WorldWideScience

Sample records for diffusion plant criticality

  1. Measurement of the Portsmouth Gaseous Diffusion Plant criticality accident alarm

    International Nuclear Information System (INIS)

    Tayloe, R.W. Jr.; D'Aquila, D.M.; McGinnis, R.B.

    1991-01-01

    The nuclear criticality accident radiation alarm system installed at the Portsmouth Gaseous Diffusion Plant was tested extensively at critical facilities located at the Los Alamos National Laboratory. The ability of the neutron scintillator radiation detection units to respond to a minimum accident of concern as defined in Standard ANSI/ANS-83.-1986 was demonstrated. Detector placement and the established trip point are based on shielding calculations performed by the Oak Ridge National Laboratory and criticality specialists at the Portsmouth plant. Based on these experiments and calculations, a detector trip point of 5 mrad/h in air is used. Any credible criticality accident is expected to produce neutron radiation fields >5 mrad/h in air at one or more radiation alarm locations. Each radiation alarm location has a cluster of three detectors that employs a two-out-of-three alarm logic. Earlier work focused on testing the alarm logic latching circuitry. This work was directed toward measurements involving the actual audible alarm signal delivered

  2. Nuclear criticality safety controls for uranium deposits during D and D at the Oak Ridge Gaseous Diffusion Plant

    International Nuclear Information System (INIS)

    Haire, M.J.; Jordan, W.C.; Jollay, L.J. III; Dahl, T.L.

    1997-01-01

    The US Department of Energy (DOE) Deputy Assistant Secretary of Energy for Environmental Management has issued a challenge to complete DOE environmental cleanup within a decade. The response for Oak Ridge facilities is in accordance with the DOE ten-year plan which calls for completion of > 95% of environmental management work by the year 2006. This will result in a 99% risk reduction and in a significant savings in base line costs in waste management (legacy waste); remedial action (groundwater, soil, etc.); and decontamination and decommissioning (D and D). It is assumed that there will be long-term institutional control of cascade equipment, i.e., there will be no walk away from sites, and that there will be firm radioactivity release limits by 1999 for recycle metals. An integral part of these plants is the removal of uranium deposits which pose nuclear criticality safety concerns in the shut down of the Oak Ridge Gaseous Diffusion Plant. DOE has initiated the Nuclear Criticality Stabilization Program to improve nuclear criticality safety by removing the larger uranium deposits from unfavorable geometry equipment. Nondestructive assay (NDA) measurements have identified the location of these deposits. The objective of the K-25 Site Nuclear Criticality Stabilization Program is to remove and place uranium deposits into safe geometry storage containers to meet the double contingency principle. Each step of the removal process results in safer conditions where multiple controls are present. Upon completion of the Program, nuclear criticality risks will be greatly reduced

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

    International Nuclear Information System (INIS)

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

    1994-06-01

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

  4. Determination of the response function for the Portsmouth Gaseous Diffusion Plant criticality accident alarm system neutron detectors

    International Nuclear Information System (INIS)

    Tayloe, R.W. Jr.; Brown, A.S.; Dobelbower, M.C.; Woollard, J.E.

    1997-03-01

    Neutron-sensitive radiation detectors are used in the Portsmouth Gaseous Diffusion Plant's (PORTS) criticality accident alarm system (CAAS). The CAAS is composed of numerous detectors, electronics, and logic units. It uses a telemetry system to sound building evacuation horns and to provide remote alarm status in a central control facility. The ANSI Standard for a CAAS uses a free-in-air dose rate to define the detection criteria for a minimum accident-of-concern. Previously, the free-in-air absorbed dose rate from neutrons was used for determining the areal coverge of criticality detection within PORTS buildings handling fissile materials. However, the free-in-air dose rate does not accurately reflect the response of the neutron detectors in use at PORTS. Because the cost of placing additional CAAS detectors in areas of questionable coverage (based on a free-in-air absorbed dose rate) is high, the actual response function for the CAAS neutron detectors was determined. This report, which is organized into three major sections, discusses how the actual response function for the PORTS CAAS neutron detectors was determined. The CAAS neutron detectors are described in Section 2. The model of the detector system developed to facilitate calculation of the response function is discussed in Section 3. The results of the calculations, including confirmatory measurements with neutron sources, are given in Section 4

  5. Criticality analysis of ASTRA critical facility using CITALDI diffusion calculation

    International Nuclear Information System (INIS)

    Zuhair; Aziz, Ferhat; Suwoto

    2002-01-01

    The ASTRA critical facility at the Russian Research Center - Kurchatov University is being used to investigate the reactor physics characteristics for High Temperature Gas Cooled Reactor (HTGCR) PBMR, South Africa. ASTRA was built with main purpose to provide various Benchmark experiments to obtained the integral data for PBMR core design using various simulation assemblies. In this paper, the criticality of ASTRA critical facility was analysed based on the calculation results of CITALDI diffusion code in 2-D R-Z reactor geometry. Cell calculation code WIMS/D4 using spherical model and four neutron energy group was employed to generate group constants of fuel zone, mixing zone and reflector. The first criticality of ASTRA is expected at the core height of 259 cm. Compared to MCNP-4A and SRA C95-CITATION calculations, the relative differences are about 4.43% and 12.61% respectively

  6. Plant air systems safety study: Portsmouth Gaseous Diffusion Plant

    International Nuclear Information System (INIS)

    1982-05-01

    The Portsmouth Gaseous Diffusion Plant Air System facilities and operations are reviewed for potential safety problems not covered by standard industrial safety procedures. Information is presented under the following section headings: facility and process description (general); air plant equipment; air distribution system; safety systems; accident analysis; plant air system safety overview; and conclusion

  7. The Tricastin gaseous diffusion plant

    International Nuclear Information System (INIS)

    Ergalant, J.; Lebrun, C.; Leduc, C.; Perrault, M.

    1975-01-01

    The building of the EURODIF plant began just over a year ago. The documents on which this enterprise was based were already assembled, which allowed construction work to start without delay. A brief description of the equipment is given, together with an approach to the problems of planning and estimates. Mention is also made of running problems and those related to safety in operation. The present state of the project promises a successful outcome, regarding both the production start-up schedule and the respecting of the building estimate [fr

  8. Diffuse-Illumination Systems for Growing Plants

    Science.gov (United States)

    May, George; Ryan, Robert

    2010-01-01

    Agriculture in both terrestrial and space-controlled environments relies heavily on artificial illumination for efficient photosynthesis. Plant-growth illumination systems require high photon flux in the spectral range corresponding with plant photosynthetic active radiation (PAR) (400 700 nm), high spatial uniformity to promote uniform growth, and high energy efficiency to minimize electricity usage. The proposed plant-growth system takes advantage of the highly diffuse reflective surfaces on the interior of a sphere, hemisphere, or other nearly enclosed structure that is coated with highly reflective materials. This type of surface and structure uniformly mixes discrete light sources to produce highly uniform illumination. Multiple reflections from within the domelike structures are exploited to obtain diffuse illumination, which promotes the efficient reuse of photons that have not yet been absorbed by plants. The highly reflective surfaces encourage only the plant tissue (placed inside the sphere or enclosure) to absorb the light. Discrete light sources, such as light emitting diodes (LEDs), are typically used because of their high efficiency, wavelength selection, and electronically dimmable properties. The light sources are arranged to minimize shadowing and to improve uniformity. Different wavelengths of LEDs (typically blue, green, and red) are used for photosynthesis. Wavelengths outside the PAR range can be added for plant diagnostics or for growth regulation

  9. Use of diffusive optical fibers for plant lighting

    Energy Technology Data Exchange (ETDEWEB)

    Kozai, T.; Kitaya, Y.; Fujiwara, K. [Chiba Univ., Matsudo (Japan); Kino, S.; Kinowaki, M. [Topy Green Ltd., Tokyo (Japan)

    1994-12-31

    Lighting is one of the most critical aspects in plant production and environmental research with plants. Much research has been repeated on the effect of light intensity, spectral distribution of light and lighting cycle, but comparatively little research done on the effect of lighting direction on the growth, development and morphology of plants. When plants are grown with lamps above, light is directed downward to the plants. Downward or overhead lighting is utilized in almost all cases. However, downward lighting does not always give the best result in terms of lighting efficiency, growth, development and morphology of plants. Kitaya et al. (1988) developed a lighting system in which two rooting beds were arranged; one above and the other under fluorescent lamps. Lettuce plants grew normally in the lower bed and suspended upside-down under the upper bed. The lettuce plants suspended upside-down were given the light in upward direction (upward lighting). No significant difference in growth, development and morphology was found between the lettuce plants grown by the downward and upward lighting. Combining upward and downward lighting, improved spacing efficiency and reduced electricity cost per plant compared with conventional, downward lighting. From the above example, when designing a lighting system for plants with lamps more lighting direction should be considered. In the present study, a sideward lighting system was developed using diffusive optical fiber belts. More higher quality tissue-cultured transplants could be produced in reduced space with sideward lighting system than with a downward lighting system. An application of the sideward lighting system using diffusive optical fiber belts is described and advantages and disadvantages are discussed.

  10. Criticality safety evaluation in Tokai Reprocessing Plant

    International Nuclear Information System (INIS)

    Shirai, Nobutoshi; Nakajima, Masayoshi; Takaya, Akikazu; Ohnuma, Hideyuki; Shirouzu, Hidetomo; Hayashi, Shinichiro; Yoshikawa, Koji; Suto, Toshiyuki

    2000-04-01

    Criticality limits for equipments in Tokai Reprocessing Plant which handle fissile material solution and are under shape and dimension control were reevaluated based on the guideline No.10 'Criticality safety of single unit' in the regulatory guide for reprocessing plant safety. This report presents criticality safety evaluation of each equipment as single unit. Criticality safety of multiple units in a cell or a room was also evaluated. The evaluated equipments were ones in dissolution, separation, purification, denitration, Pu product storage, and Pu conversion processes. As a result, it was reconfirmed that the equipments were safe enough from a view point of criticality safety of single unit and multiple units. (author)

  11. Nonergodicity, fluctuations, and criticality in heterogeneous diffusion processes.

    Science.gov (United States)

    Cherstvy, A G; Metzler, R

    2014-07-01

    We study the stochastic behavior of heterogeneous diffusion processes with the power-law dependence D(x) ∼ |x|(α) of the generalized diffusion coefficient encompassing sub- and superdiffusive anomalous diffusion. Based on statistical measures such as the amplitude scatter of the time-averaged mean-squared displacement of individual realizations, the ergodicity breaking and non-Gaussianity parameters, as well as the probability density function P(x,t), we analyze the weakly nonergodic character of the heterogeneous diffusion process and, particularly, the degree of irreproducibility of individual realizations. As we show, the fluctuations between individual realizations increase with growing modulus |α| of the scaling exponent. The fluctuations appear to diverge when the critical value α = 2 is approached, while for even larger α the fluctuations decrease, again. At criticality, the power-law behavior of the mean-squared displacement changes to an exponentially fast growth, and the fluctuations of the time-averaged mean-squared displacement do not converge for increasing number of realizations. From a systematic comparison we observe some striking similarities of the heterogeneous diffusion process with the familiar subdiffusive continuous time random walk process with power-law waiting time distribution and diverging characteristic waiting time.

  12. 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..

  13. 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

  14. Species specificity of resistance to oxygen diffusion in thin cuticular membranes from amphibious plants

    DEFF Research Database (Denmark)

    Frost-Christensen, Henning; Jørgensen, Lise Bolt; Floto, Franz

    2003-01-01

    oxygen, diffusion, cuticula, amphibious plants, Hygrophila, Berula, Lobelia, Mentha, Potamogeton, Veronica, aquatic plants, submerged plants......oxygen, diffusion, cuticula, amphibious plants, Hygrophila, Berula, Lobelia, Mentha, Potamogeton, Veronica, aquatic plants, submerged plants...

  15. Freezer-sublimer for gaseous diffusion plant

    International Nuclear Information System (INIS)

    Reti, G.R.

    1978-01-01

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

  16. Criticality analysis in uranium enrichment plant

    International Nuclear Information System (INIS)

    Okamoto, Tsuyoshi; Kiyose, Ryohei

    1977-01-01

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

  17. Application of safeguards techniques to the Eurodif gas diffusion plant

    International Nuclear Information System (INIS)

    Coates, J.H.; Goens, J.R.

    1979-01-01

    The characteristic features of gas diffusion plants are such that safeguards procedures specifically suited for this technique can be proposed. The first of these features is the fact that appreciably altering the enrichment level of the plant product is not possible without making easily detectable changes either in the plant structure itself or in the movement of incoming and outgoing materials. Furthermore, because of the size of gas diffusion plants large stocks of uranium are present in them. Although inventory differences may be small in relative terms, they are large in abosolute terms and exceed the quantities of low-enriched uranium considered significant from the standpoint of safeguards. Lastly, the impossibility for economic reasons for taking a physical inventory of the plant after it has been emptied prevents a comparison of the physical inventory with the book inventory. It would therefore seem that the safeguarding of a gas diffusion plant should be focused on the movement of nuclear material between the plant and the outside world. The verification of inputs and outputs can be considered satisfactory from the safeguards standpoint as long as it is possible to make sure of the containment of the plant and of the surveillance for the purpose of preventing clandestine alterations of structure. The description of the Eurodif plant and the movement of materials planned there at present indicate that the application of such a safeguards technique to the plant should be acceptable to the competent authorities. For this purpose a monitoring area has been set aside in which the inspectors will be able to keep track of all movements between the outside world and the enrichment plant

  18. A Critical Study of Agglomerated Multigrid Methods for Diffusion

    Science.gov (United States)

    Nishikawa, Hiroaki; Diskin, Boris; Thomas, James L.

    2011-01-01

    Agglomerated multigrid techniques used in unstructured-grid methods are studied critically for a model problem representative of laminar diffusion in the incompressible limit. The studied target-grid discretizations and discretizations used on agglomerated grids are typical of current node-centered formulations. Agglomerated multigrid convergence rates are presented using a range of two- and three-dimensional randomly perturbed unstructured grids for simple geometries with isotropic and stretched grids. Two agglomeration techniques are used within an overall topology-preserving agglomeration framework. The results show that multigrid with an inconsistent coarse-grid scheme using only the edge terms (also referred to in the literature as a thin-layer formulation) provides considerable speedup over single-grid methods but its convergence deteriorates on finer grids. Multigrid with a Galerkin coarse-grid discretization using piecewise-constant prolongation and a heuristic correction factor is slower and also grid-dependent. In contrast, grid-independent convergence rates are demonstrated for multigrid with consistent coarse-grid discretizations. Convergence rates of multigrid cycles are verified with quantitative analysis methods in which parts of the two-grid cycle are replaced by their idealized counterparts.

  19. Decommissioning of the gaseous diffusion plant at BNFL Capenhurst

    International Nuclear Information System (INIS)

    Baxter, S.G.; Bradbury, P.

    1992-01-01

    The history of the on-going dismantling and disposal program for the Capenhurst Diffusion Plant is described. Reference is made to the scale of the project and to the special techniques developed, particularly in the areas of size reduction, decontamination and protection of personnel and the environment. When the project is successfully concluded by the end of 1993 over 99% of the materials of construction of the plant will have been recycled to the environment as clean material. (author)

  20. Portsmouth Gaseous Diffusion Plant expansion: final environmental statement. Volume 1

    International Nuclear Information System (INIS)

    1977-09-01

    Volume 1 is comprised of chapters on: background and description; environmental impacts of add-on gaseous diffusion plant; unavoidable adverse environmental effects; alternatives; relationship between short-term uses and long-term productivity; relationship of program to land-use plans, policies, and controls; irreversible and irretrievable commitments of resources; cost-benefit analysis; and response to comment letters

  1. Radioactive effluents, Portsmouth Gaseous Diffusion Plant, calendar year 1982

    International Nuclear Information System (INIS)

    Acox, T.A.; Hary, L.F.; Klein, L.S.

    1983-03-01

    Radioactive discharges from the Portsmouth Gaseous Diffusion Plant are discussed and tabulated. Tables indicate both the location of the discharge and the nuclides discharged. All discharges for 1982 are well below the Radioactive Concentration Guide limits specified in DOE Order 5480.1, Chapter XI. 1 figure

  2. Portsmouth Gaseous Diffusion Plant expansion: final environmental statement. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    1977-09-01

    Volume 1 is comprised of chapters on: background and description; environmental impacts of add-on gaseous diffusion plant; unavoidable adverse environmental effects; alternatives; relationship between short-term uses and long-term productivity; relationship of program to land-use plans, policies, and controls; irreversible and irretrievable commitments of resources; cost-benefit analysis; and response to comment letters. (LK)

  3. Portsmouth Gaseous Diffusion Plant environmental report for 1992

    International Nuclear Information System (INIS)

    Horak, C.M.

    1993-09-01

    This calendar year (CY) 1992 annual report on environmental surveillance of the US Department of Energy's (DOE's) Portsmouth Gaseous Diffusion Plant (PORTS) and its environs consists of two parts: narrative, summaries, and conclusions (Part 1) and data presentation (Part 2). The objectives of this report are to: (1) report 1992 monitoring data for the installation and its environs that may have been affected by operations on the plant site, (2) provide reasonably detailed information about the plant site and plant operations, (3) provide detailed information on input and assumptions used in all calculations, (4) provide trend analyses (where appropriate) to indicate increases and decreases in environmental impact, and (5) provide general information on plant quality assurance

  4. Paducah Gaseous Diffusion Plant Environmental report for 1990

    Energy Technology Data Exchange (ETDEWEB)

    Counce-Brown, D. (ed.)

    1991-09-01

    This two-part report, Paducah Gaseous Diffusion Plant Site Environmental Report for 1990, is published annually. It reflects the results of a comprehensive, year-round program to monitor the impact of operations at Paducah Gaseous Diffusion Plant (PGDP) on the area's groundwater and surface waters, soil, air quality, vegetation, and wildlife. In addition, an assessment of the effect of PGDP effluents on the resident human population is made. PGDP's overall goal for environmental management is to protect the environment and PGDP's neighbors and to maintain full compliance with all current regulations. The current environmental strategy is to identify any deficiencies and to develop a system to resolve them. The long-range goal of environmental management is to minimize the source of pollutants, to reduce the formation of waste, and to minimize hazardous waste by substitution of materials.

  5. Paducah Gaseous Diffusion Plant environmental report for 1992

    International Nuclear Information System (INIS)

    Horak, C.M.

    1993-09-01

    This two-part report, Paducah Gaseous Diffusion Plant Environmental Report for 1992, is published annually. It reflects the results of an environmental monitoring program designed to quantify potential increases in the concentration of contaminants and potential doses to the resident human population. The Paducah Gaseous Diffusion Plant (PGDP) overall goal for environmental management is to protect the environment and PGDP's neighbors and to maintain full compliance with all current regulations. The current environmental strategy is to identify any deficiencies and to develop a system to resolve them. The long-range goal of environmental management is to minimize the source of pollutants, reduce the generation of waste, and minimize hazardous waste by substitution of materials

  6. Paducah Gaseous Diffusion Plant environmental report for 1992

    Energy Technology Data Exchange (ETDEWEB)

    Horak, C.M. [ed.] [Martin Marietta Energy Systems, Inc., Oak Ridge, TN (United States)

    1993-09-01

    This two-part report, Paducah Gaseous Diffusion Plant Environmental Report for 1992, is published annually. It reflects the results of an environmental monitoring program designed to quantify potential increases in the concentration of contaminants and potential doses to the resident human population. The Paducah Gaseous Diffusion Plant (PGDP) overall goal for environmental management is to protect the environment and PGDP`s neighbors and to maintain full compliance with all current regulations. The current environmental strategy is to identify any deficiencies and to develop a system to resolve them. The long-range goal of environmental management is to minimize the source of pollutants, reduce the generation of waste, and minimize hazardous waste by substitution of materials.

  7. Portsmouth Gaseous Diffusion Plant annual site environmental report for 1993

    Energy Technology Data Exchange (ETDEWEB)

    Horak, C.M. [ed.

    1994-11-01

    This calendar year (CY) 1993 annual report on environmental monitoring of the US Department of Energy`s (DOE`s) Portsmouth Gaseous Diffusion Plant (Portsmouth) and its environs consists of three separate documents: a summary pamphlet for the general public; a more detail discussion and of compliance status, data, and environmental impacts (this document); and a volume of detailed data that is available on request. The objectives of this report are to report compliance status during 1993; provide information about the plant site and plant operations; report 1993 monitoring data for the installation and its environs that may have been affected by operations on the plant site; document information on input and assumptions used in calculations; provide trend analyses (where appropriate) to indicate increases and decreases in environmental impact, and provide general information on quality assurance for the environmental monitoring program.

  8. Portsmouth Gaseous Diffusion Plant annual site environmental report for 1993

    International Nuclear Information System (INIS)

    Horak, C.M.

    1994-11-01

    This calendar year (CY) 1993 annual report on environmental monitoring of the US Department of Energy's (DOE's) Portsmouth Gaseous Diffusion Plant (Portsmouth) and its environs consists of three separate documents: a summary pamphlet for the general public; a more detail discussion and of compliance status, data, and environmental impacts (this document); and a volume of detailed data that is available on request. The objectives of this report are to report compliance status during 1993; provide information about the plant site and plant operations; report 1993 monitoring data for the installation and its environs that may have been affected by operations on the plant site; document information on input and assumptions used in calculations; provide trend analyses (where appropriate) to indicate increases and decreases in environmental impact, and provide general information on quality assurance for the environmental monitoring program

  9. Reliability study: maintenance facilities Portsmouth Gaseous Diffusion Plant

    International Nuclear Information System (INIS)

    Post, B.E.; Sikorski, P.A.; Fankell, R.; Johnson, O.; Ferryman, D.S.; Miller, R.L.; Gearhart, E.C.; Rafferty, M.J.

    1981-08-01

    A reliability study of the maintenance facilities at the Portsmouth Gaseous Diffusion Plant has been completed. The reliability study team analyzed test data and made visual inspections of each component contributing to the overall operation of the facilities. The impacts of facilities and equipment failures were given consideration with regard to personnel safety, protection of government property, health physics, and environmental control. This study revealed that the maintenance facilities are generally in good condition. After evaluating the physical condition and technology status of the major components, the study team made several basic recommendations. Implementation of the recommendations proposed in this report will help assure reliable maintenance of the plant through the year 2000

  10. Portsmouth Gaseous Diffusion Plant expansion: final environmental statement. Volume 2. Appendices

    International Nuclear Information System (INIS)

    1977-09-01

    Volume 2 is comprised of appendices: Portsmouth Gaseous Diffusion Plant Existing Facilities; Ecology; Civic Involvement; Social Analysis; Population Projections; Toxicity of Air Pollutants to Biota at Portsmouth Gaseous Diffusion Plant; and Assessment of Noise Effects of an Add-On to the Portsmouth Gaseous Diffusion Plant

  11. Portsmouth Gaseous Diffusion Plant expansion: final environmental statement. Volume 2. Appendices. [Appendices only

    Energy Technology Data Exchange (ETDEWEB)

    Liverman, James L.

    1977-09-01

    Volume 2 is comprised of appendices: Portsmouth Gaseous Diffusion Plant Existing Facilities; Ecology; Civic Involvement; Social Analysis; Population Projections; Toxicity of Air Pollutants to Biota at Portsmouth Gaseous Diffusion Plant; and Assessment of Noise Effects of an Add-On to the Portsmouth Gaseous Diffusion Plant. (LK)

  12. Analysis of criticality accident alarm system coverage of the X-744G, X-744H, X-342/344A and X-343 facilities at the Portsmouth Gaseous Diffusion Plant

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-09-01

    Additional services for the uranium enrichment cascade process, such as UF{sub 6} feed, sampling, and material storage are provided by several ancillary Uranium Material Handling (UMH) facilities at the PORTS site. These facilities include the X-343 Feed Vaporization and Sampling Facility, the X-744G Bulk Non-Uranium Enrichment Service Activity (UESA) Storage Building, the X-744H Waste Separation and Storage Facility, the X-344A Toll Enrichment Services Facility and the X-342A Feed Vaporization and Fluorine Generation Facility. As uranium operations are performed within these facilities, the potential for a criticality accident exists. In the event of a criticality accident within a process facility at PORTS, a Criticality Accident Alarm System (CAAS) is in place to detect the criticality accident and sound an alarm. In this report, an analysis was performed to provide verification that the existing CAAS at PORTS provides complete criticality accident coverage in the X-343, X-744G. X-744H. X-344A and X-342A facilities. The analysis has determined that all of the above-mentioned facilities have complete CAAS coverage.

  13. Criticality studies: One of the two pillars of criticality safety at the Belgonucleaire MOX plant

    International Nuclear Information System (INIS)

    Lance, B.; Maldague, T.; Evrard, G.; Renard, A.; Kockerols, P.

    2001-01-01

    The present paper focuses on the criticality studies performed by the Engineering Division of Belgonucleaire. These are one of the two pillars of the criticality prevention implemented for the Belgonucleaire MOX producing plant. (author)

  14. Buildup of 236U in the gaseous diffusion plant product

    International Nuclear Information System (INIS)

    Ford, J.S.

    1975-01-01

    A generalized projection of the average annual 236 U concentration that can be expected in future enriched uranium product from the US-ERDA gaseous diffusion plants when reprocessed fuels become available for cascade feeding is given. It is concluded that the buildup of 236 U is not an ever-increasing function, but approaches a limiting value. Projected concentrations result in only slight separative work losses and present no operational problem to ERDA in supplying light water reactor requirements. The use of recycle uranium from power reactor spent fuels will result in significant savings in natural uranium feed

  15. Evaluation of seismic hazard at the Paducah Gaseous Diffusion Plant

    International Nuclear Information System (INIS)

    Toro, G.R.; McGuire, R.K.

    1991-01-01

    Seismic hazard at the Paducah Gaseous Diffusion Plant is evaluated using a formulation that considers the rupture dimensions of potential large earthquakes in the New Madrid region. The New Madrid source zone is modeled as a system of parallel faults. A characteristic-magnitude model, based on historical seismic city and paleoseismic studies, describes seismicity in the New madrid source zone. The attenuation functions reflect distance saturation caused by the rupture size of large earthquakes. Preliminary results from this seismic hazard analysis are presented and compared to results obtained using the EPRI and LLNL methodologies

  16. Portsmouth Gaseous Diffusion Plant environmental report for 1989

    Energy Technology Data Exchange (ETDEWEB)

    Turner, J.W. (ed.) (Martin Marietta Energy Systems, Inc., Oak Ridge, TN (USA))

    1990-10-01

    This calendar year 1989 annual report on environmental surveillance of the US Department of Energy's (DOE) Portsmouth Gaseous Diffusion Plant (PORTS) and its environs consists of two parts: the Summary, Discussion, and Conclusions (Part 1) and the Data Presentation (Part 2). The objectives of this report are the following: report 1989 monitoring data for the installation and its environs that may have been affected by operations on the plant site, provide reasonably detailed information about the plant site and plant operations, provide detailed information on input and assumptions used in all calculations, provide trend analyses (where appropriate) to indicate increases and decreases in environmental impact, and provide general information on plant quality assurance. Routine monitoring and sampling for radiation, radioactive materials, and chemical substances on and off the DOE site are used to document compliance with appropriate standards, to identify trends, to provide information for the public, and to contribute to general environmental knowledge. The surveillance program assists in fulfilling the DOE policy of protecting the public, employees, and environment from harm that could be caused by its activities and reducing negative environmental impacts to the greatest degree practicable. Environmental-monitoring information complements data on specific releases, trends, and summaries. 26 refs.

  17. 78 FR 65389 - United States Enrichment Corporation, Paducah Gaseous Diffusion Plant

    Science.gov (United States)

    2013-10-31

    ... COMMISSION United States Enrichment Corporation, Paducah Gaseous Diffusion Plant AGENCY: Nuclear Regulatory...) for the Paducah Gaseous Diffusion Plant (PGDP). The current CoC for PGDP is set to expire on December... operation of a uranium enrichment facility in Paducah, Kentucky, using the gaseous ] diffusion process. PGDP...

  18. Uranium deposit removal from the Oak Ridge Gaseous Diffusion Plant K-25 Building

    International Nuclear Information System (INIS)

    Ladd, L.D.; Stinnett, E.C. Jr.; Hale, J.R.; Haire, M.J.

    1993-01-01

    The Oak Ridge Gaseous Diffusion Plant went into operation as the first plant to separate uranium by the gaseous diffusion process. It was built during World War II as part of the U.S. Army Corps of Engineers' Manhattan Project. Its war-time code name was K-25, which was also the name of the first uranium separation building constructed at the installation. The K-25 building was considered an engineering miracle at the time of its construction. Built in a U shape ∼1 mile long and 400 ft wide, it housed complex and unique separation equipment. Despite its size and complexity, it was made fully operational within <2 yr after construction began. The facility operated successfully for more than 20 yr until it was placed in a standby mode in 1964. It is now clear the K-25 gaseous diffusion plant will never again be used to enrich uranium. The U.S. Department of Energy, therefore, has initiated a decontamination and decommission program. This paper discusses various procedures and techniques for addressing critical mass, uranium deposits, and safeguards issues

  19. Control of technetium at the Portsmouth Gaseous Diffusion Plant

    International Nuclear Information System (INIS)

    Saraceno, A.J.

    1981-01-01

    Technetium-99 entered the gaseous diffusion complex as a volatile impurity in recycled uranium that was fed to the Paducah Gaseous Diffusion Plant. Subsequently, it entered the Oak Ridge and Portsmouth cascades as an impurity in Paducah product feed. Most of the technetium was adsorbed on cascade equipment in increasingly high concentrations as it moved up the cascade. Since the low energy beta radiation produced by technetium cannot penetrate cascade equipment, it presents no significant hazard to workers as long as it remains inside of equipment. However, when equipment that contains high concentrations of technetium is opened for maintenance or change-out, precautions are taken to ensure worker safety. Traps containing activated alumina are used at the plant vent streams to limit radioactive emissions as far as possible. Annual vent stream emissions have been well below DOE limits. To allow continued compliance, other potential trapping agents have been tested. Several that limit emissions more effectively than activated alumina have been found. Other traps containing magnesium fluoride are used in the upper cascade to reduce the technetium concentration. Waste solutions from decontamination can also contain technetium. These solutions must either be stored for controlled discharge or treated to remove the technetium. To allow the latter, an ion exchange facility is being installed for operation by the end of FY-1982. Liquid discharges at Portsmouth have usually been less than 5% of the DOE imposed limits

  20. IAEA verification experiment at the Portsmouth Gaseous Diffusion Plant

    International Nuclear Information System (INIS)

    Gordon, D.M.; Subudhi, M.; Calvert, O.L.; Bonner, T.N.; Cherry, R.C.; Whiting, N.E.

    1998-01-01

    In April 1996, the United States (US) added the Portsmouth Gaseous Diffusion Plant to the list of facilities eligible for the application of International Atomic Energy Agency (IAEA) safeguards. At that time, the US proposed that the IAEA carry out a Verification Experiment at the plant with respect to the downblending of about 13 metric tons of highly enriched uranium (HEU) in the form of UF 6 . This material is part of the 226 metric tons of fissile material that President Clinton has declared to be excess to US national-security needs and which will be permanently withdrawn from the US nuclear stockpile. In September 1997, the IAEA agreed to carry out this experiment, and during the first three weeks of December 1997, the IAEA verified the design information concerning the downblending process. The plant has been subject to short-notice random inspections since December 17, 1997. This paper provides an overview of the Verification Experiment, the monitoring technologies used in the verification approach, and some of the experience gained to date

  1. Paducah Gaseous Diffusion Plant Annual Site Environmental Report for 1993

    International Nuclear Information System (INIS)

    1994-10-01

    The purpose of this document is to summarize effluent monitoring and environmental surveillance results and compliance with environmental laws, regulations, and orders at the Paducah Gaseous Diffusion Plant (PGDP). Environmental monitoring at PGDP consists of two major activities: effluent monitoring and environmental surveillance. Effluent monitoring is direct measurement or the collection and analysis of samples of liquid and gaseous discharges to the environment. Environmental surveillance is direct measurement or the collection and analysis of samples of air, water, soil, foodstuff, biota, and other media. Environmental monitoring is performed to characterize and quantify contaminants, assess radiation exposures of members of the public, demonstrate compliance with applicable standards and permit requirements, and detect and assess the effects (if any) on the local environment. Multiple samples are collected throughout the year and are analyzed for radioactivity, chemical content, and various physical attributes

  2. Paducah Gaseous Diffusion Plant Annual Site Environmental Report for 1993

    Energy Technology Data Exchange (ETDEWEB)

    1994-10-01

    The purpose of this document is to summarize effluent monitoring and environmental surveillance results and compliance with environmental laws, regulations, and orders at the Paducah Gaseous Diffusion Plant (PGDP). Environmental monitoring at PGDP consists of two major activities: effluent monitoring and environmental surveillance. Effluent monitoring is direct measurement or the collection and analysis of samples of liquid and gaseous discharges to the environment. Environmental surveillance is direct measurement or the collection and analysis of samples of air, water, soil, foodstuff, biota, and other media. Environmental monitoring is performed to characterize and quantify contaminants, assess radiation exposures of members of the public, demonstrate compliance with applicable standards and permit requirements, and detect and assess the effects (if any) on the local environment. Multiple samples are collected throughout the year and are analyzed for radioactivity, chemical content, and various physical attributes.

  3. Mortality patterns among Paducah Gaseous Diffusion Plant workers.

    Science.gov (United States)

    Chan, Caroline; Hughes, Therese S; Muldoon, Susan; Aldrich, Tim; Rice, Carol; Hornung, Richard; Brion, Gail; Tollerud, David J

    2010-07-01

    To determine whether Paducah Gaseous Diffusion Plant workers had mortality patterns that differed from the general US population and to investigate whether mortality patterns were associated with job title or workplace exposures. A retrospective occupational cohort mortality study was conducted on 6759 workers. Standardized mortality ratio analyses compared the cohort with the referent US population. Internal comparisons producing standardized rate ratios were conducted by job title, metal exposure, and cumulative internal and external radiation exposures. Overall mortality and cancer rates were lower than the referent population, reflecting a strong healthy worker effect. Individual not significant standardized mortality ratios and standardized rate ratios were noted for cancers of the lymphatic and hematopoietic tissue. Although relatively low exposures to radiation and metals did not produce statistically significant health effects, no significant elevations for lymphatic and hematopoietic cancers were consistent with previous studies of nuclear workers.

  4. The critical safety functions and plant operation

    International Nuclear Information System (INIS)

    Corcoran, W.R.; Church, J.F.; Porter, N.J.; Cross, M.T.; Guinn, W.M.

    1981-01-01

    The paper outlines the operator's role in nuclear safety and introduces the concept of ''safety functions''. Safety functions are a group of actions that prevent core melt or minimize radiation releases to the general public. They can be used to provide a hierarchy of practical plant protection that an operator should use. ''An accident identical to that at Three Mile Island is not going to happen again'', said the Rogovin investigators. The concepts put forward in this paper are intended to help the operator avoid serious consequence from the next unexpected threat. On the basis of the safety evaluation, the operator has three roles in assuring that the consequences of an event will be no worse than the predicted acceptable results. These three operator roles are: first, maintain plant setup in readiness to properly respond; second, operate the plant in a manner such that fewer, milder events minimize the frequency and the severity of adverse events; third, the operator needs to monitor the plant to verify that the safety functions are accomplished. The operator needs a systematic approach to mitigating the consequences of an event. The concept of ''safety function'' introduces that systematic approach and prevents a hierarchy of protection. If the operator has difficulty in identifying an event for any reason, the systematic safety function approach allows ones to accomplish the overall path of mitigating consequences. There are ten identified functions designed to protect against core melt, preserve containment integrity, prevent indirect release of radioactivity, and maintain vital auxiliaries needed to support the other safety functions. The paper describes in detail the operator's role and the safety functions, and provides many examples of the use of alternative success paths to accomplish the safety function

  5. 78 FR 30342 - United States Enrichment Corporation, Paducah Gaseous Diffusion Plant

    Science.gov (United States)

    2013-05-22

    ... COMMISSION United States Enrichment Corporation, Paducah Gaseous Diffusion Plant AGENCY: Nuclear Regulatory... Renewal of its Certificate of Compliance (CoC) for the Paducah Gaseous Diffusion Plant (PGDP). The existing CoC (No. GDP-1) authorizes operation of a uranium enrichment facility in Paducah, Kentucky. The...

  6. Lung Cancer Mortality among Uranium Gaseous Diffusion Plant Workers: A Cohort Study 1952–2004

    OpenAIRE

    LW Figgs

    2013-01-01

    Background: 9%–15% of all lung cancers are attributable to occupational exposures. Reports are disparate regarding elevated lung cancer mortality risk among workers employed at uranium gaseous diffusion plants. Objective: To investigate whether external radiation exposure is associated with lung cancer mortality risk among uranium gaseous diffusion workers. Methods: A cohort of 6820 nuclear industry workers employed from 1952 to 2003 at the Paducah uranium gaseous diffusion plant (PGD...

  7. Critical behavior in reaction-diffusion systems exhibiting absorbing phase transition

    CERN Document Server

    Ódor, G

    2003-01-01

    Phase transitions of reaction-diffusion systems with site occupation restriction and with particle creation that requires n>1 parents and where explicit diffusion of single particles (A) exists are reviewed. Arguments based on mean-field approximation and simulations are given which support novel kind of non-equilibrium criticality. These are in contradiction with the implications of a suggested phenomenological, multiplicative noise Langevin equation approach and with some of recent numerical analysis. Simulation results for the one and two dimensional binary spreading 2A -> 4A, 4A -> 2A model display a new type of mean-field criticality characterized by alpha=1/3 and beta=1/2 critical exponents suggested in cond-mat/0210615.

  8. Bioavailability study for the Paducah Gaseous Diffusion Plant

    Energy Technology Data Exchange (ETDEWEB)

    Phipps, T.L.; Kszos, L.A.

    1996-08-01

    The overall purpose of this plan is to assess the bioavailability of metals in the continuous and intermittent outfalls. The results may be used to determine alternative metal limits that more appropriately measure the portion of metal present necessary for toxicity to aquatic life. These limits must remain protective of in-stream aquatic life; thus, the highest concentration of metal in the water will be determined concurrently with an assessment of acute or chronic toxicity on laboratory tests. Using the method developed by the Kentucky Division of Water (KDOW), biomonitoring results and chemical data will be used to recommend alternative metal limits for the outfalls of concern. The data will be used to meet the objectives of the study: (1) evaluate the toxicity of continuous outfalls and intermittent outfalls at Paducah Gaseous Diffusion Plant; (2) determine the mean ratio of dissolved to Total Recoverable metal for Cd, Cr, Cu, Pb, Ni, and Zn in the continuous and intermittent outfalls; (3) determine whether the concentration of total recoverable metal discharged causes toxicity to fathead minnows and /or Ceriodaphnia; and (4) determine alternative metal limits for each metal of concern (Cd, Cr, Cu, Pb, Ni, and Zn).

  9. Partnering efforts at the Paducah Gaseous Diffusion Plant

    International Nuclear Information System (INIS)

    Warren, C.B.

    1995-01-01

    Before individuals or agencies can effectively work together to solve common problems, they must first agree on exactly what those problems are and establish common goals and methods that will lead to mutually acceptable solutions. Then, they must make a conscientious effort to form a cohesive team that focuses on the established goals and deemphasize traditional roles, which may in some instances be considered adversarial. This kind of teamwork/partnering process can be more difficult, though not impossible, to achieve in cases where there are traditional (real or imagined) adversarial relationships between the parties, i.e. regulator vs. regulated. The US Department of Energy Site Office (DOE) at Paducah, Kentucky, the Kentucky Department of Environmental Protection (KDEP) and the US Environmental Protection Agency, Region IV (EPA) have made t strides toward teamwork and partnering at DOE's Paducah Gaseous Diffusion Plant. They have accomplished this in a number of ways, which will be discussed in greater detail but first and foremost, the agencies agreed up front that they had mutual goals and interests. These goals are to protect public health and the environment in a cost-effective and timely manner, taking care to make the wisest use of public resources (tax dollars); to evaluate and minimize risks, and to achieve ''Win-Win'' for all parties concerned

  10. Innovative Decontamination Technology for Use in Gaseous Diffusion Plant Decommissioning

    International Nuclear Information System (INIS)

    Peters, M.J.; Norton, C.J.; Fraikor, G.B.; Potter, G.L.; Chang, K.C.

    2006-01-01

    The results of bench scale tests demonstrated that TechXtract R RadPro TM technology (hereinafter referred to as RadPro R ) can provide 100% coverage of complex mockup gaseous diffusion plant (GDP) equipment and can decontaminate uranium (U) deposits with 98% to 99.99% efficiency. Deployment tests demonstrated RadPro R can be applied as foam, mist/fog, or steam, and fully cover the internal surfaces of complex mockup equipment, including large piping. Decontamination tests demonstrated that two formulations of RadPro R , one with neutron attenuators and one without neutron attenuators, could remove up to 99.99% of uranyl fluoride deposits, one of the most difficult to remove deposits in GDP equipment. These results were supplemented by results from previous tests conducted in 1994 that showed RadPro R could remove >97% of U and Tc-99 contamination from actual GDP components. Operational use of RadPro R at other DOE and commercial facilities also support these data. (authors)

  11. Self-diffusion in electrolyte solutions a critical examination of data compiled from the literature

    CERN Document Server

    Mills, R

    1989-01-01

    This compilation - the first of its kind - fills a real gap in the field of electrolyte data. Virtually all self-diffusion data in electrolyte solutions as reported in the literature have been examined and the book contains over 400 tables covering diffusion in binary and ternary aqueous solutions, in mixed solvents, and of non-electrolytes in various solvents.An important feature of the compilation is that all data have been critically examined and their accuracy assessed. Other features are an introductory chapter in which the methods of measurement are reviewed; appendices containing tables

  12. A Boundary Element-Response Matrix method for criticality diffusion problems in xyz geometry

    International Nuclear Information System (INIS)

    Cossa, G.; Giusti, V.; Montagnini, B.

    2010-01-01

    The Boundary Element-Response Matrix (BERM) method shown in the paper aims to represent an alternative to the Finite Element method in order to solve 3D multigroup diffusion (criticality) problems in xyz geometry. The theory extends the previous work on the diffusion equations in two dimensions and new techniques for the evaluation of the integrals involved in the boundary integral equations, as well as new procedures for solving the resulting linear system, have greatly enhanced the performances of the method. Results show that BERM can achieve an excellent accuracy, still keeping a good computational efficiency.

  13. Diffusivity-Based Characterization of Plant Growth Media for Earth and Space

    DEFF Research Database (Denmark)

    Chamindu, Deepagoda; Møldrup, Per; Jones, Scot B.

    Most of the plant requirements for optimal growth (air, water, and nutrient supply, and mechanical support) are closely linked with the basic physical properties of the growth media. Oxygen and nutrients supply to plant roots occur predominantly by diffusion, and gas and solute diffusivity...... are the key parameters controlling the diffusive movement of oxygen and nutrients in the root zone. As one among several essential aspects of optimal porous media design for plant growth, this study presents a diffusion-based characterization of four aggregated growth media. To account for the observed large...... percolation threshold for gas diffusivity in the selected media, we presented an Inactive Pore and Density Corrected (IPDC) model which could describe well the measured gas diffusivity in both inter- and inter-aggregate pore regions. A strong relation (r2 = 0.98) between percolation threshold for gas...

  14. The influence of different diffusion pattern to the sub- and super-critical fluid flow in brown coal

    Science.gov (United States)

    Peng, Peihuo

    2018-03-01

    Sub- and super-critical CO2 flowing in nanoscale pores are recently becoming of great interest due to that it is closely related to many engineering applications, such as geological burial and sequestration of carbon dioxide, Enhanced Coal Bed Methane recovery ( ECBM), super-critical CO2 fracturing and so on. Gas flow in nanopores cannot be described simply by the Darcy equation. Different diffusion pattern such as Fick diffusion, Knudsen diffusion, transitional diffusion and slip flow at the solid matrix separate the seepage behaviour from Darcy-type flow. According to the principle of different diffusion pattern, the flow of sub- and super-critical CO2 in brown coal was simulated by numerical method, and the results were compared with the experimental results to explore the contribution of different diffusion pattern and swelling effect in sub- and super-critical CO2 flow in nanoscale pores.

  15. Prioritizing and scheduling Portsmouth Gaseous Diffusion Plant safeguards upgrades

    International Nuclear Information System (INIS)

    Edmunds, T.; Saleh, R.; Zevanove, S.

    1992-02-01

    As part of the Site Safeguards and Security Plan (SSSP), facilities are required to develop a Resource Plan (RP). The Resource Plan provides documentation and justification for the facility's planned upgrades, including the schedule, priority, and cost estimates for the safeguards and security upgrades. Portsmouth Gaseous Diffusion Plant (PORTS) management has identified and obtained funding approval for a number of safeguards and security upgrades, including line-item construction projects. These upgrade projects were selected to address a variety of concerns identified in the PORTS vulnerability assessments and other reviews performed in support of the SSSP process. However, budgeting and scheduling constraints do not make it possible to simultaneously begin implementation of all of the upgrade projects. A formal methodology and analysis are needed to explicitly address the trade-offs between competing safeguards objectives, and to prioritize and schedule the upgrade projects to ensure that the maximum benefit can be realized in the shortest possible time frame. The purpose of this report is to describe the methodology developed to support these upgrade project scheduling decisions. The report also presents the results obtained from applying the methodology to a set of the upgrade projects selected by PORTS S ampersand S management. Data for the analysis are based on discussions with personnel familiar with the PORTS safeguards and security needs, the requirements for implementing these upgrades, and upgrade funding limitations. The analysis results presented here assume continued highly enriched uranium (HEU) operations at PORTS. However, the methodology developed is readily adaptable for the evaluation of other operational scenarios and other resource allocation issues relevant to PORTS

  16. Critical regimes driven by recurrent mobility patterns of reaction-diffusion processes in networks

    Science.gov (United States)

    Gómez-Gardeñes, J.; Soriano-Paños, D.; Arenas, A.

    2018-04-01

    Reaction-diffusion processes1 have been widely used to study dynamical processes in epidemics2-4 and ecology5 in networked metapopulations. In the context of epidemics6, reaction processes are understood as contagions within each subpopulation (patch), while diffusion represents the mobility of individuals between patches. Recently, the characteristics of human mobility7, such as its recurrent nature, have been proven crucial to understand the phase transition to endemic epidemic states8,9. Here, by developing a framework able to cope with the elementary epidemic processes, the spatial distribution of populations and the commuting mobility patterns, we discover three different critical regimes of the epidemic incidence as a function of these parameters. Interestingly, we reveal a regime of the reaction-diffussion process in which, counter-intuitively, mobility is detrimental to the spread of disease. We analytically determine the precise conditions for the emergence of any of the three possible critical regimes in real and synthetic networks.

  17. Scheduling the maintenance of gaseous diffusion and electric power distribution plants

    International Nuclear Information System (INIS)

    Chauvet, D.

    1990-01-01

    A computer aided scheduling applied to the maintenance of a uranium enrichment plant is presented. The plant exploits gaseous diffusion and electric power distribution plants, for which the operating conditions must be satisfied. The management and the execution of the maintenance actions are computer aided. Concerning the techniques, the cost, the safety and the scheduling actions were optimized [fr

  18. A critical comparison of constant and pulsed flow systems exploiting gas diffusion.

    Science.gov (United States)

    Silva, Claudineia Rodrigues; Henriquez, Camelia; Frizzarin, Rejane Mara; Zagatto, Elias Ayres Guidetti; Cerda, Victor

    2016-02-01

    Considering the beneficial aspects arising from the implementation of pulsed flows in flow analysis, and the relevance of in-line gas diffusion as an analyte separation/concentration step, influence of flow pattern in flow systems with in-line gas diffusion was critically investigated. To this end, constant or pulsed flows delivered by syringe or solenoid pumps were exploited. For each flow pattern, two variants involving different interaction times of the donor with the acceptor streams were studied. In the first one, both the acceptor and donor streams were continuously flowing, whereas in the second one, the acceptor was stopped during the gas diffusion step. Four different volatile species (ammonia, ethanol, carbon dioxide and hydrogen sulfide) were selected as models. For the flow patterns and variants studied, the efficiencies of mass transport in the gas diffusion process were compared, and sensitivity, repeatability, sampling frequency and recorded peak shape were evaluated. Analysis of the results revealed that sensitivity is strongly dependent on the implemented variant, and that flow pattern is an important feature in flow systems with in-line gas diffusion. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. 75 FR 21394 - Endangered and Threatened Wildlife and Plants; Final Revised Critical Habitat for Hine's Emerald...

    Science.gov (United States)

    2010-04-23

    ... Threatened Wildlife and Plants; Final Revised Critical Habitat for Hine's Emerald Dragonfly (Somatochlora... Plants; Final Revised Critical Habitat for Hine's Emerald Dragonfly (Somatochlora hineana) AGENCY: Fish... (Service), are designating critical habitat for the Hine's emerald dragonfly (Somatochlora hineana) under...

  20. Solutions to criticality problems in a plutonium extraction plant

    International Nuclear Information System (INIS)

    Jouannaud, C.; Rodier, J.; Fruchard, Y.; Peyresblanques, H.; Papault, C.; Tabardel-Brian, R.

    1968-08-01

    There are two aspects to nuclear criticality safety: prevention of criticality and protection against the consequences of a possible accident: this report considers these two aspects in the case of the Marcoule Plutonium Extraction Plant. After briefly recalling the various techniques used for avoiding criticality (mass, geometry, concentration, poisoning), the authors describe their application in the plant and show in particular that, a rational use of a favorable geometry is a factor both for security and from an economic point of view. The authors then describe the inside organisation which makes it possible to obtain the necessary intrinsic safety standard right from the advance project stage, and to control the workshop safety during the operation of the plant. The second part of the report deals with the system of protection against the consequences of a possible accident: definition of a typical accident, fixing of the boundaries of a critical zone, safety alarm device, individual and collective dosimetry, evacuation plan and safety instructions. (authors) [fr

  1. 78 FR 39698 - Endangered and Threatened Wildlife and Plants; Designating Critical Habitat for Three Plant...

    Science.gov (United States)

    2013-07-02

    ... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 17 [Docket No. FWS-R1-ES-2013-0028; 4500030113] RIN 1018-AZ38 Endangered and Threatened Wildlife and Plants; Designating Critical Habitat for Three Plant Species on Hawaii Island AGENCY: Fish and Wildlife Service, Interior. ACTION...

  2. 77 FR 3255 - Notice of 229 Boundary Revision at the Paducah Gaseous Diffusion Plant

    Science.gov (United States)

    2012-01-23

    ... No: 2012-1214] DEPARTMENT OF ENERGY Notice of 229 Boundary Revision at the Paducah Gaseous Diffusion... entry into or upon areas, buildings, and other facilities of the Paducah Gaseous Diffusion Plant... provided in 10 CFR 860.4, into or upon this facility, installation, or real property of the Paducah Gaseous...

  3. Prevention of criticality accidents in a fuel cycle plant

    International Nuclear Information System (INIS)

    Gatti, A.M.; Canavese, S.I.; Capadona, N.M.

    1990-01-01

    This work reports the basic considerations on criticality accidents applied to an uranium dioxide fuel cycle production plant. The different fabrication stages are briefly described, with the identification of the neutronically isolated areas. Once the areas have been defined, an evaluation is made, setting up the control parameters to be used in each of them and their variation ranges; normal operation limitations based on experimental data or validating calculations, applied specifically to 5% enriched uranium, are established. Afterwards, defined parameters deviations are analyzed due to incidental conditions in order to prevent criticality accidents under normal conditions and maintenance operations. (Author) [es

  4. Preliminary analyses on hydrogen diffusion through small break of thermo-chemical IS process hydrogen plant

    International Nuclear Information System (INIS)

    Somolova, Marketa; Terada, Atsuhiko; Takegami, Hiroaki; Iwatsuki, Jin

    2008-12-01

    Japan Atomic Energy Agency has been conducting a conceptual design study of nuclear hydrogen demonstration plant, that is, a thermal-chemical IS process hydrogen plant coupled with the High temperature Engineering Test Reactor (HTTR-IS), which will be planed to produce a large amount of hydrogen up to 1000m 3 /h. As part of the conceptual design work of the HTTR-IS system, preliminary analyses on small break of a hydrogen pipeline in the IS process hydrogen plant was carried out as a first step of the safety analyses. This report presents analytical results of hydrogen diffusion behaviors predicted with a CFD code, in which a diffusion model focused on the turbulent Schmidt number was incorporated. By modifying diffusion model, especially a constant accompanying the turbulent Schmidt number in the diffusion term, analytical results was made agreed well with the experimental results. (author)

  5. Radioepidemiological studies on workers in uranium fuel plants and gaseous diffusion plants

    International Nuclear Information System (INIS)

    Li Weilin; Tang Zhongliu; She Guizhi

    1995-01-01

    This retrospective study of causes of death includes workers in nuclear fuel element plants and gaseous diffusion plants. The observation population consisted of 3652 workers in exposure group and 5393 workers in control group, with 53813 and 81650 person-years in the above two groups respectively during the period from 1971 to 1985 (1986). The individual committed effective dose was less than 1 mSv per year and the accumulative dose was about 10 mSv in the period. In the observation period, 104 and 253 persons died in the exposure and control groups, respectively. The numbers of cancer death in these two groups were 49 and 82, respectively. The crude mortality rates were 193.26 x 10 -5 /person years and 309.86 x 10 -5 /person years, the cancer mortality rates were 91.06 x 10 -5 /person years and 100.43 x 10 -5 /person years, respectively. There was no significant difference in crude mortality rates between the two groups after age adjustment. For standardized mortality ratio (SMR) of cancer, the calculation was carried out in the light of national survey of this SMR in small cities in 1973-1975. The results showed that SMRs of both groups were less than 1 and there was no significant difference between the two groups. So, there was no evidence of incidence increment of radiogenic cancer in workers exposed to low-level ionizing radiation

  6. Minimum critical power ratio control device for nuclear power plants

    International Nuclear Information System (INIS)

    Kurosawa, Tsuneo.

    1991-01-01

    Reactor core flowrate is determined by comparing a minimum critical power ratio calculated based on the status amount of a nuclear power plant and a control value for the minimum critical power ratio that depends on the reactor core flowrate. Further, the minimum critical power ratio and a control value for the minimum critical power ratio that depends on the reactor thermal power are compared to set a reactor thermal power converted to a reactor core flowrate. Deviation between the thus determined reactor core flowrate and the present reactor core flowrate is calculated. When the obtained deviation is lower than a rated value, a reactor core flowrate set signal is generated to a reactor flowrate control means, to control the reactor power by a recycling flowrate control system of the reactor. On the other hand, when the deviation exceeds the determined value, the reactor core flowrate set signal is converted into a reactor thermal power, to control the position of control rods and control the reactor power. Then, monitor and control can be conducted safely and automatically without depending on operator's individual ability over the entire operation range corresponding to load following operation. (N.H.)

  7. Recovery of energy in a gaseous diffusion plant

    International Nuclear Information System (INIS)

    Ergalant, Jacques; Guais, J.-C.; Perrault, Michel; Vignet, Paul

    1975-01-01

    Any energy recovery, even partial, goes in the direction of savings in energy and should be sought for. The Tricastin plant, now in the course of being built, will be able to deliver several hundreds of MW for the purpose of urban and agricultural heating. The new Coredif project will more completely integrate the valorization of calories in its definition (choice of temperatures, design of the heat exchangers, recovery cycles). In fact the recent evolution in energy costs renders the otpimization of a plant equipped with a heat recovery system (1 to 2% on the cost of the uranium produced) now economically worth-while. In the same way, the choice of the site of the future plant may be conditioned by the possible uses of calories in its vicinity [fr

  8. METHOD OF AND APPARATUS FOR WITHDRAWING LIGHT ISOTOPIC PRODUCT FROM A LIQUID THERMAL DIFFUSION PLANT

    Science.gov (United States)

    Dole, M.

    1959-09-22

    An improved process and apparatus are described for removing enriched product from the columns of a thermal diffusion plant for separation of isotopes. In the removal cycle, light product at the top cf the diffusion columns is circulated through the column tops and a shipping cylinder connected thereto unttl the concertation of enriched product in the cylinder reaches the desired point. During the removal, circulation through the bottoms is blocked bv freezing. in the diffusion cycle, the bottom portion is unfrozen, fresh feed is distributed to the bottoms of the columns, ard heavy product is withdrawn from the bottoms, while the tops of the columns are blocked by freezing.

  9. Second order transient effects in a gaseous diffusion plant

    International Nuclear Information System (INIS)

    Bouligand, O.M.

    1963-01-01

    Perturbations applied to various parameters of an isotope separation plant indices an average effect on production. This effect is determined for a finite cascade over infinite reservoir. Perturbations on product flow rate and inter-stage transports are considered. (author) [fr

  10. Nitrogen-system safety study: Portsmouth Gaseous Diffusion Plant

    International Nuclear Information System (INIS)

    1982-07-01

    The Department of Energy has primary responsibility for the safety of operations at DOE-owned nuclear facilities. The guidelines for the analysis of credible accidents are outlined in DOE Order 5481.1. DOE has requested that existing plant facilities and operations be reviewed for potential safety problems not covered by standard industrial safety procedures. This review is being conducted by investigating individual facilities and documenting the results in Safety Study Reports which will be compiled to form the Existing Plant Final Safety Analysis Report which is scheduled for completion in September, 1984. This Safety Study documents the review of the Plant Nitrogen System facilities and operations and consists of Section 4.0, Facility and Process Description, and Section 5.0, Accident Analysis, of the Final Safety Analysis Report format. The existing nitrogen system consists of a Superior Air Products Company Type D Nitrogen Plant, nitrogen storage facilities, vaporization facilities and a distribution system. The system is designed to generate and distribute nitrogen gas used in the cascade for seal feed, buffer systems, and for servicing equipment when exceptionally low dew points are required. Gaseous nitrogen is also distributed to various process auxiliary buildings. The average usage is approximately 130,000 standard cubic feet per day

  11. 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

  12. Portsmouth Gaseous Diffusion Plant expansion, Piketon, Ohio. Volume 2. Draft environmental statement

    International Nuclear Information System (INIS)

    1976-06-01

    The need for additional uranium enrichment facilities and the environmental impacts of the add-on gaseous diffusion plant proposed for the Portsmouth Gaseous Diffusion Plant are discussed. A detailed description of the proposed facilities is included and unavoidable adverse environmental effects, possible alternatives, and anticipated benefits from the proposed facilities are considered. The flora and fauna of the area are tabulated and possible effects of air and water pollution on aquatic and terrestrial ecosystems are postulated. The extent of anticipated noise impact on the vicinity and the anticipated extent of civic envolvement are discussed

  13. Preliminary study of PCBs in raccoons living on or near the Paducah Gaseous Diffusion Plant, Kentucky

    Energy Technology Data Exchange (ETDEWEB)

    Halbrook, Richard S. [Southern Illinois Univ., Carbondale, IL (United States). Dept. of Zoology. Cooperative Wildlife Research Lab. Kentucky Research Consortium for Energy and Environment

    2016-01-15

    The “Ecological Monitoring at the Paducah Gaseous Diffusion Plant: Historical Evaluation and Guidelines for Future Monitoring” report (Halbrook, et al. 2007) recommended the raccoon as a species for study at the Paducah Gaseous Diffusion Plant (PGDP). This species was selected to fill data gaps in ecological resources and provide resource managers with knowledge that will be valuable in making decisions and implementing specific actions to safeguard ecological resources and reduce human exposure. The current paper reports results of a preliminary evaluation to establish protocols for collection of tissues and initial screening of polychlorinated biphenyls (PCBs) in raccoons collected near the PGDP. These data are useful in developing future more comprehensive studies.

  14. Portsmouth Gaseous Diffusion Plant expansion, Piketon, Ohio. Volume 2. Draft environmental statement

    Energy Technology Data Exchange (ETDEWEB)

    Pennington, W. H.

    1976-06-01

    The need for additional uranium enrichment facilities and the environmental impacts of the add-on gaseous diffusion plant proposed for the Portsmouth Gaseous Diffusion Plant are discussed. A detailed description of the proposed facilities is included and unavoidable adverse environmental effects, possible alternatives, and anticipated benefits from the proposed facilities are considered. The flora and fauna of the area are tabulated and possible effects of air and water pollution on aquatic and terrestrial ecosystems are postulated. The extent of anticipated noise impact on the vicinity and the anticipated extent of civic envolvement are discussed. (CH)

  15. Uranium isotope separation by gaseous diffusion and plant safety

    International Nuclear Information System (INIS)

    Simeon, Claude; Dumas, Maurice.

    1980-07-01

    This report constitutes a safety guide for operators of uranium isotope separation plants, and includes both aspects of safety and protection. Taking into account the complexity of safety problems raised at design and during operation of plants which require specialized guides, this report mainly considers both the protection of man, the environment and goods, and the principles of occupational safety. It does not claim to be comprehensive, but intends to state the general principles, the particular points related to the characteristics of the basic materials and processes, and to set forth a number of typical solutions suitable for various human and technical environments. It is based on the French experience gained during the last fifteen years [fr

  16. TRITON, 3-D Multi-Region Neutron Diffusion Burnup with Criticality Search

    International Nuclear Information System (INIS)

    1974-01-01

    1 - Nature of physical problem solved: TRITON is a multigroup diffusion depletion program in three dimensions (x,y,z). In addition to the straight K eff calculation, three types of criticality searches are possible - diluted control isotope search, region-wise smeared control isotope search, region-wise smeared control isotope search, region-wise smeared control isotope boundary search (the control isotope can be smeared over one region or over a group of regions called a control bank). The depletion equations are solved region-wise. More than one microscopic cross section library can be used in the various regions of the reactor. The same is true for self-shielding factors. Such sets of data can be changed at pre-determined time steps. 2 - Method of solution: The mathematical model employed for the solution of the finite difference equations, which is derived from a seven-point approximation of diffusion equations, is an on-line Chebyshev semi- iterative method. 3 - Restrictions on the complexity of the problem: Maximum number of: library sets: 1; self-shielding sets: 10; compositions: 100; self-shielding coefficients: 6000; groups: 10; fuel isotopes: 30; fission products: 29; isotopes: 50; burnable isotopes: 40; control banks: 100; mesh points: 15000; regions: 400; time steps: 100; control areas: 100; small time steps: 200; elements in the control list: 400; x planes: 100; y planes: 100; z planes: 100

  17. Marine monitoring surveys for desalination plants-A critical review

    KAUST Repository

    Lattemann, Sabine

    2013-01-01

    Environmental impact assessment (EIA) studies are standard practice and a regulatory requirement for most new desalination projects today. However, most of the EIA studies are limited to predictive information; that is, they gather information on the project and the project\\'s environment before project implementation to make predictions about likely impacts. The EIAs may involve comprehensive studies, such as field monitoring, laboratory toxicity testing, and modeling studies. Consequently, the"surprising paucity of useful experimental data, either from laboratory tests or from field monitoring studies", which was observed by the US National Research Council in 2008, has been gradually decreasing. However, there is still a long-term research need on the site-specific effects of desalination plants after project commissioning has taken place. A main challenge of field research is the adequate design of the monitoring studies, which have to adequately distinguish the effects of the desalination project from natural processes over long periods of time. The existing monitoring studies have so far used a wide range of approaches and methods to investigate the environmental impacts of desalination plant discharges. Shortfalls are often that they are limited in scope, short-term, or localized. In essence, many studies fall short of recognizing the potentially synergetic effects of the single waste components of the discharges on marine organisms and the complexity of the potential responses by the ecosystem. While the possible risk of damage arising from the concentrate discharge to the marine environment in close proximity to the outfall is at hand, no conclusive evidence can yet be provided concerning the long-term impacts of desalination plant discharges, let alone the cumulative impacts on certain sea areas. This paper conducts a critical review of existing monitoring programs for desalination plants. Shortcomings of current practices are identified and relevant

  18. An interim report to the manager of the Paducah Gaseous Diffusion Plant from the Paducah Environmental Advisory Committee

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, G.D.

    1987-10-01

    The Paducah Environmental Advisory Committee was formed as: (1) an outgrowth of other Environmental Advisory Committees already in existence at Oak Ridge and other Martin Marietta Energy Systems plants; (2) a result of public concern following significant nuclear incidents at Bhopal and Chernobyl; (3) a result of the new direction and commitment of the management of the Paducah Gaseous Diffusion Plant following contract acquisition by Martin Marietta Energy Systems; and (4) a means of reducing and/or preventing local and/or public concern regarding the activities of and potential risks created by PGDP. This report discusses the following issues and concerns of the Committee arrived at through a series of meetings: (1) groundwater monitoring; (2) long-range tails storage; C-404, scrap yrads, and PCB and TCE cleanup; nuclear criticality plan and alarm systems; documentation of historical data regarding hazardous waste burial grounds; dosimeter badges; and asbestos handling and removal.

  19. An interim report to the manager of the Paducah Gaseous Diffusion Plant from the Paducah Environmental Advisory Committee

    International Nuclear Information System (INIS)

    Jackson, G.D.

    1987-10-01

    The Paducah Environmental Advisory Committee was formed as: (1) an outgrowth of other Environmental Advisory Committees already in existence at Oak Ridge and other Martin Marietta Energy Systems plants; (2) a result of public concern following significant nuclear incidents at Bhopal and Chernobyl; (3) a result of the new direction and commitment of the management of the Paducah Gaseous Diffusion Plant following contract acquisition by Martin Marietta Energy Systems; and (4) a means of reducing and/or preventing local and/or public concern regarding the activities of and potential risks created by PGDP. This report discusses the following issues and concerns of the Committee arrived at through a series of meetings: (1) groundwater monitoring; (2) long-range tails storage; C-404, scrap yrads, and PCB and TCE cleanup; nuclear criticality plan and alarm systems; documentation of historical data regarding hazardous waste burial grounds; dosimeter badges; and asbestos handling and removal

  20. An interim report to the manager of the Paducah Gaseous Diffusion Plant from the Paducah Environmental Advisory Committee

    International Nuclear Information System (INIS)

    Jackson, G.D.

    1987-01-01

    The Paducah Environmental Advisory Committee was formed as: (1) an outgrowth of other Environmental Advisory Committees already in existence at Oak Ridge and other Martin Marietta Energy Systems plants; (2) a result of public concern following significant nuclear incidents at Bhopal and Chernobyl; (3) a result of the new direction and commitment of the management of the Paducah Gaseous Diffusion Plant following contract acquisition by Martin Marietta Energy Systems; and (4) a means of reducing and/or preventing local and/or public concern regarding the activities of and potential risks created by PGDP. This report discusses the following issues and concerns of the Committee arrived at through a series of meetings: (1) groundwater monitoring; (2) long-range tails storage; C-404, scrap yrads, and PCB and TCE cleanup; nuclear criticality plan and alarm systems; documentation of historical data regarding hazardous waste burial grounds; dosimeter badges; and asbestos handling and removal

  1. Detector for flow abnormalities in gaseous diffusion plant compressors

    Science.gov (United States)

    Smith, S.F.; Castleberry, K.N.

    1998-06-16

    A detector detects a flow abnormality in a plant compressor which outputs a motor current signal. The detector includes a demodulator/lowpass filter demodulating and filtering the motor current signal producing a demodulated signal, and first, second, third and fourth bandpass filters connected to the demodulator/lowpass filter, and filtering the demodulated signal in accordance with first, second, third and fourth bandpass frequencies generating first, second, third and fourth filtered signals having first, second, third and fourth amplitudes. The detector also includes first, second, third and fourth amplitude detectors connected to the first, second, third and fourth bandpass filters respectively, and detecting the first, second, third and fourth amplitudes, and first and second adders connected to the first and fourth amplitude detectors and the second and third amplitude detectors respectively, and adding the first and fourth amplitudes and the second and third amplitudes respectively generating first and second added signals. Finally, the detector includes a comparator, connected to the first and second adders, and comparing the first and second added signals and detecting the abnormal condition in the plant compressor when the second added signal exceeds the first added signal by a predetermined value. 6 figs.

  2. Site-specific earthquake response analysis for Paducah Gaseous Diffusion Plant, Paducah, Kentucky. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Sykora, D.W.; Davis, J.J.

    1993-08-01

    The Paducah Gaseous Diffusion Plant (PGDP), owned by the US Department of Energy (DOE) and operated under contract by Martin Marietta Energy systems, Inc., is located southwest of Paducah, Kentucky. An aerial photograph and an oblique sketch of the plant are shown in Figures 1 and 2, respectively. The fenced portion of the plant consists of 748 acres. This plant was constructed in the 1950`s and is one of only two gaseous diffusion plants in operation in the United States; the other is located near Portsmouth, Ohio. The facilities at PGDP are currently being evaluated for safety in response to natural seismic hazards. Design and evaluation guidelines to evaluate the effects of earthquakes and other natural hazards on DOE facilities follow probabilistic hazard models that have been outlined by Kennedy et al. (1990). Criteria also established by Kennedy et al. (1990) classify diffusion plants as ``moderate hazard`` facilities. The US Army Engineer Waterways Experiment Station (WES) was tasked to calculate the site response using site-specific design earthquake records developed by others and the results of previous geotechnical investigations. In all, six earthquake records at three hazard levels and four individual and one average soil columns were used.

  3. Behavior of thermal diffusion of hydrofluorocarbon HFC-32 near the critical region

    Science.gov (United States)

    Tsvetkov, O. B.; Laptev, Yu A.; Rykov, S. V.; Galahova, N. A.; Kolbasijk, K. S.

    2017-11-01

    HCFC-22 prohibited after 2020 Year. The thermal diffusion values of HFC-32 were determined using a received cross-over equation of state and available experimental thermal-conductivity data reported by a number of investigations including the authors of this work. Extensive measurements have been obtained for thermal conductivity of difluoromethane with a steady-state method for which coaxial-cylinder apparatus was employed. The sample fluid was located in a gap between two vertical cylinders. The occurrence of convection in the fluid was avoided one to application of small temperature differences across the gap. The range of state points studied includes those with densities from 70 to 1000 kg·m‑3, temperatures from 294 to 350 K and pressures up to 7 MPa. The isobaric specific heat values were determined from the crossover equation of state based on the phenomenological theory of a critical point and Benedek’s hypothesis. A theoretically based crossover model is capable to represent the thermodynamic properties of HFC-32 in a large range of temperatures and densities including the critical point.

  4. Long-range global warming impact of gaseous diffusion plant operation

    International Nuclear Information System (INIS)

    Trowbridge, L.D.

    1992-09-01

    The DOE gaseous diffusion plant complex makes extensive use of CFC-114 as a primary coolant. As this material is on the Montreal Protocol list of materials scheduled for production curtailment, a substitute must be found. In addition to physical cooling properties, the gaseous diffusion application imposes the unique requirement of chemical inertness to fluorinating agents. This has narrowed the selection of a near-term substitute to two fully fluorinated material, FC-318 and FC-3110, which are likely to be strong, long-lived greenhouse gases. In this document, calculations are presented showing, for a number of plausible scenarios of diffusion plant operation and coolant replacement strategy, the future course of coolant use, greenhouse gas emissions (including coolant and power-related indirect CO 2 emissions), and the consequent global temperature impacts of these scenarios

  5. Real Time Demonstration Project XRF Performance Evaluation Report for Paducah Gaseous Diffusion Plant AOC 492

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Robert L [Argonne National Laboratory

    2008-04-03

    This activity was undertaken to demonstrate the applicability of market-available XRF instruments to quantify metal concentrations relative to background and risk-based action and no action levels in Paducah Gaseous Diffusion Plant (PGDP) soils. As such, the analysis below demonstrates the capabilities of the instruments relative to soil characterization applications at the PGDP.

  6. Environmental Restoration Site-Specific Plan for the Portsmouth Gaseous Diffusion Plant, FY 93

    International Nuclear Information System (INIS)

    1993-01-01

    The purpose of this Site-Specific Plan (SSP) is to describe past, present, and future activities undertaken to implement Environmental Restoration and Waste Management goals at the Portsmouth Gaseous Diffusion Plant (PORTS). The SSP is presented in sections emphasizing Environmental Restoration description of activities, resources, and milestones

  7. 77 FR 18157 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Ipomopsis...

    Science.gov (United States)

    2012-03-27

    ... ``Penstemon debilis'' under ``Flowering Plants'' in the List of Endangered and Threatened Plants by removing...--plants. (a) Flowering plants. * * * * * Family Hydrophyllaceae: Phacelia submutica (DeBeque phacelia...-0040: 4500030114] RIN 1018-AX75 Endangered and Threatened Wildlife and Plants; Designation of Critical...

  8. Studying microstructure and microstructural changes in plant tissues by advanced diffusion magnetic resonance imaging techniques.

    Science.gov (United States)

    Morozov, Darya; Tal, Iris; Pisanty, Odelia; Shani, Eilon; Cohen, Yoram

    2017-04-01

    As sessile organisms, plants must respond to the environment by adjusting their growth and development. Most of the plant body is formed post-embryonically by continuous activity of apical and lateral meristems. The development of lateral adventitious roots is a complex process, and therefore the development of methods that can visualize, non-invasively, the plant microstructure and organ initiation that occur during growth and development is of paramount importance. In this study, relaxation-based and advanced diffusion magnetic resonance imaging (MRI) methods including diffusion tensor (DTI), q-space diffusion imaging (QSI), and double-pulsed-field-gradient (d-PFG) MRI, at 14.1 T, were used to characterize the hypocotyl microstructure and the microstructural changes that occurred during the development of lateral adventitious roots in tomato. Better contrast was observed in relaxation-based MRI using higher in-plane resolution but this also resulted in a significant reduction in the signal-to-noise ratio of the T2-weighted MR images. Diffusion MRI revealed that water diffusion is highly anisotropic in the vascular cylinder. QSI and d-PGSE MRI showed that in the vascular cylinder some of the cells have sizes in the range of 6-10 μm. The MR images captured cell reorganization during adventitious root formation in the periphery of the primary vascular bundles, adjacent to the xylem pole that broke through the cortex and epidermis layers. This study demonstrates that MRI and diffusion MRI methods allow the non-invasive study of microstructural features of plants, and enable microstructural changes associated with adventitious root formation to be followed. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  9. CITATION, 3-D Multigroup Diffusion with 1. Order Perturbation and Criticality Search

    International Nuclear Information System (INIS)

    Fowler, T.B.; Vondy, D.R.; Cunningham, G.W.

    1995-01-01

    1 - Description of problem or function: CITATION is designed to solve problems using the finite-difference representation of neutron diffusion theory, treating up to three space dimensions with arbitrary group-to-group scattering. X-y-z, theta-r-z, hexagonal-z, and trigonal-z geometries may be treated. Depletion problems may be solved and fuel managed for multi-cycle analysis. Extensive first-order perturbation results may be obtained given microscopic data and nuclide concentrations. Statics problems may be solved and perturbation results obtained with microscopic data. CITATION-2-3-VP2 is a vectorized version for FACOM VP-100 and VP-200 vector computers. 2 - Method of solution: Explicit, finite-difference approximations in space and time have been implemented. The neutron-flux-eigenvalue problems are solved by direct iteration to determine the multiplication factor or the nuclide densities required for a critical system. CITATION-2-3-VP2: Algorithms for the inner-outer iterative calculations are adapted to vector computers. The SLOR method, which is used in the original CITATION code, and the SOR method, which is adopted in the revised code, are vectorized by odd-even mesh ordering. 3 - Restrictions on the complexity of the problem: CITATION has been designed to attack problems which can be run in a reasonable amount of time. Storage of data is allocated dynamically to give the user flexibility in dimensioning. Typically, a finite-difference diffusion problem could have 200 depleting zones, 10,000 nuclide densities, and 30,000 space-energy point flux values

  10. 78 FR 39835 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Buena Vista...

    Science.gov (United States)

    2013-07-02

    ... 50 CFR Part 17 Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for... and Plants; Designation of Critical Habitat for Buena Vista Lake Shrew AGENCY: Fish and Wildlife... developed for this critical habitat designation will also be available at the Fish and Wildlife Service Web...

  11. A study on the ocean circulation and thermal diffusion near a nuclear power plant

    International Nuclear Information System (INIS)

    Shu, Kyung Suk; Han, Moon Hee; Kim, Eun Han; Hwang, Won Tae

    1994-08-01

    The thermal discharge used with cooling water at nuclear power plant is released to a neighbour sea and it is influenced on marine environment. The thermal discharge released from power plant is mainly transported and diffused by ocean circulation of neighbour sea. So the evaluation for characteristics of ocean circulation around neighbour sea is firstly performed. The purpose of this research is primarily analyzed the thermal diffusion in sea around Yongkwang nuclear power plant. For this viewpoint, fundamental oceanographic data sets are collected and analyzed in Yellow sea, west sea of Korea, sea around Yongkwang. The ocean circulation and the effects of temperature increase by thermal discharge are evaluated using these data. The characteristics of tide is interpreted by the analysis of observed tidal elevation and tidal currents. The characteristics of temperature and salinity is investigated by the long-term observation of Korea Fisheries Research and Development Agency and the short-term observation around Yongkwang. (Author)

  12. Lung Cancer Mortality among Uranium Gaseous Diffusion Plant Workers: A Cohort Study 1952–2004

    Directory of Open Access Journals (Sweden)

    LW Figgs

    2013-07-01

    Full Text Available Background: 9%–15% of all lung cancers are attributable to occupational exposures. Reports are disparate regarding elevated lung cancer mortality risk among workers employed at uranium gaseous diffusion plants. Objective: To investigate whether external radiation exposure is associated with lung cancer mortality risk among uranium gaseous diffusion workers. Methods: A cohort of 6820 nuclear industry workers employed from 1952 to 2003 at the Paducah uranium gaseous diffusion plant (PGDP was assembled. A job-specific exposure matrix (JEM was used to determine likely toxic metal exposure categories. In addition, radiation film badge dosimeters were used to monitor cumulative external ionizing radiation exposure. International Classification for Disease (ICD codes 9 and 10 were used to identify 147 lung cancer deaths. Logistic and proportional hazards regression were used to estimate lung cancer mortality risk. Results: Lung cancer mortality risk was elevated among workers who experienced external radiation >3.5 mrem and employment duration >12 years. Conclusion: Employees of uranium gaseous diffusion plants carry a higher risk of lung cancer mortality; the mortality is associated with increased radiation exposure and duration of employment.

  13. CITATION-LDI2, 2-D Multigroup Diffusion, Perturbation, Criticality Search, for PC

    International Nuclear Information System (INIS)

    2001-01-01

    1 - Description of program or function: CITATION is designed to solve problems using the finite difference representation of neutron diffusion theory, treating up to three space dimensions with arbitrary group to group scattering. X-y-z, theta-r-z, hexagonal z, and trigonal z geometries may be treated. Depletion problems may be solved and fuel managed for multi-cycle analysis. Extensive first order perturbation results may be obtained given microscopic data and nuclide concentrations. Statics problems may be solved and perturbation results obtained with microscopic data. This version of CITATION was released by ORNL as CITATION - Rev. 2, Supplement 3 in July 1972 and ran on mainframes. It was first ported to PC by AECL in October 1988. CITATION-PC included in the March 1996 package involved minor changes including the removal of overlay statements introduced in 1988. CITALDI-PC is a new modified version with list-directed input. The codes in this package accept cross sections in CITATION format. Macroscopic data may be entered according to format specifications in Section 008 of the published report. Microscopic data format is specified in Section 105. There are no codes in RSIC's code collection to generate data in CITATION format. 2 - Method of solution: Explicit, finite difference approximations in space and time have been implemented. The neutron-flux-eigenvalue problems are solved by direct iteration to determine the multiplication factor or the nuclide densities required for a critical system

  14. Dislocation Enhancement of Seismic-Frequency Attenuation: Subgrain Boundary Diffusion and Triggered, Critical Emission of Dislocations

    Science.gov (United States)

    Cooper, R. F.; McCarthy, C.

    2012-12-01

    Combined compressional creep and (Young's-modulus) attenuation experiments on polycrystalline ice-I (200 ≤ T[K] ≤ 260; 3 ≤ d[μm] ≤ 500; σmean = 1MPa and Δσ = 0.16MPa applied in a frequency range 10-4 ≤ ν[Hz] ≤ 10-1) demonstrate the attenuation behavior associated with the seismic attenuation band and the "high-temperature background," i.e., a power-law response Q-1 ∝ ν-m with m ~ 0.33. This response has, in general, been associated with grain boundary sliding rate-limited by atomic diffusion [e.g., 1-3], a mechanism that is very sensitive to grain size. In our experiments, however, with a grain size variation ~102, the attenuation response is independent of grain size, to first order. Scrutiny of the physics suggests that the attenuation is effected primarily by diffusive relaxation of subgrain boundaries [4, 5], the size of which, in materials deforming by a dislocation mechanism (as is the ice in our experiments), is set by the deviatoric stress [6, 7]. Applying the diffusion-effected physics to the subgrain size matches the universal scaling [e.g., 3] for materials that are linear-viscoelastic. Our ice specimens, however, demonstrate modest non-linearity, resulting in greater attenuation than that associated with the diffusion process [cf. 8] and yet retain the power-law form for attenuation, including the same slope m. The result is consistent with "self-organized critical" behavior in dislocation emission [9, 10] and the physics overall can be understood via models of self-similar scaling of crystalline (effective) viscosity [e.g., 11]. The potential application to seismic studies is profound: for example, if the upper mantle of Earth is convecting via a dislocation-creep or dislocation-accommodated grain-boundary-sliding mechanism, then the attenuation response is related not to the grain size, but rather to the subgrain structure associated with the creep of the rock. Thus, seismic attenuation measurements may well be useful for

  15. ac loss and dc critical current densities of Nb3Sn tapes by the solid state diffusion process

    International Nuclear Information System (INIS)

    Suenaga, M.; Klamut, C.; Bussiere, J.F.

    1976-01-01

    The effects of metallurgical processing on 60 Hz ac losses and dc critical currents in Nb 3 Sn tapes fabricated by the solid state diffusion technique were investigated. An addition of Al to the Cu--Sn alloy for the matrix resulted in large reduction in the ac losses of Nb 3 Sn tapes, but the highest linear critical current densities were observed in Nb 3 Sn tapes produced with a Nb-1 wt percent Zr core in a Cu-13 wt percent Sn matrix. Values of the losses and the critical currents in these tapes can meet the present requirements for the ac superconducting power cables

  16. Portsmouth gaseous diffusion plant environmental monitoring report for calendar year 1975

    International Nuclear Information System (INIS)

    Martin, W.E.; Netzer, W.D.

    1976-01-01

    At the Portsmouth Gaseous Diffusion Plant the ambient atmosphere and all effluent streams are sampled and analyzed regularly for conformance to applicable environmental standards. Although neither the State of Ohio nor the federal government has established standards for fluorides in the ambient atmosphere or in vegetation, these parameters also are monitored because fluoride compounds are used extensively in the gaseous diffusion process. Radioactivity is measured in air, water, food, soil, and sediments; and radiation doses are calculated for the public. All public radiation doses are well within federal standards. Non-radioactive effluent parameters either comply with federal standards, or there are projects planned to allow compliance. A disposal facility to remove chromium from recirculating cooling water blowdown will begin operation in June 1976. Also, pH adjustment facilities for liquid effluents and electrostatic precipitators for a coal-fired steam plant are planned for the near future

  17. Environmental Restoration Site-Specific Plan for the Paducah Gaseous Diffusion Plant, FY 93

    International Nuclear Information System (INIS)

    1993-01-01

    This report provides an overview of the major Environmental Restoration (ER) concerns at Paducah Gaseous Diffusion Plant (PGDP). The identified solid waste management units at PGDP are listed. In the Department of Energy (DOE) Five Year Plan development process, one or more waste management units are addressed in a series of activity data sheets (ADSs) which identify planned scope, schedule, and cost objectives that are representative of the current state of planned technical development for individual or multiple sites

  18. The new local control systems for operating gaseous diffusion plant units at Pierrelatte

    International Nuclear Information System (INIS)

    Delacroix, C.

    1990-01-01

    The development of a local control network for operating gaseous diffusion plant units is presented. The objective of the control system up date was to replace all the information network hardware. The new generation HP1000 calculators and a network architecture were chosen. The validation tests performed in laboratory and in situ, and the management policies towards the personnel during the technical changes are summarized [fr

  19. Fast exponential calculation for the IBM 370-195 at the Oak Ridge Gaseous Diffusion Plant

    Energy Technology Data Exchange (ETDEWEB)

    Whitson, J. C.; Whealton, J. H.

    1977-01-01

    The time spent for computing an exponential for the IBM 370-195 at the Oak Ridge Gaseous Diffusion Plant is about 25 times slower than that spent by the CDC-7600 CTR computer at Livermore. We propose a scheme which does not involve a function call, is 15 times faster than the IBM 370-195 scheme, and is useful when the exponential is called many times.

  20. Method for estimate the economic characteristics of an uranium enrichment plant by gaseous diffusion

    International Nuclear Information System (INIS)

    Berault, J.C.

    1975-01-01

    To estimate the economic characteristics of an uranium enrichment plant by gaseous diffusion is to determine the prospective price of the separative work unit to which leads the concerned technology, and to collect the data allowing to ascertain that this price remains in the area of development of the prices forecasted by the other projects. The prospective price estimated by the promoter is the synthesis of the components of the go decision and which are a potential market and a comprehensive industrially proven plant design, including the basic economic and technical data of the project. Procedures for estimating these components and their synthesis, exclusive of financing problems are reviewed [fr

  1. Portsmouth Gaseous Diffusion Plant expansion, Piketon, Ohio. Volume 1. Draft environmental statement

    International Nuclear Information System (INIS)

    1976-06-01

    Subject to authorizing legislation and funding, ERDA will proceed with steps for additional uranium enrichment capacity at the Portsmouth Gaseous Diffusion Plant near Piketon, Ohio. This environmental statement was prepared by ERDA to cover this action. The statement was prepared in accordance with the National Environmental Policy Act of 1969, and ERDA's implementing regulations, 10 CFR Chapter III, Part 711. The statement describes the reasonably foreseeable environmental, social, economic and technological costs and benefits of the construction and operation of the expanded enrichment plant and its reasonably available alternatives and their anticipated effects

  2. Portsmouth Gaseous Diffusion Plant expansion, Piketon, Ohio. Volume 1. Draft environmental statement

    Energy Technology Data Exchange (ETDEWEB)

    1976-06-01

    Subject to authorizing legislation and funding, ERDA will proceed with steps for additional uranium enrichment capacity at the Portsmouth Gaseous Diffusion Plant near Piketon, Ohio. This environmental statement was prepared by ERDA to cover this action. The statement was prepared in accordance with the National Environmental Policy Act of 1969, and ERDA's implementing regulations, 10 CFR Chapter III, Part 711. The statement describes the reasonably foreseeable environmental, social, economic and technological costs and benefits of the construction and operation of the expanded enrichment plant and its reasonably available alternatives and their anticipated effects.

  3. Effects of radial distribution of entropy diffusivity on critical modes of anelastic thermal convection in rotating spherical shells

    Science.gov (United States)

    Sasaki, Youhei; Takehiro, Shin-ichi; Ishiwatari, Masaki; Yamada, Michio

    2018-03-01

    Linear stability analysis of anelastic thermal convection in a rotating spherical shell with entropy diffusivities varying in the radial direction is performed. The structures of critical convection are obtained in the cases of four different radial distributions of entropy diffusivity; (1) κ is constant, (2) κT0 is constant, (3) κρ0 is constant, and (4) κρ0T0 is constant, where κ is the entropy diffusivity, T0 is the temperature of basic state, and ρ0 is the density of basic state, respectively. The ratio of inner and outer radii, the Prandtl number, the polytropic index, and the density ratio are 0.35, 1, 2, and 5, respectively. The value of the Ekman number is 10-3 or 10-5 . In the case of (1), where the setup is same as that of the anelastic dynamo benchmark (Jones et al., 2011), the structure of critical convection is concentrated near the outer boundary of the spherical shell around the equator. However, in the cases of (2), (3) and (4), the convection columns attach the inner boundary of the spherical shell. A rapidly rotating annulus model for anelastic systems is developed by assuming that convection structure is uniform in the axial direction taking into account the strong effect of Coriolis force. The annulus model well explains the characteristics of critical convection obtained numerically, such as critical azimuthal wavenumber, frequency, Rayleigh number, and the cylindrically radial location of convection columns. The radial distribution of entropy diffusivity, or more generally, diffusion properties in the entropy equation, is important for convection structure, because it determines the distribution of radial basic entropy gradient which is crucial for location of convection columns.

  4. Preduction of the vibratory behaviour of a multistage gaseous diffusion plant

    International Nuclear Information System (INIS)

    Descleve, P.; Bertaut, C.; Briot, P.

    1979-01-01

    A study has been made to predict the vibratory behaviour of the rotating machinery of a gaseous diffusion plant starting from the results obtained for a single machine. TRICASTIN gaseous diffusion plant uses several hundred of enrichment stages but only three different sizes of machine are used. Each individual machine is a vertical assembly of a compressor heat exchanger and diffusion barriers, this column is supported on four lugs on a concrete slab. This slab must accomodate thermal expansion and is placed on neoprene pads. Due to the compactness of the system the mass of concrete is relatively small. Typically the mass of a machine of the intermediate size is 84 T, the mass of associated concrete is 55 T. Furthermore this supporting slab is flexible, meaning that a dynamic analysis of the slab shows several frequencies below the compressor rotational speed. Extensive dynamic tests have been conducted on a machine supported on a rigid foundation. These tests have shown that the main source of mechanical excitation was caused at 50 Hz by the unbalance of the electrical motor rotor. Then the problem remained to predict the behaviour of a group of twenty machines in the plant itself. (orig.)

  5. Application of a diffusion model to measure ion leakage of resurrection plant leaves undergoing desiccation.

    Science.gov (United States)

    Mihailova, Gergana; Kocheva, Konstantina; Goltsev, Vasilij; Kalaji, Hazem M; Georgieva, Katya

    2018-04-01

    Haberlea rhodopensis is a chlorophyll-retaining resurrection plant, which can survive desiccation to air dry state under both low light and sunny environments. Maintaining the integrity of the membrane during dehydration of resurrection plants is extremely important. In the present study, the diffusion model was improved and used for a first time to evaluate the changes in ion leakage through different cellular compartments upon desiccation of H. rhodopensis and to clarify the reasons for significant increase of electrolyte leakage from dry leaves. The applied diffusion approach allowed us to distinguish the performance of plants subjected to dehydration and subsequent rehydration under different light intensities. Well-hydrated (control) shade plants had lower and slower electrolyte leakage compared to control sun plants as revealed by lower values of phase amplitudes, lower rate constants and ion concentration. In well-hydrated and moderately dehydrated plants (50% relative water content, RWC) ion efflux was mainly due to leakage from apoplast. The electrolyte leakage sharply increased in severely desiccated leaves (8% RWC) from both sun and shade plants mainly due to ion efflux from symplast. After 1 day of rehydration the electrolyte leakage was close to control values, indicating fast recovery of plants. We suggest that the enhanced leakage in air-dried leaves should not be considered as damage but rather as a survival mechanism based on a reversible modification in the structure of cell wall, plasma membrane and alterations in vacuolar system of the cells. However, further studies should be conducted to investigate the changes in cell wall/plasma membrane to support this conclusion. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  6. National Plant Germplasm System: Critical Role of Customer Service

    Science.gov (United States)

    The National Plant Germplasm System (NPGS) conserves plant genetic resources, not only for use by future generations, but for immediate use by scientists and educators around the world. With a great deal of interaction between genebank curators and users of plant genetic resources, customer service...

  7. 75 FR 42489 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Limnanthes...

    Science.gov (United States)

    2010-07-21

    ... Part II Department of the Interior Fish and Wildlife Service 50 CFR Part 17 Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Limnanthes floccosa ssp. grandiflora.... Fish and Wildlife Service (Service), designate critical habitat for two plants, Limnanthes floccosa ssp...

  8. 76 FR 31685 - Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for the Riverside Fairy...

    Science.gov (United States)

    2011-06-01

    ... Vol. 76 Wednesday, No. 105 June 1, 2011 Part II Department of the Interior Fish and Wildlife Service 50 CFR Part 17 Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for the... Plants; Revised Critical Habitat for the Riverside Fairy Shrimp AGENCY: Fish and Wildlife Service...

  9. Lévy flights and multifractality in quantum critical diffusion and in classical random walks on fractals.

    Science.gov (United States)

    Kravtsov, V E; Yevtushenko, O M; Snajberk, P; Cuevas, E

    2012-08-01

    We employ the method of virial expansion to compute the retarded density correlation function (generalized diffusion propagator) in the critical random matrix ensemble in the limit of strong multifractality. We find that the long-range nature of the Hamiltonian is a common root of both multifractality and Lévy flights, which show up in the power-law intermediate- and long-distance behaviors, respectively, of the density correlation function. We review certain models of classical random walks on fractals and show the similarity of the density correlation function in them to that for the quantum problem described by the random critical long-range Hamiltonians.

  10. Assessment of the traditional neutron-diffusion core-analysis method for the analysis of the Super Critical Water Reactor

    International Nuclear Information System (INIS)

    Shen, W.

    2012-01-01

    Highlights: ► The 2-group diffusion theory is insufficient to capture the spectral change of the SCWR core. ► The multi-group neutron-diffusion theory is essential for the analysis of SCWR. ► The single-lattice-cell model is insufficient to capture the environment effect for SCWR. ► The multicell method is needed to capture the environment effect for the analysis of SCWR. - Abstract: The key design quantities of the pressure-tube-based (PT-based) Super Critical Water Reactor (SCWR) core design are expected to be computed with the traditional core-analysis code which solves the two-group neutron-diffusion equation by using lattice-homogenized cross sections calculated with the lattice code. Two issues may affect the accuracy of these computed quantities for the SCWR core: one is the two-energy-group neutron-diffusion theory; the other is the generation of lattice-homogenized properties with the lattice code based on the single-lattice-cell model without considering the effects of the environment. It has been illustrated that the single-lattice-cell method is not sufficiently accurate for heterogeneous core configurations when adjacent channels experience significant spectrum interaction. To ensure the qualification of these computed quantities for the SCWR core, a 2-D SCWR benchmark problem was setup (with the reference solution provided by the continuous energy Monte-Carlo code SERPENT) to assess the traditional neutron-diffusion core-analysis method. The assessment shows that the traditional two-group neutron-diffusion theory with the single-lattice-cell-based lattice properties is not sufficient to capture either the spectral change or the environment effect for the SCWR core. The solution of the eight-group neutron-diffusion equation by using lattice-homogenized cross sections calculated with the multicell model is considered appropriate for the analysis of the PT-based SCWR core.

  11. 78 FR 39628 - Endangered and Threatened Wildlife and Plants; Critical Habitat Map for the Fountain Darter

    Science.gov (United States)

    2013-07-02

    ...-0064; 4500030114] RIN 1018-AZ68 Endangered and Threatened Wildlife and Plants; Critical Habitat Map for... U.S. Fish and Wildlife Service (Service), are correcting the critical habitat map for the fountain... threatened wildlife. On July 14, 1980, we published a final rule (45 FR 47355) designating critical habitat...

  12. 76 FR 68710 - Endangered and Threatened Wildlife and Plants; Proposed Rulemaking To Revise Critical Habitat for...

    Science.gov (United States)

    2011-11-07

    ...-BA81 Endangered and Threatened Wildlife and Plants; Proposed Rulemaking To Revise Critical Habitat for..., proposing to revise critical habitat for the Hawaiian monk seal under the Endangered Species Act and..., Attn.: Hawaiian monk seal proposed critical habitat. Instructions: Comments must be submitted to one of...

  13. 78 FR 56505 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Georgia Rockcress

    Science.gov (United States)

    2013-09-12

    ... Service 50 CFR Part 17 Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for...; Designation of Critical Habitat for Georgia Rockcress AGENCY: Fish and Wildlife Service, Interior. ACTION: Proposed rule. SUMMARY: We, the U.S. Fish and Wildlife Service, propose to designate critical habitat for...

  14. 78 FR 61293 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Brickellia...

    Science.gov (United States)

    2013-10-03

    ... herbaceous layer and permit growth and flowering of B. mosieri and L. c. var. carteri. These plants also...-0108; 4500030114] RIN 1018-AZ64 Endangered and Threatened Wildlife and Plants; Designation of Critical... areas proposed for these plants overlap, for a combined total of approximately 1,096 ha (2,707 ac). The...

  15. Empirically Grounded Agent-Based Models of Innovation Diffusion: A Critical Review

    OpenAIRE

    Zhang, Haifeng; Vorobeychik, Yevgeniy

    2016-01-01

    Innovation diffusion has been studied extensively in a variety of disciplines, including sociology, economics, marketing, ecology, and computer science. Traditional literature on innovation diffusion has been dominated by models of aggregate behavior and trends. However, the agent-based modeling (ABM) paradigm is gaining popularity as it captures agent heterogeneity and enables fine-grained modeling of interactions mediated by social and geographic networks. While most ABM work on innovation ...

  16. Portsmouth Gasseous Diffusion Plant site, Piketon, Ohio. Final environmental impact statement. Volume 1

    International Nuclear Information System (INIS)

    1977-05-01

    This environmental statement provides a detailed analysis of the environmental effects associated with continued operation of the Portsmouth Gaseous Diffusion Plant, one of the three government-owned uranium enrichment plants operated by the Energy Research and Development Administration (ERDA). The Portsmouth facility, which has been operating for over twenty years, is located in Pike County, Ohio, on a 4000-acre federally owned reservation. The uranium enrichment capacity of the plant is currently being increased through a cascade improvement program (CIP) and a cascade uprating program (CUP). This environmental statement evaluates the Portsmouth facility at the fully uprated CUP production level. Environmental impacts of the production of offsite electric power for the Portsmouth facility are also assessed. The bulk of this power is supplied by the Ohio Valley Electric Corporation (OVEC) from two coal-fired plants, the Clifty Creek Power Plant near Madison, Indiana, and the Kyger Creek Power Plant near Cheshire, Ohio. The remaining required power will be obtained on a system basis through OVEC from the 15 sponsoring utilities of OVEC. The draft statement was issued for public comment on February 15, 1977, and public hearing to afford the public further opportunity to comment was held in Cincinnati, Ohio, on April 5, 1977

  17. Plutonium Finishing Plant (PFP) Criticality Alarm System Commercial Grade Item (CGI) Critical Characteristics

    International Nuclear Information System (INIS)

    WHITE, W.F.

    1999-01-01

    This document specifies the critical characteristics for Commercial Grade Items (CGI) procured for PFP's criticality alarm system as required by HNF-PRO-268 and HNF-PRO-1819. These are the minimum specifications that the equipment must meet in order to properly perform its safety function. There may be several manufacturers or models that meet the critical characteristics for any one item. PFP's Criticality Alarm System includes the nine criticality alarm system panels and their associated hardware. This includes all parts up to the first breaker in the electrical distribution system. Specific system boundaries and justifications are contained in HNF-SD-CP-SDD-003, ''Definition and Means of Maintaining the Criticality Detectors and Alarms Portion of the PFP Safety Envelope.'' The procurement requirements associated with the system necessitates procurement of some system equipment as Commercial Grade Items in accordance with HNF-PRO-268, ''Control of Purchased Items and Services.''

  18. Deafferentation-Induced Plasticity of Visual Callosal Connections: Predicting Critical Periods and Analyzing Cortical Abnormalities Using Diffusion Tensor Imaging

    Directory of Open Access Journals (Sweden)

    Jaime F. Olavarria

    2012-01-01

    Full Text Available Callosal connections form elaborate patterns that bear close association with striate and extrastriate visual areas. Although it is known that retinal input is required for normal callosal development, there is little information regarding the period during which the retina is critically needed and whether this period correlates with the same developmental stage across species. Here we review the timing of this critical period, identified in rodents and ferrets by the effects that timed enucleations have on mature callosal connections, and compare it to other developmental milestones in these species. Subsequently, we compare these events to diffusion tensor imaging (DTI measurements of water diffusion anisotropy within developing cerebral cortex. We observed that the relationship between the timing of the critical period and the DTI-characterized developmental trajectory is strikingly similar in rodents and ferrets, which opens the possibility of using cortical DTI trajectories for predicting the critical period in species, such as humans, in which this period likely occurs prenatally. Last, we discuss the potential of utilizing DTI to distinguish normal from abnormal cerebral cortical development, both within the context of aberrant connectivity induced by early retinal deafferentation, and more generally as a potential tool for detecting abnormalities associated with neurodevelopmental disorders.

  19. Construction and operation of an industrial solid waste landfill at Portsmouth Gaseous Diffusion Plant, Piketon, Ohio

    International Nuclear Information System (INIS)

    1995-10-01

    The US Department of Energy (DOE), Office of Waste Management, proposes to construct and operate a solid waste landfill within the boundary of the Portsmouth Gaseous Diffusion Plant (PORTS), Piketon, Ohio. The purpose of the proposed action is to provide PORTS with additional landfill capacity for non-hazardous and asbestos wastes. The proposed action is needed to support continued operation of PORTS, which generates non-hazardous wastes on a daily basis and asbestos wastes intermittently. Three alternatives are evaluated in this environmental assessment (EA): the proposed action (construction and operation of the X-737 landfill), no-action, and offsite shipment of industrial solid wastes for disposal

  20. Construction and operation of an industrial solid waste landfill at Portsmouth Gaseous Diffusion Plant, Piketon, Ohio

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-10-01

    The US Department of Energy (DOE), Office of Waste Management, proposes to construct and operate a solid waste landfill within the boundary of the Portsmouth Gaseous Diffusion Plant (PORTS), Piketon, Ohio. The purpose of the proposed action is to provide PORTS with additional landfill capacity for non-hazardous and asbestos wastes. The proposed action is needed to support continued operation of PORTS, which generates non-hazardous wastes on a daily basis and asbestos wastes intermittently. Three alternatives are evaluated in this environmental assessment (EA): the proposed action (construction and operation of the X-737 landfill), no-action, and offsite shipment of industrial solid wastes for disposal.

  1. 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.

  2. Paducah Gaseous Diffusion Plant Annual Site Environmental Report summary for 1993

    International Nuclear Information System (INIS)

    1994-11-01

    This report contains summaries of the environmental programs at Paducah Gaseous Diffusion Plant, environmental monitoring and the results, and the impact of operations on the environment and the public for 1993. The environmental monitoring program at Paducah includes effluent monitoring and environmental surveillance. Effluent monitoring is measurement of releases as they occur. Contaminants are released through either airborne emissions or liquids discharged from the plant. These releases occur as part of normal site operations, such as cooling water discharged from the uranium enrichment cascade operations or airborne releases from ventilation systems. In the event of system failure, this monitoring provides timely warning so that corrective action can be taken before releases reach an unsafe level. Environmental surveillance tracks the dispersion of materials into the environment after they have been released. This involves the collection of samples from various media, such as water, soil, vegetation, and food crops, and the analysis of these samples for certain radionuclides, chemicals, and metals

  3. Portsmouth Gaseous Diffusion Plant Annual Site Environmental Report summary for 1993

    International Nuclear Information System (INIS)

    1994-11-01

    This report contains summaries of the environmental programs at Paducah Gaseous Diffusion Plant, environmental monitoring and the results, and the impact of operations on the environment and the public for 1993. The environmental monitoring program at Paducah includes effluent monitoring and environmental surveillance. Effluent monitoring is measurement of releases as they occur. Contaminants are released through either airborne emissions or liquids discharged from the plant. These releases occur as part of normal site operations, such as cooling water discharged from the uranium enrichment cascade operations or airborne releases from ventilation systems. In the event of system failure, this monitoring provides timely warning so that corrective action can be taken before releases reach an unsafe level. Environmental surveillance tracks the dispersion of materials into the environment after they have been released. This involves the collection of samples from various media, such as water, soil, vegetation, and food crops, and the analysis of these samples for certain radionuclides, chemicals, and metals

  4. Decommissioning of the gaseous diffusion plant at BNF plc Capenhurst in the UK

    International Nuclear Information System (INIS)

    Clements, D.W.; Cross, J.R.

    1993-01-01

    Since 1982, a gaseous diffusion plant located at the British Nuclear Fuels plc (BNFL) site at Capenhurst in the United Kingdom, has been undergoing decontamination, decommissioning, and dismantling. By March 1994, the decontamination and decommissioning activities will be complete with 99% of the materials used to construct the plant recycled to the environment as clean material. This paper describes the history of the decontamination, decommissioning, dismantling, and disposal program. Reference is made to the scale of the project and to the special techniques developed, particularly in the areas of size reduction, decontamination, and protection of personnel and the environment. The quantities of material involved that require decontamination and release levels for recycling materials in the U.K. metals market are discussed

  5. Effective thermal conductivity and diffusivity of containment wall for nuclear power plant OPR1000

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Hyung Gyun; Park, Hyun Sun [Div. of Advanced Nuclear Engineering (DANE), Pohang University of Science and Technology (POSTECH), Pohang (Korea, Republic of); Lee, Jong Hwi; Kang, Hie Chan [Mechanical Engineering Div., Kunsan National University (KNU), Gunsan (Korea, Republic of)

    2017-04-15

    The goal of this study is to evaluate the effective thermal conductivity and diffusivity of containment walls as heat sinks or passive cooling systems during nuclear power plant (NPP) accidents. Containment walls consist of steel reinforced concrete, steel liners, and tendons, and provide the main thermal resistance of the heat sinks, which varies with the volume fraction and geometric alignment of the rebar and tendons, as well as the temperature and chemical composition. The target geometry for the containment walls of this work is the standard Korean NPP OPR1000. Sample tests and numerical simulations are conducted to verify the correlations for models with different densities of concrete, volume fractions, and alignments of steel. Estimation of the effective thermal conductivity and diffusivity of the containment wall models is proposed. The Maxwell model and modified Rayleigh volume fraction model employed in the present work predict the experiment and finite volume method (FVM) results well. The effective thermal conductivity and diffusivity of the containment walls are summarized as functions of density, temperature, and the volume fraction of steel for the analysis of the NPP accidents.

  6. Project plan for the background soils project for the Paducah Gaseous Diffusion Plant, Paducah, Kentucky

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    The Background Soils Project for the Paducah Gaseous Diffusion Plant (BSPP) will determine the background concentration levels of selected naturally occurring metals, other inorganics, and radionuclides in soils from uncontaminated areas in proximity to the Paducah Gaseous Diffusion Plant (PGDP) in Paducah, Kentucky. The data will be used for comparison with characterization and compliance data for soils, with significant differences being indicative of contamination. All data collected as part of this project will be in addition to other background databases established for the PGDP. The BSPP will address the variability of surface and near-surface concentration levels with respect to (1) soil taxonomical types (series) and (2) soil sampling depths within a specific soil profile. The BSPP will also address the variability of concentration levels in deeper geologic formations by collecting samples of geologic materials. The BSPP will establish a database, with recommendations on how to use the data for contaminated site assessment, and provide data to estimate the potential human and health and ecological risk associated with background level concentrations of potentially hazardous constituents. BSPP data will be used or applied as follows.

  7. Project plan for the background soils project for the Paducah Gaseous Diffusion Plant, Paducah, Kentucky

    International Nuclear Information System (INIS)

    1995-09-01

    The Background Soils Project for the Paducah Gaseous Diffusion Plant (BSPP) will determine the background concentration levels of selected naturally occurring metals, other inorganics, and radionuclides in soils from uncontaminated areas in proximity to the Paducah Gaseous Diffusion Plant (PGDP) in Paducah, Kentucky. The data will be used for comparison with characterization and compliance data for soils, with significant differences being indicative of contamination. All data collected as part of this project will be in addition to other background databases established for the PGDP. The BSPP will address the variability of surface and near-surface concentration levels with respect to (1) soil taxonomical types (series) and (2) soil sampling depths within a specific soil profile. The BSPP will also address the variability of concentration levels in deeper geologic formations by collecting samples of geologic materials. The BSPP will establish a database, with recommendations on how to use the data for contaminated site assessment, and provide data to estimate the potential human and health and ecological risk associated with background level concentrations of potentially hazardous constituents. BSPP data will be used or applied as follows

  8. 50 CFR 17.96 - Critical habitat-plants.

    Science.gov (United States)

    2010-10-01

    ... quality are likely to have the following characteristics: (1) Elevations from 372 to 411 m (1,220 to 1,350... plant populations. Areas of sufficient size and quality are likely to have the following characteristics..., Dumps, Eightlar extremely stony clay, Evans loam, Foehlin gravelly loam, Josephine gravelly loam, Kerby...

  9. Structure and evolution of the plant cation diffusion facilitator family of ion transporters

    Directory of Open Access Journals (Sweden)

    Zanis Michael J

    2011-03-01

    Full Text Available Abstract Background Members of the cation diffusion facilitator (CDF family are integral membrane divalent cation transporters that transport metal ions out of the cytoplasm either into the extracellular space or into internal compartments such as the vacuole. The spectrum of cations known to be transported by proteins of the CDF family include Zn, Fe, Co, Cd, and Mn. Members of this family have been identified in prokaryotes, eukaryotes, and archaea, and in sequenced plant genomes. CDF families range in size from nine members in Selaginella moellendorffii to 19 members in Populus trichocarpa. Phylogenetic analysis suggests that the CDF family has expanded within plants, but a definitive plant CDF family phylogeny has not been constructed. Results Representative CDF members were annotated from diverse genomes across the Viridiplantae and Rhodophyta lineages and used to identify phylogenetic relationships within the CDF family. Bayesian phylogenetic analysis of CDF amino acid sequence data supports organizing land plant CDF family sequences into 7 groups. The origin of the 7 groups predates the emergence of land plants. Among these, 5 of the 7 groups are likely to have originated at the base of the tree of life, and 2 of 7 groups appear to be derived from a duplication event prior to or coincident with land plant evolution. Within land plants, local expansion continues within select groups, while several groups are strictly maintained as one gene copy per genome. Conclusions Defining the CDF gene family phylogeny contributes to our understanding of this family in several ways. First, when embarking upon functional studies of the members, defining primary groups improves the predictive power of functional assignment of orthologous/paralogous genes and aids in hypothesis generation. Second, defining groups will allow a group-specific sequence motif to be generated that will help define future CDF family sequences and aid in functional motif

  10. Structure and evolution of the plant cation diffusion facilitator family of ion transporters.

    Science.gov (United States)

    Gustin, Jeffery L; Zanis, Michael J; Salt, David E

    2011-03-24

    Members of the cation diffusion facilitator (CDF) family are integral membrane divalent cation transporters that transport metal ions out of the cytoplasm either into the extracellular space or into internal compartments such as the vacuole. The spectrum of cations known to be transported by proteins of the CDF family include Zn, Fe, Co, Cd, and Mn. Members of this family have been identified in prokaryotes, eukaryotes, and archaea, and in sequenced plant genomes. CDF families range in size from nine members in Selaginella moellendorffii to 19 members in Populus trichocarpa. Phylogenetic analysis suggests that the CDF family has expanded within plants, but a definitive plant CDF family phylogeny has not been constructed. Representative CDF members were annotated from diverse genomes across the Viridiplantae and Rhodophyta lineages and used to identify phylogenetic relationships within the CDF family. Bayesian phylogenetic analysis of CDF amino acid sequence data supports organizing land plant CDF family sequences into 7 groups. The origin of the 7 groups predates the emergence of land plants. Among these, 5 of the 7 groups are likely to have originated at the base of the tree of life, and 2 of 7 groups appear to be derived from a duplication event prior to or coincident with land plant evolution. Within land plants, local expansion continues within select groups, while several groups are strictly maintained as one gene copy per genome. Defining the CDF gene family phylogeny contributes to our understanding of this family in several ways. First, when embarking upon functional studies of the members, defining primary groups improves the predictive power of functional assignment of orthologous/paralogous genes and aids in hypothesis generation. Second, defining groups will allow a group-specific sequence motif to be generated that will help define future CDF family sequences and aid in functional motif identification, which currently is lacking for this family in

  11. Data processing and critical function status display system in the nuclear power plant monitoring systems

    International Nuclear Information System (INIS)

    Sinjeri, Lj.; Plackovic, R.

    1984-01-01

    The Critical Function Monitoring System is a data acquisition and display system designed for effective presentation of essential nuclear plant operational data enabling supervision of the safety status of the nuclear plant by the operational staff. In this article the system functional requirements have been analysed and in accordance with the results of this analysis approach to defininf the design basis for realisation of the Critical Function Monitoring System by 'RK' equipment has been briefly described. (author)

  12. Water Vapor Sorption and Diffusion in Secondary Dispersion Barrier Coatings: A Critical Comparison with Emulsion Polymers.

    Science.gov (United States)

    Liu, Yang; Soer, Willem-Jan; Scheerder, Jürgen; Satgurunathan, Guru; Keddie, Joseph L

    2015-06-10

    The conventional method for synthesizing waterborne polymer colloids is emulsion polymerization using surfactants. An emerging method is the use of secondary dispersions (SD) of polymers in water, which avoids the addition of any surfactant. Although there are numerous studies of the water barrier properties (sorption, diffusion, and permeability) of waterborne emulsion (Em) polymer coatings, the properties of SD coatings, in comparison, have not been thoroughly investigated. Here, dynamic water vapor sorption analysis is used to compare the equilibrium sorption isotherms of the two forms of styrene-acrylate copolymers (Em and SD) with the same monomer composition. From an analysis of the kinetics of vapor sorption, the diffusion coefficient of water in the polymer coatings is determined. The combined effects of particle boundaries and surfactant addition were investigated through a comparison of the properties of SD and Em coatings to those of (1) solvent-cast polymer coatings (of the same monomer composition), (2) Em polymers that underwent dialysis to partially remove the water-soluble species, and (3) SD polymers with added surfactants. The results reveal that both the particle boundaries and the surfactants increase vapor sorption. The diffusion coefficients of water are comparable in magnitude in all of the polymer systems but are inversely related to water activity because of molecular clustering. Compared to all of the other waterborne polymer systems, the SD barrier coatings show the lowest equilibrium vapor sorption and permeability coefficients at high relative humidities as well as the lowest water diffusion coefficient at low humidities. These barrier properties make SD coatings an attractive alternative to conventional emulsion polymer coatings.

  13. Increased critical current and improved magnetic field response of BSCCO material by surface diffusion of silver

    International Nuclear Information System (INIS)

    Negm, Y.Z.; Zimmerman, G.O.; Powers, R.E.; Eckhardt, K.A.

    1994-01-01

    The authors have developed a procedure of increasing the critical current of BSCCO ceramic superconducting material, the value of the critical current is increased by 30%. Moreover the degradation of the critical current with the applied magnetic field had been decreased. The procedure consists of applying a thin layer of silver to the surface of the conductor. The details of the procedure and the improved performance are discussed. This procedure has great significance for any future application of HTSC materials where high current carrying capacity is necessary. It will therefore be important in the application of HTSC materials to SSC high current leads

  14. Occupational exposure to trichloroethylene and cancer risk for workers at the Paducah Gaseous Diffusion Plant.

    Science.gov (United States)

    Bahr, Debra E; Aldrich, Timothy E; Seidu, Dazar; Brion, Gail M; Tollerud, David J; Muldoon, Susan; Reinhart, Nancy; Youseefagha, Ahmed; McKinney, Paul; Hughes, Therese; Chan, Caroline; Rice, Carol; Brewer, David E; Freyberg, Ronald W; Mohlenkamp, Adriane Moser; Hahn, Kristen; Hornung, Richard; Ho, Mona; Dastidar, Aniruddha; Freitas, Samantha; Saman, Daniel; Ravdal, Hege; Scutchfield, Douglas; Eger, Kenneth J; Minor, Steve

    2011-03-01

    The Paducah Gaseous Diffusion Plant (PGDP) became operational in 1952; it is located in the western part of Kentucky. We conducted a mortality study for adverse health effects that workers may have suffered while working at the plant, including exposures to chemicals. We studied a cohort of 6820 workers at the PGDP for the period 1953 to 2003; there were a total of 1672 deaths to cohort members. Trichloroethylene (TCE) is a specific concern for this workforce; exposure to TCE occurred primarily in departments that clean the process equipment. The Life Table Analysis System (LTAS) program developed by NIOSH was used to calculate the standardized mortality ratios for the worker cohort and standardized rate ratio relative to exposure to TCE (the U.S. population is the referent for ageadjustment). LTAS calculated a significantly low overall SMR for these workers of 0.76 (95% CI: 0.72-0.79). A further review of three major cancers of interest to Kentucky produced significantly low SMR for trachea, bronchus, lung cancer (0.75, 95% CI: 0.72-0.79) and high SMR for Non-Hodgkin's lymphoma (NHL) (1.49, 95% CI: 1.02-2.10). No significant SMR was observed for leukemia and no significant SRRs were observed for any disease. Both the leukemia and lung cancer results were examined and determined to reflect regional mortality patterns. However, the Non-Hodgkin's Lymphoma finding suggests a curious amplification when living cases are included with the mortality experience. Further examination is recommended of this recurrent finding from all three U.S. Gaseous Diffusion plants.

  15. 77 FR 37867 - Endangered and Threatened Wildlife and Plants; Proposed Rulemaking To Revise Critical Habitat for...

    Science.gov (United States)

    2012-06-25

    .... 110207102-2084-02] RIN 0648-BA81 Endangered and Threatened Wildlife and Plants; Proposed Rulemaking To Revise Critical Habitat for Hawaiian Monk Seals AGENCY: National Marine Fisheries Service (NMFS... extension of the deadline for a final critical habitat determination. SUMMARY: We, National Marine Fisheries...

  16. 75 FR 37358 - Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for the Arroyo Toad

    Science.gov (United States)

    2010-06-29

    ...-0069] [92210-0-0009-B4] RIN 1018-AV89 Endangered and Threatened Wildlife and Plants; Revised Critical...; (2) revegetation of riparian areas; (3) removal of invasive plants such as arundo (Arundo donax) and tamarisk (Tamarix sp.); (4) protecting wetlands from urban runoff by establishing a revegetated upland...

  17. PHOTOPERIODIC HISTORY AFFECTS THE CRITICAL DAYLENGTH OF THE SHORT-DAY PLANT ACROSYMPHYTON-PURPURIFERUM (RHODOPHYTA)

    NARCIS (Netherlands)

    BREEMAN, AM

    The crustose tetrasporophyte of the red alga Acrosymphyton purpuriferum is a qualitative short-day plant in the formation of its tetrasporangia. The critical daylength for the response was determined in plants precultured in various long-day regimes [20:4, 18:6, 16:8 and 14:10 (L:D, h)]. There was a

  18. Utility of surgical lung biopsy in critically ill patients with diffuse pulmonary infiltrates: a retrospective review.

    Science.gov (United States)

    Donaldson, L H; Gill, A J; Hibbert, M

    2016-11-01

    There are conflicting reports regarding the role of surgical lung biopsies in patients who present to the intensive care unit (ICU) with unexplained respiratory failure and diffuse pulmonary infiltrates on imaging. To describe the utility of surgical lung biopsies in patients presenting to the ICU with unexplained respiratory failure and diffuse pulmonary infiltrates. A retrospective cohort study was performed. All patients admitted to the ICU who underwent a surgical lung biopsy for the investigation of respiratory failure and unexplained pulmonary infiltrates between 1998 and 2012 were included. The primary outcome measures for this descriptive study were the biopsy histopathology, changes in patient management following biopsy and in-hospital mortality. A total of 30 patients was included in the review. Biopsies in 22 patients (73%) demonstrated diffuse alveolar damage (DAD), with 15 of these biopsies (50%) suggesting a specific underlying aetiology. In 73% of cases (n = 22), the biopsy finding was associated with a change in management, although this generally involved the escalation of an existing therapy rather than initiation of a new treatment. Biopsies were performed at a median 10 days after admission (interquartile range 5-17 days), with the majority of patients being treated empirically prior to the biopsy with systemic steroids and broad-spectrum antimicrobials. Mortality was 53%. In this series, DAD was the most frequent pathology. The biopsy result was associated with a change in management in a majority of the subjects, most frequently an escalation of prior empiric therapy. Mortality was high. © 2016 Royal Australasian College of Physicians.

  19. Issues and recommendations related to replacement of CFC-114 at the uranium enrichment gaseous diffusion plant

    International Nuclear Information System (INIS)

    Anderson, B.L.; Banaghan, E.

    1993-01-01

    The operating uranium enrichment gaseous diffusion plants (GDPs) in Portsmouth, Ohio and Paducah, Kentucky, which are operated for the United States Department for Energy by Martin Marietta Energy Systems (MMES), currently use a chlorofluorocarbon (CFC-114) as the primary process stream coolant. Due to recent legislation embodied in the Clean Air Act, the production of this and other related chlorofluorocarbons (CFCS) are to be phased out with no production occurring after 1995. Since the plants lose approximately 500,000 pounds per year of this process stream coolant through various leaks, the GDPs are faced with the challenge of identifying a replacement coolant that will allow continued operation of the plants. MMES formed the CFC Task Team to identify and solve the various problems associated with identifying and implementing a replacement coolant. This report includes a review of the work performed by the CFC Task Team, and recommendations that were formulated based on this review and upon original work. The topics covered include; identifying a replacement coolant, coolant leak detection and repair efforts, coolant safety concerns, coolant level sensors, regulatory issues, and an analytical decision analysis

  20. Orientation of Anopheles gambiae (Diptera: Culicidae) to Plant-Host Volatiles in a Novel Diffusion-Cage Olfactometer.

    Science.gov (United States)

    Otienoburu, Philip E; Nikbakhtzadeh, Mahmood R; Foster, Woodbridge A

    2016-01-01

    A novel diffusion-cage olfactometer tested the responses of Anopheles gambiae Giles to plant volatiles. Green-leaf volatiles are often released from cut or injured plant tissue and may alter the headspace of plants used in olfactometer assays. The diffusion-cage olfactometer is designed for use with whole, intact plants, hence giving a more realistic behavioral assay. Its simple plastic construction, ease of assembly, and accommodation to whole plants makes it a useful tool for measuring mosquito orientation to plant volatiles within large enclosures. We compared its performance to that of the more commonly used T-tube wind-tunnel olfactometer, by testing the orientation of mosquitoes to volatiles of a few prevalent plants of eastern Africa reportedly utilized by An. gambiae for sugar: Parthenium hysterophorus (Asteraceae), Ricinus communis (Euphorbiaceae), Lantana camara (Verbenaceae), and Senna occidentalis (Fabaceae). Results indicate that the diffusion-cage olfactometer is an effective alternative to conventional wind-tunnel olfactometers, to test mosquito orientation to plant volatiles under seminatural conditions. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. EUPHORBIACEAE - A CRITICAL REVIEW ON PLANT TISSUE CULTURE

    Directory of Open Access Journals (Sweden)

    Rajesh Kondamudi

    2009-05-01

    Full Text Available The members of Euphorbiaceae are valuable source of different kinds of useful products like dyes, edible tubers, oil crops, furniture, agricultural implements, ornamental plants, pharmacological products, rubber, timber and aesthetic items. Micropropagation is an alternative mean of propagation that can be employed in conservation of the flora in relatively shorter time. Tissue culture is useful for multiplying and conserving the species, which are difficult to regenerate by conservation methods and save them from extinction. Cryopreservation of germplasm would help in maintaining the genetic diversity of the endangered population. Improved cell and tissue culture technologies would help in producing the active compounds in vitro with better productivities without cutting down the natural resources. There is sufficient progress at research level to suggest that the tissue culture of Euphorbiaceae can and should be further developed. This review emphasizes the in vitro manipulation and remarkable achievements with biotechnology in this family made during the last six decades.

  2. Local drainage analyses of the Paducah and Portsmouth Gaseous Diffusion Plants during an extreme storm

    International Nuclear Information System (INIS)

    Johnson, R.O.; Wang, J.C.; Lee, D.W.

    1993-01-01

    Local drainage analyses have been performed for the Paducah and Portsmouth Gaseous Diffusion Plants during an extreme storm having an approximate 10,000-yr recurrence interval. This review discusses the methods utilized to accomplish the analyses in accordance with US Department of Energy (DOE) design and evaluation guidelines, and summarizes trends, results, generalizations, and uncertainties applicable to other DOE facilities. Results indicate that some culverts may be undersized, and that the storm sewer system cannot drain the influx of precipitation from the base of buildings. Roofs have not been designed to sustain ponding when the primary drainage system is clogged. Some underground tunnels, building entrances, and ground level air intakes may require waterproofing

  3. An in situ survey of the Paducah Gaseous Diffusion Plant and surrounding area

    International Nuclear Information System (INIS)

    Hoover, R.A.

    1994-02-01

    An in situ survey of the area surrounding the Paducah Gaseous Diffusion Plant was conducted between May 17 and 24, 1990. The survey consisted of in situ measurements and of ground sampling. A High Purity Germanium detector was used for the in situ measurements. The ground samples were taken to the, laboratory at EG ampersand G Energy Measurements, Inc., in Santa Barbara, California, for a radionuclide assay on a laboratory system. Results of the in situ measurements found evidence of naturally occurring radioisotopes, cesium-137 from international fallout, and some evidence of anomalous uranium-238. The soil sampling results show only the presence of naturally occurring radioisotopes, cesium-137, and also anomalous uranium-238

  4. Report on the Biological Monitoring Program at Paducah Gaseous Diffusion Plant December 1992--December 1993

    Energy Technology Data Exchange (ETDEWEB)

    Kszos, L.A.; Hinzman, R.L.; Peterson, M.J.; Ryon, M.G.; Smith, J.G.; Southworth, G.R.

    1995-06-01

    On September 24, 1987, the Commonwealth of Kentucky Natural Resources and Environmental Protection Cabinet issued an Agreed Order that required the development of a Biological Monitoring Program (BMP) for the Paducah Gaseous Diffusion Plant (PGDP). The goals of BMP are to demonstrate that the effluent limitations established for PGDP protect and maintain the use of Little Bayou and Big Bayou creeks for growth and propagation of fish and other aquatic life, characterize potential health and environmental impacts, document the effects of pollution abatement facilities on stream biota, and recommend any program improvements that would increase effluent treatability. The BMP for PGDP consists of three major tasks: effluent and ambient toxicity monitoring, bioaccumulation studies, and ecological surveys of stream communities (i.e., benthic macroinvertebrates and fish). This report includes ESD activities occurring from December 1992 to December 1993, although activities conducted outside this time period are included as appropriate.

  5. Report on the biological monitoring program at Paducah Gaseous Diffusion Plant December 1990 to November 1992

    Energy Technology Data Exchange (ETDEWEB)

    Kszos, L.A. [ed.

    1994-03-01

    On September 23, 1987, the Commonwealth of Kentucky Natural Resources and Environmental Protection Cabinet issued an Agreed Order that required the development of a Biological Monitoring Program (BMP) for the Paducah Gaseous Diffusion Plant (PGDP). Beginning in fall 1991, the Environmental Sciences Division (ESD) at Oak Ridge National Lab (ORNL) added data collection and report preparation to its responsibilities for the PGDP BMP. The BMP has been continued because it has proven to be extremely valuable in identifying those effluents with the potential for adversely affecting instream fauna, assessing the ecological health of receiving streams, guiding plans for remediation, and protecting human health. In September 1992, a renewed permit was issued which requires toxicity monitoring of continuous and intermittent outfalls on a quarterly basis. The BMP for PGDP consists of three major tasks: (1) effluent and ambient toxicity monitoring, (2) bioaccumulation studies, and (3) ecological surveys of stream communities. This report includes ESD/ORNL activities occurring from December 1990 to November 1992.

  6. Report on the biological monitoring program at Paducah Gaseous Diffusion Plant December 1990 to November 1992

    International Nuclear Information System (INIS)

    Kszos, L.A.

    1994-03-01

    On September 23, 1987, the Commonwealth of Kentucky Natural Resources and Environmental Protection Cabinet issued an Agreed Order that required the development of a Biological Monitoring Program (BMP) for the Paducah Gaseous Diffusion Plant (PGDP). Beginning in fall 1991, the Environmental Sciences Division (ESD) at Oak Ridge National Lab (ORNL) added data collection and report preparation to its responsibilities for the PGDP BMP. The BMP has been continued because it has proven to be extremely valuable in identifying those effluents with the potential for adversely affecting instream fauna, assessing the ecological health of receiving streams, guiding plans for remediation, and protecting human health. In September 1992, a renewed permit was issued which requires toxicity monitoring of continuous and intermittent outfalls on a quarterly basis. The BMP for PGDP consists of three major tasks: (1) effluent and ambient toxicity monitoring, (2) bioaccumulation studies, and (3) ecological surveys of stream communities. This report includes ESD/ORNL activities occurring from December 1990 to November 1992

  7. Delisting efforts for mixed radioactive and chemically hazardous waste at the Oak Ridge Gaseous Diffusion Plant

    International Nuclear Information System (INIS)

    Goodpasture, S.T.

    1987-01-01

    Presently, there are four hazardous wastes at the Oak Ridge Gaseous Diffusion Plant that are candidates for the delisting from the Resource Conservation and Recovery Act (RCRA) hazardous waste regulations. These candidates are the sludges from K-1407-B and C ponds, Central Neutralization Facility sludges, mixed sludges from Y-12 and the ash generated by the RCRA/Toxic Substances Control Act (TSCA) Incinerator. All of these hazardous wastes contain radioactive constituents as well as hazardous constituents. The delisting will be based upon the nonradioactive constituents. Whether the delisting petition is granted or not, the wastes will be handled according to the Department of Energy guidelines for radioactive wastes. The presentation discusses the methodologies for delisting these wastes and the rationale behind the processes

  8. Reassessment of liquefaction potential and estimation of earthquake- induced settlements at Paducah Gaseous Diffusion Plant, Paducah, Kentucky. Final report

    International Nuclear Information System (INIS)

    Sykora, D.W.; Yule, D.E.

    1996-04-01

    This report documents a reassessment of liquefaction potential and estimation of earthquake-induced settlements for the U.S. Department of Energy (DOE), Paducah Gaseous Diffusion Plant (PGDP), located southwest of Paducah, KY. The U.S. Army Engineer Waterways Experiment Station (WES) was authorized to conduct this study from FY91 to FY94 by the DOE, Oak Ridge Operations (ORO), Oak Ridge, TN, through Inter- Agency Agreement (IAG) No. DE-AI05-91OR21971. The study was conducted under the Gaseous Diffusion Plant Safety Analysis Report (GDP SAR) Program

  9. Critical excitation method for calculating earthquake effects on nuclear plant structures: an assessment study. Technical report

    International Nuclear Information System (INIS)

    Bedrosian, B.; Barbela, M.; Drenick, R.F.; Tsirk, A.

    1980-10-01

    The critical excitation method provides a new, alternative approach to methods presently used for seismic analysis of nuclear power plant structures. The critical excitation method offers the advantages that: (1) it side-steps the assumptions regarding the probability distribution of ground motions, and (2) it does not require an artificial, and to some extent arbitrarily generated, time history of ground motion, both features to which structural integrity analyses are sensitive. Potential utility of the critical excitation method is studied from the user's viewpoint. The method is reviewed and compared with the response spectrum method used in current practice, utilizing the reactor buildings of a PWR and a BWR plant in case studies. Two types of constraints on critical excitation were considered in the study. In one case, only an intensity limit was used. In the other case, imposition of an intensity limit together with limits on the maximum acceleration and/or velocity for the critical excitation is considered

  10. Reaction-diffusion-like formalism for plastic neural networks reveals dissipative solitons at criticality

    Science.gov (United States)

    Grytskyy, Dmytro; Diesmann, Markus; Helias, Moritz

    2016-06-01

    Self-organized structures in networks with spike-timing dependent synaptic plasticity (STDP) are likely to play a central role for information processing in the brain. In the present study we derive a reaction-diffusion-like formalism for plastic feed-forward networks of nonlinear rate-based model neurons with a correlation sensitive learning rule inspired by and being qualitatively similar to STDP. After obtaining equations that describe the change of the spatial shape of the signal from layer to layer, we derive a criterion for the nonlinearity necessary to obtain stable dynamics for arbitrary input. We classify the possible scenarios of signal evolution and find that close to the transition to the unstable regime metastable solutions appear. The form of these dissipative solitons is determined analytically and the evolution and interaction of several such coexistent objects is investigated.

  11. Probabilistic transport models for plasma transport in the presence of critical thresholds: Beyond the diffusive paradigma)

    Science.gov (United States)

    Sánchez, R.; van Milligen, B. Ph.; Carreras, B. A.

    2005-05-01

    It is argued that the modeling of plasma transport in tokamaks may benefit greatly from extending the usual local paradigm to accommodate scale-free transport mechanisms. This can be done by combining Lévy distributions and a nonlinear threshold condition within the continuous time random walk concept. The advantages of this nonlocal, nonlinear extension are illustrated by constructing a simple particle density transport model that, as a result of these ideas, spontaneously exhibits much of nondiffusive phenomenology routinely observed in tokamaks. The fluid limit of the system shows that the kind of equations that are appropriate to capture these dynamics are based on fractional differential operators. In them, effective diffusivities and pinch velocities are found that are dynamically set by the system in response to the specific characteristics of the fueling source and external perturbations. This fact suggests some dramatic consequences for the extrapolation of these transport properties to larger size systems.

  12. Probabilistic transport models for plasma transport in the presence of critical thresholds: Beyond the diffusive paradigm

    International Nuclear Information System (INIS)

    Sanchez, R.; Milligen, B.Ph. van; Carreras, B.A.

    2005-01-01

    It is argued that the modeling of plasma transport in tokamaks may benefit greatly from extending the usual local paradigm to accommodate scale-free transport mechanisms. This can be done by combining Levy distributions and a nonlinear threshold condition within the continuous time random walk concept. The advantages of this nonlocal, nonlinear extension are illustrated by constructing a simple particle density transport model that, as a result of these ideas, spontaneously exhibits much of nondiffusive phenomenology routinely observed in tokamaks. The fluid limit of the system shows that the kind of equations that are appropriate to capture these dynamics are based on fractional differential operators. In them, effective diffusivities and pinch velocities are found that are dynamically set by the system in response to the specific characteristics of the fueling source and external perturbations. This fact suggests some dramatic consequences for the extrapolation of these transport properties to larger size systems

  13. EURODIF company - Tricastin gaseous diffusion plant. Requests following the safety re-evaluation of the facility after 20 years of operation

    International Nuclear Information System (INIS)

    2000-01-01

    This decision from the French authority of nuclear safety (ASN) concerns the safety reevaluation of the EURODIF plant ('Georges Besse plant') of the Tricastin site at Pierrelatte (France) which uses the gaseous diffusion process to separate the uranium isotopes. Since the last safety reevaluation in 1988, several points have been improved: reduction of the frequency and importance of uranium hexafluoride leaks (control of the pitting corrosion in the exchangers), no incident linked with exo-thermal reactions or explosions, a mastery of the exposure to ionizing radiations etc.. On the other hand, several points need improvement: the prevention of criticality risks, the earthquake resistance of some structures, and the integration of some accident scenarios (aircraft crash, UF 6 leak) in the emergency plan to avoid the fast release of toxic materials in the environment. These points are detailed in the document. (J.S.)

  14. Determination of operating limits for radionuclides for a proposed landfill at Paducah Gaseous Diffusion Plant

    International Nuclear Information System (INIS)

    Wang, J.C.; Lee, D.W.; Ketelle, R.H.; Lee, R.R.; Kocher, D.C.

    1994-01-01

    The operating limits for radionuclides in sanitary and industrial wastes were determined for a proposed landfill at the Paducah Gaseous Diffusion Plant (PGDP), Kentucky. These limits, which may be very small but nonzero, are not mandated by law or regulation but are needed for rational operation. The approach was based on analyses of the potential contamination of groundwater at the plant boundary and the potential exposure to radioactivity of an intruder at the landfill after closure. The groundwater analysis includes (1) a source model describing the disposal of waste and the release of radionuclides from waste to the groundwater, (2) site-specific groundwater flow and contaminant transport calculations, and (3) calculations of operating limits from the dose limit and conversion factors. The intruder analysis includes pathways through ingestion of contaminated vegetables and soil, external exposure to contaminated soil, and inhalation of suspended activity from contaminated soil particles. In both analyses, a limit on annual effective dose equivalent of 4 mrem (0.04 mSv) was adopted. The intended application of the results is to refine the radiological monitoring standards employed by the PGDP Health Physics personnel to determine what constitutes radioactive wastes, with concurrence of the Commonwealth of Kentucky

  15. Regional flood hazard assessment of the Paducah and Portsmouth Gaseous Diffusion Plants

    International Nuclear Information System (INIS)

    Johnson, R.O.; Wang, J.C.; Lee, D.W.

    1991-01-01

    Regional flood-hazard assessments performed for the Paducah and Portsmouth Gaseous Diffusion Plants are reviewed, compared, and contrasted to determine the relationship of probable maximum flood methodology with respect to US Department of Energy design and evaluation guidelines. The Paducah assessment was carried out using probable minimum flood methodology, while the Portsmouth assessment utilized probabilistic techniques. Results indicated that regional flooding along nearby rivers would not inundate either plant, and that the guidelines were satisfied. A comparison of results indicated that the probable minimum flood recurrence interval associated with the Paducah assessment exceeded the 10,000-year requirement of the guidelines, while recurrence intervals obtained in the Portsmouth assessment could be above or below 10,000 years depending on the choice of the probabilistic model used to perform the assessment. It was concluded, based on an analysis of two data points, that smaller watersheds driven by single event storms could be assessed using probabilistic techniques, while probable maximum flood methodology could be applied to larger drainage basins flooded by storm sequences

  16. Environmental program audit: Oak Ridge Gaseous Diffusion Plant, Roane County, Tennessee. Final report

    International Nuclear Information System (INIS)

    Smith, W.M.; Waller, R.

    1985-01-01

    An environmental audit of the Oak Ridge Gaseous Diffusion Plant (ORGDP) was conducted by a team of NUS scientists and engineers during the week of June 3 through June 7, 1985. ORGDP is owned by the Department of Energy and operated by Martin-Marietta Energy Systems, Inc. To enrich uranium feedstocks for nuclear fuels. The team evaluated ORGDP in terms of compliance with environmental regulations and DOE Orders, the adequacy of pollution control equipment, the effectiveness of environmental monitoring, and the application of quality control procedures to environmental programs. The audit was conducted by observing operations, inspecting facilities, evaluating analysis and monitoring techniques, reviewing reports and data, and interviewing personnel. Overall, the ORGDP environmental program appears to be well structured and has attempted to address all areas of air, water, and land media likely to be affected by the operations of the facility. The plant management is knowledgeable about environmental concerns and has established clear, well-defined goals to address these areas. An adequate professional staff is available to manage the environmental program

  17. Operating limit study for the proposed solid waste landfill at Paducah Gaseous Diffusion Plant

    International Nuclear Information System (INIS)

    Lee, D.W.; Wang, J.C.; Kocher, D.C.

    1995-06-01

    A proposed solid waste landfill at Paducah Gaseous Diffusion Plant (PGDP) would accept wastes generated during normal operations that are identified as non-radioactive. These wastes may include small amounts of radioactive material from incidental contamination during plant operations. A site-specific analysis of the new solid waste landfill is presented to determine a proposed operating limit that will allow for waste disposal operations to occur such that protection of public health and the environment from the presence of incidentally contaminated waste materials can be assured. Performance objectives for disposal were defined from existing regulatory guidance to establish reasonable dose limits for protection of public health and the environment. Waste concentration limits were determined consistent with these performance objectives for the protection of off-site individuals and inadvertent intruders who might be directly exposed to disposed wastes. Exposures of off-site individuals were estimated using a conservative, site-specific model of the groundwater transport of contamination from the wastes. Direct intrusion was analyzed using an agricultural homesteader scenario. The most limiting concentrations from direct intrusion or groundwater transport were used to establish the concentration limits for radionuclides likely to be present in PGDP wastes

  18. An assessment of criticality safety at the Department of Energy Rocky Flats Plant, Golden, Colorado, July--September 1989

    Energy Technology Data Exchange (ETDEWEB)

    Mattson, Roger J.

    1989-09-01

    This is a report on the 1989 independent Criticality Safety Assessment of the Rocky Flats Plant, primarily in response to public concerns that nuclear criticality accidents involving plutonium may have occurred at this nuclear weapon component fabrication and processing plant. The report evaluates environmental issues, fissile material storage practices, ventilation system problem areas, and criticality safety practices. While no evidence of a criticality accident was found, several recommendations are made for criticality safety improvements. 9 tabs.

  19. 75 FR 76085 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Polar Bear...

    Science.gov (United States)

    2010-12-07

    ... Threatened Wildlife and Plants; Designation of Critical Habitat for the Polar Bear (Ursus maritimus) in the... Wildlife and Plants; Designation of Critical Habitat for the Polar Bear (Ursus maritimus) in the United... Wildlife Service (Service), designate critical habitat for polar bear (Ursus maritimus) populations in the...

  20. 10 CFR Appendix C to Part 110 - Illustrative List of Gaseous Diffusion Enrichment Plant Assemblies and Components Under NRC...

    Science.gov (United States)

    2010-01-01

    ... of the gas flow is of importance in a gaseous diffusion plant. All this leads to a need to equip the... are normally designed for a buffer gas in-leakage rate of less than 1000 cm3/min. 1.5 Heat Exchangers...

  1. Facile synthesis of Mn-doped ZnS nanocrystals and determination of critical temperature for lattice diffusion process.

    Science.gov (United States)

    Shen, Rongan; Zeng, Ruosheng; Yin, Yuehong; Wan, Jie; Sun, Zhiguo; Zhao, Yunqiang; Zhao, Haixing

    2012-11-01

    High-quality Mn:ZnS doped nanocrystals (d-dots) with photoluminescence (PL) quantum yield (QY) of 50-70% have been synthesized based on nucleation-doping strategy by choosing 1-dodecanethiol (DDT) as the capping ligand. Controlling the growth of small-sized MnS core nanoclusters was successfully achieved by changing the injection temperature of sulfur precursor, the growth time of MnS nuclei, and the amount of DDT. Furthermore, MnS/ZnS core/shell d-dots with a diffusion layer at the interface between the MnS core and the ZnS shell were fabricated through an overcoating of the ZnS shell layer on the presynthesized MnS core nanoclusters. The resulting monodisperse d-dots exhibited spherical shape with a zinc-blende crystal structure. The critical temperature for lattice diffusion of Mn ions in the ZnS host lattice was determined to be about 260 degrees C by annealing the presynthesized and purified Mn:ZnS d-dots.

  2. A multi-criteria decision making system for damage assessment of critical components in power plants

    International Nuclear Information System (INIS)

    Jovanovic, A.; Auerkari, P.; Brear, J.M.

    1996-01-01

    A multi-criteria decision making tool for engineering applications has been developed in the European project BE5935. The tool has been developed and applied in the area of power plants, primarily for the decisions regarding the inspection and maintenance planning in the area of power plants. Practical application of the methodology and of the software is shown here for the damage assessment of critical components. (authors)

  3. Final report for the field-reversed configuration power plant critical-issue scoping study

    Energy Technology Data Exchange (ETDEWEB)

    Santarius, John F.; Mogahed, Elsayed A.; Emmert, Gilbert A.; Khater, Hesham Y.; Nguyen, Canh N.; Ryzhkov, Sergei V.; Stubna, Michael D.; Steinhauer, Loren C.; Miley, George H.

    2001-03-01

    This report describes research in which a team from the Universities of Wisconsin, Washington, and Illinois performed a scoping study of critical issues for field-reversed configuration (FRC) power plants. The key tasks for this research were (1) systems analysis of deuterium-tritium (D-T) FRC fusion power plants, and (2) conceptual design of the blanket and shield module for an FRC fusion core.

  4. Modeling diffuse sources of surface water contamination with plant protection products

    Science.gov (United States)

    Wendland, Sandra; Bock, Michael; Böhner, Jürgen; Lembrich, David

    2015-04-01

    Entries of chemical pollutants in surface waters are a serious environmental problem. Among water pollutants plant protection products (ppp) from farming practice are of major concern not only for water suppliers and environmental agencies, but also for farmers and industrial manufacturers. Lost chemicals no longer fulfill their original purpose on the field, but lead to severe damage of the environment and surface waters. Besides point-source inputs of chemical pollutants, the diffuse-source inputs from agricultural procedures play an important and not yet sufficiently studied role concerning water quality. The two most important factors for diffuse inputs are erosion and runoff. The latter usually occurs before erosion begins, and is thus often not visible in hindsight. Only if it has come to erosion, it is obvious to expect runoff in foresight at this area, too. In addition to numerous erosion models, there are also few applications to model runoff processes available. However, these conventional models utilize approximations of catchment parameters based on long-term average values or theoretically calculated concentration peaks which can only provide indications to relative amounts. Our study aims to develop and validate a simplified spatially-explicit dynamic model with high spatiotemporal resolution that enables to measure current and forecast runoff potential not only at catchment scale but field-differentiated. This method allows very precise estimations of runoff risks and supports risk reduction measures to be targeted before fields are treated. By focusing on water pathways occurring on arable land, targeted risk reduction measures like buffer strips at certain points and adapted ppp use can be taken early and pollution of rivers and other surface waters through transported pesticides, fertilizers and their products could be nearly avoided or largely minimized. Using a SAGA-based physical-parametric modeling approach, major factors influencing runoff

  5. Nonlinear Porous Diffusion Modeling of Hydrophilic Ionic Agrochemicals in Astomatous Plant Cuticle Aqueous Pores: A Mechanistic Approach

    Directory of Open Access Journals (Sweden)

    Eloise C. Tredenick

    2017-05-01

    Full Text Available The agricultural industry requires improved efficacy of sprays being applied to crops and weeds in order to reduce their environmental impact and deliver improved financial returns. Enhanced foliar uptake is one means of improving efficacy. The plant leaf cuticle is known to be the main barrier to diffusion of agrochemicals within the leaf. The usefulness of a mathematical model to simulate uptake of agrochemicals in plant cuticles has been noted previously in the literature, as the results of each uptake experiment are specific to each formulation of active ingredient, plant species and environmental conditions. In this work we develop a mathematical model and numerical simulation for the uptake of hydrophilic ionic agrochemicals through aqueous pores in plant cuticles. We propose a novel, nonlinear, porous diffusion model for ionic agrochemicals in isolated cuticles, which extends simple diffusion through the incorporation of parameters capable of simulating: plant species variations, evaporation of surface droplet solutions, ion binding effects on the cuticle surface and swelling of the aqueous pores with water. We validate our theoretical results against appropriate experimental data, discuss the key sensitivities in the model and relate theoretical predictions to appropriate physical mechanisms. Major influencing factors have been found to be cuticle structure, including tortuosity and density of the aqueous pores, and to a lesser extent humidity and cuticle surface ion binding effects.

  6. Nonlinear Porous Diffusion Modeling of Hydrophilic Ionic Agrochemicals in Astomatous Plant Cuticle Aqueous Pores: A Mechanistic Approach.

    Science.gov (United States)

    Tredenick, Eloise C; Farrell, Troy W; Forster, W Alison; Psaltis, Steven T P

    2017-01-01

    The agricultural industry requires improved efficacy of sprays being applied to crops and weeds in order to reduce their environmental impact and deliver improved financial returns. Enhanced foliar uptake is one means of improving efficacy. The plant leaf cuticle is known to be the main barrier to diffusion of agrochemicals within the leaf. The usefulness of a mathematical model to simulate uptake of agrochemicals in plant cuticles has been noted previously in the literature, as the results of each uptake experiment are specific to each formulation of active ingredient, plant species and environmental conditions. In this work we develop a mathematical model and numerical simulation for the uptake of hydrophilic ionic agrochemicals through aqueous pores in plant cuticles. We propose a novel, nonlinear, porous diffusion model for ionic agrochemicals in isolated cuticles, which extends simple diffusion through the incorporation of parameters capable of simulating: plant species variations, evaporation of surface droplet solutions, ion binding effects on the cuticle surface and swelling of the aqueous pores with water. We validate our theoretical results against appropriate experimental data, discuss the key sensitivities in the model and relate theoretical predictions to appropriate physical mechanisms. Major influencing factors have been found to be cuticle structure, including tortuosity and density of the aqueous pores, and to a lesser extent humidity and cuticle surface ion binding effects.

  7. Criticality analysis for weapon disassembly at the Pantex-Plant part II: Staging

    International Nuclear Information System (INIS)

    Knief, R.A.

    1997-01-01

    This paper very briefly describes criticality investigations for nuclear weapon dismantlement at the Pantex Plant. The investigations performed were for pit staging, and build on previous criticality calculations for single pits. The KENO and MCNP computer models were used for pit and container combinations. Scenarios were based on administrative limits and actual or potential physical conditions in the facilities. Essentially all of the pit configurations modeled were subcritical by a substantial amount. It was concluded that a critical configuration involving pit/container combinations is not credible

  8. Life Cycle Management Managing the Aging of Critical Nuclear Plant Components

    International Nuclear Information System (INIS)

    Meyer, Theodore A.; Elder, G. Gary; Llovet, Ricardo

    2002-01-01

    Life Cycle Management is a structured process to manage equipment aging and long-term equipment reliability for nuclear plant Systems, Structures and Components (SSCs). The process enables the identification of effective repair, replace, inspect, test and maintenance activities and the optimal timing of the activities to maximize the economic value to the nuclear plant. This paper will provide an overview of the process and some of the tools that can be used to implement the process for the SSCs deemed critical to plant safety and performance objectives. As nuclear plants strive to reduce costs, extend life and maximize revenue, the LCM process and the supporting tools summarized in this paper can enable development of a long term, cost efficient plan to manage the aging of the plant SSCs. (authors)

  9. Structural inspection and wind analysis of redwood cooling towers at the Portsmouth Gaseous Diffusion Plant

    International Nuclear Information System (INIS)

    Chung, T.; Solack, T.; Hortel, J.

    1991-01-01

    As part of the plant upgrade program, structural analyses and field inspections were performed on four redwood cooling towers at the DOE Portsmouth gaseous diffusion plant located in Piketon, Ohio. The cooling towers are categorized as important hazard facilities. The loadings are derived from UCRL-15910 according to the pertinent hazard category. In addition to the seismic and wind loadings, the wood cooling towers are constantly subject to adverse environmental effects such as elevated temperature, chemical attack, icing and snow load, and motor vibrations. A thorough structural evaluation for all load combinations was performed for each of the cooling towers based on the structural code requirements of the Cooling Tower Institute and National Forest Products Association. Most stress criteria are unique for the redwood material. This evaluation was performed using finite element techniques on the global structural integrity and supplemented by hand calculations on the individual connection joints. Overloaded wood structural members and joints are identified by the analysis. The rectangular tower structure sits on a concrete basin that span across 60 ft by 200 ft. A major part of the cooling towers upgrading program involved field inspections of the individual cells of each tower. The primary purpose of these inspections was to identify any existing structural damage or deficiencies such as failed members, degraded wood, and deficiencies resulting from poor construction practice. Inspection of 40 cells identified some generic deficiencies that mostly are consistent with the analytical finding. Based on the analysis, some effective but inexpensive upgrading techniques were developed and recommended to bring the cooling towers into compliance with current DOE requirements

  10. Impacts from PCB accumulation on amphibians inhabiting streams flowing from the Paducah Gaseous Diffusion Plant.

    Science.gov (United States)

    DeGarady, C J; Halbrook, R S

    2003-11-01

    Contamination at the Paducah Gaseous Diffusion Plant (PGDP), Paducah, Kentucky, has been under evaluation for many years. We studied amphibians in selected outfalls (drainage ditches) flowing from the PGDP to determine if PCBs were accumulating in their tissues and how this might affect local populations. We determined relative amphibian species richness and abundance among seven outfalls and three reference streams by listening to their calls during audio surveys. We also captured amphibians from each study site during the summers of 2000 and 2001 and analyzed their carcasses for PCBs (Aroclor 1260 and 34 congeners) and livers for ethoxyresorufin O-deethylase (EROD) activity, a biomarker of PCBs and other organic contamination. Ten species were heard across study sites, and abundance and richness at outfalls were similar to those observed at reference sites. However, there were significant differences in abundance (p = 0.001) and richness (p = 0.048) of amphibians between continuously flowing and intermittent outfalls. There were no significant differences in PCB concentrations (p = 0.113) in amphibians captured from study sites, although Aroclor 1260 concentrations tended to be higher in amphibians collected from one outfall (outfall 12) on the east side of the plant (x = 1260 microg/kg) compared with all other study sites (x = 489 microg/kg). EROD activity measured in the liver was not indicative of Aroclor 1260 concentrations in amphibians at the PGDP, and EROD did not differ by study site, species, age class, or gender. PCB concentrations measured in amphibians at the PGDP were similar to concentrations measured at reference sites and did not appear to negatively affect individual amphibians or abundance and richness.

  11. Cooling tower drift studies at the Paducah, Kentucky Gaseous Diffusion Plant

    International Nuclear Information System (INIS)

    Taylor, F.G.; Hanna, S.R.; Parr, P.D.

    1979-01-01

    The transfer and fate of chromium from cooling tower drift to terrestrial ecosystems were quantified at the Department of Energy's uranium enrichment facility at Paducah, Kentucky. Chromium concentrations in plant materials (fescue grass) decreased with increasing distance from the cooing tower, ranging from 251 +- 19 ppM at 15 meters to 0.52 +- 0.07 ppM at 1500 meters. The site of drift contamination, size characteristics, and elemental content of drift particles were determined using a scanning electron microscope with energy dispersive x-ray analysis capabilities. Results indicate that elemental content in drift water (mineral residue) may not be equivalent to the content in the recirculating cooling water of the tower. This hypothesis is contrary to basic assumptions in calculating drift emissions. A laboratory study simulating throughfall from 1 to 6 inches of rain suggested that there are more exchange sites associated with litter than live foliage. Leachate from each one inch throughfall simulant removed 3% of the drift mass from litter compared to 7 to 9% from live foliage. Results suggest that differences in retention are related to chemical properties of the drift rather than physical lodging of the particle residue. To determine the potential for movement of drift-derived chromium to surface streams, soil--water samplers (wells) were placed along a distance gradient to Little Bayou Creek. Samples from two depths following rainstorms revealed the absence of vertical or horizontal movement with maximum concentrations of 0.13 ppb at 50 meters from the tower. Preliminary model estimates of drift deposition are compared to depositionmeasurements. Isopleths of the predicted deposition are useful to identify areas of maximum drift transport in the environs of the gaseous diffusion plant

  12. 78 FR 38897 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Arctostaphylos...

    Science.gov (United States)

    2013-06-28

    ... habitat within the Presidio; and (3) restoring the natural ecological interactions of the species with its... ecological interactions of the species with its habitat or areas with additional management that may be...-0067; 4500030114] RIN 1018-AY63 Endangered and Threatened Wildlife and Plants; Designation of Critical...

  13. 75 FR 1568 - Endangered and Threatened Wildlife and Plants; Proposed Designation of Critical Habitat for...

    Science.gov (United States)

    2010-01-12

    ... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 17 [RIN 1018-AW21] [Docket No. FWS-R1-ES-2009-0046] [MO 92210-0-0009-B4] Endangered and Threatened Wildlife and Plants; Proposed Designation of Critical Habitat for Limnanthes floccosa ssp. grandiflora (Large-Flowered Woolly Meadowfoam...

  14. 77 FR 55788 - Endangered and Threatened Wildlife and Plants; Designation of Revised Critical Habitat for the...

    Science.gov (United States)

    2012-09-11

    ... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 17 [Docket No. FWS-R8-ES-2012-0008; 45000030114] RIN 1018-AX42 Endangered and Threatened Wildlife and Plants; Designation of Revised Critical Habitat for the Allium munzii (Munz's onion) and Atriplex coronata var. notatior (San Jacinto...

  15. 75 FR 18107 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Oregon Chub...

    Science.gov (United States)

    2010-04-09

    ... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 17 [Docket No. FWS-R1-ES-2009-0010; MO 92210-0-0009-B4] RIN 1018-AV87 Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Oregon Chub (Oregonichthys crameri); Correction AGENCY: Fish and Wildlife Service...

  16. 77 FR 2254 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Mississippi...

    Science.gov (United States)

    2012-01-17

    ... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 17 [Docket No. FWS-R4-ES-2010-0024; 4500030114] RIN 1018-AW89 Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Mississippi Gopher Frog AGENCY: Fish and Wildlife Service, Interior. ACTION: Revised proposed...

  17. 75 FR 67676 - Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for Astragalus jaegerianus

    Science.gov (United States)

    2010-11-03

    ... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 17 [Docket No. FWS-R8-ES-2009-0078; MO 92210-0-0009-B4] RIN 1018-AW53 Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for Astragalus jaegerianus (Lane Mountain Milk-Vetch) AGENCY: Fish and Wildlife Service, Interior...

  18. 78 FR 51705 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Ivesia webberi

    Science.gov (United States)

    2013-08-21

    ... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 17 [Docket No. FWS-R8-ES-2013-0080; 4500030114] RIN 1018-AZ57 Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Ivesia webberi (Webber's ivesia) AGENCY: Fish and Wildlife Service, Interior. ACTION: Proposed...

  19. 78 FR 39237 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Jaguar

    Science.gov (United States)

    2013-07-01

    ... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 17 [Docket No. FWS-R2-ES-2012-0042; 4500030114] RIN 1018-AX13 Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Jaguar AGENCY: Fish and Wildlife Service, Interior. ACTION: Revised proposed rule...

  20. 78 FR 52894 - Endangered and Threatened Wildlife and Plants; Designating Critical Habitat for the Neosho Mucket...

    Science.gov (United States)

    2013-08-27

    ... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 17 [Docket No. FWS-R4-ES-2013-0007; 4500030113] RIN 1018-AZ30 Endangered and Threatened Wildlife and Plants; Designating Critical Habitat for the Neosho Mucket and Rabbitsfoot AGENCY: Fish and Wildlife Service, Interior. ACTION...

  1. 75 FR 29700 - Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for the Preble's Meadow...

    Science.gov (United States)

    2010-05-27

    ... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 17 [Docket No. FWS-R6-ES-2009-0013] [92210-1117-000-B4] RIN 1018-AV45 Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for the Preble's Meadow Jumping Mouse AGENCY: Fish and Wildlife Service, Interior. ACTION...

  2. 78 FR 53390 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Jaguar

    Science.gov (United States)

    2013-08-29

    ... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 17 [Docket No. FWS-R2-ES-2012-0042; 4500030114] RIN 1018-AX13 Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Jaguar AGENCY: Fish and Wildlife Service, Interior. ACTION: Proposed rule; reopening of...

  3. Critical area planting in the United States of America | G | African ...

    African Journals Online (AJOL)

    The importance of vegetation on disturbed or critical areas of the United States of America has long been evident. A wide range of climatic, soil and environmental conditions has resulted in a search for suitable grass species and methods for their establishment. Plant material centres have done considerable work in ...

  4. Barriers, pathways and processes for uptake, translocation and accumulation of nanomaterials in plants--Critical review.

    Science.gov (United States)

    Schwab, Fabienne; Zhai, Guangshu; Kern, Meaghan; Turner, Amalia; Schnoor, Jerald L; Wiesner, Mark R

    2016-01-01

    Uptake, transport and toxicity of engineered nanomaterials (ENMs) into plant cells are complex processes that are currently still not well understood. Parts of this problem are the multifaceted plant anatomy, and analytical challenges to visualize and quantify ENMs in plants. We critically reviewed the currently known ENM uptake, translocation, and accumulation processes in plants. A vast number of studies showed uptake, clogging, or translocation in the apoplast of plants, most notably of nanoparticles with diameters much larger than the commonly assumed size exclusion limit of the cell walls of ∼5-20 nm. Plants that tended to translocate less ENMs were those with low transpiration, drought-tolerance, tough cell wall architecture, and tall growth. In the absence of toxicity, accumulation was often linearly proportional to exposure concentration. Further important factors strongly affecting ENM internalization are the cell wall composition, mucilage, symbiotic microorganisms (mycorrhiza), the absence of a cuticle (submerged plants) and stomata aperture. Mostly unexplored are the roles of root hairs, leaf repellency, pit membrane porosity, xylem segmentation, wounding, lateral roots, nodes, the Casparian band, hydathodes, lenticels and trichomes. The next steps towards a realistic risk assessment of nanoparticles in plants are to measure ENM uptake rates, the size exclusion limit of the apoplast and to unravel plant physiological features favoring uptake.

  5. Environmental Survey preliminary report, Oak Ridge Gaseous Diffusion Plant, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    1989-02-01

    This report presents the preliminary findings from the first phase of the Environmental Survey of the US Department of Energy's (DOE) Oak Ridge Gaseous Diffusion Plant (ORGDP) conducted March 14 through 25, 1988. The Survey is being conducted by an interdisciplinary team of environmental specialists, led and managed by the Office of Environment, Safety and Health's Office of Environmental Audit. Individual team components are being supplied by a private contractor. The objective of the Survey is to identify environmental risk associated with ORGDP. The Survey covers all environmental media and all areas of environmental regulation. It is being performed in accordance with the DOE Environmental Survey Manual. This phase of the Survey involves the review of existing site environmental data, observations of the operations carried on at ORGDP, and interviews with site personnel. The Survey team developed a Sampling and Analysis Plan to assist in further assessing certain of the environmental problems identified during is on-site activities. The Sampling and Analysis Plan will be executed by Idaho National Engineering Laboratory (INEL). When completed, the results will be incorporated into the ORGDP Survey findings for in inclusion into the Environmental Survey Summary Report. 120 refs., 41 figs., 74 tabs

  6. Operating experience with aluminum bearings at the Portsmouth Gaseous Diffusion Plant

    International Nuclear Information System (INIS)

    Langebrake, C.O.

    1975-01-01

    Considerable operating experience has been gained at the Portsmouth Gaseous Diffusion Plant over the last 15 years in the use of aluminum bearings in process related and auxiliary equipment. All of this experience has been excellent and, in several cases, the use of this type of bearing material has solved significant operating problems. Aluminum 850-T101 alloy was first used as a bearing material in purge cascade (PC-9) centrifugal compressors where a fatigue problem was being experienced with babbitt-type bearings. Good experience in this application led to the extended use of this bearing material in other equipment including process related as well as auxiliary equipment. Since 1961 aluminum bearings have been installed in approximately 21 Type PC-9 (centrifugal), 97 Type 9 (centrifugal), 262 Type X-29 (axial), and 101 Type 31 (axial) compressors, and 3 speed increasers in the X-330 Evacuation Booster Station. Based on successful operation of these bearings, continued and expanded use of aluminum bearings is recommended as a means of obtaining a high fatigue resistant bearing at a cost lower than that for babbitt-type bearings. (U.S.)

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

    International Nuclear Information System (INIS)

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

    1993-07-01

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

  8. Report on the biological monitoring program at Paducah Gaseous Diffusion Plant, January--December 1997

    Energy Technology Data Exchange (ETDEWEB)

    Kszos, L.A.; Peterson, M.J.; Ryon, M.G.; Smith, J.G.; Southworth, G.R.

    1998-03-01

    On September 24, 1987, the Commonwealth of Kentucky Natural Resources and Environmental Protection Cabinet issued an Agreed Order that required the development of a Biological Monitoring Program (BMP) for the Paducah Gaseous Diffusion Plant (PGDP). A plan for the biological monitoring of the receiving streams was implemented in 1987 and consisted of ecological surveys, toxicity monitoring of effluents and receiving streams, evaluation of bioaccumulation of trace contaminants in biota, and supplemental chemical characterization of effluents. Beginning in fall 1991, the Environmental Sciences Division (ESD) at Oak Ridge National Laboratory added data collection and report preparation to its responsibilities for the PGDP BMP. The BMP has been continued because it has proven to be extremely valuable in (1) identifying those effluents with the potential for adversely affecting instream fauna, (2) assessing the ecological health of receiving streams, and (3) guiding plans for remediation and protecting human health. The BMP for PGDP consists of three major tasks: (1) effluent toxicity monitoring, (2) bioaccumulation studies, and (3) ecological surveys of benthic macroinvertebrate communities and fish. With the exception of the benthic macroinvertebrate community surveys, this report focuses on activities from January to December 1997.

  9. Report on the biological monitoring program at Paducah Gaseous Diffusion Plant, January-December 1997

    International Nuclear Information System (INIS)

    Kszos, L.A.; Peterson, M.J.; Ryon, M.G.; Smith, J.G.; Southworth, G.R.

    1998-03-01

    On September 24, 1987, the Commonwealth of Kentucky Natural Resources and Environmental Protection Cabinet issued an Agreed Order that required the development of a Biological Monitoring Program (BMP) for the Paducah Gaseous Diffusion Plant (PGDP). A plan for the biological monitoring of the receiving streams was implemented in 1987 and consisted of ecological surveys, toxicity monitoring of effluents and receiving streams, evaluation of bioaccumulation of trace contaminants in biota, and supplemental chemical characterization of effluents. Beginning in fall 1991, the Environmental Sciences Division (ESD) at Oak Ridge National Laboratory added data collection and report preparation to its responsibilities for the PGDP BMP. The BMP has been continued because it has proven to be extremely valuable in (1) identifying those effluents with the potential for adversely affecting instream fauna, (2) assessing the ecological health of receiving streams, and (3) guiding plans for remediation and protecting human health. The BMP for PGDP consists of three major tasks: (1) effluent toxicity monitoring, (2) bioaccumulation studies, and (3) ecological surveys of benthic macroinvertebrate communities and fish. With the exception of the benthic macroinvertebrate community surveys, this report focuses on activities from January to December 1997

  10. Martin Marietta Paducah Gaseous Diffusion Plant comprehensive earthquake emergency management program

    International Nuclear Information System (INIS)

    1990-01-01

    Recognizing the value of a proactive, integrated approach to earthquake preparedness planning, Martin Marietta Energy Systems, Inc. initiated a contract in June 1989 with Murray State University, Murray, Kentucky, to develop a comprehensive earthquake management program for their Gaseous Diffusion Plant in Paducah, Kentucky (PGDP -- Subcontract No. 19P-JV649V). The overall purpose of the program is to mitigate the loss of life and property in the event of a major destructive earthquake. The program includes four distinct (yet integrated) components: (1) an emergency management plan with emphasis on the catas trophic earthquake; (2) an Emergency Operations Center Duty Roster Manual; (3) an Integrated Automated Emergency Management Information System (IAEMIS); and (4) a series of five training program modules. The PLAN itself is comprised of four separate volumes: Volume I -- Chapters 1--3; Volume II -- Chapters 4--6; Volume III -- Chapter 7; and Volume IV -- 23 Appendices. The EOC Manual (which includes 15 mutual aid agreements) is designated as Chapter 7 in the PLAN and is this document numbered as Volume III

  11. Martin Marietta Paducah Gaseous Diffusion Plant comprehensive earthquake emergency management program

    International Nuclear Information System (INIS)

    1990-01-01

    Recognizing the value of a proactive, integrated approach to earthquake preparedness planning, Martin Marietta Energy Systems, Inc. initiated a contract in June 1989 with Murray State University, Murray, Kentucky, to develop a comprehensive earthquake management program for their Gaseous Diffusion Plant in Paducah, Kentucky (PGDP -- Subcontract No. 19P-JV649V). The overall purpose of the program is to mitigate the loss of life and property in the event of a major destructive earthquake. The program includes four distinct (yet integrated) components: an emergency management plan, with emphasis on the catastrophic earthquake; an Emergency Operations Center Duty Roster Manual; an Integrated Automated Emergency Management Information System (IAEMIS); and a series of five training program modules. The PLAN itself is comprised of four separate volumes: Volume I -- Chapters 1--3; Volume II -- Chapters 4--6, Volume III -- Chapter 7, and Volume IV -- 23 Appendices. The EOC Manual (which includes 15 mutual aid agreements) is designated as Chapter 7 in the PLAN and is a ''stand alone'' document numbered as Volume III. This document, Volume II, discusses methodology, engineering and environmental analyses, and operational procedures

  12. Martin Marietta Paducah Gaseous Diffusion Plant comprehensive earthquake emergency management program

    International Nuclear Information System (INIS)

    1990-01-01

    Recognizing the value of a proactive, integrated approach to earthquake preparedness planning, Martin Marietta Energy Systems, Inc. initiated a contract in June 1989 with Murray State University, Murray, Kentucky, to develop a comprehensive earthquake management program for their Gaseous Diffusion Plant in Paducah, Kentucky. The overall purpose of the program is to mitigate the loss of life and property in the event of a major destructive earthquake. The program includes four distinct (yet integrated) components: an emergency management plan, with emphasis on the catastrophic earthquake; an Emergency Operations Center Duty Roster Manual; an Integrated Automated Emergency Management Information System (IAEMIS); and a series of five training program modules. The PLAN itself is comprised of four separate volumes: Volume I -- Chapters 1--3; Volume II -- Chapters 4--6, Volume III -- Chapter 7, and Volume IV -- 23 Appendices. The EOC Manual (which includes 15 mutual aid agreements) is designated as Chapter 7 in the PLAN and is a ''stand alone'' document numbered as Volume III. This document, Volume I, provides an introduction, summary and recommendations, and the emergency operations center direction and control

  13. Environmental Survey preliminary report, Oak Ridge Gaseous Diffusion Plant, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    1989-02-01

    This report presents the preliminary findings from the first phase of the Environmental Survey of the US Department of Energy's (DOE) Oak Ridge Gaseous Diffusion Plant (ORGDP) conducted March 14 through 25, 1988. The Survey is being conducted by an interdisciplinary team of environmental specialists, led and managed by the Office of Environment, Safety and Health's Office of Environmental Audit. Individual team components are being supplied by a private contractor. The objective of the Survey is to identify environmental risk associated with ORGDP. The Survey covers all environmental media and all areas of environmental regulation. It is being performed in accordance with the DOE Environmental Survey Manual. This phase of the Survey involves the review of existing site environmental data, observations of the operations carried on at ORGDP, and interviews with site personnel. The Survey team developed a Sampling and Analysis Plan to assist in further assessing certain of the environmental problems identified during is on-site activities. The Sampling and Analysis Plan will be executed by Idaho National Engineering Laboratory (INEL). When completed, the results will be incorporated into the ORGDP Survey findings for in inclusion into the Environmental Survey Summary Report. 120 refs., 41 figs., 74 tabs.

  14. Martin Marietta Paducah Gaseous Diffusion Plant comprehensive earthquake emergency management program

    International Nuclear Information System (INIS)

    1990-01-01

    Recognizing the value of a proactive, integrated approach to earthquake preparedness planning, Martin Marietta Energy Systems, Inc, initiated a contract in June 1989 with Murray State University, Murray, Kentucky, to develop a comprehensive earthquake management program for their Gaseous Diffusion Plant in Paducah, Kentucky (PGDP--Subcontract No. 19P-JV649V). The overall purpose of the program is to mitigate the loss of life and property in the event of a major destructive earthquake. The program includes four distinct (yet integrated) components: (1) an emergency management plan, with emphasis on the catas trophic earthquake, (2) an Emergency Operations Center Duty Roster Manual, (3) an Integrated Automated Emergency Management Information System (IAEMIS), and (4) a series of five training program modules. The PLAN itself is comprised of four separate volumes: Volume I--Chapters 1--3; Volume II--Chapters 4--6, Volume III--Chapter 7, and Volume IV--23 Appendices. The EOC Manual (which includes 15 mutual aid agreements) is designated as Chapter 7 in the PLAN and is a ''stand alone'' document numbered as Volume III. This document, Volume IV contains the appendices to this report

  15. Report on the biological monitoring program at Paducah Gaseous Diffusion Plant December 1993 to December 1994

    Energy Technology Data Exchange (ETDEWEB)

    Kszos, L.A. [ed.

    1996-05-01

    On September 24, 1987, the Commonwealth of Kentucky Natural Resources and Environmental Protection Cabinet issued an Agreed Order that required the development of a Biological Monitoring Program (BMP) for the Paducah Gaseous Diffusion Plant (PGDP). The PGDP BMP was implemented in 1987 by the University of Kentucky. Research staff of the Environmental Sciences Division (ESD) at Oak Ridge National Laboratory (ORNL) served as reviewers and advisers to the University of Kentucky. Beginning in fall 1991, ESD added data collection and report preparation to its responsibilities for the PGDP BMP. The goals of BMP are to (1) demonstrate that the effluent limitations established for PGDP protect and maintain the use of Little Bayou and Big Bayou creeks for growth and propagation of fish and other aquatic life, (2) characterize potential environmental impacts, (3) document the effects of pollution abatement facilities on stream biota, and (4) recommend any program improvements that would increase effluent treatability. In September 1992, a renewed Kentucky Pollutant Discharge Elimination System (KPDES) permit was issued to PGDP. The BMP for PGDP consists of three major tasks: (1) effluent and ambient toxicity monitoring, (2) bioaccumulation studies, and (3) ecological surveys of stream communities (i.e., benthic macroinvertebrates and fish). This report includes ESD activities occurring from December 1993 to December 1994, although activities conducted outside this time period are included as appropriate.

  16. Report on the biological monitoring program at Paducah Gaseous Diffusion Plant December 1993 to December 1994

    International Nuclear Information System (INIS)

    Kszos, L.A.

    1996-05-01

    On September 24, 1987, the Commonwealth of Kentucky Natural Resources and Environmental Protection Cabinet issued an Agreed Order that required the development of a Biological Monitoring Program (BMP) for the Paducah Gaseous Diffusion Plant (PGDP). The PGDP BMP was implemented in 1987 by the University of Kentucky. Research staff of the Environmental Sciences Division (ESD) at Oak Ridge National Laboratory (ORNL) served as reviewers and advisers to the University of Kentucky. Beginning in fall 1991, ESD added data collection and report preparation to its responsibilities for the PGDP BMP. The goals of BMP are to (1) demonstrate that the effluent limitations established for PGDP protect and maintain the use of Little Bayou and Big Bayou creeks for growth and propagation of fish and other aquatic life, (2) characterize potential environmental impacts, (3) document the effects of pollution abatement facilities on stream biota, and (4) recommend any program improvements that would increase effluent treatability. In September 1992, a renewed Kentucky Pollutant Discharge Elimination System (KPDES) permit was issued to PGDP. The BMP for PGDP consists of three major tasks: (1) effluent and ambient toxicity monitoring, (2) bioaccumulation studies, and (3) ecological surveys of stream communities (i.e., benthic macroinvertebrates and fish). This report includes ESD activities occurring from December 1993 to December 1994, although activities conducted outside this time period are included as appropriate

  17. Report on the biological monitoring program at Paducah Gaseous Diffusion Plant, January - December 1996

    International Nuclear Information System (INIS)

    Kszos, L.A.; Konetsky, B.K.; Peterson, M.J.; Petrie, R.B.; Ryon, M.G.; Smith, J.G.; Southworth, G.R.

    1997-06-01

    On September 24, 1987, the Commonwealth of Kentucky Natural Resources and Environmental Protection Cabinet issued an Agreed Order that required the development of a Biological Monitoring Program (BMP) for the Paducah Gaseous diffusion Plant (PGDP). The PGDP BMP was conducted by the University of Kentucky Between 1987 and 1992 and by staff of the Environmental Sciences Division (ESD) at Oak Ridge National Laboratory (ORNL) from 1991 to present. The goals of BMP are to (1) demonstrate that the effluent limitations established for PGDP protect and maintain the use of Little Bayou and Big Bayou creeks for growth and propagation of fish and other aquatic life, (2) characterize potential environmental impacts, and (3) document the effects of pollution abatement facilities on stream. The BMP for PGDP consists of three major tasks: (1) effluent toxicity monitoring, (2) bioaccumulation studies, and (3) ecological surveys of stream communities (i.e., benthic macroinvertebrates and fish). This report focuses on ESD activities occurring from January 1996 to December 1996, although activities conducted outside this time period are included as appropriate

  18. Report on the biological monitoring program at Paducah Gaseous Diffusion Plant, January--December 1996

    Energy Technology Data Exchange (ETDEWEB)

    Kszos, L.A. [ed.; Konetsky, B.K.; Peterson, M.J.; Petrie, R.B.; Ryon, M.G.; Smith, J.G.; Southworth, G.R.

    1997-06-01

    On September 24, 1987, the Commonwealth of Kentucky Natural Resources and Environmental Protection Cabinet issued an Agreed Order that required the development of a Biological Monitoring Program (BMP) for the Paducah Gaseous diffusion Plant (PGDP). The PGDP BMP was conducted by the University of Kentucky Between 1987 and 1992 and by staff of the Environmental Sciences Division (ESD) at Oak Ridge National Laboratory (ORNL) from 1991 to present. The goals of BMP are to (1) demonstrate that the effluent limitations established for PGDP protect and maintain the use of Little Bayou and Big Bayou creeks for growth and propagation of fish and other aquatic life, (2) characterize potential environmental impacts, and (3) document the effects of pollution abatement facilities on stream. The BMP for PGDP consists of three major tasks: (1) effluent toxicity monitoring, (2) bioaccumulation studies, and (3) ecological surveys of stream communities (i.e., benthic macroinvertebrates and fish). This report focuses on ESD activities occurring from January 1996 to December 1996, although activities conducted outside this time period are included as appropriate.

  19. 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

  20. Proposed sale of radioactively contaminated nickel ingots located at the Paducah Gaseous Diffusion Plant, Paducah, Kentucky

    International Nuclear Information System (INIS)

    1995-10-01

    The U.S. Department of Energy (DOE) proposes to sell 8,500 radioactively contaminated nickel ingots (9.350 short tons), currently in open storage at the Paducah Gaseous Diffusion Plant (PGDP), to Scientific Ecology Group, Inc. (SEG) for decontamination and resale on the international market. SEG would take ownership of the ingots when they are loaded for transport by truck to its facility in Oak Ridge, Tennessee. SEG would receive approximately 200 short tons per month over approximately 48 months (an average of 180 ingots per month). The nickel decontamination process specified in SEG's technical proposal is considered the best available technology and has been demonstrated in prototype at SEG. The resultant metal for resale would have contamination levels between 0.3 and 20 becquerel per gram (Bq/g). The health hazards associated with release of the decontaminated nickel are minimal. The activity concentration of the end product would be further reduced when the nickel is combined with other metals to make stainless steel. Low-level radioactive waste from the SEG decontamination process, estimated to be approximately 382 m 3 (12,730 ft), would be shipped to a licensed commercial or DOE disposal facility. If the waste were packaged in 0.23 m 3 -(7.5 ft 3 -) capacity drums, approximately 1,500 to 1,900 drums would be transported over the 48-month contract period. Impacts from the construction of decontamination facilities and the selected site are minimal

  1. Critical aspects in management of fungal diseases of ornamental plants and directions in research

    Directory of Open Access Journals (Sweden)

    A. Garibaldi

    2007-08-01

    Full Text Available The production of ornamental plants is a thriving and expanding industry, which is economically important in the United States of America, Canada, South America, Australia, and Europe as well as in many developing countries. During the last few decades significant changes have occurred, with many new crops being introduced, new products such as pot plants replacing cut flowers, and improved techniques for growing, treating and handling plants being introduced. Such changes have had a profound influence on disease development and management. This review focuses on critical aspects of the disease management of ornamental crops, considering the role of breeding strategies, cultural practices, chemical and biological control, natural products, regulatory control and diagnostic tools. Finally, the research needs in this sector are critically analysed.

  2. Assessment of basic data for criticality safety and shielding design of Tokai Reprocessing Plant

    International Nuclear Information System (INIS)

    Suto, Toshiyuki; Shimizu, Yoshio; Nakamura, Hirohumi; Nojiri, Ichiro; Maki, Akira; Yamanouchi, Takamichi

    1999-02-01

    As a part of the safety confirmation work of Tokai Reprocessing Plant, the appropriateness was checked on the basic data used in criticality safety and shielding design of early-designed facilities in the plant on the basis of recent knowledge and safety evaluation methods. In the criticality safety design, it was confirmed that critical and subcritical values concerning mass and concentration of U and Pu and equipment dimension were appropriate. In the shielding design, it was found that the relation between shielding thickness and permissible radioactivity might give underestimated results of shielding thickness necessary to limit dose rate to the designated one on some condition. In this cases, however, it was confirmed that necessary shielding thickness has been secured because of the conservative calculation conditions for the real conditions except the operation test laboratory (OTL). However, the amount of radioactivity handled at OTL needs to be limited. From a viewpoint of criticality safety, operational control for U and Pu transfer was also investigated. As a result of it, at the transfer route where erroneous batch-wise transfer of process solution might lead to a criticality accident, the reliability of U and Pu concentration measurement needs to be improved by multiple measurements. At other transfer routes, it was confirmed that single failure of equipment or operation error would not lead to a criticality problem. (author)

  3. Criticality Calculations for a Typical Nuclear Fuel Fabrication Plant with Low Enriched Uranium

    International Nuclear Information System (INIS)

    Elsayed, Hade; Nagy, Mohamed; Agamy, Said; Shaat, Mohmaed

    2013-01-01

    The operations with the fissile materials such as U 235 introduce the risk of a criticality accident that may be lethal to nearby personnel and can lead the facility to shutdown. Therefore, the prevention of a nuclear criticality accident should play a major role in the design of a nuclear facility. The objectives of criticality safety are to prevent a self-sustained nuclear chain reaction and to minimize the consequences. Sixty criticality accidents were occurred in the world. These are accidents divided into two categories, 22 accidents occurred in process facilities and 38 accidents occurred during critical experiments or operations with research reactor. About 21 criticality accidents including Japan Nuclear Fuel Conversion Co. (JCO) accident took place with fuel solution or slurry and only one accident occurred with metal fuel. In this study the nuclear criticality calculations have been performed for a typical nuclear fuel fabrication plant producing nuclear fuel elements for nuclear research reactors with low enriched uranium up to 20%. The calculations were performed for both normal and abnormal operation conditions. The effective multiplication factor (k eff ) during the nuclear fuel fabrication process (Uranium hexafluoride - Ammonium Diuranate conversion process) was determined. Several accident scenarios were postulated and the criticalities of these accidents were evaluated. The computer code MCNP-4B which based on Monte Carlo method was used to calculate neutron multiplication factor. The criticality calculations Monte Carlo method was used to calculate neutron multiplication factor. The criticality calculations were performed for the cases of, change of moderator to fuel ratio, solution density and concentration of the solute in order to prevent or mitigate criticality accidents during the nuclear fuel fabrication process. The calculation results are analyzed and discussed

  4. Lateral diffusion of CO2 in leaves of the crassulacean acid metabolism plant Kalanchoe daigremontiana Hamet et Perrier.

    Science.gov (United States)

    Duarte, Heitor M; Jakovljevic, Ivona; Kaiser, Friedemann; Lüttge, Ulrich

    2005-04-01

    Dynamic patchiness of photosystem II (PSII) activity in leaves of the crassulacean acid metabolism (CAM) plant Kalanchoe daigremontiana Hamet et Perrier, which was independent of stomatal control and was observed during both the day/night cycle and circadian endogenous oscillations of CAM, was previously explained by lateral CO2 diffusion and CO2 signalling in the leaves [Rascher et al. (2001) Proc Natl Acad Sci USA 98:11801-11805; Rascher and Luttge (2002) Plant Biol 4:671-681]. The aim here was to actually demonstrate the importance of lateral CO2 diffusion and its effects on localized PSII activity. Covering small sections of entire leaves with silicone grease was used for local exclusion of a contribution of atmospheric CO2 to internal CO2 via transport through stomata. A setup for combined measurement of gas exchange and chlorophyll fluorescence imaging was used for recording photosynthetic activity with a spatiotemporal resolution. When remobilization of malic acid from vacuolar storage and its decarboxylation in the CAM cycle caused increasing internal CO2 concentrations sustaining high PSII activity behind closed stomata, PSII activity was also increased in adjacent leaf sections where vacuolar malic acid accumulation was minimal as a result of preventing external CO2 supply due to leaf-surface greasing, and where therefore CO2 could only be supplied by diffusion from the neighbouring malic acid-remobilizing leaf tissue. This demonstrates lateral CO2 diffusion and its effect on local photosynthetic activity.

  5. Inorganic soil and groundwater chemistry near Paducah Gaseous Diffusion Plant, Paducah, Kentucky

    International Nuclear Information System (INIS)

    Moore, G.K.

    1995-03-01

    Near-surface soils, boreholes, and sediments near the Paducah Gaseous Diffusion Plant (PGDP) were sampled in 1989-91 as were monitoring wells, TVA wells, and privately-owned wells. Most wells were sampled two or three times. The resulting chemical analyses have been published in previous reports and have been previously described (CH2M HILL 1991, 1992; Clausen et al. 1992). The two reports by CH2M HILL are controversial, however, because, the concentrations of some constituents were reported to exceed background levels or drinking water standards and because both on-site (within the perimeter fence at PGDP) and off-site pollution was reported to have occurred. The groundwater samples upon which these interpretations were based may not be representative, however. The CH2M HILL findings are discussed in the report. The purpose of this report is to characterize the inorganic chemistry of groundwater and soils near PGDP, using data from the CH2M HILL reports (1991, 1992), and to determine whether or not any contamination has occurred. The scope is limited to analysis and interpretation of data in the CH2M HILL reports because previous interpretations of these data may not be valid, because samples were collected in a relatively short period of time at several hundred locations, and because the chemical analyses are nearly complete. Recent water samples from the same wells were not considered because the characterization of inorganic chemistry for groundwater and soil requirements only one representative sample and an accurate analysis from each location

  6. Inorganic soil and groundwater chemistry near Paducah Gaseous Diffusion Plant, Paducah, Kentucky

    Energy Technology Data Exchange (ETDEWEB)

    Moore, G.K. [Tennessee Univ., Knoxville, TN (United States)

    1995-03-01

    Near-surface soils, boreholes, and sediments near the Paducah Gaseous Diffusion Plant (PGDP) were sampled in 1989-91 as were monitoring wells, TVA wells, and privately-owned wells. Most wells were sampled two or three times. The resulting chemical analyses have been published in previous reports and have been previously described (CH2M HILL 1991, 1992; Clausen et al. 1992). The two reports by CH2M HILL are controversial, however, because, the concentrations of some constituents were reported to exceed background levels or drinking water standards and because both on-site (within the perimeter fence at PGDP) and off-site pollution was reported to have occurred. The groundwater samples upon which these interpretations were based may not be representative, however. The CH2M HILL findings are discussed in the report. The purpose of this report is to characterize the inorganic chemistry of groundwater and soils near PGDP, using data from the CH2M HILL reports (1991, 1992), and to determine whether or not any contamination has occurred. The scope is limited to analysis and interpretation of data in the CH2M HILL reports because previous interpretations of these data may not be valid, because samples were collected in a relatively short period of time at several hundred locations, and because the chemical analyses are nearly complete. Recent water samples from the same wells were not considered because the characterization of inorganic chemistry for groundwater and soil requirements only one representative sample and an accurate analysis from each location.

  7. 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

  8. Reaping the benefits of evolutionary critical technology development - system 80+trademark standardized plant design

    International Nuclear Information System (INIS)

    Matzie, R.A.; Davis, G.A.; Bagnal, C.W. Jr.; Turk, R.S.

    1993-01-01

    Light water reactors have proved themselves to be a critical part of the electrical power generation infrastructure in the United States as well as in the world. As society moves to improve the safety and economical viability of our critical technologies, we must decide the most beneficial means of making those improvements. In some cases, the critical technologies are propelled in a single leap; in others, it is the result of a continuous and deliberate series of carefully chosen steps. ABB Nuclear Systems was faced with making such a choice in the development of nuclear power plant technology. We elected to focus our development and commercialization efforts on the evolutionary System 80+ Advanced Standardized plant design. Obviously, this was because we have a strong indication that this would be the most beneficial way to meet customers' needs and reap the largest possible benefit from the development of these critical technologies. The evolutionary approach to critical technology development requires a reliance on making incremental improvements over time to the technology. This has the benefit of providing the following: 1. predictable performance based on experience, 2. enhanced safety, performance, economics 3. incremental changes in technology, 4. availability of proven equipment and systems, and 5. assured acceptance and licensability

  9. Consideration of nuclear criticality when disposing of transuranic waste at the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    Rechard, Robert P.; Sanchez, Lawrence C.; Stockman, Christine T.; Trellue, Holly R.

    2000-01-01

    Based on general arguments presented in this report, nuclear criticality was eliminated from performance assessment calculations for the Waste Isolation Pilot Plant (WIPP), a repository for waste contaminated with transuranic (TRU) radioisotopes, located in southeastern New Mexico. At the WIPP, the probability of criticality within the repository is low because mechanisms to concentrate the fissile radioisotopes dispersed throughout the waste are absent. In addition, following an inadvertent human intrusion into the repository (an event that must be considered because of safety regulations), the probability of nuclear criticality away from the repository is low because (1) the amount of fissile mass transported over 10,000 yr is predicted to be small, (2) often there are insufficient spaces in the advective pore space (e.g., macroscopic fractures) to provide sufficient thickness for precipitation of fissile material, and (3) there is no credible mechanism to counteract the natural tendency of the material to disperse during transport and instead concentrate fissile material in a small enough volume for it to form a critical concentration. Furthermore, before a criticality would have the potential to affect human health after closure of the repository--assuming that a criticality could occur--it would have to either (1) degrade the ability of the disposal system to contain nuclear waste or (2) produce significantly more radioisotopes than originally present. Neither of these situations can occur at the WIPP; thus, the consequences of a criticality are also low

  10. Consideration of nuclear criticality when disposing of transuranic waste at the Waste Isolation Pilot Plant

    Energy Technology Data Exchange (ETDEWEB)

    RECHARD,ROBERT P.; SANCHEZ,LAWRENCE C.; STOCKMAN,CHRISTINE T.; TRELLUE,HOLLY R.

    2000-04-01

    Based on general arguments presented in this report, nuclear criticality was eliminated from performance assessment calculations for the Waste Isolation Pilot Plant (WIPP), a repository for waste contaminated with transuranic (TRU) radioisotopes, located in southeastern New Mexico. At the WIPP, the probability of criticality within the repository is low because mechanisms to concentrate the fissile radioisotopes dispersed throughout the waste are absent. In addition, following an inadvertent human intrusion into the repository (an event that must be considered because of safety regulations), the probability of nuclear criticality away from the repository is low because (1) the amount of fissile mass transported over 10,000 yr is predicted to be small, (2) often there are insufficient spaces in the advective pore space (e.g., macroscopic fractures) to provide sufficient thickness for precipitation of fissile material, and (3) there is no credible mechanism to counteract the natural tendency of the material to disperse during transport and instead concentrate fissile material in a small enough volume for it to form a critical concentration. Furthermore, before a criticality would have the potential to affect human health after closure of the repository--assuming that a criticality could occur--it would have to either (1) degrade the ability of the disposal system to contain nuclear waste or (2) produce significantly more radioisotopes than originally present. Neither of these situations can occur at the WIPP; thus, the consequences of a criticality are also low.

  11. 50 CFR 17.99 - Critical habitat; plants on the islands of Kauai, Niihau, Molokai, Maui, Kahoolawe, Oahu, and...

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 4 2010-10-01 2010-10-01 false Critical habitat; plants on the islands of...) Interagency Cooperation (Continued) § 17.99 Critical habitat; plants on the islands of Kauai, Niihau, Molokai... habitat unit descriptions for the islands of Kauai and Niihau, HI. The following paragraphs contain the...

  12. Environmental site description for a Uranium Atomic Vapor Laser Isotope Separation (U-AVLIS) production plant at the Portsmouth Gaseous Diffusion Plant site

    International Nuclear Information System (INIS)

    Marmer, G.J.; Dunn, C.P.; Filley, T.H.; Moeller, K.L.; Pfingston, J.M.; Policastro, A.J.; Cleland, J.H.

    1991-09-01

    Uranium enrichment in the United States has utilized a diffusion process to preferentially enrich the U-235 isotope in the uranium product. In the 1970s, the US Department of Energy (DOE) began investigating more efficient and cost-effective enrichment technologies. In January 1990, the Secretary of Energy approved a plan for the demonstration and deployment of the Uranium Atomic Vapor Laser isotope Separation (U-AVLIS) technology with the near-term goal to provide the necessary information to make a deployment decision by November 1992. Initial facility operation is anticipated for 1999. A programmatic document for use in screening DOE sites to locate a U-AVLIS production plant was developed and implemented in two parts. The first part consisted of a series of screening analyses, based on exclusionary and other criteria, that identified a reasonable number of candidate sites. The final evaluation, which included sensitivity studies, identified the Oak Ridge Gaseous Diffusion Plant (ORGDP) site, the Paducah Gaseous Diffusion Plant (PGDP) site, and the Portsmouth Gaseous Diffusion Plant (PORTS) site as having significant advantages over the other sites considered. This environmental site description (ESD) provides a detailed description of the PORTS site and vicinity suitable for use in an environmental impact statement (EIS). This report is based on existing literature, data collected at the site, and information collected by Argonne National Laboratory (ANL) staff during site visits. The organization of the ESD is as follows. Topics addressed in Sec. 2 include a general site description and the disciplines of geology, water resources, biotic resources, air resources, noise, cultural resources, land use. Socioeconomics, and waste management. Identification of any additional data that would be required for an EIS is presented in Sec. 3

  13. Environmental site description for a Uranium Atomic Vapor Laser Isotope Separation (U-AVLIS) production plant at the Portsmouth Gaseous Diffusion Plant site

    Energy Technology Data Exchange (ETDEWEB)

    Marmer, G.J.; Dunn, C.P.; Filley, T.H.; Moeller, K.L.; Pfingston, J.M.; Policastro, A.J.; Cleland, J.H.

    1991-09-01

    Uranium enrichment in the United States has utilized a diffusion process to preferentially enrich the U-235 isotope in the uranium product. In the 1970s, the US Department of Energy (DOE) began investigating more efficient and cost-effective enrichment technologies. In January 1990, the Secretary of Energy approved a plan for the demonstration and deployment of the Uranium Atomic Vapor Laser isotope Separation (U-AVLIS) technology with the near-term goal to provide the necessary information to make a deployment decision by November 1992. Initial facility operation is anticipated for 1999. A programmatic document for use in screening DOE sites to locate a U-AVLIS production plant was developed and implemented in two parts. The first part consisted of a series of screening analyses, based on exclusionary and other criteria, that identified a reasonable number of candidate sites. The final evaluation, which included sensitivity studies, identified the Oak Ridge Gaseous Diffusion Plant (ORGDP) site, the Paducah Gaseous Diffusion Plant (PGDP) site, and the Portsmouth Gaseous Diffusion Plant (PORTS) site as having significant advantages over the other sites considered. This environmental site description (ESD) provides a detailed description of the PORTS site and vicinity suitable for use in an environmental impact statement (EIS). This report is based on existing literature, data collected at the site, and information collected by Argonne National Laboratory (ANL) staff during site visits. The organization of the ESD is as follows. Topics addressed in Sec. 2 include a general site description and the disciplines of geology, water resources, biotic resources, air resources, noise, cultural resources, land use. Socioeconomics, and waste management. Identification of any additional data that would be required for an EIS is presented in Sec. 3.

  14. Criticality safety evaluation of Rocky Flats Plant one-gallon shipping containers

    International Nuclear Information System (INIS)

    Shaw, M.E.

    1991-12-01

    Criticality safety calculations have been performed to provide an analytical basis for handling, storage and transport of Rocky Flats Plant (RFP) one-gallon shipping containers. A mass limit was establish for metal (solid uranium or plutonium) and slurries (undissolved U or Pu solids in a ''mud,'' ''sludge,'' or ''slurry''). A separate volume limit was developed for plutonium solutions (liquids, either aqueous or organic, containing no visible undissolved solids)

  15. Criticality safety evaluation of Rocky Flats Plant one-gallon shipping containers

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, M.E.

    1991-12-01

    Criticality safety calculations have been performed to provide an analytical basis for handling, storage and transport of Rocky Flats Plant (RFP) one-gallon shipping containers. A mass limit was establish for metal (solid uranium or plutonium) and slurries (undissolved U or Pu solids in a mud,'' sludge,'' or slurry''). A separate volume limit was developed for plutonium solutions (liquids, either aqueous or organic, containing no visible undissolved solids).

  16. Criticality safety evaluation of Rocky Flats Plant one-gallon shipping containers

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, M.E.

    1991-12-01

    Criticality safety calculations have been performed to provide an analytical basis for handling, storage and transport of Rocky Flats Plant (RFP) one-gallon shipping containers. A mass limit was establish for metal (solid uranium or plutonium) and slurries (undissolved U or Pu solids in a ``mud,`` ``sludge,`` or ``slurry``). A separate volume limit was developed for plutonium solutions (liquids, either aqueous or organic, containing no visible undissolved solids).

  17. A Critical Review of the Concept of Transgenic Plants: Insights into Pharmaceutical Biotechnology and Molecular Farming.

    Science.gov (United States)

    Abiri, Rambod; Valdiani, Alireza; Maziah, Mahmood; Shaharuddin, Noor Azmi; Sahebi, Mahbod; Yusof, Zetty Norhana Balia; Atabaki, Narges; Talei, Daryush

    2016-01-01

    Using transgenic plants for the production of high-value recombinant proteins for industrial and clinical applications has become a promising alternative to using conventional bioproduction systems, such as bacteria, yeast, and cultured insect and animal cells. This novel system offers several advantages over conventional systems in terms of safety, scale, cost-effectiveness, and the ease of distribution and storage. Currently, plant systems are being utilised as recombinant bio-factories for the expression of various proteins, including potential vaccines and pharmaceuticals, through employing several adaptations of recombinant processes and utilizing the most suitable tools and strategies. The level of protein expression is a critical factor in plant molecular farming, and this level fluctuates according to the plant species and the organs involved. The production of recombinant native and engineered proteins is a complicated procedure that requires an inter- and multi-disciplinary effort involving a wide variety of scientific and technological disciplines, ranging from basic biotechnology, biochemistry, and cell biology to advanced production systems. This review considers important plant resources, affecting factors, and the recombinant-protein expression techniques relevant to the plant molecular farming process.

  18. Field-Reversed Configuration Power Plant Critical-Issue Scoping Study

    International Nuclear Information System (INIS)

    Santarius, J. F.; Mogahed, E. A.; Emmert, G. A.; Khater, H. Y.; Nguyen, C. N.; Ryzhkov, S. V.; Stubna, M. D.

    2000-01-01

    A team from the Universities of Wisconsin, Washington, and Illinois performed an engineering scoping study of critical issues for field-reversed configuration (FRC) power plants. The key tasks for this research were (1) systems analysis for deuterium-tritium (D-T) FRC fusion power plants, and (2) conceptual design of the blanket and shield module for an FRC fusion core. For the engineering conceptual design of the fusion core, the project team focused on intermediate-term technology. For example, one decision was to use steele structure. The FRC systems analysis led to a fusion power plant with attractive features including modest size, cylindrical symmetry, good thermal efficiency (52%), relatively easy maintenance, and a high ratio of electric power to fusion core mass, indicating that it would have favorable economics

  19. Field-Reversed Configuration Power Plant Critical-Issue Scoping Study

    Energy Technology Data Exchange (ETDEWEB)

    Santarius, J. F.; Mogahed, E. A.; Emmert, G. A.; Khater, H. Y.; Nguyen, C. N.; Ryzhkov, S. V.; Stubna, M. D.

    2000-03-31

    A team from the Universities of Wisconsin, Washington, and Illinois performed an engineering scoping study of critical issues for field-reversed configuration (FRC) power plants. The key tasks for this research were (1) systems analysis for deuterium-tritium (D-T) FRC fusion power plants, and (2) conceptual design of the blanket and shield module for an FRC fusion core. For the engineering conceptual design of the fusion core, the project team focused on intermediate-term technology. For example, one decision was to use steele structure. The FRC systems analysis led to a fusion power plant with attractive features including modest size, cylindrical symmetry, good thermal efficiency (52%), relatively easy maintenance, and a high ratio of electric power to fusion core mass, indicating that it would have favorable economics.

  20. Criticality safety of transuranic storage arrays at the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    Boyd, W.A.; Fecteau, M.W.

    1993-01-01

    The Waste Isolation Pilot Plant (WIPP) facility is designed to store transuranic waste that will consist mainly of surface contaminate articles and sludge. The fissile material in the waste is predominantly 239 Pu. The waste is grouped into two categories: contact-handled waste, which will be stored in 55-gal steel drums or in steel boxes, and remote-handled waste, which will be stored in specially designed cylindrical steel canisters. To show that criticality safety will be acceptable, criticality analyses were performed to demonstrate that a large number of containers with limiting loadings of fissile material could be stored at the site and meet a k eff limit of 0.95. Criticality analyses based on the classic worst-case moderated plutonium sphere approach would severely limit the capacity for storage of waste at the facility. Therefore, these analyses use realistic or credible worst-case assumptions to better represent the actual storage situation without compromising the margin of safety. Numerous sensitivity studies were performed to determine the importance of various parameters on the criticality of the configuration. It was determined that the plutonium loading has the dominant effect on the system reactivity. Nearly all other reactivity variations from the sensitivity studies were found to be relatively small. The analysis shows that criticality of the contact-handled waste storage drums and boxes and the remote-handled canisters is prevented by restrictions on maximum fissile loading per container and on the size of handling/storage areas

  1. Critical components of odors in evaluating the performance of food waste composting plants

    International Nuclear Information System (INIS)

    Mao, I-F.; Tsai, C.-J.; Shen, S.-H.; Lin, T.-F.; Chen, W.-K.; Chen, M.-L.

    2006-01-01

    The current Taiwan government policy toward food waste management encourages composting for resource recovery. This study used olfactometry, gas chromatography-mass spectrometry (GC-MS) and gas detector tubes to evaluate the ambient air at three of the largest food waste composting plants in Taiwan. Ambient air inside the plants, at exhaust outlets and plant boundaries was examined to determine the comprehensive odor performance, critical components, and odor elimination efficiencies of various odor control engineering. Analytical results identified 29 compounds, including ammonia, amines, acetic acid, and multiple volatile organic compounds (VOCs) (hydrocarbons, ketones, esters, terpenes and S-compounds) in the odor from food waste composting plants. Concentrations of six components - ammonia, amines, dimethyl sulfide, acetic acid, ethyl benzene and p-Cymene - exceeded human olfactory thresholds. Ammonia, amines, dimethyl sulfide and acetic acid accounted for most odors compared to numerous VOCs. The results also show that the biotrickling filter was better at eliminating the concentrations of odor, NH 3 , amines, S-compounds and VOCs than the chemical scrubber and biofilters. All levels measured by olfactometry at the boundaries of food waste composting plants (range, 74-115 Odor Concentration (OC)) exceeded Taiwan's EPA standard of 50 OC. This study indicated that the malodor problem continued to be a significant problem for food waste recovery

  2. System implementation of hazard analysis and critical control points (HACCP) in a nitrogen production plant

    International Nuclear Information System (INIS)

    Barrantes Salazar, Alexandra

    2014-01-01

    System of hazard analysis and critical control points are deployed in a production plant of liquid nitrogen. The fact that the nitrogen has become a complement to food packaging to increase shelf life, or provide a surface that protect it from manipulation, has been the main objective. Analysis of critical control points for the nitrogen production plant has been the adapted methodology. The knowledge of both the standard and the production process, as well as the on site verification process, have been necessary. In addition, all materials and/or processing units that are found in contact with the raw material or the product under study were evaluated. Such a way that the intrinsic risks of each were detected, from the physical, chemical and biological points of view according to the origin or pollution source. For each found risk was evaluated the probability of occurrence according to the frequency and gravity of it, with these variables determined was achieved the definition of the type of risk detected. In the cases that was presented a greater risk or critical, these were subjected decision tree; with which is concluded the non determination of critical control points. However, for each one of them were established the maximum permitted limits. To generate each of the results it has literature or scientific reference of reliable provenance, where is indicated properly the support of the evaluated matter. In a general way, the material matrix and the process matrix are found without critical control points; so that the project is concluded in the analysis, and it has to generate without the monitoring system and verification. To increase this project is suggested in order to cover the packaging system of gaseous nitrogen, due to it was delimited to liquid nitrogen. Furthermore, the liquid nitrogen is a 100% automated and closed process so the introduction of contaminants is very reduced, unlike the gaseous nitrogen process. (author) [es

  3. The experimental study of pollution meteorology and diffusion feature in the site of Tianwan Nuclear Power Plant

    International Nuclear Information System (INIS)

    Hu Erbang; Yao Rentai; Xin Cuntian; Chen Jiayi

    2003-01-01

    The experimental observation and study of pollution meteorology and diffusion feature in site of Tianwan nuclear power plant is described. Four sets of (10, 30, 70, 100 m) sensors set on a 100-m-height tower to measure wind speed, wind direction and temperature were used to obtain hourly meteorological information during 1997-08 to 1999-08. The feature of middle scale wind field and the example and frequency of sea and land breezes are analyzed. The observation and formula of the internal boundary layer are completed. A simulation tests were done in a wind tunnel. In order to obtain the diffusion parameter the turbulence observation on two height of 100 m-height tower and 10 sets of SF 6 tracer experiments were done in summer, 1997. Based on above measured data the annual atmospheric dispersion factor and the accident probability dispersion factor at the boundary of an area of no residences were estimated. (authors)

  4. The report of the criticality accident in a uranium conversion test plant in Tokai-mura

    International Nuclear Information System (INIS)

    Murata, Hajime; Akashi, Makoto

    2002-03-01

    The criticality accident in the title occurred at around 10:35, on Sep. 30, 1999, cost the lives of two workers and caused many residents concern on their health. Moreover, rumors had both social and economic consequences. This report is a detailed account of the roles that many individuals and groups in the National Institute of Radiological Sciences (NIRS) performed in a range of the areas, and is published to discharge NIRS responsibilities in regards to the accident. The report involves chapters of detailed outline of the accident; acceptance of the victims and communications until the identification of the ''criticality'' accident; initial treatment; dose estimation (medical, hematological, physical and biological ones and that by dental metals activated by the neutron); decision making for therapeutic strategies; cooperation with the Network Council for Radiation Emergency Medicine and other medical facilities; emergency importation of medical supplies; treatment and progress (nursing system and radiation injuries); protection from radiation in medical facilities; response to nearby residents of the Plant; international response; press release; Uranium Processing Plant Criticality Accident Investigation Committee and the Health Management Committee organized by the Nuclear Safety Commission; handling of information; and radiation emergency medical preparedness at the NIRS (future issues and prospect). The report is hoped to be useful in preventing the occurrence of future accidents. (K.H.)

  5. NIRS report of the criticality accident in a uranium conversion test plant in Tokai-mura

    International Nuclear Information System (INIS)

    2001-01-01

    This report is a detailed account of the roles that National Institute of Radiological Sciences (NIRS) played at the criticality accident in the title, which occurred at around 10:35, on Sep. 30, 1999 and resulted in death of two workers after all, and is published to discharge NIRS responsibilities in regards to the accident. The accident caused many residents concern on their health and rumors had both social and economic consequences. The report involves chapters of detailed outline of the accident; demand for acceptance of the victims and communications until the identification of the criticality'' accident; the acceptance and initial treatment; the exposure dose estimation (based on acute symptoms, on physics, on chromosomal analyses and on neutron-activated dental metals, and detailed analyses for dose distribution); decision made for therapeutic strategies; cooperation with the Network Council for Radiation Emergency and with other medical facilities; the urgent import of medicine; treatment and processes (patients, nursing system and radiation injuries); radiation protection in medical facilities; response to nearby residents of the Plant; international response; press release; Uranium Processing Plant Criticality Accident Investigation Committee and the Health Management Committee organized by the Nuclear Safety Commission; handling of information; and radiation emergency medical preparedness at the NIRS (future issues and prospect). The report is hopefully useful in preventing the occurrence of future accidents. (N.I.)

  6. The Use of Critical Levels for Determining Plant Response to Ozone in Europe and in North America

    Directory of Open Access Journals (Sweden)

    Robert C. Musselman

    2007-01-01

    Full Text Available Critical levels to determine plant response to ozone (O3 have been used in Europe since the 1980s, utilizing the concentration-based AOT40 to relate plant response to ambient O3 exposure. More recently, there has been progress in Europe toward utilizing flux-based critical levels, because plant response is more closely related to O3 uptake than to the amount of O3 in ambient air. Flux-based critical levels are plant species specific; data for parameterization of flux-based critical levels models are lacking for most plant species. Although flux-based critical levels are now being used for a limited number of agricultural crops and tree species where data are available, the use of flux-based critical levels is limited by the lack of adequate consideration and incorporation of plant internal detoxification mechanisms in flux modeling. Critical levels have not been used in North America; however, recent interest in the U.S. and Canada for using critical loads for nitrogen and sulfur has generated interest in using critical levels for O3. A major obstacle for utilization of critical levels in North America is that ambient air quality standards for O3 in the U.S. and Canada are concentration based. It appears that cumulative exposure-based metrics, particularly when implemented with a quantification of peak concentrations and environmental variables, such as a drought index, are currently the most useful to relate O3 to vegetation response. Because data are unavailable to quantify detoxification potential of vegetation, effective flux models are not available to determine plant response to O3.

  7. Replacement of the criticality accident alarm system in the Tokai reprocessing plant

    International Nuclear Information System (INIS)

    Sanada, Yukihisa; Momose, Takumaro; Suzuki, Kei; Kawai, Keiichi

    2008-01-01

    A Criticality Accident Alarm System (CAAS) was installed as part of criticality safety management for use in reducing the radiation workers could be exposed to in the rare case of a criticality accident. The initial CAAS version was installed the Tokai Reprocessing Plant (TRP) in the 1980s. It includes units that can detect gamma-rays or neutron-rays released in criticality accidents (CADs), one of which consists of three plastic scintillation gamma detectors and three solid state neutron detectors with fissile material, and in being highly reliable utilizes the 2 out of 3 voting system. The purpose of this study is to give the design principles and procedures for determining the adequate relocation of the CADs within the TRP. The optimal places for the CADs to be relocated to were determined using a conservative evaluation method. Firstly, equipment needing to be monitored for criticality accidents was selected with consideration given to the risk of excessive exposure to workers. Secondly, the detection threshold of a minimum accident was set to be an increase in power of 10 15 fissions/s occurring within a rise-time of between 0.5 ms and 1 s. The sum of neutron and gamma doses of a minimum accident (10 15 fissions) was 0.3 Gy at an unshielded distance of 1 m. Finally, doses at where the CADs were installed were evaluated using parameters calculated with MCNP and ANISN. As a result, the alarm trip level of both the gamma detector and the neutron detector being set at 2.0 mGy/h enabled minimum criticality accidents to be conservatively detected. These results were then applied to the new CAD positions. (author)

  8. Defining groundwater-dependent ecosystems and assessing critical water needs for their foundational plant communities

    Science.gov (United States)

    Stella, J. C.

    2017-12-01

    In many water-limited regions, human water use in conjunction with increased climate variability threaten the sustainability of groundwater-dependent plant communities and the ecosystems that depend on them (GDEs). Identifying and delineating vulnerable GDEs and determining critical functional thresholds for their foundational species has proved challenging, but recent research across several disciplines shows great promise for reducing scientific uncertainty and increasing applicability to ecosystem and groundwater management. Combining interdisciplinary approaches provides insights into indicators that may serve as early indicators of ecosystem decline, or alternatively demonstrate lags in responses depending on scale or sensitivity, or that even may decouple over time (Fig. 1). At the plant scale, miniaturization of plant sap flow sensors and tensiometers allow for non-destructive, continual measurements of plant water status in response to environmental stressors. Novel applications of proven tree-ring and stable isotope methods provide multi-decadal chronologies of radial growth, physiological function (using d13C ratios) and source water use (using d18O ratios) in response to annual variation in climate and subsurface water availability to plant roots. At a landscape scale, integration of disparate geospatial data such as hyperspectral imagery and LiDAR, as well as novel spectral mixing analysis promote the development of novel water stress indices such as vegetation greenness and non-photosynthetic (i.e., dead) vegetation (Fig. 2), as well as change detection using time series (Fig. 3). Furthermore, increases in data resolution across numerous data types can increasingly differentiate individual plant species, including sensitive taxa that serve as early warning indicators of ecosystem impairment. Combining and cross-calibrating these approaches provide insight into the full range of GDE response to environmental change, including increased climate drought

  9. The integrated criticality safety evaluation for the Hanford tank waste treatment and immobilization plant

    International Nuclear Information System (INIS)

    Losey, D. C.; Miles, R. E.; Perks, M. F.

    2009-01-01

    The Criticality Safety Evaluation Report (CSER) for the Hanford Tank Waste Treatment and Immobilization Plant (WTP) has been developed as a single, integrated evaluation with a scope that covers all of the planned WTP operations. This integrated approach is atypical, as the scopes of criticality evaluations are usually more narrowly defined. Several adjustments were made in developing the WTP CSER, but the primary changes were to provide introductory overview for the criticality safety control strategy and to provide in-depth analysis of the underlying physical and chemical mechanisms that contribute to ensuring safety. The integrated approach for the CSER allowed a more consistent evaluation of safety and avoided redundancies that occur when evaluation is distributed over multiple documents. While the approach used with the WTP CSER necessitated more coordination and teamwork, it has yielded a report is that more integrated and concise than is typical. The integrated approach with the CSER produced a simple criticality control scheme that uses relatively few controls. (authors)

  10. Criticality safety evaluation of Rocky Flats Plant one-gallon shipping containers

    International Nuclear Information System (INIS)

    Briggs, J.B.

    1991-02-01

    Intraplant shipment of small quantities of plutonium and uranium at the Rocky Flats Plant (RFP) are made in one-gallon shipping containers. Criticality safety calculations have been performed to provide an analytical basis upon which handling, storage, and transportation limits on these containers are based. The calculations and results are documented in this report. This analysis was categorized as Quality Level A (according to the EG ampersand G Idaho Quality Manual) in that it is a service whose failure could cause undue risks to employees or public health and safety. It is intended to comply with NQA-1. 7 refs., 7 figs., 12 tabs

  11. A New Approach of Modeling an Ultra-Super-Critical Power Plant for Performance Improvement

    Directory of Open Access Journals (Sweden)

    Guolian Hou

    2016-04-01

    Full Text Available A suitable model of coordinated control system (CCS with high accuracy and simple structure is essential for the design of advanced controllers which can improve the efficiency of the ultra-super-critical (USC power plant. Therefore, with the demand of plant performance improvement, an improved T-S fuzzy model identification approach is proposed in this paper. Firstly, the improved entropy cluster algorithm is applied to identify the premise parameters which can automatically determine the cluster numbers and initial cluster centers by introducing the concept of a decision-making constant and threshold. Then, the learning algorithm is used to modify the initial cluster center and a new structure of concluding part is discussed, the incremental data around the cluster center is used to identify the local linear model through a weighted recursive least-square algorithm. Finally, the proposed approach is employed to model the CCS of a 1000 MW USC one-through boiler power plant by using on-site measured data. Simulation results show that the T-S fuzzy model built in this paper is accurate enough to reflect the dynamic performance of CCS and can be treated as a foundation model for the overall optimizing control of the USC power plant.

  12. Modeling of immision from power plants using stream-diffusion model

    International Nuclear Information System (INIS)

    Kanevce, Lj.; Kanevce, G.; Markoski, A.

    1996-01-01

    Analyses of simple empirical and integral immision models, comparing with complex three dimensional differential models is given. Complex differential models needs huge computer power, so they can't be useful for practical engineering calculations. In this paper immision modeling, using stream-diffusion approach is presented. Process of dispersion is divided into two parts. First part is called stream part, it's near the source of the pollutants, and it's presented with defected turbulent jet in wind field. This part finished when the velocity of stream (jet) becomes equal with wind speed. Boundary conditions in the end of the first part, are initial for the second, called diffusion part, which is modeling with tri dimensional diffusion equation. Gradient of temperature, wind speed profile and coefficient of diffusion in this model must not be constants, they can change with the height. Presented model is much simpler than the complete meteorological differential models which calculates whole fields of meteorological parameters. Also, it is more complex and gives more valuable results for dispersion of pollutants from widely used integral and empirical models

  13. Calculation of diffusion coefficients for carbon dioxide + solute system near the critical conditions by non-equilibrium molecular dynamics simulation

    OpenAIRE

    Higashi, Hidenori; Oda, Tsuyoshi; Iwai, Yoshio; Arai, Yasuhiko

    2004-01-01

    A non-equilibrium molecular dynamics simulation was adopted to calculate the diffusion coefficients for a pseudo-binary system of carbon dioxide and for a carbon dioxide + solute system at 308.2 and 318.2K. The calculated results were compared with the self- and tracer diffusion coefficients calculated by an equilibrium molecular dynamics simulation. The simulated results for the pseudo-binary system of carbon dioxide by the non-equilibrium molecular dynamics simulation are in good agreement ...

  14. The Mailbox Computer System for the IAEA verification experiment on HEU downblending at the Portsmouth Gaseous Diffusion Plant

    International Nuclear Information System (INIS)

    Aronson, A.L.; Gordon, D.M.

    2000-01-01

    IN APRIL 1996, THE UNITED STATES (US) ADDED THE PORTSMOUTH GASEOUS DIFFUSION PLANT TO THE LIST OF FACILITIES ELIGIBLE FOR THE APPLICATION OF INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA) SAFEGUARDS. AT THAT TIME, THE US PROPOSED THAT THE IAEA CARRY OUT A ''VERIFICATION EXPERIMENT'' AT THE PLANT WITH RESPECT TO DOOWNBLENDING OF ABOUT 13 METRIC TONS OF HIGHLY ENRICHED URANIUM (HEU) IN THE FORM OF URANIUM HEXAFLUROIDE (UF6). DURING THE PERIOD DECEMBER 1997 THROUGH JULY 1998, THE IAEA CARRIED OUT THE REQUESTED VERIFICATION EXPERIMENT. THE VERIFICATION APPROACH USED FOR THIS EXPERIMENT INCLUDED, AMONG OTHER MEASURES, THE ENTRY OF PROCESS-OPERATIONAL DATA BY THE FACILITY OPERATOR ON A NEAR-REAL-TIME BASIS INTO A ''MAILBOX'' COMPUTER LOCATED WITHIN A TAMPER-INDICATING ENCLOSURE SEALED BY THE IAEA

  15. Analysis guide - Nuclear criticality risks and their prevention in plants and laboratories

    International Nuclear Information System (INIS)

    Galet, C.; Le Bars, I.

    2011-01-01

    This report first describes the nuclear criticality risks and the prevention principles adopted in plants and laboratories, and reminds the French Basic Safety Rule (BSR) No. I.3.c. Diagrams are then used to introduce (i) the methodology recommended by this BSR, and (ii), for the reference fissile medium and each criticality control mode, the parameters to be considered 'conventionally' in a analysis, the 'typical' failures to be investigated, and the 'standard' scenarios associated with these failures. These diagrams, developed by IRSN and subject to change as feedback is received from experience in operating facilities or in implementation analyses and assessments, constitute a guide to the analysis of nuclear criticality risks, whether this is for compiling safety documents or for assessing them. As regards the possibility of modifying this guide, a sheet to be used for suggesting changes, intended for users of the guide, is provided on the last page of this report. Lastly, this guide is nothing more than the compilation of the 'conventional' and 'essential' precautions for preventing nuclear criticality risks. Although these precautions must always be kept in mind, the reader should never forget that each configuration is a special case and that there may be scenarios that apply only to this particular case. It is therefore appropriate to remind here that all criticality accidents are the result of failures and incident scenarios that have not been considered in the analysis. This guide is therefore a tool which is not intended to be exhaustive, and does not replace the necessary analysis to adapt to every situation

  16. Predicting Plant-Accessible Water in the Critical Zone: Mountain Ecosystems in a Mediterranean Climate

    Science.gov (United States)

    Klos, P. Z.; Goulden, M.; Riebe, C. S.; Tague, C.; O'Geen, A. T.; Flinchum, B. A.; Safeeq, M.; Conklin, M. H.; Hart, S. C.; Asefaw Berhe, A.; Hartsough, P. C.; Holbrook, S.; Bales, R. C.

    2017-12-01

    Enhanced understanding of subsurface water storage, and the below-ground architecture and processes that create it, will advance our ability to predict how the impacts of climate change - including drought, forest mortality, wildland fire, and strained water security - will take form in the decades to come. Previous research has examined the importance of plant-accessible water in soil, but in upland landscapes within Mediterranean climates the soil is often only the upper extent of subsurface water storage. We draw insights from both this previous research and a case study of the Southern Sierra Critical Zone Observatory to: define attributes of subsurface storage, review observed patterns in its distribution, highlight nested methods for its estimation across scales, and showcase the fundamental processes controlling its formation. We observe that forest ecosystems at our sites subsist on lasting plant-accessible stores of subsurface water during the summer dry period and during multi-year droughts. This indicates that trees in these forest ecosystems are rooted deeply in the weathered, highly porous saprolite, which reaches up to 10-20 m beneath the surface. This confirms the importance of large volumes of subsurface water in supporting ecosystem resistance to climate and landscape change across a range of spatiotemporal scales. This research enhances the ability to predict the extent of deep subsurface storage across landscapes; aiding in the advancement of both critical zone science and the management of natural resources emanating from similar mountain ecosystems worldwide.

  17. Resilience framework for critical infrastructures: An empirical study in a nuclear plant

    International Nuclear Information System (INIS)

    Labaka, Leire; Hernantes, Josune; Sarriegi, Jose M.

    2015-01-01

    The safety and proper functioning of Critical Infrastructures (CIs) are essential for ensuring the welfare of society, which puts the issue of improving their resilience level at the forefront of the field of crisis management. Most of the resilience-building principles defined in the literature do not cover all the dimensions that make up resilience and most of them only focus within the boundaries of the CI, neglecting the role of the external agents that also have an influence on enhancing resilience. Furthermore, most of the principles that are present in the literature are theoretical and difficult to implement in practice. In light of this situation, the aim of this research is to present a holistic resilience framework for critical infrastructures in order to improve their resilience level by taking into account internal and external agents and covering all the resilience dimensions. Furthermore, this framework has been defined in close collaboration with the general management of CIs to facilitate its implementation in practice. Finally, in order to illustrate the value added of this framework it was implemented in a nuclear plant. - Highlights: • Resilience protects against foreseen and unpredicted events. • There are two types of resilience: internal resilience and external resilience. • Sixteen policies and thirty sub-policies assist on building resilience. • Power nuclear plant focused on risk management approach rather than resilience. • The plant’s event driven risk management was enhanced with an all hazard approach

  18. Qualification of safety-critical software for digital reactor safety system in nuclear power plants

    International Nuclear Information System (INIS)

    Kwon, Kee-Choon; Park, Gee-Yong; Kim, Jang-Yeol; Lee, Jang-Soo

    2013-01-01

    This paper describes the software qualification activities for the safety-critical software of the digital reactor safety system in nuclear power plants. The main activities of the software qualification processes are the preparation of software planning documentations, verification and validation (V and V) of the software requirements specifications (SRS), software design specifications (SDS) and codes, and the testing of the integrated software and integrated system. Moreover, the software safety analysis and software configuration management are involved in the software qualification processes. The V and V procedure for SRS and SDS contains a technical evaluation, licensing suitability evaluation, inspection and traceability analysis, formal verification, software safety analysis, and an evaluation of the software configuration management. The V and V processes for the code are a traceability analysis, source code inspection, test case and test procedure generation. Testing is the major V and V activity of the software integration and system integration phases. The software safety analysis employs a hazard operability method and software fault tree analysis. The software configuration management in each software life cycle is performed by the use of a nuclear software configuration management tool. Through these activities, we can achieve the functionality, performance, reliability, and safety that are the major V and V objectives of the safety-critical software in nuclear power plants. (author)

  19. 75 FR 17465 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Salt Creek...

    Science.gov (United States)

    2010-04-06

    ... salt on the soil surface, resulting in the formation of barren salt flats. Specifically, evaporation of... Threatened Wildlife and Plants; Designation of Critical Habitat for the Salt Creek Tiger Beetle; Final Rule... of Critical Habitat for the Salt Creek Tiger Beetle AGENCY: Fish and Wildlife Service, Interior...

  20. Handling and treatment of low-level radioactive wastes from gaseous diffusion plants in the United States of America

    International Nuclear Information System (INIS)

    Wing, J.F.; Behrend, J.E.

    1984-01-01

    Gaseous diffusion plants in the United States of America currently generate very small quantities of low-level radioactive wastes. These wastes consist primarily of airborne effluent solid trapping media and liquid scrubber solutions, liquid effluent treatment sludges, waste oils and solvents, scrap metals and conventional combustible wastes such as floor sweepings, cleaning rags and shoe covers. In addition to waste emanating from current operations, large quantities of scrap metal generated during the Cascade Improvement Program are stored above ground at each of the diffusion plants. The radionuclides of primary concern are uranium and 99 Tc. Current radioactive waste treatment consists of uranium dissolution in weak acids followed by chemical precipitation and/or solvent extraction for uranium recovery. Current disposal operations consist of above ground storage of scrap metals, shallow land burial of inorganic solids and incineration of combustible wastes. With increased emphasis on reducing the potential for off-site radiological dose, several new treatment and disposal options are being studied and new projects are being planned. One project of particular interest involves the installation of a high temperature incinerator to thermally degrade hazardous organic wastes contaminated with low-level radioactive wastes. Other technologies being studied include fixation of uranium-bearing sludges in concrete before burial, decontamination of scrap metals by smelting and use of specially engineered centralized burial grounds. (author)

  1. Criticality safety analysis of TK-13 cask in Bushehr nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Mohammadi, Ashgar; Omidvari, Nima [Iran Radioactive Waste Management Company, Tehran (Iran, Islamic Republic of); Hassanzadeh, Mostafa [Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of)

    2017-12-15

    Spent fuel production is one of the main problems of nuclear power plants that should be managed properly considering the strategy of each country. Today, in most of nuclear power owner countries, the interim storage has been selected as the temporary solution of spent fuel management because of absence of deep geological repositories and no tendency for reprocessing. On the other side, considering the merits of storage in dual purpose casks based on dry storage, this method was chosen for interim storage. By taking into account that the only operating reactor of Iran is of Water-Water Energetic Reactor (WWER)-1000 type, proposed TK-13 cask by Russia which is the manufacturer of these types of reactors has been considered. In this study, the calculation of basket holding spent fuel assembly criticality of this cask has been analyzed for two modes of fresh and spent fuel by ORIGEN2.1 and MCNPX2.6 nuclear codes. The criterion of the nuclear criticality safety for effective multiplication factor (k{sub eff}) should be 0.95 and 0.98 for many ordinary and accident conditions, respectively. Therefore, the results show that a cylindrical basket with 66 cm diameter and 28 cm pitch with internal holding basket made of borated steel with 0.1% borate and steel free from borate would meet the criticality of cask, respectively.

  2. The relationship of JNC and JCO in the uranium processing plant criticality accident

    International Nuclear Information System (INIS)

    Kanamori, Masashi; Yanagibashi, Katsumi; Okamoto, Naritoshi

    2002-12-01

    On September 30th 1999, the criticality accident occurred at JCO's uranium conversion building in Tokai. The accident occurred during reconversion from U 3 O 8 to uranium nitrate solution (UNH) with uranium enriched 18.8% and about 60 kgU. JCO contacted with JNC to supply UNH that is fuel material for the experimental fast breeder reactor 'JOYO'. JNC has contracted with JCO that had started nuclear fuel material processing business following a definite policy of Japanese government and developed SUMITOMO ADU PROCESS'. JNC made the first contract with JCO in 1985 and has made a contact every year. There had never been a problem in their products. JNC inspected products based on contract. JNC discharge our duty as customer inspecting products based on contract. As for safety control, JCO had taken licensing safety review and had been permitted to be 'a processing facility'. Therefore JNC understood that JCO produced following this license. 'The Uranium Processing Plant Criticality Accident Investigation' showed that JCO had been taking a different method from the permit and violating the license. However JNC had never been explained about that and JCO's operation procedures had never described about that. Therefore the Criticality Accident couldn't be avoided. This report describes the relationship of JNC and JCO in the uranium reconversion contract for JOYO, atomic development policy of Japanese government, process to the order and the contents of contract. (author)

  3. Theoretical aspects of the increase in capacity of a gaseous diffusion separation plant

    International Nuclear Information System (INIS)

    Coates, J.H.; Guais, J.C.; Lamorlette, G.

    1975-01-01

    The rapid expansion of nuclear programmes for the future implies a strong growth in the enrichment market and the need to plan capacity increases to meet the new requirements. This article deals more specifically with increased output from an existing plant, of which the characteristics were optimized earlier on the basis of a production goal and of the economic conditions at the time. The solution in such a case is either to modify the equipment already installed in the plant or to install extra equipment, optimizing its internal parameters as a function of the amount of separation work required and of its lay-out in the original plant or in a new plant [fr

  4. The implementation of a burnup credit based criticality safety assessment in the THORP head end plant

    International Nuclear Information System (INIS)

    Gulliford, J.; Edge, J.A.; Gracey, J.; Harris, N.

    2003-01-01

    A new criticality safety assessment based on Actinide-Only Burnup Credit has been developed to cover operations in BNFL's Thermal Oxide Reprocessing Plant (THORP). Reduction of the gadolinium concentration leads to significant reduction in active waste volumes. Detailed description of the methodology was presented at ICNC 1999 and the basic components of the approved safety case have remained unchanged from those proposed then. This paper presents a brief summary of the new methodology, and describes further analyses carried out to quantify additional safety margins. These additional margins are not credited in the derivation of the operating limits, but provide further evidence of the fault tolerance inherent in the new regime. As part of the arrangements to monitor the overall performance of the plant and instrumentation under the new regime, various analyses of plant data are made, including 'on-line' cross checks of measured versus expected fuel parameters (i.e. in addition to the checks on Residual Enrichment). Statistical analyses of data are made and compared with similar data from earlier batches. A summary of analyses made on some of the early fuel batches is presented here. A summary of the likely further development in the Burnup Credit methodology is given in this paper. (author)

  5. Estimating Hourly Beam and Diffuse Solar Radiation in an Alpine Valley: A Critical Assessment of Decomposition Models

    Directory of Open Access Journals (Sweden)

    Lavinia Laiti

    2018-03-01

    Full Text Available Accurate solar radiation estimates in Alpine areas represent a challenging task, because of the strong variability arising from orographic effects and mountain weather phenomena. These factors, together with the scarcity of observations in elevated areas, often cause large modelling uncertainties. In the present paper, estimates of hourly mean diffuse fraction values from global radiation data, provided by a number (13 of decomposition models (chosen among the most widely tested in the literature, are evaluated and compared with observations collected near the city of Bolzano, in the Adige Valley (Italian Alps. In addition, the physical factors influencing diffuse fraction values in such a complex orographic context are explored. The average accuracy of the models were found to be around 27% and 14% for diffuse and beam radiation respectively, the largest errors being observed under clear sky and partly cloudy conditions, respectively. The best performances were provided by the more complex models, i.e., those including a predictor specifically explaining the radiation components’ variability associated with scattered clouds. Yet, these models return non-negligible biases. In contrast, the local calibration of a single-equation logistical model with five predictors allows perfectly unbiased estimates, as accurate as those of the best-performing models (20% and 12% for diffuse and beam radiation, respectively, but at much smaller computational costs.

  6. Environmental exposure to polychlorinated biphenyls among raccoons (Procyon lotor) at the paducah gaseous diffusion plant, Western Kentucky, USA.

    Science.gov (United States)

    Smith, Philip N; Johnson, Kevin A; Anderson, Todd A; McMurry, Scott T

    2003-02-01

    An investigation involving raccoons (Procyon lotor) as a sentinel species at the Paducah Gaseous Diffusion Plant (PGDP) in Western Kentucky (USA) delineated the extent of exposure to polychlorinated biphenyls (PCBs) and PCB spatial distribution. Raccoon exposure to PCBs was demonstrated through analysis of subcutaneous fat, abdominal fat, liver, and brain tissues from raccoons collected at the PGDP but also was clearly evident in raccoons from a reference area situated along the Ohio River (USA). Raccoons with the highest tissue PCB concentrations appeared to be those inhabiting areas nearest the plant itself and most likely those that ventured into the plants interior. Male raccoons at the PGDP had similar concentrations of total PCBs in subcutaneous fat (1.86 +/- 0.64 microg/g) as males from the reference site (1.41 +/- 0.35 microg/g), but females had higher PCB body burdens than those at the reference site (9.90 +/- 6.13 microg/g vs 0.75 +/- 0.40 microg/g). Gross measurements of exposure to radiation-producing materials revealed that counts per minute exceeded background in 61% of PGDP raccoons compared with 27% at the reference site and five raccoons at the PGDP had beta counts that were more than twice the background. Differences among trapping success, growth rates, and serum chemistry parameters were noted but may have been related to habitat and other environmental and population density factors.

  7. Critical defect size assessment in pipelines on a nuclear power plant

    Directory of Open Access Journals (Sweden)

    Dimova Galya

    2018-01-01

    Full Text Available In many energy industry structures, pipeline systems are subject to the impact of mechanical forces, moments of forces and fluid flows of high pressure and temperature. These load factors cause defects in the pipeline metal. As the years of operation increase, defects may occur and grow, which may lead to the destruction of pipeline walls. Special measures have been planned and implemented to ensure the safe operation of high-energy facilities. This study focused on pipelines and nozzles of nuclear power plant equipment with bimetal welded joints on which the size of critical defects was assessed. The base of assessment covers material properties, temperature and stress fields, fracture mechanics calculations. This study involves developing of finite element models and implementing simulations on them in order to obtain temperature fields and determine the stress-strain state of the component.

  8. 78 FR 66779 - United States Enrichment Corporation, Paducah Gaseous Diffusion Plant, Including On-Site Leased...

    Science.gov (United States)

    2013-11-06

    ... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-82,862] United States Enrichment... Consultants, Inbounds Engineering, Llc, Matrix Engineering, Manpower Inc., Bartlett Nuclear, Inc., C-Plant...-site leased workers from Diversified Management Consultants, Inbounds Engineering LLC, Matrix...

  9. Final environmental impact assessment of the Paducah Gaseous Diffusion Plant site, Paducah, Kentucky

    Energy Technology Data Exchange (ETDEWEB)

    1982-08-01

    This document considers: the need for uranium enrichment facilities; site location; plant description; and describes the power generating facilities in light of its existing environment. The impacts from continuing operations are compared with alternatives of shutdown, relocation, and alternative power systems. (PSB)

  10. Intracellular signaling by diffusion: can waves of hydrogen peroxide transmit intracellular information in plant cells?

    DEFF Research Database (Denmark)

    Vestergaard, Christian L.; Flyvbjerg, Henrik; Møller, Ian Max

    2012-01-01

    Amplitude- and frequency-modulated waves of Ca(2+) ions transmit information inside cells. Reactive Oxygen Species (ROS), specifically hydrogen peroxide, have been proposed to have a similar role in plant cells. We consider the feasibility of such an intracellular communication system in view...

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

    International Nuclear Information System (INIS)

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

    1984-06-01

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

  12. A review of therapeutic potential of Ajuga bracteosa: A critically endangered plant from Himalaya

    Directory of Open Access Journals (Sweden)

    Mubashir Hussain

    2016-10-01

    Full Text Available Medicinal plants are the nature’s gift for the humanity to treat various ailments and to spend a prosperous healthy life. There are almost 300 species of Ajuga. Among them, Ajuga bracteosa Wall. ex Benth (A. bracteosa is an important medicinal plant of Himalaya regions. Its medicinal potential is due to the presence of various pharmacologically active compounds such as neo-clerodane diterpenoids, flavonol glycosides, iridoid glycosides, ergosterol-5,8- endoperoxide and phytoecdysones. The aim of this review article was to gather information about A. bracteosa which is currently scattered in form of various publications. This review article tried to attract the attention from people for therapeutic potential of A. bracteosa. The present review comprises upto date information of botanical aspects, active ingredients, traditional uses, and pharmacological activities such as antitumor, antimicrobial, antimalarial, anti-inflammatory, cardiotonic activity, antiarthritic activity, antioxidant activity and in vitro production of secondary metabolites for pharmaceuticals. Due to remarkable medicinal potential and commercialization, this species is indexed into critically endangered category and it is facing extremely high risk of extinction. Conservation practices and management techniques should be carried out to protect this important species from extinction. Recent biotechnological approaches will be quite helpful for its conservation.

  13. Correlation between heavy metals and turtle abundance in ponds near the Paducah Gaseous Diffusion Plant, Kentucky, USA.

    Science.gov (United States)

    Yu, Shuangying; Halbrook, Richard S; Sparling, Donald W

    2013-10-01

    Reptiles are declining globally, and environmental contamination has been suggested as a contributing factor; however, few studies have investigated the relationship between contamination and reptile populations. We performed a mark-recapture study at ponds near the Paducah Gaseous Diffusion Plant (PGDP), Kentucky, to determine if heavy metals had an impact on turtle populations. We measured concentrations of cadmium, chromium, copper, lead, and mercury in red-eared slider turtle (Trachemys scripta elegans) tissues and pond sediment and determined the correlation between metal concentrations and red-eared slider density. Metal concentrations measured in the current study were low, and turtle density was not significantly correlated with metal concentrations in tissues or sediment. However, we observed a trend of decreasing turtle density in ponds that had greater metal concentrations. Sex ratio and proportion of juveniles were significantly different among ponds, but it is unclear if these differences are related to contamination associated with the PGDP.

  14. A geoprocessing model for the selection of populations most affected by diffuse industrial contamination: the case of oil refinery plants

    Directory of Open Access Journals (Sweden)

    Roberto Pasetto

    2013-03-01

    Full Text Available INTRODUCTION. A method to select populations living in areas affected by diffuse environmental contamination is presented, with particular regard to oil refineries, in the Italian context. The reasons to use municipality instead of census tract populations for environment and health small-area studies of contaminated sites are discussed. METHODS. Populations most affected by diffuse environmental contamination are identified through a geoprocessing model. Data from the national census 2001 were used to estimate census tract level populations. A geodatabase was developed using the municipality and census tract layers provided by the Italian National Bureau of Statistics (ISTAT. The orthophotos of the Italian territory - year 2006 - available on the geographic information systems (GIS of the National Cartographic Portal, were considered. The area within 2 km from the plant border was used as an operational definition to identify the area at major contamination. RESULTS. The geoprocessing model architecture is presented. The results of its application to the selection of municipality populations in a case study are shown. CONCLUSIONS. The application of the proposed geoprocessing model, the availability of long time series of mortality and morbidity data, and a quali-quantitative estimate of contamination over time, could allow an appraisal of the health status of populations affected by oil refinery emissions.

  15. The host plant metabolite glucose is the precursor of diffusible signal factor (DSF) family signals in Xanthomonas campestris.

    Science.gov (United States)

    Deng, Yinyue; Liu, Xiaoling; Wu, Ji'en; Lee, Jasmine; Chen, Shaohua; Cheng, Yingying; Zhang, Chunyan; Zhang, Lian-Hui

    2015-04-01

    Plant pathogen Xanthomonas campestris pv. campestris produces cis-11-methyl-2-dodecenoic acid (diffusible signal factor [DSF]) as a cell-cell communication signal to regulate biofilm dispersal and virulence factor production. Previous studies have demonstrated that DSF biosynthesis is dependent on the presence of RpfF, an enoyl-coenzyme A (CoA) hydratase, but the DSF synthetic mechanism and the influence of the host plant on DSF biosynthesis are still not clear. We show here that exogenous addition of host plant juice or ethanol extract to the growth medium of X. campestris pv. campestris could significantly boost DSF family signal production. It was subsequently revealed that X. campestris pv. campestris produces not only DSF but also BDSF (cis-2-dodecenoic acid) and another novel DSF family signal, which was designated DSF-II. BDSF was originally identified in Burkholderia cenocepacia to be involved in regulation of motility, biofilm formation, and virulence in B. cenocepacia. Functional analysis suggested that DSF-II plays a role equal to that of DSF in regulation of biofilm dispersion and virulence factor production in X. campestris pv. campestris. Furthermore, chromatographic separation led to identification of glucose as a specific molecule stimulating DSF family signal biosynthesis in X. campestris pv. campestris. (13)C-labeling experiments demonstrated that glucose acts as a substrate to provide a carbon element for DSF biosynthesis. The results of this study indicate that X. campestris pv. campestris could utilize a common metabolite of the host plant to enhance DSF family signal synthesis and therefore promote virulence. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  16. Fissible Deposit Characterization at the Former Oak Ridge K-25 Gaseous Diffusion Plant by {sup 252}CF-Source-Driven Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Hannon, T.F.; Mihalczo, J.T.; Mullens, J.A.; Uckan, T.; Valentine, T.E.; Wyatt, M.S.

    1998-05-01

    The Deposit Removal Project was undertaken with the support of the U. S. Department of Energy at the East Tennessee Technology Park (ETTP) formerly the Oak Ridge K-25 Site. The project team performed the safe removal of the hydrated uranyl fluoride (UO{sub 2}F{sub 2}) deposits from the K-29 Building of the former Oak Ridge Gaseous Diffusion Plant. The deposits had developed as a result of air leakage into UF{sub 6} gas process pipes; UO{sub 2}F{sub 2} became hydrated by moisture from the air and deposited inside the pipes. The mass, its distribution, and the hydrogen content [that is, the ratio of H to U (H/U)], were the key parameters that controlled the nuclear criticality safety of the deposits. Earlier gamma-ray spectrometry measurements in K-29 had identified the largest deposits in the building. The first and third largest deposits in the building were measured in this program. The first deposit, found in the Unit 2, Cell 7, B-Line Outlet process pipe (called the ''Hockey Stick'') was about 1,300 kg ({+-} 50% uncertainty) at 3.34 wt% {sup 235}U enrichment ({+-}50% uncertainty) and according to the gamma-ray spectroscopy was uniformly distributed. The second deposit (the third-largest deposit in the building), found in the Unit 2, Cell 6, A-Line Outlet process pipe (called the ''Tee-Pipe''), had a uranium deposit estimated to be about 240 kg ({+-} 50% uncertainty) at 3.4 wt % {sup 235}U enrichment ({+-} 20% uncertainty). Before deposit removal activities began, the Deposit Removal Project team needed to survey the inside of the pipes intrusively to assess the nuclear criticality safety of the deposits. Therefore, the spatial distribution of the deposits, the total uranium deposit mass, and the moderation level resulting from hydration of the deposits, all of which affect nuclear criticality safety were required. To perform the task safely and effectively, the Deposit Removal Project team requested that Oak Ridge National

  17. Studies of safety and critical work situations in nuclear power plants: A human factors perspective

    International Nuclear Information System (INIS)

    Jacobsson Kecklund, L.

    1998-05-01

    The purpose of this thesis was to develop and apply different approaches for analyzing safety in critical work situations in real work settings in nuclear power plants, and also to identify safety enhancing measures by using the framework of interaction between human, organizational and technical subsystems. A Cognitive Psychology as well as a Stress Psychology framework was used. All studies were related to the annual outage operational state where the need for coping with many infrequent tasks, often carried out under high time pressure, puts great strain on the staff and organisation of the plant. In three studies the natural variations in the plant state, normal operation and annual outage operation, were used to explore human performance, work-related factors as well as coping and the operators' own resources and the relationship between them. In the annual outage condition high work demands, decreased sleepiness at night shift, more errors and less satisfaction with work performance quality was reported by maintenance as well as by control room operators. A relationship between high work demands and more organizational problems and reports of more frequent human errors and lower satisfactions with work performance quality was also identified in the annual outage condition. Moreover, a relationship between increased sleepiness during night shift, more frequent use of coping strategies and a higher frequency of human errors was reported. In two studies the Event and Barrier Function Model was applied to analyze the safety of barrier function systems inserted into work process sequences to protect the systems from the negative consequences of failures and errors. The model was also used to assess safety in relation to a technical and organizational change. The last study addressed changes in work performance and work-related factors in relation to a technical and organizational change of a safety significant work process involving increased automation and new

  18. Reliability study: steam generation and distribution system, Portsmouth Gaseous Diffusion Plant

    International Nuclear Information System (INIS)

    Baker, F.E.; Davis, E.L.; Dent, J.T.; Walters, D.E.; West, R.M.

    1982-10-01

    A reliability study for determining the ability of the Steam Generation and Distribution System to provide reliable and adequate service through the year 2000 has been completed. This study includes an evaluation of the X-600 Steam Plant and the steam distribution system. The Steam Generation and Distribution System is in good overall condition, but to maintain this condition, the reliability study team made twelve recommendations. Eight of the recommendations are for repair or replacement of existing equipment and have a total estimated cost of $540,000. The other four recommendations are for additional testing, new procedure implementation, or continued investigations

  19. Reliability modeling of safety-critical network communication in a digitalized nuclear power plant

    International Nuclear Information System (INIS)

    Lee, Sang Hun; Kim, Hee Eun; Son, Kwang Seop; Shin, Sung Min; Lee, Seung Jun; Kang, Hyun Gook

    2015-01-01

    The Engineered Safety Feature-Component Control System (ESF-CCS), which uses a network communication system for the transmission of safety-critical information from group controllers (GCs) to loop controllers (LCs), was recently developed. However, the ESF-CCS has not been applied to nuclear power plants (NPPs) because the network communication failure risk in the ESF-CCS has yet to be fully quantified. Therefore, this study was performed to identify the potential hazardous states for network communication between GCs and LCs and to develop quantification schemes for various network failure causes. To estimate the risk effects of network communication failures in the ESF-CCS, a fault-tree model of an ESF-CCS signal failure in the containment spray actuation signal condition was developed for the case study. Based on a specified range of periodic inspection periods for network modules and the baseline probability of software failure, a sensitivity study was conducted to analyze the risk effect of network failure between GCs and LCs on ESF-CCS signal failure. This study is expected to provide insight into the development of a fault-tree model for network failures in digital I&C systems and the quantification of the risk effects of network failures for safety-critical information transmission in NPPs. - Highlights: • Network reliability modeling framework for digital I&C system in NPP is proposed. • Hazardous states of network protocol between GC and LC in ESF-CCS are identified. • Fault-tree model of ESF-CCS signal failure in ESF actuation condition is developed. • Risk effect of network failure on ESF-CCS signal failure is analyzed.

  20. Study of radioactivity diffusion for bitumen-coated blocks produced by an industrial coating plant

    International Nuclear Information System (INIS)

    Rodier, J.; Lefillatre, G.

    1969-01-01

    The solidification by bitumen of chemical coprecipitation sludges from the Marcoule waste treatment station has been studied in the laboratory and has led to the construction of an industrial coating plant. The quality of the coated material obtained has been controlled by the lixiviation test carried out with ordinary water and with sea-water on 45 ml laboratory samples and on industrial coated blocks of 150 litres. Tests on blocks of such a size have necessitated the installation of three special tanks. Two, each of 2000 litres capacity, contain ordinary and sea-water which was continuously recycled at a rate of 2.5 cm/hr and renewed periodically. In the third tank having a capacity of 11000 litres, the coated block was buried in earth and sprinkled with ordinary water with a view to studying the migration of radioelements in soil. The results of these tests confirm those obtained during the laboratory experiments. (authors) [fr

  1. Refrigeration plants using carbon dioxide as refrigerant: measuring and modelling the solubility and diffusion of carbon dioxide in polymers used as sealing materials

    DEFF Research Database (Denmark)

    von Solms, Nicolas; Kristensen, Jakob

    2010-01-01

    with greater extremes of pressure, placing greater demands on the polymer materials used for seals and packing. In this work we have measured the solubility and diffusivity of gaseous CO2 in two polymers used as sealing materials in CO2 refrigeration plants. These are Hydrogenated Nitrile Butadiene Rubber...

  2. New technology for optimized I and C maintenance and management of ageing of critical equipment in nuclear power plants

    International Nuclear Information System (INIS)

    Hashemian, H.M.

    2000-01-01

    Advanced sensors and new testing and maintenance technologies have become available over the last ten years for nuclear power plants (NPPs) to replace outdated, obsolete, and troublesome instruments, provide for management of ageing of critical plant equipment, optimize maintenance activities, reduce maintenance costs and personnel radiation exposure, and at the same time, improve plant safety and availability. These new developments are reviewed in this TECDOC. The material covered here has been summarized from NUREG/CR-5501, a 1998 report written by H.M. Hashemian and his co-authors for the US Nuclear Regulatory Commission. (author)

  3. Historical collections reveal patterns of diffusion of sweet potato in Oceania obscured by modern plant movements and recombination.

    Science.gov (United States)

    Roullier, Caroline; Benoit, Laure; McKey, Doyle B; Lebot, Vincent

    2013-02-05

    The history of sweet potato in the Pacific has long been an enigma. Archaeological, linguistic, and ethnobotanical data suggest that prehistoric human-mediated dispersal events contributed to the distribution in Oceania of this American domesticate. According to the "tripartite hypothesis," sweet potato was introduced into Oceania from South America in pre-Columbian times and was then later newly introduced, and diffused widely across the Pacific, by Europeans via two historically documented routes from Mexico and the Caribbean. Although sweet potato is the most convincing example of putative pre-Columbian connections between human occupants of Polynesia and South America, the search for genetic evidence of pre-Columbian dispersal of sweet potato into Oceania has been inconclusive. Our study attempts to fill this gap. Using complementary sets of markers (chloroplast and nuclear microsatellites) and both modern and herbarium samples, we test the tripartite hypothesis. Our results provide strong support for prehistoric transfer(s) of sweet potato from South America (Peru-Ecuador region) into Polynesia. Our results also document a temporal shift in the pattern of distribution of genetic variation in sweet potato in Oceania. Later reintroductions, accompanied by recombination between distinct sweet potato gene pools, have reshuffled the crop's initial genetic base, obscuring primary patterns of diffusion and, at the same time, giving rise to an impressive number of local variants. Moreover, our study shows that phenotypes, names, and neutral genes do not necessarily share completely parallel evolutionary histories. Multidisciplinary approaches, thus, appear necessary for accurate reconstruction of the intertwined histories of plants and humans.

  4. Quantitative safety goals for nuclear power plants: critical review and reformulation within a unified theory

    International Nuclear Information System (INIS)

    Munera, H.A.; Yadigaroglu, G.

    1987-01-01

    Most suggestions for the establishment of probabilistic safety goals in the regulatory process of nuclear power plants contain some measure of total risk to the individual and to society, and/or a limit line. There is still some confusion, both on formal and informal aspects of the basic ideas. The first part of the chapter critically reviews some of the adopted and/or proposed probabilistic safety goals and criteria in several countries. Some of the difficulties identified are: Lack of an adequate delimitation of the scope of the non-deterministic choice problem. Consequently, the main components of the problem -probabilities and consequences - are not clearly defined. As a further consequence there is a conspicuous absence of a unified treatment, including notation and terminology, for concepts like risk, probability, frequency, utility, risk-aversion, limit-line, etc. The theoretical justifications and limitations of limit lines are not always fully understood, nor are the theoretical limitations realized. In the second part theoretical methods of comparing probability distributions which exist in other disciplines are mentioned and unified methodology to formulate probabilistic safety criteria is described. (author)

  5. To stay or to go? Balancing the risk of reprocessing plant control room evacuation following a criticality alarm

    International Nuclear Information System (INIS)

    Love, Suzanne; McCrindle, David; Harris, Neil; Haworth, Justin

    2003-01-01

    Following a criticality alarm within the Magnox Separation Plant at Sellafield, there is a conflict of interest between the risks associated with complete evacuation versus continued manning of the control room. The historic emergency response policy would be to completely evacuate the control room upon a criticality alarm. If, however, the alarm was found to be false, the inevitable loss in control over the plant could have environmental, operational and radiological release consequences. Maintaining control room manning following a genuine alarm might, however, result in an avoidable high dose to an operator. Based upon the estimated dose equivalent to a control room operator for a range of criticality incident morphologies a risk analysis was undertaken. The results indicate that the differential risk between an operator who evacuates immediately and an operator who remains for a short time to complete diagnostic checks is very small. As a consequence a new emergency policy was therefore developed on plant which results in a relatively low risk to control room operators, but still allows control over the plant to be retained following a false criticality alarm. (author)

  6. 77 FR 36457 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Coquí Llanero

    Science.gov (United States)

    2012-06-19

    ... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 17 [Docket No. FWS-R4-ES-2009-0022; 4500030114] RIN 1018-AX68 Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Coqu[iacute] Llanero AGENCY: Fish and Wildlife Service, Interior. ACTION: Proposed rule...

  7. Determination of Waste Isolation Pilot Plant (WIPP) management and institutional requirements documents for contact-handled (CH) critical systems

    International Nuclear Information System (INIS)

    1990-01-01

    This document lists the critical requirements documents applicable to the receipt of contact-handled waste at the Waste Isolation Pilot Plant. It also describes the processes used to determine the applicability of each document. This analysis is based on the applicable documents that were in effect in the February 1988 time frame. 2 refs

  8. Creating new populations of Apium bermejoi (Apiaceae, a critically endangered endemic plant on Menorca (Balearic Islands

    Directory of Open Access Journals (Sweden)

    Rita, Juan

    2013-06-01

    Full Text Available Apium bermejoi is a stoloniferous plant endemic to the island of Menorca (Balearic Islands. It is found only at one locality, and it is listed as Critically Endangered (according to the IUCN criteria. We describe the main results of population restoration actions undertaken under the Recovery Plan for this species, including the following: 1 introduction at two new localities (2008, 2 reinforcement of the original wild and the introduced populations, and 3 a programme for monitoring population dynamics (including both wild and introduced populations spanning four years (2006-2010. The plant material for the introduction and reinforcement projects was generated from seeds gathered in the wild. We carried out a monthly census of all of the individuals/patches and emerged seedlings, from which we assessed their survival at 3-4months. The survival rates of the planted individuals in the two new localities after three months were found to be 59.0% and 56.3%, and more than 80% of the surviving plants produced fruits. A seasonal pattern was observed based on the minimum cover values recorded in the censuses taken at the end of summer, with an increase detected during autumn, and maximal cover values recorded during May/June. The A. bermejoi populations showed large inter-annual fluctuations in both the number of patches and area of occupancy. The number of seedlings varied across the study years, and their survival was linked to specific meteorological events, such as severe storms and dry and hot spells during autumn. The initial phase of introduction for this species has been overall successful, but a final evaluation can only be made on a longterm basis.Apium bermejoi, planta estolonífera endémica de Menorca (Islas Baleares, de la que se conoce una sola localidad en el medio natural, está considerada en Peligro Crítico de extinción (según criterios UICN. Se presentan los principales resultados de las acciones de restauración de las

  9. Monitoring of (bio)available labile metal fraction in a drinking water treatment plant by diffusive gradients in thin films.

    Science.gov (United States)

    Díaz, Alfredo; Arnedo, Rebeca; Céspedes-Sánchez, Raquel; Devesa, Ricard; Martin-Alonso, Jordi

    2012-01-01

    A performance study of diffusive gradients in thin films (DGT) and inductively coupled plasma optical emission spectrometry (ICP-OES) was applied for the monitoring of the labile fraction of metals Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn, in Sant Joan Despí Drinking Water Treatment Plant located in the South of Barcelona's Metropolitan Area (Spain). The DWTP monitoring protocol was optimized by working for 1 day of deployment (24 h) with the DGT device in contact with both treated and river water matrixes. Additionally, it was demonstrated that an increase in the deployment time of 1 week did not decrease the evaluated concentrations of the studied metals. The quality parameters of the DGT device and ICP-OES determination, such as limit of quantification, accuracy expressed as relative error (%) and reproducibility expressed as relative standard deviation, were evaluated. Good results were obtained for all the metals in ultrapure water; limits of quantification ranged from 1.5 μg L( - 1) for cadmium to 28 μg L( - 1) for zinc when deployment time of 24 h was used and from 0.2 μg L( - 1) for cadmium to 4 μg L( - 1) for zinc when this time was increased by 1 week. Accuracy and precisions lower than or equal to 10% were obtained at a parametric concentration value of the metals regulated in the European Drinking Water Guidelines (98/83/EC). DGT deployment was tested in river and treated water, and good results were obtained for Cd, Ni, Co and Zn, whereas for the other metals, a continuous control of their metallic labile fractions was monitored. Therefore, DGT device allows the continuous monitoring of the labile metal species in a drinking water treatment plant.

  10. Potential Hazards Relating to Pyrolysis of c-C4F8 in Selected Gaseous Diffusion Plant Operations

    International Nuclear Information System (INIS)

    Trowbridge, L.D.

    1999-01-01

    As part of a program intended to replace the present evaporative coolant at the gaseous diffusion plants (GDPs) with a non-ozone-depleting alternate, a series of investigations of the suitability of candidate substitutes in under way. One issue concerning a primary candidate, c-C4F8, is the possibility that it might produce the highly toxic perfluoroisobutylene (PFIB) in high temperature environments. This study was commissioned to determine the likelihood and severity of decomposition under two specific high temperature thermal environments, namely the use of a flame test for the presence of coolant vapors and welding in the presence of coolant vapors. The purpose of the study was to develop and evaluate available data to provide information that will allow the technical and industrial hygiene staff at the GDPs to perform appropriate safety evaluations and to determine the need for field testing or experimental work. The scope of this study included a literature search and an evaluation of the information developed therefrom. Part of that evaluation consists of chemical kinetics modeling of coolant decomposition in the two operational environments. The general conclusions are that PFIB formation is unlikely in either situation but that it cannot be ruled out completely under extreme conditions. The presence of oxygen, moisture, and combustion products will tend to lead to formation of oxidation products (COF2, CO, CO2, and HF) rather than PFIB

  11. Mapping for the management of diffuse pollution risks related to agricultural plant protection practices: case of the Etang de l'Or catchment area in France.

    Science.gov (United States)

    Mghirbi, Oussama; Bord, Jean-Paul; Le Grusse, Philippe; Mandart, Elisabeth; Fabre, Jacques

    2018-03-08

    Faced with health, environmental, and socio-economic issues related to the heavy use of pesticides, diffuse phytosanitary pollution becomes a major concern shared by all the field actors. These actors, namely the farmers and territorial managers, have expressed the need to implement decision support tools for the territorial management of diffuse pollution resulting from the plant protection practices and their impacts. To meet these steadily increasing requests, a cartographic analysis approach was implemented based on GIS which allows the spatialization of the diffuse pollution impacts related to plant protection practices on the Etang de l'Or catchment area in the South of France. Risk mapping represents a support-decision tool that enables the different field actors to identify and locate vulnerable areas, so as to determine action plans and agri-environmental measures depending on the context of the natural environment. This work shows that mapping is helpful for managing risks related to the use of pesticides in agriculture by employing indicators of pressure (TFI) and risk on the applicator's health (IRSA) and on the environment (IRTE). These indicators were designed to assess the impact of plant protection practices at various spatial scales (field, farm, etc.). The cartographic analysis of risks related to plant protection practices shows that diffuse pollution is unequally located in the North (known for its abundant garrigues and vineyards) and in the South of the Etang de l'Or catchment area (the Mauguio-Lunel agricultural plain known for its diversified cropping systems). This spatial inequity is essentially related to land use and agricultural production system. Indeed, the agricultural lands cover about 60% of the total catchment area. Consequently, this cartographic analysis helps the territorial actors with the implementation of strategies for managing risks of diffuse pollution related to pesticides use in agriculture, based on environmental and

  12. Environmental site description for a Uranium Atomic Vapor Laser Isotope Separation (U-AVLIS) production plant at the Paducah Gaseous Diffusion Plant site

    Energy Technology Data Exchange (ETDEWEB)

    Marmer, G.J.; Dunn, C.P.; Moeller, K.L.; Pfingston, J.M.; Policastro, A.J.; Yuen, C.R.; Cleland, J.H. (ed.)

    1991-09-01

    Uranium enrichment in the United States has utilized a diffusion process to preferentially enrich the U-235 isotope in the uranium product. The U-AVLIS process is based on electrostatic extraction of photoionized U-235 atoms from an atomic vapor stream created by electron-beam vaporization of uranium metal alloy. The U-235 atoms are ionized when precisely tuned laser light -- of appropriate power, spectral, and temporal characteristics -- illuminates the uranium vapor and selectively photoionizes the U-235 isotope. A programmatic document for use in screening DOE site to locate a U-AVLIS production plant was developed and implemented in two parts. The first part consisted of a series of screening analyses, based on exclusionary and other criteria, that identified a reasonable number of candidate sites. These sites were subjected to a more rigorous and detailed comparative analysis for the purpose of developing a short list of reasonable alternative sites for later environmental examination. This environmental site description (ESD) provides a detailed description of the PGDP site and vicinity suitable for use in an environmental impact statement (EIS). The report is based on existing literature, data collected at the site, and information collected by Argonne National Laboratory (ANL) staff during a site visit. 65 refs., 15 tabs.

  13. Environmental site description for a Uranium Atomic Vapor Laser Isotope Separation (U-AVLIS) production plant at the Paducah Gaseous Diffusion Plant site

    International Nuclear Information System (INIS)

    Marmer, G.J.; Dunn, C.P.; Moeller, K.L.; Pfingston, J.M.; Policastro, A.J.; Yuen, C.R.; Cleland, J.H.

    1991-09-01

    Uranium enrichment in the United States has utilized a diffusion process to preferentially enrich the U-235 isotope in the uranium product. The U-AVLIS process is based on electrostatic extraction of photoionized U-235 atoms from an atomic vapor stream created by electron-beam vaporization of uranium metal alloy. The U-235 atoms are ionized when precisely tuned laser light -- of appropriate power, spectral, and temporal characteristics -- illuminates the uranium vapor and selectively photoionizes the U-235 isotope. A programmatic document for use in screening DOE site to locate a U-AVLIS production plant was developed and implemented in two parts. The first part consisted of a series of screening analyses, based on exclusionary and other criteria, that identified a reasonable number of candidate sites. These sites were subjected to a more rigorous and detailed comparative analysis for the purpose of developing a short list of reasonable alternative sites for later environmental examination. This environmental site description (ESD) provides a detailed description of the PGDP site and vicinity suitable for use in an environmental impact statement (EIS). The report is based on existing literature, data collected at the site, and information collected by Argonne National Laboratory (ANL) staff during a site visit. 65 refs., 15 tabs

  14. Selection of critical group in relation to the release of radionuclides from nuclear spent fuel reprocessing plant

    International Nuclear Information System (INIS)

    Ohmomo, Y.

    1980-01-01

    In respect of internal radiation due to the coastal release of radionuclides, survey on marine food consumption is most useful for the selection of critical group. Species of marine organisms they usually eat is fully over 100 in the coastal area of Ibaraki prefecture where the fuel reprocessing plant is located. Though it gives only a spot datum, one day's consumption survey a season is of convenience to obtain cooperation from housewives and is of use to pick up critical organisms and those who eat much of them. However, long-term survey is required to estimate ordinary intake of the critical foods or those who are supposed critical people. One day's consumption survey makes it easy to perform the subsequent long-term one

  15. Flower-visiting insects observed on the critically endangered alpine plant species Callianthemum kernerianum Freyn ex A. Kerner (Ranunculaceae

    Directory of Open Access Journals (Sweden)

    Mauro Gobbi

    2017-03-01

    Full Text Available In the present paper we provide the first contribution to the knowledge of the flower-visiting insect assemblages of the alpine plant species Callianthemum kernerianum Freyn ex A. Kerner (Ranunculaceae. This focal plant species was selected since it is a steno-endemic and critically endangered species belonging to the IUCN red-list. Fifteen taxa were recorded, among which very few are true pollinators, whereas all the others can be considered only indirect pollinators. The peculiar phenology of the plant and the harsh habitat conditions in which it grows probably affect the richness and abundance of flower-visiting insects as well as of true pollinators. This could be the reason for this plant to be a self-compatible species.

  16. 78 FR 49165 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Sphaeralcea...

    Science.gov (United States)

    2013-08-13

    ... trample and eat plants; however, the plants have been documented to recover from herbivory and trampling... Sphaeralcea (globemallows) are pollinated by Diadasia diminuta (globemallow bee), which specializes in pollinating plants of this genus. Globemallow bees are considered important pollinators for globemallows...

  17. 76 FR 66805 - Endangered and Threatened Wildlife and Plants: Final Rulemaking To Designate Critical Habitat for...

    Science.gov (United States)

    2011-10-27

    ... commenter stated that there are many species of plants and animals that deserve to be placed on the ESA list... of copper in the cooling water effluent of a nuclear power plant near Diablo Canyon, California, were... Atmospheric Administration 50 CFR Part 226 Endangered and Threatened Wildlife and Plants: Final Rulemaking To...

  18. The Transfer and diffusion of Cesium 137 within forest ecosystem in Fukushima after the nuclear power plant accident

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Takahiro; Murakami, Masashi [Community Ecology Lab., Biology Course, Faculty of Science, Chiba University, Chiba, 263-8522 (Japan); Ishii, Nobuyoshi [National Institute of Radiological Sciences, Chiba, 263-8555 (Japan); Tanoi, Keitaro; Hirose, Atsushi; Ohte, Nobuhito [Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 113-8657 (Japan)

    2014-07-01

    A large amount of radionuclides was released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident after the disastrous earthquake and subsequent tsunami of March 2011. Among the variety of radionuclides released from FDNPP, cesium 137 ({sup 137}Cs) is the most worrying radionuclide in the environment, with a half-life of 30 years. Since most of the Japanese land area is covered by forest, the distribution and transportation of radioactive materials within forest ecosystems should be conscientiously monitored. In Europe, many studies reported that the {sup 137}Cs deposition caused by the Chernobyl accident has still been distributed in the litter and soil layers and has become a source for the soil-to-plant transfer. Most of these studies emphasize the 'stability' of {sup 137}Cs within forest ecosystems, because {sup 137}Cs are considered to be strongly and immediately fixed in clay minerals. Even though there are many studies of the soil-to-plant transfer of {sup 137}Cs in forest after several years of Chernobyl accident, very initial distribution and transfer of {sup 137}Cs in food web within one to two years after the deposition in forest ecosystems have never been examined. The evaluation of the initial dynamics of {sup 137}Cs in forest ecosystems should be quite important because of the increasing stability of {sup 137}Cs after the deposition. The accumulation and transfer of {sup 137}Cs through food web within forest ecosystems were examined by collecting various organisms at forests in Fukushima. The {sup 137}Cs concentrations, natural Cs and K concentrations, and delta {sup 15}N of the specimens were measured to evaluate the occurrence of bioaccumulation or bio-diffusion of {sup 137}Cs through tropic interaction within forest ecosystem. {sup 137}Cs was highly concentrated on leaf litters which had been deposited in autumn 2010, before the accident. This accumulated {sup 137}Cs had transferred to higher trophic organisms mainly through

  19. Evolution of resistance to a multiple-herbivore community: genetic correlations, diffuse coevolution, and constraints on the plant's response to selection.

    Science.gov (United States)

    Wise, Michael J; Rausher, Mark D

    2013-06-01

    Although plants are generally attacked by a community of several species of herbivores, relatively little is known about the strength of natural selection for resistance in multiple-herbivore communities-particularly how the strength of selection differs among herbivores that feed on different plant organs or how strongly genetic correlations in resistance affect the evolutionary responses of the plant. Here, we report on a field study measuring natural selection for resistance in a diverse community of herbivores of Solanum carolinense. Using linear phenotypic-selection analyses, we found that directional selection acted to increase resistance to seven species. Selection was strongest to increase resistance to fruit feeders, followed by flower feeders, then leaf feeders. Selection favored a decrease in resistance to a stem borer. Bootstrapping analyses showed that the plant population contained significant genetic variation for each of 14 measured resistance traits and significant covariances in one-third of the pairwise combinations of resistance traits. These genetic covariances reduced the plant's overall predicted evolutionary response for resistance against the herbivore community by about 60%. Diffuse (co)evolution was widespread in this community, and the diffuse interactions had an overwhelmingly constraining (rather than facilitative) effect on the plant's evolution of resistance. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

  20. Invasion Success by Plant Breeding Evolutionary Changes as a Critical Factor for the Invasion of the Ornamental Plant Mahonia aquifolium

    CERN Document Server

    Ross, Christel Anne

    2009-01-01

    Invasive species are a major threat to global biodiversity and cause significant economic costs. Studying biological invasions is both essential for preventing future invasions and is also useful in order to understand basic ecological processes. Christel Ross investigates whether evolutionary changes by plant breeding are a relevant factor for the invasion success of Mahonia aquifolium in Germany. Her findings show that invasive populations differ from native populations in quantitative-genetic traits and molecular markers, whereas their genetic diversity is similar. She postulates that these evolutionary changes are rather a result of plant breeding, which includes interspecific hybridisation, than the result of a genetic bottleneck or the releases from specialist herbivores.

  1. [Introduction of hazard analysis and critical control points (HACCP) principles at the flight catering food production plant].

    Science.gov (United States)

    Popova, A Yu; Trukhina, G M; Mikailova, O M

    In the article there is considered the quality control and safety system implemented in the one of the largest flight catering food production plant for airline passengers and flying squad. The system for the control was based on the Hazard Analysis And Critical Control Points (HACCP) principles and developed hygienic and antiepidemic measures. There is considered the identification of hazard factors at stages of the technical process. There are presented results of the analysis data of monitoring for 6 critical control points over the five-year period. The quality control and safety system permit to decline food contamination risk during acceptance, preparation and supplying of in-flight meal. There was proved the efficiency of the implemented system. There are determined further ways of harmonization and implementation for HACCP principles in the plant.

  2. Biochar soil amendment on alleviation of drought and salt stress in plants: a critical review.

    Science.gov (United States)

    Ali, Shafaqat; Rizwan, Muhammad; Qayyum, Muhammad Farooq; Ok, Yong Sik; Ibrahim, Muhammad; Riaz, Muhammad; Arif, Muhammad Saleem; Hafeez, Farhan; Al-Wabel, Mohammad I; Shahzad, Ahmad Naeem

    2017-05-01

    Drought and salt stress negatively affect soil fertility and plant growth. Application of biochar, carbon-rich material developed from combustion of biomass under no or limited oxygen supply, ameliorates the negative effects of drought and salt stress on plants. The biochar application increased the plant growth, biomass, and yield under either drought and/or salt stress and also increased photosynthesis, nutrient uptake, and modified gas exchange characteristics in drought and salt-stressed plants. Under drought stress, biochar increased the water holding capacity of soil and improved the physical and biological properties of soils. Under salt stress, biochar decreased Na + uptake, while increased K + uptake by plants. Biochar-mediated increase in salt tolerance of plants is primarily associated with improvement in soil properties, thus increasing plant water status, reduction of Na + uptake, increasing uptake of minerals, and regulation of stomatal conductance and phytohormones. This review highlights both the potential of biochar in alleviating drought and salt stress in plants and future prospect of the role of biochar under drought and salt stress in plants.

  3. Link 'soil-plant' as critical in formation committed doses from uptake of long-lived radionuclides

    International Nuclear Information System (INIS)

    Kravetz, A. P.; Pavlenko, Y. A.; Grodzinsky, D. M.

    1994-01-01

    General algorithm of calculation dose from intake 137 Cs and 90 Sr depending upon level of pollution and agrochemical type of soil where trophycal chains to begin with, have been proposed. This methods consider link 'soil → plant' as critical in formation of doses from the intake long-lived radionuclides. Calculation of committed dose as function of type of soil and level of radionuclide pollution have been realized for seven main soil types of the White Russian and Ukrainian Wooded district. (author)

  4. Adverse effects of plant food supplements and botanical preparations: a systematic review with critical evaluation of causality.

    Science.gov (United States)

    Di Lorenzo, Chiara; Ceschi, Alessandro; Kupferschmidt, Hugo; Lüde, Saskia; De Souza Nascimento, Elizabeth; Dos Santos, Ariana; Colombo, Francesca; Frigerio, Gianfranco; Nørby, Karin; Plumb, Jenny; Finglas, Paul; Restani, Patrizia

    2015-04-01

    The objective of this review was to collect available data on the following: (i) adverse effects observed in humans from the intake of plant food supplements or botanical preparations; (ii) the misidentification of poisonous plants; and (iii) interactions between plant food supplements/botanicals and conventional drugs or nutrients. PubMed/MEDLINE and Embase were searched from database inception to June 2014, using the terms 'adverse effect/s', 'poisoning/s', 'plant food supplement/s', 'misidentification/s' and 'interaction/s' in combination with the relevant plant name. All papers were critically evaluated according to the World Health Organization Guidelines for causality assessment. Data were obtained for 66 plants that are common ingredients of plant food supplements; of the 492 papers selected, 402 (81.7%) dealt with adverse effects directly associated with the botanical and 89 (18.1%) concerned interactions with conventional drugs. Only one case was associated with misidentification. Adverse effects were reported for 39 of the 66 botanical substances searched. Of the total references, 86.6% were associated with 14 plants, including Glycine max/soybean (19.3%), Glycyrrhiza glabra/liquorice (12.2%), Camellia sinensis/green tea ( 8.7%) and Ginkgo biloba/gingko (8.5%). Considering the length of time examined and the number of plants included in the review, it is remarkable that: (i) the adverse effects due to botanical ingredients were relatively infrequent, if assessed for causality; and (ii) the number of severe clinical reactions was very limited, but some fatal cases have been described. Data presented in this review were assessed for quality in order to make the results maximally useful for clinicians in identifying or excluding deleterious effects of botanicals. © 2014 The British Pharmacological Society.

  5. Increased Suicide Risk among Workers following Toxic Metal Exposure at the Paducah Gaseous Diffusion Plant From 1952 to 2003: A Cohort Study

    OpenAIRE

    LW Figgs; H Holsinger; SJ Freitas; GM Brion; RW Hornung; CH Rice; D Tollerud

    2011-01-01

    Background: Suicide is a problem worldwide and occupation is an important risk factor. In the last decade, 55 200 deaths in the US were attributed to occupational risk factors. Objective: To determine if toxic metal exposure was associated with suicide risk among Paducah gaseous diffusion plant (PGDP) workers. Methods: We assembled a cohort of 6820 nuclear industry workers employed from 1952 to 2003. A job-specific exposure matrix (JEM) was used to determine metal exposure likelihoo...

  6. 76 FR 2076 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Tumbling Creek...

    Science.gov (United States)

    2011-01-12

    ... Critical Habitat for Tumbling Creek Cavesnail AGENCY: Fish and Wildlife Service, Interior. ACTION: Proposed... to timely designate critical habitat for the Tumbling Creek cavesnail (Institute for Wildlife... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 17 [Docket No. FWS-R3-ES-2010...

  7. 77 FR 73739 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Lost River...

    Science.gov (United States)

    2012-12-11

    ... that other activities that may affect critical habitat include groundwater use and wetland alteration... adverse modification. Our Response: We agree that groundwater use and wetland alteration are important.... GIS analysis indicates that areas proposed as critical habitat in Modoc County, California, are...

  8. 78 FR 25679 - Endangered and Threatened Wildlife and Plants; Proposed Revision of Critical Habitat for the...

    Science.gov (United States)

    2013-05-02

    ... likelihood of adverse social reactions to the designation of critical habitat, as discussed in the DEA, and... critical habitat include public awareness of the presence of either species and the importance of habitat... (Regulatory Planning and Review), E.O. 12630 (Takings), E.O. 13132 (Federalism), E.O. 12988 (Civil Justice...

  9. 78 FR 64446 - Endangered and Threatened Wildlife and Plants; Proposed Designation of Critical Habitat for...

    Science.gov (United States)

    2013-10-29

    ...). Furthermore, fragmentation has been shown to disrupt plant-pollinator interactions and predator-prey...] 50 CFR Part 17 RIN 1018-AZ33 Endangered and Threatened Wildlife and Plants; Proposed Designation of... Ecological Reserve and La Purisima Mission State Historic Park (SHP), respectively, provide a conservation...

  10. A critical review on energy, exergy, exergoeconomic and economic (4-E analysis of thermal power plants

    Directory of Open Access Journals (Sweden)

    Ravinder Kumar

    2017-02-01

    Full Text Available The growing energy supply, demand has created an interest towards the plant equipment efficiency and the optimization of existing thermal power plants. Also, a thermal power plant dependency on fossil fuel makes it a little bit difficult, because of environmental impacts has been always taken into consideration. At present, most of the power plants are going to be designed by the energetic performance criterion which is based on the first law of thermodynamics. Sometimes, the system energy balance is not sufficient for the possible finding of the system imperfections. Energy losses taking place in a system can be easily determined by using exergy analysis. Hence, it is a powerful tool for the measurement of energy quality, thereby helps to make complex thermodynamic systems more efficient. Nowadays, economic optimization of plant is also a big problem for researchers because of the complex nature. At a viewpoint of this, a comprehensive literature review over the years of energy, exergy, exergoeconomic and economic (4-E analysis and their applications in thermal power plants stimulated by coal, gas, combined cycle and cogeneration system have been done thoroughly. This paper is addressed to those researchers who are doing their research work on 4-E analysis in various thermal power plants. If anyone extracts an idea for the development of the concept of 4-E analysis using this article, we will achieve our goal. This review also indicates the scope of future research in thermal power plants.

  11. 78 FR 47831 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Graham's...

    Science.gov (United States)

    2013-08-06

    ... areas. Dwarf shrubs and cushion- like herbs make up the distinctive plant community type occurring on... community dominated by the dwarf shrubs, cushion-like plants, and endemic species listed above to be a... Shelter Seeds and seedlings of Graham's beardtongue require the right microclimate for germination and...

  12. Scale-up analysis and critical issues of an experimental pilot plant for edible film production using agricultural waste processing

    Directory of Open Access Journals (Sweden)

    Fabrizio Sarghini

    2013-03-01

    Full Text Available This study was developed to test a multifunctional experimental pilot plant with a reduced environmental impact that is able to process agricultural (fennel and food production (liquid whey waste. The pilot plant, using different thermal and filtration process parameters, is able to recover pectin and whey proteins in a single processing unit in order to produce edible films. An innovative feature of the proposed configuration is related to the possibility of coupling different types of waste treatment, obtaining a final product with a higher economical value, combining the two processing lines. Although an edible film production procedure based on pectin extracted from fennel matrix and whey proteins has already been published in literature, the scale-up process highlighted several critical issues, in particular related to the fennel matrix. Nonetheless, the pilot plant configuration allowed an edible film to be produced that is suitable for use as a direct coating to improve the shelf-life of food products.

  13. A quantitative and qualitative comparison of aquatic and terrestrial plant lignin phenols: Critical information for paleoecological reconstructions

    Science.gov (United States)

    Thomas, E. K.; Gao, L.; Huang, Y.

    2009-12-01

    Currently, lignin phenols are used in marine and lacustrine ecosystems as proxies for terrestrial vegetation inputs. Lignins are found in all vascular plants, where they play a crucial role in conduction of water, nutrients and photosynthates through the vascular system, and where they provide structural support. Furthermore, different types of lignin phenols are found in specific types of vegetation (e.g., both syringyl and vanillyl phenols are in angiosperm wood, but only vanillyl phenols are in gymnosperm wood). The ratio of lignin phenols (e.g. syringyl:vanillyl) is indicative of the type of plant from which the lignin phenols were derived. Studies that examine lignin phenols in sedimentary archives assume that lignin phenols are derived solely from terrestrial plants, and changes in the types of lignin phenols are therefore assumed to mark changes in terrestrial vegetation. These assumptions may be flawed, however, because many aquatic plants, including those that are submerged, are vascular, yet little is known about the type and concentration of lignin phenols present in aquatic vascular plants. This knowledge is imperative to the success of paleoecological studies that utilize lignin phenols as a geochemical proxy for terrestrial vegetation. Furthermore, lignin phenols may be important targets for compound-specific radiocarbon dating, which is useful when suitable macrofossils are unavailable. Knowing the origin of the molecules used for radiocarbon dating, however, (i.e. whether they are terrestrial or aquatic) is critical to obtaining meaningful chronologies. We isolated and analyzed lignin phenol monomers from different types of aquatic vascular plants. All plants analyzed are angiosperms, but they occupy different niches in aquatic plant communities: floating, emergent and submergent. We also analyzed different parts of aquatic plants (i.e., stems and leaves). We found lignin phenols in all aquatic species that we analyzed, which highlights the need for

  14. Critical assessment of indoor noise propagation and prediction in power plants

    Science.gov (United States)

    Brittain, Frank H.

    2005-09-01

    Accurate prediction of indoor noise propagation in power plants is important to help estimate occupational noise exposures, and to help predict community noise radiated by plant walls-from levels predicted just inside of each wall. Unfortunately, the basic theories of room acoustics are not applicable. Most power plant rooms are both too large, and too odd shaped for basic room theory, including the Sabine and Norris-Erying theories, to be applicable. Even more important, basic room theory requires empty rooms, and power plant spaces are densely packed with equipment, piping, cable trays, etc. (called fittings). This paper reviews basic room theory, and outlines deficiencies for use in predicting noise propagation inside power plant buildings. Examples are given of walk-away measurements showing that there is no reverberant field, and that reverberation measurements do not correlate well with walk-away test data. Using measurements as an alternative to levels predicted just inside of plant walls to help predict community noise radiated by each wall are discussed. Software for predicting noise in industrial spaces is identified, and their suitability for power plants, which have unusually high fitting densities, is also discussed.

  15. Does plant immunity play a critical role during initiation of the legume-rhizobium symbiosis?

    Science.gov (United States)

    Tóth, Katalin; Stacey, Gary

    2015-01-01

    Plants are exposed to many different microbes in their habitats. These microbes may be benign or pathogenic, but in some cases they are beneficial for the host. The rhizosphere provides an especially rich palette for colonization by beneficial (associative and symbiotic) microorganisms, which raises the question as to how roots can distinguish such 'friends' from possible 'foes' (i.e., pathogens). Plants possess an innate immune system that can recognize pathogens, through an arsenal of protein receptors, including receptor-like kinases (RLKs) and receptor-like proteins (RLPs) located at the plasma membrane. In addition, the plant host has intracellular receptors (so called NBS-LRR proteins or R proteins) that directly or indirectly recognize molecules released by microbes into the plant cell. A successful cooperation between legume plants and rhizobia leads to beneficial symbiotic interaction. The key rhizobial, symbiotic signaling molecules [lipo-chitooligosaccharide Nod factors (NF)] are perceived by the host legume plant using lysin motif-domain containing RLKs. Perception of the symbiotic NFs trigger signaling cascades leading to bacterial infection and accommodation of the symbiont in a newly formed root organ, the nodule, resulting in a nitrogen-fixing root nodule symbiosis. The net result of this symbiosis is the intracellular colonization of the plant with thousands of bacteria; a process that seems to occur in spite of the immune ability of plants to prevent pathogen infection. In this review, we discuss the potential of the invading rhizobial symbiont to actively avoid this innate immune response, as well as specific examples of where the plant immune response may modulate rhizobial infection and host range.

  16. Diffusion and export dynamics of 137Cs deposited on the forested area in Fukushima after the nuclear power plant accident in March 2011. Preliminary results

    International Nuclear Information System (INIS)

    Ohte, Nobuhito; Iseda, Kohei; Tanoi, Keitaro; Murakami, Masashi; Suzuki, Takahiro; Ishii, Nobuyoshi

    2013-01-01

    A massive amount of radioactive substances, including cesium-137 ( 137 Cs), emitted from the disabled nuclear power plant, has been deposited on the forested areas in the northeastern region of Honshu Island, Japan after the Fukushima Daiichi nuclear power plant accident. Forests in these regions are particularly important, not only for the forest products industry but also for source areas of drinking water and for residential environments. To clarify the mechanisms of diffusion and export of 137 Cs deposited on the forested ecosystem, we initiated intensive field observations in a small catchment that included forest and farmlands. Specifically, we were interested in the Kami-Oguni River catchment that is located in the northern part of Fukushima Prefecture. The following expected major pathways of 137 Cs export and diffusion were investigated: 1) transportation of dissolved and particulate or colloidal forms via hydrological processes within a forested catchment and export dynamics through the stream, and 2) diffusion through the food web in terrestrial and aquatic ecosystems of forests. Preliminary findings indicated the following: 1) Most of the 137 Cs was discharged as suspended matter. High water flow generated by storm acted to accelerate the transportation of 137 Cs from the forested catchments. Thus, the estimation of 137 Cs export requires precise evaluation of the high flow acceleration during storm events; 2) Because litter and its detritus may form the biggest pool of 137 Cs in the forested ecosystem, 137 Cs diffusion occurs more rapidly through the detritus food chain than the grazing food chain. Most predators have already ingested 137 Cs, particularly in aquatic environments. An urgent question that needs to be addressed is when and how 137 Cs diffuses through grazing food chains and how rapidly this process occurs. To elucidate or to be able to predict these phenomena, the mechanisms of 137 Cs release from litter and soil's organic matter

  17. Diffusion and export dynamics of 137Cs deposited on the forested area in Fukushima after the nuclear power plant accident in March 2011. Preliminary results

    International Nuclear Information System (INIS)

    Ohte, Nobuhito; Iseda, Kohei; Tanoi, Keitaro; Murakami, Masashi; Suzuki, Takahiro; Ishii, Nobuyoshi

    2012-01-01

    A massive amount of radioactive substances, including cesium-137 ( 137 Cs), emitted from the disabled nuclear power plant, has been deposited on the forested areas in the northeastern region of Honshu Island, Japan after the Fukushima Daiichi nuclear power plant accident. Forests in these regions are particularly important, not only for the forest products industry but also for source areas of drinking water and for residential environments. To clarify the mechanisms of diffusion and export of 137 Cs deposited on the forested ecosystem, we initiated intensive field observations in a small catchment that included forest and farmlands. Specifically, we were interested in the Kami-Oguni River catchment that is located in the northern part of Fukushima Prefecture. The following expected major pathways of 137 Cs export and diffusion were investigated: 1) transportation of dissolved and particulate or colloidal forms via hydrological processes within a forested catchment and export dynamics through the stream, and 2) diffusion through the food web in terrestrial and aquatic ecosystems of forests. Preliminary findings indicated the following: 1) Most of the 137 Cs was discharged as suspended matter. High water flow generated by storm acted to accelerate the transportation of 137 Cs from the forested catchments. Thus, the estimation of 137 Cs export requires precise evaluation of the high flow acceleration during storm events; 2) Because litter and its detritus may form the biggest pool of 137 Cs in the forested ecosystem, 137 Cs diffusion occurs more rapidly through the detritus food chain than the grazing food chain. Most predators have already ingested 137 Cs, particularly in aquatic environments. An urgent question that needs to be addressed is when and how 137 Cs diffuses through grazing food chains and how rapidly this process occurs. To elucidate or to be able to predict these phenomena, the mechanisms of 137 Cs release from litter and soil's organic matter

  18. Diffusion aspects of designing porous growth media for earth and space

    DEFF Research Database (Denmark)

    Chamindu, Deepagoda; Møldrup, Per; Jensen, M P

    2012-01-01

    zone. As one among several essential aspects of optimal porous media design for plant growth, this study presents a diffusion-based characterization of four commercial, aggregated growth media. To account for the observed large percolation threshold for gas diffusivity in the selected media...... to be used in future design models. Also, critical windows of diffusivity (CWD) was defined identifying the air content range where gas diffusivity (hence, oxygen supply) and solute diffusivity or the analogous electrical conductivity (hence, nutrient supply) are above pre-defined, critical minimum values....... Assuming different critical values for gas diffusivity under terrestrial and Martian conditions, the four growth media were compared and it was found that one medium did not fulfill the pre-set criteria. Overall, the analyses suggested that particle (aggregate) sizes below 0.25 and above 5 mm should likely...

  19. Effects of spray drift of glyphosate on nontarget terrestrial plants-A critical review.

    Science.gov (United States)

    Cederlund, Harald

    2017-11-01

    Glyphosate is a widely used broad-spectrum postemergent herbicide used for weed control in both agricultural and nonagricultural settings. Spray drift of glyphosate can pose a risk to nontarget terrestrial plants and plant communities outside the intended area of application, but the lack of a well-established predicted-no-effect drift rate makes properly assessing such risk difficult. For this reason, a literature review and meta-analysis was carried out with the aim to determine the level of drift that is likely to cause harm to plants and to explore what spray-reducing targets would be sufficiently protective. No-observed-adverse effect rates, lowest-observed-adverse effect rates, and effect rates giving 10, 25, and 50% effects were extracted from a total of 39 different publications. The data were combined per species, and species sensitivity distributions were constructed and fitted with a log-logistic model to assess protectiveness. No systematic differences were detected between the responses of monocotyledons or dicotyledons, but wild plants were found to be generally less sensitive to glyphosate drift than domesticated plants. The results indicate that restricting spray drift to a level below 5 g a.e./ha would protect approximately 95% of all higher plant species against minor adverse effects of glyphosate drift and that rates below 1 to 2 g a.e./ha would be almost completely protective. No studies were encountered that evaluated effects of spray drift against nonvascular plants, and therefore, the conclusions are only valid for vascular plants. Environ Toxicol Chem 2017;36:2879-2886. © 2017 SETAC. © 2017 SETAC.

  20. Does plant immunity play a critical role during initiation of the legume-rhizobium symbiosis?

    OpenAIRE

    T?th, Katalin; Stacey, Gary

    2015-01-01

    Plants are exposed to many different microbes in their habitats. These microbes may be benign or pathogenic, but in some cases they are beneficial for the host. The rhizosphere provides an especially rich palette for colonization by beneficial (associative and symbiotic) microorganisms, which raises the question as to how roots can distinguish such ‘friends’ from possible ‘foes’ (i.e., pathogens). Plants possess an innate immune system that can recognize pathogens, through an arsenal of prote...

  1. One safety critical indicators model for regulatory actions on nuclear power plants based on a level 1 PSA

    International Nuclear Information System (INIS)

    Araujo, Jefferson Borges

    2006-03-01

    This study presents a general methodology to the establishment, selection and use of safety indicators for a two loop PWR plant, as Angra 1. The study performed identifies areas considered critical for the plant operational safety. For each of these areas, strategic sub-areas are defined. For each strategic sub-area, specific safety indicators are defined. These proposed Safety Indicators are based on the contribution to risk considering a quantitative risk analysis. For each safety indicator, a goal, a bounded interval and proper bases are developed, to allow for a clear and comprehensive individual behavior evaluation. Additionally, an integrated evaluation of the indicators, using expert systems, was done to obtain an overview of the plant general safety. This methodology can be used for identifying situations where the plant safety is challenged, by giving a general overview of the plant operational condition. Additionally, this study can also identify eventual room for improvements by generating suggestions and recommendations, as a complement for regulatory actions and inspections, focusing resources on eventual existing weaknesses, in order to increase or maintain a high pattern of operational safety. (author)

  2. Selenium Cycling Across Soil-Plant-Atmosphere Interfaces: A Critical Review

    Directory of Open Access Journals (Sweden)

    Lenny H.E. Winkel

    2015-05-01

    Full Text Available Selenium (Se is an essential element for humans and animals, which occurs ubiquitously in the environment. It is present in trace amounts in both organic and inorganic forms in marine and freshwater systems, soils, biomass and in the atmosphere. Low Se levels in certain terrestrial environments have resulted in Se deficiency in humans, while elevated Se levels in waters and soils can be toxic and result in the death of aquatic wildlife and other animals. Human dietary Se intake is largely governed by Se concentrations in plants, which are controlled by root uptake of Se as a function of soil Se concentrations, speciation and bioavailability. In addition, plants and microorganisms can biomethylate Se, which can result in a loss of Se to the atmosphere. The mobilization of Se across soil-plant-atmosphere interfaces is thus of crucial importance for human Se status. This review gives an overview of current knowledge on Se cycling with a specific focus on soil-plant-atmosphere interfaces. Sources, speciation and mobility of Se in soils and plants will be discussed as well as Se hyperaccumulation by plants, biofortification and biomethylation. Future research on Se cycling in the environment is essential to minimize the adverse health effects associated with unsafe environmental Se levels.

  3. Brassinosteroids play a critical role in the regulation of pesticide metabolism in crop plants.

    Science.gov (United States)

    Zhou, Yanhong; Xia, Xiaojian; Yu, Gaobo; Wang, Jitao; Wu, Jingxue; Wang, Mengmeng; Yang, Youxin; Shi, Kai; Yu, Yunlong; Chen, Zhixiang; Gan, Jay; Yu, Jingquan

    2015-03-12

    Pesticide residues in agricultural produce pose a threat to human health worldwide. Although the detoxification mechanisms for xenobiotics have been extensively studied in mammalian cells, information about the regulation network in plants remains elusive. Here we show that brassinosteroids (BRs), a class of natural plant hormones, decreased residues of common organophosphorus, organochlorine and carbamate pesticides by 30-70% on tomato, rice, tea, broccoli, cucumber, strawberry, and other plants when treated externally. Genome-wide microarray analysis showed that fungicide chlorothalonil (CHT) and BR co-upregulated 301 genes, including a set of detoxifying genes encoding cytochrome P450, oxidoreductase, hydrolase and transferase in tomato plants. The level of BRs was closely related to the respiratory burst oxidase 1 (RBOH1)-encoded NADPH oxides-dependent H2O2 production, glutathione biosynthesis and the redox homeostasis, and the activity of glutathione S-transferase (GST). Gene silencing treatments showed that BRs decreased pesticide residues in plants likely by promoting their metabolism through a signaling pathway involving BRs-induced H2O2 production and cellular redox change. Our study provided a novel approach for minimizing pesticide residues in crops by exploiting plants' own detoxification mechanisms.

  4. A COMPARATIVE STUDY OF EXTRACT OF SUCCULENT LEAVES OF LIVING PLANT WITH METHANOLIC AND AQUEOUS EXTRACT OF BERLERIA LUPULINA LINDL. AGAINST PATHOGENIC MICROBES BY DISC DIFFUSION AND SPECTROPHOTOMETRY

    Directory of Open Access Journals (Sweden)

    Shibabrata Pattanayak

    2014-12-01

    Full Text Available Berleria lupulina Lindl. was evaluated for its reported antimicrobial activity in a novel way. The extract of succulent leaves collected from living plant was studied along with conventional methanolic and watery extracts made from the dry leaves of the plant. The extracts were tested on three pathogenic bacteria and the antimicrobial activity was tested both by conventional single disc diffusion method and a novel Spectrophotometric method. In disc diffusion study, it was found that the methanolic extract (100 mg/ml. and 200 mg/ ml. diluted in 70% of methanol and extract of succulent leaves can induce 12 mm, 13 mm and 14 mm diameter zone of inhibition comparable with 24 mm of Ceftriaxone against Escherichia coli. The zone of inhibition against Staphylococcus aureus were 13 mm, 14 mm, 15 mm and 25 mm and against Salmonella enteritides were 12 mm, 14 mm, 15 mm and 28 mm correspondingly. The watery extract made from the dry plant and the methanolic extract diluted in water failed to induce any inhibition in growth of the organisms. In spectrophotometric study, the methanolic extract showed antimicrobial efficacy in the concentration of 10 mg/ml. or above against Salmonella enteritides and Staphylococcus aureus. But against Escherichia coli, effective control was found in 20 mg/ml concentration. The fresh extract of the plant showed antimicrobial efficacy in the concentration of 16.5%. The anti microbial efficacy above that concentration cannot be detected in the available spectrophotometrical method for presence of color material in that fresh extract.

  5. The Use of LiDAR Elevation Data and Satellite Imagery to Locate Critical Source Areas to Diffuse Pollution in Agricultural Watersheds

    Science.gov (United States)

    Drouin, Ariane; Michaud, Aubert; Thériault, Georges; Beaudin, Isabelle; Rodrigue, Jean-François; Denault, Jean-Thomas; Desjardins, Jacques; Côté, Noémi

    2013-04-01

    In Quebec / Canada, water quality improvement in rural areas greatly depends on the reduction of diffuse pollution. Indeed, point source pollution has been reduced significantly in Canada in recent years by creating circumscribed pits for manure and removing animals from stream. Diffuse pollution differs from point source pollution because it is spread over large areas. In agricultural areas, sediment loss by soil and riverbank erosion along with loss of nutrients (phosphorus, nitrogen, etc.) and pesticides from fields represent the main source of non-point source pollution. The factor mainly responsible for diffuse pollution in agricultural areas is surface runoff occurring in poorly drained areas in fields. The presence of these poorly drained areas is also one of the most limiting factors in crop productivity. Thus, a reconciliation of objectives at the farm (financial concern for farmers) and off-farm concerns (environmental concern) is possible. In short, drainage, runoff, erosion, water quality and crop production are all interconnected issues that need to be tackled together. Two complementary data sources are mainly used in the diagnosis of drainage, surface runoff and erosion : elevation data and multispectral satellite images. In this study of two watersheds located in Québec (Canada), LiDAR elevation data and satellite imagery (QuickBird, Spot and Landsat) were acquired. The studied territories have been partitioned in hydrologic response units (HRUs) according to sub-basins, soils, elevation (topographic index) and land use. These HRUs are afterwards used in a P index software (P-Edit) that calculates the quantities of sediments and phosphorus exported from each HRUs. These exports of sediments and phosphorus are validated with hydrometric and water quality data obtain in two sub-basins and are also compared to soil brightness index derived from multispectral images. This index is sensitive to soil moisture and thus highlights areas where the soil is

  6. Plant Uptake of Organic Pollutants from Soil: A Critical Review ofBioconcentration Estimates Based on Modelsand Experiments

    Energy Technology Data Exchange (ETDEWEB)

    McKone, Thomas E.; Maddalena, Randy L.

    2007-01-01

    The role of terrestrial vegetation in transferring chemicals from soil and air into specific plant tissues (stems, leaves, roots, etc.) is still not well characterized. We provide here a critical review of plant-to-soil bioconcentration ratio (BCR) estimates based on models and experimental data. This review includes the conceptual and theoretical formulations of the bioconcentration ratio, constructing and calibrating empirical and mathematical algorithms to describe this ratio and the experimental data used to quantify BCRs and calibrate the model performance. We first evaluate the theoretical basis for the BCR concept and BCR models and consider how lack of knowledge and data limits reliability and consistency of BCR estimates. We next consider alternate modeling strategies for BCR. A key focus of this evaluation is the relative contributions to overall uncertainty from model uncertainty versus variability in the experimental data used to develop and test the models. As a case study, we consider a single chemical, hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and focus on variability of bioconcentration measurements obtained from 81 experiments with different plant species, different plant tissues, different experimental conditions, and different methods for reporting concentrations in the soil and plant tissues. We use these observations to evaluate both the magnitude of experimental variability in plant bioconcentration and compare this to model uncertainty. Among these 81 measurements, the variation of the plant/soil BCR has a geometric standard deviation (GSD) of 3.5 and a coefficient of variability (CV-ratio of arithmetic standard deviation to mean) of 1.7. These variations are significant but low relative to model uncertainties--which have an estimated GSD of 10 with a corresponding CV of 14.

  7. Criticality analysis of PWR spent fuel storage facilities inside nuclear power plants

    International Nuclear Information System (INIS)

    Neuber, J.C.

    1999-01-01

    This paper describes some of the main features of the actinide plus fission product burnup credit methodology used by Siemens for criticality safety design analysis of wet PWR storage pools with soluble boron in the pool water. Application of burnup credit requires knowledge of the isotopic inventory of the irradiated fuel for which burnup credit is taken. This knowledge is gained by using depletion codes. The results of the depletion analysis are a necessary input to the criticality analysis. Siemens performs depletion calculations for PWR fuel burnup credit applications with the aid of the Siemens standard design procedure SAV90. The quality of this procedure relies on statistics on the differences between calculation and measurement extracted from in-core measurement data and chemical assay data. Siemens performs criticality safety calculations with the aid of the criticality calculation modules of the SCALE code package. These modules are verified many times with the aid of various kinds of critical experiments and configurations: Application of these modules to spent LWR fuel assembly storage pools was verified by analyzing critical experiments simulating such storage pools. Actinide plus fission product burnup credit applications of these modules were verified by analyzing PWR reactor critical configurations. The result of performing a burnup credit analysis is the determination of a burnup, credit loading curve for the spent fuel storage racks designed for burnup credit. This curve specifies the loading criterion by indicating the minimum burnup necessary for the fuel assembly with a specific initial enrichment to be placed in the storage racks designed for burnup credit. The loading of the spent fuel storage racks designed for burnup credit requires the implementation of controls to ensure that the loading curve is met. The controls include the determination of fuel assembly burnup based on reactor records. (author)

  8. On-line testing of nuclear plant temperature and pressure instrumentation and other critical plant equipment. IAEA regional workshop. Working material

    International Nuclear Information System (INIS)

    1998-01-01

    Under European regional TC project RER/4/011, IAEA and VUJE Training centre organized a workshop on On-line Testing of Nuclear Power Plant Temperature and Pressure Instrumentation and Other Critical Plant Equipment in Trnava, Slovak Republic, from 25 to 29 May 1998. The objective of the workshop was to review the state-of-the-art in NPP instrumentation, cover typical instrumentation problems and solutions, describe technical and regulatory requirements for verifying the performance of nuclear power plant instrumentation, describe new methods developed and applied in NPPs for on-line verification and performance of instrumentation and present new techniques using existing instrumentation to identify the on-set problems in the plant electrical, mechanical and thermal hydraulic systems. Particular emphasis was placed on temperature measurements by Resistance Temperature Detectors (RTDs) and thermocouples and pressure measurements using motion-balanced and forced-balanced pressure transmitters. This proceedings includes papers presented by the invited speakers and the participants each with an abstract as wells as a summary of the Round-Table discussions

  9. Analyses on the diffusion of aerosol pollutants caused by the experimental plant ABI-2000 situated close to the center of Casaccia

    International Nuclear Information System (INIS)

    Carbone, A.I.; Racalbuto, S.; Grandoni, G.

    1989-12-01

    Atmospheric diffusion and ground deposit of some macro and micro-pollutants have been modelled. The considered pollutants will be emitted from the stack of the pilot plant ABI-2000 that will be soon operating in the Energy Research Center of Casaccia. In this plant, research activities will be performed in order to study the development of new processes for the fuels and/or wastes combustion and to set up technologies for pollutant containment. The average air concentration of pollutants and their deposition on ground have been evaluated both during normal operation and incidental conditions using some computer codes developed by ENEA. The comparison between the average air concentrations at ground level for various sampling times and those averages imposed by air quality standards, shows that the resulting situation following the emissions of the examined plant is by far lower than the acceptable one defined by the laws in force. Therefore, the environmental and sanitary consequences should be considered as negligible. (author)

  10. Optimization of the diffusive gradients in thin films (DGT) method for simultaneous assay of potassium and plant-available phosphorus in soils.

    Science.gov (United States)

    Zhang, Yulin; Mason, Sean; McNeill, Ann; McLaughlin, Michael J

    2013-09-15

    Potassium (K) and phosphorus (P) are two important macronutrients for crops, and are usually applied to soils as granular fertilizer before seeding. Therefore, accurate soil tests prior to planting to predict crop response to fertilizers are important in optimizing crop yields. Traditional methods used for testing both available K and P in soils, which are based on chemical extraction procedures, are to be soil-type dependent, and the predictive relationships across a broad range of soils are generally poor. The diffusive gradients in thin films (DGT) technique, based on diffusion theory, is extensively used to measure the diffusive supply of trace elements, metals and some nutrients in soils and water. When DGT is used to assess plant-available P in soils, a good relationship is found between crop response to P fertilizer and concentrations of P in soil measured by DGT, and therefore the DGT method provides a more precise recommendation of P fertilizer requirements. Adaptation of the DGT method to measure plant-available K in soils has already been attempted [1], but limitations were reported due to the non-uniform size of the resin gel, decreased K binding rate of the gel at long deployment times and a limited ability to measure a wide range of K concentrations. To eliminate these problems, a new resin gel has been developed by combining Amberlite and ferrihydrite. This mixed Amberlite and ferrihydrite (MAF) gel has improved properties in terms of handling and even distribution of Amberlite in the gel. The elution efficiencies of the MAF gel for K and P were 90% and 96%, respectively. The diffusion coefficient of K through the diffusive gel was 1.30 × 10(-5)cm(2)s(-1) at 22 ± 1°C and was stable through time. Since ferrihydrite is already used in DGT P testing, the ability of the MAF gel to assess available P simultaneously was also assessed. The MAF gel performed the same as the traditional ferrihydrite gel for available P assessment in a wide variety of

  11. Differentiating moss from higher plants is critical in studying the carbon cycle of the boreal biome

    Science.gov (United States)

    Yuan, Wenping; Liu, Shuguang; Dong, Wenjie; Liang, Shunlin; Zhao, Shuqing; Chen, Jingming; Xu, Wenfang; Li, Xianglan; Barr, Alan; Black, T. Andrew; Yan, Wende; Goulden, Michael; Kulmala, Liisa; Lindroth, Anders; Margolis, Hank A.; Matsuura, Yojiro; Moors, Eddy; van der Molen, Michiel; Ohta, Takeshi; Pilegaard, Kim; Varlagin, Andrej; Vesala, Timo

    2014-01-01

    The satellite-derived normalized difference vegetation index (NDVI), which is used for estimating gross primary production (GPP), often includes contributions from both mosses and vascular plants in boreal ecosystems. For the same NDVI, moss can generate only about one-third of the GPP that vascular plants can because of its much lower photosynthetic capacity. Here, based on eddy covariance measurements, we show that the difference in photosynthetic capacity between these two plant functional types has never been explicitly included when estimating regional GPP in the boreal region, resulting in a substantial overestimation. The magnitude of this overestimation could have important implications regarding a change from a current carbon sink to a carbon source in the boreal region. Moss abundance, associated with ecosystem disturbances, needs to be mapped and incorporated into GPP estimates in order to adequately assess the role of the boreal region in the global carbon cycle.

  12. Differentiating moss from higher plants is critical in studying the carbon cycle of the boreal biome.

    Science.gov (United States)

    Yuan, Wenping; Liu, Shuguang; Dong, Wenjie; Liang, Shunlin; Zhao, Shuqing; Chen, Jingming; Xu, Wenfang; Li, Xianglan; Barr, Alan; Andrew Black, T; Yan, Wende; Goulden, Mike L; Kulmala, Liisa; Lindroth, Anders; Margolis, Hank A; Matsuura, Yojiro; Moors, Eddy; van der Molen, Michiel; Ohta, Takeshi; Pilegaard, Kim; Varlagin, Andrej; Vesala, Timo

    2014-06-26

    The satellite-derived normalized difference vegetation index (NDVI), which is used for estimating gross primary production (GPP), often includes contributions from both mosses and vascular plants in boreal ecosystems. For the same NDVI, moss can generate only about one-third of the GPP that vascular plants can because of its much lower photosynthetic capacity. Here, based on eddy covariance measurements, we show that the difference in photosynthetic capacity between these two plant functional types has never been explicitly included when estimating regional GPP in the boreal region, resulting in a substantial overestimation. The magnitude of this overestimation could have important implications regarding a change from a current carbon sink to a carbon source in the boreal region. Moss abundance, associated with ecosystem disturbances, needs to be mapped and incorporated into GPP estimates in order to adequately assess the role of the boreal region in the global carbon cycle.

  13. Survey of bayesian belif nets for quantitative reliability assessment of safety critical software used in nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Eom, H.S.; Sung, T.Y.; Jeong, H.S.; Park, J.H.; Kang, H.G.; Lee, K

    2001-03-01

    As part of the Probabilistic Safety Assessment of safety grade digital systems used in Nuclear Power plants research, measures and methodologies applicable to quantitative reliability assessment of safety critical software were surveyed. Among the techniques proposed in the literature we selected those which are in use widely and investigated their limitations in quantitative software reliability assessment. One promising methodology from the survey is Bayesian Belief Nets (BBN) which has a formalism and can combine various disparate evidences relevant to reliability into final decision under uncertainty. Thus we analyzed BBN and its application cases in digital systems assessment area and finally studied the possibility of its application to the quantitative reliability assessment of safety critical software.

  14. 77 FR 50213 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Jaguar

    Science.gov (United States)

    2012-08-20

    ... development of the final designation of critical habitat for the jaguar. We will publish an announcement and....) including whether there are threats to the species from human activity, the degree of which can be expected... Mexico to southern South America. Jaguars are muscular cats with relatively short, massive limbs and a...

  15. 78 FR 5351 - Endangered and Threatened Wildlife and Plants; Proposed Designation of Critical Habitat for the...

    Science.gov (United States)

    2013-01-25

    ... journal articles or other publications) to allow us to verify any scientific or commercial information you include. Please note that submissions merely stating support for or opposition to the action under... taking. Critical habitat receives protection under section 7 of the Act through the requirement that...

  16. 77 FR 71875 - Endangered and Threatened Wildlife and Plants; Designation of Revised Critical Habitat for the...

    Science.gov (United States)

    2012-12-04

    ... scientific evaluation of potential management options to reduce the impact of barred owls on northern spotted... and the Northwest Forest Plan Forest Management Activities in Northern Spotted Owl Critical Habitat Research and Adaptive Management The Biology and Ecology of the Northern Spotted Owl III. Previous Federal...

  17. 75 FR 19575 - Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for Navarretia fossalis

    Science.gov (United States)

    2010-04-15

    ... Supervisor, U.S. Fish and Wildlife Service, Carlsbad Fish and Wildlife Office, 6010 Hidden Valley Road, Suite... distribution. The revisions consist of both additions and removals of land that we proposed as critical habitat... River 4,312 ac (1,745 ha) 6B. Salt Creek Seasonally Flooded Alkali 943 ac (382 ha) Plain 6C. Wickerd...

  18. 78 FR 77289 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Arctostaphylos...

    Science.gov (United States)

    2013-12-20

    ... activities in some areas, especially designated off-leash dog areas. In their comment, they noted, ``While... areas include hiking, picnicking, nature viewing, walking, jogging, dog walking (both on-and off-leash...-leash dog areas, be removed from consideration as critical habitat. Our Response: We reviewed the...

  19. 76 FR 39807 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Lepidium...

    Science.gov (United States)

    2011-07-07

    ... decision on this action. ADDRESSES: You may submit comments by one of the following methods: Federal e... designate that specific area as critical habitat will result in the extinction of the species. We are... rationale; and Whether any specific exclusions may result in the extinction of the species and why. (6) The...

  20. 75 FR 13715 - Endangered and Threatened Wildlife and Plants; Revised Designation of Critical Habitat for Bull...

    Science.gov (United States)

    2010-03-23

    ... includes 1,585.7 km (985.30 mi) of marine shoreline area in the Olympic Peninsula and Puget Sound), and 215... the availability of the draft economic analysis (DEA) of the proposed revised critical habitat...://www.fws.gov/pacific/bulltrout . The draft economic analysis is available for review at http://www...

  1. 76 FR 61599 - Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for the Marbled Murrelet

    Science.gov (United States)

    2011-10-05

    ... consideration of economic and any other relevant impacts of designation. On April 21, 2003, we published a... draft economic analysis (72 FR 35025) related to the September 12, 2006, proposed critical habitat..., Olympic Adaptive Management Area, Siskiyou and Six Rivers National Forests, Redwood National Park, and...

  2. 75 FR 12815 - Endangered and Threatened Wildlife and Plants; Revised Designation of Critical Habitat for the...

    Science.gov (United States)

    2010-03-17

    ... developed habitat suitability index models for proposed critical habitat units. The extent of the... the suitability of the California red-legged frog's habitat in the future. However, we are required to... a habitat suitability index had been established for the area. Response: We recognize this...

  3. 78 FR 26581 - Endangered and Threatened Wildlife and Plants; Listing and Designation of Critical Habitat for...

    Science.gov (United States)

    2013-05-07

    ... scenario (all costs attributed to critical habitat). Total present value impacts anticipated to result from... present value terms (91 percent of total present value impacts) under the low-end scenario, and result...-end scenario, impacts in proposed Unit 1 are estimated at $6.6 million in present value terms (49...

  4. 77 FR 28846 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Astragalus...

    Science.gov (United States)

    2012-05-16

    ... will hold a public hearing in the Palm Springs City Hall Council Chamber, 3200 E. Tahquitz Canyon Way... associated with climate change on Astragalus lentiginosus var. coachellae and proposed critical habitat. (5....m. in the Palm Springs City Hall Council Chamber, 3200 E. Tahquitz Canyon Way, Palm Springs, CA...

  5. 78 FR 51327 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Austin...

    Science.gov (United States)

    2013-08-20

    ... Act. In total, approximately 4,451 acres (ac) (1,801 hectares (ha)) in Travis and Williamson Counties... designate 4,451 ac (1,801 ha) of critical habitat for the Austin blind salamander and Jollyville Plateau... Jollyville Plateau salamander spring (Cistern) has a temperature range from 66.4 to 73.4 degrees Fahrenheit...

  6. 77 FR 32075 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Southern...

    Science.gov (United States)

    2012-05-31

    ... impacts in the draft economic analysis is complete and accurate. (8) The likelihood of adverse social... of critical habitat include public awareness of the presence of the species and the importance of.... 12630 (Takings), E.O. 13132 (Federalism), E.O. 12988 (Civil Justice Reform), E.O. 13211 (Energy, Supply...

  7. 77 FR 30988 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Cumberland...

    Science.gov (United States)

    2012-05-24

    ... description of economic impacts in the DEA is complete and accurate. (8) The likelihood of adverse social... benefits of critical habitat include public awareness of the presence of the fishes and the importance of... Justice Reform), E.O. 13211 (Energy, Supply, Distribution, and Use), the Unfunded Mandates Reform Act (2 U...

  8. Which plant traits respond to aridity? A critical step to assess functional diversity in Mediterranean drylands

    Czech Academy of Sciences Publication Activity Database

    Nunes, A.; Köbel, M.; Pihno, P.; Matos, P.; de Bello, Francesco; Correia, O.; Branquinho, C.

    2017-01-01

    Roč. 239, MAY 28 2017 (2017), s. 176-184 ISSN 0168-1923 Institutional support: RVO:67985939 Keywords : Annual plants * Climatic gradient * Functional dispersion Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 3.887, year: 2016

  9. 75 FR 27690 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Ambrosia...

    Science.gov (United States)

    2010-05-18

    ... in our proposal (see Subunit 4D: Gird Road/Monserate Hill below). The purpose of the revisions..., moisture, and periodic flooding presumed necessary for the plant's persistence (PCE 1), and nonnative... threats to A. pumila habitat and potential management considerations. Subunit 4D: Gird Road/Monserate Hill...

  10. 78 FR 62529 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Agave...

    Science.gov (United States)

    2013-10-22

    ... sufficient information with your submission (such as scientific journal articles or other publications) to... information sources may include the recovery plan for the species, articles in peer-reviewed journals.... 80; Silander et al. 1986, p. 191). Additionally, some areas were planted with Eucalyptus robusta (O...

  11. The influence of plants on productivity : A critical assessment of research findings and test methods

    NARCIS (Netherlands)

    Bakker, I; van der Voordt, Theo

    2010-01-01

    Purpose
    This paper aims to review available research into the impact of plants on people and labour productivity in order to test a number of hypotheses and the reliability and validity of “evidence based” statements.
    Methodology
    An extended literature review has been conducted of

  12. 77 FR 48367 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Ipomopsis...

    Science.gov (United States)

    2012-08-13

    ... Procedures for Rare Plant Environmental Review for Development Projects and Land Use Changes (State Board of... private and Federal lands, we mapped 16,862 ac (6,824 ha) of suitable habitat, 68 percent on private lands and 32 percent on Federal (Bureau of Land Management (BLM)) lands, with a spotty distribution...

  13. 78 FR 24007 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Eriogonum codium

    Science.gov (United States)

    2013-04-23

    ... fluctuations (Evans et al. 2003, p. 64). Monitoring by Monument staff (Newsome 2011, p. 5) suggests that the... estimated more than 50,000 flowering plants in high population years (Evans et al. 2003, p. 3-2) (see Table... roost sites, nesting grounds, seasonal wetlands, water quality, tide, soil type) that when combined...

  14. Analysis of the emergency plan of Angra dos Reis Nuclear Power Plants: a critical view related to accessibility and mobility of people with special needs

    International Nuclear Information System (INIS)

    Correa, Luanda C.A.; Correa, Samanda C.A.; Santos, Geissa; Souza, Edmilson M.

    2014-01-01

    This work intends to make a critical analysis of the emergency plan of the Angra dos Reis Nuclear Power Plants related to appropriate transportation, accommodation and infrastructure for people with special needs

  15. Summer Freezing Resistance: A Critical Filter for Plant Community Assemblies in Mediterranean High Mountains.

    Science.gov (United States)

    Pescador, David S; Sierra-Almeida, Ángela; Torres, Pablo J; Escudero, Adrián

    2016-01-01

    Assessing freezing community response and whether freezing resistance is related to other functional traits is essential for understanding alpine community assemblages, particularly in Mediterranean environments where plants are exposed to freezing temperatures and summer droughts. Thus, we characterized the leaf freezing resistance of 42 plant species in 38 plots at Sierra de Guadarrama (Spain) by measuring their ice nucleation temperature, freezing point (FP), and low-temperature damage (LT50), as well as determining their freezing resistance mechanisms (i.e., tolerance or avoidance). The community response to freezing was estimated for each plot as community weighted means (CWMs) and functional diversity (FD), and we assessed their relative importance with altitude. We established the relationships between freezing resistance, growth forms, and four key plant functional traits (i.e., plant height, specific leaf area, leaf dry matter content (LDMC), and seed mass). There was a wide range of freezing resistance responses and more than in other alpine habitats. At the community level, the CWMs of FP and LT50 responded negatively to altitude, whereas the FD of both traits increased with altitude. The proportion of freezing-tolerant species also increased with altitude. The ranges of FP and LT50 varied among growth forms, and only leaf dry matter content was negatively correlated with freezing-resistance traits. Summer freezing events represent important abiotic filters for assemblies of Mediterranean high mountain communities, as suggested by the CWMs. However, a concomitant summer drought constraint may also explain the high freezing resistance of species that thrive in these areas and the lower FD of freezing resistance traits at lower altitudes. Leaves with high dry matter contents may maintain turgor at lower water potential and enhance drought tolerance in parallel to freezing resistance. This adaptation to drought seems to be a general prerequisite for plants

  16. Environmental impact of estrogens on human, animal and plant life: A critical review.

    Science.gov (United States)

    Adeel, Muhammad; Song, Xiaoming; Wang, Yuanyuan; Francis, Dennis; Yang, Yuesuo

    2017-02-01

    Since the inception of global industrialization, steroidal estrogens have become an emerging and serious concern. Worldwide, steroid estrogens including estrone, estradiol and estriol, pose serious threats to soil, plants, water resources and humans. Indeed, estrogens have gained notable attention in recent years, due to their rapidly increasing concentrations in soil and water all over the world. Concern has been expressed regarding the entry of estrogens into the human food chain which in turn relates to how plants take up and metabolism estrogens. In this review we explore the environmental fate of estrogens highlighting their release through effluent sources, their uptake, partitioning and physiological effects in the ecological system. We draw attention to the potential risk of intensive modern agriculture and waste disposal systems on estrogen release and their effects on human health. We also highlight their uptake and metabolism in plants. We use MEDLINE and other search data bases for estrogens in the environment from 2005 to the present, with the majority of our sources spanning the past five years. Published acceptable daily intake of estrogens (μg/L) and predicted no effect concentrations (μg/L) are listed from published sources and used as thresholds to discuss reported levels of estrogens in the aquatic and terrestrial environments. Global levels of estrogens from river sources and from Waste Water Treatment Facilities have been mapped, together with transport pathways of estrogens in plants. Estrogens at polluting levels have been detected at sites close to waste water treatment facilities and in groundwater at various sites globally. Estrogens at pollutant levels have been linked with breast cancer in women and prostate cancer in men. Estrogens also perturb fish physiology and can affect reproductive development in both domestic and wild animals. Treatment of plants with steroid estrogen hormones or their precursors can affect root and shoot

  17. Installation and routing of critical embedments at the Hanford Waste Vitrification Plant

    International Nuclear Information System (INIS)

    Van Katwijk, C.; Keenan, R.M.; Watts, C.

    1993-01-01

    The Hanford Waste Vitrification Plant (HWVP) is being designed by Fluor Daniel. Waste Chem Corporation is providing specialized expertise as Fluor Daniel's major subcontractor for vitrification and remote systems technologies. Westinghouse Hanford Company (Westinghouse Hanford) is the Project Integration manager and Business manager, and as the plant operator it provides technical direction to the Architect/Engineer team and constructor on behalf of the US Department of Energy, Richland Field Office. The Hot Cell portion of HWVP Vitrification Building contains very congested piping systems in the walls that penetrate in to the cells to nozzles for remote piping jumper assemblies. These nozzles require very tight tolerances to ensure a leak-tight fit to the jumpers. An approach has been developed that minimizes the time and expense of installing these nozzles in the wall to tight construction tolerances. This approach is called the Ganged Embed Plate (GEP) design

  18. Differentiating moss from higher plants is critical in studying the carbon cycle of the boreal biome

    DEFF Research Database (Denmark)

    Yuan, Wenping; Liu, Shuguang; Dong, Wenjie

    2014-01-01

    The satellite-derived normalized difference vegetation index (NDVI), which is used for estimating gross primary production (GPP), often includes contributions from both mosses and vascular plants in boreal ecosystems. For the same NDVI, moss can generate only about one-third of the GPP that vascu......The satellite-derived normalized difference vegetation index (NDVI), which is used for estimating gross primary production (GPP), often includes contributions from both mosses and vascular plants in boreal ecosystems. For the same NDVI, moss can generate only about one-third of the GPP...... in a substantial overestimation. The magnitude of this overestimation could have important implications regarding a change from a current carbon sink to a carbon source in the boreal region. Moss abundance, associated with ecosystem disturbances, needs to be mapped and incorporated into GPP estimates in order...

  19. Colombian coca plants. A critical discussion on taxonomic aspects of cultivated Erythroxylum species (Erythroxylaceae)

    International Nuclear Information System (INIS)

    Galindo Bonilla, Aida; Fernandez Alonzo, Jose Luis

    2010-01-01

    Forensic botany is in high demand in Colombia in connection with plant material, mainly coca from illicit crops. The taxonomic study of the two species and four varieties of Erythroxylum P. Browne (Erythroxylaceae) cultivated in Colombia was carried out. Hybridization between E. coca and E. novogranatense and between the two varieties of E. coca is suggested, and important changes in the geographic distribution of all taxa are described. Both, hybridization and changes in distribution patterns are due to anthropic intervention.

  20. Assessing Risk-Based Performance Indicators in Safety-Critical Systems for Nuclear Power Plants

    OpenAIRE

    TONT Gabriela

    2011-01-01

    The paper proposes framework for a multidisciplinary nuclear risk and safety assessment by modeling uncertainty and combining diverse evidence provided in such a way that it could be used to represent an entire argument about a system's dependability. The identified safety issues are being treated by means of probabilistic safety assessment (PSA). The behavior simulation of power plant in thepresence of risk factors is analyzed from the vulnerability, risk and functional safety viewpoints, hi...

  1. Requirement analysis of the safety-critical software implementation for the nuclear power plant

    International Nuclear Information System (INIS)

    Chang, Hoon Seon; Jung, Jae Cheon; Kim, Jae Hack; Nam, Sang Ku; Kim, Hang Bae

    2005-01-01

    The safety critical software shall be implemented under the strict regulation and standards along with hardware qualification. In general, the safety critical software has been implemented using functional block language (FBL) and structured language like C in the real project. Software design shall comply with such characteristics as; modularity, simplicity, minimizing the use of sub-routine, and excluding the interrupt logic. To meet these prerequisites, we used the computer-aided software engineering (CASE) tool to substantiate the requirements traceability matrix that were manually developed using Word processors or Spreadsheets. And the coding standard and manual have been developed to confirm the quality of software development process, such as; readability, consistency, and maintainability in compliance with NUREG/CR-6463. System level preliminary hazard analysis (PHA) is performed by analyzing preliminary safety analysis report (PSAR) and FMEA document. The modularity concept is effectively implemented for the overall module configurations and functions using RTP software development tool. The response time imposed on the basis of the deterministic structure of the safety-critical software was measured

  2. COMBINED GEOPHYSICAL INVESTIGATION TECHNIQUES TO IDENTIFY BURIED WASTE IN AN UNCONTROLLED LANDFILL AT THE PADUCAH GASEOUS DIFFUSION PLANT, KENTUCKY

    International Nuclear Information System (INIS)

    Miller, Peter T.; Starmer, R. John

    2003-01-01

    The primary objective of the investigation was to confirm the presence and determine the location of a cache of 30 to 60 buried 55-gallon drums that were allegedly dumped along the course of the pre-existing, northsouth diversion ditch (NSDD) adjacent to permitted landfills at the Paducah Gaseous Diffusion Plant, Kentucky. The ditch had been rerouted and was being filled and re-graded at the time of the alleged dumping. Historic information and interviews with individuals associated with alleged dumping activities indicated that the drums were dumped prior to the addition of other fill materials. In addition, materials alleged to have been dumped in the ditch, such as buried roofing materials, roof flashing, metal pins, tar substances, fly ash, and concrete rubble complicated data interpretation. Some clean fill materials have been placed over the site and graded. This is an environment that is extremely complicated in terms of past waste dumping activities, construction practices and miscellaneous landfill operations. The combination of site knowledge gained from interviews and research of existing site maps, variable frequency EM data, classical total magnetic field data and optimized GPR lead to success where a simpler less focused approach by other investigators using EM-31 and EM-61 electromagnetic methods and unfocused ground penetrating radar (GPR)did not produce results and defined no real anomalies. A variable frequency electromagnetic conductivity unit was used to collect the EM data at 3,030 Hz, 5,070 Hz, 8,430 Hz, and 14,010 Hz. Both in-phase and quadrature components were recorded at each station point. These results provided depth estimates for targets and some information on the subsurface conditions. A standard magnetometer was used to conduct the magnetic survey that showed the locations and extent of buried metal, the approximate volume of ferrous metal present within a particular area, and allowed estimation of approximate target depths. The GPR

  3. TECHNICAL EVALUATION OF TEMPORAL GROUNDWATER MONITORING VARIABILITY IN MW66 AND NEARBY WELLS, PADUCAH GASEOUS DIFFUSION PLANT

    Energy Technology Data Exchange (ETDEWEB)

    Looney, B.; Eddy-Dilek, C.

    2012-08-28

    Evaluation of disposal records, soil data, and spatial/temporal groundwater data from the Paducah Gaseous Diffusion Plant (PGDP) Solid Waste Management Unit (SWMU) 7 indicate that the peak contaminant concentrations measured in monitoring well (MW) 66 result from the influence of the regional PGDP NW Plume, and does not support the presence of significant vertical transport from local contaminant sources in SWMU 7. This updated evaluation supports the 2006 conceptualization which suggested the high and low concentrations in MW66 represent different flow conditions (i.e., local versus regional influences). Incorporation of the additional lines of evidence from data collected since 2006 provide the basis to link high contaminant concentrations in MW66 (peaks) to the regional 'Northwest Plume' and to the upgradient source, specifically, the C400 Building Area. The conceptual model was further refined to demonstrate that groundwater and the various contaminant plumes respond to complex site conditions in predictable ways. This type of conceptualization bounds the expected system behavior and supports development of environmental cleanup strategies, providing a basis to support decisions even if it is not feasible to completely characterize all of the 'complexities' present in the system. We recommend that the site carefully consider the potential impacts to groundwater and contaminant plume migration as they plan and implement onsite production operations, remediation efforts, and reconfiguration activities. For example, this conceptual model suggests that rerouting drainage water, constructing ponds or basin, reconfiguring cooling water systems, capping sites, decommissioning buildings, fixing (or not fixing) water leaks, and other similar actions will potentially have a 'direct' impact on the groundwater contaminant plumes. Our conclusion that the peak concentrations in MW66 are linked to the regional PGDP NW Plume does not imply that

  4. Behavior of critical structures and equipment at 100-N plant during a postulated tornado

    International Nuclear Information System (INIS)

    Davis, H.S.

    1978-01-01

    The objective of this report is to document the results of an analytical study for determining the effects of tornadic wind pressures and missiles on critical structures and equipment at 100-N reactor. These particular structures and equipment are essential for maintaining the reactor in a safe, shutdown condition. The analyses show that structures, systems and components required for safe reactor shutdown and operations of the Emergency Core Cooling System (ECCS) would not be damaged by a 175 mph tornado, nor associated missiles, to the extent that the ECCS would not be able to function adequately

  5. An analysis on human factor issues in criticality accident at a uranium processing plant

    International Nuclear Information System (INIS)

    Sasou, Kunihide; Goda, Hidenori; Hirotsu, Yuko

    2000-01-01

    This report analyses latent factors of a human behavior directly contributing to the criticality accident. It is pouring some 16 kg-U with an enrichment of 18.8% into the precipitation tank. It is the fact that the direct cause of this accident is the workers' unsafe act. However, the authors find lots of latent factors relating to the production-biased company's policy, the poor climate for safety in the work place, the inadequate safety management and the unsuitable equipment. This accident was caused by many organizational factors. This paper also discusses lessons learned from this accident. (author)

  6. Development of Safety-Critical Software for Nuclear Power Plant using a CASE Tool

    International Nuclear Information System (INIS)

    Kim, Chang Ho; Oh, Do Young; Kim, Koh Eun; Choi, Woong Seock; Sohn, Se Do; Kim, Jae Hack; Kim, Hang Bae

    2011-01-01

    The Integrated SOftware Development Environment (ISODE) is developed to provide the major S/W life cycle processes that are composed of development process, V/V process, requirements traceability process, and automated document generation process and target importing process to Programmable Logic Controller (PLC) platform. This provides critical safety software developers with a certified, domain optimized, model-based development environment, and the associated services to reduce time and efforts to develop software such as debugging, simulation, code generation and document generation. This also provides critical safety software verifiers with integrated V/V features of each phase of the software life cycle using appropriate tools such as model test coverage, formal verification, and automated report generation. In addition to development and verification, the ISODE gives a complete traceability solution from the SW design phase to the testing phase. Using this information, the coverage and impact analysis can be done easily whenever software modification is necessary. The final source codes of ISODE are imported into the newly developed PLC environment, as a module based after automatically converted into the format required by PLC. Additional tests for module and unit level are performed on the target platform

  7. The automatic programming for safety-critical software in nuclear power plants

    International Nuclear Information System (INIS)

    Kim, Jang Yeol; Eom, Heung Seop; Choi, You Rark

    1998-06-01

    We defined the Korean unique safety-critical software development methodology by modifying Dr. Harel's statechart-based on formal methods in order to digitalized the reactor protection system. It is suggested software requirement specification guideline to specify design specification which is basis for requirement specification and automatic programming by the caused by shutdown parameter logic of the steam generator water level for Wolsung 2/3/4 unit SDS no.1 and simulated it by binding the Graphic User Interface (GUI). We generated the K and R C code automatically by utilizing the Statemate MAGNUM Sharpshooter/C code generator. Auto-generated K and R C code is machine independent code and has high productivity, quality and provability. The following are the summaries of major research and development. - Set up the Korean unique safety-critical software development methodology - Developed software requirement specification guidelines - Developed software design specification guidelines - Reactor trip modeling for steam generator waster level Wolsung 2/3/4 SDS no. 1 shutdown parameter logic - Graphic panel binding with GUI. (author). 20 refs., 12 tabs., 15 figs

  8. ER network homeostasis is critical for plant endosome streaming and endocytosis

    Science.gov (United States)

    Stefano, Giovanni; Renna, Luciana; Lai, YaShiuan; Slabaugh, Erin; Mannino, Nicole; Buono, Rafael A; Otegui, Marisa S; Brandizzi, Federica

    2015-01-01

    Eukaryotic cells internalize cargo at the plasma membrane via endocytosis, a vital process that is accomplished through a complex network of endosomal organelles. In mammalian cells, the ER is in close association with endosomes and regulates their fission. Nonetheless, the physiological role of such interaction on endocytosis is yet unexplored. Here, we probed the existence of ER–endosome association in plant cells and assayed its physiological role in endocytosis. Through live-cell imaging and electron microscopy studies, we established that endosomes are extensively associated with the plant ER, supporting conservation of interaction between heterotypic organelles in evolutionarily distant kingdoms. Furthermore, by analyzing ER–endosome dynamics in genetic backgrounds with defects in ER structure and movement, we also established that the ER network integrity is necessary for homeostasis of the distribution and streaming of various endosome populations as well as for efficient endocytosis. These results support a novel model that endocytosis homeostasis depends on a spatiotemporal control of the endosome dynamics dictated by the ER membrane network. PMID:27462431

  9. The critical issue of nuclear power plant safety in developing countries

    International Nuclear Information System (INIS)

    Rosen, M.

    1977-01-01

    A little more than a decade from now, large commercial nuclear power facilities will be in operation in almost 40 countries, of which approximately one-half are presently considered industrially less developed. Ambitious nuclear programmes coupled with minimal and frequently under-staffed regulatory and utility organizations are only one aspect of the difficulties related to the safety of nuclear plants that face these developing countries. Inherent problems of meeting current safety standards and requirements for the significantly non-standard nuclear power plant exports can be compounded by financial considerations that may lead to purchases of reactors of various types, from more than one supplier country and with different safety standards and requirements. An examination of these issues points to the necessity and opportunity for effective action which could include provision for adequate funding for safety considerations in the purchase contract, and for sufficient regulatory assistance and training from the developed countries. The article will introduce the topic, discuss specific examples, and offer some suggestions. (author)

  10. New research towards the full comprehension of the critical heat flux in nuclear power plants

    International Nuclear Information System (INIS)

    Garea, V.B.; Bonetto, F.J.; Clausse, A.; Converti, J.

    1990-01-01

    For the nuclear power plants' two-phase flow calculation, two fluid models are typically used. These models have the disadvantage that the number of equations is less than the number of unknown equations, thus the so-called 'closure laws' are required, that is, empirical relations among the variables of the model. In particular, one of the most important relations is the one that gives the specific interface area -the area between the phases by volume unit-. This work describes a method to calculate the boiling interface area from the measurement of the indicating function (that is 0 when fluid exists in the sensitive region of the detector and 1 when gas exists) in a point. (Author) [es

  11. An improved gate valve for critical applications in nuclear power plants

    International Nuclear Information System (INIS)

    Kalsi, M.S.; Alvarez, P.D.; Wang, J.K.; Somagyi, D.

    1996-01-01

    U.S. Nuclear Regulatory Commission Generic Letters 89-10 for motor-operated valves (MOVs) and 95-07 for all power-operated valves document in detail the problems related to the performance of the safety-related valves in nuclear power plants. The problems relate to lack of reliable operation under design basis conditions including higher than anticipated stem thrust, unpredictable valve behavior, damage to the valve internals under blowdown/high flow conditions, significant degradation of performance when cycled under AP and flow, thermal binding, and pressure locking. This paper describes an improved motor-operated flexible wedge gate valve design, the GE Sentinel Valve, which is the outcome of a comprehensive and systematic development effort undertaken to resolve the issues identified in the NRC Generic Letters 89-10 and 95-07. The new design provides a reliable, long-term, low maintenance cost solution to the nuclear power industry. One of the key features incorporated in the disc permits the disc flexibility to be varied independently of the disc thickness (pressure boundary) dictated by the ASME Section III Pressure Vessel ampersand Piping Code stress criteria. This feature allows the desired flexibility to be incorporated in the disc, thus eliminating thermal binding problems. A matrix of analyses was performed using finite element and computational fluid dynamics approaches to optimize design for stresses, flexibility, leak-tightness, fluid flow, and thermal effects. The design of the entire product line was based upon a consistent set of analyses and design rules which permit scaling to different valve sizes and pressure classes within the product line. The valve meets all of the ASME Section III Code design criteria and the N-Stamp requirements. The performance of the valve was validated by performing extensive separate effects and plant in-situ tests. This paper summarizes the key design features, analyses, and test results

  12. An improved gate valve for critical applications in nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Kalsi, M.S.; Alvarez, P.D.; Wang, J.K.; Somagyi, D. [Kalsi Engineering, Inc., Sugar Land, TX (United States)] [and others

    1996-12-01

    U.S. Nuclear Regulatory Commission Generic Letters 89-10 for motor-operated valves (MOVs) and 95-07 for all power-operated valves document in detail the problems related to the performance of the safety-related valves in nuclear power plants. The problems relate to lack of reliable operation under design basis conditions including higher than anticipated stem thrust, unpredictable valve behavior, damage to the valve internals under blowdown/high flow conditions, significant degradation of performance when cycled under AP and flow, thermal binding, and pressure locking. This paper describes an improved motor-operated flexible wedge gate valve design, the GE Sentinel Valve, which is the outcome of a comprehensive and systematic development effort undertaken to resolve the issues identified in the NRC Generic Letters 89-10 and 95-07. The new design provides a reliable, long-term, low maintenance cost solution to the nuclear power industry. One of the key features incorporated in the disc permits the disc flexibility to be varied independently of the disc thickness (pressure boundary) dictated by the ASME Section III Pressure Vessel & Piping Code stress criteria. This feature allows the desired flexibility to be incorporated in the disc, thus eliminating thermal binding problems. A matrix of analyses was performed using finite element and computational fluid dynamics approaches to optimize design for stresses, flexibility, leak-tightness, fluid flow, and thermal effects. The design of the entire product line was based upon a consistent set of analyses and design rules which permit scaling to different valve sizes and pressure classes within the product line. The valve meets all of the ASME Section III Code design criteria and the N-Stamp requirements. The performance of the valve was validated by performing extensive separate effects and plant in-situ tests. This paper summarizes the key design features, analyses, and test results.

  13. Comparison of the method of diffusive gels in thin films with conventional extraction techniques for evaluating zinc accumulation in plants and isopods

    International Nuclear Information System (INIS)

    Koster, Marijke; Reijnders, Lucas; Oost, Nathalie R. van; Peijnenburg, Willie J.G.M.

    2005-01-01

    The measurement of diffusive gels in thin films (DGT) has recently been developed to assess metal bioavailability in soils. The DGT-method is based on diffusion in a porous matrix. To test the predictive capabilities of the method with regard to metal bioavailability, a study was set up with 28 soils having a variety of textures and amounts of zinc salts added. Correlation and regression analyses were performed to compare DGT-extracted zinc levels to zinc concentrations obtained by extraction with 0.01 M CaCl 2 and 0.43 M HNO 3 , digestion with aqua regia and the zinc concentration in pore water. The amount of zinc extracted with CaCl 2 correlated well with DGT-extracted zinc levels in all soils spiked with different amounts of ZnCl 2 . A similar correlation was not found for zinc concentrations in soil samples collected in the field. Experiments were performed to compare zinc content in organisms and in soils. The organisms tested were plants (grass, lettuce and lupine) and the hard bodied soil dwelling isopod Oniscus asellus. Good correlations were found between zinc accumulation in grass and lettuce and the C E (effective concentration) measured by a DGT-device, CaCl 2 extracted zinc and the zinc content in the pore water of all soils. The correlation with C E was not significant for lupine, neither for spiked soils, nor for field soils (p ≤ 0.001). Zinc levels in the isopods were not significantly related to any set of zinc measurements. From a synthesis of all results obtained it is concluded that the DGT-methodology does not have an additional value in predicting bioavailability of zinc in terrestrial ecosystems as compared to conventional extraction methods. - Capsule: The newly developed method of diffusive gels in Thin films (DGT) does not have an added value over conventional extraction techniques in predicting zinc uptake by plants and isopods

  14. Influence of Diffuse Radiation and Its Timescale Effects on Gross Primary Productivity in a Mid-subtropical Planted Coniferous Forest Ecosystem.

    Science.gov (United States)

    Han, J.; Zhang, L.; Li, S.

    2017-12-01

    The mid-subtropical forests in East Asia monsoon zone act as an important carbon sink. Planted coniferous forests are important vegetation types in this area. However, we lack an in-depth understanding of both controlling mechanisms of environmental and biotic factors in gross primary productivity (GPP) and their timescale effects. Based on eddy covariance carbon flux data and micro-meteorological data (2003-2015) observed at a mid-subtropical planted coniferous forest in Qianyanzhou, along with leaf area index derived from MODIS products, we used the path analysis mothed to quantify standardized total effects (STE) of environmental factors on GPP and their variabilities at different timescales. We found that GPP was mainly affected by photosynthetically active radiation (PAR) at half-hour scale. Furthermore, GPP under cloudy weather conditions was greater than under sunny weather conditions across seasons. From daily to yearly scales, PAR had the positive STE with GPP, but such STE was gradually reduced toward yearly scale; diffuse radiation or air temperature had the positive STE with GPP at daily and monthly scales, while negative STE occurred at seasonal and yearly scales. Vapor pressure deficit exhibited the negative STE with GPP at all timescales, and such STE increased gradually toward the yearly scale. Therefore, on one hand, GPP was controlled by light conditions, but on the other hand, high air temperature in summer and water availability had a significant restraining effect over GPP, and such effect increased with the timescales from day to year. Based on the simulation results by the light use efficiency (LUE) model, it indicated that modelled GPP agreed well with the measurements when the influence of the seasonal variations of LUE and diffuse radiation were incorporated into the model, especially at the yearly scale. This further indicated that diffuse radiation, together with changes in air temperature and water supply, had a significant effect on

  15. Computer simulation of nuclear pollutant diffusion from Shimane nuclear power plants and development of an evacuation strategy in the event of a nuclear incident

    International Nuclear Information System (INIS)

    Yakura, Haruna; Kurimasa, Akihiro

    2012-01-01

    Beginning from Tohoku (northeastern) Earthquake on March 11, an accident at the Fukushima Dai-ichi Nuclear Power Plant resulted in a substantial release of radioactivity to the environment. The accident forced a large number of residents to evacuate from surrounding areas. Moreover, the nuclear incident was life-threatening for the elderly and for people with serious illnesses who were confined in hospital or nursing homes. Strikingly, the causes of death were not directly attributed to radiation exposure but to problems encountered during evacuation. Using nuclear diffusion data from the Fukushima incident, we simulated nuclear pollutant dispersion using computer software A2C in an area of Tottori and Shimane Prefectures surrounding the Shimane Nuclear Power Plant. We generated a model for the spread of nuclear pollutants around the Emergency Planning Zone, id est (i.e.) EPZ. From these findings, we proposed evacuation strategies for residents near the power plant to ensure a safe and reliable escape from nuclear pollutants. Our recommendations include: immediate evacuation from PAZ area (within 5 km), securing indoor shelter in the area of the UPZ (from 5 km to 30 km) and preparations to evacuate further outwards from the nuclear plant site, daytime evacuation within a 30 km area after considering wind direction and velocity, and preparation of a planned evacuation strategy that identifies secure facilities for weaker people in the event of a disaster. (author)

  16. Critical Review on the Significance of Olive Phytochemicals in Plant Physiology and Human Health

    Directory of Open Access Journals (Sweden)

    Irene Gouvinhas

    2017-11-01

    Full Text Available Olive oil displays remarkable organoleptic and nutritional features, which turn it into a foodstuff appreciated by consumers, and a basic component of the Mediterranean diet. Indeed, the noticed benefits of including olive oil in the diet have been assigned to the presence of diverse bioactive compounds with different molecular structures. These compounds confer a wide range of biological properties to this food matrix, including the prevention of distinct human diseases as well as the modulation of their severity. The most relevant bioactive compounds present in olive oil correspond to benzoic and cinnamic acids, phenolic alcohols and secoiridoids, and also flavonoids. Over the last decades, several studies, devoted to gaining a further insight into the relative contribution of the separate groups and individual compounds for their biological activities, have been conducted, providing relevant information on structure–activity relationships. Therefore, this paper critically reviews the health benefits evidenced by distinct phenolic compounds found in olive oils, thus contributing to clarify the relationship between their chemical structures and biological functions, further supporting their interest as essential ingredients of wholesome foods.

  17. Critical Review on the Significance of Olive Phytochemicals in Plant Physiology and Human Health.

    Science.gov (United States)

    Gouvinhas, Irene; Machado, Nelson; Sobreira, Carla; Domínguez-Perles, Raúl; Gomes, Sónia; Rosa, Eduardo; Barros, Ana I R N A

    2017-11-16

    Olive oil displays remarkable organoleptic and nutritional features, which turn it into a foodstuff appreciated by consumers, and a basic component of the Mediterranean diet. Indeed, the noticed benefits of including olive oil in the diet have been assigned to the presence of diverse bioactive compounds with different molecular structures. These compounds confer a wide range of biological properties to this food matrix, including the prevention of distinct human diseases as well as the modulation of their severity. The most relevant bioactive compounds present in olive oil correspond to benzoic and cinnamic acids, phenolic alcohols and secoiridoids, and also flavonoids. Over the last decades, several studies, devoted to gaining a further insight into the relative contribution of the separate groups and individual compounds for their biological activities, have been conducted, providing relevant information on structure-activity relationships. Therefore, this paper critically reviews the health benefits evidenced by distinct phenolic compounds found in olive oils, thus contributing to clarify the relationship between their chemical structures and biological functions, further supporting their interest as essential ingredients of wholesome foods.

  18. Quantitative safety goals for nuclear power plants: critical review and reformulation within a unified theory

    International Nuclear Information System (INIS)

    Munera, H.A.; Yadigaroglu, G.

    1988-01-01

    The first part of the paper critically reviews some of the adopted and/or proposed probabilistic safety goals and criteria in several countries. Some of the difficulties identified are:- Lack of an adequate delimitation of the scope of the non-deterministic choice problem. Consequently, the main components of the problem-probabilities and consequences-are not clearly defined. As a further consequence there is no unified treatment, including notation and terminology, for concepts like risk, probability, frequency, utility, risk-aversion, limit-line, etc. - The theoretical justifications and/or implications of limit-lines are not always fully understood. As a result three very different classes of limit-lines have emerged. The theoretical limitations of limit-lines are not always fully realized, leading to an over-emphasis in that approach and thus preventing the development of alternative methodologies. In the second part of the paper theoretical methods are indicated to compare probability distributions already existing in other disciplines, and a unified methodology to formulate probabilistic safety criteria is briefly described. The proposed theory gives due consideration to the whole probability distribution, and contains both limit-line concepts and global risk indices. The latter can easily incorporate regulatory and/or societal value-judgements, for instance risk-aversion. (author)

  19. A basis for standardized seismic design (SSD) for nuclear power plants/critical facilities

    International Nuclear Information System (INIS)

    O'Hara, T.F.; Jacobson, J.P.; Bellini, F.X.

    1991-01-01

    US Nuclear Power Plants (NPP's) are designed, engineered and constructed to stringent standards. Their seismic adequacy is assured by compliance with regulatory standards and demonstrated by both probabilistic risk assessments (PRAs) and seismic margin studies. However, present seismic siting criteria requires improvement. Proposed changes to siting criteria discussed here will provide a predictable licensing process and a stable regulatory environment. Two recent state-of-the-art studies evaluate the seismic design for all eastern US (EUS) NPP'S: a Lawrence Livermore National Labs study (LLNL, 1989) funded by the NRC and similar research by the Electric Power Research Institute (EPRI, 1989) supported by the utilities. Both confirm that Appendix A 10CFR Part 100 has not provided consistent seismic design levels for all sites. Standardized Seismic Design (SSD) uses a probabilistic framework to accommodate alternative deterministic interpretations. It uses seismic hazard input from EPRI or LLNL to produce consistent bases for future seismic design. SSD combines deterministic and probabilistic insights to provide a comprehensive approach for determining a future site's acceptable seismic design basis

  20. A status review on the pharmacological implications of Artemisia absinthium: A critically endangered plant

    Directory of Open Access Journals (Sweden)

    Mubashir Hussain

    2017-03-01

    Full Text Available Medicinal plants are the nature’s gift for the humanity to treat various diseases and to spend a prosperous healthy life. There are almost 500 species of Artemisia. Among them, Artemisia absinthium (A. absinthium which is commonly known as wormwood is a well-known herb. It is mentioned in almost all the herbal medicinal books of the Western world. The aim of this review article is to gather information about A. absinthium which is currently scattered in form of various publications. Through this review article tried to attract the attention of people for therapeutic potential of A. absinthium. The present review comprises upto date information of active ingredients, up and down in absinthe, controversy, essential oil, traditional uses, in vitro production of secondary metabolites for pharmaceutical, pharmacology such as antitumor, neurotoxic, neuroprotective, hepatoprotective, antimalarial, anthelminitc, antipyretic, antidepressant, antiulcer, antioxidant, antibacterial, antiprotozoal and challenges of A. absinthium. Some progress has been made, but still consistent efforts are required to explore the individual compounds isolated from A. absinthium to validate and understand its traditional uses and clinical practices. This review article provides preliminary information and gives a direction for the basic and clinical research on A. absinthium (wormwood.

  1. Anti-nuclear activities and critics concerning nuclear power plant sites

    International Nuclear Information System (INIS)

    Rhee, We-Beg

    2000-01-01

    Korea has dynamic nuclear power expansion programs, operating 16 nuclear units producing 13710 MW in total located on 4 different sites. Last year, nuclear power supplied over 40 % of national total electricity demands. In 1998, Korean government initiated re-designation work investigating circumstance changes to rule out the unnecessary sites in consideration of a long-term power supply. Korean government has determined to expand the Ulchin site and to designate one point of Woolju county as a new candidate site, and ruled out the rest candidate sites at the end of 1998. About such a governmental measure, the two areas show different reactions. Ulchin where nuclear power plant has been operated safely for about 10 years was likely to accept the governmental determination in spite of some opposition and called for several financial supports for local development. WooIju county, however, showed a strong opposition among local environmental groups and autonomous politicians, and they presented a variety of anti-nuclear activities including demonstrations mainly at the neighbouring metropolis, Ulsan city

  2. A study on the monitoring of the success path performance for maintaining critical safety function in nuclear power plant

    International Nuclear Information System (INIS)

    Kang, S. K.; Sin, Y. C.

    2002-01-01

    In this paper, we analyzed and suggested the period and the criteria of the evaluation about the performance of the success path system for maintaining critical safety function for CFM/SPM design. Each system of the success path peculiarly needs to have different evaluation period for checking the performance of the success path according to the original function of the success path system, also, we reviewed the needs of evaluation about the performance of the success path in the course of both emergency operation and normal operation. We practically reviewed and analyzed the start time of performance evaluation and evaluation criteria based on the YGN 3 and 4 RAT, EOP and FRP. Also, we reviewed the evaluation criteria of the performance for success path system through the experience of the plant operation

  3. Criticality and shielding calculations of an interim dry storage system for the spent fuel from Atucha I Nuclear Power Plant

    International Nuclear Information System (INIS)

    Silva, M

    2006-01-01

    The Atucha I Nuclear Power Plant (CNA-I) has enough room to store its spent fuel (SF) in damp in its two pool houses until the middle of 2015.Before that date there is the need to have an interim dry storage system for spent fuel that would make possible to empty at least one of the pools, whether to keep the plant operating if its useful life is extended, or to be able to empty the reactor core in case of decommissioning.Nucleolectrica Argentina S.A. (NA-SA) and the Comision Nacional de Energia Atomica (CNEA), due to their joint responsibility in the management of the SF, have proposed interim dry storage systems.These systems have to be evaluated in order to choose one of them by the end of 2006.In this work the Monte Carlo code MCNP was used to make the criticality and shielding calculations corresponding to the model proposed by CNEA.This model suggests the store of sealed containers with 36 or 37 SF in concrete modules.Each one of the containers is filled in the pool houses and transported to the module in a transference cask with lead walls.The results of the criticality calculations indicates that the solutions of SF proposed have widely fulfilled the requirements of subcriticality, even in supposed extreme accidental situations.Regarding the transference cask, the SF dose rate estimations allow us to make a feedback for the design aiming to the geometry and shielding improvements.Regarding the store modules, thicknesses ranges of concrete walls are suggested in order to fulfill the dose requirements stated by the Autoridad Regulatoria Nuclear Argentina [es

  4. Wind friction parametrisation used in emission models for wastewater treatment plants: A critical review.

    Science.gov (United States)

    Prata, Ademir A; Santos, Jane M; Timchenko, Victoria; Reis, Neyval C; Stuetz, Richard M

    2017-11-01

    Emission models are widely applied tools for estimating atmospheric emissions from wastewater treatment plants (WWTPs). The friction velocity u ∗ is a key variable for the modelling of emissions from passive liquid surfaces in WWTPs. This work evaluated different parametrisations of u ∗ for passive liquid surfaces at the scale of WWTP units, which present relatively small fetches, based on available wind friction and wave data measured at wind-wave tanks (fetches spanning from approximately 3 to 100 m, and wind speeds from 2 to 17 m s -1 ). The empirical correlation by Smith (1980; J. Phys. Oceanogr. 10, 709-726), which has been frequently adopted in air emission models (despite the fact that it was originally derived for the ocean) presented a general tendency to overestimate u ∗ , with significant (although not extreme) relative errors (mean and maximum errors of 13.5% and 36.6%, respectively); the use of Charnock's relation, with Charnock constant 0.010, performed in a very similar manner (mean and maximum errors of 13.3% and 37.8%, respectively). Better estimates of u ∗ were achieved by parametrisations based on the significant wave steepness. Simplified correlations between the wind drag and the non-dimensional fetch were obtained. An approach was devised, comprising the use of Charnock's relation (with Charnock constant 0.010) and of these simplified correlations, depending on the ranges of frequency of the peak waves, fetch and wind speed. The proposed approach predicted u ∗ with improved accuracy (mean, maximum and 95%-percentile relative errors of 6.6%, 16.7% and 13.9%, respectively), besides being able to incorporate the influence of the fetch in the wind drag, thus taking into account the size of the tanks in the WWTPs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. A framework for the system-of-systems analysis of the risk for a safety-critical plant exposed to external events

    International Nuclear Information System (INIS)

    Zio, E.; Ferrario, E.

    2013-01-01

    We consider a critical plant exposed to risk from external events. We propose an original framework of analysis, which extends the boundaries of the study to the interdependent infrastructures which support the plant. For the purpose of clearly illustrating the conceptual framework of system-of-systems analysis, we work out a case study of seismic risk for a nuclear power plant embedded in the connected power and water distribution, and transportation networks which support its operation. The technical details of the systems considered (including the nuclear power plant) are highly simplified, in order to preserve the purpose of illustrating the conceptual, methodological framework of analysis. Yet, as an example of the approaches that can be used to perform the analysis within the proposed framework, we consider the Muir Web as system analysis tool to build the system-of-systems model and Monte Carlo simulation for the quantitative evaluation of the model. The numerical exercise, albeit performed on a simplified case study, serves the purpose of showing the opportunity of accounting for the contribution of the interdependent infrastructure systems to the safety of a critical plant. This is relevant as it can lead to considerations with respect to the decision making related to safety critical-issues. -- Highlights: ► We consider a critical plant exposed to risk from external events. ► We consider also the interdependent infrastructures that support the plant. ► We use Muir Web as system analysis tool to build the system-of-systems model. ► We use Monte Carlo simulation for the quantitative evaluation of the model. ► We find that the interdependent infrastructures should be considered as they can be a support for the critical plant safety

  6. Can the critical temperature for photochemical damage in common bean plants be changed after a drought event?

    Directory of Open Access Journals (Sweden)

    Rafael Vasconcelos Ribeiro

    2015-08-01

    Full Text Available Low water availability and high temperatures occur under field conditions and we hypothesize that the critical temperature for photochemical damage (TC in common bean (Phaseolus vulgaris L. plants is increased by the occurrence of previous water deficit in a genotype-dependent manner. Five common bean cultivars A320, A222, Carioca, BAT477 and Ouro Negro were evaluated. Thirty days after seedlings emergence, one group of plants was exposed to water deficit for ten days and rehydrated and another one was maintained well hydrated during the experimental period. The minimum chlorophyll fluorescence (FO was monitored in leaf discs exposed to temperatures ranging from 25 to 45 oC and the TC values estimated. The previous water deficit did not affect TC, which varied between 38.8 and 43.8 oC when considering all cultivars and water regimes. Under well-watered conditions, BAT477 (41.9 oC and Carioca (43.8 oC presented higher TCthan Ouro Negro (38.8 oC. Our findings indicate a significant genotypic variation in thermal tolerance in Phaseolus vulgaris, an important crop trait to be considered in breeding programs.

  7. Autoclave nuclear criticality safety analysis

    Energy Technology Data Exchange (ETDEWEB)

    D`Aquila, D.M. [Martin Marietta Energy Systems, Inc., Piketon, OH (United States); Tayloe, R.W. Jr. [Battelle, Columbus, OH (United States)

    1991-12-31

    Steam-heated autoclaves are used in gaseous diffusion uranium enrichment plants to heat large cylinders of UF{sub 6}. Nuclear criticality safety for these autoclaves is evaluated. To enhance criticality safety, systems are incorporated into the design of autoclaves to limit the amount of water present. These safety systems also increase the likelihood that any UF{sub 6} inadvertently released from a cylinder into an autoclave is not released to the environment. Up to 140 pounds of water can be held up in large autoclaves. This mass of water is sufficient to support a nuclear criticality when optimally combined with 125 pounds of UF{sub 6} enriched to 5 percent U{sup 235}. However, water in autoclaves is widely dispersed as condensed droplets and vapor, and is extremely unlikely to form a critical configuration with released UF{sub 6}.

  8. Optimizing the models for rapid determination of chlorogenic acid, scopoletin and rutin in plant samples by near-infrared diffuse reflectance spectroscopy

    Science.gov (United States)

    Mao, Zhiyi; Shan, Ruifeng; Wang, Jiajun; Cai, Wensheng; Shao, Xueguang

    2014-07-01

    Polyphenols in plant samples have been extensively studied because phenolic compounds are ubiquitous in plants and can be used as antioxidants in promoting human health. A method for rapid determination of three phenolic compounds (chlorogenic acid, scopoletin and rutin) in plant samples using near-infrared diffuse reflectance spectroscopy (NIRDRS) is studied in this work. Partial least squares (PLS) regression was used for building the calibration models, and the effects of spectral preprocessing and variable selection on the models are investigated for optimization of the models. The results show that individual spectral preprocessing and variable selection has no or slight influence on the models, but the combination of the techniques can significantly improve the models. The combination of continuous wavelet transform (CWT) for removing the variant background, multiplicative scatter correction (MSC) for correcting the scattering effect and randomization test (RT) for selecting the informative variables was found to be the best way for building the optimal models. For validation of the models, the polyphenol contents in an independent sample set were predicted. The correlation coefficients between the predicted values and the contents determined by high performance liquid chromatography (HPLC) analysis are as high as 0.964, 0.948 and 0.934 for chlorogenic acid, scopoletin and rutin, respectively.

  9. Where AD plants wildly grow: The spatio-temporal diffusion of agricultural biogas production in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Martinát, Stanislav; Navrátil, J.; Dvořák, Petr; Van der Horst, D.; Klusáček, Petr; Kunc, Josef; Frantál, Bohumil

    2016-01-01

    Roč. 95, September 2016 (2016), s. 85-97 ISSN 0960-1481 Institutional support: RVO:68145535 Keywords : agricultural anaerobic digestion plants * Czech Republic * spatial determinants * Spatial analysis Subject RIV: DE - Earth Magnetism, Geodesy, Geography Impact factor: 4.357, year: 2016 http://www.sciencedirect.com/science/article/pii/S0960148116302610

  10. Diffusion tensor imaging (DTI) findings in adult civilian, military, and sport-related mild traumatic brain injury (mTBI): a systematic critical review.

    Science.gov (United States)

    Asken, Breton Michael; DeKosky, Steven T; Clugston, James R; Jaffee, Michael S; Bauer, Russell M

    2018-04-01

    This review seeks to summarize diffusion tensor imaging (DTI) studies that have evaluated structural changes attributed to the mechanisms of mild traumatic brain injury (mTBI) in adult civilian, military, and athlete populations. Articles from 2002 to 2016 were retrieved from PubMed/MEDLINE, EBSCOhost, and Google Scholar, using a Boolean search string containing the following terms: "diffusion tensor imaging", "diffusion imaging", "DTI", "white matter", "concussion", "mild traumatic brain injury", "mTBI", "traumatic brain injury", and "TBI". We added studies not identified by this method that were found via manually-searched reference lists. We identified 86 eligible studies from English-language journals using, adult, human samples. Studies were evaluated based on duration between injury and DTI assessment, categorized as acute, subacute/chronic, remote mTBI, and repetitive brain trauma considerations. Since changes in brain structure after mTBI can also be affected by other co-occurring medical and demographic factors, we also briefly review DTI studies that have addressed socioeconomic status factors (SES), major depressive disorder (MDD), and attention-deficit hyperactivity disorder (ADHD). The review describes population-specific risks and the complications of clinical versus pathophysiological outcomes of mTBI. We had anticipated that the distinct population groups (civilian, military, and athlete) would require separate consideration, and various aspects of the study characteristics supported this. In general, study results suggested widespread but inconsistent differences in white matter diffusion metrics (primarily fractional anisotropy [FA], mean diffusivity [MD], radial diffusivity [RD], and axial diffusivity [AD]) following mTBI/concussion. Inspection of study designs and results revealed potential explanations for discrepant DTI findings, such as control group variability, analytic techniques, the manner in which regional differences were reported, and

  11. Domain decomposition methods for the mixed dual formulation of the critical neutron diffusion problem; Methodes de decomposition de domaine pour la formulation mixte duale du probleme critique de la diffusion des neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Guerin, P

    2007-12-15

    The neutronic simulation of a nuclear reactor core is performed using the neutron transport equation, and leads to an eigenvalue problem in the steady-state case. Among the deterministic resolution methods, diffusion approximation is often used. For this problem, the MINOS solver based on a mixed dual finite element method has shown his efficiency. In order to take advantage of parallel computers, and to reduce the computing time and the local memory requirement, we propose in this dissertation two domain decomposition methods for the resolution of the mixed dual form of the eigenvalue neutron diffusion problem. The first approach is a component mode synthesis method on overlapping sub-domains. Several Eigenmodes solutions of a local problem solved by MINOS on each sub-domain are taken as basis functions used for the resolution of the global problem on the whole domain. The second approach is a modified iterative Schwarz algorithm based on non-overlapping domain decomposition with Robin interface conditions. At each iteration, the problem is solved on each sub domain by MINOS with the interface conditions deduced from the solutions on the adjacent sub-domains at the previous iteration. The iterations allow the simultaneous convergence of the domain decomposition and the eigenvalue problem. We demonstrate the accuracy and the efficiency in parallel of these two methods with numerical results for the diffusion model on realistic 2- and 3-dimensional cores. (author)

  12. Field evaluation of a horizontal well recirculation system for groundwater treatment: Pilot test at the Clean Test Site Portsmouth Gaseous Diffusion Plant, Piketon, Ohio

    International Nuclear Information System (INIS)

    Muck, M.T.; Kearl, P.M.; Siegrist, R.L.

    1998-01-01

    This report presents the results of field testing a horizontal well recirculation system at the Portsmouth Gaseous Diffusion Plant (PORTS). The recirculation system uses a pair of horizontal wells, one for groundwater extraction and treatment and the other for reinjection of treated groundwater, to set up a recirculation flow field. The induced flow field from the injection well to the extraction well establishes a sweeping action for the removal and treatment of groundwater contaminants. The overall purpose of this project is to study treatment of mixed groundwater contaminants that occur in a thin water-bearing zone not easily targeted by traditional vertical wells. The project involves several research elements, including treatment-process evaluation, hydrodynamic flow and transport modeling, pilot testing at an uncontaminated site, and pilot testing at a contaminated site. The results of the pilot test at an uncontaminated site, the Clean Test Site (CTS), are presented in this report

  13. Determination of the safety zones of Angra dos Reis Nuclear Power Plant, according to the model of radion diffusion in the atmosphere

    International Nuclear Information System (INIS)

    Santina, M.D.

    1978-01-01

    The safety distance for Angra dos Reis Nuclear Power Plant are calculated, based on the model of the maximum credible accident for PWR power reactors and on the calculation of the dose due to hypothetical accidental release of radioactivity, using the model of radiation dispersion in the atmosphere. The safety distances for the Angra dos Reis reactors are also calculated using the model of the nine accident categories of the Rasmussen Report. The values of probability associated to each type of accident are used with the respective fractions of radiation release to the atmosphere. The soil contamination is also calculated for all the accidents considered and for several conditions of atmospheric stability, according to the model developed by Chamberlain. The program ACRA-II is used for calculation of the diffusion of radiation in the atmosphere, and the doses associated to it [pt

  14. Potential Hazards Relating to Pyrolysis of c-C4F8O, n-C4F10 and c-C4F8 in selected gaseous diffusion plant operations

    International Nuclear Information System (INIS)

    Trowbridge, L.D.

    2000-01-01

    As part of a program intended to replace the present evaporative coolant at the gaseous diffusion plants (GDPs) with a non-ozone-depleting alternate, a series of investigations of the suitability of candidate substitutes is under way. This report summarizes studies directed at estimating the chemical and thermal stability of three candidate coolants, c-C 4 F 8 O, n-C 4 F 10 and c-C 4 4F 8 , in a few specific environments to be found in gaseous diffusion plant operations

  15. Criticality accident in uranium fuel processing plant. Emergency medical care and dose estimation for the severely overexposed patients

    Energy Technology Data Exchange (ETDEWEB)

    Akashi, Makoto; Ishigure, Nobuhito [National Inst. of Radiological Sciences, Chiba (Japan)

    2000-08-01

    A criticality accident occurred in JCO, a plant for nuclear fuel production in 1999 and three workers were exposed to extremely high-level radiation (neutron and {gamma}-ray). This report describes outlines of the clinical courses and the medical cares for the patients of this accident and the emergent medical system for radiation accident in Japan. One (A) of the three workers of JCO had vomiting and diarrhea within several minutes after the accident and another one (B) had also vomiting within one hour after. Based on these evidences, the exposure dose of A and B were estimated to be more than 8 and 4 GyEq, respectively. Generally, acute radiation syndrome (ARS) is assigned into three phases; prodromal phase, critical or manifestation phase and recovery phase or death. In the prodromal phase, anorexia, nausea, vomiting and diarrhea often develop, whereas the second phase is asymptotic. In the third phase, various syndromes including infection, hemorrhage, dehydration shock and neurotic syndromes are apt to occur. It is known that radiation exposure at 1 Gy or more might induce such acute radiation syndromes. Based on the clinical findings of Chernobyl accident, it has been thought that exposure at 0.5 Gy or more causes a lowering of lymphocyte level and a decrease in immunological activities within 48 hours. Lymphocyte count is available as an indicator for the evaluation of exposure dose in early phase, but not in later phase The three workers of JCO underwent chemical analysis of blood components, chromosomal analysis and analysis of blood {sup 24}Na immediately after the arrival at National Institute of Radiological Sciences via National Mito Hospital specified as the third and the second facility for the emergency medical care system in Japan, respectively. (M.N.)

  16. Application of Integrated Verification Approach to FPGA-based Safety-Critical I and C System of Nuclear Power Plant

    International Nuclear Information System (INIS)

    Ahmed, Ibrahim; Heo, Gyunyoung; Jung, Jaecheon

    2016-01-01

    Safety-critical instrumentation and control (I and C) system in nuclear power plant (NPP) implemented on programmable logic controllers (PLCs) plays a vital role in safe operation of the plant. The challenges such as fast obsolescence, the vulnerability to cyber-attack, and other related issues of software systems have currently led to the consideration of field programmable gate arrays (FPGAs) as an alternative to PLCs because of their advantages and hardware related benefits. Generally in FPGA design verification, the designers make use of verification techniques by writing the test benches which involved various stages of verification activities of register-transfer level (RTL), gate-level, and place and route. Writing the test benches is considerably time consuming and require a lot of efforts to achieve a satisfied desire results. Furthermore, performing the verification at each stage is a major bottleneck and demanded much activities and time. In addition, verification is conceivably, the most difficult and complicated aspect of any design. Therefore, in view of these, this work applied an integrated verification approach to the verification of FPGA-based I and C system in NPP that simultaneously verified the whole design modules using MATLAB/Simulink HDL Co-simulation models. Verification is conceivably, the most difficult and complicated aspect of any design, and an FPGA design is not an exception. Therefore, in this work, we introduced and discussed how an application of integrated verification technique to the verification and testing of FPGA-based I and C system design in NPP can facilitate the verification processes, and verify the entire design modules of the system simultaneously using MATLAB/Simulink HDL co-simulation models. In conclusion, the results showed that, the integrated verification approach through MATLAB/Simulink models, if applied to any design to be verified, could speed up the design verification and reduce the V and V tasks

  17. Application of Integrated Verification Approach to FPGA-based Safety-Critical I and C System of Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Ibrahim; Heo, Gyunyoung [Kyunghee Univ., Yongin (Korea, Republic of); Jung, Jaecheon [KEPCO, Ulsan (Korea, Republic of)

    2016-10-15

    Safety-critical instrumentation and control (I and C) system in nuclear power plant (NPP) implemented on programmable logic controllers (PLCs) plays a vital role in safe operation of the plant. The challenges such as fast obsolescence, the vulnerability to cyber-attack, and other related issues of software systems have currently led to the consideration of field programmable gate arrays (FPGAs) as an alternative to PLCs because of their advantages and hardware related benefits. Generally in FPGA design verification, the designers make use of verification techniques by writing the test benches which involved various stages of verification activities of register-transfer level (RTL), gate-level, and place and route. Writing the test benches is considerably time consuming and require a lot of efforts to achieve a satisfied desire results. Furthermore, performing the verification at each stage is a major bottleneck and demanded much activities and time. In addition, verification is conceivably, the most difficult and complicated aspect of any design. Therefore, in view of these, this work applied an integrated verification approach to the verification of FPGA-based I and C system in NPP that simultaneously verified the whole design modules using MATLAB/Simulink HDL Co-simulation models. Verification is conceivably, the most difficult and complicated aspect of any design, and an FPGA design is not an exception. Therefore, in this work, we introduced and discussed how an application of integrated verification technique to the verification and testing of FPGA-based I and C system design in NPP can facilitate the verification processes, and verify the entire design modules of the system simultaneously using MATLAB/Simulink HDL co-simulation models. In conclusion, the results showed that, the integrated verification approach through MATLAB/Simulink models, if applied to any design to be verified, could speed up the design verification and reduce the V and V tasks.

  18. Critical rearing parameters of Tetrastichus planipennisi (Hymenoptera: Eulophidae) as affected by host plant substrate and host-parasitoid group structure.

    Science.gov (United States)

    Duan, Jian J; Oppel, Craig

    2012-06-01

    In laboratory assays, we evaluated the potential impact of host plant substrate types, host-parasitoid group sizes (densities), and parasitoid-to-host ratios on select fitness parameters of the larval endoparasitoid Tetrastichus planipennisi Yang (Hymenoptera: Eulophidae), newly introduced for biological control of emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), in the United States. Results from our study showed that offspring production and critical fitness parameters (body size and sex ratio) of T. planipennisi from parasitized emerald ash borer larvae are significantly influenced by host plant substrate type, host-parasitoid group size, parasitoid-to-host ratio, or a combination in the primary exposure assay. The number of both female and male T. planipennisi progeny was significantly greater when emerald ash borer larvae were inserted into tropical ash [Fraxinus uhdei (Wenz.) Lingelsh.] logs rather than green ash (Fraxinus pensylvanica Marshall). When maintained at a constant 1:1 parasitoid-to-host ratio, assays with larger host-parasitoid group sizes (3:3-12:12) produced significantly greater numbers of both male and female offspring per parental wasp compared with those with the single host-parasitoid (1:1) group treatment. As the parasitoid-to-host ratio increased from 1:1 to 8:1 in the assay, the average brood size (number of offspring per parasitized emerald ash borer larva) increased significantly, whereas the average brood sex ratio (female to male) changed from being female-biased (6:1) to male-biased (1:2); body size of female offspring as measured by the length of ovipositor and left hind tibia also was reduced significantly. Based on these findings, we suggest that the current method of rearing T. planipennisi with artificially infested-emerald ash borer larvae use the tropical ash logs for emerald ash borer insertion, a larger (> or = 3:3) host-parasitoid group size and 1:1 parasitoid-to-host ratio in the primary

  19. Comparison of the method of diffusive gels in thin films with conventional extraction techniques for evaluating zinc accumulation in plants and isopods

    Energy Technology Data Exchange (ETDEWEB)

    Koster, Marijke [National Institute of Public Health and the Environment, Laboratory for Ecological Risk Assessment, P.O. Box 1, 3720 BA Bilthoven (Netherlands); Open University Netherlands, Heerlen (Netherlands); Reijnders, Lucas [Open University Netherlands, Heerlen (Netherlands); Oost, Nathalie R. van [National Institute of Public Health and the Environment, Laboratory for Ecological Risk Assessment, P.O. Box 1, 3720 BA Bilthoven (Netherlands); Peijnenburg, Willie J.G.M. [National Institute of Public Health and the Environment, Laboratory for Ecological Risk Assessment, P.O. Box 1, 3720 BA Bilthoven (Netherlands)]. E-mail: wjgm.peijnenburg@rivm.nl

    2005-01-01

    The measurement of diffusive gels in thin films (DGT) has recently been developed to assess metal bioavailability in soils. The DGT-method is based on diffusion in a porous matrix. To test the predictive capabilities of the method with regard to metal bioavailability, a study was set up with 28 soils having a variety of textures and amounts of zinc salts added. Correlation and regression analyses were performed to compare DGT-extracted zinc levels to zinc concentrations obtained by extraction with 0.01 M CaCl{sub 2} and 0.43 M HNO{sub 3}, digestion with aqua regia and the zinc concentration in pore water. The amount of zinc extracted with CaCl{sub 2} correlated well with DGT-extracted zinc levels in all soils spiked with different amounts of ZnCl{sub 2}. A similar correlation was not found for zinc concentrations in soil samples collected in the field. Experiments were performed to compare zinc content in organisms and in soils. The organisms tested were plants (grass, lettuce and lupine) and the hard bodied soil dwelling isopod Oniscus asellus. Good correlations were found between zinc accumulation in grass and lettuce and the C{sub E} (effective concentration) measured by a DGT-device, CaCl{sub 2} extracted zinc and the zinc content in the pore water of all soils. The correlation with C{sub E} was not significant for lupine, neither for spiked soils, nor for field soils (p {<=} 0.001). Zinc levels in the isopods were not significantly related to any set of zinc measurements. From a synthesis of all results obtained it is concluded that the DGT-methodology does not have an additional value in predicting bioavailability of zinc in terrestrial ecosystems as compared to conventional extraction methods. - Capsule: The newly developed method of diffusive gels in Thin films (DGT) does not have an added value over conventional extraction techniques in predicting zinc uptake by plants and isopods.

  20. Diffusion of the biogas technology into Switzerland: a GIS-based multiagent simulation; Diffusion der Biogastechnologie in der Schweiz: eine GIS-basierte Multiagenten-Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, Christian [Campana und Schott Realisierungsmanagement Schweiz AG, Zuerich (Switzerland); Madlener, Reinhard [Lehrstuhl fuer Wirtschaftswissenschaften insb. Energieoekonomik, Inst. for Future Energy Consumer Needs and Behavior (FCN), Fakultaet fuer Wirtschaftswissenschaften/E.ON Energy Research Center, RWTH Aachen (Germany)

    2008-12-15

    In this article we introduce a GIS-based multi-agent simulation model. It is used to study the spatial diffusion dynamics of agricultural biogas plants in Switzerland, which lags markedly behind those in the neighboring countries Austria and Germany. The investigation concentrates in particular on the impacts of economic factors and of locally available resources on the diffusion process. The model considers three different types of plants (100 kW{sub el}, 200 kW{sub el}, 1 MW{sub el}). The results show that feed-in tariffs, cosubstrate prices and the revenues from heat sales are critical parameters. They indicate further that the present promotion policy fosters smaller plants, whereas larger plants are preferred only in few areas with high substrate densities. Finally, we find evidence that increased heat sales can significantly raise diffusion dynamics, and that the higher feed-in tariffs planned in Switzerland could actually overcompensate deteriorating cosubstrate prices. (orig.)

  1. [Simultaneous determination of instant coffee, plant fat and sugar content in liquid coffee beverage by diffuse reflectance near-infrared spectroscopy].

    Science.gov (United States)

    Wang, Dong; Min, Shun-geng; Duan, Jia; Xiong, Yan-mei; Li, Qian-qian

    2012-04-01

    The diffuse reflectance near-infrared spectra of 20 liquid coffee beverage samples were collected by FT-NIR spectrometer combined with integral sphere in this thesis. The quantitative calibration models of instant coffee, plant fat and sugar were developed respectively. The result indicated that for the calibration models of instant coffee, plant fat and sugar, the dimensions of the calibration models are 4, 5 and 4 respectively; the determination coefficients (R2) are 98.97%, 99.94% and 99.18% respectively; the root mean square errors of calibration (RMSEC) are 1.62, 0.42 and 1.58 respectively; the root mean square errors of cross validation (RMSECV) are 2.12, 0.72 and 2.01 respectively. The result of F-test showed that a very remarkable correlation exists between the estimated and specified values for each calibration model. This research indicated that NIR spectroscopy can be applied in the rapid, accurate and simultaneous determination of the three main ingredients in liquid coffee beverage. This research can provide some references for the quality control of liquid coffee beverage and the determination of the substance with chemical-fixation composition in liquid formula food.

  2. Applicable or relevant and appropriate requirements (ARARs) for remedial actions at the Paducah Gaseous Diffusion Plant: A compendium of environmental laws and guidance. Environmental Restoration Program

    Energy Technology Data Exchange (ETDEWEB)

    Etnier, E.L.; Eaton, L.A. [Oak Ridge National Lab., TN (United States)

    1992-03-01

    Section 121 of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980 specifies that remedial actions for cleanup of hazardous substances found at sites placed on the National Priorities List (NPL) by the US Environmental Protection Agency (EPA) must comply with applicable or relevant and appropriate requirements (ARARs) or standards under federal and state environmental laws. To date, the US Department of Energy (DOE) Paducah Gaseous Diffusion Plant (PGDP) has not been on the NPL. Although DOE and EPA have entered into an Administrative Consent Order (ACO), the prime regulatory authority for cleanup at PGDP will be the Resource Conservation and Recovery Act (RCRA). This report supplies a preliminary list of available federal and state ARARs that might be considered for remedial response at PGDP in the event that the plant becomes included on the NPL or the ACO is modified to include CERCLA cleanup. A description of the terms ``applicable`` and ``relevant and appropriate`` is provided, as well as definitions of chemical-, location-, and action-specific ARARS. ARARs promulgated by the federal government and by the state of Kentucky are listed in tables. In addition, the major provisions of RCRA, the Safe Drinking Water Act, the Clean Water Act, the Clean Air Act, and other acts, as they apply to hazardous and radioactive waste cleanup, are discussed.

  3. Applicable or relevant and appropriate requirements (ARARs) for remedial actions at the Paducah Gaseous Diffusion Plant: A compendium of environmental laws and guidance

    Energy Technology Data Exchange (ETDEWEB)

    Etnier, E.L.; Eaton, L.A. (Oak Ridge National Lab., TN (United States))

    1992-03-01

    Section 121 of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980 specifies that remedial actions for cleanup of hazardous substances found at sites placed on the National Priorities List (NPL) by the US Environmental Protection Agency (EPA) must comply with applicable or relevant and appropriate requirements (ARARs) or standards under federal and state environmental laws. To date, the US Department of Energy (DOE) Paducah Gaseous Diffusion Plant (PGDP) has not been on the NPL. Although DOE and EPA have entered into an Administrative Consent Order (ACO), the prime regulatory authority for cleanup at PGDP will be the Resource Conservation and Recovery Act (RCRA). This report supplies a preliminary list of available federal and state ARARs that might be considered for remedial response at PGDP in the event that the plant becomes included on the NPL or the ACO is modified to include CERCLA cleanup. A description of the terms applicable'' and relevant and appropriate'' is provided, as well as definitions of chemical-, location-, and action-specific ARARS. ARARs promulgated by the federal government and by the state of Kentucky are listed in tables. In addition, the major provisions of RCRA, the Safe Drinking Water Act, the Clean Water Act, the Clean Air Act, and other acts, as they apply to hazardous and radioactive waste cleanup, are discussed.

  4. Applicable or relevant and appropriate requirements (ARARs) for remedial actions at the Paducah Gaseous Diffusion Plant: A compendium of environmental laws and guidance

    International Nuclear Information System (INIS)

    Etnier, E.L.; Eaton, L.A.

    1992-03-01

    Section 121 of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980 specifies that remedial actions for cleanup of hazardous substances found at sites placed on the National Priorities List (NPL) by the US Environmental Protection Agency (EPA) must comply with applicable or relevant and appropriate requirements (ARARs) or standards under federal and state environmental laws. To date, the US Department of Energy (DOE) Paducah Gaseous Diffusion Plant (PGDP) has not been on the NPL. Although DOE and EPA have entered into an Administrative Consent Order (ACO), the prime regulatory authority for cleanup at PGDP will be the Resource Conservation and Recovery Act (RCRA). This report supplies a preliminary list of available federal and state ARARs that might be considered for remedial response at PGDP in the event that the plant becomes included on the NPL or the ACO is modified to include CERCLA cleanup. A description of the terms ''applicable'' and ''relevant and appropriate'' is provided, as well as definitions of chemical-, location-, and action-specific ARARS. ARARs promulgated by the federal government and by the state of Kentucky are listed in tables. In addition, the major provisions of RCRA, the Safe Drinking Water Act, the Clean Water Act, the Clean Air Act, and other acts, as they apply to hazardous and radioactive waste cleanup, are discussed

  5. Environmental surveillance of the US Department of Energy Portsmouth Gaseous Diffusion Plant and surrounding environs during 1986: Volume 4

    International Nuclear Information System (INIS)

    Oakes, T.W.; Wiehle, W.E.; Valentine, B.L.

    1987-04-01

    This report provides monitoring data for the installation and surrounding environs that may have been affected by operations on the plant site; provides detailed information about the installation; provides detailed information on input and assumption used in all calculations; integrates monitoring data and related studies in one document to pull together, highlight, and summarize the information contained in many documents; provides trend analyses, where possible, to indicate increases and decreases in environmental conditions; and provides general information on the plant site and quality assurance. Routine monitoring and sampling for radiation, radioactive materials, and chemical substances on and off the DOE reservation and PORTS are used to document compliance with appropriate standards, identify trends, provide information for the public, and contribute to general environmental knowledge. The surveillance program assists in fulfilling the DOE policy of protecting the public, employees, and the environment from harm that could be caused by its activities and reducing negative environmental impacts to the greatest degree practicable. Environmental monitoring information complements data on specific releases, trends, and summaries. 68 refs., 203 figs., 112 tabs

  6. Germination Ecology and Seed Dispersal of a Critically Endangered Plant: A Case Study of Pomaderris vacciniifolia (Round-Leaf Pomaderris).

    Science.gov (United States)

    Patykowski, John; Dell, Matthew; Gibson, Maria

    2016-01-01

    Change in ecosystem disturbance regimes from human land-use poses a worldwide problem for management of rare species. Two important types of disturbance influencing the persistence of species in Australian ecosystems are habitat fragmentation and fire. In this study, seed dispersal and the germination ecology of Pomaderris vacciniifolia-a critically endangered, rare endemic Australian shrub-were examined to identify likely influences of fire and fragmentation on the decline of populations. The response of seed germination to simulated effects of wildfire and canopy openings was investigated, as was the unaided dispersal capability of seeds from parent plants. A significant increase in germination rate was observed following 100°C heat treatment to seeds, while smoke and light exposure had little influence. Seed imbibition was strongly influenced by heat treatment. The findings indicate a likely positive post-fire germination response, with implications for recruitment success determined by moisture availability following fire. Unaided seed dispersal was limited, which partly explains the apparent decline of populations. Understanding disturbance requirements for threatened species, and subsequent management of landscapes for disturbance, will aid conservation of rare species throughout the world.

  7. Germination Ecology and Seed Dispersal of a Critically Endangered Plant: A Case Study of Pomaderris vacciniifolia (Round-Leaf Pomaderris.

    Directory of Open Access Journals (Sweden)

    John Patykowski

    Full Text Available Change in ecosystem disturbance regimes from human land-use poses a worldwide problem for management of rare species. Two important types of disturbance influencing the persistence of species in Australian ecosystems are habitat fragmentation and fire. In this study, seed dispersal and the germination ecology of Pomaderris vacciniifolia-a critically endangered, rare endemic Australian shrub-were examined to identify likely influences of fire and fragmentation on the decline of populations. The response of seed germination to simulated effects of wildfire and canopy openings was investigated, as was the unaided dispersal capability of seeds from parent plants. A significant increase in germination rate was observed following 100°C heat treatment to seeds, while smoke and light exposure had little influence. Seed imbibition was strongly influenced by heat treatment. The findings indicate a likely positive post-fire germination response, with implications for recruitment success determined by moisture availability following fire. Unaided seed dispersal was limited, which partly explains the apparent decline of populations. Understanding disturbance requirements for threatened species, and subsequent management of landscapes for disturbance, will aid conservation of rare species throughout the world.

  8. Germination Ecology and Seed Dispersal of a Critically Endangered Plant: A Case Study of Pomaderris vacciniifolia (Round-Leaf Pomaderris)

    Science.gov (United States)

    Dell, Matthew; Gibson, Maria

    2016-01-01

    Change in ecosystem disturbance regimes from human land-use poses a worldwide problem for management of rare species. Two important types of disturbance influencing the persistence of species in Australian ecosystems are habitat fragmentation and fire. In this study, seed dispersal and the germination ecology of Pomaderris vacciniifolia—a critically endangered, rare endemic Australian shrub—were examined to identify likely influences of fire and fragmentation on the decline of populations. The response of seed germination to simulated effects of wildfire and canopy openings was investigated, as was the unaided dispersal capability of seeds from parent plants. A significant increase in germination rate was observed following 100°C heat treatment to seeds, while smoke and light exposure had little influence. Seed imbibition was strongly influenced by heat treatment. The findings indicate a likely positive post-fire germination response, with implications for recruitment success determined by moisture availability following fire. Unaided seed dispersal was limited, which partly explains the apparent decline of populations. Understanding disturbance requirements for threatened species, and subsequent management of landscapes for disturbance, will aid conservation of rare species throughout the world. PMID:27557152

  9. Apoplastic Diffusion Barriers in Arabidopsis

    Science.gov (United States)

    Schreiber, Lukas; Franke, Rochus Benni; Geldner, Niko; Reina-Pinto, José J.; Kunst, Ljerka

    2013-01-01

    During the development of Arabidopsis and other land plants, diffusion barriers are formed in the apoplast of specialized tissues within a variety of plant organs. While the cuticle of the epidermis is the primary diffusion barrier in the shoot, the Casparian strips and suberin lamellae of the endodermis and the periderm represent the diffusion barriers in the root. Different classes of molecules contribute to the formation of extracellular diffusion barriers in an organ- and tissue-specific manner. Cutin and wax are the major components of the cuticle, lignin forms the early Casparian strip, and suberin is deposited in the stage II endodermis and the periderm. The current status of our understanding of the relationships between the chemical structure, ultrastructure and physiological functions of plant diffusion barriers is discussed. Specific aspects of the synthesis of diffusion barrier components and protocols that can be used for the assessment of barrier function and important barrier properties are also presented. PMID:24465172

  10. Assessing saffron (Crocus sativus L.) adulteration with plant-derived adulterants by diffuse reflectance infrared Fourier transform spectroscopy coupled with chemometrics.

    Science.gov (United States)

    Petrakis, Eleftherios A; Polissiou, Moschos G

    2017-01-01

    Saffron, the dried red stigmas of the plant Crocus sativus L., is well-known as one of the most important and expensive spices worldwide. It is thus highly susceptible to fraudulent practices that employ, among others, plant-derived adulterants. This study presents an application of diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and chemometric techniques for evaluating adulteration of saffron with six characteristic adulterants of plant origin, i.e. C. sativus stamens, calendula, safflower, turmeric, buddleja, and gardenia. The proposed method involved a three-step process for the detection of adulteration as well as for the identification and quantification of adulterants. Partial least squares discriminant analysis (PLS-DA) was applied to perform authentication of saffron based on mid-infrared fingerprints (4000-600cm -1 ), resulting in 99% correct classification of pure saffron and saffron adulterated at 5-20% (w/w) levels. Adulterant identification in positive samples was performed with high sensitivity and specificity by a six-class PLS-DA model, with spectroscopic data from the region 2000-600cm -1 . Subsequently, partial least squares (PLS) regression models were built for the quantification of each adulterant. By using synergy interval PLS (siPLS) for variable selection, models with improved performance were developed, with detection limits ranging from 1.0% to 3.1% (w/w). The results obtained illustrate that this strategy based on DRIFTS has the potential to complement existing methodologies for the rapid and cost-effective assessment of typical saffron frauds. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Assessment of the Plutonium Finishing Plant Criticality Alarm System U.S. Department of Energy Richland Operations Office

    International Nuclear Information System (INIS)

    NIRIDER, L.T.

    2002-01-01

    At the request of the Assistant Manager for Safety and Engineering, the U.S. Department of Energy Richland Operations Office (RL) Engineering Support Division, performed an oversight review of the Plutonium Finishing Plant (PFP) nuclear Criticality Alarm System (CAS). The review was conducted to satisfy requirements and agreements associated with Defense Nuclear Facility Safety Board (DNFSB) Recommendation 2000-2, ''Vital Safety Systems.'' The PFP is managed by Fluor Hanford, Inc. for RL. The field assessment and staff interviews were conducted August 12 through August 19,2002. This was a limited scope assessment that consisted of a review of the nuclear CAS operations, maintenance, and compliance with National Consensus Standards Requirements. The main purpose of the assessment was to determine the adequacy of the existing alarm system and its associated infrastructure to support the PFP facility mission through the remaining facility lifetime. The Review Plan was modeled upon Criteria and Review Approach Documents (CRAD) developed for DNFSB Recommendation 2000-2 reviews conducted across the Hanford Site. Concerns regarding component degradation and failure, increasing numbers of occurrence reports associated with the alarm system, and reliability issues were addressed. Additionally, RL performed a review of the engineering aspects of the CAS including the functions of design authorities and aspects of systems engineering. However, the focus of the assessment was on operations, maintenance, and reliability of the CAS, associated procurement practices, adequacy of safety and engineering policies and procedures, safety documentation, and fundamental engineering practices including training, qualification, and systems engineering. This assessment revealed that the PFP CAS and its associated infrastructure, administrative procedures, and conduct of operations are generally effective. There are no imminent criticality safety issues associated with the operation of the

  12. Do We Need Plant Food Supplements? A Critical Examination of Quality, Safety, Efficacy, and Necessity for a New Regulatory Framework.

    Science.gov (United States)

    Abdel-Tawab, Mona

    2017-12-08

    Given the expanding market of plant food supplements (PFSs) not undergoing any pre-marketing authorization, the overall quality, safety and efficacy of PFSs were subjected to a critical examination. Although many high-quality PFSs exist on the legal market, quality concerns are in general justified. Besides economic adulteration, active ingredients dramatically differing from label claims and among products were reported in several studies. In addition, PFSs sold via the Internet may be intentionally adulterated with undeclared prescription drugs. Compared to PFSs with only one single herb, PFSs containing herbal mixtures were more involved in moderate and severe clinical courses. Although prohibited by regulation, misleading labels on PFSs are common. Above all, only vague evidence for the efficacy of PFSs exists. Notwithstanding the unproven efficacy and insufficient safety assessment, PFSs represent a relevant source for consumers to get access to herbal preparations in the United States and meanwhile also in Europe, as launching of licensed/registered European herbal medicinal products (HMPs) has steadily decreased. However, being non-vitamin, non-mineral products, PFSs are neither food nor drugs. In terms of protecting public health and providing the consumer with high-quality, effective, and safe PFSs, possibilities are shown how to deal with the many challenges of PFSs. Last but not least, suggestions are made for assigning PFSs a separate regulatory category being less regulated compared to HMPs but more strictly regulated compared to food laws including implementation of good manufacturing practices and a scientific pre-marketing review process by an expert commission. Georg Thieme Verlag KG Stuttgart · New York.

  13. Environmental site description for a Uranium Atomic Vapor Laser Isotope Separation (U-AVLIS) production plant at the Oak Ridge Gaseous Diffusion Plant Site

    Energy Technology Data Exchange (ETDEWEB)

    1991-09-01

    In January 1990, the Secretary of Energy approved a plan for the demonstration and deployment of the Uranium Atomic Vapor Laser Isotope Separation (U-AVLIS) technology, with the near-term goal to provide the necessary information to make a deployment decision by November 1992. The U-AVLIS process is based on electrostatic extraction of photoionized U-235 atoms from an atomic vapor stream created by electron-beam vaporization of uranium metal alloy. A programmatic document for use in screening DOE sites to locate the U-AVLIS production plant was developed and implemented in two parts (Wolsko et al. 1991). The first part consisted of a series of screening analyses, based on exclusionary and other criteria, that identified a reasonable number of candidate sites. These sites were then subjected to a more rigorous and detailed comparative analysis for the purpose of developing a short list of reasonable alternative sites for later environmental examination. This environmental site description (ESD) provides a detailed description of the ORGDP site and vicinity suitable for use in an environmental impact statement (EIS). The report is based on existing literature, data collected at the site, and information collected by Argonne National Laboratory (ANL) staff during a site visit. The organization of the ESD is as follows. Topics addressed in Sec. 2 include a general site description and the disciplines of geology, water resources, biotic resources, air resources, noise, cultural resources, land use, socioeconomics, and waste management. Identification of any additional data that would be required for an EIS is presented in Sec. 3. Following the site description and additional data requirements, Sec. 4 provides a short, qualitative assessment of potential environmental issues. 37 refs., 20 figs., 18 tabs.

  14. Environmental site description for a Uranium Atomic Vapor Laser Isotope Separation (U-AVLIS) production plant at the Oak Ridge Gaseous Diffusion Plant Site

    International Nuclear Information System (INIS)

    1991-09-01

    In January 1990, the Secretary of Energy approved a plan for the demonstration and deployment of the Uranium Atomic Vapor Laser Isotope Separation (U-AVLIS) technology, with the near-term goal to provide the necessary information to make a deployment decision by November 1992. The U-AVLIS process is based on electrostatic extraction of photoionized U-235 atoms from an atomic vapor stream created by electron-beam vaporization of uranium metal alloy. A programmatic document for use in screening DOE sites to locate the U-AVLIS production plant was developed and implemented in two parts (Wolsko et al. 1991). The first part consisted of a series of screening analyses, based on exclusionary and other criteria, that identified a reasonable number of candidate sites. These sites were then subjected to a more rigorous and detailed comparative analysis for the purpose of developing a short list of reasonable alternative sites for later environmental examination. This environmental site description (ESD) provides a detailed description of the ORGDP site and vicinity suitable for use in an environmental impact statement (EIS). The report is based on existing literature, data collected at the site, and information collected by Argonne National Laboratory (ANL) staff during a site visit. The organization of the ESD is as follows. Topics addressed in Sec. 2 include a general site description and the disciplines of geology, water resources, biotic resources, air resources, noise, cultural resources, land use, socioeconomics, and waste management. Identification of any additional data that would be required for an EIS is presented in Sec. 3. Following the site description and additional data requirements, Sec. 4 provides a short, qualitative assessment of potential environmental issues. 37 refs., 20 figs., 18 tabs

  15. Evaluation of alternatives for best available technology treatment and retreatment of uranium-contaminated wastewater at the Paducah Gaseous Diffusion Plant C-400 Facility

    International Nuclear Information System (INIS)

    Del Cul, G.D.; Osborne, P.E.; Beck, D.E.

    1991-01-01

    The Paducah Gaseous Diffusion Plant (PGDP) C-400 Decontamination Facility generates aqueous solutions that originate in drum washing, machine parts and equipment cleaning, and other decontamination processes. The chemical composition of the waste depends on the particular operation involved. In general, the waste contains uranyl, fluoride, carbonate, and nitrate ions, plus soaps, detergents, secondary contaminants, and particulate matter. The uranium content is rather variable ranging between 0.5 and 30 g/l. The main contaminants are fluoride, technetium, uranium, and other heavy metals. The plan included (1) a literature search to support best available technology (BAT) evaluation of treatment alternatives, (2) a quality assurance/quality control plan, (3) suggestion of alternative treatment options, (4) bench-scale tests studies of the proposed treatment alternatives, and (5) establishment of the final recommendation. The following report records the evaluation of items (1) to (3) of the action plan for the BAT evaluation of alternatives for the treatment and retreatment of uranium-contaminated wastewater at the PGDP C-400 treatment facility. After a thorough literature search, five major technologies were considered: (1) precipitation/coprecipitation, (2) reverse osmosis, (3) ultrafiltration, (4) supported liquid membranes, and (5) ion exchange. Biosorption was also considered, but as it is a fairly new technology with few demonstrations of its capabilities, it is mentioned only briefly in the report. Based on C-400's requirements and facilities, the precipitation/coprecipitation process appears to be the best suited for use at the plant. Four different treatment options using the precipitation/coprecipitation technology are proposed. Bench-scale studies of the four options are suggested. 37 refs

  16. Verification experiment on the downblending of high enriched uranium (HEU) at the Portsmouth Gaseous Diffusion Plant. Digital video surveillance of the HEU feed stations

    International Nuclear Information System (INIS)

    Martinez, R.L.; Tolk, K.; Whiting, N.; Castleberry, K.; Lenarduzzi, R.

    1998-01-01

    As part of a Safeguards Agreement between the US and the International Atomic Energy Agency (IAEA), the Portsmouth Gaseous Diffusion Plant, Piketon, Ohio, was added to the list of facilities eligible for the application of IAEA safeguards. Currently, the facility is in the process of downblending excess inventory of HEU to low enriched uranium (LEU) from US defense related programs for commercial use. An agreement was reached between the US and the IAEA that would allow the IAEA to conduct an independent verification experiment at the Portsmouth facility, resulting in the confirmation that the HEU was in fact downblended. The experiment provided an opportunity for the DOE laboratories to recommend solutions/measures for new IAEA safeguards applications. One of the measures recommended by Sandia National Laboratories (SNL), and selected by the IAEA, was a digital video surveillance system for monitoring activity at the HEU feed stations. This paper describes the SNL implementation of the digital video system and its integration with the Load Cell Based Weighing System (LCBWS) from Oak Ridge National Laboratory (ORNL). The implementation was based on commercially available technology that also satisfied IAEA criteria for tamper protection and data authentication. The core of the Portsmouth digital video surveillance system was based on two Digital Camera Modules (DMC-14) from Neumann Consultants, Germany

  17. Modification and expansion of X-7725A Waste Accountability Facility for storage of polychlorinated biphenyl wastes at Portsmouth Gaseous Diffusion Plant, Piketon, Ohio

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-11-01

    The US Department of Energy (DOE) must manage wastes containing polychlorinated biphenyls (PCBs) in accordance with Toxic Substances Control Act (TSCA) requirements and as prescribed in a Federal Facilities Compliance Agreement (FFCA) between DOE and the U.S. Environmental Protection Agency (EPA). PCB-containing wastes are currently stored in the PORTS process buildings where they are generated. DOE proposes to modify and expand the Waste Accountability facility (X-7725A) at the Portsmouth Gaseous Diffusion Plant (PORTS), Piketon, Ohio, to provide a central storage location for these wastes. The proposed action is needed to eliminate the fire and safety hazards presented by the wastes. In this EA, DOE considers four alternatives: (1) no action, which requires storing wastes in limited storage areas in existing facilities; (2) modifying and expanding the X-7725A waste accountability facility; (3) constructing a new PCB waste storage building; and (4) shipping PCB wastes to the K-25 TSCA incinerator. If no action is taken, PCB-contaminated would continue to be stored in Bldgs X-326, X-330, and X-333. As TSCA cleanup activities continue, the quantity of stored waste would increase, which would subsequently cause congestion in the three process buildings and increase fire and safety hazards. The preferred alternative is to modify and expand Bldg. X-7725A to store wastes generated by TSCA compliance activities. Construction, which could begin as early as April 1996, would last approximately five to seven months, with a total peak work force of 70.

  18. Modification and expansion of X-7725A Waste Accountability Facility for storage of polychlorinated biphenyl wastes at Portsmouth Gaseous Diffusion Plant, Piketon, Ohio

    International Nuclear Information System (INIS)

    1995-11-01

    The US Department of Energy (DOE) must manage wastes containing polychlorinated biphenyls (PCBs) in accordance with Toxic Substances Control Act (TSCA) requirements and as prescribed in a Federal Facilities Compliance Agreement (FFCA) between DOE and the U.S. Environmental Protection Agency (EPA). PCB-containing wastes are currently stored in the PORTS process buildings where they are generated. DOE proposes to modify and expand the Waste Accountability facility (X-7725A) at the Portsmouth Gaseous Diffusion Plant (PORTS), Piketon, Ohio, to provide a central storage location for these wastes. The proposed action is needed to eliminate the fire and safety hazards presented by the wastes. In this EA, DOE considers four alternatives: (1) no action, which requires storing wastes in limited storage areas in existing facilities; (2) modifying and expanding the X-7725A waste accountability facility; (3) constructing a new PCB waste storage building; and (4) shipping PCB wastes to the K-25 TSCA incinerator. If no action is taken, PCB-contaminated would continue to be stored in Bldgs X-326, X-330, and X-333. As TSCA cleanup activities continue, the quantity of stored waste would increase, which would subsequently cause congestion in the three process buildings and increase fire and safety hazards. The preferred alternative is to modify and expand Bldg. X-7725A to store wastes generated by TSCA compliance activities. Construction, which could begin as early as April 1996, would last approximately five to seven months, with a total peak work force of 70

  19. Applicable or relevant and appropriate requirements (ARARs) for remedial actions at the Portsmouth Gaseous Diffusion Plant: A compendium of environmental laws and guidance

    International Nuclear Information System (INIS)

    Houlberg, L.M.; Eaton, L.A.; Martin, J.A.; McDonald, E.P.; Etnier, E.L.

    1992-02-01

    Section 121 of the Comprehensive Environmental Response, Compensation, and Liability Act of 1990 (CERCLA) specifies that remedial actions for cleanup of hazardous substances must comply with applicable or relevant and appropriate requirements (ARARs) or standards under federal and state environmental laws. Although the US Department of Energy (DOE) Portsmouth Gaseous Diffusion Plant (PORTS) has not at this time been proposed for inclusion on the US Environmental Protection Agency National Priorities List, under Sect. I of an administrative consent order signed by DOE and the US Environmental Protection Agency on September 29, 1989, effective October 4, 1989, any necessary response actions at PORTS stipulated in the administrative consent order must be performed in a manner consistent with the Resource Conservation and Recovery Act of 1976 and CERCLA. Section 121 of CERCLA calls for the preparation of a draft listing of all ARARs. This report supplies a preliminary list of available federal and state ARARs that might be considered for remedial response at PORTS. A description of the terms ''applicable'' and ''relevant and appropriate'' is provided, as well as definitions of chemical-, location-, and action-specific ARARs. ARARs promulgated by the federal government and by the state of Ohio are listed in tables. In addition, the major provisions of the Resource Conservation and Recovery Act, Safe Drinking Water Act, Clean Water Act, and other acts, as they apply to hazardous waste cleanup, are discussed

  20. Dual wall reverse circulation drilling with multi-level groundwater sampling for groundwater contaminant plume delineation at Paducah Gaseous Diffusion Plant, Paducah, Kentucky

    International Nuclear Information System (INIS)

    Smuin, D.R.; Morti, E.E.; Zutman, J.L.; Pickering, D.A.

    1995-01-01

    Dual wall reverse circulation (DWRC) drilling was used to drill 48 borings during a groundwater contaminant investigation at the Paducah Gaseous Diffusion Plant, Paducah, Kentucky. This method was selected as an alternative to conventional hollow stem auger drilling for a number of reasons, including the expectation of minimizing waste, increasing the drilling rate, and reducing the potential for cross contamination of aquifers. Groundwater samples were collected from several water-bearing zones during drilling of each borehole. The samples were analyzed for volatile organic compounds using a field gas chromatograph. This approach allowed the investigation to be directed using near-real-time data. Use of downhole geophysical logging, in conjunction with lithologic descriptions of borehole cuttings, resulted in excellent correlation of the geology in the vicinity of the contaminant plume. The total volume of cuttings generated using the DWRC drilling method was less than half of what would have been produced by hollow stem augering; however, the cuttings were recovered in slurry form and had to be dewatered prior to disposal. The drilling rate was very rapid, often approaching 10 ft/min; however, frequent breaks to perform groundwater sampling resulted in an average drilling rate of < 1 ft/min. The time required for groundwater sampling could be shortened by changing the sampling methodology. Analytical results indicated that the drilling method successfully isolated the various water bearing zones and no cross contamination resulted from the investigation

  1. Thermal Discharges from Paducah Gaseous Diffusion Plant Outfalls: Impacts on Stream Temperatures and Fauna of Little Bayou and Big Bayou Creeks

    International Nuclear Information System (INIS)

    Roy, W.K.

    1999-01-01

    The development of a biological monitoring plan for the receiving streams of the Paducah Gaseous Diffusion Plant (PGDP) began in the late 1980s, because of an Agreed Order (AO) issued in September 1987 by the Kentucky Division of Water (KDOW). Five years later, in September 1992, more stringent effluent limitations were imposed upon the PGDP operations when the KDOW reissued Kentucky Pollutant Discharge Elimination System permit No. KY 0004049. This action prompted the US Department of Energy (DOE) to request a stay of certain limits contained in the permit. An AO is being negotiated between KDOW, the United States Enrichment Corporation (USEC), and DOE that will require that several studies be conducted, including this stream temperature evaluation study, in an effort to establish permit limitations. All issues associated with this AO have been resolved, and the AO is currently being signed by all parties involved. The proposed effluent temperature limit is 89 F (31.7C) as a mean monthly temperature. In the interim, temperatures are not to exceed 95 F (35 C) as a monthly mean or 100 F (37.8 C) as a daily maximum. This study includes detailed monitoring of instream temperatures, benthic macroinvertebrate communities, fish communities, and a laboratory study of thermal tolerances

  2. Potential Hazards Relating to Pyrolysis of c-C{sub 4}F{sub 8} in Selected Gaseous Diffusion Plant Operations

    Energy Technology Data Exchange (ETDEWEB)

    Trowbridge, L.D.

    1999-03-01

    As part of a program intended to replace the present evaporative coolant at the gaseous diffusion plants (GDPs) with a non-ozone-depleting alternate, a series of investigations of the suitability of candidate substitutes in under way. One issue concerning a primary candidate, c-C4F8, is the possibility that it might produce the highly toxic perfluoroisobutylene (PFIB) in high temperature environments. This study was commissioned to determine the likelihood and severity of decomposition under two specific high temperature thermal environments, namely the use of a flame test for the presence of coolant vapors and welding in the presence of coolant vapors. The purpose of the study was to develop and evaluate available data to provide information that will allow the technical and industrial hygiene staff at the GDPs to perform appropriate safety evaluations and to determine the need for field testing or experimental work. The scope of this study included a literature search and an evaluation of the information developed therefrom. Part of that evaluation consists of chemical kinetics modeling of coolant decomposition in the two operational environments. The general conclusions are that PFIB formation is unlikely in either situation but that it cannot be ruled out completely under extreme conditions. The presence of oxygen, moisture, and combustion products will tend to lead to formation of oxidation products (COF2, CO, CO2, and HF) rather than PFIB.

  3. Thermal discharges from Paducah Gaseous Diffusion Plant outfalls: Impacts on stream temperatures and fauna of Little Bayou and Big Bayou Creeks

    International Nuclear Information System (INIS)

    Roy, W.K.; Ryon, M.G.; Hinzman, R.L.

    1996-03-01

    The development of a biological monitoring plan for the receiving streams of the Paducah Gaseous Diffusion Plant (PGDP) began in the late 1980s, because of an Agreed Order (AO) issued in September 1987 by the Kentucky Division of Water (KDOW). Five years later, in September 1992, more stringent effluent limitations were imposed upon the PGDP operations when the KDOW reissued Kentucky Pollutant Discharge Elimination System permit No. KY 0004049. This action prompted the US Department of Energy (DOE) to request a stay of certain limits contained in the permit. An AO is being negotiated between KDOW, the US Enrichment Corporation (USEC), and DOE that will require that several studies be conducted, including this stream temperature evaluation study, in an effort to establish permit limitations. All issues associated with this AO have been resolved, and the AO is currently being signed by all parties involved. The proposed effluent temperature limit is 89 F (31.7 C) as a mean monthly temperature. In the interim, temperatures are not to exceed 95 F (35 C) as a monthly mean or 100 F (37.8 C) as a daily maximum. This study includes detailed monitoring of instream temperatures, benthic macroinvertebrate communities, fish communities, and a laboratory study of thermal tolerances

  4. Thermal Discharges from Paducah Gaseous Diffusion Plant Outfalls: Impacts on Stream Temperatures and Fauna of Little Bayou and Big Bayou Creeks

    Energy Technology Data Exchange (ETDEWEB)

    Roy, W.K.

    1999-01-01

    The development of a biological monitoring plan for the receiving streams of the Paducah Gaseous Diffusion Plant (PGDP) began in the late 1980s, because of an Agreed Order (AO) issued in September 1987 by the Kentucky Division of Water (KDOW). Five years later, in September 1992, more stringent effluent limitations were imposed upon the PGDP operations when the KDOW reissued Kentucky Pollutant Discharge Elimination System permit No. KY 0004049. This action prompted the US Department of Energy (DOE) to request a stay of certain limits contained in the permit. An AO is being negotiated between KDOW, the United States Enrichment Corporation (USEC), and DOE that will require that several studies be conducted, including this stream temperature evaluation study, in an effort to establish permit limitations. All issues associated with this AO have been resolved, and the AO is currently being signed by all parties involved. The proposed effluent temperature limit is 89 F (31.7C) as a mean monthly temperature. In the interim, temperatures are not to exceed 95 F (35 C) as a monthly mean or 100 F (37.8 C) as a daily maximum. This study includes detailed monitoring of instream temperatures, benthic macroinvertebrate communities, fish communities, and a laboratory study of thermal tolerances.

  5. Thermal discharges from Paducah Gaseous Diffusion Plant outfalls: Impacts on stream temperatures and fauna of Little Bayou and Big Bayou Creeks

    Energy Technology Data Exchange (ETDEWEB)

    Roy, W.K.; Ryon, M.G.; Hinzman, R.L. [Oak Ridge National Lab., TN (United States). Computer Science and Mathematics Div.

    1996-03-01

    The development of a biological monitoring plan for the receiving streams of the Paducah Gaseous Diffusion Plant (PGDP) began in the late 1980s, because of an Agreed Order (AO) issued in September 1987 by the Kentucky Division of Water (KDOW). Five years later, in September 1992, more stringent effluent limitations were imposed upon the PGDP operations when the KDOW reissued Kentucky Pollutant Discharge Elimination System permit No. KY 0004049. This action prompted the US Department of Energy (DOE) to request a stay of certain limits contained in the permit. An AO is being negotiated between KDOW, the US Enrichment Corporation (USEC), and DOE that will require that several studies be conducted, including this stream temperature evaluation study, in an effort to establish permit limitations. All issues associated with this AO have been resolved, and the AO is currently being signed by all parties involved. The proposed effluent temperature limit is 89 F (31.7 C) as a mean monthly temperature. In the interim, temperatures are not to exceed 95 F (35 C) as a monthly mean or 100 F (37.8 C) as a daily maximum. This study includes detailed monitoring of instream temperatures, benthic macroinvertebrate communities, fish communities, and a laboratory study of thermal tolerances.

  6. Increased Suicide Risk among Workers following Toxic Metal Exposure at the Paducah Gaseous Diffusion Plant From 1952 to 2003: A Cohort Study

    Directory of Open Access Journals (Sweden)

    LW Figgs

    2011-09-01

    Full Text Available Background: Suicide is a problem worldwide and occupation is an important risk factor. In the last decade, 55 200 deaths in the US were attributed to occupational risk factors. Objective: To determine if toxic metal exposure was associated with suicide risk among Paducah gaseous diffusion plant (PGDP workers. Methods: We assembled a cohort of 6820 nuclear industry workers employed from 1952 to 2003. A job-specific exposure matrix (JEM was used to determine metal exposure likelihood. Uranium exposure was also assessed by urinalysis. All suicide/self-injury International Classification for Disease (ICD codes were used to identify suicides. Standardized mortality ratios (SMR, odds ratios (OR, and hazard ratios (HR were used to estimate suicide risk. Results: PGDP suicide victims typically were younger white men. Within exposure likelihood categories, several suicide SMRs were typically elevated for several metals. Only beryllium exposure likelihood was associated with an increased HR. Uranium urine concentration was associated with an elevated suicide risk after stratification by urinalysis frequency. Conclusion: Suicide risk is associated with uranium exposure.

  7. Field evaluation of a horizontal well recirculation system for groundwater treatment: Field demonstration at X-701B Portsmouth Gaseous Diffusion Plant, Piketon, Ohio

    Energy Technology Data Exchange (ETDEWEB)

    Korte, N.; Muck, M.; Kearl, P.; Siegrist, R.; Schlosser, R.; Zutman, J. [Oak Ridge National Lab., TN (United States); Houk, T. [Lockheed Martin Energy Systems, Piketon, OH (United States). Portsmouth Gaseous Diffusion Plant

    1998-08-01

    This report describes the field-scale demonstration performed as part of the project, In Situ Treatment of Mixed Contaminants in Groundwater. This project was a 3{1/2} year effort comprised of laboratory work performed at Oak Ridge National Laboratory and fieldwork performed at the US Department of Energy (DOE) Portsmouth Gaseous Diffusion Plant (PORTS). The overall goal of the project was to evaluate in situ treatment of groundwater using horizontal recirculation coupled with treatment modules. Specifically, horizontal recirculation was tested because of its application to thin, interbedded aquifer zones. Mixed contaminants were targeted because of their prominence at DOE sites and because they cannot be treated with conventional methods. The project involved several research elements, including treatment process evaluation, hydrodynamic flow and transport modeling, pilot testing at an uncontaminated site, and full-scale testing at a contaminated site. This report presents the results of the work at the contaminated site, X-701B at PORTS. Groundwater contamination at X-701B consists of trichloroethene (TCE) (concentrations up to 1800 mg/L) and technetium-998 (Tc{sup 99}) (activities up to 926 pCi/L).

  8. Increased suicide risk among workers following toxic metal exposure at the Paducah gaseous diffusion plant from 1952 to 2003: a cohort study.

    Science.gov (United States)

    Figgs, L W; Holsinger, H; Freitas, S J; Brion, G M; Hornung, R W; Rice, C H; Tollerud, D

    2011-10-01

    Suicide is a problem worldwide and occupation is an important risk factor. In the last decade, 55 200 deaths in the US were attributed to occupational risk factors. To determine if toxic metal exposure was associated with suicide risk among Paducah gaseous diffusion plant (PGDP) workers. We assembled a cohort of 6820 nuclear industry workers employed from 1952 to 2003. A job-specific exposure matrix (JEM) was used to determine metal exposure likelihood. Uranium exposure was also assessed by urinalysis. All suicide/self-injury International Classification for Disease (ICD) codes were used to identify suicides. Standardized mortality ratios (SMR), odds ratios (OR), and hazard ratios (HR) were used to estimate suicide risk. PGDP suicide victims typically were younger white men. Within exposure likelihood categories, several suicide SMRs were typically elevated for several metals. Only beryllium exposure likelihood was associated with an increased HR. Uranium urine concentration was associated with an elevated suicide risk after stratification by urinalysis frequency. Suicide risk is associated with uranium exposure.

  9. Refrigeration plants using carbon dioxide as refrigerant: measuring and modelling the solubility and diffusion of carbon dioxide in polymers used as sealing materials

    Energy Technology Data Exchange (ETDEWEB)

    von Solms, Nicolas; Kristensen, Jakob [Centre for Phase Equilibria and Separation Processes (IVC-SEP), Department of Chemical and Biochemical Engineering, Technical University of Denmark, DK-2800 Kgs. Lyngby (Denmark)

    2010-01-15

    Because of increased environmental pressure, there is currently a movement away from more traditional refrigerants such as HCFC's toward refrigerants with lower global warming potential such as carbon dioxide (CO{sub 2}). However, the use of CO{sub 2} as a refrigerant requires a refrigeration cycle with greater extremes of pressure, placing greater demands on the polymer materials used for seals and packing. In this work we have measured the solubility and diffusivity of gaseous CO{sub 2} in two polymers used as sealing materials in CO{sub 2} refrigeration plants. These are Hydrogenated Nitrile Butadiene Rubber (HNBR) and Ethylene Propylene Diene Monomer (EPDM) which are used in seals such as O-rings. The experiments were performed on a high-pressure microbalance. Solubility results were modelled using an equation of state for polymers (simplified PC-SAFT). The necessary polymer parameters were obtained using a previously published method. The measured results can be successfully correlated using simplified PC-SAFT. (author)

  10. Plant-Derived Antimicrobials Reduce E. coli O157:H7 Virulence Factors Critical for Colonization in Cattle Gastrointestinal Tract In Vitro

    OpenAIRE

    Sangeetha Ananda Baskaran; Kumar Venkitanarayanan

    2014-01-01

    This study investigated the effect of subinhibitory concentrations (SIC) of five plant-derived antimicrobials (PDAs), namely, trans cinnamaldehyde, eugenol, carvacrol, thymol, and β-resorcylic acid, on E. coli O157:H7 (EHEC) attachment and invasion of cultured bovine colonic (CO) and rectoanal junction (RAJ) epithelial cells. In addition, PDAs' effect on EHEC genes critical for colonization of cattle gastrointestinal tract (CGIT) was determined in bovine rumen fluid (RF) and intestinal conten...

  11. Simplicity at the cost of predictive accuracy in diffuse large B-cell lymphoma: a critical assessment of the R-IPI, IPI, and NCCN-IPI.

    Science.gov (United States)

    Biccler, Jorne; Eloranta, Sandra; de Nully Brown, Peter; Frederiksen, Henrik; Jerkeman, Mats; Smedby, Karin E; Bøgsted, Martin; El-Galaly, Tarec C

    2018-01-01

    The international prognostic index (IPI) and similar models form the cornerstone of clinical assessment in newly diagnosed diffuse large B-cell lymphoma (DLBCL). While being simple and convenient to use, their inadequate use of the available clinical data is a major weakness. In this study, we compared performance of the International Prognostic Index (IPI) and its variations (R-IPI and NCCN-IPI) to a Cox proportional hazards (CPH) model using the same covariates in nondichotomized form. All models were tested in 4863 newly diagnosed DLBCL patients from population-based Nordic registers. The CPH model led to a substantial increase in predictive accuracy as compared to conventional prognostic scores when evaluated by the area under the curve and other relevant tests. Furthermore, the generation of patient-specific survival curves rather than assigning patients to one of few predefined risk groups is a relevant step toward personalized management and treatment. A test-version is available on lymphomapredictor.org. © 2017 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

  12. Apparent diffusion coefficient for prediction of parametrial invasion in cervical cancer: a critical evaluation based on stratification to a Likert scale using T2-weighted imaging.

    Science.gov (United States)

    Woo, Sungmin; Kim, Sang Youn; Cho, Jeong Yeon; Kim, Seung Hyup

    2018-03-01

    To evaluate the value of apparent diffusion coefficient (ADC) for determining parametrial invasion (PMI) in cervical cancer, by stratifying them into subgroups based on a Likert scale using T2-weighted imaging (T2WI). This retrospective study included 87 patients with FIGO stage IA2-IIB cervical cancer who underwent preoperative MRI followed by radical hysterectomy. Radiological PMI was assessed on T2WI using a six-point Likert scale and ADC values of the tumors were measured. MRI findings were compared between patients with and without PMI. Differences in ADC according to the Likert scale were also assessed. 19 (21.8%) patients had pathological PMI. The prevalence of PMI was significantly associated with Likert scale (P PMI had significantly lower ADC values than those without PMI (P = 0.034). However, no significant difference was seen between patients with and without PMI within each Likert score group (P = 0.180-0.857). T2WI-based Likert score for radiological PMI and ADC values of the tumor were significantly associated with pathological PMI. However, the apparent association seen between ADC values and PMI may be due to contribution of high ADC values of MRI-invisible tumors rather than reflecting their relationship.

  13. 75 FR 24545 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Polar Bear...

    Science.gov (United States)

    2010-05-05

    ... Critical Habitat for the Polar Bear in the United States AGENCY: Fish and Wildlife Service, Interior... designation of critical habitat for the polar bear (Ursus maritimus) under the Endangered Species Act of 1973... for the polar bear and on the DEA, and an amended required determinations section of the proposal. We...

  14. Plastid ribosomal protein S5 plays a critical role in photosynthesis, plant development, and cold stress tolerance in arabidopsis

    Science.gov (United States)

    Plastid ribosomal proteins (RPs) are essential components for protein synthesis machinery and exert diverse roles in plant growth and development. Mutations in plastid RPs lead to a range of developmental phenotypes in plants. However, how they regulate these processes is not fully understood and th...

  15. Final Technical Report on Quantifying Dependability Attributes of Software Based Safety Critical Instrumentation and Control Systems in Nuclear Power Plants

    International Nuclear Information System (INIS)

    Smidts, Carol; Huang, Fuqun; Li, Boyuan; Li, Xiang

    2016-01-01

    With the current transition from analog to digital instrumentation and control systems in nuclear power plants, the number and variety of software-based systems have significantly increased. The sophisticated nature and increasing complexity of software raises trust in these systems as a significant challenge. The trust placed in a software system is typically termed software dependability. Software dependability analysis faces uncommon challenges since software systems' characteristics differ from those of hardware systems. The lack of systematic science-based methods for quantifying the dependability attributes in software-based instrumentation as well as control systems in safety critical applications has proved itself to be a significant inhibitor to the expanded use of modern digital technology in the nuclear industry. Dependability refers to the ability of a system to deliver a service that can be trusted. Dependability is commonly considered as a general concept that encompasses different attributes, e.g., reliability, safety, security, availability and maintainability. Dependability research has progressed significantly over the last few decades. For example, various assessment models and/or design approaches have been proposed for software reliability, software availability and software maintainability. Advances have also been made to integrate multiple dependability attributes, e.g., integrating security with other dependability attributes, measuring availability and maintainability, modeling reliability and availability, quantifying reliability and security, exploring the dependencies between security and safety and developing integrated analysis models. However, there is still a lack of understanding of the dependencies between various dependability attributes as a whole and of how such dependencies are formed. To address the need for quantification and give a more objective basis to the review process -- therefore reducing regulatory uncertainty

  16. Final Technical Report on Quantifying Dependability Attributes of Software Based Safety Critical Instrumentation and Control Systems in Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Smidts, Carol [The Ohio State Univ., Columbus, OH (United States); Huang, Funqun [The Ohio State Univ., Columbus, OH (United States); Li, Boyuan [The Ohio State Univ., Columbus, OH (United States); Li, Xiang [The Ohio State Univ., Columbus, OH (United States)

    2016-03-25

    With the current transition from analog to digital instrumentation and control systems in nuclear power plants, the number and variety of software-based systems have significantly increased. The sophisticated nature and increasing complexity of software raises trust in these systems as a significant challenge. The trust placed in a software system is typically termed software dependability. Software dependability analysis faces uncommon challenges since software systems’ characteristics differ from those of hardware systems. The lack of systematic science-based methods for quantifying the dependability attributes in software-based instrumentation as well as control systems in safety critical applications has proved itself to be a significant inhibitor to the expanded use of modern digital technology in the nuclear industry. Dependability refers to the ability of a system to deliver a service that can be trusted. Dependability is commonly considered as a general concept that encompasses different attributes, e.g., reliability, safety, security, availability and maintainability. Dependability research has progressed significantly over the last few decades. For example, various assessment models and/or design approaches have been proposed for software reliability, software availability and software maintainability. Advances have also been made to integrate multiple dependability attributes, e.g., integrating security with other dependability attributes, measuring availability and maintainability, modeling reliability and availability, quantifying reliability and security, exploring the dependencies between security and safety and developing integrated analysis models. However, there is still a lack of understanding of the dependencies between various dependability attributes as a whole and of how such dependencies are formed. To address the need for quantification and give a more objective basis to the review process -- therefore reducing regulatory uncertainty

  17. Effects of graphite doping on critical current density and microstructure of MgB{sub 2} bulks by an improved Mg-diffusion method

    Energy Technology Data Exchange (ETDEWEB)

    Pan, X.F. [Key Laboratory of Magnetic Levitation and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Zhao, Y. [Key Laboratory of Magnetic Levitation and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); School of Materials Science and Engineering, University of New South Wales, Sydney 2052, NSW (Australia)], E-mail: yshao@home.swjtu.edu.cn; Feng, Y. [Northwest Institute for Nonferrous Metal Research, P.O. Box 51, Xi' an, Shaanxi 710016 (China); Western Superconductivity Technology Company, Xi' an (China); Yang, Y. [Key Laboratory of Magnetic Levitation and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Cheng, C.H. [Key Laboratory of Magnetic Levitation and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); School of Materials Science and Engineering, University of New South Wales, Sydney 2052, NSW (Australia)

    2008-09-15

    abstract: A series of graphite-doped MgB{sub 2} bulks with high density have been successfully prepared by an improved Mg-diffusion method in ambient pressure. The effects of graphite doping on lattice parameters, T{sub c}, J{sub c} and microstructure of MgB{sub 2} have been investigated. The results show that compared to the nano-C-doped or CNTs-doped MgB{sub 2}, C is not easy to substitute B in graphite-doped MgB{sub 2}. However, at the same C content, the graphite-doped MgB{sub 2} has a higher J{sub c}. At 10 K and self-field, the J{sub c} for MgB{sub 1.985}C{sub 0.015} reaches 0.58 MA/cm{sup 2}. For the MgB{sub 1.945}C{sub 0.055}, at 5 K, 7 T and 10 K, 6 T the J{sub c} achieves 10,000 A/cm{sup 2} which is two orders of magnitude higher than that for the undoped sample. In addition to improving electron scattering and intergranular connectivity, the unreacted graphite in the graphite-doped MgB{sub 2} is proposed to be responsible to the excellent J{sub c} properties of MgB{sub 2} in high fields, due to depressed grain growth and enhanced grain boundary flux pinning.

  18. Timeline and bibliography of early isolations of plant metabolites (1770-1820) and their impact to pharmacy: A critical study.

    Science.gov (United States)

    Drobnik, Jacek; Drobnik, Elżbieta

    2016-10-27

    Plant metabolites became objects of chemical research for pharmaceutical and medicinal reasons. The period of pure plant substances in chemistry started 1770 with isolation of tartaric acid from wine (wine in pharmacy is a plant-derived preparation). Carl Scheele isolated 7 plant acids: tartaric, benzoic, citric, oxalic, malic, glucuronic and gallic. The era of alkaloids started 1803 when narcotine was discovered and published. Since that time, pharmacists and toxicologists began to recognize alkaloids (or substances regarded as such) as highly active principles responsible for their powerful, thus easily-observed actions to humans and test animals. By 1820 when solanine was isolated, pharmaceutical chemistry has dealt with increasing number of natural plant-derived substances as organic medicines or reagents. The following historical facts have been unknown: Scheele's tartaric acid was introduced officially as a medicinal substance as early as in 1775, benzoic, citric and oxalic acids became official by the end of the 18th century. Morphine was effectively published in 1806 (not 1804), hence the first alkaloid known in isolated state is narcotine (published 1803, official since 1827). Morphine became official in French pharmacy in 1818. And, 1814 is the year when 2 first toxicological accounts on plant-derived acids (oxalic and tartaric) appeared. Practical use in therapy, sometimes soon after discovery, inspired practical pharmacy and stimulated the progress of toxicology. We studied the earliest 50years of plant metabolites isolations era. A revised bibliography and a timeline chart for 24 plant substances from this period is provided. Plants from original publications are taxonomically identified. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. The implementation of a Hazard Analysis and Critical Control Point management system in a peanut butter ice cream plant

    OpenAIRE

    Yu-Ting Hung; Chi-Te Liu; I-Chen Peng; Chin Hsu; Roch-Chui Yu; Kuan-Chen Cheng

    2015-01-01

    To ensure the safety of the peanut butter ice cream manufacture, a Hazard Analysis and Critical Control Point (HACCP) plan has been designed and applied to the production process. Potential biological, chemical, and physical hazards in each manufacturing procedure were identified. Critical control points for the peanut butter ice cream were then determined as the pasteurization and freezing process. The establishment of a monitoring system, corrective actions, verification procedures, and doc...

  20. What is critical for plant thermogenesis? Differences in mitochondrial activity and protein expression between thermogenic and non-thermogenic skunk cabbages.

    Science.gov (United States)

    Ito-Inaba, Yasuko; Hida, Yamato; Inaba, Takehito

    2009-12-01

    Thermogenesis during the blooming of inflorescence is found in several but not all aroids. To understand what is critical for thermogenesis, we investigated the difference between thermogenic and non-thermogenic skunk cabbages (Symplocarpus renifolius and Lysichiton camtschatcensis), which are closely related in morphology and phylogeny. Critical parameters of mitochondrial biogenesis, including density, respiratory activity, and protein expression were compared between these two species. Mitochondrial density, respiratory activity, and the amount of alternative oxidase (AOX) in L. camtschatcensis spadix mitochondria were lower than in S. renifolius spadix mitochondria, while the level of uncoupling protein (UCP) was higher. AOX and UCP mRNAs in L. camtschatcensis were constitutively expressed in various tissues, such as the spadix, the spathe, the stalk, and the leaves. cDNA encoding two putative thermogenic proteins, AOX and UCP were isolated from L. camtschatcensis, and their primary structure was analyzed by multiple alignment and phylogenetic tree reconstruction. AOX and UCP protein of two the skunk cabbage species are closely related in structure, compared with other isoforms in thermogenic plants. Our results suggest that mitochondrial density, respiratory activity, and protein expression, rather than the primary structure of AOX or UCP proteins, may play critical roles in thermogenesis in plants.

  1. The implementation of a Hazard Analysis and Critical Control Point management system in a peanut butter ice cream plant

    Directory of Open Access Journals (Sweden)

    Yu-Ting Hung

    2015-09-01

    Full Text Available To ensure the safety of the peanut butter ice cream manufacture, a Hazard Analysis and Critical Control Point (HACCP plan has been designed and applied to the production process. Potential biological, chemical, and physical hazards in each manufacturing procedure were identified. Critical control points for the peanut butter ice cream were then determined as the pasteurization and freezing process. The establishment of a monitoring system, corrective actions, verification procedures, and documentation and record keeping were followed to complete the HACCP program. The results of this study indicate that implementing the HACCP system in food industries can effectively enhance food safety and quality while improving the production management.

  2. Determination of Soil and Plant Water Balance and Its Critical Stages for Rainfed Wheat Using Crop Water Stress Index (CWSI)

    OpenAIRE

    V. Feiziasl; A. Fotovat; A. Astaraei; A. Lakzian; M.A. Mousavi Shalmani

    2014-01-01

    In order to determination of water stress threshold and dryland wheat genotypes water status in different nitrogen managements, this experiment was carried out in split split plot RCBD design in three replications in 2010-2011 cropping year. Treatments included: N application time (whole fertilization of N at planting time , and its split fertilization as 2/3 at planting time and 1/3 in early spring), N rates (0, 30, 60 and 90 kg ha-1) and 7 wheat genotypes. Also these genotypes were grown in...

  3. Arabidopsis LIP5, a positive regulator of multivesicular body biogenesis, is a critical target of pathogen-responsive MAPK cascade in plant basal defense.

    Directory of Open Access Journals (Sweden)

    Fei Wang

    2014-07-01

    Full Text Available Multivesicular bodies (MVBs play essential roles in many cellular processes. The MVB pathway requires reversible membrane association of the endosomal sorting complexes required for transports (ESCRTs for sustained protein trafficking. Membrane dissociation of ESCRTs is catalyzed by the AAA ATPase SKD1, which is stimulated by LYST-interacting protein 5 (LIP5. We report here that LIP5 is a target of pathogen-responsive mitogen-activated protein kinases (MPKs and plays a critical role in plant basal resistance. Arabidopsis LIP5 interacts with MPK6 and MPK3 and is phosphorylated in vitro by activated MPK3 and MPK6 and in vivo upon expression of MPK3/6-activating NtMEK2DD and pathogen infection. Disruption of LIP5 has little effects on flg22-, salicylic acid-induced defense responses but compromises basal resistance to Pseudomonas syringae. The critical role of LIP5 in plant basal resistance is dependent on its ability to interact with SKD1. Mutation of MPK phosphorylation sites in LIP5 does not affect interaction with SKD1 but reduces the stability and compromises the ability to complement the lip5 mutant phenotypes. Using the membrane-selective FM1-43 dye and transmission electron microscopy, we demonstrated that pathogen infection increases formation of both intracellular MVBs and exosome-like paramural vesicles situated between the plasma membrane and the cell wall in a largely LIP5-dependent manner. These results indicate that the MVB pathway is positively regulated by pathogen-responsive MPK3/6 through LIP5 phosphorylation and plays a critical role in plant immune system likely through relocalization of defense-related molecules.

  4. Plant-derived antimicrobials reduce E. coli O157:H7 virulence factors critical for colonization in cattle gastrointestinal tract in vitro.

    Science.gov (United States)

    Ananda Baskaran, Sangeetha; Venkitanarayanan, Kumar

    2014-01-01

    This study investigated the effect of subinhibitory concentrations (SIC) of five plant-derived antimicrobials (PDAs), namely, trans cinnamaldehyde, eugenol, carvacrol, thymol, and β-resorcylic acid, on E. coli O157:H7 (EHEC) attachment and invasion of cultured bovine colonic (CO) and rectoanal junction (RAJ) epithelial cells. In addition, PDAs' effect on EHEC genes critical for colonization of cattle gastrointestinal tract (CGIT) was determined in bovine rumen fluid (RF) and intestinal contents (BICs). Primary bovine CO and RAJ epithelial cells were established and were separately inoculated with three EHEC strains with or without (control) SIC of each PDA. Following incubation, EHEC that attached and invaded the cells were determined. Furthermore, the expression of EHEC genes critical for colonization in cattle was investigated using real-time, quantitative polymerase chain reaction in RF and BICs. All the PDAs decreased EHEC invasion of CO and RAJ epithelial cells (P cattle; however follow-up in vivo studies in cattle are warranted.

  5. Evaluation of Model Driven Development of Safety Critical Software in the Nuclear Power Plant I and C system

    International Nuclear Information System (INIS)

    Jung, Jae Cheon; Chang, Hoon Seon; Chang, Young Woo; Kim, Jae Hack; Sohn, Se Do

    2005-01-01

    The major issues of the safety critical software are formalism and V and V. Implementing these two characteristics in the safety critical software will greatly enhance the quality of software product. The structure based development requires lots of output documents from the requirements phase to the testing phase. The requirements analysis phase is open omitted. According to the Standish group report in 2001, 49% of software project is cancelled before completion or never implemented. In addition, 23% is completed and become operational, but over-budget, over the time estimation, and with fewer features and functions than initially specified. They identified ten success factors. Among them, firm basic requirements and formal methods are technically achievable factors while the remaining eight are management related. Misunderstanding of requirements due to lack of communication between the design engineer and verification engineer causes unexpected result such as functionality error of system. Safety critical software shall comply with such characteristics as; modularity, simplicity, minimizing the sub-routine, and excluding the interrupt routine. In addition, the crosslink fault and erroneous function shall be eliminated. The easiness of repairing work after the installation shall be achieved as well. In consideration of the above issues, we evaluate the model driven development (MDD) methods for nuclear I and C systems software. For qualitative analysis, the unified modeling language (UML), functional block language (FBL) and the safety critical application environment (SCADE) are tested for the above characteristics

  6. 77 FR 14061 - Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for the Northern Spotted Owl

    Science.gov (United States)

    2012-03-08

    ... critical habitat by excluding all private and State lands with active conservation agreements (HCPS, SHAs... State lands with active conservation agreements (HCPs, SHAs, and other formal agreements) in place, all... Outcome 2: Excludes private lands 711,803 ac with conservation (288,059 ha)........ agreements (HCPs, SHAs...

  7. 77 FR 43796 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Lost River...

    Science.gov (United States)

    2012-07-26

    ...) The likelihood of adverse social reactions to the designation of critical habitat, as discussed in the... the importance of habitat protection, and, where a Federal nexus exists, increased habitat protection... (Regulatory Planning and Review), E.O. 12630 (Takings), E.O. 13132 (Federalism), E.O. 12988 (Civil Justice...

  8. Criticality accidents in a fuel reprocessing plant are equivalent to a nuclear explosion. Comment on the statement by Prof. Dr. Armin Weiss, University of Munich

    International Nuclear Information System (INIS)

    Baumgaertner, F.

    1984-12-01

    The need for comment results from the fact that Prof. Weiss, endowed with the authority of a professor at the University of Munich, maintains that there could be a nuclear explosion, propagates this claim by an open letter, and that all the inhabitants of the districts adjoining Wackersdorf are concerned. The brochure points out the prerequisites for a substantial nuclear explosion, describes the consequences of a criticality accident in a fuel reprocessing plant, and looks into the background motives (scientific, private) for making such a claim. (DG) [de

  9. Radiation monitoring using imaging plate technology: A case study of leaves affected by the Chernobyl nuclear power plant and JCO criticality accidents

    Directory of Open Access Journals (Sweden)

    Kimura Shinzo

    2006-01-01

    Full Text Available This paper describes the use of a photostimulable phosphor screen imaging technique to detect radioactive contamination in the leaves of wormwood (Artemisia vulgaris L and fern (Dryopteris filix-max CL. Schoff plants affected by the Chernobyl nuclear power plant accident. The imaging plate technology is well known for many striking performances in two-dimensional radiation detection. Since imaging plate comprises an integrated detection system, it has been extensively applied to surface contamination distribution studies. In this study, plant samples were collected from high- and low-contaminated areas of Ukraine and Belarus, which were affected due to the Chernobyl accident and exposed to imaging technique. Samples from the highly contaminated areas revealed the highest photo-stimulated luminescence on the imaging plate. Moreover, the radio nuclides detected in the leaves by gamma and beta ray spectroscopy were 137Cs and 90Sr, respectively. Additionally, in order to assess contamination, a comparison was also made with leaves of plants affected during the JCO criticality accident in Japan. Based on the results obtained, the importance of imaging plate technology in environmental radiation monitoring has been suggested.

  10. Radiation monitoring using imaging plate technology: a case study of leaves affected by the Chernobyl nuclear power plant and JCO criticality accidents

    International Nuclear Information System (INIS)

    Kimura, S.; Sahoo, S. K.; Shiraishi, K.; Watanabe, Y.; Ban-nai, T.; Los, I. P.; Korzun, V. N.; Tsygankov, N.Y.; Zamostyan, P. V.; Shevchuk, V. E.; S. K. Sahoo)

    2006-01-01

    This paper describes the use of a photostimulable phosphor screen imaging technique to detect radioactive contamination in the leaves of wormwood (Artemisia vulgaris L.) and fern (Dryopteris filix-max CL. Schoff) plants affected by the Chernobyl nuclear power plant accident. The imaging plate technology is well known for many striking performances in two-dimensional radiation detection. Since imaging plate comprises an integrated detection system, it has been extensively applied to surface contamination distribution studies. In this study, plant samples were collected from high- and low-contaminated areas of Ukraine and Belarus, which were affected due to the Chernobyl accident and exposed to imaging technique. Samples from the highly contaminated areas revealed the highest photo-stimulated luminescence on the imaging plate. Moreover, the radionuclides detected in the leaves by gamma and beta ray spectroscopy were 137 Cs and 90 Sr, respectively. Additionally, in order to assess contamination, a comparison was also made with leaves of plants affected during the JCO criticality accident in Japan. Based on the results obtained, the importance of imaging plate technology in environmental radiation monitoring has been suggested. (author)

  11. Dose Modeling Evaluations and Technical Support Document For the Authorized Limits Request for the DOE-Owned Property Outside the Limited Area, Paducah Gaseous Diffusion Plant Paducah, Kentucky

    International Nuclear Information System (INIS)

    Boerner, A. J.

    2012-01-01

    Environmental assessments and remediation activities are being conducted by the U.S. Department of Energy (DOE) at the Paducah Gaseous Diffusion Plant (PGDP), Paducah, Kentucky. The Oak Ridge Institute for Science and Education (ORISE), a DOE prime contractor, was contracted by the DOE Portsmouth/Paducah Project Office (DOE-PPPO) to conduct radiation dose modeling analyses and derive single radionuclide soil guidelines (soil guidelines) in support of the derivation of Authorized Limits (ALs) for 'DOE-Owned Property Outside the Limited Area' ('Property') at the PGDP. The ORISE evaluation specifically included the area identified by DOE restricted area postings (public use access restrictions) and areas licensed by DOE to the West Kentucky Wildlife Management Area (WKWMA). The licensed areas are available without restriction to the general public for a variety of (primarily) recreational uses. Relevant receptors impacting current and reasonably anticipated future use activities were evaluated. In support of soil guideline derivation, a Conceptual Site Model (CSM) was developed. The CSM listed radiation and contamination sources, release mechanisms, transport media, representative exposure pathways from residual radioactivity, and a total of three receptors (under present and future use scenarios). Plausible receptors included a Resident Farmer, Recreational User, and Wildlife Worker. single radionuclide soil guidelines (outputs specified by the software modeling code) were generated for three receptors and thirteen targeted radionuclides. These soil guidelines were based on satisfying the project dose constraints. For comparison, soil guidelines applicable to the basic radiation public dose limit of 100 mrem/yr were generated. Single radionuclide soil guidelines from the most limiting (restrictive) receptor based on a target dose constraint of 25 mrem/yr were then rounded and identified as the derived soil guidelines. An additional evaluation using the derived soil

  12. A Technical Assessment Of The Current Water Policy Boundary At U.S. Department Of Energy, Paducah Gaseous Diffusion Plant, Paducah, Kentucky

    International Nuclear Information System (INIS)

    None

    2012-01-01

    In 1988, groundwater contaminated with trichloroethene (TCE) and technetium-99 (Tc-99) was identified in samples collected from residential water wells withdrawing groundwater from the Regional Gravel Aquifer (RGA) north of the Paducah Gaseous Diffusion Plant (PGDP) facility. In response, the U.S. Department of Energy (DOE) provided temporary drinking water supplies to approximately 100 potentially affected residents by initially supplying bottled water, water tanks, and water-treatment systems, and then by extending municipal water lines, all at no cost, to those persons whose wells could be affected by contaminated groundwater. The Water Policy boundary was established in 1993. In the Policy, DOE agreed to pay the reasonable monthly cost of water for homes and businesses and, in exchange, many of the land owners signed license agreements committing to cease using the groundwater via rural water wells. In 2012, DOE requested that Oak Ridge Associated Universities (ORAU), managing contractor of Oak Ridge Institute for Science and Education (ORISE), provide an independent assessment of the quality and quantity of the existing groundwater monitoring data and determine if there is sufficient information to support a modification to the boundary of the current Water Policy. As a result of the assessment, ORAU concludes that sufficient groundwater monitoring data exists to determine that a shrinkage and/or shift of the plume(s) responsible for the initial development of this policy has occurred. Specifically, there is compelling evidence that the TCE plume is undergoing shrinkage due to natural attenuation and associated degradation. The plume shrinkage (and migration) has also been augmented in local areas where large volumes of groundwater were recovered by pump-and treat remedial systems along the eastern and western boundaries of the Northwest Plume, and in other areas where pump-and-treat systems have been deployed by DOE to remove source contaminants. The

  13. ENZYME ACTIVITY PROBE AND GEOCHEMICAL ASSESSMENT FOR POTENTIAL AEROBIC COMETABOLISM OF TRICHLOROETHENE IN GROUNDWATER OF THE NORTHWEST PLUME, PADUCAH GASEOUS DIFFUSION PLANT, KENTUCKY

    Energy Technology Data Exchange (ETDEWEB)

    Looney, B; M. Hope Lee, M; S. K. Hampson, S

    2008-06-27

    The overarching objective of the Paducah Gaseous Diffusion Plant (PGDP) enzyme activity probe (EAP) effort is to determine if aerobic cometabolism is contributing to the attenuation of trichloroethene (TCE) and other chlorinated solvents in the contaminated groundwater beneath PGDP. The site-specific objective for the EAP assessment is to identify if key metabolic pathways are present and expressed in the microbial community--namely the pathways that are responsible for degradation of methane and aromatic (e.g. toluene, benzene, phenol) substrates. The enzymes produced to degrade methane and aromatic compounds also break down TCE through a process known as cometabolism. EAPs directly measure if methane and/or aromatic enzyme production pathways are operating and, for the aromatic pathways, provide an estimate of the number of active organisms in the sampled groundwater. This study in the groundwater plumes at PGDP is a major part of a larger scientific effort being conducted by Interstate Technology and Regulatory Council (ITRC), U.S. Department of Energy (DOE) Office of Environmental Management (EM), Savannah River National Laboratory (SRNL), and North Wind Inc. in which EAPs are being applied to contaminated groundwater from diverse hydrogeologic and plume settings throughout the U.S. to help standardize their application as well as their interpretation. While EAP data provide key information to support the site specific objective for PGDP, several additional lines of evidence are being evaluated to increase confidence in the determination of the occurrence of biodegradation and the rate and sustainability of aerobic cometabolism. These complementary efforts include: (1) Examination of plume flowpaths and comparison of TCE behavior to 'conservative' tracers in the plume (e.g., {sup 99}Tc); (2) Evaluation of geochemical conditions throughout the plume; and (3) Evaluation of stable isotopes in the contaminants and their daughter products throughout the

  14. Dose Modeling Evaluations and Technical Support Document For the Authorized Limits Request for the DOE-Owned Property Outside the Limited Area, Paducah Gaseous Diffusion Plant Paducah, Kentucky

    Energy Technology Data Exchange (ETDEWEB)

    Boerner, A. J. [Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN (United States). Independent Environmental Assessment and Verification Program; Maldonado, D. G. [Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN (United States). Independent Environmental Assessment and Verification Program; Hansen, Tom [Ameriphysics, LLC (United States)

    2012-09-01

    Environmental assessments and remediation activities are being conducted by the U.S. Department of Energy (DOE) at the Paducah Gaseous Diffusion Plant (PGDP), Paducah, Kentucky. The Oak Ridge Institute for Science and Education (ORISE), a DOE prime contractor, was contracted by the DOE Portsmouth/Paducah Project Office (DOE-PPPO) to conduct radiation dose modeling analyses and derive single radionuclide soil guidelines (soil guidelines) in support of the derivation of Authorized Limits (ALs) for 'DOE-Owned Property Outside the Limited Area' ('Property') at the PGDP. The ORISE evaluation specifically included the area identified by DOE restricted area postings (public use access restrictions) and areas licensed by DOE to the West Kentucky Wildlife Management Area (WKWMA). The licensed areas are available without restriction to the general public for a variety of (primarily) recreational uses. Relevant receptors impacting current and reasonably anticipated future use activities were evaluated. In support of soil guideline derivation, a Conceptual Site Model (CSM) was developed. The CSM listed radiation and contamination sources, release mechanisms, transport media, representative exposure pathways from residual radioactivity, and a total of three receptors (under present and future use scenarios). Plausible receptors included a Resident Farmer, Recreational User, and Wildlife Worker. single radionuclide soil guidelines (outputs specified by the software modeling code) were generated for three receptors and thirteen targeted radionuclides. These soil guidelines were based on satisfying the project dose constraints. For comparison, soil guidelines applicable to the basic radiation public dose limit of 100 mrem/yr were generated. Single radionuclide soil guidelines from the most limiting (restrictive) receptor based on a target dose constraint of 25 mrem/yr were then rounded and identified as the derived soil guidelines. An additional evaluation using the derived soil

  15. A TECHNICAL ASSESSMENT OF THE CURRENT WATER POLICY BOUNDARY AT U.S. DEPARTMENT OF ENERGY, PADUCAH GASEOUS DIFFUSION PLANT, PADUCAH, KENTUCKY

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-12-13

    In 1988, groundwater contaminated with trichloroethene (TCE) and technetium-99 (Tc-99) was identified in samples collected from residential water wells withdrawing groundwater from the Regional Gravel Aquifer (RGA) north of the Paducah Gaseous Diffusion Plant (PGDP) facility. In response, the U.S. Department of Energy (DOE) provided temporary drinking water supplies to approximately 100 potentially affected residents by initially supplying bottled water, water tanks, and water-treatment systems, and then by extending municipal water lines, all at no cost, to those persons whose wells could be affected by contaminated groundwater. The Water Policy boundary was established in 1993. In the Policy, DOE agreed to pay the reasonable monthly cost of water for homes and businesses and, in exchange, many of the land owners signed license agreements committing to cease using the groundwater via rural water wells. In 2012, DOE requested that Oak Ridge Associated Universities (ORAU), managing contractor of Oak Ridge Institute for Science and Education (ORISE), provide an independent assessment of the quality and quantity of the existing groundwater monitoring data and determine if there is sufficient information to support a modification to the boundary of the current Water Policy. As a result of the assessment, ORAU concludes that sufficient groundwater monitoring data exists to determine that a shrinkage and/or shift of the plume(s) responsible for the initial development of this policy has occurred. Specifically, there is compelling evidence that the TCE plume is undergoing shrinkage due to natural attenuation and associated degradation. The plume shrinkage (and migration) has also been augmented in local areas where large volumes of groundwater were recovered by pump-and treat remedial systems along the eastern and western boundaries of the Northwest Plume, and in other areas where pump-and-treat systems have been deployed by DOE to remove source contaminants. The

  16. A critical review of selenium biogeochemical behavior in soil-plant system with an inference to human health.

    Science.gov (United States)

    Natasha; Shahid, Muhammad; Niazi, Nabeel Khan; Khalid, Sana; Murtaza, Behzad; Bibi, Irshad; Rashid, Muhammad Imtiaz

    2018-03-01

    Selenium (Se) is an essential trace element for humans and animals, although controversial for different plant species. There exists a narrow line between essential, beneficial and toxic levels of Se to living organisms which greatly varies with Se speciation, as well as the type of living organisms. Therefore, it is crucial to monitor its solid- and solution-phase speciation, exposure levels and pathways to living organisms. Consumption of Se-laced food (cereals, vegetables, legumes and pulses) is the prime source of Se exposure to humans. Thus, it is imperative to assess the biogeochemical behavior of Se in soil-plant system with respect to applied levels and speciation, which ultimately affect Se status in humans. Based on available relevant literature, this review traces a plausible link among (i) Se levels, sources, speciation, bioavailability, and effect of soil chemical properties on selenium bioavailability/speciation in soil; (ii) role of different protein transporters in soil-root-shoot transfer of Se; and (iii) speciation, metabolism, phytotoxicity and detoxification of Se inside plants. The toxic and beneficial effects of Se to plants have been discussed with respect to speciation and toxic/deficient concentration of Se. We highlight the significance of various enzymatic (catalase, peroxidase, superoxide dismutase, ascorbate peroxidase, glutathione peroxidase) and non-enzymatic (phytochelatins and glutathione) antioxidants which help combat Se-induced overproduction of reactive oxygen species (ROS). The review also delineates Se accumulation in edible plant parts from soils containing low or high Se levels; elucidates associated health disorders or risks due to the consumption of Se-deficient or Se-rich foods; discusses the potential role of Se in different human disorders/diseases. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Criticality safety aspects of K-25 Building uranium deposit removal

    International Nuclear Information System (INIS)

    Haire, M.J.; Jordan, W.C.; Ingram, J.C. III; Stinnet, E.C. Jr.

    1995-01-01

    The K-25 Building of the Oak Ridge Gaseous Diffusion Plant (now the K-25 Site) went into operation during World War II as the first large scale production plant to separate 235 U from uranium by the gaseous diffusion process. It operated successfully until 1964, when it was placed in a stand-by mode. The Department of Energy has initiated a decontamination and decommissioning program. The primary objective of the Deposit Removal (DR) Project is to improve the nuclear criticality safety of the K-25 Building by removing enriched uranium deposits from unfavorable-geometry process equipment to below minimum critical mass. The method utilized to accomplish this are detailed in this report

  18. The implementation of a Hazard Analysis and Critical Control Point management system in a peanut butter ice cream plant.

    Science.gov (United States)

    Hung, Yu-Ting; Liu, Chi-Te; Peng, I-Chen; Hsu, Chin; Yu, Roch-Chui; Cheng, Kuan-Chen

    2015-09-01

    To ensure the safety of the peanut butter ice cream manufacture, a Hazard Analysis and Critical Control Point (HACCP) plan has been designed and applied to the production process. Potential biological, chemical, and physical hazards in each manufacturing procedure were identified. Critical control points for the peanut butter ice cream were then determined as the pasteurization and freezing process. The establishment of a monitoring system, corrective actions, verification procedures, and documentation and record keeping were followed to complete the HACCP program. The results of this study indicate that implementing the HACCP system in food industries can effectively enhance food safety and quality while improving the production management. Copyright © 2015. Published by Elsevier B.V.

  19. Management of the aging of critical safety-related concrete structures in light-water reactor plants

    International Nuclear Information System (INIS)

    Naus, D.J.; Oland, C.B.; Arndt, E.G.

    1990-01-01

    The Structural Aging Program has the overall objective of providing the USNRC with an improved basis for evaluating nuclear power plant safety-related structures for continued service. The program consists of a management task and three technical tasks: materials property data base, structural component assessment/repair technology, and quantitative methodology for continued-service determinations. Objectives, accomplishments, and planned activities under each of these tasks are presented. Major program accomplishments include development of a materials property data base for structural materials as well as an aging assessment methodology for concrete structures in nuclear power plants. Furthermore, a review and assessment of inservice inspection techniques for concrete materials and structures has been complete, and work on development of a methodology which can be used for performing current as well as reliability-based future condition assessment of concrete structures is well under way. 43 refs., 3 tabs

  20. Germination Ecology and Seed Dispersal of a Critically Endangered Plant: A Case Study of Pomaderris vacciniifolia (Round-Leaf Pomaderris)

    OpenAIRE

    Patykowski, John; Dell, Matthew; Gibson, Maria

    2016-01-01

    Change in ecosystem disturbance regimes from human land-use poses a worldwide problem for management of rare species. Two important types of disturbance influencing the persistence of species in Australian ecosystems are habitat fragmentation and fire. In this study, seed dispersal and the germination ecology of Pomaderris vacciniifolia-a critically endangered, rare endemic Australian shrub-were examined to identify likely influences of fire and fragmentation on the decline of populations. Th...

  1. Diffusion or bulk flow

    DEFF Research Database (Denmark)

    Schulz, Alexander

    2015-01-01

    assimilate movement includes an apoplasmic step, this mode is called apoplasmic loading. Well established is also the polymer-trap loading mode, where the phloem-transport sugars are raffinose-family oligomers in herbaceous plants. Also this mode depends on the investment of energy, here for sugar...... is currently matter of discussion, called passive symplasmic loading. Based on the limited material available, this review compares the different loading modes and suggests that diffusion is the driving force in apoplasmic loaders, while bulk flow plays an increasing role in plants having a continuous...

  2. Determination of Soil and Plant Water Balance and Its Critical Stages for Rainfed Wheat Using Crop Water Stress Index (CWSI

    Directory of Open Access Journals (Sweden)

    V. Feiziasl

    2014-12-01

    Full Text Available In order to determination of water stress threshold and dryland wheat genotypes water status in different nitrogen managements, this experiment was carried out in split split plot RCBD design in three replications in 2010-2011 cropping year. Treatments included: N application time (whole fertilization of N at planting time , and its split fertilization as 2/3 at planting time and 1/3 in early spring, N rates (0, 30, 60 and 90 kg ha-1 and 7 wheat genotypes. Also these genotypes were grown in supplemental irrigation condition for calculation of crop water stress index (CWSI parameters. Canopy temperature (Tc was measured in flowering and early milking stages. Crop water stress index (CWSI was calculated. A non-water stressed baseline (lower baseline were fitted as Tc-Ta=4.523-3.761×VPD; R2=0.92 and non-transpiring baseline (upper baseline determined 6 ºC for rainfed wheat genotypes. Water stress threshold was 0.4 and crossing of that occurred 8 days before heading stage. In water stress threshold boundary, was depleted 60 mm available water from 0 to 50 cm soil depth. There was negative significant relationship (p >0.01 between CWSI and grain yield in all treatments and different nitrogen rates. Nitrogen application reduced water stress and increased grain yield of rainfed wheat genotypes. Ohadi and Rasad genotypes showed highest resistance to water stress and high grain yield production for N30 in split and planting time application, respectively. Cereal4 and Rasad genotypes were suitable for N60 application in split and planting time application, respectively.

  3. V and V-based remaining fault estimation model for safety–critical software of a nuclear power plant

    International Nuclear Information System (INIS)

    Eom, Heung-seop; Park, Gee-yong; Jang, Seung-cheol; Son, Han Seong; Kang, Hyun Gook

    2013-01-01

    Highlights: ► A software fault estimation model based on Bayesian Nets and V and V. ► Use of quantified data derived from qualitative V and V results. ► Faults insertion and elimination process was modeled in the context of probability. ► Systematically estimates the expected number of remaining faults. -- Abstract: Quantitative software reliability measurement approaches have some limitations in demonstrating the proper level of reliability in cases of safety–critical software. One of the more promising alternatives is the use of software development quality information. Particularly in the nuclear industry, regulatory bodies in most countries use both probabilistic and deterministic measures for ensuring the reliability of safety-grade digital computers in NPPs. The point of deterministic criteria is to assess the whole development process and its related activities during the software development life cycle for the acceptance of safety–critical software. In addition software Verification and Validation (V and V) play an important role in this process. In this light, we propose a V and V-based fault estimation method using Bayesian Nets to estimate the remaining faults for safety–critical software after the software development life cycle is completed. By modeling the fault insertion and elimination processes during the whole development phases, the proposed method systematically estimates the expected number of remaining faults.

  4. Critical Analysis on Characterization, Systemic Effect, and Therapeutic Potential of Beta-Sitosterol: A Plant-Derived Orphan Phytosterol

    Directory of Open Access Journals (Sweden)

    Muhammad Shahdaat Bin Sayeed

    2016-11-01

    Full Text Available Beta-sitosterol (BS is a phytosterol, widely distributed throughout the plant kingdom and known to be involved in the stabilization of cell membranes. To compile the sources, physical and chemical properties, spectral and chromatographic analytical methods, synthesis, systemic effects, pharmacokinetics, therapeutic potentials, toxicity, drug delivery and finally, to suggest future research with BS, classical as well as on-line literature were studied. Classical literature includes classical books on ethnomedicine and phytochemistry, and the electronic search included Pubmed, SciFinder, Scopus, the Web of Science, Google Scholar, and others. BS could be obtained from different plants, but the total biosynthetic pathway, as well as its exact physiological and structural function in plants, have not been fully understood. Different pharmacological effects have been studied, but most of the mechanisms of action have not been studied in detail. Clinical trials with BS have shown beneficial effects in different diseases, but long-term study results are not available. These have contributed to its current status as an “orphan phytosterol”. Therefore, extensive research regarding its effect at cellular and molecular level in humans as well as addressing the claims made by commercial manufacturers such as the cholesterol lowering ability, immunological activity etc. are highly recommended.

  5. Conflict minerals from the Democratic Republic of the Congo: global tungsten processing plants, a critical part of the tungsten supply chain

    Science.gov (United States)

    Bermúdez-Lugo, Omayra

    2014-01-01

    The U.S. Geological Survey (USGS) analyzes supply chains to identify and define major components of mineral and material flows from ore extraction, through intermediate forms, to a final product. Two major reasons necessitate these analyses: (1) to identify risks associated with the supply of critical and strategic minerals to the United States and (2) to provide greater supply chain transparency so that policymakers have the information necessary to ensure domestic legislation compliance. This fact sheet focuses on the latter. The USGS National Minerals Information Center has been asked by governmental and non-governmental organizations to provide information on tin, tantalum, tungsten, and gold (collectively known as “3TG minerals”) processing facilities worldwide in response to U.S. legislation aimed at removing the link between the trade in these minerals and civil unrest in the Democratic Republic of the Congo. Post beneficiation processing plants (smelters and refineries) of 3TG mineral ores and concentrates were identified by company and industry association representatives as being the link in the 3TG mineral supply chain through which these minerals can be traced to their source of origin (mine); determining the point of origin is critical to establishing a transparent conflict mineral supply chain. This fact sheet, the first in a series of 3TG mineral fact sheets, focuses on the tungsten supply chain by listing plants that consume tungsten concentrates to produce ammonium paratungstate and ferrotungsten worldwide.

  6. Solutions to criticality problems in a plutonium extraction plant; Solutions apportees aux problemes de criticite d'une usine d'extraction du plutonium

    Energy Technology Data Exchange (ETDEWEB)

    Jouannaud, C.; Rodier, J.; Fruchard, Y.; Peyresblanques, H.; Papault, C.; Tabardel-Brian, R. [Commissariat a l' Energie Atomique, Chusclan (France). Centre de Production de Plutonium de Marcoule, service d' extraction du plutonium, service de protection contre les radiations et d' assainissement radioactif

    1968-08-01

    There are two aspects to nuclear criticality safety: prevention of criticality and protection against the consequences of a possible accident: this report considers these two aspects in the case of the Marcoule Plutonium Extraction Plant. After briefly recalling the various techniques used for avoiding criticality (mass, geometry, concentration, poisoning), the authors describe their application in the plant and show in particular that, a rational use of a favorable geometry is a factor both for security and from an economic point of view. The authors then describe the inside organisation which makes it possible to obtain the necessary intrinsic safety standard right from the advance project stage, and to control the workshop safety during the operation of the plant. The second part of the report deals with the system of protection against the consequences of a possible accident: definition of a typical accident, fixing of the boundaries of a critical zone, safety alarm device, individual and collective dosimetry, evacuation plan and safety instructions. (authors) [French] La securite vis-a-vis des risques de criticite revet deux aspects: la prevention de la criticite et la protection contre les consequences d'un accident eventuel: le present rapport developpe ces deux aspects dans le cas de l'Usine d'Extraction du Plutonium de Marcoule. Apres avoir rappele les differentes techniques de prevention de la criticite (masse, geometrie, concentration, empoisonnement), les auteurs decrivent leur application a l'Usine et montrent notamment que l'utilisation rationnelle de la geometrie favorable est un double facteur de securite et d'economie. Les auteurs decrivent ensuite l'organisation interieure qui permet de realiser la securite intrinseque des le stade d'un avant projet et de controler la securite des ateliers au cours de la vie de l'Usine. La deuxieme partie du rapport est consacree au systeme de protection contre les

  7. Critical evaluation of the nonradiological environmental technical specifications. Volume 2. Surry Power Plants, Units 1 and 2

    International Nuclear Information System (INIS)

    Adams, S.M.; Cunningham, P.A.; Gray, D.D.; Kumar, K.D.

    1976-01-01

    A comprehensive study of the data collected as part of the environmental Technical Specifications program for Units 1 and 2 of the Surry Nuclear Power Plant was carried out for the Office of Regulatory Research of the U.S. Nuclear Regulatory Commission. The program included an analysis of the hydrothermal and ecological monitoring data collected from 1973 through 1975. The hydrothermal analysis includes a discussion of models used in plume predictions prior to plant operation and an evaluation of the present hydrothermal monitoring program. The two primary methods used for temperature monitoring employ a fixed thermographs network and boat measurements. Review of data indicates that both the application and formulation of the hydrothermal monitoring program are inadequate to fully characterize the operation of the plant and the behavior of the thermal plume. Furthermore, there are no existing data that can be used to adequately verify or disprove the validity of the various Surry plume predictions. The ecological analysis includes validation of impacts predicted in the Final Environmental Statement using the operational monitoring data. Phytoplankton cell concentrations, chlorophyll a, and carbon-14 measurements were used to monitor changes in the primary producers. Densities of consumers (i.e., zooplankton, benthos, and fish) were sed to monitor changes in the primary producers. Models based on operating data were constructed to determine whether changes were occurring at each trophic level. Analysis of the monitoring data suggests that the thermal discharges at Surry are having a negative effect on the phytoplankton and zooplankton but are enhancing the benthic and nekton populations in the discharge area

  8. Critical evaluation of the nonradiological environmental technical specifications. Volume 2. Surry Power Plants, Units 1 and 2

    Energy Technology Data Exchange (ETDEWEB)

    Adams, S.M.; Cunningham, P.A.; Gray, D.D.; Kumar, K.D.

    1976-08-10

    A comprehensive study of the data collected as part of the environmental Technical Specifications program for Units 1 and 2 of the Surry Nuclear Power Plant was carried out for the Office of Regulatory Research of the U.S. Nuclear Regulatory Commission. The program included an analysis of the hydrothermal and ecological monitoring data collected from 1973 through 1975. The hydrothermal analysis includes a discussion of models used in plume predictions prior to plant operation and an evaluation of the present hydrothermal monitoring program. The two primary methods used for temperature monitoring employ a fixed thermographs network and boat measurements. Review of data indicates that both the application and formulation of the hydrothermal monitoring program are inadequate to fully characterize the operation of the plant and the behavior of the thermal plume. Furthermore, there are no existing data that can be used to adequately verify or disprove the validity of the various Surry plume predictions. The ecological analysis includes validation of impacts predicted in the Final Environmental Statement using the operational monitoring data. Phytoplankton cell concentrations, chlorophyll a, and carbon-14 measurements were used to monitor changes in the primary producers. Densities of consumers (i.e., zooplankton, benthos, and fish) were sed to monitor changes in the primary producers. Models based on operating data were constructed to determine whether changes were occurring at each trophic level. Analysis of the monitoring data suggests that the thermal discharges at Surry are having a negative effect on the phytoplankton and zooplankton but are enhancing the benthic and nekton populations in the discharge area.

  9. Plant "electrome" can be pushed toward a self-organized critical state by external cues: Evidences from a study with soybean seedlings subject to different environmental conditions.

    Science.gov (United States)

    Souza, Gustavo M; Ferreira, Arlan S; Saraiva, Gustavo F R; Toledo, Gabriel R A

    2017-03-04

    In the present study, we have investigated how the low-voltage electrical signals of soybean seedlings change their temporal dynamic under different environmental conditions (cold, low light, and low osmotic potential). We have used electrophytografic technique (EPG) with sub-dermal electrodes inserted in 15-days-old seedlings located between root and shoot, accounting for a significant part of the individual seedlings. Herein, to work on a specific framework to settle this type of the study, we are adopting the term "electrome" as a reference to the totality of electrical activity measured. Taking into account the non-linear dynamic of the plants electrophysiology, we have hypothesized that the stimuli, as applied in a constant way, could push the system to a critical state, exhibiting spikes without a characteristic size, indicating self-organized criticality (SOC). The results from the power spectral density analysis (PSD), showed that the interval of the large majority of the β exponents were between 1.5 and 3, indicating that the time series, regardless environmental conditions, showed long-range temporal correlation (long memory for β≠0 and β≠2). The analyses from the histograms of the runs showed different patterns of distributions concerning the experimental conditions. However, the runs exhibiting typical spikes, mostly under low light and osmotic stress, showed power law distribution with exponent μ ≅ 2, which is an indicative for SOC. Overall, our results have confirmed that the temporal dynamic of the electrical signaling shows a complex non-linear behavior with long-range persistence. Moreover, the hypothesis that plant electrome can exhibit a self-organized critical state evoked by environmental cues, dissipating energy by bursts of electrical spikes without a characteristic size, was reinforced. Finally, new perspectives for research and additional hypothesis were presented.

  10. Diffuse scattering

    Energy Technology Data Exchange (ETDEWEB)

    Kostorz, G. [Eidgenoessische Technische Hochschule, Angewandte Physik, Zurich (Switzerland)

    1996-12-31

    While Bragg scattering is characteristic for the average structure of crystals, static local deviations from the average lattice lead to diffuse elastic scattering around and between Bragg peaks. This scattering thus contains information on the occupation of lattice sites by different atomic species and on static local displacements, even in a macroscopically homogeneous crystalline sample. The various diffuse scattering effects, including those around the incident beam (small-angle scattering), are introduced and illustrated by typical results obtained for some Ni alloys. (author) 7 figs., 41 refs.

  11. Plant-Derived Antimicrobials Reduce E. coli O157:H7 Virulence Factors Critical for Colonization in Cattle Gastrointestinal Tract In Vitro

    Directory of Open Access Journals (Sweden)

    Sangeetha Ananda Baskaran

    2014-01-01

    Full Text Available This study investigated the effect of subinhibitory concentrations (SIC of five plant-derived antimicrobials (PDAs, namely, trans cinnamaldehyde, eugenol, carvacrol, thymol, and β-resorcylic acid, on E. coli O157:H7 (EHEC attachment and invasion of cultured bovine colonic (CO and rectoanal junction (RAJ epithelial cells. In addition, PDAs’ effect on EHEC genes critical for colonization of cattle gastrointestinal tract (CGIT was determined in bovine rumen fluid (RF and intestinal contents (BICs. Primary bovine CO and RAJ epithelial cells were established and were separately inoculated with three EHEC strains with or without (control SIC of each PDA. Following incubation, EHEC that attached and invaded the cells were determined. Furthermore, the expression of EHEC genes critical for colonization in cattle was investigated using real-time, quantitative polymerase chain reaction in RF and BICs. All the PDAs decreased EHEC invasion of CO and RAJ epithelial cells (P<0.05. The PDAs also downregulated (P<0.05 the expression of EHEC genes critical for colonization in CGIT. Results suggest that the PDAs could potentially be used to control EHEC colonization in cattle; however follow-up in vivo studies in cattle are warranted.

  12. KAERI software safety guideline for developing safety-critical software in digital instrumentation and control system of nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jang Soo; Kim, Jang Yeol; Eum, Heung Seop

    1997-07-01

    Recently, the safety planning for safety-critical software systems is being recognized as the most important phase in the software life cycle, and being developed new regulatory positions and standards by the regulatory and the standardization organization. The requirements for software important to safety of nuclear reactor are described in such positions and standards. Most of them are describing mandatory requirements, what shall be done, for the safety-critical software. The developers of such a software. However, there have been a lot of controversial factors on whether the work practices satisfy the regulatory requirements, and to justify the safety of such a system developed by the work practices, between the licenser and the licensee. We believe it is caused by the reason that there is a gap between the mandatory requirements (What) and the work practices (How). We have developed a guidance to fill such gap, which can be useful for both licenser and licensee to conduct a justification of the safety in the planning phase of developing the software for nuclear reactor protection systems. (author). 67 refs., 13 tabs., 2 figs.

  13. KAERI software safety guideline for developing safety-critical software in digital instrumentation and control system of nuclear power plant

    International Nuclear Information System (INIS)

    Lee, Jang Soo; Kim, Jang Yeol; Eum, Heung Seop.

    1997-07-01

    Recently, the safety planning for safety-critical software systems is being recognized as the most important phase in the software life cycle, and being developed new regulatory positions and standards by the regulatory and the standardization organization. The requirements for software important to safety of nuclear reactor are described in such positions and standards. Most of them are describing mandatory requirements, what shall be done, for the safety-critical software. The developers of such a software. However, there have been a lot of controversial factors on whether the work practices satisfy the regulatory requirements, and to justify the safety of such a system developed by the work practices, between the licenser and the licensee. We believe it is caused by the reason that there is a gap between the mandatory requirements (What) and the work practices (How). We have developed a guidance to fill such gap, which can be useful for both licenser and licensee to conduct a justification of the safety in the planning phase of developing the software for nuclear reactor protection systems. (author). 67 refs., 13 tabs., 2 figs

  14. Relativistic diffusion.

    Science.gov (United States)

    Haba, Z

    2009-02-01

    We discuss relativistic diffusion in proper time in the approach of Schay (Ph.D. thesis, Princeton University, Princeton, NJ, 1961) and Dudley [Ark. Mat. 6, 241 (1965)]. We derive (Langevin) stochastic differential equations in various coordinates. We show that in some coordinates the stochastic differential equations become linear. We obtain momentum probability distribution in an explicit form. We discuss a relativistic particle diffusing in an external electromagnetic field. We solve the Langevin equations in the case of parallel electric and magnetic fields. We derive a kinetic equation for the evolution of the probability distribution. We discuss drag terms leading to an equilibrium distribution. The relativistic analog of the Ornstein-Uhlenbeck process is not unique. We show that if the drag comes from a diffusion approximation to the master equation then its form is strongly restricted. The drag leading to the Tsallis equilibrium distribution satisfies this restriction whereas the one of the Jüttner distribution does not. We show that any function of the relativistic energy can be the equilibrium distribution for a particle in a static electric field. A preliminary study of the time evolution with friction is presented. It is shown that the problem is equivalent to quantum mechanics of a particle moving on a hyperboloid with a potential determined by the drag. A relation to diffusions appearing in heavy ion collisions is briefly discussed.

  15. Lack of genetic diversity of a critically endangered important medicinal plant Chlorophytum borivilianum in Central India revealed by AFLP markers.

    Science.gov (United States)

    Tripathi, Niraj; Saini, Navinder; Nair, Priya; Tiwari, Sharad

    2012-04-01

    Chlorophytum borivilianum is a traditional medicinal plant distributed throughout the tropics and subtropics. In the present investigation, AFLP analysis was used to assess the genetic similarity among 34 accessions. Nine primer sets of AFLP amplified 612 fragments, of which 246 fragments were found to be polymorphic. The average number of polymorphic bands per AFLP primer pair was 27.33. The amplified fragments ranged from 50 base pairs to 600 base pairs. Significant correlation was observed between total number of amplified fragments and polymorphic bands (p > 0.05) per primers. Cluster analysis based on AFLP data revealed limited genetic variation within the thirty four accessions collected from various parts of Central Indian forests.

  16. Theoretical reconsiderations when estimating the mesophyll conductance to CO2 diffusion in leaves of C3 plants by analysis of combined gas exchange and chlorophyll fluorescence measurements

    NARCIS (Netherlands)

    Yin, X.; Struik, P.C.

    2009-01-01

    Existing methods to estimate the mesophyll conductance to CO2 diffusion (gm) are often based on combined gas exchange and chlorophyll fluorescence measurements. However, estimations of average gm by these methods are often unreliable either because the range of usable data is too narrow or because

  17. Diffusion and dispersion heat of hydrotermal discharge from power plant; Difusion y dispersion de calor de la descarga hidrotermal de una central termoelectrica

    Energy Technology Data Exchange (ETDEWEB)

    Rendon Villalobos, J. Rodolfo

    1996-12-31

    This study describe the numerical simulation results of hydrodynamical behavior of the surface discharge cooling water to the sea incoming from the Tuxpan Power Plant under two different meteorological and oceanographic conditions; Case I, southwest variable winds average speeds of 3 m s-1 and Case II, northwest variable winds average speeds of 11.10 m s-1 . The numerical simulations were made using a three-dimensional model of coastal circulation and heat exchange. The statistical analysis of the wind speed and direction time series measured from January 1, 1981 to December 31, 1983, shows that the larger part of the winds were predominantly from 180 degrees to 315 degrees. Therefore, the southerly winds induce a sea surface circulation towards the north which move the discharged heat water away from the intake. On the contrary, the north winds drives the hydrothermal effluent towards the intake. Comparisons between the numerical simulation results and field data show that under different meteorological and oceanographic conditions, representative of the Tuxpan Site, the model correctly predicts the hydrothermal effluents surface diffusion and Dispersion measured on August 19-20 and 21, 1992 (Case I) and November 26, 1992 (Case II). The model predicts the extent of the impacted areas with cooling water with a precision of {+-} 11%. For all analyzed cases, the real size of the impacted areas that might have adverse effects on the marine ecosystems was not gibber than 0.1 km{sup 2}. Thus, these possible adverse effects are considered to be of local significance only. The simulated vertical profiles of temperature show that the cooling water discharged remains mostly o the surface of the receiving water mass and reaches a maximum depth of 3.5 m. This floatability if a consequence of the low density and small Froude number (Fr << 1), at the discharge, that characterizes the Tuxpan Power Plant Effluent. [Espanol] Este estudio describe los resultados de la simulacion

  18. Gaseous diffusion -- the enrichment workhorse

    International Nuclear Information System (INIS)

    Shoemaker, J.E. Jr.

    1984-01-01

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

  19. Plant toxin β-ODAP activates integrin β1 and focal adhesion: A critical pathway to cause neurolathyrism.

    Science.gov (United States)

    Tan, Rui-Yue; Xing, Geng-Yan; Zhou, Guang-Ming; Li, Feng-Min; Hu, Wen-Tao; Lambein, Fernand; Xiong, Jun-Lan; Zhang, Sheng-Xiang; Kong, Hai-Yan; Zhu, Hao; Li, Zhi-Xiao; Xiong, You-Cai

    2017-01-17

    Neurolathyrism is a unique neurodegeneration disease caused by β-N-oxalyl-L-α, β- diaminopropionic (β-ODAP) present in grass pea seed (Lathyrus stativus L.) and its pathogenetic mechanism is unclear. This issue has become a critical restriction to take full advantage of drought-tolerant grass pea as an elite germplasm resource under climate change. We found that, in a human glioma cell line, β-ODAP treatment decreased mitochondrial membrane potential, leading to outside release and overfall of Ca 2+ from mitochondria to cellular matrix. Increased Ca 2+ in cellular matrix activated the pathway of ECM, and brought about the overexpression of β1 integrin on cytomembrane surface and the phosphorylation of focal adhesion kinase (FAK). The formation of high concentration of FA units on the cell microfilaments further induced overexpression of paxillin, and then inhibited cytoskeleton polymerization. This phenomenon turned to cause serious cell microfilaments distortion and ultimately cytoskeleton collapse. We also conducted qRT-PCR verification on RNA-sequence data using 8 randomly chosen genes of pathway enrichment, and confirmed that the data was statistically reliable. For the first time, we proposed a relatively complete signal pathway to neurolathyrism. This work would help open a new window to cure neurolathyrism, and fully utilize grass pea germplasm resource under climate change.

  20. Challenges in the application of burn-up credit to the criticality safety of the THORP reprocessing plant

    International Nuclear Information System (INIS)

    Mayson, R.T.H.; Gunston, K.J.

    1999-01-01

    Since 1991 BNFL has made a significant investment in the development of the burn-up credit method and the application to its operations. It has recently demonstrated that using this method for the THORP dissolvers, it is possible to justify operating safety with reduced neutron poison concentrations and this has now been submitted to the regulators. The continued challenges the criticality safety community is facing are to show that we are not reducing safety levels because we are using burn-up credit. The burn-up credit method that has been developed can be summarized as follows. It consists of performing reactivity calculations for irradiated fuel using compositions generated by and inventory prediction code, generally in order to determine the limiting burn-up required for that fuel in a particular environment. In addition, it has always been envisaged that a confirmatory measurement of burn-up would be required to be made prior to certain operations such as the sharing of fuel into a dissolver. The burn-up credit method therefore relies upon three key components of inventory prediction, reactivity calculation code and the quantification and verification of burn-up. (J.P.N.)

  1. Criticality accident in uranium fuel processing plant. Cause analysis and teachings from a viewpoint of a human factor

    International Nuclear Information System (INIS)

    Furuta, Kazuo

    2000-01-01

    On the JCO criticality accident occurred on September 30, 1999, from relatively earlier time since its occurrence it was elucidated that it was formed not by accident and error operation of apparatus and instruments but by unsafe actions of operators beyond regular manual as its direct cause, and that an organizational factor on business managers and safety administration unable to control such unsafe actions of operators at its background. Then, it was judged to be essential to carry out an accident research from a viewpoint of the human factor (HF) for elucidation on essence of the accident, to establish a 'special workshop on the JCO accident research' to investigate elucidation of the accident cause and countermeasure of reoccurrence at a standpoint of HF. As a result, the essential cause of this accident was summarized that safety information such as ideals, information, teachings and so forth necessary for safety management were failed to share among different organizations. As a teaching of this accident, nuclear energy participants must recognize that safety culture is not finished only in specific organization and range but produced by protecting weathering of danger consciousness and effort of mutually exciting and learning by sharing a safety information beyond different organization, range and time. (G.K.)

  2. Criticality Calculations of Fresh LEU and MOX Assemblies for Transport and Storage at the Balakovo Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Goluoglu, S.

    2001-01-11

    Transportation of low-enriched uranium (LEU) and mixed-oxide (MOX) assemblies to and within the VVER-1000-type Balakovo Nuclear Power Plant is investigated. Effective multiplication factors for fresh fuel assemblies on the railroad platform, fresh fuel assemblies in the fuel transportation vehicle, and fresh fuel assemblies in the spent fuel storage pool are calculated. If there is no absorber between the units, the configurations with all MOX assemblies result in higher effective multiplication factors than the configurations with all LEU assemblies when the system is dry. When the system is flooded, the configurations with all LEU assemblies result in higher effective multiplication factors. For normal operating conditions, effective multiplication factors for all configurations are below the presumed upper subcritical limit of 0.95. For an accident condition of a fully loaded fuel transportation vehicle that is flooded with low-density water (possibly from a fire suppression system), the presumed upper subcritical limit is exceeded by configurations containing LEU assemblies.

  3. Critical review of the national action plans (NAcP) of the EU stress tests on nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Oda; Lorenz, Patricia

    2013-04-15

    The Fukushima catastrophe was the horrible result of decades of mistaken safety philosophy, a very lax safety regulation under strong industry influence on the regulators - not only in Japan. The first shock led to the honest attempt to change this, to also involve events which are definitely possible but were kept out of the safety cases by using probabilities. When it was possible to ''prove'' an event as having too low probability, it could be ignored. On 12 October 2012, Tokyo Electric Power Co (TEPCO) admitted that the company had failed to prevent the Fukushima accident, reversing its earlier statement that the accident could not have been foreseen. A TEPCO task force has identified several factors that had led to the accident in March 2011 [NW 18/10/2012]: TEPCO did not learn a lesson from the incident in France of loss of off-site power due to flooding at the Blayais NPP on December 27, 1999, furthermore no safety measures aimed at preventing and mitigating a severe accident had been adopted since 2002. The task force attributed those facts to multiple root causes: - First, the management assumed a severe accident was extremely unlikely in Japan, and feared that retrofitting safety systems would increase anxiety among the public, especially among the residents near the plant. - TEPCO also feared safety retrofitting would require a costly shutdown period. The TEPCO task force also underlined that there were not enough engineers at the site who were familiar with safety systems' designs, operation manuals and their locations. Basically all circumstances leading to the Fukushima accident exist for the European NPP as well - only the tsunami risk does not apply for all NPP but e.g. for several UK NPPs. However the risk of flooding events or of earthquakes exists to a different extent for all NPPs. Also common to all NPPs: the operators insist on the low probabilities to avoid high investments and anti-nuclear activities of the public

  4. Diffusion bonding

    International Nuclear Information System (INIS)

    Anderson, R.C.

    1976-01-01

    A method is described for joining beryllium to beryllium by diffusion bonding. At least one surface portion of at least two beryllium pieces is coated with nickel. A coated surface portion is positioned in a contiguous relationship with another surface portion and subjected to an environment having an atmosphere at a pressure lower than ambient pressure. A force is applied on the beryllium pieces for causing the contiguous surface portions to abut against each other. The contiguous surface portions are heated to a maximum temperature less than the melting temperature of the beryllium, and the applied force is decreased while increasing the temperature after attaining a temperature substantially above room temperature. A portion of the applied force is maintained at a temperature corresponding to about maximum temperature for a duration sufficient to effect the diffusion bond between the contiguous surface portions

  5. Multipassage diffuser

    International Nuclear Information System (INIS)

    Lalis, A.; Rouviere, R.; Simon, G.

    1976-01-01

    A multipassage diffuser having 2p passages comprises a leak-tight cylindrical enclosure closed by a top cover and a bottom end-wall, parallel porous tubes which are rigidly assembled in sectors between tube plates and through which the gas mixture flows, the tube sectors being disposed at uniform intervals on the periphery of the enclosure. The top tube plates are rigidly fixed to an annular header having the shape of a half-torus and adapted to communicate with the tubes of the corresponding sector. Each passage is constituted by a plurality of juxtaposed sectors in which the mixture circulates in the same direction, the header being divided into p portions limited by radial partition-walls and each constituting two adjacent passages. The diffuser is provided beneath the bottom end-wall with p-1 leak-tight chambers each adapted to open into two different portions of the header, and with two collector-chambers each fitted with a nozzle for introducing the gas mixture and discharging the fraction of the undiffused mixture. By means of a central orifice formed in the bottom end-wall the enclosure communicates with a shaft for discharging the diffused fraction of the gas mixture

  6. Enhancement of diffusers BRDF accuracy

    Science.gov (United States)

    Otter, Gerard; Bazalgette Courrèges-Lacoste, Gregory; van Brug, Hedser; Schaarsberg, Jos Groote; Delwart, Steven; del Bello, Umberto

    2017-11-01

    This paper reports the result of an ESA study conducted at TNO to investigate properties of various diffusers. Diffusers are widely used in space instruments as part of the on-board absolute calibration. Knowledge of the behaviour of the diffuser is therefore most important. From measurements of launched instruments in-orbit it has been discovered that when a diffuser is used in the vacuum of space the BRDF can change with respect to the one in ambient conditions. This is called the air/vacuum effect and has been simulated in this study by measuring the BRDF in a laboratory in ambient as well as vacuum conditions. Another studied effect is related to the design parameters of the optical system and the scattering properties of the diffuser. The effect is called Spectral Features and is a noise like structure superimposed on the diffuser BRDF. Modern space spectrometers, which have high spectral resolution and/or a small field of view (high spatial resolution) are suffering from this effect. The choice of diffuser can be very critical with respect to the required absolute radiometric calibration of an instrument. Even if the Spectral Features are small it can influence the error budget of the retrieval algorithms for the level 2 products. in this presentation diffuser trade-off results are presented and the Spectral Features model applied to the optical configuration of the MERIS instrument is compared to in-flight measurements of MERIS.

  7. Investigation of critical safety function “Heat sink” at low power and cold condition for Kozloduy Nuclear Power Plant WWER-1000/V320

    International Nuclear Information System (INIS)

    Andreeva, M.; Pavlova, M.P.; Groudev, P.P.

    2012-01-01

    Highlights: ► In this study we investigated three scenarios with loss of CSF “Heat Sink”. ► The reference power plant for the analyses is Unit 6 at Kozloduy NPP. ► The RELAP/MOD 3.2 computer code is used in performing the analyses. ► The results are used for analytical validation of EOP at low power. - Abstract: This paper presents the results of thermal–hydraulic calculation of accident scenarios that involve the loss of critical safety function (CSF) “Heat sink” for WWER-1000/V320 units at Kozloduy Nuclear Power Plant (KNPP), done during the development of Symptom Based Emergency Operating Procedures (SB EOPs) for this plant at low power and cold condition. The main purpose of this analysis is to provide the response of monitored plant parameters to identify symptoms available to the operators and define timing for reaching the following stages during the development of processes in the reactor system: •Reaching the saturated temperature at the outlet of the assembly. •Beginning of reactor core uncovery. •Heating up of fuel. •Defining the transition time between EOPs and SAMG at temperature of 923 K. •Restoring of water level in the core. •Defining the CSF “Heat sink” status and the time of its loss. The results of the thermal–hydraulic analyses have been used to assist KNPP specialists in analytical validation of EOPs at low power and cold condition. The principal acceptance criteria for EOPs are averting the onset of core damage. The RELAP5/MOD3.2 computer code has been used in performing the analyses in a WWER-1000 Nuclear Power Plant (NPP) model. A model of WWER-1000 based on Unit 6 of Kozloduy NPP has been developed for the systems thermal–hydraulics code RELAP5/MOD3.2 at the Institute for Nuclear Research and Nuclear Energy–Bulgarian Academy of Sciences (INRNE–BAS), Sofia. The low power and cold condition and the modifications after the modernization program are taken into account.

  8. Diffusion of treatment in social networks and mass drug administration

    NARCIS (Netherlands)

    Chami, Goylette F.; Kontoleon, Andreas A.; Bulte, Erwin; Fenwick, Alan; Kabatereine, Narcis B.; Tukahebwa, Edridah M.; Dunne, David W.

    2017-01-01

    Information, behaviors, and technologies spread when people interact. Understanding these interactions is critical for achieving the greatest diffusion of public interventions. Yet, little is known about the performance of starting points (seed nodes) for diffusion. We track routine mass drug

  9. Design verification enhancement of field programmable gate array-based safety-critical I&C system of nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Ibrahim [Department of Nuclear Engineering, Kyung Hee University, 1732 Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 17104 (Korea, Republic of); Jung, Jaecheon, E-mail: jcjung@kings.ac.kr [Department of Nuclear Power Plant Engineering, KEPCO International Nuclear Graduate School, 658-91 Haemaji-ro, Seosang-myeon, Ulju-gun, Ulsan 45014 (Korea, Republic of); Heo, Gyunyoung [Department of Nuclear Engineering, Kyung Hee University, 1732 Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 17104 (Korea, Republic of)

    2017-06-15

    Highlights: • An enhanced, systematic and integrated design verification approach is proposed for V&V of FPGA-based I&C system of NPP. • RPS bistable fixed setpoint trip algorithm is designed, analyzed, verified and discussed using the proposed approaches. • The application of integrated verification approach simultaneously verified the entire design modules. • The applicability of the proposed V&V facilitated the design verification processes. - Abstract: Safety-critical instrumentation and control (I&C) system in nuclear power plant (NPP) implemented on programmable logic controllers (PLCs) plays a vital role in safe operation of the plant. The challenges such as fast obsolescence, the vulnerability to cyber-attack, and other related issues of software systems have currently led to the consideration of field programmable gate arrays (FPGAs) as an alternative to PLCs because of their advantages and hardware related benefits. However, safety analysis for FPGA-based I&C systems, and verification and validation (V&V) assessments still remain important issues to be resolved, which are now become a global research point of interests. In this work, we proposed a systematic design and verification strategies from start to ready-to-use in form of model-based approaches for FPGA-based reactor protection system (RPS) that can lead to the enhancement of the design verification and validation processes. The proposed methodology stages are requirement analysis, enhanced functional flow block diagram (EFFBD) models, finite state machine with data path (FSMD) models, hardware description language (HDL) code development, and design verifications. The design verification stage includes unit test – Very high speed integrated circuit Hardware Description Language (VHDL) test and modified condition decision coverage (MC/DC) test, module test – MATLAB/Simulink Co-simulation test, and integration test – FPGA hardware test beds. To prove the adequacy of the proposed

  10. Design verification enhancement of field programmable gate array-based safety-critical I&C system of nuclear power plant

    International Nuclear Information System (INIS)

    Ahmed, Ibrahim; Jung, Jaecheon; Heo, Gyunyoung

    2017-01-01

    Highlights: • An enhanced, systematic and integrated design verification approach is proposed for V&V of FPGA-based I&C system of NPP. • RPS bistable fixed setpoint trip algorithm is designed, analyzed, verified and discussed using the proposed approaches. • The application of integrated verification approach simultaneously verified the entire design modules. • The applicability of the proposed V&V facilitated the design verification processes. - Abstract: Safety-critical instrumentation and control (I&C) system in nuclear power plant (NPP) implemented on programmable logic controllers (PLCs) plays a vital role in safe operation of the plant. The challenges such as fast obsolescence, the vulnerability to cyber-attack, and other related issues of software systems have currently led to the consideration of field programmable gate arrays (FPGAs) as an alternative to PLCs because of their advantages and hardware related benefits. However, safety analysis for FPGA-based I&C systems, and verification and validation (V&V) assessments still remain important issues to be resolved, which are now become a global research point of interests. In this work, we proposed a systematic design and verification strategies from start to ready-to-use in form of model-based approaches for FPGA-based reactor protection system (RPS) that can lead to the enhancement of the design verification and validation processes. The proposed methodology stages are requirement analysis, enhanced functional flow block diagram (EFFBD) models, finite state machine with data path (FSMD) models, hardware description language (HDL) code development, and design verifications. The design verification stage includes unit test – Very high speed integrated circuit Hardware Description Language (VHDL) test and modified condition decision coverage (MC/DC) test, module test – MATLAB/Simulink Co-simulation test, and integration test – FPGA hardware test beds. To prove the adequacy of the proposed

  11. Solute Diffusivity in Undisturbed Soil

    DEFF Research Database (Denmark)

    Lægdsmand, Mette K.; Møldrup, Per; Schjønning, Per

    2012-01-01

    diffusivities independent of the tracer set used. We analyzed the whole data set using Archie's law and found a linear relation between Archie's exponent and the logarithm of the soil water matric suction in centimeters of water (pF). An analysis of seven data sets from the literature showed......Solute diffusivity in soil plays a major role in many important processes with relation to plant growth and environmental issues. Soil solute diffusivity is affected by the volumetric water content as well as the morphological characteristics of water-filled pores. The solute diffusivity in intact...... soil samples from two different tillage treatments (soil from below the depth of a harrow treatment and soil from within a moldboard plowed plow layer) was estimated based on concentration profiles using a newly developed method. The method makes use of multiple tracers (two sets of counterdiffusing...

  12. Diffusion coefficient in photon diffusion theory

    NARCIS (Netherlands)

    Graaff, R; Ten Bosch, JJ

    2000-01-01

    The choice of the diffusion coefficient to be used in photon diffusion theory has been a subject of discussion in recent publications on tissue optics. We compared several diffusion coefficients with the apparent diffusion coefficient from the more fundamental transport theory, D-app. Application to

  13. Diffusing Best Practices

    DEFF Research Database (Denmark)

    Pries-Heje, Jan; Baskerville, Richard

    2014-01-01

    Both the practice and the research literature on information systems attach great value to the identification and dissemination of information on “best practices”. In the philosophy of science, this type of knowledge is regarded as technological knowledge because it becomes manifest in the succes...... that the behavior will be effective). These two factors were especially critical if the source context of the best practice is qualitatively different from the target context into which the organization is seeking to diffuse the best practice.......Both the practice and the research literature on information systems attach great value to the identification and dissemination of information on “best practices”. In the philosophy of science, this type of knowledge is regarded as technological knowledge because it becomes manifest...... approach. The study context is a design case in which an organization desires to diffuse its best practices across different groups. The design goal is embodied in organizational mechanisms to achieve this diffusion. The study used Theory of Planned Behavior (TPB) as a kernel theory. The artifacts...

  14. Dependence of Plant Uptake and Diffusion of Polycyclic Aromatic Hydrocarbons on the Leaf Surface Morphology and Micro-structures of Cuticular Waxes

    Science.gov (United States)

    Li, Qingqing; Li, Yungui; Zhu, Lizhong; Xing, Baoshan; Chen, Baoliang

    2017-04-01

    The uptake of organic chemicals by plants is considered of great significance as it impacts their environmental transport and fate and threatens crop growth and food safety. Herein, the dependence of the uptake, penetration, and distribution of sixteen polycyclic aromatic hydrocarbons (PAHs) on the morphology and micro-structures of cuticular waxes on leaf surfaces was investigated. Plant surface morphologies and wax micro-structures were examined by scanning emission microscopy, and hydrophobicities of plant surfaces were monitored through contact angle measurements. PAHs in the cuticles and inner tissues were distinguished by sequential extraction, and the cuticle was verified to be the dominant reservoir for the accumulation of lipophilic pollutants. The interspecies differences in PAH concentrations cannot be explained by normalizing them to the plant lipid content. PAHs in the inner tissues became concentrated with the increase of tissue lipid content, while a generally negative correlation between the PAH concentration in cuticles and the epicuticular wax content was found. PAHs on the adaxial and abaxial sides of a leaf were differentiated for the first time, and the divergence between these two sides can be ascribed to the variations in surface morphologies. The role of leaf lipids was redefined and differentiated.

  15. CriticalEd

    DEFF Research Database (Denmark)

    Kjellberg, Caspar Mølholt; Meredith, David

    2014-01-01

    such as Sibelius or Finale. It was hypothesized that it would be possible to develop a Sibelius plug-in, written in Manuscript 6, that would improve the critical editing work flow, but it was found that the capabilities of this scripting language were insufficient. Instead, a 3-part system was designed and built......, consisting of a Sibelius plug-in, a cross-platform application, called CriticalEd, and a REST-based solution, which handles data storage/retrieval. A prototype has been tested at the Danish Centre for Music Publication, and the results suggest that the system could greatly improve the efficiency......The best text method is commonly applied among music scholars engaged in producing critical editions. In this method, a comment list is compiled, consisting of variant readings and editorial emendations. This list is maintained by inserting the comments into a document as the changes are made...

  16. An axisymmetric diffusion experiment for the determination of diffusion and sorption coefficients of rock samples.

    Science.gov (United States)

    Takeda, M; Hiratsuka, T; Ito, K; Finsterle, S

    2011-04-25

    Diffusion anisotropy is a critical property in predicting migration of substances in sedimentary formations with very low permeability. The diffusion anisotropy of sedimentary rocks has been evaluated mainly from laboratory diffusion experiments, in which the directional diffusivities are separately estimated by through-diffusion experiments using different rock samples, or concurrently by in-diffusion experiments in which only the tracer profile in a rock block is measured. To estimate the diffusion anisotropy from a single rock sample, this study proposes an axisymmetric diffusion test, in which tracer diffuses between a cylindrical rock sample and a surrounding solution reservoir. The tracer diffusion between the sample and reservoir can be monitored from the reservoir tracer concentrations, and the tracer profile could also be obtained after dismantling the sample. Semi-analytical solutions are derived for tracer concentrations in both the reservoir and sample, accounting for an anisotropic diffusion tensor of rank two as well as the dilution effects from sampling and replacement of reservoir solution. The transient and steady-state analyses were examined experimentally and numerically for different experimental configurations, but without the need for tracer profiling. These experimental configurations are tested for in- and out-diffusion experiments using Koetoi and Wakkanai mudstones and Shirahama sandstone, and are scrutinized by a numerical approach to identify favorable conditions for parameter estimation. The analysis reveals the difficulty in estimating diffusion anisotropy; test configurations are proposed for enhanced identifiability of diffusion anisotropy. Moreover, it is demonstrated that the axisymmetric diffusion test is efficient in obtaining the sorption parameter from both steady-state and transient data, and in determining the effective diffusion coefficient if isotropic diffusion is assumed. Moreover, measuring reservoir concentrations in an

  17. An asixymmetric diffusion experiment for the determination of diffusion and sorption coefficients of rock samples

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, M.; Hiratsuka, T.; Ito, K.; Finsterle, S.

    2011-02-01

    Diffusion anisotropy is a critical property in predicting migration of substances in sedimentary formations with very low permeability. The diffusion anisotropy of sedimentary rocks has been evaluated mainly from laboratory diffusion experiments, in which the directional diffusivities are separately estimated by through-diffusion experiments using different rock samples, or concurrently by in-diffusion experiments in which only the tracer profile in a rock block is measured. To estimate the diffusion anisotropy from a single rock sample, this study proposes an axisymmetric diffusion test, in which tracer diffuses between a cylindrical rock sample and a surrounding solution reservoir. The tracer diffusion between the sample and reservoir can be monitored from the reservoir tracer concentrations, and the tracer profile could also be obtained after dismantling the sample. Semi-analytical solutions are derived for tracer concentrations in both the reservoir and sample, accounting for an anisotropic diffusion tensor of rank two as well as the dilution effects from sampling and replacement of reservoir solution. The transient and steady-state analyses were examined experimentally and numerically for different experimental configurations, but without the need for tracer profiling. These experimental configurations are tested for in- and out-diffusion experiments using Koetoi and Wakkanai mudstones and Shirahama sandstone, and are scrutinized by a numerical approach to identify favorable conditions for parameter estimation. The analysis reveals the difficulty in estimating diffusion anisotropy; test configurations are proposed for enhanced identifiability of diffusion anisotropy. Moreover, it is demonstrated that the axisymmetric diffusion test is efficient in obtaining the sorption parameter from both steady-state and transient data, and in determining the effective diffusion coefficient if isotropic diffusion is assumed. Moreover, measuring reservoir concentrations in an

  18. Uranium enrichment by diffusion process

    International Nuclear Information System (INIS)

    Petit, J.F.

    1977-01-01

    A brief history of the process is given, and existing facilities are described, and the possibility of this process meeting the needs for enriched uranium in the future is discussed. It is concluded that, since other separation techniques have not yet been proven to be competitive, the gaseous diffusion process must be relied on to meet most of these needs. However, because of the high energy consumption required by this process, attempts to improve the technology must be continued. Is the gaseous diffusion process able to meet this challenge. Considering the technical viewpoint, there is no doubt about it. From the economical standpoint, this process is mainly characterized by an important energy consumption and the necessity to build large plants, thus leading to an important investment, at least for the first plant. Other processes have been developed with a view to reduce both the energy and capital needs. However, in spite of continuous studies and technological progress no process has yet been proven to be competitive. Large increments in capacities are still expected to come from the gaseous diffusion and several projects taking into acount the improvements in the flexibility, automatization, reliability and a reduced investment, will be analysed. Coupling of new facilities to existing plants has already proven to be of great interest. This situation explains why further investigations concerning the gaseous diffusion are being carried on, together with the study of new processes [fr

  19. Theoretical reconsiderations when estimating the mesophyll conductance to CO(2) diffusion in leaves of C(3) plants by analysis of combined gas exchange and chlorophyll fluorescence measurements.

    Science.gov (United States)

    Yin, Xinyou; Struik, Paul C

    2009-11-01

    Existing methods to estimate the mesophyll conductance to CO(2) diffusion (g(m)) are often based on combined gas exchange and chlorophyll fluorescence measurements. However, estimations of average g(m) by these methods are often unreliable either because the range of usable data is too narrow or because the estimations are very sensitive to measurement errors. We describe three method variants to estimate g(m), for which a wider range of data are usable. They use curve-fitting techniques, which minimise the sum of squared model deviations from the data for A (CO(2) assimilation rate) or for J (linear electron transport rate). Like the existing approaches, they are all based on common physiological principles assuming that electron transport limits A. The proposed variants were far less sensitive than the existing approaches to 'measurement noise' either created randomly in the generated data set or inevitably existing in real data sets. Yet, the estimates of g(m) from the three variants differed by approximately 15%. Moreover, for each variant, a stoichiometric uncertainty in linear electron transport-limited photosynthesis can cause another 15% difference. Any estimation of g(m) using gas exchange and chlorophyll fluorescence measurements should be considered with caution, especially when g(m) is high.

  20. Diffusion archeology for diffusion progression history reconstruction.

    Science.gov (United States)

    Sefer, Emre; Kingsford, Carl

    2016-11-01

    Diffusion through graphs can be used to model many real-world processes, such as the spread of diseases, social network memes, computer viruses, or water contaminants. Often, a real-world diffusion cannot be directly observed while it is occurring - perhaps it is not noticed until some time has passed, continuous monitoring is too costly, or privacy concerns limit data access. This leads to the need to reconstruct how the present state of the diffusion came to be from partial diffusion data. Here, we tackle the problem of reconstructing a diffusion history from one or more snapshots of the diffusion state. This ability can be invaluable to learn when certain computer nodes are infected or which people are the initial disease spreaders to control future diffusions. We formulate this problem over discrete-time SEIRS-type diffusion models in terms of maximum likelihood. We design methods that are based on submodularity and a novel prize-collecting dominating-set vertex cover (PCDSVC) relaxation that can identify likely diffusion steps with some provable performance guarantees. Our methods are the first to be able to reconstruct complete diffusion histories accurately in real and simulated situations. As a special case, they can also identify the initial spreaders better than the existing methods for that problem. Our results for both meme and contaminant diffusion show that the partial diffusion data problem can be overcome with proper modeling and methods, and that hidden temporal characteristics of diffusion can be predicted from limited data.

  1. Environmental Assessment for the sale of excess lithium hydroxide stored at the Oak Ridge K-25 Site and the Portsmouth Gaseous Diffusion Plant

    Energy Technology Data Exchange (ETDEWEB)

    1993-04-01

    The Department of Energy (DOE) has prepared an Environmental Assessment (EA) (DOE/EA-0855) for a competitive bid market sale of 80 million pounds of government surplus lithium hydroxide monohydrate (LiOH). The LiOH is no longer required for federal activities but is worth tens of millions of dollars in the commercial market. The purpose of the sale is to limit potential environmental liabilities associated with the storage of large quantities of LiOH, free critically needed storage space, reduce storage and maintenance costs currently estimated at $1M/year, and generate revenue for the Federal government. Based on the analysis in the EA, DOE has determined that the proposed action is not a major Federal action significantly affecting the quality of the human environment within the definition of the National Environmental Policy Act (NEPA) of 1969. Therefore, the preparation of an environmental impact statement is not required.

  2. Operational experience and performance characteristics of a valve-regulated lead-acid battery energy-storage system for providing the customer with critical load protection and energy-management benefits at a lead-recycling plant

    Science.gov (United States)

    Hunt, G. W.

    The Power Control Division of GNB Technologies, commissioned on May 13, 1996 a new facility which houses a 5-MW battery energy-storage system (BESS) at GNB's Lead Recycling Centre in Vernon, CA. When the plant loses utility power (which typically happens two or three times a year), the BESS will provide up to 5 MW of power at 4160 VAC in support of all the plant loads. Since the critical loads are not isolated, it is necessary to carry the entire plant load (maximum of 5 MVA) for a short period immediately following an incident until non-critical loads have been automatically shed. Plant loading typically peaks at 3.5 MVA with critical loads of about 2.1 MVA. The BESS also provides the manufacturing plant with customer-side-of-the-meter energy management options to reduce its energy demand during peak periods of the day. The BESS has provided a reduction in monthly electric bills through daily peak-shaving. By design, the battery can provide up to 2.5 MWh of energy and still retain 2.5 MWh of capacity in reserve to handle the possibility of a power outage in protecting the critical loads for up to 1 h. By storing energy from the utility during off-peak hours of the night in the batteries when the cost is low (US4.5¢ per kWh), GNB can then discharge this energy during high demand periods of the day (US14.50 per kW). For example, by reducing its peak demand by 300 kW, the lead-recycling centre can save over US4000 per month in its electric bills. The BESS at Vernon represents a first large-scale use of valve-regulated lead-acid batteries in such a demanding application. This paper presents a summary of the operational experience and performance characteristics of the BESS over the past 2 years.

  3. Excess Entropy and Diffusivity

    Indian Academy of Sciences (India)

    First page Back Continue Last page Graphics. Excess Entropy and Diffusivity. Excess entropy scaling of diffusivity (Rosenfeld,1977). Analogous relationships also exist for viscosity and thermal conductivity.

  4. Diffusive gas transport through flooded rice systems

    NARCIS (Netherlands)

    Bodegom, van P.M.; Groot, T.; Hout, van de B.; Leffelaar, P.A.; Goudriaan, J.

    2001-01-01

    A fully mechanistic model based on diffusion equations for gas transport in a flooded rice system is presented. The model has transport descriptions for various compartments in the water-saturated soil and within the plant. Plant parameters were estimated from published data and experiments

  5. Evaluation of natural attenuation processes for trichloroethylene and technetium-99 in the Northeast and Northwest plumes at the Paducah Gaseous Diffusion Plant, Paducah, Kentucky

    Energy Technology Data Exchange (ETDEWEB)

    Clausen, J.L.; Sturchio, N.C.; Heraty, L.J.; Huang, L.; Abrajano,T.

    1997-11-25

    NA processes such as biodegradation, sorption, dilution dispersion, advection, and possibly sorption and diffusion are occurring in the Northeast and Northwest plumes. However, the overall biological attenuation rate for TCE within the plumes is not sufficiently rapid to utilize as remedial option. The mobility and toxicity of {sup 99}Tc is not being reduced by attenuating processes within the Northwest Plume. The current EPA position is that NA is not a viable remedial approach unless destructive processes are present or processes are active which reduce the toxicity and mobility of a contaminant. Therefore, active remediation of the dissolved phase plumes will be necessary to reduce contaminant concentrations before an NA approach could be justified at PGDP for either plume. Possible treatment methods for the reduction of dissolved phase concentrations within the plumes are pump-and-treat bioaugmentation, biostimulation, or multiple reactive barriers. Another possibility is the use of a regulatory instrument such as an Alternate Concentration Limit (ACL) petition. Biodegradation of TCE is occurring in both plumes and several hypothesis are possible to explain the apparent conflicts with some of the geochemical data. The first hypothesis is active intrinsic bioremediation is negligible or so slow to be nonmeasurable. In this scenario, the D.O., chloride, TCE, and isotopic results are indicative of past microbiological reactions. It is surmised in this scenario, that when the initial TCE release occurred, sufficient energy sources were available for microorganisms to drive aerobic reduction of TCE, but these energy sources were rapidly depleted. The initial degraded TCE has since migrated to downgradient locations. In the second scenario, TCE anaerobic degradation occurs in organic-rich micro-environments within a generally aerobic aquifer. TCE maybe strongly absorbed to organic-rich materials in the aquifer matrix and degraded by local Immunities of microbes

  6. National Seminar on the Diffusion of New Instructional Materials and Practices. Perspectives on Diffusion.

    Science.gov (United States)

    Rogers, Everett M.; And Others

    The nature and timing of decisions regarding the diffusion of new instructional materials and practices are critical to the ultimate utility achieved by a curriculum project. This publication is a collection of five conference papers which deal with various aspects of diffusion of innovative materials and ideas. Everett M. Rogers discusses two…

  7. Inward Cationic Diffusion and Percolation Transition in Glass-Ceramics

    DEFF Research Database (Denmark)

    Smedsklaer, Morten Mattrup; Yue, Yuanzheng; Mørup, Steen

    2010-01-01

    We show the quantitative correlation between the degree of crystallization and the cationic diffusion extent in iron-containing diopside glass–ceramics at the glass transition temperature. We find a critical degree of crystallization, above which the diffusion extent sharply drops with the degree...... of crystallization. Below the critical value, the diffusion extent decreases only slightly with the degree of crystallization. No cationic diffusion is observed in the fully crystalline materials. The critical value might be associated with a percolation transition from an interconnected to a disconnected glass...

  8. STRUKTUR KOMUNITAS TUMBUHAN DAN FAKTOR LINGKUNGAN DI LAHAN KRITIS, IMOGIRI YOGYAKARTA (Community Structure of Plant and Environmental Factor in Critical Land, Imogiri Yogyakarta

    Directory of Open Access Journals (Sweden)

    Maizer Said Nahdi

    2014-05-01

    Full Text Available ABSTRAK Penelitian bertujuan mempelajari struktur komunitas tumbuhan pada berbagai tingkat pertumbuhan  sebagai  respon  terhadap aktivitas masyarakat, dan kualitas fisik kimia tanah yang terbentuk di kawasan lahan kritis Imogiri. Metode penelitian menggunakan kuadrat plot, dengan  ukuran plot 1x1, 5x5, 10x10, ulangan 6 – 10 diletakkan secara stratified random sampling. Pengumpulan data dengan mengamati kehadiran cacah spesies, dihitung kerapatan, dominansi, frekuensi spesies, dan Nilai Penting. Analisis ordinasi dua dimensi digunakan untuk mengelompokkan komunitas pada berbagai tingkat pertumbuhan, dengan analisis t-test untuk uji signifikansi unsur fisik kimia tanah. Hasil penelitian ditemukan 303 spesies, terdiri dari 34 tingkat pohon, 62 sapling dan 207 tumbuhan bawah dengan distribusi yang bervariasi. Kemelimpahan menunjukkan bahwa pada tingkat pohon terjadi pengelompokan, sedangkan pada tingkat sapling dan tumbuhan bawah mengumpul menjadi satu. Dalbergia sisso tingkat pohon dan sapling serta tumbuhan bawah  Euphatorium inulifolium merupakan spesies paling dominan dan merespon kondisi lahan kritis sehingga dapat dijumpai pada semua lokasi kajian. Kemelimpahan tingkat pohon sangat dipengaruhi oleh aktivitas masyarakat, dan mineral organik yang terbentuk sehingga didominasi vegetasi dengan nilai ekonomi tinggi. Sedangkan kehadiran spesies tingkat sapling dan tumbuhan bawah merespon kandungan hara yang terbentuk.   ABSTRACT The purpose of this research was to study the community structure of plant at different growth-forms in response to the activities of the local community (people and the physico-chemical characteristics of soil in the critical land of Imogiri. The research methods employed random quadrat with plot size of 1 x 1, 5 x 5, 10 x 10 m.  The placement of the plot followed stratified random sampling. At each plot, species richness, density, dominance, frequency of species, importance values were calculated. The grouping of

  9. Diffusion in solids

    International Nuclear Information System (INIS)

    Tiwari, G.P.; Kale, G.B.; Patil, R.V.

    1999-01-01

    The article presents a brief survey of process of diffusion in solids. It is emphasised that the essence of diffusion is the mass transfer through the atomic jumps. To begin with formal equations for diffusion coefficient are presented. This is followed by discussions on mechanisms of diffusion. Except for solutes which form interstitial solid solution, diffusion in majority of cases is mediated through exchange of sites between an atom and its neighbouring vacancy. Various vacancy parameters such as activation volume, correlation factor, mass effect etc are discussed and their role in establishing the mode of diffusion is delineated. The contribution of dislocations and grain boundaries in diffusion process is brought out. The experimental determination of different types of diffusion coefficients are described. Finally, the pervasive nature of diffusion process in number of commercial processes is outlined to show the importance of diffusion studies in materials science and technology. (author)

  10. Diffusion archeology for diffusion progression history reconstruction

    OpenAIRE

    Sefer, Emre; Kingsford, Carl

    2015-01-01

    Diffusion through graphs can be used to model many real-world processes, such as the spread of diseases, social network memes, computer viruses, or water contaminants. Often, a real-world diffusion cannot be directly observed while it is occurring — perhaps it is not noticed until some time has passed, continuous monitoring is too costly, or privacy concerns limit data access. This leads to the need to reconstruct how the present state of the diffusion came to be from partial d...

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-07-01

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

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

    International Nuclear Information System (INIS)

    1996-07-01

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

  13. Nonlinear acceleration of transport criticality problems

    International Nuclear Information System (INIS)

    Park, H.; Knoll, D.A.; Newman, C.K.

    2011-01-01

    We present a nonlinear acceleration algorithm for the transport criticality problem. The algorithm combines the well-known nonlinear diffusion acceleration (NDA) with a recently developed, Newton-based, nonlinear criticality acceleration (NCA) algorithm. The algorithm first employs the NDA to reduce the system to scalar flux, then the NCA is applied to the resulting drift-diffusion system. We apply a nonlinear elimination technique to eliminate the eigenvalue from the Jacobian matrix. Numerical results show that the algorithm reduces the CPU time a factor of 400 in a very diffusive system, and a factor of 5 in a non-diffusive system. (author)

  14. Diffusion mechanisms in grain boundaries in solids

    International Nuclear Information System (INIS)

    Peterson, N.L.

    1982-01-01

    A critical review is given of our current knowledge of grain-boundary diffusion in solids. A pipe mechanism of diffusion based on the well-established dislocation model seems most appropriate for small-angle boundaries. Open channels, which have atomic configurations somewhat like dislocation cores, probably play a major role in large-angle grain-boundary diffusion. Dissociated dislocations and stacking faults are not efficient paths for grain-boundary diffusion. The diffusion and computer modeling experiments are consistent with a vacancy mechanism of diffusion by a rather well-localized vacancy. The effective width of a boundary for grain-boundary diffusion is about two atomic planes. These general features of grain-boundary diffusion, deduced primarily from experiments on metals, are thought to be equally applicable for pure ceramic solids. The ionic character of many ceramic oxides may cause some differences in grain-boundary structure from that observed in metals, resulting in changes in grain-boundary diffusion behavior. 72 references, 5 figures

  15. Characterizing unsaturated diffusion in porous tuff gravel

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Qinhong; Kneafsey, Timothy J.; Roberts, Jeffery J.; Tomutsa, Liviu; Wang, Joseph, S.Y.

    2003-11-12

    Evaluation of solute diffusion in unsaturated porous gravel is very important for investigations of contaminant transport and remediation, risk assessment, and waste disposal (for example, the potential high-level nuclear waste repository at Yucca Mountain, Nevada). For a porous aggregate medium such as granular tuff, the total water content is comprised of surface water and interior water. The surface water component (water film around grains and pendular water between the grain contacts) could serve as a predominant diffusion pathway. To investigate the extent to which surface water films and contact points affect solute diffusion in unsaturated gravel, we examined the configuration of water using x-ray computed tomography in partially saturated gravel, and made quantitative measurements of diffusion at multiple water contents using two different techniques. In the first, diffusion coefficients of potassium chloride in 2-4 mm granular tuff at multiple water contents were calculated from electrical conductivity measurements using the Nernst-Einstein equation. In the second, we used laser ablation with inductively coupled plasma-mass spectrometry to perform micro-scale mapping, allowing the measurement of diffusion coefficients for a mixture of chemical tracers for tuff cubes and tetrahedrons having two contact geometries (cube-cube and cube-tetrahedron). The x-ray computed tomography images show limited contact between grains, and this could hinder the pathways for diffusive transport. Experimental results show the critical role of surface water in controlling transport pathways and hence the magnitude of diffusion. Even with a bulk volumetric water content of 1.5%, the measured solute diffusion coefficient is as low as 1.5 x 10{sup -14} m{sup 2}/s for tuff gravel. Currently used diffusion models relating diffusion coefficients to total volumetric water content inadequately describe unsaturated diffusion behavior in porous gravel at very low water contents.

  16. Spin-diffusions and diffusive molecular dynamics

    Science.gov (United States)

    Farmer, Brittan; Luskin, Mitchell; Plecháč, Petr; Simpson, Gideon

    2017-12-01

    Metastable configurations in condensed matter typically fluctuate about local energy minima at the femtosecond time scale before transitioning between local minima after nanoseconds or microseconds. This vast scale separation limits the applicability of classical molecular dynamics (MD) methods and has spurned the development of a host of approximate algorithms. One recently proposed method is diffusive MD which aims at integrating a system of ordinary differential equations describing the likelihood of occupancy by one of two species, in the case of a binary alloy, while quasistatically evolving the locations of the atoms. While diffusive MD has shown itself to be efficient and provide agreement with observations, it is fundamentally a model, with unclear connections to classical MD. In this work, we formulate a spin-diffusion stochastic process and show how it can be connected to diffusive MD. The spin-diffusion model couples a classical overdamped Langevin equation to a kinetic Monte Carlo model for exchange amongst the species of a binary alloy. Under suitable assumptions and approximations, spin-diffusion can be shown to lead to diffusive MD type models. The key assumptions and approximations include a well-defined time scale separation, a choice of spin-exchange rates, a low temperature approximation, and a mean field type approximation. We derive several models from different assumptions and show their relationship to diffusive MD. Differences and similarities amongst the models are explored in a simple test problem.

  17. Microfabricated diffusion source

    Science.gov (United States)

    Oborny, Michael C [Albuquerque, NM; Frye-Mason, Gregory C [Cedar Crest, NM; Manginell, Ronald P [Albuquerque, NM

    2008-07-15

    A microfabricated diffusion source to provide for a controlled diffusion rate of a vapor comprises a porous reservoir formed in a substrate that can be filled with a liquid, a headspace cavity for evaporation of the vapor therein, a diffusion channel to provide a controlled diffusion of the vapor, and an outlet to release the vapor into a gas stream. The microfabricated diffusion source can provide a calibration standard for a microanalytical system. The microanalytical system with an integral diffusion source can be fabricated with microelectromechanical systems technologies.

  18. One safety critical indicators model for regulatory actions on nuclear power plants based on a level 1 PSA; Um modelo de indicadores criticos de seguranca para acoes regulatorias em usinas nucleares baseado em uma APS nivel 1

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Jefferson Borges

    2006-03-15

    This study presents a general methodology to the establishment, selection and use of safety indicators for a two loop PWR plant, as Angra 1. The study performed identifies areas considered critical for the plant operational safety. For each of these areas, strategic sub-areas are defined. For each strategic sub-area, specific safety indicators are defined. These proposed Safety Indicators are based on the contribution to risk considering a quantitative risk analysis. For each safety indicator, a goal, a bounded interval and proper bases are developed, to allow for a clear and comprehensive individual behavior evaluation. Additionally, an integrated evaluation of the indicators, using expert systems, was done to obtain an overview of the plant general safety. This methodology can be used for identifying situations where the plant safety is challenged, by giving a general overview of the plant operational condition. Additionally, this study can also identify eventual room for improvements by generating suggestions and recommendations, as a complement for regulatory actions and inspections, focusing resources on eventual existing weaknesses, in order to increase or maintain a high pattern of operational safety. (author)

  19. Tomato CRY1a plays a critical role in the regulation of phytohormone homeostasis, plant development, and carotenoid metabolism in fruits.

    Science.gov (United States)

    Liu, Chao-Chao; Ahammed, Golam Jalal; Wang, Guo-Ting; Xu, Chang-Jie; Chen, Kun-Song; Zhou, Yan-Hong; Yu, Jing-Quan

    2018-02-01

    Blue light photoreceptors, cryptochromes (CRYs), regulate multiple aspects of plant growth and development. However, our knowledge of CRYs is predominantly based on model plant Arabidopsis at early growth stage. In this study, we elucidated functions of CRY1a gene in mature tomato (Solanum lycopersicum) plants by using cry1a mutants and CRY1a-overexpressing lines (OE-CRY1a-1 and OE-CRY1a-2). In comparison with wild-type plants, cry1a mutants are relatively tall, accumulate low biomass, and bear more fruits, whereas OE-CRY1a plants are short stature, and they not only flower lately but also bear less fruits. RNA-seq, qRT-PCR, and LC-MS/MS analysis revealed that biosynthesis of gibberellin, cytokinin, and jasmonic acid was down-regulated by CRY1a. Furthermore, DNA replication was drastically inhibited in leaves of OE-CRY1a lines, but promoted in cry1a mutants with concomitant changes in the expression of cell cycle genes. However, CRY1a positively regulated levels of soluble sugars, phytofluene, phytoene, lycopene, and ß-carotene in the fruits. The results indicate the important role of CRY1a in plant growth and have implications for molecular interventions of CRY1a aimed at improving agronomic traits. © 2017 John Wiley & Sons Ltd.

  20. Thinking Critically about Critical Thinking

    Science.gov (United States)

    Mulnix, Jennifer Wilson

    2012-01-01

    As a philosophy professor, one of my central goals is to teach students to think critically. However, one difficulty with determining whether critical thinking can be taught, or even measured, is that there is widespread disagreement over what critical thinking actually is. Here, I reflect on several conceptions of critical thinking, subjecting…