Science.gov

Sample records for decommissioning size reduction

  1. Conceptual Methods for Decontamination and Decommissioning, Size Reduction, and Disposal of the DWPF Melter and Components

    SciTech Connect

    Smith, M.E.

    2001-06-15

    This report identifies potential methods for the disassembly, size reduction, and decontamination of large DWPF equipment. It specifically targets the DWPF Melter. Methods found to work on the melter should be easily applied to other equipment, as the melter is the most complex large-scale equipment that must be processed. It is also likely to be the most contaminated component as it could contain up to 16,000 pounds of HLW glass in it when it is shut down. This report also evaluates methods, equipment, and techniques that may be used. It also discusses possible dismantlement sequences that could be used as well as issues that need to be addressed. In addition, past experiences in dismantling and inspection of various ceramic-lined melters will be discussed.

  2. Materials selection of surface coatings in an advanced size reduction facility. [For decommissioned stainless steel equipment

    SciTech Connect

    Briggs, J. L.; Younger, A. F.

    1980-06-02

    A materials selection test program was conducted to characterize optimum interior surface coatings for an advanced size reduction facility. The equipment to be processed by this facility consists of stainless steel apparatus (e.g., glove boxes, piping, and tanks) used for the chemical recovery of plutonium. Test results showed that a primary requirement for a satisfactory coating is ease of decontamination. A closely related concern is the resistance of paint films to nitric acid - plutonium environments. A vinyl copolymer base paint was the only coating, of eight paints tested, with properties that permitted satisfactory decontamination of plutonium and also performed equal to or better than the other paints in the chemical resistance, radiation stability, and impact tests.

  3. Financing Class Size Reduction

    ERIC Educational Resources Information Center

    Achilles, C. M.

    2005-01-01

    Class size reduction has been shown to, among other things, improve academic achievement for all students and particularly for low-income and minority students. With the No Child Left Behind Act's heavy emphasis on scientifically based research, adequate yearly progress, and disaggregated results, one wonders why all children aren't enrolled in…

  4. Size reduction machine

    SciTech Connect

    Fricke, V.

    1999-12-15

    The Size Reduction Machine (SRM) is a mobile platform capable of shearing various shapes and types of metal components at a variety of elevations. This shearing activity can be performed without direct physical movement and placement of the shear head by the operator. The base unit is manually moved and roughly aligned to each cut location. The base contains the electronics: hydraulic pumps, servos, and actuators needed to move the shear-positioning arm. The movable arm allows the shear head to have six axes of movement and to cut to within 4 inches of a wall surface. The unit has a slick electrostatic capture coating to assist in external decontamination. Internal contamination of the unit is controlled by a high-efficiency particulate air (HEPA) filter on the cooling inlet fan. The unit is compact enough to access areas through a 36-inch standard door opening. This paper is an Innovative Technology Summary Report designed to provide potential users with the information they need to quickly determine if a technology would apply to a particular environmental management problem. They also are designed for readers who may recommend that a technology be considered by prospective users.

  5. Demonstration of remotely operated TRU waste size reduction and material handling equipment

    SciTech Connect

    Looper, M G; Charlesworth, D L

    1988-01-01

    The Savannah River Laboratory (SRL) is developing remote size reduction and material handling equipment to prepare /sup 238/Pu contaminated waste for permanent disposal at the Waste Isolation Pilot Plant (WIPP) in New Mexico. The waste is generated at the Savannah River Plant (SRP) from normal operation and decommissioning activity and is retrievably stored onsite. A Transuranic Waste Facility for preparing, size-reducing, and packaging this waste for disposal is scheduled for completion in 1995. A cold test facility for demonstrating the size reduction and material handling equipment was built, and testing began in January 1987. 9 figs., 1 tab.

  6. Researcher Perspectives on Class Size Reduction

    ERIC Educational Resources Information Center

    Graue, Elizabeth; Rauscher, Erica

    2009-01-01

    This article applies to class size research Grant and Graue's (1999) position that reviews of research represent conversations in the academic community. By extending our understanding of the class size reduction conversation beyond published literature to the perspectives of researchers who have studied the topic, we create a review that includes…

  7. Robotic system for glovebox size reduction

    SciTech Connect

    KWOK,KWAN S.; MCDONALD,MICHAEL J.

    2000-03-02

    The Intelligent Systems and Robotics Center (ISRC) at Sandia National Laboratories (SNL) is developing technologies for glovebox size reduction in the DOE nuclear complex. A study was performed for Kaiser-Hill (KH) at the Rocky Flats Environmental Technology Site (RFETS) on the available technologies for size reducing the glovebox lines that require size reduction in place. Currently, the baseline approach to these glovebox lines is manual operations using conventional mechanical cutting methods. The study has been completed and resulted in a concept of the robotic system for in-situ size reduction. The concept makes use of commercially available robots that are used in the automotive industry. The commercially available industrial robots provide high reliability and availability that are required for environmental remediation in the DOE complex. Additionally, the costs of commercial robots are about one-fourth that of the custom made robots for environmental remediation. The reason for the lower costs and the higher reliability is that there are thousands of commercial robots made annually, whereas there are only a few custom robots made for environmental remediation every year. This paper will describe the engineering analysis approach used in the design of the robotic system for glovebox size reduction.

  8. Size reduction of complex networks preserving modularity

    SciTech Connect

    Arenas, A.; Duch, J.; Fernandez, A.; Gomez, S.

    2008-12-24

    The ubiquity of modular structure in real-world complex networks is being the focus of attention in many trials to understand the interplay between network topology and functionality. The best approaches to the identification of modular structure are based on the optimization of a quality function known as modularity. However this optimization is a hard task provided that the computational complexity of the problem is in the NP-hard class. Here we propose an exact method for reducing the size of weighted (directed and undirected) complex networks while maintaining invariant its modularity. This size reduction allows the heuristic algorithms that optimize modularity for a better exploration of the modularity landscape. We compare the modularity obtained in several real complex-networks by using the Extremal Optimization algorithm, before and after the size reduction, showing the improvement obtained. We speculate that the proposed analytical size reduction could be extended to an exact coarse graining of the network in the scope of real-space renormalization.

  9. Particle size reduction of propellants by cryocycling

    SciTech Connect

    Whinnery, L.; Griffiths, S.; Lipkin, J.

    1995-05-01

    Repeated exposure of a propellant to liquid nitrogen causes thermal stress gradients within the material resulting in cracking and particle size reduction. This process is termed cryocycling. The authors conducted a feasibility study, combining experiments on both inert and live propellants with three modeling approaches. These models provided optimized cycle times, predicted ultimate particle size, and allowed crack behavior to be explored. Process safety evaluations conducted separately indicated that cryocycling does not increase the sensitivity of the propellants examined. The results of this study suggest that cryocycling is a promising technology for the demilitarization of tactical rocket motors.

  10. Cataclasis and processes of particle size reduction

    NASA Astrophysics Data System (ADS)

    Blenkinsop, Tom G.

    1991-05-01

    The particle size distribution (P.S.D.) of fragmented geological materials is affected by the fragmentation process, initial size distribution, number of fracturing events, energy input, strain, and confining pressure. A summary of literature shows that the fractal dimension ( D) of the P.S.D. is increased by the number of fracturing events, energy input, strain, and confining pressure. Cenozoic cataclasis of granite, granodiorites, gneisses and arkose seen in cores from the Cajon Pass drillhole, southern California, produced P.S.D.s with values of D that varied from 1.88 to 3.08. Each rock type has a characteristic and more limited range of D. Areas of dilatant texture and mode I fracture-fillings have low average values (2.32 and 2.37) compared to an average value of 2.67 in shear fracture-fillings D has a good inverse correlation with average particle size. Data from fault rocks in the San Gabriel fault zone, southern California ( Anderson et al., 1983) have been reanalyzed to show that values of D are higher (2.10 5.52) and average particle size is lower than the Cajon Pass samples, but the ranges of values overlap, and the inverse correlation between D and average particle size is extended. Microstructural observations combined with these results suggest that three processes contributed to particle size reduction during cataclasis. The first process of feldspar alteration, which leads to low values of D, has not been previously recognized. The second process is probably constrained comminution ( Sammis et al., 1987), since the average D in shear fracture-fillings is close to the value of 2.58 predicted by this theory. A further stage of particle size reduction is demonstrated by an increase of D with cataclasis. This third process is selective fracture of larger particles, which may also operate during localization and the cataclastic flow-to-faulting transition as observed in experiments. A transition from constrained comminution to selective fracture of

  11. Tritium Reduction and Control in the Vacuum Vessel during TFTR Outage and Decommissioning

    SciTech Connect

    Blanchard, W.; Camp, R.; Carnevale, H.; Casey, M.; Collins, J.; et al

    1997-11-01

    In the summer/fall of 1996 after nearly three years of D-T operations, TFTR underwent an extended outage during which large port covers were removed from the vacuum vessel in order to complete upgrades to the tokamak. Following the venting of the torus, a three tier system was developed for the outage in order to reduce and control the free tritium in the vacuum vessel so as to minimize the exposure to personnel during port cover removal and reinstallation. The first phase of the program to reduce the free tritium consisted of direct flowthrough of room air through the vacuum vessel to the molecular sieve beds using the Torus Cleanup System. Real time measurements of the effluent tritium concentration were used to derive the amount of tritium removed from the torus. Once the free tritium in the vessel had been reduced to approximately 50 Ci, a second phase was initiated using a 55 Gallon Drum Bubbler System for the direct processing of the vacuum vessel to further lower the tritium level in the torus. Tritium oxide is absorbed by the bubbler system with the exhaust vented to one of the tritium monitored HVAC ventilation stacks. To preclude the release of tritium to the Test Cell location of TFTR and to minimize the exposure of workers, a variable flow exhaust system was employed in order to maintain a negative pressure in the vacuum vessel between 0.05" and 1.5" w.c. during the removal of port covers ranging in size from approximately 5 to 1000 in(superscript2). These systems were completely successful in reducing and controlling the free tritium in TFTR and were instrumental in maintaining ALARA (As Low As Reasonably Achievable) exposures to tritium during the 1996 outage. These systems are again being utilized during the safe shutdown and decommissioning of TFTR which commenced in April of 1997. This paper describes in detail the configuration of these systems and the data obtained during the outage and safe shutdown of TFTR.

  12. Nonuniform Video Size Reduction for Moving Objects

    PubMed Central

    2014-01-01

    Moving objects of interest (MOOIs) in surveillance videos are detected and encapsulated by bounding boxes. Since moving objects are defined by temporal activities through the consecutive video frames, it is necessary to examine a group of frames (GoF) to detect the moving objects. To do that, the traces of moving objects in the GoF are quantified by forming a spatiotemporal gradient map (STGM) through the GoF. Each pixel value in the STGM corresponds to the maximum temporal gradient of the spatial gradients at the same pixel location for all frames in the GoF. Therefore, the STGM highlights boundaries of the MOOI in the GoF and the optimal bounding box encapsulating the MOOI can be determined as the local areas with the peak average STGM energy. Once an MOOI and its bounding box are identified, the inside and outside of it can be treated differently for object-aware size reduction. Our optimal encapsulation method for the MOOI in the surveillance videos makes it possible to recognize the moving objects even after the low bitrate video compressions. PMID:25258738

  13. On-Site Oxy-Lance Size Reduction of South Texas Project Reactor Vessel Heads - 12324

    SciTech Connect

    Posivak, Edward; Keeney, Gilbert; Wheeler, Dean

    2012-07-01

    On-Site Oxy-Lance size reduction of mildly radioactive large components has been accomplished at other operating plants. On-Site Oxy-Lance size reduction of more radioactive components like Reactor Vessel Heads had previously been limited to decommissioning projects. Building on past decommissioning and site experience, subcontractors for South Texas Project Nuclear Operating Company (STPNOC) developed an innovative integrated system to control smoke, radioactive contamination, worker dose, and worker safety. STP's innovative, easy to use CEDM containment that provided oxy lance access, smoke control, and spatter/contamination control was the key to successful segmentation for cost-effective and ALARA packaging and transport for disposal. Relative to CEDM milling, STP oxy-lance segmentation saved approximately 40 person- REM accrued during 9,000 hours logged into the radiological controlled area (RCA) during more than 3,800 separate entries. Furthermore there were no personnel contamination events or respiratory uptakes of radioactive material during the course of the entire project. (authors)

  14. SIGNIFICANCE OF SIZE REDUCTION IN SOLID WASTE MANAGEMENT

    EPA Science Inventory

    This report provides information from laboratory research conducted to characterize the size reduction of municipal solid waste (MSW). Results and data are presented on the relationships between refuse size distribution, particle size, grinding speed, moisture content, energy con...

  15. School Facility Recommendations for Class Size Reduction.

    ERIC Educational Resources Information Center

    Evans, Ann M.

    The California Department of Education encourages its school districts to make every effort to reduce classroom size and maintain the physical size of 960 square feet for elementary schools and 1,350 square feet for kindergartens. This report examines the Code of Regulations relative to classroom size in elementary, kindergarten, and special…

  16. Shot-size reduction of photoresist formulations

    NASA Astrophysics Data System (ADS)

    Moreau, Wayne M.; Cornett, Kathleen M.; Fahey, James T.; Linehan, Leo L.; Montgomery, Warren; Plat, Marina V.; Smith, Randolph S.; Wood, Robert L.

    1995-06-01

    The cost of expendable chemicals in the resist process is increasing and with this the economic impetus to conserve usage. The volume of liquid resist dispensed (shot size) determines the consumption rate and disposal volumes of liquid resist. The choice of resist solvent can influence the shot volume. Three formulation factors influence the shot size: (1) the surface tension of the resist and the interfacial energy of the coating surface, (2) the viscosity of the resist formulation, and (3) the evaporation rate of the solvent. The suitable resist formulation and subsequent solvent choice should be of the lowest surface tension and lowest viscosity and be balanced by an evaporation rate which allows a minimum shot volume to be spread on the surface without significant solvent loss. Of all the solvents examined, ethyl 3-ethoxy propionate (EEP) gave the lowest shot size relative to the old resist solvent standard of 2- ethoxy ethyl acetate (ECA).

  17. Research on Size Reduction of Plasma Antenna

    NASA Astrophysics Data System (ADS)

    Sun, Jian; Xu, Yuemin; Sun, Hailong

    The structure of plasma antenna is more complex than metal antenna to reach ideal gain, efficiency, matching, etc. Therefore, earlier plasma antenna prototypes were always featured with larger size and weight. The NSSC research team has developed new prototypes with equivalent performance as metal antenna. In recent research, we also optimized the antenna structure to reduce size and weight. The new plasma antenna prototype is much smaller than the former ones, and its power consumption is also reduced from more than 100 watts to about 30 watts.

  18. Competing Explanations of Class Size Reduction Effects: The California Case.

    ERIC Educational Resources Information Center

    Mitchell, Douglas E.; Mitchell, Ross E.

    Competing explanations of class size reduction effects on student academic achievement were tested using student, teacher, and school data collected from nearly 700 classrooms in over 70 schools during the first 3 years of implementation of California's (K-3) Class Size Reduction Program. Five major hypotheses were tested: (1) overall impact of…

  19. Design and operation of a remotely operated plutonium waste size reduction and material handling process

    SciTech Connect

    Stewart, III, J A; Charlesworth, D L

    1986-01-01

    Noncombustible /sup 238/Pu and /sup 239/Pu waste is generated as a result of normal operation and decommissioning activity at the Savannah River Plant, and is being retrievably stored there. As part of the long-term plant to process the stored waste and current waste for permanent disposal, a remote size reduction and material handling process is being cold-tested at Savannah River Laboratory. The process consists of a large, low-speed shredder and material handling system, a remote worktable, a bagless transfer system, and a robotically controlled manipulator. Initial testing of the shredder and material handling system and a cycle test of the bagless transfer system has been completed. Fabrication and acceptance testing of the Telerobat, a robotically controlled manipulator has been completed. Testing is scheduled to begin in 3/86. Design features maximizing the ability to remotely maintain the equipment were incorporated. Complete cold-testing of the equipment is scheduled to be completed in 1987.

  20. Evaluation of process for sludge particle size reduction

    SciTech Connect

    Precechtel, D.R.; Packer, M.J., Fluor Daniel Hanford

    1997-03-18

    This document evaluates the available technology for K Basin sludge particle size. The results can be used to demonstrate the sensitivity or lack thereof, of K Basin sludge to available reduction processes and TWRS proposed particle acceptance criteria.

  1. Policy from the Hip: Class-Size Reduction in California

    ERIC Educational Resources Information Center

    Schrag, Peter

    2007-01-01

    California was, and remains, the largest "experiment" in class-size reduction (CSR) in the country's history. Its sweeping program to reduce the state's classes in kindergarten through the third grade covered nearly 2 million students and dropped the average class size from almost twenty-nine students per class, and often a great many more, to…

  2. Decontamination and size reduction of plutonium contaminated process exhaust ductwork and glove boxes

    SciTech Connect

    LaFrate, P.; Elliott, J.; Valasquez, M.

    1996-11-15

    The Los Alamos National Laboratory (LANL) Decommissioning Program has decontaminated and demolished two filter plenum buildings at Technical Area 21 (TA-21). During the project a former hot cell was retrofitted to perform decontamination and size reduction of highly Pu contaminated process exhaust (1,100 ft) and gloveboxes. Pu-238/239 concentrations were as high a 1 Ci per linear foot and averaged approximately 1 mCi/ft. The Project decontamination objective was to reduce the plutonium contamination on surfaces below transuranic levels. If possible, metal surfaces were decontaminated further to meet Science and Ecology Group (SEG) waste classification guidelines to enable the metal to be recycled at their facility in oak Ridge, Tennessee. Project surface contamination acceptance criteria for low-level radioactive waste (LLRW), transuranic waste, and SEG waste acceptance criteria will be presented. Ninety percent of all radioactive waste for the project was characterized as LLRW. Twenty percent of this material was shipped to SEG. Process exhaust and glove boxes were brought to the project decontamination area, an old hot cell in Building 4 North. This paper focuses on process exhaust and glovebox decontamination methodology, size reduction techniques, waste characterization, airborne contamination monitoring, engineering controls, worker protection, lessons learned, and waste minimization. Decontamination objectives are discussed in detail.

  3. Size dependent reduction-oxidation-reduction behaviour of cobalt oxide nanocrystals.

    PubMed

    Sadasivan, Sajanikumari; Bellabarba, Ronan M; Tooze, Robert P

    2013-11-21

    Morphologically similar cobalt oxide nanoparticles (Co3O4) of four different sizes (3 nm, 6 nm, 11 nm and 29 nm) with narrow size distribution were prepared by subtle variation of synthesis conditions. These nanoparticles were used as model materials to understand the structural and morphological changes that occur to cobalt oxide during sequential reduction, oxidation and further re-reduction process as a function of the initial size of cobalt oxide. On reduction, spherical cobalt nanoparticles were obtained independent of the original size of cobalt oxide. In contrast, subsequent oxidation of the metal particles led to solid spheres, hollow spheres or core-shell structures depending on the size of the initial metal particle. Further re-reduction of the oxidized structures was also observed to be size dependent. The hollow oxide shells formed by the large particles (29 nm) fragmented into smaller particles on reduction, while the hollow shells of the medium sized particles (11 nm) did not re-disperse on further reduction. Similarly, no re-dispersion was observed in the case of the small particles (6 nm). This model study provides useful insights into the size dependent behavior of metal/metal oxide particles during oxidation/reduction. This has important implications in petrochemical industry where cobalt is used as a catalyst in the Fischer-Tropsch process. PMID:24065040

  4. Surface Plasmon-Driven Water Reduction: Gold Nanoparticle Size Matters

    SciTech Connect

    Qian, Kun; Sweeny, Brendan C.; Johnston-Peck, Aaron C.; Niu, Wenxin; Graham, Jeremy O.; DuChene, Joseph S.; Qiu, Jingjing; Wang, Yi-Chung; Engelhard, Mark H.; Su, Dong; Stach, Eric A.; Wei, Wei

    2014-07-16

    Water reduction under two visible light ranges (λ > 400 and λ > 435 nm) was investigated using gold-loaded titanium dioxide (Au-TiO2) with different sizes of Au nanoparticles (NPs). Two different mechanisms have been determined to clarify the specific role of Au NPs in visible light-induced photocatalytic reactions. Our study provides solid evidences showing that Au NPs sizes are essential for the surface plasmon-driven water reduction under λ > 435 nm. More specifically, we have demonstrated that the Au NPs sizes are vital for the SPR mediated electron transfer efficiency and play a critical role in determining the reduction potential of the transferred electrons in the TiO2 conduction band (CB) and their following activities. Our discovery provides a facile way to manipulate the reduction potential of transferred electrons by simply varying the Au NPs sizes, which will greatly facilitate the design of suitable plasmonic photocatalysts for water reduction and other valuable solar-to-fuel reactions.

  5. 20. VIEW OF THE INTERIOR OF THE ADVANCED SIZE REDUCTION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. VIEW OF THE INTERIOR OF THE ADVANCED SIZE REDUCTION FACILITY USED TO CUT PLUTONIUM CONTAMINATED GLOVE BOXES AND MISCELLANEOUS LARGE EQUIPMENT DOWN TO AN EASILY PACKAGED SIZE FOR DISPOSAL. ROUTINE OPERATIONS WERE PERFORMED REMOTELY, USING HOISTS, MANIPULATOR ARMS, AND GLOVE PORTS TO REDUCE BOTH INTENSITY AND TIME OF RADIATION EXPOSURE TO THE OPERATOR. (11/6/86) - Rocky Flats Plant, Plutonium Fabrication, Central section of Plant, Golden, Jefferson County, CO

  6. Size dependent reduction-oxidation-reduction behaviour of cobalt oxide nanocrystals

    NASA Astrophysics Data System (ADS)

    Sadasivan, Sajanikumari; Bellabarba, Ronan M.; Tooze, Robert P.

    2013-10-01

    Morphologically similar cobalt oxide nanoparticles (Co3O4) of four different sizes (3 nm, 6 nm, 11 nm and 29 nm) with narrow size distribution were prepared by subtle variation of synthesis conditions. These nanoparticles were used as model materials to understand the structural and morphological changes that occur to cobalt oxide during sequential reduction, oxidation and further re-reduction process as a function of the initial size of cobalt oxide. On reduction, spherical cobalt nanoparticles were obtained independent of the original size of cobalt oxide. In contrast, subsequent oxidation of the metal particles led to solid spheres, hollow spheres or core-shell structures depending on the size of the initial metal particle. Further re-reduction of the oxidized structures was also observed to be size dependent. The hollow oxide shells formed by the large particles (29 nm) fragmented into smaller particles on reduction, while the hollow shells of the medium sized particles (11 nm) did not re-disperse on further reduction. Similarly, no re-dispersion was observed in the case of the small particles (6 nm). This model study provides useful insights into the size dependent behavior of metal/metal oxide particles during oxidation/reduction. This has important implications in petrochemical industry where cobalt is used as a catalyst in the Fischer-Tropsch process.Morphologically similar cobalt oxide nanoparticles (Co3O4) of four different sizes (3 nm, 6 nm, 11 nm and 29 nm) with narrow size distribution were prepared by subtle variation of synthesis conditions. These nanoparticles were used as model materials to understand the structural and morphological changes that occur to cobalt oxide during sequential reduction, oxidation and further re-reduction process as a function of the initial size of cobalt oxide. On reduction, spherical cobalt nanoparticles were obtained independent of the original size of cobalt oxide. In contrast, subsequent oxidation of the metal

  7. Posterior dental size reduction in hominids: the Atapuerca evidence.

    PubMed

    Bermúdez de Castro, J M; Nicolas, M E

    1995-04-01

    In order to reassess previous hypotheses concerning dental size reduction of the posterior teeth during Pleistocene human evolution, current fossil dental evidence is examined. This evidence includes the large sample of hominid teeth found in recent excavations (1984-1993) in the Sima de los Huesos Middle Pleistocene cave site of the Sierra de Atapuerca (Burgos, Spain). The lower fourth premolars and molars of the Atapuerca hominids, probably older than 300 Kyr, have dimensions similar to those of modern humans. Further, these hominids share the derived state of other features of the posterior teeth with modern humans, such as a similar relative molar size and frequent absence of the hypoconulid, thus suggesting a possible case of parallelism. We believe that dietary changes allowed size reduction of the posterior teeth during the Middle Pleistocene, and the present evidence suggests that the selective pressures that operated on the size variability of these teeth were less restrictive than what is assumed by previous models of dental reduction. Thus, the causal relationship between tooth size decrease and changes in food-preparation techniques during the Pleistocene should be reconsidered. Moreover, the present evidence indicates that the differential reduction of the molars cannot be explained in terms of restriction of available growth space. The molar crown area measurements of a modern human sample were also investigated. The results of this study, as well as previous similar analyses, suggest that a decrease of the rate of cell proliferation, which affected the later-forming crown regions to a greater extent, may be the biological process responsible for the general and differential dental size reduction that occurred during human evolution. PMID:7604890

  8. The False Promise of Class-Size Reduction

    ERIC Educational Resources Information Center

    Chingos, Matthew M.

    2011-01-01

    Class-size reduction, or CSR, is enormously popular with parents, teachers, and the public in general. Many parents believe that their children will benefit from more individualized attention in a smaller class and many teachers find smaller classes easier to manage. The pupil-teacher ratio is an easy statistic for the public to monitor as a…

  9. SIGNIFICANCE OF SIZE REDUCTION IN SOLID WASTE MANAGEMENT. VOLUME 2

    EPA Science Inventory

    This report presents results of shredder tests using raw municipal solid waste, air-classified light fraction, and screened light fraction. The tests simulated single- and multiple-stage size reduction, using a 10-ton per hour swing hammermill and a small, high-speed fixed hammer...

  10. Decommissioning Handbook

    SciTech Connect

    Not Available

    1994-03-01

    The Decommissioning Handbook is a technical guide for the decommissioning of nuclear facilities. The decommissioning of a nuclear facility involves the removal of the radioactive and, for practical reasons, hazardous materials to enable the facility to be released and not represent a further risk to human health and the environment. This handbook identifies and technologies and techniques that will accomplish these objectives. The emphasis in this handbook is on characterization; waste treatment; decontamination; dismantling, segmenting, demolition; and remote technologies. Other aspects that are discussed in some detail include the regulations governing decommissioning, worker and environmental protection, and packaging and transportation of the waste materials. The handbook describes in general terms the overall decommissioning project, including planning, cost estimating, and operating practices that would ease preparation of the Decommissioning Plan and the decommissioning itself. The reader is referred to other documents for more detailed information. This Decommissioning Handbook has been prepared by Enserch Environmental Corporation for the US Department of Energy and is a complete restructuring of the original handbook developed in 1980 by Nuclear Energy Services. The significant changes between the two documents are the addition of current and the deletion of obsolete technologies and the addition of chapters on project planning and the Decommissioning Plan, regulatory requirements, characterization, remote technology, and packaging and transportation of the waste materials.

  11. Biofuel Manufacturing from Woody Biomass: Effects of Sieve Size Used in Biomass Size Reduction

    PubMed Central

    Zhang, Meng; Song, Xiaoxu; Deines, T. W.; Pei, Z. J.; Wang, Donghai

    2012-01-01

    Size reduction is the first step for manufacturing biofuels from woody biomass. It is usually performed using milling machines and the particle size is controlled by the size of the sieve installed on a milling machine. There are reported studies about the effects of sieve size on energy consumption in milling of woody biomass. These studies show that energy consumption increased dramatically as sieve size became smaller. However, in these studies, the sugar yield (proportional to biofuel yield) in hydrolysis of the milled woody biomass was not measured. The lack of comprehensive studies about the effects of sieve size on energy consumption in biomass milling and sugar yield in hydrolysis process makes it difficult to decide which sieve size should be selected in order to minimize the energy consumption in size reduction and maximize the sugar yield in hydrolysis. The purpose of this paper is to fill this gap in the literature. In this paper, knife milling of poplar wood was conducted using sieves of three sizes (1, 2, and 4 mm). Results show that, as sieve size increased, energy consumption in knife milling decreased and sugar yield in hydrolysis increased in the tested range of particle sizes. PMID:22665985

  12. Reduction in bearing size due to superconductors in magnetic bearings

    NASA Technical Reports Server (NTRS)

    Rao, Dantam K.; Lewis, Paul; Dill, James F.

    1991-01-01

    A design concept that reduces the size of magnetic bearings is assessed. The small size will enable magnetic bearings to fit into limited available bearing volume of cryogenic machinery. The design concept, called SUPERC, uses (high Tc) superconductors or high-purity aluminum conductors in windings instead of copper. The relatively high-current density of these conductors reduces the slot radial thickness for windings, which reduces the size of the bearings. MTI developed a sizing program called SUPERC that translates the high-current density of these conductors into smaller sized bearings. This program was used to size a superconducting bearing to carry a 500 lb. load. The sizes of magnetic bearings needed by various design concepts are as follows: SUPERC design concept = 3.75 in.; magnet-bias design concept = 5.25 in.; and all electromagnet design concept = 7.0 in. These results indicate that the SUPERC design concept can significantly reduce the size of the bearing. This reduction, in turn, reduces the weight and yields a lighter bearing. Since the superconductors have inherently near-zero resistance, they are also expected to save power needed for operation considerably.

  13. Effect of bubble size on micro-bubble drag reduction

    NASA Astrophysics Data System (ADS)

    Shen, Xiaochun

    2005-11-01

    The effect of bubble size on micro-bubble drag reduction was investigated experimentally in a high-speed turbulent channel flow of water. A variety of near-wall injection techniques were used to create a bubbly turbulent boundary layer. The resulting wall friction force was measured directly by a floating element force balance. The bubble size was determined from photographic imaging. Using compressed nitrogen to force flow through a slot injector located in the plate beneath the boundary layer of the tunnel test section, a surfactant solution (Triton X-100, 19ppm) and salt water solution (35ppt) generated bubbles of average size between ˜500 microns and ˜200 microns and ˜100 microns, respectively (40 < d^+ < 200). In addition hollow spherical glass beads (˜75 microns (d^+ = 30) and specific gravity 0.18) and previously prepared lipid stabilized gas bubbles of ˜ 30 micron (d^+ =12) were injected. The results indicate that the drag reduction is related strongly to the injected gas volume flux and the static pressure in the boundary layer. Changing bubble size had essentially no influence on the measured friction drag, suggesting that friction drag is not a strong function of bubble size. [Sponsored by the Office of Naval Research.

  14. [Theory and practice of electrospray crystallization in particle size reduction].

    PubMed

    Szunyogh, Tímea; Ambrus, Rita; Szabóné Révész, Piroska

    2015-01-01

    Nowdays, one of the most challenges for the researchers is the formulation of poorly water soluble drugs. Reduction of particle size of active agents to submicron range could result in a faster dissolution rate and higher bioavailability. Integration as crystallization process is an often used particle size decreasing technique. The aim of this study was to show the theoretical background and practical application of the electros pray crystallization as an innovative particle size decreasing technique. Our model drug was the niflumic acid (NIF), which belongs to the BCS Class II. After the optimization of the process parameters, the physico-chemical properties of the samples were characterized. Particle size and shape were visualized by scanning electron microscopy (SEM). Crystalline state of NIF and the samples were investigated using differential scanning calorimetry (DSC) and X-ray powder diffraction. Physico-chemical properties were determined using dissolution test from simulated media. The electrospray crytallization resulted in particle size reduction but the aggregation of nanonized NIF crystals (NIF-nano) could not avoid without excipient. Aggregates with poor secondary forces are suitable for production of the interactive physical mixture. It was found that NIF-nano could be well distributed on the surface of the mannitol as carrier and the Poloxamer R protected the NIF-nano crystals (320 nm)from aggregation. Consequently, the physical mixture resulted in product with higher polarity, better wettability and faster dissolution rate of NIF as raw NIF or NIF-nano. PMID:26390735

  15. Powered Remote Manipulators Perform Hazardous Retrieval, Handling, and Size Reduction Operations

    SciTech Connect

    Cole, M.D.; Owen, J.R.; Adams, S.R.

    2006-07-01

    This paper describes a new lightweight, powered remote manipulator (PRM) that S.A.Robotics has developed for remote material handling and size reduction in hazardous environments such as reactor decommissioning projects. PRMs can be mounted to various deployment platforms such as remote controlled track-driven vehicles, commercial All Terrain Vehicles, or crane-mounted arms. They can also be installed as replacements for traditional Master-Slave Manipulators (MSMs) in hot cells. The PRM is a six degree of freedom manipulator with carbon fiber structural components that can provide up to a 3 meter (10 foot) reach. Either electric or hydraulic power options can be used and a variety of hydraulic fluids are available to meet combustible material limitations. The PRM is operated with easy-to-use joystick controls that allow operators to sit in a comfortable work station and handle 90 kg (200 pound) loads with a hydraulic power pack or 45 kg (100 pounds) with electric servo-motor driven equipment. With a quick disconnect tool changer, the manipulator can operate grippers, drills, shears, saws, sampling and survey instruments, and the arm can also deploy cameras and lights to support a wide range of remote applications. (authors)

  16. Improvement of Photosynthetic Efficiency Through Reduction of Chlorophyll Antenna Size

    SciTech Connect

    Blankinship, S.L.; Greenbaum, E.; Lee, J.W.; Mets, L.

    1999-05-03

    We have previously presented a graphical illustration of a strategy to improve photosynthetic conversion efficiencies by a reduction of the antenna size in photosynthetic reaction centers. During the current reporting period, we have made progress in demonstrating the conceptual correctness of this idea. Light-saturation studies for CO, in air were performed with an antenna-deficient mutant of Chlamydomonas (DS521) and the wild type (DES15). The light-saturated rate for CO(2), assimilation in mutant DS521 was about two times higher (187 Mu-mol.h(-1).mg chl(-1)) than that of the wild type, DES15 (95 Mu-mol.h(-1).mg chl(-1). Significantly, a partial linearization of the light-saturation curve was also observed. The light intensities that give half-saturation of the photosynthetic rate were 276 and 152 Mu-E.m(-2).s(-1) in DS521 and DES15, respectively. These results confirmed that DS521 has a smaller chlorophyll antenna size and demonstrated that the reduction of antenna size can indeed improve the overall efficiency of photon utilization. Corresponding experiments were also performed with CO(2), in helium. Under this anaerobic condition, no photoinhibition was observed, even at elevated light intensities. Photoinhibition occurs under aerobic conditions. The antenna-deficient mutant DS521 can also provide significant resistance to photoinhibition, in addition to the improvement in the overall efficiency in CO(2), fixation.

  17. Size reduction of energetic materials by fluid jet machining

    SciTech Connect

    Carlson, G.A.; Austin, A.L.; Kang, Sang-Wook; Peterman, K.A.; Do, B.

    1993-08-01

    High velocity fluid jets (especially non-abrasive waterjets) may be ideally suited for the size reduction of excess high explosives that are to be recycled or destroyed. The fundamental interaction mechanisms between a waterjet and its target are investigated for the purpose of assessing the safety of waterjet machining of explosives. Experiments indicate that an effectively cutting waterjet has disintegrated into droplets before reaching its target; so impact shock pressures are evaluated and compared to the critical values required for detonation. For typical waterjet parameters, the achievable shock pressure is a factor of 100 below critical for PBX 9404; for the more sensitive PETN the safety factor is 20.

  18. Influence of bubble size on micro-bubble drag reduction

    NASA Astrophysics Data System (ADS)

    Shen, Xiaochun; Ceccio, Steven L.; Perlin, Marc

    2006-09-01

    Micro-bubble drag reduction experiments were conducted in a turbulent water channel flow. Compressed nitrogen was used to force flow through a slot injector located in the plate beneath the boundary layer of the tunnel test section. Gas and bubbly mixtures were injected into a turbulent boundary layer (TBL), and the resulting friction drag was measured downstream of the injector. Injection into tap water, a surfactant solution (Triton X-100, 20 ppm), and a salt-water solution (35 ppt) yielded bubbles of average diameter 476, 322 and 254 μm, respectively. In addition, lipid stabilized gas bubbles (44 μm) were injected into the boundary layer. Thus, bubbles with d + values of 200 to 18 were injected. The results indicate that the measured drag reduction by micro-bubbles in a TBL is related strongly to the injected gas volumetric flow rate and the static pressure in the boundary layer, but is essentially independent of the size of the micro-bubbles over the size range tested.

  19. Decommissioning handbook

    SciTech Connect

    Manion, W.J.; LaGuardia, T.S.

    1980-11-01

    This document is a compilation of information pertinent to the decommissioning of surplus nuclear facilities. This handbook is intended to describe all stages of the decommissioning process including selection of the end product, estimation of the radioactive inventory, estimation of occupational exposures, description of the state-of-the-art in re decontamination, remote csposition of wastes, and estimation of program costs. Presentation of state-of-the-art technology and data related to decommissioning will aid in consistent and efficient program planning and performance. Particular attention is focused on available technology applicable to those decommissioning activities that have not been accomplished before, such as remote segmenting and handling of highly activated 1100 MW(e) light water reactor vessel internals and thick-walled reactor vessels. A summary of available information associated with the planning and estimating of a decommissioning program is also presented. Summarized in particular are the methodologies associated with the calculation and measurement of activated material inventory, distribution, and surface dose level, system contamination inventory and distribution, and work area dose levels. Cost estimating techniques are also presented and the manner in which to account for variations in labor costs as impacting labor-intensive work activities is explained.

  20. Direct measures of mechanical energy for knife mill size reduction

    SciTech Connect

    Bitra, V.S.P.; Womac, A.R.; Igathinathane, C.; Miu, P.I; Yang, Y.T.; Smith, D.R.; Chevanan, Nehru; Sokhansanj, Shahabaddine

    2009-08-01

    Lengthy straw/stalk of biomass may not be directly fed into grinders such as hammer mills and disc refiners. Hence, biomass needs to be preprocessed using coarse grinders like a knife mill to allow for efficient feeding in refiner mills without bridging and choking. Size reduction mechanical energy was directly measured for switchgrass (Panicum virgatum L.), wheat straw (Triticum aestivum L.), and corn stover (Zea mays L.) in an instrumented knife mill. Direct power inputs were determined for different knife mill screen openings from 12.7 to 50.8 mm, rotor speeds between 250 and 500 rpm, and mass feed rates from 1 to 11 kg/min. Overall accuracy of power measurement was calculated to be 0.003 kW. Total specific energy (kWh/Mg) was defined as size reduction energy to operate mill with biomass. Effective specific energy was defined as the energy that can be assumed to reach the biomass. The difference is parasitic or no-load energy of mill. Total specific energy for switchgrass, wheat straw, and corn stover chopping increased with knife mill speed, whereas, effective specific energy decreased marginally for switchgrass and increased for wheat straw and corn stover. Total and effective specific energy decreased with an increase in screen size for all the crops studied. Total specific energy decreased with increase in mass feed rate, but effective specific energy increased for switchgrass and wheat straw, and decreased for corn stover at increased feed rate. For knife mill screen size of 25.4 mm and optimum speed of 250 rpm, optimum feed rates were 7.6, 5.8, and 4.5 kg/min for switchgrass, wheat straw, and corn stover, respectively, and the corresponding total specific energies were 7.57, 10.53, and 8.87 kWh/Mg and effective specific energies were 1.27, 1.50, and 0.24 kWh/Mg for switchgrass, wheat straw, and corn stover, respectively. Energy utilization ratios were calculated as 16.8%, 14.3%, and 2.8% for switchgrass, wheat straw, and corn stover, respectively. These

  1. Comparative Evaluation of Cutting Methods of Activated Concrete from Nuclear Power Plant Decommissioning - 13548

    SciTech Connect

    Kim, HakSoo; Chung, SungHwan; Maeng, SungJun

    2013-07-01

    The amount of radioactive wastes from decommissioning of a nuclear power plant varies greatly depending on factors such as type and size of the plant, operation history, decommissioning options, and waste treatment and volume reduction methods. There are many methods to decrease the amount of decommissioning radioactive wastes including minimization of waste generation, waste reclassification through decontamination and cutting methods to remove the contaminated areas. According to OECD/NEA, it is known that the radioactive waste treatment and disposal cost accounts for about 40 percentage of the total decommissioning cost. In Korea, it is needed to reduce amount of decommissioning radioactive waste due to high disposal cost, about $7,000 (as of 2010) per a 200 liter drum for the low- and intermediate-level radioactive waste (LILW). In this paper, cutting methods to minimize the radioactive waste of activated concrete were investigated and associated decommissioning cost impact was assessed. The cutting methods considered are cylindrical and volume reductive cuttings. The study showed that the volume reductive cutting is more cost-effective than the cylindrical cutting. Therefore, the volume reductive cutting method can be effectively applied to the activated bio-shield concrete. (authors)

  2. Crowding Peter to Educate Paul: Lessons from a Class Size Reduction Externality

    ERIC Educational Resources Information Center

    Sims, David P.

    2009-01-01

    This paper examines an increase in upper elementary class sizes in California associated with the K-3 class size reduction program. I also use the variation in fourth and fifth grade class size generated by idiosyncratic first and second grade reductions required to meet program rules to identify a negative impact of larger class sizes on…

  3. Subnanometer poly-silicon gap structure formation: Comparison study between size expansion and size reduction

    NASA Astrophysics Data System (ADS)

    Hashim, U.; Nazwa, T.; Dhahi, Th. S.

    2012-06-01

    This study describes the comparison among the three fabrication methods of an array of poly-silicon nanogap structures. The three different methods are size expansion technique (SET), size reduction technique (SRT) and e-beam lithography (EBL) technique. Generally, SRT involves the breaking of the primarily pattern with no gap structure into nanogap scale. Conversely, SET engages in the process of enhancing the initially microgap pattern into nanogap scale. EBL refers to a lithographic process that uses a focused beam of electrons to form the circuit patterns needed for material deposition on or removal from the wafer. Using conventional photolithography, a procedure to fabricate poly-silicon nanogap structure on the wafer scale is designed. The nanogap (NG) fabrication procedure is based on the standard CMOS technology follows by employing both methods respectively. The lateral nanogap is introduced in the fabrication process using poly-silicon as an anode electrode. The similarity and distinction will be highlighted for each particular process involved in the fabrication of nanogap structures. The simple least-cost method does not require complicated nanolithography method of fabrication but it is still possible to measure the electrical properties of a single molecule. On top of that, these techniques can be applied extensively to different designs of nanogap structure down to several nanometer levels of dimensions. The innovative method reported here can easily produce a nanogap electrode in a reproducible manner.

  4. Tuning the catalytic activity of graphene nanosheets for oxygen reduction reaction via size and thickness reduction.

    PubMed

    Benson, John; Xu, Qian; Wang, Peng; Shen, Yuting; Sun, Litao; Wang, Tanyuan; Li, Meixian; Papakonstantinou, Pagona

    2014-11-26

    Currently, the fundamental factors that control the oxygen reduction reaction (ORR) activity of graphene itself, in particular, the dependence of the ORR activity on the number of exposed edge sites remain elusive, mainly due to limited synthesis routes of achieving small size graphene. In this work, the synthesis of low oxygen content (<2.5±0.2 at. %), few layer graphene nanosheets with lateral dimensions smaller than a few hundred nanometers were achieved using a combination of ionic liquid assisted grinding of high purity graphite coupled with sequential centrifugation. We show for the first time that the graphene nanosheets possessing a plethora of edges exhibited considerably higher electron transfer numbers compared to the thicker graphene nanoplatelets. This enhanced ORR activity was accomplished by successfully exploiting the plethora of edges of the nanosized graphene as well as the efficient electron communication between the active edge sites and the electrode substrate. The graphene nanosheets were characterized by an onset potential of -0.13 V vs Ag/AgCl and a current density of -3.85 mA/cm2 at -1 V, which represent the best ORR performance ever achieved from an undoped carbon based catalyst. This work demonstrates how low oxygen content nanosized graphene synthesized by a simple route can considerably impact the ORR catalytic activity and hence it is of significance in designing and optimizing advanced metal-free ORR electrocatalysts. PMID:25334050

  5. Submicrometer-sized hollow nickel spheres synthesized by autocatalytic reduction

    SciTech Connect

    Deng Yida . E-mail: denyda@sjtu.edu.cn; Zhao Ling; Liu Lei; Shen Bin; Hu Wenbin

    2005-10-06

    A facile method to fabricate submicrometer-sized hollow nickel spheres by autocatalyzing the redox reaction around a sacrificial colloidal particle surface is presented in this paper. The size distribution of these spheres can be controlled by regulating the concentration of the alkali solution. The hollow nickel particles were characterized by field emission scanning electron microscopy, transmission electron microscopy and X-ray powder diffraction. The hollow spheres produced by this process may have potential applications in many fields, including chemistry, biotechnology and materials science.

  6. Particle size separation via soil washing to obtain volume reduction.

    PubMed

    Anderson, R; Rasor, E; Van Ryn, F

    1999-04-23

    A pilot-plant study was performed using a soil washing pilot plant originally designed by the Environmental Protection Agency (EPA) to demonstrate scale-up and potential full-scale remediation. This pilot plant named VORCE (Volume Reduction/Chemical Extraction) was modified to meet the specific requirements for treatment of the Formerly Utilized Sites Remedial Action Program (FUSRAP) and a Department of Energy site soils. After a series of tests on clean soils to develop operating parameters and system performance, the machine was used to treat soils, one contaminated with Thorium-232 and the other with Cesium-137. All indicate that soil washing is very promising for volume reduction treatment. In addition, cost data was generated and is given herein. PMID:10379032

  7. Femtosecond laser-induced size reduction of carbon nanodots in solution: Effect of laser fluence, spot size, and irradiation time

    SciTech Connect

    Nguyen, Vanthan; Yan, Lihe Si, Jinhai; Hou, Xun

    2015-02-28

    Photoluminescent carbon nanodots (C-dots) with size tunability and uniformity were fabricated in polyethylene glycol (PEG{sub 200N}) solution using femtosecond laser ablation method. The size distributions and photoluminescence (PL) properties of C-dots are well controlled by adjusting the combined parameters of laser fluence, spot size, and irradiation time. The size reduction efficiency of the C-dots progressively increases with decreasing laser fluence and spot size. The optimal PL spectra are red-shifted and the quantum yields decrease with the increase in C-dots size, which could be attributed to the more complex surface functional groups attached on C-dots induced at higher laser fluence and larger spot size. Moreover, an increase in irradiation time leads to a decrease in size of C-dots, but long-time irradiation will result in the generation of complex functional groups on C-dots, subsequently the PL spectra are red-shifted.

  8. Class Size Reduction in Practice: Investigating the Influence of the Elementary School Principal

    ERIC Educational Resources Information Center

    Burch, Patricia; Theoharis, George; Rauscher, Erica

    2010-01-01

    Class size reduction (CSR) has emerged as a very popular, if not highly controversial, policy approach for reducing the achievement gap. This article reports on findings from an implementation study of class size reduction policy in Wisconsin entitled the Student Achievement Guarantee in Education (SAGE). Drawing on case studies of nine schools,…

  9. Effect of four different size reduction methods on the particle size, solubility enhancement and physical stability of nicergoline nanocrystals.

    PubMed

    Martena, Valentina; Shegokar, Ranjita; Di Martino, Piera; Müller, Rainer H

    2014-09-01

    Nicergoline, a poorly soluble active pharmaceutical ingredient, possesses vaso-active properties which causes peripheral and central vasodilatation. In this study, nanocrystals of nicergoline were prepared in an aqueous solution of polysorbate 80 (nanosuspension) by using four different laboratory scale size reduction techniques: high pressure homogenization (HPH), bead milling (BM) and combination techniques (high pressure homogenization followed by bead milling HPH + BM, and bead milling followed by high pressure homogenization BM + HPH). Nanocrystals were investigated regarding to their mean particles size, zeta potential and particle dissolution. A short term physical stability study on nanocrystals stored at three different temperatures (4, 20 and 40 °C) was performed to evaluate the tendency to change in particle size, aggregation and zeta potential. The size reduction technique and the process parameters like milling time, number of homogenization cycles and pressure greatly affected the size of nanocrystals. Among the techniques used, the combination techniques showed superior and consistent particle size reduction compared to the other two methods, HPH + BM and BM + HPH giving nanocrystals of a mean particle size of 260 and 353 nm, respectively. The particle dissolution was increased for any nanocrystals samples, but it was particularly increased by HPH and combination techniques. Independently to the production method, nicergoline nanocrystals showed slight increase in particle size over the time, but remained below 500 nm at 20 °C and refrigeration conditions. PMID:23815299

  10. Laser Cutting and Size Reduction. Innovative Technology Summary Report

    SciTech Connect

    2001-09-01

    The project utilizes a Neodymium Yttrium Aluminum Garnet (Nd:YAG) laser to cut and size reduce equipment in the 324 Laboratory B Hot Cell located at Pacific Northwest National Laboratory. This project will demonstrate the ability of the Nd:Yag laser to remotely and safely dismantle equipment faster, cheaper, and more efficiently than baseline cutting methods, such as the plasma torch and the water knife, in a highly radioactive area using fiber optics.

  11. Size reduction techniques for vital compliant VHDL simulation models

    DOEpatents

    Rich, Marvin J.; Misra, Ashutosh

    2006-08-01

    A method and system select delay values from a VHDL standard delay file that correspond to an instance of a logic gate in a logic model. Then the system collects all the delay values of the selected instance and builds super generics for the rise-time and the fall-time of the selected instance. Then, the system repeats this process for every delay value in the standard delay file (310) that correspond to every instance of every logic gate in the logic model. The system then outputs a reduced size standard delay file (314) containing the super generics for every instance of every logic gate in the logic model.

  12. Reductive genome evolution at both ends of the bacterial population size spectrum.

    PubMed

    Batut, Bérénice; Knibbe, Carole; Marais, Gabriel; Daubin, Vincent

    2014-12-01

    Bacterial genomes show substantial variations in size. The smallest bacterial genomes are those of endocellular symbionts of eukaryotic hosts, which have undergone massive genome reduction and show patterns that are consistent with the degenerative processes that are predicted to occur in species with small effective population sizes. However, similar genome reduction is found in some free-living marine cyanobacteria that are characterized by extremely large populations. In this Opinion article, we discuss the different hypotheses that have been proposed to account for this reductive genome evolution at both ends of the bacterial population size spectrum. PMID:25220308

  13. Liquid crystal size selection of large-size graphene oxide for size-dependent N-doping and oxygen reduction catalysis.

    PubMed

    Lee, Kyung Eun; Kim, Ji Eun; Maiti, Uday Narayan; Lim, Joonwon; Hwang, Jin Ok; Shim, Jongwon; Oh, Jung Jae; Yun, Taeyeong; Kim, Sang Ouk

    2014-09-23

    Graphene oxide (GO) is aqueous-dispersible oxygenated graphene, which shows colloidal discotic liquid crystallinity. Many properties of GO-based materials, including electrical conductivity and mechanical properties, are limited by the small flake size of GO. Unfortunately, typical sonochemical exfoliation of GO from graphite generally leads to a broad size and shape distribution. Here, we introduce a facile size selection of large-size GO exploiting liquid crystallinity and investigate the size-dependent N-doping and oxygen reduction catalysis. In the biphasic GO dispersion where both isotropic and liquid crystalline phases are equilibrated, large-size GO flakes (>20 μm) are spontaneously concentrated within the liquid crystalline phase. N-Doping and reduction of the size-selected GO exhibit that N-dopant type is highly dependent on GO flake size. Large-size GO demonstrates quaternary dominant N-doping and the lowest onset potential (-0.08 V) for oxygen reduction catalysis, signifying that quaternary N-dopants serve as principal catalytic sites in N-doped graphene. PMID:25145457

  14. Deactivation, Decontamination and Decommissioning Project Summaries

    SciTech Connect

    Peterson, David Shane; Webber, Frank Laverne

    2001-07-01

    This report is a compilation of summary descriptions of Deactivation, Decontamination and Decommissioning, and Surveillance and Maintenance projects planned for inactive facilities and sites at the INEEL from FY-2002 through FY-2010. Deactivations of contaminated facilities will produce safe and stable facilities requiring minimal surveillance and maintenance pending further decontamination and decommissioning. Decontamination and decommissioning actions remove contaminated facilities, thus eliminating long-term surveillance and maintenance. The projects are prioritized based on risk to DOE-ID, the public, and the environment, and the reduction of DOE-ID mortgage costs and liability at the INEEL.

  15. Simple and cost-effective fabrication of size-tunable zinc oxide architectures by multiple size reduction technique

    NASA Astrophysics Data System (ADS)

    Park, Hyeong-Ho; Zhang, Xin; Hwang, Seon-Yong; Jung, Sang Hyun; Kang, Semin; Shin, Hyun-Beom; Kang, Ho Kwan; Park, Hyung-Ho; Hill, Ross H.; Ko, Chul Ki

    2012-04-01

    We present a simple size reduction technique for fabricating 400 nm zinc oxide (ZnO) architectures using a silicon master containing only microscale architectures. In this approach, the overall fabrication, from the master to the molds and the final ZnO architectures, features cost-effective UV photolithography, instead of electron beam lithography or deep-UV photolithography. A photosensitive Zn-containing sol-gel precursor was used to imprint architectures by direct UV-assisted nanoimprint lithography (UV-NIL). The resulting Zn-containing architectures were then converted to ZnO architectures with reduced feature sizes by thermal annealing at 400 °C for 1 h. The imprinted and annealed ZnO architectures were also used as new masters for the size reduction technique. ZnO pillars of 400 nm diameter were obtained from a silicon master with pillars of 1000 nm diameter by simply repeating the size reduction technique. The photosensitivity and contrast of the Zn-containing precursor were measured as 6.5 J cm-2 and 16.5, respectively. Interesting complex ZnO patterns, with both microscale pillars and nanoscale holes, were demonstrated by the combination of dose-controlled UV exposure and a two-step UV-NIL.

  16. The Impact of a Universal Class-Size Reduction Policy: Evidence from Florida's Statewide Mandate

    ERIC Educational Resources Information Center

    Chingos, Matthew M.

    2012-01-01

    Class-size reduction (CSR) mandates presuppose that resources provided to reduce class size will have a larger impact on student outcomes than resources that districts can spend as they see fit. I estimate the impact of Florida's statewide CSR policy by comparing the deviations from prior achievement trends in districts that were required to…

  17. Class Size Reduction in California: Summary of the 1998-99 Evaluation Findings.

    ERIC Educational Resources Information Center

    Stecher, Brian M.; Bohrnstedt, George W.

    This report discusses the results of the third year--1998-99--of California's Class Size Reduction (CSR) program. Assessments of the program show that CSR was almost fully implemented by 1998-99, with over 92 percent of students in K-3 in classes of 20 or fewer students. Those K-3 classes that had not been reduced in size were concentrated in…

  18. The Cost of Class Size Reduction: Advice for Policymakers. RAND Graduate School Dissertation.

    ERIC Educational Resources Information Center

    Reichardt, Robert E.

    This dissertation provides information to state-level policymakers that will help them avoid two implementation problems seen in the past in California's class-size-reduction (CSR) reform. The first problem was that flat, per student reimbursement did not adequately cover costs in districts with larger pre-CSR class-sizes or smaller schools. The…

  19. What We Have Learned about Class Size Reduction in California. Capstone Report.

    ERIC Educational Resources Information Center

    Bohrnstedt, George W., Ed.; Stecher, Brian M., Ed.

    This final report on the California Class Size Reduction (CSR) initiative summarizes findings from three earlier reports dating back to 1997. Chapter 1 recaps the history of California's CSR initiative and includes a discussion of what state leaders' expectations were when CSR was passed. The chapter also describes research on class-size reduction…

  20. Focus on California's Class-Size Reduction: Smaller Classes Aim To Launch Early Literacy.

    ERIC Educational Resources Information Center

    McRobbie, Joan

    Smaller class sizes in California were viewed as a way to improve K-3 education, especially in the area of literacy. The urgency to act prompted state leaders to adopt class-size reduction (CSR) without knowing for sure that it would work and without establishing a formal procedure for evaluating the program. This report looks at past research on…

  1. Estimating the Cost of National Class Size Reductions under Different Policy Alternatives.

    ERIC Educational Resources Information Center

    Brewer, Dominic J.; Krop, Cathy; Gill, Brian P.; Reichardt, Robert

    1999-01-01

    Estimates the operational costs of nationwide class-size-reduction programs under various policy alternatives, including the specified class size, flexibility in implementation, and whether the policy is targeted toward at-risk students. Depending on the options, estimated costs range from about $2 billion per year to over $11 billion per year.…

  2. Combinative Particle Size Reduction Technologies for the Production of Drug Nanocrystals

    PubMed Central

    Salazar, Jaime; Müller, Rainer H.; Möschwitzer, Jan P.

    2014-01-01

    Nanosizing is a suitable method to enhance the dissolution rate and therefore the bioavailability of poorly soluble drugs. The success of the particle size reduction processes depends on critical factors such as the employed technology, equipment, and drug physicochemical properties. High pressure homogenization and wet bead milling are standard comminution techniques that have been already employed to successfully formulate poorly soluble drugs and bring them to market. However, these techniques have limitations in their particle size reduction performance, such as long production times and the necessity of employing a micronized drug as the starting material. This review article discusses the development of combinative methods, such as the NANOEDGE, H 96, H 69, H 42, and CT technologies. These processes were developed to improve the particle size reduction effectiveness of the standard techniques. These novel technologies can combine bottom-up and/or top-down techniques in a two-step process. The combinative processes lead in general to improved particle size reduction effectiveness. Faster production of drug nanocrystals and smaller final mean particle sizes are among the main advantages. The combinative particle size reduction technologies are very useful formulation tools, and they will continue acquiring importance for the production of drug nanocrystals. PMID:26556191

  3. Shippingport Station Decommissioning Project decommissioning plan. Volume XII

    SciTech Connect

    Not Available

    1983-01-01

    Information is presented concerning allowable residual contamination levels in soil for decommissioning the Shippingport reactor site; draft statement of work for the decommissioning operations contractor; the Shippingport Station Decommissioning Project Change Control Board charter; the surplus facilities management program; the Shippingport Station Decommissioning Project charter; DOE-RL/DOE-PNR program management agreement; and draft occupational medical plan for the decommissioning project.

  4. The effects of size reduction techniques on TCLP analysis of solidified mixed waste

    SciTech Connect

    Thiel, R.D.; McLaurin, A.W.; Kochen, R.L.

    1993-07-01

    The Rocky Flats Plant (RFP) generates and stores mixed wastes that are subject to regulation under the Resource Conservation and Recovery Act (RCRA) Land Disposal Restrictions (LDR). Low level mixed wastes at RFP are destined for disposal at the Nevada Test Site (NTS), and thus must meet stringent NTS Waste Acceptance Criteria (WAC), including free liquids, dispersible solids, and Toxicity Characteristic Leaching Procedure (TCLP) requirements. TCLP requires size reduction of the waste form to less than 0.95 centimeters. This can be accomplished by cutting, crushing, or grinding. These classic size reduction methods have the effect of exposing more surface area of the waste. Stabilization technologies under investigation at RFP include polymer encapsulation by co-extruding the waste with low density polyethylene and microwave melting. The objective of this study is to evaluate the effects of different size reduction methods on TCLP results for polyethylene-encapsulated and microwave melted surrogate waste.

  5. Rates of microbial sulfate reduction control the sizes of biogenic iron sulfide aggregates

    NASA Astrophysics Data System (ADS)

    Jin, Q.

    2005-12-01

    Sulfide minerals occur widely in freshwater and marine sediments as byproducts of microbial sulfate reduction and as end products of heavy metal bioremediation. They form when metals in the environments combine with sulfide produced from the metabolism of sulfate reducing bacteria. We used chemostat bioreactors to study sizes and crystal structures of iron sulfide (FeS) minerals produced by Desulfovibrio vulgaris, D. desulfuricans strain G20, and subspecies desulfuricans. FeS nanoparticles and their aggregates are characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and dynamic light scattering (DLS). FeS nanoparticles produced by sulfate reducing bacteria are extremely small, usually less than around 10 nm in diameter. Nanoparticles do not occur as individual nanoparticles, but as aggregates. The sizes of FeS aggregates are affected by sulfate reduction rates, Fe(II) concentration, pH, ionic strength, organic matter concentration, bacterial species, etc. Aggregate size ranges from about 500 nm at very large sulfate reduction rates to about 1,500 nm at very small rates. Variations in Fe(II) concentration also lead to a difference up to 500 nm in FeS aggregate size. Different bacterial species produce nanoparticle aggregates of different sizes under similar growth conditions. For example, D. vulgaris produces FeS aggregates with sizes 500 nm smaller than those by strain G20. The inverse relationship between FeS aggregate sizes and sulfate reduction rates is important in evaluating metal bioremediation strategies. Previous approaches have focused on stimulating microbial activities in natural environments. However, our experimental results suggest that increasing metabolic rates may decrease the aggregate size, increasing the mobility of colloidal aggregates. Therefore, the balance between microbial activities and sizes of biogenic aggregates may be an important consideration in the design and

  6. Preconditioning ischemia time determines the degree of glycogen depletion and infarct size reduction in rat hearts.

    PubMed

    Barbosa, V; Sievers, R E; Zaugg, C E; Wolfe, C L

    1996-02-01

    The cardioprotective effect of preconditioning is associated with glycogen depletion and attenuation of intracellular acidosis during subsequent prolonged ischemia. This study determined the effects of increasing preconditioning ischemia time on myocardial glycogen depletion and on infarct size reduction. In addition, this study determined whether infarct size reduction by preconditioning correlates with glycogen depletion before prolonged ischemia. Anesthetized rats underwent a single episode of preconditioning lasting 1.25, 2.5, 5, or 10 minutes or multiple episodes cumulating in 10 (2 x 5 min) or 20 minutes (4 x 5 or 2 x 10 min) of preconditioning ischemia time, each followed by 5 minutes of reperfusion. Then both preconditioned and control rats underwent 45 minutes of ischemia induced by left coronary artery (LCA) occlusion and 120 minutes of reperfusion. After prolonged ischemia, infarct size was determined by dual staining with triphenyltetrazolium chloride and phthalocyanine blue dye. Glycogen levels were determined by an enzymatic assay in selected rats from each group before prolonged ischemia. We found that increasing preconditioning ischemia time resulted in glycogen depletion and infarct size reduction that could both be described by exponential functions. Furthermore, infarct size reduction correlated with glycogen depletion before prolonged ischemia (r = 0.98; p < 0.01). These findings suggest a role for glycogen depletion in reducing ischemic injury in the preconditioned heart. PMID:8579012

  7. Size control of noble metal clusters and metallic heterostructures through the reduction kinetics of metal precursors

    NASA Astrophysics Data System (ADS)

    Sevonkaev, Igor V.; Herein, Daniel; Jeske, Gerald; Goia, Dan V.

    2014-07-01

    Eight precious metal salts/complexes were reduced in propylene glycol at temperatures ranging between 110 and 170 °C. We found that the reduction temperature and the size of precipitated metallic nanoparticles formed were significantly affected by the structure and reactivity of the metal precursors. The choice of noble metal precursor offers flexibility for designing, fabricating and controlling the size of metallic heterostructures with tunable properties.Eight precious metal salts/complexes were reduced in propylene glycol at temperatures ranging between 110 and 170 °C. We found that the reduction temperature and the size of precipitated metallic nanoparticles formed were significantly affected by the structure and reactivity of the metal precursors. The choice of noble metal precursor offers flexibility for designing, fabricating and controlling the size of metallic heterostructures with tunable properties. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr03045a

  8. Body-size reduction in vertebrates following the end-Devonian mass extinction.

    PubMed

    Sallan, Lauren; Galimberti, Andrew K

    2015-11-13

    Following the end-Devonian mass extinction (359 million years ago), vertebrates experienced persistent reductions in body size for at least 36 million years. Global shrinkage was not related to oxygen or temperature, which suggests that ecological drivers played a key role in determining the length and direction of size trends. Small, fast-breeding ray-finned fishes, sharks, and tetrapods, most under 1 meter in length from snout to tail, radiated to dominate postextinction ecosystems and vertebrae biodiversity. The few large-bodied, slow-breeding survivors failed to diversify, facing extinction despite earlier evolutionary success. Thus, the recovery interval resembled modern ecological successions in terms of active selection on size and related life histories. Disruption of global vertebrate, and particularly fish, biotas may commonly lead to widespread, long-term reduction in body size, structuring future biodiversity. PMID:26564854

  9. Insular dwarfism in hippos and a model for brain size reduction in Homo floresiensis

    PubMed Central

    Weston, Eleanor M.; Lister, Adrian M.

    2009-01-01

    Body size reduction in mammals is usually associated with only moderate brain size reduction as the brain and sensory organs complete their growth before the rest of the body during ontogeny1,2. On this basis “phyletic dwarfs” are predicted to have a higher relative brain size than “phyletic giants”1,3. This trend has been questioned, however, in the special case of dwarfism of mammals on islands4. Here we show that the endocranial capacities of extinct dwarf species of hippopotamus from Madagascar are up to 30% smaller than those of a mainland African ancestor scaled to equivalent body mass. These results show brain size reduction is much greater than predicted from an intraspecific ‘late ontogenetic’ model of dwarfism where brain size scales to body size with an exponent of 0.35. The nature of the proportional change or grade shift2,5 observed here indicates that selective pressures upon brain size are potentially independent from those on body size. This study demonstrates empirically that it is mechanistically possible for dwarf mammals on islands to evolve significantly smaller brains than would be predicted from a model of dwarfing based on the intraspecific scaling of the mainland ancestor. Our findings challenge our understanding of brain-body allometric relationships in mammals and suggest that the process of dwarfism could in principle explain small brain size, a factor relevant to the interpretation of the small-brained hominin found on the Island of Flores, Indonesia6. PMID:19424156

  10. Atomic-scale modeling of particle size effects for the oxygen reduction reaction on Pt.

    SciTech Connect

    Tritsaris, G. A.; Greeley, J.; Rossmeisl, J.; Norskov, J. K.

    2011-07-01

    We estimate the activity of the oxygen reduction reaction on platinum nanoparticles of sizes of practical importance. The proposed model explicitly accounts for surface irregularities and their effect on the activity of neighboring sites. The model reproduces the experimentally observed trends in both the specific and mass activities for particle sizes in the range between 2 and 30 nm. The mass activity is calculated to be maximized for particles of a diameter between 2 and 4 nm. Our study demonstrates how an atomic-scale description of the surface microstructure is a key component in understanding particle size effects on the activity of catalytic nanoparticles.

  11. Two Roads to Reform: Comparing the Research on Vouchers and Class-Size Reduction.

    ERIC Educational Resources Information Center

    Neas, Ralph G.

    Both educational vouchers and class size reduction are high-profile proposals for improving education. While the body of research on vouchers is small and unconvincing, the research on smaller classes is abundant and compelling. Researchers have been able to compare the impact of both of these policy alternatives on student performance. Their…

  12. What the Research Tells Us: Class Size Reduction. Information Capsule. Volume 1001

    ERIC Educational Resources Information Center

    Romanik, Dale

    2010-01-01

    This Information Capsule examines the background and history in addition to research findings pertaining to class size reduction (CSR). This Capsule concludes that although educational researchers have not definitively agreed upon the effectiveness of CSR, given its almost universal public appeal, there is little doubt it is here to stay in some…

  13. Class Size Reduction in a Large Urban School District: A Mixed Methodology Evaluation Research Study.

    ERIC Educational Resources Information Center

    Munoz, Marco A.

    This study evaluated the Class Size Reduction (CSR) program in 34 elementary schools in Kentucky's Jefferson County Public Schools. The CSR program is a federal initiative to help elementary schools improve student learning by hiring additional teachers. Qualitative data were collected using unstructured interviews, site observations, and document…

  14. A Plan for the Evaluation of California's Class Size Reduction Initiative.

    ERIC Educational Resources Information Center

    Kirst, Michael; Bomstedt, George; Stecher, Brian

    In July 1996, California began its Class Size Reduction (CSR) Initiative. To gauge the effectiveness of this initiative, an analysis of its objectives and an overview of proposed strategies for evaluating CSR are presented here. An outline of the major challenges that stand between CSR and its mission are provided. These include logistical…

  15. Class Size Reduction or Rapid Formative Assessment?: A Comparison of Cost-Effectiveness

    ERIC Educational Resources Information Center

    Yeh, Stuart S.

    2009-01-01

    The cost-effectiveness of class size reduction (CSR) was compared with the cost-effectiveness of rapid formative assessment, a promising alternative for raising student achievement. Drawing upon existing meta-analyses of the effects of student-teacher ratio, evaluations of CSR in Tennessee, California, and Wisconsin, and RAND cost estimates, CSR…

  16. Class Size Reduction: Lessons Learned from Experience. Policy Brief No. Twenty-Three.

    ERIC Educational Resources Information Center

    McRobbie, Joan; Finn, Jeremy D.; Harman, Patrick

    New federal proposals have fueled national interest in class-size reduction (CSR). However, CSR raises numerous concerns, some of which are addressed in this policy brief. The text draws on the experiences of states and districts that have implemented CSR. The brief addresses the following 15 concerns: Do small classes in and of themselves affect…

  17. A Comparison of QEIA and Non-QEIA Schools: Implications of Class Size Reduction

    ERIC Educational Resources Information Center

    Platt, Louise Carolyn Sater

    2013-01-01

    The purpose of this research study is to compare student achievement changes between matched QEIA and non-QEIA schools in an effort to infer effects of the most significant feature of QEIA funding, class size reduction. The study addressed the critical question--are there demonstrated, significant differences in student achievement gains between…

  18. Class-Size Reduction: Using What's Been Learned To Inform Educational Decisions. The Informed Educator Series.

    ERIC Educational Resources Information Center

    Boniface, Russell; Protheroe, Nancy

    Class-size reduction (CSR) has been a complex and contentious issue for the last quarter century. Although the small-class concept was adopted because it appealed to common sense, research over time has revealed a mix of confounding variables, instead of a definitive conclusion. Some CSR efforts, such as Tennessee's Project STAR and Wisconsin's…

  19. Shortened cecropin A-melittin hybrids. Significant size reduction retains potent antibiotic activity.

    PubMed

    Andreu, D; Ubach, J; Boman, A; Wåhlin, B; Wade, D; Merrifield, R B; Boman, H G

    1992-01-20

    We have earlier reported two 26-residue antibacterial peptides made up from different segments of cecropin A (CA) and melittin (M). We now report a substantial reduction in size at the C-terminal section of the highly active hybrid CA(1-8)M(1-18), leading to a series of 20-, 18- and 15-residue analogs with antibiotic properties similar to the larger molecule. In particular, the 15-residue hybrids CA(1-7)M(2-9), CA(1-7)M(4-11) and CA(1-7)M(5-12) are the shortest cecropin-based peptide antibiotics described so far, with antibacterial activity and spectra similar or better than cecropin A and a 60% reduction in size. Their reduced size and highly alpha-helical structure require an alternative mechanism for their interaction with bacterial membranes. PMID:1733777

  20. Effects of cutting orientation in poplar wood biomass size reduction on enzymatic hydrolysis sugar yield.

    PubMed

    Zhang, Meng; Ju, Xiaohui; Song, Xiaoxu; Zhang, Xiao; Pei, Z J; Wang, Donghai

    2015-10-01

    The aim of this study was to understand how cutting orientation in poplar wood biomass size reduction affects enzymatic hydrolysis sugar yield of wood particles. A metal cutting (milling) machine was used to produce poplar wood particles from three cutting orientations. Results showed that cutting orientation significantly affected enzymatic hydrolysis sugar yield of wood particles. In this study, size reduction from the optimum cutting orientation produced 50% more sugars than the other two cutting orientations. Particles from the cutting orientation with the highest sugar yield had a large enzyme accessible area (125 mg orange dye/g biomass, as evaluated by Simons' stain procedure) and low crystallinity (50% crystallinity index, as calculated by the Segal method). Furthermore, small particle size did not necessarily lead to improvement in enzymatic digestibility. PMID:26220047

  1. Size-controlled synthesis of monodispersed gold nanoparticles via carbon monoxide gas reduction

    PubMed Central

    2011-01-01

    An in depth analysis of gold nanoparticle (AuNP) synthesis and size tuning, utilizing carbon monoxide (CO) gas as a reducing agent, is presented for the first time. The sizes of the AuNPs are tunable from ~4 to 100 nm by altering the concentration of HAuCl4 and inlet CO gas-injection flow rate. It is also found that speciation of aqueous HAuCl4, prior to reduction, influences the size, morphology, and properties of AuNPs when reduced with CO gas. Ensemble extinction spectra and TEM images provide clear evidence that CO reduction offers a high level of monodispersity with standard deviations as low as 3%. Upon synthesis, no excess reducing agent remains in solution eliminating the need for purification. The time necessary to synthesize AuNPs, using CO, is less than 2 min. PMID:21711955

  2. Effect of the mechanical activation on size reduction of crystalline acetaminophen drug particles.

    PubMed

    Biazar, Esmaeil; Beitollahi, Ali; Rezayat, S Mehdi; Forati, Tahmineh; Asefnejad, Azadeh; Rahimi, Mehdi; Zeinali, Reza; Ardeshir, Mahmoud; Hatamjafari, Farhad; Sahebalzamani, Ali; Heidari, Majid

    2009-01-01

    The decrease in particle size may offer new properties to drugs. In this study, we investigated the size reduction influence of the acetaminophen (C(8)H(9)O(2)N) particles by mechanical activation using a dry ball mill. The activated samples with the average size of 1 microm were then investigated in different time periods with the infrared (IR), inductively coupled plasma (ICP), atomic force microscopy (AFM), and X-ray diffraction (XRD) methods. The results of the IR and XRD images showed no change in the drug structure after the mechanical activation of all samples. With the peak height at full width at half maximum from XRD and the Scherrer equation, the size of the activated crystallite samples illustrated that the AFM images were in sound agreement with the Scherrer equation. According to the peaks of the AFM images, the average size of the particles in 30 hours of activation was 24 nm with a normal particle distribution. The ICP analysis demonstrated the presence of tungsten carbide particle impurities after activation from the powder sample impacting with the ball and jar. The greatest reduction in size was after milling for 30 hours. PMID:20054432

  3. Statistical relationship between pyrite grain size distribution and pyritic sulfur reduction in Ohio coal

    USGS Publications Warehouse

    Mazumdar, M.; Carlton, R.W.; Irdi, G.A.

    1988-01-01

    This paper presents a statistical relationship between the pyrite particle size distribution and the potential amount of pyritic sulfur reduction achieved by specific-gravity-based separation. This relationship is obtained from data on 26 Ohio coal samples crushed to 14 ?? 28 mesh. In this paper a prediction equation is developed that considers the complete statistical distribution of all the pyrite particle sizes in the coal sample. Assuming that pyrite particles occurring in coal have a lognormal distribution, the information about the particle size distribution can be encapsulated in terms of two parameters only, the mean and the standard deviation of the logarithms of the grain diameters. When the pyritic sulfur reductions of the 26 coal samples are related to these two parameters, a very satisfactory regression equation (R2 = 0.91) results. This equation shows that information on both these parameters is needed for an accurate prediction of potential sulfur reduction, and that the mean and the standard deviation interact negatively insofar as their influence on pyritic sulfur reduction is concerned. ?? 1988.

  4. Size Reduction Techniques for Large Scale Permanent Magnet Generators in Wind Turbines

    NASA Astrophysics Data System (ADS)

    Khazdozian, Helena; Hadimani, Ravi; Jiles, David

    2015-03-01

    Increased wind penetration is necessary to reduce U.S. dependence on fossil fuels, combat climate change and increase national energy security. The U.S Department of Energy has recommended large scale and offshore wind turbines to achieve 20% wind electricity generation by 2030. Currently, geared doubly-fed induction generators (DFIGs) are typically employed in the drivetrain for conversion of mechanical to electrical energy. Yet, gearboxes account for the greatest downtime of wind turbines, decreasing reliability and contributing to loss of profit. Direct drive permanent magnet generators (PMGs) offer a reliable alternative to DFIGs by eliminating the gearbox. However, PMGs scale up in size and weight much more rapidly than DFIGs as rated power is increased, presenting significant challenges for large scale wind turbine application. Thus, size reduction techniques are needed for viability of PMGs in large scale wind turbines. Two size reduction techniques are presented. It is demonstrated that 25% size reduction of a 10MW PMG is possible with a high remanence theoretical permanent magnet. Additionally, the use of a Halbach cylinder in an outer rotor PMG is investigated to focus magnetic flux over the rotor surface in order to increase torque. This work was supported by the National Science Foundation under Grant No. 1069283 and a Barbara and James Palmer Endowment at Iowa State University.

  5. Reduction of Energetic Demands through Modification of Body Size and Routine Metabolic Rates in Extremophile Fish.

    PubMed

    Passow, Courtney N; Greenway, Ryan; Arias-Rodriguez, Lenin; Jeyasingh, Punidan D; Tobler, Michael

    2015-01-01

    Variation in energy availability or maintenance costs in extreme environments can exert selection for efficient energy use, and reductions in organismal energy demand can be achieved in two ways: reducing body mass or metabolic suppression. Whether long-term exposure to extreme environmental conditions drives adaptive shifts in body mass or metabolic rates remains an open question. We studied body size variation and variation in routine metabolic rates in locally adapted populations of extremophile fish (Poecilia mexicana) living in toxic, hydrogen sulfide-rich springs and caves. We quantified size distributions and routine metabolic rates in wild-caught individuals from four habitat types. Compared with ancestral populations in nonsulfidic surface habitats, extremophile populations were characterized by significant reductions in body size. Despite elevated metabolic rates in cave fish, the body size reduction precipitated in significantly reduced energy demands in all extremophile populations. Laboratory experiments on common garden-raised fish indicated that elevated routine metabolic rates in cave fish likely have a genetic basis. The results of this study indicate that adaptation to extreme environments directly impacts energy metabolism, with fish living in cave and sulfide spring environments expending less energy overall during routine metabolism. PMID:26052634

  6. Body size reductions in nonmammalian eutheriodont therapsids (Synapsida) during the end-Permian mass extinction.

    PubMed

    Huttenlocker, Adam K

    2014-01-01

    The extent to which mass extinctions influence body size evolution in major tetrapod clades is inadequately understood. For example, the 'Lilliput effect,' a common feature of mass extinctions, describes a temporary decrease in body sizes of survivor taxa in post-extinction faunas. However, its signature on existing patterns of body size evolution in tetrapods and the persistence of its impacts during post-extinction recoveries are virtually unknown, and rarely compared in both geologic and phylogenetic contexts. Here, I evaluate temporal and phylogenetic distributions of body size in Permo-Triassic therocephalian and cynodont therapsids (eutheriodonts) using a museum collections-based approach and time series model fitting on a regional stratigraphic sequence from the Karoo Basin, South Africa. I further employed rank order correlation tests on global age and clade rank data from an expanded phylogenetic dataset, and performed evolutionary model testing using Brownian (passive diffusion) models. Results support significant size reductions in the immediate aftermath of the end-Permian mass extinction (ca. 252.3 Ma) consistent with some definitions of Lilliput effects. However, this temporal succession reflects a pattern that was underscored largely by Brownian processes and constructive selectivity. Results also support two recent contentions about body size evolution and mass extinctions: 1) active, directional evolution in size traits is rare over macroevolutionary time scales and 2) geologically brief size reductions may be accomplished by the ecological removal of large-bodied species without rapid originations of new small-bodied clades or shifts from long-term evolutionary patterns. PMID:24498335

  7. Processing, mixing, and particle size reduction of forages for dairy cattle.

    PubMed

    Heinrichs, A J; Buckmaster, D R; Lammers, B P

    1999-01-01

    Adequate forage amounts in both physical and chemical forms are necessary for proper ruminal function in dairy cows. Under conditions in which total amounts of forage or particle size of the forage are reduced, cows spend less time ruminating and have a decreased amount of buoyant digesta in the rumen. These factors reduce saliva production and allow ruminal pH to fall, depressing activity of cellulolytic bacteria and causing a prolonged period of low ruminal pH. Insufficient particle size of the diet decreases the ruminal acetate-to-propionate ratio and reduces ruminal pH. The mean particle size of the diet, the variation in particle size, and the amount of chemical fiber (i.e., NDF or ADF) are all nutritionally important for dairy cows. Defining amounts and physical characteristics of fiber is important in balancing dairy cattle diets. Because particle size plays such an important role in digestion and animal performance, it must be an important consideration from harvest through feeding. Forages should not be reduced in particle size beyond what is necessary to achieve minimal storage losses and what can be accommodated by existing equipment. Forage and total mixed ration (TMR) particle sizes are potentially reduced in size by all phases of harvesting, storing, taking out of storage, mixing, and delivery of feed to the dairy cow. Mixing feed causes a reduction in size of all feed particles and is directly related to TMR mixing time; field studies show that the longest particles (>27 mm) may be reduced in size by 50%. Forage and TMR particle size as fed to the cows should be periodically monitored to maintain adequate nutrition for the dairy cow. PMID:10064042

  8. Crystal size induced reduction in thermal hysteresis of Ni-Ti-Nb shape memory thin films

    NASA Astrophysics Data System (ADS)

    Li, K.; Li, Y.; Yu, K. Y.; Liu, C.; Gibson, D.; Leyland, A.; Matthews, A.; Fu, Y. Q.

    2016-04-01

    Ni41.7Ti38.8Nb19.5 shape memory alloy films were sputter-deposited onto silicon substrates and annealed at various temperatures. A narrow thermal hysteresis was obtained in the Ni-Ti-Nb films with a grain size of less than 50 nm. The small grain size, which means an increase in the volume fraction of grain boundaries, facilitates the phase transformation and reduces the hysteresis. The corresponding less transformation friction and lower heat transfer during the shear process, as well as reduced spontaneous lattice distortion, are responsible for this reduction of the thermal hysteresis.

  9. TECHNOLOGY EVALUATION FOR CONDITIONING OF HANFORD TANK WASTE USING SOLIDS SEGREGATION AND SIZE REDUCTION

    SciTech Connect

    Restivo, M.; Stone, M.; Herman, D.; Lambert, D.; Duignan, M.; SMITH, G.; WELLS, B.; LUMETTA, G.; ENDRELIN, C.; ADKINS, H.

    2014-04-15

    The Savannah River National Laboratory (SRNL) and the Pacific Northwest National Laboratory (PNNL) team performed a literature search on current and proposed technologies for solids segregation and size reduction of particles in the slurry feed from the Hanford Tank Farm (HTF). The team also investigated technology research performed on waste tank slurries, both real and simulated, and reviewed academic theory applicable to solids segregation and size reduction. This review included text book applications and theory, commercial applications suitable for a nuclear environment, research of commercial technologies suitable for a nuclear environment, and those technologies installed in a nuclear environment, including technologies implemented at Department of Energy (DOE) facilities. Information on each technology is provided in this report along with the advantages and disadvantages of the technologies for this application.

  10. Technology Evaluation for Conditioning of Hanford Tank Waste Using Solids Segregation and Size Reduction

    SciTech Connect

    Restivo, Michael L.; Stone, M. E.; Herman, D. T.; Lambert, Daniel P.; Duignan, Mark R.; Smith, Gary L.; Wells, Beric E.; Lumetta, Gregg J.; Enderlin, Carl W.; Adkins, Harold E.

    2014-04-24

    The Savannah River National Laboratory and the Pacific Northwest National Laboratory team performed a literature search on current and proposed technologies for solids segregation and size reduction of particles in the slurry feed from the Hanford Tank Farm. The team also investigated technology research performed on waste tank slurries, both real and simulated, and reviewed academic theory applicable to solids segregation and size reduction. This review included text book applications and theory, commercial applications suitable for a nuclear environment, research of commercial technologies suitable for a nuclear environment, and those technologies installed in a nuclear environment, including technologies implemented at Department of Energy facilities. Information on each technology is provided in this report along with the advantages and disadvantages of the technologies for this application. Any technology selected would require testing to verify the ability to meet the High-Level Waste Feed Waste Acceptance Criteria to the Hanford Tank Waste Treatment and Immobilization Plant Pretreatment Facility.

  11. Decommissioning at AWE

    SciTech Connect

    Biles, K.; Hedges, M.; Campbell, C

    2008-07-01

    AWE (A) has been at the heart of the UK Nuclear deterrent since it was established in the early 1950's. It is a nuclear licensed site and is governed by the United Kingdoms Nuclear Installation Inspectorate (NII). AWE plc on behalf of the Ministry of Defence (MOD) manages the AWE (A) site and all undertakings including decommissioning. Therefore under NII license condition 35 'Decommissioning', AWE plc is accountable to make and implement adequate arrangements for the decommissioning of any plant or process, which may affect safety. The majority of decommissioning projects currently being undertaken are to do with Hazard category 3, 4 or 5 facilities, systems or plant that have reached the end of their operational span and have undergone Post-Operational Clean-Out (POCO). They were either built for the production of fissile components, for supporting the early reactor fuels programmes or for processing facility waste arisings. They either contain redundant contaminated gloveboxes associated process areas, process plant or systems or a combination of all. In parallel with decommissioning project AWE (A) are undertaking investigation into new technologies to aid decommissioning projects; to remove the operative from hands on operations; to develop and implement modifications to existing process and techniques used. AWE (A) is currently going thorough a sustained phase of upgrading its facilities to enhance its scientific capability, with older facilities, systems and plant being replaced, making decommissioning a growth area. It is therefore important to the company to reduce these hazards progressively and safety over the coming years, making decommissioning an important feature of the overall legacy management aspects of AWE PLC's business. This paper outlines the current undertakings and progress of Nuclear decommissioning on the AWE (A) site. (authors)

  12. Size reduction of high- and low-moisture corn stalks by linear knife grid system

    SciTech Connect

    Womac, A.R.; Igathinathane, C.; Sokhansanj, Shahabaddine; Narayan, S.

    2009-04-01

    High- and low-moisture corn stalks were tested using a linear knife grid size reduction device developed for first-stage size reduction. The device was used in conjunction with a universal test machine that quantified shearing stress and energy characteristics for forcing a bed of corn stalks through a grid of sharp knives. No published engineering performance data for corn stover with similar devices are available to optimize performance; however, commercial knife grid systems exist for forage size reduction. From the force displacement data, mean and maximum ultimate shear stresses, cumulative and peak mass-based cutting energies for corn stalks, and mean new surface area-based cutting energies were determined from 4 5 refill runs at two moisture contents (78.8% and 11.3% wet basis), three knife grid spacings (25.4, 50.8, and 101.6 mm), and three bed depths (50.8, 101.6, and 152.4 mm). In general, the results indicated that peak failure load, ultimate shear stress, and cutting energy values varied directly with bed depth and inversely with knife grid spacing. Mean separation analysis established that high- and low-moisture conditions and bed depths 101.6 mm did not differ significantly (P < 0.05) for ultimate stress and cutting energy values, but knife grid spacing were significantly different. Linear knife grid cutting energy requirements for both moisture conditions of corn stalks were much smaller than reported cutting energy requirements. Ultimate shear stress and cutting energy results of this research should aid the engineering design of commercial scale linear knife gird size reduction equipment for various biomass feedstocks.

  13. Preferential cataclastic grain size reduction of feldspar in deformation bands in poorly consolidated arkosic sands

    NASA Astrophysics Data System (ADS)

    Exner, Ulrike; Tschegg, Cornelius

    2012-10-01

    This study presents microstructural as well as bulk and mineral chemical investigations of deformation bands in uncemented, friable arkosic sands of Miocene age (Vienna Basin, Austria). Our microstructural study indicates grain size reduction by grain flaking in deformation bands with small offsets (0.5-8 cm), and dominant intragranular fracturing and cataclasis of altered feldspar grains at larger displacements (up to 60 cm). Relative to quartz, the sericitized feldspar grains are preferably fractured and abraded, which additionally leads to an enrichment of mainly phyllosilicates by mechanical expulsion from feldspar. Both cataclasis of quartz and feldspar grains and enrichment of phyllosilicates result in grain size reduction within the deformation bands. The measured reduction in porosity of up to 20% is in some cases associated with a permeability reduction, reflected in the retention of iron-oxide rich fluids along deformation bands. These deformation bands formed at very shallow burial depths in unconsolidated sediments indicate that fault sealing may occur in the absence of chemical alteration of the deformation bands and lead to a compartmentalization of a groundwater or hydrocarbon reservoir.

  14. Preferential cataclastic grain size reduction of feldspar in deformation bands in poorly consolidated arkosic sands

    PubMed Central

    Exner, Ulrike; Tschegg, Cornelius

    2012-01-01

    This study presents microstructural as well as bulk and mineral chemical investigations of deformation bands in uncemented, friable arkosic sands of Miocene age (Vienna Basin, Austria). Our microstructural study indicates grain size reduction by grain flaking in deformation bands with small offsets (0.5–8 cm), and dominant intragranular fracturing and cataclasis of altered feldspar grains at larger displacements (up to 60 cm). Relative to quartz, the sericitized feldspar grains are preferably fractured and abraded, which additionally leads to an enrichment of mainly phyllosilicates by mechanical expulsion from feldspar. Both cataclasis of quartz and feldspar grains and enrichment of phyllosilicates result in grain size reduction within the deformation bands. The measured reduction in porosity of up to 20% is in some cases associated with a permeability reduction, reflected in the retention of iron-oxide rich fluids along deformation bands. These deformation bands formed at very shallow burial depths in unconsolidated sediments indicate that fault sealing may occur in the absence of chemical alteration of the deformation bands and lead to a compartmentalization of a groundwater or hydrocarbon reservoir. PMID:26523078

  15. Defeaturing CAD models using a geometry-based size field and facet-based reduction operators.

    SciTech Connect

    Quadros, William Roshan; Owen, Steven James

    2010-04-01

    We propose a method to automatically defeature a CAD model by detecting irrelevant features using a geometry-based size field and a method to remove the irrelevant features via facet-based operations on a discrete representation. A discrete B-Rep model is first created by obtaining a faceted representation of the CAD entities. The candidate facet entities are then marked for reduction by using a geometry-based size field. This is accomplished by estimating local mesh sizes based on geometric criteria. If the field value at a facet entity goes below a user specified threshold value then it is identified as an irrelevant feature and is marked for reduction. The reduction of marked facet entities is primarily performed using an edge collapse operator. Care is taken to retain a valid geometry and topology of the discrete model throughout the procedure. The original model is not altered as the defeaturing is performed on a separate discrete model. Associativity between the entities of the discrete model and that of original CAD model is maintained in order to decode the attributes and boundary conditions applied on the original CAD entities onto the mesh via the entities of the discrete model. Example models are presented to illustrate the effectiveness of the proposed approach.

  16. Potential of size reduction of flat-plate solar collectors when applying MWCNT nanofluid

    NASA Astrophysics Data System (ADS)

    Faizal, M.; Saidur, R.; Mekhilef, S.

    2013-06-01

    Flat-plate solar collector is the most popular type of collector for hot water system to replace gas or electric heater. Solar thermal energy source is clean and infinite to replace fossil fuel source that is declining and harmful to the environment. However, current solar technology is still expensive, low in efficiency and takes up a lot of space. One effective way to increase the efficiency is by applying high conductivity fluid as nanofluid. This paper analyzes the potential of size reduction of solar collector when MWCNT nanofluid is used as absorbing medium. The analysis is based on different mass flow rate, nanoparticles mass fraction, and presence of surfactant in the fluid. For the same output temperature, it can be observed that the collector's size can be reduced up to 37% of its original size when applying MWCNT nanofluid as the working fluid and thus can reduce the overall cost of the system.

  17. Metabolic ‘engines’ of flight drive genome size reduction in birds

    PubMed Central

    Wright, Natalie A.; Gregory, T. Ryan; Witt, Christopher C.

    2014-01-01

    The tendency for flying organisms to possess small genomes has been interpreted as evidence of natural selection acting on the physical size of the genome. Nonetheless, the flight–genome link and its mechanistic basis have yet to be well established by comparative studies within a volant clade. Is there a particular functional aspect of flight such as brisk metabolism, lift production or maneuverability that impinges on the physical genome? We measured genome sizes, wing dimensions and heart, flight muscle and body masses from a phylogenetically diverse set of bird species. In phylogenetically controlled analyses, we found that genome size was negatively correlated with relative flight muscle size and heart index (i.e. ratio of heart to body mass), but positively correlated with body mass and wing loading. The proportional masses of the flight muscles and heart were the most important parameters explaining variation in genome size in multivariate models. Hence, the metabolic intensity of powered flight appears to have driven genome size reduction in birds. PMID:24478299

  18. Genome size reduction can trigger rapid phenotypic evolution in invasive plants

    PubMed Central

    Lavergne, Sébastien; Muenke, Nikolas J.; Molofsky, Jane

    2010-01-01

    Background and Aims The study of rapid evolution in invasive species has highlighted the fundamental role played by founder events, emergence of genetic novelties through recombination and rapid response to new selective pressures. However, whether rapid adaptation of introduced species can be driven by punctual changes in genome organization has received little attention. In plants, variation in genome size, i.e. variation in the amount of DNA per monoploid set of chromosomes through loss or gain of repeated DNA sequences, is known to influence a number of physiological, phenological and life-history features. The present study investigated whether change in genome size has contributed to the evolution of greater potential of vegetative growth in invasive populations of an introduced grass. Methods The study was based on the recent demonstration that invasive genotypes of reed canarygrass (Phalaris arundinacea) occurring in North America have emerged from recombination between introduced European strains. The genome sizes of more than 200 invasive and native genotypes were measured and their genome size was related to their phenotypic traits measured in a common glasshouse environment. Population genetics data were used to infer phylogeographical relationships between study populations, and the evolutionary history of genome size within the study species was inferred. Key Results Invasive genotypes had a smaller genome than European native genotypes from which they are derived. This smaller genome size had phenotypic effects that increased the species' invasive potential, including a higher early growth rate, due to a negative relationship between genome size and rate of stem elongation. Based on inferred phylogeographical relationships of invasive and native populations, evolutionary models were consistent with a scenario of genome reduction by natural selection during the invasion process, rather than a scenario of stochastic change. Conclusions Punctual

  19. Metamorphic reactions, grain size reduction and deformation of mafic lower crustal rocks

    NASA Astrophysics Data System (ADS)

    Degli Alessandrini, Giulia; Menegon, Luca; Beltrando, Marco; Dijkstra, Arjan; Anderson, Mark

    2016-04-01

    This study investigates grain-scale deformation mechanisms associated with strain localization in the mafic continental lower crust, with particular focus on the role of syn-kinematic metamorphic reactions and their product - symplectites - in promoting grain size reduction and phase mixing. The investigated shear zone is hosted in the Finero mafic-ultramafic complex in the Italian Southern Alps. Shearing occurred at T ≥ 650° C and P ≥ 0.4-0.6 GPa. The shear zone reworks both mafic and ultramafic lithologies and displays anastomosing patterns of (ultra)mylonitic high strain zones wrapping less foliated, weakly deformed low strain domains. Field and microstructural observations indicate that different compositional layers of the shear zone responded differently to deformation, resulting in strain partitioning. Four distinct microstructural domains have been identified: (1) an ultramylonitic domain characterized by an amph + pl matrix (grain size < 30μm) with large amphibole porphyroclasts (grain size between 200μm and 5000μm) and rare garnets; (2) a domain rich in garnet porphyroclasts embedded in a matrix of monomineralic plagioclase displaying a core and mantle structure (average grain size 45μm) (3) a metagabbroic domain with porphyroclasts of clinopyroxene, orthopyroxene and garnets (200μm average grain size) wrapped by monomineralic ribbons of recrystallized plagioclase and (4) a garnet-free ultramylonitic domain composed of an intermixed amph + cpx + opx + pl matrix (6μm average grain size). In these domains, each porphyroclastic mineral responds differently to deformation: amphibole readily breaks down to symplectitic intergrowths of amph + pl or opx + pl. Garnet undergoes fracturing (in domain 2) or reacts to give symplectites of pl + opx (in domain 3). Plagioclase dynamically recrystallizes in mono-phase aggregates, whereas clinopyroxene undergoes fracturing and orthopyroxene undergoes plastic deformation. The behaviour of the different phases

  20. SIGNIFICANCE OF SIZE REDUCTION IN SOLID WASTE MANAGEMENT. VOLUME 3. EFFECTS OF MACHINE PARAMETERS ON SHREDDER PERFORMANCE

    EPA Science Inventory

    Hammermill shredders for size reduction of refuse were examined at three sites to determine the influence of key machine parameters on their performance. Internal machine configuration and single-versus two stage size reduction were studied. Key parameters that were investigated ...

  1. Duodenal myotomy blocks reduction of meal size and prolongation of intermeal interval by cholecystokinin.

    PubMed

    Lateef, Dalya M; Washington, Martha C; Raboin, Shannon J; Roberson, Allison E; Mansour, Mahmoud M; Williams, Carol S; Sayegh, Ayman I

    2012-02-01

    We have shown that vagotomy (VGX) attenuates the reduction of meal size (MS) produced by cholecystokinin (CCK) -8 and -33 and that celiaco-mesenteric ganglionectomy (CMGX) attenuates the prolongation of the intermeal interval (IMI) produced by CCK-33. Here, we report the following novel data. First, by determining the distribution of CCK(1) receptor messenger RNA, which mediates reduction of MS and prolongation of IMI by CCK, in seven regions of the gastrointestinal tract in the adult rat we found that the duodenum contains the highest concentration of this receptor in the gut. Second, based on the previous finding we performed a unique surgical technique known as duodenal myotomy (MYO), which severs all the nerves of the gut wall in the duodenum including vagus, splanchnic and enteric nerves. Third, we determined MS and IMI in duodenal MYO rats in responses to endogenous CCK-58 released by the non-nutrient, trypsin inhibitor, camostat and CCK-8 to test the possibility that the duodenum is the site of action for reduction of MS and prolongation of IMI. We found that, similar to the previous work reported by using CCK-8 and MS, duodenal MYO also blocked reduction of MS by camostat. Forth, duodenal MYO blocked prolongation of IMI by camostat. As such, our current results suggest that the duodenum is the gut site that communicates both feeding signals of endogenous CCK, MS and IMI, with the brain through vagal and splanchnic afferents. PMID:22047890

  2. Reduction in size and unsteadiness of a VTOL ground vortex by ground fences

    NASA Technical Reports Server (NTRS)

    Cimbala, John M.; Billet, Michael L.; Harman, Todd B.

    1993-01-01

    A ground vortex, produced when a jet impinges on the ground in the presence of cross flow, is encountered by V/STOL aircraft hovering near the ground and is known to be hazardous to the aircraft. The objective of this research was to identify a ground-based technique by which both the mean size and fluctuation in size of the ground vortex could be reduced. A simple passive method was identified and examined in the laboratory. Specifically, one or two fine wire mesh screens (ground fences) bent in a horseshoe shape and located on the ground in front of the jet impingement point proved to be very effective. The ground fences work by decreasing the momentum of the upstream-traveling wall jet, effectively causing a higher freestream-to-jet velocity ratio (V(sub infinity)/V(sub j)) and thus, a ground vortex smaller in size and unsteadiness. At(V(sub infinity)/V(sub j)) = 0.15, the addition of a single ground fence resulted in a 70 percent reduction in mean size of the ground vortex. With two ground fences, the mean size decreased by about 85 percent. Fluctuations in size decreased nearly in proportion to the mean size, for both the single and double fence configurations. These results were consistent over a wide range of jet Reynolds number (10(exp 4) less than Re(sub jet) less than 10(exp 5)); further development and full-scale Reynolds number testing are required, however, to determine if this technique can be made practical for the case of actual VTOL aircraft.

  3. Model-size reduction for the buckling and vibration analyses of anisotropic panels

    NASA Technical Reports Server (NTRS)

    Noor, A. K.; Whitworth, S. L.

    1986-01-01

    A computational procedure is presented for reducing the size of the model used in the buckling and vibration analyses of symmetric anisotropic panels to that of the corresponding orthotropic model. The key elements of the procedure are the application of an operator splitting technique through the decomposition of the material stiffness matrix of the panel into the sum of orthotropic and nonorthotropic (anisotropic) parts and the use of a reduction method through successive application of the finite element method and the classical Rayleigh-Ritz technique. The effectiveness of the procedure is demonstrated by numerical examples.

  4. Latest pixel size reduction of uncooled IR-FPA at CEA, LETI

    NASA Astrophysics Data System (ADS)

    Becker, Sebastien; Imperinetti, Pierre; Yon, Jean-Jacques; Ouvrier-Buffet, Jean-Louis; Goudon, Valérie; Hamelin, Antoine; Vialle, Claire; Arnaud, Agnès.

    2012-10-01

    Recent developments at the Infrared Lab (LIR) of CEA, LETI have been concentrated on the pixel size reduction of uncooled infrared detectors. With the support from French company ULIS, we have successfully demonstrated the technological integration of 12μm pixels on a commercial TV-format read-out circuit (VGA-ROIC) supplied by ULIS. The 12μm pixel has been designed, processed and characterized in CEA, LETI and first results showed exceptional performances. This paper presents the characterization and associated imagery results.

  5. Size Reduction in Early European Domestic Cattle Relates to Intensification of Neolithic Herding Strategies.

    PubMed

    Manning, Katie; Timpson, Adrian; Shennan, Stephen; Crema, Enrico

    2015-01-01

    Our analysis of over 28,000 osteometric measurements from fossil remains dating between c. 5600 and 1500 BCE reveals a substantial reduction in body mass of 33% in Neolithic central European domestic cattle. We investigate various plausible explanations for this phenotypic adaptation, dismissing climatic change as a causal factor, and further rejecting the hypothesis that it was caused by an increase in the proportion of smaller adult females in the population. Instead we find some support for the hypothesis that the size decrease was driven by a demographic shift towards smaller newborns from sub-adult breeding as a result of intensifying meat production strategies during the Neolithic. PMID:26630287

  6. Demonstration of spot size reduction by focussing amplitude modulated radially polarized light on a photoresist

    NASA Astrophysics Data System (ADS)

    Ushakova, K.; van den Berg, Q. Y.; Pereira, S. F.; Urbach, H. P.

    2015-12-01

    Spot size reduction is demonstrated by printing focused spots from amplitude-modulated radially polarized light at the wavelength λ = 405 nm on a photoresist. Amplitude modulation is realized by ring illumination and by application of an optimized amplitude distribution function. Amplitude modulation is implemented via spatial light modulator, which is followed by a specially designed radial wire grid polarizer to obtain high-quality radially polarized light. Comparison between full and amplitude modulated apertures of the written focused spots on a photoresist is performed. Rigorous simulations based on the Richards-Wolf integral are made to confirm experimental data.

  7. Design of an Axial Gradient Lens for Reduction of Laser Beam Size

    NASA Astrophysics Data System (ADS)

    Kassim, Abed. M.

    2011-10-01

    A new design of an optimized optical system for the reduction of a laser beam size at a certain wavelength is presented. The technique of this design is based upon replacing the elements of a four-lenses optical system, which is designed for this purpose, by one element made of an axial gradient index material. The optical performance of this new design, which has a power as that of its counterpart, is tested by the evaluation of many merit functions. The graphical comparisons between the corresponding values of both systems merit functions show that the new design has a less amount of geometrical aberrations relative to that of its counterpart.

  8. Particle size reduction of Si3N4 with Si3N4 milling hardware

    NASA Technical Reports Server (NTRS)

    Herbell, T. P.; Freedman, M. R.; Kiser, J. D.

    1986-01-01

    The grinding of Si3N4 powder using reaction bonded Si3N4 attrition, vibratory, and ball mills with Si3N4 media was examined. The rate of particle size reduction and the change in the chemical composition of the powder were determined in order to compare the grinding efficiency and the increase in impurity content resulting from mill and media wear for each technique. Attrition and vibratory milling exhibited rates of specific surface area increase that were approximately eight times that observed in ball milling. Vibratory milling introduced the greatest impurity pickup.

  9. Size, weight, and power reduction regimes in achromatic gradient-index singlets.

    PubMed

    Campbell, Sawyer D; Brocker, Donovan E; Nagar, Jogender; Werner, Douglas H

    2016-05-01

    By analyzing the limitations that achromatic gradient-index (GRIN) lens solutions in the radial and axial extremes place on lens thickness and surface curvature, a radial-axial hybrid GRIN theory is developed in order to overcome these restrictions and expose a larger solution space. With the achromatic hybrid GRIN theory, the trade-offs between thickness, curvature, and GRIN type can be directly studied in the context of size, weight, and power (SWaP) reduction. Finally, the achromatic solution space of a silicon-germanium-based material system is explored, and several designs are verified with ray tracing. PMID:27140376

  10. Size Reduction in Early European Domestic Cattle Relates to Intensification of Neolithic Herding Strategies

    PubMed Central

    Manning, Katie; Timpson, Adrian; Shennan, Stephen; Crema, Enrico

    2015-01-01

    Our analysis of over 28,000 osteometric measurements from fossil remains dating between c. 5600 and 1500 BCE reveals a substantial reduction in body mass of 33% in Neolithic central European domestic cattle. We investigate various plausible explanations for this phenotypic adaptation, dismissing climatic change as a causal factor, and further rejecting the hypothesis that it was caused by an increase in the proportion of smaller adult females in the population. Instead we find some support for the hypothesis that the size decrease was driven by a demographic shift towards smaller newborns from sub-adult breeding as a result of intensifying meat production strategies during the Neolithic. PMID:26630287

  11. Summary of an Analysis of Pupil-Teacher Ratio and Class Size: Differences That Make a Difference and Its Implications on Staffing for Class-Size Reduction.

    ERIC Educational Resources Information Center

    Sharp, Mark A.

    The purpose of this paper was to share findings from an earlier study and to provide a framework for administrators to use in the implementation of class-size reduction (CSR) in their buildings. The study examined actual and average class size (CS), pupil-teacher ratios (PTR), and their differences. A primary goal was to clarify the ramifications…

  12. Particle size reduction in debris flows: Laboratory experiments compared with field data from Inyo Creek, California

    NASA Astrophysics Data System (ADS)

    Arabnia, O.; Sklar, L. S.; Mclaughlin, M. K.

    2014-12-01

    Rock particles in debris flows are reduced in size through abrasion and fracture. Wear of coarse sediments results in production of finer particles, which alter the bulk material rheology and influence flow dynamics and runout distance. Particle wear also affects the size distribution of coarse particles, transforming the initial sediment size distribution produced on hillslopes into that delivered to the fluvial channel network. A better understanding of the controls on particle wear in debris flows would aid in the inferring flow conditions from debris flow deposits, in estimating the initial size of sediments entrained in the flow, and in modeling debris flow dynamics and mapping hazards. The rate of particle size reduction with distance traveled should depend on the intensity of particle interactions with other particles and the flow boundary, and on rock resistance to wear. We seek a geomorphic transport law to predict rate of particle wear with debris flow travel distance as a function of particle size distribution, flow depth, channel slope, fluid composition and rock strength. Here we use four rotating drums to create laboratory debris flows across a range of scales. Drum diameters range from 0.2 to 4.0 m, with the largest drum able to accommodate up to 2 Mg of material, including boulders. Each drum has vanes along the boundary to prevent sliding. Initial experiments use angular clasts of durable granodiorite; later experiments will use less resistant rock types. Shear rate is varied by changing drum rotational velocity. We begin experiments with well-sorted coarse particle size distributions, which are allowed to evolve through particle wear. The fluid is initially clear water, which rapidly acquires fine-grained wear products. After each travel increment all coarse particles (mass > 0.4 g) are weighed individually. We quantify particle wear rates using statistics of size and mass distributions, and by fitting various comminution functions to the data

  13. The effect of simultaneous size reduction and transient network formation on the dynamics of microemulsions

    NASA Astrophysics Data System (ADS)

    Amirkhani, Masoud; Sharifi, Soheil; Marti, Othmar

    2012-09-01

    We studied a mixture of C12E5 microemulsion with an end-capped hydrophobically modified polymer (C12-PEO-C12). The end-capped polymer adsorbed on the core of the microemulsion, changed the bending properties of the interface and connected two nearby droplets. The core size and width of the structure factor of the microemulsion decreased upon adding the end-capped polymer. For all polymer concentrations, two relaxational modes corresponding to different diffusion coefficients were observed. The fast and slow diffusion coefficients showed a repulsive and an attractive interaction, respectively. The results of both small-angle x-ray scattering and dynamic light scattering suggested that fast relaxation is affected by size reduction and increasing the repulsive interaction between droplets.

  14. Classification improvement by optimal dimensionality reduction when training sets are of small size

    NASA Technical Reports Server (NTRS)

    Starks, S. A.; Defigueiredo, R. J. P.; Vanrooy, D. L.

    1976-01-01

    A computer simulation was performed to test the conjecture that, when the sizes of the training sets are small, classification in a subspace of the original data space may give rise to a smaller probability of error than the classification in the data space itself; this is because the gain in the accuracy of estimation of the likelihood functions used in classification in the lower dimensional space (subspace) offsets the loss of information associated with dimensionality reduction (feature extraction). A number of pseudo-random training and data vectors were generated from two four-dimensional Gaussian classes. A special algorithm was used to create an optimal one-dimensional feature space on which to project the data. When the sizes of the training sets are small, classification of the data in the optimal one-dimensional space is found to yield lower error rates than the one in the original four-dimensional space.

  15. Application of the combinative particle size reduction technology H 42 to produce fast dissolving glibenclamide tablets.

    PubMed

    Salazar, Jaime; Müller, Rainer H; Möschwitzer, Jan P

    2013-07-16

    Standard particle size reduction techniques such as high pressure homogenization or wet bead milling are frequently used in the production of nanosuspensions. The need for micronized starting material and long process times are their evident disadvantages. Combinative particle size reduction technologies have been developed to overcome the drawbacks of the standard techniques. The H 42 combinative technology consists of a drug pre-treatment by means of spray-drying followed by standard high pressure homogenization. In the present paper, spray-drying process parameters influencing the diminution effectiveness, such as drug and surfactant concentration, were systematically analyzed. Subsequently, the untreated and pre-treated drug powders were homogenized for 20 cycles at 1500 bar. For untreated, micronized glibenclamide, the particle size analysis revealed a mean particle size of 772 nm and volume-based size distribution values of 2.686 μm (d50%) and 14.423 μm (d90%). The use of pre-treated material (10:1 glibenclamide/docusate sodium salt ratio spray-dried as ethanolic solution) resulted in a mean particle size of 236 nm and volume-based size distribution values of 0.131 μm (d50%) and 0.285 μm (d90%). These results were markedly improved compared to the standard process. The nanosuspensions were further transferred into tablet formulations. Wet granulation, freeze-drying and spray-drying were investigated as downstream methods to produce dry intermediates. Regarding the dissolution rate, the rank order of the downstream processes was as follows: Spray-drying>freeze-drying>wet granulation. The best drug release (90% within 10 min) was obtained for tablets produced with spray-dried nanosuspension containing 2% mannitol as matrix former. In comparison, the tablets processed with micronized glibenclamide showed a drug release of only 26% after 10 min. The H 42 combinative technology could be successfully applied in the production of small drug nanocrystals. A

  16. Sequential repetitive chemical reduction technique to study size-property relationships of graphene attached Ag nanoparticle

    NASA Astrophysics Data System (ADS)

    Haider, M. Salman; Badejo, Abimbola Comfort; Shao, Godlisten N.; Imran, S. M.; Abbas, Nadir; Chai, Young Gyu; Hussain, Manwar; Kim, Hee Taik

    2015-06-01

    The present study demonstrates a novel, systematic and application route synthesis approach to develop size-property relationship and control the growth of silver nanoparticles (AgNPs) embedded on reduced graphene oxide (rGO). A sequential repetitive chemical reduction technique to observe the growth of silver nanoparticles (AgNPs) attached to rGO, was performed on a single solution of graphene oxide (GO) and silver nitrate solution (7 runs, R1-R7) in order to manipulate the growth and size of the AgNPs. The physical-chemical properties of the samples were examined by RAMAN, XPS, XRD, SEM-EDAX, and HRTEM analyses. It was confirmed that AgNPs with diameter varying from 4 nm in first run (R1) to 50 nm in seventh run (R7) can be obtained using this technique. A major correlation between particle size and activities was also observed. Antibacterial activities of the samples were carried out to investigate the disinfection performance of the samples on the Gram negative bacteria (Escherichia coli). It was suggested that the sample obtained in the third run (R3) exhibited the highest antibacterial activity as compared to other samples, toward disinfection of bacteria due to its superior properties. This study provides a unique and novel application route to synthesize and control size of AgNPs embedded on graphene for various applications.

  17. Size-Controlled and Optical Properties of Monodispersed Silver Nanoparticles Synthesized by the Radiolytic Reduction Method

    PubMed Central

    Saion, Elias; Gharibshahi, Elham; Naghavi, Kazem

    2013-01-01

    Size-controlled and monodispersed silver nanoparticles were synthesized from an aqueous solution containing silver nitrate as a metal precursor, polyvinyl alcohol as a capping agent, isopropyl alcohol as hydrogen and hydroxyl radical scavengers, and deionized water as a solvent with a simple radiolytic method. The average particle size decreased with an increase in dose due to the domination of nucleation over ion association in the formation of the nanoparticles by gamma reduction. The silver nanoparticles exhibit a very sharp and strong absorption spectrum with the absorption maximum λmax blue shifting with an increased dose, owing to a decrease in particle size. The absorption spectra of silver nanoparticles of various particle sizes were also calculated using a quantum physics treatment and an agreement was obtained with the experimental absorption data. The results suggest that the absorption spectrum of silver nanoparticles possibly derived from the intra-band excitations of conduction electrons from the lowest energy state (n = 5, l = 0) to higher energy states (n ≥ 6; Δl = 0, ±1; Δs = 0, ±1), allowed by the quantum numbers principle. This demonstrates that the absorption phenomenon of metal nanoparticles based on a quantum physics description could be exploited to be added into the fundamentals of metal nanoparticles and the related fields of nanoscience and nanotechnology. PMID:23579953

  18. Size-Reduction Template Stripping of Smooth Curved Metallic Tips for Adiabatic Nanofocusing of Surface Plasmons.

    PubMed

    Johnson, Timothy W; Klemme, Daniel J; Oh, Sang-Hyun

    2016-06-01

    We present a new technique to engineer metallic interfaces to produce sharp tips with smooth curved surfaces and variable tip angles, as well as ridges with arbitrary contour shapes, all of which can be integrated with grating couplers for applications in plasmonics and nanophotonics. We combine template stripping, a nanofabrication scheme, with atomic layer deposition (ALD) to produce the ultrasharp nanoscale tips and wedges using only conventional photolithography. Conformal ALD coating of insulators over silicon trench molds of various shapes reduces their widths to make nanoscale features without high-resolution lithography. Along with a metal deposition and template stripping, this size-reduction scheme can mass-produce narrow and ultrasharp (<10 nm radius of curvature) metallic wedges and tips over an entire 4 in. wafer. This size-reduction scheme can create metallic tips out of arbitrary trench patterns that have smooth curved surfaces to facilitate efficient adiabatic nanofocusing which will benefit applications in near-field optical spectroscopy, plasmonic waveguides, particle trapping, hot-electron plasmonics, and nonlinear optics. PMID:27156522

  19. Reduction of crystalline iron(III) oxyhydroxides using hydroquinone: Influence of phase and particle size

    PubMed Central

    Anschutz, Amy J; Penn, R Lee

    2005-01-01

    Iron oxides and oxyhydroxides are common and important materials in the environment, and they strongly impact the biogeochemical cycle of iron and other species at the Earth's surface. These materials commonly occur as nanoparticles in the 3–10 nm size range. This paper presents quantitative results demonstrating that iron oxide reactivity is particle size dependent. The rate and extent of the reductive dissolution of iron oxyhydroxide nanoparticles by hydroquinone in batch experiments were measured as a function of particle identity, particle loading, and hydroquinone concentration. Rates were normalized to surface areas determined by both transmission electron microscopy and Braunauer-Emmett-Teller surface. Results show that surface-area-normalized rates of reductive dissolution are fastest (by as much as 100 times) in experiments using six-line ferrihydrite versus goethite. Furthermore, the surface-area-normalized rates for 4 nm ferrihydrite nanoparticles are up to 20 times faster than the rates for 6 nm ferrihydrite nanoparticles, and the surface-area-normalized rates for 5 × 64 nm goethite nanoparticles are up to two times faster than the rates for 22 × 367 nm goethite nanoparticles.

  20. Durable Scar Size Reduction Due to Allogeneic Mesenchymal Stem Cell Therapy Regulates Whole‐Chamber Remodeling

    PubMed Central

    Williams, Adam R.; Suncion, Viky Y.; McCall, Frederic; Guerra, Danny; Mather, Jacques; Zambrano, Juan P.; Heldman, Alan W.; Hare, Joshua M.

    2013-01-01

    Background Intramyocardial injection of mesenchymal stem cells (MSCs) in chronic ischemic cardiomyopathy is associated with reverse remodeling in experimental models and humans. Here, we tested the hypothesis that allogeneic MSC therapy drives ventricular remodeling by producing durable and progressive scar size reduction in ischemic cardiomyopathy. Methods and Results Gottingen swine (n=12) underwent left anterior descending coronary artery myocardial infarction (MI), and 3 months post‐MI animals received either intramyocardial allogeneic MSC injection (200 mol/L cells; n=6) or left ventricle (LV) catheterization without injection (n=6). Swine were followed with serial cardiac magnetic resonance imaging for 9 months to assess structural and functional changes of the LV. Intramyocardial injection was performed using an integrated imaging platform combining electroanatomical mapping unipolar voltage and 3‐dimensional cardiac magnetic resonance imaging angiography–derived anatomy to accurately target infarct border zone injections. MSC‐treated animals had a 19.62±2.86% reduction in scar size at 3 months postinjection, which progressed to 28.09±2.31% from 3 to 6 months postinjection (P<0.0001). MSC‐treated animals had unchanged end‐diastolic volume (EDV; P=0.08) and end‐systolic volume (ESV; P=0.28) from preinjection to 6 months postinjection, whereas controls had progressive dilatation in both EDV (P=0.0002) and ESV (P=0.0002). In addition, MSC‐treated animals had improved LV sphericity index. Percentage change in infarct size correlated with percentage change in EDV (r=0.68; P=0.01) and ESV (r=0.77; P=0.001). Ejection fraction increased from 29.69±1.68% to 35.85±2.74% at 3 months post‐MSC injection and progressed to 39.02±2.42% 6 months postinjection (P=0.0001), whereas controls had a persistently depressed ejection fraction during follow‐up (P=0.33). Conclusion Intramyocardial injection of allogeneic MSCs leads to a sustained and

  1. Ash reduction strategies in corn stover facilitated by anatomical and size fractionation

    DOE PAGESBeta

    Lacey, Jeffrey A.; Emerson, Rachel M.; Thompson, David N.; Westover, Tyler L.

    2016-04-22

    There is growing interest internationally to produce fuels from renewable biomass resources. Inorganic components of biomass feedstocks, referred to collectively as ash, damage equipment and decrease yields in thermal conversion processes, and decrease feedstock value for biochemical conversion processes. Decreasing the ash content of feedstocks improves conversion efficiency and lowers process costs. Because physiological ash is unevenly distributed in the plant, mechanical processes can be used to separate fractions of the plant based on ash content. This study focuses on the ash separation that can be achieved by separating corn stover by particle size and anatomical fraction. Baled corn stovermore » was hand-separated into anatomical fractions, ground to <19.1 mm, and size separated using six sieves ranging from 9.5 to 0.150 mm. Size fractions were analyzed for total ash content and ash composition. Particle size distributions observed for the anatomical fractions varied considerably. Cob particles were primarily 2.0 mm or greater, while most of the sheath and husk particles were 2.0 mm and smaller. Particles of leaves greater than 0.6 mm contained the greatest amount of total ash, ranging from approximately 8 to 13% dry weight of the total original material, while the fractions with particles smaller than 0.6 mm contained less than 2% of the total ash of the original material. As a result, based on the overall ash content and the elemental ash, specific anatomical and size fractions can be separated to optimize the feedstocks being delivered to biofuels conversion processes and minimize the need for more expensive ash reduction treatments.« less

  2. Site decommissioning management plan

    SciTech Connect

    Fauver, D.N.; Austin, J.H.; Johnson, T.C.; Weber, M.F.; Cardile, F.P.; Martin, D.E.; Caniano, R.J.; Kinneman, J.D.

    1993-10-01

    The Nuclear Regulatory Commission (NRC) staff has identified 48 sites contaminated with radioactive material that require special attention to ensure timely decommissioning. While none of these sites represent an immediate threat to public health and safety they have contamination that exceeds existing NRC criteria for unrestricted use. All of these sites require some degree of remediation, and several involve regulatory issues that must be addressed by the Commission before they can be released for unrestricted use and the applicable licenses terminated. This report contains the NRC staff`s strategy for addressing the technical, legal, and policy issues affecting the timely decommissioning of the 48 sites and describes the status of decommissioning activities at the sites.

  3. Decommissioning of the secondary containment of the steam generating heavy water reactor at UKAEA-Winfrith

    SciTech Connect

    Miller, Keith; Cornell, Rowland; Parkinson, Steve; McIntyre, Kevin; Staples, Andy

    2007-07-01

    Available in abstract form only. Full text of publication follows: The Winfrith SGHWR was a prototype nuclear power plant operated for 23 years by the United Kingdom Atomic Energy Authority (UKAEA) until 1990 when it was shut down permanently. The current Stage 1 decommissioning contract is part of a multi-stage strategy. It involves the removal of all the ancillary plant and equipment in the secondary containment and non-containment areas ahead of a series of contracts for the decommissioning of the primary containment, the reactor core and demolition of the building and all remaining facilities. As an outcome of a competitive tending process, the Stage 1 decommissioning contract was awarded to NUKEM with operations commencing in April 2005. The decommissioning processes involved with these plant items will be described with some emphasis of the establishment of multiple work-fronts for the production, recovery, treatment and disposal of mainly tritium-contaminated waste arising from its contact with the direct cycle reactor coolant. The means of size reduction of a variety of large, heavy and complex items of plant made from a range of materials will also be described with some emphasis on the control of fumes during hot cutting operations and establishing effective containments within a larger secondary containment structure. Disposal of these wastes in a timely and cost-effective manner is a major challenge facing the decommissioning team and has required the development of a highly efficient means of packing the resultant materials into mainly one-third height ISO containers for disposal as LLW. Details of the quantities of LLW and exempt wastes handled during this process will be given with a commentary about the difficulty in segregating these two waste streams efficiently. (authors)

  4. Size reduction of cosolvent-infused microbubbles to form acoustically responsive monodisperse perfluorocarbon nanodroplets.

    PubMed

    Seo, Minseok; Williams, Ross; Matsuura, Naomi

    2015-09-01

    Perfluorocarbon (PFC) nanodroplet agents are exciting new biomaterials that can be remotely vapourized by ultrasound or light to change into micron-scale gas bubbles in situ. After PFC nanodroplet vapourization, the micron-scale gas bubble can interact strongly with ultrasound radiation, such that the bubbles can be used for cancer imaging and therapy. For these phase-change agents to be useful, however, PFC nanodroplets must be produced in the range of 100 to 400 nm in diameter with high size control and monodispersity, restrictions that remain a challenge. Here, we address this challenge by taking advantage of the size control offered by microfluidics, in combination with the size reduction provided by cosolvent-infused PFC bubbles through both condensation and cosolvent dissolution. In this approach, PFC bubbles with a high percentage of cosolvent (in this study, diethyl ether, DEE) are produced using microfluidics at a temperature above the boiling point. After synthesis, these bubbles become much smaller through both condensation of the gas into liquid droplets and from dissolution of the DEE into the continuous phase. This approach demonstrates that monodisperse, cosolvent-incorporated PFC bubbles can directly form monodisperse PFC nanodroplets a factor of 24 times smaller than the precursor bubbles. We also demonstrate that these nanoscale droplets can be converted to echogenic microbubbles after exposure to ultrasound, showing that these PFC nanodroplets are viable for the in situ production of ultrasound contrast agents. We show that this system can overcome the minimum droplet size limit of standard microfluidics, and is a powerful new tool for generating monodisperse, PFC phase-change ultrasound contrast agents for treating and imaging cancer. PMID:26220563

  5. Effect of particle size reduction, hydrothermal and fermentation treatments on phytic acid content and some physicochemical properties of wheat bran.

    PubMed

    Majzoobi, Mahsa; Pashangeh, Safoora; Farahnaky, Asgar; Eskandari, Mohammad Hadi; Jamalian, Jalal

    2014-10-01

    With the aim of reducing phytic acid content of wheat bran, particle size reduction (from 1,200 to 90 μm), hydrothermal (wet steeping in acetate buffer at pH 4.8 at 55 °C for 60 min) and fermentation (using bakery yeast for 8 h at 30 °C) and combination of these treatments with particle size reduction were applied and their effects on some properties of the bran were studied. Phytic acid content decreased from 50.1 to 21.6, 32.8 and 43.9 mg/g after particle size reduction, hydrothermal and fermentation, respectively. Particle size reduction along with these treatments further reduced phytic acid content up to 76.4 % and 57.3 %, respectively. Hydrothermal and fermentation decreased, while particle size reduction alone or in combination increased bran lightness. With reducing particle size, total, soluble and insoluble fiber content decreased from 69.7 to 32.1 %, 12.2 to 7.9 % and 57.4 to 24.3 %, respectively. The highest total (74.4 %) and soluble (21.4 %) and the lowest insoluble fiber (52.1 %) content were determined for the hydrothermaled bran. Particle size reduction decreased swelling power, water solubility and water holding capacity. Swelling power and water holding capacity of the hydrothermaled and fermented brans were lower, while water solubility was higher than the control. The amount of Fe(+2), Zn(+2) and Ca(+2) decreased with reducing particle size. Fermentation had no effect on Fe(+2)and Zn(+2) but slightly reduced Ca(+2). The hydrothermal treatment slightly decreased these elements. Amongst all, hydrothermal treatment along with particle size reduction resulted in the lowest phytic acid and highest fiber content. PMID:25328222

  6. Size-reduction techniques for the determination of efficient aeroservoelastic models

    NASA Technical Reports Server (NTRS)

    Karpel, Mordechay

    1992-01-01

    Size-reduction techniques for determining efficient time-domain state-space aeroservoelastic models are presented. Various rational function approximation methods of the unsteady aerodynamic force coefficients are brought to a common motion, emphasizing their differences. Among these, the classic Roger's method is the easier to apply but its resulting number of aerodynamic states is typically equal to or larger than the number of structural states. On the other hand, the minimum-state (MS) method, which typically reduces the number of aerodynamic states by 70 percent or more, requires the solution of an iterative nonlinear least-square solution. The MS computational efforts are reduced significantly when three approximation constraints are applied.

  7. Spatial run-length limited code for reduction of hologram size in holographic data storage

    NASA Astrophysics Data System (ADS)

    Yoshida, Shuhei; Takahata, Yosuke; Horiuchi, Shuma; Yamamoto, Manabu

    2016-01-01

    With holographic data storage (HDS), which is the next generation of optical storage, a Fourier-transformed hologram is usually recorded. As a result, it is characterized by the fact that a smaller high frequency component in the page data corresponds to reductions in the size of the hologram. Therefore, in this study, we have constructed spatial run-length limited (SRLL) codes that have been adapted for HDS, and then evaluated the performance of these codes. By using SRLL codes, it is possible to reduce the high frequency component in the page data with setting run-length bits and narrow the bandwidth with the spatial filtering; therefore, improvements can be expected in the recording density. Utilizing SRLL code, we have shown that it is possible to achieve improvements in the theoretical maximum recording density which are at least double that of instances without SRLL code. Under practical conditions, numerical evaluation results show that there is an increase of least 20%.

  8. Tick size reduction and price clustering in a FX order book

    NASA Astrophysics Data System (ADS)

    Lallouache, Mehdi; Abergel, Frédéric

    2014-12-01

    We investigate the statistical properties of the EBS order book for the EUR/USD and USD/JPY currency pairs and the impact of a ten-fold tick size reduction on its dynamics. A large fraction of limit orders are still placed right at or halfway between the old allowed prices. This generates price barriers where the best quotes lie for much of the time, which causes the emergence of distinct peaks in the average shape of the book at round distances. Furthermore, we argue that this clustering is mainly due to manual traders who remained set to the old price resolution. Automatic traders easily take price priority by submitting limit orders one tick ahead of clusters, as shown by the prominence of buy (sell) limit orders posted with rightmost digit one (nine).

  9. How Class Size Makes a Difference: What the Research Says. The Impact of Class-Size Reduction (CSR).

    ERIC Educational Resources Information Center

    Achilles, C. M.

    Class size in elementary grades has taken on added importance recently. Research on the topic is finally getting some attention. Legislative and administrative actions to reduce deficits are pushing for larger class sizes, in addition to eliminating nonessential curricular activities, such as music, drama, and art. In Florida, various institutions…

  10. Sonochemical effect on size reduction of CaCO3 nanoparticles derived from waste eggshells.

    PubMed

    Hassan, Tarig A; Rangari, Vijay K; Rana, Rohit K; Jeelani, Shaik

    2013-09-01

    A novel combination of mechanochemical and sonochemical techniques was developed to produce high-surface-area, bio-based calcium carbonate (CaCO3) nanoparticles from eggshells. Size reduction of eggshell achieved via mechanochemical and followed by sonochemical method. First, eggshells were cleaned and ground, then ball milled in wet condition using polypropylene glycol for ten hours to produce fine particles. The ball milled eggshell particles were then irradiated with a high intensity ultrasonic horn (Ti-horn, 20 kHz, and 100 W/cm(2)) in the presence of N,N-dimethylformamide (DMF); decahydronaphthalene (Decalin); or tetrahydrofuran (THF). The ultrasonic irradiation times varied from 1 to 5 h. Transmission electron microscopic (TEM) studies showed that the resultant particle shapes and sizes were different from each solvent. The sonochemical effect of DMF is more pronounced and the particles were irregular platelets of ~10 nm. The BET surface area (43.687 m(2)/g) of these nanoparticles is much higher than that of other nanoparticles derived from eggshells. PMID:23473569

  11. Size dependent microbial oxidation and reduction of magnetite nano- and micro-particles.

    PubMed

    Byrne, James M; van der Laan, Gerrit; Figueroa, Adriana I; Qafoku, Odeta; Wang, Chongmin; Pearce, Carolyn I; Jackson, Michael; Feinberg, Joshua; Rosso, Kevin M; Kappler, Andreas

    2016-01-01

    The ability for magnetite to act as a recyclable electron donor and acceptor for Fe-metabolizing bacteria has recently been shown. However, it remains poorly understood whether microbe-mineral interfacial electron transfer processes are limited by the redox capacity of the magnetite surface or that of whole particles. Here we examine this issue for the phototrophic Fe(II)-oxidizing bacteria Rhodopseudomonas palustris TIE-1 and the Fe(III)-reducing bacteria Geobacter sulfurreducens, comparing magnetite nanoparticles (d ≈ 12 nm) against microparticles (d ≈ 100-200 nm). By integrating surface-sensitive and bulk-sensitive measurement techniques we observed a particle surface that was enriched in Fe(II) with respect to a more oxidized core. This enables microbial Fe(II) oxidation to occur relatively easily at the surface of the mineral suggesting that the electron transfer is dependent upon particle size. However, microbial Fe(III) reduction proceeds via conduction of electrons into the particle interior, i.e. it can be considered as more of a bulk electron transfer process that is independent of particle size. The finding has potential implications on the ability of magnetite to be used for long range electron transport in soils and sediments. PMID:27492680

  12. Size dependent microbial oxidation and reduction of magnetite nano- and micro-particles

    PubMed Central

    Byrne, James M.; van der Laan, Gerrit; Figueroa, Adriana I.; Qafoku, Odeta; Wang, Chongmin; Pearce, Carolyn I.; Jackson, Michael; Feinberg, Joshua; Rosso, Kevin M.; Kappler, Andreas

    2016-01-01

    The ability for magnetite to act as a recyclable electron donor and acceptor for Fe-metabolizing bacteria has recently been shown. However, it remains poorly understood whether microbe-mineral interfacial electron transfer processes are limited by the redox capacity of the magnetite surface or that of whole particles. Here we examine this issue for the phototrophic Fe(II)-oxidizing bacteria Rhodopseudomonas palustris TIE-1 and the Fe(III)-reducing bacteria Geobacter sulfurreducens, comparing magnetite nanoparticles (d ≈ 12 nm) against microparticles (d ≈ 100–200 nm). By integrating surface-sensitive and bulk-sensitive measurement techniques we observed a particle surface that was enriched in Fe(II) with respect to a more oxidized core. This enables microbial Fe(II) oxidation to occur relatively easily at the surface of the mineral suggesting that the electron transfer is dependent upon particle size. However, microbial Fe(III) reduction proceeds via conduction of electrons into the particle interior, i.e. it can be considered as more of a bulk electron transfer process that is independent of particle size. The finding has potential implications on the ability of magnetite to be used for long range electron transport in soils and sediments. PMID:27492680

  13. Size dependent microbial oxidation and reduction of magnetite nano- and micro-particles

    NASA Astrophysics Data System (ADS)

    Byrne, James M.; van der Laan, Gerrit; Figueroa, Adriana I.; Qafoku, Odeta; Wang, Chongmin; Pearce, Carolyn I.; Jackson, Michael; Feinberg, Joshua; Rosso, Kevin M.; Kappler, Andreas

    2016-08-01

    The ability for magnetite to act as a recyclable electron donor and acceptor for Fe-metabolizing bacteria has recently been shown. However, it remains poorly understood whether microbe-mineral interfacial electron transfer processes are limited by the redox capacity of the magnetite surface or that of whole particles. Here we examine this issue for the phototrophic Fe(II)-oxidizing bacteria Rhodopseudomonas palustris TIE-1 and the Fe(III)-reducing bacteria Geobacter sulfurreducens, comparing magnetite nanoparticles (d ≈ 12 nm) against microparticles (d ≈ 100–200 nm). By integrating surface-sensitive and bulk-sensitive measurement techniques we observed a particle surface that was enriched in Fe(II) with respect to a more oxidized core. This enables microbial Fe(II) oxidation to occur relatively easily at the surface of the mineral suggesting that the electron transfer is dependent upon particle size. However, microbial Fe(III) reduction proceeds via conduction of electrons into the particle interior, i.e. it can be considered as more of a bulk electron transfer process that is independent of particle size. The finding has potential implications on the ability of magnetite to be used for long range electron transport in soils and sediments.

  14. Formulation and particle size reduction improve bioavailability of poorly water-soluble compounds with antimalarial activity.

    PubMed

    Wang, Hongxing; Li, Qigui; Reyes, Sean; Zhang, Jing; Xie, Lisa; Melendez, Victor; Hickman, Mark; Kozar, Michael P

    2013-01-01

    Decoquinate (DQ) is highly effective at killing malaria parasites in vitro; however, it is extremely insoluble in water. In this study, solid dispersion method was used for DQ formulation which created a suitable physical form of DQ in aqueous phase for particle manipulation. Among many polymers and surfactants tested, polyvinylpyrrolidone 10, a polymer, and L- α -phosphatidylcholine or polysorbate, two surfactants, were chosen as DQ formulation components. The formulation particles were reduced to a mean size between 200 to 400 nm, which was stable in aqueous medium for at least three weeks. Pharmacokinetic (PK) studies showed that compared to DQ microparticle suspension, a nanoparticle formulation orally dosed to mice showed a 14.47-fold increase in area under the curve (AUC) of DQ plasma concentration and a 4.53-fold increase in AUC of DQ liver distribution. WR 299666, a poorly water-soluble compound with antimalarial activity, was also tested and successfully made into nanoparticle formulation without undergoing solid dispersion procedure. We concluded that nanoparticles generated by using appropriate formulation components and sufficient particle size reduction significantly increased the bioavailability of DQ and could potentially turn this antimalarial agent to a therapeutic drug. PMID:23766925

  15. Grain size reduction and shear heating: a recipe for intermediate-depth earthquake generation?

    NASA Astrophysics Data System (ADS)

    Thielmann, Marcel; Rozel, Antoine

    2016-04-01

    The mechanisms resulting in intermediate-depth earthquakes remain enigmatic, with two processes - dehydration embrittlement and thermal runaway - being the most promising candidates. Using a simple shear one-dimensional model, Thielmann et al. (2015) have shown that the feedback between grain size evolution and shear heating significantly reduces the stress needed to initiate thermal runaway. However, at intermediate depths, Peierls creep as well as dislocation accommodated grain boundary sliding (disGBS) are also viable deformation mechanisms. Here we investigate the impact of those additional creep mechanisms (grain boundary sliding and Peierls creep) on the formation of shear zones. As in Thielmann et al. (2015), we consider both thermal and microstructural damage mechanisms (shear heating and grain size reduction). Depending on material and deformation parameters different creep mechanisms are dominant during deformation, which affects the occurrence and timing of thermal runaway (e.g. at low temperatures and/or high strain rates Peierls creep is dominant and limits the strength of the material which delays thermal runaway). We derive regime diagrams and from them regime boundaries that allow for easy determination of the governing mechanisms and of the localization potential for given material parameters. In one-dimensional models however, the shear zone - once formed - extends infinitely. In nature however, this is not the case. This has potentially a large impact on rupture velocities during shear zone formation. For this reason, we compare the 1D predictions to 2D simulations where fault length is finite.

  16. The impact of BPO on cost reduction in mid-sized health care systems.

    PubMed

    Perry, Andy; Kocakülâh, Mehmet C

    2010-01-01

    At the convergence of two politico-economic "hot topics" of the day--outsourcing and the cost of health care-lie opportunities for mid-sized health systems to innovate, collaborate, and reduce overhead. Competition in the retail health care market can serve as both an impetus and an inhibitor to such measures, though. Here we are going to address the motivations, influences, opportunities, and limitations facing mid-sized, US non-profit health systems in business process outsourcing (BPO). Advocates cite numerous benefits to BPO, particularly in cost reduction and strategy optimization. BPO can elicit cost savings due to specialization among provider firms, returns to scale and technology, standardization and automation, and gains in resource arbitrage (off-shoring capabilities). BPO can also free an organization of non-critical tasks and focus resources on core competencies (treating patients). The surge in BPO utilization has rarely extended to the back-office functions of many mid-sized health systems. Health care providers, still a largely fragmented bunch with many rural, independent non-profit systems, have not experienced the consolidation and organizational scale growth to make BPO as attractive as other industries. Smaller firms, spurning merger and acquisition pressure from large, tertiary health systems, often wish to retain their autonomy and identity; hence, they face a competitive cost disadvantage compared to their larger competitors. This article examines the functional areas for these health systems in which BPO is not currently utilized and dissects the various methods available in which to practice BPO. We assess the ongoing adoption of BPO in these areas as well as the barriers to adoption, and identify the key processes that best represent opportunity for success. An emphasis is placed on a collaborative model with other health systems compared to a single system, unilateral BPO arrangement. PMID:22329330

  17. Physical Restriction of Pods Causes Seed Size Reduction of a Brassinosteroid-deficient Faba Bean (Vicia faba)

    PubMed Central

    FUKUTA, N.; FUKUZONO, K.; KAWAIDE, H.; ABE, H.; NAKAYAMA, M.

    2006-01-01

    • Background and Aims A brassinosteroid-deficient mutant faba bean (Vicia faba ‘Rinrei’) shows dwarfism in many organs including pods and seeds. ‘Rinrei’ has normal-sized seeds together with dwarf seeds, suggesting that dwarfism in the seed may be indirectly caused by brassinosteroid deficiency. The mechanism of seed size reduction in this mutant was investigated. • Methods The associations between seed orientation in the pod, seed numbers per pod and pod lengths with seed sizes were analysed in ‘Rinrei’ and the wild-type plant. • Key Results ‘Rinrei’ seeds are tightly arranged in pods containing two or three seeds. Seed size decreased as the number of seeds per pod increased or as the length of the pod decreased. Where no physical restriction occurred between seeds in a pod, the wild-type faba bean seeds had a nearly constant size regardless of seed number per pod or pod length. ‘Rinrei’ seeds in pods containing single seeds were the same size as wild-type seeds. Brassinolide treatment increased the seed size and the length of pods containing three seeds in ‘Rinrei’. • Conclusion Seed size of ‘Rinrei’ is mainly regulated through a reduction of pod length due to brassinosteroid deficiency; physical restriction within pods causes a reduction in seed size. These results suggest a possible mechanism for increasing faba bean yields to optimal levels. PMID:16303772

  18. Size-controlled large-diameter and few-walled carbon nanotube catalysts for oxygen reduction

    NASA Astrophysics Data System (ADS)

    Wang, Xianliang; Li, Qing; Pan, Hengyu; Lin, Ye; Ke, Yujie; Sheng, Haiyang; Swihart, Mark T.; Wu, Gang

    2015-11-01

    We demonstrate a new strategy for tuning the size of large-diameter and few-walled nitrogen-doped carbon nanotubes (N-CNTs) from 50 to 150 nm by varying the transition metal (TM = Fe, Co, Ni or Mn) used to catalyze graphitization of dicyandiamide. Fe yielded the largest tubes, followed by Co and Ni, while Mn produced a clot-like carbon morphology. We show that morphology is correlated with electrocatalytic activity for the oxygen reduction reaction (ORR). A clear trend of Fe > Co > Ni > Mn for the ORR catalytic activity was observed, in both alkaline media and more demanding acidic media. The Fe-derived N-CNTs exhibited the highest BET (~870 m2 g-1) and electrochemically accessible (~450 m2 g-1) surface areas and, more importantly, the highest concentration of nitrogen incorporated into the carbon planes. Thus, in addition to the intrinsic high activity of Fe-derived catalysts, the high surface area and nitrogen doping contribute to high ORR activity. This work, for the first time, demonstrates size-controlled synthesis of large-diameter N-doped carbon tube electrocatalysts by varying the metal used in N-CNT generation. Electrocatalytic activity of the Fe-derived catalyst is already the best among studied metals, due to the high intrinsic activity of possible Fe-N coordination. This work further provides a promising route to advanced Fe-N-C nonprecious metal catalysts by generating favorable morphology with more active sites and improved mass transfer.We demonstrate a new strategy for tuning the size of large-diameter and few-walled nitrogen-doped carbon nanotubes (N-CNTs) from 50 to 150 nm by varying the transition metal (TM = Fe, Co, Ni or Mn) used to catalyze graphitization of dicyandiamide. Fe yielded the largest tubes, followed by Co and Ni, while Mn produced a clot-like carbon morphology. We show that morphology is correlated with electrocatalytic activity for the oxygen reduction reaction (ORR). A clear trend of Fe > Co > Ni > Mn for the ORR catalytic

  19. INTERNATIONAL DECOMMISSIONING SYMPOSIUM 2000

    SciTech Connect

    M.A. Ebadian, Ph.D.

    2001-01-01

    The purpose of IDS 2000 was to deliver a world-class conference on applicable global environmental issues. The objective of this conference was to publicize environmental progress of individual countries, to provide a forum for technology developer and problem-holder interaction, to facilitate environmental and technology discussions between the commercial and financial communities, and to accommodate information and education exchange between governments, industries, universities, and scientists. The scope of this project included the planning and execution of an international conference on the decommissioning of nuclear facilities, and the providing of a business forum for vendors and participants sufficient to attract service providers, technology developers, and the business and financial communities. These groups, when working together with attendees from regulatory organizations and government decision-maker groups, provide an opportunity to more effectively and efficiently expedite the decommissioning projects.

  20. Significant enhancement of magnetoresistance with the reduction of particle size in nanometer scale.

    PubMed

    Das, Kalipada; Dasgupta, P; Poddar, A; Das, I

    2016-01-01

    The Physics of materials with large magnetoresistance (MR), defined as the percentage change of electrical resistance with the application of external magnetic field, has been an active field of research for quite some times. In addition to the fundamental interest, large MR has widespread application that includes the field of magnetic field sensor technology. New materials with large MR is interesting. However it is more appealing to vast scientific community if a method describe to achieve many fold enhancement of MR of already known materials. Our study on several manganite samples [La(1-x)Ca(x)MnO3 (x = 0.52, 0.54, 0.55)] illustrates the method of significant enhancement of MR with the reduction of the particle size in nanometer scale. Our experimentally observed results are explained by considering model consisted of a charge ordered antiferromagnetic core and a shell having short range ferromagnetic correlation between the uncompensated surface spins in nanoscale regime. The ferromagnetic fractions obtained theoretically in the nanoparticles has been shown to be in the good agreement with the experimental results. The method of several orders of magnitude improvement of the magnetoresistive property will have enormous potential for magnetic field sensor technology. PMID:26837285

  1. Genesis of Pseudotachylytes: Role of Water and Grain-size Reduction

    NASA Astrophysics Data System (ADS)

    Riedel, M. R.

    2009-12-01

    The role of water in the genesis of pseudotachylytes is still unresolved. Melts formed by frictional fusion have a very transient existence, with cooling half-lives for injection veins of 1 cm in width, of the order of 40 seconds (Sibson 1975). Under such conditions water will be critical to melting, not only because it reduces the temperature of fusion and lowers the viscosity of the resultant melt, but primarily because it acts as a catalyst during fusion. A significant water content locked up chiefly in the lattices of hydrous minerals, principally biotite, may significantly promote melting, whilst the absence of sufficient water may inhibit the production of a melt regardless of the strain rates involved. In addition, rheological weakening of most rock-forming silicates by minute water content and, also, due to hydration-related resp. metastable reaction-related grain-size reduction will critically control the generation of melts by frictional sliding. Based on a recent quantitative approach (John et al., 2009), we investigate numerically the influence of both weakening mechanisms on the formation of pseudotachylytes accompanying a metastable gabbro-eclogite transformation. References: T. John, S. Medvedev, L.H. Rüpke, T.B. Andersen, Y.Y. Podladchikov, H. Austrheim, Generation of intermediate-depth earthquakes by self-localizing thermal runaway, Nature Geoscience 2 (2009) 137-140.

  2. Milk Lacking α-Casein Leads to Permanent Reduction in Body Size in Mice

    PubMed Central

    Kolb, Andreas F.; Huber, Reinhard C.; Lillico, Simon G.; Carlisle, Ailsa; Robinson, Claire J.; Neil, Claire; Petrie, Linda; Sorensen, Dorte B.; Olsson, I. Anna S.; Whitelaw, C. Bruce A.

    2011-01-01

    The major physiological function of milk is the transport of amino acids, carbohydrates, lipids and minerals to mammalian offspring. Caseins, the major milk proteins, are secreted in the form of a micelle consisting of protein and calcium-phosphate. We have analysed the role of the milk protein α-casein by inactivating the corresponding gene in mice. Absence of α-casein protein significantly curtails secretion of other milk proteins and calcium-phosphate, suggesting a role for α-casein in the establishment of casein micelles. In contrast, secretion of albumin, which is not synthesized in the mammary epithelium, into milk is not reduced. The absence of α-casein also significantly inhibits transcription of the other casein genes. α-Casein deficiency severely delays pup growth during lactation and results in a life-long body size reduction compared to control animals, but has only transient effects on physical and behavioural development of the pups. The data support a critical role for α-casein in casein micelle assembly. The results also confirm lactation as a critical window of metabolic programming and suggest milk protein concentration as a decisive factor in determining adult body weight. PMID:21789179

  3. Significant enhancement of magnetoresistance with the reduction of particle size in nanometer scale

    NASA Astrophysics Data System (ADS)

    Das, Kalipada; Dasgupta, P.; Poddar, A.; Das, I.

    2016-02-01

    The Physics of materials with large magnetoresistance (MR), defined as the percentage change of electrical resistance with the application of external magnetic field, has been an active field of research for quite some times. In addition to the fundamental interest, large MR has widespread application that includes the field of magnetic field sensor technology. New materials with large MR is interesting. However it is more appealing to vast scientific community if a method describe to achieve many fold enhancement of MR of already known materials. Our study on several manganite samples [La1-xCaxMnO3 (x = 0.52, 0.54, 0.55)] illustrates the method of significant enhancement of MR with the reduction of the particle size in nanometer scale. Our experimentally observed results are explained by considering model consisted of a charge ordered antiferromagnetic core and a shell having short range ferromagnetic correlation between the uncompensated surface spins in nanoscale regime. The ferromagnetic fractions obtained theoretically in the nanoparticles has been shown to be in the good agreement with the experimental results. The method of several orders of magnitude improvement of the magnetoresistive property will have enormous potential for magnetic field sensor technology.

  4. Spontaneous high piezoelectricity in poly(vinylidene fluoride) nanoribbons produced by iterative thermal size reduction technique.

    PubMed

    Kanik, Mehmet; Aktas, Ozan; Sen, Huseyin Sener; Durgun, Engin; Bayindir, Mehmet

    2014-09-23

    We produced kilometer-long, endlessly parallel, spontaneously piezoelectric and thermally stable poly(vinylidene fluoride) (PVDF) micro- and nanoribbons using iterative size reduction technique based on thermal fiber drawing. Because of high stress and temperature used in thermal drawing process, we obtained spontaneously polar γ phase PVDF micro- and nanoribbons without electrical poling process. On the basis of X-ray diffraction (XRD) analysis, we observed that PVDF micro- and nanoribbons are thermally stable and conserve the polar γ phase even after being exposed to heat treatment above the melting point of PVDF. Phase transition mechanism is investigated and explained using ab initio calculations. We measured an average effective piezoelectric constant as -58.5 pm/V from a single PVDF nanoribbon using a piezo evaluation system along with an atomic force microscope. PVDF nanoribbons are promising structures for constructing devices such as highly efficient energy generators, large area pressure sensors, artificial muscle and skin, due to the unique geometry and extended lengths, high polar phase content, high thermal stability and high piezoelectric coefficient. We demonstrated two proof of principle devices for energy harvesting and sensing applications with a 60 V open circuit peak voltage and 10 μA peak short-circuit current output. PMID:25133594

  5. Significant enhancement of magnetoresistance with the reduction of particle size in nanometer scale

    PubMed Central

    Das, Kalipada; Dasgupta, P.; Poddar, A.; Das, I.

    2016-01-01

    The Physics of materials with large magnetoresistance (MR), defined as the percentage change of electrical resistance with the application of external magnetic field, has been an active field of research for quite some times. In addition to the fundamental interest, large MR has widespread application that includes the field of magnetic field sensor technology. New materials with large MR is interesting. However it is more appealing to vast scientific community if a method describe to achieve many fold enhancement of MR of already known materials. Our study on several manganite samples [La1−xCaxMnO3 (x = 0.52, 0.54, 0.55)] illustrates the method of significant enhancement of MR with the reduction of the particle size in nanometer scale. Our experimentally observed results are explained by considering model consisted of a charge ordered antiferromagnetic core and a shell having short range ferromagnetic correlation between the uncompensated surface spins in nanoscale regime. The ferromagnetic fractions obtained theoretically in the nanoparticles has been shown to be in the good agreement with the experimental results. The method of several orders of magnitude improvement of the magnetoresistive property will have enormous potential for magnetic field sensor technology. PMID:26837285

  6. Thickness- and Particle-Size-Dependent Electrochemical Reduction of Carbon Dioxide on Thin-Layer Porous Silver Electrodes.

    PubMed

    Zhang, Lin; Wang, Zhiyong; Mehio, Nada; Jin, Xianbo; Dai, Sheng

    2016-03-01

    The electrochemical reduction of CO2 can not only convert it back into fuels, but is also an efficient manner to store forms of renewable energy. Catalysis with silver is a possible technology for CO2 reduction. We report that in the case of monolithic porous silver, the film thickness and primary particle size of the silver particles, which can be controlled by electrochemical growth/reduction of AgCl film on silver substrate, have a strong influence on the electrocatalytic activity towards CO2 reduction. A 6 μm thick silver film with particle sizes of 30-50 nm delivers a CO formation current of 10.5 mA cm(-2) and a mass activity of 4.38 A gAg (-1) at an overpotential of 0.39 V, comparable to levels achieved with state-of-the-art gold catalysts. PMID:26822587

  7. Investigation of optimal route to fabricate submicron-sized Sm2Fe17 particles with reduction-diffusion method

    NASA Astrophysics Data System (ADS)

    Okada, Shusuke; Takagi, Kenta; Ozaki, Kimihiro

    2016-05-01

    Submicron-sized Sm2Fe17 powder samples were fabricated by a non-pulverizing process through reduction-diffusion of precursors prepared by a wet-chemical technique. Three precursors having different morphologies, which were micron-sized porous Sm-Fe oxide-impregnated iron nitrate, acicular goethite impregnated-samarium nitrate, and a conventional Sm-Fe coprecipitate, were prepared and subjected to hydrogen reduction and reduction-diffusion treatment to clarify whether these precursors could be convert to Sm2Fe17 without impurity phases and which precursor is the most attractive for producing submicron-sized Sm2Fe17 powder. As a result, all three precursors were successfully converted to Sm2Fe17 powders without impurity phases, and the synthesis route using iron-oxide particle-impregnated samarium oxide was revealed to have the greatest potential among the three routes.

  8. International Research Reactor Decommissioning Project

    SciTech Connect

    Leopando, Leonardo; Warnecke, Ernst

    2008-01-15

    Many research reactors have been or will be shut down and are candidates for decommissioning. Most of the respective countries neither have a decommissioning policy nor the required expertise and funds to effectively implement a decommissioning project. The IAEA established the Research Reactor Decommissioning Demonstration Project (R{sup 2}D{sup 2}P) to help answer this need. It was agreed to involve the Philippine Research Reactor (PRR-1) as model reactor to demonstrate 'hands-on' experience as it is just starting the decommissioning process. Other facilities may be included in the project as they fit into the scope of R{sup 2}D{sup 2}P and complement to the PRR-1 decommissioning activities. The key outcome of the R{sup 2}D{sup 2}P will be the decommissioning of the PRR-1 reactor. On the way to this final goal the preparation of safety related documents (i.e., decommissioning plan, environmental impact assessment, safety analysis report, health and safety plan, cost estimate, etc.) and the licensing process as well as the actual dismantling activities could provide a model to other countries involved in the project. It is expected that the R{sup 2}D{sup 2}P would initiate activities related to planning and funding of decommissioning activities in the participating countries if that has not yet been done.

  9. Size, weight, and power reduction of mercury cadmium telluride infrared detection modules

    NASA Astrophysics Data System (ADS)

    Breiter, Rainer; Ihle, Tobias; Wendler, Joachim C.; Lutz, Holger; Rutzinger, Stefan; Schallenberg, Timo; Hofmann, Karl C.; Ziegler, Johann

    2011-06-01

    Application requirements driving present IR technology development activities are improved capability to detect and identify a threat as well as the need to reduce size weight and power consumption (SWaP) of thermal sights. In addition to the development of 3rd Gen IR modules providing dual-band or dual-color capability, AIM is focused on IR FPAs with reduced pitch and high operating temperature for SWaP reduction. State-of-the-art MCT technology allows AIM the production of mid-wave infrared (MWIR) detectors operating at temperatures exceeding 120 K without any need to sacrifice the 5-μm cut-off wavelength. These FPAs allow manufacturing of low cost IR modules with minimum size, weight, and power for state-of-the-art high performance IR systems. AIM has realized full TV format MCT 640×512 mid-wave and long-wave IR detection modules with a 15-μm pitch to meet the requirements of critical military applications like thermal weapon sights or thermal imagers in unmanned aerial vehicles applications. In typical configurations like an F/4.6 cold shield for the 640×512 MWIR module an noise equivalent temperature difference (NETD) <25 mK @ 5 ms integration time is achieved, while the long-wavelength infrared (LWIR) modules achieve an NETD <38 mK @ F/2 and 180 μs integration time. For the LWIR modules, FPAs with a cut-off up to 10 μm have been realized. The modules are available either with different integral rotary cooler configurations for portable applications that require minimum cooling power or a new split linear cooler providing long lifetime with a mean time to failure (MTTF) > 20000, e.g., for warning sensors in 24/7 operation. The modules are available with optional image processing electronics providing nonuniformity correction and further image processing for a complete IR imaging solution. The latest results and performance of those modules and their applications are presented.

  10. Effects of spray drying and size reduction of edible bird's nest on in-vitro digestibility

    NASA Astrophysics Data System (ADS)

    Muslim, Masitah; Babji, Abdul Salam; Mustapha, Wan Aida Wan

    2015-09-01

    The purpose of this study is to determine the effects of spray drying and size reduction of edible bird's nest (EBN) on in-vitro digestibility respectively. Sample prepared were EBN microparticulates; 710 µm (EBN710), 300 µm (EBN300) and 38 µm (EBN38), EBN spray died (EBNSD) and raw EBN (EBNraw) as control. Protein content and solubility were determined before the samples being subjected to in-vitro digestibility. Protein content of EBN710 (55.37±0.269%), EBN300 (56.57±0.163%) EBN38 (56.77±0.021%) and EBNraw (55.46±0.269%) was not significantly different (p>0.05) but EBNSD (60.33b+0.346%) was the highest (p<0.05). Solubility results showed that EBNSD had the highest solubility (94.38±1.24%) in water significantly (p<0.05) compared to EBNraw (16.01±0.231%), EBN710 (21.89+0.41%), EBN300 (22.52+0.072%) and EBN38 (27.51±0.321%). Digestibility of EBN300 (88.43±0.95%) was higher (p<0.05) compared to EBNSD (85.23±0.27%). However, treatment of microparticulates and spray drying were not significantly different with EBNraw (85.38±1.12%). Digestibility of EBN microparticulates and spray dried powder were all lower (p<0.05) than casein (98.36+0.95%). Lower EBN digestibility could be due to the nature of EBN protein as glycoprotein. Proteolytic (tryptic) digestion of native glycoprotein is often incomplete due to ste aric hindrance from the presence of bulky oligosaccharides.

  11. Decommissioning of the secondary containment of the steam generating heavy water reactor at UKAEA Winfrith

    SciTech Connect

    Miller, K.D.; Cornell, R.M.; Parkinson, S.J.; McIntyre, K.; Staples, A.

    2007-07-01

    The Winfrith SGHWR was a prototype nuclear power plant operated for 23 years by the United Kingdom Atomic Energy Authority (UKAEA) until 1990 when it was shut down permanently. The current Stage 1 decommissioning contract is part of a multi-stage strategy. It involves the removal of all the ancillary plant and equipment in the secondary containment and non-containment areas ahead of a series of contracts for the decommissioning of the primary containment, the reactor core and demolition of the building and ail remaining facilities. As an outcome of a competitive tending process, the Stage 1 decommissioning contract was awarded to NUKEM with operations commencing in April 2005. The decommissioning processes involved with these plant items will be described with some emphasis of the establishment of multiple work-fronts for the production, recovery, treatment and disposal of mainly tritium-contaminated waste arising from its contact with the direct cycle reactor coolant. The means of size reduction of a variety of large, heavy and complex items of plant made from a range of materials will also be described with some emphasis on the control of fumes during hot cutting operations and establishing effective containments within a larger secondary containment structure. Disposal of these wastes in a timely and cost-effective manner is a major challenge facing the decommissioning team and has required the development of a highly efficient means of packing the resultant materials into mainly one-third height IS0 containers for disposal as LLW. Details of the quantities of LLW and exempt wastes handled during this process will be given with a commentary about the difficulty in segregating these two waste streams efficiently. The paper sets out to demonstrate the considerable progress that has been made with these challenging decommissioning operations at the SGHWR plant and to highlight some of the techniques and processes that have contributed to the overall success of the

  12. Crystallographic studies of V44 mutants of Clostridium pasteurianum rubredoxin: Effects of side-chain size on reduction potential

    SciTech Connect

    Park, Il Yeong; Eidsness, Marly K.; Lin, I-Jin; Gebel, Erika B.; Youn, Buhyun; Harley, Jill L.; Machonkin, Timothy E.; Frederick, Ronnie O.; Markley, John L.; Smith, Eugene T.; Ichiye, Toshiko; Kang, ChulHee

    2010-11-16

    Understanding the structural origins of differences in reduction potentials is crucial to understanding how various electron transfer proteins modulate their reduction potentials and how they evolve for diverse functional roles. Here, the high-resolution structures of several Clostridium pasteurianum rubredoxin (Cp Rd) variants with changes in the vicinity of the redox site are reported in order to increase this understanding. Our crystal structures of [V44L] (at 1.8 {angstrom} resolution), [V44A] (1.6 {angstrom}), [V44G] (2.0 {angstrom}) and [V44A, G45P] (1.5 {angstrom}) Rd (all in their oxidized states) show that there is a gradual decrease in the distance between Fe and the amide nitrogen of residue 44 upon reduction in the size of the side chain of residue 44; the decrease occurs from leucine to valine, alanine or glycine and is accompanied by a gradual increase in their reduction potentials. Mutation of Cp Rd at position 44 also changes the hydrogen-bond distance between the amide nitrogen of residue 44 and the sulfur of cysteine 42 in a size-dependent manner. Our results suggest that residue 44 is an important determinant of Rd reduction potential in a manner dictated by side-chain size. Along with the electric dipole moment of the 43-44 peptide bond and the 44-42 NHS type hydrogen bond, a modulation mechanism for solvent accessibility through residue 41 might regulate the redox reaction of the Rds. Proteins 2004.

  13. You Just Feed Them with a Long-Handled Spoon: Families Evaluate Their Experiences in a Class Size Reduction Reform

    ERIC Educational Resources Information Center

    Graue, M. Elizabeth; Oen, Denise

    2009-01-01

    Emerging from an evaluation of Wisconsin's Student Achievement Guarantee in Education program (SAGE), a multidimensional program popularly known for its class size reduction component, this article examines SAGE's "lighted schoolhouse" initiative aimed to strengthen links between home and school. Drawing on family focus groups held at nine SAGE…

  14. District Resource Capacity and the Effects of Educational Policy: The Case of Primary Class Size Reduction in Ontario

    ERIC Educational Resources Information Center

    Mascall, Blair; Leung, Joannie

    2012-01-01

    In a study of Ontario, Canada's province-wide Primary Class Size Reduction (PCS) Initiative, school districts' ability to direct and support schools was related to their experience with planning and monitoring, interest in innovation, and its human and fiscal resource base. Districts with greater "resource capacity" were able to coordinate local…

  15. Principals as Middle Managers: School Leadership during the Implementation of Primary Class Size Reduction Policy in Ontario

    ERIC Educational Resources Information Center

    Flessa, Joseph J.

    2012-01-01

    Previous work on policy implementation has often suggested that schools leave their "thumbprints" on policies received from above. During the implementation of Primary Class Size Reduction (PCS) Initiative in Ontario, Canada, however, school principals spoke with remarkable uniformity about the ways PCS affected their work. This article reports…

  16. The View from the Lighted Schoolhouse: Conceptualizing Home-School Relations within a Class Size Reduction Reform

    ERIC Educational Resources Information Center

    Graue, M. Elizabeth; Sherfinski, Melissa

    2011-01-01

    In this essay we examine how educators work within a component of a class size reduction reform designed to strengthen the connections between families' home and school lives. We describe the accomplishments and struggles experienced by educators enacting this "lighted schoolhouse" based on our research in nine schools over three years.…

  17. Three Essays on the Economics of Education: Class-Size Reduction, Teacher Labor Markets, and Teacher Effectiveness

    ERIC Educational Resources Information Center

    Dieterle, Steven

    2012-01-01

    Prior research has established the potential for achievement gains from attending smaller classes. However, large statewide class-size reduction (CSR) policies have not been found to consistently realize such gains. A leading explanation for the disappointing performance of CSR policies is that schools are forced to hire additional teachers of…

  18. RELATIONSHIP OF FORAGE FIBER CONTENT AND MECHANICAL STRENGTH TO PARTICLE SIZE REDUCTION DURING INGESTIVE MASTICATION BY STEERS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Forage fiber content and mechanical toughness have been proposed as factors that limit particle size reduction and feed intake of ruminants. Three coarsely chopped forages were available ad lib to six mature rumen- fistulated steers. The oaten and mature alfalfa hays were similar in NDF concentratio...

  19. ORNL decontamination and decommissioning program

    SciTech Connect

    Bell, J.P.

    1980-01-01

    A program has been initiated at ORNL to decontaminate and decommission surplus or abandoned nuclear facilities. Program planning and technical studies have been performed by UCC-ND Engineering. A feasibility study for decommissioning the Metal Recovery Facility, a fuel reprocessing pilot plant, has been completed.

  20. Effect of tail size reductions on longitudinal aerodynamic characteristics of a three surface F-15 model with nonaxisymmetric nozzles

    NASA Technical Reports Server (NTRS)

    Frassinelli, Mark C.; Carson, George T., Jr.

    1990-01-01

    An investigation was conducted in the Langley 16-Foot Transonic Tunnel to determine the effects of horizontal and vertical tail size reductions on the longitudinal aerodynamic characteristics of a modified F-15 model with canards and 2-D convergent-divergent nozzles. Quantifying the drag decrease at low angles of attack produced by tail size reductions was the primary focus. The model was tested at Mach numbers of 0.40, 0.90, and 1.20 over an angle of attack of -2 degree to 10 degree. The nozzle exhaust flow was simulated using high pressure air at nozzle pressure ratios varying from 1.0 (jet off) to 7.5. Data were obtained on the baseline configuration with and without tails as well as with reduced horizontal and/or vertical tail sizes that were 75, 50, and 25 percent of the baseline tail areas.

  1. Using What We Know: A Review of the Research on Implementing Class-Size Reduction Initiatives for State and Local Policymakers.

    ERIC Educational Resources Information Center

    Laine, Sabrina W. M., Ed.; Ward, James G., Ed.

    This book contains a collection of essays involving new research on class-size reduction. Six chapters include: (1) "Reducing Class Size in Public Schools: Cost-Benefit Issues and Implications" (John F. Witte); (2) "Making Policy Choices: Is Class-Size Reduction the Best Alternative?" (Doug Harris and David N. Plank); (3) "Smaller Classes, Lower…

  2. Class-Size Reduction: Policy, Politics, and Implications for Equity. Equity Matters. Research Review No. 2

    ERIC Educational Resources Information Center

    Ready, Douglas D.

    2008-01-01

    Over the past several decades, researchers, politicians, and corporate leaders have focused reform efforts on the size of educational contexts. Hundreds of billions of public and private dollars have been invested to reduce the size and scope of both classrooms and schools (Lee & Ready, 2007). Unlike many education reforms, these downsizing plans…

  3. Offshore-platform decommissioning perceptions change

    SciTech Connect

    Twachtman, R.

    1997-12-08

    The oil and gas industry has seen a change in the perceptions about decommissioning offshore facilities. Now, decommissioning projects are being planned ahead of actual field development, and new concepts derived during decommissioning often are used to provide feedback for new development projects. The current trends and concepts applicable to decommissioning can be summarized as: advanced planning; engineered solutions; research and development; reuse; expanded use of offshore reefs; and deepwater disposal. Planning the platform decommissioning ahead of time (at least 2 years before production ceases) is key to a safe, environmentally conscious, and efficient decommissioning project. The paper discusses decommissioning projects, engineered solutions, research and development; reuse of platforms, and deepwater disposal.

  4. A new method for speckle reduction in Synthetic Aperture Radar (SAR) images using optimal window size

    NASA Astrophysics Data System (ADS)

    Mahdavi, S.; Salehi, B.; Moloney, C.; Huang, W.; Brisco, B.

    2016-04-01

    Speckle degrades the radiometric quality of a Synthetic Aperture Radar (SAR) image and makes its visual interpretation difficult. The approaches proposed previously for speckle filtering of SAR images exploit a window of fixed size for this purpose. But a fixed size window is not sufficient as the size of objects may vary throughout the image. In this paper, a method is introduced by which each pixel in the image is filtered using a window size which is optimal for that pixel. Real and imaginary parts of a single-channel SAR image are used for the selection of the best window size for each pixel, and then intensity image is filtered by applying that window size. The Average and Minimum Mean Square Error (MMSE) filters are modified using the Adaptive Window Size method. This approach is implemented on the HH-channel of a RADARSAT-2 image acquired over the Avalon Peninsula near St. John's, Newfoundland, Canada. This filter can supress speckle effectively while retaining the details reasonably.

  5. Revised Analyses of Decommissioning Reference Non-Fuel-Cycle Facilities

    SciTech Connect

    MC Bierschbach; DR Haffner; KJ Schneider; SM Short

    2002-12-01

    facility, DECON requires that contaminated components either be: (1) decontaminated to restricted or unrestricted release levels or (2) packaged and shipped to an authorized disposal site. This study considers unrestricted release only. The new decommissioning criteria of July 1997 are too recent for this study to include a cost analysis of the restricted release option, which is now allowed under these new criteria. The costs of decommissioning facility components are generally estimated to be in the range of $140 to $27,000, depending on the type of component, the type and amount of radioactive contamination, the remediation options chosen, and the quantity of radioactive waste generated from decommissioning operations. Estimated costs for decommissioning the example laboratories range from $130,000 to $205,000, assuming aggressive low-level waste (LLW) volume reduction. If only minimal LLW volume reduction is employed, decommissioning costs range from $150,000 to $270,000 for these laboratories. On the basis of estimated decommissioning costs for facility components, the costs of decommissioning typical non-fuel-cycle laboratory facilities are estimated to range from about $25,000 for the decommissioning of a small room containing one or two fume hoods to more than $1 million for the decommissioning of an industrial plant containing several laboratories in which radiochemicals and sealed radioactive sources are prepared. For the reference sites of this study, the basic decommissioning alternatives are: (1) site stabilization followed by long-term care and (2) removal of the waste or contaminated soil to an authorized disposal site. Cost estimates made for decommissioning three reference sites range from about $130,000 for the removal of a contaminated drain line and hold-up tank to more than $23 million for the removal of a tailings pile that contains radioactive residue from ore-processing operations in which tin slag is processed for the recovery of rare metals. Total

  6. Downstream reduction of rural channel size with contrasting urban effects in small coastal streams of southeastern Australia

    NASA Astrophysics Data System (ADS)

    Nanson, G. C.; Young, R. W.

    1981-07-01

    Although most streams show a downstream increase in channel size corresponding to a downstream increase in flood discharges, those flowing off the Illawarra escarpment of New South Wales show a marked reduction of channel size, accompanied by a down-stream increase in flood frequency in their lower reaches. Within the confined and steeply sloping valleys of the escarpment foothills, bed and bank sediments are relatively coarse and uncohesive, and channels increase in size, corresponding to increasing discharge downstream. However, once these streams emerge into more open rural valleys at lower slopes and are accompanied by extensive floodplains formed of fine cohesive sediment, there is a dramatic reduction in channel size. This decrease in channel size apparently results from a sudden decline in channel slope and associated stream power, the cohesive nature of downstream alluvium, its retention on the channel banks by a dense cover of pasture grasses, and the availability of an extensive floodplain to carry displaced floodwater. Under these conditions floodwaters very frequently spill out over the floodplain and the downstream channel-flow becomes a relatively unimportant component of the total peak discharge. This emphasizes the importance of these floodplains as a part of the total channel system. In situations where urban development has increased peak runoff and reduced the available area of effective floodplain, stream channels formed in this fine alluvium rapidly entrench and increase in cross-sectional area by 2-3 times. Minor man-induced channel alteration and maintenance appears to trigger this enlargement.

  7. Decontamination & decommissioning focus area

    SciTech Connect

    1996-08-01

    In January 1994, the US Department of Energy Office of Environmental Management (DOE EM) formally introduced its new approach to managing DOE`s environmental research and technology development activities. The goal of the new approach is to conduct research and development in critical areas of interest to DOE, utilizing the best talent in the Department and in the national science community. To facilitate this solutions-oriented approach, the Office of Science and Technology (EM-50, formerly the Office of Technology Development) formed five Focus AReas to stimulate the required basic research, development, and demonstration efforts to seek new, innovative cleanup methods. In February 1995, EM-50 selected the DOE Morgantown Energy Technology Center (METC) to lead implementation of one of these Focus Areas: the Decontamination and Decommissioning (D & D) Focus Area.

  8. Reduction of effective terahertz focal spot size by means of nested concentric parabolic reflectors

    SciTech Connect

    Neumann, V. A.; Laurita, N. J.; Pan, LiDong; Armitage, N. P.

    2015-09-15

    An ongoing limitation of terahertz spectroscopy is that the technique is generally limited to the study of relatively large samples of order 4 mm across due to the generally large size of the focal beam spot. We present a nested concentric parabolic reflector design which can reduce the terahertz focal spot size. This parabolic reflector design takes advantage of the feature that reflected rays experience a relative time delay which is the same for all paths. The increase in effective optical path for reflected light is equivalent to the aperture diameter itself. We have shown that the light throughput of an aperture of 2 mm can be increased by a factor 15 as compared to a regular aperture of the same size at low frequencies. This technique can potentially be used to reduce the focal spot size in terahertz spectroscopy and enable the study of smaller samples.

  9. Longitudinal Effects of Class Size Reductions on Attainment: Results from Hong Kong Primary Classrooms

    ERIC Educational Resources Information Center

    Galton, Maurice; Pell, Tony

    2012-01-01

    In a four-year study of the effect of class size on pupil outcomes in a sample of 36 primary schools in Hong Kong, it has been found that there are few positive differences in attainment between classes set at less than 25 pupils and those of normal size averaging 38. Three cohorts of pupils were studied. In Cohort 1 pupils spent 3 years in small…

  10. HEAVY WATER COMPONENTS TEST REACTOR DECOMMISSIONING

    SciTech Connect

    Austin, W.; Brinkley, D.

    2011-10-13

    The Heavy Water Components Test Reactor (HWCTR) Decommissioning Project was initiated in 2009 as a Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) Removal Action with funding from the American Recovery and Reinvestment Act (ARRA). This paper summarizes the history prior to 2009, the major D&D activities, and final end state of the facility at completion of decommissioning in June 2011. The HWCTR facility was built in 1961, operated from 1962 to 1964, and is located in the northwest quadrant of the Savannah River Site (SRS) approximately three miles from the site boundary. The HWCTR was a pressurized heavy water test reactor used to develop candidate fuel designs for heavy water power reactors. In December of 1964, operations were terminated and the facility was placed in a standby condition as a result of the decision by the U.S. Atomic Energy Commission to redirect research and development work on heavy water power reactors to reactors cooled with organic materials. For about one year, site personnel maintained the facility in a standby status, and then retired the reactor in place. In the early 1990s, DOE began planning to decommission HWCTR. Yet, in the face of new budget constraints, DOE deferred dismantlement and placed HWCTR in an extended surveillance and maintenance mode. The doors of the reactor facility were welded shut to protect workers and discourage intruders. In 2009 the $1.6 billion allocation from the ARRA to SRS for site footprint reduction at SRS reopened the doors to HWCTR - this time for final decommissioning. Alternative studies concluded that the most environmentally safe, cost effective option for final decommissioning was to remove the reactor vessel, both steam generators, and all equipment above grade including the dome. The transfer coffin, originally above grade, was to be placed in the cavity vacated by the reactor vessel and the remaining below grade spaces would be grouted. Once all above equipment

  11. Size Control and Characterization of Sn-Ag-Cu Lead-Free Nanosolders by a Chemical Reduction Process

    NASA Astrophysics Data System (ADS)

    Yung, K. C.; Law, C. M. T.; Lee, C. P.; Cheung, B.; Yue, T. M.

    2012-02-01

    Sn-3.0Ag-0.5Cu nanosolders were synthesized via a chemical reduction method. Polyvinyl pyrrolidone (PVP) and sodium borohydride (NaBH4) were employed as surfactant and reducing agent, respectively. Ultraviolet-visible (UV-visible) absorption and x-ray diffraction patterns revealed that alloying had successfully taken place during the reduction process. Different amounts of PVP and NaBH4 additions influenced the nanosolder particle size. Under varying reaction temperatures and pH values, various ranges of nanosolder size were obtained. Optimized nanosolders were studied by differential scanning calorimetry to investigate the depression of the melting temperature, and were analyzed by transmission electron microscopy to measure actual particle sizes. The dependence of the particle size on the melting temperature was observed. The melting point was depressed to 204.4°C when the average diameter of the nanosolders was 20 nm. Although SnO2 was formed on the nanosolders, it could be cleaned by citric acid. These low-melting-temperature Sn-Ag-Cu nanosolders are candidates for use in lead-free interconnect applications.

  12. Windscale pile reactors - Decommissioning progress on a fifty year legacy

    SciTech Connect

    Sexton, Richard J.

    2007-07-01

    The decommissioning of the Windscale Pile 1 reactor, fifty years after the 1957 fire, is one of the most technically challenging decommissioning projects in the UK, if not the world. This paper presents a summary of the 1957 Windscale Pile 1 accident, its unique challenges and a new technical approach developed to safely and efficiently decommission the two Windscale Pile Reactors. The reactors will be decommissioned using a top down approach that employs an array of light weight, carbon fiber, high payload robotic arms to remove the damaged fuel, the graphite core, activated metals and concrete. This relatively conventional decommissioning approach has been made possible by a recently completed technical assessment of reactor core fire and criticality risk which concluded that these types of events are not credible if relatively simple controls are applied. This paper presents an overview of the design, manufacture and testing of equipment to remove the estimated 15 tons of fire damaged fuel and isotopes from the Pile 1 reactor. The paper also discusses recently conducted characterization activities which have allowed for a refined waste estimate and conditioning strategy. These data and an innovative approach have resulted in a significant reduction in the estimated project cost and schedule. (authors)

  13. Consideration of sample size for estimating contaminant load reductions using load duration curves

    NASA Astrophysics Data System (ADS)

    Babbar-Sebens, Meghna; Karthikeyan, R.

    2009-06-01

    SummaryIn Total Maximum Daily Load (TMDL) programs, load duration curves are often used to estimate reduction of contaminant loads in a watershed. A popular method for calculating these load reductions involves estimation of the 90th percentiles of monitored contaminant concentrations during different hydrologic conditions. However, water quality monitoring is expensive and can pose major limitations in collecting enough data. Availability of scarce water quality data can, therefore, deteriorate the precision in the estimates of the 90th percentiles, which, in turn, affects the accuracy of estimated load reductions. This paper proposes an adaptive sampling strategy that the data collection agencies can use for not only optimizing their collection of new samples across different hydrologic conditions, but also ensuring that newly collected samples provide opportunity for best possible improvements in the precision of the estimated 90th percentile with minimum sampling costs. The sampling strategy was used to propose sampling plans for Escherichia coli monitoring in an actual stream and different sampling procedures of the strategy were tested for hypothetical stream data. Results showed that improvement in precision using the proposed distributed sampling procedure is much better and faster than that attained via the lumped sampling procedure, for the same sampling cost. Hence, it is recommended that when agencies have a fixed sampling budget, they should collect samples in consecutive monitoring cycles as proposed by the distributed sampling procedure, rather than investing all their resources in only one monitoring cycle.

  14. Solvent-induced size reduction of self-assembled siRNA/copolymer nanoparticles

    NASA Astrophysics Data System (ADS)

    Qu, Wei; Wu, Juan; Mao, Hai-Quan; Luijten, Erik

    2013-03-01

    Small interfering RNA (siRNA) therapeutics has a demonstrated potential for treating numerous liver diseases. However, traditional polycation vectors used for siRNA delivery typically produce siRNA-containing particles of large size (> 100 nm), along with high cytotoxicity and low colloidal stability. Inspired by earlier work on nanoparticles for plasmid DNA delivery, we graft hydrophilic and biocompatible polyethylene glycol (PEG) blocks to the polycation vector to overcome these limitations. We find that the PEG-grafted polycations result in slightly larger particle size, even though the hydrophilic PEG blocks are expected to hinder the formation of larger aggregates. To explain this observation, we investigate siRNA/copolymer self-assembly via computer simulations of coarse-grained polymer and siRNA models. Our calculations suggest that hydrogen bonding between PEG and the polycation leads to the increased particle size, and that smaller particles can be obtained by inhibiting hydrogen bonding in such system. Subsequent experiments employing solvents of lower polarity indeed lead to particles with smaller size.

  15. The Political Economy of Education Policy: The Case of Class Size Reduction.

    ERIC Educational Resources Information Center

    Mitchell, Douglas E.; Mitchell, Ross E.

    2003-01-01

    Develops a political economy framework for mapping and interpreting the competing purposes of schooling by examining five paradoxes in national policy debates addressing class size in public elementary schools. The framework highlights answers to the question: What kind of an economic good is education? (education as a service industry, producer…

  16. Reduction of Salmonella Enteritidis Population Sizes on Almond Kernels with Infrared Heat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Catalytic infrared (IR) heating was investigated to determine its effect on Salmonella enterica serovar Enteritidis population sizes on raw almond kernels. Using a double-sided catalytic infrared heating system, a radiation intensity of 5458 W/m2 caused a fast temperature increase at the kernel surf...

  17. Money Related Decommissioning and Funding Decision Making

    SciTech Connect

    Goodman, Lynne S.

    2008-01-15

    'Money makes the world go round', as the song says. It definitely influences decommissioning decision-making and financial assurance for future decommissioning. This paper will address two money-related decommissioning topics. The first is the evaluation of whether to continue or to halt decommissioning activities at Fermi 1. The second is maintaining adequacy of financial assurance for future decommissioning of operating plants. Decommissioning costs considerable money and costs are often higher than originally estimated. If costs increase significantly and decommissioning is not well funded, decommissioning activities may be deferred. Several decommissioning projects have been deferred when decision-makers determined future spending is preferable than current spending, or when costs have risen significantly. Decommissioning activity timing is being reevaluated for the Fermi 1 project. Assumptions for waste cost-escalation significantly impact the decision being made this year on the Fermi 1 decommissioning project. They also have a major impact on the estimated costs for decommissioning currently operating plants. Adequately funding full decommissioning during plant operation will ensure that the users who receive the benefit pay the full price of the nuclear-generated electricity. Funding throughout operation also will better ensure that money is available following shutdown to allow decommissioning to be conducted without need for additional funds.

  18. The effects of ulcer size on the wound radius reductions and healing times in neuropathic diabetic foot ulcers.

    PubMed

    Zimny, S; Schatz, H; Pfohl, M

    2004-04-01

    The main problems in the treatment of diabetic foot ulcers are prolonged wound healing and not necessary amputations, which may sometimes be caused by the impression that the results of conservative treatment are somewhat unpredictable. The aim of this study was to determine the effects of ulcer size on the wound radius reduction and healing times using a previously established equation for wound healing in neuropathic diabetic foot ulcers. This prospective study evaluates wound healing in 120 diabetic patients with neuropathic foot ulcers who were grouped according to four different ulcer areas (A 100 150 200 mm (2)). Ulcer healing was assessed by planimetric measurement of the wound area every second week until wound healing. The time course of wound healing in the different groups was compared by the weekly wound radius reduction using the equation R = sqrt A/pi. The average healing time in group A was 70 (95 %-CI 64 - 77) days with a wound radius reduction of 0.42 mm/week (95 %-CI 0.28 - 0.56). In group B the average healing time was 79 (95 %-CI 75 - 82) days and the weekly wound radius reduction was 0.47 mm (95 %-CI 0.45 - 0.49). The average healing time in group C was 85 (95 %-CI 80 - 89) days with a wound radius reduction of 0.53 mm/week (95 %-CI 0.42 - 0.56). In group D the average healing time was 97 (95 %-CI 91 - 103) days. The weekly wound radius reduction was 0.57 mm (95 %-CI 0.49 - 0.81). Wound radius reductions and the time needed for healing are affected by the ulcer area, a measure of ulcer size, in neuropathic diabetic foot ulcers. The calculation of the weekly wound radius reduction for different ulcer areas may be a useful tool in daily clinical practice to identify ulcers who do not respond adequately to the treatment. PMID:15127323

  19. Model-size reduction for the non-linear dynamic analysis of quasi-symmetric structures

    NASA Technical Reports Server (NTRS)

    Noor, Ahmed K.; Peters, Jeanne M.

    1987-01-01

    A numerical technique is developed to reduce the size of models describing the nonlinear dynamic response of quasi-symmetric structures (i.e., structures with unsymmetric geometry). The response vectors of the structure are approximated by a linear combination of the symmetric and antisymmetric vectors at each time step. The mathematical formulation and numerical implementation of the method are described in detail, and results for a shallow laminated anisotropic panel of quadrilateral planform are presented in graphs and normalized contour plots.

  20. Muscle regeneration during hindlimb unloading results in a reduction in muscle size after reloading

    NASA Technical Reports Server (NTRS)

    Mozdziak, P. E.; Pulvermacher, P. M.; Schultz, E.

    2001-01-01

    The hindlimb-unloading model was used to study the ability of muscle injured in a weightless environment to recover after reloading. Satellite cell mitotic activity and DNA unit size were determined in injured and intact soleus muscles from hindlimb-unloaded and age-matched weight-bearing rats at the conclusion of 28 days of hindlimb unloading, 2 wk after reloading, and 9 wk after reloading. The body weights of hindlimb-unloaded rats were significantly (P < 0.05) less than those of weight-bearing rats at the conclusion of hindlimb unloading, but they were the same (P > 0.05) as those of weight-bearing rats 2 and 9 wk after reloading. The soleus muscle weight, soleus muscle weight-to-body weight ratio, myofiber diameter, number of nuclei per millimeter, and DNA unit size were significantly (P < 0.05) smaller for the injured soleus muscles from hindlimb-unloaded rats than for the soleus muscles from weight-bearing rats at each recovery time. Satellite cell mitotic activity was significantly (P < 0.05) higher in the injured soleus muscles from hindlimb-unloaded rats than from weight-bearing rats 2 wk after reloading, but it was the same (P > 0.05) as in the injured soleus muscles from weight-bearing rats 9 wk after reloading. The injured soleus muscles from hindlimb-unloaded rats failed to achieve weight-bearing muscle size 9 wk after reloading, because incomplete compensation for the decrease in myonuclear accretion and DNA unit size expansion occurred during the unloading period.

  1. Technology, safety, and costs of decommissioning reference nuclear research and test reactors: sensitivity of decommissioning radiation exposure and costs to selected parameters

    SciTech Connect

    Konzek, G.J.

    1983-07-01

    Additional analyses of decommissioning at the reference research and test (R and T) reactors and analyses of five recent reactor decommissionings are made that examine some parameters not covered in the initial study report (NUREG/CR-1756). The parameters examined for decommissioning are: (1) the effect on costs and radiation exposure of plant size and/or type; (2) the effects on costs of increasing disposal charges and of unavailability of waste disposal capacity at licensed waste disposal facilities; and (3) the costs of and the available alternatives for the disposal of nuclear R and T reactor fuel assemblies.

  2. IF-WS{sub 2} nanoparticles size design and synthesis via chemical reduction

    SciTech Connect

    Ghoreishi, S.M.; Meshkat, S.S.; Dadkhah, A.A.

    2010-05-15

    An innovative synthesis of inorganic fullerene-like disulfide tungsten (IF-WS{sub 2}) nanoparticles was developed using a chemical reduction reaction in a horizontal quartz reactor. In this process, first tungsten trisulfide (WS{sub 3}) was formed via a chemical reaction of tetra thiotungstate ammonium ((NH{sub 4}){sub 2}WS{sub 4}), polyethylene glycol (PEG), and hydrochloric acid (HCl) at ambient temperature and pressure. Subsequently, WS{sub 3} was reacted with hydrogen (H{sub 2}) at high temperature (1173-1373 K) in a quartz tube. The produced WS{sub 2} nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDAX), and transmission electron microscopy (TEM). The characterization results indicated that the high-purity (100%) IF-WS{sub 2} nanoparticles were produced. Moreover, addition of surfactant (PEG) and higher operating temperature (1173-1373 K) decreased the particles agglomeration, and consequently led to the reduction of average diameter of WS{sub 2} particles in the range of 50-78 nm. The developed method is simple, environmentally compatible, and cost-effective in contrast to the conventional techniques.

  3. Transformation products of submicron-sized aluminum-substituted magnetite: Color and reductant solubility

    NASA Technical Reports Server (NTRS)

    Golden, D. C.; Ming, D. W.; Lauer, H. V., Jr.

    1991-01-01

    Magnetite, when present as fine particles, is soluble in acid ammonium oxalate (pH equals 3). However, the commonly used extractant for free iron oxides (i.e., citrate dithionite-bicarbonate (CDB) is not very effective in dissolving magnetite in soils and geologic materials. Upon oxidation, magnetite transforms to maghemite; at elevated temperatures, maghemite inverts to hematite. This transformation causes a change in color from black to red and may affect the reductant solubility as well. The objectives here were to examine the color and reflectance spectral characteristics of products during the transformation of magnetite to maghemite to hematite and to study the effect of Al-substitution in magnetite on the above process. Reductant solubility of Al-substituted magnetite, maghemite, and hematite was also studied. In summary, the transformation of magnetite to maghemite was accompanied by a change in color from black to red because of the oxidation of Fe2(+) to Fe3(+). The phase change maghemite to hematite had a relatively minor effect on the color and the reflectance spectra.

  4. Identification and evaluation of facilitation techniques for decommissioning light water power reactors

    SciTech Connect

    LaGuardia, T.S.; Risley, J.F.

    1986-06-01

    This report describes a study sponsored by the US Nuclear Regulatory Commission to identify practical techniques to facilitate the decommissioning of nuclear power generating facilities. The objective of these ''facilitation techniques'' is to reduce the radioactive exposures and/or volumes of waste generated during the decommissioning process. The report presents the possible facilitation techniques identified during the study and discusses the corresponding facilitation of the decommissioning process. Techniques are categorized by their applicability of being implemented during the three stages of power reactor life: design/construction, operation, or decommissioning. Detailed cost-benefit analyses were performed for each technique to determine the anticipated exposure and/or radioactive waste reduction; the estimated costs for implementing each technique were then calculated. Finally, these techniques were ranked by their effectiveness in facilitating the decommissioning process. This study is a part of the Nuclear Regulatory Commission's evaluation of decommissioning policy and its modification of regulations pertaining to the decommissioning process. The findings can be used by the utilities in the planning and establishment of activities to ensure that all objectives of decommissioning will be achieved.

  5. Size reduction and harmonic supression in coplanar rat-race coupler using defected ground structures

    NASA Astrophysics Data System (ADS)

    Bhadauria, Avanish; Sharma, Sonia

    2016-03-01

    In this paper, we have proposed, verified and studied defected ground structures (DGS) in coplanar rat-race coupler to reduce its size and harmonic suppression in transmission characteristics. The dumbbell geometry has been chosen as a DGS unit-cell in a systematic manner in the proposed structure. The EM simulation results from IE3D tool presented with experimental validation to study the transmission behavior of proposed structures. The operation frequency has been reduced from 5.4 GHz down to 4.4 GHz after introduction of defected ground structures along the suppression of higher order harmonics.

  6. Reduction of weight loss and tumour size in a cachexia model by a high fat diet.

    PubMed Central

    Tisdale, M. J.; Brennan, R. A.; Fearon, K. C.

    1987-01-01

    An attempt has been made to reverse cachexia and to selectively deprive the tumour of metabolic substrates for energy production by feeding a ketogenic regime, since ketone bodies are considered important in maintaining homeostasis during starvation. As a model we have used a transplantable mouse adenocarcinoma of the colon (MAC 16) which produces extensive weight loss without a reduction in food intake. When mice bearing the MAC16 tumour were fed on diets in which up to 80% of the energy was supplied as medium chain triglycerides (MCT) with or without arginine 3-hydroxybutyrate host weight loss was reduced in proportion to the fat content of the diet, and there was also a reduction in the percentage contribution of the tumour to the final body weight. The increase in carcass weight in tumour-bearing mice fed high levels of MCT was attributable to an increase in both the fat and the non-fat carcass mass. Blood levels of free fatty acids (FFA) were significantly reduced by MCT addition. The levels of both acetoacetate and 3-hydroxybutyrate were elevated in mice fed the high fat diets, and tumour-bearing mice fed the normal diet did not show increased plasma levels of ketone bodies over the non-tumour-bearing group despite the loss of carcass lipids. Both blood glucose and plasma insulin levels were reduced in mice bearing the MAC16 tumour and this was not significantly altered by feeding the high fat diets. The elevation in ketone bodies may account for the retention of both the fat and the non-fat carcass mass. This is the first example of an attempt to reverse cachexia by a diet based on metabolic differences between tumour and host tissues, which aims to selectively feed the host at the expense of the tumour. PMID:3620317

  7. Liberation as a function of size reduction in the coal-ash-pyrite system

    SciTech Connect

    Perez, J.W.

    1981-01-01

    The effect of crushing on the liberation behavior of the coal-ash-pyrite system was investigated. To facilitate evaluation of this complex system, a classification system was developed to describe the different types of feed assemblages and their relationship to the liberation behavior. The liberation behavior of the different species was described in terms of fractional yields within a given size range. Fractional yield is defined as the yield of the designed product in a given size interval. Experimental data were generated to assess liberation in the coal-ash-pyrite system following crushing with a smooth roll crusher, hammer mills, rod mill, jaw crusher and rotary breaker. These data were then used to test the various mathematical models proposed in the literature. The available models were generally found to be inadequate, unless modified. However, a simple negative exponential model was developed which was found to fit the data well and can be used to simulate yields of coal and pyrite out of either whole coal or narrow specific gravity feeds. Furthermore, it was found to apply in other systems such as that of galena-sphalerite-gangue.

  8. Disintegration and size reduction of slags and metals after melt refining of contaminated metallic wastes

    SciTech Connect

    Heshmatpour, B.; Copeland, G.L.; Heestand, R.L.

    1981-04-01

    Melting under an oxidizing slag is an attractive method of decontaminating and reducing the volume of radioactively contaminated metal scrap. The contaminants are concentrated in a relatively small volume of slag, which leaves the metal essentially clean. A potential method of permanently disposing of the resulting slags (and metals if necessary) is emplacing them into deep shale by grout hydrofracture. Suspension in grout mixtures requires that the slag and metal be granular. The feasibility of size-reducing slags and disintegrating metals and subsequently incorporating both into grout mixtures was demonstrated. Various types of slags were crushed with a small jaw crusher into particles smaller than 3 mm. Several metals were also melted and water-blasted into coarse metal powder or shot ranging in size from 0.05 to 3 mm. A simple low-pressure water atomizer having a multiple nozzle with a converging-line jet stream was developed and used for this purpose. No significant slag dust and steam were generated during slag crushing and liquid-metal water-blasting tests, indicating that contamination can be well contained within the system. The crushed slags and the coarse metal powders were suspendable in group fluids, which indicates probable disposability by shale hydrofracture. The granulation of slags and metals facilitates their containment, transport, and storage.

  9. Model-size reduction technique for the analysis of symmetric anisotropic structures

    NASA Technical Reports Server (NTRS)

    Noor, A. K.; Peters, J. M.

    1985-01-01

    A two-step computational procedure is presented for reducing the size of the analysis model for an anisotropic symmetric structure to that of the corresponding orthotropic structure. The key elements of the procedure are: (1) decomposition of the stiffness matrix into the sum of an orthotropic and nonorthotropic (anisotropic) parts; and (2) successive application of the finite element method and the classical Rayleigh-Ritz technique. The finite element method is first used to generate few global approximation vectors (or modes). Then the amplitudes of these modes are computed by using the Rayleigh-Ritz technique. The global approximation vectors are selected to be the solution corresponding to zero nonorthotropic matrix and its various-order derivatives with respect to an anisotropic tracing parameter (identifying the nonorthotropic material coefficients). The size of the analysis model used in generating the global approximation vectors is identical to that of the corresponding orthotropic structure. The effectiveness of the proposed technique is demonstrated by means of numerical examples and its potential for solving other quasi-symmetric problems is discussed.

  10. Reduction of feral cat (Felis catus Linnaeus 1758) colony size following hysterectomy of adult female cats.

    PubMed

    Mendes-de-Almeida, Flavya; Remy, Gabriella L; Gershony, Liza C; Rodrigues, Daniela P; Chame, Marcia; Labarthe, Norma V

    2011-06-01

    The size of urban cat colonies is limited only by the availability of food and shelter; therefore, their population growth challenges all known population control programs. To test a new population control method, a free-roaming feral cat colony at the Zoological Park in the city of Rio de Janeiro was studied, beginning in 2001. The novel method consisted of performing a hysterectomy on all captured female cats over 6 months of age. To estimate the size of the colony and compare population from year to year, a method of capture-mark-release-recapture was used. The aim was to capture as many individuals as possible, including cats of all ages and gender to estimate numbers of cats in all population categories. Results indicated that the feral cat population remained constant from 2001 to 2004. From 2004 to 2008, the hysterectomy program and population estimates were performed every other year (2006 and 2008). The population was estimated to be 40 cats in 2004, 26 in 2006, and 17 cats in 2008. Although pathogens tend to infect more individuals as the population grows older and maintains natural behavior, these results show that free-roaming feral cat colonies could have their population controlled by a biannual program that focuses on hysterectomy of sexually active female cats. PMID:21440475

  11. Porous Carbon-Supported Gold Nanoparticles for Oxygen Reduction Reaction: Effects of Nanoparticle Size.

    PubMed

    Wang, Likai; Tang, Zhenghua; Yan, Wei; Yang, Hongyu; Wang, Qiannan; Chen, Shaowei

    2016-08-17

    Porous carbon-supported gold nanoparticles of varied sizes were prepared using thiolate-capped molecular Au25, Au38, and Au144 nanoclusters as precursors. The organic capping ligands were removed by pyrolysis at controlled temperatures, resulting in good dispersion of gold nanoparticles within the porous carbons, although the nanoparticle sizes were somewhat larger than those of the respective nanocluster precursors. The resulting nanocomposites displayed apparent activity in the electroreduction of oxygen in alkaline solutions, which increased with decreasing nanoparticle dimensions. Among the series of samples tested, the nanocomposite prepared with Au25 nanoclusters displayed the best activity, as manifested by the positive onset potential at +0.95 V vs RHE, remarkable sustainable stability, and high numbers of electron transfer at (3.60-3.92) at potentials from +0.50 to +0.80 V. The performance is comparable to that of commercial 20 wt % Pt/C. The results demonstrated the unique feasibility of porous carbon-supported gold nanoparticles as high-efficiency ORR catalysts. PMID:27454707

  12. Rational Design of Bi Nanoparticles for Efficient Electrochemical CO2 Reduction: The Elucidation of Size and Surface Condition Effects

    DOE PAGESBeta

    Zhang, Zhiyong; Chi, Miaofang; Veith, Gabriel M.; Zhang, Pengfei; Lutterman, Daniel A.; Rosenthal, Joel; Overbury, Steven H.; Dai, Sheng; Zhu, Huiyuan

    2016-08-08

    Here we report an efficient electrochemical conversion of CO2 to CO on surface-activated bismuth nanoparticles (NPs) in acetonitrile (MeCN) under ambient conditions, with the assistance of 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([bmim][OTf]). Through the comparison between electrodeposited Bi films (Bi-ED) and different types of Bi NPs, we, for the first time, demonstrate the effects of catalyst’s size and surface condition on organic phase electrochemical CO2 reduction. Our study reveals that the surface inhibiting layer (hydrophobic surfactants and Bi3+ species) formed during the synthesis and purification process hinders the CO2 reduction, leading to a 20% drop in Faradaic efficiency for CO evolution (FECO). Bimore » particle size showed a significant effect on FECO when the surface of Bi was air-oxidized, but this effect of size on FECO became negligible on surface-activated Bi NPs. After the surface activation (hydrazine treatment) that effectively removed the native inhibiting layer, activated 36-nm Bi NPs exhibited an almost-quantitative conversion of CO2 to CO (96.1% FECO), and a mass activity for CO evolution (MACO) of 15.6 mA mg–1, which is three-fold higher than the conventional Bi-ED, at ₋2.0 V (vs Ag/AgCl). Ultimately, this work elucidates the importance of the surface activation for an efficient electrochemical CO2 conversion on metal NPs and paves the way for understanding the CO2 electrochemical reduction mechanism in nonaqueous media.« less

  13. Particle-size reduction of Si3N4 powder with Si3N4 milling hardware

    NASA Technical Reports Server (NTRS)

    Herbell, T. P.; Freedman, M. R.; Kiser, J. D.

    1986-01-01

    The grinding of Si3N4 powder using reaction bonded Si3N4 attrition, vibratory, and ball mills with Si3N4 media was examined. The rate of particle size reduction and the change in the chemical composition of the powder were determined in order to compare the grinding efficiency and the increase in impurity content resulting from mill and media wear for each technique. Attrition and vibratory milling exhibited rates of specific surface area increase that were approximately eight times that observed in ball milling. Vibratory milling introduced the greatest impurity pickup.

  14. Effect of meal size reduction and protein enrichment on intake and satiety in vital community-dwelling older adults.

    PubMed

    Ziylan, Canan; Kremer, Stefanie; Eerens, Jessie; Haveman-Nies, Annemien; de Groot, Lisette C P G M

    2016-10-01

    Undernutrition risk among community-dwelling older adults is partly caused by inadequate protein intake. Enriching readymade meals with protein could be beneficial in increasing protein intake. Moreover, reduced-size meals could suit older adults with diminished appetite. In this single-blind randomized crossover study with 120 participants (age: 70.5 ± 4.5 y, BMI: 27.2 ± 4.4 kg/m(2)), 60 participants consumed four beef meals and another 60 consumed four chicken meals on four different days, once per week. These meals were produced according to a 2 × 2 factorial design: the protein content was either ∼25 g (lower) or ∼30 g (enriched), and the portion size was either 450 g (normal) or of 400 g (reduced). Palatability evaluation, meal intake, and subsequent satiety ratings after 120 min were measured. No significant differences in palatability among meals were found. While absolute intake (g) of the normal-size meals was significantly higher than that of the reduced-size meals, the relative intake (%) of the served meals did not differ between the four meals. Both protein and energy intakes were significantly higher for the enriched meals, regardless of portion size. Protein intakes were 5.4 g and 5.1 g higher in the normal-size and reduced-size enriched beef meals, respectively, and 6.1 g and 7.1 g higher in the enriched chicken meals, respectively. The normal-size enriched beef meal and reduced-size enriched chicken meal led to slightly but significantly higher ratings of satiety than the non-enriched meals. Due to these mixed satiety findings, separate effects of meal-size reduction and protein enrichment could not be distinguished in this study. The intake findings show that palatable protein-enriched meals support higher protein and energy intakes in vital community-dwelling older adults during a single meal. PMID:27238898

  15. Model-size reduction for the analysis of symmetric structures with asymmetric boundary conditions

    NASA Technical Reports Server (NTRS)

    Noor, Ahmed K.; Whitworth, Sandra L.

    1987-01-01

    A simple computational procedure is presented for reducing the size of the analysis model for a symmetric structure with asymmetric boundary conditions to that of the corresponding structure with symmetric boundary conditions. The procedure is based on approximating the asymmetric response of the structure by a linear combination of symmetric and antisymmetric global approximation vectors (or modes). The key elements of the procedure are (1) restructuring the governing finite-element equations to delineate the contributions to the symmetric and antisymmetric components of the asymmetric response, (2) successive application of the finite element method and the classical Rayleigh-Ritz technique. The finite-element method is first used to generate a few global approximation vectors (or modes). Then the amplitudes of these modes are computed by using the Rayleigh-Ritz technique. The effectiveness of the computational procedure is demonstrated by means of numerical examples of linear static problems of shells, and its potential for solving nonlinear problems is discussed.

  16. Copper reverses cardiomyocyte hypertrophy through vascular endothelial growth factor-mediated reduction in the cell size.

    PubMed

    Zhou, Yang; Jiang, Youchun; Kang, Y James

    2008-07-01

    Previous studies have shown that dietary copper supplementation reversed heart hypertrophy induced by pressure overload in a mouse model. The present study was undertaken to understand the cellular basis of copper-induced regression of cardiac hypertrophy. Primary cultures of neonatal rat cardiomyocytes were treated with phenylephrine (PE) at a final concentration of 100 microM in cultures for 48 h to induce cellular hypertrophy. The hypertrophied cardiomyocytes were exposed to copper sulfate at a final concentration of 5 microM in cultures for additional 24 h. This copper treatment reduced the size of the hypertrophied cardiomyocytes, as measured by flow cytometry, protein content in cells, cell volume and cardiomyocyte hypertrophy markers including beta-myosin heavy chain protein, skeletal alpha-actin, and atrial natriuretic peptide. Cell cycle analysis and cell sorting of p-histone-3 labeled cardiomyocytes indicated that cell division was not involved in the copper-induced regression of cardiomyocyte hypertrophy. Copper also inhibited PE-induced apoptosis, determined by a TUNEL assay. Because copper stimulates vascular endothelial growth factor (VEGF) production through activation of hypoxia-inducible transcription factor, an anti-VEGF antibody at a final concentration of 2 ng/ml in cultures was used and shown to blunt copper-induced regression of cell hypertrophy. Conversely, VEGF alone at a final concentration of 0.2 microg/ml reversed cell hypertrophy as the same as copper did. This study demonstrates that both copper and VEGF reduce the size of hypertrophied cardiomyocytes, and copper regression of cardiac hypertrophy is VEGF-dependent. PMID:18495151

  17. Size-Dependent Enhancement of Electrocatalytic Oxygen-Reduction and Hydrogen-Evolution Performance of MoS2 Particles.

    PubMed

    Wang, Tanyuan; Gao, Dongliang; Zhuo, Junqiao; Zhu, Zhiwei; Papakonstantinou, Pagona; Li, Yan; Li, Meixian

    2013-09-01

    MoS2 particles with different size distributions were prepared by simple ultrasonication of bulk MoS2 followed by gradient centrifugation. Relative to the inert microscale MoS2, nanoscale MoS2 showed significantly improved catalytic activity toward the oxygen-reduction reaction (ORR) and hydrogen-evolution reaction (HER). The decrease in particle size was accompanied by an increase in catalytic activity. Particles with a size of around 2 nm exhibited the best dual ORR and HER performance with a four-electron ORR process and an HER onset potential of -0.16 V versus the standard hydrogen electrode (SHE). This is the first investigation on the size-dependent effect of the ORR activity of MoS2, and a four-electron transfer route was found. The exposed abundant Mo edges of the MoS2 nanoparticles were proven to be responsible for the high ORR catalytic activity, whereas the origin of the improved HER activity of the nanoparticles was attributed to the plentiful exposed S edges. This newly discovered process provides a simple protocol to produce inexpensive highly active MoS2 catalysts that could easily be scaled up. Hence, it opens up possibilities for wide applications of MoS2 nanoparticles in the fields of energy conversion and storage. PMID:23873743

  18. Waste minimization value engineering workshop for the Los Alamos National Laboratory Omega West Reactor Decommissioning Project

    SciTech Connect

    Hartnett, S.; Seguin, N.; Burns, M.

    1995-12-31

    The Los Alamos National Laboratory Pollution Prevention Program Office sponsored a Value Engineering (VE) Workshop to evaluate recycling options and other pollution prevention and waste minimization (PP/WMin) practices to incorporate into the decommissioning of the Omega West Reactor (OWR) at the laboratory. The VE process is an organized, systematic approach for evaluating a process or design to identify cost saving opportunities, or in this application, waste reduction opportunities. This VE Workshop was a facilitated process that included a team of specialists in the areas of decontamination, decommissioning, PP/WMin, cost estimating, construction, waste management, recycling, Department of Energy representatives, and others. The uniqueness of this VE Workshop was that it used an interdisciplinary approach to focus on PP/WMin practices that could be included in the OWR Decommissioning Project Plans and specifications to provide waste reduction. This report discusses the VE workshop objectives, summarizes the OWR decommissioning project, and describes the VE workshop activities, results, and lessons learned.

  19. The effect of drying and size reduction pretreatments on recovery of inorganic crop nutrients from inedible wheat residues

    NASA Technical Reports Server (NTRS)

    Strayer, R. F.; Alazraki, M. P.; Judkins, J.

    2003-01-01

    Inorganic nutrients can be easily recovered from ALS crop residue solid wastes by aqueous leaching. However, oven drying and milling pretreatment of these residues has been frequently required to accommodate crop scientists and facility storage limitations. As part of a research study that will compare three different bioreactor technologies for processing these wastes, we realized that different drying and size-reduction pretreatments had been utilized for each technology. This paper compares the effects of residue pretreatment on recovery of nutrients by leaching. Pretreatments included three drying methods [fresh, oven-dried (70 degrees C overnight), and freeze-dried] and two size reduction methods [chopped (2 cm length) and milled (2 mm diameter)]. Determination of mass balances (dry weight and ash content of solids) before and after leaching indicated solubilization was least for fresh residues (23% dry weight loss and 50% for ash loss), and most for freeze-dried residues (41-47% dry weight loss and nearly 100% for ash loss). Mineral recovery of major elements (NO3, PO4, K, Ca, and Mg) in leachates was poorest for fresh residues. P and K recovery in leachates were best for oven-dried residues and Ca, Mg, and N recovery best for freeze-dried residues. The differences in recovery for N, P, and K in leachates were minimal between chopping and milling and slightly better for Ca and Mg from milled residues.

  20. Evaluating the effect of a haemoglobin spray on size reduction in chronic DFUs: clinical outcomes at 12 weeks.

    PubMed

    Dawn Hunt, Sharon; Haycocks, Samantha; McCardle, Joanne; Guttormsen, Karl

    2016-06-23

    A recent multi-centre observational evaluation investigated the effect of a topical haemoglobin spray (Granulox, Infirst), used as an adjunct to standard care, on wound size reduction in 17 patients (4 females/13 males) with 20 chronic diabetic foot ulcers (DFUs) over a 4-week period. In 14 of the 18 wounds that completed the evaluation (one patient dropped out due to an infection) there was a mean reduction of 53.8% (range: 11.9-100%). The product was acceptable to both patients and clinicians, who all found it easy to use. This article describes the outcomes for the remaining 13 patients (with 15 wounds) who continued using the spray after the 4-week evaluation ended. (Data are not available for two patients and the one patient who healed during the 4-week evaluation.) By 12 weeks, three wounds (20%) had healed, eight (53%) were progressing towards healing, three (20%) increased in size and one (7%) was slow healing. PMID:27345086

  1. STM verification of the reduction of the Young's modulus of CdS nanoparticles at smaller sizes

    NASA Astrophysics Data System (ADS)

    Hazarika, A.; Peretz, E.; Dikovsky, V.; Santra, P. K.; Shneck, R. Z.; Sarma, D. D.; Manassen, Y.

    2014-12-01

    We demonstrate the first STM evaluation of the Young's modulus (E) of nanoparticles (NPs) of different sizes. The sample deformation induced by tip-sample interaction has been determined using current-distance (I-Z) spectroscopy. As a result of tip-sample interaction, and the induced surface deformations, the I-z curves deviates from pure exponential dependence. Normally, in order to analyze the deformation quantitatively, the tip radius must be known. We show, that this necessity is eliminated by measuring the deformation on a substrate with a known Young's modulus (Au(111)) and estimating the tip radius, and afterwards, using the same tip (with a known radius) to measure the (unknown) Young's modulus of another sample (nanoparticles of CdS). The Young's modulus values found for 3 NP's samples of average diameters of 3.7, 6 and 7.5 nm, were E ~ 73%, 78% and 88% of the bulk value, respectively. These results are in a good agreement with the theoretically predicted reduction of the Young's modulus due to the changes in hydrostatic stresses which resulted from surface tension in nanoparticles with different sizes. Our calculation using third order elastic constants gives a reduction of E which scales linearly with 1/r (r is the NP's radius). This demonstrates the applicability of scanning tunneling spectroscopy for local mechanical characterization of nanoobjects. The method does not include a direct measurement of the tip-sample force but is rather based on the study of the relative elastic response.

  2. 77 FR 41107 - Decommissioning Planning During Operations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-12

    ... Decommissioning Planning Rule (DPR) (June 17, 2011, 76 FR 33512). The DPR applies to the operational phase of a..., ``Decommissioning Planning During Operations'' (December 13, 2011, 76 FR 77431). The NRC received more than 100...; ] NUCLEAR REGULATORY COMMISSION 10 CFR Parts 20, 30, 40, 50, 70, and 72 Decommissioning Planning...

  3. Stabilization of Novel Narrow Gap Semiconductor Phases Through Size Reduction to the Nanoscale

    NASA Astrophysics Data System (ADS)

    Soriano, Ronald B.

    The work on this dissertation is aimed at (1) preparations of multinary narrow gap semiconductor nanoparticles using hot-injection technique, (2) stabilization of novel narrow gap semiconductor nanocrystal phases, (3) elucidate the resulting structure and investigate their properties, and (4) understand the thermodynamic stability of the prepared nanomaterials. The first colloidal synthetic route for the synthesis of amorphous GeTe NPs using an amido-germanium precursor was reported. Interestingly, the amorphous particles prepared at low temperature conditions exhibit a well-defined local structure related to that of high-pressure orthorhombic GeTe. Furthermore, the amorphous GeTe NPs display nearly spherical morphology, narrow size dispersity and undergo amorphous-to-crystalline phase transition at slightly elevated temperatures compared to the bulk material. Nearly all activity in nanoparticle science to date has focused on preparing nanocrystals of almost any known bulk phase to investigate size-dependent properties. An unexplored frontier in this field is stabilizing materials with compositions and structures in the nanoscale that do not exist in the bulk, representing an unprecedented approach with the potential to introduce entirely new nanomaterials. The synthesis of single phase semiconductor Pb 2-xSnxS2 nanocrystals with cubic rock salt structure (Fm m) in a composition range that exists in the bulk as an orthorhombic structure (0.6 < x < 1) was demonstrated. New ternary nanocrystals of Pb-Sb-Te with cubic rock-salt type structure, which are mixtures of PbTe and Sb2Te3 in the bulk was successfully prepared. Pbm Sb2n Tem+3n nanocrystals are single phases and tend to phase separate at moderately high temperature. The new Pbm Sb2n Tem+3n nanocrystals define a new class of nanomaterials that only exist on the nanoscale but are unstable in the bulk. This approach of stabilizing novel phases is extended to both Pb-Sb-Se and Pb-Sb-S systems. Novel Pbm Sb2n Sem+3n

  4. Reduction of Infarct Size by the Therapeutic Protein Tat-Ndi1 in vivo

    PubMed Central

    Mentzer, Robert M.; Wider, Joseph; Gottlieb, Roberta A.

    2015-01-01

    Lethal myocardial ischemia-reperfusion injury has been attributed in part to mitochondrial respiratory dysfunction (including damage to Complex I) and the resultant excessive production of reactive oxygen species. Recent evidence has shown that Ndi1 (the single-subunit protein that in yeast serves the analogous function as Complex I), transduced by addition of the TAT-conjugated protein to culture media and perfusion buffer, can preserve mitochondrial function and attenuate ischemia-reperfusion injury in neonatal rat cardiomyocytes and Langendorffperfused rat hearts. However, this novel metabolic strategy to salvage ischemic-reperfused myocardium has not been tested in vivo. In this study, TAT-conjugated Ndi1 and placebo control protein were synthesized using a cell-free system. Mitochondrial uptake and functionality of TAT-Ndi1 was demonstrated in mitochondrial preparations from rat hearts after intraperitoneal administration of the protein. Rats were randomized to receive either TAT-Ndi1 or placebo protein, and two hours later all animals underwent 45 min coronary artery occlusion followed by 2 hours of reperfusion. Infarct size was delineated by tetrazolium staining and normalized to the volume of at-risk myocardium, with all analysis conducted in a blinded manner. Risk region was comparable in the two cohorts. Pre-ischemic administration of TATNdi1 was profoundly cardioprotective. These results demonstrate that it is possible to target therapeutic proteins to the mitochondrial matrix, and that yeast Ndi1 can substitute for Complex I to ameliorate ischemia/reperfusion injury in the heart. Moreover, these data suggest that cell-permeable delivery of mitochondrial proteins may provide a novel molecular strategy to treat mitochondrial dysfunction in patients. PMID:24367006

  5. 76 FR 35511 - Decommissioning Planning

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-17

    ... regulations in 1997 as Subpart E of 10 CFR part 20 (62 FR 39058; July 21, 1997). This set of requirements is... the January 27, 1988 (53 FR 24018), rule on planning for decommissioning require licensees to provide... contamination and the amount of funds set aside and expended on cleanup. (62 FR 39082; July 21, 1997)....

  6. STATUS OF THE NRC'S DECOMMISSIONING PROGRAM

    SciTech Connect

    Orlando, D. A.; Camper, L. W.; Buckley, J.

    2002-02-25

    On July 21, 1997, the U.S. Nuclear Regulatory Commission published the final rule on Radiological Criteria for License Termination (the License Termination Rule) as Subpart E to 10 CFR Part 20. NRC regulations require that materials licensees submit Decommissioning Plans to support the decommissioning of its facility if it is required by license condition, or if the procedures and activities necessary to carry out the decommissioning have not been approved by NRC and these procedures could increase the potential health and safety impacts to the workers or the public. NRC regulations also require that reactor licensees submit Post-shutdown Decommissioning Activities Reports and License Termination Plans to support the decommissioning of nuclear power facilities. This paper provides an update on the status of the NRC's decommissioning program. It discusses the status of permanently shut-down commercial power reactors, complex decommissioning sites, and sites listed in the Site Decommissioning Management Plan. The paper provides the status of various tools and guidance the NRC is developing to assist licensees during decommissioning, including a Standard Review Plan for evaluating plans and information submitted by licensees to support the decommissioning of nuclear facilities and the D and D Screen software for determining the potential doses from residual radioactivity. Finally, it discusses the status of the staff's current efforts to streamline the decommissioning process.

  7. Background field removal technique using regularization enabled sophisticated harmonic artifact reduction for phase data with varying kernel sizes.

    PubMed

    Kan, Hirohito; Kasai, Harumasa; Arai, Nobuyuki; Kunitomo, Hiroshi; Hirose, Yasujiro; Shibamoto, Yuta

    2016-09-01

    An effective background field removal technique is desired for more accurate quantitative susceptibility mapping (QSM) prior to dipole inversion. The aim of this study was to evaluate the accuracy of regularization enabled sophisticated harmonic artifact reduction for phase data with varying spherical kernel sizes (REV-SHARP) method using a three-dimensional head phantom and human brain data. The proposed REV-SHARP method used the spherical mean value operation and Tikhonov regularization in the deconvolution process, with varying 2-14mm kernel sizes. The kernel sizes were gradually reduced, similar to the SHARP with varying spherical kernel (VSHARP) method. We determined the relative errors and relationships between the true local field and estimated local field in REV-SHARP, VSHARP, projection onto dipole fields (PDF), and regularization enabled SHARP (RESHARP). Human experiment was also conducted using REV-SHARP, VSHARP, PDF, and RESHARP. The relative errors in the numerical phantom study were 0.386, 0.448, 0.838, and 0.452 for REV-SHARP, VSHARP, PDF, and RESHARP. REV-SHARP result exhibited the highest correlation between the true local field and estimated local field. The linear regression slopes were 1.005, 1.124, 0.988, and 0.536 for REV-SHARP, VSHARP, PDF, and RESHARP in regions of interest on the three-dimensional head phantom. In human experiments, no obvious errors due to artifacts were present in REV-SHARP. The proposed REV-SHARP is a new method combined with variable spherical kernel size and Tikhonov regularization. This technique might make it possible to be more accurate backgroud field removal and help to achive better accuracy of QSM. PMID:27114339

  8. One-step synthesis of hollow porous gold nanoparticles with tunable particle size for the reduction of 4-nitrophenol.

    PubMed

    Guo, Mingzhen; He, Jiang; Li, Yan; Ma, Shuang; Sun, Xiaohan

    2016-06-01

    Hollow porous gold nanoparticles (HPGNPs) were synthesized via a one-step solution phase method at ambient temperature. The particle size, ranging from 80nm to 350nm, was easily controlled by changing the concentration of HAuCl4. The morphology and the structure of the as-prepared HPGNPs were investigated by SEM, TEM, HRTEM and XPS. Langmuir isotherm analysis yielded values of 8973m(2)/g for the outer surface area and 58724m(2)/g for the inner surface area for the 80nm HPGNPs. Due to a special hollow porous nanostructure, the HPGNPs exhibited superior catalytic activity and stability for the reduction of 4-nitrophenol (4-NP). No significant inactivation of the 80nm HPGNPs was observed, even after recycling for six cycles or storing for more than 1 month. Due to these excellent properties, it is expected that HPGNPs can be used in such applications as water pollutant removal and environmental remediation. PMID:26905608

  9. Application of Robotics in Decommissioning and Decontamination - 12536

    SciTech Connect

    Banford, Anthony; Kuo, Jeffrey A.; Bowen, R.A.; Szilagyi, Andrew; Kirk, Paula

    2012-07-01

    Decommissioning and dismantling of nuclear facilities is a significant challenge worldwide and one which is growing in size as more plants reach the end of their operational lives. The strategy chosen for individual projects varies from the hands-on approach with significant manual intervention using traditional demolition equipment at one extreme to bespoke highly engineered robotic solutions at the other. The degree of manual intervention is limited by the hazards and risks involved, and in some plants are unacceptable. Robotic remote engineering is often viewed as more expensive and less reliable than manual approaches, with significant lead times and capital expenditure. However, advances in robotics and automation in other industries offer potential benefits for future decommissioning activities, with the high probability of reducing worker exposure and other safety risks as well as reducing the schedule and costs required to complete these activities. Some nuclear decommissioning tasks and facility environments are so hazardous that they can only be accomplished by exclusive use of robotic and remote intervention. Less hazardous tasks can be accomplished by manual intervention and the use of PPE. However, PPE greatly decreases worker productivity and still exposes the worker to both risk and dose making remote operation preferable to achieve ALARP. Before remote operations can be widely accepted and deployed, there are some economic and technological challenges that must be addressed. These challenges will require long term investment commitments in order for technology to be: - Specifically developed for nuclear applications; - At a sufficient TRL for practical deployment; - Readily available as a COTS. Tremendous opportunities exist to reduce cost and schedule and improve safety in D and D activities through the use of robotic and/or tele-operated systems. - Increasing the level of remote intervention reduces the risk and dose to an operator. Better

  10. Structural and optical properties of SrS nanophosphors influenced by Ce3+ ions concentrations and particle size reduction

    NASA Astrophysics Data System (ADS)

    Mishra, Shubhra; Khare, Ayush; Kshatri, D. S.; Tiwari, Sanjay

    2015-10-01

    The SrS nanophosphors doped with different concentrations of Ce3+ are synthesized by solid state diffusion method (SSDM). Various characterization and spectral studies are reported in the light of varied dopant concentrations and reduction in particle size by milling. The as-obtained phosphors are characterized by means of X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM) including selected area electron diffraction (SAED) and energy dispersive X-ray spectroscopic (EDX) studies. The FESEM and HRTEM results explain the surface morphology, agglomeration of particles, crystallite size, etc. The results of XRD studies confirm the cubic structure of most intense SrS: Ce3+ nanophosphors and exhibit wider diffraction peaks for 4 h milled sample. The EDX profiles are used to authenticate the occurrence of different starting materials in final products. Upon excitation with UV light (375 nm), two emission peaks are observed at around 459 nm and 551 nm due to transitions of electrons from the 2T2g(5d) → 2F5/2(4f) and 2T2g(5d) → 2F7/2(4f) energy levels. The afterglow decay behavior of different SrS: Ce3+ nanophosphors is presented and discussed systematically.

  11. The Impact of a Universal Class-Size Reduction Policy: Evidence from Florida's Statewide Mandate. Program on Education Policy and Governance Working Papers Series. PEPG 10-03

    ERIC Educational Resources Information Center

    Chingos, Matthew M.

    2010-01-01

    Class-size reduction (CSR) mandates presuppose that resources provided to reduce class size will have a larger impact on student outcomes than resources that districts can spend as they see fit. I estimate the impact of Florida's statewide CSR policy by comparing the deviations from prior achievement trends in districts that were required to…

  12. Effects of Extent of Chlorination, Extraction Rate, and Particle Size Reduction on Flour and Gluten Functionality Explored by Solvent Retention Capacity (SRC) and Mixograph

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chlorination is an essential soft wheat flour treatment for production of high-ratio cakes in the USA, frequently coupled with a post-milling treatment to reduce flour particle size. The effects of extent of chlorination, extraction rate, and particle size reduction on flour and gluten functionalit...

  13. Enhanced reductive dechlorination of tetrachloroethene by nano-sized mackinawite with cyanocobalamin in a highly alkaline condition.

    PubMed

    Kim, Sangwoo; Park, Taehyung; Lee, Woojin

    2015-03-15

    In this study, we characterize the reductive dechlorination of tetrachloroethene (PCE) by nano-sized mackinawite (nFeS) with cobalamin (Cbl(III)) at a high pH and investigate the effects of environmental factors, including the concentrations of the target contaminant, reductant, and catalyst and suspension ions on the dechlorination kinetics of PCE. Ninety five percent of the PCE was degraded by nFeS with Cbl(III) in 15 h. Cyclic voltammetry conducted with regard to the reductive dechlorination showed a higher redox potential of mackinawite under a high-pH condition (-1.01 V), suggesting that the oxidation state of the central cobalt ion in the cobalamin could be reduced to Cbl(I). The change of cobalamin species on the nFeS surface was verified under different pH conditions by UV-vis spectroscopy. The rate constant of PCE dechlorination increased from 0.1582 to 0.4284 h(-1) due to the increase in the nFeS content (2.085-20.85 g/L). As the concentration of Cbl(III) increased from 0 to 0.5 mM, the dechlorination kinetics of PCE was accelerated (0-1.4091 h(-1)) but reached a state of equilibrium from 0.5 to 1 mM. The increase in the initial PCE concentration (0.035-1.0 mM) slowed down the dechlorination kinetics (0.2036-0.0962 h(-1)). The dechlorination kinetics was enhanced by 1.5-11 times when 10 mM of ions (Na(+), K(+), Mg(2+), Ca(2+), CO3(2-), SO4(2-), and NO3(-)) were added, while an addition of HCO3 decelerated it by 10 times. This study can provide background knowledge pertaining to the PCE dechlorination by a natural reductant under a high-pH condition and the effect of environmental factors on the dechlorination kinetics for the development of novel remediation technologies. PMID:25590608

  14. Nano-sized Minerals of Elemental Selenium and Tellurium Formed by Bacterial Dissimilatory Reduction of Se- and Te-Oxyanions.

    NASA Astrophysics Data System (ADS)

    Oremland, R. S.

    2007-12-01

    Selenium and tellurium are both Group 16 elements that have curious opto-electrical properties making them of potential interest for photovoltaic applications. The process of dissimilatory reduction of selenate and selenite by 3 diverse species of anaerobes, Bacillus selenitireducens, Sulfurospirillum barnesii, and Selenihalanaerobacter shriftii resulted in the accumulation of many uniformly-sized nanospheres (diameter = approx. 300 nm) that aggregated on the outside of their cell envelopes (Oremland et al., 2004). Despite their uniformity of shape, purified Se-nanospheres from the 3 different species displayed significantly different spectral properties (UV- visible light and Raman) indicating differing internal arrangements of their Se atoms. Se-nanospheres from all 3 species also had lower bandgap energies than that of elemental selenium formed by chemical means. We subsequently determined that S. barnesii and B. selenitireducens could grow by dissimilatory reduction of Te- oxyanions, although progress was hampered by the fact that Te concentrations above 0.6 mM proved toxic to cells (Baesman et al., 2007). Unlike the case for Se-nanospheres, the Te-nanoparticles formed by the two microbes were entirely different. S. barnesii formed small, irregularly shaped spheroids (smaller than 50 nm diameter) that coalesced into larger aggregates. In contrast, B. selenitreducens formed nano-rods (10 nm diameter x 200 nm length) that coalesced into larger shards which formed even larger rosette-shaped aggregates once they sloughed off the cells. Spectroscopy of purified Te-rosettes indicated an internal trigonally-shaped array of Te atoms. Future research on Te(0) nano-materials formed by anaerobic bacteria would be aided by isolation of novel species adapted to growth at high batch culture concentrations of Te-oxyanions (approx. 10 mM). Furthermore, the ability of microbes like B. selenitreducens to form selenide by reduction of Se(0) suggests an application in the

  15. Decontamination, decommissioning, and vendor advertorial issue, 2005

    SciTech Connect

    Agnihotri, Newal

    2005-07-15

    The focus of the July-August issue is on Decontamination, decommissioning, and vendor advertorials. Major interviews, articles and reports in this issue include: Increasing momentum, by Gary Taylor, Entergy Nuclear, Inc.; An acceptable investment, by Tom Chrisopher, Areva, Inc.; Fuel recycling for the U.S. and abroad, by Philippe Knoche, Areva, France; We're bullish on nuclear power, by Dan R. Keuter, Entergy Nuclear, Inc.; Ten key actions for decommissioning, by Lawrence E. Boing, Argonne National Laboratory; Safe, efficient and cost-effective decommissioning, by Dr. Claudio Pescatore and Torsten Eng, OECD Nuclear Energy Agency (NEA), France; and, Plant profile: SONGS decommissioning.

  16. Unveiling the Metabolic Pathways Associated with the Adaptive Reduction of Cell Size During Vibrio harveyi Persistence in Seawater Microcosms.

    PubMed

    Kaberdin, Vladimir R; Montánchez, Itxaso; Parada, Claudia; Orruño, Maite; Arana, Inés; Barcina, Isabel

    2015-10-01

    Owing to their ubiquitous presence and ability to act as primary or opportunistic pathogens, Vibrio species greatly contribute to the diversity and evolution of marine ecosystems. This study was aimed at unveiling the cellular strategies enabling the marine gammaproteobacterium Vibrio harveyi to adapt and persist in natural aquatic systems. We found that, although V. harveyi incubation in seawater microcosm at 20 °C for 2 weeks did not change cell viability and culturability, it led to a progressive reduction in the average cell size. Microarray analysis revealed that this morphological change was accompanied by a profound decrease in gene expression affecting the central carbon metabolism, major biosynthetic pathways, and energy production. In contrast, V. harveyi elevated expression of genes closely linked to the composition and function of cell envelope. In addition to triggering lipid degradation via the β-oxidation pathway and apparently promoting the use of endogenous fatty acids as a major energy and carbon source, V. harveyi upregulated genes involved in ancillary mechanisms important for sustaining iron homeostasis, cell resistance to the toxic effect of reactive oxygen species, and recycling of amino acids. The above adaptation mechanisms and morphological changes appear to represent the major hallmarks of the initial V. harveyi response to starvation. PMID:25903990

  17. Size of donor chromosome segments around introgressed loci and reduction of linkage drag in marker-assisted backcross programs.

    PubMed Central

    Hospital, F

    2001-01-01

    This article investigates the efficiency of marker-assisted selection in reducing the length of the donor chromosome segment retained around a locus held heterozygous by backcrossing. First, the efficiency of marker-assisted selection is evaluated from the length of the donor segment in backcrossed individuals that are (double) recombinants for two markers flanking the introgressed gene on each side. Analytical expressions for the probability density function, the mean, and the variance of this length are given for any number of backcross generations, as well as numerical applications. For a given marker distance, the number of backcross generations performed has little impact on the reduction of donor segment length, except for distant markers. In practical situations, the most important parameter is the distance between the introgressed gene and the flanking markers, which should be chosen to be as closely linked as possible to the introgressed gene. Second, the minimal population sizes required to obtain double recombinants for such closely linked markers are computed and optimized in the context of a multigeneration backcross program. The results indicate that it is generally more profitable to allow for three or more successive backcross generations rather than to favor recombinations in early generations. PMID:11454782

  18. STANDARD OPERATING PROTOCOLS FOR DECOMMISSIONING

    SciTech Connect

    Foss, D. L.; Stevens, J. L.; Gerdeman, F. W.

    2002-02-25

    Decommissioning projects at Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) sites are conducted under project-specific decision documents, which involve extensive preparation time, public comment periods, and regulatory approvals. Often, the decision documents must be initiated at least one year before commencing the decommissioning project, and they are expensive and time consuming to prepare. The Rocky Flats Environmental Technology Site (RFETS) is a former nuclear weapons production plant at which hazardous substances and wastes were released or disposed during operations. As a result of the releases, RFETS was placed on the National Priorities List in 1989, and is conducting cleanup activities under a federal facilities compliance agreement. Working closely with interested stakeholders and state and federal regulatory agencies, RFETS has developed and implemented an improved process for obtaining the approvals. The key to streamlining the approval process has been the development of sitewide decision documents called Rocky Flats Cleanup Agreement Standard Operating Protocols or ''RSOPs.'' RSOPs have broad applicability, and could be used instead of project-specific documents. Although no two decommissioning projects are exactly the same and they may vary widely in contamination and other hazards, the basic steps taken for cleanup are usually similar. Because of this, using RSOPs is more efficient than preparing a separate project-specific decision documents for each cleanup action. Over the Rocky Flats cleanup life cycle, using RSOPs has the potential to: (1) Save over 5 million dollars and 6 months on the site closure schedule; (2) Eliminate preparing one hundred and twenty project-specific decision documents; and (3) Eliminate writing seventy-five closure description documents for hazardous waste unit closure and corrective actions.

  19. Rancho Seco--Decommissioning Update

    SciTech Connect

    Newey, J. M.; Ronningen, E. T.; Snyder, M. W.

    2003-02-26

    The Rancho Seco Nuclear Generating Station ceased operation in June of 1989 and entered an extended period of SAFSTOR to allow funds to accumulate for dismantlement. Incremental dismantlement was begun in 1997 of steam systems and based on the successful completion of work, the Sacramento Municipal Utility District (SMUD) board of directors approved full decommissioning in July 1999. A schedule has been developed for completion of decommissioning by 2008, allowing decommissioning funds to accumulate until they are needed. Systems removal began in the Auxiliary Building in October of 1999 and in the Reactor Building in January of 2000. Systems dismantlement continues in the Reactor Building and should be completed by the end of 2003. System removal is near completion in the Auxiliary Building with removal of the final liquid waste tanks in progress. The spent fuel has been moved to dry storage in an onsite ISFSI, with completion on August 21, 2002. The spent fuel racks are currently being removed from the pool, packaged and shipped, and then the pool will be cleaned. Also in the last year the reactor coolant pumps and primary piping were removed and shipped. Characterization and planning work for the reactor vessel and internals is also in progress with various cut-up and/or disposal options being evaluated. In the year ahead the remaining systems in the Reactor Building will be removed, packaged and sent for disposal, including the pressurizer. Work will be started on embedded and underground piping and the large outdoor tanks. Building survey and decontamination will begin. RFP's for removal of the vessel and internals and the steam generators are planned to fix the cost of those components. If the costs are consistent with current estimates the work will go forward. If they are not, hardened SAFSTOR/entombment may be considered.

  20. 76 FR 3837 - Nuclear Decommissioning Funds; Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-21

    ... 23, 2010 (75 FR 80697) relating to deductions for contributions to trusts maintained for decommissioning nuclear power plants. DATES: This correction is effective on January 21, 2011, and is applicable... Internal Revenue Service 26 CFR Part 1 RIN 1545-BF08 Nuclear Decommissioning Funds; Correction...

  1. Radiochemistry Lab Decommissioning and Dismantlement. AECL, Chalk River Labs, Ontario, Canada

    SciTech Connect

    Kenny, Stephen

    2008-01-15

    Atomic Energy of Canada (AECL) was originally founded in the mid 1940's to perform research in radiation and nuclear areas under the Canadian Defense Department. In the mid 50's The Canadian government embarked on several research and development programs for the development of the Candu Reactor. AECL was initially built as a temporary site and is now faced with many redundant buildings. Prior to 2004 small amounts of Decommissioning work was in progress. Many reasons for deferring decommissioning activities were used with the predominant ones being: 1. Reduction in radiation doses to workers during the final dismantlement, 2. Development of a long-term solution for the management of radioactive wastes in Canada, 3. Financial constraints presented by the number of facilities shutdown that would require decommissioning funds and the absence of an approved funding strategy. This has led to the development of a comprehensive decommissioning plan that is all inclusive of AECL's current and legacy liabilities. Canada does not have a long-term disposal site; therefore waste minimization becomes the driving factor behind decontamination for decommissioning before and during dismantlement. This decommissioning job was a great learning experience for decommissioning and the associated contractors who worked on this project. Throughout the life of the project there was a constant focus on waste minimization. This focus was constantly in conflict with regulatory compliance primarily with respect to fire regulations and protecting the facility along with adjacent facilities during the decommissioning activities. Discrepancies in historical documents forced the project to treat every space as a contaminated space until proven differently. Decommissioning and dismantlement within an operating site adds to the complexity of the tasks especially when it is being conducted in the heart of the plant. This project was very successful with no lost time accidents in over one hundred

  2. Grain size reduction of feldspar and pyroxene, phase mixing, and strain localization in lower crustal shear zones (Lofoten, Norway)

    NASA Astrophysics Data System (ADS)

    Menegon, L.; Stunitz, H.; Nasipuri, P.; Svahnberg, H.; Heilbronner, R.

    2011-12-01

    compositional domains are indistinguishable and the degree of phase mixing is higher. Fractured fragments of mesoperthite are not preserved, the grain size of plagioclase, K-feldspar and quartz is further reduced compared to the mylonite (20 μm Vs. 25-30 μm), and the main constituent phases do not show a CPO. Diffusion creep is interpreted to be the dominant deformation mechanism. In summary, shear zone formation is invariably associated with a preliminary stage of cracking and fluid infiltration, which triggers syndeformational metamorphic reactions, strong grain size reduction, and activation of diffusion creep. Initial cracking at the estimated deformation conditions requires high differential stresses (in the absence of high pore pressures), and indicates a high strength of the lower continental crust at the onset of the deformation. A strain-dependent transition from dislocation creep to diffusion creep is not observed, and diffusion creep appears to be the dominant deformation mechanism in all compositional domains from the mylonite to ultramylonite stage.

  3. Correction: Decrease in thermal conductivity in polymeric P3HT nanowires by size-reduction induced by crystal orientation: new approaches towards thermal transport engineering of organic materials.

    PubMed

    Muñoz Rojo, Miguel; Martín, Jaime; Grauby, Stéphane; Borca-Tasciuc, Theodorian; Dilhaire, Stefan; Martin-Gonzalez, Marisol

    2015-03-01

    Correction for 'Decrease in thermal conductivity in polymeric P3HT nanowires by size-reduction induced by crystal orientation: new approaches towards thermal transport engineering of organic materials' by Miguel Muñoz Rojo et al., Nanoscale, 2014, 6, 7858-7865. PMID:25668105

  4. Class Size.

    ERIC Educational Resources Information Center

    Johnston, Holly R.

    Exploring the class-size issue, this paper focuses on the primary grades and asks questions such as "does a reduction in class size promote an increase in academic achievement?" and "how substantial does the reduction in numbers have to be in order for a significant increase to occur?" The paper surveys debates on class size and the social factors…

  5. Do Reductions in Class Size Raise Students' Test Scores? Evidence from Population Variation in Minnesota's Elementary Schools

    ERIC Educational Resources Information Center

    Cho, Hyunkuk; Glewwe, Paul; Whitler, Melissa

    2012-01-01

    Many U.S. states and cities spend substantial funds to reduce class size, especially in elementary (primary) school. Estimating the impact of class size on learning is complicated, since children in small and large classes differ in many observed and unobserved ways. This paper uses a method of Hoxby (2000) to assess the impact of class size on…

  6. FACILITY DEACTIVATION AND DECOMMISSIONING AT THE SAVANNAH RIVER SITE

    SciTech Connect

    Gilmour, J; William Austin, W; Cathy Sizemore, C

    2007-01-31

    In February 2002, the U.S. Department of Energy initiated actions to expedite Cleanup, focus on significant and early risk reduction, and reduce costs at the Savannah River Site (SRS). In response SRS started on a project focused on completing the decommissioning of inactive facilities in T, D, and M Areas, areas that on the perimeter of the Site, by the end of 2006. In June 2003, the Department of Energy Savannah River Operations Office (DOE-SR), the South Carolina Department of Health and Environmental Control (SCDHEC), and the Environmental Protection Agency, Region 4 (EPA-4) endorsed a Memorandum of Agreement (MOA) concerning cleanup at the Savannah River Site (SRS). The vision of the Agreement is that SRS will reduce its operations footprint to establish a buffer zone at the perimeter if the Site, while the central core area of the Site will be reserved for continuing or future long-term operations. DOE-SR, EPA-4, and SCDHEC agreed that establishing this buffer zone and appropriately sequencing environmental restoration and decommissioning activities can lead to greater efficiency and accelerate completion of entire site areas. This vision is embodied in the concept of Area Completion--which integrated operations, deactivation and decommissioning (D&D), and soils and groundwater cleanup into a time-phased approach to completing all the work necessary to address the Cold War legacy. D&D addresses the ''footprint'' of the building or structure, while the soils and groundwater project addresses any environmental remediation that may be required in the underlying and surrounding soils and groundwater. Since then, {approx}250 facilities have been decommissioned at the SRS, ranging from guard stations to nuclear fuel production facilities.

  7. Decontamination and decommissioning of the Chemical Process Cell (CPC): Topical report for the period January 1985-March 1987

    SciTech Connect

    Meigs, R. A.

    1987-07-01

    To support interim storage of vitrified High-Level Waste (HLW) at the West Valley Demonstration Project, the shielded, remotely operated Chemical Process Cell (CPC) was decommissioned and decontaminated. All equipment was removed, packaged and stored for future size reduction and decontamination. Floor debris was sampled, characterized, and vacuumed into remotely handled containers. The cell walls, ceiling, and floor were decontaminated. Three 20 Mg (22.5 ton) concrete neutron absorber cores were cut with a high-pressure water/abrasive jet cutting system and packaged for disposal. All operations were performed remotely using two overhead bridge cranes which included two 1.8 Mg (2 ton) hoists, one 14.5 Mg (16 ton) hoist, and an electromechanical manipulator or an industrial robot mounted on a mobile platform. Initial general area dose rates in the cell ranged from 1 to 50 R/h. Target levels of less than 10 mR/h general area readings were established before decontamination and decommissioning was initiated; general area dose rates between 200 mR/h and 1200 mR/h were obtained at the completion of the decontamination work. 4 refs., 11 figs., 8 tabs.

  8. Particle-size effect of nanoscale platinum catalysts in oxygen reduction reaction: an electrochemical and 195Pt EC-NMR study.

    PubMed

    Yano, Hiroshi; Inukai, Junji; Uchida, Hiroyuki; Watanabe, Masahiro; Babu, Panakkattu K; Kobayashi, Takeshi; Chung, Jong Ho; Oldfield, Eric; Wieckowski, Andrzej

    2006-11-14

    Oxygen reduction reaction (ORR) measurements and (195)Pt electrochemical nuclear magnetic resonance (EC-NMR) spectroscopy were combined to study a series of carbon-supported platinum nanoparticle electrocatalysts (Pt/CB) with average diameters in the range of roughly 1-5 nm. ORR rate constants and H(2)O(2) yields evaluated from hydrodynamic voltammograms did not show any particle size dependency. The apparent activation energy of 37 kJ mol(-1), obtained for the ORR rate constant, was identical to that obtained for bulk platinum electrodes. Pt/CB catalysts on Nafion produced only 0.7-1% of H(2)O(2), confirming that the direct four-electron reduction of O(2) to H(2)O is the predominant reaction. NMR spectral features showed characteristic size dependence, and the line shapes were reproduced by using the layer-deconvolution model. Namely, the variations in the NMR spectra with particle size can be explained as due to the combined effect of the layer-by-layer variation of the s-type and d-type local density of states. However, the surface peak position of (195)Pt NMR spectra and the spin-lattice relaxation time of surface platinum atoms showed practically no change with the particle size variation. We conclude that there is a negligible difference in the surface electronic properties of these Pt/CB catalysts due to size variations and therefore, the ORR activities are not affected by the differences in the particle size. PMID:17066184

  9. Dental size reduction in Indonesian Homo erectus: Implications for the PU-198 premolar and the appearance of Homo sapiens on Java.

    PubMed

    Polanski, Joshua M; Marsh, Hannah E; Maddux, Scott D

    2016-01-01

    The recent recovery of a hominin maxillary third premolar, PU-198, within the faunal collections from Punung Cave (East Java) has led to assertions that Homo sapiens appeared on Java between 143,000 and 115,000 years ago. The taxonomic assignment of PU-198 to H. sapiens was based predominantly on the small size of the specimen, following an analysis which found little to no overlap in premolar size between Homo erectus and terminal Pleistocene/Holocene H. sapiens. Here, we re-evaluate the use of size in the taxonomic assignment of PU-198 in light of 1) new buccolingual and mesiodistal measurements taken on the fossil, 2) comparisons to a larger sample of H. erectus and H. sapiens maxillary third premolars, and 3) evidence of a diachronic trend in post-canine dental size reduction among Javan H. erectus. Our results demonstrate PU-198 to be slightly larger than previously suggested, reveal substantial overlap in premolar size between H. erectus and H. sapiens, and indicate a statistically significant reduction in premolar size between early and late Javan H. erectus. Our findings cast doubt on the assignment of PU-198 to H. sapiens, and accordingly, question the appearance of H. sapiens on Java between 143,000 and 115,000 years ago. PMID:26767959

  10. Controlling the pulsed-laser-induced size reduction of Au and Ag nanoparticles via changes in the external pressure, laser intensity, and excitation wavelength.

    PubMed

    Werner, Daniel; Hashimoto, Shuichi

    2013-01-29

    The laser-induced size reduction of aqueous noble metal nanoparticles has been the subject of intensive research, because of the mechanistic interest in the light-nanoparticle interactions and its potential application to size control. The photothermal evaporation hypothesis has gained solid support. However, the polydispersity of the final products is considered as an inherent drawback of the method. It is likely that the polydispersity arises from the uncontrolled heat dissipation caused by vapor bubble formation in the ambient atmosphere. To overcome this problem, we applied high pressures of 30-100 MPa. The particle size was regulated by adjusting three parameters: the pressure, laser intensity, and excitation wavelength. For example, starting from a colloidal solution of 100 nm diameter gold nanoparticles, highly monodisperse (±3-5%) spheres with various diameters ranging from 90 to 30 nm were fabricated by tuning the laser intensity at 100 MPa, using an excitation wavelength of 532 nm. Further size reduction of the diameter to 20 nm was achieved by reducing the pressure and switching the excitation wavelength to 355 nm. It was found that the application of high pressures led to the heat loss-controlled size-reduction of the gold nanoparticles. More complicated results were obtained for 100 nm silver nanoparticles, possibly because of the different size-dependent light-absorbing nature of these particles. Based on our extensive experimental studies, a detailed picture was developed for the nanosecond laser-induced fabrication of gold and silver nanoparticles, leading to unprecedented size control. PMID:23259708

  11. The Role of Granule Size on the Kinetics of Electrochemical Reduction of SiO2 Granules in Molten CaCl2

    NASA Astrophysics Data System (ADS)

    Yang, Xiao; Yasuda, Kouji; Nohira, Toshiyuki; Hagiwara, Rika; Homma, Takayuki

    2016-02-01

    As a fundamental study to develop a new process for producing solar-grade silicon, the effect of granule size on the kinetics of the electrochemical reduction of SiO2 granules in molten CaCl2 was investigated. SiO2 granules with different size ranges were electrolyzed in molten CaCl2 at 1123 K (850 °C). The reduction kinetics was evaluated on the basis of the growth rate of the reduced Si layer and the behavior of the current during electrolysis. The results indicated that finer SiO2 granules are more favorable for a high reduction rate because the contact resistance between the bottom Si plate and the reduced Si particles is small and the diffusion of O2- ions in CaCl2 inside the porous Si shell is easy. Electrolysis using SiO2 granules less than 0.1 mm in size maintained a current density of no less than 0.4 A cm-2 within 20 minutes, indicating that the electrochemical reduction of fine SiO2 granules in molten CaCl2 has the potential of becoming a high-yield production process for solar-grade silicon.

  12. Pipeline Decommissioning Trial AWE Berkshire UK - 13619

    SciTech Connect

    Agnew, Kieran

    2013-07-01

    This Paper details the implementation of a 'Decommissioning Trial' to assess the feasibility of decommissioning the redundant pipeline operated by AWE located in Berkshire UK. The paper also presents the tool box of decommissioning techniques that were developed during the decommissioning trial. Constructed in the 1950's and operated until 2005, AWE used a pipeline for the authorised discharge of treated effluent. Now redundant, the pipeline is under a care and surveillance regime awaiting decommissioning. The pipeline is some 18.5 km in length and extends from AWE site to the River Thames. Along its route the pipeline passes along and under several major roads, railway lines and rivers as well as travelling through woodland, agricultural land and residential areas. Currently under care and surveillance AWE is considering a number of options for decommissioning the pipeline. One option is to remove the pipeline. In order to assist option evaluation and assess the feasibility of removing the pipeline a decommissioning trial was undertaken and sections of the pipeline were removed within the AWE site. The objectives of the decommissioning trial were to: - Demonstrate to stakeholders that the pipeline can be removed safely, securely and cleanly - Develop a 'tool box' of methods that could be deployed to remove the pipeline - Replicate the conditions and environments encountered along the route of the pipeline The onsite trial was also designed to replicate the physical prevailing conditions and constraints encountered along the remainder of its route i.e. working along a narrow corridor, working in close proximity to roads, working in proximity to above ground and underground services (e.g. Gas, Water, Electricity). By undertaking the decommissioning trial AWE have successfully demonstrated the pipeline can be decommissioned in a safe, secure and clean manor and have developed a tool box of decommissioning techniques. The tool box of includes; - Hot tapping - a method

  13. Modelling of nuclear power plant decommissioning financing.

    PubMed

    Bemš, J; Knápek, J; Králík, T; Hejhal, M; Kubančák, J; Vašíček, J

    2015-06-01

    Costs related to the decommissioning of nuclear power plants create a significant financial burden for nuclear power plant operators. This article discusses the various methodologies employed by selected European countries for financing of the liabilities related to the nuclear power plant decommissioning. The article also presents methodology of allocation of future decommissioning costs to the running costs of nuclear power plant in the form of fee imposed on each megawatt hour generated. The application of the methodology is presented in the form of a case study on a new nuclear power plant with installed capacity 1000 MW. PMID:25979740

  14. Effective reduction in the nanoparticle sizes of NiO obtained via the pyrolysis of nickel malonate precursor modified using oleylamine surfactant

    NASA Astrophysics Data System (ADS)

    Lontio Fomekong, Roussin; Ngolui Lambi, John; Ebede, Guy Roland; Kenfack Tsobnang, Patrice; Tedjieukeng Kamta, Hypolite Mathias; Ngnintedem Yonti, Cedrik; Delcorte, Arnaud

    2016-09-01

    Nickel oxide nanoparticles were synthesized via thermal decomposition of two precursors, the first, a simple nickel malonate and the second, a nickel malonate modified by oleylamine, a surfactant, both having been synthesized by precipitation. While FTIR, TGA and ToF-SIMS were used to characterize the two precursors and to show the presence of oleylamine in the modified precursor, XRD, SEM, TEM and BET were employed to investigate the structure, the morphology and the specific surface area of the decomposition products obtained after pyrolysis. The results showed that the modification of nickel malonate by oleylamine was effective. The XRD results, which showed a cubic structure for the NiO obtained, suggest with SEM an important particle size reduction (at least 54%) when oleylamine was used to modify the nickel malonate precursor. The SEM images also showed a well-defined spherical nanoparticle morphology in both cases, not affected by the presence of oleylamine. The TEM also confirmed the reduction of particle size and their spherical nature but at the same time showed that, in the presence of oleylamine, there was no agglomeration resulting in a more uniform particle size distribution. The specific surface area of the NiO obtained by the oleylamine-modified precursor was 4.7 times larger than that obtained with the regular precursor. This again confirms the particle size reduction.

  15. Effects of spot size and spot spacing on lateral penumbra reduction when using a dynamic collimation system for spot scanning proton therapy

    NASA Astrophysics Data System (ADS)

    Hyer, Daniel E.; Hill, Patrick M.; Wang, Dongxu; Smith, Blake R.; Flynn, Ryan T.

    2014-11-01

    The purpose of this work was to investigate the reduction in lateral dose penumbra that can be achieved when using a dynamic collimation system (DCS) for spot scanning proton therapy as a function of two beam parameters: spot size and spot spacing. This is an important investigation as both values impact the achievable dose distribution and a wide range of values currently exist depending on delivery hardware. Treatment plans were created both with and without the DCS for in-air spot sizes (σair) of 3, 5, 7, and 9 mm as well as spot spacing intervals of 2, 4, 6 and 8 mm. Compared to un-collimated treatment plans, the plans created with the DCS yielded a reduction in the mean dose to normal tissue surrounding the target of 26.2-40.6% for spot sizes of 3-9 mm, respectively. Increasing the spot spacing resulted in a decrease in the time penalty associated with using the DCS that was approximately proportional to the reduction in the number of rows in the raster delivery pattern. We conclude that dose distributions achievable when using the DCS are comparable to those only attainable with much smaller initial spot sizes, suggesting that the goal of improving high dose conformity may be achieved by either utilizing a DCS or by improving beam line optics.

  16. Effects of spot size and spot spacing on lateral penumbra reduction when using a dynamic collimation system for spot scanning proton therapy.

    PubMed

    Hyer, Daniel E; Hill, Patrick M; Wang, Dongxu; Smith, Blake R; Flynn, Ryan T

    2014-11-21

    The purpose of this work was to investigate the reduction in lateral dose penumbra that can be achieved when using a dynamic collimation system (DCS) for spot scanning proton therapy as a function of two beam parameters: spot size and spot spacing. This is an important investigation as both values impact the achievable dose distribution and a wide range of values currently exist depending on delivery hardware. Treatment plans were created both with and without the DCS for in-air spot sizes (σair) of 3, 5, 7, and 9 mm as well as spot spacing intervals of 2, 4, 6 and 8 mm. Compared to un-collimated treatment plans, the plans created with the DCS yielded a reduction in the mean dose to normal tissue surrounding the target of 26.2-40.6% for spot sizes of 3-9 mm, respectively. Increasing the spot spacing resulted in a decrease in the time penalty associated with using the DCS that was approximately proportional to the reduction in the number of rows in the raster delivery pattern. We conclude that dose distributions achievable when using the DCS are comparable to those only attainable with much smaller initial spot sizes, suggesting that the goal of improving high dose conformity may be achieved by either utilizing a DCS or by improving beam line optics. PMID:25330783

  17. Sellafield Decommissioning Programme - Update and Lessons Learned

    SciTech Connect

    Lutwyche, P. R.; Challinor, S. F.

    2003-02-24

    The Sellafield site in North West England has over 240 active facilities covering the full nuclear cycle from fuel manufacture through generation, reprocessing and waste treatment. The Sellafield decommissioning programme was formally initiated in the mid 1980s though several plants had been decommissioned prior to this primarily to create space for other plants. Since the initiation of the programme 7 plants have been completely decommissioned, significant progress has been made in a further 16 and a total of 56 major project phases have been completed. This programme update will explain the decommissioning arrangements and strategies and illustrate the progress made on a number of the plants including the Windscale Pile Chimneys, the first reprocessing plan and plutonium plants. These present a range of different challenges and requiring approaches from fully hands on to fully remote. Some of the key lessons learned will be highlighted.

  18. Trip report: European Communities 1989 International Conference on Decommissioning of Nuclear Installations, Brussels, Belgium, October 24-27, 1989

    SciTech Connect

    Rankin, W.N.

    1989-01-01

    The European community is conducting research on the decommissioning of nuclear installations. The prime objective is to develop effective techniques to ensure the protection of man and his environment against the potential hazards of nuclear installations that have been shut down. The results of the 1979--1983 research program were presented in a conference held in Luxembourg. This program was primarily concerned with decommissioning nuclear power plants. The 1984--1988 program was extended to all types of nuclear installations. Fuel fabrication, enrichment and reprocessing plants, and research and development facilities having fulfilled their useful purposes are also awaiting decommissioning. This Program has produced numerous scientific and technical achievements. Great progress has in particular been achieved in the reduction of metal waste arising from decommissioning, due to advances in areas such as the development of aggressive decontamination procedures and of techniques for melting and recycling low-level radioactive waste metal.

  19. Safety of Decommissioning of Nuclear Facilities

    SciTech Connect

    Batandjieva, B.; Warnecke, E.; Coates, R.

    2008-01-15

    Full text of publication follows: ensuring safety during all stages of facility life cycle is a widely recognised responsibility of the operators, implemented under the supervision of the regulatory body and other competent authorities. As the majority of the facilities worldwide are still in operation or shutdown, there is no substantial experience in decommissioning and evaluation of safety during decommissioning in majority of Member States. The need for cooperation and exchange of experience and good practices on ensuring and evaluating safety of decommissioning was one of the outcomes of the Berlin conference in 2002. On this basis during the last three years IAEA initiated a number of international projects that can assist countries, in particular small countries with limited resources. The main IAEA international projects addressing safety during decommissioning are: (i) DeSa Project on Evaluation and Demonstration of Safety during Decommissioning; (ii) R{sup 2}D{sup 2}P project on Research Reactors Decommissioning Demonstration Project; and (iii) Project on Evaluation and Decommissioning of Former Facilities that used Radioactive Material in Iraq. This paper focuses on the DeSa Project activities on (i) development of a harmonised methodology for safety assessment for decommissioning; (ii) development of a procedure for review of safety assessments; (iii) development of recommendations on application of the graded approach to the performance and review of safety assessments; and (iv) application of the methodology and procedure to the selected real facilities with different complexities and hazard potentials (a nuclear power plant, a research reactor and a nuclear laboratory). The paper also outlines the DeSa Project outcomes and planned follow-up activities. It also summarises the main objectives and activities of the Iraq Project and introduces the R{sup 2}D{sup 2} Project, which is a subject of a complementary paper.

  20. Russian nuclear-powered submarine decommissioning

    SciTech Connect

    Bukharin, O.; Handler, J.

    1995-11-01

    Russia is facing technical, economic and organizational difficulties in dismantling its oversized and unsafe fleet of nuclear powered submarines. The inability of Russia to deal effectively with the submarine decommissioning crisis increases the risk of environmental disaster and may hamper the implementation of the START I and START II treaties. This paper discusses the nuclear fleet support infrastructure, the problems of submarine decommissioning, and recommends international cooperation in addressing these problems.

  1. Influence of reduction temperature on composition, particle size, and magnetic properties of CoFe alloy nanomaterials derived from layered double hydroxide precursors.

    PubMed

    Yang, Shuangxia; Wang, Lianying; Yue, Shuang; Lu, Yanluo; He, Jing; Zhao, Dongye

    2014-06-14

    Individual CoFe alloy nanoparticles and CoFe-MgO nanocomposites were prepared through thermal reduction of single-source layered double hydroxide (LDH) precursors at various temperatures. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM) analyses to investigate the influence of reduction temperature on the composition, particle size and size distribution, as well as the magnetic properties of the resulting materials. XRD and SEM results show that the as-prepared CoFe alloy nanoparticles and CoFe-MgO nanocomposites display high crystallinity and high purity. The average particle size of individual CoFe nanoparticles increases with the increase of reduction temperature. In the presence of the MgO matrix, uniform CoFe alloy nanoparticles with a narrow diameter distribution (8-11 nm) were obtained. Magnetic measurements indicate that the saturation magnetization strength (Ms) of the resulting materials increases with reduction temperature. The individual CoFe alloy nanoparticles exhibit excellent soft magnetic behavior with an extremely high Ms value (213 emu g(-1) at 800 °C), comparable to that of bulk CoFe alloy (230 emu g(-1)). For CoFe-MgO nanocomposites, small Ms values were obtained due to the small CoFe alloy particle size and low percentage of magnetic component. However, the coercivities are greatly enhanced (663 Oe at 450 °C) for the composites, implying their potential applications in data storage and other magnetic devices. PMID:24695765

  2. ASTM standards in radiological decontamination and decommissioning

    SciTech Connect

    Meservey, R.H.

    1994-12-31

    The American Society for Testing and Materials (ASTM) Subcommittee E10.03 was formed following a steering committee meeting held in April 1980. The meeting was initiated as a result of labor union concern for the safety of workers on decommissioning projects. Of particular concern at that time was the need for proper training of the workers and a means of tracking worker radiation-exposure records as they traveled to various decommissioning job sites. The steering committee concluded not only that worker protection standards were necessary for decommissioning activities but also that all phases of a decommissioning project could benefit from the appropriate guides or standards. These would provide worker protection, technical guidance, and consistency for decommissioning work. It recommended that Subcommittee E10.03 be formed and dedicated to the preparation of guides and standards that would support all phases of nuclear facility decontamination and decommissioning. Subcommittee E10.03 has met regularly on a semiannual basis since that time.

  3. Solid-state characterization studies and effect of PEG 20000 and P90G on particle size reduction and stability of complexed glimepiride nanocrystals

    PubMed Central

    Sajeev Kumar, Babasahib; Saraswathi, Raman; Dhanaraj, Sokkalingam Arumugham

    2013-01-01

    Objective The objective of the present study is to formulate and characterize the properties of complexed glimepiride nanocrystals (GLP) by various techniques at different stages of its development, and to study the effect of PEG 20000 and P90G on particle size reduction and stability of nanocrystals. Method Precipitated (GLP-PEG) and complexed NCs (GLP-PEG-P90G) of glimepiride were characterized for particle size, size distribution, zeta potential and stability assessment using photon correlation spectroscopy (PCS). The crystallinity was analyzed using differential scanning calorimetry (DSC) and X-ray powder diffraction spectroscopy (XRPD). The surface morphology and chemical stability were assessed by means of scanning electron microscopy (SEM) and infrared spectroscopy (FTIR). Results A formulation with drug–polymer ratio of 1:1 was most ideal in developing stable NCs as it exhibited smaller particle size and high stability. A high zeta potential was observed in all NCs after complexation indicating improved stability. DSC and XRPD studies showed no change in crystallinity after complexation. SEM analysis of complexed NCs showed presence of spherical shape particles (size below 1 μm) with a lipid coat on the surface. Stability studies on optimized formulation (F1) revealed no change in particle size during 3-month period. FTIR studies prove that the chemical identity of GLP was preserved in the samples and the formulation was stable. Conclusion Solid-state characterization studies reveal that complexed GLP NCs are promising carriers for drug delivery and they can be safely and effectively used in design of various formulations. Also, PEG 20000 and P90G are excellent polymer and lipid for particle size reduction (nanonization) and stabilization of nanocrystals. PMID:24396247

  4. Strategy for decommissioning of the glove-boxes in the Belgonucleaire Dessel MOX fuel fabrication plant

    SciTech Connect

    Vandergheynst, Alain; Cuchet, Jean-Marie

    2007-07-01

    Available in abstract form only. Full text of publication follows: BELGONUCLEAIRE has been operating the Dessel plant from the mid-80's at industrial scale. In this period, over 35 metric tons of plutonium (HM) was processed into almost 100 reloads of MOX fuel for commercial West-European Light Water Reactors. In late 2005, the decision was made to stop the production because of the shortage of MOX fuel market remaining accessible to BELGONUCLEAIRE after the successive capacity increases of the MELOX plant (France) and the commissioning of the SMP plant (UK). As a significant part of the decommissioning project of this Dessel plant, about 170 medium-sized glove-boxes are planned for dismantling. In this paper, after having reviewed the different specifications of {+-}-contaminated waste in Belgium, the authors introduce the different options considered for cleaning, size reduction and packaging of the glove-boxes, and the main decision criteria (process, {alpha}-containment, mechanization and radiation protection, safety aspects, generation of secondary waste, etc) are analyzed. The selected strategy consists in using cold cutting techniques and manual operation in shielded disposable glove-tents, and packaging {alpha}-waste in 200-liter drums for off-site conditioning and intermediate disposal. (authors)

  5. Impact of Component Sizing in Plug-In Hybrid Electric Vehicles for Energy Resource and Greenhouse Emissions Reduction

    SciTech Connect

    Malikopoulos, Andreas

    2013-01-01

    Widespread use of alternative hybrid powertrains currently appears inevitable and many opportunities for substantial progress remain. The necessity for environmentally friendly vehicles, in conjunction with increasing concerns regarding U.S. dependency on foreign oil and climate change, has led to significant investment in enhancing the propulsion portfolio with new technologies. Recently, plug-in hybrid electric vehicles (PHEVs) have attracted considerable attention due to their potential to reduce petroleum consumption and greenhouse gas (GHG) emissions in the transportation sector. PHEVs are especially appealing for short daily commutes with excessive stop-and-go driving. However, the high costs associated with their components, and in particular, with their energy storage systems have been significant barriers to extensive market penetration of PEVs. In the research reported here, we investigated the implications of motor/generator and battery size on fuel economy and GHG emissions in a medium duty PHEV. An optimization framework is proposed and applied to two different parallel powertrain configurations, pre-transmission and post-transmission, to derive the Pareto frontier with respect to motor/generator and battery size. The optimization and modeling approach adopted here facilitates better understanding of the potential benefits from proper selection of motor/generator and battery size on fuel economy and GHG emissions. This understanding can help us identify the appropriate sizing of these components and thus reducing the PHEV cost. Addressing optimal sizing of PHEV components could aim at an extensive market penetration of PHEVs.

  6. Pore-size reduction protocol for SiN membrane nanopore using the thermal reflow in nanoimprinting for nanobio-based sensing.

    PubMed

    Lee, Dae-Sik; Song, Hyun-Woo; Choi, Choon-Gi; Jung, Mun Youn

    2014-05-01

    Micro- and nano-fabrication methods facilitate the use of nanostructures for the separation of collections of particles and nanobio-based optical and electrochemical sensing. We have presented an easy and simple nanopore size reduction method of a low-stressed silicon nitride (SiN) membrane nanosieve (100×100  μm2) using a nanoimprinting method based on a natural thermal reflow of the contact imprinting polymer, possibly maintaining compatibility with complementary metal-oxide semiconductor integrated circuit processes. The nanopore pattern size of this nanosieve membrane was precisely patterned by a nanoimprinting process using an electron beam patterned silicon master, to about 30-nm diameter. By employing mainly an electron beam resist reflow phenomena after a nanoimprinting process and anisotropic reactive ion etch, the etch holes' size was fabricated to be the same with nanopatterns on the polymer. The contact imprinting master can be used continually for the generation of nanopore patterns simply and easily. It can endure harsh conditions like high temperature up to 800°C, and it is inert to many aggressive and strong chemicals. Also, this would be a low-cost, simple, and easy fabrication method for the precise and reliable size-reduction control of nanopores for mass production of nanobio sensors or chips. PMID:24503699

  7. Pore-size reduction protocol for SiN membrane nanopore using the thermal reflow in nanoimprinting for nanobio-based sensing

    NASA Astrophysics Data System (ADS)

    Lee, Dae-Sik; Song, Hyun-Woo; Choi, Choon-Gi; Jung, Mun Youn

    2014-05-01

    Micro- and nano-fabrication methods facilitate the use of nanostructures for the separation of collections of particles and nanobio-based optical and electrochemical sensing. We have presented an easy and simple nanopore size reduction method of a low-stressed silicon nitride (SiN) membrane nanosieve (100×100 μ) using a nanoimprinting method based on a natural thermal reflow of the contact imprinting polymer, possibly maintaining compatibility with complementary metal-oxide semiconductor integrated circuit processes. The nanopore pattern size of this nanosieve membrane was precisely patterned by a nanoimprinting process using an electron beam patterned silicon master, to about 30-nm diameter. By employing mainly an electron beam resist reflow phenomena after a nanoimprinting process and anisotropic reactive ion etch, the etch holes' size was fabricated to be the same with nanopatterns on the polymer. The contact imprinting master can be used continually for the generation of nanopore patterns simply and easily. It can endure harsh conditions like high temperature up to 800°C, and it is inert to many aggressive and strong chemicals. Also, this would be a low-cost, simple, and easy fabrication method for the precise and reliable size-reduction control of nanopores for mass production of nanobio sensors or chips.

  8. Synergistic effect of nano-sized mackinawite with cyano-cobalamin in cement slurries for reductive dechlorination of tetrachloroethylene.

    PubMed

    Kyung, Daeseung; Sihn, Youngho; Kim, Sangwoo; Bae, Sungjun; Amin, Muhammad Tahir; Alazba, Abdulrahman Ali; Lee, Woojin

    2016-07-01

    Experiments were conducted to investigate the reductive dechlorination of tetrachloroethylene (PCE) by nano-Mackinawite (nFeS) with cyano-cobalamin (Cbl(III)) in cement slurries. Almost complete degradation of PCE by nFeS-Cbl(III) was observed in cement slurries in 5h and its degradation kinetics (kobs-PCE=0.57h(-1)) was 6-times faster than that of nFeS-Cbl(III) without the cement slurries. PCE was finally transformed to non-chlorinated organic compounds such as ethylene, acetylene, and C3-C4 hydrocarbons by nFeS-Cbl(III) in cement slurries. X-ray photoelectron spectroscopy and PCE degradation by cement components (SiO2, Al2O3, and CaO) revealed that both the reduced Co species in Cbl(III) and the presence of Ca in cement played an important role for the enhanced reductive dechlorination of PCE. The increase in the concentration of Cbl(III) (0.005-0.1mM), cement ratio (0.05-0.2), and suspension pH (11.5-13.5) accelerated the PCE degradation kinetics by providing more favorable environments for the production of reactive Ca species and reduction of Co species. We also observed that the degradation efficiency of PCE by nFeS-Cbl(III)-cement lasted even at high concentration of PCE. The experimental results obtained from this study could provide fundamental knowledge of redox interactions among nFeS, Cbl(III), and cement, which could significantly enhance reductive dechlorination of chlorinated organics in contaminated natural and engineered environments. PMID:26950611

  9. Monodisperse Pt{sub 3}Co nanoparticles as electrocatalyst : the effects of particle size and pretretment on electrocatalytic reduction of oxygen.

    SciTech Connect

    Wang, C.; Wang, G.; van der Vliet, D.; Chang, K.-C.; Markovic, N. M.; Stamenkovic, V. R.; Materials Science Division; Indiana Univ.-Purdue Univ.

    2010-07-14

    Monodisperse Pt{sub 3}Co nanoparticles have been synthesized with size control via an organic solvothermal approach. The obtained nanoparticles were incorporated into a carbon matrix and applied as electrocatalysts for the oxygen reduction reaction to investigate the effects of particle size and pretreatment on their catalytic performance. It has been found that the optimal conditions for maximum mass activity were with particles of {approx}4.5 nm and a mild annealing temperature of about 500 C. While the particle size effect can be correlated to the average surface coordination number, Monte Carlo simulations have been introduced to depict the nanoparticle structure and segregation profile, which revealed that the annealing temperature has a direct influence on the particle surface relaxation, segregation and adsorption/catalytic properties. The obtained fundamental understanding of activity enhancement in Pt-bimetallic alloy catalysts could be utilized to guide the development of advanced nanomaterials for catalytic applications.

  10. Do Class Size Reductions Make a Difference to Classroom Practice? The Case of Hong Kong Primary Schools

    ERIC Educational Resources Information Center

    Galton, Maurice; Pell, Tony

    2012-01-01

    This paper describes changes which took place in 37 Hong Kong primary schools where class sizes were reduced from 38 to between 20 and 25. Chinese, English and mathematics classes were observed over three years from Primary 1 (aged 6) to Primary 3. For 75% of observations no child was the focus of the teacher's attention in large classes. Reducing…

  11. Evolution of specific antigen recognition: size reduction and restricted length distribution of the CDRH3 regions in the rainbow trout.

    PubMed

    Roman, T; De Guerra, A; Charlemagne, J

    1995-01-01

    The immunoglobulin heavy chain repertoire in fish was investigated by cloning a total of 88 rearranged VDJ junctions from the head kidney B cell mRNA of a salmonid, the rainbow trout (Oncorhynchus mykiss). Trout DH segments are short and cannot be classified into independent DH families. Several of the ten identified putative DH segments had stretches of nucleotide sequence identity with mouse (DQ52, DFL 16.2 and Dsp 2.1), human (DM1) and chicken (DH4) DH. There was a clear preference for one or two of the three putative DH reading frames and a stop codon is often present in the less used reading frame. Four of the six JH segments are preferentially used, and analysis of the VH-DH and DH-JH junctions suggest the presence of N-nucleotides. The absolute size and size heterogeneity of the rainbow trout CDRH3 are smaller than those of the Xenopus, mouse and human CDRH3. About 75% of the 84 in-frame trout CDRH3 have 8, 9 or 10 residues and none of them have more than 11 residues. This homogeneization of the CDRH3 loop size may partly explain the restricted antibody diversity in lower vertebrates. PMID:7843242

  12. Synthesis of Nano-Size AlN Powders by Carbothermal Reduction from Plasma-Assisted Ball Milling Precursor

    NASA Astrophysics Data System (ADS)

    Liu, Zhijie; Wang, Wenchun; Yang, Dezheng; Wang, Sen; Dai, Leyang

    2016-07-01

    Nano-size aluminum nitride (AlN) powders have been successfully synthesized with a high efficiency method through annealing from milling assisted by discharge plasma (p-milling) alumina (Al2O3) precursors. The characterization of the p-milling Al2O3 powders and the synthesized AlN are investigated. Compared to conventional ball milling (c-milling), it can be found that the precursors by p-milling have a finer grain size with a higher specific surface area, which lead to a faster reaction efficiency and higher conversion to AlN at lower temperatures. The activation energy of p-milling Al2O3 is found to be 371.5 kJ/mol, a value that is much less than the reported value of the unmilled and the conventional milled Al2O3. Meanwhile, the synthesized AlN powders have unique features, such as an irregular lamp-like morphology with uniform particle distribution and fine average particle size. The results are attributed to the unique synergistic effect of p-milling, which is the effect of deformation, fracture, and cold welding of Al2O3 powders resulting from ball milling, that will be enhanced due to the introduction of discharge plasma. supported by National Natural Science Foundation of China (No. 51177008)

  13. Interplay between grain size reduction, chemical reaction, and shear localization in lower crustal rocks: a case study from Archaean Bundelkhand Craton, North-Central India

    NASA Astrophysics Data System (ADS)

    Bhandari, Ankit; Nasipuri, Pritam; Saha, Lopamudra; Pati, Jayanta Kumar; Sarkar, Saheli; Purohit, Rohan

    2016-04-01

    Weakening of the rocks is pronounced during the formation of shear zone. Crustal scale shear zones at the plate boundary develop due to grain size reduction, either by mechanical breakdown of minerals or by the development of new minerals due to change in pressure (P) - temperature (T) conditions. In either of the mechanisms for grain size reduction, the Gibb's free energy of the system should be minimum in value to stabilize the mineral.In this contribution, we have studied the deformation mechanism and P-T conditions from acrustal scale shear zone, in the North Central Part of Archaean Bundelkhand Craton. In the Archaean Buldelkhand craton, tens of kilometre wide E-W trending shear zone developed in the sodic-potassic granite. The undeformed rock (protolith) is characterized by euhedral to subhedral sodic feldspar (XAb =0.80) and subordinate quartz, whereas the deformed rock is characterized by the development of extremely deformed feldspar and quartz associated with chlorite. The onset of the strain localization and shear zone formation in the proto-mylonite has been accompanied by developing brittle fractures in the euhedral feldspar grains. In contrast to the brittle deformation in feldspar, quartz grains are characterized by development of small bulges around the grain boundary. Chlorite develops at the fractures in the feldspar that are indicative of fluid infiltration in the proto-mylonite.In the extremely deformed samples (ultramylonite) grain size reduction occurs by bulging recrystallization in quartz. Flow stress obtained from grain size analysis of quartz indicates that the palaeo-stress varies from ~44-46 MPa in proto-mylonite to ~ 61-63 MPa in Ultra-mylonite. Mineral chemical analysis of undeformed feldspar grains in the protolith and mylonite indicate significant changes in the chemical composition that leads to minimum Gibbs energy. Also the presence of chlorite indicates hydration reaction, which has reduced the chemical energy of the system

  14. Effect of Lactobacillus plantarum FH185 on the Reduction of Adipocyte Size and Gut Microbial Changes in Mice with Diet-induced Obesity

    PubMed Central

    2015-01-01

    This study aimed to investigate the effects of Lactobacillus plantarum FH185 on the reduction of adipocyte size and gut microbial changes in mice with diet-induced obesity. The strain was found to have a lipase inhibitory activity of 70.09±2.04% and inhibited adipocyte differentiation of 3T3-L1 cells (18.63±0.98%) at a concentration of 100 µg/mL. To examine the effect of the strain supplementation on gut microbial changes in mice with diet-induced obesity, male C57BL/6J mice were fed on four different diets (i.e., A, normal diet (ND); B, high-fat diet (HFD); C, HFD with ABT-3 (109 CFU/day); and D, HFD with L. plantarum FH185 (109 CFU/day)) for 6 wk. According to the results of fecal pyrosequencing, the ratio of Firmicutes to Bacteroidetes in groups C and D was lower than in the control groups at the phylum level. At the family level, Lactobacillaceae in groups C and D was observed to dominate, while Lachnospiraceae in groups A and B was observed to dominate. At the genus level, Lactobacillus in groups C and D was comparatively higher than in groups A and B. To examine the effects of strain supplementation on the reduction of adipocyte size, the left and right epididymal fat pads were quickly isolated after the animals were sacrificed, and the adipocyte sizes were measured. In groups A, C and D, the percentage of 2,000 m2 of adipocyte was higher than in the other size of adipocyte, while the percentage of over 5,000 m2 of adipocyte was highest in group B. The mean adipocyte size of group D was significantly larger than that of group A, but smaller than that of group B. PMID:26761825

  15. Ultrafine sputter-deposited Pt nanoparticles for triiodide reduction in dye-sensitized solar cells: impact of nanoparticle size, crystallinity and surface coverage on catalytic activity.

    PubMed

    Mukherjee, Somik; Ramalingam, Balavinayagam; Griggs, Lauren; Hamm, Steven; Baker, Gary A; Fraundorf, Phil; Sengupta, Shramik; Gangopadhyay, Shubhra

    2012-12-01

    This paper presents a detailed electrochemical impedance spectroscopy and cyclic voltammetry (CV) investigation into the electrocatalytic activity of ultrafine (i.e., smaller than 2 nm) platinum (Pt) nanoparticles generated on a fluorine-doped tin oxide (FTO) surface via room temperature tilted target sputter deposition. In particular, the Pt-decorated FTO electrode surfaces were tested as counter electrode candidates for triiodide (I3(-)) reduction in dye-sensitized solar cells (DSSCs). We observed a direct correlation between size-dependent Pt nanoparticle crystallinity and the I3(-) reduction activity underlying DSSC performance. CV analysis confirmed the higher electrocatalytic activities of sputter-deposited crystalline Pt nanoparticles (1-2 nm) compared with either sub-nanometre Pt clusters or a continuous Pt thin film. While the low catalytic activity and DSSC performance of Pt clusters smaller in size than 1 nm is believed to arise from their non-crystalline nature and charge-trapping attributes, we attribute the high catalytic performance of larger Pt nanoparticles in the 1-2 nm regime to their well-defined crystallinity and fast electron transfer kinetics. For DSSC applications, the optimized Pt loading was calculated to be ~2.54 × 10(-7) g cm(-2), which corresponds to surface coverage by ~1.6 nm sized Pt nanoparticles. PMID:23138541

  16. CO2 Reduction on Supported Ru/Al2O3 Catalysts: Cluster Size Dependence of Product Selectivity

    SciTech Connect

    Kwak, Ja Hun; Kovarik, Libor; Szanyi, Janos

    2013-11-01

    The catalytic performance of a series of Ru/Al2O3 catalysts with Ru content in the 0.1-5% range was examined in the reduction of CO2 with H2. At low Ru loadings (≤0.5 %) where the active metal phase is highly dispersed (mostly atomically) on the alumina support CO is formed with high selectivity. With increasing metal loading the selectivity toward CH4 formation increases, while that for CO production decreases. In the 0.1% Ru/Al2O3 catalyst Ru is mostly present in atomic dispersion as STEM images obtained from the fresh sample prior to catalytic testing reveal. STEM images recorded form this same sample following temperature programmed reaction test clearly show the agglomeration of small metal particles (and atoms) into 3D clusters. The clustering of the highly dispersed metal phase is responsible for the observed dramatic selectivity change during elevated temperature tests: dramatic decrease in CO, and large increase in CH4 selectivity. Apparent activation energies, estimated from the slopes of Arrhenius plots, of 82 kJ/mol and 62 kJ/mol for CO and CH4 formation were determined, respectively, regardless of Ru loading. These results suggest that the formation of CO and CH4 follow different reaction pathways, or proceed on active centers of different nature. Reactions with CO2/H2 and CO/H2 mixtures (under otherwise identical reaction conditions) reveal that the onset temperature of CO2 reduction is about 150 ºC lower than of CO reduction. We thank Dr. Feng Gao for carrying out the H2 chemisorption measurements on all the Ru/Al2O3 catalysts discussed in this work. The catalyst preparation and catalytic measurements were supported by a Laboratory Directed Research and Development (LDRD) project, while the TEM work was supported by the Chemical Imaging Initiative at the Pacific Northwest National Laboratory (PNNL). PNNL is operated for the US Department of Energy by Battelle under contract number DE-AC05-76RL01830. JHK also acknowledges the support of this work

  17. Class Size.

    ERIC Educational Resources Information Center

    Underwood, Siobhan; Lumsden, Linda S.

    1994-01-01

    The items featured in this annotated bibliography touch on several aspects of the multifaceted class-size debate. Allen Odden reviews the literature and contends that class-size reduction should be used "sparingly and strategically." C. M. Achilles and colleagues examines two different class-size situations and find student test performance in the…

  18. Decommissioning of the Iraq former nuclear complex

    SciTech Connect

    Abbas, Mohammed; Helou, Tuama; Ahmead, Bushra; Al-Atia, Mousa; Al-Mubarak, Mowaffak; Danneels, Jeffrey; Cochran, John; Sorenson, Ken; Coates, Roger

    2007-07-01

    Available in abstract form only. Full text of publication follows: A number of sites in Iraq have some degree of radiological contamination and require decommissioning and remediation in order to ensure radiological safety. Many of these sites in Iraq are located at the nuclear research centre at Al Tuwaitha. The International Atomic Energy Agency (IAEA) Board of Governors has approved a project to assist the Government of Iraq in the evaluation and decommissioning of former facilities that used radioactive materials. The project is divided into three phases: Phase 1: collect and analyze all available data and conduct training of the Iraqi staff, Phase 2: develop a decommissioning and remediation plan, and Phase 3: implement field activities relating to decommissioning, remediation and site selection suitable for final disposal of waste. Four working groups have been established to complete the Phase 1 work and significant progress has been made in drafting a new nuclear law which will provide the legal basis for the licensing of the decommissioning of the former nuclear complex. Work is also underway to collect and analysis existing date, to prioritize future activities and to develop a waste management strategy. This will be a long-term and costly project. (authors)

  19. Quantifying solubility enhancement due to particle size reduction and crystal habit modification: case study of acetyl salicylic acid.

    PubMed

    Hammond, Robert B; Pencheva, Klimentina; Roberts, Kevin J; Auffret, Tony

    2007-08-01

    The poor solubility of potential drug molecules is a significant problem in the design of pharmaceutical formulations. It is well known, however, that the solubility of crystalline materials is enhanced when the particle size is reduced to submicron levels and this factor can be expected to enhance drug product bioavailability. Direct estimation of solubility enhancement, as calculated via the Gibbs-Thompson relationship, demands reasonably accurate values for the particle/solution interfacial tension and, in particular, its anisotropy with respect to the crystal product's habit and morphology. In this article, an improved, more molecule-centered, approach is presented towards the calculation of solubility enhancement factors in which molecular modeling techniques are applied, and the effects associated with both crystal habit modification and solvent choice are examined. A case study for facetted, acetyl salicylic acid (aspirin) crystals in equilibrium with saturated aqueous ethanol solution reveals that their solubility will be enhanced in the range (7-58%) for a crystal size of 0.02 microm, with significantly higher enhancement for crystal morphologies in which the hydrophobic crystal faces are more predominant than the hydrophilic faces and for solvents in which the solubility is smaller. PMID:17323349

  20. Decommissioning the Tokamak Fusion Test Reactor

    SciTech Connect

    Spampinato, P.T.; Walton, G.R.

    1993-10-01

    The Tokamak Fusion Test Reactor (TFTR) at Princeton Plasma Physics Laboratory (PPPL) will complete its experimental lifetime with a series of deuterium-tritium pulses in 1994. As a result, the machine structures will become radioactive, and vacuum components will also be contaminated with tritium. Dose rate levels will range from less than 1 mr/h for external structures to hundreds of mr/h for the vacuum vessel. Hence, decommissioning operations will range from hands on activities to the use of remotely operated equipment. After 21 months of cool down, decontamination and decommissioning (D and D) operations will commence and continue for approximately 15 months. The primary objective is to render the test cell complex re-usable for the next machine, the Tokamak Physics Experiment (TPX). This paper presents an overview of decommissioning TFTR and discusses the D and D objectives.

  1. Size reduction and radiation pattern shaping of multi-fed DCC slot antennas used in conformal microwave array hyperthermia applicators

    NASA Astrophysics Data System (ADS)

    Maccarini, Paolo F.; Arunachalam, Kavitha; Martins, Carlos D.; Stauffer, Paul R.

    2009-02-01

    The use of conformal antenna array in the treatment of superficial diseases can significantly increase patient comfort while enhancing the local control of large treatment area with irregular shapes. Originally a regular square multi-fed slot antenna (Dual Concentric Conductor - DCC) was proposed as basic unit cell of the array. The square DCC works well when the outline of the treatment area is rectangular such as in the main chest or back area but is not suitable to outline diseases spreading along the armpit and neck area. In addition as the area of the patch increases, the overall power density decreases affecting the efficiency and thus the ability to deliver the necessary thermal dose with medium power amplifier (<50W). A large number of small efficient antennas is preferable as the disease is more accurately contoured and the lower power requirement for the amplifiers correlates with system reliability, durability, linearity and overall reduced cost. For such reason we developed a set of design rules for multi-fed slot antennas with irregular contours and we implemented a design that reduce the area while increasing the perimeter of the slot, thus increasing the antenna efficiency and the power density. The simulation performed with several commercial packages (Ansoft HFSS, Imst Empire, SemcadX and CST Microwave Studio) show that the size reducing method can be applied to several shapes and for different frequencies. The SAR measurements of several DCCs are performed using an in-house high resolution scanning system with tumor equivalent liquid phantom both at 915 MHz for superficial hyperthermia systems in US) and 433 MHz (Europe). The experimental results are compared with the expected theoretical predictions and both simulated and measured patterns of single antennas of various size and shapes are then summed in various combinations using Matlab to show possible treatment irregular contours of complex diseases. The local control is expected to

  2. Size reduction and radiation pattern shaping of multi-fed DCC slot antennas used in conformal microwave array hyperthermia applicators.

    PubMed

    Maccarini, Paolo F; Arunachalam, Kavitha; Martins, Carlos D; Stauffer, Paul R

    2009-02-23

    The use of conformal antenna array in the treatment of superficial diseases can significantly increase patient comfort while enhancing the local control of large treatment area with irregular shapes. Originally a regular square multi-fed slot antenna (Dual Concentric Conductor - DCC) was proposed as basic unit cell of the array. The square DCC works well when the outline of the treatment area is rectangular such as in the main chest or back area but is not suitable to outline diseases spreading along the armpit and neck area. In addition as the area of the patch increases, the overall power density decreases affecting the efficiency and thus the ability to deliver the necessary thermal dose with medium power amplifier (<50W). A large number of small efficient antennas is preferable as the disease is more accurately contoured and the lower power requirement for the amplifiers correlates with system reliability, durability, linearity and overall reduced cost. For such reason we developed a set of design rules for multi-fed slot antennas with irregular contours and we implemented a design that reduce the area while increasing the perimeter of the slot, thus increasing the antenna efficiency and the power density. The simulation performed with several commercial packages (Ansoft HFSS, Imst Empire, SemcadX and CST Microwave Studio) show that the size reducing method can be applied to several shapes and for different frequencies. The SAR measurements of several DCCs are performed using an in-house high resolution scanning system with tumor equivalent liquid phantom both at 915 MHz for superficial hyperthermia systems in US) and 433 MHz (Europe). The experimental results are compared with the expected theoretical predictions and both simulated and measured patterns of single antennas of various size and shapes are then summed in various combinations using Matlab to show possible treatment irregular contours of complex diseases. The local control is expected to

  3. Development of optimized filter for TARC and developer with the goal of having small pore size and minimizing microbubble reduction

    NASA Astrophysics Data System (ADS)

    Umeda, Toru; Tsuzuki, Shuichi; Boucher, Mikal; Dinh, Hung; Ma, L. C.; Boten, Russell

    2006-03-01

    Microbubble in filtering Tetra Methyl Ammonium Hydroxide (TMAH) were counted to find the filter which generates the lowest microbubble in resist development process. Hydrophilic Highly Asymmetric Poly Aryl Sulfone (HAPAS) filter was developed and tested. The result showed that generation of microbubbles was as low as that of the Nylon 6,6 filter which had the best performance to date. Microbubbles in TARC are counted using the same method as the developer testing described above except for mainstream flow rate and the counter model. The results show that counts in the small channel could be reduced by smaller pore size filter such as conventional 0.02um rated filter. However, counts in the larger channel could be reduced by larger pore size filter such as 0.1um rated filter. Based on the above results, 0.02um rated asymmetric nylon 6,6 filter was developed. As a result, 0.02um rated asymmetric Nylon 6,6 filter achieved relatively lower count at any channel as compared to the standard 0.04um rated Nylon 6,6 filter. Nylon 6,6 filters were installed in resist as an improvement for preventive maintenance (PM) at Wafertech, L.L.C. instead of the currently used filter which has more hydrophobic membrane material. Using the Nylon 6,6 membrane, the number of defects immediately after filter change greatly decreased from 493 pcs of the more hydrophobic filter to 6 pcs/wafer, then after purging with about 250ml, the number of defects reduced within the process specification while the more hydrophobic filter had required 2L purging and 12-36 hours of PM time.

  4. Decommissioning of the Plutonium Purification and Residues Recovery Plant

    SciTech Connect

    Hunt, J. G.

    2006-07-01

    British Nuclear Group is continuing to build on BNFL's successful record of decommissioning redundant nuclear facilities. Challenging radiological conditions and complex technical problems have been overcome to reduce the hazard associated with the UK's nuclear legacy. The former Plutonium Purification and Residues Recovery Plant at Sellafield operated from 1954 through to 1987. This is the only plant to have experienced an uncontrolled criticality incident in the UK, in August 1970 during operations. The plant comprised of two mirror image cells approximately 6.5 m x 13.5 m x 16 m, constructed of bare brick. The cell structure provided secondary containment, the process vessels and pipes within the cell providing primary containment. The plant utilized a solvent extraction process to purify the plutonium stream. Surrounding the two process cells to the north, east and south is an annulus area that housed the operational control panels, feed and sample glove-boxes, and ancillary equipment. The building was ventilated by an unfiltered extract on the process cells and a filtered extract from the vessels and glove-boxes. During the long operational lifetime of the plant, the primary containment deteriorated to such an extent that the process cells eventually became the main containment, with levels of radioactive contamination in excess of 14,256 pCi alpha. This led to significant aerial effluent discharges towards the end of the plant's operational life and onerous working conditions during decommissioning. Implementation of a phased decommissioning strategy from 1991 has led to: - A reduction of approximately 60% in the Sellafield site's aerial alpha discharges following installation of a new ventilation system, - Removal of 12 plutonium contaminated glove-boxes and sample cabinets from the building, - Disposal of the approximately 500 m{sup 2} of asbestos building cladding, - Removal of over 90% of the active pipes and vessels from the highly contaminated process

  5. Landscape Planning for Agricultural Non-Point Source Pollution Reduction. II. Balancing Watershed Size, Number of Watersheds, and Implementation Effort

    NASA Astrophysics Data System (ADS)

    Maxted, Jeffrey T.; Diebel, Matthew W.; Vander Zanden, M. Jake

    2009-01-01

    Agricultural non-point source (NPS) pollution poses a severe threat to water quality and aquatic ecosystems. In response, tremendous efforts have been directed toward reducing these pollution inputs by implementing agricultural conservation practices. Although conservation practices reduce pollution inputs from individual fields, scaling pollution control benefits up to the watershed level (i.e., improvements in stream water quality) has been a difficult challenge. This difficulty highlights the need for NPS reduction programs that focus efforts within target watersheds and at specific locations within target watersheds, with the ultimate goal of improving stream water quality. Fundamental program design features for NPS control programs—i.e., number of watersheds in the program, total watershed area, and level of effort expended within watersheds—have not been considered in any sort of formal analysis. Here, we present an optimization model that explores the programmatic and environmental trade-offs between these design choices. Across a series of annual program budgets ranging from 2 to 200 million, the optimal number of watersheds ranged from 3 to 27; optimal watershed area ranged from 29 to 214 km2; and optimal expenditure ranged from 21,000 to 35,000/km2. The optimal program configuration was highly dependent on total program budget. Based on our general findings, we delineated hydrologically complete and spatially independent watersheds ranging in area from 20 to 100 km2. These watersheds are designed to serve as implementation units for a targeted NPS pollution control program currently being developed in Wisconsin.

  6. 26 CFR 1.88-1 - Nuclear decommissioning costs.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 2 2010-04-01 2010-04-01 false Nuclear decommissioning costs. 1.88-1 Section 1... (CONTINUED) INCOME TAXES (CONTINUED) Items Specifically Included in Gross Income § 1.88-1 Nuclear decommissioning costs. (a) In general. Section 88 provides that the amount of nuclear decommissioning...

  7. 26 CFR 1.88-1 - Nuclear decommissioning costs.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 2 2011-04-01 2011-04-01 false Nuclear decommissioning costs. 1.88-1 Section 1... (CONTINUED) INCOME TAXES (CONTINUED) Items Specifically Included in Gross Income § 1.88-1 Nuclear decommissioning costs. (a) In general. Section 88 provides that the amount of nuclear decommissioning...

  8. Decision framework for platform decommissioning in California.

    PubMed

    Bernstein, Brock B

    2015-10-01

    This article describes the overall decision framework for eventual decisions about decommissioning the 27 operating oil and gas platforms offshore southern California. These platforms will eventually reach the end of their useful lifetimes (estimated between 2015 and 2030, although specific dates have not been determined). Current law and regulations allow for alternative uses in lieu of the complete removal required in existing leases. To prepare for eventual decommissioning, the California Natural Resources Agency initiated an in-depth process to identify and investigate issues surrounding possible decommissioning alternatives. The detailed evaluation of alternatives focused on 2-complete removal and artificial reefing that included partial removal to 85 feet below the waterline. These were selected after a comparison of the technical and economic feasibility of several potential alternatives, availability of a legal framework for implementation, degree of interest from proponents, and relative acceptance by state and federal decision makers. Despite California's history of offshore oil and gas production, only 7 decommissioning projects have been completed and these were all relatively small and close to shore. In contrast, nearly 30% of the California platforms are in water depths (as much as 1200 feet) that exceed any decommissioning project anywhere in the world. Most earlier projects considered an artificial reefing alternative but none were implemented and all platforms were completely removed. Future decisions about decommissioning must grapple with a more complex decision context involving greater technological and logistical challenges and cost, a wider range of viable options, tradeoffs among environmental impacts and benefits, and an intricate maze of laws, regulations, and authorities. The specific engineering differences between complete and partial removal provide an explicit basis for a thorough evaluation of their respective impacts. PMID:26259879

  9. Decommissioning of a tritium-contaminated laboratory

    SciTech Connect

    Harper, J.R.; Garde, R.

    1981-11-01

    A tritium laboratory facility at the Los Alamos National Laboratory, Los Alamos, New Mexico, was decommissioned in 1979. The project involved dismantling the laboratory equipment and disposing of the equipment and debris at an on-site waste disposal/storage area. The laboratory was constructed in 1953 and was in service for tritium research and fabrication of lithium tritide components until 1974. The major features of the laboratory included some 25 meters of gloveboxes and hoods, associated vacuum lines, utility lines, exhaust ducts, electrodryers, blowers, and laboratory benches. This report presents details on the decommissioning, health physics, waste management, environmental surveillance, and costs for the operation.

  10. Reduction of the neuroprotective transcription factor Npas4 results in increased neuronal necrosis, inflammation and brain lesion size following ischaemia.

    PubMed

    Choy, Fong Chan; Klarić, Thomas S; Leong, Wai Khay; Koblar, Simon A; Lewis, Martin D

    2016-08-01

    Stroke is the second leading cause of death and the most frequent cause of adult disability. Neuronal Per-Arnt-Sim domain protein 4 (Npas4) is an activity-dependent transcription factor whose expression is induced in various brain insults, including cerebral ischaemia. Although previous studies have demonstrated that Npas4 plays a critical role in protecting neurons against neurodegenerative insults, the neuroprotective effect of Npas4 in response to ischaemic brain injury remains unknown. In this study, we used a loss-of-function approach to examine the neuroprotective potential of Npas4 in the context of ischaemic damage. Using oxygen and glucose deprivation, we demonstrated that the knockdown of Npas4 in mouse cortical neurons resulted in increased susceptibility to cell death. The protective effect of Npas4 was further investigated in vivo using a photochemically-induced stroke model in mice. We found a significantly larger lesion size and increased neurodegeneration in Npas4 knockout mice as compared to wild-type mice. Moreover, we also showed that ablation of Npas4 caused an increase in activated astrocytes and microglia, pro-inflammatory cytokines interleukin-6 and tumour necrosis factor alpha levels and a switch from apoptotic to necrotic cell death. Taken together, these data suggest that Npas4 plays a neuroprotective role in ischaemic stroke by limiting progressive neurodegeneration and neuroinflammation. PMID:26661154

  11. Effect of pretreatment atmosphere on the particle size and oxygen reduction activity of low-loading platinum impregnated titanium carbide powder electrocatalysts

    NASA Astrophysics Data System (ADS)

    Yang, Leerang; Kimmel, Yannick C.; Lu, Qi; Chen, Jingguang G.

    2015-08-01

    Low-loading Pt supported on TiC powder catalysts were synthesized by an impregnation method. After the Pt(NH3)4(NO3)2 precursor was impregnated onto the TiC support, different pretreatment atmospheres were used to study the influence on Pt dispersion, surface composition, and catalytic activity towards oxygen reduction reaction (ORR). Direct reduction of the Pt precursor in hydrogen led to small Pt particles with an average size of ∼2.2 nm and superior ORR activity at low overpotential compared to commercial Pt/C. However, calcination of the Pt precursor in air resulted in larger Pt particles with an average size of ∼6.7 nm and lower ORR specific activity. The decrease in ORR activity was primarily attributed to the surface oxidation of the TiC support during calcination. X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) confirmed that the TiC powder was oxidized when the catalyst was calcined in air. The finding reported here demonstrates the importance of pretreatment atmosphere for synthesizing Pt-modified transition metal carbides as highly active electrocatalysts.

  12. Facile fabrication of a silicon nanowire sensor by two size reduction steps for detection of alpha-fetoprotein biomarker of liver cancer

    NASA Astrophysics Data System (ADS)

    Binh Pham, Van; ThanhTung Pham, Xuan; Nhat Khoa Phan, Thanh; Thanh Tuyen Le, Thi; Chien Dang, Mau

    2015-12-01

    We present a facile technique that only uses conventional micro-techniques and two size-reduction steps to fabricate wafer-scale silicon nanowire (SiNW) with widths of 200 nm. Initially, conventional lithography was used to pattern SiNW with 2 μm width. Then the nanowire width was decreased to 200 nm by two size-reduction steps with isotropic wet etching. The fabricated SiNW was further investigated when used with nanowire field-effect sensors. The electrical characteristics of the fabricated SiNW devices were characterized and pH sensitivity was investigated. Then a simple and effective surface modification process was carried out to modify SiNW for subsequent binding of a desired receptor. The complete SiNW-based biosensor was then used to detect alpha-fetoprotein (AFP), one of the medically approved biomarkers for liver cancer diagnosis. Electrical measurements showed that the developed SiNW biosensor could detect AFP with concentrations of about 100 ng mL-1. This concentration is lower than the necessary AFP concentration for liver cancer diagnosis.

  13. Gold nanoparticles in aqueous solutions: influence of size and pH on hydrogen dissociative adsorption and Au(iii) ion reduction.

    PubMed

    Ershov, B G; Abkhalimov, E V; Solovov, R D; Roldughin, V I

    2016-05-21

    The shift of the localized surface plasmon resonance (LSPR) band of gold nanoparticles to shorter wavelengths upon saturation of the hydrosol with hydrogen is used as a tool to study the electrochemical processes on the particle surface. It is shown that dissociative adsorption of hydrogen takes place on the surface of a particle and results in the migration of a proton into the dispersion medium, while the electron remains on the nanoparticle, i.e., a hydrogen-like nanoelectrode is formed. It is shown that Au(iii) ions can be reduced on the gold nanoelectrodes. A thermodynamic scheme explaining the shift of the LSPR band is used to explain the peculiarities of the Au(iii) ion reduction. The reduction rate does not depend on the ion concentration and varies linearly with pH. The observed correlations are explained in terms of a simple model of electrochemical processes taking place on the nanoparticle as an electrode. It is shown that with an increase in the particle size, its capacity for dissociative adsorption of hydrogen decreases and the Au(iii) reduction slows down. PMID:27125624

  14. Halons: The hidden dangers of accelerated decommissioning

    SciTech Connect

    Dalzell, G.A.

    1996-12-31

    Many operators have introduced a decommissioning programme for halon systems following the Montreal Protocol and the cessation of production of 1211 and 1301. Some have already decommissioned all their systems. This paper questions whether rapid decommissioning, particularly when faced with external pressure or a desire to be {open_quotes}seen to be green{close_quotes} does reduce the environmental impact. It examines the lifecycle of the halon in an existing system until it is finally destroyed, used, or lost to the atmosphere. Halon is one of the most difficult gases to contain. It is more prone to leakage than almost any other gas. Fixed systems, which contain the majority of 1301 also have valve arrangements which are designed to open with the minimum of energy input. As a result they are also prone to accidental discharge. This paper examines these aspects and the potential for loss to the atmosphere when decommissioning, transporting, recycling and storing the halon. Controlling leakage and preventing accidental discharges within systems has been addressed in other work.

  15. 78 FR 663 - Decommissioning Planning During Operations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-04

    ... complying with the NRC's Decommissioning Planning Rule (DPR) (76 FR 35512; June 17, 2011). The DPR went into... use by holders of licenses in complying with the DPR. On December 13, 2011 (76 FR 77431), the NRC... was extended from February 10, 2012 to March 30, 2012 (77 FR 8751; February 15, 2012) to allow...

  16. University of Virginia Reactor Facility Decommissioning Results

    SciTech Connect

    Ervin, P. F.; Lundberg, L. A.; Benneche, P. E.; Mulder, R. U.; Steva, D. P.

    2003-02-24

    The University of Virginia Reactor Facility started accelerated decommissioning in 2002. The facility consists of two licensed reactors, the CAVALIER and the UVAR. This paper will describe the progress in 2002, remaining efforts and the unique organizational structure of the project team.

  17. Decommissioning of the Northrop TRIGA reactor

    SciTech Connect

    Cozens, George B.; Woo, Harry; Benveniste, Jack; Candall, Walter E.; Adams-Chalmers, Jeanne

    1986-07-01

    An overview of the administrative and operational aspects of decommissioning and dismantling the Northrop Mark F TRIGA Reactor, including: planning and preparation, personnel requirements, government interfacing, costs, contractor negotiations, fuel shipments, demolition, disposal of low level waste, final survey and disposition of the concrete biological shielding. (author)

  18. Decontamination and decommissioning of Shippingport commercial reactor

    SciTech Connect

    Schreiber, J.

    1989-11-01

    To a certain degree, the decontamination and decommissioning (D and D) of the Shippingport reactor was a joint venture with Duquesne Light Company. The structures that were to be decommissioned were to be removed to at least three feet below grade. Since the land had been leased from Duquesne Light, there was an agreement with them to return the land to them in a radiologically safe condition. The total enclosure volume for the steam and nuclear containment systems was about 1.3 million cubic feet, more than 80% of which was below ground. Engineering plans for the project were started in July of 1980 and the final environmental impact statement (EIS) was published in May of 1982. The plant itself was shut down in October of 1982 for end-of-life testing and defueling. The engineering services portion of the decommissioning plans was completed in September of 1983. DOE moved onto the site and took over from the Navy in September of 1984. Actual physical decommissioning began after about a year of preparation and was completed about 44 months later in July of 1989. This paper describes the main parts of D and D.

  19. Sodium Reactor Experiment decommissioning. Final report

    SciTech Connect

    Carroll, J.W.; Conners, C.C.; Harris, J.M.; Marzec, J.M.; Ureda, B.F.

    1983-08-15

    The Sodium Reactor Experiment (SRE) located at the Rockwell International Field Laboratories northwest of Los Angeles was developed to demonstrate a sodium-cooled, graphite-moderated reactor for civilian use. The reactor reached full power in May 1958 and provided 37 GWh to the Southern California Edison Company grid before it was shut down in 1967. Decommissioning of the SRE began in 1974 with the objective of removing all significant radioactivity from the site and releasing the facility for unrestricted use. Planning documentation was prepared to describe in detail the equipment and techniques development and the decommissioning work scope. A plasma-arc manipulator was developed for remotely dissecting the highly radioactive reactor vessels. Other important developments included techniques for using explosives to cut reactor vessel internal piping, clamps, and brackets; decontaminating porous concrete surfaces; and disposing of massive equipment and structures. The documentation defined the decommissioning in an SRE dismantling plan, in activity requirements for elements of the decommissioning work scope, and in detailed procedures for each major task.

  20. Peptide mediated active targeting and intelligent particle size reduction-mediated enhanced penetrating of fabricated nanoparticles for triple-negative breast cancer treatment.

    PubMed

    Hu, Guanlian; Chun, Xingli; Wang, Yang; He, Qin; Gao, Huile

    2015-12-01

    Triple-negative breast cancer (TNBC) is one of the most invasively malignant human cancers and its incidence increases year by year. Effective therapeutics against them needs to be developed urgently. In this study, a kind of angiopep-2 modified and intelligently particle size-reducible NPs, Angio-DOX-DGL-GNP, was designed for accomplishing both high accumulation and deep penetration within tumor tissues. On one hand, for improving the cancerous targeting efficiency of NPs, angiopep-2 was anchored on the surface of NPs to facilitate their accumulation via binding with low density lipoprotein-receptor related protein (LRP) overexpressed on TNBC. On the other hand, for achieving high tumor retention and increasing tumor penetration, an intelligently particle size-reducible NPs were constructed through fabricating gelatin NPs (GNP) with doxorubicin (DOX) loaded dendrigraft poly-lysine (DGL). In vitro cellular uptake and ex-vivo imaging proved the tumor targeting effect of Angio-DOX-DGL-GNP. Additionally, the degradation of large-sized Angio-DOX-DGL-GNP by matrix metalloproteinase-2 (MMP-2) led to the size reduction from 185.7 nm to 55.6 nm. More importantly, the penetration ability of Angio-DOX-DGL-GNP after incubation with MMP-2 was dominantly enhanced in tumor spheroids. Due to a combinational effect of active targeting and deep tumor penetration, the tumor growth inhibition rate of Angio-DOX-DGL-GNP was 74.1% in a 4T1 breast cancer bearing mouse model, which was significantly higher than other groups. Taken together, we successfully demonstrated a promising and effective nanoplatform for TNBC treatment. PMID:26517810

  1. Peptide mediated active targeting and intelligent particle size reduction-mediated enhanced penetrating of fabricated nanoparticles for triple-negative breast cancer treatment

    PubMed Central

    Hu, Guanlian; Chun, Xingli; Wang, Yang; He, Qin; Gao, Huile

    2015-01-01

    Triple-negative breast cancer (TNBC) is one of the most invasively malignant human cancers and its incidence increases year by year. Effective therapeutics against them needs to be developed urgently. In this study, a kind of angiopep-2 modified and intelligently particle size-reducible NPs, Angio-DOX-DGL-GNP, was designed for accomplishing both high accumulation and deep penetration within tumor tissues. On one hand, for improving the cancerous targeting efficiency of NPs, angiopep-2 was anchored on the surface of NPs to facilitate their accumulation via binding with low density lipoprotein-receptor related protein (LRP) overexpressed on TNBC. On the other hand, for achieving high tumor retention and increasing tumor penetration, an intelligently particle size-reducible NPs were constructed through fabricating gelatin NPs (GNP) with doxorubicin (DOX) loaded dendrigraft poly-lysine (DGL). In vitro cellular uptake and ex-vivo imaging proved the tumor targeting effect of Angio-DOX-DGL-GNP. Additionally, the degradation of large-sized Angio-DOX-DGL-GNP by matrix metalloproteinase-2 (MMP-2) led to the size reduction from 185.7 nm to 55.6 nm. More importantly, the penetration ability of Angio-DOX-DGL-GNP after incubation with MMP-2 was dominantly enhanced in tumor spheroids. Due to a combinational effect of active targeting and deep tumor penetration, the tumor growth inhibition rate of Angio-DOX-DGL-GNP was 74.1% in a 4T1 breast cancer bearing mouse model, which was significantly higher than other groups. Taken together, we successfully demonstrated a promising and effective nanoplatform for TNBC treatment. PMID:26517810

  2. The Impacts of Budget Reductions on Indiana's Public Schools: The Impact of Budget Changes on Student Achievement, Personnel, and Class Size for Public School Corporations in the State of Indiana

    ERIC Educational Resources Information Center

    Jarman, Del W.; Boyland, Lori G.

    2011-01-01

    In recent years, economic downturn and changes to Indiana's school funding have resulted in significant financial reductions in General Fund allocations for many of Indiana's public school corporations. The main purpose of this statewide study is to examine the possible impacts of these budget reductions on class size and student achievement. This…

  3. NMSS handbook for decommissioning fuel cycle and materials licensees

    SciTech Connect

    Orlando, D.A.; Hogg, R.C.; Ramsey, K.M.

    1997-03-01

    The US Nuclear Regulatory Commission amended its regulations to set forth the technical and financial criteria for decommissioning licensed nuclear facilities. These regulations were further amended to establish additional recordkeeping requirements for decommissioning; to establish timeframes and schedules for the decommissioning; and to clarify that financial assurance requirements must be in place during operations and updated when licensed operations cease. Reviews of the Site Decommissioning Management Plan (SDMP) program found that, while the NRC staff was overseeing the decommissioning program at nuclear facilities in a manner that was protective of public health and safety, progress in decommissioning many sites was slow. As a result NRC determined that formal written procedures should be developed to facilitate the timely decommissioning of licensed nuclear facilities. This handbook was developed to aid NRC staff in achieving this goal. It is intended to be used as a reference document to, and in conjunction with, NRC Inspection Manual Chapter (IMC) 2605, ``Decommissioning Inspection Program for Fuel Cycle and Materials Licensees.`` The policies and procedures discussed in this handbook should be used by NRC staff overseeing the decommissioning program at licensed fuel cycle and materials sites; formerly licensed sites for which the licenses were terminated; sites involving source, special nuclear, or byproduct material subject to NRC regulation for which a license was never issued; and sites in the NRC`s SDMP program. NRC staff overseeing the decommissioning program at nuclear reactor facilities subject to regulation under 10 CFR Part 50 are not required to use the procedures discussed in this handbook.

  4. 30 CFR 250.1750 - When may I decommission a pipeline in place?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false When may I decommission a pipeline in place... Decommissioning Activities Pipeline Decommissioning § 250.1750 When may I decommission a pipeline in place? You may decommission a pipeline in place when the Regional Supervisor determines that the pipeline...

  5. 30 CFR 250.1754 - When must I remove a pipeline decommissioned in place?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false When must I remove a pipeline decommissioned in... Decommissioning Activities Pipeline Decommissioning § 250.1754 When must I remove a pipeline decommissioned in place? You must remove a pipeline decommissioned in place if the Regional Supervisor determines that...

  6. 30 CFR 250.1750 - When may I decommission a pipeline in place?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false When may I decommission a pipeline in place... Decommissioning Activities Pipeline Decommissioning § 250.1750 When may I decommission a pipeline in place? You may decommission a pipeline in place when the Regional Supervisor determines that the pipeline...

  7. 30 CFR 250.1754 - When must I remove a pipeline decommissioned in place?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false When must I remove a pipeline decommissioned in... Decommissioning Activities Pipeline Decommissioning § 250.1754 When must I remove a pipeline decommissioned in place? You must remove a pipeline decommissioned in place if the Regional Supervisor determines that...

  8. 30 CFR 250.1753 - After I decommission a pipeline, what information must I submit?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false After I decommission a pipeline, what... SHELF Decommissioning Activities Pipeline Decommissioning § 250.1753 After I decommission a pipeline, what information must I submit? Within 30 days after you decommission a pipeline, you must submit...

  9. 30 CFR 250.1753 - After I decommission a pipeline, what information must I submit?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false After I decommission a pipeline, what... SHELF Decommissioning Activities Pipeline Decommissioning § 250.1753 After I decommission a pipeline, what information must I submit? Within 30 days after you decommission a pipeline, you must submit...

  10. 30 CFR 250.1753 - After I decommission a pipeline, what information must I submit?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false After I decommission a pipeline, what... SHELF Decommissioning Activities Pipeline Decommissioning § 250.1753 After I decommission a pipeline, what information must I submit? Within 30 days after you decommission a pipeline, you must submit...

  11. 30 CFR 250.1750 - When may I decommission a pipeline in place?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false When may I decommission a pipeline in place... Decommissioning Activities Pipeline Decommissioning § 250.1750 When may I decommission a pipeline in place? You may decommission a pipeline in place when the Regional Supervisor determines that the pipeline...

  12. 30 CFR 250.1754 - When must I remove a pipeline decommissioned in place?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false When must I remove a pipeline decommissioned in... Decommissioning Activities Pipeline Decommissioning § 250.1754 When must I remove a pipeline decommissioned in place? You must remove a pipeline decommissioned in place if the Regional Supervisor determines that...

  13. 30 CFR 250.1754 - When must I remove a pipeline decommissioned in place?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false When must I remove a pipeline decommissioned in... SHELF Decommissioning Activities Pipeline Decommissioning § 250.1754 When must I remove a pipeline decommissioned in place? You must remove a pipeline decommissioned in place if the Regional Supervisor...

  14. 30 CFR 250.1753 - After I decommission a pipeline, what information must I submit?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false After I decommission a pipeline, what... OUTER CONTINENTAL SHELF Decommissioning Activities Pipeline Decommissioning § 250.1753 After I decommission a pipeline, what information must I submit? Within 30 days after you decommission a pipeline,...

  15. 30 CFR 250.1753 - After I decommission a pipeline, what information must I submit?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false After I decommission a pipeline, what... Decommissioning Activities Pipeline Decommissioning § 250.1753 After I decommission a pipeline, what information must I submit? Within 30 days after you decommission a pipeline, you must submit a written report...

  16. Self-reduction and size controlled synthesis of silver nanoparticles on carbon nanospheres by grafting triazine-based molecular layer for conductivity improvement

    NASA Astrophysics Data System (ADS)

    Sang, Jing; Aisawa, Sumio; Hirahara, Hidetoshi; Kudo, Takahiro; Mori, Kunio

    2016-02-01

    A facile, self-reduction and size controlled synthesis method has been explored to fabricate silver nanoparticles (Ag NPs) on carbon nanosphere (CNs) under mild conditions. Without using predeposition of seed metals and reducing agent, a uniform and complete layer of Ag NPs was formed through grafting a molecular layer on CNs surfaces under UV irradiation. The size and thickness of Ag NPs were effectively tuned by adjusting the UV irradiation time. This direct formation of Ag NPs was attributed to self seed in aqueous Ag(NH3)2+ complex solution through a triazine-based silane coupling agent molecular layer, even at 25 °C. Scanning electron microscopy (SEM), Transmission electron microscope (TEM), and X-ray photoelectron spectroscopy (XPS) were employed to characterize the Ag NPs' properties. A substantial conductivity improvement of prepared Ag NPs on carbon nanosphere was demonstrated. The presented method is simple and environmentally friendly and thus should be of significant value for the industrial fabrication of Ag NPs on carbon nanosphere in conduct electricity paint and coating applications.

  17. In Situ Decommissioning (ISD) Concepts and Approaches for Excess Nuclear Facilities Decommissioning End State - 13367

    SciTech Connect

    Serrato, Michael G.; Musall, John C.; Bergren, Christopher L.

    2013-07-01

    The United States Department of Energy (DOE) currently has numerous radiologically contaminated excess nuclear facilities waiting decommissioning throughout the Complex. The traditional decommissioning end state is complete removal. This commonly involves demolishing the facility, often segregating various components and building materials and disposing of the highly contaminated, massive structures containing tons of highly contaminated equipment and piping in a (controlled and approved) landfill, at times hundreds of miles from the facility location. Traditional demolition is costly, and results in significant risks to workers, as well as risks and costs associated with transporting the materials to a disposal site. In situ decommissioning (ISD or entombment) is a viable alternative to demolition, offering comparable and potentially more protective protection of human health and the environment, but at a significantly reduced cost and worker risk. The Savannah River Site (SRS) has completed the initial ISD deployment for radiologically contaminated facilities. Two reactor (P and R Reactors) facilities were decommissioned in 2011 using the ISD approach through the American Recovery and Reinvestment Act. The SRS ISD approach resolved programmatic, regulatory and technical/engineering issues associated with avoiding the potential hazards and cost associated with generating and disposing of an estimated 124,300 metric tons (153,000 m{sup 3}) of contaminated debris per reactor. The DOE Environmental Management Office of Deactivation and Decommissioning and Facility Engineering, through the Savannah River National Laboratory, is currently investigating potential monitoring techniques and strategies to assess ISD effectiveness. As part of SRS's strategic planning, the site is seeking to leverage in situ decommissioning concepts, approaches and facilities to conduct research, design end states, and assist in regulatory interactions in broad national and international

  18. Rates of particle size reduction and passage are faster for legume compared with cool-season grass, resulting in lower rumen fill and less effective fiber.

    PubMed

    Kammes, K L; Allen, M S

    2012-06-01

    Effects of forage family on rates of particle size reduction in, and passage from, the rumen and the relationship of these effects with preliminary dry matter intake (pDMI) were evaluated using 13 ruminally and duodenally cannulated Holstein cows in a crossover design with a 14-d preliminary period and two 18-d treatment periods. During the preliminary period, pDMI of individual cows ranged from 19.6 to 29.5 kg/d (mean = 25.9 kg/d). Experimental treatments were diets containing either a) alfalfa silage (AL) or b) orchardgrass silage (OG) as the sole forage. Silages were chopped to 10-mm theoretical length of cut and contained 42.3 and 58.2% neutral detergent fiber (NDF) for alfalfa and orchardgrass, respectively. Both diets contained approximately 25% forage NDF and 30% total NDF. Feed, orts, rumen, and duodenal samples were wet sieved to fractionate particles above (large) and below (small) 2.36 mm. Indigestible NDF (iNDF) was used as a flow marker. Preliminary DMI, an index of nutrient demand, was determined during the last 4 d of the preliminary period when cows were fed a common diet and used as a covariate. Main effects of forage family and their interaction with pDMI were tested by ANOVA. Approximately 75% of the NDF consumed was large and 25% was small for both treatments, but cows fed AL consumed more iNDF and less potentially digestible NDF (pdNDF) than cows fed OG. The AL diet increased the reduction rate (large to small) compared with OG despite less rumination per unit of forage NDF for AL than OG, suggesting alfalfa NDF was more fragile than orchardgrass NDF. Over 55% of particles in the rumen were below 2.36 mm for AL and OG, indicating that particle size was not a limiting constraint to passage. Passage rates (k(p)) of large iNDF and large pdNDF were similar for AL and OG, but AL increased k(p) of large pdNDF and OG decreased it as pDMI increased. The AL diet increased k(p) of small iNDF and small pdNDF compared with OG, resulting in lower rumen fill

  19. Decommissioning of the Tokamak Fusion Test Reactor

    SciTech Connect

    E. Perry; J. Chrzanowski; C. Gentile; R. Parsells; K. Rule; R. Strykowsky; M. Viola

    2003-10-28

    The Tokamak Fusion Test Reactor (TFTR) at the Princeton Plasma Physics Laboratory was operated from 1982 until 1997. The last several years included operations with mixtures of deuterium and tritium. In September 2002, the three year Decontamination and Decommissioning (D&D) Project for TFTR was successfully completed. The need to deal with tritium contamination as well as activated materials led to the adaptation of many techniques from the maintenance work during TFTR operations to the D&D effort. In addition, techniques from the decommissioning of fission reactors were adapted to the D&D of TFTR and several new technologies, most notably the development of a diamond wire cutting process for complex metal structures, were developed. These techniques, along with a project management system that closely linked the field crews to the engineering staff who developed the techniques and procedures via a Work Control Center, resulted in a project that was completed safely, on time, and well below budget.

  20. Gnome site decontamination and decommissioning project

    SciTech Connect

    Orcutt, J.A.; Sorom, E.R.

    1982-08-01

    In July 1977, DOE/Headquarters directed DOE/NV to design a decontamination and decommissioning plan for the Gnome site, 48 kilometers southeast of Carlsbad, New Mexico. The plan incorporated three distinct phases. During Phase I, both aerial and ground radiological surveys were conducted on the site. Radiological decontamination criteria were established, and a decontamination plan was developed based on the radiological survey results. During Phase II, site preparatory and rehabilitation work was completed. The actual land area decontamination was accomplished during Phase III with conventional earthmoving equipment. A gravity water injection system deposited 36,700 metric tons of contaminated soil and salt in the Gnome cavity. After completion of the decontamination and decommissioning operations, the Gnome site was returned to the Bureau of Land Management for unrestricted surface use.

  1. P2 integration into conduct of decommissioning

    SciTech Connect

    Boing, L.E.; Lindley, R.

    1997-08-01

    Over the last five years, the D and D Program at the ANL-East site has completed decommissioning of three facilities. Currently, decommissioning of two facilities continues at the site with completion of the JANUS Reactor scheduled for September 1997 and completion of the CP-5 Reactor scheduled for late in CY 1999. In the course of this work, certain waste minimization pollution prevention (WMin/P2) activities have been integrated into all these projects. In most cases, the P2 aspects were key components of the operations that made the best use of available project resources to complete the work safely, within the budget and on or ahead of schedule. This paper will highlight those WMin/P2 activities found most suitable for these D and D operations. Activities covered will include: re-use of lead bricks from a research reactor for shielding material at an accelerator facility, re-use of a reactor out building structure by the on-site plant services group, and several other smaller scope activities which have also helped heighten WMin/P2 awareness in decommissioning.

  2. Investment management for nuclear decommissioning trusts

    SciTech Connect

    Stimes, P.C.; Flaherty, R.T. )

    1990-11-22

    According to Nuclear Regulatory Commission estimates, and assuming a 4 percent annual inflation rate, minimum decommissioning requirements for a single reactor could total almost $350 million after 30 years. Consequently, reducing customer contributions to decommissioning funds is a potentially rewarding activity. In fact, improving the after-tax return earned on an NDT fund by as little as one percentage point can reduce customer contributions to the fund by 15% over its life. Unfortunately, many electric utilities are headed in the wrong direction and are unlikely to achieve satisfactory results. The main problem is the prevalence of the conventional wisdom, most of which has been appropriated from the area of pension fund management. This is an area which is familiar to most utility managements, but which has only superficial similarity to the issue of NDT investing. The differences are pronounced: NDTs, unlike pensions, are fully taxable at corporate income tax rates. In addition, NDT managers should be concerned with protecting the inflation-adjusted or real value of fund investments at a single, future decommissioning date. Pension managers, on the other hand, may be concerned with satisfying nominal contractual obligations spread over an extended future time horizon. In view of the large stakes involved in the management of NDTs, the authors summarize five key tenets of the conventional wisdom in this area and demonstrate where they feel they are in error.

  3. Decommissioning nuclear power plants - the wave of the future

    SciTech Connect

    Griggs, F.S. Jr.

    1994-12-31

    The paper discusses the project controls developed in the decommissioning of a nuclear power plant. Considerations are given to the contaminated piping and equipment that have to be removed and the spent and used fuel that has to be disposed of. The storage issue is of primary concern here. The cost control aspects and the dynamics of decommissioning are discussed. The effects of decommissioning laws on the construction and engineering firms are mentioned. 5 refs.

  4. Uranium determination in samples from decommissioning of nuclear facilities related to the first stage of the nuclear fuel cycle

    PubMed

    Alvarez; Correa; Navarro; Sancho

    2000-07-01

    Large amounts of waste materials are generated during the decommissioning of nuclear facilities. Clearance levels are established by regulatory authorities and are normally quite low. Determination of those activity concentration levels becomes more difficult when it is necessary to quantify alpha emitters such as uranium, especially when complex matrixes are involved. In addition, an adequate workplace monitoring must be carried out during the decommissioning activities, to ensure the protection of workers involved in these tasks. Several methods for uranium determination in samples obtained during the decommissioning of a facility related to the first stage of the nuclear fuel cycle are presented in this work. According to the kind and sample size, together with the minimum detectable activity (MDA) that must be reached in each case, measurements were carried out by laboratory and 'in situ' gamma spectrometry, as well as by alpha spectrometry. A comparison among the different techniques was also performed by analysing the results obtained in some practical applications. PMID:10879885

  5. First-generation litter-size reduction following irradiation of spermatogonial stem cells in mice and its use in risk estimation

    SciTech Connect

    Selby, P.B.; Russell, W.L.

    1985-01-01

    Litter-size reduction (LSR) is a useful measure of part of the overall F/sub 1/ radiation-induced damage. Extensive LSR data were obtained as a by-product of specific-locus experiments. Fourteen such experiments involving 158,490 F/sub 1/ litters have been analyzed for the extent of LSR induced by x- or gamma-irradiation of spermatogonia. Litter sizes were compared between experimental and control groups at about 3 weeks after birth. At the high dose rate of 90 R/min, the LSRs showed a humped dose-response curve. There was a pronounced dose-rate effect, the mutational responses being much less at dose rates of 0.009 R/min and 0.001 R/min. It is estimated that if men were exposed to 1 R of radiation delivered at low linear energy transfer (low LET) and low dose rate, the number of deaths caused by induced dominant mutations among their children before late childhood would be about 19 per million live-born. This can be added to the earlier estimate of an approximately equal number of viable disorders in all body systems as based on dominant skeletal mutations. This gives a total estimate of induced dominant damage, but much of this addition represents death in very early embryonic life that would not be recognized in humans. The LSR data also permit the conclusion that only an extremely small proportion of serious radiation-induced genetic disorders among live-born humans would be expected to result from segmental aneuploidy.

  6. Brittle grain size reduction of feldspar, phase mixing and strain localization in granitoids at mid-crustal conditions (Pernambuco shear zone, NE Brazil)

    NASA Astrophysics Data System (ADS)

    Viegas, Gustavo; Menegon, Luca; Archanjo, Carlos

    2016-04-01

    localized much of the strain. Extensive grain-size reduction and weakening of feldspars is attained in the East Pernambuco shear zone mainly via fracturing under relatively fluid-absent conditions which would trigger a switch to diffusion creep and further strain localization without a prominent role of metamorphic reactions.

  7. Brittle grain size reduction of feldspar, phase mixing and strain localization in granitoids at mid-crustal conditions (Pernambuco shear zone, NE Brazil)

    NASA Astrophysics Data System (ADS)

    Viegas, G.; Menegon, L.; Archanjo, C. J.

    2015-10-01

    feldspathic material localized much of the strain. Extensive grain-size reduction and weakening of feldspars is attained in the East Pernambuco mylonites mainly via fracturing under relatively fluid-absent conditions which would trigger a switch to diffusion creep and further strain localization without a prominent role of metamorphic reactions.

  8. Size and structure effects of Pt{sub N} (N = 12 − 13) clusters for the oxygen reduction reaction: First-principles calculations

    SciTech Connect

    Rodríguez-Kessler, P. L.; Rodríguez-Domínguez, A. R.

    2015-11-14

    Size and structure effects on the oxygen reduction reaction on Pt{sub N} clusters with N = 12–13 atoms have been investigated using periodic density functional theory calculations with the generalized gradient approximation. To describe the catalytic activity, we calculated the O and OH adsorption energies on the cluster surface. The oxygen binding on the 3-fold hollow sites on stable Pt{sub 12−13} cluster models resulted more favorable for the reaction with O, compared with the Pt{sub 13}(I{sub h}) and Pt{sub 55}(I{sub h}) icosahedral particles, in which O binds strongly. However, the rate-limiting step resulted in the removal of the OH species due to strong adsorptions on the vertex sites, reducing the utility of the catalyst surface. On the other hand, the active sites of Pt{sub 12−13} clusters have been localized on the edge sites. In particular, the OH adsorption on a bilayer Pt{sub 12} cluster is the closest to the optimal target; with 0.0-0.2 eV weaker than the Pt(111) surface. However, more progress is necessary to activate the vertex sites of the clusters. The d-band center of Pt{sub N} clusters shows that the structural dependence plays a decisive factor in the cluster reactivity.

  9. Preparation of onion-like Pt-terminated Pt-Cu bimetallic nano-sized electrocatalysts for oxygen reduction reaction in fuel cells

    NASA Astrophysics Data System (ADS)

    Lim, Taeho; Kim, Ok-Hee; Sung, Yung-Eun; Kim, Hyun-Jong; Lee, Ho-Nyun; Cho, Yong-Hun; Kwon, Oh Joong

    2016-06-01

    Onion-like Pt-terminated Pt-Cu bimetallic nano-sized electrocatalysts (Pt/Cu/Pt/C) were synthesized by using an electroless deposition method. The synthesized Pt/Cu/Pt/C consisted of a Pt-enriched shell, a sandwiched Pt-Cu alloy layer, and a Pt core. The Pt/Cu/Pt/C showed higher electrocatalytic activity toward oxygen reduction reaction in half-cell test than that of commercial Pt/C due to an electronic structure change in the Pt-enriched shell, resulting from the sandwiched Pt-Cu alloy layer underneath. The stability of the Pt/Cu/Pt/C was examined by using both half-cell and single-cell degradation tests. In both tests, the Pt/Cu/Pt/C exhibited stronger resistance to catalyst degradation than that of the commercial Pt/C. It is notable that cell performance with the Pt/Cu/Pt/C was fully recovered by N2 purging after single-cell degradation testing, indicating there was no permanent damage to the electrocatalyst during the test. It is suggested that thermodynamically-stable structure of the Pt/Cu/Pt/C contributed to the improved stability.

  10. Evaluation of minimum coverage size and orbital accuracy at different orbital regimes for one order of magnitude reduction of the catastrophic collision risk

    NASA Astrophysics Data System (ADS)

    Sánchez-Ortiz, Noelia; Domínguez-González, Raúl; Krag, Holger

    2015-03-01

    One of the main objectives of Space Surveillance and Tracking (SST) systems is to support space collision avoidance activities. This collision avoidance capability aims to significantly reduce the catastrophic collision risk of space objects. In particular, for the case of the future European SST, the objective is translated into a risk reduction of one order of magnitude whilst keeping a low number of false alarm events. In order to translate this aim into system requirements, an evaluation of the current catastrophic collision risk for different orbital regimes is addressed. The reduction of such risk depends on the amount of catalogued objects (coverage) and the knowledge of the associated orbits in the catalogue (accuracy). This paper presents an analysis of the impact of those two aspects in the capability to reduce the catastrophic collision risk at some orbital regimes. A reliable collision avoidance support depends on the accuracy of the predicted miss-events. The assessment of possible conjunctions is normally done by computing the estimated miss-distances between objects (which is compared with a defined distance threshold) or by computing the associated collision risk (which is compared with the corresponding accepted collision probability level). This second method is normally recommended because it takes into account the reliability of the orbits and allows reducing false alarm events. The collision risk depends on the estimated miss-distance, the object sizes and the accuracy of the two orbits at the time of event. This accuracy depends on the error of the orbits at the orbit determination epoch and the error derived from the propagation from that epoch up to the time of event. The modified DRAMA ARES (Domínguez-González et al., 2012, 2013a,b; Gelhaus et al., 2014) provides information on the expected number of encounters for a given mission and year. It also provides information on the capacity to reduce the risk of collision by means of avoidance

  11. Lessons Learned Following the Successful Decommissioning of a Reaction Vessel Containing Lime Sludge and Technetium-99

    SciTech Connect

    Dawson, P. M.; Watson, D. D.; Hylko, J. M.

    2002-02-25

    This paper documents how WESKEM, LLC utilized available source term information, integrated safety management, and associated project controls to safely decommission a reaction vessel and repackage sludge containing various Resource Conservation and Recovery Act constituents and technetium-99 (Tc-99). The decommissioning activities were segmented into five separate stages, allowing the project team to control work related decisions based on their knowledge, experience, expertise, and field observations. The information and experience gained from each previous stage and rehearsals contributed to modifying subsequent entries, further emphasizing the importance of developing hold points and incorporating lessons learned. The hold points and lessons learned, such as performing detailed personal protective equipment (PPE) inspections during sizing and repackaging operations, and using foam-type piping insulation to prevent workers from cutting or puncturing their PPE on sharp edge s or small shards generated during sizing operations, minimized direct contact with the Tc-99. To prevent the spread of contamination, the decommissioning activities were performed inside a containment enclosure connected to negative air machines. After performing over 235 individual entries totaling over 285 project hours, only one first aid was recorded during this five-stage project.

  12. Evaluation of decommissioning alternatives for the Pilot Plant Complex, Aberdeen Proving Ground

    SciTech Connect

    Rueda, J.; Zimmerman, R.E.

    1995-09-01

    This report presents an evaluation of four decommissioning alternatives for the Pilot Plant Complex (PPC), an inactive chemical weapons research, development, and production facility consisting of nine buildings located in the Edgewood Area of the Aberdeen Proving Ground in Maryland. Decommissioning the PPC involves six steps: (1) assessing existing conditions; (2) dismantling the aboveground portions of the buildings (including the floor slabs, paved roads, and sidewalks within the PPC); (3) reducing the size of the demolition debris and sealing the debris in containers for later testing and evaluation; (4) testing and evaluating the debris; (5) conducting site operation and maintenance activities; and (6) recycling or disposing of the debris with or without prior treatment, as appropriate.

  13. Decommissioning: Nuclear Power's Missing Link. Worldwatch Paper 69.

    ERIC Educational Resources Information Center

    Pollock, Cynthia

    The processes and associated dilemmas of nuclear power plant decommissioning are reviewed in this publication. Decommissioning involves the clearing up and disposal of a retired nuclear plant and its equipment of such a way as to safeguard the public from the dangers of radioactivity. Related problem areas are identified and include: (1) closure…

  14. 18 CFR 2.24 - Project decommissioning at relicensing.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Project decommissioning at relicensing. 2.24 Section 2.24 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY... Policy and Interpretations Under the Federal Power Act § 2.24 Project decommissioning at relicensing....

  15. Decommissioning considerations at a time of nuclear renaissance

    SciTech Connect

    Devgun, Jas S.

    2007-07-01

    At a time of renaissance in the nuclear power industry, when it is estimated that anywhere between 60 to 130 new power reactors may be built worldwide over the next 15 years, why should we focus on decommissioning? Yet it is precisely the time to examine what decommissioning considerations should be taken into account as the industry proceeds with developing final designs for new reactors and the construction on the new build begins. One of the lessons learned from decommissioning of existing reactors has been that decommissioning was not given much thought when these reactors were designed three or four decades ago. Even though decommissioning may be sixty years down the road from the time they go on line, eventually all reactors will be decommissioned. It is only prudent that new designs be optimized for eventual decommissioning, along with the other major considerations. The overall objective in this regard is that when the time comes for decommissioning, it can be completed in shorter time frames, with minimum generation of radioactive waste, and with better radiological safety. This will ensure that the tail end costs of the power reactors are manageable and that the public confidence in the nuclear power is sustained through the renaissance and beyond. (author)

  16. Optimising waste management performance - The key to successful decommissioning

    SciTech Connect

    Keep, Matthew

    2007-07-01

    Available in abstract form only. Full text of publication follows: On the 1. of April 2005 the United Kingdom's Nuclear Decommissioning Authority became responsible for the enormous task of decommissioning the UK's civilian nuclear liabilities. The success of the NDA in delivering its key objectives of safer, cheaper and faster decommissioning depends on a wide range factors. It is self-evident, however, that the development of robust waste management practices by those charged with decommissioning liability will be at the heart of the NDA's business. In addition, the implementation of rigorous waste minimisation techniques throughout decommissioning will deliver tangible environmental benefits as well as better value for money and release funds to accelerate the decommissioning program. There are mixed views as to whether waste minimisation can be achieved during decommissioning. There are those that argue that the radioactive inventory already exists, that the amount of radioactivity cannot be minimised and that the focus of activities should be focused on waste management rather than waste minimisation. Others argue that the management and decommissioning of the UK's civilian nuclear liability will generate significant volumes of additional radioactive waste and it is in this area where the opportunities for waste minimisation can be realised. (author)

  17. Environmental Impact Assessment (EIA) Process of V1 NPP Decommissioning

    SciTech Connect

    Matejovic, Igor; Polak, Vincent

    2007-07-01

    Through the adoption of Governmental Resolution No. 801/99 the Slovak Republic undertook a commitment to shutdown units 1 and 2 of Jaslovske Bohunice V 1 NPP (WWER 230 reactor type) in 2006 and 2008 respectively. Therefore the more intensive preparation of a decommissioning documentation has been commenced. Namely, the VI NPP Conceptual Decommissioning Plan and subsequently the Environmental Impact Assessment Report of VI NPP Decommissioning were developed. Thus, the standard environmental impact assessment process was performed and the most suitable alternative of V1 NPP decommissioning was selected as a basis for development of further decommissioning documents. The status and main results of the environmental impact assessment process and EIA report are discussed in more detail in this paper. (authors)

  18. Brittle grain-size reduction of feldspar, phase mixing and strain localization in granitoids at mid-crustal conditions (Pernambuco shear zone, NE Brazil)

    NASA Astrophysics Data System (ADS)

    Viegas, Gustavo; Menegon, Luca; Archanjo, Carlos

    2016-03-01

    feldspar. Overall, our data set indicates that feldspar underwent a brittle-viscous transition while quartz was deforming via crystal plasticity. The resulting rock microstructure consists of a two-phase rheological mixture (fine-grained feldspars and recrystallized quartz) in which the polyphase feldspathic material localized much of the strain. Extensive grain-size reduction and weakening of feldspars is attained in the East Pernambuco mylonites mainly via fracturing which would trigger a switch to diffusion creep and strain localization without a prominent role of metamorphic reactions.

  19. Development and Testing of Techniques for In-Ground Stabilization, Size Reduction and Safe Removal of Radioactive Wastes Stored in Large Containments in Burial Grounds - 13591

    SciTech Connect

    Halliwell, Stephen

    2013-07-01

    Radioactive waste materials, including Transuranic (TRU) wastes from laboratories have been stored below ground in large containments at a number of sites in the US DOE Complex, and at nuclear sites in Europe. These containments are generally referred to as caissons or shafts. The containments are in a range of sizes and depths below grade. The caissons at the DOE's Hanford site are cylindrical, of the order of 2,500 mm in diameter, 3,050 mm in height and are buried about 6,000 mm below grade. One type of caisson is made out of corrugated pipe, whereas others are made of concrete with standard re-bar. However, the larger shafts in the UK are of the order of 4,600 mm in diameter, 53,500 mm deep, and 12,000 below grade. This paper describes the R and D work and testing activities performed to date to evaluate the concept of in-ground size reduction and stabilization of the contents of large containments similar to those at Hanford. In practice, the height of the Test Facility provided for a test cell that was approximately 22' deep. That prevented a 'full scale mockup' test in the sense that the Hanford Caisson configuration would be an identical replication. Therefore, the project was conducted in two phases. The first phase tested a simulated Caisson with surrogate contents, and part of a Chute section, and the second phase tested a full chute section. These tests were performed at VJ Technologies Test Facility located in East Haven, CT, as part of the Proof of Design Concept program for studying the feasibility of an in-situ grout/grind/mix/stabilize technology for the remediation of four caissons at the 618-11 Burial Ground at US Department of Energy Hanford Site. The test site was constructed such that multiple testing areas were provided for the evaluation of various tools, equipment and procedures under conditions that simulated the Hanford site, with representative soils and layout dimensions. (authors)

  20. Nuclear facility decommissioning and site remedial actions

    SciTech Connect

    Owen, P.T.; Knox, N.P.; Ferguson, S.D.; Fielden, J.M.; Schumann, P.L.

    1989-09-01

    The 576 abstracted references on nuclear facility decommissioning, uranium mill tailings management, and site remedial actions constitute the tenth in a series of reports prepared annually for the US Department of Energy's Remedial Action Programs. Citations to foreign and domestic literature of all types--technical reports, progress reports, journal articles, symposia proceedings, theses, books, patents, legislation, and research project descriptions--have been included. The bibliography contains scientific, technical, economic, regulatory, and legal information pertinent to the US Department of Energy's Remedial Action Programs. Major sections are (1) Surplus Facilities Management Program, (2) Nuclear Facilities Decommissioning, (3) Formerly Utilized Sites Remedial Action Program, (4) Facilities Contaminated with Naturally Occurring Radionuclides, (5) Uranium Mill Tailings Remedial Action Program, (6) Uranium Mill Tailings Management, (7) Technical Measurements Center, and (8) General Remedial Action Program Studies. Within these categories, references are arranged alphabetically by first author. Those references having no individual author are listed by corporate affiliation or by publication description. Indexes are provided for author, corporate affiliation, title work, publication description, geographic location, subject category, and keywords.

  1. Nuclear facility decommissioning and site remedial actions

    SciTech Connect

    Knox, N.P.; Webb, J.R.; Ferguson, S.D.; Goins, L.F.; Owen, P.T.

    1990-09-01

    The 394 abstracted references on environmental restoration, nuclear facility decommissioning, uranium mill tailings management, and site remedial actions constitute the eleventh in a series of reports prepared annually for the US Department of Energy's Remedial Action Programs. Citations to foreign and domestic literature of all types -- technical reports, progress reports, journal articles, symposia proceedings, theses, books, patents, legislation, and research project descriptions -- have been included. The bibliography contains scientific, technical, economic, regulatory, and legal information pertinent to the US Department of Energy's Remedial Action Programs. Major sections are (1) Surplus Facilities Management Program, (2) Nuclear Facilities Decommissioning, (3) Formerly Utilized Sites Remedial Action Programs, (4) Facilities Contaminated with Naturally Occurring Radionuclides, (5) Uranium Mill Tailings Remedial Action Program, (6) Grand Junction Remedial Action Program, (7) Uranium Mill Tailings Management, (8) Technical Measurements Center, (9) Remedial Action Program, and (10) Environmental Restoration Program. Within these categories, references are arranged alphabetically by first author. Those references having no individual author are listed by corporate affiliation or by publication title. Indexes are provided for author, corporate affiliation, title word, publication description, geographic location, subject category, and keywords. This report is a product of the Remedial Action Program Information Center (RAPIC), which selects and analyzes information on remedial actions and relevant radioactive waste management technologies.

  2. Lessons learnt from Ignalina NPP decommissioning project

    SciTech Connect

    NAISSE, Jean-Claude

    2007-07-01

    The Ignalina Nuclear Power Plant (INPP) is located in Lithuania, 130 km north of Vilnius, and consists of two 1500 MWe RBMK type units, commissioned respectively in December 1983 and August 1987. On the 1. of May 2004, the Republic of Lithuania became a member of the European Union. With the protocol on the Ignalina Nuclear Power in Lithuania which is annexed to the Accession Treaty, the Contracting Parties have agreed: - On Lithuanian side, to commit closure of unit 1 of INPP before 2005 and of Unit 2 by 31 December 2009; - On European Union side, to provide adequate additional Community assistance to the efforts of Lithuania to decommission INPP. The paper is divided in two parts. The first part describes how, starting from this agreement, the project was launched and organized, what is its present status and which activities are planned to reach the final ambitious objective of a green field. To give a global picture, the content of the different projects that were defined and the licensing process will also be presented. In the second part, the paper will focus on the lessons learnt. It will explain the difficulties encountered to define the decommissioning strategy, considering both immediate or differed dismantling options and why the first option was finally selected. The paper will mention other challenges and problems that the different actors of the project faced and how they were managed and solved. The paper will be written by representatives of the Ignalina NPP and of the Project Management Unit. (author)

  3. Pre-decommissioning radiological characterization of concrete

    SciTech Connect

    Boden, Sven; Cantrel, Eric

    2007-07-01

    The decommissioning of the BR3 (Belgian Reactor 3) approaches its final phase, in which the building structures are being decontaminated and either denuclearized for possible reuse or demolished. Apart from the presence of naturally occurring radionuclides in building materials, other radionuclides might be present due to contamination or activation. The overall process of the BR3 building structure D and D (Decontamination and Decommissioning) consists of the following steps: - make a complete inventory and preliminary categorize all elements based on historical data; characterize and determine the contamination or activation depth; - determine the decontamination method; - perform the decontamination and clean up; - a possible intermediate characterization followed by an additional decontamination step; and characterize for clearance. A good knowledge of the contamination and activation depth (second step) is fundamental in view of cost minimization. Currently, the method commonly used for the determination of the depth is based on core drilling and destructive analysis. Recently, we have introduced a complementary non destructive assay based on in-situ gamma spectroscopy. Field tests at BR3, both for contamination and activation, showed promising results. (authors)

  4. Application of RVA and Time-Lapse Photography to Explore Effects of Extent of Chlorination, Milling Extraction Rate, and Particle-Size Reduction of Flour on Cake-Baking Functionality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three factors (extent of chlorination, milling extraction rate and particle-size reduction) in the cake-bakeing functionality of Croplan 594W flour were explored by Rapid Visco-Analyzer (RVA) and time-lapse photography. The extent of chlorination and milling extraction rate showed dramatic effects,...

  5. 26 CFR 1.468A-4 - Treatment of nuclear decommissioning fund.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 6 2011-04-01 2011-04-01 false Treatment of nuclear decommissioning fund. 1...-4 Treatment of nuclear decommissioning fund. (a) In general. A nuclear decommissioning fund is... by the assets of the nuclear decommissioning fund. (b) Modified gross income. For purposes of...

  6. 26 CFR 1.468A-4T - Treatment of nuclear decommissioning fund (temporary).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 6 2010-04-01 2010-04-01 false Treatment of nuclear decommissioning fund...-4T Treatment of nuclear decommissioning fund (temporary). (a) In general. A nuclear decommissioning... income earned by the assets of the nuclear decommissioning fund. (b) Modified gross income. For...

  7. 30 CFR 250.1750 - When may I decommission a pipeline in place?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false When may I decommission a pipeline in place... Pipeline Decommissioning § 250.1750 When may I decommission a pipeline in place? You may decommission a pipeline in place when the Regional Supervisor determines that the pipeline does not constitute a...

  8. 30 CFR 250.1754 - When must I remove a pipeline decommissioned in place?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false When must I remove a pipeline decommissioned in... Activities Pipeline Decommissioning § 250.1754 When must I remove a pipeline decommissioned in place? You must remove a pipeline decommissioned in place if the Regional Supervisor determines that the...

  9. 26 CFR 1.468A-4 - Treatment of nuclear decommissioning fund.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 6 2013-04-01 2013-04-01 false Treatment of nuclear decommissioning fund. 1...-4 Treatment of nuclear decommissioning fund. (a) In general. A nuclear decommissioning fund is... by the assets of the nuclear decommissioning fund. (b) Modified gross income. For purposes of...

  10. 26 CFR 1.468A-4 - Treatment of nuclear decommissioning fund.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 6 2012-04-01 2012-04-01 false Treatment of nuclear decommissioning fund. 1...-4 Treatment of nuclear decommissioning fund. (a) In general. A nuclear decommissioning fund is... by the assets of the nuclear decommissioning fund. (b) Modified gross income. For purposes of...

  11. 26 CFR 1.468A-4 - Treatment of nuclear decommissioning fund.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 6 2014-04-01 2014-04-01 false Treatment of nuclear decommissioning fund. 1...-4 Treatment of nuclear decommissioning fund. (a) In general. A nuclear decommissioning fund is... by the assets of the nuclear decommissioning fund. (b) Modified gross income. For purposes of...

  12. DECOMMISSIONING OF A CAESIUM-137 SEALED SOURCE PRODUCTION FACILITY

    SciTech Connect

    Murray, A.; Abbott, H.

    2003-02-27

    Amersham owns a former Caesium-137 sealed source production facility. They commissioned RWE NUKEM to carry out an Option Study to determine a strategy for the management of this facility and then the subsequent decommissioning of it. The decommissioning was carried out in two sequential phases. Firstly robotic decommissioning followed by a phase of manual decommissioning. This paper describes the remote equipment designed built and operated, the robotic and manual decommissioning operations performed, the Safety Management arrangements and summarizes the lessons learned. Using the equipment described the facility was dismantled and decontaminated robotically. Some 2300kg of Intermediate Level Waste containing in the order of 4000Ci were removed robotically from the facility. Ambient dose rates were reduced from 100's of R per hour {gamma} to 100's of mR per hour {gamma}. The Telerobotic System was then removed to allow man access to complete the decommissioning. Manual decommissioning reduced ambient dose rates further to less than 1mR per hour {gamma} and loose contamination levels to less than 0.25Bq/cm2. This allowed access to the facility without respiratory protection.

  13. Optimal policies for aggregate recycling from decommissioned forest roads.

    PubMed

    Thompson, Matthew; Sessions, John

    2008-08-01

    To mitigate the adverse environmental impact of forest roads, especially degradation of endangered salmonid habitat, many public and private land managers in the western United States are actively decommissioning roads where practical and affordable. Road decommissioning is associated with reduced long-term environmental impact. When decommissioning a road, it may be possible to recover some aggregate (crushed rock) from the road surface. Aggregate is used on many low volume forest roads to reduce wheel stresses transferred to the subgrade, reduce erosion, reduce maintenance costs, and improve driver comfort. Previous studies have demonstrated the potential for aggregate to be recovered and used elsewhere on the road network, at a reduced cost compared to purchasing aggregate from a quarry. This article investigates the potential for aggregate recycling to provide an economic incentive to decommission additional roads by reducing transport distance and aggregate procurement costs for other actively used roads. Decommissioning additional roads may, in turn, result in improved aquatic habitat. We present real-world examples of aggregate recycling and discuss the advantages of doing so. Further, we present mixed integer formulations to determine optimal levels of aggregate recycling under economic and environmental objectives. Tested on an example road network, incorporation of aggregate recycling demonstrates substantial cost-savings relative to a baseline scenario without recycling, increasing the likelihood of road decommissioning and reduced habitat degradation. We find that aggregate recycling can result in up to 24% in cost savings (economic objective) and up to 890% in additional length of roads decommissioned (environmental objective). PMID:18481140

  14. Decommissioning Plan of the Musashi Reactor and Its Progress

    SciTech Connect

    Tanzawa, Tomio

    2008-01-15

    The Musashi Reactor is a TRIGA-II, tank-type research reactor, as shown in Table 1. The reactor had been operated at maximum thermal power level of 100 kW since first critical, January 30, 1963. Reactor operation was shut down due to small leakage of water from the reactor tank on December 21,1989. After shutdown, investigation of the causes, making plan of repair and discussions on restart or decommissioning had been done. Finally, decision of decommissioning was made in May, 2003. The initial plan of the decommissioning was submitted to the competent authority in January, 2004. Now, the reactor is under decommissioning. The plan of decommissioning and its progress are described. In conclusion: considering the status of undertaking plan of the waste disposal facility for the low level radioactive waste from research reactors, the phased decommissioning was selected for the Musashi Reactor. First phase of the decommissioning activities including the actions of permanent shutdown and delivering the spent nuclear fuels to US DOE was completed.

  15. Optimal Policies for Aggregate Recycling from Decommissioned Forest Roads

    NASA Astrophysics Data System (ADS)

    Thompson, Matthew; Sessions, John

    2008-08-01

    To mitigate the adverse environmental impact of forest roads, especially degradation of endangered salmonid habitat, many public and private land managers in the western United States are actively decommissioning roads where practical and affordable. Road decommissioning is associated with reduced long-term environmental impact. When decommissioning a road, it may be possible to recover some aggregate (crushed rock) from the road surface. Aggregate is used on many low volume forest roads to reduce wheel stresses transferred to the subgrade, reduce erosion, reduce maintenance costs, and improve driver comfort. Previous studies have demonstrated the potential for aggregate to be recovered and used elsewhere on the road network, at a reduced cost compared to purchasing aggregate from a quarry. This article investigates the potential for aggregate recycling to provide an economic incentive to decommission additional roads by reducing transport distance and aggregate procurement costs for other actively used roads. Decommissioning additional roads may, in turn, result in improved aquatic habitat. We present real-world examples of aggregate recycling and discuss the advantages of doing so. Further, we present mixed integer formulations to determine optimal levels of aggregate recycling under economic and environmental objectives. Tested on an example road network, incorporation of aggregate recycling demonstrates substantial cost-savings relative to a baseline scenario without recycling, increasing the likelihood of road decommissioning and reduced habitat degradation. We find that aggregate recycling can result in up to 24% in cost savings (economic objective) and up to 890% in additional length of roads decommissioned (environmental objective).

  16. A three dimensional two-phase debris flow model: Reduction to one free model parameter by linking rheology to grain size distribution and water content

    NASA Astrophysics Data System (ADS)

    von Boetticher, Albrecht; McArdell, Brian; Rickenmann, Dieter; Hübl, Johannes; Scheidl, Christian

    2014-05-01

    Attempts to model debris flow material either as a granular or as a viscous matter can not account for the wide range of debris flow processes, leading to the development of two-phase models with one phase accounting for the fluid and the other for the grains. Within this group of models, depth-averaged approaches are wide-spread, but since the rheology of true material is sensitive to pressure and shear gradient, three dimensional simulations are necessary to predict flows in complex geometries. Phase interaction can be modelled by solving the Navier-Stokes equation system for each phase and linking the phases with drag force models. However, this is a numerically expensive way that introduces a number of free parameters because too little is known about drag of non-spherical grains in non-Newtonian fluids. The approach proposed here solves one phase-averaged Navier-stokes equation system by applying the Volume of Fluid method, while still allowing to account for the sensitivity of the local rheology to pressure and shear in dependency to phase concentrations. One phase with a Herschel-Bulkley rheology represents the interstitial fluid and can mix with a second phase with the Coulomb-viscoplastic rheology of Pudasaini (Birte et al. 2013) that represents the gravel. A third phase is kept separate and represents the air. This setup allows modelling key properties of debris flow processes like run out or impact in high detail. By linking the Herschel Bulkley parameters to water content, clay mineral proportion and grain size distribution (Kaitna et al. 2007, Yu et al. 2013), and the parameters of the Coulomb-viscoplastic rheology to the angle of repose of the gravel, a reduction to one free model parameter was achieved. The resulting model is tested with laboratory experiments for its capability to reproduce the sensitivity of debris flow material to water content and channel curvature. Existing large scale flume experiments are used to corroborate the model and

  17. Safety Oversight of Decommissioning Activities at DOE Nuclear Sites

    SciTech Connect

    Zull, Lawrence M.; Yeniscavich, William

    2008-01-15

    The Defense Nuclear Facilities Safety Board (Board) is an independent federal agency established by Congress in 1988 to provide nuclear safety oversight of activities at U.S. Department of Energy (DOE) defense nuclear facilities. The activities under the Board's jurisdiction include the design, construction, startup, operation, and decommissioning of defense nuclear facilities at DOE sites. This paper reviews the Board's safety oversight of decommissioning activities at DOE sites, identifies the safety problems observed, and discusses Board initiatives to improve the safety of decommissioning activities at DOE sites. The decommissioning of former defense nuclear facilities has reduced the risk of radioactive material contamination and exposure to the public and site workers. In general, efforts to perform decommissioning work at DOE defense nuclear sites have been successful, and contractors performing decommissioning work have a good safety record. Decommissioning activities have recently been completed at sites identified for closure, including the Rocky Flats Environmental Technology Site, the Fernald Closure Project, and the Miamisburg Closure Project (the Mound site). The Rocky Flats and Fernald sites, which produced plutonium parts and uranium materials for defense needs (respectively), have been turned into wildlife refuges. The Mound site, which performed R and D activities on nuclear materials, has been converted into an industrial and technology park called the Mound Advanced Technology Center. The DOE Office of Legacy Management is responsible for the long term stewardship of these former EM sites. The Board has reviewed many decommissioning activities, and noted that there are valuable lessons learned that can benefit both DOE and the contractor. As part of its ongoing safety oversight responsibilities, the Board and its staff will continue to review the safety of DOE and contractor decommissioning activities at DOE defense nuclear sites.

  18. When a plant shuts down: The psychology of decommissioning

    SciTech Connect

    Schulz, J.; Crawford, A.C. )

    1993-07-01

    Within the next decade, 10 to 25 nuclear plants in the United States may be taken off line. Many will have reached the end of their 40-year life cycles, but others will be retired because the cost of operating them has begun to outweigh their economic benefit. Such was the case at Fort St. Vrain, the first decommissioning of a US commercial plant under new Nuclear Regulatory Commission (NRC) regulations. Two major problems associated with decommissioning plants have been obvious: (1) the technical challenges and costs of decommissioning, and (2) the cost of maintaining and finally decommissioning a plant after a safe storage (SAFSTOR) period of approximately 60 years. What has received little attention is the challenge that affects not only the people who make a plant work, but the quality of the solutions to these problems: how to maintain effective organizational performance during the process of downsizing and decommissioning and/or SAFSTOR. The quality of technical solutions for closing a plant, as well as how successfully the decommissioning process is held within or below budget, will depend largely on how effectively the nuclear organization functions as a social unit. Technical and people issues are bound together. The difficulty is how to operate a plant effectively when plant personnel have no sense of long-term security. As the nuclear power industry matures and the pace for closing operating plants accelerates, the time has come to prepare for the widespread decommissioning of plants. The industry would be well served by conducting a selective, industry-wide evaluation of plants to assess its overall readiness for the decommissioning process. A decommissioning is not likely to be trouble free, but with a healthy appreciation for the human side of the process, it will undoubtedly go more smoothly than if approached as a matter of dismantling a machine.

  19. Some aspects of the decommissioning of nuclear power plants

    SciTech Connect

    Khvostova, M. S.

    2012-03-15

    The major factors influencing the choice of a national concept for the decommissioning of nuclear power plants are examined. The operating lifetimes of power generating units with nuclear reactors of various types (VVER-1000, VVER-440, RBMK-1000, EGP-6, and BN-600) are analyzed. The basic approaches to decommissioning Russian nuclear power plants and the treatment of radioactive waste and spent nuclear fuel are discussed. Major aspects of the ecological and radiation safety of personnel, surrounding populations, and the environment during decommissioning of nuclear installations are identified.

  20. MARSSIM recommended in states' guidance document for decommissioning.

    PubMed

    McBaugh, Debra; Stoffey, Phillip; Shuman, Howard; Young, Robert; Zannoni, Dennis

    2003-06-01

    States appreciate guidance for activities done infrequently or at only a few locations in the state. For many states, this is the case for decommissioning. Some states have reactors being decommissioned, some DOE sites undergoing cleanup, and some uranium mill or radium sites. Many, however, only occasionally do a small facility cleanup or, once in a great while, a large one. For this reason, most states participated in the readily available MARSSIM training and now recommend its use. For this same reason, the CRCPD Committee on Decontamination and Decommissioning (E24) developed a brief guidance document for state and licensee use. PMID:12792402

  1. Cost Savings through Innovation in Decontamination, Decommissioning, and Dismantlement

    SciTech Connect

    Neal A. Yancey

    2003-02-27

    The United States Department of Energy (DOE) continually seeks safer and more cost effective technologies for the decontamination and decommissioning (D&D) of nuclear facilities. The Deactivation and Decommissioning Focus Area (DDFA) of the DOE's Office of Science and Technology (OST) sponsored large-scale demonstration and deployment projects (LSDDPs) to help bring new technologies into the D&D programs. The Idaho National Engineering and Environmental Laboratory (INEEL) LSDDP generated a list of needs defining specific problems where improved technologies could be incorporated into ongoing D&D tasks. The needs fell into 5 major categories--characterization, dismantlement, safety, material dispositioning, and decontamination. Technologies were carefully selected that provide a large benefit for a small investment. The technologies must provide significant improvements in cost, safety, radiation exposure, waste volume reduction, or schedule savings and widely applicable throughout the DOE complex. The LSDDP project provided training for the new technologies and worked with technology suppliers to resolve any questions that arose. Since 1998, 26 technologies have been demonstrated or deployed through the LSDDP for the D&D program at the INEEL. Of the 26 demonstrated and deployed technologies, 14 were in characterization, 3 were in decontamination, 4 were in dismantlement, 3 were in safety, and 2 were in material dispositioning. To promote the use of these technologies at other sites within the DOE complex, the LSDDP team published fact sheets, videos, technology summary reports, articles in INEEL star newspaper, posters, and maintained an internet home page on the project. As a result, additional deployments have taken place at the Hanford, Mound, Fernald, Oak Ridge, Ashtabula, and West Valley. Eight of the 26 technologies evaluated were developed in foreign countries. The technologies demonstrated have been shown to be faster, less expensive, and/or safer. The

  2. Constructing Predictive Estimates for Worker Exposure to Radioactivity During Decommissioning: Analysis of Completed Decommissioning Projects - Master Thesis

    SciTech Connect

    Dettmers, Dana Lee; Eide, Steven Arvid

    2002-10-01

    An analysis of completed decommissioning projects is used to construct predictive estimates for worker exposure to radioactivity during decommissioning activities. The preferred organizational method for the completed decommissioning project data is to divide the data by type of facility, whether decommissioning was performed on part of the facility or the complete facility, and the level of radiation within the facility prior to decommissioning (low, medium, or high). Additional data analysis shows that there is not a downward trend in worker exposure data over time. Also, the use of a standard estimate for worker exposure to radioactivity may be a best estimate for low complete storage, high partial storage, and medium reactor facilities; a conservative estimate for some low level of facility radiation facilities (reactor complete, research complete, pits/ponds, other), medium partial process facilities, and high complete research facilities; and an underestimate for the remaining facilities. Limited data are available to compare different decommissioning alternatives, so the available data are reported and no conclusions can been drawn. It is recommended that all DOE sites and the NRC use a similar method to document worker hours, worker exposure to radiation (person-rem), and standard industrial accidents, injuries, and deaths for all completed decommissioning activities.

  3. Uranium enrichment decontamination and decommissioning fund

    SciTech Connect

    1994-12-31

    One of the most challenging issues facing the Department of Energy`s Office of Environmental Management is the cleanup of the three gaseous diffusion plants. In October 1992, Congress passed the Energy Policy Act of 1992 and established the Uranium Enrichment Decontamination and Decommissioning Fund to accomplish this task. This mission is being undertaken in an environmentally and financially responsible way by: devising cost-effective technical solutions; producing realistic life-cycle cost estimates, based on practical assumptions and thorough analysis; generating coherent long-term plans which are based on risk assessments, land use, and input from stakeholders; and, showing near-term progress in the cleanup of the gaseous diffusion facilities at Oak Ridge.

  4. Decontamination, decommissioning, and vendor advertorial issue, 2008

    SciTech Connect

    Agnihotri, Newal

    2008-07-15

    The focus of the July-August issue is on Decontamination, decommissioning, and vendor advertorials. Articles and reports in this issue include: D and D technical paper summaries; The role of nuclear power in turbulent times, by Tom Chrisopher, AREVA, NP, Inc.; Enthusiastic about new technologies, by Jack Fuller, GE Hitachi Nuclear Energy; It's important to be good citizens, by Steve Rus, Black and Veatch Corporation; Creating Jobs in the U.S., by Guy E. Chardon, ALSTOM Power; and, and, An enviroment and a community champion, by Tyler Lamberts, Entergy Nuclear Operations, Inc. The Industry Innovations article is titled Best of the best TIP achievement 2008, by Edward Conaway, STP Nuclear Operating Company.

  5. Decontamination and Decommissioning of the Tokamak Fusion Test Reactor

    SciTech Connect

    E. Perry; J. Chrzanowski; K. Rule; M. Viola; M. Williams; R. Strykowsky

    1999-11-01

    The Tokamak Fusion Test Reactor (TFTR) is a one-of-a-kind, tritium-fueled fusion research reactor that ceased operation in April 1997. The Decontamination and Decommissioning (D and D) of the TFTR is scheduled to occur over a period of three years beginning in October 1999. This is not a typical Department of Energy D and D Project where a facility is isolated and cleaned up by ''bulldozing'' all facility and hardware systems to a greenfield condition. The mission of TFTR D and D is to: (a) surgically remove items which can be re-used within the DOE complex, (b) remove tritium contaminated and activated systems for disposal, (c) clear the test cell of hardware for future reuse, (d) reclassify the D-site complex as a non-nuclear facility as defined in DOE Order 420.1 (Facility Safety) and (e) provide data on the D and D of a large magnetic fusion facility. The 100 cubic meter volume of the donut-shaped reactor makes it the second largest fusion reactor in the world. The record-breaking deuterium-tritium experiments performed on TFTR resulted in contaminating the vacuum vessel with tritium and activating the materials with 14 Mev neutrons. The total tritium content within the vessel is in excess of 7,000 Curies while dose rates approach 75 mRem/hr. These radiological hazards along with the size and shape of the Tokamak present a unique and challenging task for dismantling.

  6. Disruption of de novo purine biosynthesis in Pseudomonas fluorescens Pf0-1 leads to reduced biofilm formation and a reduction in cell size of surface-attached but not planktonic cells

    PubMed Central

    Newell, Peter D.

    2016-01-01

    Pseudomonas fluorescens Pf0-1 is one of the model organisms for biofilm research. Our previous transposon mutagenesis study suggested a requirement for the de novo purine nucleotide biosynthesis pathway for biofilm formation by this organism. This study was performed to verify that observation and investigate the basis for the defects in biofilm formation shown by purine biosynthesis mutants. Constructing deletion mutations in 8 genes in this pathway, we found that they all showed reductions in biofilm formation that could be partly or completely restored by nucleotide supplementation or genetic complementation. We demonstrated that, despite a reduction in biofilm formation, more viable mutant cells were recovered from the surface-attached population than from the planktonic phase under conditions of purine deprivation. Analyses using scanning electron microscopy revealed that the surface-attached mutant cells were 25 ∼ 30% shorter in length than WT, which partly explains the reduced biomass in the mutant biofilms. The laser diffraction particle analyses confirmed this finding, and further indicated that the WT biofilm cells were smaller than their planktonic counterparts. The defects in biofilm formation and reductions in cell size shown by the mutants were fully recovered upon adenine or hypoxanthine supplementation, indicating that the purine shortages caused reductions in cell size. Our results are consistent with surface attachment serving as a survival strategy during nutrient deprivation, and indicate that changes in the cell size may be a natural response of P. fluorescens to growth on a surface. Finally, cell sizes in WT biofilms became slightly smaller in the presence of exogenous adenine than in its absence. Our findings suggest that purine nucleotides or related metabolites may influence the regulation of cell size in this bacterium. PMID:26788425

  7. Decommissioning the UHTREX Reactor Facility at Los Alamos, New Mexico

    SciTech Connect

    Salazar, M.; Elder, J.

    1992-08-01

    The Ultra-High Temperature Reactor Experiment (UHTREX) facility was constructed in the late 1960s to advance high-temperature and gas-cooled reactor technology. The 3-MW reactor was graphite moderated and helium cooled and used 93% enriched uranium as its fuel. The reactor was run for approximately one year and was shut down in February 1970. The decommissioning of the facility involved removing the reactor and its associated components. This document details planning for the decommissioning operations which included characterizing the facility, estimating the costs of decommissioning, preparing environmental documentation, establishing a system to track costs and work progress, and preplanning to correct health and safety concerns in the facility. Work to decommission the facility began in 1988 and was completed in September 1990 at a cost of $2.9 million. The facility was released to Department of Energy for other uses in its Los Alamos program.

  8. Lessons Learned from the NASA Plum Brook Reactor Facility Decommissioning

    NASA Technical Reports Server (NTRS)

    2010-01-01

    NASA has been conducting decommissioning activities at its PBRF for the last decade. As a result of all this work there have been several lessons learned both good and bad. This paper presents some of the more exportable lessons.

  9. The Decommissioning of the Trino Nuclear Power Plant

    SciTech Connect

    Brusa, L.; DeSantis, R.; Nurden, P. L.; Walkden, P.; Watson, B.

    2002-02-27

    Following a referendum in Italy in 1987, the four Nuclear Power Plants (NPPs) owned and operated by the state utility ENEL were closed. After closing the NPPs, ENEL selected a ''safestore'' decommissioning strategy; anticipating a safestore period of some 40-50 years. This approach was consistent with the funds collected during plant operation, and was reinforced by the lack of both a waste repository and a set of national free release limits for contaminated materials in Italy. During 1999, twin decisions were made to privatize ENEL and to transform the nuclear division into a separate subsidiary of the ENEL group. This group was renamed Sogin and during the following year, ownership of the company was transferred to the Italian Treasury. On formation, Sogin was asked by the Italian government to review the national decommissioning strategy. The objective of the review was to move from a safestore strategy to a prompt decommissioning strategy, with the target of releasing all of the nuclear sites by 2020. It was recognized that this target was conditional upon the availability of a national LLW repository together with interim stores for both spent fuel and HLW by 2009. The government also agreed that additional costs caused by the acceleration of the decommissioning program would be considered as stranded costs. These costs will be recovered by a levy on the kWh price of electricity, a process established and controlled by the Regulator of the Italian energy sector. Building on the successful collaboration to develop a prompt decommissioning strategy for the Latina Magnox reactor (1), BNFL and Sogin agreed to collaborate on an in depth study for the prompt decommissioning of the Sogin PWR at Trino. BNFL is currently decommissioning six NPPs and is at an advanced stage of planning for two further units, having completed a full and rigorous exercise to develop Baseline Decommissioning Plans (BDP's) for these stations. The BDP exercise utilizes the full range of

  10. Progress in Decommissioning the Humboldt Bay Power Plant - 13604

    SciTech Connect

    Rod, Kerry; Shelanskey, Steven K.; Kristofzski, John

    2013-07-01

    Decommissioning of the Pacific Gas and Electric (PG and E) Company Humboldt Bay Power Plant (HBPP) Unit 3 nuclear facility has now, after more than three decades of SAFSTOR and initial decommissioning work, transitioned to full-scale decommissioning. Decommissioning activities to date have been well orchestrated and executed in spite of an extremely small work site with space constricted even more by other concurrent on-site major construction projects including the demolition of four fossil units, construction of a new generating station and 60 KV switchyard upgrade. Full-scale decommissioning activities - now transitioning from Plant Systems Removal (PG and E self-perform) to Civil Works Projects (contractor performed) - are proceeding in a safe, timely, and cost effective manner. As a result of the successful decommissioning work to date (approximately fifty percent completed) and the intense planning and preparations for the remaining work, there is a high level of confidence for completion of all HBPP Unit 3 decommissions activities in 2018. Strategic planning and preparations to transition into full-scale decommissioning was carried out in 2008 by a small, highly focused project team. This planning was conducted concurrent with other critical planning requirements such as the loading of spent nuclear fuel into dry storage at the Independent Spent Fuel Storage Installation (ISFSI) finishing December 2008. Over the past four years, 2009 through 2012, the majority of decommissioning work has been installation of site infrastructure and removal of systems and components, known as the Plant System Removal Phase, where work scope was dynamic with significant uncertainty, and it was self-performed by PG and E. As HBPP Decommissioning transitions from the Plant System Removal Phase to the Civil Works Projects Phase, where work scope is well defined, a contracting plan similar to that used for Fossil Decommissioning will be implemented. Award of five major work scopes

  11. Decommissioning of Active Ventilation Systems in a Nuclear R and D Facility to Prepare for Building Demolition (Whiteshell Laboratories Decommissioning Project, Canada) - 13073

    SciTech Connect

    Wilcox, Brian; May, Doug; Howlett, Don; Bilinsky, Dennis

    2013-07-01

    Whiteshell Laboratories (WL) is a nuclear research establishment owned by the Canadian government and operated by Atomic Energy of Canada Limited (AECL) since the early 1960's. WL is currently under a decommissioning license and the mandate is to remediate the nuclear legacy liabilities in a safe and cost effective manner. The WL Project is the first major nuclear decommissioning project in Canada. A major initiative underway is to decommission and demolish the main R and D Laboratory complex. The Building 300 R and D complex was constructed to accommodate laboratories and offices which were mainly used for research and development associated with organic-cooled reactors, nuclear fuel waste management, reactor safety, advanced fuel cycles and other applications of nuclear energy. Building 300 is a three storey structure of approximately 16,000 m{sup 2}. In order to proceed with building demolition, the contaminated systems inside the building have to be characterized, removed, and the waste managed. There is a significant focus on volume reduction of radioactive waste for the WL project. The active ventilation system is one of the significant contaminated systems in Building 300 that requires decommissioning and removal. The active ventilation system was designed to manage hazardous fumes and radioactivity from ventilation devices (e.g., fume hoods, snorkels and glove boxes) and to prevent the escape of airborne hazardous material outside of the laboratory boundary in the event of an upset condition. The system includes over 200 ventilation devices and 32 active exhaust fan units and high efficiency particulate air (HEPA) filters. The strategy to remove the ventilation system was to work from the laboratory end back to the fan/filter system. Each ventilation duct was radiologically characterized. Fogging was used to minimize loose contamination. Sections of the duct were removed by various cutting methods and bagged for temporary storage prior to disposition

  12. Northrop Triga facility decommissioning plan versus actual results

    SciTech Connect

    Gardner, F.W.

    1986-01-01

    This paper compares the Triga facility decontamination and decommissioning plan to the actual results and discusses key areas where operational activities were impacted upon by the final US Nuclear Regulatory Commission (NRC)-approved decontamination and decommissioning plan. Total exposures for fuel transfer were a factor of 4 less than planned. The design of the Triga reactor components allowed the majority of the components to be unconditionally released.

  13. Decontamination and Decommissioning Experience at a Sellafield Uranium Purification Plant

    SciTech Connect

    Prosser, J.L.

    2006-07-01

    Built in the 1950's, this plant was originally designed to purify depleted uranyl nitrate solution arising from reprocessing operations at the Primary Separation and Head End Plant (Fig. 1). The facility was used for various purposes throughout its life cycle such as research, development and trial based processes. Test rigs were operated in the building from the 1970's until 1984 to support development of the process and equipment now used at Sellafield's Thermal Oxide Reprocessing Plant (THORP). The extensive decommissioning program for this facility began over 15 years ago. Many challenges have been overcome throughout this program such as decommissioning the four main process cells, which were very highly alpha contaminated. The cells contained vessels and pipeline systems that were contaminated to such levels that workers had to use pressurized suits to enter the cells. Since decommissioning at Sellafield was in its infancy, this project has trialed various decontamination/decommissioning methods and techniques in order to progress the project, and this has provided valuable learning for other decommissioning projects. The project has included characterization, decontamination, dismantling, waste handling, and is now ready for demolition during late 2005, early 2006. This will be the first major facility within the historic Separation Area at Sellafield to be demolished down to base slab level. The lessons learnt from this project will directly benefit numerous decommissioning projects as the cleanup at Sellafield continues. (authors)

  14. Completed Decommissioning of the Research Reactor TRIGA Heidelberg We are specialised in Decommissioning a Research Reactor in Germany now

    SciTech Connect

    Juenger-Graef, B.; Hoever, K.; Moser, T.; Berthold, M.; Blenski, H.J.

    2006-07-01

    This paper describes the decommissioning of the TRIGA Heidelberg II reactor which was used until 1999, and of the TRIGA Heidelberg I reactor, which was for the last 20 years in a safe containment. (authors)

  15. The unit cost factors and calculation methods for decommissioning - Cost estimation of nuclear research facilities

    SciTech Connect

    Kwan-Seong Jeong; Dong-Gyu Lee; Chong-Hun Jung; Kune-Woo Lee

    2007-07-01

    Available in abstract form only. Full text of publication follows: The uncertainties of decommissioning costs increase high due to several conditions. Decommissioning cost estimation depends on the complexity of nuclear installations, its site-specific physical and radiological inventories. Therefore, the decommissioning costs of nuclear research facilities must be estimated in accordance with the detailed sub-tasks and resources by the tasks of decommissioning activities. By selecting the classified activities and resources, costs are calculated by the items and then the total costs of all decommissioning activities are reshuffled to match with its usage and objectives. And the decommissioning cost of nuclear research facilities is calculated by applying a unit cost factor method on which classification of decommissioning works fitted with the features and specifications of decommissioning objects and establishment of composition factors are based. Decommissioning costs of nuclear research facilities are composed of labor cost, equipment and materials cost. Of these three categorical costs, the calculation of labor costs are very important because decommissioning activities mainly depend on labor force. Labor costs in decommissioning activities are calculated on the basis of working time consumed in decommissioning objects and works. The working times are figured out of unit cost factors and work difficulty factors. Finally, labor costs are figured out by using these factors as parameters of calculation. The accuracy of decommissioning cost estimation results is much higher compared to the real decommissioning works. (authors)

  16. Development of a Preliminary Decommissioning Plan Following the International Structure for Decommissioning Costing (ISDC) of Nuclear Installations - 13361

    SciTech Connect

    Moshonas Cole, Katherine; Dinner, Julia; Grey, Mike; Daniska, Vladimir

    2013-07-01

    The International Structure for Decommissioning Costing (ISDC) of Nuclear Installations, published by OECD/NEA, IAEA and EC is intended to provide a uniform list of cost items for decommissioning projects and provides a standard format that permits international cost estimates to be compared. Candesco and DECOM have used the ISDC format along with two costing codes, OMEGA and ISDCEX, developed from the ISDC by DECOM, in three projects: the development of a preliminary decommissioning plan for a multi-unit CANDU nuclear power station, updating the preliminary decommissioning cost estimates for a prototype CANDU nuclear power station and benchmarking the cost estimates for CANDU against the cost estimates for other reactor types. It was found that the ISDC format provides a well defined and transparent basis for decommissioning planning and cost estimating that assists in identifying gaps and weaknesses and facilitates the benchmarking against international experience. The use of the ISDC can also help build stakeholder confidence in the reliability of the plans and estimates and the adequacy of decommissioning funding. (authors)

  17. An overview of U.S. decommissioning experience -- A basic introduction

    SciTech Connect

    Boing, L.E.

    1998-03-09

    This paper presents an overview of the US experiences in the decommissioning technical area. Sections included are: (1) an overview of the magnitude of the problem, (2) a review of the US decommissioning process, (3) regulation of decommissioning, (4) regulatory and funding requirements for decommissioning, and (5) a general overview of all on-going and completed decommissioning projects to date in the US. The final section presents a review of some issues in the decommissioning area currently being debated in the technical specialists community.

  18. Evaluation of nuclear facility decommissioning projects. Project summary report, Elk River Reactor

    SciTech Connect

    Miller, R.L.; Adams, J.A.

    1982-12-01

    This report summarizes information concerning the decommissioning of the Elk River Reactor. Decommissioning data from available documents were input into a computerized data-handling system in a manner that permits specific information to be readily retrieved. The information is in a form that assists the Nuclear Regulatory Commission in its assessment of decommissioning alternatives and ALARA methods for future decommissionings projects. Samples of computer reports are included in the report. Decommissioning of other reactors, including NRC reference decommissioning studies, will be described in similar reports.

  19. Reduction of fibroblast size/mechanical force down-regulates TGF-β type II receptor: implications for human skin aging.

    PubMed

    Fisher, Gary J; Shao, Yuan; He, Tianyuan; Qin, Zhaoping; Perry, Daniel; Voorhees, John J; Quan, Taihao

    2016-02-01

    The structural integrity of human skin is largely dependent on the quality of the dermal extracellular matrix (ECM), which is produced, organized, and maintained by dermal fibroblasts. Normally, fibroblasts attach to the ECM and thereby achieve stretched, elongated morphology. A prominent characteristic of dermal fibroblasts in aged skin is reduced size, with decreased elongation and a more rounded, collapsed morphology. Here, we show that reduced size of fibroblasts in mechanically unrestrained three-dimensional collagen lattices coincides with reduced mechanical force, measured by atomic force microscopy. Reduced size/mechanical force specifically down-regulates TGF-β type II receptor (TβRII) and thus impairs TGF-β/Smad signaling pathway. Both TβRII mRNA and protein were decreased, resulting in 90% loss of TGF-β binding to fibroblasts. Down-regulation of TβRII was associated with significantly decreased phosphorylation, DNA-binding, and transcriptional activity of its key downstream effector Smad3 and reduced expression of Smad3-regulated essential ECM components type I collagen, fibronectin, and connective tissue growth factor (CTGF/CCN2). Restoration of TβRII significantly increased TGF-β induction of Smad3 phosphorylation and stimulated expression of ECM components. Reduced expression of TβRII and ECM components in response to reduced fibroblast size/mechanical force was fully reversed by restoring size/mechanical force. Reduced fibroblast size was associated with reduced expression of TβRII and diminished ECM production, in aged human skin. Taken together, these data reveal a novel mechanism that provides a molecular basis for loss of dermal ECM, with concomitant increased fragility, which is a prominent feature of human skin aging. PMID:26780887

  20. Mobile workstation for decontamination and decommissioning operations

    SciTech Connect

    Whittaker, W.L.; Osborn, J.F.; Thompson, B.R.

    1993-10-01

    This project is an interdisciplinary effort to develop effective mobile worksystems for decontamination and decommissioning (D&D) of facilities within the DOE Nuclear Weapons Complex. These mobile worksystems will be configured to operate within the environmental and logistical constraints of such facilities and to perform a number of work tasks. Our program is designed to produce a mobile worksystem with capabilities and features that are matched to the particular needs of D&D work by evolving the design through a series of technological developments, performance tests and evaluations. The project has three phases. In this the first phase, an existing teleoperated worksystem, the Remote Work Vehicle (developed for use in the Three Mile Island Unit 2 Reactor Building basement), was enhanced for telerobotic performance of several D&D operations. Its ability to perform these operations was then assessed through a series of tests in a mockup facility that contained generic structures and equipment similar to those that D&D work machines will encounter in DOE facilities. Building upon the knowledge gained through those tests and evaluations, a next generation mobile worksystem, the RWV II, and a more advanced controller will be designed, integrated and tested in the second phase, which is scheduled for completion in January 1995. The third phase of the project will involve testing of the RWV II in the real DOE facility.

  1. Decontamination & Decommissioning Equipment Tracking System (DDETS)

    SciTech Connect

    Cook, S.

    1994-07-01

    At the request of the Department of Energy (DOE)(EM-50), the Scientific Computing Unit developed a prototype system to track information and data relevant to equipment and tooling removed during decontamination and decommissioning activities. The DDETS proof-of-concept tracking system utilizes a one-dimensional (1D) and two-dimensional (2D) bar coding technology to retain and track information such as identification number, manufacturer, requisition information, and various contaminant information, etc. The information is encoded in a bar code, printed on a label and can be attached to corresponding equipment. The DDETS was developed using a proven relational database management system which allows the addition, modification, printing, and deletion of data. In addition, communication interfaces with bar code printers and bar code readers were developed. Additional features of the system include: (a) Four different reports available for the user (REAPS, transaction, and two inventory), (b) Remote automated inventory tracking capabilities, (c) Remote automated inventory tracking capability (2D bar codes allow equipment to be scanned/tracked without being linked to the DDETS database), (d) Edit, update, delete, and query capabilities, (e) On-line bar code label printing utility (data from 2D bar codes can be scanned directly into the data base simplifying data entry), and (f) Automated data backup utility. Compatibility with the Reportable Excess Automated Property System (REAPS) to upload data from DDETS is planned.

  2. HOW THE ROCKY FLATS ENVIRONMENTAL TECHNOLOGY SITE DEVELOPED A NEW WASTE PACKAGE USING A POLYUREA COATING THAT IS SAFELY AND ECONOMICALLY ELIMINATING SIZE REDUCTION OF LARGE ITEMS

    SciTech Connect

    Dorr, Kent A.; Hogue, Richard S.; Kimokeo, Margaret K.

    2003-02-27

    One of the major challenges involved in closing the Rocky Flats Environmental Technology Site (RFETS) is the disposal of extremely large pieces of contaminated production equipment and building debris. Past practice has been to size reduce the equipment into pieces small enough to fit into approved, standard waste containers. Size reducing this equipment is extremely expensive, and exposes workers to high-risk tasks, including significant industrial, chemical, and radiological hazards. RFETS has developed a waste package using a Polyurea coating for shipping large contaminated objects. The cost and schedule savings have been significant.

  3. Performance and review of safety assessment for decommissioning

    SciTech Connect

    Percival, K.; Thierfeldt, S.; Joubert, A.; Kaulard, J.; Manson, P.; Ferch, R.; Batandjieva, B.

    2007-07-01

    Available in abstract form only. Full text of publication follows: Safety assessment is required by national and international safety standards to be performed for all stages of life cycle of facilities that are using radioactive material. It is required to be performed by operators and reviewed by regulators in support of a decommissioning plan for every facility before decommissioning commences. With the growing amount of decommissioning activities world-wide, the need for assistance to Member States in development and review of such assessments was highlighted in the Berlin Conference in 2002 and reflected in the International Action Plan on Decommissioning of Nuclear Facilities, approved by the International Atomic Energy Agency (IAEA) Board of Governors in 2004. In order to respond to this need, the IAEA initiated an international project on Evaluation and Demonstration of Safety during Decommissioning of Nuclear Facilities (DeSa Project) in the same year. More than fifty experts from over thirty Member States have been working over the last three years on (i) the establishment of a harmonized safety assessment methodology for decommissioning; (ii) development of recommendations for a regulatory approach and procedure for review of such assessments; (iii) development of recommendations on the application of the graded approach to development and review of safety assessments; and (iv) application of the methodology, the regulatory review procedure and graded approach recommendations to three test cases - safety assessment for decommissioning of a nuclear power plant (NPP), a research reactor and a nuclear laboratory. This paper presents the current status of the DeSa project work, the consensus achieved, the main preliminary outcomes and lessons learned. The project results are envisaged to be presented and discussed at the 4. Joint DeSa meeting in October 2007 in Vienna, where the scope and objectives of a follow- up project will be also discussed. (authors)

  4. Engineering Evaluation/Cost Analysis (EE/CA) for Decommissioning of TAN-607 Hot Shop Area

    SciTech Connect

    J. P. Floerke

    2007-02-05

    Test Area North (TAN) -607, the Technical Support Facility, is located at the north end of the Idaho National Laboratory (INL) Site. U.S. Department of Energy Idaho Operations Office (DOE-ID) is proposing to decommission the northern section of the TAN-607 facility, hereinafter referred to as TAN-607 Hot Shop Area, under a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) non-time-critical removal action (NTCRA). Despite significant efforts by the United States (U.S.) Department of Energy (DOE) to secure new business, no future mission has been identified for the TAN-607 Hot Shop Area. Its disposition has been agreed to by the Idaho State Historical Preservation Office documented in the Memorandum of Agreement signed October 2005 and it is therefore considered a surplus facility. A key element in DOE's strategy for surplus facilities is decommissioning to the maximum extent possible to ensure risk and building footprint reduction and thereby eliminating operations and maintenance cost. In addition, the DOE's 2006 Strategic Plan is ''complete cleanup of the contaminated nuclear weapons manufacturing and testing sites across the United States. DOE is responsible for the risk reduction and cleanup of the environmental legacy of the Nation's nuclear weapons program, one of the largest, most diverse, and technically complex environmental programs in the world. The Department will successfully achieve this strategic goal by ensuring the safety of the DOE employees and U.S. citizens, acquiring the best resources to complete the complex tasks, and managing projects throughout the United States in the most efficient and effective manner.'' TAN-607 is designated as a historical Signature Property by DOE Headquarters Advisory Council on Historic Preservation and, as such, public participation is required to determine the final disposition of the facility. The decommissioning action will place the TAN-607 Hot Shop Area in a final configuration that

  5. Effect of natural Bayah zeolite particle size reduction to physico-chemical properties and absortion against potassium permanganate (KMnO4)

    NASA Astrophysics Data System (ADS)

    Widayanti, Siti Mariana; Syamsu, Khaswar; Warsiki, Endang; Yuliani, Sri

    2016-02-01

    Recently, researches on nanotechnology have been developed very rapid, as well as the utilization of nano-zeolites. Nano-sized material has several advantages which are expanding absorptive surfaces so it will enhance the material absorption and shorten the absorption time. Zeolite as a KMnO4 binder, has been widely recognized for its ability to extend the shelf life of vegetables and fruits. This study was conducted to determine zeolites physico-chemical characters from different particle size and the effect on KMnO4 absorption. Potassium permanganate (KMnO4) is a strong oxidizer for reducing the quantity of ethylene in storage process of fresh horticultural products. The treatment consisted of (1) different length of milling time (10, 20, 30, 40, and 60 minutes) and (2) the duration of chemical activation with 1 N KOH solution. Physical and chemical characters of zeolite were analyzed using BET, PSA, XRD and SEM. The research design was randomized design. The result implied that milling time was significantly affecting the zeolite particle size, material surface area, and the size of pore diameter and volume. Milling treatment for 40 minutes produced higher zeolite surface area and pore volume than other treatments. While the duration of chemical activation using 1 N KOH solution gives different effect on zeolite absorption to KMnO4 solution. Milling time for 60 minutes and activated for 48 hours has higher initial adsorption than other treatments.

  6. Effect of particle size reduction on dissolution and oral absorption of a poorly water-soluble drug, cilostazol, in beagle dogs.

    PubMed

    Jinno, Jun-ichi; Kamada, Naoki; Miyake, Masateru; Yamada, Keigo; Mukai, Tadashi; Odomi, Masaaki; Toguchi, Hajime; Liversidge, Gary G; Higaki, Kazutaka; Kimura, Toshikiro

    2006-03-10

    The purpose of the present study was to investigate the effects of particle size on the dissolution and oral absorption of cilostazol. Three types of suspensions having different particle size distributions were prepared of the hammer-milled, the jet-milled cilostazol crystals and the NanoCrystal spray-dried powder of cilostazol. In vitro dissolution rate of cilostazol was significantly increased by reducing the particle size. The dissolution curves of the cilostazol suspensions were in good agreement with the simulation based on the Noyes-Whitney equation. The bioavailability of cilostazol after oral administration to dogs was increased with reducing the particle size. While positive food effect on the absorption was observed for the suspensions made of the hammer-milled and the jet-milled crystals, no significant food effect was found for the suspension made of the NanoCrystal cilostazol spray-dried powder. These results could be qualitatively predicted from the in vitro dissolution data using the bio-relevant media, FaSSIF and FeSSIF. In conclusion, the NanoCrystal technology is found to be efficient to improve the oral bioavailability of cilostazol and to avoid the food effect on the absorption. PMID:16410029

  7. 75 FR 15423 - U.S. Nuclear Regulatory Commission Technical Evaluation Report for the Phase 1 Decommissioning...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-29

    ... and consider the comments provided prior to the initiation of decontamination and decommissioning... initiation of decontamination and decommissioning operations. As indicated by NRC, ``Should the EIS...

  8. Development of Safety Assessment Code for Decommissioning of Nuclear Facilities

    NASA Astrophysics Data System (ADS)

    Shimada, Taro; Ohshima, Soichiro; Sukegawa, Takenori

    A safety assessment code, DecDose, for decommissioning of nuclear facilities has been developed, based on the experiences of the decommissioning project of Japan Power Demonstration Reactor (JPDR) at Japan Atomic Energy Research Institute (currently JAEA). DecDose evaluates the annual exposure dose of the public and workers according to the progress of decommissioning, and also evaluates the public dose at accidental situations including fire and explosion. As for the public, both the internal and the external doses are calculated by considering inhalation, ingestion, direct radiation from radioactive aerosols and radioactive depositions, and skyshine radiation from waste containers. For external dose for workers, the dose rate from contaminated components and structures to be dismantled is calculated. Internal dose for workers is calculated by considering dismantling conditions, e.g. cutting speed, cutting length of the components and exhaust velocity. Estimation models for dose rate and staying time were verified by comparison with the actual external dose of workers which were acquired during JPDR decommissioning project. DecDose code is expected to contribute the safety assessment for decommissioning of nuclear facilities.

  9. The Chernobyl NPP decommissioning: Current status and alternatives

    SciTech Connect

    Mikolaitchouk, H.; Steinberg, N.

    1996-08-01

    After the Chernobyl accident of April 26, 1986, many contradictory decisions were taken concerning the Chernobyl nuclear power plant (NPP) future. The principal source of contradictions was a deadline for a final shutdown of the Chernobyl NPP units. Alterations in a political and socioeconomic environment resulted in the latest decision of the Ukrainian Authorities about 2000 as a deadline for a beginning of the Chernobyl NPP decommissioning. The date seems a sound compromise among the parties concerned. However, in order to meet the data a lot of work should be done. First of all, a decommissioning strategy has to be established. The problem is complicated due to both site-specific aspects and an absence of proven solutions for the RBMK-type reactor decommissioning. In the paper the problem of decommissioning option selection is considered taking into account an influence of the following factors: relevant legislative and regulatory requirements; resources required to carry out decommissioning (man-power, equipment, technologies, waste management infrastructure, etc.); radiological and physical status of the plant, including structural integrity and predictable age and weather effects; impact of planned activities at the destroyed unit 4 and within the 30-km exclusion zone of the Chernobyl NPP; planed use of the site; socio-economic considerations.

  10. 30 CFR 285.907 - How will MMS process my decommissioning application?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... decommissioning application with the decommissioning general concept in your approved SAP, COP, or GAP to..., COP, or GAP, and MMS will begin the appropriate NEPA analysis and other regulatory reviews as...

  11. Technology needs for decommissioning and decontamination

    SciTech Connect

    Bundy, R.D.; Kennerly, J.M.

    1993-12-01

    This report summarizes the current view of the most important decontamination and decommissioning (D & D) technology needs for the US Department of Energy facilities for which the D & D programs are the responsibility of Martin Marietta Energy Systems, Inc. The source of information used in this assessment was a survey of the D & D program managers at each facility. A summary of needs presented in earlier surveys of site needs in approximate priority order was supplied to each site as a starting point to stimulate thinking. This document reflects a brief initial assessment of ongoing needs; these needs will change as plans for D & D are finalized, some of the technical problems are solved through successful development programs, and new ideas for D and D technologies appear. Thus, this assessment should be updated and upgraded periodically, perhaps, annually. This assessment differs from others that have been made in that it directly and solely reflects the perceived need for new technology by key personnel in the D & D programs at the various facilities and does not attempt to consider the likelihood that these technologies can be successfully developed. Thus, this list of technology needs also does not consider the cost, time, and effort required to develop the desired technologies. An R & D program must include studies that have a reasonable chance for success as well as those for which there is a high need. Other studies that considered the cost and probability of successful development as well as the need for new technology are documented. However, the need for new technology may be diluted in such studies; this document focuses only on the need for new technology as currently perceived by those actually charged with accomplishing D & D.

  12. Reductions of oxygen, carbon dioxide, and acetonitrile by the magnesium(II)/magnesium(I) couple in aqueous media: theoretical insights from a nano-sized water droplet.

    PubMed

    Lam, Tim-Wai; Zhang, Han; Siu, Chi-Kit

    2015-03-26

    Reductions of O2, CO2, and CH3CN by the half-reaction of the Mg(II)/Mg(I) couple (Mg(2+) + e(-) → Mg(+•)) confined in a nanosized water droplet ([Mg(H2O)16](•+)) have been examined theoretically by means of density functional theory based molecular dynamics methods. The present works have revealed many intriguing aspects of the reaction dynamics of the water clusters within several picoseconds or even in subpicoseconds. The reduction of O2 requires an overall doublet spin state of the system. The reductions of CO2 and CH3CN are facilitated by their bending vibrations and the electron-transfer processes complete within 0.5 ps. For all reactions studied, the radical anions, i.e., O2(•-), CO2(•-), and CH3CN(•-), are initially formed on the cluster surface. O2(•-) and CO2(•-) can integrate into the clusters due to their high hydrophilicity. They are either solvated in the second solvation shell of Mg(2+) as a solvent-separated ion pair (ssip) or directly coordinated to Mg(2+) as a contact-ion pair (cip) having the (1)η-[MgO2](•+) and (1)η-[MgOCO](•+) coordination modes. The (1)η-[MgO2](•+) core is more crowded than the (1)η-[MgOCO](•+) core. The reaction enthalpies of the formation of ssip and cip of [Mg(CO2)(H2O)16](•+) are -36 ± 4 kJ mol(-1) and -30 ± 9 kJ mol(-1), respectively, which were estimated based on the average temperature changes during the ion-molecule reaction between CO2 and [Mg(H2O)16](•+). The values for the formation of ssip and cip of [Mg(O2)(H2O)16](•+) are estimated to be -112 ± 18 kJ mol(-1) and -128 ± 28 kJ mol(-1), respectively. CH3CN(•-) undergoes protonation spontaneously to form the hydrophobic [CH3CN, H](•). Both CH3CN and [CH3CN, H](•) cannot efficiently penetrate into the clusters with activation barriers of 22 kJ mol(-1) and ∼40 kJ mol(-1), respectively. These results provide fundamental insights into the solvation dynamics of the Mg(2+)/Mg(•+) couple on the molecular level. PMID:25738586

  13. DEACTIVATION AND DECOMMISSIONING PLANNING AND ANALYSIS WITH GEOGRAPHIC INFORMATION SYSTEMS

    SciTech Connect

    Bollinger, J; William Austin, W; Larry Koffman, L

    2007-09-17

    From the mid-1950's through the 1980's, the U.S. Department of Energy's Savannah River Site produced nuclear materials for the weapons stockpile, for medical and industrial applications, and for space exploration. Although SRS has a continuing defense-related mission, the overall site mission is now oriented toward environmental restoration and management of legacy chemical and nuclear waste. With the change in mission, SRS no longer has a need for much of the infrastructure developed to support the weapons program. This excess infrastructure, which includes over 1000 facilities, will be decommissioned and demolished over the forthcoming years. Dispositioning facilities for decommissioning and deactivation requires significant resources to determine hazards, structure type, and a rough-order-of-magnitude estimate for the decommissioning and demolition cost. Geographic information systems (GIS) technology was used to help manage the process of dispositioning infrastructure and for reporting the future status of impacted facilities.

  14. The shielding design process--new plants to decommissioning.

    PubMed

    Jeffries, Graham; Cooper, Andrew; Hobson, John

    2005-01-01

    BNFL have over 25 years experience of designing nuclear plant for the whole-fuel cycle. In the UK, a Nuclear Decommissioning Authority (NDA) is to be set up to ensure that Britain's nuclear legacy is cleaned up safely, securely and cost effectively. The resulting challenges and opportunities for shielding design will be substantial as the shielding design process was originally devised for the design of new plants. Although its underlying principles are equally applicable to decommissioning and remediation of old plants, there are many aspects of detailed application that need to adapt to this radically different operating environment. The paper describes both the common issues and the different challenges of shielding design at different operational phases. Sample applications will be presented of both new plant and decommissioning projects that illustrate not only the robust nature of the processes being used, but also how they lead to cost-effective solutions making a substantive and appropriate contribution to radiological protection goals. PMID:16604700

  15. Managing Decommissioning Projects Using D&D Trak

    SciTech Connect

    Stegen, R.; Wilkinson, R.; Frink, P.; Karas, T.

    2003-02-26

    Numerous buildings throughout the DOE complex are being decommissioned. The decommissioning process typically includes dismantling equipment and utility systems for disposal, decontaminating remaining surfaces to meet regulatory limits, demolishing the building structure, and remediating the surrounding environment to address any historical releases. Typically, a large amount of information and radiation survey data needs to be processed and evaluated. Rapid assessment of project information is required to effectively manage unanticipated conditions that are frequently encountered as building components are dismantled. Parsons has developed a relational database called D&D TRAK to estimate, plan, manage, and track decommissioning projects. D&D TRAK has been successfully used at DOE and other federal facilities to terminate radioactive licenses thus allowing the unrestricted free-release of these buildings to public and private sectors.

  16. Beneficial Re-use of Decommissioned Former Nuclear Facilities

    SciTech Connect

    Boing, L.E.

    1997-06-01

    With the decision to decommission a nuclear facility, it is necessary to evaluate whether to fully demolish a facility or to re-use the facility in some capacity. This evaluation is often primarily driven by both the past mission of the site and the facility and the site's perceived future mission. In the case where the facility to be decommissioned is located within a large research or industrial complex and represents a significant resource to the site's future mission, it may be a perfect candidate to be re-used in some fashion. However, if the site is a rather remote older facility with little chance of being modified to today's standards for its re-use, the chances for its re-use will be substantially reduced. In this presentation, some specific cases of former nuclear facilities being decommissioned and re-used will be reviewed and some factors required to be considered in making this decision will be reviewed.

  17. Completion of decommissioning: Monitoring for site release and license termination

    SciTech Connect

    Boing, L.E.

    1997-08-01

    To request termination of a license upon completion of dismantling or decommissioning activities, documenting any residual radioactivity to show that the levels are environmentally acceptable will be necessary. When the regulators approve the decommissioning plan, they establish what the release criteria for the decommissioned site will be at the time of the site release and license termination. The criteria are numeric guidelines for direct radiation in soils and on surfaces. If the regulatory body finds that the measured on-site values are below the guidelines, the site will be acceptable for unrestricted release (no radiological controls or future use). If areas are found above those values, more decontamination or cleanup of these areas may be required unless the regulatory body grants an exemption.

  18. Decrease in thermal conductivity in polymeric P3HT nanowires by size-reduction induced by crystal orientation: new approaches towards thermal transport engineering of organic materials.

    PubMed

    Rojo, Miguel Muñoz; Martín, Jaime; Grauby, Stéphane; Borca-Tasciuc, Theodorian; Dilhaire, Stefan; Martin-Gonzalez, Marisol

    2014-07-21

    To date, there is no experimental characterization of thermal conductivity of semiconductor polymeric individual nanowires embedded in a matrix. This work reports on scanning thermal microscopy measurements in a 3ω configuration to determine how the thermal conductivity of individual nanowires made of a model conjugated polymer (P3HT) is modified when decreasing their diameters. We observe a reduction of thermal conductivity, from λNW = 2.29 ± 0.15 W K(-1) m(-1) to λNW = 0.5 ± 0.24 W K(-1) m(-1), when the diameter of nanowires is reduced from 350 nm to 120 nm, which correlates with the polymer crystal orientation measured by WAXS. Through this work, the foundations for future polymer thermal transport engineering are presented. PMID:24933655

  19. 77 FR 75198 - Standard Format and Content for Post-Shutdown Decommissioning Activities Report

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-19

    ... COMMISSION Standard Format and Content for Post-Shutdown Decommissioning Activities Report AGENCY: Nuclear... Format and Content for Post-shutdown Decommissioning Activities Report.'' This guide describes a method...) 1.185, ``Standard Format and Content for Post-shutdown Decommissioning Activities Report,''...

  20. 26 CFR 1.468A-1T - Nuclear decommissioning costs; general rules (temporary).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 6 2010-04-01 2010-04-01 false Nuclear decommissioning costs; general rules...-1T Nuclear decommissioning costs; general rules (temporary). (a) Introduction. Section 468A provides an elective method for taking into account nuclear decommissioning costs for Federal income...

  1. 26 CFR 1.468A-1 - Nuclear decommissioning costs; general rules.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 6 2011-04-01 2011-04-01 false Nuclear decommissioning costs; general rules. 1...-1 Nuclear decommissioning costs; general rules. (a) Introduction. Section 468A provides an elective method for taking into account nuclear decommissioning costs for Federal income tax purposes. In...

  2. ADVANTAGES, DISADVANTAGES, AND LESSONS LEARNED FROM MULTI-REACTOR DECOMMISSIONING PROJECTS

    SciTech Connect

    Morton, M.R.; Nielson, R.R.; Trevino, R.A.

    2003-02-27

    This paper discusses the Reactor Interim Safe Storage (ISS) Project within the decommissioning projects at the Hanford Site and reviews the lessons learned from performing four large reactor decommissioning projects sequentially. The advantages and disadvantages of this multi-reactor decommissioning project are highlighted.

  3. 77 FR 8902 - Draft Regulatory Guide: Issuance, Availability Decommissioning of Nuclear Power Reactors

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-15

    ... COMMISSION Draft Regulatory Guide: Issuance, Availability Decommissioning of Nuclear Power Reactors AGENCY... ``Decommissioning of Nuclear Power Reactors.'' This guide describes a method NRC considers acceptable for use in... Revision 1 of Regulatory Guide 1.184, ``Decommissioning of Nuclear Power Reactors,'' dated July 2000....

  4. A costing model for offshore decommissioning in California.

    PubMed

    Bressler, Andrew; Bernstein, Brock B

    2015-10-01

    California's 27 offshore oil and gas platforms will reach the end of their useful lifetimes sometime in the near future and will require decommissioning. Although existing leases require complete removal of all platforms and associated infrastructure, the underlying laws and regulations have changed in recent years to allow a number of alternative uses after decommissioning. In particular, AB 2503, signed into law in September 2010, provides for a rigs-to-reefs program that allows the state to accept ownership of decommissioned platforms in federal waters. Decisions about whether to remove platforms completely or leave them in place as artificial reefs will depend in part on the relative cost of the 2 options. In this study, we describe the design and use of a mathematical decision model that provides detailed cost estimates of complete and partial removal (to 85 feet below the water line) for California's offshore platforms. The model, PLATFORM, is loaded with Bureau of Safety and Environmental Enforcement (BSEE) and Bureau of Ocean Energy Management (BOEM) costs for complete removal, along with costs for partial removal calculated for this study and estimates of the uncertainty associated with decommissioning cost estimates. PLATFORM allows users to define a wide range of decommissioning and costing scenarios (e.g., number of platforms, choice of heavy lift vessel, shell mound removal, reef enhancement). As a benchmark cost, complete removal of all 27 offshore platforms, grouped into the 7 decommissioning projects defined by the most recent federal cost estimates produced in 2010, would cost an estimated $1.09 billion, whereas partial removal of these platforms, grouped into the same set of projects, would cost $478 million, with avoided costs of $616 million (with minor rounding). PMID:25914378

  5. Characterization of decontamination and decommissioning wastes expected from the major processing facilities in the 200 Areas

    SciTech Connect

    Amato, L.C.; Franklin, J.D.; Hyre, R.A.; Lowy, R.M.; Millar, J.S.; Pottmeyer, J.A.; Duncan, D.R.

    1994-08-01

    This study was intended to characterize and estimate the amounts of equipment and other materials that are candidates for removal and subsequent processing in a solid waste facility when the major processing and handling facilities in the 200 Areas of the Hanford Site are decontaminated and decommissioned. The facilities in this study were selected based on processing history and on the magnitude of the estimated decommissioning cost cited in the Surplus Facilities Program Plan; Fiscal Year 1993 (Winship and Hughes 1992). The facilities chosen for this study include B Plant (221-B), T Plant (221-T), U Plant (221-U), the Uranium Trioxide (UO{sub 3}) Plant (224-U and 224-UA), the Reduction Oxidation (REDOX) or S Plant (202-S), the Plutonium Concentration Facility for B Plant (224-B), and the Concentration Facility for the Plutonium Finishing Plant (PFP) and REDOX (233-S). This information is required to support planning activities for current and future solid waste treatment, storage, and disposal operations and facilities.

  6. Grain size reduction and recording performance improvement by using NiW as a partial interlayer in CoCrPt/SiO2 recording medium

    NASA Astrophysics Data System (ADS)

    Zhang, Hong-Wei

    2011-12-01

    We report the effect of NiW, as an interlayer to partially replace Ru, on the microstructure, magnetic properties, and recording performance of CoCrPt/SiO2 perpendicular recording media. It was found that the full width at half maximum of the rocking curves of the Co (0002) peak changed little with NiW thickness up to 10 nm. However, further increase of NiW thickness caused a larger c-axis dispersion. The grain size of the CoCrPt/SiO2 recording layer was reduced from 10.9±1.8 nm for the films without NiW to 7.7±1.5 nm for films with 10-nm NiW as a partial interlayer. The coercivity, H c, nucleation field, H n, and the reverse overwrite, Rev_OV, of the CoCrPt/SiO2 layer did not change much (less than 15%) with increased NiW thickness. However, it did affect the switching field distribution of the CoCrPt/SiO2 layer (more than double). The recording performance was improved by using NiW as a partial interlayer, which was mainly attributed to the reduced grain size.

  7. Technology demonstrations in the Decontamination and Decommissioning Focus Area

    SciTech Connect

    Bossart, S.J.

    1996-02-01

    This paper describes three large-scale demonstration projects sponsored jointly by the Decontamination and Decommissioning Focus Area (DDFA), and the three US Department of Energy (DOE) Operations Offices that successfully offered to deactivate or decommission (D&D) one of its facilities using a combination of innovative and commercial D&D technologies. The paper also includes discussions on recent technology demonstrations for an Advanced Worker Protection System, an Electrohydraulic Scabbling System, and a Pipe Explorer{trademark}. The references at the conclusion of this paper should be consulted for more detailed information about the large-scale demonstration projects and recent technology demonstrations sponsored by the DDFA.

  8. Multifunctional T Lymphocytes Generated After Therapy With an Antitumor Gallotanin-Rich Normalized Fraction Are Related to Primary Tumor Size Reduction in a Breast Cancer Model.

    PubMed

    Urueña, Claudia; Gomez, Alejandra; Sandoval, Tito; Hernandez, John; Li, Shaoping; Barreto, Alfonso; Fiorentino, Susana

    2015-09-01

    Natural compounds are promising sources for anticancer therapies because of their multifunctional activity and low toxicity. Although the host immune response (IR) is clearly implicated in tumor control, the relationship between natural therapies and IR has not yet been elucidated. The present work evaluates IR induction after treatment with a gallotannin-rich fraction from Caesalpinia spinosa (P2Et). Breast tumor 4T1 cells were used to evaluate antitumor properties and IR activation. Apoptosis and expression of immunogenic cell death (ICD) markers were assessed in vitro, whereas IR and postvaccination tumor evolution were assessed in vivo. P2Et fraction induced apoptotic cell death, displaying phosphatidylserine externalization and DNA fragmentation. ICD markers such as calreticulin, high-mobility group box 1 translocation from nuclei to cytoplasm, and ATP secretion were observed. Primary tumor control was improved by vaccination with P2Et-pretreated 4T1 cells (t-P2Et), yielding long-lasting ex vivo multifunctional CD4(+) and CD8(+) T lymphocytes (interleukin [IL]-2(+), tumor necrosis factor [TNF]-α(+), interferon [IFN]-γ(+)) that secrete IL-2, TNF-α, IL-4, IL-5, and IFN-γ after specific 4T1 cell stimulation. The present study constitutes the first demonstration of a long-lasting antitumor IR induction and primary tumor reduction induced by a complex natural fraction. These data reveal the potential use of this fraction as an adjuvant in breast cancer treatment. PMID:26220604

  9. Fixed-Price Subcontracting for Decontamination and Decommissioning of Small Facilities at Oak Ridge National Laboratory

    SciTech Connect

    Harper, M. A.; Julius, J. F. K.; McKenna, M. K.

    2002-02-26

    Abandoned facilities were decontaminated and decommissioned in preparation for final remediation of Solid Waste Storage Area (SWSA) 4 at Oak Ridge National Laboratory. The facilities varied in age from approximately 5 years to more than 40 years, with radiological conditions ranging from clean to highly contaminated with fission products. A fixed-price subcontract (FPSC) was awarded by the U.S. Department of Energy's (DOE's) Environmental Management (EM) Management and Integration (M&I) contractor for decontamination and decommissioning (D&D) of these facilities. Included in the FPSC scope were the following: preparation of pre-D&D regulatory documentation; demolition of surface structures to slab; stabilization of below-grade structures; waste management and disposal; and preparation of post-D&D regulatory documentation. Using stand-off techniques to the extent possible, building structures and ancillary equipment were prepared for demolition and demolished. A fixative coating system was used in conjunction with continuous water misting to control airborne contamination. Demolition waste consisted of two major streams: clean construction and demolition waste and low-level (radioactive) waste. The debris was size-reduced and packaged, again via remote means. At all times during the D&D, personnel safety, environmental compliance, and as low as reasonably achievable exposure considerations were paramount. Upon completion of D&D activities, each site was inspected and accepted by the M&I contractor. This project is a success story for fixed-price subcontracting of D&D work under DOE's M&I arrangement.

  10. Reduction of ectopic bone growth in critically-sized rat mandible defects by delivery of rhBMP-2 from kerateine biomaterials

    PubMed Central

    Kowalczewski, Christine J.; Tombyln, Seth; Wasnick, David C.; Hughes, Michael R.; Ellenburg, Mary D.; Callahan, Michael F.; Smith, Thomas L.; Van Dyke, Mark E.; Burnett, Luke R.; Saul, Justin M.

    2014-01-01

    Absorbable collagen sponges (ACS) are used clinically as carriers of recombinant human bone morphogenetic protein 2 (rhBMP-2) to promote bone regeneration. ACS exhibit ectopic bone growth due to delivery of supraphysiological levels of rhBMP-2, which is particularly problematic in craniofacial bone injuries for both functional and esthetic reasons. We hypothesized that hydrogels from the reduced form of keratin proteins (kerateine) would serve as a suitable alternative to ACS carriers of rhBMP-2. The rationale for this hypothesis is that keratin biomaterials degrade slowly in vivo, have modifiable material properties, and have demonstrated capacity to deliver therapeutic agents. We investigated kerateine hydrogels and freeze-dried scaffolds as rhBMP-2 carriers in a critically-sized rat mandibular defect model. ACS, kerateine hydrogels, and kerateine scaffolds loaded with rhBMP-2 achieved bridging in animals by 8 weeks as indicated by micro-computed tomography. Kerateine scaffolds achieved statistically increased bone mineral density compared to ACS and kerateine hydrogels, with levels reaching those of native bone. Importantly, both kerateine hydrogels and kerateine scaffolds had significantly less ectopic bone growth than ACS sponges at both 8 and 16 weeks post-operatively. These studies demonstrate the suitability of keratins as rhBMP-2 carriers due to equal regenerative capacity with reduced ectopic growth compared to ACS. PMID:24439399

  11. 18 CFR 2.24 - Project decommissioning at relicensing.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Project decommissioning at relicensing. 2.24 Section 2.24 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES GENERAL POLICY AND INTERPRETATIONS Statements of...

  12. 26 CFR 1.88-1 - Nuclear decommissioning costs.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... electric energy generated by a nuclear power plant must be included in the gross income of such taxpayer in the same manner as amounts charged for electric energy. For this purpose, decommissioning costs... consumers are liable to pay by reason of electric energy furnished by the taxpayer during the taxable...

  13. 26 CFR 1.88-1 - Nuclear decommissioning costs.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... electric energy generated by a nuclear power plant must be included in the gross income of such taxpayer in the same manner as amounts charged for electric energy. For this purpose, decommissioning costs... consumers are liable to pay by reason of electric energy furnished by the taxpayer during the taxable...

  14. 26 CFR 1.88-1 - Nuclear decommissioning costs.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... electric energy generated by a nuclear power plant must be included in the gross income of such taxpayer in the same manner as amounts charged for electric energy. For this purpose, decommissioning costs... consumers are liable to pay by reason of electric energy furnished by the taxpayer during the taxable...

  15. 10 CFR 72.130 - Criteria for decommissioning.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Criteria for decommissioning. 72.130 Section 72.130 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL, HIGH-LEVEL RADIOACTIVE WASTE, AND REACTOR-RELATED GREATER THAN CLASS C WASTE General...

  16. 78 FR 64028 - Decommissioning of Nuclear Power Reactors

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-25

    ... Register on February 14, 2012 (77 FR 8902), for a 60-day public comment period. The public comment period... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Decommissioning of Nuclear Power Reactors AGENCY: Nuclear Regulatory Commission....

  17. Korea Research Reactor -1 & 2 Decommissioning Project in Korea

    SciTech Connect

    Park, S. K.; Chung, U. S.; Jung, K. J.; Park, J. H.

    2003-02-24

    Korea Research Reactor 1 (KRR-1), the first research reactor in Korea, has been operated since 1962, and the second one, Korea Research Reactor 2 (KRR-2) since 1972. The operation of both of them was phased out in 1995 due to their lifetime and operation of the new and more powerful research reactor, HANARO (High-flux Advanced Neutron Application Reactor; 30MW). Both are TRIGA Pool type reactors in which the cores are small self-contained units sitting in tanks filled with cooling water. The KRR-1 is a TRIGA Mark II, which could operate at a level of up to 250 kW. The second one, the KRR-2 is a TRIGA Mark III, which could operate at a level of up 2,000 kW. The decontamination and decommissioning (D & D) project of these two research reactors, the first D & D project in Korea, was started in January 1997 and will be completed to stage 3 by 2008. The aim of this decommissioning program is to decommission the KRR-1 & 2 reactors and to decontaminate the residual building structure s and the site to release them as unrestricted areas. KAERI (Korea Atomic Energy Research Institute) submitted the decommissioning plan and the environmental impact assessment reports to the Ministry of Science and Technology (MOST) for the license in December 1998, and was approved in November 2000.

  18. Recent Trends in the Adequacy of Nuclear Plant Decommissioning Funding

    SciTech Connect

    Williams, D. G.

    2002-02-26

    Concerned about the potential cost and sufficiency of funds to decommission the nation's nuclear power plants, the Congress asked the U.S. General Accounting Office (GAO) to assess the adequacy, as of December 31, 1997, of electric utilities'; funds to eventually decommission their plants. GAO's report (GAO/RCED-99-75) on this issue addressed three alternative assumption scenarios--baseline (most likely), optimistic, and pessimistic; and was issued in May 1999. This paper updates GAO's baseline assessment of fund adequacy in 1997, and extends the analysis through 2000. In 2000, we estimate that the present value cost to decommission the nation's nuclear plants is about $35 billion; utility fund balances are about $29 billion. Both our two measures of funding adequacy for utilities are on average not only much above ideal levels, but also overall have greatly improved since 1997. However, certain utilities still show less than ideal fund balances and annual contributions. We suggest that the range of these results among the individual utilities is a more important policy measure to assess the adequacy of decommissioning funding than is the funding adequacy for the industry as a whole.

  19. Integration of improved decontamination and characterization technologies in the decommissioning of the CP-5 research reactor

    SciTech Connect

    Bhattacharyya, S. K.; Boing, L. E.

    2000-02-17

    The aging of research reactors worldwide has resulted in a heightened awareness in the international technical decommissioning community of the timeliness to review and address the needs of these research institutes in planning for and eventually performing the decommissioning of these facilities. By using the reactors already undergoing decommissioning as test beds for evaluating enhanced or new/innovative technologies for decommissioning, it is possible that new techniques could be made available for those future research reactor decommissioning projects. Potentially, the new technologies will result in: reduced radiation doses to the work force, larger safety margins in performing decommissioning and cost and schedule savings to the research institutes in performing the decommissioning of these facilities. Testing of these enhanced technologies for decontamination, dismantling, characterization, remote operations and worker protection are critical to furthering advancements in the technical specialty of decommissioning. Furthermore, regulatory acceptance and routine utilization for future research reactor decommissioning will be assured by testing and developing these technologies in realistically contaminated environments prior to use in the research reactors. The decommissioning of the CP-5 Research Reactor is currently in the final phase of dismantlement. In this paper the authors present results of work performed at Argonne National Laboratory (ANL) in the development, testing and deployment of innovative and/or enhanced technologies for the decommissioning of research reactors.

  20. Reductions in the number of mid-sized antral follicles are associated with markers of premature ovarian senescence in dairy cows.

    PubMed

    Modina, Silvia C; Tessaro, Irene; Lodde, Valentina; Franciosi, Federica; Corbani, Davide; Luciano, Alberto M

    2014-01-01

    High-producing dairy cows are subfertile; however, the mechanisms responsible for the decreased fertility are unknown. The aim of the present study was to test the hypothesis that culled dairy cows (4-8 years old) characterised by 'Lo' ovaries (i.e. those with <10 mid-antral follicles) are affected by premature ovarian senescence. Cows in which both ovaries were 'Lo' ovaries represented 5% of the total population analysed, and exhibited reduced ovarian size (P<0.001) and increased perifollicular stroma (P<0.05) compared with age-matched controls (i.e. cows in which both ovaries had >10 mid-antral follicles; 'Hi' ovaries). The total number of follicles, including healthy and atretic primordial, primary, secondary and small antral follicles, was lower in Lo ovaries (P<0.01). Interestingly, the primordial follicle population in Lo ovaries was lower (P<0.05) than in the control. Finally, the follicular fluid of mid-antral follicles from Lo ovaries had reduced oestradiol and anti-Müllerian hormone levels (P<0.05), but increased progesterone concentrations (P<0.05). Together, these data account for the reduced fertility of cows with Lo ovaries and are in agreement with previous observations that oocytes isolated from Lo ovaries have reduced embryonic developmental competence. Cows with a specific Lo ovary condition may represent a suitable model to address the causes of low fertility in high-yielding dairy cows, as well as the condition of premature ovarian aging in single-ovulating species. PMID:23327793

  1. Technology, safety, and costs of decommissioning a reference large irradiator and reference sealed sources

    SciTech Connect

    Haffner, D.R.; Villelgas, A.J.

    1996-01-01

    This report contains the results of a study sponsored by the US Nuclear Regulatory Commission (NRC) to examine the decommissioning of large radioactive irradiators and their respective facilities, and a broad spectrum of sealed radioactive sources and their respective devices. Conceptual decommissioning activities are identified, and the technology, safety, and costs (in early 1993 dollars) associated with decommissioning the reference large irradiator and sealed source facilities are evaluated. The study provides bases and background data for possible future NRC rulemaking regarding decommissioning, for evaluation of the reasonableness of planned decommissioning actions, and for determining if adequate funds are reserved by the licensees for decommissioning of their large irradiator or sealed source facilities. Another purpose of this study is to provide background and information to assist licensees in planning and carrying out the decommissioning of their sealed radioactive sources and respective facilities.

  2. In-house developed methodologies and tools for decommissioning projects

    SciTech Connect

    Detilleux, Michel; Centner, Baudouin

    2007-07-01

    The paper describes different methodologies and tools developed in-house by Tractebel Engineering to facilitate the engineering works to be carried out especially in the frame of decommissioning projects. Three examples of tools with their corresponding results are presented: - The LLWAA-DECOM code, a software developed for the radiological characterization of contaminated systems and equipment. The code constitutes a specific module of more general software that was originally developed to characterize radioactive waste streams in order to be able to declare the radiological inventory of critical nuclides, in particular difficult-to-measure radionuclides, to the Authorities. In the case of LLWAA-DECOM, deposited activities inside contaminated equipment (piping, tanks, heat exchangers...) and scaling factors between nuclides, at any given time of the decommissioning time schedule, are calculated on the basis of physical characteristics of the systems and of operational parameters of the nuclear power plant. This methodology was applied to assess decommissioning costs of Belgian NPPs, to characterize the primary system of Trino NPP in Italy, to characterize the equipment of miscellaneous circuits of Ignalina NPP and of Kozloduy unit 1 and, to calculate remaining dose rates around equipment in the frame of the preparation of decommissioning activities; - The VISIMODELLER tool, a user friendly CAD interface developed to ease the introduction of lay-out areas in a software named VISIPLAN. VISIPLAN is a 3D dose rate assessment tool for ALARA work planning, developed by the Belgian Nuclear Research Centre SCK.CEN. Both softwares were used for projects such as the steam generators replacements in Belgian NPPs or the preparation of the decommissioning of units 1 and 2 of Kozloduy NPP; - The DBS software, a software developed to manage the different kinds of activities that are part of the general time schedule of a decommissioning project. For each activity, when relevant

  3. Decommissioning of U.S. uranium production facilities

    SciTech Connect

    Not Available

    1995-02-01

    From 1980 to 1993, the domestic production of uranium declined from almost 44 million pounds U{sub 3}O{sub 8} to about 3 million pounds. This retrenchment of the U.S. uranium industry resulted in the permanent closing of many uranium-producing facilities. Current low uranium prices, excess world supply, and low expectations for future uranium demand indicate that it is unlikely existing plants will be reopened. Because of this situation, these facilities eventually will have to be decommissioned. The Uranium Mill Tailings and Radiation Control Act of 1978 (UMTRCA) vests the U.S. Environmental Protection Agency (EPA) with overall responsibility for establishing environmental standards for decommissioning of uranium production facilities. UMTRCA also gave the U.S. Nuclear Regulatory Commission (NRC) the responsibility for licensing and regulating uranium production and related activities, including decommissioning. Because there are many issues associated with decommissioning-environmental, political, and financial-this report will concentrate on the answers to three questions: (1) What is required? (2) How is the process implemented? (3) What are the costs? Regulatory control is exercised principally through the NRC licensing process. Before receiving a license to construct and operate an uranium producing facility, the applicant is required to present a decommissioning plan to the NRC. Once the plan is approved, the licensee must post a surety to guarantee that funds will be available to execute the plan and reclaim the site. This report by the Energy Information Administration (EIA) represents the most comprehensive study on this topic by analyzing data on 33 (out of 43) uranium production facilities located in Colorado, Nebraska, New Mexico, South Dakota, Texas, Utah, and Washington.

  4. Education in nuclear decommissioning in the north of Scotland

    SciTech Connect

    Catlow, F.; Reeves, G.M.

    2007-07-01

    This paper describes the work covered and experience gained in the first two years of operation of DERC, a Centre for Decommissioning and Environmental Remediation in the Highlands of Scotland. The Centre is a unique development which was set up to teach nuclear decommissioning as a separate discipline, address the problem of a declining skills base in the field of nuclear technologies and to take advantage of the unique and exceptional innovative, technical and research opportunities offered through the decommissioning of Britain's fast reactor site at Dounreay. The Centre is an offshoot from North Highland College which is a member of UHI, the University in embryo of the Highlands and Islands. The Centre currently supports ten PhD students completing various diverse projects mainly in the field of nuclear environmental remediation. In addition there area number of full and part time MSc students who participate in NTEC (Nuclear Technology Education Consortium) a consortium of British Universities set up specifically to engender interest and skills in nuclear technology at postgraduate level. At undergraduate level, courses are offered in Nuclear Decommissioning and related subjects as part of Electrical and Mechanical degree courses. In addition to our relationship with the United Kingdom Atomic Energy Authority (UKAEA) the Dounreay site licensee, we have links with Rolls-Royce and the Ministry of Defence who also share the Dounreay site and with other stakeholders such as, the UK regulator (HSE/NII), the Scottish Environmental Protection Agency (SEPA), local and international contractors and we liaise with the newly formed Nuclear Decommissioning Authority (NDA), who provide some sponsorship and support. We possess our own equipment and laboratories for taking and analysing soil samples and for conducting environmental surveys. Recently we commissioned an aerial survey of contamination in the locality from natural sources, other background levels such as

  5. Atmospheric discharges from nuclear facilities during decommissioning: German experiences

    SciTech Connect

    Braun, H.; Goertz, R.; Weil, L.

    1997-08-01

    In Germany, a substantial amount of experience is available with planning, licensing and realization of decommissioning projects. In total, a number of 18 nuclear power plants including prototype facilities as well as 6 research reactors and 3 fuel cycle facilities have been shut down finally and are at different stages of decommissioning. Only recently the final {open_quotes}green field{close_quotes} stage of the Niederaichbach Nuclear Power Plant total dismantlement project has been achieved. From the regulatory point of view, a survey of the decommissioning experience in Germany is presented highlighting the aspects of production and retention of airborne radioactivity. Nuclear air cleaning technology, discharge limits prescribed in licences and actual discharges are presented. As compared to operation, the composition of the discharged radioactivity is different as well as the off-gas discharge rate. In practically all cases, there is no significant amount of short-lived radionuclides. The discussion further includes lessons learned, for example inadvertent discharges of radionuclides expected not to be in the plants inventory. It is demonstrated that, as for operation of nuclear power plants, the limits prescribed in the Ordinance on Radiological Protection can be met using existing air cleaning technology, Optimization of protection results in public exposures substantially below the limits. In the frame of the regulatory investigation programme a study has been conducted to assess the airborne radioactivity created during certain decommissioning activities like decontamination, segmentation and handling of contaminated or activated parts. The essential results of this study are presented, which are supposed to support planning for decommissioning, for LWRs, Co-60 and Cs-137 are expected to be the dominant radionuclides in airborne discharges. 18 refs., 2 figs., 1 tab.

  6. Packaging, Transportation, and Disposal Logistics for Large Radioactively Contaminated Reactor Decommissioning Components

    SciTech Connect

    Lewis, Mark S.

    2008-01-15

    The packaging, transportation and disposal of large, retired reactor components from operating or decommissioning nuclear plants pose unique challenges from a technical as well as regulatory compliance standpoint. In addition to the routine considerations associated with any radioactive waste disposition activity, such as characterization, ALARA, and manifesting, the technical challenges for large radioactively contaminated components, such as access, segmentation, removal, packaging, rigging, lifting, mode of transportation, conveyance compatibility, and load securing require significant planning and execution. In addition, the current regulatory framework, domestically in Titles 49 and 10 and internationally in TS-R-1, does not lend itself to the transport of these large radioactively contaminated components, such as reactor vessels, steam generators, reactor pressure vessel heads, and pressurizers, without application for a special permit or arrangement. This paper addresses the methods of overcoming the technical and regulatory challenges. The challenges and disposition decisions do differ during decommissioning versus component replacement during an outage at an operating plant. During decommissioning, there is less concern about critical path for restart and more concern about volume reduction and waste minimization. Segmentation on-site is an available option during decommissioning, since labor and equipment will be readily available and decontamination activities are routine. The reactor building removal path is also of less concern and there are more rigging/lifting options available. Radionuclide assessment is necessary for transportation and disposal characterization. Characterization will dictate the packaging methodology, transportation mode, need for intermediate processing, and the disposal location or availability. Characterization will also assist in determining if the large component can be transported in full compliance with the transportation

  7. The Role of Piece Monitors for the Assay of Plutonium Waste in Alpha Plant Decommissioning Operations

    SciTech Connect

    Wilson, M.; Mullarkey, P.; Orr, C.H.H.; Sharpe, J.; Carr, E.

    2008-07-01

    Plutonium contaminated (TRU) wastes arising during decommissioning and waste retrievals operations at a UK reprocessing facility include small process items, strippable coatings, size-reduced pieces of glove box and metal pipes, etc. These waste materials are generally assayed in a 'Piece Monitor' employing neutron coincidence counting and gamma assay technologies. The major function of the TRU D{sup R} Piece Monitor is to provide an accurate assay of the TRU content of waste pieces/packages, primarily for nuclear safety purposes. The Piece Monitor follows each waste measurement by calculating the cumulative plutonium content of a waste drum as it is filled with this waste, allowing maximum filling of the drum whilst ensuring it remains within fissile content limits. TRU Piece Monitors are deployed at the interface between clean-air (C2) and the active decommissioning (C5) areas by attaching them to the wall of removable modular containment structures (MCSs). In the C5 area, the plant operator uses a variety of cold-cutting processes to size-reduce plant equipment and then places waste items in the monitor chamber for assay, prior to placing the waste in a 200 litre drum. The 're-entrant bulge' design of the assay chamber provides access from the active operations side, whilst the detection equipment remains in the C2 area. This ensures that the Piece Monitor equipment does not become contaminated and remains readily accessible for maintenance or repair. Piece monitors measure and report the plutonium content of each waste item immediately prior to placing in the waste drum, and provides a continuous 'tally' of the drum content. Warnings are shown when a drum is close to exceeding its allowable plutonium content and the waste drum can therefore be changed when either physically full or nearing its nuclear safety limits. (authors)

  8. Carbon-14 Bioassay for Decommissioning of Hanford Reactors

    SciTech Connect

    Carbaugh, Eugene H.; Watson, David J.

    2012-05-01

    The old production reactors at the US Department of Energy Hanford Site used large graphite piles as the moderator. As part of long-term decommissioning plans, the potential need for 14C radiobioassay of workers was identified. Technical issues associated with 14C bioassay and worker monitoring were investigated, including anticipated graphite characterization, potential intake scenarios, and the bioassay capabilities that may be required to support the decommissioning of the graphite piles. A combination of urine and feces sampling would likely be required for the absorption type S 14C anticipated to be encountered. However the concentrations in the graphite piles appear to be sufficiently low that dosimetrically significant intakes of 14C are not credible, thus rendering moot the need for such bioassay.

  9. Decontamination and Decommissioning activities photobriefing book FY 1997

    SciTech Connect

    1998-04-01

    The Decontamination and Decommissioning (D and D) Program at Argonne National Laboratory-East (ANL-E) is dedicated to the safe and cost effective D{ampersand}D of surplus nuclear facilities. There is currently a backlog of more than 7,000 contaminated US Department of Energy facilities nationwide. Added to this are 110 licensed commercial nuclear power reactors operated by utilities learning to cope with deregulation and an aging infrastructure that supports the commercial nuclear power industry, as well as medical and other uses of radioactive materials. With this volume it becomes easy to understand the importance of addressing the unique issues and objectives associated with the D{ampersand}D of surplus nuclear facilities. This photobriefing book summarizes the decontamination and decommissioning projects and activities either completed or continuing at the ANL-E site during the year.

  10. Accelerated Decontamination and Decommissioning at the Hanford Site

    SciTech Connect

    Hughes, M.C.; Douglas, L.M.; Marske, S.G.

    1994-01-01

    The Hanford Site has over 100 facilities that have been declared surplus and are scheduled to be decommissioned. In addition to these surplus facilities, there is a significant number of facilities that are currently being shut down, deactivated, and transferred to the Decontamination and Decommissioning (D&D) program. In the last year, Westinghouse Hanford Company and the US Department of Energy, Richland Operations Office, have developed and implemented an initiative to accelerate the D&D work at the Hanford Site. The strategy associated with accelerated D&D is to reduce the number of surplus facilities, eliminate potential safety hazards, demonstrate meaningful cleanup progress, and recycle materials for other uses. This initiative has been extremely successful and has resulted in the safe demolition of 13 facilities in fiscal year (FY) 1993. In addition, four facilities have been completed in FY 1994 and demolition of several other facilities is currently underway.

  11. Reducing environmental risk associated with laboratory decommissioning and property transfer.

    PubMed Central

    Dufault, R; Abelquist, E; Crooks, S; Demers, D; DiBerardinis, L; Franklin, T; Horowitz, M; Petullo, C; Sturchio, G

    2000-01-01

    The need for more or less space is a common laboratory problem. Solutions may include renovating existing space, leaving or demolishing old space, or acquiring new space or property for building. All of these options carry potential environmental risk. Such risk can be the result of activities related to the laboratory facility or property (e.g., asbestos, underground storage tanks, lead paint), or the research associated with it (e.g., radioactive, microbiological, and chemical contamination). Regardless of the option chosen to solve the space problem, the potential environmental risk must be mitigated and the laboratory space and/or property must be decommissioned or rendered safe prior to any renovation, demolition, or property transfer activities. Not mitigating the environmental risk through a decommissioning process can incur significant financial liability for any costs associated with future decommissioning cleanup activities. Out of necessity, a functioning system, environmental due diligence auditing, has evolved over time to assess environmental risk and reduce associated financial liability. This system involves a 4-phase approach to identify, document, manage, and clean up areas of environmental concern or liability, including contamination. Environmental due diligence auditing includes a) historical site assessment, b) characterization assessment, c) remedial effort and d) final status survey. General practice standards from the American Society for Testing and Materials are available for conducting the first two phases. However, standards have not yet been developed for conducting the third and final phases of the environmental due diligence auditing process. Individuals involved in laboratory decommissioning work in the biomedical research industry consider this a key weakness. PMID:11121365

  12. TECHNOLOGY REQUIREMENTS FOR IN SITU DECOMMISSIONING WORKSHOP REPORT

    SciTech Connect

    Jannik, T.; Lee, P.; Gladden, J.; Langton, C.; Serrato, M.; Urland, C.; Reynolds, E.

    2009-06-30

    In recognition of the increasing attention being focused on In Situ Decommissioning (ISD or entombment) as an acceptable and beneficial decommissioning end state, the Department of Energy's (DOE) Office of Environmental Management (EM) is developing guidance for the implementation of ISD of excess facilities within the DOE complex. Consistent with the overarching DOE goals for increased personnel and environmental safety, reduced technical uncertainties and risks, and overall gains in efficiencies and effectiveness, EM's Office of Deactivation and Decommissioning and Facility Engineering (EM-23) initiated efforts to identify the technical barriers and technology development needs for the optimal implementation of ISD. Savannah River National Laboratory (SRNL), as the EM Corporate Laboratory, conducted an ISD Technology Needs Workshop to identify the technology needs at DOE sites. The overall goal of the workshop was to gain a full understanding of the specific ISD technical challenges, the technologies available, and those needing development. The ISD Workshop was held December 9-10, 2008 in Aiken, SC. Experienced decommissioning operations personnel from Richland Operations Office (RL), Idaho National Laboratory (INL) and Savannah River Site (SRS) along with scientists and engineers specific expertise were assembled to identify incremental and 'game changing' solutions to ISD technology challenges. The workshop and follow-up activities yielded 14 technology needs statements and the recommendation that EM-23 prioritize and pursue the following specific technology development and deployment actions. For each action, the recommended technology acquisition mechanisms (competitive solicitation (CS) or direct funding (TCR)) are provided. Activities that are time critical for ISD projects, or require unique capabilities that reside in the DOE Laboratory system will be funded directly to those institutions. Activities that have longer lead times and where the private

  13. Reducing environmental risk associated with laboratory decommissioning and property transfer.

    PubMed

    Dufault, R; Abelquist, E; Crooks, S; Demers, D; DiBerardinis, L; Franklin, T; Horowitz, M; Petullo, C; Sturchio, G

    2000-12-01

    The need for more or less space is a common laboratory problem. Solutions may include renovating existing space, leaving or demolishing old space, or acquiring new space or property for building. All of these options carry potential environmental risk. Such risk can be the result of activities related to the laboratory facility or property (e.g., asbestos, underground storage tanks, lead paint), or the research associated with it (e.g., radioactive, microbiological, and chemical contamination). Regardless of the option chosen to solve the space problem, the potential environmental risk must be mitigated and the laboratory space and/or property must be decommissioned or rendered safe prior to any renovation, demolition, or property transfer activities. Not mitigating the environmental risk through a decommissioning process can incur significant financial liability for any costs associated with future decommissioning cleanup activities. Out of necessity, a functioning system, environmental due diligence auditing, has evolved over time to assess environmental risk and reduce associated financial liability. This system involves a 4-phase approach to identify, document, manage, and clean up areas of environmental concern or liability, including contamination. Environmental due diligence auditing includes a) historical site assessment, b) characterization assessment, c) remedial effort and d) final status survey. General practice standards from the American Society for Testing and Materials are available for conducting the first two phases. However, standards have not yet been developed for conducting the third and final phases of the environmental due diligence auditing process. Individuals involved in laboratory decommissioning work in the biomedical research industry consider this a key weakness. PMID:11121365

  14. Aroma potential of oak battens prepared from decommissioned oak barrels.

    PubMed

    Li, Sijing; Crump, Anna M; Grbin, Paul R; Cozzolino, Daniel; Warren, Peter; Hayasaka, Yoji; Wilkinson, Kerry L

    2015-04-01

    During barrel maturation, volatile compounds are extracted from oak wood and impart aroma and flavor to wine, enhancing its character and complexity. However, barrels contain a finite pool of extractable material, which diminishes with time. As a consequence, most barrels are decommissioned after 5 or 6 years. This study investigated whether or not decommissioned barrels can be "reclaimed" and utilized as a previously untapped source of quality oak for wine maturation. Oak battens were prepared from staves of decommissioned French and American oak barrels, and their composition analyzed before and after toasting. The oak lactone glycoconjugate content of untoasted reclaimed oak was determined by liquid chromatography-tandem mass spectrometry, while the concentrations of cis- and trans-oak lactone, guaiacol, 4-methlyguaiacol, vanillin, eugenol, furfural, and 5-methylfurfural present in toasted reclaimed oak were determined by gas chromatography-mass spectrometry. Aroma potential was then evaluated by comparing the composition of reclaimed oak with that of new oak. Comparable levels of oak lactone glycoconjugates and oak volatiles were observed, demonstrating the aroma potential of reclaimed oak and therefore its suitability as a raw material for alternative oak products, i.e., chips or battens, for the maturation of wine. The temperature profiles achieved during toasting were also measured to evaluate the viability of any yeast or bacteria present in reclaimed oak. PMID:25771908

  15. Practitioner versus analyst methods: a nuclear decommissioning case study.

    PubMed

    Walker, Guy; Cooper, Mhairi; Thompson, Pauline; Jenkins, Dan

    2014-11-01

    A requirement arose during decommissioning work at a UK Magnox Nuclear Power Station to identify the hazards involved in removing High Dose Rate Items from a Cartridge Cooling Pond. Removing objects from the cooling pond under normal situations is a routine event with well understood risks but the situation described in this paper is not a routine event. The power station has shifted from an operational phase in its life-cycle to a decommissioning phase, and as such the risks, and procedures to deal with them, have become more novel and uncertain. This raises an important question. Are the hazard identification methods that have proven useful in one phase of the system lifecycle just as useful in another, and if not, what methods should be used? An opportunity arose at this site to put the issue to a direct test. Two methods were used, one practitioner focussed and in widespread use during the plant's operational phase (the Structured What-If method), the other was an analyst method (Cognitive Work Analysis). The former is proven on this site but might not be best suited to the novelty and uncertainty brought about by a shift in context from operations to decommissioning. The latter is not proven on this site but it is designed for novelty and uncertainty. The paper presents the outcomes of applying both methods to a real-world hazard identification task. PMID:24947001

  16. A NOVEL APPROACH TO SPENT FUEL POOL DECOMMISSIONING

    SciTech Connect

    R. L. Demmer

    2011-04-01

    The Idaho National Laboratory (INL) has been at the forefront of developing methods to reduce the cost and schedule of deactivating spent fuel pools (SFP). Several pools have been deactivated at the INL using an underwater approach with divers. These projects provided a basis for the INL cooperation with the Dresden Nuclear Power Station Unit 1 SFP (Exelon Generation Company) deactivation. It represents the first time that a commercial nuclear power plant (NPP) SFP was decommissioned using this underwater coating process. This approach has advantages in many aspects, particularly in reducing airborne contamination and allowing safer, more cost effective deactivation. The INL pioneered underwater coating process was used to decommission three SFPs with a total combined pool volume of over 900,000 gallons. INL provided engineering support and shared project plans to successfully initiate the Dresden project. This report outlines the steps taken by INL and Exelon to decommission SFPs using the underwater coating process. The rationale used to select the underwater coating process and the advantages and disadvantages are described. Special circumstances are also discussed, such as the use of a remotely-operated underwater vehicle to visually and radiologically map the pool areas that were not readily accessible. A larger project, the INTEC-603 SFP in-situ (grouting) deactivation, is reviewed. Several specific areas where special equipment was employed are discussed and a Lessons Learned evaluation is included.

  17. Decontamination and decommissioning of the Mayaguez (Puerto Rico) facility

    SciTech Connect

    Jackson, P.K.; Freemerman, R.L.

    1989-11-01

    On February 6, 1987 the US Department of Energy (DOE) awarded the final phase of the decontamination and decommissioning of the nuclear and reactor facilities at the Center for Energy and Environmental Research (CEER), in Mayaguez, Puerto Rico. Bechtel National, Inc., was made the decontamination and decommissioning (D and D) contractor. The goal of the project was to enable DOE to proceed with release of the CEER facility for use by the University of Puerto Rico, who was the operator. This presentation describes that project and lesson learned during its progress. The CEER facility was established in 1957 as the Puerto Rico Nuclear Center, a part of the Atoms for Peace Program. It was a nuclear training and research institution with emphasis on the needs of Latin America. It originally consisted of a 1-megawatt Materials Testing Reactor (MTR), support facilities and research laboratories. After eleven years of operation the MTR was shutdown and defueled. A 2-megawatt TRIGA reactor was installed in 1972 and operated until 1976, when it woo was shutdown. Other radioactive facilities at the center included a 10-watt homogeneous L-77 training reactor, a natural uranium graphite-moderated subcritical assembly, a 200KV particle accelerator, and a 15,000 Ci Co-60 irradiation facility. Support facilities included radiochemistry laboratories, counting rooms and two hot cells. As the emphasis shifted to non-nuclear energy technology a name change resulted in the CEER designation, and plans were started for the decontamination and decommissioning effort.

  18. Evaluating alternatives for decommissioning California's offshore oil and gas platforms.

    PubMed

    Bernstein, Brock B

    2015-10-01

    This paper introduces a series of 6 additional papers in this issue that describe an in-depth analysis of options for decommissioning oil and gas platforms offshore southern California. Although current leases require lessees in both state and federal waters to completely remove all production facilities and restore the seafloor to its pre-platform condition, other options have emerged since these leases were signed. Laws and regulations in other jurisdictions (particularly in federal waters) have evolved to allow a number of other uses such as aquaculture, alternative energy production, and artificial reefing. In response, the California Natural Resources Agency initiated an effort to investigate the issues associated with these and other decommissioning alternatives. The papers in this series are the result of the second phase in this process, a broad investigation of the engineering, economic, and environmental costs and benefits of the most feasible and likely options. In addition to the project's final report, the authors produced an interactive mathematical decision model, PLATFORM, that enables users to explore the implications of different decommissioning projects and options, as well as the effects of different approaches to valuing the associated costs and benefits. PMID:25914401

  19. NRC proposes changes to nuke decommissioning funding rules

    SciTech Connect

    Not Available

    1993-02-15

    The Nuclear Regulatory Commission (NRC) has proposed to amend its regulations to allow self-guarantee as a means of assuring adequate funding for nuclear plant decommissioning. It acted in response to a rulemaking petition filed by General Electric Co. and Westinghouse Electric Corp. The proposal would allow self-guarantees if certain conditions are met: Tangible net worth of at least $1 billion; Tangible net worth at least 10 times the present decommissioning cost estimate for all activities the utility is responsible for as a self-guaranteeing licensee and as parent guarantor; Domestic assets amounting to at least 90 percent of total assets or at least 10 times the present decommissioning cost estimate; A credit rating for the utility's most recent bond issuance of AAA, AA, or A (Standard Poor's), or Aaa, Aa, or A (Moody's). Additional requirements include that the utility licensee must have at least one class of equity securities registered under the Securities Exchange Act of 1934, and that an independent auditor must verify that the utility met the financial test. A utility also would be responsible for reporting any change in circumstances affecting the criteria used to meet the financial test, and would be responsible for meeting that test within 90 days of each financial year. The NRC will accept written comments until March 29, 1993.

  20. Hydrologic Uncertainty Assessment for Decommissioning Sites: Hypothetical Test Case Applications

    SciTech Connect

    Meyer, Philip D.; Taira, Randal Y.

    2001-03-19

    This report uses hypothetical decommissioning test cases to illustrate an uncertainty assessment methodology for dose assessments conducted as part of decommissioning analyses (see NUREG/CR-6656). The hypothetical test case source term and scenarios are based on an actual decommissioning case and the physcial setting is based on the site of a field experiment carried out for the NRC in Arizona. The emphasis in the test case was on parameter uncertainty. The analysis is limited to the hydrologic aspects of the exposure pathway involving infiltration of water at the ground surface, leaching of contaminants, and transport of contaminants through the groundwater to a point of exposure. The methodology uses generic parameter distributions based on national or regiounal databases for estimating parameter uncertainty. A Bayesian updating method is used in one of the test case applications to combine site-specific information with the generic parameter distributions. Sensitivity analysis and probabilisitc siumlation are used to describe the impact of parameter uncertainty on predicted dose. Emphasis is placed on understanding the conceptual and computational behavior of the dose assessment codes as they are applied to the test cases. The primary code used in this application was RESRAD v.6.0 although DandD v.1.0 results are also reported. The methods presented and the issues discussed are applicable to other codes as well.

  1. Hydrologic Uncertainty Assessment for Decommissioning Sites: Hypothetical Test Case Applications

    SciTech Connect

    Meyer, Philip D; Taira, Randal Y

    2001-03-19

    This report uses hypothetical decommissioning test cases to illustrate an uncertainty assessment methodology for dose assessments conducted as part of decommissioning analyses (see NUREG/CR-6656). The hypothetical test case source term and scenarios are based on an actual decommissioning case and the physical setting is based on the site of a field experiment carried out for the NRC in Arizona. The emphasis in the test case was on parameter uncertainty. The analysis is limited to the hydrologic aspects of the exposure pathway involving infiltration of water at the ground surface, leaching of contaminants, and transport of contaminants through the groundwater to a point of exposure. The methodology uses generic parameter distributions based on national or regional databases for estimating parameter uncertainty. A Bayesian updating method is used in one of the test case applications to combine site-specific information with the generic parameter distributions. Sensitivity analysis and probabilistic simulation are used to describe the impact of parameter uncertainty on predicted dose. Emphasis is placed on understanding the conceptual and computational behavior of the dose assessment codes as they are applied to the test cases. The primary code used in this application was RESRAD v.6.0 although D and D v.1.0 results are also reported. The methods presented and the issues discussed are applicable to other codes as well.

  2. Decontamination and decommissioning surveillance and maintenance report for FY 1991

    SciTech Connect

    Gunter, David B.; Burwinkle, T. W.; Cannon, T. R.; Ford, M. K.; Holder, Jr., L.; Clotfelter, O. K.; Faulkner, R. L.; Smith, D. L.; Wooten, H. O.

    1991-12-01

    The Decontamination and Decommissioning (D D) Program has three distinct phases: (1) surveillance and maintenance (S M); (2) decontamination and removal of hazardous materials and equipment (which DOE Headquarters in Washington, D.C., calls Phase I of remediation); and (3) decommissioning and ultimate disposal, regulatory compliance monitoring, and property transfer (which DOE Headquarters calls Phase II of remediation). A large part of D D is devoted to S M at each of the sites. Our S M activities, which are performed on facilities awaiting decommissioning, are designed to minimize potential hazards to human health and the environment by: ensuring adequate containment of residual radioactive and hazardous materials; and, providing physical safety and security controls to minimize potential hazards to on-site personnel and the general public. Typically, we classify maintenance activities as either routine or special (major repairs). Routine maintenance includes such activities as painting, cleaning, vegetation control, minor structural repairs, filter changes, and building system(s) checks. Special maintenance includes Occupational Safety and Health Act facility upgrades, roof repairs, and equipment overhaul. Surveillance activities include inspections, radiological measurements, reporting, records maintenance, and security (as required) for controlling and monitoring access to facilities. This report summarizes out FY 1991 S M activities for the Tennessee plant sites, which include the K-25 Site, the Gas Centrifuge facilities, ORNL, and the Y-12 Plant.

  3. Decommissioning and Cutting Methods in the Nuclear Field

    SciTech Connect

    Bensoussan, E.

    2008-07-01

    A few states started in the early forties/fifties the first development of nuclear technologies. Some of them now own a great amount of nuclear installations which entirely fulfil their assignment. In some cases, the life time of the nuclear power plants which were scheduled for approximately 30 years have been extended by more than 50%, the other ones as well as fuel production and enrichment plants, experimental or research reactors, will have to be dismantled in the near future. The decommissioning of those installations is definitely one of the twenty first century challenge. It is differently managed depending on the countries and their energetic and development policies, their financial consideration, the availability of qualified engineers or specialized companies to handle such projects. The final aim of decommissioning is to recover the geographic site in its original condition. A real cooperation is existing in between the people involved in different countries through different types of conferences and meetings during which the main subjects are: - The safety of the operators during all the phases of decommissioning operations; - Restrictions and dimensioning of the required equipment; - Storage and waste management; - Elaboration of procedures for recording all different steps and processes. Some of the techniques are described in this paper without being exhaustive: Hot cutting, oxy-fuel and plasma cutting; Band saw; Milling saw; Milling; Cutting tool; Wheel cutting; Shear cutting; And any other cutting processes or dismantling methods. (authors)

  4. The Regulatory Challenges of Decommissioning Nuclear Power Plants in Korea - 13101

    SciTech Connect

    Lee, Jungjoon; Ahn, Sangmyeon; Choi, Kyungwoo; Kim, Juyoul; Kim, Juyub

    2013-07-01

    As of 2012, 23 units of nuclear power plants are in operation, but there is no experience of permanent shutdown and decommissioning of nuclear power plant in Korea. It is realized that, since late 1990's, improvement of the regulatory framework for decommissioning has been emphasized constantly from the point of view of International Atomic Energy Agency (IAEA)'s safety standards. And it is known that now IAEA prepare the safety requirement on decommissioning of facilities, its title is the Safe Decommissioning of Facilities, General Safety Requirement Part 6. According to the result of IAEA's Integrated Regulatory Review Service (IRRS) mission to Korea in 2011, it was recommended that the regulatory framework for decommissioning should require decommissioning plans for nuclear installations to be constructed and operated and these plans should be updated periodically. In addition, after the Fukushima nuclear disaster in Japan in March of 2011, preparedness for early decommissioning caused by an unexpected severe accident became also important issues and concerns. In this respect, it is acknowledged that the regulatory framework for decommissioning of nuclear facilities in Korea need to be improved. First of all, we identify the current status and relevant issues of regulatory framework for decommissioning of nuclear power plants compared to the IAEA's safety standards in order to achieve our goal. And then the plan is to be established for improvement of regulatory framework for decommissioning of nuclear power plants in Korea. After dealing with it, it is expected that the revised regulatory framework for decommissioning could enhance the safety regime on the decommissioning of nuclear power plants in Korea in light of international standards. (authors)

  5. Technology, safety and costs of decommissioning a reference boiling water reactor power station. Appendices. Volume 2

    SciTech Connect

    Oak, H.D.; Holter, G.M.; Kennedy, W.E. Jr.; Konzek, G.J.

    1980-06-01

    Appendices are presented concerning the evaluations of decommissioning financing alternatives; reference site description; reference BWR facility description; radiation dose rate and concrete surface contamination data; radionuclide inventories; public radiation dose models and calculated maximum annual doses; decommissioning methods; generic decommissioning information; immediate dismantlement details; passive safe storage, continuing care, and deferred dismantlement details; entombment details; demolition and site restoration details; cost estimating bases; public radiological safety assessment details; and details of alternate study bases.

  6. In Situ Site Characterization Technologies Demonstrated at the INEEL in Decommissioning Projects

    SciTech Connect

    Wright, Kelly Clyde; Meservey, Richard Harlan; Whitmill, Larry Joseph

    1999-04-01

    The United States Department of Energy (DOE)continually seeks safer, more cost-effective, and better performing technologies for decontamination and decommissioning (D&D) of nuclear facilities. The Deactivation and Decommissioning Focus Area (DDFA) of the DOE Federal Energy Technology Center (FETC) sponsors Large Scale Demonstration and Deployment Projects (LSDDPs) which are conducted at various DOE sites. The Idaho National Engineering and Environmental Laboratory (INEEL) is one of the DOE sites for demonstration of these newa and improved technologies. The INEEL needs statement defines specific needs or problems for their D&D program. One of the needs identified at the INEEL was for new or improved site characterization technologies. A variety of in-situ site characterization technologies have been demonstrated through the INEEL LSDDP. These technologies provide a safer means of characterization, improved documentation, real-time information, improved D&D schedules, and reduction in costs and radiation exposures to workers. These technologies have provided vast improvements to the D&D site characterizations. Some of these technologies include: • The Global Positioning Radiometric Scanner System for large-area, surface gamma radiation surveys • Remote underwater characterization system• Identifying heavy metals in painted surfaces and determining the alloy composition in metallic material • In-Situ Object Counting System for free release • Real-time radiological data acquisition with the Surveillance and Measurement’s sodium iodide detector • Electromagnetic radiography to locate contaminated soils. Historically, site characterization has been a slow, costly, and tedious process. However, through these demonstrations, new technologies have provided more accurate data, real-time information, and enhanced site characterization documentation. In addition, a safer work environment has been established as a result of decreasing the worker’s time

  7. Technology, safety and costs of decommissioning a reference boiling water reactor power station. Classification of decommissioning wastes. Addendum 2

    SciTech Connect

    Murphy, E.S.

    1984-09-01

    The radioactive wastes expected to result from decommissioning of the reference boiling water reactor power station are reviewed and classified in accordance with 10 CFR 61. The 18,949 cubic meters of waste from DECON are classified as follows: Class A, 97.5%; Class B, 2.0%; Class C, 0.3%. About 0.2% (47 cubic meters) of the waste would be generally unacceptable for disposal using near-surface disposal methods.

  8. Technology, safety and costs of decommissioning a reference pressurized water reactor power station. Classification of decommissioning wastes. Addendum 3

    SciTech Connect

    Murphy, E.S.

    1984-09-01

    The radioactive wastes expected to result from decommissioning of the reference pressurized water reactor power station are reviewed and classified in accordance with 10 CFR 61. The 17,885 cubic meters of waste from DECON are classified as follows: Class A, 98.0%; Class B, 1.2%; Class C, 0.1%. About 0.7% (133 cubic meters) of the waste would be generally unacceptable for disposal using near-surface disposal methods.

  9. Role of decommissioning plan and its progress for the PUSPATI TRIGA Reactor

    SciTech Connect

    Zakaria, Norasalwa Mustafa, Muhammad Khairul Ariff Anuar, Abul Adli Idris, Hairul Nizam Ba'an, Rohyiza

    2014-02-12

    Malaysian nuclear research reactor, the PUSPATI TRIGA Reactor, reached its first criticality in 1982, and since then, it has been serving for more than 30 years for training, radioisotope production and research purposes. Realizing the age and the need for its decommissioning sometime in the future, a ground basis of assessment and an elaborative project management need to be established, covering the entire process from termination of reactor operation to the establishment of final status, documented as the Decommissioning Plan. At international level, IAEA recognizes the absence of Decommissioning Plan as one of the factors hampering progress in decommissioning of nuclear facilities in the world. Throughout the years, IAEA has taken initiatives and drawn out projects in promoting progress in decommissioning programmes, like CIDER, DACCORD and R2D2P, for which Malaysia is participating in these projects. This paper highlights the concept of Decommissioning plan and its significances to the Agency. It will also address the progress, way forward and challenges faced in developing the Decommissioning Plan for the PUSPATI TRIGA Reactor. The efforts in the establishment of this plan helps to provide continual national contribution at the international level, as well as meeting the regulatory requirement, if need be. The existing license for the operation of PUSPATI TRIGA Reactor does not impose a requirement for a decommissioning plan; however, the renewal of license may call for a decommissioning plan to be submitted for approval in future.

  10. Proceedings of the 2007 ANS Topical Meeting on Decommissioning, Decontamination, and Reutilization - DD and R 2007

    SciTech Connect

    2008-01-15

    The American Nuclear Society (ANS) Topical Meeting on Decommissioning, Decontamination, and Reutilization (DD and R 2007), 'Capturing Decommissioning Lessons Learned', is sponsored by the ANS Decommissioning, Decontamination and Reutilization; Environmental Sciences; and Fuel Cycle and Waste Management Divisions. This meeting provides a forum for an international exchange of technical knowledge and project management experience gained from the ongoing process of decommissioning nuclear facilities. Of particular note is the number of projects that are approaching completion. This document gathers 113 presentations given at this meeting.

  11. Role of decommissioning plan and its progress for the PUSPATI TRIGA Reactor

    NASA Astrophysics Data System (ADS)

    Zakaria, Norasalwa; Mustafa, Muhammad Khairul Ariff; Anuar, Abul Adli; Idris, Hairul Nizam; Ba'an, Rohyiza

    2014-02-01

    Malaysian nuclear research reactor, the PUSPATI TRIGA Reactor, reached its first criticality in 1982, and since then, it has been serving for more than 30 years for training, radioisotope production and research purposes. Realizing the age and the need for its decommissioning sometime in the future, a ground basis of assessment and an elaborative project management need to be established, covering the entire process from termination of reactor operation to the establishment of final status, documented as the Decommissioning Plan. At international level, IAEA recognizes the absence of Decommissioning Plan as one of the factors hampering progress in decommissioning of nuclear facilities in the world. Throughout the years, IAEA has taken initiatives and drawn out projects in promoting progress in decommissioning programmes, like CIDER, DACCORD and R2D2P, for which Malaysia is participating in these projects. This paper highlights the concept of Decommissioning plan and its significances to the Agency. It will also address the progress, way forward and challenges faced in developing the Decommissioning Plan for the PUSPATI TRIGA Reactor. The efforts in the establishment of this plan helps to provide continual national contribution at the international level, as well as meeting the regulatory requirement, if need be. The existing license for the operation of PUSPATI TRIGA Reactor does not impose a requirement for a decommissioning plan; however, the renewal of license may call for a decommissioning plan to be submitted for approval in future.

  12. A Plutonium Finishing Plant Model for the Cercla Removal Action and Decommissioning Construction Final Report

    SciTech Connect

    Hopkins, A.

    2008-07-01

    The joint policy between the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Energy (DOE) for decommissioning buildings at DOE facilities documents an agreement between the agencies to perform decommissioning activities including demolition under the Comprehensive Environmental Response Compensation and Liability Act (CERCLA). The use of removal actions for decommissioning integrates EPA oversight authority, DOE lead agency responsibility, and state authority for decommissioning activities. Once removal actions have been performed under CERCLA, a construction completion report is required to document the completion of the required action. Additionally, a decommissioning report is required under DOE guidance. No direct guidance was found for documenting completion of decommissioning activities and preparing a final report that satisfies the CERCLA requirements and the DOE requirements for decommissioning. Additional guidance was needed for the documentation of construction completion under CERCLA for D and D projects undertaken under the joint policy that addresses the requirements of both agencies. A model for the construction completion report was developed to document construction completion for CERCLA D and D activities performed under the joint EPA/DOE policy at the Plutonium Finishing Plant (PFP). The model documentation report developed at PFP integrates the DOE requirements for establishing decommissioning end-points, documenting end-point completion and preparing a final decommissioning report with the CERCLA requirements to document completion of the action identified in the Action Memorandum (AM). The model includes the required information on health and safety, data management, cost and schedule and end-points completion. (authors)

  13. Evaluation of nuclear facility decommissioning projects: summary report. Plum Brook Reactor Facility

    SciTech Connect

    Doerge, D.H.; Miller, R.L.

    1984-02-01

    This document summarizes information concerning the decommissioning of the Plum Brook Reactor Facility, which was placed in a Nuclear Regulatory Commission (NRC) approved safe storage configuration. The data were placed in a computerized information retrieval/manipulation system which permits future utilization of this information in decommissioning of similar facilities. The information is presented both in computer output form and a manually assembled summarization. Complete cost data were not readily available and decommissioning activities did not in all cases conform with current criteria for the SAFSTOR decommissioning mode, therefore no cost comparisons were made.

  14. DECOMMISSIONING THE PHYSICS LABORATORY, BUILDING 777-10A, AT THE SAVANNAH RIVER SITE (SRS)

    SciTech Connect

    Musall, J; Cathy Sizemore, C

    2007-01-17

    SRS recently completed a four-year mission to decommission {approx}250 excess facilities. As part of that effort, SRS decommissioned a 48,000 ft{sup 2} laboratory that housed four low-power test reactors, formerly used by SRS to determine reactor physics. This paper describes and reviews the decommissioning, with a focus on component segmentation and handling (i.e. hazardous material removal, demolition, and waste handling). The paper is intended to be a resource for engineers, planners, and project managers who face similar decommissioning challenges.

  15. Considerations in evaluating potential socioeconomic impacts of offshore platform decommissioning in California.

    PubMed

    Kruse, Sarah A; Bernstein, Brock; Scholz, Astrid J

    2015-10-01

    The 27 oil and gas platforms offshore southern California will eventually reach the end of their useful lifetimes (estimated between 2015 and 2030) and will be decommissioned. Current state and federal laws and regulations allow for alternative uses in lieu of the complete removal required in existing leases. Any decommissioning pathway will create a complex mix of costs, benefits, opportunities, and constraints for multiple user groups. To assist the California Natural Resources Agency in understanding these issues, we evaluated the potential socioeconomic impacts of the 2 most likely options: complete removal and partial removal of the structure to 85 feet below the waterline with the remaining structure left in place as an artificial reef-generally defined as a manmade structure with some properties that mimic a natural reef. We estimated impacts on commercial fishing, commercial shipping, recreational fishing, nonconsumptive boating, and nonconsumptive SCUBA diving. Available data supported quantitative estimates for some impacts, semiquantitative estimates for others, and only qualitative approximations of the direction of impact for still others. Even qualitative estimates of the direction of impacts and of user groups' likely preferred options have been useful to the public and decision makers and provided valuable input to the project's integrative decision model. Uncertainty surrounds even qualitative estimates of the likely direction of impact where interactions between multiple impacts could occur or where user groups include subsets that would experience the same option differently. In addition, we were unable to quantify effects on ecosystem value and on the larger regional ecosystem, because of data gaps on the population sizes and dynamics of key species and the uncertainty surrounding the contribution of platforms to available hard substrate and related natural populations offshore southern California. PMID:25914391

  16. Decommissioning Nuclear Facilities: First lessons Learned from UP1, Marcoule, France

    SciTech Connect

    Chabeuf, Jean-Michel; Boya, Didier

    2008-01-15

    On September 30, 1997, UP1, Marcoule Fuel reprocessing facility, dissolved its last spent Fuel rod. Final shutdown and stage 1 decommissioning began immediately after, under the supervision of CODEM , a consortium composed of The French Atomic Energy Commission, COGEMA, France fuel Cycle Company and EDF, the French Electricity Utility. The goal of the decommissioning program was to achieve stage 2 decommissioning , as per IAEA standards, within a period of about 15 years. 10 years later, a significant amount of decontamination and decommissioning works has been conducted with success. The contractual structure under which the program was launched has been profoundly modified, and the capacity of The French Atomic Energy Commission (CEA) and AREVA NC to complete full decommissioning programs has been confirmed. In the present document, we propose to examine the main aspects involved in the management of such decommissioning programs, and highlight, with significant examples, the main lessons learnt. In conclusion: As of 2007, UP1 decommissioning program proves to be a success. The choice of early decommissioning, the partnership launched between the French Atomic Energy Commission as owner of the site and decommissioning fund, with AREVA NC as operator and main contractor of the decommissioning works has been a success. The French Atomic Energy commission organized a contractual framework ensuring optimal safety conditions and work completion, while AREVA NC gained a unique experience at balancing the various aspects involved in the conduction of complete decommissioning programs. Although such a framework may not be applicable to all situations and facilities, it provides a positive example of a partnership combining institutional regulations and industrial efficiency.

  17. Low Level Radioactive Wastes Conditioning during Decommissioning of Salaspils Research Reactor

    SciTech Connect

    Abramenkova, G.; Klavins, M.; Abramenkovs, A.

    2008-01-15

    The decommissioning of Salaspils research reactor is connected with the treatment of 2200 tons different materials. The largest part of all materials ({approx}60 % of all dismantled materials) is connected with low level radioactive wastes conditioning activities. Dismantled radioactive materials were cemented in concrete containers using water-cement mortar. According to elaborated technology, the tritiated water (150 tons of liquid wastes from special canalization tanks) was used for preparation of water-cement mortar. Such approach excludes the emissions of tritiated water into environment and increases the efficiency of radioactive wastes management system for decommissioning of Salaspils research reactor. The Environmental Impact Assessment studies for Salaspils research reactor decommissioning (2004) and for upgrade of repository 'Radons' for decommissioning purposes (2005) induced the investigations of radionuclides release parameters from cemented radioactive waste packages. These data were necessary for implementation of quality assurance demands during conditioning of radioactive wastes and for safety assessment modeling for institutional control period during 300 years. Experimental studies indicated, that during solidification of water- cement samples proceeds the increase of temperature up to 81 deg. C. It is unpleasant phenomena since it can result in damage of concrete container due to expansion differences for mortar and concrete walls. Another unpleasant factor is connected with the formation of bubbles and cavities in the mortar structure which can reduce the mechanical stability of samples and increase the release of radionuclides from solidified cement matrix. The several additives, fly ash and PENETRON were used for decrease of solidification temperature. It was found, that addition of fly ash to the cement-water mortar can reduce the solidification temperature up to 62 deg. C. Addition of PENETRON results in increasing of solidification

  18. Heavy Water Components Test Reactor Decommissioning - Major Component Removal

    SciTech Connect

    Austin, W.; Brinkley, D.

    2010-05-05

    The Heavy Water Components Test Reactor (HWCTR) facility (Figure 1) was built in 1961, operated from 1962 to 1964, and is located in the northwest quadrant of the Savannah River Site (SRS) approximately three miles from the site boundary. The HWCTR facility is on high, well-drained ground, about 30 meters above the water table. The HWCTR was a pressurized heavy water test reactor used to develop candidate fuel designs for heavy water power reactors. It was not a defense-related facility like the materials production reactors at SRS. The reactor was moderated with heavy water and was rated at 50 megawatts thermal power. In December of 1964, operations were terminated and the facility was placed in a standby condition as a result of the decision by the U.S. Atomic Energy Commission to redirect research and development work on heavy water power reactors to reactors cooled with organic materials. For about one year, site personnel maintained the facility in a standby status, and then retired the reactor in place. In 1965, fuel assemblies were removed, systems that contained heavy water were drained, fluid piping systems were drained, deenergized and disconnected and the spent fuel basin was drained and dried. The doors of the reactor facility were shut and it wasn't until 10 years later that decommissioning plans were considered and ultimately postponed due to budget constraints. In the early 1990s, DOE began planning to decommission HWCTR again. Yet, in the face of new budget constraints, DOE deferred dismantlement and placed HWCTR in an extended surveillance and maintenance mode. The doors of the reactor facility were welded shut to protect workers and discourage intruders. The $1.6 billion allocation from the American Recovery and Reinvestment Act to SRS for site clean up at SRS has opened the doors to the HWCTR again - this time for final decommissioning. During the lifetime of HWCTR, 36 different fuel assemblies were tested in the facility. Ten of these

  19. Is Entombment an Acceptable Option for Decommissioning? An International Perspective - 13488

    SciTech Connect

    Belencan, Helen; Nys, Vincent; Guskov, Andrey; Francois, Patrice; Watson, Bruce; Ljubenov, Vladan

    2013-07-01

    Selection of a decommissioning strategy is one of the key steps in the preparation for decommissioning of nuclear facilities and other facilities using radioactive material. Approaches being implemented or considered by Member States include immediate dismantling, deferred dismantling and entombment. Other options or slight modifications of these strategies are also possible. Entombment has been identified in the current International Atomic Energy Agency (IAEA) Safety Standards as one of the three basic decommissioning strategies and has been defined as a decommissioning strategy by which radioactive contaminants are encased in a structurally long lived material until radioactivity decays to a level permitting the unrestricted release of the facility, or release with restrictions imposed by the regulatory body. Although all three strategies have been considered, in principle, applicable to all facilities, their application to some facilities may not be appropriate owing to political concerns, safety or environmental requirements, technical considerations, local conditions or financial considerations. The IAEA is currently revising the decommissioning Safety Standards and one of the issues widely discussed has been the applicability of entombment in the context of decommissioning and its general objective to enable removal of regulatory control from the decommissioned facility. The IAEA recently established a consultancy to collect and discuss experience and lessons learned from entombment projects, to identify regulatory requirements and expectations for applying entombment as a decommissioning option strategy, in compliance with the internationally agreed standards. (authors)

  20. 75 FR 72737 - Proposed Generic Communications Reporting for Decommissioning Funding Status Reports

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-26

    ... Funding Status Reports AGENCY: Nuclear Regulatory Commission. ACTION: Notice of opportunity for public... present to the NRC in the Decommissioning Funding Status (DFS) reports to ensure that the NRC staff... INFORMATION: NRC Regulatory Issue Summary 2010-XXX 10 CFR 50.75 Reporting for Decommissioning Funding...

  1. 10 CFR 30.35 - Financial assurance and recordkeeping for decommissioning.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 CFR part 20, Appendix G, must provide financial assurance in an amount based on a decommissioning... to meet the license termination criteria of 10 CFR part 20. The decommissioning funding plan must be...) All areas designated and formerly designated restricted areas as defined in 10 CFR 20.1003...

  2. 10 CFR 30.35 - Financial assurance and recordkeeping for decommissioning.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 CFR part 20, Appendix G, must provide financial assurance in an amount based on a decommissioning... to meet the license termination criteria of 10 CFR part 20. The decommissioning funding plan must be...) All areas designated and formerly designated restricted areas as defined in 10 CFR 20.1003...

  3. 10 CFR 30.35 - Financial assurance and recordkeeping for decommissioning.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 CFR part 20, Appendix G, must provide financial assurance in an amount based on a decommissioning... to meet the license termination criteria of 10 CFR part 20. The decommissioning funding plan must be submitted by December 2, 2005. (6) If, in surveys made under 10 CFR 20.1501(a), residual radioactivity...

  4. 10 CFR 30.35 - Financial assurance and recordkeeping for decommissioning.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 CFR part 20, Appendix G, must provide financial assurance in an amount based on a decommissioning... to meet the license termination criteria of 10 CFR part 20. The decommissioning funding plan must be submitted by December 2, 2005. (6) If, in surveys made under 10 CFR 20.1501(a), residual radioactivity...

  5. 30 CFR 285.907 - How will MMS process my decommissioning application?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... compare your decommissioning application with the decommissioning general concept in your approved SAP... to revise your SAP, COP, or GAP, and MMS will begin the appropriate NEPA analysis and other... a significant change in the impacts previously identified and evaluated in your SAP, COP, or GAP;...

  6. 30 CFR 585.907 - How will BOEM process my decommissioning application?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... decommissioning application with the decommissioning general concept in your approved SAP, COP, or GAP to determine what technical and environmental reviews are needed. (b) You will likely have to revise your SAP... change in the impacts previously identified and evaluated in your SAP, COP, or GAP; (2) Require...

  7. 30 CFR 585.907 - How will BOEM process my decommissioning application?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Environmental and Safety Management, Inspections, and Facility Assessments for Activities Conducted Under SAPs... your decommissioning application with the decommissioning general concept in your approved SAP, COP, or... revise your SAP, COP, or GAP, and BOEM will begin the appropriate NEPA analysis and other...

  8. 30 CFR 585.907 - How will BOEM process my decommissioning application?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... decommissioning application with the decommissioning general concept in your approved SAP, COP, or GAP to determine what technical and environmental reviews are needed. (b) You will likely have to revise your SAP... change in the impacts previously identified and evaluated in your SAP, COP, or GAP; (2) Require...

  9. 26 CFR 1.468A-0 - Nuclear decommissioning costs; table of contents.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 6 2011-04-01 2011-04-01 false Nuclear decommissioning costs; table of contents...-0 Nuclear decommissioning costs; table of contents. This section lists the paragraphs contained in.... (b) Definitions. (c) Special rules applicable to certain experimental nuclear facilities. §...

  10. 10 CFR 50.75 - Reporting and recordkeeping for decommissioning planning.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Reporting and recordkeeping for decommissioning planning. 50.75 Section 50.75 Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION FACILITIES Inspections, Records, Reports, Notifications § 50.75 Reporting and recordkeeping for decommissioning planning. (a) This...

  11. 26 CFR 1.468A-0 - Nuclear decommissioning costs; table of contents.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 6 2014-04-01 2014-04-01 false Nuclear decommissioning costs; table of contents...-0 Nuclear decommissioning costs; table of contents. This section lists the paragraphs contained in.... (b) Definitions. (c) Special rules applicable to certain experimental nuclear facilities. §...

  12. 26 CFR 1.468A-0 - Nuclear decommissioning costs; table of contents.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 6 2013-04-01 2013-04-01 false Nuclear decommissioning costs; table of contents...-0 Nuclear decommissioning costs; table of contents. This section lists the paragraphs contained in.... (b) Definitions. (c) Special rules applicable to certain experimental nuclear facilities. §...

  13. 26 CFR 1.468A-0 - Nuclear decommissioning costs; table of contents.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 6 2012-04-01 2012-04-01 false Nuclear decommissioning costs; table of contents...-0 Nuclear decommissioning costs; table of contents. This section lists the paragraphs contained in.... (b) Definitions. (c) Special rules applicable to certain experimental nuclear facilities. §...

  14. Remote machine engineering applications for nuclear facilities decommissioning

    SciTech Connect

    Toto, G.; Wyle, H.R.

    1983-01-01

    Decontamination and decommissioning of a nuclear facility require the application of techniques that protect the worker and the enviroment from radiological contamination and radiation. Remotely operated portable robotic arms, machines, and devices can be applied. The use of advanced systems should enhance the productivity, safety, and cost facets of the efforts; remote automatic tooling and systems may be used on any job where job hazard and other factors justify application. Many problems based on costs, enviromental impact, health, waste generation, and political issues may be mitigated by use of remotely operated machines. The work that man can not do or should not do will have to be done by machines.

  15. Decontamination and decommissioning of a fuel reprocessing pilot plant

    SciTech Connect

    Heine, W.F.; Speer, D.R.

    1988-01-01

    SYNOPSIS The strontium Semiworks Pilot Fuel Reprocessing Plant at the Hanford Site in Washington State was decommissioned by a combination of dismantlement and entombment. The facility contained 9600 Ci of Sr-90 and 10 Ci of plutonium. Process cells were entombed in place. The above-grade portion of one cell with 1.5-m- (5-ft-) thick walls and ceilings was demolished by means of expanding grout. A contaminated stack was remotely sandblasted and felled by explosives. The entombed structures were covered with a 4.6-m- (15-ft-) thick engineered earthen barrier. 5 figs., 2 tabs.

  16. Decommissioning Cost Estimating Factors And Earned Value Integration

    SciTech Connect

    Sanford, P.C.; Cimmarron, E.

    2008-07-01

    The Rocky Flats 771 Project progressed from the planning stage of decommissioning a plutonium facility, through the strip-out of highly-contaminated equipment, removal of utilities and structural decontamination, and building demolition. Actual cost data was collected from the strip-out activities and compared to original estimates, allowing the development of cost by equipment groupings and types and over time. Separate data was developed from the project control earned value reporting and compared with the equipment data. The paper discusses the analysis to develop the detailed factors for the different equipment types, and the items that need to be considered during characterization of a similar facility when preparing an estimate. The factors are presented based on direct labor requirements by equipment type. The paper also includes actual support costs, and examples of fixed or one-time start-up costs. The integration of the estimate and the earned value system used for the 771 Project is also discussed. The paper covers the development of the earned value system as well as its application to a facility to be decommissioned and an existing work breakdown structure. Lessons learned are provided, including integration with scheduling and craft supervision, measurement approaches, and verification of scope completion. In summary: The work of decommissioning the Rocky Flats 771 Project process equipment was completed in 2003. Early in the planning process, we had difficulty in identifying credible data and implementing processes for estimating and controlling this work. As the project progressed, we were able to collect actual data on the costs of removing plutonium contaminated equipment from various areas over the life of this work and associate those costs with individual pieces of equipment. We also were able to develop and test out a system for measuring the earned value of a decommissioning project based on an evolving estimate. These were elements that

  17. SAVANNAH RIVER SITE R REACTOR DISASSEMBLY BASIN IN SITU DECOMMISSIONING

    SciTech Connect

    Langton, C.; Blankenship, J.; Griffin, W.; Serrato, M.

    2009-12-03

    The US DOE concept for facility in-situ decommissioning (ISD) is to physically stabilize and isolate in tact, structurally sound facilities that are no longer needed for their original purpose of, i.e., generating (reactor facilities), processing(isotope separation facilities) or storing radioactive materials. The 105-R Disassembly Basin is the first SRS reactor facility to undergo the in-situ decommissioning (ISD) process. This ISD process complies with the105-R Disassembly Basin project strategy as outlined in the Engineering Evaluation/Cost Analysis for the Grouting of the R-Reactor Disassembly Basin at the Savannah River Site and includes: (1) Managing residual water by solidification in-place or evaporation at another facility; (2) Filling the below grade portion of the basin with cementitious materials to physically stabilize the basin and prevent collapse of the final cap - Sludge and debris in the bottom few feet of the basin will be encapsulated between the basin floor and overlying fill material to isolate if from the environment; (3) Demolishing the above grade portion of the structure and relocating the resulting debris to another location or disposing of the debris in-place; and (4) Capping the basin area with a concrete slab which is part of an engineered cap to prevent inadvertent intrusion. The estimated total grout volume to fill the 105-R Reactor Disassembly Basin is 24,424 cubic meters or 31,945 cubic yards. Portland cement-based structural fill materials were design and tested for the reactor ISD project and a placement strategy for stabilizing the basin was developed. Based on structural engineering analyses and work flow considerations, the recommended maximum lift height is 5 feet with 24 hours between lifts. Pertinent data and information related to the SRS 105-R-Reactor Disassembly Basin in-situ decommissioning include: regulatory documentation, residual water management, area preparation activities, technology needs, fill material designs

  18. Waste management for Shippingport Station Decommissioning Project: Extended summary

    SciTech Connect

    Mullee, G.R.; Schulmeister, A.R.

    1987-01-01

    The Shippingport Station (SSDP) is demonstrating that the techniques and methodologies of waste management, which are currently employed by the nuclear industry, provide adequate management and control of waste activities for the decommissioning of a large scale nuclear plant. The SSDP has some unique aspects in that as part of the objective to promote technology transfer, multiple subcontractors are being utilized in the project. The interfaces resulting from multiple subcontractors require additional controls. Effective control has been accomplished by the use of a process control and inventory system, coupled with personnel training in waste management activities. This report summarizes the waste management plan and provides a status of waste management activities for SSDP.

  19. Environmental restoration and decontamination & decommissioning safety documentation. Revision 2

    SciTech Connect

    Hansen, J.L.; Frauenholz, L.H.; Kerr, N.R.

    1993-05-18

    This document presents recommendations of a working group designated by the Environmental Restoration and Remediation (ER) and Decontamination and Decommissioning (D&D) subcommittees of the Westinghouse M&O (Management and Operation) Nuclear Facility Safety Committee. A commonalty of approach to safety documentation specific to ER and D&D activities was developed and is summarized below. Allowance for interpretative tolerance and documentation flexibility appropriate to the activity, graded for hazard category, duration, and complexity, was a primary consideration in development of this guidance.

  20. 10 CFR 30.36 - Expiration and termination of licenses and decommissioning of sites and separate buildings or...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... accordance with the criteria for decommissioning in 10 CFR part 20, subpart E. The licensee shall, as... are suitable for release in accordance with the criteria for decommissioning in 10 CFR part 20... premises are suitable for release in accordance with the criteria for decommissioning in 10 CFR part...

  1. 10 CFR 30.36 - Expiration and termination of licenses and decommissioning of sites and separate buildings or...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... accordance with the criteria for decommissioning in 10 CFR part 20, subpart E. The licensee shall, as... are suitable for release in accordance with the criteria for decommissioning in 10 CFR part 20... premises are suitable for release in accordance with the criteria for decommissioning in 10 CFR part...

  2. 10 CFR 30.36 - Expiration and termination of licenses and decommissioning of sites and separate buildings or...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... accordance with the criteria for decommissioning in 10 CFR part 20, subpart E. The licensee shall, as... are suitable for release in accordance with the criteria for decommissioning in 10 CFR part 20... premises are suitable for release in accordance with the criteria for decommissioning in 10 CFR part...

  3. 10 CFR 30.36 - Expiration and termination of licenses and decommissioning of sites and separate buildings or...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... accordance with the criteria for decommissioning in 10 CFR part 20, subpart E. The licensee shall, as... are suitable for release in accordance with the criteria for decommissioning in 10 CFR part 20... premises are suitable for release in accordance with the criteria for decommissioning in 10 CFR part...

  4. 30 CFR 585.902 - What are the general requirements for decommissioning for facilities authorized under my SAP, COP...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... decommissioning for facilities authorized under my SAP, COP, or GAP? 585.902 Section 585.902 Mineral Resources... authorized under my SAP, COP, or GAP? (a) Except as otherwise authorized by BOEM under § 585.909, within 2... decommissioning the facilities under your SAP, COP, or GAP, you must submit a decommissioning application...

  5. 30 CFR 585.902 - What are the general requirements for decommissioning for facilities authorized under my SAP, COP...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... decommissioning for facilities authorized under my SAP, COP, or GAP? 585.902 Section 585.902 Mineral Resources... authorized under my SAP, COP, or GAP? (a) Except as otherwise authorized by BOEM under § 585.909, within 2... decommissioning the facilities under your SAP, COP, or GAP, you must submit a decommissioning application...

  6. 26 CFR 1.468A-5T - Nuclear decommissioning fund qualification requirements; prohibitions against self-dealing...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 6 2010-04-01 2010-04-01 false Nuclear decommissioning fund qualification requirements; prohibitions against self-dealing; disqualification of nuclear decommissioning fund; termination of fund upon substantial completion of decommissioning (temporary). 1.468A-5T Section 1.468A-5T Internal Revenue INTERNAL REVENUE...

  7. Decommissioning Small Research and Training Reactors; Experience on Three Recent University Projects - 12455

    SciTech Connect

    Gilmore, Thomas; DeWitt, Corey; Miller, Dustin; Colborn, Kurt

    2012-07-01

    Decommissioning small reactors within the confines of an active University environment presents unique challenges. These range from the radiological protection of the nearby University population and grounds, to the logistical challenges of working in limited space without benefit of the established controlled, protected, and vital areas common to commercial facilities. These challenges, and others, are discussed in brief project histories of three recent (calendar year 2011) decommissioning activities at three University training and research reactors. These facilities include three separate Universities in three states. The work at each of the facilities addresses multiple phases of the decommissioning process, from initial characterization and pre-decommissioning waste removal, to core component removal and safe storage, through to complete structural dismantlement and site release. The results of the efforts at each University are presented, along with the challenges that were either anticipated or discovered during the decommissioning efforts, and results and lessons learned from each of the projects. (authors)

  8. Genome size evolution in macroparasites.

    PubMed

    Sundberg, Lotta-Riina; Pulkkinen, Katja

    2015-04-01

    Reduction in genome size has been associated not only with a parasitic lifestyle in intracellular microparasites but also in some macroparasitic insects and nematodes. We collected the available data on genome size for flatworms, annelids, nematodes and arthropods, compared those with available data for the phylogenetically closest free-living taxa and found evidence of smaller genome sizes for parasites in six of nine comparisons. Our results suggest that despite great differences in evolutionary history and life cycles, parasitism as a lifestyle promotes convergent genome size reduction in macroparasites. We discuss factors that could be associated with small genome size in parasites which require further exploration in the future. PMID:25724591

  9. DECOMMISSIONING THE BROOKHAVEN NATIONAL LABORATORY BUILDING 830 GAMMA IRRADIATION FACILITY.

    SciTech Connect

    BOWERMAN, B.S.; SULLIVAN, P.T.

    2001-08-13

    The Building 830 Gamma Irradiation Facility (GIF) at Brookhaven National Laboratory (BNL) was decommissioned because its design was not in compliance with current hazardous tank standards and its cobalt-60 sources were approaching the end of their useful life. The facility contained 354 stainless steel encapsulated cobalt-60 sources in a pool, which provided shielding. Total cobalt-60 inventory amounted to 24,000 Curies when the sources were shipped for disposal. The decommissioning project included packaging, transport, and disposal of the sources and dismantling and disposing of all other equipment associated with the facility. Worker exposure was a major concern in planning for the packaging and disposal of the sources. These activities were planned carefully according to ALARA (As Low As Reasonably Achievable) principles. As a result, the actual occupational exposures experienced during the work were within the planned levels. Disposal of the pool water required addressing environmental concerns, since the planned method was to discharge the slightly contaminated water to the BNL sewage treatment plant. After the BNL evaluation procedure for discharge to the sewage treatment plant was revised and reviewed by regulators and BNL's Community Advisory Council, the pool water was discharged to the Building 830 sanitary system. Because the sources were sealed and the pool water contamination levels were low, most of the remaining equipment was not contaminated; therefore disposal was straightforward, as scrap metal and construction debris.

  10. Radiological characterization of a vitrification facility for decommissioning

    SciTech Connect

    Asou, M.

    2007-07-01

    Cleanup operations in the Marcoule Vitrification Facility (AVM) will start in 2007. This plant includes 20 highly irradiating storage tanks for high-level liquid waste before vitrification. The objective of the cleanup phase is to significantly decrease the amount of highly radioactive waste resulting from dismantling. A comprehensive radiological survey of the plant was initiated in 2000. Most of the tanks were characterized using advanced technologies: gamma imaging, CdZnTe gamma spectroscopy, dose rate measurements and 3D calculations codes. At the same time, inspections were conducted to develop 3D geometrical models of the tanks. The techniques used and the main results obtained are described as well as lessons learned from these operations. The rinsing program was defined in 2006. Decontamination operations are expected to begin in 2007, and radiological surveys will be followed up to monitor the efficiency of the decontamination process. Specific rinsing of all tanks and equipment will be carried out from 2007 to 2009. Concentrated liquid solutions will be vitrified between 2008 and 2010; the decommissioning of AVM will be delayed until the end of 2010. This strategy aims at producing less than 5% 'B' type (long-lived intermediate-level) waste from the decommissioning operations, as well as reducing the dose rate and risks by simplified remote dismantling. The paper reviews the main options selected for decontamination, as well as the radiological characterization strategy. Some cost-related aspects will also be analyzed. (authors)

  11. The AVR (HTGR) decommissioning project with new strategy

    SciTech Connect

    Sterner, Hakan; Rittscher, Dieter

    2007-07-01

    The 15-MWel prototype pilot reactor AVR is a pebble bed HTGR. It was designed in the late 50's and was connected to the grid end of 1967. After 21 y of successful operation the reactor was shut down end of 1988. In 1994 the first decommissioning license was granted and work with defueling, dismantling and preparation of a Safe Enclosure started. The primary system is contaminated with the fission products Sr{sup 90} and Cs{sup 137} and the activation products are Co{sup 60}, C{sup 14} and H{sup 3}. Due to the large amounts of Sr and Cs bound to graphite dust, the dismantling of systems connected to the pressure vessel is very tedious. In 2003 the AVR company was restructured and the strategy of the decommissioning was changed from safe enclosure to green field, i.e. the complete direct dismantling of all facilities and clean up of the site. The highlight during the dismantling is the removal of the reactor vessel (diameter ca. 7.6 m and length ca. 26 m) in one piece. Before handling the reactor vessel it will be filled with low density cellular concrete. Subsequently the reactor building will be cut open and the reactor vessel (total weight ca. 2100 Mg) lifted out and transported to an interim store. (authors)

  12. Characterisation of radioactive waste products associated with plant decommissioning.

    PubMed

    Sejvar, J; Fero, A H; Gil, C; Hagler, R J; Santiago, J L; Holgado, A; Swenson, R

    2005-01-01

    The inventory of radioactivity that must be considered in the decommissioning of a typical 1000 MWe Spanish pressurised water reactor (PWR) was investigated as part of a generic plant decommissioning study. Analyses based on DORT models (in both R-Z and R-theta geometries) were used with representative plant operating history and core power distribution data in defining the expected neutron environment in regions near the reactor core. The activation analyses were performed by multiplying the DORT scalar fluxes by energy-dependent reaction cross sections (based on ENDF/B-VI data) to generate reaction rates on a per atom basis. The results from the ORIGEN2 computer code were also used for determining the activities associated with certain nuclides where multi-group cross section data were not available. In addition to the bulk material activation of equipment and structures near the reactor, the activated corrosion-product (or 'crud') deposits on system and equipment surfaces were considered. The projected activities associated with these sources were primarily based on plant data and experience from operating PWR plants. PMID:16381771

  13. Resource book: Decommissioning of contaminated facilities at Hanford

    SciTech Connect

    Not Available

    1991-09-01

    In 1942 Hanford was commissioned as a site for the production of weapons-grade plutonium. The years since have seen the construction and operation of several generations of plutonium-producing reactors, plants for the chemical processing of irradiated fuel elements, plutonium and uranium processing and fabrication plants, and other facilities. There has also been a diversification of the Hanford site with the building of new laboratories, a fission product encapsulation plant, improved high-level waste management facilities, the Fast Flux test facility, commercial power reactors and commercial solid waste disposal facilities. Obsolescence and changing requirements will result in the deactivation or retirement of buildings, waste storage tanks, waste burial grounds and liquid waste disposal sites which have become contaminated with varying levels of radionuclides. This manual was established as a written repository of information pertinent to decommissioning planning and operations at Hanford. The Resource Book contains, in several volumes, descriptive information of the Hanford Site and general discussions of several classes of contaminated facilities found at Hanford. Supplementing these discussions are appendices containing data sheets on individual contaminated facilities and sites at Hanford. Twelve appendices are provided, corresponding to the twelve classes into which the contaminated facilities at Hanford have been organized. Within each appendix are individual data sheets containing administrative, geographical, physical, radiological, functional and decommissioning information on each facility within the class. 68 refs., 54 figs., 18 tabs.

  14. Nuclear facility decommissioning and site remedial actions: a selected bibliography

    SciTech Connect

    Owen, P.T.; Knox, N.P.; Fielden, J.M.; Johnson, C.A.

    1982-09-01

    This bibliography contains 693 references with abstracts on the subject of nuclear facility decommissioning, uranium mill tailings management, and site remedial actions. Foreign, as well as domestic, literature of all types - technical reports, progress reports, journal articles, conference papers, symposium proceedings, theses, books, patents, legislation, and research project descriptions - has been included in this publication. The bibliography contains scientific (basic research as well as applied technology), economic, regulatory, and legal literature pertinent to the US Department of Energy's Remedial Action Program. Major chapters are Surplus Facilities Management Program, Nuclear Facilities Decommissioning, Formerly Utilized Sites Remedial Action Program, Uranium Mill Tailings Remedial Action Program, Grand Junction Remedial Action Program, and Uranium Mill Tailings Management. Chapter sections for chapters 1 and 2 include: Design, Planning, and Regulations; Site Surveys; Decontamination Studies; Dismantlement and Demolition; Land Decontamination and Reclamation; Waste Disposal; and General Studies. The references within each chapter are arranged alphabetically by leading author. References having no individual author are arranged by corporate author or by title. Indexes are provided for (1) author; (2) corporate affiliation; (3) title; (4) publication description; (5) geographic location; and (6) keywords. An appendix of 202 bibliographic references without abstracts or indexes has been included in this bibliography. This appendix represents literature identified but not abstracted due to time constraints.

  15. Lessons Learned in Decommissioning of NPP A-1 After Accident

    SciTech Connect

    Prazska, M.; Rezbarik, J.; Majersky, D.; Sekely, S.; Solcanyi, S.

    2002-02-25

    Decommissioning of the NPP A-1 in Jaslovske Bohunice is encountered with great variation of the problems connected primarily with the high radiation fields and the high activity of the contaminated materials. Decontamination of the contaminated objects and the thorough radiological protection of decontamination workers are therefore the tasks of top priority. The successful realization of these jobs is based on the experience, good working practice and the utilization of all proven methods together with the newly developed ones. Since 1996, AllDeco Ltd. has applied the decontamination methods and processes in a wide scale in the decommissioning and dismantling of the NPP A-1 in the cooperation with SE-VYZ Inc. The monitoring of the radiation situation and the investigation of the type and character of the radioactive waste were first steps in the decontamination of all objects. For this works, remote controlled mechanical manipulators and remote controlled electrical carriage equipped with instruments recording the levels of dose rates and with telemetric data transmission system were used. The recorded data were used for the modeling and 3D visualization of the radiation fields and for following planning and preparation of the decontamination projects or ''working programs'' based on the ALARA principle. The minimization of the radioactive waste was also taken into consideration. A lot of time and energy was spent on the preparation and training of the staff including non-active trials of planned procedures. The gained experience was evaluated and lessons learned were given in the final reports.

  16. Investigation on cutting stability of jacket in decommissioning process

    NASA Astrophysics Data System (ADS)

    Li, Mei-qiu; Duan, Meng-lan; Huang, Yi

    2015-10-01

    Jacket cutting operation is one of the most complicated and highest risk operations in the process of decommissioning offshore piled platform, the security and stability of which must be assured. In this paper, the current research on offshore structure removal and jacket cutting is introduced, on the basis of which the types of load along with the load calculation method are determined. The main influences on the stability of a jacket in cutting are analyzed. The experiment test plan is drawn by using orthogonal testing method, and the formula of critical load during the cutting procedure is deduced by differential evolution algorithm. To verify the method and results of this paper, an offshore piled platform to be decommissioned in the South China Sea is taken for an example, and the detailed schedule for jacket cutting is made with the three-dimensional finite element model of the jacket established. The natural frequency, stress, strain and stability of the jacket during cutting process are calculated, which indicates that the results of finite element analysis agree well with that of the deduced formula. The result provides the scientific reference for guaranteeing the safety of jacket in cutting operation.

  17. Technology, Safety and Costs of Decommissioning Nuclear Reactors At Multiple-Reactor Stations

    SciTech Connect

    Wittenbrock, N. G.

    1982-01-01

    Safety and cost information is developed for the conceptual decommissioning of large (1175-MWe) pressurized water reactors (PWRs) and large (1155-MWe) boiling water reactors {BWRs) at multiple-reactor stations. Three decommissioning alternatives are studied: DECON (immediate decontamination), SAFSTOR (safe storage followed by deferred decontamination), and ENTOMB (entombment). Safety and costs of decommissioning are estimated by determining the impact of probable features of multiple-reactor-station operation that are considered to be unavailable at a single-reactor station, and applying these estimated impacts to the decommissioning costs and radiation doses estimated in previous PWR and BWR decommissioning studies. The multiple-reactor-station features analyzed are: the use of interim onsite nuclear waste storage with later removal to an offsite nuclear waste disposal facility, the use of permanent onsite nuclear waste disposal, the dedication of the site to nuclear power generation, and the provision of centralized services. Five scenarios for decommissioning reactors at a multiple-reactor station are investigated. The number of reactors on a site is assumed to be either four or ten; nuclear waste disposal is varied between immediate offsite disposal, interim onsite storage, and immediate onsite disposal. It is assumed that the decommissioned reactors are not replaced in one scenario but are replaced in the other scenarios. Centralized service facilities are provided in two scenarios but are not provided in the other three. Decommissioning of a PWR or a BWR at a multiple-reactor station probably will be less costly and result in lower radiation doses than decommissioning an identical reactor at a single-reactor station. Regardless of whether the light water reactor being decommissioned is at a single- or multiple-reactor station: • the estimated occupational radiation dose for decommissioning an LWR is lowest for SAFSTOR and highest for DECON • the estimated

  18. Ecological and political issues surrounding decommissioning of offshore oil facilities in the Southern California Bight

    USGS Publications Warehouse

    Schroeder, Donna M.; Love, Milton S.

    2004-01-01

    To aid legislators, resource managers, and the general public, this paper summarizes and clarifies some of the issues and options that the federal government and the state of California face in decommissioning offshore oil and gas production platforms, particularly as these relate to platform ecology. Both local marine ecology and political climate play a role in decommissioning offshore oil production platforms. Compared to the relatively supportive political climate in the Gulf of Mexico for “rigs-to-reefs” programs, conflicting social values among stakeholders in Southern California increases the need for understanding ecological impacts of various decommissioning alternatives (which range from total removal to allowing some or all of platform structure to remain in the ocean). Additional scientific needs in the decommissioning process include further assessment of platform habitat quality, estimation of regional impacts of decommissioning alternatives to marine populations, and determination of biological effects of any residual contaminants. The principal management need is a ranking of environmental priorities (e.g. species-of-interest and marine habitats). Because considerable numbers of economically important species reside near oil platforms, National Oceanic and Atmospheric Administration Fisheries should consider the consequences of decommissioning alternatives in their overall management plans. Management strategies could include designating reefed platforms as marine protected areas. The overarching conclusion from both ecological and political perspectives is that decommissioning decisions should be made on a case-by-case basis.

  19. Environmental assessment for the construction, operation, and decommissioning of the Waste Segregation Facility at the Savannah River Site

    SciTech Connect

    1998-01-01

    This Environmental Assessment (EA) has been prepared by the Department of Energy (DOE) to assess the potential environmental impacts associated with the construction, operation and decontamination and decommissioning (D&D) of the Waste Segregation Facility (WSF) for the sorting, shredding, and compaction of low-level radioactive waste (LLW) at the Savannah River Site (SRS) located near Aiken, South Carolina. The LLW to be processed consists of two waste streams: legacy waste which is currently stored in E-Area Vaults of SRS and new waste generated from continuing operations. The proposed action is to construct, operate, and D&D a facility to process low-activity job-control and equipment waste for volume reduction. The LLW would be processed to make more efficient use of low-level waste disposal capacity (E-Area Vaults) or to meet the waste acceptance criteria for treatment at the Consolidated Incineration Facility (CIF) at SRS.

  20. Asset Decommissioning Risk Metrics for Floating Structures in the Gulf of Mexico.

    PubMed

    Kaiser, Mark J

    2015-08-01

    Public companies in the United States are required to report standardized values of their proved reserves and asset retirement obligations on an annual basis. When compared, these two measures provide an aggregate indicator of corporate decommissioning risk but, because of their consolidated nature, cannot readily be decomposed at a more granular level. The purpose of this article is to introduce a decommissioning risk metric defined in terms of the ratio of the expected value of an asset's reserves to its expected cost of decommissioning. Asset decommissioning risk (ADR) is more difficult to compute than a consolidated corporate risk measure, but can be used to quantify the decommissioning risk of structures and to perform regional comparisons, and also provides market signals of future decommissioning activity. We formalize two risk metrics for decommissioning and apply the ADR metric to the deepwater Gulf of Mexico (GOM) floater inventory. Deepwater oil and gas structures are expensive to construct, and at the end of their useful life, will be expensive to decommission. The value of proved reserves for the 42 floating structures in the GOM circa January 2013 is estimated to range between $37 and $80 billion for future oil prices between 60 and 120 $/bbl, which is about 10 to 20 times greater than the estimated $4.3 billion to decommission the inventory. Eni's Allegheny and MC Offshore's Jolliet tension leg platforms have ADR metrics less than one and are approaching the end of their useful life. Application of the proposed metrics in the regulatory review of supplemental bonding requirements in the U.S. Outer Continental Shelf is suggested to complement the current suite of financial metrics employed. PMID:25692712

  1. Decommissioning successes at Rocky Flats Environmental Technology Site

    SciTech Connect

    Crawford, A.C.; Hughes, F.P.; Trice, K.D.; Wolf, H.C.; Wheeler, M.

    1999-07-01

    Building 779, a cluster of 13 buildings located at Rocky Flats Environmental Technology Site (RFETS), was originally constructed in the early 1960s. The building was used to perform research and development associated with the nuclear weapons programs. The primary contaminants were plutonium and uranium, and these contaminants were dispersed throughout the facility. In 1998, Building 779 was selected to be the first plutonium facility at RFETS to be decommissioned. After extensive training, fieldwork was initiated with a single crew of 14 workers. Dismantling of the facility started with the removal and disposition of excess property. Today, thousands of pieces of property have been dispositioned and either recycled or disposed of as radioactive waste. The second facility at RFETS to begin D and D is Building 771. This facility was selected because of its extreme complexity and the desire to accelerate the RFETS closure to 2006. Building 771 is a 200,000-ft{sup 2}, 10-structure, multistory facility with more than 230 glove boxes and 8 miles of plutonium processing piping. Building 771 was used for processing plutonium and actinides between 1953 and 1989. The facility experienced many modifications, substantial variation in operations, and several upsets resulting in radiological contamination over its 40-yr operating history. The most significant event was a major fire in 1957. The 1994 Plutonium Working Group Report on Environmental Safety and Health Vulnerabilities Associated with the Department of Energy's Plutonium Storage determined that Building 771 was the most dangerous building in America. Since the report was issued, a significant quantity of special nuclear material (SNM) has been removed, hydrogen has been vented, and the draining of high- and low-level solutions from tanks has been completed. Although these activities have lowered the risk, numerous complex tasks still remain to take the building to its final end point of a slab. Three major areas of

  2. How Does Decommissioning Forest Roads Effect Hydrologic and Geomorphic Risk?

    NASA Astrophysics Data System (ADS)

    Black, T.; Luce, C.; Cissel, R. M.; Nelson, N.; Staab, B.

    2010-12-01

    The US Forest Service is investigating road decommissioning projects to understand how treatments change hydrologic and geomorphic risks. Road treatment effect was measured using a before after control impact design (BACI), using the Geomorphic Road Analysis and Inventory Package (http://www.fs.fed.us/GRAIP). This suite of inventory and analysis tools evaluates: road-stream hydrologic connectivity, fine sediment production and delivery, shallow landslide risk, gully initiation risk, and risks associated with stream crossing failures. The Skokomish River study site is steep and wet and received a high intensity treatment including the removal of stream crossing pipes and fills, all ditch relief pipes and a full hillslope recontouring. Road to stream hydrologic connectivity was reduced by 70%. The treatments reduced fine sediment delivery by 21.8 tons or 81%. The removal of the stream crossing culverts and large associated road fills eliminated the risk of pipe plugging related failures and the eventual erosion of over 4,000 m3 of fill. The slope stability risk was assessed using a modified version of SINMAP (Pack et al, 2005). Risk below drain point locations on the original road was reduced as water was redistributed across the hillslope to waterbars and diffuse drainage. It is unclear; however, if landslide risk was reduced across the entire treated road length because treatments slightly increased risk in some areas where new concentrated drainage features were added above steep slopes. Similarly, values of a gully index ESI (Istanbulluoglu et al, 2003), were reduced at many of the original drainage points, however some new drainage was added. ESI values still exceed a predicted conservative initiation thresholds at some sites, therefore it is uncertain if gully risk will be changed. Mann Creek occupies a moderately steep mid-elevation site in Southern Idaho. The high intensity treatments removed all constructed road drainage features including stream crossing

  3. CPP-603 Chloride Removal System Decontamination and Decommissioning. Final report

    SciTech Connect

    Moser, C.L.

    1993-02-01

    The CPP-603 (annex) Chloride Removal System (CRS) Decontamination and Decommissioning (D&D) Project is described in this report. The CRS was used for removing Chloride ions and other contaminants that were suspended in the waters of the underwater fuel storage basins in the CPP-603 Fuel Receiving and Storage Facility (FRSF) from 1975 to 1981. The Environmental Checklist and related documents, facility characterization, decision analysis`, and D&D plans` were prepared in 1991. Physical D&D activities were begun in mid summer of 1992 and were completed by the end of November 1992. All process equipment and electrical equipment were removed from the annex following accepted asbestos and radiological contamination removal practices. The D&D activities were performed in a manner such that no radiological health or safety hazard to the public or to personnel at the Idaho National Engineering Laboratory (INEL) occurred.

  4. Sensor Network Demonstration for In Situ Decommissioning - 13332

    SciTech Connect

    Lagos, L.; Varona, J.; Awwad, A.; Rivera, J.; McGill, J.

    2013-07-01

    Florida International University's (FIU's) Applied Research Center is currently supporting the Department of Energy's (DOE) Environmental Management Office of D and D and Facility Engineering program. FIU is supporting DOE's initiative to improve safety, reduce technical risks, and limit uncertainty within D and D operations by identifying technologies suitable to meet specific facility D and D requirements, assessing the readiness of those technologies for field deployment, and conducting feasibility studies and large scale demonstrations of promising technologies. During FY11, FIU collaborated with Savannah River National Laboratory in the development of an experimental test site for the demonstration of multiple sensor systems for potential use in the in situ decommissioning process. In situ decommissioning is a process in which the above ground portion of a facility is dismantled and removed, and the underground portion is filled with a cementious material such as grout. In such a scenario, the question remains on how to effectively monitor the structural health of the grout (cracking, flexing, and sinking), as well as track possible migration of contaminants within and out of the grouted monolith. The right types of sensors can aid personnel in better understanding the conditions within the entombed structure. Without sensors embedded in and around the monolith, it will be very difficult to estimate structural integrity and contaminant transport. Yet, to fully utilize the appropriate sensors and the provided data, their performance and reliability must be evaluated outside a laboratory setting. To this end, a large scale experimental setup and demonstration was conducted at FIU. In order to evaluate a large suite of sensor systems, FIU personnel designed and purchased a pre-cast concrete open-top cube, which served as a mock-up of an in situ DOE decommissioned facility. The inside of the cube measures 10 ft x 10 ft x 8 ft. In order to ensure that the

  5. Deactivation and Decommissioning Planning and Analysis with Geographic Information Systems

    SciTech Connect

    Bollinger, James S.; Koffman, Larry D.; Austin, William E.

    2008-01-15

    From the mid-1950's through the 1980's, the U.S. Department of Energy's Savannah River Site produced nuclear materials for the weapons stockpile, for medical and industrial applications, and for space exploration. Although SRS has a continuing defense-related mission, the overall site mission is now oriented toward environmental restoration and management of legacy chemical and nuclear waste. With the change in mission, SRS no longer has a need for much of the infrastructure developed to support the weapons program. This excess infrastructure, which includes over 1000 facilities, will be decommissioned and demolished over the forthcoming years. Dis-positioning facilities for decommissioning and deactivation requires significant resources to determine hazards, structure type, and a rough-order-of-magnitude estimate for the decommissioning and demolition cost. Geographic information systems (GIS) technology was used to help manage the process of dis-positioning infrastructure and for reporting the future status of impacted facilities. Several thousand facilities of various ages and conditions are present at SRS. Many of these facilities, built to support previous defense-related missions, now represent a potential hazard and cost for maintenance and surveillance. To reduce costs and the hazards associated with this excess infrastructure, SRS has developed an ambitious plan to decommission and demolish unneeded facilities in a systematic fashion. GIS technology was used to assist development of this plan by: providing locational information for remote facilities, identifying the location of known waste units adjacent to buildings slated for demolition, and for providing a powerful visual representation of the impact of the overall plan. Several steps were required for the development of the infrastructure GIS model. The first step involved creating an accurate and current GIS representation of the infrastructure data. This data is maintained in a Computer Aided Design

  6. TA-2 water boiler reactor decommissioning (Phase 1)

    SciTech Connect

    Elder, J.C.; Knoell, C.L.

    1986-12-01

    Removal of external structures and underground piping associated with the gaseous effluent (stack) line from the TA-2 Water Boiler Reactor was performed as Phase I of reactor decommissioning. Six concrete structures were dismantled and 435 ft of contaminated underground piping was removed. Extensive soil contamination by /sup 137/Cs was encountered around structure TA-2-48 and in a suspected leach field near the stream flowing through Los Alamos Canyon. Efforts to remove all contaminated soil were hampered by infiltrating ground water and heavy rains. Methods, cleanup guidelines, and ALARA decisions used to successfully restore the area are described. The cost of the project was approximately $320K; 970 m/sup 3/ of low-level solid radioactive waste resulted from the cleanup operations.

  7. Decontamination and decommissioning experience at the Savannah River Site

    SciTech Connect

    Monson, R.W.

    1994-07-01

    A continuing concern within the DOE complex is how to address the retirement contains special of a facility which nuclear material (SNM). When the life expectancy of a facility has been reached, decisions must be made pertaining to (1) rial from the facility, removing the mate (2) accounting for the material and (3) final disposition of the material. This paper will discuss such a decontamination and decommissioning (D&D) process which we are presently dealing with at the Savannah River Site. The process must follow DOE Order 5633.3A as well as internal Company procedures regarding MC&A. In some D&D cases the material can be exempt from the DOE Order when all of the following criteria are met: (1) the material has been declared waste, (2) the material has been written off the MC&A books, and (3) the material is under the control of a waste management organization.

  8. Overcoming decommissioning challenges through client/laboratory co-operation

    SciTech Connect

    Wharton, Mike; Gray, Lesley

    2007-07-01

    Available in abstract form only. Full text of publication follows: Accelerated decommissioning projects of the type underway at the former gaseous diffusion plant at BNG Capenhurst, UK, involve characterisation and radiochemical fingerprinting of a variety of unusual materials derived from legacy wastes. The project management and technical challenges that can occur during such a program can be successfully surmounted if a close working relationship between the client and the analytical laboratory is achieved. The Capenhurst Integrated Decommissioning Program (IDP) is an example of how such co-operation can reduce costs and time scales by providing the analytical laboratory with key sample and technical information prior to the shipping of the samples to the lab. This ensures that challenges associated with unusual sample matrices can be anticipated and dealt with at an early stage in the project. Gamma spectrometry is the most common analytical technique when analysing samples for radioactive content as it is non-destructive, relatively inexpensive and fast. However, accurate measurement generally requires samples of a known density to be counted in calibrated geometries. This becomes a challenge as many legacy wastes comprise materials of uneven geometry and/or varying density, as has been the case during the Capenhurst IDP. Liaising with the client to ensure a representative sub-sample of the material is taken on-site, and a series of additional checks when analysing the sample ensure that accurate results are obtained even for non-routine materials. Often it is only one or two radionuclides that dominate the radioactive inventory for legacy wastes. (authors)

  9. Collection and characterization of aerosols from metal cutting techniques typically used in decommissioning nuclear facilities.

    PubMed

    Newton, G J; Hoover, M D; Barr, E B; Wong, B A; Ritter, P D

    1987-11-01

    This study was designed to collect and characterize aerosols released during metal cutting activities typically used in decommissioning radioactively contaminated facilities. Such information can guide in the selection of appropriate control technologies for these airborne materials. Mechanical cutting tools evaluated included a multi-wheel pipe cutter, reciprocating saw, band saw, chop saw, and large and small grinding wheels. Melting-vaporization cutting techniques included an oxy-acetylene torch, electric arc cut rod and plasma torch. With the exception of the multi-wheel pipe cutter, all devices created aerosols in the respirable size range (less than 10 micron aerodynamic diameter). Time required to cut 2-in. (5-cm) Schedule 40, Type 304L, stainless steel ranged from about 0.6 min for the plasma torch to about 3.0 min for the reciprocating saw. Aerosol production rate ranged from less than 10 mg/min for the reciprocating saw to more than 3000 mg/min for the electric arc cut rod. Particles from mechanical tools were irregular in shape, whereas particles from vaporization tools were spheres and ultrafine branched-chain aggregates. PMID:3425551

  10. A survey of commercially available manipulators, end-effectors, and delivery systems for reactor decommissioning activities

    SciTech Connect

    Henley, D.R.; Litka, T.J.

    1996-05-01

    Numerous nuclear facilities owned by the U.S. Department of Energy (DOE) are under consideration for decommissioning. Currently, there are no standardized, automated, remote systems designed to dismantle and thereby reduce the size of activated reactor components and vessels so that they can be packaged and shipped to disposal sites. Existing dismantling systems usually consist of customized, facility-specific tooling that has been developed to dismantle a specific reactor system. Such systems have a number of drawbacks. Generally, current systems cannot be disassembled, moved, and reused. Developing and deploying the tooling for current systems is expensive and time-consuming. In addition, the amount of manual work is significant because long-handled tools must be used; as a result, personnel are exposed to excessive radiation. A standardized, automated, remote system is therefore needed to deliver the tooling necessary to dismantle nuclear facilities at different locations. Because this system would be reusable, it would produce less waste. The system would also save money because of its universal design, and it would be more reliable than current systems.

  11. Collection and characterization of aerosols from metal cutting techniques typically used in decommissioning nuclear facilities

    SciTech Connect

    Newton, G.J.; Hoover, M.D.; Barr, E.B.; Wong, B.A.; Ritter, P.D.

    1987-11-01

    This study was designed to collect and characterize aerosols released during metal cutting activities typically used in decommissioning radioactively contaminated facilities. Such information can guide in the selection of appropriate control technologies for these airborne materials. Mechanical cutting tools evaluated included a multi-wheel pipe cutter, reciprocating saw, band saw, chop saw, and large and small grinding wheels. Melting-vaporization cutting techniques included an oxy-acetylene torch, electric arc cut rod and plasma torch. With the exception of the multi-wheel pipe cutter, all devices created aerosols in the respirable size range (less than 10 micron aerodynamic diameter). Time required to cut 2-in. (5-cm) Schedule 40, Type 304L, stainless steel ranged from about 0.6 min for the plasma torch to about 3.0 min for the reciprocating saw. Aerosol production rate ranged from less than 10 mg/min for the reciprocating saw to more than 3000 mg/min for the electric arc cut rod. Particles from mechanical tools were irregular in shape, whereas particles from vaporization tools were spheres and ultrafine branched-chain aggregates.

  12. 78 FR 49553 - Three Mile Island, Unit 2; Post Shutdown Decommissioning Activities Report

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-14

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Three Mile Island, Unit 2; Post Shutdown Decommissioning Activities Report AGENCY: Nuclear...) for Three Mile Island, Unit 2 (TMI-2). The PSDAR provides an overview of GPUN's...

  13. Nuclear facility decommissioning and site remedial actions: A selected bibliography, Volume 13: Part 2, Indexes

    SciTech Connect

    Goins, L.F.; Webb, J.R.; Cravens, C.D.; Mallory, P.K.

    1992-09-01

    This is part 2 of a bibliography on nuclear facility decommissioning and site remedial action. This report contains indexes on the following: authors, corporate affiliation, title words, publication description, geographic location, subject category, and key word.

  14. 75 FR 13568 - MMS Information Collection Activity: 1010-0142, Decommissioning Activities, Extension of a...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-22

    ... Minerals Management Service MMS Information Collection Activity: 1010-0142, Decommissioning Activities, Extension of a Collection; Comment Request AGENCY: Minerals Management Service (MMS), Interior. ACTION... comments to the Department of the Interior; Minerals Management Service; Attention: Cheryl Blundon;...

  15. Environmental Problems Associated with Decommissioning of Chernobyl Power Plant Cooling Pond

    NASA Astrophysics Data System (ADS)

    Foley, T. Q.; Oskolkov, B. Y.; Bondarkov, M. D.; Gashchak, S. P.; Maksymenko, A. M.; Maksymenko, V. M.; Martynenko, V. I.; Jannik, G. T.; Farfan, E. B.; Marra, J. C.

    2009-12-01

    Decommissioning of nuclear power plants and other nuclear fuel cycle facilities associated with residual radioactive contamination is a fairly pressing issue. Significant problems may result from decommissioning of cooling ponds. The Chernobyl Nuclear Power Plant (ChNPP) Cooling Pond is one of the largest self-contained bodies of water in the Chernobyl Region and Ukrainian Polesye with a water surface area of 22.9 km2. The major hydrological feature of the ChNPP Cooling Pond is that its water level is 6-7 m higher than the water level in the Pripyat River and water losses due to seepage and evaporation are replenished by pumping water from the Pripyat River. In 1986, the accident at the ChNPP #4 Reactor Unit significantly contaminated the ChNPP Cooling Pond. According to the 2001 data, the total radionuclide inventory in the ChNPP Cooling Pond bottom deposits was as follows: 16.28 ± 2.59 TBq for 137Cs; 2.4 ± 0.48 TBq for 90Sr, and 0.00518 ± 0.00148 TBq for 239+240Pu. Since ChNPP is being decommissioned, the ChNPP Cooling Pond of such a large size will no longer be needed and cost effective to maintain. However, shutdown of the water feed to the Pond would expose the contaminated bottom deposits and change the hydrological features of the area, destabilizing the radiological and environmental situation in the entire region in 2007 - 2008, in order to assess potential consequences of draining the ChNPP Cooling Pond, the authors conducted preliminary radio-ecological studies of its shoreline ecosystems. The radioactive contamination of the ChNPP Cooling Pond shoreline is fairly variable and ranges from 75 to 7,500 kBq/m2. Three areas with different contamination levels were selected to sample soils, vegetation, small mammals, birds, amphibians, and reptilians in order to measure their 137Cs and 90Sr content. Using the ERICA software, their dose exposures were estimated. For the 2008 conditions, the estimated dose rates were found to be as follows: amphibians - 11

  16. Nuclear reactor decommissioning. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    1997-10-01

    The bibliography contains citations concerning nuclear power and research reactor decommissioning and decontamination plans, costs, and safety standards. References discuss the design and evaluation of protective confinement, entombment, and dismantling systems. Topics include decommissioning regulations and rules, public and occupational radiation exposure estimates, comparative evaluation, and reactor performance under high neutron flux conditions. Waste packaging and disposal, environmental compliance, and public opinion are examined. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  17. Technology, safety, and costs of decommissioning reference nuclear research and test reactors. Main report

    SciTech Connect

    Konzek, G.J.; Ludwick, J.D.; Kennedy, W.E. Jr.; Smith, R.I.

    1982-03-01

    Safety and Cost Information is developed for the conceptual decommissioning of two representative licensed nuclear research and test reactors. Three decommissioning alternatives are studied to obtain comparisons between costs (in 1981 dollars), occupational radiation doses, potential radiation dose to the public, and other safety impacts. The alternatives considered are: DECON (immediate decontamination), SAFSTOR (safe storage followed by deferred decontamination), and ENTOMB (entombment). The study results are presented in two volumes. Volume 1 (Main Report) contains the results in summary form.

  18. Engineering Evaluation/Cost Analysis for Decommissioning of the Engineering Test Reactor Complex

    SciTech Connect

    A. B. Culp

    2006-10-01

    Preparation of this Engineering Evaluation/Cost Analysis is consistent with the joint U.S. Department of Energy and U.S. Environmental Protection Agency Policy on Decommissioning of Department of Energy Facilities Under the Comprehensive Environmental Response, Compensation, and Liability Act, which establishes the Comprehensive Environmental Response, Compensation, and Liability Act non-time-critical removal action (NTCRA) process as an approach for decommissioning.

  19. Analysis of decommissioning costs for the AFRRI TRIGA reactor facility. Technical report

    SciTech Connect

    Forsbacka, M.; Moore, M.

    1989-12-01

    This report provides a cost analysis for decommissioning the Armed Forces Radiobiology Research Institute (AFRRI) TRIGA reactor facility. AFRRI is not suggesting that the AFRRI TRIGA reactor facility be decommissioned. This report was prepared in compliance with paragraph 50.33 of Title 10, Code of Federal Regulations, which requires that funding for the decommissioning of reactor facilities be available when licensed activities cease. The planned method of decommissioning is complete decontamination (DECON) of the AFRRI TRIGA reactor site to allow for restoration of the site to full public access. The cost of DECON in 1990 dollars is estimated to be $3,200,000. The anticipated ancillary costs of facility site demobilization and spent fuel shipment will be an additional $600,000. Thus, the total cost of terminating reactor operations at AFRRI will be about $3,800,000. The primary basis for developing this cost estimate was a study of the decommissioning costs of similar reactor facility performed by Battelle Pacific Northwest Laboratory, as provided in U.S. Nuclear Regulatory Commission publication NUREG/CR-1756. The data in this study were adapted to reflect the decommissioning requirements of the AFRRI TRIGA reactor facility.

  20. An analysis of decommissioning costs for the AFRRI TRIGA reactor facility

    SciTech Connect

    Forsbacka, Matt

    1990-07-01

    A decommissioning cost analysis for the AFRRI TRIGA Reactor Facility was made. AFRRI is not at this time suggesting that the AFRRI TRIGA Reactor Facility be decommissioned. This report was prepared to be in compliance with paragraph 50.33 of Title 10, Code of Federal Regulations which requires the assurance of availability of future decommissioning funding. The planned method of decommissioning is the immediate decontamination of the AFRRI TRIGA Reactor site to allow for restoration of the site to full public access - this is called DECON. The cost of DECON for the AFRRI TRIGA Reactor Facility in 1990 dollars is estimated to be $3,200,000. The anticipated ancillary costs of facility site demobilization and spent fuel shipment is an additional $600,000. Thus the total cost of terminating reactor operations at AFRRI will be about $3,800,000. The primary basis for this cost estimate is a study of the decommissioning costs of a similar reactor facility that was performed by Battelle Pacific Northwest Laboratory (PNL) as provided in USNRC publication NUREG/CR-1756. The data in this study were adapted to reflect the decommissioning requirements of the AFRRI TRIGA. (author)