium (III) fluoro-complex of the formula K 5Li 2UF 10 has been synthesised and characterised by X-ray powder diffraction and electronic absorption spectra measurements. The compound crystallises in the orthorhombic system, space group Pnma, with a = 20.723, b = 7.809, c = 6.932 Å, V = 1121.89 Å 3, Z = 4 and is isostructural with its K 5Li 2NdF 10 and K 5Li 2LaF 10 analogous. The absorption spectrum of a polycrystalline sample of K 5Li 2UF 10 was recorded at 4.2 K in the 3500-45,000 cm -1 range and is discussed. The observed crystal-field levels were assigned and fitted to parameters of the simplified angular overlap model (AOM) and next to those of a semi-empirical Hamiltonian, which was representing the combined atomic and one-electron crystal-field interactions. The starting values of the AOM parameters were obtained from ab initio calculations. The analysis of the spectra enabled the assignment of 71 crystal-field levels of U 3+ with a relatively small r.m.s. deviation of 37 cm -1. The total splitting of 714 cm -1 was calculated for the 4I 9/2 ground multiplet.

  10. Computer programs for developing source terms for a UF{sub 6} dispersion model to simulate postulated UF{sub 6} releases from buildings

    Energy Technology Data Exchange (ETDEWEB)

    Williams, W.R.

    1985-03-01

    Calculational methods and computer programs for the analysis of source terms for postulated releases of UF{sub 6} are presented. Required thermophysical properties of UF{sub 6}, HF, and H{sub 2}O are described in detail. UF{sub 6} reacts with moisture in the ambient environment to form HF and H{sub 2}O. The coexistence of HF and H{sub 2}O significantly alters their pure component properties, and HF vapor polymerizes. Transient compartment models for simulating UF{sub 6} releases inside gaseous diffusion plant feed and withdrawl buildings and cascade buildings are also described. The basic compartment model mass and energy balances are supported by simple heat transfer, ventilation system, and deposition models. A model that can simulate either a closed compartment or a steady-state ventilation system is also discussed. The transient compartment models provide input to an atmospheric dispersion model as output.

  11. The applicability of fluoride volatility process to producing UF6 from yellow cake

    International Nuclear Information System (INIS)

    Xia Dechang

    2005-01-01

    The schematic diagrams producing UF 6 from yellow cake are showed in this paper. The characteristics and process improvements of the fluoride volatility process are explained. The applicability of the fluoride volatility process to producing UF 6 from yellow cake is discussed. (authors)

  12. Évolution qualitative et quantitative des composantes de l'œuf ...

    African Journals Online (AJOL)

    SARAH

    28 févr. 2014 ... contrôle de coquille et de calibre dans les fermes. Mots clés : œuf, pondeuse, ... dynamique qualitative des composantes de l'œuf . Certains auteurs ont ... programme de conduite et de gestion d'élevage. Élevées en bande ...

  13. 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

  14. Avslag på uførepensjon

    Directory of Open Access Journals (Sweden)

    Anders M. Galaasen

    2010-01-01

    Full Text Available Introduksjon: Mens mye er skrevet om hvem som får uførepensjon, foreligger det få vitenskapelige artikler om avslag på søknad om uførepensjon.Mål: Vi har gjennomført en undersøkelse over hvem som får avslag på søknad om uførepensjon og hvorledes det går med dem i en 6-7 års oppfølging.Metoder: Data fra FD-trygd, koplet med Statistisk sentralbyrås demografiske data er brukt for å sammenlikne dem som får avslag med dem som blir innvilget uførepensjon 1993 ut fra alder, kjønn, utdanning, etnisitet og inntekt. Trygdestatus for dem med avslag er så fulgt til 2000.Resultater: Vi har funnet at kvinner oftere får avslag enn menn, at de eldste og yngste sjeldnere får avslag og at de med minst inntekt og ikke-vestlig bakgrunn oftere får avslag, mens avslagsprosenten er omtrent den samme på alle utdanningsnivåer. I en oppfølging frem til 2000 viser det seg at de fleste ender opp med trygdeytelser, og at kjønnsforskjellene ytterligere forsterkes. De få av de yngste som får avslag, er relativt hyppig fortsatt uten ytelser.Konklusjon: Selv om noen av dem som får avslag, klarer å komme tilbake til normalt lønnsarbeid, og derigjennom bidra til økt produktivitet, resulterer avslag oftere kun i en utsettelse av overgang til permanente trygdeytelser. Hva den eventuelle samfunnsøkonomiske gevinsten av en slik utsettelse er, når man også tar i betraktning økt saksbehandling fra NAV, samt utgifter til attføring og rehabilitering, er et spørsmål for videre forskning. Galaasen AM, Bruusgaard D, Claussen B. Denial of disability pension. Nor J Epidemiol 2009; 19 (2: 203-208. ENGLISH SUMMARYIntroduction: While much is written about who gets disability pensions, there are few scientific articles on the denial of disability pension.Objective: We conducted a survey of who is rejected disability pension and how their life situation evolves in a 6- 7-year follow-up.Methods: Data from FD-trygd, coupled with Statistics Norway

  15. Dynamic coating of mf/uf membranes for fouling mitigation

    KAUST Repository

    Tabatabai, S. Assiyeh Alizadeh

    2017-01-19

    A membrane system including an anti-fouling layer and a method of applying an anti-fouling layer to a membrane surface are provided. In an embodiment, the surface is a microfiltration (MF) or an ultrafiltration (UF) membrane surface. The anti-fouling layer can include a stimuli responsive layer and a dynamic protective layer applied over the stimuli responsive layer that can be a coating on a surface of the membrane. The stimuli responsive polymer layer can act as an adhesive prior to coating with the dynamic protective layer to aid in adhering the dynamic protective layer to the membrane surface. The dynamic protective layer can be formed by suitable nanoparticles that can prevent adhesion of foulants directly to the membrane surface. The stimuli responsive layer can be responsive to physio- chemical stimuli to cause a release of the stimuli responsive layer and the dynamic protective layer including foulants from the membrane.

  16. UF6 breeder reactor power plants for electric power generation

    International Nuclear Information System (INIS)

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

    1976-01-01

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

  17. Study on UF6 condensing receiving system improvement

    International Nuclear Information System (INIS)

    Zhang Zhenxing; Li Yingfeng; Li Zhenfeng; He Ping; Wang Yanping; Tian Yushan

    2012-01-01

    In order to improve receiving capacity of UF 6 condensing system, the pressure release mode is changed through modifying gas phase inlet of the first-grade condenser, thus pressure release time is reduced from 13.1 h to 8.1 h. Be- cause of improvement of utility condensers of the two product lines, both the flexibility of feeding nitrogen and the emergency capacity of condensers are improved greatly. And modification of fluid transferring and sampling system make the remains in system transfer flexibly. The practise shows that metal direct recovery rises to the extent, and capacity of the first-grade condensing receiving system improves 8.4%, which strongly guarantees fluorination production safely, continuously and stably run. (authors)

  18. 2D modelling of a UF6 container in a fire

    International Nuclear Information System (INIS)

    Duret, B.; Seiler, J.M.

    1993-01-01

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

  19. FTIR spectroscopy of UF6 clustering in a supersonic Laval nozzle

    International Nuclear Information System (INIS)

    Tanimura, Shinobu; Okada, Yoshiki; Takeuchi, Kazuo

    1996-01-01

    The clustering of UF 6 seeded in Ar was observed in a continuous supersonic Laval nozzle flow. The onset conditions for UF 6 clustering were investigated by measuring the FTIR spectra of UF 6 monomer and clusters in the nozzle. The onset conditions for the clustering, temperature, density of UF 6 (or partial pressure), and cooling rate, were determined. The onset temperature determined here was higher by 40-50 K than that determined by a light-scattering method. The frequency shift of the main peak of the UF 6 clusters from the monomer peak was about -17 cm -1 , which was smaller than the shift of the crystalline UF 6 by about 11 cm -1 . The increase in temperature caused by the heat of condensation and the change of the spectra of UF 6 clusters with the growth after the onset were also observed. It was shown that the clustering rate due to the collision between the monomer and cluster is much higher than that due to the collision between the monomers. 19 refs., 9 figs

  20. Surface Activity of Sulfactin Recovered and Purified from Fermentation Broth Using a Two-Step Ultrafiltration (UF) Process

    International Nuclear Information System (INIS)

    Mohd Hafez Mohd Isa; Frazier, A.R.; Jauregi, P.

    2011-01-01

    B. subtilis under certain types of media and fermentation conditions can produce surfactant, a bio surfactant which belongs to the lipo peptide class. Surfactant has exceptional surfactant activity, and exhibits some interesting biological characteristics such as antibacterial activity, anti tumoral activity against ascites carcinoma cells, and a hypercholesterolaemia activity that inhibits cAMP phosphodiesterase, as well as having anti-HIV properties. A cost effective recovery and purification of surfactant from fermentation broth using a two-step ultrafiltration (UF) process has been developed in order to reduce the cost of surfactant production. In this study, competitive adsorption of surfactant and proteins at the air-water interface was studied using surface pressure measurements. Small volumes of bovine serum albumin (BSA) and β-casein solutions were added to the air-water interface on a Langmuir trough and allowed to stabilise before the addition of surfactant to the sub phase. Contrasting interfacial behaviour of proteins was observed with β-casein showing faster initial adsorption compared to BSA. On introduction of surfactant both proteins were displaced but a longer time were taken to displace β-casein. Overall the results showed surfactant were highly surface-active by forming a β-sheet structure at the air-water interface after reaching its critical micelle concentration (CMC) and were effective in removing both protein films, which can be explained following the orogenic mechanism. Results showed that the two-step UF process was effective to achieve high purity and fully functional surfactant. (author)

  1. Determination of UO2 little quantity in UF4 by X-rays diffraction

    International Nuclear Information System (INIS)

    Costa, M.I.; Sato, I.M.; Imakuma, K.

    1977-01-01

    In the fluorination process, the final product UF 4 contain different levels of UO 2 as a contaminant. A routine method for quantitative analysis by x-ray diffraction has been developed. Standard curves have been plotted using mixtures of UO 2 /UF 4 with measures of intensity of (III) peak of UO 2 by the step scanning process. The integrated intensity versus UO 2 concentration curves present a linear behavior in the range from 0 to 4%. A good reprodutibility of measuring process has been observed through statistical analysis which permits to determine low fractions of UO 2 in UF 4 with +- 0,08% of accuracy [pt

  2. Preliminary Hazard Analysis applied to Uranium Hexafluoride - UF6 production plant

    International Nuclear Information System (INIS)

    Tomzhinsky, David; Bichmacher, Ricardo; Braganca Junior, Alvaro; Peixoto, Orpet Jose

    1996-01-01

    The purpose of this paper is to present the results of the Preliminary hazard Analysis applied to the UF 6 Production Process, which is part of the UF 6 Conversion Plant. The Conversion Plant has designed to produce a high purified UF 6 in accordance with the nuclear grade standards. This Preliminary Hazard Analysis is the first step in the Risk Management Studies, which are under current development. The analysis evaluated the impact originated from the production process in the plant operators, members of public, equipment, systems and installations as well as the environment. (author)

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

    International Nuclear Information System (INIS)

    Aparo, M.; Cresti, P.

    1988-01-01

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

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

    Science.gov (United States)

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

    1984-06-01

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

  5. Effect of high and low ultrafiltration volume during hemodialysis on relative blood volume

    NARCIS (Netherlands)

    Dasselaar, JJ; de Jong, PE; Huisman, RM; Franssen, CFM

    2006-01-01

    Achieving an optimal posthemodialysis hydration status may be difficult because objective criteria for dry weight are lacking. Both relative blood volume changes (Delta RBV) at the end of hemodialysis and Delta RBV normalized for ultrafiltration volume (Delta RBV/UF ratio) have been reported to

  6. HEU to LEU Conversion and Blending Facility: UF{sub 6} blending alternative to produce LEU UF{sub 6} for commercial use

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

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

  7. Impact of Acid Cleaning on the Performance of PVDF UF Membranes in Seawater Reverse Osmosis Pretreatment

    KAUST Repository

    Alsogair, Safiya

    2016-01-01

    required to maintain the characteristics of the membrane. This research was made with the purpose of investigating the effects of acid cleaning during chemically enhanced backwashing (CEB) on the performance of ultrafiltration (UF) membranes in seawater

  8. 18 years experience on UF{sub 6} handling at Japanese nuclear fuel manufacturer

    Energy Technology Data Exchange (ETDEWEB)

    Fujinaga, H.; Yamazaki, N.; Takebe, N. [Japan Nucelar Fuel Conversion Co., Ltd., Ibaraki (Japan)

    1991-12-31

    In the spring of 1991, a leading nuclear fuel manufacturing company in Japan, celebrated its 18th anniversary. Since 1973, the company has produced over 5000 metric ton of ceramic grade UO{sub 2} powder to supply to Japanese fabricators, without major accident/incident and especially with a successful safety record on UF{sub 6} handling. The company`s 18 years experience on nuclear fuel manufacturing reveals that key factors for the safe handling of UF{sub 6} are (1) installing adequate facilities, equipped with safety devices, (2) providing UF{sub 6} handling manuals and executing them strictly, and (3) repeating on and off the job training for operators. In this paper, equipment and the operation mode for UF{sub 6} processing at their facility are discussed.

  9. Aspects of uranium chemistry pertaining to UF{sub 6} cylinder handling

    Energy Technology Data Exchange (ETDEWEB)

    Ritter, R.L.; Barber, E.J. [Martin Marietta Energy Systems, Inc., Oak Ridge, TN (United States)

    1991-12-31

    Under normal conditions, the bulk of UF{sub 6} in storage cylinders will be in the solid state with an overpressure of gaseous UF{sub 6} well below one atmosphere. Corrosion of the interior of the cylinder will be very slow, with formation of a small amount of reduced fluoride, probably U{sub 2}F{sub 9}. The UO{sub 3}-HF-H{sub 2}O phase diagram indicates that reaction of any inleaking water vapor with the solid UF{sub 6} will generate the solid material [H{sub 3}O]{sub 2}(U(OH){sub 4}F{sub 4}) in equilibrium with an aqueous HF solution containing only small amounts of uranium. The corrosion of the steel cylinder by these materials may be enhanced over that observed with gaseous anhydrous UF{sub 6}.

  10. Electron affinity of UF6. Final report, March 1, 1976--June 30, 1977

    International Nuclear Information System (INIS)

    Rothe, E.W.

    1977-06-01

    Ionization reactions are observed in crossed molecular beams, usually of thermal energy, alkalis and MoF 6 , WF 6 and UF 6 . Previous studies have indicated large electron affinities for these hexafluorides, and this is confirmed here. Ionization at thermal energies proceeds with the alkali dimers, A 2 , for all three hexafluorides, but with alkali atoms, A, only for UF 6 . Several ionization paths are observed, allowing the deduction of molecular energies. A few experiments are done with eV-range beams. Lower limits for the elecron affinities are 4.5, 3.3, 4.9, 4.3 and 1.9 eV for MoF 6 , MoF 5 , WF 6 , UF 6 and UF 5 , respectively. Possible mechanisms are discussed

  11. Validation of the Cristallini Sampling Method for UF6 by High Precision Double-Spike Measurements

    OpenAIRE

    RICHTER STEPHAN; JAKOBSSON ULF; HIESS JOE; AMARAGGI D.

    2017-01-01

    The so-called "Cristallini Method" for sampling of UF6 by adsorption and hydrolysis in alumina pellets inside a fluorothene P-10 tube was developed by the Brazilian-Argentine Agency for Accounting and Control of Nuclear Materials (ABACC) several years ago. This method has several advantages compared to the currently used sampling method, for which UF6 is distilled into a stainless steel tube for transportation, with hydrolysis and isotopic analysis being performed after shipping to the analyt...

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

    International Nuclear Information System (INIS)

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

    1992-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Crabol, B.; Boulaud, D.; Deville-Cavelin, G. [CEA Centre d`Etudes de Fontenay-aux-Roses, 92 (France). Dept. de Protection de l`Environnement et des Installations; Geisse, C.; Iacona, L. [EURODIF, 26 - Pierrelatte (France)

    1992-12-31

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

  14. From the Lab to the real world : sources of error in UF6 gas enrichment monitoring

    International Nuclear Information System (INIS)

    Lombardi, Marcie L.

    2012-01-01

    Safeguarding uranium enrichment facilities is a serious concern for the International Atomic Energy Agency (IAEA). Safeguards methods have changed over the years, most recently switching to an improved safeguards model that calls for new technologies to help keep up with the increasing size and complexity of today's gas centrifuge enrichment plants (GCEPs). One of the primary goals of the IAEA is to detect the production of uranium at levels greater than those an enrichment facility may have declared. In order to accomplish this goal, new enrichment monitors need to be as accurate as possible. This dissertation will look at the Advanced Enrichment Monitor (AEM), a new enrichment monitor designed at Los Alamos National Laboratory. Specifically explored are various factors that could potentially contribute to errors in a final enrichment determination delivered by the AEM. There are many factors that can cause errors in the determination of uranium hexafluoride (UF 6 ) gas enrichment, especially during the period when the enrichment is being measured in an operating GCEP. To measure enrichment using the AEM, a passive 186-keV (kiloelectronvolt) measurement is used to determine the 235 U content in the gas, and a transmission measurement or a gas pressure reading is used to determine the total uranium content. A transmission spectrum is generated using an x-ray tube and a 'notch' filter. In this dissertation, changes that could occur in the detection efficiency and the transmission errors that could result from variations in pipe-wall thickness will be explored. Additional factors that could contribute to errors in enrichment measurement will also be examined, including changes in the gas pressure, ambient and UF 6 temperature, instrumental errors, and the effects of uranium deposits on the inside of the pipe walls will be considered. The sensitivity of the enrichment calculation to these various parameters will then be evaluated. Previously, UF 6 gas enrichment

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

    International Nuclear Information System (INIS)

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

    1984-06-01

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

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

    International Nuclear Information System (INIS)

    Lux, C.J.

    1982-01-01

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

  17. Natural phenomena evaluations of the K-25 site UF6 cylinder storage yards

    International Nuclear Information System (INIS)

    Fricke, K.E.

    1996-01-01

    The K-25 Site UF 6 cylinder storage yards are used for the temporary storage of UF 6 normal assay cylinders and long-term storage of other UF 6 cylinders. The K-25 Site UF 6 cylinder storage yards consist of six on-site areas: K-1066-B, K-1066-E, K-1066-F, K-1066-J, K-1066-K and K-1066-L. There are no permanent structures erected on the cylinder yards, except for five portable buildings. The operating contractor for the K-25 Site is preparing a Safety Analysis Report (SAR) to examine the safety related aspects of the K-25 Site UF 6 cylinder storage yards. The SAR preparation encompasses many tasks terminating in consequence analysis for the release of gaseous and liquid UF 6 , one of which is the evaluation of natural phenomena threats, such as earthquakes, floods, and winds. In support of the SAR, the six active cylinder storage yards were evaluated for vulnerabilities to natural phenomena, earthquakes, high winds and tornados, tornado-generated missiles, floods (local and regional), and lightning. This report summarizes those studies. 30 refs

  18. Reduction of UF4 to U-metal

    International Nuclear Information System (INIS)

    Namkung, H.; Min, B.T.; Kim, J.S.; Whang, S.C.

    1982-01-01

    In the second years of study for the production of the metallic uranium with reactors which can produce 1 Kg and 4 Kg U-metal, various factors on the yield of U-metal and the leaching condition for uranium recovery with nitric acid are examined. The jolter has been used for the charging with liner (MgF 2 ) while the hand-tamping method for the filling of reaction mixtures (UF 4 -Mg) in the reactor, and their average densities are 1.23g/cc and 2.90g/cc, respectively. The various effects on the yield such as magnesium excess, furnace control temperatue, charge densities of liner and reaction mixtures, have been studied but the yields of crude metal production are in the wide range from 93 % down to about 65 %. Generally, six percent magnesium excess produced higher yields than did either 2 or 10 percent excess. The leaching condition for the uranium recovery from slag are also investigated with dilute nitric acid (3-6N) as well as higher concentrated nitric acid (9.5N) but the leaching yields are same in either solution. Uranium recovery from the slag is very effective with dilute nitric acid (3N) leaching for less than one hour at 60degC. (Author)

  19. Investigation of breached depleted UF{sub 6} cylinders

    Energy Technology Data Exchange (ETDEWEB)

    DeVan, J.H. [Martin Marietta Energy Systems, Inc., Oak Ridge, TN (United States)

    1991-12-31

    In June 1990, during a three-site inspection of cylinders being used for long-term storage of solid depleted UF{sub 6}, two 14-ton cylinders at Portsmouth, Ohio, were discovered with holes in the barrel section of the cylinders. An investigation team was immediately formed to determine the cause of the failures and their impact on future storage procedures and to recommend corrective actions. Subsequent investigation showed that the failures most probably resulted from mechanical damage that occurred at the time that the cylinders had been placed in the storage yard. In both cylinders evidence pointed to the impact of a lifting lug of an adjacent cylinder near the front stiffening ring, where deflection of the cylinder could occur only by tearing the cylinder. The impacts appear to have punctured the cylinders and thereby set up corrosion processes that greatly extended the openings in the wall and obliterated the original crack. Fortunately, the reaction products formed by this process were relatively protective and prevented any large-scale loss of uranium. The main factors that precipitated the failures were inadequate spacing between cylinders and deviations in the orientations of lifting lugs from their intended horizontal position. After reviewing the causes and effects of the failures, the team`s principal recommendation for remedial action concerned improved cylinder handling and inspection procedures. Design modifications and supplementary mechanical tests were also recommended to improve the cylinder containment integrity during the stacking operation.

  20. A realidade da pesquisa no DEN/UFS

    Directory of Open Access Journals (Sweden)

    Delvair de Brito Alves

    1998-12-01

    Full Text Available Esta pesquisa trata do processo de pesquisar no Departamento de Enfermagem e Nutrição da Universidade Federal de Sergipe - DEN/UFS. Ela foi desenvolvida a partir de entrevistas semi estruturadas realizadas com as docentes. Dos materiais obtidos, apresentamos concepções das docentes sobre grupos, linhas e projetos de pesquisa; a produção científica docente e discente; dificuldades e possibilidades relativas à atividade de pesquisar; estratégias que esse Departamento vem utilizando para o desenvolvimento da pesquisa, para a capacitação docente e formação de pesquisadores, além da inserção de estudantes (de graduação e de pós graduação no "mundo científico". Ela conclui pela necessidade de aprofundamento dessa atividade e pela divulgação e aplicação dos seus resultados na prática de enfermagem.

  1. 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).

  2. Confirmatory measurements of UF6 using the neutron self-interrogation method

    International Nuclear Information System (INIS)

    Stewart, J.E.; Ensslin, N.; Menlove, H.O.; Cowder, L.R.; Polk, P.J.

    1985-01-01

    A passive neutron counting method has been developed for measurement of the 235 U mass in Model 5A cylinders of UF 6 . The unique neutronic properties of UF 6 containing highly enriched uranium (HEU) permit 235 U assay using only passive neutron counting. The sample effectively assays itself by self-interrogation. Shipped from enrichment plants and received at fuel fabrication and conversion facilities, 5A UF 6 cylinders hold up to approx.17 kg of 235 U each. Field measurements at the Portsmouth Gaseous Diffusion Plant (GDP) showed an average assay accuracy of 6.8% (1sigma) for 44 cylinders with enrichments from 6 to 98% and with a range of fill heights. Further measurements on 38 cylinders containing 97%-enriched material yielded an accuracy of 2.8% (1sigma). Typical counting times for these measurements were less than 5 min. An in-plant instrument for receipts confirmation measurements of 5A UF 6 cylinders has been developed for the Savannah River Plant. The Receipts Assay Monitor (RAM) is currently being tested and calibrated. It is designed to confirm declared fissile mass in all incoming 5A cylinders containing HEU in the form of UF 6 . One of the computer-controlled features is a removable cadmium liner for the sample cavity. The liner allows a sample fill-height correction, which significantly improves assay accuracy

  3. [Experimental evaluation of the Sysmex UF-1000i for ruling out non-gonococcal urethritis].

    Science.gov (United States)

    Grosso, Shamanta; Bruschetta, Graziano; Camporese, Alessandro

    2012-09-01

    Acute nongonococcal urethritis (NGU) is one of the commonest sexually transmitted infections affecting men and women. The diagnosis of NGU has traditionally required microscopic evidence of urethritis. However, a significant proportion of patients with urethral symptoms do not have microscopic evidence of urethritis. The purpose of the present study was to evaluate the analytical performance of the UF1000i, a recently introduced fluorescence flow cytometer intended for urinalysis purposes which provides new analytical features that seem particularly suitable for microbiological diagnostics, for ruling out NGU or predicting the presence of infection. The Sysmex UF1000i is a flow cytometry analyzer capable of quantifying a lot of particles, including bacteria (BACT) and white blood cells (WBCs). To evaluate the analytical performance of the UF1000i as a method for ruling out NGU, we examined 200 urethral smear samples, collected in a new liquid transport medium (Copan), and compared the UF1000i results with standard culture/molecular and microscopic Gram stain results. With instrument cut-off values of 200 BACT x 10^6/L and 500 WBCs x 10^6/L, we obtained a sensitivity of 84%, a specificity of 82%, and a high negative predictive value (96%). Culture/molecular detection of pathogens remains the gold standard technique for the diagnosis of NGU. However, the Sysmex UF1000i is capable of improving the efficiency of NGU presumptive diagnosis, providing results in a few minutes, with a high negative predictive value and high values of sensitivity.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1991-12-31

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

  5. Evaluation of a dry process for conversion of U-AVLIS product to UF{sub 6}. Milestone U361

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-05-01

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

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

    International Nuclear Information System (INIS)

    1992-05-01

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

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

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

    International Nuclear Information System (INIS)

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

    1992-01-01

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

  9. UF{sub 6} tiedowns for truck transport - right way/wrong way

    Energy Technology Data Exchange (ETDEWEB)

    Stout, F.W. Jr. [Martin Marietta Energy Systems, Inc., Oak Ridge, TN (United States)

    1991-12-31

    Tiedown systems for truck transport of UF{sub 6} must be defined and controlled to assure the least risk for hauling the material over the highways. This paper and an associated poster display will present the current status of regulatory criteria for tiedowns, analyze the structural stresses involved in tiedowns for two major UF{sub 6} packaging systems, the 21PF series of overpacks and the 48 in. diameter shipping cylinders, and will present photographs showing some {open_quote}right ways{close_quotes} and some {open_quotes}wrong (or risky) ways{close_quotes} currently used for tiedown systems. Risky tiedown methods must be replaced with safer less risky methods to insure the safe transport of UF{sub 6}.

  10. Testing of one-inch UF{sub 6} cylinder valves under simulated fire conditions

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, P.G. [Martin Marietta Energy Systems, Inc., Paducah, KY (United States)

    1991-12-31

    Accurate computational models which predict the behavior of UF{sub 6} cylinders exposed to fires are required to validate existing firefighting and emergency response procedures. Since the cylinder valve is a factor in the containment provided by the UF{sub 6} cylinder, its behavior under fire conditions has been a necessary assumption in the development of such models. Consequently, test data is needed to substantiate these assumptions. Several studies cited in this document provide data related to the behavior of a 1-inch UF{sub 6} cylinder valve in fire situations. To acquire additional data, a series of tests were conducted at the Paducah Gaseous Diffusion Plant (PGDP) under a unique set of test conditions. This document describes this testing and the resulting data.

  11. The toxic and radiological risk equivalence approach in UF6 transport

    International Nuclear Information System (INIS)

    Ringot, C.; Hamard, J.

    1988-12-01

    After a brief description of the safety in transport of UF 6 , we discuss the equivalence of the radioactive and chemical risks in UF 6 transport regulations. As the concept of low specific activity appears to be ill-suited for a toxic gas, we propose a quantity of material limit designated T 2 (equivalent to A 2 for radioactive substances) for packagings unable to withstand accident conditions (9 m drop, 800 0 C fire environment for 30 minutes). It is proposed that this limit be chosen for the amount of release acceptable after AIEA tests. Different possible scenarios are described, with fire assumed to be the most severe toxic risk situation

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

    International Nuclear Information System (INIS)

    Legeay, A.J.

    1978-01-01

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

  13. Nuclear criticality safety aspects of gaseous uranium hexafluoride (UF{sub 6}) in the diffusion cascade

    Energy Technology Data Exchange (ETDEWEB)

    Huffer, J.E. [Parallax, Inc., Atlanta, GA (United States)

    1997-04-01

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

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

    International Nuclear Information System (INIS)

    Huffer, J.E.

    1997-04-01

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

  15. Presentation and interpretation of field experiments of gaseous UF{sub 6} releases in the atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Crabol, B.; Boulaud, D.; Deville-Cavelin, G. [CEA/Inst. de Protection et de Surete Nucleaire, Dept. de Protection de l' Environnement et des Installations, Fontenay-aux-Roses (France); Geisse, C.; Iacona, L. [EURODIF/Production, Site de Tricastin, Pierrelatte Cedex (France)

    1992-07-01

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

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

    Science.gov (United States)

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

    2009-11-01

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

  17. MF/UF rejection and fouling potential of algal organic matter from bloom-forming marine and freshwater algae

    KAUST Repository

    Villacorte, Loreen O.; Ekowati, Yuli; Winters, Harvey; Amy, Gary L.; Schippers, Jan Cornelis; Kennedy, Maria Dolores

    2015-01-01

    the latter were poorly rejected. MF (0.4μm and 0.1μm pore size) rejected 14%-56% of biopolymers while conventional UF (100kDa) and tight UF (10kDa) rejected up to 83% and 97%, respectively. The retention of AOM resulted in a rapid increase in trans

  18. Application of fixed bed trapping technology for the removal of low concentration UF6 from plant gaseous effluent streams

    International Nuclear Information System (INIS)

    Russell, R.G.

    1987-01-01

    For the trapping of UF 6 in nitrogen, NaF > Al 2 O 3 > CaSO 4 . UF 6 inlet concentration has little effect on loading of alumina. Velocity shows an effect on UF 6 loading on alumina, with higher loading at low velocity. There is no significant difference in UF 6 loading between alumina 201A and 202HF. UF 6 outlet concentrations prior to breakthrough were measured to be as low as 2 O 3 until breakthrough (6.6% vs 5.3%), after which NaF experiences more loading (7.5% vs 11.5% at 1 ppM in the outlet). Higher trap loadings at lower pressures for both NaF and Al 2 O 3 . Al 2 O 3 was more efficient than NaF at higher velocities

  19. Greater autonomy at work

    NARCIS (Netherlands)

    Houtman, I.L.D.

    2004-01-01

    In the past 10 years, workers in the Netherlands increasingly report more decision-making power in their work. This is important for an economy in recession and where workers face greater work demands. It makes work more interesting, creates a healthier work environment, and provides opportunities

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

    International Nuclear Information System (INIS)

    1997-12-01

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

  1. The determination of UO2 and UF4 in fused fluoride salts

    International Nuclear Information System (INIS)

    Batiste, D.J.; Lee, D.A.

    1989-01-01

    The determination of uranium oxide solubilities in fused fluoride salts is important in the electrolytic preparation of uranium metal. This project was initiated to develop a method for the determination of UO 2 separately from UF 4 in UF 4 -CaF 2 -LiF fused salts. Previous methods used for the determination of UO 2 in fused fluoride salts involved inert gas fusions where oxygen was liberated as CO 2 , and hydrofluorination where oxygen was released as H 2 O; but the special equipment used for these procedures was no longer available. These methods assumed that all of the oxygen liberated was due to UO 2 and does not consider impurities from reagents and other oxygen sources that amount to a bias of approximately 0.3 wt %. This titrimetric method eliminates the bias by selectively extracting the UF 4 with a Na 2 EDTA-H 3 BO 3 solution. The remaining uranium oxide residue is treated and titrated gravimetrically to a potentiometric endpoint with NBS standard K 2 Cr 2 O 7 . An aliquot of the Na 2 EDTA-H 3 BO 3 extract is also titrated gravimetrically to a potentiometric endpoint, this uranium component is determined and calculated as UF 4 . 4 refs., 2 figs., 2 tabs

  2. LX-17 and ufTATB Data for Corner-Turning, Failure and Detonation

    Energy Technology Data Exchange (ETDEWEB)

    Souers, P C; Lauderbach, L; Garza, R; Vitello, P; Hare, D E

    2010-02-03

    Data is presented for the size (diameter) effect for ambient and cold confined LX-17, unconfined ambient LX-17, and confined ambient ultrafine TATB. Ambient, cold and hot double cylinder corner-turning data for LX-17, PBX 9502 and ufTATB is presented. Transverse air gap crossing in ambient LX-17 is studied with time delays given for detonations that cross.

  3. Depleted UF6 Management Information Network - A resource for the public,

    Science.gov (United States)

    Depleted UF6 Management Information Network Web Site is an online repository of information about the U.S ) and DUF6, research and development efforts for beneficial uses of DU, DOE's program for management of line DUF6 Guide DUF6 Guide line Introductory information about depleted uranium: how it is created

  4. Electrically Cooled Germanium System for Measurements of Uranium Enrichments in UF6 Cylinders

    International Nuclear Information System (INIS)

    Dvornyak, P.; Koestlbauer, M.; Lebrun, A.; Murray, M.; Nizhnik, V.; Saidler, C.; Twomey, T.

    2010-01-01

    Measurements of Uranium enrichment in UF6 cylinders is a significant part of the IAEA Safeguards verification activities at enrichment and conversion plants. Nowadays, one of the main tools for verification of Uranium enrichment in UF6 cylinders used by Safeguards inspectors is the gamma spectroscopy system with HPGe detector cooled with liquid nitrogen. Electrically Cooled Germanium System (ECGS) is a new compact and portable high resolution gamma spectrometric system free from liquid nitrogen cooling, which can be used for the same safeguards applications. It consists of the ORTEC Micro-trans-SPEC HPGe Portable Spectrometer, a special tungsten collimator and UF6 enrichment measurement software. The enrichment of uranium is determined by of quantifying the area of the 185.7 keV peak provided that the measurement is performed with a detector viewing an infinite thickness of material. Prior starting the verification of uranium enrichment at the facility, the ECGS has to be calibrated with a sample of known uranium enrichment, material matrix, container wall thickness and container material. Evaluation of the ECGS capabilities was performed by carrying out a field test on actual enrichment verification of uranium in UF6 cylinder or other forms of uranium under infinite thickness conditions. The results of these evaluations allow to say that the use of ECGS will enhance practicality of the enrichment measurements and support unannounced inspection activities at enrichment and conversion plants. (author)

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

    International Nuclear Information System (INIS)

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

    2001-01-01

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

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

    International Nuclear Information System (INIS)

    Dekker, B.G.

    2004-01-01

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

  7. Obtaining of uranium tetrafluoride UF4 by electrodialysis reactive from uranium concentrates

    International Nuclear Information System (INIS)

    Munoz Lay, Danny Mauricio

    2014-01-01

    The generation of uranium fuels has always been a topic worldwide. The uranium fuel manufacturing base is made under very strict parameters of radiological and industrial safety, being a stage called 'nuclear fuel cycle'. In Chile, it is done constant research for fuels. This report focuses primarily on participating in such research; mainly in the production of uranium tetrafluoride (UF 4 ) .The tetrafluoride production is very crucial for the nuclear fuel industry. Its production varies from precipitation in stirred conditions to electrolysis in mercury. However, both processes has shortcomings either in performance and environmental pollution, which is why it is proposed a new method of production based on a friendly process to the environment and easier to operate, the reactive electrodialysis (RED). Electrodialysis is a hybrid reactive process of separation by membranes, cationic and / or anionic, namely, ionic species. In the process, ions are induced to move by an electric potential applied and separated by these membranes, a highly selective physical barrier which allows passage of ions with certain charge, and prevents the passage of oppositely charged ions. And in turn, it is reactive because it forces a chemical reaction, redox, to obtain uranium tetrafluoride (UF 4 ). The results of these experiments show that by reactive electrodialysis, NH 4 UF 5 deposits were obtained. However, calcinating the NH 4 UF 5 to 450 o C, it decomposes to obtain uranium tetrafluoride, UF 4 . The best working conditions were obtained with an electric current of 0.5 (A), 41 o C and a flow of 16 (ml / s) of the electrolyte. It was possible to obtain 5,995 (g) to 3 (h), giving a current efficiency of 71.42%. In turn, working at high temperatures and flow recirculation is possible to operate with a potential difference of 1.7 (V)

  8. The Comparing Options for Management: Patient-centered Results for Uterine Fibroids (COMPARE-UF) Registry: Rationale and Design.

    Science.gov (United States)

    Stewart, Elizabeth A; Lytle, Barbara L; Thomas, Laine; Wegienka, Ganesa R; Jacoby, Vanessa; Diamond, Michael P; Nicholson, Wanda K; Anchan, Raymond M; Venable, Sateria; Wallace, Kedra; Marsh, Erica E; Maxwell, George L; Borah, Bijan J; Catherino, William H; Myers, Evan R

    2018-05-08

    To design and establish a uterine fibroid (UF) registry based in the United States (US) to provide comparative effectiveness data regarding UF treatment. We report here the design and initial recruitment for the Comparing Options for Management: Patient-centered Results for Uterine Fibroids (COMPARE-UF) registry (Clinicaltrials.gov, NCT02260752), funded by the Agency for Healthcare Research and Quality (AHRQ) in collaboration with the-Patient-Centered Outcomes Research Institute (PCORI). COMPARE-UF is designed to help answer critical questions about treatment options for women with symptomatic UF. Women undergoing a procedure for UF (hysterectomy, myomectomy [abdominal, hysteroscopic, vaginal and laparoscopic/robotic], endometrial ablation, radiofrequency fibroid ablation, uterine artery embolization, magnetic resonance guided focused ultrasound or progestin-releasing intrauterine device insertion) at one of the COMPARE-UF sites are invited to participate in a prospective registry with three years follow-up for post-procedural outcomes. Enrolled participants provide annual follow-up through an online portal or through traditional phone contact. A central data abstraction center provides information obtained from imaging, operative or procedural notes and pathology reports. Women with uterine fibroids and other stakeholders are a key part of the COMPARE-UF registry and participate at all points from study design to dissemination of results. We built a network of nine clinical sites across the US with expertise in the care of women with UF to capture geographic, racial, ethnic and procedural diversity. Of the initial 2031 women enrolled in COMPARE-UF, 42% are self-identified as Black or African-American and 40% are age 40 years or younger with 16% of participants under age 35. Women undergoing myomectomy comprise the largest treatment group at 46% of all procedures with laparoscopic or robotic myomectomy comprising the largest subset of myomectomies at 19% of all

  9. Greater-confinement disposal

    International Nuclear Information System (INIS)

    Trevorrow, L.E.; Schubert, J.P.

    1989-01-01

    Greater-confinement disposal (GCD) is a general term for low-level waste (LLW) disposal technologies that employ natural and/or engineered barriers and provide a degree of confinement greater than that of shallow-land burial (SLB) but possibly less than that of a geologic repository. Thus GCD is associated with lower risk/hazard ratios than SLB. Although any number of disposal technologies might satisfy the definition of GCD, eight have been selected for consideration in this discussion. These technologies include: (1) earth-covered tumuli, (2) concrete structures, both above and below grade, (3) deep trenches, (4) augered shafts, (5) rock cavities, (6) abandoned mines, (7) high-integrity containers, and (8) hydrofracture. Each of these technologies employ several operations that are mature,however, some are at more advanced stages of development and demonstration than others. Each is defined and further described by information on design, advantages and disadvantages, special equipment requirements, and characteristic operations such as construction, waste emplacement, and closure

  10. More features, greater connectivity.

    Science.gov (United States)

    Hunt, Sarah

    2015-09-01

    Changes in our political infrastructure, the continuing frailties of our economy, and a stark growth in population, have greatly impacted upon the perceived stability of the NHS. Healthcare teams have had to adapt to these changes, and so too have the technologies upon which they rely to deliver first-class patient care. Here Sarah Hunt, marketing co-ordinator at Aid Call, assesses how the changing healthcare environment has affected one of its fundamental technologies - the nurse call system, argues the case for wireless such systems in terms of what the company claims is greater adaptability to changing needs, and considers the ever-wider range of features and functions available from today's nurse call equipment, particularly via connectivity with both mobile devices, and ancillaries ranging from enuresis sensors to staff attack alert 'badges'.

  11. Greater oil investment opportunities

    International Nuclear Information System (INIS)

    Arenas, Ismael Enrique

    1997-01-01

    Geologically speaking, Colombia is a very attractive country for the world oil community. According to this philosophy new and important steps are being taken to reinforce the oil sector: Expansion of the exploratory frontier by including a larger number of sedimentary areas, and the adoption of innovative contracting instruments. Colombia has to offer, Greater economic incentives for the exploration of new areas to expand the exploratory frontier, stimulation of exploration in areas with prospectivity for small fields. Companies may offer Ecopetrol a participation in production over and above royalties, without it's participating in the investments and costs of these fields, more favorable conditions for natural gas seeking projects, in comparison with those governing the terms for oil

  12. Finite element modelling of fire situations in UF6 transport containers; Modelado por elementos finitos de situaciones de incendio en contenedores para el transporte de UF6

    Energy Technology Data Exchange (ETDEWEB)

    Basombrio, F G

    1997-12-31

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

  13. Numerical modeling of the vertical hydrofluorination zone in the moving bed furnace for the production of UF{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Jourde, J.; Patisson, F.; Ablitzer, D. [Ecole des Mines, Nancy (France). Lab. de Science et Genie des Materiaux Metalliques; Houzelot, J.L. [Ecole des Mines, Nancy (France). Lab. des Sciences du Genie Chimique

    1996-12-31

    Uranium tetrafluoride UF{sub 4} is produced in the moving bed furnace, a reactor in which solid- and gas counterflow. Due to the highly exothermic nature of the chemical reactions involved, the-reactor operation requires a careful temperature control. To provide operators with an appropriate tool for the predictive simulation, optimization and control of the process an overall numerical model of the furnace has been developed. This article describes the part of the model concerning the vertical hydrofluorination zone. The differential equations representing the mass, energy and momentum balances are solved using the finite volume method. The physicochemical parameters necessary for the calculation are detailed. The rate of the main reaction, the hydrofluorination of UO{sub 2}, has been determined with the aid of a specific kinetic model. The computed parameters, namely the temperature and solid and gas compositions, are visualized in the form of isovalue maps. The initial results reveal the influence of a thermodynamic limitation of the reaction at temperatures higher than 650 K. (author)

  14. Numerical modeling of the vertical hydrofluorination zone in the moving bed furnace for the production of UF{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Jourde, J; Patisson, F; Ablitzer, D [Ecole des Mines, Nancy (France). Lab. de Science et Genie des Materiaux Metalliques; Houzelot, J L [Ecole des Mines, Nancy (France). Lab. des Sciences du Genie Chimique

    1997-12-31

    Uranium tetrafluoride UF{sub 4} is produced in the moving bed furnace, a reactor in which solid- and gas counterflow. Due to the highly exothermic nature of the chemical reactions involved, the-reactor operation requires a careful temperature control. To provide operators with an appropriate tool for the predictive simulation, optimization and control of the process an overall numerical model of the furnace has been developed. This article describes the part of the model concerning the vertical hydrofluorination zone. The differential equations representing the mass, energy and momentum balances are solved using the finite volume method. The physicochemical parameters necessary for the calculation are detailed. The rate of the main reaction, the hydrofluorination of UO{sub 2}, has been determined with the aid of a specific kinetic model. The computed parameters, namely the temperature and solid and gas compositions, are visualized in the form of isovalue maps. The initial results reveal the influence of a thermodynamic limitation of the reaction at temperatures higher than 650 K. (author)

  15. Modelling of the behaviour of a UF_6 container in a fire

    International Nuclear Information System (INIS)

    Pinton, Eric

    1996-01-01

    This thesis is justified by the safety needs about storage and transport of UF_6 containers. To define their behaviour under fire conditions, a modelling was developed. Before tackling the numerical modelling, a phenomenological interpretation with experimental results of containers inside a furnace (800 C) during a fixed period was carried out. The internal heat transfers were considerably improved with these results. The 2D elaborated model takes into account most of the physical phenomena encountered in this type of situation (boiling, evaporation, condensation, radiant heat transfers through an absorbing gas, convection, pressurisation, thermal contact resistance, UF_6 expansion, solid core sinking in the liquid, elastic and plastic deformations of the steel container). This model was successfully confronted with experiments. (author) [fr

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

    International Nuclear Information System (INIS)

    Jordan, W.C.

    1993-02-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-01-01

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

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

    International Nuclear Information System (INIS)

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

    1997-01-01

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

  19. A 1D coordination polymer of UF{sub 5} with HCN as a ligand

    Energy Technology Data Exchange (ETDEWEB)

    Scheibe, Benjamin; Rudel, Stefan S.; Buchner, Magnus R.; Kraus, Florian [Fachbereich Chemie, Philipps-Universitaet Marburg (Germany); Karttunen, Antti J. [Department of Chemistry, Aalto University (Finland)

    2017-01-05

    β-Uranium(V) fluoride was reacted with liquid anhydrous hydrogen cyanide to obtain a 1D coordination polymer with the composition {sup 1}{sub ∞}[UF{sub 5}(HCN){sub 2}], {sup 1}{sub ∞}[UF{sub 4/1}F{sub 2/2}-(HCN){sub 2/1}], revealed by single-crystal X-ray structure determination. The reaction system was furthermore studied by means of vibrational and NMR spectroscopy, as well as by quantum chemical calculations. The compound presents the first described polymeric HCN Lewis adduct and the first HCN adduct of a uranium fluoride. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. A probabilistic safety analysis of UF{sub 6} handling at the Portsmouth Gaseous Diffusion Plant

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, G.J.; Lewis, S.R.; Summitt, R.L. [Safety and Reliability Optimization Services (SAROS), Inc., Knoxville, TN (United States)

    1991-12-31

    A probabilistic safety study of UF{sub 6} handling activities at the Portsmouth Gaseous Diffusion Plant has recently been completed. The analysis provides a unique perspective on the safety of UF{sub 6} handling activities. The estimated release frequencies provide an understanding of current risks, and the examination of individual contributors yields a ranking of important plant features and operations. Aside from the probabilistic results, however, there is an even more important benefit derived from a systematic modeling of all operations. The integrated approach employed in the analysis allows the interrelationships among the equipment and the required operations to be explored in depth. This paper summarizes the methods used in the study and provides an overview of some of the technical insights that were obtained. Specific areas of possible improvement in operations are described.

  1. Recycling Cellulase from Enzymatic Hydrolyzate of Laser-Pretreated Corn Stover by UF Membrane

    Directory of Open Access Journals (Sweden)

    Shuang-Qi Tian

    2015-09-01

    Full Text Available The ultrafiltration membrane reactor, utilizing a membrane module with a suitable molecular weight alleyway, retains the larger cellulase components. Smaller molecules, such as the fermentable reducing sugars and water, pass through the membrane. The purpose of this work was to investigate the capability of recycling cellulase in the UF membrane. PS30 hollow fiber membrane, an ultrafiltration method using internal pressure, was found to be an ideal membrane separation device, allowing re-use of the enzyme. A Box-Behnken experimental design (BBD established the following optimum pretreatment parameters: operation pressure at 1.73 bar, temperature at 36.38 °C, and a pH of 5.92. Under these conditions, the model predicted a membrane flux yield of 2.3174 L/(m2•h. The rejection rate of the UF membrane was over 95%.

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

    International Nuclear Information System (INIS)

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

    1988-12-01

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

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

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  4. Thermodynamic assessment of the LiF–ThF4–PuF3–UF4 system

    NARCIS (Netherlands)

    Capelli, E.; Benes, O.; Konings, R.J.M.

    2015-01-01

    The LiF–ThF4–PuF3–UF4 system is the reference salt mixture considered for the Molten Salt Fast Reactor (MSFR) concept started with PuF3. In order to obtain the complete thermodynamic description of this quaternary system, two binary systems (ThF4–PuF3 and UF4–PuF3) and two ternary systems

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

    OpenAIRE

    Chan, CYG; Valentine, JD; Russo, RE

    2017-01-01

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

  6. UF6 reconversion experience by means of Sumitomo ADU process at JCO

    International Nuclear Information System (INIS)

    Ogawa, H.; Yamazaki, N.

    1994-01-01

    Since 1973, Japan Nuclear Fuel Conversion Co., Ltd. (JCO), a leading company in Japan on nuclear fuel manufacturing, has been involved in UF 6 reconversion to ceramic grade uranium dioxide (UO 2 ) for LWR fuel by means of the original ADU process developed by Sumitomo Metal Mining Co., Ltd.. This paper deals with the details of the Sumitomo ADU process as well as the performance results of it, especially from the standpoint of product quality

  7. Whole-body voxel phantoms of paediatric patients—UF Series B

    Science.gov (United States)

    Lee, Choonik; Lee, Choonsik; Williams, Jonathan L.; Bolch, Wesley E.

    2006-09-01

    Following the previous development of the head and torso voxel phantoms of paediatric patients for use in medical radiation protection (UF Series A), a set of whole-body voxel phantoms of paediatric patients (9-month male, 4-year female, 8-year female, 11-year male and 14-year male) has been developed through the attachment of arms and legs from segmented CT images of a healthy Korean adult (UF Series B). Even though partial-body phantoms (head-torso) may be used in a variety of medical dose reconstruction studies where the extremities are out-of-field or receive only very low levels of scatter radiation, whole-body phantoms play important roles in general radiation protection and in nuclear medicine dosimetry. Inclusion of the arms and legs is critical for dosimetry studies of paediatric patients due to the presence of active bone marrow within the extremities of children. While the UF Series A phantoms preserved the body dimensions and organ masses as seen in the original patients who were scanned, comprehensive adjustments were made for the Series B phantoms to better match International Commission on Radiological Protection (ICRP) age-interpolated reference body masses, body heights, sitting heights and internal organ masses. The CT images of arms and legs of a Korean adult were digitally rescaled and attached to each phantom of the UF series. After completion, the resolutions of the phantoms for the 9-month, 4-year, 8-year, 11-year and 14-year were set at 0.86 mm × 0.86 mm × 3.0 mm, 0.90 mm × 0.90 mm × 5.0 mm, 1.16 mm × 1.16 mm × 6.0 mm, 0.94 mm × 0.94 mm × 6.00 mm and 1.18 mm × 1.18 mm × 6.72 mm, respectively.

  8. The legal status of UF{sub 6}-cylinder testing and licensing in Germany (and Europe)

    Energy Technology Data Exchange (ETDEWEB)

    Wieser, K.E. [Federal Institute for Material Research and Testing (BAM), Berlin (Germany); Tietze, A. [Bergische Universitaet - Gesamthochschule Wuppertal (Germany)

    1991-12-31

    New German and European transport regulations for road and rail transport of UF{sub 6}-cylinders are presented, in particular those provisions which have direct impact on the majority of cylinders used in shipments touching ADR and RID member states. First experiences and difficulties in it`s application are highlighted taking into account experiences of a for running German regulation. A summary of research efforts on the behaviour of cylinders in fire environments concludes the paper.

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

    International Nuclear Information System (INIS)

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

    1993-05-01

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

  10. Benchmark calculation of APOLLO-2 and SLAROM-UF in a fast reactor lattice

    International Nuclear Information System (INIS)

    Hazama, T.

    2009-07-01

    A lattice cell benchmark calculation is carried out for APOLLO2 and SLAROM-UF on the infinite lattice of a simple pin cell featuring a fast reactor. The accuracy in k-infinity and reaction rates is investigated in their reference and standard level calculations. In the 1. reference level calculation, APOLLO2 and SLAROM-UF agree with the reference value of k-infinity obtained by a continuous energy Monte Carlo calculation within 50 pcm. However, larger errors are observed in a particular reaction rate and energy range. The major problem common to both codes is in the cross section library of 239 Pu in the unresolved energy range. In the 2. reference level calculation, which is based on the ECCO 1968 group structure, both results of k-infinity agree with the reference value within 100 pcm. The resonance overlap effect is observed by several percents in cross sections of heavy nuclides. In the standard level calculation based on the APOLLO2 library creation methodology, a discrepancy appears by more than 300 pcm. A restriction is revealed in APOLLO2. Its standard cross section library does not have a sufficiently small background cross section to evaluate the self shielding effect on 56 Fe cross sections. The restriction can be removed by introducing the mixture self-shielding treatment recently introduced to APOLLO2. SLAROM-UF original standard level calculation based on the JFS-3 library creation methodology is the best among the standard level calculations. Improvement from the SLAROM-UF standard level calculation is achieved mainly by use of a proper weight function for light or intermediate nuclides. (author)

  11. From the Lab to the real world : sources of error in UF {sub 6} gas enrichment monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Lombardi, Marcie L.

    2012-03-01

    Safeguarding uranium enrichment facilities is a serious concern for the International Atomic Energy Agency (IAEA). Safeguards methods have changed over the years, most recently switching to an improved safeguards model that calls for new technologies to help keep up with the increasing size and complexity of today’s gas centrifuge enrichment plants (GCEPs). One of the primary goals of the IAEA is to detect the production of uranium at levels greater than those an enrichment facility may have declared. In order to accomplish this goal, new enrichment monitors need to be as accurate as possible. This dissertation will look at the Advanced Enrichment Monitor (AEM), a new enrichment monitor designed at Los Alamos National Laboratory. Specifically explored are various factors that could potentially contribute to errors in a final enrichment determination delivered by the AEM. There are many factors that can cause errors in the determination of uranium hexafluoride (UF{sub 6}) gas enrichment, especially during the period when the enrichment is being measured in an operating GCEP. To measure enrichment using the AEM, a passive 186-keV (kiloelectronvolt) measurement is used to determine the {sup 235}U content in the gas, and a transmission measurement or a gas pressure reading is used to determine the total uranium content. A transmission spectrum is generated using an x-ray tube and a “notch” filter. In this dissertation, changes that could occur in the detection efficiency and the transmission errors that could result from variations in pipe-wall thickness will be explored. Additional factors that could contribute to errors in enrichment measurement will also be examined, including changes in the gas pressure, ambient and UF{sub 6} temperature, instrumental errors, and the effects of uranium deposits on the inside of the pipe walls will be considered. The sensitivity of the enrichment calculation to these various parameters will then be evaluated. Previously, UF

  12. Experimental study of lactose hydrolysis and separation in cstr-uf membrane reactor

    Directory of Open Access Journals (Sweden)

    M. Namvar-Mahboub

    2012-09-01

    Full Text Available In this study, the effect of processing conditions on the performance of continuous stirred tank -ultrafiltration (CSTR-UF in dead - end mode was investigated. An UF membrane with a molecular weight cutoff of 3 kDa made of regenerated cellulose material was used to separate enzyme from products. The effect of operating pressure ranging between 2 and 5 bar and time on the performance of the CSTR-UF system was studied. The experiments were performed with a 0.139 molar aqueous solution of lactose as feed. According to the experimental data, the lactose concentration in the permeate decreased with time due to concentration polarization and hydrolysis. It was found that the rejection factor of lactose increases from 33 to 77% with time from 5 to 85 min. Permeation flux of the membrane was evaluated in terms of pure water flux (PWF and lactose aqueous solution. Results showed that a high operating pressure led to a high permeation flux for both mentioned cases. Also, adding lactose and enzyme to pure water caused a reduction of the permeation flux due to concentration polarization.

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

    International Nuclear Information System (INIS)

    Wagner, P.

    1977-04-01

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

  14. Removal of a synthetic organic chemical by PAC-UF systems. II: Model application.

    Science.gov (United States)

    Matsui, Y; Colas, F; Yuasa, A

    2001-02-01

    This paper describes several application potentials with a recently developed model for predicting the synthetic organic chemical (SOC) removal by powdered activated carbon (PAC) adsorption during ultrafiltration (UF) and discusses the removal mechanism. The model was successfully applied, without any modification, to dead-end mode operation as well as to cross-flow mode operation, validating the assumption of the internal diffusion control mechanism and the continuously-stirred-tank-reactor (CSTR) concept. Even when UF was operated in a cross-flow mode, PAC added was re-circulating in suspension for only a short time. Then, solute uptake took place mostly by PAC immobilized in membrane tubes not only for dead-end operation but also for cross-flow operation. Therefore, cross-flow operation did not have any advantage regarding the SOC mass transfer on PAC in UF loop over dead-end operation. The model simulation implied that pulse PAC addition at the beginning of filtration cycle resulted better SOC removal than continuous PAC addition. However, for the pulse PAC addition mode, the model predicted somewhat lower effluent SOC concentration than the observed values, and the benefit of pulse PAC application in terms of reducing SOC over its continuous dosage was not confirmed. Longer detention time of PAC dosed in a pulse than continuously dosed PAC could possibly further decrease internal diffusivity.

  15. Actual and Idealized Crystal Field Parameterizations for the Uranium Ions in UF 4

    Science.gov (United States)

    Gajek, Z.; Mulak, J.; Krupa, J. C.

    1993-12-01

    The crystal field parameters for the actual coordination symmetries of the uranium ions in UF 4, C2 and C1, and for their idealizations to D2, C2 v , D4, D4 d , and the Archimedean antiprism point symmetries are given. They have been calculated by means of both the perturbative ab initio model and the angular overlap model and are referenced to the recent results fitted by Carnall's group. The equivalency of some different sets of parameters has been verified with the standardization procedure. The adequacy of several idealized approaches has been tested by comparison of the corresponding splitting patterns of the 3H 4 ground state. Our results support the parameterization given by Carnall. Furthermore, the parameterization of the crystal field potential and the splitting diagram for the symmetryless uranium ion U( C1) are given. Having at our disposal the crystal field splittings for the two kinds of uranium ions in UF 4, U( C2) and U( C1), we calculate the model plots of the paramagnetic susceptibility χ( T) and the magnetic entropy associated with the Schottky anomaly Δ S( T) for UF 4.

  16. UF6 Density and Mass Flow Measurements for Enrichment Plants using Acoustic Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Good, Morris S.; Smith, Leon E.; Warren, Glen A.; Jones, Anthony M.; Ramuhalli, Pradeep; Roy, Surajit; Moran, Traci L.; Denslow, Kayte M.; Longoni, Gianluca

    2017-09-01

    A key enabling capability for enrichment plant safeguards being considered by the International Atomic Energy Agency (IAEA) is high-accuracy, noninvasive, unattended measurement of UF6 gas density and mass flow rate. Acoustic techniques are currently used to noninvasively monitor gas flow in industrial applications; however, the operating pressures at gaseous centrifuge enrichment plants (GCEPs) are roughly two orders magnitude below the capabilities of commercial instrumentation. Pacific Northwest National Laboratory is refining acoustic techniques for estimating density and mass flow rate of UF6 gas in scenarios typical of GCEPs, with the goal of achieving 1% measurement accuracy. Proof-of-concept laboratory measurements using a surrogate gas for UF6 have demonstrated signatures sensitive to gas density at low operating pressures such as 10–50 Torr, which were observed over the background acoustic interference. Current efforts involve developing a test bed for conducting acoustic measurements on flowing SF6 gas at representative flow rates and pressures to ascertain the viability of conducting gas flow measurements under these conditions. Density and flow measurements will be conducted to support the evaluation. If successful, the approach could enable an unattended, noninvasive approach to measure mass flow in unit header pipes of GCEPs.

  17. Styrene process condensate treatment with a combination process of UF and NF for reuse.

    Science.gov (United States)

    Wang, Aijun; Liu, Guangmin; Huang, Jin; Wang, Lijuan; Li, Guangbin; Su, Xudong; Qi, Hong

    2013-01-15

    Aiming at reusing the SPC to save water resource and heat energy, a combination treatment process of UF/NF was applied to remove inorganic irons, suspended particles and little amount of organic contaminants in this article. To achieve the indexes of CODM≤5.00 mg L(-1), oil≤2.00 mg L(-1), conductivity≤10.00 μs cm(-1), pH of 6.0-8.0, the NF membrane process was adopted. It was necessary to employ a pretreatment process to reduce NF membrane fouling. Hence UF membrane as an efficient pretreatment unit was proposed to remove the inorganic particles, such as iron oxide catalyst, to meet the influent demands of NF. The effluent of UF, which was less than 0.02 mg L(-1) of total iron, went into a security filter and then was pumped into the NF process unit. High removal efficiencies of CODM, oil and conductivity were achieved by using NF process. The ABS grafting copolymerization experiment showed that the effluent of the combination process met the criteria of ABS production process, meanwhile the process could alleviate the environment pollution. It was shown that this combination process concept was feasible and successful in treating the SPC. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Translation and validation of the Uterine Fibroid Symptom and Quality of Life (UFS-QOL questionnaire for the Brazilian Portuguese language

    Directory of Open Access Journals (Sweden)

    Luiz Gustavo Oliveira Brito

    2017-03-01

    Full Text Available ABSTRACT CONTEXT AND OBJECTIVE: Uterine fibroids (UF, also known as leiomyomas, are the most prevalent gynecological tumors. The Uterine Fibroid Symptoms and Quality of Life (UFS-QOL is the only specific questionnaire that assesses symptom intensity and quality-of-life issues for women with symptomatic UF; however, it only exists in the English language. Thus, we aimed to translate and culturally validate the UFS-QOL questionnaire for the Brazilian Portuguese language. DESIGN AND SETTING: Cross-sectional study, Department of Gynecology and Obstetrics, FMRP-USP. METHODS: 113 patients with UF (case group and 55 patients without UF (control group were interviewed using the UFS-QOL questionnaire after translation and cultural adaptation. The Short Form-36 questionnaire was used as a control. Demographic and psychometric variables were analyzed. RESULTS: Women with UF presented higher mean age, body mass index, weight, parity and comorbidities than the control group (P < 0.05. The most prevalent complaints were abnormal uterine bleeding (93.8%, pelvic pain (36.3% and extrinsic compression (10.6% and these presented adequate construct validity regarding UFS-QOL severity (P < 0.05. The UFS-QOL questionnaire presented good internal consistency regarding symptom severity and quality-of-life-related domains (intraclass correlation coefficient, ICC = 0.82/0.88. Structural validity presented correlation coefficients ranging from 0.59 to 0.91. Test-retest comparison did not show differences among the UFS-QOL subscales. After treatment, women with UF presented improvements on all subscales. CONCLUSION: The UFS-QOL questionnaire presented adequate translation to the Brazilian Portuguese language, with good internal consistency, discriminant validity, construct validity, structural validity and responsiveness, along with adequate test-retest results.

  19. An Unattended Verification Station for UF6 Cylinders: Development Status

    International Nuclear Information System (INIS)

    Smith, E.; McDonald, B.; Miller, K.; Garner, J.; March-Leuba, J.; Poland, R.

    2015-01-01

    In recent years, the International Atomic Energy Agency (IAEA) has pursued innovative techniques and an integrated suite of safeguards measures to address the verification challenges posed by advanced centrifuge technologies and the growth in separative work unit capacity at modern centrifuge enrichment plants. These measures would include permanently installed, unattended instruments capable of performing the routine and repetitive measurements previously performed by inspectors. Among the unattended instruments currently being explored by the IAEA is an Unattended Cylinder Verification Stations (UCVS) that could provide independent verification of the declared relative enrichment, U-235 mass and total uranium mass of all declared cylinders moving through the plant, as well as the application and verification of a ''Non-destructive Assay Fingerprint'' to preserve verification knowledge on the contents of each cylinder throughout its life in the facility. As IAEA's vision for a UCVS has evolved, Pacific Northwest National Laboratory (PNNL) and Los Alamos National Laboratory have been developing and testing candidate non-destructive assay (NDA) methods for inclusion in a UCVS. Modeling and multiple field campaigns have indicated that these methods are capable of assaying relative cylinder enrichment with a precision comparable to or substantially better than today's high-resolution handheld devices, without the need for manual wall-thickness corrections. In addition, the methods interrogate the full volume of the cylinder, thereby offering the IAEA a new capability to assay the absolute U-235 mass in the cylinder, and much-improved sensitivity to substituted or removed material. Building on this prior work, and under the auspices of the United States Support Programme to the IAEA, a UCVS field prototype is being developed and tested. This paper provides an overview of: a) hardware and software design of the prototypes, b) preparation

  20. Testing and evaluation of used UF6 shipping packages

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  1. The state-of-the-practice in low enriched UF6 isotopic measurements in the European Community: results of REIMEP UF6

    International Nuclear Information System (INIS)

    Bolle, W. de; Damen, R.; Bievre, P. de; Nagel, W.; Meyer, H.; Lycke, W.; Wolters, W.H.

    1991-01-01

    After the interruption of the SALE programme, CBNM has established a Regular European Interlaboratory Measurement Evaluation Programme (REIMEP) with the support of the ESARDA Working Group for techniques and standards for destructive analysis (WGDA), the ESARDA Working Group for techniques and standards for non-destructive analysis (WGNDA) and the IAEA. On the basis of a questionnaire with answers from 41 laboratories, 36 laboratories have announced their interest for such a programme. In this paper we report on the 1986/87 round of the programme establishing the measurement capability or State Of the Practice in UF 6 isotopic measurements by methods left at the discretion of the participants (thermal ionization mass spectrometry, electron impact mass spectrometry and gamma-ray spectrometry). Pictures of the State Of the Practice are presented as graphs displaying participants results

  2. The Accuracy of the Sysmex UF-1000i in Urine Bacterial Detection Compared With the Standard Urine Analysis and Culture.

    Science.gov (United States)

    Erdman, Patrick; Anderson, Brian; Zacko, J Christopher; Taylor, Kirk; Donaldson, Keri

    2017-11-01

    - Urinary tract infections are characterized by the presence of microbial pathogens within the urinary tract. They represent one of the most common infections in hospitalized and clinic patients. - To model the parameters of the Sysmex UF-1000i to the gold standard, urine culture, and to compare the detection of dipstick leukocyte esterase and nitrates to urine cultures and UF-1000i results. - Data were compared from urine samples collected in sterile containers for bacterial culture and microscopic analysis. One sample was used to inoculate a 5% sheep blood agar and MacConkey agar plate using a 0.001-mL calibrated loop. The second sample was analyzed by urinalysis-associated microscopy. The media plates were investigated for growth after 18 to 24 hours of aerobic incubation at 37°C. The second sample was analyzed for bacteria and leukocytes with the Sysmex UF-1000i according to the manufacturer's guidelines. Three definitions for culture results, sensitivity, and specificity at different cutoff values were calculated for the UF-1000i. - The negative predictive value for any positive culture in the adult population included in the study was 95.5%, and the negative predictive value for positive cultures containing growth of 100 000 or more colony-forming units was 99.3% using the Sysmex UF-1000i. - Sysmex UF-1000i showed 98% sensitivity and 93.7% specificity with a 95.5% negative predictive value. Thus, a negative screen with the UF-1000i using defined thresholds for white blood cell counts and bacteria was likely to be a true negative, decreasing the need for presumptive antibiotics.

  3. Method for selectively removing fluorine and fluorine-containing contaminants from gaseous UF/sub 6/. [ClF/sub 3/

    Science.gov (United States)

    Jones, R.L.; Otey, M.G.; Perkins, R.W.

    1980-11-24

    This invention is a method for effecting preferential removal and immobilization of certain gaseous contaminants from gaseous UF/sub 6/. The contaminants include fluorine and fluorides which are more reactive with CaCO/sub 3/ than is UF/sub 6/. The method comprises contacting the contaminant-carrying UF/sub 6/ with particulate CaCO/sub 3/ at a temperature effecting reaction of the contaminant and the CaCO/sub 3/.

  4. Metals, heavy metals and microorganism removal from spent filter backwash water by hybrid coagulation-UF processes

    Directory of Open Access Journals (Sweden)

    Mokhtar Mahdavi

    2018-04-01

    Full Text Available Spent filter backwash water (SFBW reuse has attracted particular attention, especially in countries that experience water scarcity. It can act as a permanent water source until the water treatment plant is working. In this study, the concentrations of Fe, Al, Pb, As, and Cd with total and fecal coliform (TC/FC were investigated in raw and treated SFBW by hybrid coagulation-UF processes. The pilot plant consisted of pre-sedimentation, coagulation, flocculation, clarification, and ultrafiltration (UF units. Poly-aluminum ferric chloride (PAFCL and ferric chloride (FeCl3 were used as pretreatment. The results showed that, at the optimum dose of PAFCl, the average removal of TC and FC was 88 and 79% and with PAFCl-UF process, it reached 100 and 100%, respectively. For FeCl3, removal efficiency of TC and FC were 81 and 72% and by applying FeCl3-UF process, it reached 100 and 100%, respectively. In comparison with FeCl3, PAFCl showed better removal efficiency for Fe, Pb, As, and Cd, except residual Al concentration. Coagulation-UF process could treat SFBW efficiently and treated SFBW could meet the US-EPA drinking water standard. Health risk index values of Fe, AL, Pb, AS, and Cd in treated SFBW indicate no risk of exposure to the use of this water.

  5. MF/UF rejection and fouling potential of algal organic matter from bloom-forming marine and freshwater algae

    KAUST Repository

    Villacorte, Loreen O.

    2015-07-01

    Pretreatment with microfiltration (MF) or ultrafiltration (UF) membranes has been proposed for seawater reverse osmosis (SWRO) plants to address operational issues associated with algal blooms. Here, we investigated the MF/UF rejection and fouling potential of algal organic matter (AOM) released by common species of bloom-forming marine (Alexandrium tamarense and Chaetoceros affinis) and freshwater (Microcystis sp.) algae. Batch culture monitoring of the three algal species illustrated varying growth pattern, cell concentration, AOM released and membrane fouling potential. The high membrane fouling potential of the cultures can be directly associated (R2>0.85) with AOM such as transparent exopolymer particle (TEP) while no apparent relationship with algal cell concentration was observed. The AOM comprised mainly biopolymers (e.g., polysaccharides and proteins) and low molecular weight organic compounds (e.g., humic-like substances). The former were largely rejected by MF/UF membranes while the latter were poorly rejected. MF (0.4μm and 0.1μm pore size) rejected 14%-56% of biopolymers while conventional UF (100kDa) and tight UF (10kDa) rejected up to 83% and 97%, respectively. The retention of AOM resulted in a rapid increase in trans-membrane pressure (δP) over time, characterised by pore blocking followed by cake filtration with enhanced compression as illustrated by an exponential progression of δP. © 2015 Elsevier B.V.

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

    International Nuclear Information System (INIS)

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

    1996-06-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-07-01

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

  8. Calculations of electronic structure of UF6 molecule and crystal UO2 with relativistic pseudopotential

    International Nuclear Information System (INIS)

    Ehvarestov, R.A.; Panin, A.I.; Bandura, A.V.

    2008-01-01

    Account of relativistic effects on the properties of uranium hexafluoride is testified. Detailed comparison of single electron energies spectrum revealed in nonrelativistic (by Hartree-Fock method), relativistic (by Dirac-Fock method), and scalar-relativistic (using relativistic potential of atomic uranium frame) has been conducted. Optimization procedures of atomic basis in LCAO calculations of molecules and crystals permissive taking into account distortion of atomic orbitals when chemical bonding are discussed, and optimization effect of atomic basis on the results of scalar-relativistic calculations of UF 6 molecule properties is analyzed. Calculations of electronic structure and properties of UO 2 crystal having relativistic and nonrelativistic pseudopotentials have been realized [ru

  9. UF6 fissile mass flow simulation at Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Mihalczo, J.T.; March-Leuba, J.; Valentine, T.E.; Mattingly, J.K.; Uckan, T.; McEvers, J.A.

    1997-01-01

    Basis for measuring fissile mass flow in slurries, liquid, and gaseous streams is activation of a fissile stream by neutrons and then detection of delayed radiation from resulting fission products. This paper describes recent simulation measurements with the first prototype of the system for fissile mass flow measurements with HEU UF 6 gas for use in blenddown facilities. Theory was only 15% higher than actual measured; thus calibration factor would be 0.85. This simulation of HEU gas flow confirms well the understanding of the physical phenomena associated with this measurement system

  10. Practical experience of backwashing with SWRO permeate for UF fouling control

    KAUST Repository

    Li, Sheng; Heijman, Sebastiaan G J; Verberk, J. Q J C; Amy, Gary L.; Van Dijk, Johannis C.

    2013-01-01

    Effectiveness of seawater reverse osmosis (SWRO) permeate backwash on fouling control of seawater ultrafiltration was investigated at a pilot scale. A standard membrane module was used in this pilot to represent full-scale desalination plants. Results of the pilot show a good reproducibility. When the UF permeate was used for backwash, the frequency of chemically enhanced backwash (CEB) was around once per day. However, results of the pilot show that SWRO permeate backwashing could significantly reduce the CEB frequency. © 2013 Desalination Publications.

  11. Development of a UF{sub 6} cylinder transient heat transfer/stress analysis model

    Energy Technology Data Exchange (ETDEWEB)

    Williams, W.R. [Martin Marietta Energy Systems, Inc., Oak Ridge, TN (United States)

    1991-12-31

    A heat transfer/stress analysis model is being developed to simulate the heating to a point of rupture of a cylinder containing UF{sub 6} when it is exposed to a fire. The assumptions underlying the heat transfer portion of the model, which has been the focus of work to date, will be discussed. A key aspect of this model is a lumped parameter approach to modeling heat transfer. Preliminary results and future efforts to develop an integrated thermal/stress model will be outlined.

  12. Development and design of a UF{sub 6} gas pressure meter for 42 mm pipes

    Energy Technology Data Exchange (ETDEWEB)

    Peters, E.; Wichers, V.A.

    1995-08-01

    X-ray fluorescence (XRF) has proved to be a feasible method of measuring the pressure of UF{sub 6}-gas for enrichment verification purposes. Complications will arise under extreme conditions, such as high uranium deposit to gas ratios, pipe diameters smaller than 40 mm and pressures less than 100 Pa. This report presents an experimental analysis of the XRF method for design worst case conditions for 42 outer diameter cascade-to-header pipes and the development of a prototype measurement device. This prototype is integrated in the construction of the enrichment verification system. (orig.).

  13. Development and design of a UF6 gas pressure meter for 42 mm pipes

    International Nuclear Information System (INIS)

    Peters, E.; Wichers, V.A.

    1995-08-01

    X-ray fluorescence (XRF) has proved to be a feasible method of measuring the pressure of UF 6 -gas for enrichment verification purposes. Complications will arise under extreme conditions, such as high uranium deposit to gas ratios, pipe diameters smaller than 40 mm and pressures less than 100 Pa. This report presents an experimental analysis of the XRF method for design worst case conditions for 42 outer diameter cascade-to-header pipes and the development of a prototype measurement device. This prototype is integrated in the construction of the enrichment verification system. (orig.)

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

    International Nuclear Information System (INIS)

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

    1976-01-01

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

  15. Developments of solid materials for UF6 sampling

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Nicholas [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Hebden, Andrew [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Savina, Joseph [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division

    2017-11-15

    This project demonstrated that a device using majority Commercial Off the Shelf (COTS) components could be used to collect uranium hexafluoride samples safely from gaseous or solid sources. The device was based on the successful Cristallini method developed by ABACC over the past 10 years. The system was designed to capture and store the UF6 as an inert fluoride salt to ease transportation regulations. In addition, the method was considerably faster than traditional cryogenic methods, collected enough material to perform analyses without undue waste, and could be used either inside a facility or in the storage yard.

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

    International Nuclear Information System (INIS)

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

    2017-01-01

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

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

    International Nuclear Information System (INIS)

    Basombrio, F.G.

    1996-01-01

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

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

    International Nuclear Information System (INIS)

    1986-08-01

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

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

    International Nuclear Information System (INIS)

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

    1987-01-01

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

  20. Determination of UO2F2, UO2 and UF4 in tetrafluoride of uranium samples

    International Nuclear Information System (INIS)

    Contreras Guzman, Ariel; Arlegui Hormazabal, Oscar

    2003-01-01

    The combustible elements for investigation reactors that at the present are manufacturing by the Chilean Nuclear Energy Commission (CCHEN) they are based on aluminum and silicide uranium powdered which is obtained from metallic uranium. At the present the Conversion Units, is developing the technology of transformation UF 6 in metallic Uranium, reason for which is necessary that the Chemical Analysis Laboratory have a methodology that allows to quantify the presence of UO 2 F 2 , UO 2 and UF 4 in the samples obtained in this transformation process. For this reason we are implements the methodology of sequential analysis that had been developed previously, for the Institute of Energy and Nuclear Investigations, IPEN Brasil, and to adapt it to the present conditions in the Laboratory of Chemical Analysis of the CCHEN. This method is based on the different solubilities that present those sample in front of solvents as ethanol and solutions of ammonium oxalate, what allows the separation of these compounds for a later analysis by means of the method of Davies and Gray. This method is based on the reduction of the uranium (VI) to uranium (IV) with ferrous ion amid phosphoric acid, quantifying the present uranium in the samples by means of titration with potassium dicromate. With the purpose of checking the efficiency of the method, the sum of all values of uranium coming from each compound and compares it with the total uranium of the sample (author)

  1. UF/sub 6/ test loop for evaluation and implementation of international enrichment plant safeguards

    International Nuclear Information System (INIS)

    Cooley, J.N.; Fields, L.W.; Swindle, D.W. Jr.

    1987-01-01

    A functional test loop capable of simulating UF/sub 6/ flows, pressures, and pipe deposits characteristic of gas centrifuge enrichment plant piping has been designed and fabricated by the Enrichment Safeguards Program of Martin Marietta Energy Systems, Inc., for use by the International Atomic Energy Agency (IAEA) at its Safeguards Analytical Laboratory in Seibersdorf, Austria. The purpose of the test loop is twofold: (1) to enable the IAEA to evaluate and to calibrate enrichment safeguards measurement instrumentation to be used in limited frequency-unannounced access (LFUA) inspection strategy measurements at gas centrifuge enrichment plants and (2) to train IAEA inspectors in the use of such instrumentation. The test loop incorporates actual sections of cascade header pipes from the centrifuge enrichment plants subject to IAEA inspections. The test loop is described, applications for its use by the IAEA are detailed, and results from an initial demonstration session using the test loop are summarized. By giving the IAEA the in-house capability to evaluate LFUA inspection strategy approaches, to develop inspection procedures, to calibrate instrumentation, and to train inspectors, the UF/sub 6/ cascade header pipe test loop will contribute to the IAEA's success in implementing LFUA strategy inspections at gas centrifuge enrichment facilities subject to international safeguards inspections

  2. RESPEITO À CIDADANIA: PROVENDO ACESSIBILIDADE WEB NA UNIVERSIDADE FEDERAL DE SERGIPE (UFS

    Directory of Open Access Journals (Sweden)

    Quelita Araújo Diniz da Silva

    2012-03-01

    Full Text Available O acesso à informação facilitado pelas Tecnologias de Informação e Comunicação (TIC é um dos principais elementos da sociedade do conhecimento, sendo visto como possibilidade de inclusão social. Entretanto, alguns indivíduos possuem necessidades, permanentes ou temporárias, que os limitam no acesso às informações disponibilizadas, mantendo-os à periferia da sociedade. Este trabalho tem como objetivo discutir a acessibilidade na Web, discutindo os principais padrões, as diretrizes e técnicas para o projeto de webapps acessíveis. Como também, expor o conceito de tecnologias assistivas e como elas adequam às funcionalidades computacionais ao internauta com necessidades especiais auxiliando-o na navegação. Por fim, descrever um estudo de caso realizado no site da POSGRAP – UFS objetivando viabilizar à comunidade Sergipana à inclusão provendo acessibilidade aos produtos e serviços da UFS.

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

    International Nuclear Information System (INIS)

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

    1995-03-01

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

  4. Electrochemical separation of uranium in the molten system LiF-NaF-KF-UF4

    Science.gov (United States)

    Korenko, M.; Straka, M.; Szatmáry, L.; Ambrová, M.; Uhlíř, J.

    2013-09-01

    This article is focused on the electrochemical investigation (cyclic voltammetry and related studies) of possible reduction of U4+ ions to metal uranium in the molten system LiF-NaF-KF(eut.)-UF4 that can provide basis for the electrochemical extraction of uranium from molten salts. Two-step reduction mechanism for U4+ ions involving one electron exchange in soluble/soluble U4+/U3+ system and three electrons exchange in the second step were found on the nickel working electrode. Both steps were found to be reversible and diffusion controlled. Based on cyclic voltammetry, the diffusion coefficients of uranium ions at 530 °C were found to be D(U4+) = 1.64 × 10-5 cm2 s-1 and D(U3+) 1.76 × 10-5 cm2 s-1. Usage of the nickel spiral electrode for electrorefining of uranium showed fairly good feasibility of its extraction. However some oxidant present during the process of electrorefining caused that the solid deposits contained different uranium species such as UF3, UO2 and K3UO2F5.

  5. The approach of toxic and radiological risk equivalence in UF6 transport

    International Nuclear Information System (INIS)

    Ringot, C.; Hamard, J.

    1989-01-01

    After a brief description of the present situation concerning the safety of the transport of UF6 and the new regulation project which is being developed under the behalf of IAEA, the equivalence of radioactive and chemical risks is considered for UF6 transport regulations. The concept of low specific activity appearing misfitting to toxic gas, it is proposed a quantity limit of material, T 2 (equivalent to A 2 for radioactive materials), for packagings which do not resist to accidental conditions, (9 m drop, 800 0 C, 30 minutes fire environment). It is proposed that this limit is chosen as the release rate which is acceptable after the IAEA tests for packages having a capacity higher than T 2 kilograms. The fire being considered as the most severe situation for the toxic risk, different possible scenarios are described. This approach of risk equivalence leads to impose that the packaging resists a 800 0 C - 30 minutes fire and that in this condition the release is less than T 2 . The problem of the behaviour of the shell and the openings (in particular the valve) is raised in this context [fr

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  7. Criticality Safety Evaluation for 30B and 48X UF6 Cylinders for Transportation and Storage

    International Nuclear Information System (INIS)

    Mokhatri, Homami Zahra; Nematollahi, Mohammadreza; Kamyab, Shahabeddin

    2011-01-01

    30B and 48X cylinders are two standard containers have been used for transportation and storage of uranium hexafluoride with 21/2-ton and 10-ton loading capacity, respectively. For the sake of nuclear safety, the long-term safe storage and transportation of the cylinders are necessary to be concerned. Safe limits in handling and storage of 30B and 48X cylinders from the criticality safety considerations, has been investigated in this paper, by using the MCNP.4C code with ENDF/B-VI library data for the neutron cross sections. An infinite array model (with and without over pack) incorporating an internal H/U ratio of 0.088 was then developed to determine the optimal interstitial moderation. The maximum k eff value for the conditions of optimal interstitial moderation with the premise of no water leakage into the UF 6 cylinder has been shown to be 0.79209 ± 0.0011 for the 30B cylinder and 0.7625±0.0013 for 48X cylinder with 5 wt % 235 U enrichment. Based on this evaluation, the 30B and 48X UF 6 cylinders with 5 wt % 235 U enrichment meet the 10 CFR part 71 criteria for Fissile Class I packages, even in the worst case, and has a Transport Index (TI) of zero for criticality safety purposes

  8. Computer simulation of cooling properties of UF5 hot-clusters in argon

    International Nuclear Information System (INIS)

    Okamoto, Tsuyoshi; Ohno, Fubito

    1999-01-01

    Brownian collision-coalescence models have been proposed by many researchers to describe a cluster or a particle growth process. In these mathematical models, the effect of a cluster temperature on a sticking probability is not included, although the cluster temperature is one of the most important factors which determines the particle growth rate at the incipient stage of coagulation. A hot-cluster consisting of 30 UF 5 molecules is formed in a computer and is bombarded with argon atoms. Measuring a kinetic energy of argon atom scattered from the hot-cluster, the cluster temperature can be estimated by molecular dynamics simulations. It is concluded that the hot-cluster is rapidly cooled under the conditions of molecular laser isotope separation (MLIS) process, so that the cluster-argon system can reach its thermal equilibrium state. Therefore, in the analysis of the dynamics of clustering process, the temperature of UF 5 molecular cluster may be set equal to that of argon gas. (author)

  9. Impact of Acid Cleaning on the Performance of PVDF UF Membranes in Seawater Reverse Osmosis Pretreatment

    KAUST Repository

    Alsogair, Safiya

    2016-05-05

    Low-pressure membrane systems such as Microfiltration (MF) and Ultrafiltration (UF) have been presented as viable option to pre-treatment systems in potable water applications. UF membranes are sporadically backwashed with ultra-filtered water to remove deposited matter from the membrane and restore it. Several factors that may cause permeability and selectivity decrease are involved and numerous procedures are applicable to achieve this objective. Membrane cleaning is the most important step required to maintain the characteristics of the membrane. This research was made with the purpose of investigating the effects of acid cleaning during chemically enhanced backwashing (CEB) on the performance of ultrafiltration (UF) membranes in seawater reverse osmosis (SWRO) pretreatment. To accomplish this, the questions made were: Does the acid addition (before or after the alkali CEB) influence the overall CEB cleaning effectiveness on Dow UF membrane? Does the CEB order of alkali (NaOCl) and acid (H2SO4) affect the overall CEB cleaning effectiveness? If yes, which order is better/worse? What is the optimal acid CEB frequency that will ensure the most reliable performance of the UF?. To answer this queries, a series of sequences were carried out with different types of chemical treatments: Only NaOCl, daily NaOCl plus weekly acid, daily NaOCl plus daily acid, and weekly acid plus daily NaOCl. To investigate the consequence of acid by studying the effect of operational data like the trans-pressure membrane, resistance or permeability and support that by the analytical experiments (organic, inorganic and microbial characterization). Microorganisms were removed almost completely at hydraulic cleaning and showed no difference with addition of acid. As a conclusion of the operational data the organic and inorganic chatacterization resulted in the elimination of the first sequence due to the acummulation of fouling over time, which produces that the cleaning increases downtime

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

    Energy Technology Data Exchange (ETDEWEB)

    Wylie, Joann; Hockert, John

    2014-04-24

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-09-14

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

  12. Tight ceramic UF membrane as RO pre-treatment: The role of electrostatic interactions on phosphate rejection

    NARCIS (Netherlands)

    Shang, R.; Verliefde, A.R.D.; Hu, J.; Zeng, Z; Lu, L.; Lu, L.; Kemperman, Antonius J.B.; Deng, H.; Nijmeijer, Dorothea C.; Heijman, S.G.J.; Rietveld, L.C.

    2014-01-01

    Phosphate limitation has been reported as an effective approach to inhibit biofouling in reverse osmosis (RO) systems for water purification. The rejection of dissolved phosphate by negatively charged TiO2 tight ultrafiltration (UF) membranes (1 kDa and 3 kDa) was observed. These membranes can

  13. PGDP [Paducah Gaseous Diffusion Plant]-UF6 handling, sampling, analysis and associated QC/QA and safety related procedures

    International Nuclear Information System (INIS)

    Harris, R.L.

    1987-01-01

    This document is a compilation of Paducah Gaseous Diffusion Plant procedures on UF 6 handling, sampling, and analysis, along with associated QC/QA and safety related procedures. It was assembled for transmission by the US Department of Energy to the Korean Advanced Energy Institute as a part of the US-Korea technical exchange program

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

    Science.gov (United States)

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

    2016-07-01

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

  15. P-T-x phase diagrams of MeF-UF4(Me=Li-Cs) systems

    International Nuclear Information System (INIS)

    Korenev, Yu.M.; Rykov, A.N.; Varkov, M.V.; Novoselova, A.V.

    1988-01-01

    Vapor composition and general pressure at three-phase equilibria in the MeF-UF 4 (Me=Li-Cs) systems are calculated using the values of independent component activities obtained earlier together with the data on fusibility diagrams. P-T and T-x projections of phase diagrams of these systems are constructed

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

    International Nuclear Information System (INIS)

    1983-12-01

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

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

    International Nuclear Information System (INIS)

    Perkins, B.L.

    1982-10-01

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

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

    International Nuclear Information System (INIS)

    Kusahara, Helena Sueco

    1979-01-01

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

  19. Portable load-cell based system for weighing UF6 cylinders

    International Nuclear Information System (INIS)

    Fainberg, A.; Gordon, D.; Dermendjiev, E.; Terrey, D.; Mitchell, R.

    1982-01-01

    A load-cell-based portable weighing system which is capable of verifying the weights of 2.2 tonne 30-inch UF 6 cylinders has been developed by the US National Bureau of Standards (NBS). This system weighs about 13 kg and has an attainable accuracy of about 1 kg. After an initial calibration at NBS, the system is ready for use in the field. Approximately 5 to 10 minutes are needed for assembly, and, if an overhead crane has access to all cylinders to be weighed, from 10 to 15 weighings may be performed in one hour. During the past year the system has been tested at several facilities around the world with satisfactory results and with favorable comments from the facility operators. Results of several tests are presented in this paper

  20. Magnesio-thermic reduction of UF4 to uranium metal : plant operating experience

    International Nuclear Information System (INIS)

    Mayekar, S.V.; Singh, H.; Meghal, A.M.; Koppiker, K.S.

    1991-01-01

    Uranium Metal Plant has switched over from calcio-thermy to magnesio-thermy for production of uranium ingots. In this paper, the plant operating experience for magnesio-thermic reduction is described. Based on trials, the production has been stepped up from 40 kg ingots to 200 kg ingots. The operating parameters optimised include : heating schedule, UF 4 quality, magnesium quantity and quality, and particle size. The effect of quality of refractory lining has been discussed. Conditions for lining are optimised with regard to type of material used and size. Developmental work has also been carried out on use of pelletised charge and on use of graphite sleeves. Some experience in the machining of ingots for removal of surface slag is also discussed. Impurity problems, occasionally encountered, have been investigated and results are discussed. Based on the experience gained, specifications for operation have been laid down, and areas for further improvement are identified. (author). 5 refs., 1 fig., 1 tab

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

    International Nuclear Information System (INIS)

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

    1997-01-01

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

  2. UF6 test loop for evaluation and implementation of international enrichment plant safeguards

    International Nuclear Information System (INIS)

    Cooley, J.N.; Fields, L.W.; Swindle, D.W. Jr.

    1987-06-01

    A functional test loop capable of simulating UF 6 flows, pressures, and pipe deposits characteristic of gas centrifuge enrichment plant piping has been designed and fabricated by the Enrichment Safeguards Program of Martin Marietta Energy Systems, Inc., for use by International Atomic Energy Agency (IAEA) at its Safeguards Analytical Laboratory in Seibersdorf, Austria. Purpose of the test loop is twofold: (1) to enable the IAEA to evaluate and to calibrate enrichment safeguards measurement instrumentation to be used in limited frequency-unannounced access (LFUA) inspection strategy measurements at gas centrifuge enrichment plants and (2) to train IAEA inspectors in the use of such instrumentation. The test loop incorporates actual sections of cascade header pipes from the centrifuge enrichment plants subject to IAEA inspections. The test loop is described, applications for its use by the IAEA are detailed, and results from an initial demonstration session using the test loop are summarized

  3. Cracked lifting lug welds on ten-ton UF{sub 6} cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Dorning, R.E. [Martin Marietta Energy Systems, Inc., Piketon, OH (United States)

    1991-12-31

    Ten-ton, Type 48X, UF{sub 6} cylinders are used at the Portsmouth Gaseous Diffusion Plant to withdraw enriched uranium hexafluoride from the cascade, transfer enriched uranium hexafluoride to customer cylinders, and feed enriched product to the cascade. To accomplish these activities, the cylinders are lifted by cranes and straddle carriers which engage the cylinder lifting lugs. In August of 1988, weld cracks on two lifting lugs were discovered during preparation to lift a cylinder. The cylinder was rejected and tagged out, and an investigating committee formed to determine the cause of cracking and recommend remedial actions. Further investigation revealed the problem may be general to this class of cylinder in this use cycle. This paper discusses the actions taken at the Portsmouth site to deal with the cracked lifting lug weld problem. The actions include inspection activities, interim corrective actions, metallurgical evaluation of cracked welds, weld repairs, and current monitoring/inspection program.

  4. Thermodynamic assessment of the LiF-NaF-ThF4-UF4 system

    International Nuclear Information System (INIS)

    Benes, O.; Beilmann, M.; Konings, R.J.M.

    2010-01-01

    A thermodynamic assessment of the LiF-NaF-ThF 4 -UF 4 system is presented in this study. The binary phase diagrams are optimized based on the known experimental data and the excess Gibbs energies of liquid and solid solutions are described using a modified quasi chemical model and polynomial formalism respectively. The higher order systems are extrapolated according to asymmetric Toop mathematical formalism. Based on the developed thermodynamic database the fuel composition of the molten salt fast reactor is optimized. In total three different fuel compositions are identified. Properties of these fuel compositions such as melting point, vapour pressure and the boiling temperature are derived from the obtained thermodynamic assessment and are presented in this study.

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

    International Nuclear Information System (INIS)

    Neveu, Claude

    1965-01-01

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

  6. 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)

  7. Electronic, magnetic, transport, and thermal properties of single-crystalline UF e2A l10

    Science.gov (United States)

    Troć, R.; Samsel-Czekała, M.; Talik, E.; Wawryk, R.; Gajek, Z.; Pasturel, M.

    2015-09-01

    The valence and core-level x-ray photoemission spectra (XPS), performed on an UF e2A l10 single crystal, were measured using the Al Kα radiation. The results of valence XPS show practically two separate regions of spectral intensity, one just at the Fermi level (EF) and the other one being a wide content with its maximum at about 0.8 eV below EF. These give rise to two electronic configurations of the 5 f states in the studied aluminide, itinerant and localized ones, i.e., their dual character. In such a situation the corresponding valence spectra, calculated within the local density approximation (LDA), well explain the former configuration, being responsible for a metallic behavior of the studied compound. Moreover, this behavior is confirmed clearly also by our results of magnetotransport measurements. On the other hand, the obtained magnetic susceptibility, specific heat, electrical resistivity, and thermoelectric power data support very well the local character of the 5 f2 -electron configuration of the U4 + ion in UF e2A l10 having the orthorhombic and cage-type crystal structure. Based on that configuration, the magnetic and thermal characteristics of the compound were modeled by the effective crystal field (CF) potential in the intermediate coupling scheme using initial parameters obtained by the angular overlap model (AOM). The obtained final CF parameters yielded the CF level scheme, composed of only singlets, proper for orthorhombic symmetry. Such a set of singlets reproduces in a satisfactory way both the strongly anisotropic temperature variations of the magnetic susceptibility, measured along the three main crystallographic directions, as well as the Schottky anomaly, evaluated using specific heat results of isomorphic ThF e2A l10 as a phonon reference. Also, the strongly anisotropic behavior of the Seebeck coefficient and its low temperature maxima observed for the compound studied here have been explained roughly by the CF effect.

  8. 235U enrichment determination on UF6 cylinders with CZT detectors

    Science.gov (United States)

    Berndt, Reinhard; Mortreau, Patricia

    2018-04-01

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

  9. Spectroscopic properties of K{sub 5}Li{sub 2}UF{sub 10}

    Energy Technology Data Exchange (ETDEWEB)

    Karbowiak, M. [Faculty of Chemistry, University of WrocIaw, ul. F. Joliot-Curie 14, 50-383 WrocIaw (Poland)]. E-mail: karb@wchuwr.chem.uni.wroc.pl; Gajek, Z. [W. Trzebiatowski Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 1410, 50-950 WrocIaw (Poland); Drozdzynski, J. [Faculty of Chemistry, University of WrocIaw, ul. F. Joliot-Curie 14, 50-383 WrocIaw (Poland)

    2005-04-04

    A new uranium (III) fluoro-complex of the formula K{sub 5}Li{sub 2}UF{sub 10} has been synthesised and characterised by X-ray powder diffraction and electronic absorption spectra measurements. The compound crystallises in the orthorhombic system, space group Pnma, with a = 20.723, b = 7.809, c = 6.932 A, V = 1121.89 A{sup 3}, Z = 4 and is isostructural with its K{sub 5}Li{sub 2}NdF{sub 10} and K{sub 5}Li{sub 2}LaF{sub 10} analogous. The absorption spectrum of a polycrystalline sample of K{sub 5}Li{sub 2}UF{sub 10} was recorded at 4.2 K in the 3500-45,000 cm{sup -1} range and is discussed. The observed crystal-field levels were assigned and fitted to parameters of the simplified angular overlap model (AOM) and next to those of a semi-empirical Hamiltonian, which was representing the combined atomic and one-electron crystal-field interactions. The starting values of the AOM parameters were obtained from ab initio calculations. The analysis of the spectra enabled the assignment of 71 crystal-field levels of U{sup 3+} with a relatively small r.m.s. deviation of 37 cm{sup -1}. The total splitting of 714 cm{sup -1} was calculated for the {sup 4}I{sub 9/2} ground multiplet.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-07-12

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

  11. Probing the electronic structures of low oxidation-state uranium fluoride molecules UF{sub x}{sup −} (x = 2−4)

    Energy Technology Data Exchange (ETDEWEB)

    Li, Wei-Li; Jian, Tian; Lopez, Gary V.; Wang, Lai-Sheng, E-mail: lai-sheng-wang@brown.edu [Department of Chemistry, Brown University, Providence, Rhode Island 02912 (United States); Hu, Han-Shi; Li, Jun, E-mail: junli@tsinghua.edu.cn [Department of Chemistry and Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Tsinghua University, Beijing 100084 (China); William R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352 (United States); Su, Jing [Department of Chemistry and Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Tsinghua University, Beijing 100084 (China)

    2013-12-28

    We report the experimental observation of gaseous UF{sub x}{sup −} (x = 2−4) anions, which are investigated using photoelectron spectroscopy and relativistic quantum chemistry. Vibrationally resolved photoelectron spectra are obtained for all three species and the electron affinities of UF{sub x} (x = 2−4) are measured to be 1.16(3), 1.09(3), and 1.58(3) eV, respectively. Significant multi-electron transitions are observed in the photoelectron spectra of U(5f{sup 3}7s{sup 2})F{sub 2}{sup −}, as a result of strong electron correlation effects of the two 7s electrons. The U−F symmetric stretching vibrational modes are resolved for the ground states of all UF{sub x} (x = 2−4) neutrals. Theoretical calculations are performed to qualitatively understand the photoelectron spectra. The entire UF{sub x}{sup −} and UF{sub x} (x = 1−6) series are considered theoretically to examine the trends of U−F bonding and the electron affinities as a function of fluorine coordination. The increased U−F bond lengths and decreased bond orders from UF{sub 2}{sup −} to UF{sub 4}{sup −} indicate that the U−F bonding becomes weaker as the oxidation state of U increases from I to III.

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

    International Nuclear Information System (INIS)

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

    1977-06-01

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

  13. Laboratory and pilot-plant studies on the conversion of uranyl nitrate hexahydrate to UF/sub 6/ by fluidized-bed processes

    Energy Technology Data Exchange (ETDEWEB)

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

    1977-06-01

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

  14. The UF family of reference hybrid phantoms for computational radiation dosimetry

    International Nuclear Information System (INIS)

    Lee, Choonsik; Lodwick, Daniel; Hurtado, Jorge; Pafundi, Deanna; Williams, Jonathan L; Bolch, Wesley E

    2010-01-01

    Computational human phantoms are computer models used to obtain dose distributions within the human body exposed to internal or external radiation sources. In addition, they are increasingly used to develop detector efficiencies for in vivo whole-body counters. Two classes of computational human phantoms have been widely utilized for dosimetry calculation: stylized and voxel phantoms that describe human anatomy through mathematical surface equations and 3D voxel matrices, respectively. Stylized phantoms are flexible in that changes to organ position and shape are possible given avoidance of region overlap, while voxel phantoms are typically fixed to a given patient anatomy, yet can be proportionally scaled to match individuals of larger or smaller stature, but of equivalent organ anatomy. Voxel phantoms provide much better anatomical realism as compared to stylized phantoms which are intrinsically limited by mathematical surface equations. To address the drawbacks of these phantoms, hybrid phantoms based on non-uniform rational B-spline (NURBS) surfaces have been introduced wherein anthropomorphic flexibility and anatomic realism are both preserved. Researchers at the University of Florida have introduced a series of hybrid phantoms representing the ICRP Publication 89 reference newborn, 15 year, and adult male and female. In this study, six additional phantoms are added to the UF family of hybrid phantoms-those of the reference 1 year, 5 year and 10 year child. Head and torso CT images of patients whose ages were close to the targeted ages were obtained under approved protocols. Major organs and tissues were segmented from these images using an image processing software, 3D-DOCTOR(TM). NURBS and polygon mesh surfaces were then used to model individual organs and tissues after importing the segmented organ models to the 3D NURBS modeling software, Rhinoceros(TM). The phantoms were matched to four reference datasets: (1) standard anthropometric data, (2) reference

  15. Level 4 Milestone (M4): M41UF033201 - Review of Radiolysis of Brines on the Surface of a Waste Package

    Energy Technology Data Exchange (ETDEWEB)

    Sutton, Mark [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2011-08-12

    This milestone report (M41UF033201) documents a literature review of relevant publications for gamma radiolysis occurring within a droplet of water on the outside of a waste package in a repository environment within the “

  16. Biodegradation behavior of natural organic matter (NOM) in a biological aerated filter (BAF) as a pretreatment for ultrafiltration (UF) of river water

    KAUST Repository

    Huang, Guocheng; Meng, Fangang; Zheng, Xing; Wang, Yuan; Wang, Zhigang; Liu, Huijun; Jekel, Martin R.

    2011-01-01

    In this study, biodegradation of natural organic matter (NOM) in a biological aerated filter (BAF) as pretreatment of UF treating river water was investigated. Photometric measurement, three-dimensional excitation-emission matrix (EEM) fluorescence

  17. Analysis of enriched HF-UF6 systems. Influence by impurity and density upon the value of the multiplication

    International Nuclear Information System (INIS)

    Acosta, N.B.; Canavese, S.I.; Lopez, M.L.

    1990-01-01

    The purpose of this paper is analyzing the influence of impurity in hydrogen fluoride and in density variation (UF 6 -HF) upon the value of the effective multiplication factor (Kef) in enriched uranium hexafluoride and hydrogen fluoride systems. The identification of the values of such multiplication factors were performed by means of the Monte-Carlo (MONK V.II) code, which is specific for criticality problems. Diverse systems were considered by keeping the same geometry and varying the density value and the impurity percentages, while the assumptions made for each model were described on a case-by-case basis. Also, systems with and without water infinite reflector were evaluated. Finally, an analysis is made of the influence of each parameter upon the effective multiplication factor, in the postulated enriched UF 6 -HF systems. (Author) [es

  18. Influence of UF4 physico-chemical properties on the assessment of the chronic exposure to this compound

    International Nuclear Information System (INIS)

    Ansoborlo, E.; Chalabreysse, J.

    1990-01-01

    A method was developed in order to assess uranium exposure hazards at work stations based on the industrial experience acquired by Comurhex Malvesi at Narbonne. Applied to uranium tetrafluoride (UF 4 ) the method involves 4 steps: 1. characterization of the industrial compound, including its physico-chemical properties (density, surface area, X-ray spectrum and uranium enrichment); 2. assessment of work station concentrations and particle size distribution (AMAD); 3. In vitro biological solubility with different synthetic fluids such as Gamble solutions with different gases or compounds added (oxygen or superoxide ions O 2 - ) in order to determine the solubility class D, W or Y; 4. workers' monitoring by routine measurements of urinary excretion completed, if necessary, by fecal excretion and γ-spectrometry. Results and present data on UF 4 are presented. 3 tabs., 4 figs [fr

  19. Removal of uranium and thorium from aqueous solution by ultrafiltration (UF) and PAMAM dendrimer assisted ultrafiltration (DAUF)

    International Nuclear Information System (INIS)

    Ilaiyaraja, P.; Ashish Kumar Singha Deb; Ponraju, D.

    2015-01-01

    Studies on removal of U(VI) and Th(IV) from aqueous solution have been carried out by ultrafiltration (UF) and dendrimer assisted ultrafiltration (DAUF) using regenerated cellulose acetate membrane and PAMAM [poly(amido)amine] dendrimer chelating agent. In UF, the U(VI) and Th(IV) are removed from aqueous solution by adsorption/mass deposition on the membrane at pH > 4. In DAUF, the water soluble PAMAM dendrimer chelating agent effectively concentrates these metal ions in retentate thereby preventing the mass deposition on membrane. At acidic pH (≤3), the binding of metal ions with PAMAM dendrimer is very weak and hence PAMAM can be regenerated and reused. Electronic supplementary material. The online version of this article (doi:10.1007/s10967-014-3462-x) contains supplementary material, which is available to authorized users. (author)

  20. Validation of Cristallini Sampling Method for UF6 by High Precision Double-Spike Measurements Collaboration between JRC-G.2, Team METRO and SGAS/IAEA

    OpenAIRE

    RICHTER Stephan; HIESS Joe; JAKOBSSON Ulf

    2016-01-01

    The so-called "Cristallini Method" for sampling of UF6 by adsorption and hydrolysis in alumina pellets inside a fluorothene P-10 tube has been developed by the Brazilian-Argentine Agency for Accounting and Control of Nuclear Materials (ABACC) several years ago [1]. This method has several advantages compared to the currently used sampling method, for which UF6 is distilled into a stainless steel tube for transportation, with hydrolysis and isotopic analysis being performed after shipping to t...

  1. Conceptual design for the field test and evaluation of the gas-phase UF6 enrichment meter

    International Nuclear Information System (INIS)

    Strittmatter, R.B.; Leavitt, J.N.; Slice, R.W.

    1980-12-01

    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. Data from proof-of-principle measurements using a laboratory prototype system are presented. A conceptual design for an enrichment monitor to be field tested and evaluated at the Oak Ridge Gaseous Diffusion Plant is reported

  2. Evaluation of a RF-Based Approach for Tracking UF6 Cylinders at a Uranium Enrichment Plant

    International Nuclear Information System (INIS)

    Pickett, Chris A; Younkin, James R; Kovacic, Donald N; Laughter, Mark D; Hines, Jairus B; Boyer, Brian Martinez

    2008-01-01

    Approved industry-standard cylinders are used globally to handle and store uranium hexafluoride (UF 6 ) feed, product, tails, and samples at uranium enrichment plants. The International Atomic Energy Agency (IAEA) relies on time-consuming physical inspections to verify operator declarations and detect possible diversion of UF 6 . Development of a reliable, automated, and tamper-resistant system for near real-time tracking and monitoring UF 6 cylinders (as they move within an enrichment facility) would greatly improve the inspector function. This type of system can reduce the risk of false or misreported cylinder tare weights, diversion of nuclear material, concealment of excess production, utilization of undeclared cylinders, and misrepresentation of the cylinders contents. This paper will describe a proof-of-concept approach that was designed to evaluate the feasibility of using radio frequency (RF)-based technologies to track individual UF 6 cylinders throughout a portion of their life cycle, and thus demonstrate the potential for improved domestic accountability of materials, and a more effective and efficient method for application of site-level IAEA safeguards. The evaluation system incorporates RF-based identification devices (RFID) which provide a foundation for establishing a reliable, automated, and near real-time tracking system that can be set up to utilize site-specific, rules-based detection algorithms. This paper will report results from a proof-of-concept demonstration at a real enrichment facility that is specifically designed to evaluate both the feasibility of using RF to track cylinders and the durability of the RF equipment to survive the rigors of operational processing and handling. The paper also discusses methods for securely attaching RF devices and describes how the technology can effectively be layered with other safeguard systems and approaches to build a robust system for detecting cylinder diversion. Additionally, concepts for off

  3. In-line coagulation prior to UF of treated domestic wastewater - foulants removal, fouling control and phosphorus removal

    KAUST Repository

    Zheng, Xing; Plume, Stephan; Ernst, Mathias; Croue, Jean-Philippe; Jekel, Martin R.

    2012-01-01

    The present work investigated fouling control and phosphorus removal by applying in-line coagulation prior to ultrafiltration (UF) of treated domestic wastewater. Experiments were conducted in both lab- and pilot-scale under close to neutral pH condition. Lab-scale foulant removal tests showed that increasing the dosage of FeCl3, AlCl3 and polymeric aluminum chloride (PACl) can improve biopolymer removal. Specifically, PACl reduced preferentially the proteinaceous fraction of biopolymer while the other two coagulants showed no significant preference. The filterability of water samples was improved after coagulation, which is contributed to biopolymer removal and the formation of larger particles. Pilot UF experiments demonstrated that in-line coagulation improved the performance of UF to a large extent. Within 0.037-0.148mmol Me3+/L dosage range, adding more FeCl3 and AlCl3 slowed down the development of trans-membrane pressure (TMP) correspondingly, while changing PACl dosage showed little effect on the variation of TMP increase rate. Further investigations indicated that PACl related precipitates contributed to more irreversible fouling than that which the monomeric coagulants made. Fouling control is thus considered as a co-effect determined by foulant removal efficiency, fouling layer structure and the adherence of hydrolysis products/precipitates onto the membrane. With respect to phosphorus removal, dosing FeCl3 and AlCl3 achieved higher removal efficiency than using PACl. Based on lab- and pilot-scale results, dosing FeCl3 and AlCl3 at a relative dosage of over 2.5mol Me3+ per mol total phosphorus (TP) in feedwater is necessarily required to keep the TP concentration under 50μg/L in UF permeate. © 2012 Elsevier B.V.

  4. In-line coagulation prior to UF of treated domestic wastewater - foulants removal, fouling control and phosphorus removal

    KAUST Repository

    Zheng, Xing

    2012-06-01

    The present work investigated fouling control and phosphorus removal by applying in-line coagulation prior to ultrafiltration (UF) of treated domestic wastewater. Experiments were conducted in both lab- and pilot-scale under close to neutral pH condition. Lab-scale foulant removal tests showed that increasing the dosage of FeCl3, AlCl3 and polymeric aluminum chloride (PACl) can improve biopolymer removal. Specifically, PACl reduced preferentially the proteinaceous fraction of biopolymer while the other two coagulants showed no significant preference. The filterability of water samples was improved after coagulation, which is contributed to biopolymer removal and the formation of larger particles. Pilot UF experiments demonstrated that in-line coagulation improved the performance of UF to a large extent. Within 0.037-0.148mmol Me3+/L dosage range, adding more FeCl3 and AlCl3 slowed down the development of trans-membrane pressure (TMP) correspondingly, while changing PACl dosage showed little effect on the variation of TMP increase rate. Further investigations indicated that PACl related precipitates contributed to more irreversible fouling than that which the monomeric coagulants made. Fouling control is thus considered as a co-effect determined by foulant removal efficiency, fouling layer structure and the adherence of hydrolysis products/precipitates onto the membrane. With respect to phosphorus removal, dosing FeCl3 and AlCl3 achieved higher removal efficiency than using PACl. Based on lab- and pilot-scale results, dosing FeCl3 and AlCl3 at a relative dosage of over 2.5mol Me3+ per mol total phosphorus (TP) in feedwater is necessarily required to keep the TP concentration under 50μg/L in UF permeate. © 2012 Elsevier B.V.

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

    Energy Technology Data Exchange (ETDEWEB)

    None

    1983-12-01

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

  6. Environmental Monitoring and Characterization of Radiation Sources on UF Campus Using a Large Volume NaI Detector

    Science.gov (United States)

    Bruner, Jesse A.; Gardiner, Hannah E.; Jordan, Kelly A.; Baciak, James E.

    2016-09-01

    Environmental radiation surveys are important for applications such as safety and regulations. This is especially true for areas exposed to emissions from nuclear reactors, such as the University of Florida Training Reactor (UFTR). At the University of Florida, surveys are performed using the RSX-1 NaI detector, developed by Radiation Solutions Inc. The detector uses incoming gamma rays and an Advanced Digital Spectrometer module to produce a linear energy spectrum. These spectra can then be analyzed in real time with a personal computer using the built in software, RadAssist. We report on radiation levels around the University of Florida campus using two mobile detection platforms, car-borne and cart-borne. The car-borne surveys provide a larger, broader map of campus radiation levels. On the other hand, cart-borne surveys provide a more detailed radiation map because of its ability to reach places on campus cars cannot go. Throughout the survey data, there are consistent radon decay product energy peaks in addition to other sources such as medical I-131 found in a large crowd of people. Finally, we investigate further applications of this mobile detection platform, such as tracking the Ar-41 plume emitted from the UFTR and detection of potential environmental hazards.

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

    International Nuclear Information System (INIS)

    Pickrell, P.W.

    1985-10-01

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

  8. Fate of antibiotics in activated sludge followed by ultrafiltration (CAS-UF) and in a membrane bioreactor (MBR).

    Science.gov (United States)

    Sahar, Eyal; Messalem, Rami; Cikurel, Haim; Aharoni, Avi; Brenner, Asher; Godehardt, Manuel; Jekel, Martin; Ernst, Mathias

    2011-10-15

    The fates of several macrolide, sulphonamide, and trimethoprim antibiotics contained in the raw sewage of the Tel-Aviv wastewater treatment plant (WWTP) were investigated after the sewage was treated using either a full-scale conventional activated sludge (CAS) system coupled with a subsequent ultrafiltration (UF) step or a pilot membrane bioreactor (MBR) system. Antibiotics removal in the MBR system, once it achieved stable operation, was 15-42% higher than that of the CAS system. This advantage was reduced to a maximum of 20% when a UF was added to the CAS. It was hypothesized that the contribution of membrane separation (in both systems) to antibiotics removal was due either to sorption to biomass (rather than improvement in biodegradation) or to enmeshment in the membrane biofilm (since UF membrane pores are significantly larger than the contaminant molecules). Batch experiments with MBR biomass showed a markedly high potential for sorption of the tested antibiotics onto the biomass. Moreover, methanol extraction of MBR biomass released significant amounts of sorbed antibiotics. This finding implies that more attention must be devoted to the management of excess sludge. Copyright © 2011 Elsevier Ltd. All rights reserved.

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

    International Nuclear Information System (INIS)

    1986-06-01

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

  10. Argon/UF6 plasma exhaust gas reconstitution experiments using preheated fluorine and on-line diagnostics. [fissioning uranium plasma core reactor design

    Science.gov (United States)

    Roman, W. C.

    1979-01-01

    The feasibility of employing a flowing, high-temperature, pure fluorine/UF6 regeneration system to efficiently convert a large fraction of the effluent plasma exhaust back to pure UF6 was demonstrated. The custom built T.O.F. mass spectrometer sampling system permitted on-line measurements of the UF6 concentration at different locations in the exhaust system. Negligible amounts ( 100 ppm) of UF6 were detected in the axial bypass exhaust duct and the exhaust ducts downstream of the cryogenic trap system used to collect the UF6, thus verifying the overall system efficiency over a range of operating conditions. Use of a porous Monel duct as part of the exhaust duct system, including provision for injection of pure fluorine, provided a viable technique to eliminate uranium compound residue on the inside surface of the exhaust ducts. Typical uranium compound mass deposition per unit area of duct was 2 micron g/sq cm. This porous duct technique is directly applicable to future uranium compound transfer exhaust systems. Throughout these experiments, additional basic data on the corrosion aspects of hot, pressurized UF6/fluorine were also accumulated.

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

    International Nuclear Information System (INIS)

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

    1996-10-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-09-23

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

  13. Influence of hydraulic retention time on UASB post-treatment with UF membranes.

    Science.gov (United States)

    Salazar-Peláez, M L; Morgan-Sagastume, J M; Noyola, A

    2011-01-01

    A pilot UASB reactor coupled with an external ultrafiltration (UF) membrane was operated under three different hydraulic retention times (HRT) for domestic wastewater treatment. The aim was to assess the HRT influence on system performance and fouling. The highest concentrations of COD, total solids, extracellular polymeric substances (EPS) and soluble microbial products (SMP) in UASB effluent and permeate were found when the UASB reactor was operated under the lowest HRT studied (4 hours); although the fulfillment of Mexican Standard for wastewater reclamation was not compromised. This fact could be attributed to the higher shear stress forces inside the UASB reactor when it was operated at low HRT, which promoted the release of biopolymeric substances in its effluent. Besides, the fouling propensity in the UASB effluent was worsened with HRT reduction, by increasing the fouling rate and the specific cake resistance. Based on these results, it is recommended to avoid operating the UASB reactor at low HRTs (less than 4 hours) in order to control SMP and EPS fouling potential. The results presented also suggest that HRT reduction has a detrimental effect on performance and fouling.

  14. Investigation of severe UF membrane fouling induced by three marine algal species

    KAUST Repository

    Merle, Tony

    2016-02-06

    Reducing membrane fouling caused by seawater algal bloom is a challenge for regions of the world where most of their freshwater is produced by seawater desalination. This study aims to compare ultrafiltration (UF) fouling potential of three ubiquitous marine algal species cultures (i.e., Skeletonena costatum-SKC, Tetraselmis sp.-TET, and Hymenomonas sp.-HYM) sampled at different phases of growth. Results showed that flux reduction and irreversible fouling were more severe during the decline phase as compared to the exponential phase, for all species. SKC and TET were responsible for substantial irreversible fouling but their impact was significantly lower than HYM. The development of a transparent gel layer surrounding the cell during the HYM growth and accumulating in water is certainly responsible for the more severe observed fouling. Chemical backwash with a standard chlorine solution did not recover any membrane permeability. For TET and HYM, the Hydraulically Irreversible Fouling Index (HIFI) was correlated to their biopolymer content but this correlation is specific for each species. Solution pre-filtration through a 1.2 μm membrane proved that cells and particulate algal organic matter (p-AOM) considerably contribute to fouling, especially for HYM for which the HIFI was reduced by a factor of 82.3.

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

    International Nuclear Information System (INIS)

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

    1979-01-01

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

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

    International Nuclear Information System (INIS)

    Ruppel, F.R.

    1992-03-01

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

  17. Greater confinement disposal of radioactive wastes

    International Nuclear Information System (INIS)

    Trevorrow, L.E.; Gilbert, T.L.; Luner, C.; Merry-Libby, P.A.; Meshkov, N.K.; Yu, C.

    1985-01-01

    Low-level radioactive waste (LLW) includes a broad spectrum of different radionuclide concentrations, half-lives, and hazards. Standard shallow-land burial practice can provide adequate protection of public health and safety for most LLW. A small volume fraction (approx. 1%) containing most of the activity inventory (approx. 90%) requires specific measures known as greater-confinement disposal (GCD). Different site characteristics and different waste characteristics - such as high radionuclide concentrations, long radionuclide half-lives, high radionuclide mobility, and physical or chemical characteristics that present exceptional hazards - lead to different GCD facility design requirements. Facility design alternatives considered for GCD include the augered shaft, deep trench, engineered structure, hydrofracture, improved waste form, and high-integrity container. Selection of an appropriate design must also consider the interplay between basic risk limits for protection of public health and safety, performance characteristics and objectives, costs, waste-acceptance criteria, waste characteristics, and site characteristics

  18. [Autoerotic fatalities in Greater Dusseldorf].

    Science.gov (United States)

    Hartung, Benno; Hellen, Florence; Borchard, Nora; Huckenbeck, Wolfgang

    2011-01-01

    Autoerotic fatalities in the Greater Dusseldorf area correspond to the relevant medicolegal literature. Our results included exclusively young to middle-aged, usually single men who were found dead in their city apartments. Clothing and devices used showed a great variety. Women's or fetish clothing and complex shackling or hanging devices were disproportionately frequent. In most cases, death occurred due to hanging or ligature strangulation. There was no increased incidence of underlying psychiatric disorders. In most of the deceased no or at least no remarkable alcohol intoxication was found. Occasionally, it may be difficult to reliably differentiate autoerotic accidents, accidents occurring in connection with practices of bondage & discipline, dominance & submission (BDSM) from natural death, suicide or homicide.

  19. Planning for greater confinement disposal

    International Nuclear Information System (INIS)

    Gilbert, T.L.; Luner, C.; Meshkov, N.K.; Trevorrow, L.E.; Yu, C.

    1985-01-01

    A report that provides guidance for planning for greater-confinement disposal (GCD) of low-level radioactive waste is being prepared. The report addresses procedures for selecting a GCD technology and provides information for implementing these procedures. The focus is on GCD; planning aspects common to GCD and shallow-land burial are covered by reference. Planning procedure topics covered include regulatory requirements, waste characterization, benefit-cost-risk assessment and pathway analysis methodologies, determination of need, waste-acceptance criteria, performance objectives, and comparative assessment of attributes that support these objectives. The major technologies covered include augered shafts, deep trenches, engineered structures, hydrofracture, improved waste forms, and high-integrity containers. Descriptive information is provided, and attributes that are relevant for risk assessment and operational requirements are given. 10 refs., 3 figs., 2 tabs

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

    International Nuclear Information System (INIS)

    Salama, M.

    2004-01-01

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

  1. Emergency preparedness and response in case of a fire accident with (UF{sub 6}) packages tracking Suez Canal

    Energy Technology Data Exchange (ETDEWEB)

    Salama, M. [National Center for Nuclear Safety and Radiation Control (NCNSRC), Nasr City, Cairo (Egypt)

    2004-07-01

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

  2. Modeling of UF{sub 6} enrichment with gas centrifuges for nuclear safeguards activities

    Energy Technology Data Exchange (ETDEWEB)

    Mercurio, G.; Peerani, P.; Richir, P.; Janssens, W.; Eklund, G. [European Commission, Joint Research Centre, Institute for Transuranium Elements Via Fermi, 2749-TP181,20127 Ispra (Italy)

    2012-09-26

    The physical modeling of uranium isotopes ({sup 235}U, {sup 238}U) separation process by centrifugation of is a key aspect for predicting the nuclear fuel enrichment plant performances under surveillance by the Nuclear Safeguards Authorities. In this paper are illustrated some aspects of the modeling of fast centrifuges for UF{sub 6} gas enrichment and of a typical cascade enrichment plant with the Theoretical Centrifuge and Cascade Simulator (TCCS). The background theory for reproducing the flow field characteristics of a centrifuge is derived from the work of Cohen where the separation parameters are calculated using the solution of a differential enrichment equation. In our case we chose to solve the hydrodynamic equations for the motion of a compressible fluid in a centrifugal field using the Berman - Olander vertical velocity radial distribution and the solution was obtained using the Matlab software tool. The importance of a correct estimation of the centrifuge separation parameters at different flow regimes, lies in the possibility to estimate in a reliable way the U enrichment plant performances, once the separation external parameters are set (feed flow rate and feed, product and tails assays). Using the separation parameters of a single centrifuge allow to determine the performances of an entire cascade and, for this purpose; the software Simulink was used. The outputs of the calculation are the concentrations (assays) and the flow rates of the enriched (product) and depleted (tails) gas mixture. These models represent a valid additional tool, in order to verify the compliance of the U enrichment plant operator declarations with the 'on site' inspectors' measurements.

  3. Waste management in Greater Vancouver

    Energy Technology Data Exchange (ETDEWEB)

    Carrusca, K. [Greater Vancouver Regional District, Burnaby, BC (Canada); Richter, R. [Montenay Inc., Vancouver, BC (Canada)]|[Veolia Environmental Services, Vancouver, BC (Canada)

    2006-07-01

    An outline of the Greater Vancouver Regional District (GVRD) waste-to-energy program was presented. The GVRD has an annual budget for solid waste management of $90 million. Energy recovery revenues from solid waste currently exceed $10 million. Over 1,660,00 tonnes of GVRD waste is recycled, and another 280,000 tonnes is converted from waste to energy. The GVRD waste-to-energy facility combines state-of-the-art combustion and air pollution control, and has processed over 5 million tonnes of municipal solid waste since it opened in 1988. Its central location minimizes haul distance, and it was originally sited to utilize steam through sales to a recycle paper mill. The facility has won several awards, including the Solid Waste Association of North America award for best facility in 1990. The facility focuses on continual improvement, and has installed a carbon injection system; an ammonia injection system; a flyash stabilization system; and heat capacity upgrades in addition to conducting continuous waste composition studies. Continuous air emissions monitoring is also conducted at the plant, which produces a very small percentage of the total air emissions in metropolitan Vancouver. The GVRD is now seeking options for the management of a further 500,000 tonnes per year of solid waste, and has received 23 submissions from a range of waste energy technologies which are now being evaluated. It was concluded that waste-to-energy plants can be located in densely populated metropolitan areas and provide a local disposal solution as well as a source of renewable energy. Other GVRD waste reduction policies were also reviewed. refs., tabs., figs.

  4. Emergency preparedness and response in case of a fire accident with UF6 packages traversing the Suez Canal

    International Nuclear Information System (INIS)

    Salama, M.

    2004-01-01

    Egypt has a unique problem, the Suez Canal. Radioactive cargo passes regularly through the canal carrying new and spent reactor fuel. There are also about 1000 metric tonnes of uranium hexafluoride (UF 6 ) passing through the canal every year. In spite of all the precautions taken in the transport, accidents with packages containing UF 6 shipped through the Suez Canal may arise, even though the probability is minimal. Such accidents may be accompanied by injuries to or death of persons and damage to property including radiation and criticality hazards and high chemical toxicity, particularly if the accident occurred close to one of the three densely populated cities (Port Said, Ismailia and Suez), which are located along the west bank of the Suez Canal. The government of Egypt has established a national radiological emergency plan in order to deal with any radiological accidents which may arise inside the country. This paper considers the effect of a fire accident to industrial packages containing UF 6 on board a cargo ship passing along the Suez Canal near Port Said City. The accident scenario and emergency response actions taken during the different phases of the accident are presented and discussed. The paper highlights the importance of public awareness for populations located in densely populated areas along the bank of the Suez Canal, in order to react in a timely and effective way to avoid the toxic and radiological hazards resulting from such a type of accident. The possibility of upgrading the capabilities of civil defence and fire-fighting personnel is also discussed (author)

  5. Thermodynamic assessment of the LiF–ThF{sub 4}–PuF{sub 3}–UF{sub 4} system

    Energy Technology Data Exchange (ETDEWEB)

    Capelli, E. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe (Germany); Department of Radiation Science and Technology, Faculty of Applied Physics, Delft University of Technology, Delft 2629JB (Netherlands); Beneš, O., E-mail: ondrej.benes@ec.europa.eu [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe (Germany); Konings, R.J.M. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe (Germany); Department of Radiation Science and Technology, Faculty of Applied Physics, Delft University of Technology, Delft 2629JB (Netherlands)

    2015-07-15

    The LiF–ThF{sub 4}–PuF{sub 3}–UF{sub 4} system is the reference salt mixture considered for the Molten Salt Fast Reactor (MSFR) concept started with PuF{sub 3}. In order to obtain the complete thermodynamic description of this quaternary system, two binary systems (ThF{sub 4}–PuF{sub 3} and UF{sub 4}–PuF{sub 3}) and two ternary systems (LiF–ThF{sub 4}–PuF{sub 3} and LiF–UF{sub 4}–PuF{sub 3}) have been assessed for the first time. The similarities between CeF{sub 3}/PuF{sub 3} and ThF{sub 4}/UF{sub 4} compounds have been taken into account for the presented optimization as well as in the experimental measurements performed, which have confirmed the temperatures predicted by the model. Moreover, the experimental results and the thermodynamic database developed have been used to identify potential compositions for the MSFR fuel and to evaluate the influence of partial substitution of ThF{sub 4} by UF{sub 4} in the salt.

  6. PERFORMA NEUTRONIK BAHAN BAKAR LiF-BeF2-ThF4-UF4 PADA SMALL MOBILE-MOLTEN SALT REACTOR

    Directory of Open Access Journals (Sweden)

    S. N. Rokhman

    2015-04-01

    been carried out for the molten salt fuel LiF-BeF2-ThF4-UF4 on a Small Mobile-Molten Salt Reactor (SM-SMR. The core configurations and operating temperature should be adjusted in using the new fuel in order to get the calculated keff and CR (conversion ratio are > 1 in the fraction of 0.5% 233U, 20% 232Th, 28% Li, 51.5% Be. After obtained that keff and CR close to 1, then the analysis of changes in the Th to Be and Be to Li are carried out, it indicates the changes of keff and CR. Then the 233U fraction is varied between 0.5–0.46% to obtain the condition keff > 1 and CR > 1. To determine the temperature coefficient of reactivity (αT,the temperature of core is changed about +25K dan +50K. To determine the void reactivity coefficient (αV, fuel density is reduced to 90%. The result shows that the reduction of Th causes the decrease of CR and increase of keff due to the number fertile material is less. The addition of Be to Li will make the keff is increase and the CR is decrease, because the macroscopic absorption cross section of Li is greater than Be. From the five 233U composition in the ranges 0.5–0.46%, the calculated keff and CR varies in the range of 1.00001 – 1.00327 and 1.00016 – 1.00731, respectively. For power peaking factor (PPF, the calculation results give the value in the range of 2.4311 - 2.4714. However, for the safety parameters, the negative temperature reactivity coefficient (αT and negative void reactivity CR (αV in the range of 4.972×10-5 – 5.909×10-5 and 2.596×10-2 - 2,8287×10-2 ∆k/k/K, respectively. It can be concluded that the SM-MSR core has negative value for those reactivity for all fractions, so the core fulfill the safety criteria and inherent safety. Keywords: small mobile molten salt reactor (SM-MSR, LiF-BeF2-ThF4-UF4 fuel, inherent safety, temperature coefficient reactivity, void coefficient reactivity.

  7. Om direktørers fuldmagt på baggrund af UfR 2012.2533 H

    DEFF Research Database (Denmark)

    Andersen, Lennart Lynge; Schaumburg-Muller, Peer

    2012-01-01

    Den bemyndigelse, en adm. direktør - og den øvrige direktion - har til (bl.a.) at fastsætte løn- og ansættelsesvilkår for selskabets medarbejdere har hverken i den arbejdsretlige, selskabsretlige eller den aftaleretlige teori og praksis påkaldt sig megen opmærksomhed gennem årene. Højesterets dom...... af 2. maj 2012 (UfR 2012.2533 H) omhandler netop dette forhold, og afgørelsen må af flere grunde anses for principiel....

  8. Implementation of conduct of operations at Paducah uranium hexafluoride (UF{sub 6}) sampling and transfer facility

    Energy Technology Data Exchange (ETDEWEB)

    Penrod, S.R. [Martin Marietta Energy Systems, Inc., KY (United States)

    1991-12-31

    This paper describes the initial planning and actual field activities associated with the implementation of {open_quotes}Conduct of Operations{close_quotes}. Conduct of Operations is an operating philosophy that was developed through the Institute of Nuclear Power Operations (INPO). Conduct of Operations covers many operating practices and is intended to provide formality and discipline to all aspects of plant operation. The implementation of these operating principles at the UF{sub 6} Sampling and Transfer Facility resulted in significant improvements in facility operations.

  9. Implementation of conduct of operations at Paducah uranium hexafluoride (UF{sub 6}) sampling and transfer facility

    Energy Technology Data Exchange (ETDEWEB)

    Penrod, S.R. [Martin Marietta Energy Systems, Inc., KY (United States)

    1991-12-31

    This paper describes the initial planning and actual field activities associated with the implementation of {open_quotes}Conduct of Operations{close_quotes}, Conduct of Operations is an operating philosophy that was developed through the Institute of Nuclear Power Operations (INPO). Conduct of Operations covers many operating practices and is intended to provide formality and discipline to all aspects of plant operation. The implementation of these operating principles at the UF{sub 6} Sampling and Transfer Facility resulted in significant improvements in facility operations.

  10. CISG DEL II og Værneting i UfR 1998.1092 ØLK

    DEFF Research Database (Denmark)

    Lookofsky, Joseph

    1998-01-01

    I UfR 1998.1092 ØLK anvender en dansk domstol reglerne om købsaftalers indgåelse i CISG-konventionens del II. Det sker for at afgøre, om der er værneting i Danmark efter EF-domskonventionens artikel 5, nr. 1, når sagsøgte bestrider, at der er indgået en købsaftale. Sagen sætter fokus på behovet...

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

    International Nuclear Information System (INIS)

    Amarante, J.A.A. do.

    1979-10-01

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

  12. A comparative study between inhibitory effect of L. lactis and nisin on important pathogenic bacteria in Iranian UF Feta cheese

    Directory of Open Access Journals (Sweden)

    Saeed Mirdamadi

    2015-02-01

    Full Text Available   Introduction : In the present study, the inhibitory effect of nisin-producing Lactococcus lactis during co-culture and pure standard nisin were assessed against selected foodborne pathogenes in growth medium and Iranian UF Feta cheese. In comparison L lactis, not only proves flavor but also plays a better role in microbial quality of Iranian UF Feta cheese as a model of fermented dairy products.   Materials and method s: L. lactis subsp. lactis as nisin producer strain, Listeria monocytogenes, Escherichia coli and Staphylococcus aureus as pathogenic strains were inoculated in Ultra-Filtered Feta cheese. Growth curve of bacterial strains were studied by colony count method in growth medium and UF Feta cheese separately and during co-culture with L. lactis. Nisin production was determined by agar diffusion assay method against susceptible test strain and confirmed by RP-HPLC analysis method.   Results : Counts of L. monocytogenes decreased in cheese sample containing L. lactis and standard nisin, to 103 CFU/g after 7 days and it reached to undetectable level within 2 weeks. S. aureus counts remained at its initial number, 105 CFU/g, after 7 days then decreased to 104 CFU/g on day 14 and it was not detectable on day 28. E. coli numbers increased in both treatments after 7 days and then decreased to 104 CFU/g after 28 days. Despite the increasing number of E. coli in growth medium containing nisin, due to the synergistic effect of nisin and other metabolites produced by Lactococcus lactis and starter cultures, the number of E. coli decreased with slow rate . Discussion and conclusion : The results showed, L. monocytogenes was inhibited by L. lactis before entering the logarithmic phase during co-culture. S. aureus was also inhibited during co-culture, but it showed less sensitivity in comparison with L. monocytogenes. However, the number of E. coli remained steady in co-culture with L. lactis. Also, we found that, in all cheese samples, E

  13. Viability Study for an Unattended UF_6 Cylinder Verification Station: Phase I Final Report

    International Nuclear Information System (INIS)

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

    2016-01-01

    In recent years, the International Atomic Energy Agency (IAEA) has pursued innovative techniques and an integrated suite of safeguards measures to address the verification challenges posed by the front end of the nuclear fuel cycle. Among the unattended instruments currently being explored by the IAEA is an Unattended Cylinder Verification Station (UCVS) that could provide automated, independent verification of the declared relative enrichment, "2"3"5U mass, total uranium mass and identification for all declared UF_6 cylinders in a facility (e.g., uranium enrichment plants and fuel fabrication plants). Under the auspices of the United States and European Commission Support Programs to the IAEA, a project was undertaken to assess the technical and practical viability of the UCVS concept. The US Support Program team consisted of Pacific Northwest National Laboratory (PNNL, lead), Los Alamos National Laboratory (LANL), Oak Ridge National Laboratory (ORNL) and Savanah River National Laboratory (SRNL). At the core of the viability study is a long-term field trial of a prototype UCVS system at a Westinghouse fuel fabrication facility. A key outcome of the study is a quantitative performance evaluation of two nondestructive assay (NDA) methods being considered for inclusion in a UCVS: Hybrid Enrichment Verification Array (HEVA), and Passive Neutron Enrichment Meter (PNEM). This report provides context for the UCVS concept and the field trial: potential UCVS implementation concepts at an enrichment facility; an overview of UCVS prototype design; field trial objectives and activities. Field trial results and interpretation are presented, with a focus on the performance of PNEM and HEVA for the assay of over 200 ''typical'' Type 30B cylinders, and the viability of an ''NDA Fingerprint'' concept as a high-fidelity means to periodically verify that the contents of a given cylinder are consistent with previous scans. A modeling study, combined with field-measured instrument

  14. The UF family of hybrid phantoms of the developing human fetus for computational radiation dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Maynard, Matthew R; Geyer, John W; Bolch, Wesley [Department of Nuclear and Radiological Engineering, University of Florida, Gainesville, FL (United States); Aris, John P [Department of Anatomy and Cell Biology, University of Florida, Gainesville, FL (United States); Shifrin, Roger Y, E-mail: wbolch@ufl.edu [Department of Radiology, University of Florida, Gainesville, FL (United States)

    2011-08-07

    Historically, the development of computational phantoms for radiation dosimetry has primarily been directed at capturing and representing adult and pediatric anatomy, with less emphasis devoted to models of the human fetus. As concern grows over possible radiation-induced cancers from medical and non-medical exposures of the pregnant female, the need to better quantify fetal radiation doses, particularly at the organ-level, also increases. Studies such as the European Union's SOLO (Epidemiological Studies of Exposed Southern Urals Populations) hope to improve our understanding of cancer risks following chronic in utero radiation exposure. For projects such as SOLO, currently available fetal anatomic models do not provide sufficient anatomical detail for organ-level dose assessment. To address this need, two fetal hybrid computational phantoms were constructed using high-quality magnetic resonance imaging and computed tomography image sets obtained for two well-preserved fetal specimens aged 11.5 and 21 weeks post-conception. Individual soft tissue organs, bone sites and outer body contours were segmented from these images using 3D-DOCTOR(TM) and then imported to the 3D modeling software package Rhinoceros(TM) for further modeling and conversion of soft tissue organs, certain bone sites and outer body contours to deformable non-uniform rational B-spline surfaces. The two specimen-specific phantoms, along with a modified version of the 38 week UF hybrid newborn phantom, comprised a set of base phantoms from which a series of hybrid computational phantoms was derived for fetal ages 8, 10, 15, 20, 25, 30, 35 and 38 weeks post-conception. The methodology used to construct the series of phantoms accounted for the following age-dependent parameters: (1) variations in skeletal size and proportion, (2) bone-dependent variations in relative levels of bone growth, (3) variations in individual organ masses and total fetal masses and (4) statistical percentile variations

  15. The UF family of hybrid phantoms of the developing human fetus for computational radiation dosimetry

    International Nuclear Information System (INIS)

    Maynard, Matthew R; Geyer, John W; Bolch, Wesley; Aris, John P; Shifrin, Roger Y

    2011-01-01

    Historically, the development of computational phantoms for radiation dosimetry has primarily been directed at capturing and representing adult and pediatric anatomy, with less emphasis devoted to models of the human fetus. As concern grows over possible radiation-induced cancers from medical and non-medical exposures of the pregnant female, the need to better quantify fetal radiation doses, particularly at the organ-level, also increases. Studies such as the European Union's SOLO (Epidemiological Studies of Exposed Southern Urals Populations) hope to improve our understanding of cancer risks following chronic in utero radiation exposure. For projects such as SOLO, currently available fetal anatomic models do not provide sufficient anatomical detail for organ-level dose assessment. To address this need, two fetal hybrid computational phantoms were constructed using high-quality magnetic resonance imaging and computed tomography image sets obtained for two well-preserved fetal specimens aged 11.5 and 21 weeks post-conception. Individual soft tissue organs, bone sites and outer body contours were segmented from these images using 3D-DOCTOR(TM) and then imported to the 3D modeling software package Rhinoceros(TM) for further modeling and conversion of soft tissue organs, certain bone sites and outer body contours to deformable non-uniform rational B-spline surfaces. The two specimen-specific phantoms, along with a modified version of the 38 week UF hybrid newborn phantom, comprised a set of base phantoms from which a series of hybrid computational phantoms was derived for fetal ages 8, 10, 15, 20, 25, 30, 35 and 38 weeks post-conception. The methodology used to construct the series of phantoms accounted for the following age-dependent parameters: (1) variations in skeletal size and proportion, (2) bone-dependent variations in relative levels of bone growth, (3) variations in individual organ masses and total fetal masses and (4) statistical percentile variations in

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

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2001-01-01

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

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

    International Nuclear Information System (INIS)

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

    1995-01-01

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

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

    International Nuclear Information System (INIS)

    1999-04-01

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

  19. Role of contaminants in the fluorination of β-UO3 to UF4 by freon-12

    International Nuclear Information System (INIS)

    Girgis, B.S.; Rofail, N.H.

    1992-01-01

    Ammonium uranate was precipitated from uranyl nitrate or sulphate by NH 3 gas or urea, and decomposed to β-UO 3 by calcination at 623 or 773 K. Oxides contaminated by high contents of nitrates (non-washed uranate) displayed higher conversion to UF 4 in comparison to the respective pre-washed uranate. Products of thermal treatment at 623 K were also more reactive towards fluorination, which was ascribed to the highly-disordered, loosely bound, high surface area products. The presence of residual nitrate, and probably ammonium, ions help in the partial reduction to lower oxides and in preventing recrystallization of the reaction solids. Ammonium uranate precipitated from uranyl sulphate and decomposed at 623 K is more easily fluorinated than the product decomposed at 773 K; it is also better product for fluorination than the uranate precipitated from uranyl nitrate. The complete conversion to UF 4 i attained after 45 min with the uranate precipitated from uranyl sulphate and treated at 623 K, but it needs 120 min with the product formed from uranyl nitrate and decomposed at the same temperature. (orig.)

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  1. Electrochemical separation of uranium in the molten system LiF–NaF–KF–UF{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Korenko, M., E-mail: Michal.Korenko@savba.sk [Fluorine Chemistry Department, Nuclear Research Institute (NRI) Řež Plc., Husinec-Řež 130, CZ-250 68 (Czech Republic); Department of Inorganic Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 36 Bratislava (Slovakia); Straka, M.; Szatmáry, L. [Fluorine Chemistry Department, Nuclear Research Institute (NRI) Řež Plc., Husinec-Řež 130, CZ-250 68 (Czech Republic); Ambrová, M. [Institute of Inorganic Chemistry, Technology and Materials, Slovak University of Technology, Radlinského 9, SK-812 37 Bratislava (Slovakia); Uhlíř, J. [Fluorine Chemistry Department, Nuclear Research Institute (NRI) Řež Plc., Husinec-Řež 130, CZ-250 68 (Czech Republic)

    2013-09-15

    This article is focused on the electrochemical investigation (cyclic voltammetry and related studies) of possible reduction of U{sup 4+} ions to metal uranium in the molten system LiF–NaF–KF(eut.)–UF{sub 4} that can provide basis for the electrochemical extraction of uranium from molten salts. Two-step reduction mechanism for U{sup 4+} ions involving one electron exchange in soluble/soluble U{sup 4+}/U{sup 3+} system and three electrons exchange in the second step were found on the nickel working electrode. Both steps were found to be reversible and diffusion controlled. Based on cyclic voltammetry, the diffusion coefficients of uranium ions at 530 °C were found to be D(U{sup 4+}) = 1.64 × 10{sup −5} cm{sup 2} s{sup −1} and D(U{sup 3+}) 1.76 × 10{sup −5} cm{sup 2} s{sup −1}. Usage of the nickel spiral electrode for electrorefining of uranium showed fairly good feasibility of its extraction. However some oxidant present during the process of electrorefining caused that the solid deposits contained different uranium species such as UF{sub 3}, UO{sub 2} and K{sub 3}UO{sub 2}F{sub 5}.

  2. Temperature evaluation of UF6 and cluster detection in nozzle expansion using low-resolution infrared absorption spectroscopy

    International Nuclear Information System (INIS)

    Sbampato, M.E.; Antunes, L.M.D.; Miranda, S.F.; Sena, S.C.; Santos, A.M.

    1998-01-01

    The continuous supersonic expansion of pure gaseous UF 6 and mixtures of UF 6 with argon and nitrogen through a bidimensional nozzle was studied using low-resolution infrared spectroscopy in the ν 3 absorption band region. The experiments were carried out in order to calculate the molecular temperature of the beam and also to verify cluster formation in the expansion. The molecular beam temperature evaluation was based on the measurements of the low-resolution bandwidth, which were compared to simulated spectra results. The temperatures were also evaluated using the measured pressure at the end of the nozzle by a Pitot tube. In the conditions where no cluster formation was observed the calculated theoretical temperatures using an equilibrium expansion model are in good agreement with the data obtained through the analysis of the experimental spectra and through the Pitot tube pressure measurement. Cluster formation was observed for temperatures below about 120 K. In these conditions the infrared spectra showed shoulders in the region above 630 cm -1 and a shoulder or band between 616 and 600 cm -1 . (orig.)

  3. Development of a fine and ultra-fine group cell calculation code SLAROM-UF for fast reactor analyses

    International Nuclear Information System (INIS)

    Hazama, Taira; Chiba, Go; Sugino, Kazuteru

    2006-01-01

    A cell calculation code SLAROM-UF has been developed for fast reactor analyses to produce effective cross sections with high accuracy in practical computing time, taking full advantage of fine and ultra-fine group calculation schemes. The fine group calculation covers the whole energy range in a maximum of 900-group structure. The structure is finer above 52.5 keV with a minimum lethargy width of 0.008. The ultra-fine group calculation solves the slowing down equation below 52.5 keV to treat resonance structures directly and precisely including resonance interference effects. Effective cross sections obtained in the two calculations are combined to produce effective cross sections over the entire energy range. Calculation accuracy and improvements from conventional 70-group cell calculation results were investigated through comparisons with reference values obtained with continuous energy Monte Carlo calculations. It was confirmed that SLAROM-UF reduces the difference in k-infinity from 0.15 to 0.01% for a JOYO MK-I fuel subassembly lattice cell calculation, and from - 0.21% to less than a statistical uncertainty of the reference calculation of 0.03% for a ZPPR-10A core criticality calculation. (author)

  4. Ultrafiltration (UF Pilot Plant for Municipal Wastewater Reuse in Agriculture: Impact of the Operation Mode on Process Performance

    Directory of Open Access Journals (Sweden)

    Dario Falsanisi

    2010-11-01

    Full Text Available Following increasing interest in the use of UltraFiltration (UF membrane processes as an alternative advanced disinfection technique, the performance of a UF pilot plant was investigated under two opposite operating conditions (“stressed operating condition” versus “conventional operating condition”. The results indicate that for both conditions, the reclaimed effluent complied with the Italian regulations for unrestricted wastewater reuse (i.e., Total Suspended Solids (TSS < 10 mg/L; Chemical Oxygen Demand (COD < 100 mg/L and Escherichia coli < 10 CFU/100 mL. On the other hand, when compared with the Title 22 of the California Wastewater Reclamation Criteria, only the effluent produced under the “conventional operating condition” met the stipulated water quality standards (i.e., TSS and turbidity undetectable and total coliforms < 2.2 CFU/100 mL. It should be noted that, in spite of the nominal cut-off size, total coliforms breakthrough was indeed occasionally observed. A localized membrane pore micro-enlargement mechanism was hypothesized to explain the total coliforms propagation in the ultrafiltered effluent, as monitoring of the membrane permeability and transmembrane pressure highlighted that gel/cake formation had only a minor contribution to the overall membrane fouling mechanism with respect to pore plugging and pore narrowing mechanisms.

  5. Study on treating of low-level radioactive reactor wastewater by combined membrane process (UF-RO)

    International Nuclear Information System (INIS)

    Lu Yunyun; Cao Qiru; Chen Yunming; Huang Lijuan; Bai Xiaofeng; Li Bing; Feng Liang

    2013-01-01

    According to the characteristics of radionuclide exists in the low-level radioactive reactor waste water from HFETR, we use a new combined membrane process separation technology to study the efficient treating of low-lever radioactive reactor wastewater. First, the prepared the simulated wastewater contained Cs + , Sr 2+ , CO 2+ , Ni 2+ , and Fe 3+ . Then, we sequentially investigated the pressure, ion concentration, pH value and EDTA, which have effects on the desalination rate of membrane processing metal ions in wastewater. The results show that: in the condition of pH = 7, and added 0.15 mol/L EDTA, the simulated wastewater separated by UF-RO, desalination rates of Cs + , Sr 2+ , CO 2+ , Ni 2+ and Fe 3+ are all above 95%; In the subsequent trials, adding 0.15 mol/L EDTA into the radioactive residuary solution, and then treating by UF-RO-RO, the decontamination efficiency can reach 95.7%. (authors)

  6. Automation of the Process to Obtain U F{sub 4} Powders; Ingenieria Basica para la Automatizacion del Proceso de Obtencion de Polvos de UF{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Fenocchio, A D [Instituto Balseiro, Universidad Nacional de Cuyo, Centro Atomico Bariloche, Universidad de Buenos Aires (Argentina)

    2001-07-01

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

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

    International Nuclear Information System (INIS)

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

    1984-12-01

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

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

    OpenAIRE

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

    2017-01-01

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

  9. Application of volume-retarded osmosis and low-pressure membrane hybrid process for water reclamation

    KAUST Repository

    Im, Sung-Ju

    2017-11-15

    A new concept of volume-retarded osmosis and low-pressure membrane (VRO-LPM) hybrid process was developed and evaluated for the first time in this study. Commercially available forward osmosis (FO) and ultrafiltration (UF) membranes were employed in a VRO-LPM hybrid process to overcome energy limitations of draw solution (DS) regeneration and production of permeate in the FO process. To evaluate its feasibility as a water reclamation process, and to optimize the operational conditions, cross-flow FO and dead-end mode UF processes were individually evaluated. For the FO process, a DS concentration of 0.15 g mL−1 of polysulfonate styrene (PSS) was determined to be optimal, having a high flux with a low reverse salt flux. The UF membrane with a molecular weight cut-off of 1 kDa was chosen for its high PSS rejection in the LPM process. As a single process, UF (LPM) exhibited a higher flux than FO, but this could be controlled by adjusting the effective membrane area of the FO and UF membranes in the VRO-LPM system. The VRO-LPM hybrid process only required a circulation pump for the FO process. This led to a decrease in the specific energy consumption of the VRO-LPM process for potable water production, that was similar to the single FO process. Therefore, the newly developed VRO-LPM hybrid process, with an appropriate DS selection, can be used as an energy efficient water production method, and can outperform conventional water reclamation processes.

  10. Application of volume-retarded osmosis and low-pressure membrane hybrid process for water reclamation

    KAUST Repository

    Im, Sung-Ju; Choi, Jungwon; Lee, Jung Gil; Jeong, Sanghyun; Jang, Am

    2017-01-01

    A new concept of volume-retarded osmosis and low-pressure membrane (VRO-LPM) hybrid process was developed and evaluated for the first time in this study. Commercially available forward osmosis (FO) and ultrafiltration (UF) membranes were employed in a VRO-LPM hybrid process to overcome energy limitations of draw solution (DS) regeneration and production of permeate in the FO process. To evaluate its feasibility as a water reclamation process, and to optimize the operational conditions, cross-flow FO and dead-end mode UF processes were individually evaluated. For the FO process, a DS concentration of 0.15 g mL−1 of polysulfonate styrene (PSS) was determined to be optimal, having a high flux with a low reverse salt flux. The UF membrane with a molecular weight cut-off of 1 kDa was chosen for its high PSS rejection in the LPM process. As a single process, UF (LPM) exhibited a higher flux than FO, but this could be controlled by adjusting the effective membrane area of the FO and UF membranes in the VRO-LPM system. The VRO-LPM hybrid process only required a circulation pump for the FO process. This led to a decrease in the specific energy consumption of the VRO-LPM process for potable water production, that was similar to the single FO process. Therefore, the newly developed VRO-LPM hybrid process, with an appropriate DS selection, can be used as an energy efficient water production method, and can outperform conventional water reclamation processes.

  11. Application of volume-retarded osmosis and low-pressure membrane hybrid process for water reclamation.

    Science.gov (United States)

    Im, Sung-Ju; Choi, Jungwon; Lee, Jung-Gil; Jeong, Sanghyun; Jang, Am

    2018-03-01

    A new concept of volume-retarded osmosis and low-pressure membrane (VRO-LPM) hybrid process was developed and evaluated for the first time in this study. Commercially available forward osmosis (FO) and ultrafiltration (UF) membranes were employed in a VRO-LPM hybrid process to overcome energy limitations of draw solution (DS) regeneration and production of permeate in the FO process. To evaluate its feasibility as a water reclamation process, and to optimize the operational conditions, cross-flow FO and dead-end mode UF processes were individually evaluated. For the FO process, a DS concentration of 0.15 g mL -1 of polysulfonate styrene (PSS) was determined to be optimal, having a high flux with a low reverse salt flux. The UF membrane with a molecular weight cut-off of 1 kDa was chosen for its high PSS rejection in the LPM process. As a single process, UF (LPM) exhibited a higher flux than FO, but this could be controlled by adjusting the effective membrane area of the FO and UF membranes in the VRO-LPM system. The VRO-LPM hybrid process only required a circulation pump for the FO process. This led to a decrease in the specific energy consumption of the VRO-LPM process for potable water production, that was similar to the single FO process. Therefore, the newly developed VRO-LPM hybrid process, with an appropriate DS selection, can be used as an energy efficient water production method, and can outperform conventional water reclamation processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Experimental determination of the thickness of aluminum cascade pipes in the presence of UF{sub 6} gas during enrichment measurements

    Energy Technology Data Exchange (ETDEWEB)

    Lombardi, M.L., E-mail: lombardi@lanl.gov [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos NM 87545 (United States); Favalli, A.; Goda, J.M.; Ianakiev, K.D.; MacArthur, D.W.; Moss, C.E. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos NM 87545 (United States)

    2012-04-21

    We present a method of determining the wall thickness of a pipe in a Gas Centrifuge Enrichment Plant (GCEP) when an empty pipe measurement is not feasible. Our method uses an X-ray tube for transmission measurements and a lanthanum bromide (LaBr{sub 3}) scintillation detector on the opposite side of the pipe. Two filters, molybdenum (K-edge 20.0 keV) and palladium (K-edge 24.35 keV) are used to transform the bremsstrahlung spectra produced by the X-ray tube into more useful, sharply peaked, spectra. The maximum energies of the peaks are determined by the K-edges of the filters. The attenuation properties of the uranium hexafluoride (UF{sub 6}) gas allow us to determine wall thickness by looking at the ratio of selected regions of interest (ROIs) of the Mo and Pd transmitted spectra. While the attenuation factor at these two transmission energies in the UF{sub 6} gas is nearly equal, attenuation in the aluminum pipe wall at these two energies differs by a factor of about 60. This difference allows measurement of attenuation in the pipe independent of attenuation in the UF{sub 6} gas. Feasibility studies were performed using analytical calculations, and filter thicknesses were optimized. In order to experimentally validate our attenuation measurement method, a UF{sub 6} source with variable enrichment and pipe thickness was built. We describe the experimental procedure used to verify our previous calculations and present recent results.

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

    International Nuclear Information System (INIS)

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

    1997-01-01

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

  14. Refurbishment and modification of existing protective shipping packages (for 30-inch UF{sub 6} cylinders) per USDOT specification No. USA-DOT-21PF-1A

    Energy Technology Data Exchange (ETDEWEB)

    Housholder, W.R. [Nuclear Containers, Incorporated, Elizabethton, TN (United States)

    1991-12-31

    This paper addresses the refurbishment procedures for existing shipping containers for 30-inch diameter UF{sub 6} cylinders in accordance with DOT Specification 21PF-1 and the criteria used to determine rejection when such packages are unsuitable for refurbishment.

  15. Fluorescence from gaseous UF/sub 6/ excited by a near-UV dye laser. [Decay time,quenching rate,room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Benetti, P [Pavia Univ. (Italy); Cubeddu, R; Sacchi, C A; Svelto, O; Zaraga, F [Politecnico di Milano (Italy)

    1976-06-01

    Preliminary data are reported on the visible fluorescence of gaseous UF/sub 6/ excited by a dye laser at 374 nm. A decay time of 500 ns at p = 0 and a quenching rate of 5.7 x 10/sup -12/cm/sup 3/molec/sup -1/s/sup -1/ have been measured at room temperature.

  16. Contribution of effluent organic matter (EfOM) to ultrafiltration (UF) membrane fouling: Isolation, characterization, and fouling effect of EfOM fractions

    KAUST Repository

    Zheng, Xing; Khan, Muhammad; Croue, Jean-Philippe

    2014-01-01

    EfOM has been regarded as a major organic foulant resulting in UF membrane fouling in wastewater reclamation. To investigate fouling potential of different EfOM fractions, the present study isolated EfOM into hydrophobic neutrals (HPO-N), colloids

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

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  18. Evaluation of the MF/UF Performance for the Reuse of Sand Filter Backwash Water from Drinking Water Treatment Plants

    Directory of Open Access Journals (Sweden)

    Neda Shirzadi

    2015-05-01

    Full Text Available The aim of this study was to investigate the application of micro-filtration and ultra-filtration membrane systems in order to improve the physical and microbial quality and the reuse of backwash water from the sand filter units in water treatment plants. The backwash water from filters makes up for 3 to 5 percent of the total water treated, which is disposed in most WTPs. However, the treatment and reuse of the backwash water is more admissible from technical and economic viewpoints, especially in view of the present water scarcity. For the purposes of this study, use was made of membrane modules of micro- and ultra-filters on a pilot scale. The micro-filter employed consisted of a polypropylene membrane module with a porosity of 1 micron in size and a fiberglass module with a porosity of 5 microns. The ultra-filter was made of PVC hollow fiber with a molecular weight of 100,000 Dalton. In order to feed the two pilots, backwash water from a sand filter was collected from one of the WTPs in Tehran. After samples were taken from the backwash water, the physical and microbial removal efficiency was periodically evaluated based on the standard method and the micro-filtration, ultra-filtration, and combined MF/UF processes were compared with respect to their performance. The results indicate that the combined MF/UF process is able to decrease turbidity, MPN, COD, TSS, and Fe with efficiency values of 99.9, 100, 61.5, 99.9 and 98.8 percent, respectively. Overall, the findings confirmed the technical capabilities of this method for the recovery and reuse of the effluent produced in the backwashing mechanism of sand filters in WTPs.

  19. A nuclear criticality safety assessment of the loss of moderation control in 2 1/2 and 10-ton cylinders containing enriched UF6

    International Nuclear Information System (INIS)

    Newvahner, R.L.; Pryor, W.A.

    1991-01-01

    Moderation control for maintaining nuclear criticality safety in 2-1/2-ton, 10-ton, and 14-ton cylinders containing enriched uranium hexafluoride (UF 6 ) has been used safely within the nuclear industry for over thirty years, and is dependent on cylinder integrity and containment. This assessment evaluates the loss of moderation control by the breaching of containment and entry of water into the cylinders. The first objective of this study was to estimate the required amounts of water entering these large UF 6 cylinders to react with, and to moderate the uranium compounds sufficiently to cause criticality. Hypothetical accident situations were modeled as a uranyl fluoride (UO 2 F 2 ) slab above a UF 6 hemicylinder, and a UO 2 sphere centered within a UF 6 hemicylinder. These situations were investigated by computational analyses utilizing the KENO V.a Monte Carlo Computer Code. The results were used to estimate both the masses of water required for criticality, and the limiting masses of water that could be considered safe. The second objective of the assessment was to calculate the time available for emergency control actions before a criticality would occur, i.e., a ''safetime,'' for various sources of water and different size openings in a breached cylinder. In the situations considered, except the case for a fire hose, the safetime appears adequate for emergency control actions. The assessment shows that current practices for handling moderation controlled cylinders of low enriched UF 6 , along with the continuation of established personnel training programs, ensure nuclear criticality safety for routine and emergency operations. 2 refs., 5 figs., 1 tab

  20. A nuclear criticality safety assessment of the loss of moderation control in 2 1/2 and 10-ton cylinders containing enriched UF{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Newvahner, R.L. [Martin Marietta Energy Systems, Inc., Piketon, OH (United States); Pryor, W.A. [PAI Corp., Oak Ridge, TN (United States)

    1991-12-31

    Moderation control for maintaining nuclear criticality safety in 2 {1/2}-ton, 10-ton, and 14-ton cylinders containing enriched uranium hexafluoride (UF{sub 6}) has been used safely within the nuclear industry for over thirty years, and is dependent on cylinder integrity and containment. This assessment evaluates the loss of moderation control by the breaching of containment and entry of water into the cylinders. The first objective of this study was to estimate the required amounts of water entering these large UF{sub 6} cylinders to react with, and to moderate the uranium compounds sufficiently to cause criticality. Hypothetical accident situations were modeled as a uranyl fluoride (UO{sub 2}F{sub 2}) slab above a UF{sub 6} hemicylinder, and a UO{sub 2}F{sub 2} sphere centered within a UF{sub 6} hemicylinder. These situations were investigated by computational analyses utilizing the KENO V.a Monte Carlo Computer Code. The results were used to estimate both the masses of water required for criticality, and the limiting masses of water that could be considered safe. The second objective of the assessment was to calculate the time available for emergency control actions before a criticality would occur, i.e., a {open_quotes}safetime{close_quotes}, for various sources of water and different size openings in a breached cylinder. In the situations considered, except the case for a fire hose, the safetime appears adequate for emergency control actions. The assessment shows that current practices for handling moderation controlled cylinders of low enriched UF{sub 6}, along with the continuation of established personnel training programs, ensure nuclear criticality safety for routine and emergency operations.

  1. The feasibility of nanofiltration membrane bioreactor (NF-MBR)+reverse osmosis (RO) process for water reclamation: Comparison with ultrafiltration membrane bioreactor (UF-MBR)+RO process.

    Science.gov (United States)

    Tay, Ming Feng; Liu, Chang; Cornelissen, Emile R; Wu, Bing; Chong, Tzyy Haur

    2018-02-01

    This study examines the feasibility of a novel nanofiltration membrane bioreactor (NF-MBR) followed by reverse osmosis (RO) process for water reclamation at 90% recovery and using an ultrafiltration MBR (UF-MBR)+RO as baseline for comparison. Both MBRs adopted the same external hollow fiber membrane configurations and operating conditions. The collected permeates of the MBRs were subsequently fed to the respective RO systems. The results showed that the NF-MBR (operated at a constant flux of 10 L/m 2 h) achieved superior MBR permeate quality due to enhanced biodegradation and high rejection capacity of the NF membrane, leading to lower RO fouling rates (∼3.3 times) as compared to the UF-MBR. Further analysis indicated that the cake layer fouling that caused the cake-enhanced osmotic pressure (CEOP) effect contributed predominantly to the transmembrane pressure (TMP) increase in the NF-MBR, while irreversible pore fouling was the major reason for UF membrane fouling. Furthermore, it was found that the biopolymers (i.e., organics with MW > 10 kDa) were the main components present in the foulants of the NF/UF membranes and RO membranes. The analysis indicated that the NF-MBR + RO system at recovery of 90% has comparable energy consumption as the UF-MBR + RO system at recovery of 75%. Our findings proved the feasibility of the NF-MBR + RO for water reclamation at a high recovery rate. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Greater-than-Class C low-level radioactive waste characterization. Appendix E-4: Packaging factors for greater-than-Class C low-level radioactive waste

    International Nuclear Information System (INIS)

    Quinn, G.; Grant, P.; Winberg, M.; Williams, K.

    1994-09-01

    This report estimates packaging factors for several waste types that are potential greater-than-Class C (GTCC) low-level radioactive waste (LLW). The packaging factor is defined as the volume of a GTCC LLW disposal container divided by the as-generated or ''unpackaged'' volume of the waste loaded into the disposal container. Packaging factors reflect any processes that reduce or increase an original unpackaged volume of GTCC LLW, the volume inside a waste container not occupied by the waste, and the volume of the waste container itself. Three values are developed that represent (a) the base case or most likely value for a packaging factor, (b) a high case packaging factor that corresponds to the largest anticipated disposal volume of waste, and (c) a low case packaging factor for the smallest volume expected. GTCC LLW is placed in three categories for evaluation in this report: activated metals, sealed sources, and all other waste

  3. Greater trochanteric pain syndrome diagnosis and treatment.

    Science.gov (United States)

    Mallow, Michael; Nazarian, Levon N

    2014-05-01

    Lateral hip pain, or greater trochanteric pain syndrome, is a commonly seen condition; in this article, the relevant anatomy, epidemiology, and evaluation strategies of greater trochanteric pain syndrome are reviewed. Specific attention is focused on imaging of this syndrome and treatment techniques, including ultrasound-guided interventions. Copyright © 2014 Elsevier Inc. All rights reserved.

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

    International Nuclear Information System (INIS)

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

    1985-01-01

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

  5. Acute toxicity of the hydrolysis products of uranium hexafluoride (UF6) when inhaled by the rat and guinea pig. Final report

    International Nuclear Information System (INIS)

    Leach, L.J.; Gelein, R.M.; Panner, B.J.; Yulie, C.L.; Cox, C.C.; Balys, M.M.; Rolchigo, P.M.

    1984-04-01

    This report presents the experimental animal data base from which human health consequences may be predicted from exposures mimicing accidental discharges of uranium hexafluoride (UF 6 ) in the uranium industry. Rats or guinea pigs were exposed for two, five, or ten minutes duration to air having 0.44 g U/m 3 + 0.16 g HF/m 3 to 276.67 g U/m 3 + 94.07 g HF/m 3 . Survivors of each exposure were observed for 14 days for signs of U or HF intoxication. Selected animals were necropsied and samples of major organs were studied histopathologically. When enriched UF 6 (94 percent 235 U) was used, the urine and feces from each animal were measured daily for U content. Selected samples of urine were bioassayed in order to trace the course of renal injury during the two week postexposure period. 28 references, 51 figures, 23 tables

  6. Economical and neutronic performance of HYLIFE-II with mixture of 90% flibe + 10% UF4 (or ThF4)

    International Nuclear Information System (INIS)

    Uenalan, Sebahattin

    2004-01-01

    This work investigated the neutronics behavior and the economics of the HYLIFE-II reactor with ThF 4 and UF 4 , which produces an electrical power of 1 GW from the fusion power of 2.857 GW during the operation period of 30 years. The use of ThF 4 and UF 4 is realized by a mixture zone consisted of 90% flibe (Li 2 BeF 4 ) and 10% fuel, instead of 100% flibe coolant. The mixture compositions are selected as 90% flibe + 10% UF 4 , 90% flibe + 10% ThF 4 and 90% flibe + 5% UF 4 + 5% ThF 4 . The capacity factor of the reactor is 0.75. The mixtures, with zone thickness of 65 cm were circulated with periods of 20.22, 19.89 and 20.11 s during the operation period of 30 years, respectively. In addition, for flibe + UF 4 , power stabilization by means of plutonium separation from the mixture was applied. The use of fuel materials in the HYLIFE-II reactor resulted in high energy production, sufficient tritium breeding, significant fissile fuel breeding and low radiation damage in the first wall. The average values of tritium breeding ratio over 30 years are between 1.08 and 1.12, higher than 1.0 indicating sufficient tritium breeding. Generally, the mixtures with ThF 4 show better performance than the mixture with UF 4 in terms of more energy production and significant fissile fuel breeding. The neutronic performance of the reactor increases with the operational period. However, the stabilization process performed after operation for 6 years causes all neutronic values to remain nearly constant during the followed operation time. At the 6th year of operation, the power production, which is ∼1540 MW(electric) at startup, reached the electrical power of 2 GW for flibe + UF 4 . The power production without the separation process reached ∼3500 MW(electric) for the mixtures with ThF 4 and ∼3000 MW(electric) for the mixture with UF 4 . At the end of the operation period, helium production values in the first wall, made of Hastelloy, are calculated as 590 ppm without the

  7. Research of heat releasing element of an active zone of gaseous nuclear reactor with pumped through nuclear fuel - uranium hexafluoride (UF6)

    International Nuclear Information System (INIS)

    Batyrbekov, G.; Batyrbekov, E.; Belyakova, E.; Kunakov, S.; Koltyshev, S.

    1996-01-01

    The purpose of the offered project is learning physics and substantiation of possibility of creation gaseous nuclear reactor with pumped through nuclear fuel-hexafluoride of uranium (Uf6).Main problems of this work are'. Determination of physic-chemical, spectral and optical properties of non-equilibrium nuclear - excited plasma of hexafluoride of uranium and its mixtures with other gases. Research of gas dynamics of laminar, non-mixing two-layer current of gases of hexafluoride of uranium and helium at availability and absence of internal energy release in hexafluoride of uranium with the purpose to determinate a possibility of isolation of hexafluoride of uranium from walls by inert helium. Creation and research of gaseous heat releasing element with pumped through fuel Uf6 in an active zone of research nuclear WWR-K reactor. Objects of a research: Non-equilibrium nuclear - excited plasma of hexafluoride of uranium and its mixtures with other gases. With use of specially created ampoules will come true in-reactor probe and spectral diagnostics of plasma. Calculations of kinetics with the account of main elementary processes proceeding in it, will be carried out. Two-layer non-mixed streams of hexafluoride of uranium and helium at availability and absence of internal energy release. Conditions of obtaining and characteristics of such streams will be investigated. Gaseous heat releasing element with pumped through fuel - Uf6 in an active zone of nuclear WWR-K reactor

  8. Thermodynamic assessment of the LiF–NaF–BeF{sub 2}–ThF{sub 4}–UF{sub 4} system

    Energy Technology Data Exchange (ETDEWEB)

    Capelli, E.; Beneš, O., E-mail: ondrej.benes@ec.europa.eu; Konings, R.J.M.

    2014-06-01

    The present study describes the full thermodynamic assessment of the LiF–NaF–BeF{sub 2}–ThF{sub 4}–UF{sub 4} system which is one of the key systems considered for a molten salt reactor fuel. The work is an extension of the previously assessed LiF–NaF–ThF{sub 4}–UF{sub 4} system with addition of BeF{sub 2} which is characterized by very low neutron capture cross section and a relatively low melting point. To extend the database the binary BeF{sub 2}–ThF{sub 4} and BeF{sub 2}–UF{sub 4} systems were optimized and the novel data were used for the thermodynamic assessment of BeF{sub 2} containing ternary systems for which experimental data exist in the literature. The obtained database is used to optimize the molten salt reactor fuel composition and to assess its properties with the emphasis on the melting behaviour.

  9. Biodegradation behavior of natural organic matter (NOM) in a biological aerated filter (BAF) as a pretreatment for ultrafiltration (UF) of river water

    KAUST Repository

    Huang, Guocheng

    2011-04-15

    In this study, biodegradation of natural organic matter (NOM) in a biological aerated filter (BAF) as pretreatment of UF treating river water was investigated. Photometric measurement, three-dimensional excitation-emission matrix (EEM) fluorescence spectroscopy and liquid chromatography with online organic carbon detector (LC-OCD) were used to investigate the fate of NOM fractions in the BAF+UF process. Results showed that the BAF process could effectively remove particles and parts of dissolved organic matter, which led to a lower NOM loading in the UF system, but different NOM fractions showed different biodegradation potentials. Further biodegradation batch experiments confirmed this observation and identified that polysaccharides and proteins (quantified using photometric methods) contained a large proportion of readily biodegradable matter while humic substances were mainly composed of inert organic substances. According to EEM measurements, it is evident that protein-like substances were more readily eliminated by microorganisms than humic-like substances. LC-OCD data also supported the phenomena that the polysaccharides and large-size proteins were more degradable than humic substances. © 2011 Springer-Verlag.

  10. Hybrid coagulation-UF processes for spent filter backwash water treatment: a comparison studies for PAFCl and FeCl3 as a pre-treatment.

    Science.gov (United States)

    Ebrahimi, Afshin; Amin, Mohammad Mehdi; Pourzamani, Hamidreza; Hajizadeh, Yaghoub; Mahvi, Amir Hossein; Mahdavi, Mokhtar; Rad, Mohammad Hassan Rabie

    2017-08-01

    In this study, the reclamation of clean water from spent filter backwash water (SFBW) was investigated through pilot-scale experiments. The pilot plant consisted of pre-sedimentation, coagulation, flocculation, clarification, and ultrafiltration (UF). Two coagulants of PAFCl and FeCl 3 were investigated with respect to their performance on treated SFBW quality and UF membrane fouling. At the optimum dose of PAFCl and FeCl 3 turbidity removal of 99.6 and 99.4% was attained, respectively. PAFCl resulted in an optimum UV 254 , TOC, and DOC removal of 80, 83.6, and 72.7%, respectively, and FeCl 3 caused the removal of those parameters by 76.7, 80.9, and 65.9%, respectively. PAFCl removed hydrophilic and transphilic constituent better than FeCl 3 , but FeCl 3 had, to some extent, higher affinities to a hydrophobic fraction. It was concluded that PAFCl showed a better coagulation performance in most cases and caused a lower membrane fouling rate compared to FeCl 3 . Finally, the treated SFBW with both coagulant-UF systems met the drinking water standards.

  11. A Role of Sp1 Binding Motifs in Basal and Large T-Antigen-Induced Promoter Activities of Human Polyomavirus HPyV9 and Its Variant UF-1

    Directory of Open Access Journals (Sweden)

    Ugo Moens

    2017-11-01

    Full Text Available Human polyomavirus 9 (HPyV9 was originally detected in the serum of a renal transplant patient. Seroepidemiological studies showed that ~20–50% of the human population have antibodies against this virus. HPyV9 has not yet been associated with any disease and little is known about the route of infection, transmission, host cell tropism, and genomic variability in circulating strains. Recently, the HPyV9 variant UF-1 with an eight base-pair deletion, a thirteen base-pair insertion and with point mutations, creating three putative Sp1 binding sites in the late promoter was isolated from an AIDS patient. Transient transfection studies with a luciferase reporter plasmid driven by HPyV9 or UF1 promoter demonstrated that UF1 early and late promoters were stronger than HPyV9 promoters in most cell lines, and that the UF1 late promoter was more potently activated by HPyV9 large T-antigen (LTAg. Mutation of two Sp1 motifs strongly reduced trans-activation of the late UF1 promoter by HPyV9 LTAg in HeLa cells. In conclusion, the mutations in the UF1 late promoter seem to strengthen its activity and its response to stimulation by HPyV9 LTAg in certain cells. It remains to be investigated whether these promoter changes have an influence on virus replication and affect the possible pathogenic properties of the virus.

  12. Salts purification and redox potential measurement for the molten LiF-ThF4-UF4 mixture

    International Nuclear Information System (INIS)

    Afonichkin, V.; Bovet, A.; Shishkin, V.

    2010-01-01

    The 'dry' techniques of producing and clearing of some metals fluorides, their mixtures and cakes of a given composition obtained without usage gaseous HF for experiments under the Project ISTC No. 3749 are developed. The products of synthesizing and purification of oxygen-containing compounds, are studied by methods X-ray diffraction analysis, gravimetry or IR spectrometry. The experimental studies confirmed that solid NH 4 HF 2 can be efficiently used instead of an unsafe and corrosive HF gas for removal of oxygen-containing impurities from metal fluorides and for conversion of uranium and thorium dioxides to anhydrous tetra-fluorides. These processes do not require expensive equipment and special measures of safety. The electrochemical behavior of UF 4 solutions in a melt 77 LiF-23ThF 4 (mole%) was studied by cyclic voltammetry. Formal analysis of the obtained dependencies showed that in our experimental conditions the recharge U(IV) to U(III) is qualitatively consistent with voltammetric criteria and can be classified as reversible. However, the results of mathematical processing of voltammograms show that the basic calculated characteristics of this reaction differ from the theoretical values corresponding one-electron process controlled by the diffusion rate. This indicates quasi-reversibility of the studied reaction. (authors)

  13. A summary of recent refinements to the WAKE dispersion model, a component of the HGSYSTEM/UF6 model suite

    International Nuclear Information System (INIS)

    Yambert, M.W.; Lombardi, D.A.; Goode, W.D. Jr.; Bloom, S.G.

    1998-08-01

    The original WAKE dispersion model a component of the HGSYSTEM/UF 6 model suite, is based on Shell Research Ltd.'s HGSYSTEM Version 3.0 and was developed by the US Department of Energy for use in estimating downwind dispersion of materials due to accidental releases from gaseous diffusion plant (GDP) process buildings. The model is applicable to scenarios involving both ground-level and elevated releases into building wake cavities of non-reactive plumes that are either neutrally or positively buoyant. Over the 2-year period since its creation, the WAKE model has been used to perform consequence analyses for Safety Analysis Reports (SARs) associated with gaseous diffusion plants in Portsmouth (PORTS), Paducah (PGDP), and Oak Ridge. These applications have identified the need for additional model capabilities (such as the treatment of complex terrain and time-variant releases) not present in the original utilities which, in turn, has resulted in numerous modifications to these codes as well as the development of additional, stand-alone postprocessing utilities. Consequently, application of the model has become increasingly complex as the number of executable, input, and output files associated with a single model run has steadily grown. In response to these problems, a streamlined version of the WAKE model has been developed which integrates all calculations that are currently performed by the existing WAKE, and the various post-processing utilities. This report summarizes the efforts involved in developing this revised version of the WAKE model

  14. Method and equipment for continuous transformation of UF6 into (NH4)2U2O7

    International Nuclear Information System (INIS)

    Fuller, R.R.

    1975-01-01

    Uranium hexafluoride is, in a three-stage method, transformed into ammonium diuvanate which can be calcined to UO 2 of good ceramic quality. At the solution of UF 6 in water, UO 2 F 2 and HF form in condsiderably acid solution. This aqueous hydrolysis solution is with standardized using NH 4 O 4 (24-29% NH 3 ) at a pH-value between 5.0 and 6.0 and brought into a precipitation tank. The bulk of the ammonium diuvanate then precipitating is drained in the lower portion of the tank and added again to the suspension, close to the surface of the fluid, under intensive pressure. The intensive vigorous revolution of the entire tank content affects the size of the particles and the size of the surface of the precipitating uranate as well. The equipment for the calcination of the ammonium diuvanate is described. The method represents an improvement of the method described in OS 2162578; the pellets produced are more satisfying to critical requirements. (UWI) [de

  15. Separation Properties of Wastewater Containing O/W Emulsion Using Ceramic Microfiltration/Ultrafiltration (MF/UF Membranes

    Directory of Open Access Journals (Sweden)

    Kanji Matsumoto

    2013-06-01

    Full Text Available Washing systems using water soluble detergent are used in electrical and mechanical industries and the wastewater containing O/W emulsion are discharged from these systems. Membrane filtration has large potential for the efficient separation of O/W emulsion for reuses of treated water and detergent. The separation properties of O/W emulsions by cross-flow microfiltration and ultrafiltration were studied with ceramic MF and UF membranes. The effects of pore size; applied pressure; cross-flow velocity; and detergent concentration on rejection of O/W emulsion and flux were systematically studied. At the condition achieving complete separation of O/W emulsion the pressure-independent flux was observed and this flux behavior was explained by gel-polarization model. The O/W emulsion tended to permeate through the membrane at the conditions of larger pore size; higher emulsion concentration; and higher pressure. The O/W emulsion could permeate the membrane pore structure by destruction or deformation. These results imply the stability of O/W emulsion in the gel-layer formed on membrane surface play an important role in the separation properties. The O/W emulsion was concentrated by batch cross-flow concentration filtration and the flux decline during the concentration filtration was explained by the gel- polarization model.

  16. Separation Properties of Wastewater Containing O/W Emulsion Using Ceramic Microfiltration/Ultrafiltration (MF/UF) Membranes

    Science.gov (United States)

    Nakamura, Kazuho; Matsumoto, Kanji

    2013-01-01

    Washing systems using water soluble detergent are used in electrical and mechanical industries and the wastewater containing O/W emulsion are discharged from these systems. Membrane filtration has large potential for the efficient separation of O/W emulsion for reuses of treated water and detergent. The separation properties of O/W emulsions by cross-flow microfiltration and ultrafiltration were studied with ceramic MF and UF membranes. The effects of pore size; applied pressure; cross-flow velocity; and detergent concentration on rejection of O/W emulsion and flux were systematically studied. At the condition achieving complete separation of O/W emulsion the pressure-independent flux was observed and this flux behavior was explained by gel-polarization model. The O/W emulsion tended to permeate through the membrane at the conditions of larger pore size; higher emulsion concentration; and higher pressure. The O/W emulsion could permeate the membrane pore structure by destruction or deformation. These results imply the stability of O/W emulsion in the gel-layer formed on membrane surface play an important role in the separation properties. The O/W emulsion was concentrated by batch cross-flow concentration filtration and the flux decline during the concentration filtration was explained by the gel- polarization model. PMID:24958621

  17. Computational fluid dynamics tracking of UF6 reaction products release into a gaseous diffusion plant cell housing

    International Nuclear Information System (INIS)

    Wendel, M.W.; Chen, N.C.J.; Kim, S.H.; Taleyarkhan, R.P.; Keith, K.D.; Schmidt, R.W.

    1996-01-01

    A three-dimensional (3-D) computational fluid dynamics (CFD) model has been developed using CFDS-FLOW3D Version 3.3 to model the transport of aerosol products formed during a release of uranium hexafluoride (UF 6 ) into a gaseous diffusion plant (GDP) process building. As part of a facility-wide safety evaluation, a one-dimensional (1-D) analysis of aerosol/vapor transport following such an hypothesized severe accident is being performed. The objective of this study is to supplement the 1-D analysis with more detailed 3-D results. Specifically, the goal is to quantify the distribution of aerosol passing out of the process building during the hypothetical accident. This work demonstrates a useful role for CFD in large 3-D problems, where some experimental data are available for calibrating key parameters and the desired results are global (total time-integrated aerosol flow rates across a few boundary surfaces) as opposed to local velocities, temperatures, or heat transfer coefficients

  18. Hydraulically irreversible fouling on ceramic MF/UF membranes: comparison of fouling indices, foulant composition and irreversible pore narrowing

    KAUST Repository

    Shang, Ran

    2015-05-06

    The application of ceramic membranes in water treatment is becoming increasing attractive because of their long life time and excellent chemical, mechanical and thermal stability. However, fouling of ceramic membranes, especially hydraulically irreversible fouling, is still a critical aspect affecting the operational cost and energy consumption in water treatment plants. In this study, four ceramic membranes with pore sizes or molecular weight cut-off (MWCO) of 0.20 μm, 0.14 μm, 300 kDa and 50 kDa were compared during natural surface water filtration with respect to hydraulically irreversible fouling index (HIFI), foulant composition and narrowing of pore size due to the irreversible fouling. Our results showed that the hydraulically irreversible fouling index (HIFI) was proportional to the membrane pore size (r2=0.89) when the same feed water was filtrated. The UF membranes showed lower HIFI values than the MF membranes. Pore narrowing (internal fouling) was found to be a main fouling pattern of the hydraulically irreversible fouling. The internal fouling was caused by monolayer adsorption of foulants with different sizes that is dependent on the size of the membrane pore.

  19. Hydraulically irreversible fouling on ceramic MF/UF membranes: comparison of fouling indices, foulant composition and irreversible pore narrowing

    KAUST Repository

    Shang, Ran; Vuong, Francois; Hu, Jingyi; Li, Sheng; Kemperman, Antoine J.B.; Nijmeijer, Kitty; Cornelissen, Emile R.; Heijman, Sebastiaan G.J.; Rietveld, Luuk C.

    2015-01-01

    The application of ceramic membranes in water treatment is becoming increasing attractive because of their long life time and excellent chemical, mechanical and thermal stability. However, fouling of ceramic membranes, especially hydraulically irreversible fouling, is still a critical aspect affecting the operational cost and energy consumption in water treatment plants. In this study, four ceramic membranes with pore sizes or molecular weight cut-off (MWCO) of 0.20 μm, 0.14 μm, 300 kDa and 50 kDa were compared during natural surface water filtration with respect to hydraulically irreversible fouling index (HIFI), foulant composition and narrowing of pore size due to the irreversible fouling. Our results showed that the hydraulically irreversible fouling index (HIFI) was proportional to the membrane pore size (r2=0.89) when the same feed water was filtrated. The UF membranes showed lower HIFI values than the MF membranes. Pore narrowing (internal fouling) was found to be a main fouling pattern of the hydraulically irreversible fouling. The internal fouling was caused by monolayer adsorption of foulants with different sizes that is dependent on the size of the membrane pore.

  20. Simultaneous bilateral isolated greater trochanter fracture

    Directory of Open Access Journals (Sweden)

    Maruti Kambali

    2013-01-01

    Full Text Available A 48-year-old woman sustained simultaneous isolated bilateral greater trochanteric fracture, following a road traffic accident. The patient presented to us 1 month after the injury. She presented with complaints of pain in the left hip and inability to walk. Roentgenograms revealed displaced comminuted bilateral greater trochanter fractures. The fracture of the left greater trochanter was reduced and fixed internally using the tension band wiring technique. The greater trochanter fracture on the right side was asymptomatic and was managed conservatively. The patient regained full range of motion and use of her hips after a postoperative follow-up of 6 months. Isolated fractures of the greater trochanter are unusual injuries. Because of their relative rarity and the unsettled controversy regarding their etiology and pathogenesis, several methods of treatment have been advocated. Furthermore, the reports of this particular type of injury are not plentiful and the average textbook coverage afforded to this entity is limited. In our study we discuss the mechanism of injury and the various treatment options available.

  1. Meta-Analysis of Ultrafiltration versus Diuretics Treatment Option for Overload Volume Reduction in Patients with Acute Decompensated Heart Failure.

    Science.gov (United States)

    Barkoudah, Ebrahim; Kodali, Sindhura; Okoroh, Juliet; Sethi, Rosh; Hulten, Edward; Suemoto, Claudia; Bittencourt, Marcio Sommer

    2015-05-01

    Although diuretics are mainly used for the treatment of acute decompensated heart failure (ADHF), inadequate responses and complications have led to the use of extracorporeal ultrafiltration (UF) as an alternative strategy for reducing volume overloads in patients with ADHF. The aim of our study is to perform meta-analysis of the results obtained from studies on extracorporeal venous ultrafiltration and compare them with those of standard diuretic treatment for overload volume reduction in acute decompensated heart failure. MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials databases were systematically searched using a pre‑specified criterion. Pooled estimates of outcomes after 48 h (weight change, serum creatinine level, and all-cause mortality) were computed using random effect models. Pooled weighted mean differences were calculated for weight loss and change in creatinine level, whereas a pooled risk ratio was used for the analysis of binary all-cause mortality outcome. A total of nine studies, involving 613 patients, met the eligibility criteria. The mean weight loss in patients who underwent UF therapy was 1.78 kg [95% Confidence Interval (CI): -2.65 to -0.91 kg; p diuretic therapy. The post-intervention creatinine level, however, was not significantly different (mean change = -0.25 mg/dL; 95% CI: -0.56 to 0.06 mg/dL; p = 0.112). The risk of all-cause mortality persisted in patients treated with UF compared with patients treated with standard diuretics (Pooled RR = 1.00; 95% CI: 0.64-1.56; p = 0.993). Compared with standard diuretic therapy, UF treatment for overload volume reduction in individuals suffering from ADHF, resulted in significant reduction of body weight within 48 h. However, no significant decrease of serum creatinine level or reduction of all-cause mortality was observed.

  2. Prices dip along with volume

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    The summer doldrums took hold in July, with only eight deals taking place, four on the spot concentrates market, two in conversion and two in enrichment. Spot concentrates volume dropped by 23% to nearly 1.2 million lbs U308 equivalent, resulting in slight declines in NUKEM's restricted and unrestricted price ranges. There were four deals on the spot market in July, totaling nearly 1.2 million lbs U3O8 equivalent. One of the buyers, a US utility, bought low-enriched uranium containing up to 440,000 lbs equivalent. Two of the buyers, a European and a US utility, purchased nearly 580,000 lbs of concentrates, with most going to the European utility. And another US utility bought UF6 containing 149,000 lbs equivalent. As for new demand, four buyers - including the European and US utilities that bought concentrates, as well as an East European utility and a non-US producer - entered the market during the month seeking 1.4 million lbs equivalent. The latter two buyers, along with another European utility and another US utility, are now weighing offers for more than 2.2 million lbs U3O8 equivalent. Looking ahead, we anticipate that as many as 17 buyers may enter the market for nearly 5 million lbs equivalent

  3. Greater trochanteric fracture with occult intertrochanteric extension.

    Science.gov (United States)

    Reiter, Michael; O'Brien, Seth D; Bui-Mansfield, Liem T; Alderete, Joseph

    2013-10-01

    Proximal femoral fractures are frequently encountered in the emergency department (ED). Prompt diagnosis is paramount as delay will exacerbate the already poor outcomes associated with these injuries. In cases where radiography is negative but clinical suspicion remains high, magnetic resonance imaging (MRI) is the study of choice as it has the capability to depict fractures which are occult on other imaging modalities. Awareness of a particular subset of proximal femoral fractures, namely greater trochanteric fractures, is vital for both radiologists and clinicians since it has been well documented that they invariably have an intertrochanteric component which may require surgical management. The detection of intertrochanteric or cervical extension of greater trochanteric fractures has been described utilizing MRI but is underestimated with both computed tomography (CT) and bone scan. Therefore, if MRI is unavailable or contraindicated, the diagnosis of an isolated greater trochanteric fracture should be met with caution. The importance of avoiding this potential pitfall is demonstrated in the following case of an elderly woman with hip pain and CT demonstrating an isolated greater trochanteric fracture who subsequently returned to the ED with a displaced intertrochanteric fracture.

  4. Butterfly valves: greater use in power plants

    International Nuclear Information System (INIS)

    McCoy, M.

    1975-01-01

    Improvements in butterfly valves, particularly in the areas of automatic control and leak tightness are described. The use of butterfly valves in nuclear power plants is discussed. These uses include service in component cooling, containment cooling, and containment isolation. The outlook for further improvements and greater uses is examined. (U.S.)

  5. Greater Somalia, the never-ending dream?

    DEFF Research Database (Denmark)

    Zoppi, Marco

    2015-01-01

    This paper provides an historical analysis of the concept of Greater Somalia, the nationalist project that advocates the political union of all Somali-speaking people, including those inhabiting areas in current Djibouti, Ethiopia and Kenya. The Somali territorial unification project of “lost...

  6. Development of ultrafiltration and inorganic adsorbents for reducing volumes of low-level and intermediate-level liquid waste: April--June 1977

    International Nuclear Information System (INIS)

    Koenst, J.W.; Herald, W.R.; Roberts, R.C.

    1977-01-01

    Ultrafication (UF) membranes have demonstrated 90 to 98% rejection of gross alpha in laboratory tests. In the treatment of laundry wastes, rejection of activity ranged from 98 to 99.9% gross alpha. The pilot UF system was installed and started up. Flux decline curves and volume reduction performance were determined. Volume reductions of 210 : 1 were achieved at flux rates of 1.1 gal/min (system is rated at 2 to 3 gal/min, 90% recovery) at activity rejection of 99.94% gross alpha. Adsorbent studies demonstrated capacities in excess of 10 9 dis/min/g for uranium-233 and in excess of 10 8 dis/min/g for plutonium-238. Construction and start-up of the Engineering Test Facility has been completed

  7. Utilization of wind energy in greater Hanover

    International Nuclear Information System (INIS)

    Sahling, U.

    1993-01-01

    Since the beginning of the Eighties, the association of communities of Greater Hanover has dealt intensively with energy and ecopolitical questions in the scope of regional planning. Renewable energy sources play a dominant role in this context. This brochure is the third contribution to the subject ''Energy policy and environmental protection''. Experts as well as possibly interested parties are addressed especially. For all 8 contributions contained, separate entries have been recorded in this database. (BWI) [de

  8. Small cities face greater impact from automation

    OpenAIRE

    Frank, Morgan R.; Sun, Lijun; Cebrian, Manuel; Youn, Hyejin; Rahwan, Iyad

    2017-01-01

    The city has proven to be the most successful form of human agglomeration and provides wide employment opportunities for its dwellers. As advances in robotics and artificial intelligence revive concerns about the impact of automation on jobs, a question looms: How will automation affect employment in cities? Here, we provide a comparative picture of the impact of automation across U.S. urban areas. Small cities will undertake greater adjustments, such as worker displacement and job content su...

  9. The Greater Sekhukhune-CAPABILITY outreach project.

    Science.gov (United States)

    Gregersen, Nerine; Lampret, Julie; Lane, Tony; Christianson, Arnold

    2013-07-01

    The Greater Sekhukhune-CAPABILITY Outreach Project was undertaken in a rural district in Limpopo, South Africa, as part of the European Union-funded CAPABILITY programme to investigate approaches for capacity building for the translation of genetic knowledge into care and prevention of congenital disorders. Based on previous experience of a clinical genetic outreach programme in Limpopo, it aimed to initiate a district clinical genetic service in Greater Sekhukhune to gain knowledge and experience to assist in the implementation and development of medical genetic services in South Africa. Implementing the service in Greater Sekhukhune was impeded by a developing staff shortage in the province and pressure on the health service from the existing HIV/AIDS and TB epidemics. This situation underscores the need for health needs assessment for developing services for the care and prevention of congenital disorders in middle- and low-income countries. However, these impediments stimulated the pioneering of innovate ways to offer medical genetic services in these circumstances, including tele-teaching of nurses and doctors, using cellular phones to enhance clinical care and adapting and assessing the clinical utility of a laboratory test, QF-PCR, for use in the local circumstances.

  10. Operational technology for greater confinement disposal

    International Nuclear Information System (INIS)

    Dickman, P.T.; Vollmer, A.T.; Hunter, P.H.

    1984-12-01

    Procedures and methods for the design and operation of a greater confinement disposal facility using large-diameter boreholes are discussed. It is assumed that the facility would be located at an operating low-level waste disposal site and that only a small portion of the wastes received at the site would require greater confinement disposal. The document is organized into sections addressing: facility planning process; facility construction; waste loading and handling; radiological safety planning; operations procedures; and engineering cost studies. While primarily written for low-level waste management site operators and managers, a detailed economic assessment section is included that should assist planners in performing cost analyses. Economic assessments for both commercial and US government greater confinement disposal facilities are included. The estimated disposal costs range from $27 to $104 per cubic foot for a commercial facility and from $17 to $60 per cubic foot for a government facility. These costs are based on average site preparation, construction, and waste loading costs for both contact- and remote-handled wastes. 14 figures, 22 tables

  11. Washing water treatment process for UF_6 cylinder by adjusting evaporation technology in a low temperature and low pressure

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  12. Greater happiness for a greater number: Is that possible in Austria?

    NARCIS (Netherlands)

    R. Veenhoven (Ruut)

    2011-01-01

    textabstractWhat is the final goal of public policy? Jeremy Bentham (1789) would say: greater happiness for a greater number. He thought of happiness as subjective enjoyment of life; in his words as “the sum of pleasures and pains”. In his time the happiness of the great number could not be measured

  13. Greater happiness for a greater number: Is that possible? If so how? (Arabic)

    NARCIS (Netherlands)

    R. Veenhoven (Ruut); E. Samuel (Emad)

    2012-01-01

    textabstractWhat is the final goal of public policy? Jeremy Bentham (1789) would say: greater happiness for a greater number. He thought of happiness as subjective enjoyment of life; in his words as “the sum of pleasures and pains”. In his time, the happiness of the great number could not be

  14. Greater happiness for a greater number: Is that possible in Germany?

    NARCIS (Netherlands)

    R. Veenhoven (Ruut)

    2009-01-01

    textabstractWhat is the final goal of public policy? Jeremy Bentham (1789) would say: greater happiness for a greater number. He thought of happiness as subjective enjoyment of life; in his words as “the sum of pleasures and pains”. In his time the Happiness of the great number could not be measured

  15. Search for greater stability in nuclear regulation

    International Nuclear Information System (INIS)

    Asselstine, J.K.

    1985-01-01

    The need for greater stability in nuclear regulation is discussed. Two possible approaches for dealing with the problems of new and rapidly changing regulatory requirements are discussed. The first approach relies on the more traditional licensing reform initiatives that have been considered off and on for the past decade. The second approach considers a new regulator philosophy aimed at the root causes of the proliferation of new safety requirements that have been imposed in recent years. For the past few years, the concepts of deregulation and regulatory reform have been in fashion in Washington, and the commercial nuclear power program has not remained unaffected. Many look to these concepts to provide greater stability in the regulatory program. The NRC, the nuclear industry and the administration have all been avidly pursuing regulatory reform initiatives, which take the form of both legislative and administrative proposals. Many of these proposals look to the future, and, if adopted, would have little impact on currently operating nuclear power plants or plants now under construction

  16. Greater Sudbury fuel efficient driving handbook

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-12-15

    Reducing the amount of fuel that people use for personal driving saves money, improves local air quality, and reduces personal contributions to climate change. This handbook was developed to be used as a tool for a fuel efficient driving pilot program in Greater Sudbury in 2009-2010. Specifically, the purpose of the handbook was to provide greater Sudbury drivers with information on how to drive and maintain their personal vehicles in order to maximize fuel efficiency. The handbook also provides tips for purchasing fuel efficient vehicles. It outlines the benefits of fuel maximization, with particular reference to reducing contributions to climate change; reducing emissions of air pollutants; safe driving; and money savings. Some tips for efficient driving are to avoid aggressive driving; use cruise control; plan trips; and remove excess weight. Tips for efficient winter driving are to avoid idling to warm up the engine; use a block heater; remove snow and ice; use snow tires; and check tire pressure. The importance of car maintenance and tire pressure was emphasized. The handbook also explains how fuel consumption ratings are developed by vehicle manufacturers. refs., figs.

  17. Women at greater risk of HIV infection.

    Science.gov (United States)

    Mahathir, M

    1997-04-01

    Although many people believe that mainly men get infected with HIV/AIDS, women are actually getting infected at a faster rate than men, especially in developing countries, and suffer more from the adverse impact of AIDS. As of mid-1996, the Joint UN Program on AIDS estimated that more than 10 million of the 25 million adults infected with HIV since the beginning of the epidemic are women. The proportion of HIV-positive women is growing, with almost half of the 7500 new infections daily occurring among women. 90% of HIV-positive women live in a developing country. In Asia-Pacific, 1.4 million women have been infected with HIV out of an estimated total 3.08 million adults from the late 1970s until late 1994. Biologically, women are more vulnerable than men to infection because of the greater mucus area exposed to HIV during penile penetration. Women under age 17 years are at even greater risk because they have an underdeveloped cervix and low vaginal mucus production. Concurrent sexually transmitted diseases increase the risk of HIV transmission. Women's risk is also related to their exposure to gender inequalities in society. The social and economic pressures of poverty exacerbate women's risk. Prevention programs are discussed.

  18. Greater Confinement Disposal Program at the Savannah River Plant

    International Nuclear Information System (INIS)

    Towler, O.A.; Cook, J.R.; Peterson, D.L.

    1983-01-01

    Plans for improved LLW disposal at the Savannah River Plant include Greater Confinement Disposal (GCD) for the higher activity fractions of this waste. GCD practices will include waste segregation, packaging, emplacement below the root zone, and stabilizing the emplacement with cement. Statistical review of SRP burial records showed that about 95% of the radioactivity is associated with only 5% of the waste volume. Trigger values determined in this study were compared with actual burials in 1982 to determine what GCD facilities would be needed for a demonstration to begin in Fall 1983. Facilities selected include 8-feet-diameter x 30-feet-deep boreholes to contain reactor scrap, tritiated waste, and selected wastes from offsite

  19. Automated urinalysis: first experiences and a comparison between the Iris iQ200 urine microscopy system, the Sysmex UF-100 flow cytometer and manual microscopic particle counting.

    Science.gov (United States)

    Shayanfar, Noushin; Tobler, Ulrich; von Eckardstein, Arnold; Bestmann, Lukas

    2007-01-01

    Automated analysis of insoluble urine components can reduce the workload of conventional microscopic examination of urine sediment and is possibly helpful for standardization. We compared the diagnostic performance of two automated urine sediment analyzers and combined dipstick/automated urine analysis with that of the traditional dipstick/microscopy algorithm. A total of 332 specimens were collected and analyzed for insoluble urine components by microscopy and automated analyzers, namely the Iris iQ200 (Iris Diagnostics) and the UF-100 flow cytometer (Sysmex). The coefficients of variation for day-to-day quality control of the iQ200 and UF-100 analyzers were 6.5% and 5.5%, respectively, for red blood cells. We reached accuracy ranging from 68% (bacteria) to 97% (yeast) for the iQ200 and from 42% (bacteria) to 93% (yeast) for the UF-100. The combination of dipstick and automated urine sediment analysis increased the sensitivity of screening to approximately 98%. We conclude that automated urine sediment analysis is sufficiently precise and improves the workflow in a routine laboratory. In addition, it allows sediment analysis of all urine samples and thereby helps to detect pathological samples that would have been missed in the conventional two-step procedure according to the European guidelines. Although it is not a substitute for microscopic sediment examination, it can, when combined with dipstick testing, reduce the number of specimens submitted to microscopy. Visual microscopy is still required for some samples, namely, dysmorphic erythrocytes, yeasts, Trichomonas, oval fat bodies, differentiation of casts and certain crystals.

  20. Evaluation of the UF/NCI hybrid computational phantoms for use in organ dosimetry of pediatric patients undergoing fluoroscopically guided cardiac procedures

    Science.gov (United States)

    Marshall, Emily L.; Borrego, David; Tran, Trung; Fudge, James C.; Bolch, Wesley E.

    2018-03-01

    Epidemiologic data demonstrate that pediatric patients face a higher relative risk of radiation induced cancers than their adult counterparts at equivalent exposures. Infants and children with congenital heart defects are a critical patient population exposed to ionizing radiation during life-saving procedures. These patients will likely incur numerous procedures throughout their lifespan, each time increasing their cumulative radiation absorbed dose. As continued improvements in long-term prognosis of congenital heart defect patients is achieved, a better understanding of organ radiation dose following treatment becomes increasingly vital. Dosimetry of these patients can be accomplished using Monte Carlo radiation transport simulations, coupled with modern anatomical patient models. The aim of this study was to evaluate the performance of the University of Florida/National Cancer Institute (UF/NCI) pediatric hybrid computational phantom library for organ dose assessment of patients that have undergone fluoroscopically guided cardiac catheterizations. In this study, two types of simulations were modeled. A dose assessment was performed on 29 patient-specific voxel phantoms (taken as representing the patient’s true anatomy), height/weight-matched hybrid library phantoms, and age-matched reference phantoms. Two exposure studies were conducted for each phantom type. First, a parametric study was constructed by the attending pediatric interventional cardiologist at the University of Florida to model the range of parameters seen clinically. Second, four clinical cardiac procedures were simulated based upon internal logfiles captured by a Toshiba Infinix-i Cardiac Bi-Plane fluoroscopic unit. Performance of the phantom library was quantified by computing both the percent difference in individual organ doses, as well as the organ dose root mean square values for overall phantom assessment between the matched phantoms (UF/NCI library or reference) and the patient

  1. Analysis of risk and dose when using thermal protection on non-fissile and fissile-excepted UF{sub 6} 48-inch cylinder packages

    Energy Technology Data Exchange (ETDEWEB)

    Chambers, D.B.; Lowe, L.M. [SENES Consultants Ltd., Richmond Hill, ON (Canada); Elizabeth Darrough, M.; Jones, R.H.

    2004-07-01

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

  2. On Line Enrichment Monitor (OLEM) UF6 Tests for 1.5" Sch40 SS Pipe, Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    March-Leuba, José A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Garner, Jim [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Younkin, Jim [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Simmons, Darrell W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-01-01

    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 while working within budgetary constraints. The “Model Safeguards Approach for Gas Centrifuge Enrichment Plants” (GCEPs) developed by the IAEA Division of Concepts and Planning in June 2006, defines the three primary Safeguards objectives to be the timely detection of: 1) diversion of significant quantities of natural (NU), depleted (DU) or low-enriched uranium (LEU) from declared plant flow, 2) facility misuse to produce undeclared LEU product from undeclared feed, and 3) facility misuse to produce enrichments higher than the declared maximum, in particular, highly enriched uranium (HEU). The ability to continuously and independently (i.e. with a minimum of information from the facility operator) monitor not only the uranium mass balance but also the 235U mass balance in the facility could help support all three verification objectives described above. Two key capabilities required to achieve an independent and accurate material balance are 1) continuous, unattended monitoring of in-process UF6 and 2) monitoring of cylinders entering and leaving the facility. The continuous monitoring of in-process UF6 would rely on a combination of load-cell monitoring of the cylinders at the feed and withdrawal stations, online monitoring of gas enrichment, and a high-accuracy net weight measurement of the cylinder contents. The Online Enrichment Monitor (OLEM) is the instrument that would continuously measure the time-dependent relative uranium enrichment, E(t), in weight percent 235U, of the gas filling or being withdrawn from the cylinders. The OLEM design concept combines gamma-ray spectrometry using a collimated NaI(Tl) detector with gas pressure and temperature data to calculate the enrichment of the UF6

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

    International Nuclear Information System (INIS)

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

    2004-01-01

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

  4. 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

    This report describes an engineering-scale, mock UF6 feed and withdrawal (F and W) system, its operation, and its intended uses. This system has been assembled to provide a test bed for evaluating and demonstrating new methodologies that can be used in remote, unattended, continuous monitoring of nuclear material process operations. These measures are being investigated to provide independent inspectors improved assurance that operations are being conducted within declared parameters, and to increase the overall effectiveness of safeguarding nuclear material. Testing applicable technologies on a mock F and W system, which uses water as a surrogate for UF6, enables thorough and cost-effective investigation of hardware, software, and operational strategies before their direct installation in an industrial nuclear material processing environment. Electronic scales used for continuous load-cell monitoring also are described as part of the basic mock F and W system description. Continuous monitoring components on the mock F and W system are linked to a data aggregation computer by a local network, which also is depicted. Data collection and storage systems are described only briefly in this report. The mock UF 6 F and W system is economical to operate. It uses a simple process involving only a surge tank between feed tanks and product and withdrawal (or waste) tanks. The system uses water as the transfer fluid, thereby avoiding the use of hazardous UF 6 . The system is not tethered to an operating industrial process involving nuclear materials, thereby allowing scenarios (e.g., material diversion) that cannot be conducted otherwise. These features facilitate conducting experiments that yield meaningful results with a minimum of expenditure and quick turnaround time. Technologies demonstrated on the engineering-scale system lead to field trials (described briefly in this report) for determining implementation issues and performance of the monitoring technologies under

  5. Effects of adding nano-clay (montmorillonite) on performance of polyvinyl acetate (PVAc) and urea-formaldehyde (UF) adhesives in Carapa guianensis, a tropical species

    OpenAIRE

    Rodríguez-Zúñiga, Ana; Vega-Baudrit, José; Alvarez, Vera; Moya-Roque, Roger

    2015-01-01

    http://www.scopus.com/inward/record.url?eid=2-s2.0-84923601829&partnerID=40&md5=5c91a6df9afec4f33b7be09b86735a75 The aim of this study was to improve the bond strength resistance of polyvinyl acetate (PVAc) and urea-formaldehyde (UF) adhesives modified with nano-clay (montmorillonite) with a tropical species of wood known to exhibit adhesion related problems. These adhesives were evaluated with 1.0 and 1.5 wt% nano-clay concentrations with lap shear strength (SS), and the percentage of woo...

  6. Small cities face greater impact from automation.

    Science.gov (United States)

    Frank, Morgan R; Sun, Lijun; Cebrian, Manuel; Youn, Hyejin; Rahwan, Iyad

    2018-02-01

    The city has proved to be the most successful form of human agglomeration and provides wide employment opportunities for its dwellers. As advances in robotics and artificial intelligence revive concerns about the impact of automation on jobs, a question looms: how will automation affect employment in cities? Here, we provide a comparative picture of the impact of automation across US urban areas. Small cities will undertake greater adjustments, such as worker displacement and job content substitutions. We demonstrate that large cities exhibit increased occupational and skill specialization due to increased abundance of managerial and technical professions. These occupations are not easily automatable, and, thus, reduce the potential impact of automation in large cities. Our results pass several robustness checks including potential errors in the estimation of occupational automation and subsampling of occupations. Our study provides the first empirical law connecting two societal forces: urban agglomeration and automation's impact on employment. © 2018 The Authors.

  7. Small cities face greater impact from automation

    Science.gov (United States)

    Sun, Lijun; Cebrian, Manuel; Rahwan, Iyad

    2018-01-01

    The city has proved to be the most successful form of human agglomeration and provides wide employment opportunities for its dwellers. As advances in robotics and artificial intelligence revive concerns about the impact of automation on jobs, a question looms: how will automation affect employment in cities? Here, we provide a comparative picture of the impact of automation across US urban areas. Small cities will undertake greater adjustments, such as worker displacement and job content substitutions. We demonstrate that large cities exhibit increased occupational and skill specialization due to increased abundance of managerial and technical professions. These occupations are not easily automatable, and, thus, reduce the potential impact of automation in large cities. Our results pass several robustness checks including potential errors in the estimation of occupational automation and subsampling of occupations. Our study provides the first empirical law connecting two societal forces: urban agglomeration and automation's impact on employment. PMID:29436514

  8. Planning for greater-confinement disposal

    International Nuclear Information System (INIS)

    Gilbert, T.L.; Luner, C.; Meshkov, N.K.; Trevorrow, L.E.; Yu, C.

    1984-01-01

    This contribution is a progress report for preparation of a document that will summarize procedures and technical information needed to plan for and implement greater-confinement disposal (GCD) of low-level radioactive waste. Selection of a site and a facility design (Phase I), and construction, operation, and extended care (Phase II) will be covered in the document. This progress report is limited to Phase I. Phase I includes determination of the need for GCD, design alternatives, and selection of a site and facility design. Alternative designs considered are augered shafts, deep trenches, engineered structures, high-integrity containers, hydrofracture, and improved waste form. Design considerations and specifications, performance elements, cost elements, and comparative advantages and disadvantages of the different designs are covered. Procedures are discussed for establishing overall performance objectives and waste-acceptance criteria, and for comparative assessment of the performance and cost of the different alternatives. 16 references

  9. Planning for greater-confinement disposal

    International Nuclear Information System (INIS)

    Gilbert, T.L.; Luner, C.; Meshkov, N.K.; Trevorrow, L.E.; Yu, C.

    1984-01-01

    This contribution is a progress report for preparation of a document that will summarize procedures and technical information needed to plan for and implement greater-confinement disposal (GCD) of low-level radioactive waste. Selection of a site and a facility design (Phase I), and construction, operation, and extended care (Phase II) will be covered in the document. This progress report is limited to Phase I. Phase I includes determination of the need for GCD, design alternatives, and selection of a site and facility design. Alternative designs considered are augered shafts, deep trenches, engineered structures, high-integrity containers, hydrofracture, and improved waste form. Design considerations and specifications, performance elements, cost elements, and comparative advantages and disadvantages of the different designs are covered. Procedures are discussed for establishing overall performance objecties and waste-acceptance criteria, and for comparative assessment of the performance and cost of the different alternatives. 16 refs

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

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Leon E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Miller, Karen A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Garner, James R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Branney, Sean [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); McDonald, Benjamin S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Webster, Jennifer B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zalavadia, Mital A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Todd, Lindsay C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kulisek, Jonathan A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Nordquist, Heather [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Deshmukh, Nikhil S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Stewart, Scott [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-05-31

    In recent years, the International Atomic Energy Agency (IAEA) has pursued innovative techniques and an integrated suite of safeguards measures to address the verification challenges posed by the front end of the nuclear fuel cycle. Among the unattended instruments currently being explored by the IAEA is an Unattended Cylinder Verification Station (UCVS) that could provide automated, independent verification of the declared relative enrichment, 235U mass, total uranium mass and identification for all declared UF6 cylinders in a facility (e.g., uranium enrichment plants and fuel fabrication plants). Under the auspices of the United States and European Commission Support Programs to the IAEA, a project was undertaken to assess the technical and practical viability of the UCVS concept. The US Support Program team consisted of Pacific Northwest National Laboratory (PNNL, lead), Los Alamos National Laboratory (LANL), Oak Ridge National Laboratory (ORNL) and Savanah River National Laboratory (SRNL). At the core of the viability study is a long-term field trial of a prototype UCVS system at a Westinghouse fuel fabrication facility. A key outcome of the study is a quantitative performance evaluation of two nondestructive assay (NDA) methods being considered for inclusion in a UCVS: Hybrid Enrichment Verification Array (HEVA), and Passive Neutron Enrichment Meter (PNEM). This report provides context for the UCVS concept and the field trial: potential UCVS implementation concepts at an enrichment facility; an overview of UCVS prototype design; field trial objectives and activities. Field trial results and interpretation are presented, with a focus on the performance of PNEM and HEVA for the assay of over 200 “typical” Type 30B cylinders, and the viability of an “NDA Fingerprint” concept as a high-fidelity means to periodically verify that the contents of a given cylinder are consistent with previous scans. A modeling study, combined with field

  11. Greater-confinement disposal of low-level radioactive wastes

    International Nuclear Information System (INIS)

    Trevorrow, L.E.; Gilbert, T.L.; Luner, C.; Merry-Libby, P.A.; Meshkov, N.K.; Yu, C.

    1985-01-01

    Low-level radioactive wastes include a broad spectrum of wastes that have different radionuclide concentrations, half-lives, and physical and chemical properties. Standard shallow-land burial practice can provide adequate protection of public health and safety for most low-level wastes, but a small volume fraction (about 1%) containing most of the activity inventory (approx.90%) requires specific measures known as ''greater-confinement disposal'' (GCD). Different site characteristics and different waste characteristics - such as high radionuclide concentrations, long radionuclide half-lives, high radionuclide mobility, and physical or chemical characteristics that present exceptional hazards - lead to different GCD facility design requirements. Facility design alternatives considered for GCD include the augered shaft, deep trench, engineered structure, hydrofracture, improved waste form, and high-integrity container. Selection of an appropriate design must also consider the interplay between basic risk limits for protection of public health and safety, performance characteristics and objectives, costs, waste-acceptance criteria, waste characteristics, and site characteristics. This paper presents an overview of the factors that must be considered in planning the application of methods proposed for providing greater confinement of low-level wastes. 27 refs

  12. Greater Caregiving Risk, Better Infant Memory Performance?

    Science.gov (United States)

    Rifkin-Graboi, Anne; Quan, Jeffry; Richmond, Jenny; Goh, Shaun Kok Yew; Sim, Lit Wee; Chong, Yap Seng; Francois-Bureau, Jean; Chen, Helen; Qiu, Anqi

    2018-04-16

    Poor early life care often relates to cognitive difficulties. However, newer work suggests that in early-life, adversity may associate with enhanced or accelerated neurodevelopment. We examine associations between postnatal caregiving risks (i.e., higher self-reported postnatal-anxiety and lower observed maternal sensitivity) and infant relational memory (i.e. via deferred imitation and relational binding). Using subsamples of 67-181 infants (aged 433-477 post-conceptual days, or roughly five to seven months since birth) taking part in the GUSTO study, we found such postnatal caregiving risk significantly predictive of "better" performance on a relational binding task following a brief delay, after Bonferroni adjustments. Subsequent analyses suggest that the association between memory and these risks may specifically be apparent amongst infants spending at least 50% of their waking hours in the presence of their mothers. Our findings echo neuroimaging research concerning similar risk exposure and larger infant hippocampal volume, and likewise underscore the importance of considering developmental context in understanding early life experience. With this in mind, these findings caution against the use of cognitive outcomes as indices of experienced risk. This article is protected by copyright. All rights reserved. © 2018 Wiley Periodicals, Inc.

  13. Intergranular tellurium cracking of nickel-based alloys in molten Li, Be, Th, U/F salt mixture

    Science.gov (United States)

    Ignatiev, Victor; Surenkov, Alexander; Gnidoy, Ivan; Kulakov, Alexander; Uglov, Vadim; Vasiliev, Alexander; Presniakov, Mikhail

    2013-09-01

    In Russia, R&D on Molten Salt Reactor (MSR) are concentrated now on fast/intermediate spectrum concepts which were recognized as long term alternative to solid fueled fast reactors due to their attractive features: strong negative feedback coefficients, easy in-service inspection, and simplified fuel cycle. For high-temperature MSR corrosion of the metallic container alloy in primary circuit is the primary concern. Key problem receiving current attention include surface fissures in Ni-based alloys probably arising from fission product tellurium attack. This paper summarizes results of corrosion tests conducted recently to study effect of oxidation state in selected fuel salt on tellurium attack and to develop means of controlling tellurium cracking in the special Ni-based alloys recently developed for molten salt actinide recycler and tranforming (MOSART) system. Tellurium corrosion of Ni-based alloys was tested at temperatures up to 750 °C in stressed and unloaded conditions in molten LiF-BeF2 salt mixture fueled by about 20 mol% of ThF4 and 2 mol% of UF4 at different [U(IV)]/[U(III)] ratios: 0.7, 4, 20, 100 and 500. Following Ni-based alloys (in mass%): HN80М-VI (Mo—12, Cr—7.6, Nb—1.5), HN80МТY (Mo—13, Cr—6.8, Al—1.1, Ti—0.9), HN80МТW (Mo—9.4, Cr—7.0, Ti—1.7, W—5.5) and ЕМ-721 (W—25.2, Cr—5.7, Ti—0.17) were used for the study in the corrosion facility. If the redox state the fuel salt is characterized by uranium ratio [U(IV)]/[U(III)] uranium intermetallic compounds and alloys with nickel and molybdenum. This leads to spontaneous behavior of alloy formation processes on the specimens' surface and further diffusion of uranium deep into the metallic phase. As consequence of this films of intermetallic compounds and alloys of nickel, molybdenum, tungsten with uranium are formed on the alloys specimens' surface, and intergranular corrosion does not take place. In the fuel salt with [U(IV)]/[U(III)] = 4-20 the potentials of uranium

  14. Urban acid deposition in Greater Manchester

    Energy Technology Data Exchange (ETDEWEB)

    Lee, D.S.; Longhurst, J.W.S.; Gee, D.R.; Hare, S.E. (Manchester Polytechnic, Manchester (UK). Acid Rain Information Centre)

    1989-08-01

    Data are presented from a monitoring network of 18 bulk precipitation collectors and one wet-only collector in the urban area of Greater Manchester, in the north west of England. Weekly samples were analysed for all the major ions in precipitation along with gaseous nitrogen dioxide concentrations from diffusion tubes. Statistical analysis of the data shows significant spatial variation of non marine sulphate, nitrate, ammonium, acidity and calcium concentrations, and nitrogen dioxide concentrations. Calcium is thought to be responsible for the buffering of acidity and is of local origin. Wet deposition is the likely removal process for calcium in the atmosphere and probably by below cloud scavenging. Nitrate and ammonium concentrations and depositions show close spatial, temporal and statistical association. Examination of high simultaneous episodes of nitrate and ammonium deposition shows that these depositions cannot be explained in terms of trajectories and it is suggested that UK emissions of ammonia may be important. Statistical analysis of the relationships between nitrate and ammonium depositions, concentrations and precipitation amount suggest that ammonia from mesoscale sources reacts reversibly with nitric acid aerosol and is removed by below cloud scavenging. High episodes of the deposition of non marine sulphate are difficult to explain by trajectory analysis alone, perhaps suggesting local sources. In a comparison between wet deposition and bulk deposition, it was shown that only 15.2% of the non marine sulphur was dry deposited to the bulk precipitation collector. 63 refs., 86 figs., 31 tabs.

  15. Effect of essential oil of Pistacia atlantica subsp. Kurdica gum on growth of Penicillium citrinum and organoleptic properties of UF-cheese

    Directory of Open Access Journals (Sweden)

    Sh Ostowar

    2014-08-01

    Full Text Available Nowadays, due to the antioxidant and antimicrobial properties of essential oil and the trend towards the substitution of chemical materials by natural ones, the use of this natural product is prevalent. The essential oil of Pistacia atlantica subsp. kurdica is among essential oils which demonstrate antimicrobial activity against some microorganisms. In Iran, the growth of mould on UF-cheese has been a constant problem resulted in the increased number of returns. The most common type of cheese contamination among fungi is Penicillium, especially P. citrinum. This study investigates the effect of P. atlantica subsp. kurdicaʼs essential oil on the growth of P. citrinum in culture media and UF-cheese. According to the results, the essential oil with concentration of 2500 µL/L reduced the growth of P. citrinum in culture medium and its minimum inhibitory concentration was estimated at 3000 µL/L. The effective inhibitory concentration of the essential oil on the growth of fungus on cheese was 24000 µL/L. From the organoleptic point of view, the use of this essential oil in cheese is partly acceptable.

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

    International Nuclear Information System (INIS)

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

    1977-04-01

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

  17. Fouling Removal of UF Membrane with Coated TiO2 Nanoparticles under UV Irradiation for Effluent Recovery during TFT-LCD Manufacturing

    Directory of Open Access Journals (Sweden)

    S. H. You

    2013-01-01

    Full Text Available An ultrafiltration (UF membrane process was employed to treat the secondary effluent discharged from a manufacturing of thin film transistor-liquid crystal display (TFT-LCD in this study. A bench-scale system was performed to evaluate the fouling removal of a UF membrane with coated titanium dioxide (TiO2 nanoparticles under UV irradiation. The operating pressure and feed temperature were controlled at 300 KN/m2 and 25°C, respectively. It was found that the optimum operating conditions were attained with TiO2 concentrations of 10 wt% for both 5 KD and 10 KD MWCO. Continuous UV irradiation of 5 KD MWCO improved the permeate flux rate from 45.0% to 59.5% after 4 hours of operation. SEM-EDS analysis also showed that the photocatalytic effect had reduced the average thickness of cake fouling on the membrane from 6.40 μm to 2.70 μm for 5 KD MWCO and from 6.70 μm to 3.1 μm for 10 KD MWCO. In addition, the membrane contact angle was reduced from 54° to 44°. The photocatalytic properties of TiO2 apparently increased the hydrophilicity of the membrane surface, thereby reducing membrane fouling.

  18. Contribution of effluent organic matter (EfOM) to ultrafiltration (UF) membrane fouling: Isolation, characterization, and fouling effect of EfOM fractions

    KAUST Repository

    Zheng, Xing

    2014-11-01

    EfOM has been regarded as a major organic foulant resulting in UF membrane fouling in wastewater reclamation. To investigate fouling potential of different EfOM fractions, the present study isolated EfOM into hydrophobic neutrals (HPO-N), colloids, hydrophobic acids (HPO-A), transphilic neutrals and acids (TPI), and hydrophilics (HPI), and tested their fouling effect in both salt solution and pure water during ultrafiltration (UF). Major functional groups and chemical structure of the isolates were identified using Fourier transform infrared spectroscopy (FT-IR) and solid-state carbon nuclear magnetic resonance (13C NMR) analysis. The influence of the isolation process on the properties of EfOM fractions was minor because the raw and reconstituted secondary effluents were found similar with respect to UV absorbance, molecular size distribution, and fluorescence character. In membrane filtration tests, unified membrane fouling index (UMFI) and hydraulic resistance were used to quantify irreversible fouling potential of different water samples. Results show that under similar DOC level in feed water, colloids present much more irreversible fouling than other fractions. The fouling effect of the isolates is related to their size, chemical properties, and solution chemistry. Further investigations have identified that the interaction between colloids and other fractions also influences the performance of colloids in fouling phenomena. © 2014 Elsevier Ltd.

  19. Smaller self-inflating bags produce greater guideline consistent ventilation in simulated cardiopulmonary resuscitation.

    Science.gov (United States)

    Nehme, Ziad; Boyle, Malcolm J

    2009-02-20

    Suboptimal bag ventilation in cardiopulmonary resuscitation (CPR) has demonstrated detrimental physiological outcomes for cardiac arrest patients. In light of recent guideline changes for resuscitation, there is a need to identify the efficacy of bag ventilation by prehospital care providers. The objective of this study was to evaluate bag ventilation in relation to operator ability to achieve guideline consistent ventilation rate, tidal volume and minute volume when using two different capacity self-inflating bags in an undergraduate paramedic cohort. An experimental study using a mechanical lung model and a simulated adult cardiac arrest to assess the ventilation ability of third year Monash University undergraduate paramedic students. Participants were instructed to ventilate using 1600 ml and 1000 ml bags for a length of two minutes at the correct rate and tidal volume for a patient undergoing CPR with an advanced airway. Ventilation rate and tidal volume were recorded using an analogue scale with mean values calculated. Ethics approval was granted. Suboptimal ventilation with the use of conventional 1600 ml bag was common, with 77% and 97% of participants unable to achieve guideline consistent ventilation rates and tidal volumes respectively. Reduced levels of suboptimal ventilation arouse from the use of the smaller bag with a 27% reduction in suboptimal tidal volumes (p = 0.015) and 23% reduction in suboptimal minute volumes (p = 0.045). Smaller self-inflating bags reduce the incidence of suboptimal tidal volumes and minute volumes and produce greater guideline consistent results for cardiac arrest patients.

  20. Greater-than-Class-C Low-Level Waste Data Base user's manual

    International Nuclear Information System (INIS)

    1992-07-01

    The Greater-than-Class-C Low-level Waste (GTCC LLW) Data Base characterizes GTCC LLW using low, base, and high cases for three different scenarios: unpackaged, packaged, and concentration averages. The GTCC LLW Data Base can be used to project future volumes and radionuclide activities. This manual provides instructions for users of the GTCC LLW Data Base

  1. Membrane Bioreactor (MBR) as Alternative to a Conventional Activated Sludge System Followed by Ultrafiltration (CAS-UF) for the Treatment of Fischer-Tropsch Reaction Water from Gas-to-Liquids Industries

    NARCIS (Netherlands)

    Laurinonyte, Judita; Meulepas, Roel J.W.; Brink, van den Paula; Temmink, Hardy

    2017-01-01

    The potential of a membrane bioreactor (MBR) system to treat Fischer-Tropsch (FT) reaction water from gas-to-liquids (GTL) industries was investigated and compared with the current treatment system: a conventional activated sludge system followed by an ultrafiltration (CAS-UF) unit. The MBR and

  2. Greater confinement disposal program at the Savannah River Plant

    International Nuclear Information System (INIS)

    Towler, O.A.; Cook, J.R.; Peterson, D.L.; Reddick, J.A.

    1984-01-01

    A facility to demonstrate Greater Confinement Disposal (GCD) of low-level solid radioactive waste in a humid environment has been built and is operating at the Savannah River Plant (SRP). GCD practices of waste segregation into high and low activity concentrations, emplacement of waste below the root zone, waste stabilization, and capping are being used in the demonstration. Activity concentrations to select wastes for GCD are based on the volume/activity distribution of low-level solid wastes as obtained from SRP burial records, and are equal to or less than those for Class B waste in 10 CFR 61. The first disposal units constructed are twenty 9-ft-diam, 30-ft-deep boreholes. These holes will be used to dispose of wastes from the production reactors, tritiated wastes, and selected wastes from offsite. In 1984, construction will begin on an engineered GCD trench for disposal of boxed waste and large bulky items that meet the activity concentration criteria. 4 references, 5 figures, 2 tables

  3. Process for decontamination of surfaces in an facility of natural uranium hexafluoride production (UF{sub 6}); Processo de descontaminação de superfícies em uma instalação de produção de hexafluoreto de urânio natural (UF{sub 6})

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Claudio C. de; Silva, Teresinha M.; Rodrigues, Demerval L.; Carneiro, Janete C.G.G., E-mail: calmeida@ipen.br [Instituto de Pesquisas Energéticas e Nucleares(IPEN/CNEN-SP), São Paulo, SP (Brazil). Gerência de Radioproteção

    2017-07-01

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

  4. Cost-effectiveness of safety measures to reduce public risk associated with the transportation of UF{sub 6} by truck and trains

    Energy Technology Data Exchange (ETDEWEB)

    Hubert, Philippe; Pages, Pierre

    1989-08-01

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

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

    International Nuclear Information System (INIS)

    Hubert, Philippe; Pages, Pierre

    1989-01-01

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

  6. Crystal field effect in the uranium compounds - model calculations for CsUF/sub 6/, Cs/sub 2/UCl/sub 6/ and UCl/sub 4/

    Energy Technology Data Exchange (ETDEWEB)

    Gajek, Z.; Mulak, J.; Faucher, M.

    1987-01-01

    A practical crystal field model allowing one to estimate the crystal field parameters from first principles is presented and applied to the actinide compounds. The model results directly from the renormalization (and reduction) procedure of the true Schroedinger equation for an effective Hamiltonian acting on the 5f spin-orbitals only. In practice this approach becomes convergent with the ab initio model of Newman. Three ionic uranium compounds: CsUF/sub 6/, Cs/sub 2/UCl/sub 6/ and UCl/sub 4/ have served as examples of the application. The results obtained, particularly for the first two compounds, are in good agreement with the experimental data. The contributions of different mechanisms responsible for the crystal field effect are discussed.

  7. Crystal field effect in the uranium compounds - model calculations for CsUF6, Cs2UCl6 and UCl4

    International Nuclear Information System (INIS)

    Gajek, Z.; Mulak, J.

    1987-01-01

    A practical crystal field model allowing one to estimate the crystal field parameters from first principles is presented and applied to the actinide compounds. The model results directly from the renormalization (and reduction) procedure of the true Schroedinger equation for an effective Hamiltonian acting on the 5f spin-orbitals only. In practice this approach becomes convergent with the ab initio model of Newman. Three ionic uranium compounds: CsUF 6 , Cs 2 UCl 6 and UCl 4 have served as examples of the application. The results obtained, particularly for the first two compounds, are in good agreement with the experimental data. The contributions of different mechanisms responsible for the crystal field effect are discussed. (author)

  8. Treatment of cosmetic effluent in different configurations of ceramic UF membrane based bioreactor: Toxicity evaluation of the untreated and treated wastewater using catfish (Heteropneustes fossilis).

    Science.gov (United States)

    Banerjee, Priya; Dey, Tanmoy Kumar; Sarkar, Sandeep; Swarnakar, Snehasikta; Mukhopadhyay, Aniruddha; Ghosh, Sourja

    2016-03-01

    Extensive usage of pharmaceutical and personal care products (PPCPs) and their discharge through domestic sewage have been recently recognized as a new generation environmental concern which deserves more scientific attention over the classical environmental pollutants. The major issues of this type of effluent addressed in this study were its colour, triclosan and anionic surfactant (SDS) content. Samples of cosmetic effluent were collected from different beauty treatment salons and spas in and around Kolkata, India and treated in bioreactors containing a bacterial consortium isolated from activated sludge samples collected from a common effluent treatment plant. Members of the consortium were isolated and identified as Klebsiella sp., Pseudomonas sp., Salmonella sp. and Comamonas sp. The biotreated effluent was subjected to ultrafiltration (UF) involving indigenously prepared ceramic membranes in both side-stream and submerged mode. Analysis of the MBR treated effluent revealed 99.22%, 98.56% and 99.74% removal of colour, triclosan and surfactant respectively. Investigation of probable acute and chronic cyto-genotoxic potential of the untreated and treated effluents along with their possible participation in triggering oxidative stress was carried out with Heteropneustes fossilis (Bloch). Comet formation recorded in both liver and gill cells and micronucleus count in peripheral erythrocytes of individuals exposed to untreated effluent increased with duration of exposure and was significantly higher than those treated with UF permeates which in turn neared control levels. Results of this study revealed successful application of the isolated bacterial consortium in MBR process for efficient detoxification of cosmetic effluent thereby conferring the same suitable for discharge and/or reuse. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    International Nuclear Information System (INIS)

    McAuley, W.A.

    1984-01-01

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

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

    International Nuclear Information System (INIS)

    Oliveira, Dirceu Paulo de

    2008-01-01

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

  11. Evaluation of the treatability of a winery distillery (vinasse) wastewater by UASB, anoxic-aerobic UF-MBR and chemical precipitation/adsorption.

    Science.gov (United States)

    Petta, Luigi; De Gisi, Sabino; Casella, Patrizia; Farina, Roberto; Notarnicola, Michele

    2017-10-01

    A multi-stage pilot-scale treatment cycle consisting of an Upflow Anaerobic Sludge Blanket reactor (UASB) followed by an anoxic-aerobic Ultra Filtration Membrane Bio Reactor (UF-MBR) and a post treatment based on chemical precipitation with lime or adsorption on Granular Activated Carbons (GAC), was applied in order to evaluate the treatment feasibility of a real winery distillery wastewater at laboratory and bench scale. The wastewater was classified as high strength with acidic pH (3.8), and concentrations of 44,600, 254, 604 and 660 mg/l for COD tot , total nitrogen, total phosphorous and phenols, respectively. The UASB reactor was operated at Organic Loading Rates (OLR) in the range 3.0-11.5 kgCOD tot /m 3 /d achieving treatment efficiency up to 97%, with an observed methane production of 340 L of CH 4 /kgCOD. The MBR system was operated with an organic load in the range 0.070-0.185 kgCOD/kgVSS/d, achieving a removal up to 48%, 67% and 65% of the influent COD, total nitrogen and phenols, respectively. The combination of UASB and UF-MBR treatment units was not effective in phosphate and colour removal assigning to further chemical precipitation and adsorption processes, respectively, their complete removal in order to comply with legal standards for wastewater discharge. Subsequently, the optimization of the investigated treatment chain was assessed by applying a chemical precipitation step upstream and downstream the UASB reactor, and a related treatment unit cost assessment is presented in view of a further technological scale-up. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Technical feasibility study of a low-cost hybrid PAC-UF system for wastewater reclamation and reuse: a focus on feedwater production for low-pressure boilers.

    Science.gov (United States)

    Amosa, Mutiu Kolade; Jami, Mohammed Saedi; Alkhatib, Ma'an Fahmi R; Majozi, Thokozani

    2016-11-01

    This study has applied the concept of the hybrid PAC-UF process in the treatment of the final effluent of the palm oil industry for reuse as feedwater for low-pressure boilers. In a bench-scale set-up, a low-cost empty fruit bunch-based powdered activated carbon (PAC) was employed for upstream adsorption of biotreated palm oil mill effluent (BPOME) with the process conditions: 60 g/L dose of PAC, 68 min of mixing time and 200 rpm of mixing speed, to reduce the feedwater strength, alleviate probable fouling of the membranes and thus improve the process flux (productivity). Three polyethersulfone ultrafiltration membranes of molecular weight cut-off (MWCO) of 1, 5 and 10 kDa were investigated in a cross-flow filtration mode, and under constant transmembrane pressures of 40, 80, and 120 kPa. The permeate qualities of the hybrid processes were evaluated, and it was found that the integrated process with the 1 kDa MWCO UF membrane yielded the best water quality that falls within the US EPA reuse standard for boiler-feed and cooling water. It was also observed that the permeate quality is fit for extended reuse as process water in the cement, petroleum and coal industries. In addition, the hybrid system's operation consumed 37.13 Wh m -3 of energy at the highest applied pressure of 120 kPa, which is far lesser than the typical energy requirement range (0.8-1.0 kWh m -3 ) for such wastewater reclamation.

  13. Gamma Knife radiosurgery for large vestibular schwannomas greater than 3 cm in diameter.

    Science.gov (United States)

    Huang, Cheng-Wei; Tu, Hsien-Tang; Chuang, Chun-Yi; Chang, Cheng-Siu; Chou, Hsi-Hsien; Lee, Ming-Tsung; Huang, Chuan-Fu

    2018-05-01

    OBJECTIVE Stereotactic radiosurgery (SRS) is an important alternative management option for patients with small- and medium-sized vestibular schwannomas (VSs). Its use in the treatment of large tumors, however, is still being debated. The authors reviewed their recent experience to assess the potential role of SRS in larger-sized VSs. METHODS Between 2000 and 2014, 35 patients with large VSs, defined as having both a single dimension > 3 cm and a volume > 10 cm 3 , underwent Gamma Knife radiosurgery (GKRS). Nine patients (25.7%) had previously undergone resection. The median total volume covered in this group of patients was 14.8 cm 3 (range 10.3-24.5 cm 3 ). The median tumor margin dose was 11 Gy (range 10-12 Gy). RESULTS The median follow-up duration was 48 months (range 6-156 months). All 35 patients had regular MRI follow-up examinations. Twenty tumors (57.1%) had a volume reduction of greater than 50%, 5 (14.3%) had a volume reduction of 15%-50%, 5 (14.3%) were stable in size (volume change 3 cm and a volume > 10 cm 3 and tolerable mass effect can be managed satisfactorily with GKRS. Tumor volume ≥ 15 cm 3 is a significant factor predicting poor tumor control following GKRS.

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

    International Nuclear Information System (INIS)

    1999-04-01

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

  15. Smaller self-inflating bags produce greater guideline consistent ventilation in simulated cardiopulmonary resuscitation

    Directory of Open Access Journals (Sweden)

    Boyle Malcolm J

    2009-02-01

    Full Text Available Abstract Background Suboptimal bag ventilation in cardiopulmonary resuscitation (CPR has demonstrated detrimental physiological outcomes for cardiac arrest patients. In light of recent guideline changes for resuscitation, there is a need to identify the efficacy of bag ventilation by prehospital care providers. The objective of this study was to evaluate bag ventilation in relation to operator ability to achieve guideline consistent ventilation rate, tidal volume and minute volume when using two different capacity self-inflating bags in an undergraduate paramedic cohort. Methods An experimental study using a mechanical lung model and a simulated adult cardiac arrest to assess the ventilation ability of third year Monash University undergraduate paramedic students. Participants were instructed to ventilate using 1600 ml and 1000 ml bags for a length of two minutes at the correct rate and tidal volume for a patient undergoing CPR with an advanced airway. Ventilation rate and tidal volume were recorded using an analogue scale with mean values calculated. Ethics approval was granted. Results Suboptimal ventilation with the use of conventional 1600 ml bag was common, with 77% and 97% of participants unable to achieve guideline consistent ventilation rates and tidal volumes respectively. Reduced levels of suboptimal ventilation arouse from the use of the smaller bag with a 27% reduction in suboptimal tidal volumes (p = 0.015 and 23% reduction in suboptimal minute volumes (p = 0.045. Conclusion Smaller self-inflating bags reduce the incidence of suboptimal tidal volumes and minute volumes and produce greater guideline consistent results for cardiac arrest patients.

  16. Reserves in western basins: Part 1, Greater Green River basin

    Energy Technology Data Exchange (ETDEWEB)

    1993-10-01

    This study characterizes an extremely large gas resource located in low permeability, overpressured sandstone reservoirs located below 8,000 feet drill depth in the Greater Green River basin, Wyoming. Total in place resource is estimated at 1,968 Tcf. Via application of geologic, engineering and economic criteria, the portion of this resource potentially recoverable as reserves is estimated. Those volumes estimated include probable, possible and potential categories and total 33 Tcf as a mean estimate of recoverable gas for all plays considered in the basin. Five plays (formations) were included in this study and each was separately analyzed in terms of its overpressured, tight gas resource, established productive characteristics and future reserves potential based on a constant $2/Mcf wellhead gas price scenario. A scheme has been developed to break the overall resource estimate down into components that can be considered as differing technical and economic challenges that must be overcome in order to exploit such resources: in other words, to convert those resources to economically recoverable reserves. Total recoverable reserves estimates of 33 Tcf do not include the existing production from overpressured tight reservoirs in the basin. These have estimated ultimate recovery of approximately 1.6 Tcf, or a per well average recovery of 2.3 Bcf. Due to the fact that considerable pay thicknesses can be present, wells can be economic despite limited drainage areas. It is typical for significant bypassed gas to be present at inter-well locations because drainage areas are commonly less than regulatory well spacing requirements.

  17. Greater-than-Class C low-level waste characterization technical review process

    Energy Technology Data Exchange (ETDEWEB)

    Hutchison, D.; Magleby, M.

    1990-01-01

    Existing volume projections of greater-than-Class C low-level waste (GTCC LLW) vary significantly. The Department of Energy (DOE) National Low-Level Waste Management Program (NLLWMP) has undertaken activities to develop a best estimate of GTCC LLW volumes and activities for use as the planning basis. Initial information about the generation of GTCC LLW was obtained through a DOE Energy Information Administration survey. That information, combined with information from other related literature, formed the basis of a computer model, which projects potential GTCC LLW. This paper describes uncertainties in existing GTCC LLW characterization and volume projections data and describes the technical review process that is being used to assist in projections of GTCC LLW expected for storage and disposal. 8 refs., 2 tabs.

  18. Greater-than-Class C low-level waste characterization technical review process

    International Nuclear Information System (INIS)

    Hutchison, D.; Magleby, M.

    1990-01-01

    Existing volume projections of greater-than-Class C low-level waste (GTCC LLW) vary significantly. The Department of Energy (DOE) National Low-Level Waste Management Program (NLLWMP) has undertaken activities to develop a best estimate of GTCC LLW volumes and activities for use as the planning basis. Initial information about the generation of GTCC LLW was obtained through a DOE Energy Information Administration survey. That information, combined with information from other related literature, formed the basis of a computer model, which projects potential GTCC LLW. This paper describes uncertainties in existing GTCC LLW characterization and volume projections data and describes the technical review process that is being used to assist in projections of GTCC LLW expected for storage and disposal. 8 refs., 2 tabs

  19. Anisotropy of the Chemical Shift Tensor for Fluorines in UF{sub 6} : Application to the Fluorine Atom Movement Model; Anisotropie du Tenseur de Deplacement Chimique des Fluors dans UF{sub 6}: Application au Modele du Mouvement des Atomes de Fluor; Anizotropiya tenzora khimicheskogo zameshcheniya ftora v UF{sub 6}. Primenenie k modeli dvizheniya atomov ftora; Anisotropia del Tensor de Desplazamiento Quimico de los Atomos de Fluor en el UF{sub 6}: Aplicacion al Modelo del Movimiento de los Atomos de Fluor

    Energy Technology Data Exchange (ETDEWEB)

    Rigny, P. [Centre d' Etudes Nucleaires de Saclay (France)

    1965-10-15

    R. Blinc et al. have made an initial study of polycrystalline uranium hexafluoride using the magnetic resonance of fluorine at 40 Mc/s. The low-temperattire spectrum (t < -20 Degree-Sign C can be analysed into a two-line superposition; this confirms the structure found by Hoard and Stroupe by X-ray investigation in which, since the UF{sub 6} octahedron has one long axis and two short axes, the fluorine atoms are divided among two different types of site. The change in the spectrum with temperature (coalescence of the two lines) suggests movement of the fluorine atoms between the two types of site. By repeating these experiments at 56.4 Mc/s and 94 Mc/s, we have been able to demonstrate the existence of considerable axial anisotropy of the chemical shift tensor (about 650 ppm). The absorption line obtained for a powder in these conditions is complex, and to study it we must envisage a line-shape function f(h), which is the probability that a grain of powder is so orientated that it resonates for the value h of the field. In the absence of movement (low-temperature spectrum) the line-shape function for each of the two lines (corresponding to the two types of site) is of the form obtained for equivalent atoms. It is known that the parameters of chemical shift tensors give information on chemical bond character. We are thus led, for example, to attribute a considerable ionic character (I Asymptotically-Equal-To 1/2) to the bonds between the uranium and the two most distant fluorine atoms. In the presence of movement the line-shape function is very different, and depends on the type of movement. For UF{sub 6}, study of the shape of the single line (t > 20 Degree-Sign C) in cases where we have anisotropy, shows that the fluorine atoms of the same molecule interchange with each other, each atom remaining in each of the positions for about 5 {mu}sec at 30 Degree-Sign C, with an activation energy of about 0.5 eV. (author) [French] Une premiere etude de l'hexafluorure d

  20. A simple fabrication of plasmonic surface-enhanced Raman scattering (SERS) substrate for pesticide analysis via the immobilization of gold nanoparticles on UF membrane

    Science.gov (United States)

    Hong, Jangho; Kawashima, Ayato; Hamada, Noriaki

    2017-06-01

    In this study, we developed a facile fabrication method to access a highly reproducible plasmonic surface enhanced Raman scattering substrate via the immobilization of gold nanoparticles on an Ultrafiltration (UF) membrane using a suction technique. This was combined with a simple and rapid analyte concentration and detection method utilizing portable Raman spectroscopy. The minimum detectable concentrations for aqueous thiabendazole standard solution and thiabendazole in orange extract are 0.01 μg/mL and 0.125 μg/g, respectively. The partial least squares (PLS) regression plot shows a good linear relationship between 0.001 and 100 μg/mL of analyte, with a root mean square error of prediction (RMSEP) of 0.294 and a correlation coefficient (R2) of 0.976 for the thiabendazole standard solution. Meanwhile, the PLS plot also shows a good linear relationship between 0.0 and 2.5 μg/g of analyte, with an RMSEP value of 0.298 and an R2 value of 0.993 for the orange peel extract. In addition to the detection of other types of pesticides in agricultural products, this highly uniform plasmonic substrate has great potential for application in various environmentally-related areas.

  1. Use of HGSYSTEM/UF6 and MACCS2 for the Building 9204-2E safety analysis report consequence analysis: General overview and comparison of models

    International Nuclear Information System (INIS)

    Lombardi, D.A.; Brock, W.R.

    1998-01-01

    Building 9204-2E is used for assembly, disassembly, and storage of weapons components, and quality operations. The building, built in 1971, is a three story structure approximately 101 m long, 51 m wide, and 21 m high located in the western exclusion area of the Y-12 Plant, Oak Ridge, Tennessee. For these activities, several types of hazardous and radioactive materials are used and stored in Building 9204-2E. During a fire, criticality event, or other accident, the potential exists for the release of uranium and other hazardous materials from the building to the atmosphere. A Safety Analysis Report (SAR) is being prepared for Building 9204-2E, in which the consequences of such releases to on-site workers and the off-site public are being analyzed. Consequence estimates from accidental airborne releases are generally calculated using computer models that simulate dispersion and transport of the plume as it travels downwind. For the Building 9204-2E SAR, two candidate atmospheric dispersion candidate models have bene identified for use: (1) the Heavy Gas System-Uranium Hexafluoride (HGSYSTEM/UF 6 ) Model Suite, and (2) the MELCOR Accident Consequence Code System-2 (MACCS2). The purpose of this paper is to provide a general description of the two model suites and compared model results for generic release cases, representative of those that will be analyzed in the Building 9204-2E SAR. Recommendations for use of the model suites in the SAR are also discussed

  2. Correlation study among the International Atomic Energy Agency standards and market standards on management system applicable to a UF{sub 6} conversion plant operation; Estudo da correlacao entre normas da Agencia Internacional de Energia Atomica e de mercado sobre sistema de gestao aplicavel a operacao de planta de conversao de UF{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Dirceu Paulo de

    2008-07-01

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

  3. Viability Assessment Volume 2

    International Nuclear Information System (INIS)

    1998-01-01

    This volume describes the major design features of the Monitored Geologic Repository. This document is not intended to provide an exhaustive, detailed description of the repository design. Rather, this document summarizes the major systems and primary elements of the design that are radiologically significant, and references the specific technical documents and design analyses wherein the details can be found. Not all portions of the design are at the same level of completeness. Highest priority has been given to assigning resources to advance the design of the Monitored Geologic Repository features that are important to radiological safety and/or waste isolation and for which there is no NRC licensing precedent. Those features that are important to radiological safety and/or waste isolation, but for which there is an NRC precedent, receive second priority. Systems and features that have no impact on radiological safety or waste isolation receive the lowest priority. This prioritization process, referred to as binning, is discussed in more detail in Section 2.3. Not every subject discussed in this volume is given equal treatment with regard to the level of detail provided. For example, less detail is provided for the surface facility design than for the subsurface and waste package designs. This different level of detail is intentional. Greater detail is provided for those functions, structures, systems, and components that play key roles with regard to protecting radiological health and safety and that are not common to existing nuclear facilities already licensed by NRC. A number of radiological subjects are not addressed in the VA, (e.g., environmental qualification of equipment). Environmental qualification of equipment and other radiological safety considerations will be addressed in the LA. Non-radiological safety considerations such as silica dust control and other occupational safety considerations are considered equally important but are not addressed in

  4. Velocity Drives Greater Power Observed During Back Squat Using Cluster Sets.

    Science.gov (United States)

    Oliver, Jonathan M; Kreutzer, Andreas; Jenke, Shane C; Phillips, Melody D; Mitchell, Joel B; Jones, Margaret T

    2016-01-01

    This investigation compared the kinetics and kinematics of cluster sets (CLU) and traditional sets (TRD) during back squat in trained (RT) and untrained (UT) men. Twenty-four participants (RT = 12, 25 ± 1 year, 179.1 ± 2.2 cm, 84.6 ± 2.1 kg; UT = 12, 25 ± 1 year, 180.1 ± 1.8 cm, 85.4 ± 3.8 kg) performed TRD (4 × 10, 120-second rest) and CLU (4 × (2 × 5) 30 seconds between clusters; 90 seconds between sets) with 70% one repetition maximum, randomly. Kinematics and kinetics were sampled through force plate and linear position transducers. Resistance-trained produced greater overall force, velocity, and power; however, similar patterns were observed in all variables when comparing conditions. Cluster sets produced significantly greater force in isolated repetitions in sets 1-3, while consistently producing greater force due to a required reduction in load during set 4 resulting in greater total volume load (CLU, 3302.4 ± 102.7 kg; TRD, 3274.8 ± 102.8 kg). Velocity loss was lessened in CLU resulting in significantly higher velocities in sets 2 through 4. Furthermore, higher velocities were produced by CLU during later repetitions of each set. Cluster sets produced greater power output for an increasing number of repetitions in each set (set 1, 5 repetitions; sets 2 and 3, 6 repetitions; set 4, 8 repetitions), and the difference between conditions increased over subsequent sets. Time under tension increased over each set and was greater in TRD. This study demonstrates greater power output is driven by greater velocity when back squatting during CLU; therefore, velocity may be a useful measure by which to assess power.

  5. Technical concept for a greater-confinement-disposal test facility

    International Nuclear Information System (INIS)

    Hunter, P.H.

    1982-01-01

    Greater confinement disposal (GCO) has been defined by the National Low-Level Waste Program as the disposal of low-level waste in such a manner as to provide greater containment of radiation, reduce potential for migration or dispersion or radionuclides, and provide greater protection from inadvertent human and biological intrusions in order to protect the public health and safety. This paper discusses: the need for GCD; definition of GCD; advantages and disadvantages of GCD; relative dose impacts of GCD versus shallow land disposal; types of waste compatible with GCD; objectives of GCD borehole demonstration test; engineering and technical issues; and factors affecting performance of the greater confinement disposal facility

  6. BLANCHIMENT ACCÉLÉRÉ DES ŒUFS NON FÉCONDÉS DE TRUITE ARC-EN-CIEL (ONCORHYNCHUS MYKISS SOUS L’EFFET DE SOLUTIONS SALINES EN VUE DE LEUR TRI MÉCANIQUE

    Directory of Open Access Journals (Sweden)

    MILLA S.

    2007-01-01

    Full Text Available Le blanchiment des œufs non fécondés dans les pontes de salmonidés en incubation artificielle permet leur élimination par tri mécanique. Le déclenchement de ce phénomène normalement plus ou moins tardif durant l’incubation a pu être accéléré grâce à une brève exposition des œufs à une solution de sel de mer. Les modalités et les effets de cette exposition sur les taux de mortalité et de malformations des embryons ont été testés sur des pontes de truite arc-en-ciel à divers stades de développement (140, 190 et 240 degrés*jours. Le passage durant 1 à 20 min dans une solution saline de 30 à 120 g/l a permis d’augmenter significativement le taux de blanchiment des œufs non fécondés sans affecter celui des œufs fécondés. Toutefois, par un effet mécanique, la manipulation nécessaire au traitement a entraîné une augmentation significative de la mortalité embryonnaire pour une manipulation à 140 degrés*jours et du taux de malformations larvaires pour une manipulation à 190 degrés*jours. A 240 degrés*jours, la manipulation n’a pas affecté le développement embryonnaire mais a entraîné un retard de l’éclosion de quelques heures. Cette étude offre de nouvelles perspectives pour améliorer le tri mécanique des œufs fécondés et non fécondés au cours de l’incubation chez la truite arc-en-ciel.

  7. Greater-than-Class C low-level radioactive waste characterization. Appendix E-3: GTCC LLW assumptions matrix

    International Nuclear Information System (INIS)

    1995-01-01

    This study identifies four categories of GTCC LLW: nuclear utility; sealed sources; DOE-held; and other generators. Within each category, inventory and projection data are modeled in three scenarios: (1) Unpackaged volume--this is the unpackaged volume of waste that would exceed Class C limits if the waste calculation methods in 10 CFR 61.55 were applied to the discrete items before concentration averaging methods were applied to the volume; (2) Not-concentration-averaged (NCA) packaged volume--this is the packaged volume of GTCC LLW assuming that no concentration averaging is allowed; and (3) After-concentration-averaging (ACA) packaged volume--this is the packaged volume of GTCC LLW, which, for regulatory or practical reasons, cannot be disposed of in a LLW disposal facility using allowable concentration averaging practices. Three cases are calculated for each of the volumes described above. These values are defined as the low, base, and high cases. The following tables explain the assumptions used to determine low, base, and high case estimates for each scenario, within each generator category. The appendices referred to in these tables are appendices to Greater-Than-Class C Low-Level Radioactive Waste Characterization: Estimated Volumes, Radionuclide Activities, and Other Characteristics (DOE/LLW-114, Revision 1)

  8. Assessing Human Impacts on the Greater Akaki River, Ethiopia ...

    African Journals Online (AJOL)

    We assessed the impacts of human activities on the Greater Akaki River using physicochemical parameters and macroinvertebrate metrics. Physicochemical samples and macroinvertebrates were collected bimonthly from eight sites established on the Greater Akaki River from February 2006 to April 2006. Eleven metrics ...

  9. Comparative Education in Greater China: Contexts, Characteristics, Contrasts and Contributions.

    Science.gov (United States)

    Bray, Mark; Qin, Gui

    2001-01-01

    The evolution of comparative education in Greater China (mainland China, Taiwan, Hong Kong, and Macau) has been influenced by size, culture, political ideologies, standard of living, and colonialism. Similarities and differences in conceptions of comparative education are identified among the four components and between Greater China and other…

  10. Greater temperature sensitivity of plant phenology at colder sites

    DEFF Research Database (Denmark)

    Prevey, Janet; Vellend, Mark; Ruger, Nadja

    2017-01-01

    Warmer temperatures are accelerating the phenology of organisms around the world. Temperature sensitivity of phenology might be greater in colder, higher latitude sites than in warmer regions, in part because small changes in temperature constitute greater relative changes in thermal balance...

  11. Breeding of Greater and Lesser Flamingos at Sua Pan, Botswana ...

    African Journals Online (AJOL)

    to fledging was unknown owing to the rapid drying of the pan in late March 1999. No Greater Flamingo breeding was seen that season. Exceptional flooding during 1999–2000 produced highly favourable breeding conditions, with numbers of Greater and Lesser Flamingos breeding estimated to be 23 869 and 64 287 pairs, ...

  12. Surgical anatomy of greater occipital nerve and its relation to ...

    African Journals Online (AJOL)

    Introduction: The knowledge of the anatomy of greater occipital nerve and its relation to occipital artery is important for the surgeon. Blockage or surgical release of greater occipital nerve is clinically effective in reducing or eliminating chronic migraine symptoms. Aim: The aim of this research was to study the anatomy of ...

  13. Surgical anatomy of greater occipital nerve and its relation to ...

    African Journals Online (AJOL)

    Nancy Mohamed El Sekily

    2014-08-19

    Aug 19, 2014 ... Abstract Introduction: The knowledge of the anatomy of greater occipital nerve and its relation to occipital artery is important for the surgeon. Blockage or surgical release of greater occipital nerve is clinically effective in reducing or eliminating chronic migraine symptoms. Aim: The aim of this research was to ...

  14. INDUSTRIAL LAND DEVELOPMENT AND MANUFACTURING DECONCENTRATION IN GREATER JAKARTA

    NARCIS (Netherlands)

    Hudalah, Delik; Viantari, Dimitra; Firman, Tommy; Woltjer, Johan

    2013-01-01

    Industrial land development has become a key feature of urbanization in Greater Jakarta, one of the largest metropolitan areas in Southeast Asia. Following Suharto's market-oriented policy measures in the late 1980s, private developers have dominated the land development projects in Greater Jakarta.

  15. Strategies for Talent Management: Greater Philadelphia Companies in Action

    Science.gov (United States)

    Council for Adult and Experiential Learning (NJ1), 2008

    2008-01-01

    Human capital is one of the critical issues that impacts the Greater Philadelphia region's ability to grow and prosper. The CEO Council for Growth (CEO Council) is committed to ensuring a steady and talented supply of quality workers for this region. "Strategies for Talent Management: Greater Philadelphia Companies in Action" provides…

  16. Trabecular microstructure and surface changes in the greater tuberosity in rotator cuff tears

    International Nuclear Information System (INIS)

    Jiang, Yebin; Zhao, Jenny; Ouyang, Xiaolong; Genant, Harry K.; Holsbeeck, Marnix T. van; Flynn, Michael J.

    2002-01-01

    Abstract Objective. When planning surgery in patients with rotator cuff tear, strength of bone at the tendon insertion and trabecular bone structure in the greater tuberosity are usually taken into consideration. We investigated radiographic changes in bone structure of the greater tuberosity in rotator cuff tears.Design. Twenty-two human cadaveric shoulders from subjects ranging from 55 to 75 years of age were obtained. The integrity of the rotator cuff was examined by sonography to determine if it is intact without any tear, or torn partially or completely. The humeral head was sectioned in 3 mm thick coronal slab sections and microradiographed. After digitization of the microradiographs and imaging processing with in-house semi-automated image processing software tools developed using software interfaces on a Sun workstation, the trabecular histomorphometrical structural parameters and connectivity in the greater tuberosity were quantified. The degenerative changes on the surface of the greater tuberosity were interpreted blindly by 2 independent readers.Results. Among the 22 shoulder specimens, the rotator cuff was found intact in 10 shoulders, partially in 7 and fully torn in 5. Statistically significant loss in apparent trabecular bone volume fraction, number of trabecular nodes, and number of trabecular branches, and a statistically significant increase in apparent trabecular separation and number of trabecular free ends were found in the greater tuberosity of the shoulders with tears. The loss was greater in association with full tear than in partial tear. Thickening of the cortical margin of the enthesis, irregularity of its surface, and calcification beyond the tidemark were observed in 2 (20%) shoulders with intact rotator cuff, in 6 (86%) shoulders with partial tear, and in 5 (100%) shoulders with full tear.Conclusions. Rotator cuff tears are associated with degenerative changes on the bone surface and with disuse osteopenia of the greater tuberosity

  17. Fractures of the greater trochanter following total hip replacement.

    Science.gov (United States)

    Brun, Ole-Christian L; Maansson, Lukas

    2013-01-01

    We studied the incidence of greater trochanteric fractures at our department following THR. In all we examined 911 patients retrospectively and found the occurance of a greater trochanteric fracture to be 3%. Patients with fractures had significantly poorer outcome on Oxford Hip score, Pain VAS, Satisfaction VAS and EQ-5D compared to THR without fractures. Greater trochanteric fracture following THR is one of the most common complications following THR. It has previously been thought to have little impact on the overall outcome following THR, but our study suggests otherwise.

  18. Washing water treatment process for UF{sub 6} cylinder by adjusting evaporation technology in a low temperature and low pressure

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki-tae; Ju, Young-jong; Cho, Nam-chan [KEPCO Nuclear Fuel Co., Daejeon (Korea, Republic of); Kim, Yun-kwan; Jin, Chang-suk [Jeontech CO., Suwon (Korea, Republic of)

    2016-10-15

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

  19. The UF/NCI family of hybrid computational phantoms representing the current US population of male and female children, adolescents, and adults—application to CT dosimetry

    International Nuclear Information System (INIS)

    Geyer, Amy M; O'Reilly, Shannon; Long, Daniel J; Bolch, Wesley E; Lee, Choonsik

    2014-01-01

    Substantial increases in pediatric and adult obesity in the US have prompted a major revision to the current UF/NCI (University of Florida/National Cancer Institute) family of hybrid computational phantoms to more accurately reflect current trends in larger body morphometry. A decision was made to construct the new library in a gridded fashion by height/weight without further reference to age-dependent weight/height percentiles as these become quickly outdated. At each height/weight combination, circumferential parameters were defined and used for phantom construction. All morphometric data for the new library were taken from the CDC NHANES survey data over the time period 1999–2006, the most recent reported survey period. A subset of the phantom library was then used in a CT organ dose sensitivity study to examine the degree to which body morphometry influences the magnitude of organ doses for patients that are underweight to morbidly obese in body size. Using primary and secondary morphometric parameters, grids containing 100 adult male height/weight bins, 93 adult female height/weight bins, 85 pediatric male height/weight bins and 73 pediatric female height/weight bins were constructed. These grids served as the blueprints for construction of a comprehensive library of patient-dependent phantoms containing 351 computational phantoms. At a given phantom standing height, normalized CT organ doses were shown to linearly decrease with increasing phantom BMI for pediatric males, while curvilinear decreases in organ dose were shown with increasing phantom BMI for adult females. These results suggest that one very useful application of the phantom library would be the construction of a pre-computed dose library for CT imaging as needed for patient dose-tracking. (paper)

  20. 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

  1. A new concept and a comprehensive evaluation of SYSMEX UF-1000i  flow cytometer to identify culture-negative urine specimens in patients with UTI.

    Science.gov (United States)

    Monsen, T; Ryden, P

    2017-09-01

    Urinary tract infections (UTIs) are among the most common bacterial infections in men and urine culture is gold standard for diagnosis. Considering the high prevalence of culture-negative specimens, any method that identifies such specimens is of interest. The aim was to evaluate a new screening concept for flow cytometry analysis (FCA). The outcomes were evaluated against urine culture, uropathogen species and three conventional screening methods. A prospective, consecutive study examined 1,312 urine specimens, collected during January and February 2012. The specimens were analyzed using the Sysmex UF1000i FCA. Based on the FCA data culture negative specimens were identified in a new model by use of linear discriminant analysis (FCA-LDA). In total 1,312 patients were included. In- and outpatients represented 19.6% and 79.4%, respectively; 68.3% of the specimens originated from women. Of the 610 culture-positive specimens, Escherichia coli represented 64%, enterococci 8% and Klebsiella spp. 7%. Screening with FCA-LDA at 95% sensitivity identified 42% (552/1312) as culture negative specimens when UTI was defined according to European guidelines. The proposed screening method was either superior or similar in comparison to the three conventional screening methods. In conclusion, the proposed/suggested and new FCA-LDA screening method was superior or similar to three conventional screening methods. We recommend the proposed screening method to be used in clinic to exclude culture negative specimens, to reduce workload, costs and the turnaround time. In addition, the FCA data may add information that enhance handling and support diagnosis of patients with suspected UTI pending urine culture [corrected].

  2. Prey selection by a reintroduced lion population in the Greater ...

    African Journals Online (AJOL)

    Prey selection by a reintroduced lion population in the Greater Makalali Conservancy, South Africa. Dave Druce, Heleen Genis, Jonathan Braak, Sophie Greatwood, Audrey Delsink, Ross Kettles, Luke Hunter, Rob Slotow ...

  3. LiveDiverse: Case study area, Greater Kruger South Africa

    CSIR Research Space (South Africa)

    Nortje, Karen

    2011-01-01

    Full Text Available Livelihoods and Biodiversity in Developing Countries Case study area: Greater Kruger, South Africa January 2011 Kolhapur, India Where are we? HARDSHIP LIVELIHOODS NATURE & BIODIVERSITY BELIEFS & CULTURAL PRACTISE threesansinv foursansinv onesansinv...

  4. Exploration of the Energy Efficiency of the Greater London Authority ...

    African Journals Online (AJOL)

    GLA Building/City Hall) ... Journal Home > Vol 11, No 2 (2007) > ... The Greater London Authority building was acclaimed as being energy efficient, with claims of 75 % reduction in its annual energy consumption compared to a high specification ...

  5. Molecular insights into the biology of Greater Sage-Grouse

    Science.gov (United States)

    Oyler-McCance, Sara J.; Quinn, Thomas W.

    2011-01-01

    Recent research on Greater Sage-Grouse (Centrocercus urophasianus) genetics has revealed some important findings. First, multiple paternity in broods is more prevalent than previously thought, and leks do not comprise kin groups. Second, the Greater Sage-Grouse is genetically distinct from the congeneric Gunnison sage-grouse (C. minimus). Third, the Lyon-Mono population in the Mono Basin, spanning the border between Nevada and California, has unique genetic characteristics. Fourth, the previous delineation of western (C. u. phaios) and eastern Greater Sage-Grouse (C. u. urophasianus) is not supported genetically. Fifth, two isolated populations in Washington show indications that genetic diversity has been lost due to population declines and isolation. This chapter examines the use of molecular genetics to understand the biology of Greater Sage-Grouse for the conservation and management of this species and put it into the context of avian ecology based on selected molecular studies.

  6. The relationship between age, rotator cuff integrity, and osseous microarchitecture of greater tuberosity: Where should we put anchor?

    Science.gov (United States)

    Kholinne, Erica; Lee, Hyun Joo; Kim, Sung Jung; Park, So Hyun; Jeon, In-Ho

    2018-01-01

    The aim of this study was to compare the microarchitecture of the greater tuberosity with or without rotator cuff tear and to obtain optimum location for anchor screw insertion for rotator cuff repair. Twenty-five humeral heads were harvested from 13 male cadavers of mean age 58.4 years, including 6 humeri with rotator cuff tear and 19 intact humeri. Six regions of interest (proximal, intermediate, and distal zones of the superficial and deep regions) were divided into the anterior (G1), middle (G2), and posterior (G3) areas of the greater tuberosity. Trabecular bone volume and cortical thickness were evaluated. Total trabecular bone volume was greater in subjects 50 years old but did not differ significantly in subjects with and without rotator cuff tear. Cortical thickness in both intact and torn rotator cuff groups was significantly greater in the proximal and intermediate zones than in the distal zone. Cortical thickness was related to anatomic location rather than age or cuff tear. The optimal location for anchor screw insertion during rotator cuff repair is either the proximal or intermediate region of the greater tuberosity. Age has more influence in terms of trabecular bone volume loss than rotator cuff integrity. Copyright © 2017. Production and hosting by Elsevier B.V.

  7. Greater saphenous vein anomaly and aneurysm with subsequent pulmonary embolism

    OpenAIRE

    Ma, Truong; Kornbau, Craig

    2017-01-01

    Abstract Venous aneurysms often present as painful masses. They can present either in the deep or superficial venous system. Deep venous system aneurysms have a greater risk of thromboembolism. Though rare, there have been case reports of superficial aneurysms and thrombus causing significant morbidity such as pulmonary embolism. We present a case of an anomalous greater saphenous vein connection with an aneurysm and thrombus resulting in a pulmonary embolism. This is the only reported case o...

  8. GREATER OMENTUM: MORPHOFUNCTIONAL CHARACTERISTICS AND CLINICAL SIGNIFICANCE IN PEDIATRICS

    Directory of Open Access Journals (Sweden)

    A.V. Nekrutov

    2007-01-01

    Full Text Available The review analyzes the structure organization and pathophysiological age specificities of the greater omentum, which determine its uniqueness and functional diversity in a child's organism. the article discusses protective functions of the organ, its role in the development of post operative complications of children, and the usage in children's reconstructive plastic surgery.Key words: greater omentum, omentitis, of post operative complications, children.

  9. Alternatives for packaging and transport of greater-than-class C low-level waste

    International Nuclear Information System (INIS)

    Smith, R.I.

    1990-06-01

    Viable methods for packaging greater-than-class C (GTCC) low-level wastes and for transporting those wastes from the waste generator sites or from an eastern interim storage site to the Yucca Mountain repository site have been identified and evaluated. Estimated costs for packaging and transporting the population of GTCC wastes expected to be accumulated through the year 2040 have been developed for three waste volume scenarios, for two preferred packaging methods for activated metals from reactor operations and from reactor decommissioning, and for two packaging density assumptions for the activated metals from reactor decommissioning. 7 refs. 7 tabs

  10. Socio-economic considerations of cleaning Greater Vancouver's air

    International Nuclear Information System (INIS)

    2005-08-01

    Socio-economic considerations of better air quality on the Greater Vancouver population and economy were discussed. The purpose of the study was to provide socio-economic information to staff and stakeholders of the Greater Vancouver Regional District (GVRD) who are participating in an Air Quality Management Plan (AQMP) development process and the Sustainable Region Initiative (SRI) process. The study incorporated the following methodologies: identification and review of Canadian, American, and European quantitative socio-economic, cost-benefit, cost effectiveness, competitiveness and health analyses of changes in air quality and measures to improve air quality; interviews with industry representatives in Greater Vancouver on competitiveness impacts of air quality changes and ways to improve air quality; and a qualitative analysis and discussion of secondary quantitative information that identifies and evaluates socio-economic impacts arising from changes in Greater Vancouver air quality. The study concluded that for the Greater Vancouver area, the qualitative analysis of an improvement in Greater Vancouver air quality shows positive socio-economic outcomes, as high positive economic efficiency impacts are expected along with good social quality of life impacts. 149 refs., 30 tabs., 6 appendices

  11. Radiocardiographic determination of the stroke volume and of the heart minute volume in athletes

    Energy Technology Data Exchange (ETDEWEB)

    Sattler, R; Stoll, W [Friedrich-Schiller-Universitaet, Jena (German Democratic Republic). Radiologische Klinik

    1981-11-01

    Radiocardiography, a novel radioisotope method for the problemless determination of many cardiodynamic parameters which can be applied also at given physical exercise is presented. On the basis of stroke volume and heart minute volume values from 35 athletes practising different sports and of a comparison with normal values reported in the literature, differences in the cardiac adaptation and the function of athletic hearts and so-called normal hearts are pointed out. The stroke volume of endurance-trained athletes exceeds that of untrained individuals by 30-40 ml. Under exercise the increase of the stroke volume is considerably greater in endurance athletes than in individuals practising other sports or in untrained subjects. At rest the values of the heart minute volume are almost the same in athletes and untrained individuals. Under exercise the heart minute volume of endurance athletes (40 l/min) is nearly twice that of untrained individuals (volume reserve of the athlete).

  12. Radiocardiographic determination of the stroke volume and of the heart minute volume in athletes

    International Nuclear Information System (INIS)

    Sattler, R.; Stoll, W.

    1981-01-01

    Radiocardiography, a novel radioisotope method for the problemless determination of many cardiodynamic parameters which can be applied also at given physical exercise is presented. On the basis of stroke volume and heart minute volume values from 35 athletes practising different sports and of a comparison with normal values reported in the literature, differences in the cardiac adaptation and the function of athletic hearts and so-called normal hearts are pointed out. The stroke volume of endurance-trained athetes exceed that of untrained individuals by 30-40 ml. Under exercise the increase of the stroke volume is considerably greater in endurance athletes than in individuals practising other sports or in untrained subjects. At rest the values of the heart minute volume are almost the same in athletes and untrained individuals. Under exercise the heart minute volume of endurance athletes (40 l/min) is nearly twice that of untrained individuals (volume reserve of the athlete). (author)

  13. Improving greater trochanteric reattachment with a novel cable plate system.

    Science.gov (United States)

    Baril, Yannick; Bourgeois, Yan; Brailovski, Vladimir; Duke, Kajsa; Laflamme, G Yves; Petit, Yvan

    2013-03-01

    Cable-grip systems are commonly used for greater trochanteric reattachment because they have provided the best fixation performance to date, even though they have a rather high complication rate. A novel reattachment system is proposed with the aim of improving fixation stability. It consists of a Y-shaped fixation plate combined with locking screws and superelastic cables to reduce cable loosening and limit greater trochanter movement. The novel system is compared with a commercially available reattachment system in terms of greater trochanter movement and cable tensions under different greater trochanteric abductor application angles. A factorial design of experiments was used including four independent variables: plate system, cable type, abductor application angle, and femur model. The test procedure included 50 cycles of simultaneous application of an abductor force on the greater trochanter and a hip force on the femoral head. The novel plate reduces the movements of a greater trochanter fragment within a single loading cycle up to 26%. Permanent degradation of the fixation (accumulated movement based on 50-cycle testing) is reduced up to 46%. The use of superelastic cables reduces tension loosening up to 24%. However this last improvement did not result in a significant reduction of the grater trochanter movement. The novel plate and cables present advantages over the commercially available greater trochanter reattachment system. The plate reduces movements generated by the hip abductor. The superelastic cables reduce cable loosening during cycling. Both of these positive effects could decrease the risks related to grater trochanter non-union. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.

  14. Technical concept for a Greater Confinement Disposal test facility

    International Nuclear Information System (INIS)

    Hunter, P.H.

    1982-01-01

    For the past two years, Ford, Bacon and Davis has been performing technical services for the Department of Energy at the Nevada Test Site in specific development of defense low-level waste management concepts for greater confinement disposal concept with particular application to arid sites. The investigations have included the development of Criteria for Greater Confinement Disposal, NVO-234, which was published in May of 1981 and the draft of the technical concept for Greater Confinement Disposal, with the latest draft published in November 1981. The final draft of the technical concept and design specifications are expected to be published imminently. The document is prerequisite to the actual construction and implementation of the demonstration facility this fiscal year. The GCD Criteria Document, NVO-234 is considered to contain information complimentary and compatible with that being developed for the reserved section 10 CFR 61.51b of the NRCs proposed licensing rule for low level waste disposal facilities

  15. Expatriate job performance in Greater China: Does age matter?

    DEFF Research Database (Denmark)

    Selmer, Jan; Lauring, Jakob; Feng, Yunxia

    to expatriates in Chinese societies. It is possible that older business expatriates will receive more respect and be treated with more deference in a Chinese cultural context than their apparently younger colleagues. This may have a positive impact on expatriates’ job performance. To empirically test...... this presumption, business expatriates in Greater Chine were targeted by a survey. Controlling for the potential bias of a number of background variables, results indicate that contextual/managerial performance, including general managerial functions applied to the subsidiary in Greater China, had a positive...

  16. Absenteeism movement in Greater Poland in 1840–1902

    OpenAIRE

    Izabela Krasińska

    2013-01-01

    The article presents the origins and development of the idea of absenteeism in Greater Poland in the 19th century. The start date for the research is 1840, which is considered to be a breakthrough year in the history of an organized absenteeism movement in Greater Poland. It was due to the Association for the Suppression of the Use of Vodka (Towarzystwo ku Przytłumieniu Używania Wódki) in the Great Duchy of Posen that was then established in Kórnik. It was a secular organization that came int...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-12-01

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

  18. The UF GEM Research Center Mobile Terrestrial Laser Scanner System M-TLSS Applied to Beach Morphology Studies in St. Augustine, Florida.

    Science.gov (United States)

    Fernandez, J. C.; Shrestha, R. L.; Carter, W. E.; Slatton, C. K.; Singhania, A.

    2006-12-01

    The UF GEM Research Center is working towards developing a Mobile Terrestrial Laser Scanning System (M- TLSS). The core of the M-TLSS is a commercial 2-axis ground based laser scanner, Optech ILRIS-36D, which is capable of generating XYZ with laser intensity or RGB textured point clouds in a range from 3m to 1500m. The laser operates at a wavelength of 1535 nm. The sample separation can be adjusted down to 0.00115°, and the scanning speed is 2,000 points per second. The scanner is integrated to a mobile telescoping, rotating and tilting platform which is essentially a telescopic lift mounted on the back of a pick up truck. This provides up to 6 degrees of freedom for performing scanning operations. A scanner built-in 6 megapixel digital camera and a digital video camera provide the M-TLSS moving and still imagining capability. The applications of the M-TLSS data sets are numerous in both the fields of science and engineering. This paper will focus on the application of M-TLSS as a complement to ALSM in the study of beach morphology in the St. Augustine, Florida area. ALSM data covers a long stretch of beach with a moderate sample density of approximately 1 laser return per square meter, which enables the detection of submeter-scale changes in shoreline position and dune heights over periods of few months. The M-TLSS, on the other hand, can provide high density point clouds (centimeter scale point spacing) of smaller areas known to be highly prone to erosion. From these point clouds centimeter level surface grids are created. These grids will be compared with the ALSM data and with a time series of M-TLSS data over the same area to provide high resolution, short term beach erosion monitoring. Surface morphological parameters that will be compared among the ALSM and M-TLSS data sets include shoreline position and gradients and standard deviations of elevations on cross- shore transects.

  19. Adjustment of Business Expatriates in Greater China: A Strategic Perspective

    DEFF Research Database (Denmark)

    Selmer, Jan

    2006-01-01

    Research has found that due to similarities, firms which have gained business experience elsewhere in Greater China may exhibit relatively better performance in mainland China. Hence, the experience of business expatriates could be of strategic importance for the expansion path of their firms...

  20. College Students with ADHD at Greater Risk for Sleep Disorders

    Science.gov (United States)

    Gaultney, Jane F.

    2014-01-01

    The pediatric literature indicates that children with ADHD are at greater risk for sleep problems, daytime sleepiness, and some sleep disorders than children with no diagnosed disability. It has not been determined whether this pattern holds true among emerging adults, and whether comorbid sleep disorders with ADHD predict GPA. The present study…

  1. Ecology of greater sage-grouse in the Dakotas

    Science.gov (United States)

    Christopher C. Swanson

    2009-01-01

    Greater sage-grouse (Centrocercus urophasianus) populations and the sagebrush (Artemisia spp.) communities that they rely on have dramatically declined from historic levels. Moreover, information regarding sage-grouse annual life-history requirements at the eastern-most extension of sagebrush steppe communities is lacking....

  2. The Easterlin Illusion: Economic growth does go with greater happiness

    NARCIS (Netherlands)

    R. Veenhoven (Ruut); F. Vergunst (Floris)

    2014-01-01

    markdownabstract__Abstract__ The 'Easterlin Paradox' holds that economic growth in nations does not buy greater happiness for the average citizen. This thesis was advanced in the 1970s on the basis of the then available data on happiness in nations. Later data have disproved most of the empirical

  3. Job-Sharing at the Greater Victoria Public Library.

    Science.gov (United States)

    Miller, Don

    1978-01-01

    Describes the problems associated with the management of part-time library employees and some solutions afforded by a job sharing arrangement in use at the Greater Victoria Public Library. This is a voluntary work arrangement, changing formerly full-time positions into multiple part-time positions. (JVP)

  4. Radiographic features of tuberculous osteitis in greater trochanter and lschium

    International Nuclear Information System (INIS)

    Hahm, So Hee; Lee, Ye Ri; Kim, Dong Jin; Sung, Ki Jun; Lim, Jong Nam

    1996-01-01

    To evaluate, if possible, the radiographic features of tuberculous osteitis in the greater trochanter and ischium, and to determine the cause of the lesions. We reterospectively reviewed the plain radiographic findings of 14 ptients with histologically proven tuberculous osteitis involving the greater trochanter and ischium. In each case, the following were analyzed:morphology of bone destruction, including cortical erosion;periosteal reaction;presence or abscence of calcific shadows in adjacent soft tissue. On the basis of an analysis of radiographic features and correlation of the anatomy with adjacent structures we attempted to determine causes. Of the 14 cases evaluated, 12 showed varrious degrees of extrinsic erosion on the outer cortical bone of the greater trochanter and ischium ; in two cases, bone destruction was so severe that the radiographic features of advanced perforated osteomyelitis were simulated. In addition to findings of bone destruction, in these twelve cases, the presence of sequestrum or calcific shadows was seen in adjacent soft tissue. Tuberculous osteitis in the greater trochanter and ischium showed the characteristic findings of chronic extrinsic erosion. On the basis of these findings we can suggest that these lesions result from an extrinsic pathophysiologic cause such as adjacent bursitis

  5. Radiographic features of tuberculous osteitis in greater trochanter and lschium

    Energy Technology Data Exchange (ETDEWEB)

    Hahm, So Hee; Lee, Ye Ri [Hanil Hospital Affiliated to KEPCO, Seoul (Korea, Republic of); Kim, Dong Jin; Sung, Ki Jun [Yonsei Univ. Wonju College of Medicine, Wonju (Korea, Republic of); Lim, Jong Nam [Konkuk Univ. College of Medicine, Seoul (Korea, Republic of)

    1996-11-01

    To evaluate, if possible, the radiographic features of tuberculous osteitis in the greater trochanter and ischium, and to determine the cause of the lesions. We reterospectively reviewed the plain radiographic findings of 14 ptients with histologically proven tuberculous osteitis involving the greater trochanter and ischium. In each case, the following were analyzed:morphology of bone destruction, including cortical erosion;periosteal reaction;presence or abscence of calcific shadows in adjacent soft tissue. On the basis of an analysis of radiographic features and correlation of the anatomy with adjacent structures we attempted to determine causes. Of the 14 cases evaluated, 12 showed varrious degrees of extrinsic erosion on the outer cortical bone of the greater trochanter and ischium ; in two cases, bone destruction was so severe that the radiographic features of advanced perforated osteomyelitis were simulated. In addition to findings of bone destruction, in these twelve cases, the presence of sequestrum or calcific shadows was seen in adjacent soft tissue. Tuberculous osteitis in the greater trochanter and ischium showed the characteristic findings of chronic extrinsic erosion. On the basis of these findings we can suggest that these lesions result from an extrinsic pathophysiologic cause such as adjacent bursitis.

  6. Greater Confinement Disposal trench and borehole operations status

    International Nuclear Information System (INIS)

    Harley, J.P. Jr.; Wilhite, E.L.; Jaegge, W.J.

    1987-01-01

    Greater Confinement Disposal (GCD) facilities have been constructed within the operating burial ground at the Savannah River Plant (SRP) to dispose of the higher activity fraction of SRP low-level waste. GCD practices of waste segregation, packaging, emplacement below the root zone, and waste stabilization are being used in the demonstration. 2 refs., 2 figs., 2 tabs

  7. The Mesozoic-Cenozoic tectonic evolution of the Greater Caucasus

    NARCIS (Netherlands)

    Saintot, A.N.; Brunet, M.F.; Yakovlev, F.; Sébrier, M.; Stephenson, R.A.; Ershov, A.V.; Chalot-Prat, F.; McCann, T.

    2006-01-01

    The Greater Caucasus (GC) fold-and-thrust belt lies on the southern deformed edge of the Scythian Platform (SP) and results from the Cenoozoic structural inversion of a deep marine Mesozoic basin in response to the northward displacement of the Transcaucasus (lying south of the GC subsequent to the

  8. Introduction. China and the Challenges in Greater Middle East

    DEFF Research Database (Denmark)

    Sørensen, Camilla T. N.; Andersen, Lars Erslev; Jiang, Yang

    2016-01-01

    This collection of short papers is an outcome of an international conference entitled China and the Challenges in Greater Middle East, organized by the Danish Institute for International Studies and Copenhagen University on 10 November 2015. The conference sought answers to the following questions...

  9. On the Occurrence of Standardized Regression Coefficients Greater than One.

    Science.gov (United States)

    Deegan, John, Jr.

    1978-01-01

    It is demonstrated here that standardized regression coefficients greater than one can legitimately occur. Furthermore, the relationship between the occurrence of such coefficients and the extent of multicollinearity present among the set of predictor variables in an equation is examined. Comments on the interpretation of these coefficients are…

  10. The Educational Afterlife of Greater Britain, 1903-1914

    Science.gov (United States)

    Gardner, Philip

    2012-01-01

    Following its late nineteenth-century emergence as an important element within federalist thinking across the British Empire, the idea of Greater Britain lost much of its political force in the years following the Boer War. The concept however continued to retain considerable residual currency in other fields of Imperial debate, including those…

  11. Dynamic Study of Soil Erosion in Greater Khingan Forest

    OpenAIRE

    Wei Li; Wenyi Fan; Xuegang Mao; Xiaojie Wang

    2015-01-01

    Based on the amended model of RUSLE universal soil loss equation and GIS technology, combined with the natural geographical features of Great Khingan, it has conducted quantitative analysis of the factor in Soil loss equation. Uses 2000 and 2010 years TM images classification are land uses/cover type figure, we gets all factors values of space distribution in the RUSLE model, gets soil erosion volume estimates data and soil erosion strength distribution figure based on grid cell data and obta...

  12. Depleted UF6 Internet Resources

    Science.gov (United States)

    government agencies, international organizations, trade associations, private entities and information ) Honeywell General Atomics International Organizations International Atomic Energy Agency (IAEA) Nuclear , Recommendation 95-1 Administrative Governmental Organizations Department of Defense Department of Transportation

  13. Nuclear carrier business volume projections, 1980-2000

    International Nuclear Information System (INIS)

    Lebo, R.G.; McKeown, M.S.; Rhyne, W.R.

    1980-05-01

    The expected number of shipments of commodities in the nuclear fuel cycle are projected for the years 1980 thru 2000. Projections are made for: yellowcake (U 3 O 8 ); natural, enriched and reprocessed uranium hexafluoride (UF 6 ); uranium dioxide powder (UO 2 ); plutonium dioxide powder (PuO 2 ); fresh UO 2 and mixed oxide (MOX) fuel; spent UO 2 fuel; low-level waste (LLW); transuranic (TRU) waste; high-activity TRU waste; high-level waste (HLW), and cladding hulls. Projections are also made for non-fuel cycle commodities such as defense TRU wastes and institutional wastes, since they also are shipped by the commercial transportation industry. Projections of waste shipments from LWRs are based on the continuation of current volume reduction and solidification techniques now used by the utility industry. Projections are also made based on a 5% per year reduction in LWR waste volume shipped which is assumed to occur as a result of increased implementation of currently available volume reduction systems. This assumption results in a net 64% decrease in the total waste shipped by the year 2000. LWR waste shipment projections, and essentially all other projections for fuel cycle commodities covered in this report, are normalized to BWR and PWR generating capacity projections set forth by the Department of Energy (DOE) in their low-growth projection of April, 1979. Therefore these commodity shipment projections may be altered to comply with future changes in generating capacity projections. Projected shipments of waste from the reprocessing of spent UO 2 fuel are based on waste generation rates proposed by Nuclear Fuels Services, Allied-General Nuclear Services, Exxon Nuclear, and the DOE. Reprocessing is assumed to begin again in 1990, with mixed oxide fresh fuel available for shipment by 1991

  14. Review of Department of Defense Education Activity (DODEA) Schools. Volume II: Quantitative Analysis of Educational Quality

    National Research Council Canada - National Science Library

    Anderson, Lowell

    2000-01-01

    This volume compiles, and presents in integrated form, IDA's quantitative analysis of educational quality provided by DoD's dependent schools, It covers the quantitative aspects of volume I in greater...

  15. Defining greater-than-class-C low-level radioactive waste

    International Nuclear Information System (INIS)

    Knecht, M.A.; Oztunali, O.I.

    1986-01-01

    The Low-Level Radioactive Waste Policy Amendments Act of 1985 (LLRWPAA) was signed by President Reagan on January 15, 1986. This act requires the federal government to be responsible for the disposal of greater-than-class-C low-level radioactive waste (LLRW) that is generated commercially by state agencies and by federal entities (other than waste generated by atomic weapons research, development, or testing, or by decommissioning of vessels of the nuclear navy). To plan for disposal, the federal government will require estimates of the volume of waste involved and characterization of this waste. A clear definition of greater-than-class-C LLRW is the first step in determining what wastes will be included in the waste to be received by the federal government. This definition will influence major policy decisions to be made for management of such waste. The purpose of this paper is to examine the existing information on greater-than-class-C LLRW in view of the current definition of such waste and potential changes in this definition - for example, an upper limit on the concentrations of radionuclides in LLRW. The paper identifies further information needs to develop a clear definition of such waste for use in federal planning for acceptance of responsibility for disposal of such waste

  16. Higher motivation - greater control? The effect of arousal on judgement.

    Science.gov (United States)

    Riemer, Hila; Viswanathan, Madhu

    2013-01-01

    This research examines control over the effect of arousal, a dimension of affect, on judgement. Past research shows that high processing motivation enhances control over the effects of affect on judgement. Isolating and studying arousal as opposed to valence, the other dimension of affect, and its effect on judgement, we identify boundary conditions for past findings. Drawing from the literature on processes by which arousal influences judgement, we demonstrate that the role of motivation is contingent upon the type of judgement task (i.e., memory- versus stimulus-based judgement). In stimulus-based judgement, individuals exert greater control over the effect of arousal on judgement under low compared to high motivation. In contrast, in memory-based judgement individuals exert greater control over the effect of arousal under high compared to low motivation. Theoretical implications and avenues for future research are discussed.

  17. Patient expectations predict greater pain relief with joint arthroplasty.

    Science.gov (United States)

    Gandhi, Rajiv; Davey, John Roderick; Mahomed, Nizar

    2009-08-01

    We examined the relationship between patient expectations of total joint arthroplasty and functional outcomes. We surveyed 1799 patients undergoing primary hip or knee arthroplasty for demographic data and Western Ontario McMaster University Osteoarthritis Index scores at baseline, 3 months, and 1 year of follow-up. Patient expectations were determined with 3 survey questions. The patients with the greatest expectations of surgery were younger, male, and had a lower body mass index. Linear regression modeling showed that a greater expectation of pain relief with surgery independently predicted greater reported pain relief at 1 year of follow-up, adjusted for all relevant covariates (P relief after joint arthroplasty is an important predictor of outcomes at 1 year.

  18. Torsion of the greater omentum: A rare preoperative diagnosis

    International Nuclear Information System (INIS)

    Tandon, Ankit Anil; Lim, Kian Soon

    2010-01-01

    Torsion of the greater omentum is a rare acute abdominal condition that is seldom diagnosed preoperatively. We report the characteristic computed tomography (CT) scan findings and the clinical implications of this unusual diagnosis in a 41-year-old man, who also had longstanding right inguinal hernia. Awareness of omental torsion as a differential diagnosis in the acute abdomen setting is necessary for correct patient management

  19. Ecological specialization and morphological diversification in Greater Antillean boas.

    Science.gov (United States)

    Reynolds, R Graham; Collar, David C; Pasachnik, Stesha A; Niemiller, Matthew L; Puente-Rolón, Alberto R; Revell, Liam J

    2016-08-01

    Colonization of islands can dramatically influence the evolutionary trajectories of organisms, with both deterministic and stochastic processes driving adaptation and diversification. Some island colonists evolve extremely large or small body sizes, presumably in response to unique ecological circumstances present on islands. One example of this phenomenon, the Greater Antillean boas, includes both small (<90 cm) and large (4 m) species occurring on the Greater Antilles and Bahamas, with some islands supporting pairs or trios of body-size divergent species. These boas have been shown to comprise a monophyletic radiation arising from a Miocene dispersal event to the Greater Antilles, though it is not known whether co-occurrence of small and large species is a result of dispersal or in situ evolution. Here, we provide the first comprehensive species phylogeny for this clade combined with morphometric and ecological data to show that small body size evolved repeatedly on separate islands in association with specialization in substrate use. Our results further suggest that microhabitat specialization is linked to increased rates of head shape diversification among specialists. Our findings show that ecological specialization following island colonization promotes morphological diversity through deterministic body size evolution and cranial morphological diversification that is contingent on island- and species-specific factors. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  20. Moderate Baseline Vagal Tone Predicts Greater Prosociality in Children

    Science.gov (United States)

    Miller, Jonas G.; Kahle, Sarah; Hastings, Paul D.

    2016-01-01

    Vagal tone is widely believed to be an important physiological aspect of emotion regulation and associated positive behaviors. However, there is inconsistent evidence for relations between children’s baseline vagal tone and their helpful or prosocial responses to others (Hastings & Miller, 2014). Recent work in adults suggests a quadratic association (inverted U-shape curve) between baseline vagal tone and prosociality (Kogan et al., 2014). The present research examined whether this nonlinear association was evident in children. We found consistent evidence for a quadratic relation between vagal tone and prosociality across 3 samples of children using 6 different measures. Compared to low and high vagal tone, moderate vagal tone in early childhood concurrently predicted greater self-reported prosociality (Study 1), observed empathic concern in response to the distress of others and greater generosity toward less fortunate peers (Study 2), and longitudinally predicted greater self-, mother-, and teacher-reported prosociality 5.5 years later in middle childhood (Study 3). Taken together, our findings suggest that moderate vagal tone at rest represents a physiological preparedness or tendency to engage in different forms of prosociality across different contexts. Early moderate vagal tone may reflect an optimal balance of regulation and arousal that helps prepare children to sympathize, comfort, and share with others. PMID:27819463

  1. Absenteeism movement in Greater Poland in 1840–1902

    Directory of Open Access Journals (Sweden)

    Izabela Krasińska

    2013-12-01

    Full Text Available The article presents the origins and development of the idea of absenteeism in Greater Poland in the 19th century. The start date for the research is 1840, which is considered to be a breakthrough year in the history of an organized absenteeism movement in Greater Poland. It was due to the Association for the Suppression of the Use of Vodka (Towarzystwo ku Przytłumieniu Używania Wódki in the Great Duchy of Posen that was then established in Kórnik. It was a secular organization that came into being on an initiative of doctor De La Roch, who was a German surgeon of a French origin. However, as early as 1844, the idea of absenteeism raised an interest of catholic clergymen of Greater Poland with high ranking clergy such as Rev. Leon Michał Przyłuski, Archbishop of Gniezno and Rev. Jan Kanty Dąbrowski, Archbishop of Posen, and later on Archbishops Rev. Mieczysław Halka Ledóchowski and Rev. Florian Oksza Stablewski. They were fascinated with activities of Rev. Jan Nepomucen Fick, Parish Priest of Piekary Śląskie and several other priests on whose initiative a lot of church brotherhoods of so called holy continence were set up in Upper Silesia as early as the first half-year of 1844. It was due to Bishop Dąbrowski that 100 000 people took vows of absenteeism in 1844–1845, becoming members of brotherhoods of absenteeism. In turn, it was an initiative of Archbishop Przyłuski that Jesuit missionaries – Rev. Karol Bołoz Antoniewicz, Rev. Teofil Baczyński and Rev. Kamil Praszałowicz, arrived in Greater Poland from Galicia in 1852 to promote the idea of absenteeism. Starting from 1848, they were helping Silesian clergymen to spread absenteeism. Clergymen of Greater Poland were also active in secular absenteeism associations. They became involved in the workings of the Association for the Promotion of Absenteeism that was set up by Zygmunt Celichowski in Kórnik in 1887, and especially in the Jutrzenka Absenteeism Association

  2. Humidification and secretion volume in mechanically ventilated patients.

    Science.gov (United States)

    Solomita, Mario; Palmer, Lucy B; Daroowalla, Feroza; Liu, Jeffrey; Miller, Dori; LeBlanc, Deniese S; Smaldone, Gerald C

    2009-10-01

    To determine potential effects of humidification on the volume of airway secretions in mechanically ventilated patients. Water vapor delivery from devices providing non-heated-wire humidification, heated-wire humidification, and heat and moisture exchanger (HME) were quantified on the bench. Then, patients requiring 24-hour mechanical ventilation were exposed sequentially to each of these humidification devices, and secretions were removed and measured by suctioning every hour during the last 4 hours of the 24-hour study period. In vitro water vapor delivery was greater using non-heated-wire humidification, compared to heated-wire humidification and HME. In vivo, a total of 9 patients were studied. Secretion volume following humidification by non-heated-wire humidification was significantly greater than for heated-wire humidification and HME (P=.004). The volume of secretions appeared to be linked to humidification, as greater water vapor delivery measured in vitro was associated with greater secretion volume in vivo.

  3. The post-orgasmic prolactin increase following intercourse is greater than following masturbation and suggests greater satiety.

    Science.gov (United States)

    Brody, Stuart; Krüger, Tillmann H C

    2006-03-01

    Research indicates that prolactin increases following orgasm are involved in a feedback loop that serves to decrease arousal through inhibitory central dopaminergic and probably peripheral processes. The magnitude of post-orgasmic prolactin increase is thus a neurohormonal index of sexual satiety. Using data from three studies of men and women engaging in masturbation or penile-vaginal intercourse to orgasm in the laboratory, we report that for both sexes (adjusted for prolactin changes in a non-sexual control condition), the magnitude of prolactin increase following intercourse is 400% greater than that following masturbation. The results are interpreted as an indication of intercourse being more physiologically satisfying than masturbation, and discussed in light of prior research reporting greater physiological and psychological benefits associated with coitus than with any other sexual activities.

  4. Warsaw Pact: The Question of Cohesion. Phase II, Volume 1. The Greater Socialist Army: Integration and Reliability,

    Science.gov (United States)

    1984-02-01

    235 CHAPTER 9 - Military Political Socialization : Themes and Effectiveness .................................... 268 CHAPTER 10 - Factors...by comprehensive political socialization efforts,6 the last two also coordinated by Moscow. An in-depth analysis of the national attitudes of all... Political Socialization ...," below. See Chapter 5, "Historical Precedents...," below. 8 See, for example, S.I. Bruk and M.I. Kabuzan, "Dinamika chislennosti

  5. Sexual predators, energy development, and conservation in greater Yellowstone.

    Science.gov (United States)

    Berger, Joel; Beckmann, Jon P

    2010-06-01

    In the United States, as elsewhere, a growing debate pits national energy policy and homeland security against biological conservation. In rural communities the extraction of fossil fuels is often encouraged because of the employment opportunities it offers, although the concomitant itinerant workforce is often associated with increased wildlife poaching. We explored possible positive and negative factors associated with energy extraction in the Greater Yellowstone Ecosystem (GYE), an area known for its national parks, intact biological diversity, and some of the New World's longest terrestrial migrations. Specifically, we asked whether counties with different economies-recreation (ski), agrarian (ranching or farming), and energy extractive (petroleum)-differed in healthcare (gauged by the abundance of hospital beds) and in the frequency of sexual predators. The absolute and relative frequency of registered sex offenders grew approximately two to three times faster in areas reliant on energy extraction. Healthcare among counties did not differ. The strong conflation of community dishevel, as reflected by in-migrant sexual predators, and ecological decay in Greater Yellowstone is consistent with patterns seen in similar systems from Ecuador to northern Canada, where social and environmental disarray exist around energy boomtowns. In our case, that groups (albeit with different aims) mobilized campaigns to help maintain the quality of rural livelihoods by protecting open space is a positive sign that conservation can matter, especially in the face of rampant and poorly executed energy extraction projects. Our findings further suggest that the public and industry need stronger regulatory action to instill greater vigilance when and where social factors and land conversion impact biological systems.

  6. Land cover mapping of Greater Mesoamerica using MODIS data

    Science.gov (United States)

    Giri, Chandra; Jenkins, Clinton N.

    2005-01-01

    A new land cover database of Greater Mesoamerica has been prepared using moderate resolution imaging spectroradiometer (MODIS, 500 m resolution) satellite data. Daily surface reflectance MODIS data and a suite of ancillary data were used in preparing the database by employing a decision tree classification approach. The new land cover data are an improvement over traditional advanced very high resolution radiometer (AVHRR) based land cover data in terms of both spatial and thematic details. The dominant land cover type in Greater Mesoamerica is forest (39%), followed by shrubland (30%) and cropland (22%). Country analysis shows forest as the dominant land cover type in Belize (62%), Cost Rica (52%), Guatemala (53%), Honduras (56%), Nicaragua (53%), and Panama (48%), cropland as the dominant land cover type in El Salvador (60.5%), and shrubland as the dominant land cover type in Mexico (37%). A three-step approach was used to assess the quality of the classified land cover data: (i) qualitative assessment provided good insight in identifying and correcting gross errors; (ii) correlation analysis of MODIS- and Landsat-derived land cover data revealed strong positive association for forest (r2 = 0.88), shrubland (r2 = 0.75), and cropland (r2 = 0.97) but weak positive association for grassland (r2 = 0.26); and (iii) an error matrix generated using unseen training data provided an overall accuracy of 77.3% with a Kappa coefficient of 0.73608. Overall, MODIS 500 m data and the methodology used were found to be quite useful for broad-scale land cover mapping of Greater Mesoamerica.

  7. Practicing more retrieval routes leads to greater memory retention.

    Science.gov (United States)

    Zheng, Jun; Zhang, Wei; Li, Tongtong; Liu, Zhaomin; Luo, Liang

    2016-09-01

    A wealth of research has shown that retrieval practice plays a significant role in improving memory retention. The current study focused on one simple yet rarely examined question: would repeated retrieval using two different retrieval routes or using the same retrieval route twice lead to greater long-term memory retention? Participants elaborately learned 22 Japanese-Chinese translation word pairs using two different mediators. Half an hour after the initial study phase, the participants completed two retrieval sessions using either one mediator (Tm1Tm1) or two different mediators (Tm1Tm2). On the final test, which was performed 1week after the retrieval practice phase, the participants received only the cue with a request to report the mediator (M1 or M2) followed by the target (Experiment 1) or only the mediator (M1 or M2) with a request to report the target (Experiment 2). The results of Experiment 1 indicated that the participants who practiced under the Tm1Tm2 condition exhibited greater target retention than those who practiced under the Tm1Tm1 condition. This difference in performance was due to the significant disadvantage in mediator retrieval and decoding of the unpracticed mediator under the Tm1Tm1 condition. Although mediators were provided to participants on the final test in Experiment 2, decoding of the unpracticed mediators remained less effective than decoding of the practiced mediators. We conclude that practicing multiple retrieval routes leads to greater memory retention than focusing on a single retrieval route. Thus, increasing retrieval variability during repeated retrieval practice indeed significantly improves long-term retention in a delay test. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Taino and African maternal heritage in the Greater Antilles.

    Science.gov (United States)

    Bukhari, Areej; Luis, Javier Rodriguez; Alfonso-Sanchez, Miguel A; Garcia-Bertrand, Ralph; Herrera, Rene J

    2017-12-30

    Notwithstanding the general interest and the geopolitical importance of the island countries in the Greater Antilles, little is known about the specific ancestral Native American and African populations that settled them. In an effort to alleviate this lacuna of information on the genetic constituents of the Greater Antilles, we comprehensively compared the mtDNA compositions of Cuba, Dominican Republic, Haiti, Jamaica and Puerto Rico. To accomplish this, the mtDNA HVRI and HVRII regions, as well as coding diagnostic sites, were assessed in the Haitian general population and compared to data from reference populations. The Taino maternal DNA is prominent in the ex-Spanish colonies (61.3%-22.0%) while it is basically non-existent in the ex-French and ex-English colonies of Haiti (0.0%) and Jamaica (0.5%), respectively. The most abundant Native American mtDNA haplogroups in the Greater Antilles are A2, B2 and C1. The African mtDNA component is almost fixed in Haiti (98.2%) and Jamaica (98.5%), and the frequencies of specific African haplogroups vary considerably among the five island nations. The strong persistence of Taino mtDNA in the ex-Spanish colonies (and especially in Puerto Rico), and its absence in the French and English excolonies is likely the result of different social norms regarding mixed marriages with Taino women during the early years after the first contact with Europeans. In addition, this article reports on the results of an integrative approach based on mtDNA analysis and demographic data that tests the hypothesis of a southward shift in raiding zones along the African west coast during the period encompassing the Transatlantic Slave Trade. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Raman Investigation of The Uranium Compounds U3O8, UF4, UH3 and UO3 under Pressure at Room Temperature

    International Nuclear Information System (INIS)

    Lipp, M.J.; Jenei, Z.; Park-Klepeis, J.; Evans, W.J.

    2011-01-01

    Our current state-of-the-art X-ray diffraction experiments are primarily sensitive to the position of the uranium atom. While the uranium - low-Z element bond (such as U-H or U-F) changes under pressure and temperature the X-ray diffraction investigations do not reveal information about the bonding or the stoichiometry. Questions that can be answered by Raman spectroscopy are (i) whether the bonding strength changes under pressure, as observed by either blue- or red-shifted peaks of the Raman active bands in the spectrum and (ii) whether the low-Z element will eventually be liberated and leave the host lattice, i.e. do the fluorine, oxygen, or hydrogen atoms form dimers after breaking the bond to the uranium atom. Therefore Raman spectra were also collected in the range where those decomposition products would appear. Raman is particularly well suited to these types of investigations due to its sensitivity to trace amounts of materials. One challenge for Raman investigations of the uranium compounds is that they are opaque to visible light. They absorb the incoming radiation and quickly heat up to the point of decomposition. This has been dealt with in the past by keeping the incoming laser power to very low levels on the tens of milliWatt range consequently affecting signal to noise. Recent modern investigations also used very small laser spot sizes (micrometer range) but ran again into the problem of heating and chemical sensitivity to the environment. In the studies presented here (in contrast to all other studies that were performed at ambient conditions only) we employ micro-Raman spectroscopy of samples situated in a diamond anvil cell. This increases the trustworthiness of the obtained data in several key-aspects: (a) We surrounded the samples in the DAC with neon as a pressure transmitting medium, a noble gas that is absolutely chemically inert. (b) Through the medium the sample is thermally heat sunk to the diamond anvils, diamond of course possessing the

  10. Absorption spectrum of DNA for wavelengths greater than 300 nm

    International Nuclear Information System (INIS)

    Sutherland, J.C.; Griffin, K.P.

    1981-01-01

    Although DNA absorption at wavelengths greater than 300 nm is much weaker than that at shorter wavelengths, this absorption seems to be responsible for much of the biological damage caused by solar radiation of wavelengths less than 320 nm. Accurate measurement of the absorption spectrum of DNA above 300 nm is complicated by turbidity characteristic of concentrated solutions of DNA. We have measured the absorption spectra of DNA from calf thymus, Clostridium perfringens, Escherichia coli, Micrococcus luteus, salmon testis, and human placenta using procedures which separate optical density due to true absorption from that due to turbidity. Above 300 nm, the relative absorption of DNA increases as a function of guanine-cytosine content, presumably because the absorption of guanine is much greater than the absorption of adenine at these wavelengths. This result suggests that the photophysical processes which follow absorption of a long-wavelength photon may, on the average, differ from those induced by shorter-wavelength photons. It may also explain the lower quantum yield for the killing of cells by wavelengths above 300 nm compared to that by shorter wavelengths

  11. Black breast cancer survivors experience greater upper extremity disability.

    Science.gov (United States)

    Dean, Lorraine T; DeMichele, Angela; LeBlanc, Mously; Stephens-Shields, Alisa; Li, Susan Q; Colameco, Chris; Coursey, Morgan; Mao, Jun J

    2015-11-01

    Over one-third of breast cancer survivors experience upper extremity disability. Black women present with factors associated with greater upper extremity disability, including: increased body mass index (BMI), more advanced disease stage at diagnosis, and varying treatment type compared with Whites. No prior research has evaluated the relationship between race and upper extremity disability using validated tools and controlling for these factors. Data were drawn from a survey study among 610 women with stage I-III hormone receptor positive breast cancer. The disabilities of the arm, shoulder and hand (QuickDASH) is an 11-item self-administered questionnaire that has been validated for breast cancer survivors to assess global upper extremity function over the past 7 days. Linear regression and mediation analysis estimated the relationships between race, BMI and QuickDASH score, adjusting for demographics and treatment types. Black women (n = 98) had 7.3 points higher average QuickDASH scores than White (n = 512) women (p disability by 40 %. Even several years post-treatment, Black breast cancer survivors had greater upper extremity disability, which was partially mediated by higher BMIs. Close monitoring of high BMI Black women may be an important step in reducing disparities in cancer survivorship. More research is needed on the relationship between race, BMI, and upper extremity disability.

  12. Strategies, technologies, and economics for managing greater-than-class C waste

    International Nuclear Information System (INIS)

    Danna, J.G.; Baird, R.D.; Chau, T.K.

    1994-01-01

    The Low-Level Radioactive Waste Policy Amendments Act 0f 1985, Public Law 99-240, transferred responsibility for disposing of Greater-Than-Class C (GTCC) low-level radioactive waste (LLW) generated by commercial licensees from the states to the U.S. Department of Energy (DOE). Development of permanent disposal capacity for GTCC LLW requires the evaluation of potential disposal concepts in terms of technical feasibility, economics, and institutional concerns. Previous studies have identified 13 potential GTCC LLW disposal concepts and have characterized volumes and types of GTCC LLW. Data from these studies, along with newly developed data pertaining to concept designs and hypothetical sites, were used to evaluate each concept's technical feasibility. An evaluation of the cost effectiveness of the technically feasible disposal concepts was also conducted

  13. Aerobic fitness is associated with greater hippocampal cerebral blood flow in children

    Directory of Open Access Journals (Sweden)

    Laura Chaddock-Heyman

    2016-08-01

    Full Text Available The present study is the first to investigate whether cerebral blood flow in the hippocampus relates to aerobic fitness in children. In particular, we used arterial spin labeling (ASL perfusion MRI to provide a quantitative measure of blood flow in the hippocampus in 73 7- to 9-year-old preadolescent children. Indeed, aerobic fitness was found to relate to greater perfusion in the hippocampus, independent of age, sex, and hippocampal volume. Such results suggest improved microcirculation and cerebral vasculature in preadolescent children with higher levels of aerobic fitness. Further, aerobic fitness may influence how the brain regulates its metabolic demands via blood flow in a region of the brain important for learning and memory. To add specificity to the relationship of fitness to the hippocampus, we demonstrate no significant association between aerobic fitness and cerebral blood flow in the brainstem. Our results reinforce the importance of aerobic fitness during a critical period of child development.

  14. Mean nuclear volume

    DEFF Research Database (Denmark)

    Mogensen, O.; Sørensen, Flemming Brandt; Bichel, P.

    1999-01-01

    We evaluated the following nine parameters with respect to their prognostic value in females with endometrial cancer: four stereologic parameters [mean nuclear volume (MNV), nuclear volume fraction, nuclear index and mitotic index], the immunohistochemical expression of cancer antigen (CA125...

  15. [Clinical Results of Endoscopic Treatment of Greater Trochanteric Pain Syndrome].

    Science.gov (United States)

    Zeman, P; Rafi, M; Skala, P; Zeman, J; Matějka, J; Pavelka, T

    2017-01-01

    PURPOSE OF THE STUDY This retrospective study aims to present short-term clinical outcomes of endoscopic treatment of patients with greater trochanteric pain syndrome (GTPS). MATERIAL AND METHODS The evaluated study population was composed of a total of 19 patients (16 women, 3 men) with the mean age of 47 years (19-63 years). In twelve cases the right hip joint was affected, in the remaining seven cases it was the left side. The retrospective evaluation was carried out only in patients with greater trochanteric pain syndrome caused by independent chronic trochanteric bursitis without the presence of m. gluteus medius tear not responding to at least 3 months of conservative treatment. In patients from the followed-up study population, endoscopic trochanteric bursectomy was performed alone or in combination with iliotibial band release. The clinical results were evaluated preoperatively and with a minimum follow-up period of 1 year after the surgery (mean 16 months). The Visual Analogue Scale (VAS) for assessment of pain and WOMAC (Western Ontario MacMaster) score were used. In both the evaluated criteria (VAS and WOMAC score) preoperative and postoperative results were compared. Moreover, duration of surgery and presence of postoperative complications were assessed. Statistical evaluation of clinical results was carried out by an independent statistician. In order to compare the parameter of WOMAC score and VAS pre- and post-operatively the Mann-Whitney Exact Test was used. The statistical significance was set at 0.05. RESULTS The preoperative VAS score ranged 5-9 (mean 7.6) and the postoperative VAS ranged 0-5 (mean 2.3). The WOMAC score ranged 56.3-69.7 (mean 64.2) preoperatively and 79.8-98.3 (mean 89.7) postoperatively. When both the evaluated parameters of VAS and WOMAC score were compared in time, a statistically significant improvement (ppain syndrome yields statistically significant improvement of clinical results with the concurrent minimum incidence of

  16. Blood volume studies

    International Nuclear Information System (INIS)

    Lewis, S.M.; Yin, J.A.L.

    1986-01-01

    The use of dilution analysis with such radioisotopes as 51 Cr, 32 P, sup(99m)Tc and sup(113m)In for measuring red cell volume is reviewed briefly. The use of 125 I and 131 I for plasma volume studies is also considered and the subsequent determination of total blood volume discussed, together with the role of the splenic red cell volume. Substantial bibliography. (UK)

  17. Strontium isotopic geochemistry of intrusive rocks, Puerto Rico, Greater Antilles

    International Nuclear Information System (INIS)

    Jones, L.M.; Kesler, S.E.

    1980-01-01

    The strontium isotope geochemistry is given for three Puerto Rican intrusive rocks: the granodioritic Morovis and San Lorenzo plutons and the Rio Blanco stock of quartz dioritic composition. The average calculated initial 87 Sr/ 86 Sr ratios are 0.70370, 0.70355 and 0.70408, respectively. In addition, the San Lorenzo data establish a whole-rock isochron of 71 +- 2 m.y., which agrees with the previously reported K-Ar age of 73 m.y. Similarity of most of the intrusive rocks in the Greater Antilles with respect to their strontium isotopic geochemistry regardless of their major element composition indicates that intrusive magmas with a wide range of composition can be derived from a single source material. The most likely source material, in view of the available isotopic data, is the mantle wedge overlying the subduction zone. (orig.)

  18. Slimness is associated with greater intercourse and lesser masturbation frequency.

    Science.gov (United States)

    Brody, Stuart

    2004-01-01

    I examined the relationship of recalled and diary recorded frequency of penile-vaginal intercourse (FSI), noncoital partnered sexual activity, and masturbation to measured waist and hip circumference in 120 healthy adults aged 19-38. Slimmer waist (in men and in the sexes combined) and slimmer hips (in men and women) were associated with greater FSI. Slimmer waist and hips were associated with rated importance of intercourse for men. Noncoital partnered sexual activity had a less consistent association with slimness. Slimmer waist and hips were associated with less masturbation (in men and in the sexes combined). I discuss the results in terms of differences between different sexual behaviors, attractiveness, emotional relatedness, physical sensitivity, sexual dysfunction, sociobiology, psychopharmacological aspects of excess fat and carbohydrate consumption, and implications for sex therapy.

  19. ADR characteristics and corporate governance in the Greater China region

    Directory of Open Access Journals (Sweden)

    Lee-Hsien Pan

    2012-04-01

    Full Text Available We examine the relationship between firm valuation and governance mechanisms, firm characteristics, and institutional factors of the American Depository Receipts (ADRs domiciled in the Greater China region. We find that China ADRs have the highest market-to-book value ratio followed by Hong Kong and Taiwan ADRs. It appears that Chinese firms with the poorest external governance environment stand to benefit the most from cross listing under the ADR programs. Listing in the U.S. that requires more stringent regulations and disclosure rules may strengthen the firms’ governance practices and thereby enhance their firm value. Among the internal governance mechanisms, institutional ownership and insider ownership are important for firm value.

  20. Greater confinement disposal program at the Savannah River Plant

    International Nuclear Information System (INIS)

    Cook, J.R.; Towler, O.A.; Peterson, D.L.; Johnson, G.M.; Helton, B.D.

    1984-01-01

    The first facility to demonstrate Greater Confinement Disposal (GCD) in a humid environment in the United States has been built and is operating at the Savannah River Plant. GCD practices of waste segregation, packaging, emplacement below the root zone, and waste stabilization are being used in the demonstration. Activity concentrations to select wastes for GCD are based on a study of SRP burial records, and are equal to or less than those for Class B waste in 10CFR61. The first disposal units to be constructed are 9-foot diameter, thirty-foot deep boreholes which will be used to dispose of wastes from production reactors, tritiated wastes, and selected wastes from off-site. In 1984 an engineered GCD trench will be constructed for disposal of boxed wastes and large bulky items. 2 figures, 1 table

  1. Evil genius? How dishonesty can lead to greater creativity.

    Science.gov (United States)

    Gino, Francesca; Wiltermuth, Scott S

    2014-04-01

    We propose that dishonest and creative behavior have something in common: They both involve breaking rules. Because of this shared feature, creativity may lead to dishonesty (as shown in prior work), and dishonesty may lead to creativity (the hypothesis we tested in this research). In five experiments, participants had the opportunity to behave dishonestly by overreporting their performance on various tasks. They then completed one or more tasks designed to measure creativity. Those who cheated were subsequently more creative than noncheaters, even when we accounted for individual differences in their creative ability (Experiment 1). Using random assignment, we confirmed that acting dishonestly leads to greater creativity in subsequent tasks (Experiments 2 and 3). The link between dishonesty and creativity is explained by a heightened feeling of being unconstrained by rules, as indicated by both mediation (Experiment 4) and moderation (Experiment 5).

  2. Use of renewable energy in the greater metropolitan area

    International Nuclear Information System (INIS)

    Arias Garcia, Rocio; Castro Gomez, Gustavo; Fallas Cordero, Kenneth; Grant Chaves, Samuel; Mendez Parrales, Tony; Parajeles Fernandez, Ivan

    2012-01-01

    A study is conducted on different renewable energy within the larger metropolitan area, selecting the most suitable for the area and the implementation for distributed generation. A research methodology is practiced type pretending gather the necessary information to make proposals selected of different type of energy. The geography of the greater metropolitan area is studied along with the different existing renewable energy: distributed generation, remote measurement of energy which is one of the elements of the concept of intelligent networks (Smart Grid) in the electricity sector, legislation of Costa Rica regarding the generation of renewable energy and environmental impact. An analysis of economic feasibility is covered for each of the proposals estimating current rates for leading distributors of a future value, concluding with the viability of projects for possible execution of the same. (author) [es

  3. The hydrogen village in the Greater Toronto Area (GTA)

    International Nuclear Information System (INIS)

    Kimmel, T.B.; Smith, R.

    2004-01-01

    'Full text:' A Hydrogen Village (H2V) is a public/private partnership with an objective to accelerate the commercialization of hydrogen and fuel cell technology in Canada and firmly position Canada as the international leader in this sector. The first Hydrogen Village is planned for the Greater Toronto Area (GTA) and will make use of existing hydrogen and fuel cell deployments to assist in its creation. This five year GTA Hydrogen Village program is planned to begin operations in 2004. The Hydrogen Village will demonstrate and deploy various hydrogen production and delivery techniques as well as fuel cells for stationary, transportation (mobile) and portable applications. This paper will provide an overview of the Hydrogen Village and identify the missions, objectives, members and progress within the H2V. (author)

  4. Age and Expatriate Job Performance in Greater China

    DEFF Research Database (Denmark)

    Selmer, Jan; Lauring, Jakob; Feng, Yunxia

    2009-01-01

    a positive impact on expatriates' job performance. Therefore, the purpose of this paper is toexamine the association between the age of business expatriates and their work performance in a Chinese cultural setting. Design/methodology/approach - Controlling for the potential bias of a number of background......, companies should not discriminate against older candidatesin expatriate selection for Greater China. Furthermore, older expatriates destined for a Chinesecultural context could be trained how to exploit their age advantage. Originality/value - In contrast to previous studies, this investigation attempts...... to match a certain personal characteristic of expatriates with a specific host culture. The results have implications for and contribute to the literature on expatriate selection as well as to the body of research on crosscultural training....

  5. The Greater Caucasus Glacier Inventory (Russia, Georgia and Azerbaijan)

    Science.gov (United States)

    Tielidze, Levan G.; Wheate, Roger D.

    2018-01-01

    There have been numerous studies of glaciers in the Greater Caucasus, but none that have generated a modern glacier database across the whole mountain range. Here, we present an updated and expanded glacier inventory at three time periods (1960, 1986, 2014) covering the entire Greater Caucasus. Large-scale topographic maps and satellite imagery (Corona, Landsat 5, Landsat 8 and ASTER) were used to conduct a remote-sensing survey of glacier change, and the 30 m resolution Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model (ASTER GDEM; 17 November 2011) was used to determine the aspect, slope and height distribution of glaciers. Glacier margins were mapped manually and reveal that in 1960 the mountains contained 2349 glaciers with a total glacier surface area of 1674.9 ± 70.4 km2. By 1986, glacier surface area had decreased to 1482.1 ± 64.4 km2 (2209 glaciers), and by 2014 to 1193.2 ± 54.0 km2 (2020 glaciers). This represents a 28.8 ± 4.4 % (481 ± 21.2 km2) or 0.53 % yr-1 reduction in total glacier surface area between 1960 and 2014 and an increase in the rate of area loss since 1986 (0.69 % yr-1) compared to 1960-1986 (0.44 % yr-1). Glacier mean size decreased from 0.70 km2 in 1960 to 0.66 km2 in 1986 and to 0.57 km2 in 2014. This new glacier inventory has been submitted to the Global Land Ice Measurements from Space (GLIMS) database and can be used as a basis data set for future studies.

  6. Myiasis in Dogs in the Greater Accra Region of Ghana.

    Science.gov (United States)

    Johnson, Sherry A M; Gakuya, Daniel W; Mbuthia, Paul G; Mande, John D; Afakye, Kofi; Maingi, Ndichu

    2016-01-01

    Myiasis is the infestation of tissues of live vertebrate animals and humans with dipterous larvae. In sub-Saharan Africa, Cordylobia anthropohaga and Cordylobia rodhaini are known to be responsible for cutaneous myiasis in animals and humans. Human cases of myiasis, purportedly acquired in Ghana but diagnosed in other countries, have been reported; however, published data on its occurrence in animals in Ghana is unavailable. This study assessed the prevalence of canine myiasis among owned dogs in the Greater Accra region (GAR) of Ghana. A cross-sectional study was conducted in the Greater Accra region of Ghana, selected for being the region with the highest estimated population density of owned dogs. Physical examination and demographic characteristics of the study dogs were assessed. Management of the dogs was assessed through a questionnaire administered to the dog owners. A total of 392 owned dogs were sampled. Twenty-nine (7.4%) had cutaneous myiasis caused by C. rodhaini. In addition, one (0.2%) of the dogs had intestinal myiasis, with Dermatobia hominis as the offending larvae. Among the breeds of dogs with myiasis, the mongrel was most affected, with 24 (82.8%) out of the 29 cases. The mongrels, majority of which (24; 82.8%) were males, were left to roam freely in the community. Results from this study demonstrate that C. rodhaini and D. hominis are important causes of myiasis in owned dogs in the GAR of Ghana. Dogs could play a role in the spread of myiasis to humans, with its attendant public health implications.

  7. Economic and geographic factors affecting the development of Greater Baku

    Directory of Open Access Journals (Sweden)

    Vusat AFANDIYEV

    2014-12-01

    Full Text Available Globally, the responsible factors for the ongoing development of urbanization are the high speed of population growth, and the mass migration of humans to cities and large urban areas. In most countries, this process resulted in the emergence of ‘pseudo-urbanization’ which is difficult to be regulated. The purpose of the carried researches to determine the development priorities in the territory of Greater Baku – the capital city of the Republic of Azerbaijan; to define the problems that take place in this connection; and to develop ways of elimination of these problems. The reason of taking Baku as a research area is connected with some of the factors. Firstly, studies on Baku have been conducted based on the Soviet geographical and urban planning school and their methods for a long period. In this regard, it is necessary to carry out research in this field based on the principles adopted in most countries. Secondly, since 1992, the intensive accumulation of population in the territory of the capital city and the surrounding areas is being observed because of socio-economic problems. As a result, the process of pseudo-urbanization intensified, entailing a densely-populated area. Thirdly, low-rise buildings still continue to exist in the large areas within the territory of Baku, and they are not associated with the functional structure of the city. This situation creates many challenges, particularly in terms of density growth and effective use of the city’s territory. Finally, numerous new buildings have been constructed in the residential areas of Baku in recent years, and this may entailserious problems in water supply, energy provision, and utilities. The study is carried out referring to previous works of researchers, statistic data, and the results of the population census conducted in 1959-2009.The practical significance of the scientific work is that positive and negative factors affecting the further development of Greater Baku

  8. Greater learnability is not sufficient to produce cultural universals.

    Science.gov (United States)

    Rafferty, Anna N; Griffiths, Thomas L; Ettlinger, Marc

    2013-10-01

    Looking across human societies reveals regularities in the languages that people speak and the concepts that they use. One explanation that has been proposed for these "cultural universals" is differences in the ease with which people learn particular languages and concepts. A difference in learnability means that languages and concepts possessing a particular property are more likely to be accurately transmitted from one generation of learners to the next. Intuitively, this difference could allow languages and concepts that are more learnable to become more prevalent after multiple generations of cultural transmission. If this is the case, the prevalence of languages and concepts with particular properties can be explained simply by demonstrating empirically that they are more learnable. We evaluate this argument using mathematical analysis and behavioral experiments. Specifically, we provide two counter-examples that show how greater learnability need not result in a property becoming prevalent. First, more learnable languages and concepts can nonetheless be less likely to be produced spontaneously as a result of transmission failures. We simulated cultural transmission in the laboratory to show that this can occur for memory of distinctive items: these items are more likely to be remembered, but not generated spontaneously once they have been forgotten. Second, when there are many languages or concepts that lack the more learnable property, sheer numbers can swamp the benefit produced by greater learnability. We demonstrate this using a second series of experiments involving artificial language learning. Both of these counter-examples show that simply finding a learnability bias experimentally is not sufficient to explain why a particular property is prevalent in the languages or concepts used in human societies: explanations for cultural universals based on cultural transmission need to consider the full set of hypotheses a learner could entertain and all of

  9. Greater general startle reflex is associated with greater anxiety levels: a correlational study on 111 young women

    Directory of Open Access Journals (Sweden)

    Eleonora ePoli

    2015-02-01

    Full Text Available Startle eyeblink reflex is a valid non-invasive tool for studying attention, emotion and psychiatric disorders. In the absence of any experimental manipulation, the general (or baseline startle reflex shows a high inter-individual variability, which is often considered task-irrelevant and therefore normalized across participants. Unlike the above view, we hypothesized that greater general startle magnitude is related to participants’ higher anxiety level. 111 healthy young women, after completing the State-Trait Anxiety Inventory, were randomly administered 10 acoustic white noise probes (50 ms, 100 dBA acoustic level while integrated EMG from left and right orbicularis oculi was recorded. Results showed that participants with greater state anxiety levels exhibited larger startle reflex magnitude from the left eye (r109=0.23, p<0.05. Furthermore, individuals who perceived the acoustic probe as more aversive reported the largest anxiety scores (r109=0.28, p<0.05 and had the largest eyeblinks, especially in the left eye (r109 = 0.34, p<0.001. Results suggest that general startle may represent a valid tool for studying the neural excitability underlying anxiety and emotional dysfunction in neurological and mental disorders.

  10. Analysis of Type A packaging systems based on greater than 400 individual packaging tests

    International Nuclear Information System (INIS)

    Edling, D.A.

    1976-01-01

    Type A packagings commonly used within the U.S. were studied to determine their performance with respect to, ''Tests for demonstrating ability to withstand normal conditions of transport,'' (e.g., water spray, free drop (4 ft), penetration, corner drop, and compression). There are several differences in U.S. and IAEA Type A packaging requirements and these are outlined. For purposes of this study, U. S. requirements were used. More than 100 separate packagings (greater than 400 individual tests) were studied and evaluated. Most of these packagings can be divided into four basic groups: steel drums, wooden boxes, fiberboard containers, and steel boxes. The steel drums met all the requirements with a minimum of qualification and restrictions on use. The wooden boxes performed well, with three-way corner construction providing the best results. The Type A performance requirements had a much greater effect on fiberboard packagings (boxes and drums). In most cases penetration of the fiberboard container did occur, but this was dependent on the inner packagings and materials used. Steel boxes offer a wide flexibility in types of construction, materials usable, volumes, and authorized gross weights. Material usage and construction for wooden and fiberboard containers, such as use of plywood in box construction, banding of boxes, and use of ''firm'' cushioning materials within fiberboard containers, are also discussed

  11. China's soaring vehicle population: Even greater than forecasted?

    International Nuclear Information System (INIS)

    Wang Yunshi; Teter, Jacob; Sperling, Daniel

    2011-01-01

    China's vehicle population is widely forecasted to grow 6-11% per year into the foreseeable future. Barring aggressive policy intervention or a collapse of the Chinese economy, we suggest that those forecasts are conservative. We analyze the historical vehicle growth patterns of seven of the largest vehicle producing countries at comparable times in their motorization history. We estimate vehicle growth rates for this analogous group of countries to have 13-17% per year-roughly twice the rate forecasted for China by others. Applying these higher growth rates to China results in the total vehicle fleet reaching considerably higher volumes than forecasted by others, implying far higher global oil use and carbon emissions than projected by the International Energy Agency and others. - Highlights: → We use large, car-producing countries as models in forecasting vehicle ownership in China. → We find that vehicle growth rates in China could be twice as high as forecasted by others (including IEA). → Motorization is occurring quickly across all regions in China, not just the richer coastal areas.

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  13. The Active Structure of the Greater Dead Sea Basin

    Science.gov (United States)

    Shamir, G.

    2002-12-01

    The Greater Dead Sea Basin (GDSB) is a 220km long depression situated along the southern section of the Dead Sea Transform (DST), between two structurally and gravitationally elevated points, Wadi Malih in the north and Paran fault zone in the south. In its center is the Dead Sea basin 'sensu strictu' (DSB), which has been described since the 1970s as a pull-apart basin at a left step-over along the DST. However, several observations, or their lack thereof, contradict this scheme, e.g. (i) It is not supported by recent seismological and geomorphic data; (ii) It does not explain the fault pattern and mixed sinistral and dextral offset along the DSB western boundary; (iii) It does not simply explain the presence of intense deformation outside the presumed fault step zone; (iv) It is inconsistent with the orientation of seismically active faults within the Dead Sea and Jericho Valley; (v) The length of the DSB exceeds the total offset along the Dead Sea Transform, while its subsidence is about the age of the DST. In this study, newly acquired and analyzed data (high resolution seismic reflection and earthquake relocation and fault plane solutions) has been integrated with previously published data (structural mapping, fracture orientation distribution, Bouguer anomaly maps, sinkhole distribution, geomorphic lineaments). The results show that the GDSB is dominated by two active fault systems, one trending NNE and showing normal-dextral motion, the other trending NW. These systems are identified by earthquake activity, seismic reflection observations, alignment of recent sinkholes, and distribution of Bouguer anomaly gradients. As a result, the intra-basin structure is of a series of rectangular blocks. The dextral slip component along NNE trending faults, the mixed sense of lateral offset along the western boundary of the DSB and temporal change in fracture orientation in the Jericho Valley suggest that the intra-basin blocks have rotated counterclockwise since the

  14. A new probabilistic seismic hazard assessment for greater Tokyo

    Science.gov (United States)

    Stein, R.S.; Toda, S.; Parsons, T.; Grunewald, E.; Blong, R.; Sparks, S.; Shah, H.; Kennedy, J.

    2006-01-01

    Tokyo and its outlying cities are home to one-quarter of Japan's 127 million people. Highly destructive earthquakes struck the capital in 1703, 1855 and 1923, the last of which took 105 000 lives. Fuelled by greater Tokyo's rich seismological record, but challenged by its magnificent complexity, our joint Japanese-US group carried out a new study of the capital's earthquake hazards. We used the prehistoric record of great earthquakes preserved by uplifted marine terraces and tsunami deposits (17 M???8 shocks in the past 7000 years), a newly digitized dataset of historical shaking (10 000 observations in the past 400 years), the dense modern seismic network (300 000 earthquakes in the past 30 years), and Japan's GeoNet array (150 GPS vectors in the past 10 years) to reinterpret the tectonic structure, identify active faults and their slip rates and estimate their earthquake frequency. We propose that a dislodged fragment of the Pacific plate is jammed between the Pacific, Philippine Sea and Eurasian plates beneath the Kanto plain on which Tokyo sits. We suggest that the Kanto fragment controls much of Tokyo's seismic behaviour for large earthquakes, including the damaging 1855 M???7.3 Ansei-Edo shock. On the basis of the frequency of earthquakes beneath greater Tokyo, events with magnitude and location similar to the M??? 7.3 Ansei-Edo event have a ca 20% likelihood in an average 30 year period. In contrast, our renewal (time-dependent) probability for the great M??? 7.9 plate boundary shocks such as struck in 1923 and 1703 is 0.5% for the next 30 years, with a time-averaged 30 year probability of ca 10%. The resulting net likelihood for severe shaking (ca 0.9g peak ground acceleration (PGA)) in Tokyo, Kawasaki and Yokohama for the next 30 years is ca 30%. The long historical record in Kanto also affords a rare opportunity to calculate the probability of shaking in an alternative manner exclusively from intensity observations. This approach permits robust estimates

  15. Mass spectrometer introduction line: application to the analysis of impurities in uranium hexafluoride; Ligne d'introduction pour spectrometre de masse: application a l'analyse des impuretes contenues dans l'UF{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Besson, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires. Departement de physico-chimie, service des isotopes stables, section de spectrometrie de masse

    1967-01-01

    The continuous mass-spectrometric analysis of impurities in UF{sub 6} is possible industrially if certain conditions imposed by the nature of the gas are respected. The gas introduction line arriving at the spectrometer's source makes it possible to fix the flow-rate, to control the inlet pressure and to selectively destroy the gas containing the impurities. The operational conditions for the line are defined and a description is given of the theoretical and experimental study of the various elements of which it is composed, i.e. the leak valve, the flow-meter, the chemical trap and the servo-mechanism making it possible to regulate and control the gas flow. The dynamic characteristics of the line's various components and the performance of the equipment in the case of the analyses considered are given. (author) [French] L'analyse en continu par spectrometrie de masse des impuretes contenus dans l'UF{sub 6} est possible industriellement moyennant certaines conditions imposees par la nature du gaz. La ligne d'introduction des gaz dans la source du spectrometre permet de regler le debit, de controler la pression d'introduction et de detruire selectivement le gaz porteur d'impuretes. Les conditions de fonctionnement de la ligne etant definies, on decrit l'etude theorique et experimentale des differents elements qui la composent, c'est-a-dire: le robinet a fuite, le debitmetre, le piege chimique et l'ensemble d'asservissement permettant la regulation et le controle du debit. On donne les caracteristiques dynamiques des differents constituants de la ligne et les performances de l'ensemble pour les analyses considerees. (auteur)

  16. Mass spectrometer introduction line: application to the analysis of impurities in uranium hexafluoride; Ligne d'introduction pour spectrometre de masse: application a l'analyse des impuretes contenues dans l'UF{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Besson, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires. Departement de physico-chimie, service des isotopes stables, section de spectrometrie de masse

    1967-01-01

    The continuous mass-spectrometric analysis of impurities in UF{sub 6} is possible industrially if certain conditions imposed by the nature of the gas are respected. The gas introduction line arriving at the spectrometer's source makes it possible to fix the flow-rate, to control the inlet pressure and to selectively destroy the gas containing the impurities. The operational conditions for the line are defined and a description is given of the theoretical and experimental study of the various elements of which it is composed, i.e. the leak valve, the flow-meter, the chemical trap and the servo-mechanism making it possible to regulate and control the gas flow. The dynamic characteristics of the line's various components and the performance of the equipment in the case of the analyses considered are given. (author) [French] L'analyse en continu par spectrometrie de masse des impuretes contenus dans l'UF{sub 6} est possible industriellement moyennant certaines conditions imposees par la nature du gaz. La ligne d'introduction des gaz dans la source du spectrometre permet de regler le debit, de controler la pression d'introduction et de detruire selectivement le gaz porteur d'impuretes. Les conditions de fonctionnement de la ligne etant definies, on decrit l'etude theorique et experimentale des differents elements qui la composent, c'est-a-dire: le robinet a fuite, le debitmetre, le piege chimique et l'ensemble d'asservissement permettant la regulation et le controle du debit. On donne les caracteristiques dynamiques des differents constituants de la ligne et les performances de l'ensemble pour les analyses considerees. (auteur)

  17. Scaling and allometry in the building geometries of Greater London

    Science.gov (United States)

    Batty, M.; Carvalho, R.; Hudson-Smith, A.; Milton, R.; Smith, D.; Steadman, P.

    2008-06-01

    Many aggregate distributions of urban activities such as city sizes reveal scaling but hardly any work exists on the properties of spatial distributions within individual cities, notwithstanding considerable knowledge about their fractal structure. We redress this here by examining scaling relationships in a world city using data on the geometric properties of individual buildings. We first summarise how power laws can be used to approximate the size distributions of buildings, in analogy to city-size distributions which have been widely studied as rank-size and lognormal distributions following Zipf [ Human Behavior and the Principle of Least Effort (Addison-Wesley, Cambridge, 1949)] and Gibrat [ Les Inégalités Économiques (Librarie du Recueil Sirey, Paris, 1931)]. We then extend this analysis to allometric relationships between buildings in terms of their different geometric size properties. We present some preliminary analysis of building heights from the Emporis database which suggests very strong scaling in world cities. The data base for Greater London is then introduced from which we extract 3.6 million buildings whose scaling properties we explore. We examine key allometric relationships between these different properties illustrating how building shape changes according to size, and we extend this analysis to the classification of buildings according to land use types. We conclude with an analysis of two-point correlation functions of building geometries which supports our non-spatial analysis of scaling.

  18. Comparing statistical tests for detecting soil contamination greater than background

    International Nuclear Information System (INIS)

    Hardin, J.W.; Gilbert, R.O.

    1993-12-01

    The Washington State Department of Ecology (WSDE) recently issued a report that provides guidance on statistical issues regarding investigation and cleanup of soil and groundwater contamination under the Model Toxics Control Act Cleanup Regulation. Included in the report are procedures for determining a background-based cleanup standard and for conducting a 3-step statistical test procedure to decide if a site is contaminated greater than the background standard. The guidance specifies that the State test should only be used if the background and site data are lognormally distributed. The guidance in WSDE allows for using alternative tests on a site-specific basis if prior approval is obtained from WSDE. This report presents the results of a Monte Carlo computer simulation study conducted to evaluate the performance of the State test and several alternative tests for various contamination scenarios (background and site data distributions). The primary test performance criteria are (1) the probability the test will indicate that a contaminated site is indeed contaminated, and (2) the probability that the test will indicate an uncontaminated site is contaminated. The simulation study was conducted assuming the background concentrations were from lognormal or Weibull distributions. The site data were drawn from distributions selected to represent various contamination scenarios. The statistical tests studied are the State test, t test, Satterthwaite's t test, five distribution-free tests, and several tandem tests (wherein two or more tests are conducted using the same data set)

  19. Distribution of grizzly bears in the Greater Yellowstone Ecosystem, 2004

    Science.gov (United States)

    Schwartz, C.C.; Haroldson, M.A.; Gunther, K.; Moody, D.

    2006-01-01

    The US Fish and Wildlife Service (USFWS) proposed delisting the Yellowstone grizzly bear (Ursus arctos horribilis) in November 2005. Part of that process required knowledge of the most current distribution of the species. Here, we update an earlier estimate of occupied range (1990–2000) with data through 2004. We used kernel estimators to develop distribution maps of occupied habitats based on initial sightings of unduplicated females (n = 481) with cubs of the year, locations of radiomarked bears (n = 170), and spatially unique locations of conflicts, confrontations, and mortalities (n = 1,075). Although each data set was constrained by potential sampling bias, together they provided insight into areas in the Greater Yellowstone Ecosystem (GYE) currently occupied by grizzly bears. The current distribution of 37,258 km2 (1990–2004) extends beyond the distribution map generated with data from 1990–2000 (34,416 km2 ). Range expansion is particularly evident in parts of the Caribou–Targhee National Forest in Idaho and north of Spanish Peaks on the Gallatin National Forest in Montana.

  20. Greater utilization of wood residue fuels through improved financial planning

    International Nuclear Information System (INIS)

    Billings, C.D.; Ziemke, M.C.; Stanford, R.

    1991-01-01

    Recent events have focused attention on the promotion of greater utilization of biomass fuel. Considerations include the need to reduce increases in global warming and also to improve ground level air quality by limiting the use of fossil fuels. However, despite all these important environmentally related considerations, economics remains the most important factor in the decision process used to determine the feasibility of using available renewable fuels instead of more convenient fossil fuels. In many areas of the Southeast, this decision process involves choosing between wood residue fuels such as bark, sawdust and shavings and presently plentiful natural gas. The primary candidate users of wood residue fuels are industries that use large amounts of heat and electric power and are located near centers of activity in the forest products industry such as sawmills, veneer mills and furniture factories. Given that such facilities both produce wood residues and need large amounts of heat and electricity, it is understandable that these firms are often major users of wood-fired furnaces and boilers. The authors have observed that poor or incomplete financial planning by the subject firms is a major barrier to economic utilization of inexpensive and widely available renewable fuels. In this paper, the authors suggest that wider usage of improved financial planning could double the present modest annual incidence of new commercial wood-fueled installation