WorldWideScience

Sample records for carolinas virginia tube reactor

  1. Pressure tube type reactor

    International Nuclear Information System (INIS)

    Heretofore, a pressure tube type reactor has a problem in that the evaluation for the reactor core performance is complicate and no sufficient consideration is made for the economical property, to increase the size of a calandria tank and make the cost expensive. Then, in the present invention, the inner diameter of a pressure tube is set to greater than 50% of the lattice gap in a square lattice like arrangement, and the difference between the inner and the outer diameters of the calandria tube is set smaller than 20% of the lattice gap. Further, the inner diameter of the pressure tube is set to greater than 40% and the difference between the inner and the outer diameters of the calandria tube is set smaller than 30% of the lattice gap in a triangle lattice arrangement. Then, heavy water-to-fuel volume ratio can be determined appropriately and the value for the coolant void coefficient is made more negative side, to improve the self controllability inherent to the reactor. In particular, when 72 to 90 fuel rods are arranged per one pressure tube, the power density per one fuel rod is can be increased by about twice. Accordingly, the number of the pressure tubes can be reduced about to one-half, thereby enabling to remarkably decrease the diameter of the reactor core and to reduce the size of the calandria, which is economical. (N.H.)

  2. Decommissioning Experience: University of Virginia Reactors, United States of America

    International Nuclear Information System (INIS)

    Full text: There were two research reactors at the University of Virginia. CAVALIER operated at a maximum power of 100 W from 1974 to 1988. The other reactor (generally referred to as the UVA reactor) operated at a maximum power of 1 MW or 2 MW from 1960 to 1998. The water contained in the pool was utilized to provide shielding during the segmenting and removal of highly contaminated components in the pool. This work was performed by divers using plasma arc cutting equipment. A cask liner was first placed in the reactor pool. The higher activity items were preferentially loaded nearest the centre of the cask, and the lower activity items loaded in the liner annulus to provide shielding. Because air sampling performed during segmentation proved that no airborne contamination was produced, no confinement structure was necessary. After shipment of the removed components, the remaining pool water was sampled and confirmed suitable for discharge to the sanitary sewer (through filters). Decontamination of the pool structures was performed using a water jet cutting process. Once the pool surfaces had been cleaned to bare concrete, surfaces were sampled for activation. The only activated concrete was detected radially around the beam tubes through the pool wall (author)

  3. CFD Simulation on Ethylene Furnace Reactor Tubes

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Different mathematical models for ethylene furnace reactor tubes were reviewed. On the basis of these models a new mathematical simulation approach for reactor tubes based on computational fluid dynamics (CFD) technique was presented. This approach took the flow, heat transfer, mass transfer and thermal cracking reactions in the reactor tubes into consideration. The coupled reactor model was solved with the SIMPLE algorithm. Some detailed information about the flow field, temperature field and concentration distribution in the reactor tubes was obtained, revealing the basic characteristics of the hydrodynamic phenomena and reaction behavior in the reactor tubes. The CFD approach provides the necessary information for conclusive decisions regarding the production optimization, the design and improvement of reactor tubes, and the new techniques implementation.

  4. The Future Role of Instructional Technology in Agricultural Education in North Carolina and Virginia.

    Science.gov (United States)

    Alston, Antoine J.; Miller, W. Wade; Williams, David L.

    2003-01-01

    A stratified random sample of agriculture teachers in North Carolina (n=210) and Virginia (n=170) returned 85 and 110 usable surveys respectively. Teachers were undecided about future uses of instructional technology although they perceived benefits. Accessing Internet lesson plans was a primary use. Hardware/software costs were the principal…

  5. Population Abundance and Genetic Structure of Black Bears in Coastal North Carolina and Virginia Using Noninvasive Genetic Techniques.

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Master thesis on the population abundance and genetic structure of black bears in coastal North Carolina and Virginia using noninvasive genetic technigues on...

  6. Documentation of Data Collection in Currituck Sound, North Carolina and Virginia, 2006-2007

    Science.gov (United States)

    Fine, Jason M.

    2008-01-01

    During 2006 and 2007, scientists from Elizabeth City State University, North Carolina Estuarine Research Reserve, the U.S. Fish and Wildlife Service, and the U.S. Geological Survey collected hydrologic and water-quality data at nine sites in and around Currituck Sound. Hydrologic and water-quality data were collected at five tributary sites--the Northwest River near Moyock, Tull Creek near Currituck, and Intracoastal Waterway near Coinjock in North Carolina, and the Albemarle and Chesapeake Canal near Princess Anne, and the North Landing River near Creeds in Virginia. In addition, data were collected at one site at the mouth of Currituck Sound (Currituck Sound at Point Harbor, North Carolina). Only water-quality data were collected at three sites in Currituck Sound and Back Bay-Currituck Sound near Jarvisburg, and Upper Currituck Sound near Corolla in North Carolina, and Back Bay near Back Bay in Virginia. The hydrologic data included water elevation and velocity, and discharge. The water-quality data included discrete samples and continuous measurements of water temperature, specific conductance, dissolved oxygen, pH, turbidity, and chlorophyll a. The hydrologic and water-quality data collected for this study were quality assured by the U.S. Geological Survey and stored in the National Water Information System database. The data collected for this project are being used to develop an unsteady multidimensional hydrodynamic and water-quality model of Currituck Sound by the U.S. Army Corps of Engineers. The purpose of this model is to provide the basis for planning and the development of best-management practices and restoration projects for Currituck Sound and its tributaries.

  7. Siting of USArray Seismic Stations in North Carolina and southern Virginia: Experience of NC-1 Team

    Science.gov (United States)

    Martin, P.; Howard, J.; Horne, T.

    2012-12-01

    The USArray component of the EarthScope, a transportable array of 400 seismometers installed in a grid about 70 km apart, is in the next two years entering its final stage with station deployment along the Atlantic coast of the United States. Here, we present the experience of the student-faculty team from North Carolina Central University (NCCU) in finding and documenting the suitable sites for the twenty five USArray stations in North Carolina and southern Virginia. The ideal sites are easily accessible yet far from traffic and other sources of noise, with good cell phone coverage, sun exposure and out of flood-prone areas. Although the initial selection of potential locations was done using geospatial mapping and analysis software provided by EarthScope, finding and finalizing the sites involved driving more then 1,000 miles each week for over two months inspecting possible site locations. Aside from driving, the majority of time was spent talking about the EarthScope project and hosting of USArray stations to mostly reluctant landowners. In addition to facing various challenges in finding appropriate sites due to land use issues, such as suburban sprawl of central North Carolina, or topography factors, such as low lying flood prone coastal areas, by far the major challenge was finding the landowners willing to host the seismic station for the necessary three years. In addition to involving students from an HBCU in seismology related project and increasing the visibility of NCCU geophysics program in the University and local community through publicity releases in local media and on university web site, the project had an important outreach component. As North Carolina is located along the seismically quiet, passive Atlantic margin, most residents are not familiar with earthquakes and seismology and the siting experience provided students an opportunity to practice explaining the earthquake research to the general public. The dialog also highlighted science

  8. A common DLX3 gene mutation is responsible for tricho-dento-osseous syndrome in Virginia and North Carolina families.

    Science.gov (United States)

    Price, J A; Wright, J T; Kula, K; Bowden, D W; Hart, T C

    1998-10-01

    Tricho-dento-osseous syndrome (TDO) is characterised by a variable clinical phenotype primarily affecting the hair, teeth, and bone. Different clinical features are observed between and within TDO families. It is not known whether the variable clinical features are the result of genetic heterogeneity or clinical variability. A gene for TDO was localised recently to chromosome 17q21 in four North Carolina families, and a 4 bp deletion in the human distal-less 3 gene (DLX3) was identified in all affected members. A previous genetic linkage study in a large Virginia kindred with TDO indicated possible linkage to the ABO, Gc, and Kell blood group loci. To examine whether TDO exhibits genetic heterogeneity, we have performed molecular genetic analysis to determine whether affected members of this Virginia kindred have the DLX3 gene deletion identified in North Carolina families. Results show that affected subjects (n=3) from the Virginia family have the same four nucleotide deletion previously identified in the North Carolina families. A common haplotype for three genetic markers surrounding the DLX3 gene was identified in all affected subjects in the North Carolina and Virginia families. These findings suggest that all people with TDO who have been evaluated have inherited the same DLX3 gene deletion mutation from a common ancestor. The variable clinical phenotype observed in these North Carolina and Virginia families, which share a common gene mutation, suggests that clinical variability is not the result of genetic heterogeneity at the major locus, but may reflect genetic heterogeneity at other epigenetic loci or contributing environmental factors or both. PMID:9783705

  9. Influence of Cultural and Pest Management Practices on Performance of Runner, Spanish, and Virginia Market Types in North Carolina

    Directory of Open Access Journals (Sweden)

    Bridget R. Lassiter

    2016-01-01

    Full Text Available Virginia market type peanut (Arachis hypogaea L. cultivars are grown primarily in North Carolina, South Carolina, and Virginia in the US, although growers in these states often plant other market types if marketing opportunities are available. Information on yield potential and management strategies comparing these market types is limited in North Carolina. In separate experiments, research was conducted to determine response of runner, Spanish, and Virginia market types to calcium sulfate and inoculation with Bradyrhizobium at planting, planting and digging dates, planting patterns, and seeding rates. In other experiments, control of thrips (Frankliniella spp. using aldicarb, southern corn rootworm (Diabrotica undecimpunctata Howardi using chlorpyrifos, eclipta (Eclipta prostrata L. using threshold-based postemergence herbicides, and leaf spot disease (caused by the fungi Cercospora arachidicola and Cercosporidium personatum fungicide programs was compared in these market types. Results showed that management practice and market types interacted for peanut pod yield in only the planting date experiment. Yield of runner and Virginia market types was similar and exceeded yield of the Spanish market type in most experiments.

  10. Isopach grid of the Quaternary sediment thickness, inner shelf and back-barrier from Virginia border to Cape Lookout, North Carolina (q0thick, ESRI binary grid, 200 m cell size, UTM Zone 18N, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  11. Isopach grid of the modern marine sand above the top of Pleistocene surface along the inner shelf from Virginia border to Cape Hatteras, North Carolina (modsand, ESRI binary grid, 100 m cellsize, UTM Zone 18N, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  12. YouTube researcher presents future of technology in education at Virginia Tech

    OpenAIRE

    Caldwell, T. Lynn

    2008-01-01

    More than 200 graduate students, faculty, and staff gathered in Virginia Tech's Graduate Life Center on Thursday, Sept. 11, to hear Michael Wesch present on the future of technology in education and his use of YouTube in the classroom.

  13. Post-Hurricane Irene coastal oblique aerial photographs collected from Ocracoke Inlet, North Carolina, to Virginia Beach, Virginia, August 30-31, 2011

    Science.gov (United States)

    Morgan, Karen L. M.; Krohn, M. Dennis

    2016-02-17

    The U.S. Geological Survey (USGS), as part of the National Assessment of Coastal Change Hazards project, conducts baseline and storm-response photography missions to document and understand the changes in vulnerability of the Nation's coasts to extreme storms (Morgan, 2009). On August 30-31, 2011, the USGS conducted an oblique aerial photographic survey from Ocracoke Inlet, North Carolina, to Virginia Beach, Virginia, aboard a Piper Navajo Chieftain (aircraft) at an altitude of 500 feet (ft) and approximately 1,200 ft offshore. This mission was flown to collect post-Hurricane Irene data for assessing incremental changes in the beach and nearshore area since the last survey, flown in May 2008, and the data can be used in the assessment of future coastal change.

  14. Nesting and pollen preference of Osmia lignaria lignaria (Hymenoptera: Megachilidae) in Virginia and North Carolina orchards.

    Science.gov (United States)

    Kraemer, M E; Favi, F D; Niedziela, C E

    2014-08-01

    Cavity-nesting megachilid bees in the genus Osmia, found throughout the Palearctic and Nearctic regions, are good candidates for domestication. In North America, Osmia lignaria Say has been reported to be an excellent pollinator of tree fruit and is currently being developed for commercial use in orchards. This is largely because of research over several decades with the western subspecies of this bee, Osmia lignaria propinqua Cresson, in western orchards. The behavior of the eastern subspecies, O. lignaria lignaria Say, in eastern orchards has not previously been reported. This study evaluated the nesting activity and pollen preference of a population of the eastern subspecies in five orchards in the foothills and piedmont regions of North Carolina and Virginia over a 2-yr period. Apple was present in all orchards and all were bordered by hardwood forest. Shelters were placed both within orchards and the forest border. Emergence dates, nest construction, and orchard bloom were monitored weekly. Bee populations increased by 2-3 times annually at most orchards. Pollen species comprising nest provisions from 720 individual nest cells were identified and quantified using scanning electron microscopy. The greatest amount of pollen (46-82%) was that of a small understory tree, Eastern redbud (Cercis canadensis L.), at all orchard sites where these trees were present nearby. The quantity of orchard pollen was relatively low, <20% at full apple bloom, except for one orchard (53%) without nearby redbud. O. lignaria lignaria appears to prefer Eastern redbud pollen over orchard pollen. PMID:24865141

  15. Human exposure to mosquito-control pesticides--Mississippi, North Carolina, and Virginia, 2002 and 2003.

    Science.gov (United States)

    2005-06-01

    Public health officials weigh the risk for mosquito-borne diseases against the risk for human exposure to pesticides sprayed to control mosquitoes. Response to outbreaks of mosquito-borne diseases has focused on vector control through habitat reduction and application of pesticides that kill mosquito larvae. However, in certain situations, public health officials control adult mosquito populations by spraying ultra-low volume (ULV) (naled, permethrin, and d-phenothrin. These ULV applications generate aerosols of fine droplets of pesticides that stay aloft and kill mosquitoes on contact while minimizing the risk for exposure to persons, wildlife, and the environment. This report summarizes the results of studies in Mississippi, North Carolina, and Virginia that assessed human exposure to ULV naled, permethrin, and d-phenothrin used in emergency, large-scale MC activities. The findings indicated ULV application in MC activities did not result in substantial pesticide exposure to humans; however, public health interventions should focus on the reduction of home and workplace exposure to pesticides. PMID:15931155

  16. Farm succession planning workshops scheduled for Virginia and North Carolina farmers

    OpenAIRE

    Stott, Charlie

    2005-01-01

    The average age of a Virginia farmer is now 56 years old, and a large transfer of farm assets could occur over the next two decades. To address this important issue, the Virginia Cooperative Extension has scheduled two workshops on farm business succession planning during May in eastern Virginia.

  17. PROGRESS IN PROCESS INTENSIFICATION: SYNTHESIS OF IMINES USING A SPINNING TUBE-IN-TUBE REACTOR

    Science.gov (United States)

    The high purity, high throughput synthesis of a number of imines (Schiff bases) using a spinning tube-in-tube reactor (STT, Kreido Laboratories, Camarillo, CA) has been carried out. The STT reactor allows the high throughput production of high purity imines from a wide variety of...

  18. EPOXIDATION OF SMALL ORGANIC MOLECULES USING A SPINNING TUBE-IN-TUBE REACTOR

    Science.gov (United States)

    The commodity-scale epoxidation of several organic molecules has been carried out using a Spinning Tube-in-Tube (STTr) reactor (manufactured by Kreido Laboratories). This reactor, which embodies and facilitates the use of Green Chemistry principles and Process Intensification, a...

  19. PROGRESS IN PROCESS INTENSIFICATION: SYNTHESIS OF IMIDAZOLE DERIVATIVES USING A SPINNING TUBE-IN-TUBE REACTOR

    Science.gov (United States)

    The high purity, high throughput synthesis of a number of imidazole derivatives using a spinning tube-in-tube reactor (STT®, Kreido Laboratories, Camarillo California) has been carried out. The STT® reactor allows the high throughput production of high purity imidazole derivativ...

  20. Anatomy of a shoreface sand ridge revisted using foraminifera: False Cape Shoals, Virginia/North Carolina inner shelf

    Science.gov (United States)

    Robinson, Marci M.; McBride, Randolph A.

    2008-01-01

    Certain details regarding the origin and evolution of shelf sand ridges remain elusive. Knowledge of their internal stratigraphy and microfossil distribution is necessary to define the origin and to determine the processes that modify sand ridges. Fourteen vibracores from False Cape Shoal A, a well-developed shoreface-attached sand ridge on the Virginia/North Carolina inner continental shelf, were examined to document the internal stratigraphy and benthic foraminiferal assemblages, as well as to reconstruct the depositional environments recorded in down-core sediments. Seven sedimentary and foraminiferal facies correspond to the following stratigraphic units: fossiliferous silt, barren sand, clay to sandy clay, laminated and bioturbated sand, poorly sorted massive sand, fine clean sand, and poorly sorted clay to gravel. The units represent a Pleistocene estuary and shoreface, a Holocene estuary, ebb tidal delta, modern shelf, modern shoreface, and swale fill, respectively. The succession of depositional environments reflects a Pleistocene sea-level highstand and subsequent regression followed by the Holocene transgression in which barrier island/spit systems formed along the Virginia/North Carolina inner shelf not, vert, ~5.2 ka and migrated landward and an ebb tidal delta that was deposited, reworked, and covered by shelf sand.

  1. Anatomy of a shoreface sand ridge revisited using foraminifera: False Cape Shoals, Virginia/North Carolina inner shelf

    Science.gov (United States)

    Robinson, M.M.; McBride, R.A.

    2008-01-01

    Certain details regarding the origin and evolution of shelf sand ridges remain elusive. Knowledge of their internal stratigraphy and microfossil distribution is necessary to define the origin and to determine the processes that modify sand ridges. Fourteen vibracores from False Cape Shoal A, a well-developed shoreface-attached sand ridge on the Virginia/North Carolina inner continental shelf, were examined to document the internal stratigraphy and benthic foraminiferal assemblages, as well as to reconstruct the depositional environments recorded in down-core sediments. Seven sedimentary and foraminiferal facies correspond to the following stratigraphic units: fossiliferous silt, barren sand, clay to sandy clay, laminated and bioturbated sand, poorly sorted massive sand, fine clean sand, and poorly sorted clay to gravel. The units represent a Pleistocene estuary and shoreface, a Holocene estuary, ebb tidal delta, modern shelf, modern shoreface, and swale fill, respectively. The succession of depositional environments reflects a Pleistocene sea-level highstand and subsequent regression followed by the Holocene transgression in which barrier island/spit systems formed along the Virginia/North Carolina inner shelf ???5.2 ka and migrated landward and an ebb tidal delta that was deposited, reworked, and covered by shelf sand.

  2. Northward extension of Carolina slate belt stratigraphy and structure, South-Central Virginia: Results from geologic mapping

    Science.gov (United States)

    Hackley, P.C.; Peper, J.D.; Burton, W.C.; Horton, J.W.

    2007-01-01

    Geologic mapping in south-central Virginia demonstrates that the stratigraphy and structure of the Carolina slate belt extend northward across a steep thermal gradient into upper amphibolite-facies correlative gneiss and schist. The Neoproterozoic greenschist-facies Hyco, Aaron, and Virgilina Formations were traced northward from their type localities near Virgilina, Virginia, along a simple, upright, northeast-trending isoclinal syncline. This syncline is called the Dryburg syncline and is a northern extension of the more complex Virgilina synclinorium. Progressively higher-grade equivalents of the Hyco and Aaron Formations were mapped northward along the axial trace of the refolded and westwardly-overturned Dryburg syncline through the Keysville and Green Bay 7.5-minute quadrangles, and across the northern end of the Carolina slate belt as interpreted on previous geologic maps. Hyco rocks, including felsic metatuff, metawacke, and amphibolite, become gneisses upgrade with areas of local anatexis and the segregation of granitic melt into leucosomes with biotite selvages. Phyllite of the Aaron Formation becomes garnet-bearing mica schist. Aaron Formation rocks disconformably overlie the primarily felsic volcanic and volcaniclastic rocks of the Hyco Formation as evidenced by repeated truncation of internal contacts within the Hyco on both limbs of the Dryburg syncline at the Aaron-Hyco contact. East-northeast-trending isograds, defined successively by the first appearance of garnet, then kyanite ?? staurolite in sufficiently aluminous rocks, are superposed on the stratigraphic units and synclinal structure at moderate to high angles to strike. The textural distinction between gneisses and identifiable sedimentary structures occurs near the kyanite ?? staurolite-in isograd. Development of the steep thermal gradient and regional penetrative fabric is interpreted to result from emplacement of the Goochland terrane adjacent to the northern end of the slate belt during

  3. Ultrasonic measurement method of calandria tube sagging in CANDU reactor

    International Nuclear Information System (INIS)

    Calandria tube wrapping each pressure tube is one of the key structural components of CANDU reactor (calandria) which is consisted of many pressure tubes containing nuclear fuel assemblies. As the calandria tube (made of zirconium alloy) is sagging due to its thermal and irradiation creep during the plant operation, it possibly contacts with liquid injection nozzle crossing beneath the calandria tube, which subsequently results in difficulties on the safe operation. It is therefore necessary to check the gap for the confirmation of no contacts between the two tubes, calandria tube and liquid inject ion tube, with a proper measure during the life of plant. In this study, an ultrasonic measurement method was selected among several methods investigated. The ultrasonic device being developed for the measurement of the gap was introduced and its preliminary performance test results were presented here

  4. The Relationship between Habitat Structure and Small Mammal Communities in Southeastern Virginia and Northeastern North Carolina

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The objectives of this study were: 1 to evaluate the small mammal communities in the range of natural habitats present in southeastern Virginia and northeastern...

  5. Sediment distribution and hydrologic conditions of the Potomac aquifer in Virginia and parts of Maryland and North Carolina

    Science.gov (United States)

    McFarland, E. Randolph

    2013-01-01

    Sediments of the heavily used Potomac aquifer broadly contrast across major structural features of the Atlantic Coastal Plain Physiographic Province in eastern Virginia and adjacent parts of Maryland and North Carolina. Thicknesses and relative dominance of the highly interbedded fluvial sediments vary regionally. Vertical intervals in boreholes of coarse-grained sediment commonly targeted for completion of water-supply wells are thickest and most widespread across the central and southern parts of the Virginia Coastal Plain. Designated as the Norfolk arch depositional subarea, the entire sediment thickness here functions hydraulically as a single interconnected aquifer. By contrast, coarse-grained sediment intervals are thinner and less widespread across the northern part of the Virginia Coastal Plain and into southern Maryland, designated as the Salisbury embayment depositional subarea. Fine-grained intervals that are generally avoided for completion of water-supply wells are increasingly thick and widespread northward. Fine-grained intervals collectively as thick as several hundred feet comprise two continuous confining units that hydraulically separate three vertically spaced subaquifers. The subaquifers are continuous northward but merge southward into the single undivided Potomac aquifer. Lastly, far southeastern Virginia and northeastern North Carolina are designated as the Albemarle embayment depositional subarea, where both coarse- and fine-grained intervals are of only moderate thickness. The entire sediment thickness functions hydraulically as a single interconnected aquifer. A substantial hydrologic separation from overlying aquifers is imposed by the upper Cenomanian confining unit. Potomac aquifer sediments were deposited by a fluvial depositional complex spanning the Virginia Coastal Plain approximately 100 to 145 million years ago. Westward, persistently uplifted granite and gneiss source rocks sustained a supply of coarse-grained sand and gravel

  6. Welding of tube-to-tube joints between martensitic and austenitic stainless steels for reactor applications

    International Nuclear Information System (INIS)

    Studies of the welding of tube-to-tube joints between dissimilar steels are described. The material combination was martensitic F6NM (0Cr13Ni4Mo) and austenitic AISI 347 stainless steels. Such joints are important parts in the primary circuit of a pressurized water reactor. A welding procedure was developed based on a series of weldability tests. The joints were subjected to various mechanical property tests including tensile test, bending test and impact test at various temperatures. A prototype product was made and subjected to pressure testing. Results of various tests indicated that the quality of the tube-to-tube joints is satisfactory for meeting all the design requirements. The joints can be used in the primary circuit of a pressurized water reactor. (author)

  7. Heavy-water-moderated pressure-tube reactor safety

    International Nuclear Information System (INIS)

    Several countries have heavy-water-moderated, pressure-tube reactors either in commercial operation or in late prototype stages. The supporting safety research and development includes such areas as the thermohydraulics of circuit depressurization, heat transfer from the fuel, heat rejection to the moderator from dry fuel, fuel and sheath behaviour, and fuel channel integrity. We review the work done in Canada, Great Britain, Italy and Japan, and describe some of the experimental tests underlaying the methods of accident analysis. The reactors have safety systems which, in the event of an accident, are able to shut down the reactor, keep the fuel cooled, and contain any released radioactivity. We summarize the characteristics of these safety systems (shutdown, emergency core cooling, and containment) in the various reactors, and discuss other reactor characteristics which either prevent accidents or reduce their potential demand on the safety systems. (author)

  8. Structure grid of the depth to the top of Pleistocene (Q99), inner shelf and back-barrier from Virginia border to Cape Lookout, North Carolina (q99depth, ESRI binary grid, 400 m cell size, UTM Zone 18N, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  9. Grid of the thickness of sediment above the Pleistocene surface Q30, inner shelf and back-barrier from Virginia border to Cape Lookout, North Carolina (q30thick, ESRI binary grid, 200 m cell size, UTM, Zone 18N, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  10. Structure grid of the depth to the Pleistocene surface (Q50), inner shelf and back-barrier from Virginia border to Cape Lookout, North Carolina (q50depth, ESRI binary grid, 200 m cell size, UTM Zone 18N, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  11. Structure grid of the depth to the Pleistocene surface (Q30), inner shelf and back-barrier from Virginia border to Cape Lookout, North Carolina (q30depth, ESRI binary grid, 200 m cell size, UTM Zone 18N, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  12. Grid of the thickness of sediment above the Pleistocene surface Q50, inner shelf and back-barrier from Virginia border to Cape Lookout, North Carolina (q50thick, ESRI binary grid, 200 m cell size, UTM Zone 18N, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  13. Structure grid of the depth to the Pliocene surface (Q0), inner shelf and back-barrier from Virginia border to Cape Lookout, North Carolina (q0depth,ESRI binary grid, 200 m cell size, UTM Zone 18N, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  14. COMMODITY SCALE SYNTHESIS OF 1-METHYLIMIDAZOLE BASED IONIC LIQUIDS USING A SPINNING TUBE-IN-TUBE REACTOR

    Science.gov (United States)

    The continuous large-scale preparation of several 1-methylimidazole based ionic liquids was carried out using a Spinning Tube-in-Tube (STT) reactor (manufactured by Kreido Laboratories). This reactor, which embodies and facilitates the use of Green Chemistry principles and Proce...

  15. When folic acid fails: Insights from 20 years of neural tube defect surveillance in South Carolina.

    Science.gov (United States)

    Bupp, Caleb P; Sarasua, Sara M; Dean, Jane H; Stevenson, Roger E

    2015-10-01

    Neural tube defects (NTDs) are the most common of the severe malformations of the brain and spinal cord. Increased maternal intake of folic acid (FA) during the periconceptional period is known to reduce NTD risk. Data from 1046 NTD cases in South Carolina were gathered over 20 years of surveillance. It was possible to determine maternal periconceptional FA use in 615 NTD-affected pregnancies. In 163 occurrent (26.9%) and two recurrent (22%) NTD cases, the mothers reported periconceptional FA use. These women were older and more likely to be white. Maternal periconceptional FA usage was reported in 40.4% of cases of spina bifida with other anomalies but in only 25.2% of isolated spina bifida cases (P = 0.02). This enrichment for associated anomalies was not noted among cases of anencephaly or of encephalocele. Among the 563 subsequent pregnancies to mothers with previous NTD-affected pregnancies, those taking FA had a 0.4% NTD recurrence rate, but the recurrence without FA was 8.5%. NTDs with other associated findings were less likely to be prevented by FA, suggesting there is a background NTD rate that cannot be further reduced by FA. Nonetheless, the majority (73.9%) of NTDs in pregnancies in which the mothers reported periconceptional FA use were isolated NTDs of usual types. Cases in which FA failed in prevention of NTDs provide potential areas for further study into the causation of NTDs. The measures and techniques implemented in South Carolina can serve as an effective and successful model for prevention of NTD occurrence and recurrence. PMID:26108864

  16. Baseline coastal oblique aerial photographs collected from Owls Head, Maine, to the Virginia/North Carolina border, May 19-22, 2009

    Science.gov (United States)

    Morgan, Karen L.M.; Hapke, Cheryl J.; Himmelstoss, Emily A.

    2015-01-01

    The U.S. Geological Survey (USGS) conducts baseline and storm response photography missions to document and understand the changes in vulnerability of the Nation's coasts to extreme storms. On May 19-22, 2009, the USGS conducted an oblique aerial photographic survey from Owls Head, Maine, to the Virginia/North Carolina border aboard a Cessna 207A at an altitude of 500 feet (ft) and approximately 1,200 ft offshore. This mission was flown to collect baseline data for assessing incremental changes since the last survey, and the data can be used in the assessment of future coastal change.

  17. Safety Evaluation Report related to renewal of the operating license for the CAVALIER Training Reactor at the University of Virginia (Docket No. 50-396)

    International Nuclear Information System (INIS)

    This Safety Evaluation Report for the application filed by the University of Virginia for a renewal of Operating License R-123 to continue to operate the CAVALIER (Cooperatively Assembled Virginia Low Intensity Educational Reactor) has been prepared by the Office of Nuclear Reactor Regulation of the US Nuclear Regulatory Commission. The facility is owned and operated by the University of Virginia and is located on the campus in Charlottesville, Virginia. Based on its technical review, the staff concludes that the reactor facility can continue to be operated by the university without endangering the health and safety of the public or the environment

  18. Pressure Tube and Pressure Vessel Reactors; certain comparisons

    International Nuclear Information System (INIS)

    In a comparison between pressure tube and pressure vessel type reactors for pressurized D2O coolant and natural uranium, one can say that reactors of these two types having the same net electrical output, overall thermal efficiency, reflected core volume and fuel lattice have roughly the same capital cost. In these circumstances, the fuel burn-up obtainable has a significant influence on the relative economics. Comparisons of burn-up values made on this basis are presented in this report and the influence on the results of certain design assumptions are discussed. One of the comparisons included is based on the dimensions and ratings proposed for CANDU. Moderator temperature coefficients are compared and differences in kinetic behaviour which generally result in different design philosophies for the two types are mentioned, A comparison of different methods of obtaining flux flattening is presented. The influence of slight enrichment and other coolants, (boiling D2O and gases) on the comparison between pressure tube and pressure vessel designs is discussed and illustrated with comparative designs for 400 MW electrical output. This paper was presented at the EAES Enlarged Symposium on Heterogeneous Heavy Water Power Reactors, Mallorca, October 10 - 14, 1960

  19. Wet channel measurement of pressure tube to calandria tube spacing in CANDU reactors

    International Nuclear Information System (INIS)

    The pressure tube (PT) to calandria tube (CT) spacing in CANDU reactors is an important parameter that relates to the general condition of the fuel channels. The measurement system that was developed to measure this parameter during the wet channel inspections of Pickering Units 1 and 2 is described in this paper. A send-receive eddy current probe was designed which is primarily sensitive to variations in PT/CT spacing but is also affected by pressure tube wall thickness. A computer simulation showed that the phase angles of the response to these variables are similar for all usable frequencies, thus eliminating the possibility of multifrequency compensation. A marriage of technologies was proposed involving the ultrasonic measurement of wall thickness values which are then used to extract the spacing information from the eddy current signal. The accuracy of the system is approximately ±(30% +.1mm) which has been sufficient to determine if and where any of the pressure tubes have come in contact with their calandria tube. Field experience with the new system is discussed and areas for development are also outlined

  20. Hydrodynamics of a self-agitated draft tube airlift reactor

    Directory of Open Access Journals (Sweden)

    Tekić Miodrag N.

    2014-01-01

    Full Text Available The main hydrodynamic characteristics of a novel-constructed, self-agitated draft tube airlift reactor (DT-ALR were investigated. Ten impellers, driven only by the means of gas throughput and induced liquid circulation, were inserted in the draft tube. The insertion of impellers caused bubble breakup and reduction of both mean bubble size and coalescence, even under the conditions of high gas throughputs. Although the impellers induced energy losses, the resistance to the flow was relatively lower due to their rotation, unlike the internals used in other research reported in the literature. In comparison to the conventional configuration of a DT-ALR, it was found that the presence of impellers led to significant changes in hydrodynamics: riser gas holdup and mixing time increased, while overall gas holdup and liquid velocity in the downcomer decreased. [Projekat Ministarstva nauke Republike Srbije, br. 172025

  1. Ultrasonic crack-tip diffraction in CANDU reactor pressure tubes

    International Nuclear Information System (INIS)

    Currently there is no reliable method of measuring defect depths in CANDU reactor pressure tubes. The demonstrated success of crack-tip diffraction (or time-of-flight-testing) in round-robins on thick components has promoted an interest in this technique. In CANDU reactors, pressure tubes are effectively accessible only from the inside. Development work has concentrated on outside surface defects using 45 degree shear waves in contrast to the longitudinal waves usually used for testing thick components with this technique. Due to the small wall thickness of the pressure tubes (4.2 mm) and the typical sizes of defects of interest (0.15 mm or greater), frequencies of the order of 20 MHz are being used. A further complication comes from the orientation of the defects, which may be at any angle in pressure tubes. Initial studies have been performed on a series of outside surface notches and slots, plus a real fatigue crack. This crack was on the inside surface, so the technique required measuring this defect's depth from the outside. Initial results are encouraging. Even without signal processing, crack-tip diffracted signals were detectable from all but very large (2.5 mm) and very small (less than 0.076 mm) notches. Errors in estimates of defect depths were typically less than 0.1 mm for all the notches, and the results were consistent. Measurements on the fatigue crack showed similar random errors, though there appeared to be a deterministic error of about 0.1 mm as well

  2. Tube-in-tube reactor as a useful tool for homo- and heterogeneous olefin metathesis under continuous flow mode.

    Science.gov (United States)

    Skowerski, Krzysztof; Czarnocki, Stefan J; Knapkiewicz, Paweł

    2014-02-01

    A tube-in-tube reactor was successfully applied in homo- and heterogeneous olefin metathesis reactions under continuous flow mode. It was shown that the efficient removal of ethylene facilitated by connection of the reactor with a vacuum pump significantly improves the outcome of metathesis reactions. The beneficial aspects of this approach are most apparent in reactions performed at low concentration, such as macrocyclization reactions. The established system allows achievement of both improved yield and selectivity, and is ideal for industrial applications.

  3. Towards a sustainable future using pressure tube reactor technology

    International Nuclear Information System (INIS)

    We describe the contribution nuclear energy will make to global energy needs based on the sound foundation of existing technology, infrastructure, natural resources and human knowledge, while meeting the requirements of security of supply (energy independence) and growing demand. Currently all reactors internationally operate on an unsustainable once-through nuclear fuel cycle using uranium fuel. Future decisions will be increasingly based on strategic considerations involving the complete nuclear fuel cycle, including requirements related to supply assurances, resource utilization, proliferation resistance and radioactive waste disposal. Pressure tube reactor (PTR) technology using fuel channels is uniquely suited to respond to the future needs because of its inherent technical characteristics and associated fuel cycle flexibility. PTR channel technology concepts have also continued to advance based on 50 years of continuous development and improvement, with strategic considerations involving the complete nuclear fuel cycle related to: Fuel Availability and Supply Assurances, Uranium, Plutonium and Thorium utilization, Waste Minimization, Proliferation Resistance (Safeguards) ,Assured Licensability, Improved Safety Cost, Competitiveness. We show how nuclear technology development and global sustainability is determined by R and D progress, with challenging technology goals for nuclear energy systems in the four areas of sustainability, economics, safety and reliability, and proliferation resistance and physical protection, leading naturally to the next phase of PTR channel development, namely the high efficiency Supercritical Water Reactor (SCWR). Aggressive targets have been set for R and D and advanced concepts, complementary to the approaches taken in India, which support enhanced safety, cost reduction, resource sustainability, and economical and efficient operation. (author)

  4. Flow chemistry: intelligent processing of gas-liquid transformations using a tube-in-tube reactor.

    Science.gov (United States)

    Brzozowski, Martin; O'Brien, Matthew; Ley, Steven V; Polyzos, Anastasios

    2015-02-17

    reactive gas in a given reaction mixture. We have developed a tube-in-tube reactor device consisting of a pair of concentric capillaries in which pressurized gas permeates through an inner Teflon AF-2400 tube and reacts with dissolved substrate within a liquid phase that flows within a second gas impermeable tube. This Account examines our efforts toward the development of a simple, unified methodology for the processing of gaseous reagents in flow by way of development of a tube-in-tube reactor device and applications to key C-C, C-N, and C-O bond forming and hydrogenation reactions. We further describe the application to multistep reactions using solid-supported reagents and extend the technology to processes utilizing multiple gas reagents. A key feature of our work is the development of computer-aided imaging techniques to allow automated in-line monitoring of gas concentration and stoichiometry in real time. We anticipate that this Account will illustrate the convenience and benefits of membrane tube-in-tube reactor technology to improve and concomitantly broaden the scope of gas/liquid/solid reactions in organic synthesis.

  5. Catalytic cracking of endothermic fuels in coated tube reactor

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Suspensoid of HZSM-5 or HY zeolites mixed with a self-made ceramic-like binder was coated on the inner wall of a tubular reactor by gas-aided fluid displacement technology.The coated zeolites were characterized by means of X-ray diffraction (XRD),Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM).The coating thickness is 10-20 μm and the particle size of the zeolites is in the range of 1-5 μm.In the coated reactor,cracking of endothermic fuels including n-dodecane and aviation fuel RP-3 was carried out separately under supercritical conditions at 600℃ and 625℃ to investigate their heat sinks and conversion of catalytic reactions.For the reaction catalyzed by HY (25% mass fraction) coating,the heat sink capacity of ndodecane are 815.7 and 901.9 kJ/kg higher than that of the bare tube at 600℃ and at 625℃,respectively.Conversion of n-dodecane also increases from 42% to 60% at 600℃ and from 66% to 80% at 625℃.The coated zeolite can significantly inhibit the carbon deposition during supercritical cracking reactions.

  6. Irradiation of zircaloy calandria tube samples for growth measurement in Dhruva reactor

    International Nuclear Information System (INIS)

    In our PHWRs, the calandria tubes are made of seamwelded zircaloy-2 material which is placed in service in fully annealed condition. The available literature contains considerable information on the irradiation response of seamwelded calandria tubes thereby generating enough confidence towards assuming satisfactory behaviour of seamwelded calandria tubes in the reactor. However it is known that garter spring transmits a load from the pressure tube to the calandria tube and after a few years of reactor operation, creep of the calandria tube is the controlling factor in resisting the sag of the coolant channels. There is a proposal from Nuclear Fuel Complex (NFC), Hyderabad to manufacture the seamless zircaloy calandria tubes in place of welded tubes which will result in increased production of calandria tubes at a much lower cost and will also meet the increased production demand for calandria tubes for future power programme. In view of the necessity to change over from seamwelded to seamless zircaloy calandria tubes, it is very important to generate the irradiation creep, growth and mechanical properties data for seamless and seamwelded zircaloy calandria tubes by irradiating their samples in the reactor. One such irradiation programme has been started in Dhruva reactor where the samples of seamless and seamwelded zircaloy calandria tubes have been loaded in specially designed tiers in a slug rod and the slug rod has been installed in the reactor. Dhruva being a high flux reactor, the irradiation growth behaviour of seamless and seamwelded zircaloy sample can be studied in a much shorter time. This paper describes the details of the zircaloy sample irradiation programme including the design of special zircaloy sample tiers, the zircaloy slug rod and a precision zircaloy irradiation growth measuring jig towards collecting a meaningful zircaloy irradiation growth data. (author). 4 figs

  7. Tube-in-tube reactor as a useful tool for homo- and heterogeneous olefin metathesis under continuous flow mode.

    Science.gov (United States)

    Skowerski, Krzysztof; Czarnocki, Stefan J; Knapkiewicz, Paweł

    2014-02-01

    A tube-in-tube reactor was successfully applied in homo- and heterogeneous olefin metathesis reactions under continuous flow mode. It was shown that the efficient removal of ethylene facilitated by connection of the reactor with a vacuum pump significantly improves the outcome of metathesis reactions. The beneficial aspects of this approach are most apparent in reactions performed at low concentration, such as macrocyclization reactions. The established system allows achievement of both improved yield and selectivity, and is ideal for industrial applications. PMID:24167003

  8. Computation and measurement of calandria tube sag in pressurized heavy water reactor

    International Nuclear Information System (INIS)

    Calandria tubes and liquid injection shutdown system nozzles in a pressurized heavy water reactor are to sag due to irradiation creep and growth during plant operation. When the sag of calandria tube becomes bigger, the calandria tube possibly comes in contact with liquid injection shutdown system tube crossing beneath the calandria tube. The contact subsequently may cause the damage on the calandria tube resulting in unpredicted outage of the plant. It is therefore necessary to check the gap between the two tubes in order to periodically confirm no contact by using a proper measure during the plant life. An ultrasonic gap measurement probe assembly which can be inserted into two viewing ports of the calandria was developed in Korea and utilized to measure the sag between both tubes in the reactor. It was found that the centerlines of calandria tubes and liquid injection shutdown system tubes can be precisely detected by ultrasonic wave. The gaps between two tubes were easily obtained from the relative distance of the measured centerline elevations of the tubes. Based on the irradiation creep equation and the measurement data, a computer program to calculate the sags was also developed. With the computer program, the sag at the end of plant life was predicted

  9. Non destructive examination of Reactor DR-3. Reactor wall, horisontal experimental tubes, up- and down comers

    International Nuclear Information System (INIS)

    The initial scope of work was to perform thickness/corrosion measurements of one up-comer and one down-comer, perform thickness/corrosion measurements in selected areas of the reactor wall and horizontal experimental pipes inside the reactor. Furthermore the lower circumferential weld and the connected longitudinal weld should be inspected to the extent possible, without major changes of the manipulator. Eddy current was performed in the same areas. Also hardness tests were carried out in four positions inside the reactor. Due to the outcome of the above examinations, additional metallurgical and dye penetrant examinations (PT) were carried out. The examination of the up- and down comers showed no sign of serious service induced defects. The eddy current testing did not reveal any inner surface breaking defects. The thickness/corrosion ultrasonic measurement showed only minor local indications with small or no reductions of original nominal wall thickness. The examination of the horizontal tubes showed no sign of serious service induced defects. The eddy current testing did not reveal any inner surface breaking defects. The thickness/corrosion ultrasonic measurement showed only minor local indications with small or no reductions of original nominal wall thickness. The hardness test showed increased hardness compared to calibration values. The examination of the reactor wall base material revealed several indications located in different depths in the plate. Some indications have been proved to be connected to the inner surface, while most indications appear to be either inclusions or areas corroded from the outside reactor wall. Minimum measured wall thickness is between 4.2 and 11.0 mm. There is, however, no evidence that these values are caused by corrosion at the outer reactor surface. The ET showed no signs of service induced cracks. The hardness test showed values close to calibration values. The extensive number of indications has resulted in additional

  10. Ultrasonic measurement of gap between calandria tube and liquid injection nozzle in CANDU reactor

    International Nuclear Information System (INIS)

    Calandria tube wrapping each pressure tube is one of the key structural components of CANDU reactor(Calandria) which is consisted of many pressure tubes containing nuclear fuel assemblies. As the Calandria tube(made of zirconium alloy) is sagging due to its thermal and irradiation creep during the plant operation, ti possibly contacts with liquid injection nozzle crossing beneath the Calandria tube, which subsequently results in difficulties on the safe operation. It is therefore necessary to check the gap for the confirmation of no contacts between the two tubes, Calandria tube and liquid injection tube, with a proper measure during the life of plant. In this study, an ultrasonic measurement method was selected among several methods investigated. The ultrasonic device being developed for the measurement of the gap was introduced and its preliminary performance test results were presented here. The gap between LIN and CT at site was measured using by this ultrasonic device at site

  11. Contrasting styles of Hurricane Irene washover sedimentation on three east coast barrier islands: Cape Lookout, North Carolina; Assateague Island, Virginia; and Fire Island, New York

    Science.gov (United States)

    Williams, H. F. L.

    2015-02-01

    Storm surge and wind-driven waves generated by Hurricane Irene, which made landfall on the U.S. east coast on August 27 2011, resulted in overwash of sandy barrier islands from North Carolina to New York State. Overwash has significant impacts on barrier island geomorphology: it represents a sediment pathway into island interiors, a component of island sediment budgets, and can cause considerable aggradation of backshore surfaces, important for potentially offsetting the effects of rising sea level. This study describes the morphology, texture and microfossil content of Hurricane Irene washover deposits at three contrasting barrier island sites: Cape Lookout, North Carolina, Assateague Island, Virginia and Fire Island, New York. At all three sites, run-up overwash occurred, wherein waves were sufficient to overtop parts of the beach system and transport sediment inland. However, at Fire Island, overwash was restricted by a higher elevational threshold to low spots in the beach system coinciding with pre-existing breaches in foredunes. The result was the formation of isolated, thinner, low-volume washover fans. At Assateague Island and Cape Lookout, lower elevational thresholds allowed waves to overtop longer continuous sections of beach systems, resulting in the formation of laterally-continuous, thicker, larger-volume washover terraces. Overall, the deposits lacked consistent trends in thickness and texture (such as thinning and fining inland, reflecting a progressive reduction in overwash competence). Thickness and texture of the deposits were both spatially variable and probably reflect infilling of low points on the former surface and the influence of beach and foredune sediment sources. All the washover deposits were essentially barren of foraminiferal microfossils, supporting the textural evidence that the adjacent beach and foredunes were the predominant sediment sources.

  12. High-speed roll-to-roll manufacturing of graphene using a concentric tube CVD reactor

    OpenAIRE

    Polsen, Erik S.; McNerny, Daniel Q.; B. Viswanath; Pattinson, Sebastian W.; A. John Hart

    2015-01-01

    We present the design of a concentric tube (CT) reactor for roll-to-roll chemical vapor deposition (CVD) on flexible substrates, and its application to continuous production of graphene on copper foil. In the CTCVD reactor, the thin foil substrate is helically wrapped around the inner tube, and translates through the gap between the concentric tubes. We use a bench-scale prototype machine to synthesize graphene on copper substrates at translation speeds varying from 25 mm/min to 500 mm/min, a...

  13. IN-SITU MONITORING OF PRODUCT STREAMS FROM A SPINNING TUBE-IN-TUBE REACTOR USING A METTLER-TOLEDO REACT-IR

    Science.gov (United States)

    A Mettler-Toledo ReactIR system has been used for in-line, real-time monitoring of the product stream from a spinning tube-in-tube reactor (STT®, Kreido Laboratories, Camarillo California). This combination of a process intensified continuous-flow reactor and an in-situ analytic...

  14. Clinch River Breeder Reactor Plant Steam Generator Few Tube Test model post-test examination

    International Nuclear Information System (INIS)

    The Steam Generator Few Tube Test (FTT) was part of an extensive testing program carried out in support of the Clinch River Breeder Reactor Plant (CRBRP) steam generator design. The testing of full-length seven-tube evaporator and three-tube superheater models of the CRBRP design was conducted to provide steady-state thermal/hydraulic performance data to full power per tube and to verify the absence of multi-year endurance problems. This paper describes the problems encountered with the mechanical features of the FTT model design which led to premature test termination, and the results of the post-test examination. Conditions of tube bowing and significant tube and tube support gouging was observed. An interpretation of the visual and metallurgical observations is also presented. The CRBRP steam generator has undergone design evaluations to resolve observed deficiences found in the FFTM

  15. Ultrasonic inspection of liquid-metal fast breeder reactor steam generator duplex tubing

    International Nuclear Information System (INIS)

    Two ultrasonic inspections of the Experimental Breeder Reactor II steam generator duplex tubing have been completed. Inspections performed on one evaporator in 1976 provided baseline data, and a subsequent inspection in 1978 revealed no change in tube condition. With the completion of the 1978 inspection, all available tubes in one evaporator have been inspected. The steam generator contains duplex tubes fabricated from 2 1/4 Cr-1 Mo ferritic steel. Access to the bore (water) side of the tubes was gained through the steam outlet piping. The inspection included a complete volumertic (100% of the tube material) examination, measurement of wall thickness, and evaluation of the condition of the braze bonding the two walls of the tube together. The test equipment was routinely calibrated against a standard containing artificial flaws. Artificial flaws as small as 1.6 mm long x 0.25 mm deep were readily detected

  16. Erythorbic acid promoted formation of CdS QDs in a tube-in-tube micro-channel reactor

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Yan; Tan, Jiawei; Wang, Jiexin; Chen, Jianfeng [State Key Laboratory of Organic–Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China); Research Center of the Ministry of Education for High Gravity Engineering and Technology, Beijing University of Chemical Technology, Beijing 100029 (China); Sun, Baochang, E-mail: sunbc@mail.buct.edu.cn [State Key Laboratory of Organic–Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China); Research Center of the Ministry of Education for High Gravity Engineering and Technology, Beijing University of Chemical Technology, Beijing 100029 (China); Shao, Lei, E-mail: shaol@mail.buct.edu.cn [State Key Laboratory of Organic–Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China); Research Center of the Ministry of Education for High Gravity Engineering and Technology, Beijing University of Chemical Technology, Beijing 100029 (China)

    2014-12-15

    Erythorbic acid assistant synthesis of CdS quantum dots (QDs) was conducted by homogeneous mixing of two continuous liquids in a high-throughput microporous tube-in-tube micro-channel reactor (MTMCR) at room temperature. The effects of the micropore size of the MTMCR, liquid flow rate, mixing time and reactant concentration on the size and size distribution of CdS QDs were investigated. It was found that the size and size distribution of CdS QDs could be tuned in the MTMCR. A combination of erythorbic acid promoted formation technique with the MTMCR may be a promising pathway for controllable mass production of QDs.

  17. Formerly utilized MED/AEC sites remedial action program: radiological survey of the former Virginia-Carolina Chemical Corporation Uranium Recovery Pilot Plant, Nichols, Florida. Final report

    International Nuclear Information System (INIS)

    The results of a radiological survey conducted at the site of a former uranium recovery pilot plant operated by the Virginia-Carolina Chemical Corporation is presented. All that remains of this operation is a concrete pad situated within the boundary of a phosphate products plant now operated by Conserv, Inc., at the Nichols, Florida site. The survey included measurements designed to characterize the residual radioactivity in the vicinity of this pilot plant and to compare the quantities with federal guidelines for the release of decontaminated property for unrestricted use. The results of this survey indicate that only small quantities of radioactivity exist above normal background levels for that area. Some soil contamination was found in the vicinity of a concrete pad on which the pilot plant stood. Much of this contamination was due to 226Ra and 238U. Some beta-gamma dose rates in excess of applicable guidelines were observed in this same area. External gamma-ray exposure rates at 1 m above the ground range from 20 to 100 μR/hr. None of the direct measurements of alpha contamination were above guideline levels

  18. Occurrence of Brown Marmorated Stink Bug (Hemiptera: Pentatomidae) on Wild Hosts in Nonmanaged Woodlands and Soybean Fields in North Carolina and Virginia.

    Science.gov (United States)

    Bakken, A J; Schoof, S C; Bickerton, M; Kamminga, K L; Jenrette, J C; Malone, S; Abney, M A; Herbert, D A; Reisig, D; Kuhar, T P; Walgenbach, J F

    2015-08-01

    Nonmanaged plants occurring along forest edges and in suburban settings were sampled for brown marmorated stink bug, Halyomorpha halys (Stål), in North Carolina (NC) and Virginia (VA) over the course of three growing seasons. Commercial soybeans (Glycine max), an attractive cultivated host, were also sampled in 2014 in NC and in VA from 2010-2014. Very few H. halys were found on nonmanaged plants or soybean fields in the coastal plain region of either state, but substantial populations were recorded in the piedmont and mountain regions. From 2011 to 2013, H. halys comprised from 51 to 97% of all stink bug species observed on nonmanaged plants in the piedmont and mountain regions. In VA, the distribution expanded from detection in 12 counties in 2010 to 53 counties in 2014, with economically damaging levels occurring in the piedmont region. During these studies, H. halys were observed to complete one and a partial second generation per year in western NC and southwestern VA, similar to that previously observed in regions farther north. Several plants were identified as preferred hosts, with tree of heaven, catalpa, yellowwood, paulownia, cherry, walnut, redbud, and grape having consistently high numbers of H. halys. Knowing that these plants are preferred by H. halys during certain stages of the insects' development will aid in the search for H. halys in new areas, as well as serve as one predictor of the likelihood of a certain area to attract and sustain large H. halys populations. PMID:26314046

  19. Clinch River Breeder Reactor Plant steam generator: FEW tube test model post test examination

    International Nuclear Information System (INIS)

    The Steam Generator Few Tube Test (FTT) is part of an extensive testing program being carried out in support of the Clinch River Breeder Reactor Plant (CRBRP) steam generator design. The testing of full-length seven-tube evaporator and three-tube superheater models of the CRBRP design was conducted to provide steady-state thermal/hydraulic performance data to full power per tube and to verify the absence of multi-year endurance problems. The problems encountered with the mechanical features of the FTT model design which led to premature test termination and the results of the post-test examination are described

  20. Simulation of Water Quality in the Tull Creek and West Neck Creek Watersheds, Currituck Sound Basin, North Carolina and Virginia

    Science.gov (United States)

    Garcia, Ana Maria

    2009-01-01

    A study of the Currituck Sound was initiated in 2005 to evaluate the water chemistry of the Sound and assess the effectiveness of management strategies. As part of this study, the Soil and Water Assessment Tool (SWAT) model was used to simulate current sediment and nutrient loadings for two distinct watersheds in the Currituck Sound basin and to determine the consequences of different water-quality management scenarios. The watersheds studied were (1) Tull Creek watershed, which has extensive row-crop cultivation and artificial drainage, and (2) West Neck Creek watershed, which drains urban areas in and around Virginia Beach, Virginia. The model simulated monthly streamflows with Nash-Sutcliffe model efficiency coefficients of 0.83 and 0.76 for Tull Creek and West Neck Creek, respectively. The daily sediment concentration coefficient of determination was 0.19 for Tull Creek and 0.36 for West Neck Creek. The coefficient of determination for total nitrogen was 0.26 for both watersheds and for dissolved phosphorus was 0.4 for Tull Creek and 0.03 for West Neck Creek. The model was used to estimate current (2006-2007) sediment and nutrient yields for the two watersheds. Total suspended-solids yield was 56 percent lower in the urban watershed than in the agricultural watershed. Total nitrogen export was 45 percent lower, and total phosphorus was 43 percent lower in the urban watershed than in the agricultural watershed. A management scenario with filter strips bordering the main channels was simulated for Tull Creek. The Soil and Water Assessment Tool model estimated a total suspended-solids yield reduction of 54 percent and total nitrogen and total phosphorus reductions of 21 percent and 29 percent, respectively, for the Tull Creek watershed.

  1. Surface treatment method for cladding tube of LMFBR type reactor

    Energy Technology Data Exchange (ETDEWEB)

    Suda, Yoshitaka; Matsumoto, Kunio; Ito, Kenji.

    1994-06-07

    Upon surface finishing by polishing, shot peening or blasting is applied on the outer surface of a cladding tube to eliminate orientation of residual stresses on the surface layer in order to eliminate residual stresses formed on the outer surface in the circumferential direction. This can suppress occurrence of cracks in oxide membranes formed on the outer surface to suppress development of corrosion on the outer surface irrespective of the ingredient composition of fuel cladding tube made of zircaloy. (T.M.).

  2. Tube sheet structural analysis of intermediate heat exchanger for fast breeder reactor 'Monju'

    International Nuclear Information System (INIS)

    The Prototype Fast Breeder Reactor 'Monju' is the first power generating fast breeder reactor in Japan. We have been designing the components of the plant for manufacturing. Among these is the intermediate heat exchanger (IHX) which exchanges heat between primary and secondary sodium loop. The tube sheet of IHX (shell to ligament junction) is a difficult area from the view point of structural strength design under elevated temperature. To validate the structural integrity of tube sheet we performed the series of inelastic analysis and tube sheet thermal shock test using test pieces and half scale model of actual design. The results of inelastic analyses showed there is little progressive deformation around shell to ligament structural discontinuous junction. Furthermore, thermal shock tests showed no increase of an accumulative deformation. By these analyses and experiments, structural reliability of tube sheet could be shown. (author)

  3. Safety evaluation report related to the renewal of the operating license for the research reactor at North Carolina State University

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-04-01

    This safety evaluation report (SER) summarizes the findings of a safety review conducted by the staff of the U.S. Nuclear Regulatory Commission (NRC), Office of Nuclear Reactor Regulation (NRR). The staff conducted this review in response to a timely application filed by North Carolina State University (the licensee or NCSU) for a 20-year renewal of Facility Operating License R-120 to continue to operate the NCSU PULSTAR research reactor. The facility is located in the Burlington Engineering Laboratory complex on the NCSU campus in Raleigh, North Carolina. In its safety review, the staff considered information submitted by the licensee (including past operating history recorded in the licensee`s annual reports to the NRC), as well as inspection reports prepared by NRC Region H personnel and first-hand observations. On the basis of this review, the staff concludes that NCSU can continue to operate the PULSTAR research reactor, in accordance with its application, without endangering the health and safety of the public. 16 refs., 31 figs., 7 tabs.

  4. Automatic Inspection of Nuclear-Reactor Tubes During Production and Processing, Using Eddy-Current Methods

    International Nuclear Information System (INIS)

    The possibilities of automatic and semi-automatic inspection of tubes using eddy-current methods are described. The paper deals in particular with modem processes, compared to the use of other non-destructive methods. The essence of the paper is that the methods discussed are ideal for objective automatic inspection. Not only are the known methods described, but certain new methods and their application to the detection of flaws in reactor tubes are discussed. (author)

  5. Thermal-hydraulic instabilities in pressure tube graphite - moderated boiling water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Tsiklauri, G.; Schmitt, B.

    1995-09-01

    Thermally induced two-phase instabilities in non-uniformly heated boiling channels in RBMK-1000 reactor have been analyzed using RELAP5/MOD3 code. The RELAP5 model of a RBMK-1000 reactor was developed to investigate low flow in a distribution group header (DGH) supplying 44 fuel pressure tubes. The model was evaluated against experimental data. The results of the calculations indicate that the period of oscillation for the high power tube varied from 3.1s to 2.6s, over the power range of 2.0 MW to 3.0 MW, respectively. The amplitude of the flow oscillation for the high powered tube varied from +100% to -150% of the tube average flow. Reverse flow did not occur in the lower power tubes. The amplitude of oscillation in the subcooled region at the inlet to the fuel region is higher than in the saturated region at the outlet. In the upper fuel region and outlet connectors the flow oscillations are dissipated. The threshold of flow instability for the high powered tubes of a RBMK reactor is compared to Japanese data and appears to be in good agreement.

  6. Organic Synthesis in a Spinning Tube-in-Tube (STT¢) Reactor

    Science.gov (United States)

    Continuous-flow reactors have been designed to minimize and potentially overcome the limitations of heat and mass transfer that are encountered in chemical reactors and further experienced upon scale up of a reaction. With process intensification, optimization of the reaction i...

  7. Calculation of fuel element temperature TRIGA 2000 reactor in sipping test tubes using CFD

    International Nuclear Information System (INIS)

    It has been calculated the fuel element temperature in the sipping test of Bandung TRIGA 2000 reactor. The calculation needs to be done to ascertain that the fuel element temperatures are below or at the limit of the allowable temperature fuel elements during reactor operation. ensuring that the implementation of the test by using this device, the temperature is still within safety limits. The calculation is done by making a model sipping test tubes containing a fuel element surrounded by 9 fuel elements. according to the position sipping test tubes in the reactor core. by using Gambit. Dimensional model adapted to the dimensions of the tube and the fuel element in the reactor core of Bandung TRIGA 2000 reactor. Sipping test Operation for each fuel element performed for 30 minutes at 300 kW power. Calculations were performed using CFD software and as input adjusted parameters of TRIGA 2000 reactor. Simulations carried out on the operation of the 30, 60, 90, 120, 150, 180 and 210 minutes. The calculation result shows that the temperature of the fuel in tubes sipping test of 236.06 °C, while the temperature of the wall is 87.58 °C. The maximum temperature in the fuel center of TRIGA 2000 reactor in normal operation is 650 °C. and the boiling is not allowed in the reactor. So it can be concluded that the operation of the sipping test device are is very safe because the fuel center temperature is below the temperature limits the allowable fuel under normal operating conditions as well as the fuel element wall temperature is below the boiling temperature of water. (author)

  8. Waterproofed Photomultiplier Tube Assemblies for the Daya Bay Reactor Neutrino Experiment

    CERN Document Server

    Chow, Ken; Edwards, Emily; Edwards, William; Ely, Ry; Hoff, Matthew; Lebanowski, Logan; Li, Bo; Li, Piyi; Lin, Shih-Kai; Liu, Dawei; Liu, Jinchang; Luk, Kam-Biu; Miao, Jiayuan; Napolitano, Jim; Ochoa-Ricoux, Juan Pedro; Peng, Jen-Chieh; Qi, Ming; Steiner, Herbert; Stoler, Paul; Stuart, Mary; Wang, Lingyu; Yang, Changgen; Zhong, Weili

    2015-01-01

    In the Daya Bay Reactor Neutrino Experiment 960 20-cm-diameter waterproof photomultiplier tubes are used to instrument three water pools as Cherenkov detectors for detecting cosmic-ray muons. Of these 960 photomultiplier tubes, 341 are recycled from the MACRO experiment. A systematic program was undertaken to refurbish them as waterproof assemblies. In the context of passing the water leakage check, a success rate better than 97% was achieved. Details of the design, fabrication, testing, operation, and performance of these waterproofed photomultiplier-tube assemblies are presented.

  9. Pressure tube creep impact on the physics parameters for CANDU-6 reactors

    Energy Technology Data Exchange (ETDEWEB)

    Kim, W. Y.; Min, B. J. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of); Kam, S. C.; Kim, M. E. [Korea Institute of Nuclear Safety, Taejon (Korea, Republic of)

    2004-07-01

    The lattice cell calculations are performed to assess the sensitivity of the reactor physics parameters to pressure tube creep resulting from radiation aging. The physics parameters of the lattice cell are calculated by using WIMSD-5B code, WIMS- AECL code, and MCNP code. The reference model(normal state) and two perturbed models accounting for the pressure tube creep are developed on the basis of CANDU-6 lattice cell. The 2.5% and 5% values of pressure tube diameter creep are considered. Also, The effects of the analyzed lattice parameters which are the coolant void reactivity, the fuel fission density and the atom density of Pu isotopes on the lattice.

  10. Waterproofed photomultiplier tube assemblies for the Daya Bay reactor neutrino experiment

    International Nuclear Information System (INIS)

    In the Daya Bay Reactor Neutrino Experiment 960 20-cm-diameter waterproof photomultiplier tubes are used to instrument three water pools as Cherenkov detectors for detecting cosmic-ray muons. Of these 960 photomultiplier tubes, 341 are recycled from the MACRO experiment. A systematic program was undertaken to refurbish them as waterproof assemblies. In the context of passing the water leakage check, a success rate better than 97% was achieved. Details of the design, fabrication, testing, operation, and performance of these waterproofed photomultiplier-tube assemblies are presented

  11. Waterproofed photomultiplier tube assemblies for the Daya Bay reactor neutrino experiment

    Energy Technology Data Exchange (ETDEWEB)

    Chow, Ken [Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Cummings, John [Department of Physics and Astronomy, Siena College, Loudonville, NY 12211 (United States); Edwards, Emily [Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Edwards, William [Physics Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Ely, Ry [Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Hoff, Matthew [Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Lebanowski, Logan [Department of Physics, University of Houston, Houston, TX 77204-5005 (United States); Li, Bo; Li, Piyi [School of Physics, Shandong University, Jinan 250100 (China); Lin, Shih-Kai [Department of Physics, University of Houston, Houston, TX 77204-5005 (United States); Liu, Dawei [Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Liu, Jinchang [Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Beijing 100049 (China); Luk, Kam-Biu, E-mail: k_luk@berkeley.edu [Department of Physics, University of California, Berkeley, CA 94720 (United States); Physics Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Miao, Jiayuan [School of Physics, Shandong University, Jinan 250100 (China); Napolitano, Jim [Department of Physics, Temple University, Philadelphia, PA 19122 (United States); Ochoa-Ricoux, Juan Pedro [Physics Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Peng, Jen-Chieh [Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Qi, Ming [Department of Physics, Nanjing University, Nanjing 210000 (China); and others

    2015-09-11

    In the Daya Bay Reactor Neutrino Experiment 960 20-cm-diameter waterproof photomultiplier tubes are used to instrument three water pools as Cherenkov detectors for detecting cosmic-ray muons. Of these 960 photomultiplier tubes, 341 are recycled from the MACRO experiment. A systematic program was undertaken to refurbish them as waterproof assemblies. In the context of passing the water leakage check, a success rate better than 97% was achieved. Details of the design, fabrication, testing, operation, and performance of these waterproofed photomultiplier-tube assemblies are presented.

  12. Polyamide-6 Polymerization in the VK Tube Reactor with Baffle Structure

    Institute of Scientific and Technical Information of China (English)

    WANG Xia-qin; TANG Zhi-lian

    2002-01-01

    The melt flow mechanism of polyamide-6 (PA6) was simulated with the mathematical flow model and tested by Particle Image Velotrimitry (PIV). The complete mathematical model for PA6 polymerization while flowing through the VK tube reactor was established according to PA6 hydrolytic polymerization kinetics. The characteristic data such as residence time, caprolactam conversion and the degree of polymerization (D. P.), at every stage of polymerization reaction and at every point of the VK tube were presented for the melt flowing through ten alternate conical baffles in VK tube.

  13. Effect of processing on properties of thin walled calandria tubes for pressurised heavy water reactor

    Science.gov (United States)

    Kapoor, K.; Padmaprabu, C.; Ramana Rao, S. V.; Sanyal, T.; Kashyap, B. P.

    2003-02-01

    Thin walled calandria tubes for pressurised heavy water reactors are manufactured either by seam welding of Zircaloy-4 sheets or by seamless route. In the present study, the effect of processing on the critical properties such as texture, microstructure, hydriding behaviour and residual stress for both the routes as well as the mechanical anisotropy developed due to seam welding are investigated. The properties of the seam welded tube in the fusion and adjoining region are markedly different from the base material and from the seamless tube. Residual stress measurements indicate that heat affected zone (HAZ) of seam welded tubes have longitudinal tensile residual stress and the seamless tubes have uniform compressive stress along the circumference. The phase transition in the presence of residual stresses due to thermal gradient is found to modify the texture in the HAZ. The hydride orientation and mechanical anisotropy in these regions are found to be dependent on the texture of the material.

  14. Effect of processing on properties of thin walled calandria tubes for pressurised heavy water reactor

    International Nuclear Information System (INIS)

    Thin walled calandria tubes for pressurised heavy water reactors are manufactured either by seam welding of Zircaloy-4 sheets or by seamless route. In the present study, the effect of processing on the critical properties such as texture, microstructure, hydriding behaviour and residual stress for both the routes as well as the mechanical anisotropy developed due to seam welding are investigated. The properties of the seam welded tube in the fusion and adjoining region are markedly different from the base material and from the seamless tube. Residual stress measurements indicate that heat affected zone (HAZ) of seam welded tubes have longitudinal tensile residual stress and the seamless tubes have uniform compressive stress along the circumference. The phase transition in the presence of residual stresses due to thermal gradient is found to modify the texture in the HAZ. The hydride orientation and mechanical anisotropy in these regions are found to be dependent on the texture of the material

  15. Thickness measurement of A-1 reactor caisson tube walls

    International Nuclear Information System (INIS)

    The equipment is described of measuring the thickness of caisson pipes built in the Bohunice A-1 reactor. The pulse-type ultrasonic thickness gauge is based on the reflection method using the double probe. The measurement accuracy is 0.1 mm. (J.B.)

  16. A probabilistic method for leak-before-break analysis of CANDU reactor pressure tubes

    Energy Technology Data Exchange (ETDEWEB)

    Puls, M.P.; Wilkins, B.J.S.; Rigby, G.L. [Whiteshell Labs., Pinawa (Canada)] [and others

    1997-04-01

    A probabilistic code for the prediction of the cumulative probability of pressure tube ruptures in CANDU type reactors is described. Ruptures are assumed to result from the axial growth by delayed hydride cracking. The BLOOM code models the major phenomena that affect crack length and critical crack length during the reactor sequence of events following the first indications of leakage. BLOOM can be used to develop unit-specific estimates of the actual probability of pressure rupture in operating CANDU reactors and supplement the existing leak before break analysis.

  17. A probabilistic method for leak-before-break analysis of CANDU reactor pressure tubes

    International Nuclear Information System (INIS)

    A probabilistic code for the prediction of the cumulative probability of pressure tube ruptures in CANDU type reactors is described. Ruptures are assumed to result from the axial growth by delayed hydride cracking. The BLOOM code models the major phenomena that affect crack length and critical crack length during the reactor sequence of events following the first indications of leakage. BLOOM can be used to develop unit-specific estimates of the actual probability of pressure rupture in operating CANDU reactors and supplement the existing leak before break analysis

  18. Evaluation and analysis of critical crack length of irradiated pressure tubes from Indian pressurised heavy water reactors

    International Nuclear Information System (INIS)

    Results of fracture toughness KJic were computed from transverse tensile properties of reactor operated pressure tubes, and axial critical crack length values derived from KJic are presented. Similarly fracture resistance curves derived from tensile properties of reactor operated pressure tubes and axial critical crack length values computed therefrom are presented. Under normal operating condition of the reactors the pressure tubes experience temperatures ranging from 250 deg C to 300 deg C. In occurrence of contact between pressure tube and calandria tube, the contact region may not be expected to have a mean through wall temperature below 200 deg C. The axial critical crack length of three reactor operated pressure tubes, therefore were evaluated in the temperature range 200 deg C to 300 deg C. The significance of the magnitude of the evaluated critical crack length is discussed. (author)

  19. Fracture analysis of axially cracked pressure tube of pressurized heavy water reactor

    Energy Technology Data Exchange (ETDEWEB)

    Krishnan, S.; Bhasin, V.; Mahajan, S.C. [Bhabha Atomic Research Centre, Bombay (India)] [and others

    1997-04-01

    Three Dimensional (313) finite element elastic plastic fracture analysis was done for through wall axially cracked thin pressure tubes of 220 MWe Indian Pressurized Heavy Water Reactor. The analysis was done for Zr-2 and Zr-2.5Nb pressure tubes operating at 300{degrees}C and subjected to 9.5 Mpa internal pressure. Critical crack length was determined based on tearing instability concept. The analysis included the effect of crack face pressure due to the leaking fluid from tube. This effect was found to be significant for pressure tubes. The available formulae for calculating J (for axially cracked tubes) do not take into account the effect of crack face pressure. 3D finite element analysis also gives insight into variation of J across the thickness of pressure tube. It was observed that J is highest at the mid-surface of tube. The results have been presented in the form of across the thickness average J value and a peak factor on J. Peak factor on J is ratio of J at mid surface to average J value. Crack opening area for different cracked lengths was calculated from finite element results. The fracture assessment of pressure tubes was also done using Central Electricity Generating Board R-6 method. Ductile tearing was considered.

  20. Fracture analysis of axially cracked pressure tube of pressurized heavy water reactor

    International Nuclear Information System (INIS)

    Three Dimensional (313) finite element elastic plastic fracture analysis was done for through wall axially cracked thin pressure tubes of 220 MWe Indian Pressurized Heavy Water Reactor. The analysis was done for Zr-2 and Zr-2.5Nb pressure tubes operating at 300 degrees C and subjected to 9.5 Mpa internal pressure. Critical crack length was determined based on tearing instability concept. The analysis included the effect of crack face pressure due to the leaking fluid from tube. This effect was found to be significant for pressure tubes. The available formulae for calculating J (for axially cracked tubes) do not take into account the effect of crack face pressure. 3D finite element analysis also gives insight into variation of J across the thickness of pressure tube. It was observed that J is highest at the mid-surface of tube. The results have been presented in the form of across the thickness average J value and a peak factor on J. Peak factor on J is ratio of J at mid surface to average J value. Crack opening area for different cracked lengths was calculated from finite element results. The fracture assessment of pressure tubes was also done using Central Electricity Generating Board R-6 method. Ductile tearing was considered

  1. Underwater plasma arc cutting of in-reactor tube of In-Pile Creep Test Facility

    International Nuclear Information System (INIS)

    The in-reactor tube of the In-Pile Creep Facility had been irradiated periodically for over 6 years in the Japan Materials Testing Reactor (JMTR) up to the end of 1978 under an operating condition of high temperature and high pressure identical to that of the Prototype Advanced Thermal Reactor, FUGEN, to gain the basic data for estimating the amount of creep which would occur in the pressure tubes of FUGEN. Following the removal of the in-reactor tube out of the JMTR, the test sections in the tube which were to be subjected to post irradiation examination were cut out. Underwater plasma arc cutting was employed to prevent the spread of contamination to the work area, to confine the heat affected zone in the test pieces to a minimum and to simplify disposal of the unneeded portions of the pressure tube. Setup of the cutting machine, cutting operations, radiological conditions during cutting of the highly radioactive portion of the tube and disassembly of the cutting equipment are described. In addition a brief description of the underwater plasma arc cutting machine is presented. The hot-cutting operations were done remotely to control personal exposure. The containment envelope prevented the spread of contamination to the environment and radioactive particles deposited on the cutting machine were removed without any difficulties. External exposure received by cutting personnel was small. Internal radionuclide deposit examinations were conducted, determining no crew member inhaled radioactive substances. Contamination spreads to the work area were minimal and release of radionuclide was well controlled. (author)

  2. Ultrasonic systems for examining butt-fillet tube to tube plate welds in the evaporators of the Dounreay Prototype Fast Reactor

    International Nuclear Information System (INIS)

    Ultrasonic techniques and comprehensive data recording systems are described which have been developed for the in-service inspection of the tube to tube plate welds in the evaporator steam generator units of the Prototype Fast Reactor at Dounreay, Caithness, Scotland

  3. Measurement of internal diameter of pressure tubes in pressurized heavy water reactors using ultrasonics

    International Nuclear Information System (INIS)

    The Pressure Tube in Pressurized Heavy Water Reactors (PHWRs) undergoes dimensional changes due to the effects of creep and growth as it is subjected to high pressure and temperature, which causes Pressure Tubes to permanently increase in length and diameter and to sag because of weight of fuel and coolant (heavy water) contained in it. These dimensional changes are due to prolonged stresses under high temperature and radiation. Pressure Tube stresses are evaluated for both beginning and end of life for accounting the Pressure Tube dimensional changes that occur during its design life. At the beginning of life, the initial wall thickness and un-irradiated material properties are applied. At the end of life, Pressure Tube diameter and length increases, while wall thickness decreases. Material strength also increases during that period. The increase in Pressure Tube diameter results in squeezing of garter spring spacer between the pressure and calandria Tubes. It also causes unacceptable heat removal from the fuel due to an increased amount of primary coolant that bypasses the fuel bundles. This reduces the critical channel power at constant flow. Hence the periodic monitoring of pressure Tube diameter is important for these reasons. This is also required as per the applicable codes and standards for In-Service Inspection of PHWRs. Mechanical measurement from ID of the Tube during periodic monitoring is not practically feasible due to high radiation and inaccessibility. This necessitates the development of NDT technique using Ultrasonics for periodic in-situ measurement of ID of pressure Tubes with a BARC made remotely operated drive system called BARCIS (BARC Channel Inspection system). The development of Ultrasonic based ID measurement techniques and their actual applications in PHWRs Pressure tubes are being discussed in this paper. (author)

  4. Testing of a 7-tube palladium membrane reactor for potential use in TEP

    International Nuclear Information System (INIS)

    A Palladium Membrane Reactor (PMR) consists of a palladium/silver membrane permeator filled with catalyst (catalyst may be inside or outside the membrane tubes). The PMR is designed to recover tritium from the methane, water, and other impurities present in fusion reactor effluent. A key feature of a PMR is that the total hydrogen isotope content of a stream is significantly reduced as (1) methane-steam reforming and/or water-gas shift reactions proceed on the catalyst bed and (2) hydrogen isotopes are removed via permeation through the membrane. With a PMR design matched to processing requirements, nearly complete hydrogen isotope removals can be achieved. A 3-tube PMR study was recently completed. From the results presented in this study, it was possible to conclude that a PMR is appropriate for TEP, perforated metal tube protectors function well, platinum on aluminum (PtA) catalyst performs the best, conditioning with air is probably required to properly condition the Pd/Ag tubes, and that CO/CO2 ratios maybe an indicator of coking. The 3-tube PMR had a permeator membrane area of 0.0247 m2 and a catalyst volume to membrane area ratio of 4.63 cc/cm2 (with the catalyst on the outside of the membrane tubes and the catalyst only covering the membrane tube length). A PMR for TEP will require a larger membrane area (perhaps 0.35 m2). With this in mind, an intermediate sized PMR was constructed. This PMR has 7 permeator tubes and a total membrane area of 0.0851 m2. The catalyst volume to membrane area ratio for the 7-tube PMR was 5.18 cc/cm2. The total membrane area of the 7-tube PMR (0.0851 m2) is 3.45 times larger than total membrane area of the 3-tube PMR (0.0247 m2). The following objectives were identified for the 7-tube PMR tests: (1) Refine test measurements, especially humidity and flow; (2) Refine maintenance procedures for Pd/Ag tube conditioning; (3) Evaluate baseline PMR operating conditions; (4) Determine PMR scaling method; (5) Evaluate PMR with realistic

  5. SOLAR REFRIGERATING UNIT WITH AN ADSORPTION REACTOR AND EVACUATED TUBE COLLECTORS

    Directory of Open Access Journals (Sweden)

    M.E. Vieira

    1997-09-01

    Full Text Available This work presents the principles of operation of a solar refrigerator with the following basic components: a reactor, a set of evacuated tube solar collectors, a condenser, a heat exchanger, and an evaporator. During the heating phase, solar radiation is collected and transferred to the reactor for desorption by a vapor thermal siphon loop. During the cooling phase, heat from the reactor is released to the ambient by a second water vapor loop. Ambient data collected daily during a period of 18 years were divided into hourly values and used to simulate the temperatures of the reactor, which uses salt impregnated with graphite and ammonia, during the adsorption / desorption processes. The results show that the refrigerator operates well in Fortaleza and that better results are expected for the countryside of the state of Ceara. It is concluded that only a high efficiency collector set can be used in the system

  6. Solar refrigerating unit with an adsorption reactor and evacuated tube collectors

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, M.E.; Moreira, H.B.C. [Ceara Univ., Fortaleza, CE (Brazil). Dept. de Engenharia Quimica. Lab. de Energia Solar Aplicada

    1997-09-01

    This work presents the principles of operation of a solar refrigerator with the following basic components: a reactor, a set of evacuated tube solar collectors, a condenser, a heat exchanger, and an evaporator. During the heating phase, solar radiation is collected and transferred to the reactor for desorption by a vapor thermal siphon loop. During the cooling phase, heat from the reactor is released to the ambient by a second water vapor loop. Ambient data collected daily during a period of 18 years were divided into hourly values and used to simulate the temperatures of the reactors, which uses salt impregnated with graphite and ammonia, during the adsorption / desorption processes. The results show that the refrigerator operates well in Fortaleza and that better results are expected from the countryside of the state of Ceara. It is concluded that only a high efficiency collector set can be used in the system. (author) 10 refs., 4 figs.; e-mail: eugenia at ufc.br

  7. Design of an ion transport membrane reactor for application in fire tube boilers

    International Nuclear Information System (INIS)

    A design of an ITM (ion transport membranes) reactor is introduced in a two-pass fire tube boiler furnace to produce steam for power generation toward the ZEPP (zero emission power plant) applications. Oxygen separation, combustion and heat exchange occur in the first pass containing the multiple-units ITM reactor. In the second pass, heat exchange between the combustion gases and the surrounding water at 485 K (Psat = 20 bar) occurs mainly by convection. The emphasis is to extract sufficient oxygen for combustion while maintaining the reactor size as compact as possible. Based on a required power in the range of 5–8 MWe, the fuel and gases flow rates were calculated. Accordingly, the channel width was determined to maximize oxygen permeation flux and keep the viscous pressure drop within a safe range for fixed reactor length of 1.8 m. Three-dimensional simulations were conducted for both counter and co-current flow configurations. Counter-current flow configuration proved its suitability in fire tube boilers for steam generation over the co-current flow configuration. The resultant reactor consists of 12,500 ITM units with a height of 5 m, membrane surface area of 2700 m2 and a total volume of 45.45 m3. - Highlights: • A novel two-path fire tube boiler design is presented utilizing ITMs (ion transport membranes). • A new multi-unit ITM reactor design for boiler furnace substitution is presented. • Flow rates have been optimized for maximum oxygen flux and power generation. • Counter-current flow configuration is much more efficient than co-current flow. • Total number of ITM units was calculated to produce power of 5:8 MWe

  8. GERDA test facility for pressurized water reactors with straight tube steam generators

    International Nuclear Information System (INIS)

    A number of large-scale experimental facilities have been constructed and operate in order to experiment on the thermodynamic and thermohydraulic behaviour of nuclear facilities in case of LOCA. Most of them were designed for ''large leak'' accidents, but as ''small leak'' accidents became the focus of interest, such experiments were also carried out. Experiments carried out with this arrangement for PWR-type reactors with straight-tube steam generators are only partially evaluable. BBR and B and W therefore cooperated in the construction of the test facility GERDA, designed for testing reactors of BBR design. It supplied relevant experimental results for the nuclear power plant at Muelheim-Kaerlich. (orig.)

  9. Beam tube experiments and correlated research projects at the TRIGA reactor Vienna

    International Nuclear Information System (INIS)

    The four beam tubes and the thermal column at the TRIGA reactor Vienna were used intensively during the reporting period. Three of the beam tubes are mainly used for neutron spectroscopy such as small angle scattering, neutron interferometry and polarized neutrons where now investigations of magnetic structures in pulsed high magnetic fields (25 T) synchronized with the pulsed mode of the reactor have been started. The thermalizing column will be modified from the present cold neutron source to a comfortable neutron radiography installation which allows investigations of objects of a size up to 30 cm diameters. The thermal column is also used for neutron radiography and as a strong gamma source to investigate gamma irradiation effects on various materials such as glass fiber cables. In view of flexible utilization of the thermal column a movable shielding construction has been designed which is simple rolled away on the rails of the thermal column doors when access to the thermal column in necessary. (orig.)

  10. Study of the U3O8-Al thermite reaction and strength of reactor fuel tubes

    International Nuclear Information System (INIS)

    Heating tests using 53 wt % U3O8-Al pellets show that an exothermic reaction occurs between 875 and 10000C and takes 10 to 20 seconds to reach maximum temperature. The maximum temperature is a function of particle size of the U3O8 with large particles exhibiting lower peak temperatures. The calculated energy release was 123 cal/g of U3O8-aluminum fuel. Tests using aluminum clad outer fuel tube sections gave lower peak temperatures than for pellets. No violent reactions occurred. The results are reasonably consistent with recent reported data indicating that the exothermic U3O8-Al reaction is not an important energy source. The compressive and tensile strengths of U3O8 tubes above 6600C are low. In compression, sections with 2 psi average axial stress failed at 9170C, while sections with 7 psi failed at 6690C. Tubes with U-Al alloy cores failed at about 6700C with no applied load. The stresses in fuel tubes during a reactor transient may range up to several hundred psi and are less than 7 psi only in the upper part of the fuel tube

  11. Advanced eddy current technique for measurement of annular gap between pressure tube and calandria tube in Indian Pressurized Heavy Water Reactors (PHWRs)

    International Nuclear Information System (INIS)

    In Indian Pressurised Heavy Water Reactors (PHWRs), the PT (pressure tube) is designed to be nominally concentric with the encircling CT (calandria tube). Due to various factors PT becomes eccentric with respect to CT over the life of reactor. If this becomes excessive, hot PT will come in contact with cold CT. Such a cold spot could act as potential location for initiating blister formation and premature failure of PT. Hence it is important to periodically measure annular gap between PT and CT. An advanced eddy current technique has been successfully developed and incorporated in BARCIS (BARC Channel Inspection System) for measurement of PT-CT gap. (author). 4 refs., 3 figs

  12. Uses of Plutonium Fuel in Pressure-Tube-Type, Heavy-Water-Moderated Thermal Reactors

    International Nuclear Information System (INIS)

    In 1962, a feasibility study was begun in the JAERI on the uses of various nuclear fuels for pressure-tube-type, heavy-water-moderated thermal reactors. This study began with analysis of the use of uranium in heavy-water-moderated thermal reactors such as the CANDU-PHW, CANDU-BLW, SGHW, EL-4, and Ref. 15, D and E lattices, which is designed in the JAERI, from the standpoint of the core design. Then, the ways of using plutonium fuel in the same types were investigated using WATCHTOWER, FLARE and VENUS codes, including: (1) direct substitution of the plutonium from light-water reactors or Magnox reactors, (2) recycle use of the plutonium from heavy-water-moderated reactors, (3) plutonium self-sustaining cycle, and (4) plutonium phoenix fuel. The following conclusions are reported: (1) In the direct substitution of plutonium, somewhat depleted plutonium is more suitable for core design than the plutonium from Magnox reactors or light-water reactors, because the increase in the initial reactivity due to large plutonium absorption cross-section must be prevented. (2) In the plutonium self-sustaining cycle, the fuel burn-up of about 15 000 ∼20000 MWd/t would be expected from natural uranium, and the positive void reactivity which always occurs in the uraniumloaded SGHW or CANDU-BLW lattices is greatly reduced, the latter property giving some margin to bum-out heat flux. (3) It may be concluded from the fuel cycle analysis that the plutonium self-sustaining cycle is equivalent to using slightly enriched uranium (about 1.0 at.%). It may be concluded that the use of plutonium in heavy-water-moderated reactors is technologically feasible and economically advantageous. (author)

  13. Do existing research reactors teach us all about beam tube optimization?

    International Nuclear Information System (INIS)

    The contribution makes the attempt to analyse the data base available in the literature and in Siemens' own projects and to find out potential systematics from the existing research reactor with beam tubes, separated into reactors with different reflectors and distinguished for tangential and radial tubes and cold neutron sources, resp. Some generic calculations serve as gauging data. The contribution is not meant as critics on any design.The results might serve supporting designers and operators when evaluating the pros and cons of existing or planned design in terms of the optimum beam tubes. Existing lacks of systematics are evaluated in view of suitable explanations and constraints, which do not allow optimisation. Examples pf such constraints are the different material layers between fuel zone and reflector zone which have various reasons. The limited data in the literature plus the numerous lacks of precision of the representation of those data should be an incentive to improve the performed analysis by collecting more exact data and re-doing the evaluation before answering the title-question really. (author)

  14. Manipulator for inspection and possible repair of the tubes of heat exchangers, especially of steam generators for nuclear reactors

    International Nuclear Information System (INIS)

    Manipulator for inspecting and, if required, repairing the tubes of heat exchangers, especially for nuclear reactors, comprises a tube bundle set in a tube sheet leading into a steam generator chamber and a manipulator is brought in through a lead-in nozzle. An inspection arm can be inserted and removed through the lead-in nozzle and the nozzle can be closed off tight by a blind flange. The inspection arm comprises a guide tube supported in the leadin nozzle, and a swivel arm supported at the end of the guide tube so that it can rotate in a plane parallel to the tube sheet. The swivel arm carries at its outer end an extendable and retractable mouthpiece carrier with a mouthpiece which can be aligned onto the tube openings. The outer contour of the swivel arm and the mouthpiece carrier in the stretched-out transport position is not greater than the inner contour of the lead-in nozzle

  15. Preliminary evaluation of steam generator tube rupture (SGTR) accident in lead cooled reactor

    International Nuclear Information System (INIS)

    In this paper some contributions are provided to the development of a European Lead-cooled System, known as the ELSY project (within EU-6 Framework Project); that will constitute a possible reference system for a large lead-cooled reactor of GEN IV. Steam generator (SG) tubing of this system type might be subject to a variety of degradation processes, such as cracking, wall thinning and potential leakage or rupture, eventually leading to the failure of one or more SG tubes that constitute a steam generator tube rupture (SGTR) accident with possible consequences for the safety of the primary systems. It is therefore of interest for the designer to know how the SG itself, as well as the vessel and internals structures, behave under impulsive loading conditions (in form of a rapid and strong increase of pressure) that can arise as consequences of the interaction between the primary and secondary coolants (lead-water interaction). The analysed initiator event, as already mentioned, is a large break (up to a double ended guillotine break) of one (or more) SG cooling tubes that may become severe enough to determine dangerous effects on the interested structures. In order to better simulate and perform the mentioned postulated SGTR accident sequence analyses, an appropriate numerical model with the available computing resources (FEM codes) was set up at the DIMNP of Pisa University. That model was used to evaluate the effects of the propagation of the blast pressure waves inside the SG structures, taking into account also the sloshing phenomenon that could be induced by the lead primary coolant motions. Therefore the SGTR effects study may be considered as a transient and non linear problem the solution of which provides the 'time histories' of hydrodynamic pressures and stresses on the reactor pressure vessel and internals walls. (author)

  16. Advanced nondestructive examination of the reactor vessel head penetration tube welds

    International Nuclear Information System (INIS)

    Beside a referent code examination requirements, appearance of the service induced flaws on the Reactor Vessel Head (RVH) penetration tube welds forced development of remotely operated examination tools and techniques. Several systems were developed for examination of RVH PWR type while only one system for examination of VVER - 440 type RVH has been developed by Inetec. In this article the most advanced RVH VVER - 440 type examination techniques such as ultrasonic, eddy current and visual testing techniques as well as remotely operated tool are described. (author)

  17. Investigation of hydrodynamic parameters in a draft tube reactor using radioisotope based techniques and conventional method

    International Nuclear Information System (INIS)

    In this study, various techniques were attempted to investigate flow dynamics in the enclosed reactor and the results from the techniques were compared. Radioactive particle tracking (RPT) and industrial single photon emission computed tomography (SPECT) were carried out and the circulation times from them showed a deviation of 17.5%. The circulation time of the RPT was longer than that of SPECT, and it is speculated that the physical dimension of the/ fabricated radioactive particle creates the discrepancy. Particle image velocimetry (PIV) measurements and computational fluid dynamic (CFD) simulations were conducted. The velocity patterns from them were similar to each other in the entire reactor region except near the propeller installed at the bottom of the reactor. - Highlights: • Radioisotope based techniques were used to investigate flow dynamics in a draft tube reactor. • The circulation time measured using RPT is longer than the circulation time measured by the SPECT. • Radioactive particle tracking technique is expected to be helpful to investigate flow dynamics

  18. Oxidation and deuterium uptake of Zr-2.5Nb pressure tubes in CANDU-PHW reactors

    International Nuclear Information System (INIS)

    Oxidation and deuterium uptake in Zr-2.5Nb pressure tubes are being monitored by destructive examination of tubes removed from commercial Canadian deuterium uranium pressurized heavy-water (CANDU-PHW) stations and by analyses of microsamples, obtained in-situ, from the inside surface of tubes in the reactor. Unlike Zircaloy-2, there is no evidence for any acceleration in the oxidation rate for exposures up to about 4500 effective full power days. Changes towards a more equilibrium microstructure during irradiation may be partly responsible for maintaining the low oxidation rate, since thermal aging treatments, producing similar microstructural changes in initially cold worked tubes, were found to improve out-reactor corrosion resistance in 589 K water. With one exception, the deuterium uptake in Zr-2.5Nb tubes has been remarkably low and no greater than 3-mg/kg deuterium per year (0.39 mg/dm2 hydrogen per year) . The exception is the most recent surveillance tube removed from Pickering (NGS) Unit 3, which had a deuterium content near the outlet end about five times higher than that seen in the previous tube examined. Current investigations suggest that most of the uptake in that tube may have come from the gas annulus surrounding the tube where deuterium exists as an impurity, and oxidation has been insufficient to maintain a protective oxide film. Results from weight gain measurements, chemical analyses, metallography, scanning electron microscopy, and transmission electron microscopy of irradiated pressure tubes and of small coupons exposed out reactor are presented and discussed with respect to the observed corrosion and hydriding behavior of CANDU-PHW pressure tubes. (author)

  19. A plan to preserve the environmental integrity of the False Cape Outer Banks area : Virginia and North Carolina [Back Bay National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is a plan meant to gain control of certain lands in the False Cape area of Virginia. Various methods of acquiring the land and their pros and cons are...

  20. Study of the U3O8-Al thermite reaction and strength of reactor fuel tubes

    International Nuclear Information System (INIS)

    Research and test reactors are presently operated with aluminum-clad fuel elements containing highly enriched uranium-aluminum alloy cores. To lower the enrichment and still maintain reactivity, the uranium content of the fuel element will need to be higher than currently achievable with alloy fuels. This will necessitate conversion to other forms such as U3O8-aluminum cermets. Above the aluminum melting point, U3O8 and aluminum undergo an exothermic thermite reaction and cermet fuel cores tend to keep their original shape. Both factors could affect the course and consequences of a reactor accident, and prompted an investigation of the behavior of cermet fuels at elevated temperatures. Tests were carried out using pellets and extruded tube-sections with 53 wt % U3O8 in aluminum. This content corresponds to a theoretical uranium density of 1.9 g/cc. Results indicate that the thermite reaction occurs at about 9000C in air without a violent effect. The heat of reaction was approximately 123 cal/g of U3O8-aluminum fuel. Tensile and compressive strength of the fuel tube section is low above 6600C. In tension, sections failed at about the aluminum melting point. In compression with 2-psi average axial stress, failure occurred at 9170C, while 7 psi average axial stress produced failure at 6690C

  1. The Economical Application of Non-Destructive Testing to Reactor Components, Especially Jacket Tubing

    International Nuclear Information System (INIS)

    The ideal reactor design, in addition to its other desirable characteristics, would require no non-destructive testing. This ideal, like others, will probably never be attained. In any reactor design where cost is an important factor, the question of whether components can be economically tested should be proposed at the same time that questions of fabricability are being considered. Some development of these points as well as a discussion of the importance of non- destructive tests in specification writing is included in this section. Responsibility also rests on the fabricator to use the help provided by non-destructive testing in maintaining quality in the product through various stages in the fabrication process, and to use the test results to indicate those steps in the process most likely to introduce defects in the component. Often it develops that non-destructive testing in earlier stages of component fabrication cannot be replaced economically, if at all, by inspection of the component in finished or semi-finished form. Examples are cited to illustrate this point, particularly with regard to tubing for fuel jacket and heat-exchanger applications. The application of various non-destructive tests during a tube-fabrication development programme is described in some detail. The fabrication and inspection costs for some tubing used for jacket applications by Argonne National Laboratory are compared. Although component inspection in finished form can be minimized by these procedures, it cannot in all cases be eliminated entirely. The economical testing of plates and tubes, especially the latter, is discussed in detail. The discussion is centred around components of stainless steel, Zircaloy, and certain refractory metal alloys. It is shown through various examples that although the use of radiography and penetrants may be useful or even essential steps in the testing, critical inspection of thin-wall tubing must usually be made by either an ultrasonic or an

  2. Shot navigation for North Carolina barrier island ground penetrating radar collected by East Carolina University in 2005 (ilgpr2005_shots.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  3. Ground Penetrating Radar (GPR) trackline navigation collected by East Carolina University along the North Carolina barrier islands in 2002 (ilgpr2002_tracklines.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  4. Shot navigation for North Carolina barrier island ground penetrating radar collected by East Carolina University in 2001 (ilgpr2001_shots.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  5. Ground Penetrating Radar (GPR) trackline navigation collected by East Carolina University along the North Carolina barrier islands in 2005 (ilgpr2005_tracklines.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  6. Ground Penetrating Radar (GPR) trackline navigation collected by East Carolina University along the North Carolina barrier islands in 2001 (ilgpr2001_tracklines.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  7. JPEG Images of Ground Penetrating Radar (GPR) data collected by East Carolina University along North Carolina Outer Banks 2002-2005

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  8. Shot navigation for North Carolina barrier island ground penetrating radar collected by East Carolina University in 2002 (ilgpr2002_shots.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  9. Present and future beam tube experiments at the 250 kW TRIGA Mark II reactor Wien

    International Nuclear Information System (INIS)

    The four beam tubes and the thermal column at the TRIGA reactor Wien were well used in the reporting period. Since the thermal column is used as a gamma source for different irradiation experiments and as a neutron source for radiography, the other facilities are mainly used for neutron spectroscopy experiments: polarized neutrons, neutron interferometry, small angle scattering and neutron choppers, In the piercing beam tube a fast rabbit system is installed which is mainly used for high precision activation analysis. (author)

  10. Method of experimental and theoretical modeling for multiple pressure tube rupture for RBMK reactor

    International Nuclear Information System (INIS)

    The rupture of single RBMK reactor channels has occurred at a number of stations with a variety of initiating events. It is assumed in RBMK Safety Cases that the force of the escaping fluid will not cause neighbouring channels to break. This assumption has not been justified. A chain reaction of tube breaks could over-pressurise the reactor cavity leading to catastrophic failure of the containment. To validate the claims of the RBMK Safety Cases the Electrogorsk Research and Engineering Centre, in participation with experts from the Institute of Mechanics of RAS, has developed the method of interacting multiscale physical and mathematical modelling for coupled thermophysical, hydrogasodynamic processes and deformation and break processes causing and (or) accompanying potential failures, design and beyond the design RBMK reactor accidents. To realise the method the set of rigs, physical and mathematical models and specialized computer codes are under creation. This article sets out an experimental philosophy and programme for achieving this objective to solve the problem of credibility or non-credibility for multiple fuel channel rupture in RBMK.(author)

  11. The Influence of Slight Protuberances in a Micro-Tube Reactor on Methane/Moist Air Catalytic Combustion

    Directory of Open Access Journals (Sweden)

    Ruirui Wang

    2016-05-01

    Full Text Available The combustion characteristics of methane/moist air in micro-tube reactors with different numbers and shapes of inner wall protuberances are investigated in this paper. The micro-reactor with one rectangular protuberance (six different sizes was studied firstly, and it is shown that reactions near the protuberance are mainly controlled by diffusion, which has little effect on the outlet temperature and methane conversion rate. The formation of cavities and recirculation zones in the vicinity of protuberances leads to a significant increase of the Arrhenius reaction rate of CH4 and gas velocity. Next, among the six different simulated conditions (0–5 rectangular protuberances, the micro-tube reactor with five rectangular protuberances shows the highest methane conversion rate. Finally, the effect of protuberance shape on methane/moist air catalytic combustion is confirmed, and it is found that the protuberance shape has a greater influence on methane conversion rate than the number of protuberances. The methane conversion rate in the micro-tube decreases progressively in the following order: five triangular slight protuberances > five rectangular protuberances > five trapezoidal protuberances > smooth tube. In all tests of methane/moist air combustion conditions, the micro-tube with five triangular protuberances has the peak efficiency and is therefore recommended for high efficiency reactors.

  12. Modeling and simulation of tube-shell reactor for dimethyl-ether synthesis from coal-based synthesis gas

    Institute of Scientific and Technical Information of China (English)

    CHEN Da-sheng; ZHANG Hai-tao; YING Wei-yong; FANG Ding-ye

    2011-01-01

    Mathematical simulation was performed on tube-shell reactor for dimethyl ether (DME) synthesis from coal-based syngas. The model was established based on kinetics of dimethyl-ether synthesis from syngas over a bifunctional catalyst,which is mixed by methanol synthesis catalyst and dehydration catalyst as 1:1 mass ratio. Methanol synthesis from CO and CO2 and methanol dehydration were selected as three-independent reactions, CO, CO2, and DME as key components to establish the one-dimensional mathematical model of the reactor. The gas concentration and temperature profiles inside the reactor tubes were obtained. The operating conditions affecting DME synthesis were also discussed based on the model. The simulations indicate that higher pressure and lower temperature at the inlet and rich hydrogen in the reactant are favorable in direct DME synthesis in fixed-bed process, and the temperature of boiling water affect the reactor performance seriously.

  13. The Influence of Slight Protuberances in a Micro-Tube Reactor on Methane/Moist Air Catalytic Combustion

    OpenAIRE

    Ruirui Wang; Jingyu Ran; Xuesen Du; Juntian Niu; Wenjie Qi

    2016-01-01

    The combustion characteristics of methane/moist air in micro-tube reactors with different numbers and shapes of inner wall protuberances are investigated in this paper. The micro-reactor with one rectangular protuberance (six different sizes) was studied firstly, and it is shown that reactions near the protuberance are mainly controlled by diffusion, which has little effect on the outlet temperature and methane conversion rate. The formation of cavities and recirculation zones in the vicinity...

  14. Virginia Tech among eight schools working to increase underrepresented students pursuing science and engineering

    OpenAIRE

    Owczarski, Mark

    2007-01-01

    Virginia Tech is among eight Virginia and North Carolina colleges and universities working together on a new National Science Foundation sponsored program to increase the number of students from underrepresented groups who pursue degrees in science, technology, engineering and mathematics.

  15. Internal welding of tube-to-tubesheet joints of steam generator for sodium-cooled fast breeder reactor

    International Nuclear Information System (INIS)

    In the steam generator for a sodium-cooled fast breeder reactor, there are many joints of tubes and tube sheets. For the internal welding of small diameter, thick walled tubes and tubesheets, welding method has been developed, which gives high quality welding with good reproducibility. In this method, the pressure of shield gas is controlled suitably, and consideration is given to the composition of the shield gas. As a means to ensure the quality of welds, the technique of internal radiographic test has also been established. Both the welding method and the test were able to be applied successfully to the steam generator of practical size. (Mori, K.)

  16. Combustion, cofiring and emissions characteristics of torrefied biomass in a drop tube reactor

    International Nuclear Information System (INIS)

    The study investigates cofiring characteristics of torrefied biomass fuels at 50% thermal shares with coals and 100% combustion cases. Experiments were carried out in a 20 kW, electrically heated, drop-tube reactor. Fuels used include a range of torrefied biomass fuels, non-thermally treated white wood pellets, a high volatile bituminous coal and a lignite coal. The reactor was maintained at 1200 °C while the overall stoichiometric ratio was kept constant at 1.15 for all combustion cases. Measurements were performed to evaluate combustion reactivity, emissions and burn-out. Torrefied biomass fuels in comparison to non-thermally treated wood contain a lower amount of volatiles. For the tests performed at a similar particle size distribution, the reduced volatile content did not impact combustion reactivity significantly. Delay in combustion was only observed for test fuel with a lower amount of fine particles. The particle size distribution of the pulverised grinds therefore impacts combustion reactivity more. Sulphur and nitrogen contents of woody biomass fuels are low. Blending woody biomass with coal lowers the emissions of SO2 mainly as a result of dilution. NOX emissions have a more complex dependency on the nitrogen content. Factors such as volatile content of the fuels, fuel type, furnace and burner configurations also impact the final NOX emissions. In comparison to unstaged combustion, the nitrogen conversion to NOX declined from 34% to 9% for air-staged co-combustion of torrefied biomass and hard coal. For the air-staged mono-combustion cases, nitrogen conversion to NOX declined from between 42% and 48% to about 10%–14%. - Highlights: • Impact of torrefaction on cofiring was studied at high heating rates in a drop tube. • Cofiring of torrefied biomasses at high thermal shares (50% and higher) is feasible. • Particle size impacts biomass combustion reactivity more than torrefaction. • In a drop tube reactor, torrefaction has no negative impact

  17. Break flow modeling for a steam generator tube rupture (SGTR) incident in a pressurized water reactor (PWR)

    International Nuclear Information System (INIS)

    The design-basis steam generator tube rupture (SGTR) scenario for the pressurized water reactor (PWR) postulates an instantaneous double-ended break of a steam generator (SG) U-tube. The flow rate through the broken U-tube depends on the primary-to-secondary side differential pressure in the affected SG, the primary coolant subcooling, and the break location along the U-tube. In this report, the RELAP5/MOD2 code's capability in predicting the SGTR break flow rate is assessed against experiments conducted on the Large Scale Test Facility (LSTF). The code is then used to predict break flow rate in the PWR for typical SGTR situations. It is shown that the code simulates well the break flow rates in the LSTF experiments for both single-phase and two-phase discharges, including two-phase critical flow discharge. The calculated PWR break flow rate takes a maximum for a break occurring at the lower end of the U-tube, on its cold leg side, because of the combined influence of tube-inlet fluid subcooling and frictional pressure drop along the broken tube. Modeling the tube frictional pressure drop is important to predict the break flow rate dependence on inlet fluid sub-cooling; simplified break flow modeling which applies a constant discharge coefficient less than unity, instead of modeling explicitly the tube frictional length, fails to predict the change in break flow rate accurately if the inlet subcooling varies for a wide range. (author)

  18. Liquid Circulation in a Multi-tube Air-lift Loop Reactor

    Institute of Scientific and Technical Information of China (English)

    刘永民; 刘铮; 穆克; 袁乃驹

    2000-01-01

    A multi-tube air-lift loop reactor (MT-ALR) is presented in this paper. Based on the energy conservation, a mathematical model describing the liquid circulation flow rate was developed, which was determined by gas velocity, the cross areas of riser and downcomer, gas hold-up and the local frictional loss coefficient. The experimental data indicate that either increase of gas flow rate or reduction of the downcomer diameter contributes to higher liquid circulation rate. The correlation between total and the local frictional loss coefficients was also established.Effects of gas flowrate in two risers and diameter of downcomer on the liquid circulation rate were examined. The value of total frictional loss coefficient was measured as a function of the cross area of downcomer and independent of the gas flow rate. The calculated results of liquid circulation rates agreed well with the experimental data with an average relative error of 9.6%.

  19. Sizing cracks in thin-walled CANDU reactor pressure tubes using crack-tip diffraction

    International Nuclear Information System (INIS)

    The most practical nondestructive means of measuring the depth of cracks approximately 0.4 mm deep in CANDU reactor pressure tubes is the ultrasonic crack-tip diffraction method. Initially, optimum ultrasonic parameters for wave mode, transducer frequency, main-bang pulse characteristics, incident and diffracted angles were obtained on three fatigue cracks, based on the criteria of maximum signal amplitude and accuracy in determination of crack depth. In addition, three signal processing techniques, auto and cross-correlation, rectification and smoothing and the magnitude of the analytic signal, were used to obtain time measurements. The results of these measurements are presented. Except for the first fatigue crack, the depth calculations were accurate to within the specified range of ± 0.1 mm

  20. Characteristics and kinetics of cattle litter pyrolysis in a tubing reactor.

    Science.gov (United States)

    Ngo, Thanh-An; Kim, Jinsoo; Kim, Seung-Soo

    2010-01-01

    The kinetic parameters for the pyrolysis of cattle litter were evaluated by thermogravimetric analysis (TGA). The cattle litter was pyrolyzed in a tubing reactor at 340, 360 and 380 degrees C with various retention times from 4 to 20 min. The influence of the pyrolysis conditions on the product yields was also examined. The maximum yields of gas and liquid products, 16.1 and 17.2 wt%, respectively, were obtained after pyrolysis at 380 degrees C for 20 min. The gas products were mainly C(1)-C(4) hydrocarbons. The experimental results of the product distribution were well fitted with the lumped kinetic model. The reaction pathway was investigated based on the calculated kinetic constants.

  1. 75 FR 15704 - Old Dominion Electric Cooperative; North Carolina Electric Membership Corporation, Complainants v...

    Science.gov (United States)

    2010-03-30

    ... Energy Regulatory Commission Old Dominion Electric Cooperative; North Carolina Electric Membership Corporation, Complainants v. Virginia Electric and Power Company, Respondent; Notice of Complaint March 23...), Old Dominion Electric Cooperative and North Carolina Electric Membership Corporation...

  2. 78 FR 16816 - Television Broadcasting Services; Hampton-Norfolk, Virginia; Norfolk, Virginia-Elizabeth City...

    Science.gov (United States)

    2013-03-19

    ... From the Federal Register Online via the Government Publishing Office FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 73 Television Broadcasting Services; Hampton-Norfolk, Virginia; Norfolk, Virginia..., North Carolina, and to modify its television station, WHRO-TV's license to specify Norfolk,...

  3. Preliminary fracture analysis of the core pressure boundary tube for the Advanced Neutron Source Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, K.C. [Univ. of Turabo, Gurabo, Puerto (Puerto Rico). College of Engineering; Yahr, G.T. [Oak Ridge National Lab., TN (United States)

    1995-08-01

    The outer core pressure boundary tube (CPBT) of the Advanced neutron Source (ANS) reactor being designed at Oak Ridge National Laboratory is currently specified as being composed of 6061-T6 aluminum. ASME Boiler and Pressure Vessel Code fracture analysis rules for nuclear components are based on the use of ferritic steels; the expressions, tables, charts and equations were all developed from tests and analyses conducted for ferritic steels. Because of the nature of the Code, design with thin aluminum requires analytical approaches that do not directly follow the Code. The intent of this report is to present a methodology comparable to the ASME Code for ensuring the prevention of nonductile fracture of the CPBT in the ANS reactor. 6061-T6 aluminum is known to be a relatively brittle material; the linear elastic fracture mechanics (LEFM) approach is utilized to determine allowable flaw sizes for the CPBT. A J-analysis following the procedure developed by the Electric Power Research Institute was conducted as a check; the results matched those for the LEFM analysis for the cases analyzed. Since 6061-T6 is known to embrittle when irradiated, the reduction in K{sub Q} due to irradiation is considered in the analysis. In anticipation of probable requirements regarding maximum allowable flaw size, a survey of nondestructive inspection capabilities is also presented. A discussion of probabilistic fracture mechanics approaches, principally Monte Carlo techniques, is included in this report as an introduction to what quantifying the probability of nonductile failure of the CPBT may entail.

  4. Development of poison injection code-COPJET for high pressure liquid poison injection in pressure tube type heavy water reactor

    International Nuclear Information System (INIS)

    Shut Down System-2 (SDS-2) in advanced vertical pressure tube type reactor, provides rapid reactor shutdown by high pressure injection of a neutron absorbing liquid called poison, into the moderator in the calandria. Poison inside the calandria is distributed by poison jets issued from holes provided in the injection tubes. Effectiveness of the system depends on the rate and spread of the poison in the moderator. In this study, a transient one-dimensional (1-D) hydraulic code, COPJET is developed, to predict the performance of system by predicting poison jet length with time. Validation of the COPJET is done with the data available in literature. Thereafter, it is applied for poison jet length prediction of advanced vertical pressure type reactor. (author)

  5. Design and manufacture of tube to tubesheet joints of steam generator for 500 MWe Prototype Fast Breeder Reactor

    International Nuclear Information System (INIS)

    Prototype Fast Breeder Reactor (PFBR) is 500 MWe pool type sodium cooled fast reactor. Presently this reactor is at advanced stage of construction at Kalpakkam. The main function of the steam generator is to extract the reactor heat through secondary sodium system and convert the feed water into superheated steam in the tubes of steam generators. The steam generator is a vertical shell and tube type heat exchanger with liquid sodium in the shell side and water/steam in the tube side. Operating experience of FBRs have shown that steam generator (SG) holds the key to commercial success of such reactors. Tube leakage is a serious problem and the prevention of sodium water reaction incident in the SG is essential to maintain the plant availability. In case of crack/failure in tube, high pressure water/steam reacts with shell side sodium and results in exothermic reaction with evolution of hydrogen, corrosive reaction products and intense local heat depending on leak size. This high reactive nature of sodium with water/steam requires that sodium to water/steam boundaries of steam generators must possess a high degree of reliability against failure. This is achieved in design and manufacturing by maximising the tube integrity and more importantly by proper selection of tube to tubesheet joint configuration. The principal material of construction of SG is Modified 9Cr-1Mo steel. The tubes are seamless and produced by electric arc melting followed by Electro Slag Refining (ESR) with tight control on inclusion content. Ultrasonic and eddy current testing is done on entire tube length in accordance with ASME SEC III Class I. Long seamless tubes (each 23m) are used in order to reduce the number of tube to tubesheet welds.Each SG has 547 tubes and there are 9 SG in the reactor including one spare module. There is no tube to tube joint as the aim is to minimise the number of welds to increase reliability.Tube to tubesheet joint selected for PFBR steam generator is of internal

  6. Monte Carlo simulation of the thermal column and beam tube of the TRIGA Mark II research reactor

    International Nuclear Information System (INIS)

    Highlights: → Neutronics parameters of the reactor shielding. → Biological shielding of the TRIGA reactor. → Thermal flux measurement in the thermal column and BT-A. → MCNP model validation. - Abstract: The Monet Carlo simulation of the TRIGA Mark II research reactor core has been performed employing the radiation transport computer code MCNP5. The model has been confirmed experimentally in the PhD research work at the Atominstitute (ATI) of the Vienna University of Technology. The MCNP model has been extended to complete biological shielding of the reactor including the thermal column, radiographic collimator and four beam tubes. This paper presents the MCNP simulated results in the thermal column and one of the beam tubes (beam tube A) of the reactor. To validate these theoretical results, thermal neutron flux density measurements using the gold foil activation method have been performed in the thermal column and beam tube A (BT-A). In the thermal column, the theoretical and experimental results are in fairly good agreement i.e. maximum thermal flux density in the centre decreases in radial direction. Further, it is also agreed that thermal flux densities in the lower part is greater than the upper part of the thermal column. In the BT-A experiment, the thermal flux density distribution is measured using gold foil. The experimental and theoretical diffusion lengths have been determined as 10.77 cm and 9.36 cm respectively with only 13% difference, reflecting good agreement between the experimental and simulated results. To save the computational cost and to incorporate the accurate and complete information of each individual Monte Carlo MC particle tracks, the surface source writing capability of MCNP has been utilized to the TRIGA shielding model. The variance reduction techniques have been applied to improve the statistics of the problem and to save computational efforts.

  7. Catalytic Chan–Lam coupling using a ‘tube-in-tube’ reactor to deliver molecular oxygen as an oxidant

    Science.gov (United States)

    Mallia, Carl J; Burton, Paul M; Smith, Alexander M R; Walter, Gary C

    2016-01-01

    Summary A flow system to perform Chan–Lam coupling reactions of various amines and arylboronic acids has been realised employing molecular oxygen as an oxidant for the re-oxidation of the copper catalyst enabling a catalytic process. A tube-in-tube gas reactor has been used to simplify the delivery of the oxygen accelerating the optimisation phase and allowing easy access to elevated pressures. A small exemplification library of heteroaromatic products has been prepared and the process has been shown to be robust over extended reaction times. PMID:27559412

  8. High-definition radiography of tube-to-tubesheet welds of steam generator of prototype fast breeder reactor

    International Nuclear Information System (INIS)

    In the steam generator of the Prototype Fast Breeder Reactor (PFBR), steam is generated by the transfer of heat from secondary sodium to water. Due to the inherent dangers of sodium-water reaction, the integrity of weld joints separating sodium and water/steam is of paramount importance. This is particularly true and very important for the tube-to-tubesheet joints. This paper discusses the use of projective magnification technique by microfocal radiography for the quality evaluation and optimisation of the welding parameters of such small tube-to-tubesheet welds of the steam generator of PFBR. (author)

  9. Development of magnetic flux leakage technique for examination of steam generator tubes of prototype fast breeder reactor

    International Nuclear Information System (INIS)

    Highlights: • For non-destructive detection of small localized defects in SG tubes of PFBR, tandem GMR array sensors based MFL technique developed. • 3D-finite element modeling performed for optimization of magnetizing current and spacing between the magnetizing coils. • The optimized magnetizing structure with ferrite core and guides detected 0.54 mm deep OD circumferential notch, 0.56 mm deep flat bottom hole, and 1.08 mm diameter hole in the tube with a SNR better than 6 dB. • Images of notches have been obtained using the tandem GMR array sensor. • The use of MFL and remote field eddy current techniques is expected to ensure comprehensive inspection of SG tubes of PFBR. - Abstract: For non-destructive examination of small diameter (outer diameter, OD 17.2 mm) and thick walled (wall thickness, 2.3 mm) ferromagnetic Modified 9Cr–1Mo steel steam generator (SG) tubes of Prototype Fast Breeder Reactor (PFBR), this paper proposes magnetic flux leakage (MFL) technique. Three dimensional finite element (3D-FE) modeling has been performed to optimize the magnetizing unit and inter-coil spacing of bobbin coils used for axial magnetization of the tube. The performance of the technique has been evaluated experimentally by measuring the axial (Ba) component of the leakage fields from localized machined defects in SG tubes. The MFL technique has shown capability to detect and image tube outside defects with a signal-to-noise ratio (SNR) better than 6 dB. Study reveals that Inconel support plates surrounding the SG tubes do not influence the MFL signals. As the MFL technique can detect localized defects in the presence of support plates as well as sodium and the remote field eddy current technique is sensitive to distributed wall thinning, their combined use will ensure comprehensive inspection of the SG tubes

  10. Influence of the biogas reburning for reducing nitric oxide emissions in an alundum-tube reactor

    Science.gov (United States)

    Zhao, Jie; Wang, Qingcheng; Yu, Lihui; Wu, Liyan

    2016-05-01

    The experimental study on reburning reduction reaction between biogas and NO is very important in de-NOx technology. The reburning experiments by the simulated biogas with different operation variables have been performed in an alundum-tube reactor. Results showed that the uppermost constituent in NO-reduction was CH4, H2 second, and NO-reduction by CO in biogas reburning was negligible at the same conditions. In the condition of oxygen-poor, H2 could promote CH4 oxidation and enhance the concentration of CH3 radicals, thereby increasing the reduction efficiency of NO accordingly. At the same temperature, with the increase of stoichiometric ratio, it would increase O radicals and decrease NO reduction efficiency. With the increase of reaction temperature, the reduction efficiency behaved a trend of first increased then decreased at the same stoichiometric ratio, and obtained the maximum value 51.38% at the condition of 1200 °C and λ = 0.6. Additionally, increasing the NO input concentration also could improve the reduction efficiency under the condition of fuel-rich.

  11. Results from integral tests of single reformer tubes under simulated nuclear reactor conditions

    International Nuclear Information System (INIS)

    The possibility of supplying high temperature heat from a HTGR for process application is being investigated at some places in the world. In all programmes or projects existing with respect to this application, the endothermic steam reforming of methane is one main step in the transmission of heat produced by nuclear fission to different chemical processes. The KFA is involved in the two German projects PNP - Prototypanlage Nukleare Prozesswaerme (Prototype-plant Nuclear Process-heat), and NFE -Nukleare Fernenergie (Long Distance Energy Transport). In a HTGR, helium generally serves as reactor coolant. It transports the heat from the core to the different components which take over this heat for various purposes. In case of arranging a steam reformer in the helium circuit, it is necessary for economic reasons to reach very high temperatures. In the two German projects mentioned above, the helium temperature at HTGR core outlet is determined to 9500C. Thus the main design data for a steam reformer supplied by heat from a HTGR are maximum helium temperature 9500C, helium pressure 40 bar. By an extensive utilization of the available advanced conventional steam reforming technology, the helium heated steam reformer design is using normal steam reforming tubes arranged in compact bundles

  12. Analyses of the reflector tank, cold source, and beam tube cooling for ANS reactor

    Energy Technology Data Exchange (ETDEWEB)

    Marland, S. [Tennessee Univ., Knoxville, TN (United States)

    1992-07-01

    This report describes my work as an intern with Martin Marietta Energy Systems, Inc., in the summer of 1991. I was assigned to the Reactor Technology Engineering Department, working on the Advanced Neutron Source (ANS). My first project was to select and analyze sealing systems for the top of the diverter/reflector tank. This involved investigating various metal seals and calculating the forces necessary to maintain an adequate seal. The force calculations led to an analysis of several bolt patterns and lockring concepts that could be used to maintain a seal on the vessel. Another project involved some pressure vessel stress calculations and the calculation of the center of gravity for the cold source assembly. I also completed some sketches of possible cooling channel patterns for the inner vessel of the cold source. In addition, I worked on some thermal design analyses for the reflector tank and beam tubes, including heat transfer calculations and assisting in Patran and Pthermal analyses. To supplement the ANS work, I worked on other projects. I completed some stress/deflection analyses on several different beams. These analyses were done with the aid of CAASE, a beam-analysis software package. An additional project involved bending analysis on a carbon removal system. This study was done to find the deflection of a complex-shaped beam when loaded with a full waste can.

  13. Pyrolysis characteristics and kinetics of oak trees using thermogravimetric analyzer and micro-tubing reactor.

    Science.gov (United States)

    Park, Young-Hun; Kim, Jinsoo; Kim, Seung-Soo; Park, Young-Kwon

    2009-01-01

    In this work, pyrolysis characteristics were investigated using thermogravimetric analysis (TGA) at heating rates of 5-20 degrees C/min. Most of the materials were decomposed between 330 degrees C and 370 degrees C at each heating rate. The average activation energy was 236.2 kJ/mol when the pyrolytic conversion increased from 5% to 70%. The pyrolysis kinetics of oak trees was also investigated experimentally and mathematically. The experiments were carried out in a tubing reactor at a temperature range of 330-370 degrees C with a reaction time of 2-8 min. A lump model of combined series and parallel reactions for bio-oil and gas formation was proposed. The kinetic parameters were determined by nonlinear least-squares regression from the experimental data. It was found from the reaction kinetic constants that the predominant reaction pathway from the oak trees was to bio-oil formation rather than to gas formation at the investigated temperature range.

  14. JPEG images of chirp seismic data from a 2002 nearshore survey collected by Virginia Institute of Marine Science

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  15. JPEG images of chirp seismic data from a 2005 nearshore survey collected by Virginia Institute of Marine Science

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  16. Nondestructive inspection of the tubes of TRIGA IPR-R1 reactor heat exchanger by eddy current testing

    Energy Technology Data Exchange (ETDEWEB)

    Silva Junior, Silverio F.; Silva, Roger F.; Oliveira, Paulo F., E-mail: silvasf@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Barreto, Erika S.; Ribeiro, Isabela G.; Fraiz, Felipe C. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

    2013-07-01

    The IPR-R1 TRIGA MARK 1 reactor is an open pool type reactor, cooled light water. It is used for research activities, personnel training and radioisotopes production, in operation since 1960 at the Nuclear Technology Development Center - CDTN/CNEN. It operates at a maximum thermal power of 100 kW and usually, the fuel cooling is done by natural circulation. If necessary, an external auxiliary cooling system, with a shell-and-tube type heat exchanger, can be used to improve the water heat removal. As part of the ageing management program of the reactor, a nondestructive evaluation of their heat exchanger stainless steel tubes will be performed, in order to verify its integrity. The examinations will be performed using the eddy current test method, which allows the detection and characterization of structural discontinuities in the wall of the tubes, if existing. For this purpose, probes and reference standards were designed and manufactured at CDTN facilities and test procedures were established and validated. In this paper, a description of the proposed infrastructure as well as the test methodology to be used in the examinations are presented and discussed. (author)

  17. Boomer shotpoint navigation from USGS cruise 2004-006-FA from Pamlico Sound, North Carolina (bbb2004006_shots.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  18. Location of vibracores collected from nearshore off of Duck, North Carolina in 2005 (vims_cores.shp, geographic, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  19. Chirp trackline navigation from USGS cruise 2004-005-FA from Pamlico Sound, North Carolina (bbc2004005_tracklines.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  20. Chirp shotpoint navigation from USGS cruise 2002-015-FA from Pamlico Sound, North Carolina (bbc2002015_shots.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  1. Boomer shotpoint navigation from USGS cruise 2003-042-FA from Pamlico Sound, North Carolina (bbb2003042_shot200.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  2. Boomer shotpoint navigation from USGS cruise 2002-015-FA from Pamlico Sound, North Carolina (bbb2002015_shots.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  3. Boomer seismic tracklines from USGS cruise 2003-042-FA from Pamlico Sound, North Carolina (bbb2003042_tracklines.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  4. Boomer seismic tracklines from USGS cruise 2004-005-FA from Pamlico Sound, North Carolina (bbb2004005_tracklines.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  5. Boomer shotpoint navigation from USGS cruise 2004-005-FA from Pamlico Sound, North Carolina (bbb2004005_shots.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  6. Boomer shotpoint navigation from USGS cruise 2003-005-FA from Pamlico Sound, North Carolina (bbb2003005_shots.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  7. Chirp shotpoint navigation from USGS cruise 2003-042-FA from Pamlico Sound, North Carolina (bbc2003042_shot.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  8. Location of vibracores from offshore of Dare County, North Carolina (ncd_cores.shp, geographic, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  9. Boomer seismic tracklines from USGS cruise 2004-006-FA from Pamlico Sound, North Carolina (bbb2004006_tracklines.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  10. Chirp shotpoint navigation (from USGS cruise 2003-005-FA from Pamlico Sound, North Carolina (bbc2003005_shots.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  11. Chirp navigation tracklines from USGS cruise 2001-013-FA from Albemarle Sound, North Carolina (bbc2001013_tracklines.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  12. Boomer seismic tracklines from USGS cruise 2003-005-FA from Pamlico Sound, North Carolina (bbb2003005_tracklines.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  13. Chirp shotpoint navigation from USGS cruise 2001-013-FA from Pamlico Sound, North Carolina (bbc2001013_shots.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  14. Chirp navigation tracklines from USGS cruise 2002-015-FA from Pamlico Sound, North Carolina (bbc2002015_tracklines.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  15. Boomer seismic navigation from USGS cruise 2002-015-FA from Pamlico Sound, North Carolina (bbb2002015_tracklines.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  16. Boomer shotpoint navigation from USGS cruise 2001-013-FA from Albemarle Sound, North Carolina (bbb2001013_shots.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  17. bbc2004005_shots.shp: Chirp shotpoint navigation from USGS cruise 2004-005-FA from Pamlico Sound, North Carolina

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  18. Experimental determination of thermal contact conductance between pressure and calandria tubes of Indian pressurised heavy water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Dureja, A.K., E-mail: akdureja@barc.gov.in [Reactor Design & Development Group, Bhabha Atomic Research Centre, Mumbai (India); Pawaskar, D.N.; Seshu, P. [Department of Mechanical Engineering, Indian Institute of Technology Bombay, Mumbai (India); Sinha, S.K. [Reactor Design & Development Group, Bhabha Atomic Research Centre, Mumbai (India); Sinha, R.K. [Department of Atomic Energy, OYC, Near Gateway of India, Mumbai (India)

    2015-04-01

    Highlights: • We established an experimental facility to measure thermal contact conductance between disc shaped specimens. • We measured thermal contact conductance between Zr-2.5Nb alloy pressure tube (PT) material and Zr-4 calandria tube (CT) material. • We concluded that thermal contact conductance is a linear function of contact pressure for interface of PT and CT up to 10 MPa contact pressure. • We concluded that thermal contact conductance is a weak function of interface temperature. - Abstract: Thermal contact conductance (TCC) is one of the most important parameters in determining the temperature distribution in contacting structures. Thermal contact conductance between the contacting structures depends on the mechanical properties of underlying materials, thermo-physical properties of the interstitial fluid and surface condition of the structures coming in contact. During a postulated accident scenario of loss of coolant with coincident loss of emergency core cooling system in a tube type heavy water nuclear reactor, the pressure tube is expected to sag/balloon and come in contact with outer cooler calandria tube to dissipate away the heat generated to the moderator. The amount of heat thus transferred is a function of thermal contact conductance and the nature of contact between the two tubes. An experimental facility was designed, fabricated and commissioned to measure thermal contact conductance between pressure tube and calandria tube specimens. Experiments were conducted on disc shaped specimens under axial contact pressure in between mandrels. Experimental results of TCC and a linear correlation as a function of contact pressure have been reported in this paper.

  19. Heat transfer characteristics of sodium-water reaction jet around a tube in steam generator of sodium-cooled fast reactor

    International Nuclear Information System (INIS)

    Overheating tube rupture of adjacent tubes arises from water/steam leak in steam generators of sodium-cooled fast reactors. It is very important to predict the tube wall stress (tube wall temperature) with a high degree of accuracy on evaluation of overheating tube rupture, and is crucial to estimate quantitatively the heat transfer coefficient between reaction jet and adjacent tubes which is one of the major influencing factor. The authors carried out the sodium-water reaction test (SWAT-1R) under the simulated operation condition of a real plant, and measured the correlation between heat transfer coefficient and void fraction around an adjacent tube. The authors confirmed that thermal environment around an adjacent tube was inferable from measured data, and heat transfer correlation equation proposed by Hamada et al. was applicable to the operation condition at elevated pressure and temperature. (author)

  20. Study of the U/sub 3/O/sub 8/-Al thermite reaction and strength of reactor fuel tubes

    Energy Technology Data Exchange (ETDEWEB)

    Peacock, H.B.

    1983-08-01

    Heating tests using 53 wt % U/sub 3/O/sub 8/-Al pellets show that an exothermic reaction occurs between 875 and 1000/sup 0/C and takes 10 to 20 seconds to reach maximum temperature. The maximum temperature is a function of particle size of the U/sub 3/O/sub 8/ with large particles exhibiting lower peak temperatures. The calculated energy release was 123 cal/g of U/sub 3/O/sub 8/-aluminum fuel. Tests using aluminum clad outer fuel tube sections gave lower peak temperatures than for pellets. No violent reactions occurred. The results are reasonably consistent with recent reported data indicating that the exothermic U/sub 3/O/sub 8/-Al reaction is not an important energy source. The compressive and tensile strengths of U/sub 3/O/sub 8/ tubes above 660/sup 0/C are low. In compression, sections with 2 psi average axial stress failed at 917/sup 0/C, while sections with 7 psi failed at 669/sup 0/C. Tubes with U-Al alloy cores failed at about 670/sup 0/C with no applied load. The stresses in fuel tubes during a reactor transient may range up to several hundred psi and are less than 7 psi only in the upper part of the fuel tube.

  1. Natural gas pyrolysis in double-walled reactor tubes using thermal plasma or concentrated solar radiation as external heating source

    Institute of Scientific and Technical Information of China (English)

    Stèphane Abanades; Stefania Tescari; Sylvain Rodat; Gilles Flamant

    2009-01-01

    The thermal pyrolysis of natural gas as a clean hydrogen production route is examined.The concept of a double-walled reactor tube is proposed and implemented.Preliminary experiments using an external plasma heating source are carded out to validate this concept.The results point out the efficient CH4 dissociation above 1850 K (CH4 conversion over 90%) and the key influence of the gas residence time.Simulations are performed to predict the conversion rate of CH4 at the reactor outlet,and are consistent with experimental tendencies.A solar reactor prototype featuring four independent double-walled tubes is then developed.The heat in high temperature process required for the endothermic reaction of natural gas pyrolysis is supplied by concentrated solar energy.The tubes are heated uniformly by radiation using the blackbody effect of a cavity-receiver absorbing the concentrated solar irradiation through a quartz window.The gas composition at the reactor outlet,the chemical conversion of CH4,and the yield to H2 are determined with respect to reaction temperature,inlet gas flow-rates,and feed gas composition.The longer the gas residence time,the higher the CH4 conversion and H2 yield,whereas the lower the amount of acetylene.A CH4 conversion of 99% and H2 yield of about 85% are measured at 1880 K with 30% CH4 in the feed gas (6 L/min injected and residence time of 18 ms).A temperature increase from 1870 K to 1970 K does not improve the H2 yield.

  2. Burnup calculations of light water-cooled pressure tube blanket for a fusion-fission hybrid reactor

    Energy Technology Data Exchange (ETDEWEB)

    Zu, Tiejun, E-mail: tiejun@mail.xjtu.edu.cn; Wu, Hongchun; Zheng, Youqi; Cao, Liangzhi

    2014-06-15

    Highlights: • Detailed burnup calculations are performed on pressurized water cooled blankets with pressure tube assemblies. • The blanket is fueled with simple fuel, namely spent nuclear fuel discharged from light water reactors or natural uranium oxide. • The refueling strategies are proposed, and the uranium resource utilization rate can reach 5–6%. - Abstract: A fusion-fission hybrid reactor (FFHR) with pressure tube blanket has recently been proposed based on an ITER-type tokamak fusion neutron source and the well-developed pressurized water cooling technologies. In this paper, detailed burnup calculations are carried out on an updated blanket. Two different blankets respectively fueled with the spent nuclear fuel (SNF) discharged from light water reactors (LWRs) or natural uranium oxide is investigated. In the first case, a three-batch out-to-in refueling strategy is designed. In the second case, some SNF assemblies are loaded into the blanket to help achieve tritium self-sufficiency. And a three-batch in-to-out refueling strategies is adopted to realize direct use of natural uranium oxide fuel in the blanket. The results show that only about 80 tonnes of SNF or natural uranium are needed every 1500 EFPD (Equivalent Full Power Day) with a 3000 MWth output and tritium self-sufficiency (TBR > 1.15), while the required maximum fusion powers are lower than 500 MW for both the two cases. Based on the proposed refueling strategies, the uranium utilization rate can reach about 4.0%.

  3. Application of automatic inspection system to nondestructive test of heat transfer tubes of primary pressurized water cooler in the high temperature engineering test reactor. Joint research

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Takeshi; Furusawa, Takayuki [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment; Miyamoto, Satoshi [Japan Atomic Power Company, Tokyo (Japan)

    2001-07-01

    Heat transfer tubes of a primary pressurized water cooled (PPWC) in the high temperature engineering test reactor (HTTR) form the reactor pressure boundary of the primary coolant, therefore are important from the viewpoint of safety. To establish inspection techniques for the heat transfer tubes of the PPWC, an automatic inspection system was developed. The system employs a bobbin coil probe, a rotating probe for eddy current testing (ECT) and a rotating probe for ultrasonic testing (UT). Nondestructive test of a half of the heat transfer tubes of the PPWC was carried out by the automatic inspection system during reactor shutdown period of the HTTR (about 55% in the maximum reactor power in this paper). The nondestructive test results showed that the maximum signal-to-noise ratio was 1.8 in ECT. Pattern and phase of Lissajous wave, which were obtained for the heat transfer tube of the PPWC, were different from those obtained for the artificially defected tube. In UT echo amplitude of the PPWC tubes inspected was lower than 20% of distance-amplitude calibration curve. Thus, it was confirmed that there was no defect in depth, which was more than the detecting standard of the probes, on the outer surface of the heat transfer tubes of the PPWC inspected. (author)

  4. Analysis of the Hydrogen Reduction Rate of Magnetite Concentrate Particles in a Drop Tube Reactor Through CFD Modeling

    Science.gov (United States)

    Fan, Deqiu; Mohassab, Yousef; Elzohiery, Mohamed; Sohn, H. Y.

    2016-06-01

    A computational fluid dynamics (CFD) approach, coupled with experimental results, was developed to accurately evaluate the kinetic parameters of iron oxide particle reduction. Hydrogen reduction of magnetite concentrate particles was used as a sample case. A detailed evaluation of the particle residence time and temperature profile inside the reactor is presented. This approach eliminates the errors associated with assumptions like constant particle temperature and velocity while the particles travel down a drop tube reactor. The gas phase was treated as a continuum in the Eulerian frame of reference, and the particles are tracked using a Lagrangian approach in which the trajectory and velocity are determined by integrating the equation of particle motion. In addition, a heat balance on the particle that relates the particle temperature to convection and radiation was also applied. An iterative algorithm that numerically solves the governing coupled ordinary differential equations was developed to determine the pre-exponential factor and activation energy that best fit the experimental data.

  5. Chirp navigation tracklines collected by Virginia Institute of Marine Science in 2005 along the nearshore region of the northern Outer Banks, NC (nsc2005_tracklines.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  6. Chirp shotpoint navigation collected by Virginia Institute of Marine Science along the nearshore region of the northern Outer Banks, NC (nsc2002_shots.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  7. Chirp shotpoint navigation collected by Virginia Institute of Marine Science along the nearshore region of the northern Outer Banks, NC (nsc2005_shots.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  8. Chirp navigation tracklines collected by Virginia Institute of Marine Science in 2002 along the nearshore region of the northern Outer Banks, NC (nsc2002_tracklines.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  9. In-service inspection of zircaloy pressure tube of CIRUS reactor

    International Nuclear Information System (INIS)

    The pressurized water loop (PWL) of Cirus uses a 10 meter long zircaloy tube of 57.9 mm ID and 5.4 mm wall thickness. The loop has been used for irradiation testing of various experimental fuel pins since 1972. As part of the refurbishment programme, the condition of Zircaloy-2 pressure tube of the pressurized water loop was investigated by Eddy current and ultrasonic testing. The eddy current probe was balanced over a portion of the tube and the differential signals were recorded for the entire length of the tube. For ultrasonic flaw scanning, gadgets were fabricated and scanning was carried out to evaluate the condition of irradiated pressure tube. For ultrasonic testing an annular probe holder matching to the internal diameter of the zircaloy tube was used for immersion scanning. The probe holder fitted with 10 MHz line focused ultrasonic probes inclined at 28 deg in axial and circumferential directions. A normal spot focused probe was also used to measure wall thickness and detection of laminar flaws. Axial and circumferential grooves of 3% wall thickness depth on ID and OD were used as standard calibration defects. The eddy current and ultrasonic tests did not detect any defect of unacceptable size in the zircaloy pressure tube. (author)

  10. Control rod drive/reactor vessel stub tube penetration experience and repair programmes

    International Nuclear Information System (INIS)

    Two heats of furnace sensitized Type 304 stainless steel were used in the material qualification tests for the Nuclear stub tube repair program. The carbon contents of the steels were 0.047 and 0.06 percent, which were intentionally selected to be conservatively higher than the actual stub tube materials. The furnace sensitized treatment consisted of heating at 1150 F (621 C) for 20 hours followed by furnace cooling. Welding was performed on the steel after furnace sensitizing to simulate the welding required to install a partial sleeve onto the stub tube. (author)

  11. Boomer shotpoint navigation from USGS cruise 1999-045-FA along the inner continental shelf of northern North Carolina (isb1999045_shots.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  12. Chirp trackline navigation data from USGS cruise 2003-005-FA from Pamlico Sound, North Carolina (bbc2003005_tracklines.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  13. Location of MMS (Minerals Management Service) vibracores from offshore northern Dare County, North Carolina (mms_cores.shp, geographic, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  14. Sidescan sonar navigation from USGS cruise 2002-012-FA along the inner continental shelf of northern North Carolina (iss2002012_tracklines.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  15. Location of SNL vibracores collected on Debris Barge (D/B) Snell from offshore northern Dare and Hyde Counties, North Carolina (snl_cores.shp, geographic, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  16. Boomer seismic trackline data from USGS cruise 1999-045-FA along the inner continental shelf of northern North Carolina (isb1999045_tracklines.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  17. Boomer shotpoint navigation from USGS cruise 2001-005-FA along the inner continental shelf of northern North Carolina (isb2001005_shots.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  18. Sidescan sonar navigation from USGS cruise 2002-013-FA along the inner continental shelf of northern North Carolina (iss2002013_tracklines.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  19. isc2002012_tracklines.shp: Chirp navigation tracklines from USGS cruise 2002-012-FA along the inner continental shelf of northern North Carolina

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  20. Chirp shotpoint navigation from USGS cruise 2001-005-FA along the inner continental shelf of northern North Carolina (isc2001005_shots.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  1. Boomer seismic trackline data from USGS cruise 2001-005-FA along the inner continental shelf of northern North Carolina (isb2001005_tracklines.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  2. Chirp navigation tracklines from USGS cruise 2002-013-FA along the inner continental shelf of northern North Carolina (isc2002013_tracklines.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  3. Sidescan sonar navigation from USGS cruise 2001-005-FA along the inner continental shelf of northern North Carolina (iss2001005_tracklines.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  4. Chirp shotpoint navigation from USGS cruise 2003-003-FA along the inner continental shelf of northern North Carolina (isc2003003_shots.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  5. Chirp navigation tracklines from USGS cruise 2004-003-FA along the inner continental shelf of northern North Carolina (isc2004003_tracklines.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  6. Boomer seismic trackline data from USGS cruise 2002-013-FA along the inner continental shelf of northern North Carolina (isb2002013_tracklines.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  7. Boomer shotpoint navigation from USGS cruise 2002-013-FA along the inner continental shelf of northern North Carolina (isb2002013_shots.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  8. Boomer seismic trackline data from USGS cruise 2002-012-FA along the inner continental shelf of northern North Carolina (isb2002012_tracklines.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  9. Sidescan sonar navigation from USGS cruise 1999-045-FA along the inner continental shelf of northern North Carolina (iss1999045_tracklines.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  10. Chirp shotpoint navigation from USGS cruise 1999-045-FA along the inner continental shelf of northern North Carolina (isc1999045_shots.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  11. Boomer seismic trackline data from USGS cruise 2001-013-FA from Albemarle Sound, North Carolina (bbb2001013_tracklines.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  12. Chirp navigation tracklines from USGS cruise 1999-045-FA along the inner continental shelf of northern North Carolina (isc1999045_tracklines.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  13. Chirp shotpoint navigation from USGS cruise 2002-012-FA along the inner continental shelf of northern North Carolina (isc2002012_shots.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  14. Chirp shotpoint navigation from USGS cruise 2004-003-FA along the inner continental shelf of northern North Carolina (isc2004003_shots.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  15. Chirp navigation tracklines from USGS cruise 2001-005-FA along the inner continental shelf of northern North Carolina (isc2001005_tracklines.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  16. Sidescan sonar navigation from USGS cruise 2004-003-FA along the inner continental shelf of northern North Carolina (iss2004003_tracklines.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  17. Chirp trackline navigation data from USGS cruise 2003-042-FA from Pamlico Sound, North Carolina (bbc2003042_tracklines.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  18. Chirp shotpoint navigation from USGS cruise 2002-013-FA along the inner continental shelf of northern North Carolina (isc2002013_shots.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  19. Boomer shotpoint navigation from USGS cruise 2002-012-FA along the inner continental shelf of northern North Carolina (isb2002012_shots.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  20. Sidescan sonar navigation from USGS cruise 2003-003-FA along the inner continental shelf of northern North Carolina (iss2003003_tracklines.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  1. Chirp navigation tracklines from USGS cruise 2003-003-FA along the inner continental shelf of northern North Carolina (isc2003003_tracklines.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  2. Ageing Management and Preventice Measures for Reactor Pool Liners, Beam Tubes and Spent Fuel Storage Tank at the Dalat Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Dien, Nguyen Nhi; Dien, Nguyen Minh; Su, Trang Cao [Nuclear Research Institute, Henoi (Viet Nam)

    2013-07-01

    The 500-kw Dalat Nuclear Research Reactor (DNRR) was reconstructed from the original 250-kW TRIGA Mark II as named of VN-001. In the framework of the reconstruction project during the 1982-1984 period, some structures of the TRIGA reactor constructed in the early sixties, such as the aluminum tank, graphite reflector, thermal column, four horizontal beam tubes, etc. have been remained. It means, such components are more than 50 years old and are facing with ageing issues. The structural materials of the pool liner and other components of TRIGA were made of aluminum alloy 6061 and aluminum cladding fuel assemblies. Some other parts, such as reactor core, irradiation rotary rack around the core, vertical irradiation facilities, etc. were replaced by the former Soviet Union's design with structural materials of aluminum alloy CAV-1. The reactor core has been loaded with HEU VVR-M2 fuel assemblies of 36% enrichment alloy CAV-1. The reactor core has been loaded with HEU VVR-M2 fuel assemblies of U-Al alloy 36% and of UO{sub 2} 19.75% enrichment used aluminum as fuel cladding. For ageing management and preventive measures of corrosion, an underwater high-resolution video camera system had been designed for visual inspections. A home-made cleaning system was also designed for cleaning the pool and other components. Water chemistry of the reactor pool and spent fuel storage was monitored regularly. In September-November 2011, all four horizontal channels were cleaned inside and visual inspection was done using special camera system. It was the first time from 1963 such activity could be done. Based on results obtained we could convince that inside all horizontal channels are in good condition and leakage could not be occurred. All 106 HEU spent fuel assemblies stored in the spent fuel pool in good condition. The visual inspection was done using under water camera too. The results obtained show that the surface of all HEU SFA is good and leakage was not occurred. The

  3. Study of the U/sub 3/O/sub 8/-Al thermite reaction and strength of reactor fuel tubes

    Energy Technology Data Exchange (ETDEWEB)

    Peacock, H B

    1983-01-01

    Research and test reactors are presently operated with aluminum-clad fuel elements containing highly enriched uranium-aluminum alloy cores. To lower the enrichment and still maintain reactivity, the uranium content of the fuel element will need to be higher than currently achievable with alloy fuels. This will necessitate conversion to other forms such as U/sub 3/O/sub 8/-aluminum cermets. Above the aluminum melting point, U/sub 3/O/sub 8/ and aluminum undergo an exothermic thermite reaction and cermet fuel cores tend to keep their original shape. Both factors could affect the course and consequences of a reactor accident, and prompted an investigation of the behavior of cermet fuels at elevated temperatures. Tests were carried out using pellets and extruded tube-sections with 53 wt % U/sub 3/O/sub 8/ in aluminum. This content corresponds to a theoretical uranium density of 1.9 g/cc. Results indicate that the thermite reaction occurs at about 900/sup 0/C in air without a violent effect. The heat of reaction was approximately 123 cal/g of U/sub 3/O/sub 8/-aluminum fuel. Tensile and compressive strength of the fuel tube section is low above 660/sup 0/C. In tension, sections failed at about the aluminum melting point. In compression with 2-psi average axial stress, failure occurred at 917/sup 0/C, while 7 psi average axial stress produced failure at 669/sup 0/C.

  4. Proceedings of the twenty-fourth water reactor safety information meeting. Volume 2: Reactor pressure vessel embrittlement and thermal annealing; Reactor vessel lower head integrity; Evaluation and projection of steam generator tube condition and integrity

    International Nuclear Information System (INIS)

    This three-volume report contains papers presented at the Twenty-Fourth Water Reactor Safety Information Meeting held at the Bethesda Marriott Hotel, Bethesda, Maryland, October 21--23, 1996. The papers are printed in the order of their presentation in each session and describe progress and results of programs in nuclear safety research conducted in this country and abroad. Foreign participation in the meeting included papers presented by researchers from Czech Republic, Finland, France, Japan, Norway, Russia and United Kingdom. This volume is divided into the following sections: reactor pressure vessel embrittlement and thermal annealing; reactor vessel lower head integrity; and evaluation and projection of steam generator tube condition and integrity. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database

  5. Conceptual design of a passive moderator cooling system for a pressure tube type natural circulation boiling water cooled reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Mukesh [Reactor Engineering Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Pal, Eshita, E-mail: eshi.pal@gmail.com [Homi Bhabha National Institute, Anushaktinagar, Mumbai 400 094 (India); Nayak, Arun K.; Vijayan, Pallipattu K. [Reactor Engineering Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)

    2015-09-15

    Highlights: • Passive moderator cooling system is designed to cool moderator passively during SBO. • PMCS is a system of two natural circulation loops, coupled via a heat exchanger. • RELAP5 analyses show that PMCS maintains moderator within safe limits for 7 days. - Abstract: The recent Fukushima accident has raised strong concern and apprehensions about the safety of reactors in case of a prolonged Station Black Out (SBO) continuing for several days. In view of this, a detailed study was performed simulating this condition in Advanced Heavy Water Reactor. In this study, a novel concept of moderator cooling by passive means has been introduced in the reactor design. The Passive Moderator Cooling System (PMCS) consists of a shell and tube heat exchanger designed to remove 2 MW heat from the moderator inside Calandria. The heat exchanger is located at a suitable elevation from the Calandria of the reactor, such that the hot moderator rises due to buoyancy into the heat exchanger and upon cooling from shell side water returns to Calandria forming a natural circulation loop. The shell side of the heat exchanger is also a natural circulation loop connected to an overhead large water reservoir, namely the GDWP. The objective of the PMCS is to remove the heat from the moderator in case of an SBO and maintaining its temperature below the permissible safe limit (100 °C) for at least 7 days. The paper first describes the concept of the PMCS. The concept has been assessed considering a prolonged SBO for at least 7 days, through an integrated analysis performed using the code RELAP5/MOD3.2 considering all the major components of the reactor. The analysis shows that the PMCS is able to maintain the moderator temperature below boiling conditions for 7 days.

  6. Advanced NDE (ANDE) and its application for pressure tube inspections in OPG reactors

    International Nuclear Information System (INIS)

    Periodic and in-service inspections of CANDU fuel channels are essential for the proper assessment of the structural integrity of these vital components. The arrival of new delivery devices for fuel channel inspections (Universal Delivery Machine) has driven new methods for gathering and analyzing NDE data. The Advanced Non-Destructive Examination (ANDE) system has been designed and field implemented as a high speed data acquisition system to meet the requirements of the CSA N285.4 code. It was built from the solid foundation of CIGAR experience and uses cutting edge hardware and software to attain high speed data collection enabling relatively quick inspection of a large number of fuel channels. The capabilities of the ANDE inspection system include: Surface and volumetric inspection of pressure tube by ultrasonics; Flaw characterization by ultrasonics; Pressure tube diameter measurements; Pressure tube thickness measurements; Garter Spring location by Eddy Current; Garter Spring location by ultrasonics; Pressure tube sag measurement. In addition to the above, selected flaws/areas of a pressure tube can be replicated using a two plate ANDE replica tool. At the heart of the inspection system is a set of twelve ultrasonic probes positioned in such a way that the inspected areas are examined from various angles and directions and by various ultrasonic wave modes (shear and longitudinal). High frequency ultrasound used for the examinations allows for reliable detection of small flaws. Separate sensors have been installed on the inspection head for Garter Spring location and sag measurements. (author)

  7. Application of RCC-MR for the structural design of tube sheet of intermediate heat exchanger for a sodium cooled fast reactor

    International Nuclear Information System (INIS)

    Highlights: • The structural mechanics behavior of tube sheets has been studied in detailed by FEM analysis software CAST3M. • Practical guidelines are provided to accurately derive the primary stress intensities particularly at the interface. • Linearization of stress components along the radial directions and the effect of filet radius at the interfaces have been covered in detailed. • Estimation of creep–fatigue damage as per RCC-MR. • These investigations thus help to optimize the design of IHX tube sheets with high confidence. - Abstract: The structural mechanics behavior of tube sheets of a sodium to sodium heat exchanger for a fast reactor, with circular tube holes pattern, less addressed subject in the literature, is investigated in detail. The tube sheet design rules recommended in the French design code RCC-MR-2007 and the associated solid mechanics basis are explained. A finite element analysis of tube sheets of intermediate heat exchanger of a typical 500 MWe pool type fast reactor is presented to study the effects of some specific parameters viz., (i) small solid rim portion with connecting shell and (ii) grooves on rim area. For the analysis, the distribution of holes on the last row is assumed to be symmetric and axial stiffening of tubes on tube sheet is included toward realistic estimation of stresses in the tube sheets. The effects are studied on the primary and secondary stresses induced along the interface between solid to perforated region. The aspects covered include linearization of radial and circumferential stress components, thereby deriving primary membrane and bending stress intensities along the radial directions with particular focus at the interfaces between solid portions and perforated portions including the effect of filet radius at the junction of tube sheet and shell. These investigations thus help to optimize the design of IHX tube sheets with high confidence. The analysis has been carried out by CAST3M, a structure

  8. The metallurgical properties of Zircaloy-2 relevant to its use in reactor pressure tubes

    International Nuclear Information System (INIS)

    The paper reviews the properties of the zirconium-base alloy Zircaloy as used in UK steam-generating heavy water reactor. It describes the major engineering requirements for this use and how the alloy can be fabricated. Some comparisons with other alloys and other metallurgical conditions are provided throughout the review. In the section on corrosion aspects the important effect of reactor irradiation in producing higher corrosion rates is emphasized by results obtained from surveillance samples taken after several years of large-scale reactor operation. In addition to oxidation effects the associated rate of hydrogen pickup is discussed and it is shown that reactor life exposure could lead to total loss of section of 0.20 mm with a total hydrogen pickup of about 100 ppm. Locally higher corrosion rates associated with nodular corrosion, and the conditions for stress corrosion are described. With regard to short-term mechanical properties, the major part of the discussion is devoted to fracture toughness aspects because of the embrittling effects of hydriding and of neutron irradiation. The experimental work shows that fast fracture could only occur under reactor conditions if a large defect was present, typically ten or more centimetres long and 80% of the wall thickness deep. Moreover, such large defects are likely to lead to leakage rather than fast fracture, satisfying 'leak-before-break' arguments. Information on fragmentation behaviour is also reported. Turning to time-dependent properties, emphasis is again put on information from long-term reactor measurements. The important aspect of irradiation-accelerated creep is reviewed with the evidence for an associated increase in strain-to-failure. It is concluded that the creep strain occurring during 25 full power years exposure to reactor conditions would not exceed 2 1/2%, a value well within the acceptable limit. (author)

  9. Intercomparison of techniques for inspection and diagnostics of heavy water reactor pressure tubes. Additional information

    International Nuclear Information System (INIS)

    The reports from Argentina, Canada, India, Korea and Romania are presented concerning the projects carried out under the Coordinated Research Program (CRP) I3.30.10 of the International Agency for Atomic Energy - Vienna related to 'Intercomparison of Techniques for Pressure Tube Inspection and Diagnostics'

  10. Fast reactor steam generators with sodium on the tube side. Design and operational parameters

    International Nuclear Information System (INIS)

    A comparison of design and operational characteristics as well as analysis of experience gained during the long terms operation of the Micro Module Inverse Steam Generator and Module Inverse Steam Generator at BOR 60 reactor are main aims of this technical report. 20 refs, 47 figs, 14 tabs

  11. Weldability of stabilized 2 1/4Cr 1Mo Nb steel for tubes of fast reactor steam generators

    International Nuclear Information System (INIS)

    Thermorestor-W equipment was used in the study of hot and cold crackability of low-alloy chromium-molybdenum steel stabilized with niobium. The steel is designed for tubes of fast reactor steam generators. The effect of pre-heating was studied with respect to weldability. The steel is stabilized to a degree which excludes sodium-induced decarburization. Samples of three melts were used in the experiments. The steel was found not to be subject to cold crackability; however, hot crackability may be expected. It was also found that overstabilization of the steel led to an amount of eutectic sufficient for crack self-sealing. This effect, however, is not acceptable with regard to notch impact strength. In view of the possible occurrence of annealing cracks, heating rate control is recommended when the steel is heated to the annealing point. (Z.M.)

  12. Analysis of two-phase flow instability in helical tube steam generator in high temperature gas cooled reactor

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Yu; Lv, Xuefeng; Wang, Shengfei; Niu, Fenglei; Tian, Li [North China Electric Power Univ., Beijing (Switzerland)

    2012-03-15

    The steam generator composed of multi-helical tubes is used in high temperature gas cooled reactors and two-phase flow instability should be avoided in design. And density-wave oscillation which is mainly due to flow, density and the relationship between the pressure drop delays and feedback effects is one of the two-phase flow instability phenomena easily to occur. Here drift-flux model is used to simulate the performance of the fluid in the secondary side and frequency domain and time domain methods are used to evaluate whether the density-wave oscillation will happen or not. Several operating conditions with nominal power from 15% to 30% are calculated in this paper. The results of the two methods are in accordance, flow instability will occur when power is less than 20% nominal power, which is also according with the result of the experiments well.

  13. Steam condensation model onto horizontal finned tubes: first approximation to the containment cooling system of advanced reactors European Designs

    International Nuclear Information System (INIS)

    European designs of advanced reactors, such as EPR pr SWR 1000, have considered the use of innovative passive safety systems to preserve containment integrity even in the case of a hypothetical accident. These systems consist of several units of bundles of quasi-horizontal finned tubes. Steam released into the containment atmosphere condenses onto these structures, which are internally cooled by water under natural circulation regime. The energy absorbed by the coolant is then discharged into a pool which acts as a heat sink for at least three days. This paper presents the work carried out under the auspices of European Union within the CONGA project to simulate steam condensation onto the above mentioned quasi-horizontal finned tubes. To date calculation methodologies have been pearly reviewed and and an approximation (''Nusselt type'') has been accepted to be the most suitable for safety studies, because of its mechanistic nature and its compatibility with current safety computation tools. Two versions of this approach have been properly adapted and subsequently implemented into independent codes for their validation. An experimental database built up from the open literature allowed to point out models accuracy, showing error well within the experimental uncertainly margin. Therefore, condensate film resistance to heat transfer has been modelled satisfactorily. Nevertheless, further work remains to be done to account for the effects of noncondensable gas presence and aerosol deposition onto heat transfer surfaces. (Author) 22 refs

  14. 4 meter sidescan-sonar GeoTIFF image of inner shelf with stretched histogram, from Virginia border to Cape Hatteras, NC (composite_nhatt_str.tif, UTM, Zone 18N, WGS84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  15. 4 meter sidescan-sonar GeoTIFF image of inner shelf from Virginia border to Cape Hatteras, NC (composite_nhatt.tif, UTM, Zone 18N, WGS84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  16. 40 meter ESRI binary grid of single beam and swath bathymetry of inner continental shelf north of Cape Hatteras, NC to Virginia border (nhatt, UTM Zone 18N, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  17. Heat transfer burnout in tube-type fuel elements of nuclear power reactors

    International Nuclear Information System (INIS)

    The conditions are formulated under which the results of the experimental research of the boilino. water heat transfer burnout carried out on models may be applied to fuel elements of nuclear reactors. Experimental material providing data on the heat transfer burnout was expanded by the results of measurements of the uneven (cosine) longitudinal distribution of heat sources. The results of the effects of helical fins or wires on heat transfer burnout are presented. (F.M.)

  18. Intercomparison of techniques for inspection and diagnostics of heavy water reactor pressure tubes: Flaw detection and characterization [Phase 1

    International Nuclear Information System (INIS)

    Nuclear power plants with heavy water reactors (HWRs) comprise nine percent of today's operating nuclear units, and more are under construction. Efficient and accurate inspection and diagnostic techniques for various reactor components and systems are an important factor in assuring reliable and safe plant operation. To foster international collaboration in the efficient and safe use of nuclear power, the IAEA conducted a Coordinated Research Programme (CRP) on Inter-comparison of Techniques for HWR Pressure Tube Inspection and Diagnostics. This CRP was carried out within the frame of the IAEA Department of Nuclear Energy's Technical Working Group on Advanced Technologies for HWRs (the TWG-HWR). The TWG-HWR is a group of experts nominated by their governments and designated by the IAEA to provide advice and to support implementation of the IAEA's project on advanced technologies for HWRs. The objective of the CRP was to inter-compare non-destructive inspection and diagnostic techniques, in use and being developed, for structural integrity assessment of HWR pressure tubes. During the first phase of this CRP, participants have investigated the capability of different techniques to detect and characterize flaws. During the second phase of this CRP, participants collaborated to detect and characterize hydride blisters and to determine the hydrogen concentration in Zirconium alloys. The intent was to identify the most effective pressure tube inspection and diagnostic methods, and to identify further development needs. The organizations that have participated in this CRP are: - The Comision Nacional de Energia Atomica (CNEA), Argentina; - Atomic Energy of Canada Ltd. (AECL); Chalk River Laboratories (CRL), Canada; - The Research Institute of Nuclear Power Operations (RINPO), China National Nuclear Corporation (CNNC), China; - Bhabha Atomic Research Centre (BARC), India; - The Korea Electric Power Research Institute (KEPRI), Republic of Korea; - The Korea Atomic Energy

  19. Fuel cladding tube for nuclear reactor or method of manufacturing the same

    International Nuclear Information System (INIS)

    In a fuel cladding tube, an inner liner layer comprises, in zirconium at high purity, trace additive of one or more of tin, iron, chromium, nickel, niobium, vanadium and molybdenum, not more than 1200ppm of oxygen, and other inevitable impurities in an amount of not greater than 2000ppm in total, in which the trace additive is deposited as an intermetallic compound having an average grain size of from 0.07μm to 0.3μm inclusive. Therefore, stress corrosion cracks resistance can be improved while maintaining suppression force against abrupt oxidation at the inner surface. (T.M.)

  20. Performance of COD removal from acid scarlet BS-containing solution in a novel packed-bed hollow-tube photocatalytic (PHP) reactor.

    Science.gov (United States)

    Xiong, Ya; He, Chun; An, Taicheng; Yu, Quan; Zha, Changhong; Zhu, Xihai

    2003-05-01

    A novel packed-bed hollow-tube photocatalytic (PHP) reactor using TiO2-coated Ti particles as fillers was designed and applied to treat a simulated dye wastewater containing Acid Scarlet BS. The experimental results showed that PHP reactor could efficiently remove chemical oxygen demand (COD) from the dye solution and the COD removal efficiency was considerably dependent on the operating parameters, airflow, initial dye concentration and initial pH value of solution. It was also found that the inserting of the hollow tubes could apparently increase the COD removal efficiency of the packed-bed photo-reactor while the application of external electric field could improve the degradation efficiency of the dye but not obviously promote COD removal.

  1. Location of rotasonic cores from northeastern North Carolina Volumes I to IV: Cores OBX-01 through OBX-18 and MLD-01 through MLD-10 (obx_cores.shp, geographic, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  2. Steam generator tube performance

    International Nuclear Information System (INIS)

    A survey of steam generator operating experience for 1986 has been carried out for 184 pressurized water and pressurized heavy-water reactors, and 1 water-cooled, graphite-moderated reactor. Tubes were plugged at 75 of the reactors (40.5%). In 1986, 3737 tubes were plugged (0.14% of those in service) and 3148 tubes were repaired by sleeving. A small number of reactors accounted for the bulk of the plugged tubes, a phenomenon consistent with previous years. For 1986, the available tubesheet sludge data for 38 reactors has been compiled into tabular form, and sludge/deposit data will be incorporated into all future surveys

  3. Measurement of mechanical properties of a reactor operated Zr–2.5Nb pressure tube using an in situ cyclic ball indentation system

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, S., E-mail: subrata@barc.gov.in; Panwar, Sanjay; Madhusoodanan, K.

    2015-07-15

    Highlights: • Measurement of mechanical properties of pressure tube is required for its fitness assessment. • Pressure tube removal from the core consumes large amount of radiation for laboratory test. • A remotely operable In situProperty Measurement System has been designed in house. • The tool head is capable to carry out in situ ball indentation trials inside pressure tube. • The paper describes the theory and results of the trials conducted on irradiated pressure tube. - Abstract: Periodic measurement of mechanical properties of pressure tubes of Indian Pressurised Heavy Water Reactors is required for assessment of their fitness for continued operation. Removal of pressure tube from the core for preparation of specimens to test for mechanical properties in laboratories consumes large amounts of radiation and hence is to be avoided as far as possible. In the field of in situ estimation of properties of materials, cyclic ball indentation is an emerging technique. Presently, commercial systems are available for doing indentation test either on outside surface of a component at site or on a test piece in a laboratory. However, these systems cannot be used inside a pressure tube for carrying out ball indentation trials under in situ condition. Considering this, a remotely operable hydraulic In situProperty Measurement System (IProMS) based on cyclic ball indentation technique has been designed and developed in house. The tool head of IProMS can be located inside a pressure tube at any axial location under in situ condition and the properties can be estimated from an analysis of the data on load and depth of indentation, recorded during the test. In order to qualify the system, a number of experimental trials have been conducted on spool pieces and specimens prepared from Zr–2.5Nb pressure tube having different mechanical properties. Based on the encouraging results obtained from the qualification trials, IProMS has been used inside a reactor operated

  4. Measurement of mechanical properties of a reactor operated Zr–2.5Nb pressure tube using an in situ cyclic ball indentation system

    International Nuclear Information System (INIS)

    Highlights: • Measurement of mechanical properties of pressure tube is required for its fitness assessment. • Pressure tube removal from the core consumes large amount of radiation for laboratory test. • A remotely operable In situProperty Measurement System has been designed in house. • The tool head is capable to carry out in situ ball indentation trials inside pressure tube. • The paper describes the theory and results of the trials conducted on irradiated pressure tube. - Abstract: Periodic measurement of mechanical properties of pressure tubes of Indian Pressurised Heavy Water Reactors is required for assessment of their fitness for continued operation. Removal of pressure tube from the core for preparation of specimens to test for mechanical properties in laboratories consumes large amounts of radiation and hence is to be avoided as far as possible. In the field of in situ estimation of properties of materials, cyclic ball indentation is an emerging technique. Presently, commercial systems are available for doing indentation test either on outside surface of a component at site or on a test piece in a laboratory. However, these systems cannot be used inside a pressure tube for carrying out ball indentation trials under in situ condition. Considering this, a remotely operable hydraulic In situProperty Measurement System (IProMS) based on cyclic ball indentation technique has been designed and developed in house. The tool head of IProMS can be located inside a pressure tube at any axial location under in situ condition and the properties can be estimated from an analysis of the data on load and depth of indentation, recorded during the test. In order to qualify the system, a number of experimental trials have been conducted on spool pieces and specimens prepared from Zr–2.5Nb pressure tube having different mechanical properties. Based on the encouraging results obtained from the qualification trials, IProMS has been used inside a reactor operated

  5. A ceramic breeder in a poloidal tube blanket for a tokamak reactor

    Energy Technology Data Exchange (ETDEWEB)

    Amici, A.; Anzidei, L.; Gallina, M.; Rado, V.; Simbolotti, G.; Violante, V.; Zampaglione, V.; Petrizzi, L. (Associazione Euratom-CNEN sulla Fusione, Centro di Frascati (Italy))

    1989-04-01

    A conceptual study of a helium-cooled solid breeder blanket for a tokamak reactor is presented. Tritium breeding capability together with system reliability are taken as the main design criteria. The blanket consists of tubular poloidal modules made of a central bundle of ceramic rods ({gamma}LiAlO/sub 2/) with a coaxial distribution of the inlet/outlet coolant flow (He) surrounded by a multiplier material (Be) in the form of bored bricks. The Be to {gamma}LiAlO/sub 2/ volume ratio is 4/1. The He inlet and outlet branches are cooling Be and {gamma}LiAlO/sub 2/, respectively. A purge He flow running through small central holes of the ceramic rods is derived from the main flow. Under the typical conditions of a tokamak reactor (neutron wall load=2 MW/m/sup 2/), a full coverage tritium breeding ratio of 1.47 is achieved for the following design and operating parameters: outlet He temperature=570/sup 0/C; inlet He temperature=250/sup 0/; total extracted power=2700 MW; He pumping power percentage=2%; minimum/maximum {gamma}LiAlO/sub 2/ temperature=400/900/sup 0/C; maximum structural temperature=475/sup 0/C; and maximum Be temperature=525/sup 0/C. (orig.).

  6. Characterization of excel alloy pressure tube material for CANDU SCW reactors

    International Nuclear Information System (INIS)

    The phase transformation temperatures, aging response, and creep rupture strength of Zr alloy Excel (Zr- 3.5%Sn- 0.8%Nb- 0.8%Mo) pressure tube material were investigated. The α → α+β and α+β → β transus temperatures were found to be in the range of 600-690 °C and 962-975 °C respectively. Precipitation hardening was observed in the microstructures water-quenched from high in the α+β or β regions followed by aging at 400-500 °C for 1 hr. The results of creep-rupture experiments at 400 °C suggest that a fully martensitic and aged microstructure has better creep properties at high stress levels (>700 MPa) and a microstructure obtained by air-cooling from high in the α+β region shows good creep properties at lower stresses (<560 MPa). (author)

  7. Effect of gadolinium nitrate concentration on the corrosion compatibility of structural materials in a proposed Indian tube type boiling reactor

    International Nuclear Information System (INIS)

    Gadolinium (Gd3+) is added with nitric acid to moderator heavy water as a neutron poison in nuclear reactors to control reactivity and pH is maintained in the range of 5 to 5.5 to prevent Gd3+ precipitation. Usually ∼15 ppm of Gd3+ is used during actuation of secondary shutdown system and is subsequently removed on ion exchange up to a residual ∼2 ppm before start-up. In the moderator system of a proposed tube type boiling water reactor of Indian origin, a higher concentration (20-400ppm) of Gd(NO3)3 was proposed to be used in the emergency safety shutdown system. With higher concentration of Gd3+, the pH can go down and affect the radiolytic yields and thus affecting the integrity of the structural materials. Considering a long life of 100 years of operation for the proposed reactor, the concentration dependence of Gd3+ on the yields of molecular products like H2 and H2O2 during radiolysis and corrosion compatibility of structural materials like (1) SS 304 LN (proposed structural material for this reactor) and (2) SS 410 (proposed to be used in the valves of the moderator system as an alternative to hard facing alloy, colmonoy) is of interest. The pH and conductivity of the system were observed to be in the range of 5.33-3.76 and 50-870 μS/cm for 20-400 ppm of Gd3+. From the electrochemical studies it was observed that the electrochemical potential increased to more positive potential with increase in Gd3+ concentrations. The yield of H2 and H2O2 was also found to increase with increase in [Gd3+] concentrations. A detailed study on corrosion of the above said alloys at varying [Gd3+] concentrations, temperature, pH and simulated irradiation conditions and its effect on microstructure will be described in the paper. (author)

  8. The study on water ingress mass in the steam generator heat-exchange tube rupture accident of modular high temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    The steam generator heat-exchange tube rupture (SGTR) accident is an important and particular accident which will result in water ingress to the primary loop of reactor. Water ingress will result in chemical reaction of graphite fuel and structure with water, which may cause overpressure due to generation of explosive gaseous in large quantity. The study on the water ingress accident is significant for the verification of the inherent characteristics of high temperature gas-cooled reactor. The previous research shows that the amount of water ingress mass is the dominant key factor on the severity of the accident consequence. The 200 MWe high temperature gas-cooled reactor (HTR-PM), which is the first modular pebble-bed high temperature gas-cooled reactor in China designed by the Institute of Nuclear and New Energy Technology of Tsinghua University, is selected to be analyzed in this paper. The different DBA accident scenarios of double-ended break of single heat-exchange tube are simulated respectively by the thermal-hydraulic analysis code RETRAN-02. The results show the water ingress mass through the broken heat-exchange tube is related to the break location. The amount of water ingress mass is affected obviously by the capacity of the emptier system. With the balance of safety and economical efficiency, the amount of water ingress mass from the secondary side of steam generator into the primary coolant loop will be reduced by increasing properly the diameter of the draining lines. (authors)

  9. Analysis of the impact of coolant density variations in the high efficiency channel of a pressure tube super critical water reactor

    International Nuclear Information System (INIS)

    The Pressure Tube (PT) Supercritical Water Reactor (SCWR) is based on a light water coolant operating at pressures above the thermodynamic critical pressure; a separate low temperature and low pressure moderator. The coolant density changes by an order of magnitude depending on its local enthalpy in the porous ceramic insulator tube. This causes significant changes in the neutron transport characteristics, axially and radially, in the fuel channel. This work performs lattice physics calculations for a 78-element Pu-Th fuel at zero burnup and examines the effect of assumptions related to coolant density in the radial direction of a HEC, using the neutron transport code WIMS-AECL. (author)

  10. Pressure drop and heat transfer in the sodium to air heat exchanger tube banks on advanced sodium-cooled fast reactor

    International Nuclear Information System (INIS)

    A numerical study was performed to investigate the thermal and hydraulic characteristics and build up design model of the AHX (sodium-to-air heat exchanger) unit of a sodium-cooled fast reactor. Helical-coiled tube banks in the AHX were modeled as porous media and simulated heat and momentum transfer. Two-dimensional flow characteristic appeared at the most region of AHX annulus. Pressure drop and heat transfer coefficient for rectangular, parallelogram and staggered tube banks as the main components of the AHX were evaluated and compared with Zhukauskas empirical correlations. (author)

  11. Analyses of the reflector tank, cold source, and beam tube cooling for ANS reactor. [Advanced Neutron Source (ANS)

    Energy Technology Data Exchange (ETDEWEB)

    Marland, S. (Tennessee Univ., Knoxville, TN (United States))

    1992-07-01

    This report describes my work as an intern with Martin Marietta Energy Systems, Inc., in the summer of 1991. I was assigned to the Reactor Technology Engineering Department, working on the Advanced Neutron Source (ANS). My first project was to select and analyze sealing systems for the top of the diverter/reflector tank. This involved investigating various metal seals and calculating the forces necessary to maintain an adequate seal. The force calculations led to an analysis of several bolt patterns and lockring concepts that could be used to maintain a seal on the vessel. Another project involved some pressure vessel stress calculations and the calculation of the center of gravity for the cold source assembly. I also completed some sketches of possible cooling channel patterns for the inner vessel of the cold source. In addition, I worked on some thermal design analyses for the reflector tank and beam tubes, including heat transfer calculations and assisting in Patran and Pthermal analyses. To supplement the ANS work, I worked on other projects. I completed some stress/deflection analyses on several different beams. These analyses were done with the aid of CAASE, a beam-analysis software package. An additional project involved bending analysis on a carbon removal system. This study was done to find the deflection of a complex-shaped beam when loaded with a full waste can.

  12. An Investigation on Cocombustion Behaviors of Hydrothermally Treated Municipal Solid Waste with Coal Using a Drop-Tube Reactor

    Directory of Open Access Journals (Sweden)

    Liang Lu

    2012-01-01

    Full Text Available This work aims at demonstrating the feasibility of replacing Indonesian coal (INC with hydrothermally treated municipal solid waste (MSWH in cocombustion with high ash Indian coal (IC. The combustion efficiencies and emissions (CO, NO of MSWH, INC and their blends with IC for a series of tests performed under a range of temperatures and air conditions were tested in a drop-tube reactor (DTR. The results showed the following. The combustion efficiency of IC was increased by blending both MSWH and INC and CO emission was reduced with increasing temperature. For NO emission, the blending of MSWH led to the increase of NO concentration whereas the effects of INC depended on the temperature. The combustion behaviors of IC-MSWH blend were comparable to those of the IC-INC blend indicating it is possible for MSWH to become a good substitute for INC supporting IC combustion. Moreover, the CO emission fell while the NO emission rose with increasing excess air for IC-MSWH blend at 900°C and the highest combustion efficiency was obtained at the excess air of 1.9. The existence of moisture in the cocombustion system of IC-MSWH blend could slightly improve the combustion efficiency, reduce CO, and increase NO.

  13. Development of an in-service inspection technique for the intermediate heat exchanger tubes of the High-Temperature Engineering Test Reactor

    International Nuclear Information System (INIS)

    An experimental study is carried out to clarify the performance of an eddy current testing probe and probe-inserting equipment for the in-service inspection of the intermediate heat exchanger tubes of the High-Temperature Engineering Test Reactor. Artificial discontinuities are made with reference to the American Society of Mechanical Engineers standards for steam generator tubes in a light water reactor. It is confirmed that the probe can detect these discontinuities as well as smaller ones, such as a 0.5-mm-diam 100% through-wall hole and a 0.5-mm-wide groove, in a base-metal tube. For the welded joints, the back-excess weld metal is a main noise contributor, and a multiple-frequency method can remove the noise. The inspection performance, however, is lower. The probe-inserting equipment can smoothly insert and extract the probe. The winding of the cable causes a scattering in the probe traveling velocity values an a measurement error regarding the probe's location in the tube

  14. The application of an innovative continuous multiple tube reactor as a strategy to control the specific organic loading rate for biohydrogen production by dark fermentation.

    Science.gov (United States)

    Gomes, Simone D; Fuess, Lucas T; Penteado, Eduardo D; Lucas, Shaiane D M; Gotardo, Jackeline T; Zaiat, Marcelo

    2015-12-01

    Biohydrogen production in fixed-bed reactors often leads to unstable and decreasing patterns because the excessive accumulation of biomass in the bed negatively affects the specific organic loading rate (SOLR) applied to the reactor. In this context, an innovative reactor configuration, i.e., the continuous multiple tube reactor (CMTR), was assessed in an attempt to better control the SOLR for biohydrogen production. The CMTR provides a continuous discharge of biomass, preventing the accumulation of solids in the long-term. Sucrose was used as the carbon source and mesophilic temperature conditions (25°C) were applied in three continuous assays. The reactor showed better performance when support material was placed in the outlet chamber to enhance biomass retention within the reactor. Although the SOLR could not be effectively controlled, reaching values usually higher than 10gsucroseg(-1)VSSd(-1), the volumetric hydrogen production and molar hydrogen production rates peaked, respectively, at 1470mLH2L(-1)d(-1) and 45mmolH2d(-1), indicating that the CMTR was a suitable configuration for biohydrogen production. PMID:26340028

  15. The application of an innovative continuous multiple tube reactor as a strategy to control the specific organic loading rate for biohydrogen production by dark fermentation.

    Science.gov (United States)

    Gomes, Simone D; Fuess, Lucas T; Penteado, Eduardo D; Lucas, Shaiane D M; Gotardo, Jackeline T; Zaiat, Marcelo

    2015-12-01

    Biohydrogen production in fixed-bed reactors often leads to unstable and decreasing patterns because the excessive accumulation of biomass in the bed negatively affects the specific organic loading rate (SOLR) applied to the reactor. In this context, an innovative reactor configuration, i.e., the continuous multiple tube reactor (CMTR), was assessed in an attempt to better control the SOLR for biohydrogen production. The CMTR provides a continuous discharge of biomass, preventing the accumulation of solids in the long-term. Sucrose was used as the carbon source and mesophilic temperature conditions (25°C) were applied in three continuous assays. The reactor showed better performance when support material was placed in the outlet chamber to enhance biomass retention within the reactor. Although the SOLR could not be effectively controlled, reaching values usually higher than 10gsucroseg(-1)VSSd(-1), the volumetric hydrogen production and molar hydrogen production rates peaked, respectively, at 1470mLH2L(-1)d(-1) and 45mmolH2d(-1), indicating that the CMTR was a suitable configuration for biohydrogen production.

  16. Combination of helical ferritic-steel inserts and flux-tube-expansion divertor for the heat control in tokamak DEMO reactor

    Energy Technology Data Exchange (ETDEWEB)

    Takizuka, T., E-mail: takizuka.tomonori@gmail.com [Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita 565-0871 (Japan); Tokunaga, S.; Hoshino, K. [Japan Atomic Energy Agency, 2-166, Omotedate, Obuchi, Rokkasho, Aomori 039-3212 (Japan); Shimizu, K. [Japan Atomic Energy Agency, 801-1, Mukoyama, Naka 311-0193 (Japan); Asakura, N. [Japan Atomic Energy Agency, 2-166, Omotedate, Obuchi, Rokkasho, Aomori 039-3212 (Japan)

    2015-08-15

    Edge localized modes (ELMs) in the H-mode operation of tokamak reactors may be suppressed/mitigated by the resonant magnetic perturbation (RMP), but RMP coils are considered incompatible with DEMO reactors under the strong neutron flux. We propose an innovative concept of the RMP without installing coils but inserting ferritic steels of the helical configuration. Helically perturbed field is naturally formed in the axisymmetric toroidal field through the helical ferritic steel inserts (FSIs). When ELMs are avoided, large stationary heat load on divertor plates can be reduced by adopting a flux-tube-expansion (FTE) divertor like an X divertor. Separatrix shape and divertor-plate inclination are similar to those of a simple long-leg divertor configuration. Combination of the helical FSIs and the FTE divertor is a suitable method for the heat control to avoid transient ELM heat pulse and to reduce stationary divertor heat load in a tokamak DEMO reactor.

  17. Location of grab samples from inner continental shelf of North Carolina during U.S. Geological Survey research cruises 1999-045-FA, 2001-005-FA, 2002-013-FA, 2004-003-FA (grabsamples.shp, geographic, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  18. Virginia Offshore Wind Cost Reduction Through Innovation Study (VOWCRIS) (Poster)

    Energy Technology Data Exchange (ETDEWEB)

    Maples, B.; Campbell, J.; Arora, D.

    2014-10-01

    The VOWCRIS project is an integrated systems approach to the feasibility-level design, performance, and cost-of-energy estimate for a notional 600-megawatt offshore wind project using site characteristics that apply to the Wind Energy Areas of Virginia, Maryland and North Carolina.

  19. Flaw detecting method for welded portion between lower end plate and stab tube of reactor pressure vessel and liquid medium-filling device used for the method

    International Nuclear Information System (INIS)

    The present invention provides a method of reliably performing an ultrasonic flaw detecting test for a welded portion between a lower end plate and a stab tube of a reactor pressure vessel. Namely, a liquid medium is filled into a space formed between the outer circumference of a housing of a driving device, and an inner surface of a driving device-insertion hole and the stab tube. Ultrasonic waves are appropriately transferred to the welded portion by means of the liquid medium. Accordingly, the ultrasonic test can reliably be performed for the welded portion between the lower end plate and the stab tube. In addition, the housing of the driving device is coated at a portion where it is situated to the outer side of the main body of the pressure vessel. The liquid medium is continuously supplied from a medium supply device into the inside of the main body of the filling device. The liquid medium is filled into the space formed by the outer circumference of the housing of the driving device, and the inner surface of the insertion hole of the driving device and the stab tube. Accordingly, ultrasonic test can reliably performed for the welded portion between the lower end plate and the stab tube. (I.S.)

  20. A repair process for an heterogenous welded joint between a nuclear reactor component tube and a pipe

    International Nuclear Information System (INIS)

    The repairing process involves cutting a tubular section of the tube and the pipe, which includes the welded joint, and preparing an austenitic stainless steel tubular section for substitution; the section is then narrow-joint welded with the low-alloy steel tube, and finally welded to the austenitic stainless steel pipe. Application to repairing a welded joint between a PWR pressurizer tube and the expansion pipe of the pressurizer. (authors). 7 refs., 3 figs

  1. Use of a packed-bed airlift reactor with net draft tube to study kinetics of naphthalene degradation by Ralstonia eutropha.

    Science.gov (United States)

    Jalilnejad, Elham; Vahabzadeh, Farzaneh

    2014-03-01

    Biodegradation of naphthalene by Ralstonia eutropha (also known as Cupriavidus necator) in a packed-bed airlift reactor with net draft tube (PBALR-nd) was studied; the Kissiris pieces were the packing material. The reactor hydrodynamics has been characterized under abiotic conditions and the dependencies of the superficial gas velocity (U G) on the gas holdup (εG), liquid mixing time, and mass transfer coefficient were determined. The improving role of the net draft tube in this small column reactor (height 42 cm, ID 5 cm) was confirmed. The flow regime was described using the εG α U G (n) expression, and bubbly flow was observed in PBALR-nd at U G kinetics of biodegradation was modeled using the Haldane and Aiba equations. The fitting of the experimental results to the models were done according to the nonlinear least square regression technique. The biokinetic constants (q m, K s, and K i) were estimated and q m as the specific biodegradation rate was equaled to 0.415 and 0.24 mgnaph./mgcell h for the Haldane and Aiba equations, respectively. The goodness of fit reported as R (2) and root-mean-square error (RMSE) showed the adequate fitness of the Haldane and Aiba models in predicting naphthalene biodegradation kinetics. On the basis of the HPLC results, a hypothetical pathway for the biodegradation was presented.

  2. Case study of the failure of supercritical water oxidation reactor tubing during the treatment of 2,4 DNP with ammonium sulphate

    International Nuclear Information System (INIS)

    During the process of Supercritical Water Oxidation (SCWO) organic chemical streams are oxidized at high temperature and pressure, typically in excess of 647 K and 22.1 MPa. Due to high operating temperatures and pressures severely corrosive environments often ensue and eventually lead to SCWO reactor tube failures. This case study looked at one such failure of Alloy 625 (61Ni-21.5Cr-9Mo) tubing which occurred at the UBC/NORAM SCWO pilot plant while treating a feed of waste water containing 2.4 wt% 2,4 dinitrophenolate, 2% ammonium sulphate and 6% excess ammonia. Although the feed pH was approximately 9 and therefore not expected to be corrosive, in fact the tube failed when exposed to this feed (with oxygen) for a period of about 1 hour at 650-655 K. Through the examination of the ensuing thermodynamic system as well as SEM and Optical Microscope analysis of the ruptured portions of tubing, it was found that the addition of ammonium sulphate to the treated media caused rapid failure due to de-alloying. Findings show that the high sub-critical temperature and high density of the feed water at failure points, as well as the corrosion morphology are consistent with attack by ammonia. The formation of a stable soluble nickel-ammine phase is suspected. (author)

  3. Tests for development of estimation technology of reactor core deformation. Report No.1: fundamental mechanical properties of wrapper tube (test report)

    Energy Technology Data Exchange (ETDEWEB)

    Nishiura, Takeo; Shimazaki, Yuji; Horikiri, Morito [Japan Nuclear Cycle Development Inst., Oarai, Ibaraki (Japan). Oarai Engineering Center

    1998-10-01

    Mechanical properties such as local contact compression stiffness, bending stiffness, deformation properties, material properties, and friction properties of a wrapper tube structure were clarified experimentally, which can be used as the basic data for development of estimation technology of reactor core deformation. Contents of the Tests data as follows: (1) Effects of load supporting boundary conditions, whether or not a contact-proof pad is attached, and length of duct, on cross section deformation of wrapper tube were made clear as the local contact compression stiffness characteristics. (2) Bending stiffness does not depend on the difference of load supporting boundary conditions. The property of cross section deformation under bending load was obtained. (3) The deformation modes and the strain distributions were obtained by the deformation tests of wrapper tube. (4) The stress-strain diagrams including plastic range under various strain variation rates were obtained by the material tests at room temperature. (5) The static and the dynamic friction coefficients by various contact angles and the contact loads between contact-proof pads of two wrapper tubes were obtained by friction property tests. (author)

  4. A repair process for an heterogenous welded joint between a nuclear reactor component tube and a pipe

    International Nuclear Information System (INIS)

    The repairing process involves cutting a tubular section of the tube (made of low alloy steel) and the pipe (made of austenitic stainless steel), which includes the welded joint, and preparing an heterogenous tubular section for substitution (a first section, made of ferritic steel, is butt welded to a second section, made of austenitic stainless steel); the tubular section is then narrow-joint welded with the low-alloy steel tube, and finally welded to the austenitic stainless steel pipe. Application to repairing a welded joint between a pressurizer tube and an expansion pipe connected to the primary circuit. (author). 5 refs., 4 figs

  5. Methodical and experimental features of operative periodic control of mechanic properties in metal tubes of WWER-1000 reactors

    International Nuclear Information System (INIS)

    The results of the methodical development and the results of the base material of the weld metal mechanical properties control for the RU WWER-1000 tubing after 100 thousand hours of service are generalized. The problem of the tubing service life extension for the operating Power Station blocks of WWER-1000 of Russia and Ukraine is considered on the base of the control of mechanical properties that depend on ageing

  6. Biodegradation of 2,4,6-trichlorophenol in a packed-bed biofilm reactor equipped with an internal net draft tube riser for aeration and liquid circulation

    International Nuclear Information System (INIS)

    For the aerobic biodegradation of the fungicide and defoliant 2,4,6-trichlorophenol (2,4,6-TCP), a bench-scale packed-bed bioreactor equipped with a net draft tube riser for liquid circulation and oxygenation (PB-ALR) was constructed. To obtain a high packed-bed volume relative to the whole bioreactor volume, a high AD/AR ratio was used. Reactor's downcomer was packed with a porous support of volcanic stone fragments. PB-ALR hydrodynamics and oxygen mass transfer behavior was evaluated and compared to the observed behavior of the unpacked reactor operating as an internal airlift reactor (ALR). Overall gas holdup values εG, and zonal oxygen mass transfer coefficients determined at various airflow rates in the PB-ALR, were higher than those obtained with the ALR. When comparing mixing time values obtained in both cases, a slight increment in mixing time was observed when reactor was operated as a PB-ALR. By using a mixed microbial community, the biofilm reactor was used to evaluate the aerobic biodegradation of 2,4,6-TCP. Three bacterial strains identified as Burkholderia sp., Burkholderia kururiensis and Stenotrophomonas sp. constituted the microbial consortium able to cometabolically degrade the 2,4,6-TCP, using phenol as primary substrate. This consortium removed 100% of phenol and near 99% of 2,4,6-TCP. Mineralization and dehalogenation of 2,4,6-TCP was evidenced by high COD removal efficiencies (∼95%), and by the stoichiometric release of chloride ions from the halogenated compound (∼80%). Finally, it was observed that the microbial consortium was also capable to metabolize 2,4,6-TCP without phenol as primary substrate, with high removal efficiencies (near 100% for 2,4,6-TCP, 92% for COD and 88% for chloride ions)

  7. Biodegradation of 2,4,6-trichlorophenol in a packed-bed biofilm reactor equipped with an internal net draft tube riser for aeration and liquid circulation

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-De Jesus, A.; Romano-Baez, F.J.; Leyva-Amezcua, L.; Juarez-Ramirez, C.; Ruiz-Ordaz, N. [Departamento de Ingenieria Bioquimica, Escuela Nacional de Ciencias Biologicas, IPN. Prol. Carpio y Plan de Ayala, Colonia Santo Tomas, s/n. CP 11340, Mexico, D.F. (Mexico); Galindez-Mayer, J. [Departamento de Ingenieria Bioquimica, Escuela Nacional de Ciencias Biologicas, IPN. Prol. Carpio y Plan de Ayala, Colonia Santo Tomas, s/n. CP 11340, Mexico, D.F. (Mexico)], E-mail: cmayer@encb.ipn.mx

    2009-01-30

    For the aerobic biodegradation of the fungicide and defoliant 2,4,6-trichlorophenol (2,4,6-TCP), a bench-scale packed-bed bioreactor equipped with a net draft tube riser for liquid circulation and oxygenation (PB-ALR) was constructed. To obtain a high packed-bed volume relative to the whole bioreactor volume, a high A{sub D}/A{sub R} ratio was used. Reactor's downcomer was packed with a porous support of volcanic stone fragments. PB-ALR hydrodynamics and oxygen mass transfer behavior was evaluated and compared to the observed behavior of the unpacked reactor operating as an internal airlift reactor (ALR). Overall gas holdup values {epsilon}{sub G}, and zonal oxygen mass transfer coefficients determined at various airflow rates in the PB-ALR, were higher than those obtained with the ALR. When comparing mixing time values obtained in both cases, a slight increment in mixing time was observed when reactor was operated as a PB-ALR. By using a mixed microbial community, the biofilm reactor was used to evaluate the aerobic biodegradation of 2,4,6-TCP. Three bacterial strains identified as Burkholderia sp., Burkholderia kururiensis and Stenotrophomonas sp. constituted the microbial consortium able to cometabolically degrade the 2,4,6-TCP, using phenol as primary substrate. This consortium removed 100% of phenol and near 99% of 2,4,6-TCP. Mineralization and dehalogenation of 2,4,6-TCP was evidenced by high COD removal efficiencies ({approx}95%), and by the stoichiometric release of chloride ions from the halogenated compound ({approx}80%). Finally, it was observed that the microbial consortium was also capable to metabolize 2,4,6-TCP without phenol as primary substrate, with high removal efficiencies (near 100% for 2,4,6-TCP, 92% for COD and 88% for chloride ions)

  8. Simulation of steam condensation in the presence of noncondensable gases in horizontal condenser tubes using RELAP5 for advanced nuclear reactors

    International Nuclear Information System (INIS)

    Horizontal heat exchangers are used in advanced light water nuclear reactors in their passive cooling systems, such as residual heat removal (RHRS) and passive containment cooling system (PCCS). Condensation studies of steam and noncondensable gases mixtures in these heat exchangers are very important due to the phenomena multidimensional nature and the condensate stratification effects. This work presents a comparison between simulation results and experimental data in steady state conditions for some inlet pressure, steam and noncondensable gases (air) inlet mass fractions. The test section is three meters long and consists of two concentric tubes containing pressure, temperature and flow rate sensors. The internal tube, called condenser, contains steam-air mixture flow and external tube is a counter current cooler with water flow rate at low temperature. This test section was modeled and simulations were performed with RELAP5 code. Experimental tests were carried out for 200 to 400 kPa inlet pressure and 5, 10, 15 and 20% of inlet air mass fractions. Comparisons between experimental data and simulation results are presented for 200 and 400 kPa pressure conditions and showed good agreement. However, for 400 kPa inlet steam pressure and inlet air mass fractions above 5%, the simulated temperatures are lower than the experimental data at the final third from the inlet condenser tube, indicating a code overestimation of heat transfer coefficient. New correlations for heat transfer coefficient in these steam-air conditions must be theoretical and experimentally studied and implemented in RELAP5 code for better representing the condensation phenomena. (author)

  9. Selection of instruments used for vibration measurement of fuel bundles in a pressure tube under CANDU reactor operating conditions

    International Nuclear Information System (INIS)

    Vibration characteristics of CANDU fuel bundle and fuel elements is a key parameter considered in the design of a fuel bundle. Out-reactor frequency and temperature sweep tests, under reactor operating conditions, are performed to verify vibration characteristics of CANDU fuel bundles. Several options have been considered in the selection of vibration instrumentation to perform out-reactor frequency and temperature sweep tests. This paper compares the benefits and disadvantages of various vibration instruments and summarizes the rationale behind the selection of instruments used for vibration measurements over a range of temperature and pressure pulsation frequencies. The conclusions are presented from the bench tests performed, which confirm the use of the selected instruments. (author)

  10. Fuel composition optimization in a 78-element fuel bundle for use in a pressure tube type supercritical water-cooled reactor

    International Nuclear Information System (INIS)

    A 78-element fuel bundle containing a plutonium-thorium fuel mixture has been proposed for a Generation IV pressure tube type supercritical water-cooled reactor. In this work, using a lattice cell model created with the code DRAGON,the lattice pitch, fuel composition (fraction of PuO2 in ThO2) and radial enrichment profile of the 78-element bundle is optimized using a merit function and a metaheuristic search algorithm.The merit function is designed such that the optimal fuel maximizes fuel utilization while minimizing peak element ratings and coolant void reactivity. A radial enrichment profile of 10 wt%, 11 wt% and 20 wt% PuO2 (inner to outer ring) with a lattice pitch of 25.0 cm was found to provide the optimal merit score based on the aforementioned criteria. (author)

  11. Steam generator tube failures

    International Nuclear Information System (INIS)

    A review and summary of the available information on steam generator tubing failures and the impact of these failures on plant safety is presented. The following topics are covered: pressurized water reactor (PWR), Canadian deuterium uranium (CANDU) reactor, and Russian water moderated, water cooled energy reactor (VVER) steam generator degradation, PWR steam generator tube ruptures, the thermal-hydraulic response of a PWR plant with a faulted steam generator, the risk significance of steam generator tube rupture accidents, tubing inspection requirements and fitness-for-service criteria in various countries, and defect detection reliability and sizing accuracy. A significant number of steam generator tubes are defective and are removed from service or repaired each year. This wide spread damage has been caused by many diverse degradation mechanisms, some of which are difficult to detect and predict. In addition, spontaneous tube ruptures have occurred at the rate of about one every 2 years over the last 20 years, and incipient tube ruptures (tube failures usually identified with leak detection monitors just before rupture) have been occurring at the rate of about one per year. These ruptures have caused complex plant transients which have not always been easy for the reactor operators to control. Our analysis shows that if more than 15 tubes rupture during a main steam line break, the system response could lead to core melting. Although spontaneous and induced steam generator tube ruptures are small contributors to the total core damage frequency calculated in probabilistic risk assessments, they are risk significant because the radionuclides are likely to bypass the reactor containment building. The frequency of steam generator tube ruptures can be significantly reduced through appropriate and timely inspections and repairs or removal from service

  12. Steam generator tube failures

    Energy Technology Data Exchange (ETDEWEB)

    MacDonald, P.E.; Shah, V.N.; Ward, L.W.; Ellison, P.G.

    1996-04-01

    A review and summary of the available information on steam generator tubing failures and the impact of these failures on plant safety is presented. The following topics are covered: pressurized water reactor (PWR), Canadian deuterium uranium (CANDU) reactor, and Russian water moderated, water cooled energy reactor (VVER) steam generator degradation, PWR steam generator tube ruptures, the thermal-hydraulic response of a PWR plant with a faulted steam generator, the risk significance of steam generator tube rupture accidents, tubing inspection requirements and fitness-for-service criteria in various countries, and defect detection reliability and sizing accuracy. A significant number of steam generator tubes are defective and are removed from service or repaired each year. This wide spread damage has been caused by many diverse degradation mechanisms, some of which are difficult to detect and predict. In addition, spontaneous tube ruptures have occurred at the rate of about one every 2 years over the last 20 years, and incipient tube ruptures (tube failures usually identified with leak detection monitors just before rupture) have been occurring at the rate of about one per year. These ruptures have caused complex plant transients which have not always been easy for the reactor operators to control. Our analysis shows that if more than 15 tubes rupture during a main steam line break, the system response could lead to core melting. Although spontaneous and induced steam generator tube ruptures are small contributors to the total core damage frequency calculated in probabilistic risk assessments, they are risk significant because the radionuclides are likely to bypass the reactor containment building. The frequency of steam generator tube ruptures can be significantly reduced through appropriate and timely inspections and repairs or removal from service.

  13. Implementation of Wolsong Pump Model, Pressure Tube Deformation Model and Off-take Model into MARS Code for Regulatory Auditing of CANDU Reactors

    International Nuclear Information System (INIS)

    Korea currently has four operating units of the CANDU-6 type reactor in Wolsong. However, the safety assessment system for CANDU reactors has not been fully established due to lack of self-reliance technology. Although the CATHENA code had been introduced from AECL, it is undesirable to use vendor's code for regulatory auditing analysis. In Korea, the MARS code has been developed for decades and is being considered by KINS as a thermal hydraulic regulatory auditing tool for nuclear power plants. Before this decision, KINS (Korea Institute of Nuclear Safety) had developed RELAP5/MOD3/CANDU code for CANDU safety analyses by modifying the model of existing PWR auditing tool, RELAP5/MOD3. The main purpose of this study is to transplant the CANDU models of RELAP5/MOD3/CANDU code to MARS code including quality assurance of the developed models. This first part of the research series presents the implementation and verification of the Wolsong pump model, the pressure tube deformation model, and the off-take model for arbitrary-angled branch pipes

  14. Implementation of Wolsong Pump Model, Pressure Tube Deformation Model and Off-take Model into MARS Code for Regulatory Auditing of CANDU Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, C.; Rhee, B. W.; Chung, B. D. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Cho, Y. J.; Kim, M. W. [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2008-05-15

    Korea currently has four operating units of the CANDU-6 type reactor in Wolsong. However, the safety assessment system for CANDU reactors has not been fully established due to lack of self-reliance technology. Although the CATHENA code had been introduced from AECL, it is undesirable to use vendor's code for regulatory auditing analysis. In Korea, the MARS code has been developed for decades and is being considered by KINS as a thermal hydraulic regulatory auditing tool for nuclear power plants. Before this decision, KINS (Korea Institute of Nuclear Safety) had developed RELAP5/MOD3/CANDU code for CANDU safety analyses by modifying the model of existing PWR auditing tool, RELAP5/MOD3. The main purpose of this study is to transplant the CANDU models of RELAP5/MOD3/CANDU code to MARS code including quality assurance of the developed models. This first part of the research series presents the implementation and verification of the Wolsong pump model, the pressure tube deformation model, and the off-take model for arbitrary-angled branch pipes.

  15. Automatic thickness measuring system of zirconium and zircaloy-2 layers of zirconium liner cladding tubes for boiling water reactor

    International Nuclear Information System (INIS)

    An automatic measuring system using ultrasonic method and electromagnetic method has been developed to measure the thickness of zirconium and zircaloy-2 layers. The sophisticated mechanism and the unique signal processing for suppression of several types of error enable high accurate measurement. The standard deviation of the liner thickness measurement is 2.2 μm and that of mother layer measurement is 3.0 μm. This system is very useful to assure the thickness of each layer and to produce high quality zirconium liner cladding tubes. (author)

  16. Straightening tubes

    International Nuclear Information System (INIS)

    Hexagonal wrapper tubes, especially for nuclear reactor core sub-assemblies, may suffer from unacceptable bow as a result of welding wear pads to the wrapper and heat treatment. Straightening of the bow is effected by a method wherein at each of a series of axially spaced locations the faces or vertices of the tube are measured relative to a reference to determine the direction of bow at the locations. From these measurements, the appropriate axial locations for the application of corrective loading can be determined, whereby by application of the loading at a selected face or vertex for such measurements the bow is reduced. Such loading, by an actuator, can be repeated at the locations until the bow is reduced to within tolerances. (author)

  17. Manipulator for inspection or repair of heat exchanger tubes, in particular in steam generators for nuclear reactors

    International Nuclear Information System (INIS)

    The manipulator used to inspect or repair pipes in the steam generator chamber of a PWR can be introduced and removed through a penetration nozzle which can be sealed tightly by means of a blind flange. The front end of the manipulator carries a swivel arm which can be operated remotely to be moved in a plane parallel to the tube plate. The end of the swivel arm carries a holder for a mouthpiece which can be extended and retracted. This carrier can also be operated remotely so as to be aligned to the pipe orifices in a direction normal to the swivel plane of the swivel arm. The manipulator is supported in antifriction bearings in the penetration nozzle so as to be movable longitudinally. (DG)

  18. 77 FR 20438 - Independent Spent Fuel Storage Installation, Virginia Electric and Power Company: North Anna...

    Science.gov (United States)

    2012-04-04

    ... COMMISSION Independent Spent Fuel Storage Installation, Virginia Electric and Power Company: North Anna Power... Virginia Electric and Power Company (Dominion or licensee) pursuant to 10 CFR 72.7 from the requirements of... with the operation of Dominion's nuclear power reactors, North Anna Power Station Units 1 and...

  19. Liquid metal reactor KALIMER development - Study on the high temperature properties of the steam generator tubing for LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yong Soo; Kim, Soon Tae; Park, Hui Sang; Kim, Soo Han [Yonsei University, Seoul (Korea); Kim, Young Sik [Andong National University, Andong (Korea)

    1999-04-01

    This work dealt with the evaluation of super stainless steels for steam generator tubing of LMFBR. The experimental alloys were designed to simulate the elimination of alloying elements, in special, C and N. Regardless of carbon contents, super stainless steels showed the excellent properties (tensile properties and corrosion resistance) than those of 9Cr-1Mo steel. Nitrogen content has affected positively the ultimate tensile strength and yield strength by TT(Thermal Treatment), but the elongation was reduced by TT in case of nitrogen free alloy and the elongation was largely increased by TT in case of nitrogen bearing alloys. In acidic chloride environment, nitrogen has influenced a little on corrosion potential and critical current density, but largely on passive current density, especially, at high potential. However, the trend of corrosion potential and critical current density by nitrogen was similar to the results in acidic solutions, but passive current density was largely affected by nitrogen content of stainless steels. 29 refs., 24 figs., 8 tabs. (Author)

  20. Degradation of phenol solution by ozone oxidation in a microporous tube-in-tube microchannel reactor%采用套管式微反应器臭氧氧化降解苯酚水溶液的研究

    Institute of Scientific and Technical Information of China (English)

    李鹏飞; 李文军; 王洁欣; 付纪文; 陈建峰; 邵磊

    2011-01-01

    将新型套管式微反应器应用于苯酚溶液的臭氧氧化处理体系,考察了套管式微反应器微孔孔径、内外管环隙、苯酚溶液初始质量浓度、温度、pH值和气液比等因素对苯酚去除率的影响.结果表明,苯酚去除率随着套管微孔孔径、内外管环隙和苯酚溶液初始质量浓度的增大而减小;随着气液比和温度的增大而增大;而随着溶液pH值的增大,苯酚去除率则先增大后减小.初始质量浓度为100mg/L的苯酚溶液在pH为11,气液比为13,套管内管孔径为10μm,内外管环隙为250μm,温度为25℃的条件下,苯酚去除率可达99%以上.%The degradation of phenol in aqueous solution by ozone oxidation has been studied in a microporous tube-in-tube microchannel reactor (MTMCR). The results indicated that the removal percentage of phenol decreased with increasing micropore size, annular channel width and initial phenol concentration, and increased with increasing ratio of gas volumetric flow rate to liquid volumetric flow rate and reaction temperature. It was also observed that the removal percentage of phenol initially increased, and subsequently decreased with increasing pH value. A phenol removal percentage of over 99% was achieved under the following reaction conditions: initial phenol concentration of 100 mg/L, micropore size of 10μm, annular channel width of 250μm, ratio of gas volumetric flow rate to liquid volumetric flow rate of 13, pH value of 11 and reaction temperature of 25 ℃.

  1. Virginia Water Central

    OpenAIRE

    Virginia Water Resources Research Center

    2006-01-01

    This newsletter features articles on water-related science, policy, and law. Distributed to state agency representatives, faculty, students and interested citizens, it aims to provide current information, statistics, news, and notices related to water resources in Virginia.

  2. Virginia Water Central

    OpenAIRE

    Virginia Water Resources Research Center

    2005-01-01

    This newsletter features articles on water-related science, policy, and law. Distributed to state agency representatives, faculty, students and interested citizens, it aims to provide current information, statistics, news, and notices related to water resources in Virginia.

  3. Virginia Water Central

    OpenAIRE

    Virginia Water Resources Research Center

    2012-01-01

    This newsletter features articles on water-related science, policy, and law. Distributed to state agency representatives, faculty, students and interested citizens, it aims to provide current information, statistics, news, and notices related to water resources in Virginia.

  4. Virginia Water Central

    OpenAIRE

    Virginia Water Resources Research Center

    1999-01-01

    This newsletter features articles on water-related science, policy, and law. Distributed to state agency representatives, faculty, students and interested citizens, it aims to provide current information, statistics, news, and notices related to water resources in Virginia.

  5. Virginia Water Central

    OpenAIRE

    Virginia Water Resources Research Center

    2001-01-01

    This newsletter features articles on water-related science, policy, and law. Distributed to state agency representatives, faculty, students and interested citizens, it aims to provide current information, statistics, news, and notices related to water resources in Virginia.

  6. Virginia Water Central

    OpenAIRE

    Virginia Water Resources Research Center

    2000-01-01

    This newsletter features articles on water-related science, policy, and law. Distributed to state agency representatives, faculty, students and interested citizens, it aims to provide current information, statistics, news, and notices related to water resources in Virginia.

  7. Virginia Water Central

    OpenAIRE

    Virginia Water Resources Research Center

    1998-01-01

    This newsletter features articles on water-related science, policy, and law. Distributed to state agency representatives, faculty, students and interested citizens, it aims to provide current information, statistics, news, and notices related to water resources in Virginia.

  8. Virginia Water Central

    OpenAIRE

    Virginia Water Resources Research Center

    2003-01-01

    This newsletter features articles on water-related science, policy, and law. Distributed to state agency representatives, faculty, students and interested citizens, it aims to provide current information, statistics, news, and notices related to water resources in Virginia.

  9. Virginia Water Central

    OpenAIRE

    Virginia Water Resources Research Center

    2007-01-01

    This newsletter features articles on water-related science, policy, and law. Distributed to state agency representatives, faculty, students and interested citizens, it aims to provide current information, statistics, news, and notices related to water resources in Virginia.

  10. Virginia Water Central

    OpenAIRE

    Virginia Water Resources Research Center

    2010-01-01

    This newsletter features articles on water-related science, policy, and law. Distributed to state agency representatives, faculty, students and interested citizens, it aims to provide current information, statistics, news, and notices related to water resources in Virginia.

  11. Virginia Water Central

    OpenAIRE

    Virginia Water Resources Research Center

    2009-01-01

    This newsletter features articles on water-related science, policy, and law. Distributed to state agency representatives, faculty, students and interested citizens, it aims to provide current information, statistics, news, and notices related to water resources in Virginia.

  12. Virginia Water Central

    OpenAIRE

    Virginia Water Resources Research Center

    2011-01-01

    This newsletter features articles on water-related science, policy, and law. Distributed to state agency representatives, faculty, students and interested citizens, it aims to provide current information, statistics, news, and notices related to water resources in Virginia.

  13. Virginia Water Central

    OpenAIRE

    Virginia Water Resources Research Center

    2008-01-01

    This newsletter features articles on water-related science, policy, and law. Distributed to state agency representatives, faculty, students and interested citizens, it aims to provide current information, statistics, news, and notices related to water resources in Virginia.

  14. Virginia Water Central

    OpenAIRE

    Virginia Water Resources Research Center

    2004-01-01

    This newsletter features articles on water-related science, policy, and law. Distributed to state agency representatives, faculty, students and interested citizens, it aims to provide current information, statistics, news, and notices related to water resources in Virginia.

  15. Virginia Water Central

    OpenAIRE

    Virginia Water Resources Research Center

    2013-01-01

    This newsletter features articles on water-related science, policy, and law. Distributed to state agency representatives, faculty, students and interested citizens, it aims to provide current information, statistics, news, and notices related to water resources in Virginia.

  16. Virginia Water Central

    OpenAIRE

    Virginia Water Resources Research Center

    2002-01-01

    This newsletter features articles on water-related science, policy, and law. Distributed to state agency representatives, faculty, students and interested citizens, it aims to provide current information, statistics, news, and notices related to water resources in Virginia.

  17. Virginia Water Central

    OpenAIRE

    Virginia Water Resources Research Center

    2014-01-01

    This newsletter features articles on water-related science, policy, and law. Distributed to state agency representatives, faculty, students and interested citizens, it aims to provide current information, statistics, news, and notices related to water resources in Virginia.

  18. Impacts of COD and DCP loading rates on biological treatment of 2,4-dichlorophenol (DCP) containing wastewater in a perforated tubes biofilm reactor.

    Science.gov (United States)

    Eker, Serkan; Kargi, Fikret

    2006-08-01

    Biofilm processes offer considerable advantages for biological treatment of chlorophenol containing wastewaters since such industrial effluents are difficult to treat by conventional activated sludge processes. A rotating perforated tubes biofilm reactor (RTBR) was developed and used for treatment of 2,4-dichlorophenol (DCP) containing synthetic wastewater. Effects of COD and DCP loading rates on COD, DCP and toxicity removals were investigated. Percent COD removal decreased and effluent COD increased with increasing COD and DCP loading rates due to toxic effects of high DCP content in the feed. DCP and toxicity removals showed similar trends. As the DCP loading rate increased the effluent DCP content increased yielding high toxicity levels in the effluent. COD and DCP loading rates should be below 90gCODm(-2)d(-1) and 2.8gDCPm(-2)d(-1) in order to obtain more than 90% DCP and toxicity removals. However, DCP loading rates lower than 1gDCPm(-2)d(-1) are required to obtain more than 90% COD removal. Empirical equations were developed to estimate percent COD, DCP and toxicity removals as functions of COD and DCP loading rates. The coefficients of the empirical equations were determined by using the experimental data. Empirical model predictions for percent COD, DCP and toxicity removals were in good agreement with the experimental data.

  19. Hydrology of the Dismal Swamp Virginia and North Carolina 1974

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The purpose of this report is to summarize and interpret information on the hydrology of the Dismal Swamp area and the related geology and to suggest aspects of the...

  20. 75 FR 3942 - Carolina Power & Light Company Shearon Harris Nuclear Power Plant, Unit 1 Environmental...

    Science.gov (United States)

    2010-01-25

    ... impact (Part 73, Power Reactor Security Requirements, 74 FR 13926 through 13967, dated March 27, 2009... Carolina Power & Light Company (the licensee), now doing business as Progress Energy Carolinas, Inc. (PEC... promulgating its revisions to 10 CFR Part 73 as discussed in a Federal Register (FR) notice dated March...

  1. Use of Zircaloy 4 material for the pressure vessels of hot and cold neutron sources and beam tubes for research reactors

    International Nuclear Information System (INIS)

    The material Zircaloy 4 can be used for the pressure retaining walls for the cold and hot neutron sources and beam tubes. For the research reactor FRM-II of the Technical University Munich, Germany, the material Zircaloy 4 were chosen for the vessels of the cold and hot neutron source and for the beam tube No. 6. The sheets and forgings of Zircaloy 4 were examined in the temperature range between -256degC and 250degC. The thickness of the sheets are 3, 4, 5 and 10 mm, the maximum diameter of the forgings was 560 mm. This great forging diameters are not be treated in the ASTM rule B 351 for nuclear material, so a special approval with independent experts was necessary. The requirements for the material examinations were specified in a material specification and material test sheets which based on the ASTM rules B 351 and B 352 with additional restriction and additional requirements of the basic safety concept for nuclear power plants in Germany, which was taken into consideration in the nuclear licensing procedure. Charpy-V samples were carried out in the temperature range between -256degC and 150degC to get more information on the ductile behaviour of the Zircaloy 4. The results of the sheet examination confirm the requirements of the specifications, the results of the forging examination in the tangential testing direction are lower than specified and expected for the tensile strength. The axial and transverse values confirm the specification requirements. For the strength calculation of the pressure retaining wall a reduced material value for the forgings has to taken into consideration. The material behaviour of Zircaloy 4 under irradiation up to a fluence of ∼1·1022 n/cm2 was investigated. The loss of ductility was determined. As an additional criteria the variation of the fracture toughness was studies. Fracture mechanic calculations of the material were carried out in the licensing procedure with the focus to fulfill the leak before rupture criteria of the

  2. Use of Zircaloy 4 material for the pressure vessels of hot and cold neutron sources and beam tubes for research reactors

    International Nuclear Information System (INIS)

    The material Zircaloy 4 can be used for the pressure retaining walls for the cold and hot neutron sources and beam tubes. For the research reactor FRM-II of the Technical University Munich, Germany, the material Zircaloy 4 were chosen for the vessels of the cold and hot neutron source and for the beam tube No. 6. The sheets and forgings of Zircaloy 4 were examined in the temperature range between -256 deg. C and 250 deg. C. The thickness of the sheets are 3, 4, 5 and 10 mm, the maximum diameter of the forgings was 560 mm. This great forging diameters are not be treated in the ASTM rule B 351 for nuclear material, so a special approval with independent experts was necessary. The requirements for the material examinations were specified in a material specification and material test sheets which based on the ASTM rules B 351 and B 352 with additional restriction and additional requirements of the basic safety concept for nuclear power plants in Germany, which was take into consideration in the nuclear licensing procedure. Charpy-V samples were carried out in the temperature range between -256 deg. C and 150 deg. C to get more information on the ductile behaviour of the Zircaloy 4. The results of the sheet examination confirm the requirements of the specifications, the results of the forging examination in the tangential testing direction are lower than specified and expected for the tensile strength. The axial and transverse values confirm the specification requirements. For the strength calculation of the pressure retaining wall a reduced material value for the forgings has to take into consideration. The material behaviour of Zircaloy 4 under irradiation up to a fluence of ∼ 1x1022 n/cm2 was investigated. The loss of ductility was determined. As an additional criteria the variation of the fracture toughness was studies. Fracture mechanic calculations of the material were carried out in the licensing procedure with the focus to fulfill the leak before rupture

  3. 77 FR 8903 - Environmental Assessment and Finding of No Significant Impact; Carolina Power and Light Company...

    Science.gov (United States)

    2012-02-15

    ..., Division of Operating Reactor Licensing, Office of Nuclear Reactor Regulation, U.S. Nuclear Regulatory...\\ alloy fuel rod cladding for Renewed Facility Operating License No. NPF-63, issued to Carolina Power and... 50.46, paragraph (a)(1)(i) provides requirements for reactors containing uranium oxide fuel...

  4. Virginia Atlantic Coast Recreational Use

    Data.gov (United States)

    Virginia Department of Environmental Quality — As a member of the Mid-Atlantic Regional Council on the Ocean (MARCO), Virginia, through its Coastal Zone Management (CZM) Program, collected information on how the...

  5. Product yields and characteristics of rice husk, rice straw and corncob during fast pyrolysis in a drop-tube/fixed-bed reactor

    Directory of Open Access Journals (Sweden)

    Janewit Wannapeera

    2008-05-01

    Full Text Available Fast pyrolysis of rice husk, rice straw and corncob were investigated in a newly constructed drop-tube/fixed-bedreactor, which enables pyrolysis experiments under conditions closely simulating those occurring in commercial gasifierssuch as fluidised-bed gasifiers. Biomass samples were pyrolysed with a fast heating rate (i.e. > 1,000oC s-1, up to 850oC andholding times ranging from 1 to 10,800 seconds. Within 1 second after the biomass was injected into the reactor, considerableweight loss occurred instantaneously, leaving only a small amount of char, i.e. ~10-30 %. For all three samples, theweight loss continued throughout the range of holding times used but at an extremely slow rate, i.e. 1.3 % hr-1. The weightloss rates observed for the three biomass samples were affected by the proportion of the biomass chemical componentsas well as the metal species contents. Corncob, which had the lowest lignin content but highest cellulose content, had thehighest pyrolysis weight loss rate. On the other hand, rice husk containing a relatively high lignin content, had the lowestpyrolysis rate. The metal species (Na, K, Ca and Mg were found to increase devolatilisation yield depending on theircontents in biomass. The influence of the metal species was the most pronounced for rice straw, having the highest totalmetal species content. As the pyrolysis progressed, each biomass exhibited different char characteristics. Scanning electronmicroscopy (SEM pictures clearly showed the individual changes in geometry for all biomass-derived chars as well astheir decrease in combustion reactivities. The gas formation profiles for all three biomass samples showed almost the sametrend, with CO contributed by cellulose decomposition as the major gas product.

  6. Fabrication of seamless calandria tubes

    International Nuclear Information System (INIS)

    Full text: Calandria tube is a large diameter, thin walled zircaloy-4 tube and is an important structural component of PHWR type of reactors. These tubes are lifetime components and remain during the full life of the reactor. Calandria tubes are classified as extremely thin walled tubes with a diameter to wall thickness ratio of around 96. Such thin walled tubes are conventionally produced by seam welded route comprising of extrusion of slabs followed by a series of hot and rolling passes, shaping into O-shape and eventual welding. An alternative and superior method of fabricating the calandria tubes, the seamless route, has been developed, which involves hot extrusion of mother blanks followed by three successive cold pilger reductions. Eccentricity correction of the extruded blanks is carried out on a special purpose grinding equipment to bring the wall thickness variation within permissible limits. Predominant wall thickness reductions are given during cold pilgering to ensure high Q-factor values. The texture in the finished tubes could be closely, controlled with an average fr value of 0.65. Pilgering parameters and tube guiding system have been specially designed to facilities rolling of thin walled tubes. Seamless calandria tubes have distinct advantages over welded tubes. In addition to the absence of weld, they are dimensionally more stable, lighter in weight and possess uniform grains with superior grain size. The cycle time from billet to finished product is substantially reduced and the product is amenable to high level of quality assurance. The most significant feature of the seamless route is its material recovery over welded route. Residual stresses measured in the tubes indicate that these are negligible and uniform along the length of the tube. In view of their superior quality, the first charge of seamless calandria tubes will be rolled into the first 500 MWe Pressurised Heavy Water Reactor at Tarapur

  7. Water quality assessment for the Kanawha River basin (North Carolina, Virginia, West Virginia)

    Energy Technology Data Exchange (ETDEWEB)

    George, R.C.; Cantor, R.I.

    1973-09-01

    The purpose of this document is to provide answers to four questions: (1) what is the current water quality situation; (2) why does the situation exist; (3) what has been the trend in recent years; and (4) what will the water quality be in years to come. In so doing, identification is made of significant water bodies that, in 1973, met the 1983 goal of water quality adequate for swimming and for the protection and propagation of fish and wildlife and water bodies that might achieve the 1983 goal by 1977, 1983 or some later date. (GRA)

  8. Virginia Water Central

    OpenAIRE

    Virginia Water Resources Research Center

    1999-01-01

    This newsletter features articles on water-related science, policy, and law. Distributed to state agency representatives, faculty, students and interested citizens, it aims to provide current information, statistics, news, and notices related to water resources in Virginia. Special Issue on Water Research

  9. Pressure tube life management in CANDU-6 nuclear plant

    International Nuclear Information System (INIS)

    Operating parameters of pressure tube in CANDU-6 reactor, the relation between pressure tube life and plant life improvement of pressure tube by AECL in past years were summarized, and the factors affecting pressure tube life, idea and main measures of pressure tube life management in QINSHAN CANDU-6 power plant introduced

  10. Institutional framework for rural water supply in North Carolina, South Carolina, and Virginia

    OpenAIRE

    Cox, William Edward, 1944-; Patrizi, Kurt S.

    1983-01-01

    William E. Cox (Department of Civil Engineering, VPI & SU), Kurt S. Patrizi (Ohio Environmental Protection Agency) The work upon which this report is based was supported in part by funds provided by the United States Department of the Interior. " Project B-095-VA"

  11. Developing a Topographic Model to Predict the Northern Hardwood Forest Type within Carolina Northern Flying Squirrel (Glaucomys sabrinus coloratus) Recovery Areas of the Southern Appalachians

    OpenAIRE

    Andrew Evans; Richard Odom; Lynn Resler; W. Mark Ford; Steve Prisley

    2014-01-01

    The northern hardwood forest type is an important habitat component for the endangered Carolina northern flying squirrel (CNFS; Glaucomys sabrinus coloratus) for den sites and corridor habitats between boreo-montane conifer patches foraging areas. Our study related terrain data to presence of northern hardwood forest type in the recovery areas of CNFS in the southern Appalachian Mountains of western North Carolina, eastern Tennessee, and southwestern Virginia. We recorded overstory species co...

  12. University to promote Virginia Cycling and Pedestrian Awareness Week

    OpenAIRE

    West, Hilary

    2009-01-01

    Virginia Tech has joined DRIVE SMART Virginia, Bike Walk Virginia, the Virginia Highway Safety Office of the Commonwealth's Department of Motor Vehicles to promote Virginia Cycling and Pedestrian Awareness Week scheduled for Sept. 13-20.

  13. Carolinas Communication Annual, 1998.

    Science.gov (United States)

    McLennan, David B.

    1998-01-01

    This 1998 issue of "Carolinas Communication Annual" contains the following articles: "Give Me That Old Time Religion?: A Study of Religious Themes in the Rhetoric of the Ku Klux Klan" (John S. Seiter); "The Three Stooges versus the Third Reich" (Roy Schwartzman); "Interdisciplinary Team Teaching: Implementing Collaborative Instruction in an…

  14. Sealing device for nuclear power reactor

    International Nuclear Information System (INIS)

    The sealing device is to stop a leak on a reactor pressure vessel where control of the output of reactor is arranged by control rods which are handled by drives connected to control rods and bars in tubes which penetrate the reactor wall. Each tube has a supporting case on the inside of the wall opened to the hole and welded to the tube. The weld may crack and leak. Then an inner sealing tube made of soft metallic material whose outer surface is conical is drawn on to the tube over which an outer sealing tube made of hard metallic material and conical inner surface is placed. On both sides of the crack special adhering planes are formed between the inner sealing tube and the tubes or the supporting case. When the outer sealing tube is pressed over the inner sealing tube, the conical surfaces tighten it against the tube and the supporting case

  15. Metabolic responses to hypoxia of Lycenchelys verrillii (wolf eelpout) and Glyptocephalus cynoglossus (witch flounder): Sedentary bottom fishes of the Hatteras/Virginia middle slope

    Science.gov (United States)

    Moser, M.L.; Ross, S.W.; Sulak, K.J.

    1996-01-01

    We collected wolf eelpouts Lycenchelys verrillii and witch flounder Glyptocephalus cynoglossus from Hatteras (North Carolina, USA) and Virginia (USA) Middle Slope sites using a submersible, and made shipboard measurements of their respiration rates and survival in hypoxic (Virginia site maintained a constant respiration rate until oxygen saturation dropped below 20%. Moreover, eelpouts from the Hatteras site were significantly more tolerant of hypoxic conditions than fish from the Virginia site and survived anoxia for short periods. These results and our submersible observations of fish behavior support the hypothesis that the Hatteras Middle Slope fauna is exposed to short-term hypoxia events.

  16. Current practices for ultrasonic and radiographic examination of tubes, tube plates and tube-plate welds of tube bundles in heat exchangers. Chapter 3

    International Nuclear Information System (INIS)

    The chapter describes the ultrasonic and radiographic inspection procedures that are applied to heat exchanger tube bundles. The inspection process starts with the ultrasonic examination of the tubes and tube plates during manufacture, followed by radiography of the tube-to-tube-plate welds during fabrication of the tube bundle. Ultrasonic methods are explained for welds which are amenable to this type of inspection. For the in-service inspection of tube bundles the chapter relates the authors' experiences on the ultrasonic inspection of tubes and tube plates in the Prototype Fast Breeder Reactor at Dounreay. At the end of the chapter some comments are made about future ultrasonic and radiographic developments for tube bundles. (author)

  17. Status of R and D Activities related to Axial and Radial Creep of Pressure tubes of Heavy Water Reactors in India

    International Nuclear Information System (INIS)

    Scope of presentation: • R and D Strength of the organisation; • Brief introduction about PHWRs in India – Operating and under construction; • Issues associated with axial elongation and radial expansion due to neutron enhanced creep in pressure tube; • Status of work done till date; • Important Points related to present CRP

  18. Design, fabrication, and testing of gadolinium-shielded metal fuel samples in the hydraulic tube of the high flux isotope reactor

    International Nuclear Information System (INIS)

    The use of hydraulic rabbit capsules inserted into and ejected from the core of the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL) during full power operation allows for precise control of the neutron fluence in fueled experiments. Rabbit capsules with strong thermal neutron absorbers must be used to screen out thermal neutrons, thereby reducing the heat generation rate while maintaining the fast neutron flux that produces displacement damage similar to fast reactor type conditions. However, rapid insertion and ejection of rabbit capsules containing a strong neutron absorber causes a reactivity response in the reactor that has the potential to engage the HFIR safety response system which could result in an unplanned shutdown. Therefore, a set of tests were performed to provide the data needed to establish limits on the reactivity worth that can be ejected from the hydraulic facility without causing a reactor shutdown. This paper will describe the design, operation, and results of the reactivity measurements undertaken to understand the reactor response to insertion of the gadolinium-lined rabbit capsules. (author)

  19. Physical aspects of liquid-impelled loop reactors.

    NARCIS (Netherlands)

    Sonsbeek, van H.M.

    1992-01-01

    The liquid-impelled loop reactor (LLR) is a reactor that consists of two parts : the main tube and the circulation tube. Both parts are in open connection at the bottom and at the top. The reactor is filled with a liquid phase: the continuous phase. Another liquid phase is injected in the main tube

  20. Numerical analysis on the calandria tubes in the moderator of a heavy water reactor using OpenFOAM and other codes

    International Nuclear Information System (INIS)

    CANDU, a prototype of heavy water reactor is modeled for the moderator system with porous media buoyancy-effect heat-transfer turbulence model. OpenFOAM, a set of C++ classes and libraries developed under the object-oriented concept, is selected as the tool of numerical analysis. The result from this computational code is compared with experiments and other commercial code data through ANSYS-CFX and COMSOL Multi-physics. The three-dimensional code concerning buoyancy force, turbulence, and heat transfer is tested and shown to be successful for the analysis of thermo-hydraulic system of heavy water reactors. (authors)

  1. Numerical Analysis on the Calandria Tubes in the Moderator of a Heavy Water Reactor Using OpenFOAM and Other Codes

    Science.gov (United States)

    Chang, Se-Myong; Kim, Hyoung Tae

    2014-06-01

    CANDU, a prototype of heavy water reactor is modeled for the moderator system with porous media buoyancy-effect heat-transfer turbulence model. OpenFOAM, a set of C++ classes and libraries developed under the object-oriented concept, is selected as the tool of numerical analysis. The result from this computational code is compared with experiments and other commercial code data through ANSYS-CFX and COMSOL Multi-physics. The three-dimensional code concerning buoyancy force, turbulence, and heat transfer is tested and shown to be successful for the analysis of thermo-hydraulic system of heavy water reactors.

  2. Update on seamless calandria tube development and qualification

    International Nuclear Information System (INIS)

    AECL is undertaking the qualification of the production of seamless calandria tubes as replacement components for installation in reactors during retubing. Seamless tube prototypes made from Zircaloy-2 possessing a suitable crystallographic texture have been shown to be significantly stronger than seam-welded tubes under both rising pressure and sustained pressure conditions in a simulated reactor loading. This paper describes the seamless calandria tube development program and current status. (author)

  3. Flock sizes and sex ratios of canvasbacks in Chesapeake Bay and North Carolina

    Science.gov (United States)

    Haramis, G.M.; Derleth, E.L.; Link, W.A.

    1994-01-01

    Knowledge of the distribution, size, and sex ratios of flocks of wintering canvasbacks (Aythya valisineria) is fundamental to understanding the species' winter ecology and providing guidelines for management. Consequently, in winter 1986-87, we conducted 4 monthly aerial photographic surveys to investigate temporal changes in distribution, size, and sex ratios of canvasback flocks in traditional wintering areas of Chesapeake Bay and coastal North Carolina. Surveys yielded 35mm imagery of 194,664 canvasbacks in 842 flocks. Models revealed monthly patterns of flock size in North Carolina and Virginia, but no pattern of change in Maryland. A stepwise analysis of flock size and sex ratio fit a common positive slope (increasing proportion male) for all state-month datasets, except for North Carolina in February where the slope was larger (P lt 0.001). State and month effects on intercepts were significant (P lt 0.001) and confirmed a previously identified latitudinal gradient in sex ratio in the survey region. There was no relationship between flock purity (% canvasbacks vs. other species) and flock size except in North Carolina in January, February, and March when flock purity was related to flock size. Contrasting characteristics in North Carolina with regard to flock size (larger flocks) and flock purity suggested that proximate factors were reinforcing flocking behavior and possibly species fidelity there. Of possible factors, the need to locate foraging sites within this large, open-water environment was hypothesized to be of primary importance. Comparison of January 1981 and 1987 sex ratios indicated no change in Maryland, but lower (P lt 0.05) canvasback sex ratios (proportion male) in Virginia and North Carolina.

  4. Nuclear reactor repairing device

    International Nuclear Information System (INIS)

    Purpose: To enable free repairing of an arbitrary position in an LMFBR reactor. Constitution: A laser light emitted from a laser oscillator installed out of a nuclear reactor is guided into a portion to be repaired in the reactor by using a reflecting mirror, thereby welding or cutting it. The guidance of the laser out of the reactor into the reactor is performed by an extension tube depending into a through hole of a rotary plug, and the guidance of the laser light into a portion to be repaired is performed by the transmitting and condensing action of the reflecting mirror. (Kamimura, M.)

  5. Source Terms for HFIR Beam Tube Shielding Analyses, and a Complete Shielding Analysis of the HB-3 Tube

    Energy Technology Data Exchange (ETDEWEB)

    Bucholz, J.A.

    2000-07-01

    The High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory is in the midst of a massive upgrade program to enhance experimental facilities. The reactor presently has four horizontal experimental beam tubes, all of which will be replaced or redesigned. The HB-2 beam tube will be enlarged to support more guide tubes, while the HB-4 beam tube will soon include a cold neutron source.

  6. Analysis of the effect of tube arrangement and inclination on pressure drop in an intermediate heat exchanger of liquid metal reactor

    Energy Technology Data Exchange (ETDEWEB)

    ChoiI, Seok Ki; Choi, Il Kon; Nam, Ho Yun; Choi, Jong Hyeun [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2002-05-01

    An experimental study on the effect of tube arrangement and inclination on the pressure drop in the intermediate heat exchanger is performed. Measurements are made for pressure drop in the triangular and rotated triangular tue arrays whose inclined angles are 30, 45, 60, 75 and 90 degrees. The pitch to tube diameter ratio is 1.6 and the range of Reynolds number based on the free stream velocity and tube diameter is 870-64,000. The experimental results show that the magnitude of dimensionless pressure drop increases with the inclined angle and decreases significantly when the inclined angle is less than 45 degree. The previous correlations are evaluated using the experimental data. The ESDU correlation agrees well with the present data for the triangular arrays. But some discrepancies are observed for the rotated triangular arrays when the inclined angles are 45 and 30 degrees. The Idel'chik correlation generally agrees well with the measured data for the rotated triangular arrays except for inclined angle of 30 degree. The Idel'chik correlation needs modification for the triangular arrays. The modified Idel'chik correlation agrees well with the measure data within 10%. 32 refs., 59 figs., 11 tabs. (Author)

  7. North Carolina surgical workforce trends.

    Science.gov (United States)

    Poley, Stephanie T; Kasper, Elizabeth W; Walker, Elizabeth K; Lyons, Jessica C; Newkirk, Vann R; Thompson, Kristie

    2011-01-01

    Between 1997 and 2008, the number of general surgeons in North Carolina increased and shifted demographically, geographically, and by specialty. However, surgeon numbers--overall and by specialty--do not appear to have increased as quickly or to have shifted in the same ways as North Carolina's general population.

  8. Nuclear reactor spacer assembly

    International Nuclear Information System (INIS)

    A fuel assembly for a nuclear reactor is disclosed wherein the fuel element receiving and supporting grid is comprised of a first metal, the guide tubes which pass through the grid assembly are comprised of a second metal and the grid is supported on the guide tubes by means of expanded sleeves located intermediate the grid and guide tubes. The fuel assembly is fabricated by inserting the sleeves, of initial outer diameter commensurate with the guide tube outer diameters, through the holes in the grid assembly provided for the guide tubes and thereafter expanding the sleeves radially outwardly along their entire length such that the guide tubes can subsequently be passed through the sleeves. The step of radial expansion, as a result of windows provided in the sleeves having dimensions commensurate with the geometry of the grid, mechanically captures the grid and simultaneously preloads the sleeve against the grid whereby relative motion between the grid and guide tube will be precluded

  9. Use of Zircaloy 4 material for the pressure vessels of hot and cold neutron sources and beam tubes for research reactors results of forming the material and welding processes

    International Nuclear Information System (INIS)

    The material Zircaloy 4 can be used for the pressure retaining walls for the cold and hot neutron sources and beam tubes. For the research reactor FRM-II of the Technical University Munich, Germany, the material Zircaloy 4 were chosen for the vessels of the cold and hot neutron source and for the beam tube no. 6. For fabrication of the vessels and piping parts it was necessary to form the base material and calibrate the sheets or welded parts with necessary heat treatments. Additional to the technical specifications preliminary material investigations and production test of welded and unwelded material were carried out of the formed parts up to a cold work of 5%. Further one with respect to the material thickness of 3, 4, 5 and 10 mm of the used sheets, welding procedure test before the fabrication and welding production tests during fabrication were carried out of the base material combination sheet/sheet and sheet/forging. Electronic beam welding was used for the welding process. Material tests as tensile tests, charpy-V-tests, bend tests, metallographic tests, hardness tests, radiographic tests a.s.o. were carried out. The results of the examinations confirm the specified requirements. For the material forming process an optimization was necessary after the preliminary results to get final sufficient material behaviour results. (orig.)

  10. Virginia ESI: FISH (Fish Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, estuarine, anadromous, and brackishwater fish species in Virginia. Vector polygons in this...

  11. Virginia ESI: REPTILES (Reptile Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for sea turtles and estuarine turtles in Virginia. Vector polygons in this data set represent turtle...

  12. Virginia ESI: HABITATS (Habitat Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for submerged aquatic vegetation (SAV) and rare terrestrial plants/communities in Virginia. Vector...

  13. Virginia ESI: REPTPT (Reptile Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for sea turtles in Virginia. Vector points in this data set represent nesting sites. Species-specific...

  14. Virginia ESI: Wetlands (Wetland Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector polygons representing the coastal wetlands for Virginia, classified according to the Environmental Sensitivity Index (ESI)...

  15. The Analysis of Virginia Woolf

    Institute of Scientific and Technical Information of China (English)

    戴寒路

    2014-01-01

    <正>Virginia Woolf is a British writer,one of the representatives criticism at home,stream of consciousness novel."Mark on the Wall"is her first article typical stream of consciousness works.Virginia Woolf has a complicated family background.The nine homes,two groups of children between age and personality clashes often occur some contradictions and conflicts.Woolf’s half-brother and two of her injuries left her permanently

  16. Three Dimensional Coupled Simulation of Furnaces and Reactor Tubes for the Thermal Cracking of Hydrocarbons Simulation tridimensionnelle et couplée des fours et des tubes de réacteurs pour le craquage thermique des hydrocarbures

    Directory of Open Access Journals (Sweden)

    Detemmerman T.

    2006-12-01

    Full Text Available Thermal cracking of hydrocarbons has gone through a significant evolution over the past 20 years. Improved metallurgical properties together with a better understanding of the chemical aspects have led to new configurations for furnace and reactor, all aiming for high severity cracking. A full 3D CFD model containing transport equations for mass, momentum and energy has been implemented in the software code FLOWSIM, together with the k-epsilon turbulence model. It has been coupled with the appropriate kinetic models (the radical reaction scheme CRACKSIM for the reactor and combustion kinetics for the furnace and an overall iteration scheme has been developed for a coupled furnace-reactor simulation allowing to simulate industrial units. This approach has been applied for a propane cracking furnace, providing detailed understanding of the transport mechanisms taking place. Le craquage thermique des hydrocarbures a évolué d'une manière significative au cours des 20 dernières années. Des progrès dans les métallurgies associés à une meilleure compréhension des mécanismes de réaction ont conduit à de nouvelles configurations pour les fours et les réacteurs qui s'orientent toutes vers des conditions de craquage plus sévères. Une modélisation directe et tridimensionnelle comprenant des équations de transport de masse, de moment et d'énergie a été implantée dans le code FLOWSIM, en même temps que le modèle k-epsilon de turbulence. Cette modélisation a été couplée avec les modèles cinétiques appropriés (le schéma CRACKSIM pour les réactions radicalaires dans le réacteur et les cinétiques de combustion dans le four et un schéma itératif global a été développé pour la simulation couplée four-réacteur permettant de simuler des unités industrielles. Cette approche a été appliquée à un four de craquage pour le propane, apportant une compréhension détaillée des mécanismes de transport qui s'y déroulent.

  17. Carolinas Energy Career Center

    Energy Technology Data Exchange (ETDEWEB)

    Classens, Anver; Hooper, Dick; Johnson, Bruce

    2013-03-31

    Central Piedmont Community College (CPCC), located in Charlotte, North Carolina, established the Carolinas Energy Career Center (Center) - a comprehensive training entity to meet the dynamic needs of the Charlotte region's energy workforce. The Center provides training for high-demand careers in both conventional energy (fossil) and renewable energy (nuclear and solar technologies/energy efficiency). CPCC completed four tasks that will position the Center as a leading resource for energy career training in the Southeast: • Development and Pilot of a New Advanced Welding Curriculum, • Program Enhancement of Non-Destructive Examination (NDE) Technology, • Student Support through implementation of a model targeted toward Energy and STEM Careers to support student learning, • Project Management and Reporting. As a result of DOE funding support, CPCC achieved the following outcomes: • Increased capacity to serve and train students in emerging energy industry careers; • Developed new courses and curricula to support emerging energy industry careers; • Established new training/laboratory resources; • Generated a pool of highly qualified, technically skilled workers to support the growing energy industry sector.

  18. Infectious uveitis in Virginia

    Directory of Open Access Journals (Sweden)

    Engelhard SB

    2015-08-01

    Full Text Available Stephanie B Engelhard,1 Zeina Haddad,1 Asima Bajwa,1 James Patrie,2 Wenjun Xin,2 Ashvini K Reddy1 1Department of Ophthalmology, 2Department of Public Health Sciences, University of Virginia, Charlottesville, VA, USA Purpose: To report the causes, clinical features, and outcomes of infectious uveitis in patients managed in a mid-Atlantic tertiary care center.Methods: Retrospective, observational study of infectious uveitis patients seen at the University of Virginia from 1984 to 2014.Results: Seventy-seven of 491 patients (15.7% were diagnosed with infectious uveitis (mean age 58 years, 71.4% female, 76.6% Caucasian. The mean follow-up was 5 years. Anterior uveitis was the most common anatomic classification (39 patients, 50.6% followed by panuveitis (20 patients, 26.0% and posterior uveitis (18 patients, 23.4%. The most common infectious etiology was herpetic anterior uveitis (37 patients, 48.1% followed by toxoplasma uveitis (14 patients, 18.2%. The most prevalent viral pathogen was varicella-zoster virus (21 patients, 27.3% followed by herpes simplex virus (20 patients, 26.0%. Acute retinal necrosis (ARN was diagnosed in 14 patients (18.2%. Aqueous humor yielded an etiologic diagnosis in seven (50% of ARN patients, four of whom tested positive for cytomegalovirus and three for varicella-zoster virus. On presentation, 43 patients (55.8% had a visual acuity (VA better than 20/40 and 17 (22.1% had a VA worse than 20/200. VA at the final follow-up was better than 20/40 in 39 patients (50.6% and worse than 20/200 in 22 patients (28.6%. In all, 16 (20.8% and 10 (13.0% patients required cataract and vitrectomy surgery, respectively. A total of 14 patients (18.2% were on glaucoma topical treatment and four (5.2% required glaucoma surgery.Conclusion: The most common type of infectious uveitis seen over the study period was herpetic anterior uveitis secondary to varicella-zoster virus or herpes simplex virus, found to be most prevalent in patients

  19. Analysis of autofrettaged metal tubes

    International Nuclear Information System (INIS)

    Thick-walled cylinders are widely used as compressor cylinders, pump cylinders, high pressure tubing, process reactors and vessels, nuclear reactors, isostatic vessels and gun barrels. In practice, cylinders are generally subjected to sudden and frequently drastic pressure fluctuations, such as the pressure generated in a gun barrel upon the firing of the weapon, pressure reversals in pump cylinders or in process reactors employing high-pressure piping, necessitating enhanced strength of such cylinders. A process for enhancing the strength of thick-walled cylinders has been in service, and is referred to as 'autofrettage'. It extends the service life of the cylinder. The autofrettage is achieved by increasing elastic strength of a cylinder with various methods such as hydraulic pressurization, mechanical swaging, or by utilizing the pressure of a powder gas. This research work deals with the hydraulic and mechanical autofrettage of metal tubes with the objective to attain enhanced strength. Five metal tubes are taken randomly for analysis purpose. The experimental data for five metal tubes is obtained to analyze the behavior of different parameters used during, before, and after autofrettage process. For this research, two-stage autofrettage is taken into consideration. The modeling of the metal tube is carried out in WildFire-ProEngineering, and for analysis purpose, finite element software ANSYS7 and COSMOS are used. The graphical analysis of swage autofrettage is carried out using MATLAB7. The results are validated using available experimental and numerical data. (author)

  20. Alternate tube plugging criteria for steam generator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Cueto-Felgueroso, C.; Aparicio, C.B. [Tecnatom, S.A., Madrid (Spain)

    1997-02-01

    The tubing of the Steam Generators constitutes more than half of the reactor coolant pressure boundary. Specific requirements governing the maintenance of steam generator tubes integrity are set in Plant Technical Specifications and in Section XI of the ASME Boiler and Pressure Vessel Code. The operating experience of Steam Generator tubes of PWR plants has shown the existence of some types of degradatory processes. Every one of these has an specific cause and affects one or more zones of the tubes. In the case of Spanish Power Plants, and depending on the particular Plant considered, they should be mentioned the Primary Water Stress Corrosion Cracking (PWSCC) at the roll transition zone (RTZ), the Outside Diameter Stress Corrosion Cracking (ODSCC) at the Tube Support Plate (TSP) intersections and the fretting with the Anti-Vibration Bars (AVBs) or with the Support Plates in the preheater zone. The In-Service Inspections by Eddy Currents constitutes the standard method for assuring the SG tubes integrity and they permit the monitoring of the defects during the service life of the plant. When the degradation reaches a determined limit, called the plugging limit, the SG tube must be either repaired or retired from service by plugging. Customarily, the plugging limit is related to the depth of the defect. Such depth is typically 40% of the wall thickness of the tube and is applicable to any type of defect in the tube. In its origin, that limit was established for tubes thinned by wastage, which was the predominant degradation in the seventies. The application of this criterion for axial crack-like defects, as, for instance, those due to PWSCC in the roll transition zone, has lead to an excessive and unnecessary number of tubes being plugged. This has lead to the development of defect specific plugging criteria. Examples of the application of such criteria are discussed in the article.

  1. Reactor control rod

    International Nuclear Information System (INIS)

    Object: To enable quick descent of a control rod body even when some relative phase deviation between upper drive means and wrapper tube is produced, while permitting a coolant to effectively flow into a protective tube irrespective of the position of the control rod body. Structure: In a control rod used for a nuclear reactor such as a fast breeder, an orifice which dispenses with a cylindrical guide tube and has a greater inner diameter than the outer diameter of the protective tube of the control rod body is provided on the inner side of a wrapper tube, thus permitting smooth operation of the control rod body and also permitting the coolant to effectively flow into the protective tube irrespective of the control rod body. (Horiuchi, T.)

  2. Study on laser welding of fuel clad tubes and end plugs made of modified 9Cr-1Mo steel for metallic fuel of Fast Breeder Reactors

    Science.gov (United States)

    Harinath, Y. V.; Gopal, K. A.; Murugan, S.; Albert, S. K.

    2013-04-01

    A procedure for Pulsed Laser Beam Welding (PLBW) has been developed for fabrication of fuel pins made of modified 9Cr-1Mo steel for metallic fuel proposed to be used in future in India's Fast Breeder Reactor (FBR) programme. Initial welding trials of the samples were carried out with different average power using Nd-YAG based PLBW process. After analyzing the welds, average power for the weld was optimized for the required depth of penetration and weld quality. Subsequently, keeping the average power constant, the effect of various other welding parameters like laser peak power, pulse frequency, pulse duration and energy per pulse on weld joint integrity were studied and a procedure that would ensure welds of acceptable quality with required depth of penetration, minimum size of fusion zone and Heat Affected Zone (HAZ) were finalized. This procedure is also found to reduce the volume fraction delta-ferrite in the fusion zone.

  3. Whither North Carolina furniture manufacturing?

    OpenAIRE

    Robert L. Lacy

    2004-01-01

    North Carolina's furniture manufacturing industry has contracted in recent years as imports have gained a greater share of the domestic furniture market. Rapid growth of the furniture industry in China and a surge in exports from that country to the United States in particular have contributed to plant closings and consolidation of operations in the state. North Carolina's furniture manufacturers are adapting to the emergence of global competition and are developing new corporate strategies t...

  4. Virginia Regional Seismic Network. Final report (1986--1992)

    Energy Technology Data Exchange (ETDEWEB)

    Bollinger, G.A.; Sibol, M.S.; Chapman, M.C.; Snoke, J.A. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (US). Seismological Observatory

    1993-07-01

    In 1986, the Virginia Regional Seismic Network was one of the few fully calibrated digital seismic networks in the United States. Continued operation has resulted in the archival of signals from 2,000+ local, regional and teleseismic sources. Seismotectonic studies of the central Virginia seismic zone showed the activity in the western part to be related to a large antiformal structure while seismicity in the eastern portion is associated spatially with dike swarms. The eastern Tennessee seismic zone extends over a 300x50 km area and is the result of a compressive stress field acting at the intersection between two large crustal blocks. Hydroseismicity, which proposes a significant role for meteoric water in intraplate seismogenesis, found support in the observation of common cyclicities between streamflow and earthquake strain data. Seismic hazard studies have provided the following results: (1) Damage areas in the eastern United States are three to five times larger than those observed in the west. (2) Judged solely on the basis of cataloged earthquake recurrence rates, the next major shock in the southeast region will probably occur outside the Charleston, South Carolina area. (3) Investigations yielded necessary hazard parameters (for example, maximum magnitudes) for several sites in the southeast. Basic to these investigations was the development and maintenance of several seismological data bases.

  5. LOGGERHEAD SEA TURTLE LATE NESTING ECOLOGY IN VIRGINIA BEACH, VIRGINIA

    Science.gov (United States)

    T'he.loggerhead sea turtle (Caretta came is the only recurrent nesting species of sea turtle in southeastern Virginia (Lutcavage & Musick, 1985; Dodd, 1988). Inasmuch as the loggerhead is a federally threatened species, the opportunity to gather data on its nesting ecology is imp...

  6. Gastrostomy Tube (G-Tube)

    Science.gov (United States)

    ... endoscope (a thin, flexible tube with a tiny camera and light at the tip) inserted through the ... Nemours Foundation, iStock, Getty Images, Corbis, Veer, Science Photo Library, Science Source Images, Shutterstock, and Clipart.com

  7. Ear tube insertion

    Science.gov (United States)

    Myringotomy; Tympanostomy; Ear tube surgery; Pressure equalization tubes; Ventilating tubes; Ear infection - tubes; Otitis - tubes ... trapped fluid can flow out of the middle ear. This prevents hearing loss and reduces the risk ...

  8. A method and sensor for the eddy current non destructive testing of thin tubes; Procede de controle non destructif d`un tube mince par courants de Foucault

    Energy Technology Data Exchange (ETDEWEB)

    Sartre, B.; Miller, D.; Placko, D.

    1995-06-02

    In order to control the wear (cracking or thinning) of vapor generator tubes, especially in PWR reactors, due to the friction between the tubes and dampers, an eddy current control system is proposed where the transducer is run through the tubes, and measures the tube wall thickness or tube-block clearance through impedance measurements, taking into account the variation of the sensor-to-tube distance. 8 fig.

  9. Nuclear Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Hogerton, John

    1964-01-01

    This pamphlet describes how reactors work; discusses reactor design; describes research, teaching, and materials testing reactors; production reactors; reactors for electric power generation; reactors for supply heat; reactors for propulsion; reactors for space; reactor safety; and reactors of tomorrow. The appendix discusses characteristics of U.S. civilian power reactor concepts and lists some of the U.S. reactor power projects, with location, type, capacity, owner, and startup date.

  10. Role of insecticides in reducing thrips injury to plants and incidence of tomato spotted wilt virus in Virginia market-type peanut.

    Science.gov (United States)

    Herbert, D Ames; Malone, S; Aref, S; Brandenburg, R L; Jordan, D L; Royals, B M; Johnson, P D

    2007-08-01

    Tomato spotted wilt virus (family Bunyaviridae, genus Tospovirus, TSWV), transmitted by many thrips species, is a devastating pathogen of peanut, Arachis hypogaea L. TSWV has become a serious problem in the Virginia/Carolina peanut-growing region of the United States. During 2002, TSWV was present in 47% of the North Carolina hectarage and caused a 5% yield reduction in Virginia. Factors influencing levels of TSWV in runner market-type peanut cultivars, which are primarily grown in Alabama, Flordia, Georgia, and Texas, have been integrated into an advisory to help those peanut growers reduce losses. An advisory based on the southeast runner market-type version is currently under development for virginia market-type peanut cultivars that are grown primarily in the Virginia/ Carolina region. A version based on preliminary field experiments was released in 2003. One factor used in both advisories relates to insecticide use to reduce the vector populations and disease incidence. This research elucidated the influence of insecticides on thrips populations, thrips plant injury, incidence of TSWV, and pod yield in virginia market-type peanut. Eight field trials from 2003 to 2005 were conducted at two locations. In-furrow application of aldicarb and phorate resulted in significant levels of thrips control, significant reductions in thrips injury to seedlings, reduced incidence of TSWV, and significant increases in pod yield. Foliar application of acephate after aldicarb or phorate applied in the seed furrow further reduced thrips plant injury and incidence of TSWV and improved yield. These findings will be used to improve the current virginia market-type TSWV advisory.

  11. Reading "Terebithia" in Southern Virginia

    Science.gov (United States)

    Baker, Dori Grinenko

    2008-01-01

    The author discusses reading "The Bridge to Terebithia" to a third-grade class prior to release of the film version. Reading of the final chapter followed by two days the April 16, 2007 shootings at Virginia Tech University, just seventy miles from the classroom. Although none of the college students from the author's town died, everyone knew…

  12. 75 FR 80547 - Carolina Power & Light Company, Shearon Harris Nuclear Power Plant, Unit No. 1; Exemption

    Science.gov (United States)

    2010-12-22

    ... COMMISSION Carolina Power & Light Company, Shearon Harris Nuclear Power Plant, Unit No. 1; Exemption 1.0... License No. NPF-63, which authorizes operation of the Shearon Harris Nuclear Power Plant (HNP), Unit 1... nuclear power reactors against radiological sabotage,'' published as a final rule in the Federal...

  13. 75 FR 9958 - Carolina Power & Light Company, Shearon Harris Nuclear Power Plant, Unit 1; Exemption

    Science.gov (United States)

    2010-03-04

    ... COMMISSION Carolina Power & Light Company, Shearon Harris Nuclear Power Plant, Unit 1; Exemption 1.0... of the Shearon Harris Nuclear Power Plant, Unit 1 (HNP). The license provides, among other things... for physical protection of licensed activities in nuclear power reactors against radiological...

  14. Participation in the United States Department of Energy Reactor Sharing Program. Annual report, September 1981-August 1982

    International Nuclear Information System (INIS)

    The University of Virginia Reactor Facility is an integral part of the Department of Nuclear Engineering and Engineering Physics and is used to support educational programs in engineering and science at the University of Virginia and at other area colleges and universities. The University of Virginia Research Reactor (UVAR) is the highest power (two megawatts thermal power) and most utilized (total power production in 1981 and nearly 5000 megawatt-hours) research reactor in the mid-Atlantic States. In addition, a second, small (50 watt) reactor is also available for use in educational programs in the region. The University of Virginia has received support under the US Department of Energy (DOE) Reactor Sharing Program every year since 1978 to assist in meeting this objective. This report documents the major educational accomplishments under the Reactor Sharing Program for the period September 1981 through August 1982

  15. Characterization of oxides on Bruce A NGS liner tubes and steam generator tubes

    International Nuclear Information System (INIS)

    Oxide deposits on end-fitting liner tubes and steam generator tubes from the Bruce A Nuclear Generating Station (NGS) were characterized in advance of the decontamination of the heat transport system (HTS) of Bruce Unit 2. Oxide loadings, and Co-60 surface activities and specific activities were determined for the oxides on inlet and outlet end-fitting liner tubes from Bruce Unit l, Bruce Unit 2 and Bruce Unit 4. Oxides on the inner surfaces of steam generator tubes from Bruce NGS Units 1 and 2 were also characterized. The consistency in the deposit characteristics on the inlet liner tubes and steam generator tubes from Bruce A, along with the absence of magnetite on the outlet liner tubes has led to the development of a model for iron transport in the HTS of pressurized heavy water reactors (PHWRs). The activity transport/fouling mechanism involves flow-accelerated corrosion of the outlet feeder pipes, followed by deposition of iron in the steam generators, along the inlet feeder pipes, on the inlet end fittings, on the inlet fuel bundles and on the inlet region of the pressure tube. The results of loop experiments using decontamination solutions indicated that the oxide was rapidly removed from inlet liner tubes. However, removal of the Cr-rich oxide from the outlet liner tubes was less efficient, requiring the Alkaline Permangante (AP) oxidizing pre-treatment that is typically used in light water reactors (LWRs). The steam generator tubes were effectively decontaminated

  16. Ultrasonic measurement of gap between calandria tube and liquid injection shutdown system tube in PHWR

    International Nuclear Information System (INIS)

    Sag of CT or liquid injection shutdown system tubes in pressurized heavy water reactor is known to occur due to irradiation creep and growth during plant operation. When the sag of CT is big enough, the CT tube possibly comes in contact with liquid injection shutdown system tube (LIN) crossing beneath the CT, which subsequently may prevent the safe operation. It is therefore necessary to check the gap between the two tubes in order to confirm no contacts when using a proper measure periodically during the plant life. An ultrasonic gap measuring probe assembly which can be fed through viewing port installed on the calandria was developed and utilized to measure the sags of both tubes in a pressurized heavy water reactor in Korea. It was found that the centerlines of CT and LIN can be precisely detected by ultrasonic wave. The gaps between two tubes were easily obtained from the relative distance of the measured centerline elevations of the tubes. But the measured gap data observed at the viewing port were actually not the data at the crossing point of CT and LIN. To get the actual gap between two tubes, mathematical modeling for the deflection curves of two tubes was used. The sags of CT and LIN tubes were also obtained by comparison of the present centerlines with the initial elevations at the beginning of plant operation. The gaps between two tubes in the unmeasurable regions were calculated based on the measurement data and the channel power distribution

  17. Ear Tubes

    Science.gov (United States)

    ... of the ear drum or eustachian tube, Down Syndrome, cleft palate, and barotrauma (injury to the middle ear caused by a reduction of air pressure, ... specialist) may be warranted if you or your child has experienced repeated ... fluid in the middle ear, barotrauma, or have an anatomic abnormality that ...

  18. The cottontail rabbits of Virginia

    Science.gov (United States)

    Llewellyn, L.M.; Handley, C.O.

    1945-01-01

    Five races of cottontail rabbits belonging to three species occur in Virginia. One of them, the Mearns cottontail (Sylvilagus floridanus mearnsi), is reported here for the first time. It occurs in six southwestern counties of the state, while the eastern cottontail (S. f. mallurus) occurs in the remainder of the state with the exception of Smith and Fishermans islands off the eastern coast of Cape Charles, where it is replaced by Hitchens cottontail (S. f. hitchensi). The New England cottontail (S. transitionalis) is found on the higher mountain peaks, above 3000 feet, and the swamp rabbit (S. palustris) occurs in the Dismal Swamp region of southeastern Virginia.....The height of the breeding season for the eastern cottontail in Virginia is March and April, but breeding continues through the entire year except in December and January. The average litter size based on embryo counts was 4.7. The sex ratio of 234 specimens from all parts of the state, taken mostly in the December to February period, was 53 males to 47 females. That of a group of 145 rabbits live-trapped at Blacksburg during February and Marchwas 58 males to 42 females. The figures show that males are more active than females during the winter months, and therefore are more easily taken then....In transplanting cottontails from one section of the state to another, it is recommended that only cottontails of the same race as those originally present in the region being restocked be released there....Tularemia is not a common disease among rabbits in Virginia, but the rabbit ticks are often carriers of the disease and may transmit it to rabbits. Rabbit ticks are also found to be carriers of Rocky Mountain fever and American Q. fever. After the ticks drop off the rabbits to hibernate in the ground, which is likely to occur during mid-winter in Virginia, there is relatively little danger of humans contracting tularemia by contact with rabbits. Present laws in Virginia which prohibit rabbit hunting until the

  19. Safety issues at the defense production reactors

    International Nuclear Information System (INIS)

    The United States produces plutonium and tritium for use in nuclear weapons at the defense production reactors - the N Reactor in Washington and the Savannah River reactors in South Carolina. This report reaches general conclusions about the management of those reactors and highlights a number of safety and technical issues that should be resolved. The report provides an assessment of the safety management, safety review, and safety methodology employed by the Department of Energy and the private contractors who operate the reactors for the federal government. This report examines the safety objective established by the Department of Energy for the production reactors and the process the Department of its contractors use to implement the objective; focuses on a variety of uncertainties concerning the production reactors, particularly those related to potential vulnerabilities to severe accidents; and identifies ways in which the DOE approach to management of the safety of the production reactors can be improved

  20. Safety review, assessment and inspection on research reactors, experimental reactors, nuclear heating reactors and critical facilities

    International Nuclear Information System (INIS)

    The NNSA organized mainly in 1999 to complete the verification loop in core of the high flux experimental reactor with the 2000 kW fuel elements, the re-starting of China Pulsed Reactor, review and assessment on nuclear safety for the restarting of the Uranium-water critical Facility and treat the fracture event with the fuel tubes in the HWRR

  1. Development of a supermirror neutron guide tube

    International Nuclear Information System (INIS)

    A supermirror neutron guide tube with a characteristic wavelength of 1.2 A was developed and installed at the Kyoto University Reactor (KUR). The apparent critical wavelength of the present supermirrors is about 250 A. The geometrical parameters of the guide tube are : 11.7 m total length, and 10 mm wide x 74 mm high beam cross section. The supermirror neutron guide tube presents decisive advantages over the conventional nickel mirror guide tube higher transmission of neutrons, brought about through the contribution of neutrons of shorter wavelengths and of those presenting large divergent angles. The total neutron flux obtained from the KUR supermirror guide tube is about 5 x 107 n/cm2 · s, which is about 25 times what is obtainable with the conventional KUR nickel mirror neutron guide tube of the same geometrical parameters. (author)

  2. Ballooning of CANDU pressure tubes. Model assessment

    International Nuclear Information System (INIS)

    The transient creep equations used to analyze the possible ballooning and failure of Zr-2.5% Nb pressure tubes during a loss-of-coolant accident (LOCA) were developed and verified using as-received Zr-2.5% Nb pressure tube material. But in a CANDU reactor, the pressure tubes absorb deuterium and are exposed to a continuous neutron fluence. Consequently, a literature survey was done to determine how irradiation damage and deuterium might affect the creep rate and ductility of Zr-2.5% Nb pressure tubes in the temperature range from 600 to 800 degrees C. It was found that irradiation damage, dissolved deuterium and deuteride blisters could possibly affect the creep rate and ductility of ZR-2.5% Nb pressure tubes in this temperature range, but deuteride platelets are expected to have little effect. Further tests are required to determine the effect of irradiation damage and deuterium on the creep rate and ductility of pressure tubes

  3. Ceramic oxygen transport membrane array reactor and reforming method

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Sean M.; Christie, Gervase Maxwell; Rosen, Lee J.; Robinson, Charles; Wilson, Jamie R.; Gonzalez, Javier E.; Doraswami, Uttam R.

    2016-09-27

    A commercially viable modular ceramic oxygen transport membrane reforming reactor for producing a synthesis gas that improves the thermal coupling of reactively-driven oxygen transport membrane tubes and catalyst reforming tubes required to efficiently and effectively produce synthesis gas.

  4. Neutron tubes

    Science.gov (United States)

    Leung, Ka-Ngo; Lou, Tak Pui; Reijonen, Jani

    2008-03-11

    A neutron tube or generator is based on a RF driven plasma ion source having a quartz or other chamber surrounded by an external RF antenna. A deuterium or mixed deuterium/tritium (or even just a tritium) plasma is generated in the chamber and D or D/T (or T) ions are extracted from the plasma. A neutron generating target is positioned so that the ion beam is incident thereon and loads the target. Incident ions cause D-D or D-T (or T-T) reactions which generate neutrons. Various embodiments differ primarily in size of the chamber and position and shape of the neutron generating target. Some neutron generators are small enough for implantation in the body. The target may be at the end of a catheter-like drift tube. The target may have a tapered or conical surface to increase target surface area.

  5. Safety review, assessment and inspection on research reactors, experimental reactors, nuclear heating reactors and critical facilities

    International Nuclear Information System (INIS)

    In 1998, the NNSA organized to complete the nuclear safety review on the test loop in-reactor operation of the High-flux Engineering Experimental Reactor (HFEER) and the re-operation of the China Pulsed Reactor and the Uranium-water Criticality Facility. The NNSA conducted the nuclear safety review on the CP application of the China Experimental Fast Reactor (CEFR) and the siting of China Advanced Research Reactor (CARR), and carried out the construction supervision on HTR-10, and dealt with the event about the technological tube breakage of HWRR and other events

  6. NCSU reactor sharing program. Final technical report

    International Nuclear Information System (INIS)

    The Nuclear Reactor Program at North Carolina State University provides the PULSTAR Research Reactor and associated facilities to eligible institutions with support, in part, from the Department of Energy Reactor Sharing Program. Participation in the NCSU Reactor Sharing Program continues to increase steadily with visitors ranging from advance high school physics and chemistry students to Ph.D. level research from neighboring universities. This report is the Final Technical Report for the DOE award reference number DE-FG05-95NE38136 which covers the period September 30, 1995 through September 30, 1996

  7. Underwater nuclear fuel inspection and reconstitution at Virginia Power

    International Nuclear Information System (INIS)

    Virginia Power has experienced fuel cladding defects in three of its four nuclear reactors, dating back to 1981. The first indication of fuel failure occurred at Surry Unit 1 following steam generator replacement. Subsequent examinations indicated that these failures were probably caused by debris-induced fretting. Fuel cladding defects which have occurred at the North Anna reactors are the result of both debris-induced fretting and baffle jetting. Post irradiation examinations to eliminate defective fuel assemblies have included several different techniques. A combination of wet sipping and ultrasonic testing (UT) was first used at Surry in 1983. The North Anna fuel examinations in 1984 were performed using only vacuum sipping. Each leak-detection campaign included underwater video examinations of the defective fuel assemblies and the occasional use of fibre optics and high magnification video. Because the Westinghouse fuel used by Virginia Power is not easily reconstitutable, failed fuel cannot be repaired during a refueling outage but must be replaced through a redesign of the core loading pattern using depleted fuel from the spent fuel pool. Reconstitution of a small number of once-burned fuel assemblies from Surry 1 was performed during 1985. This work occurred during a non-outage period and involved fuel assembly inversion and bottom nozzle removal. The repaired assemblies are being re-irradiated in small groups and will be used over a period of years in several fuel cycles. (author). 2 figs, 1 tab

  8. Pickering NGS A: Assessment of calandria tube integrity following a sudden pressure tube failure

    International Nuclear Information System (INIS)

    The issue of calandria tube integrity following a sudden rupture of the pressure tube in Pickering NGS A reactor is addressed. Based on operating experience, only fish-mouth ruptures of the pressure tube are considered to be credible. The calandria tube response to the pressure tube break is delineated into three distinct stages, i.e. the initial transient response during the annulus filling stage, transient overpressurization and the final steady-state loading after bellows failure. The annulus response in the second stage is dominated by a waterhammer type overpressure transient with attenuation of this transient due to plastic straining of the calandria tube. The annulus pressure transients for various breaks and the sensitivity of the results to various parameters are presented. The strength margins of the calandria tube are evaluated to be relatively large. (author). 7 refs., 6 tabs., 6 figs

  9. A tubular focused sonochemistry reactor

    Institute of Scientific and Technical Information of China (English)

    ZHOU GuangPing; LIANG ZhaoFeng; LI ZhengZhong; ZHANG YiHui

    2007-01-01

    This paper presents a new sonochemistry reactor, which consists of a cylindrical tube with a certain length and piezoelectric transducers at tube's end with the longitudinal vibration. The tube can effectively transform the longitudinal vibration into the radial vibration and thereby generates ultrasound. Furthermore, ultrasound can be focused to form high-intensity ultrasonic field inside tube. The reactor boasts of simple structure and its whole vessel wall can radiate ultrasound so that the electroacoustic transfer efficiency is high. The focused ultrasonic field provides good condition for sonochemical reaction. The length of the reactor can be up to 2 meters, and liquids can pass through it continuously, so it can be widely applied in liquid processing such as sonochemistry.

  10. Virginia Tech Featured On Science Coalition's website

    OpenAIRE

    Trulove, Susan

    2004-01-01

    Research at Virginia Tech that impacts everyday life will be featured May 16-22 on the Science Coalition's website, a comprehensive resource for information on federally funded science research. The Science Coalition website featuring Virginia Tech will present research by faculty members and students looking at obesity and stiff arteries, wireless networks and smart garments, brain tumors, cultural and archeological history of Southside Virginia, recovering discarded coal, theater production...

  11. Mahajan, Dean to lead Virginia Tech Carilion Medical Research Institute

    OpenAIRE

    Trulove, Susan

    2008-01-01

    Roop Mahajan, the James S. Tucker Professor of Engineering at Virginia Tech, has been named director of the Virginia Tech Carilion Medical Research Institute, announced Mark McNamee, Virginia Tech senior vice president and provost.

  12. 77 FR 27120 - Safety Zone; Virginia Beach Oceanfront Air Show, Atlantic Ocean, Virginia Beach, VA

    Science.gov (United States)

    2012-05-09

    ..., Virginia Beach, VA in the Federal Register (76 FR 13519). We received one comment on the proposed rule. No... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Virginia Beach Oceanfront Air Show, Atlantic Ocean, Virginia Beach, VA AGENCY: Coast Guard, DHS. ACTION: Temporary final rule. SUMMARY:...

  13. 77 FR 13519 - Safety Zone; Virginia Beach Oceanfront Air Show, Atlantic Ocean, Virginia Beach, VA

    Science.gov (United States)

    2012-03-07

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Virginia Beach Oceanfront Air Show, Atlantic Ocean, Virginia Beach, VA AGENCY: Coast Guard, DHS. ACTION: Notice of proposed rulemaking. SUMMARY... Virginia Beach, VA. This action is necessary to provide for the safety of life on navigable waters...

  14. Virginia Cooperative Extension and Virginia Department of Education form educational partnership

    OpenAIRE

    Burcham, Linda

    2008-01-01

    Virginia Cooperative Extension and the Virginia Department of Education have formed a partnership that will improve the educational experience of youth enrolled in family and consumer sciences programs in Virginia's public schools while also advancing the mission of both state agencies.

  15. Organic agriculture in North Carolina

    NARCIS (Netherlands)

    Wossink, G.A.A.; Kuminoff, N.

    2002-01-01

    This issue of the NC State Economist provides an overview of organic agriculture with an emphasis on North Carolina. Research results are reported and some of the new policies and programs that may affect organic agriculture in the near future are described

  16. The Impact of Competition on Raising Mathematics Competency at Camelot Elementary School in Chesapeake, Virginia

    Science.gov (United States)

    Hayden, L. B.; Johnson, D.

    2012-12-01

    In 1995, the Virginia Department of Education approved a federal mandate for No Child Left Behind 2001 Education Act implementing the Standards of Learning (SOL) in four content areas: Mathematics, Science, English, and History and Social Sciences. These new guidelines set forth learning and achievement expectations for content areas for grades K-12 in Virginia's Public Schools. Given the SOL mandates, Virginia's elementary teachers and school leaders utilized research for specific teaching methods intended to encourage score improvements on end of year mathematics tests. In 2001, the concept of the Math Sprint Competition was introduced to Camelot Elementary School in Chesapeake Virginia, by researchers at Elizabeth City State University of Elizabeth City, North Carolina. Camelot Elementary, a K-5 school, is a Title I school nestled in a lower middle class neighborhood and houses a high number of minority students. On average, these students achieve lower test score gains than students in higher socioeconomic status district schools. Defined as a test-review based in relay format that utilizes released SOL test items, Math Sprint promotes mathematical skills outlined in Virginia SOL's and encourages competition among students that motivated them to quickly pick up on new material and retain the old material in order to out-do the others. Research identified was based on specific relationships between student competition and statewide testing results in mathematics for grades three, four, and five at Camelot Elementary. Data was compiled from results of the Math Sprint Competition and research focused on methods for motivating students encouraged by the use of a math sprint competition. Individual Pearson Product Moment Correlations were conducted to determine which variables possess strong and statistically significant relationships. Significantly, positive results came from 2005 to 2010 math sprints data from which students participated.

  17. 75 FR 24757 - Virginia Disaster #VA-00029

    Science.gov (United States)

    2010-05-05

    ... Commonwealth of Virginia (FEMA-1905-DR), dated 04/27/2010. Incident: Severe Winter Storms and Snowstorms..., Manassas Park City, Nelson, Orange, Prince William, Rappahannock, Shenandoah, Spotsylvania,...

  18. Iris reactor conceptual design

    Energy Technology Data Exchange (ETDEWEB)

    Carelli, M.D.; Conway, L.E.; Petrovic, B.; Paramonov, D.V. [Westinghouse Electric Comp., Pittsburgh, PA (United States); Galvin, M.; Todreas, N.E. [Massachusetts Inst. of Tech., Cambridge, MA (United States); Lombardi, C.V.; Maldari, F.; Ricotti, M.E. [Politecnico di Milano, Milan (Italy); Cinotti, L. [Ansaldo SpA, Genoa (Italy)

    2001-07-01

    IRIS (International Reactor Innovative and Secure) is a modular, integral, light water cooled, low-to-medium power (100-350 MWe) reactor which addresses the requirements defined by the US DOE for Generation IV reactors, i.e., proliferation resistance, enhanced safety, improved economics and fuel cycle sustainability. It relies on the proven technology of light water reactors and features innovative engineering, but it does not require new technology development. This paper discusses the current reference IRIS design, which features a 1000 MWt thermal core with proven 5%-enriched uranium oxide fuel and five-year long straight burn fuel cycle, integral reactor vessel housing helical tube steam generators and immersed spool pumps. Other major contributors to the high level of safety and economic attractiveness are the safety by design and optimized maintenance approaches, which allow elimination of some classes of accidents, lower capital cost, long operating cycle, and high capacity factors. (author)

  19. Health and safety impact of steam generator tube degradation

    Energy Technology Data Exchange (ETDEWEB)

    Marston T. [PLG, Inc., Newport Beach, CA (United States)

    1997-02-01

    In this paper the author addresses the problems inherent in evaluating the safety of steam generators with respect to tube rupture as part of a probabilistic safety analysis (PSA) of a reactor plant. He reviews the history of PSA as applied to reactors, and then looks at tube rupture histories as a start toward establishing event frequencies. He considers tube ruptures from the aspect of being an initiating event to being a conditional event to some other event, and then the question of performance of the steam generator in the face of a severe accident in the reactor.

  20. Manufacturing and testing the HTGR refueling tube

    International Nuclear Information System (INIS)

    The paper describes the manufacturing technique for a refueling tube of a high-temperature gas-cooled nuclear reactor (HTGR). Four refueling tube sections were made: two sections from GSP-50 material and two sections from carbon-carbon (C-C) composite materials. Radiation tests were carried out in the reactor BOR-60. Experimental results show that the strength characteristics and thermophysical properties of graphitized carbon materials, from which the sections have been manufactured, are higher by a factor of 2.5-3.5 as compared with the HTGR refueling tube requirements. The dimensional changes of GSP-50 and C-C composite materials at temperatures between 300 and 600 deg C up to the neutron fluence of 1·1021 n/cm2 are comparable and meet the specifications for HTGR refueling tube

  1. Bearing pad to pressure tube contact simulation

    Energy Technology Data Exchange (ETDEWEB)

    Talebi, F.; Behdadi, A.; Luxat, J.C., E-mail: farshat@mcmaster.ca, E-mail: behdada@mcmaster.ca, E-mail: luxatj@mcmaster.ca [McMaster Univ., Dept. of Engineering Physics, Hamilton, Ontario (Canada)

    2011-07-01

    Thermal creep strain deformation is a very important pressure tube failure mechanism. During a postulated LOCA (loss of coolant accident) with failure of emergency core injection sys- tem (ECIS), the fuel cladding temperature rapidly increases and the pressure tube becomes completely dry in a few seconds after flow stagnation occurs. Subsequently, the pressure tube circumference is heated by thermal radiation except at the spots where the bearing pads are in direct contact with the pressure tube. Therefore, the localized hot spots are developed on the pressure tube's inner surface under the bearing pads. The main objective of this paper is to evaluate the local thermal-mechanical deformation of a pressure tube in a CANDU reactor and to investigate the fuel channel integrity under localized contact between bearing pad and pressure tube. Furthermore, the mechanistic models are validated against the experimental works per- formed at WRL (Whiteshell research laboratory). Calculations are performed using the finite element method in which the heat, thermal mechanical and creep strain equations are solved, simultaneously. According to the experimental set up, the heat conduction from bearing pads to the inner surface of the pressure tube with appropriate convective and radiation boundary conditions has been simulated. Furthermore, the thermal creep strain deformation has been obtained for when the pressure tube is still under operational condition. It is observed that the pressure tube thermal strain will occur if sufficient high temperature is reached however, depending on the severity of flow degradation in the fuel channel, these localized hot spots could represent a potential creep strain failure of the pressure tube. Whether the pressure tube would fail at these hot spots before contacting the calandria tube depends on the localized temperature and experienced pressure transients. Sensitivity analysis is performed in order to evaluate the contact conductance

  2. 77 FR 75448 - Welded Tube-Berkeley Including On-Site Leased Workers From Snelling, Aerotek and Express...

    Science.gov (United States)

    2012-12-20

    ... Employment and Training Administration Welded Tube--Berkeley Including On-Site Leased Workers From Snelling... Worker Adjustment Assistance on October 10, 2012, applicable to workers of Welded Tube--Berkeley... Register on October 29, 2012 (77 FR 65583). At the request of South Carolina State, the Department...

  3. photomultiplier tubes

    CERN Multimedia

    photomultiplier tubes. A device to convert light into an electric signal (the name is often abbreviated to PM). Photomultipliers are used in all detectors based on scintillating material (i.e. based on large numbers of fibres which produce scintillation light at the passage of a charged particle). A photomultiplier consists of 3 main parts: firstly, a photocathode where photons are converted into electrons by the photoelectric effect; secondly, a multiplier chain consisting of a serie of dynodes which multiply the number of electron; finally, an anode, which collects the resulting current.

  4. photomultiplier tube

    CERN Multimedia

    photomultiplier tubes. A device to convert light into an electric signal (the name is often abbreviated to PM). Photomultipliers are used in all detectors based on scintillating material (i.e. based on large numbers of fibres which produce scintillation light at the passage of a charged particle). A photomultiplier consists of 3 main parts: firstly, a photocathode where photons are converted into electrons by the photoelectric effect; secondly, a multiplier chain consisting of a serie of dynodes which multiply the number of electron; finally, an anode, which collects the resulting current.

  5. Tube furnace

    Science.gov (United States)

    Foster, Kenneth G.; Frohwein, Eugene J.; Taylor, Robert W.; Bowen, David W.

    1991-01-01

    A vermiculite insulated tube furnace is heated by a helically-wound resistance wire positioned within a helical groove on the surface of a ceramic cylinder, that in turn is surroundingly disposed about a doubly slotted stainless steel cylindrical liner. For uniform heating, the pitch of the helix is of shorter length over the two end portions of the ceramic cylinder. The furnace is of large volume, provides uniform temperature, offers an extremely precise programmed heating capability, features very rapid cool-down, and has a modest electrical power requirement.

  6. 77 FR 47489 - Virginia Disaster #VA-00048

    Science.gov (United States)

    2012-08-08

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Virginia Disaster VA-00048 AGENCY: Small Business Administration. ACTION: Notice. SUMMARY: This is... State of Virginia (FEMA- 4072-DR), dated 07/27/2012. Incident: Severe Storms and Straight-line...

  7. IMPACT: Virginia Potato Disease Advisory Impact

    OpenAIRE

    Herbert, D. Ames (David Ames), 1949-; Long, Theresa; Deitch, Ursula T.; Laub, Curtis A., 1955-; Rideout, Steven Lewis; Moore, David; Tucker, Lindy; Archibald, Tom

    2014-01-01

    To help potato growers more efficiently manage disease problems, Virginia Cooperative Extension initiated the Virginia Potato Disease Advisory to provide growers with weather-based disease forecast information. Advisories not only alert growers to periods of risk, they also assist growers in making management decisions, such as when protective fungicide applications are needed.

  8. Nuclear cluster strategy Carolinas - Ontario - Saskatchewan

    International Nuclear Information System (INIS)

    Organization of Candu Industries (OCI) is an industry association representing the interests of 170 private sector suppliers of products and services to the Canadian and offshore nuclear industries. OCI member companies, mainly in Ontario, employ over 30,000 highly specialized workers with over 12,000 working in nuclear area. OCI's objectives are to sustain the domestic nuclear program by building support among political leaders, the public and local communities, assist OCI member companies in becoming the preferred suppliers for domestic nuclear projects (competitive), assist OCI member companies in international nuclear markets - trade missions and vendor workshops. OCI is at the heart of an 'Ontario nuclear cluster'. The Carolinas have shown what can be achieved when industry, academia, S&T centers and governments collaborate with a shared vision to achieve a common goals. Ontario has the assets to become a stronger center for nuclear excellence. OCI is working to bring the pieces together. Saskatchewan has the assets to become a center of excellence in Small Modular Reactors (SMR) by licensing and constructing the first SMR in Canada.

  9. Nuclear reactor fuelling machine

    International Nuclear Information System (INIS)

    The refuelling machine described comprises a rotatable support structure having a guide tube attached to it by a parellel linkage mechanism, whereby the guide tube can be displaced sideways from the support structure. A gripper unit is housed within the guide tube for gripping the end of a fuel assembly or other reactor component and has means for maintenance in the engaging condition during travel of the unit along the guide tube, except for a small portion of the travel at one end of the guide tube, where the inner surface of the guide tube is shaped so as to maintain the gripper unit in a disengaging condition. The gripper unit has a rotatable head, means for moving it linearly within the guide tube so that a component carried by the unit can be housed in the guide tube, and means for rotating the head of the unit through 1800 relative to its body, to effect rotation of a component carried by the unit. The means for rotating the head of the gripper unit comprises ring and pinion gearing, operable through a series of rotatable shafts interconnected by universal couplings. The reason for provision for 1800 rotation is that due to the variation in the neutron flux across the reactor core the side of a fuel assembly towards the outside of the core will be subjected to a lower neutron flux and therefore will grow less than the side of the fuel assembly towards the inside of the core. This can lead to bowing and possible jamming of the fuel assemblies. Full constructional details are given. See also BP 1112384. (U.K.)

  10. Chernobyl reactor transient simulation study

    International Nuclear Information System (INIS)

    This paper deals with the Chernobyl nuclear power station transient simulation study. The Chernobyl (RBMK) reactor is a graphite moderated pressure tube type reactor. It is cooled by circulating light water that boils in the upper parts of vertical pressure tubes to produce steam. At equilibrium fuel irradiation, the RBMK reactor has a positive void reactivity coefficient. However, the fuel temperature coefficient is negative and the net effect of a power change depends upon the power level. Under normal operating conditions the net effect (power coefficient) is negative at full power and becomes positive under certain transient conditions. A series of dynamic performance transient analysis for RBMK reactor, pressurized water reactor (PWR) and fast breeder reactor (FBR) have been performed using digital simulator codes, the purpose of this transient study is to show that an accident of Chernobyl's severity does not occur in PWR or FBR nuclear power reactors. This appears from the study of the inherent, stability of RBMK, PWR and FBR under certain transient conditions. This inherent stability is related to the effect of the feed back reactivity. The power distribution stability in the graphite RBMK reactor is difficult to maintain throughout its entire life, so the reactor has an inherent instability. PWR has larger negative temperature coefficient of reactivity, therefore, the PWR by itself has a large amount of natural stability, so PWR is inherently safe. FBR has positive sodium expansion coefficient, therefore it has insufficient stability it has been concluded that PWR has safe operation than FBR and RBMK reactors

  11. Development of INCONEL 600 precision tube (1)

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Yeong Han; Jo, Bong Hyeon; Lee, Dong Hee; Kim, Wan Kyo; Jeong, Pyeong Keun; Yoon, Hwang Lo; Chio, Seok Sik [Sammi Steel Co. Ltd., Changwon (Korea, Republic of)

    1994-07-01

    Steam generator, being connected with nuclear fuel reactor is one of the most important part of nuclear power plant and consists of a large number of INCONEL 600 tubes. Approximately 160 tons of tubes are needed for a single nuclear power plant. All of INCONEL 600 steam generator tubes for domestic nuclear power plants have been imported. The aim of this research is to develop INCONEL 600 precision tubes for steam generator of nuclear power plant. If this research is conducted successfully, we can produce nuclear fuel tubes, Ni-alloy precision tubes and stainless steel precision tubes for many purposes and technology of INCONEL 600 steam generator tubes are similar to those of other tubes above mentioned. In the current study, development of preliminary manufacturing process of INCONEL 600 precision tubes for steam generator and investigation of material`s metallurgical characteristics were conducted. The main scope of this research is as follows. First, the preliminary manufacturing process design was conducted after investigations of foreign manufacturing processes and technical reports. Second, the results of investigations of material`s metallurgical characteristics through the manufacturing process were applied to the production technology of tentative INCONEL 600 precision tubes for sample. Third, preliminary process routes were established and samples of INCONEL 600 precision tube were produced by this process. As the results of this research, 14 pieces of INCONEL 600 precision tubes were produced by preliminary manufacturing process and the material`s metallurgical characteristics were investigated through the processes. But the SCC test could not be conducted due to the absence of equipment. In order to apply the results of SCC test to the manufacturing process, we need a SCC tester which can simulate SCC characteristics under high temperature and high pressurized circulating water. 95 refs., 55 figs., 20 tabs.

  12. Development of CRD stub tube welding system

    International Nuclear Information System (INIS)

    The reactor pressure vessel (RPV) of nuclear power plants include control rod drive (CRD) stub tubes installed on the inner surface of the bottom head by welding. Weld seams are located at the root of each stub tube, to which accessibility is limited. The weld travel requires an elliptical movement with inclination along the inner bottom head surface, and furthermore the location on the bottom head of each stub tube has different angle of inclination. CRD stub tubes were installed by skilled welders using MIG welding in previous RPV construction. Recently, a CRD stub tube TIG welding system was developed for RPV construction in the near future, which can be applied to such 3 dimensional welding orbit. (author)

  13. A tube-in-tube thermophotovoltaic generator

    Energy Technology Data Exchange (ETDEWEB)

    Ashcroft, J.; Campbell, B.; Depoy, D.

    1996-12-31

    A thermophotovoltaic device includes at least one thermal radiator tube, a cooling tube concentrically disposed within each thermal radiator tube and an array of thermophotovoltaic cells disposed on the exterior surface of the cooling tube. A shell having a first end and a second end surrounds the thermal radiator tube. Inner and outer tubesheets, each having an aperture corresponding to each cooling tube, are located at each end of the shell. The thermal radiator tube extends within the shell between the inner tubesheets. The cooling tube extends within the shell through the corresponding apertures of the two inner tubesheets to the corresponding apertures of the two outer tubesheets. A plurality of the thermal radiator tubes can be arranged in a staggered or an in-line configuration within the shell.

  14. Virginia in the spotlight at the Sunbelt Agricultural Exposition

    OpenAIRE

    Greiner, Lori A.

    2007-01-01

    Virginia will be featured at the 2007 Sunbelt Agricultural Exposition to be held Oct. 16-18 in Moultrie, Ga. Virginia's exhibit, "Virginia Agriculture: Proud History, Prosperous Future," will highlight the role Virginia has played in the history of agriculture as well as showcase new directions being explored today.

  15. Experience with Kamini reactor

    International Nuclear Information System (INIS)

    Kamini is a 233U fuelled, 30 kW(th) research reactor. It is one of the best neutron source facility with a core average flux of 1012 n/cm2/s in IGCAR used for neutron radiography of active and nonradioactive objects, activation analysis and radiation physics research. The core consists of nine plate type fuel elements with a total fuel inventory of 590 g of 233U. Two safety control plates made of cadmium are used for start up and shutdown of the reactor. Three beam tubes, two-thimble irradiation site outside reflector and one irradiation site nearer to the core constitute the testing facilities of Kamini. Kamini attained first criticality on 29th October 96 and nominal power of 30 kW in September 1997. This paper covers the design features of the reactor, irradiation facilities and their utilities and operating experience of the reactor. (author)

  16. 75 FR 65695 - North Carolina Disaster Number NC-00030

    Science.gov (United States)

    2010-10-26

    ... following areas as adversely affected by the disaster: Primary Counties: (Physical Damage and Economic... Carolina: Bladen, Columbus, Edgecombe, Greene, New Hanover, Sampson, Wilson. South Carolina: Horry....

  17. 75 FR 2564 - Virginia Electric and Power Company D/B/A Dominion Virginia Power and Old Dominion Electric...

    Science.gov (United States)

    2010-01-15

    ... COMMISSION Virginia Electric and Power Company D/B/A Dominion Virginia Power and Old Dominion Electric Cooperative; Combined License Application for North Anna Unit 3; Exemption 1.0 Background Virginia Electric and Power Company, doing business as Dominion Virginia Power (Dominion), acting on its own behalf...

  18. 76 FR 6638 - Virginia Electric and Power Company D/B/A/ Dominion Virginia Power and Old Dominion Electric...

    Science.gov (United States)

    2011-02-07

    ... COMMISSION Virginia Electric and Power Company D/B/A/ Dominion Virginia Power and Old Dominion Electric... Environmental Impact Statement and Conduct Scoping Process On June 28, 2010, Virginia Electric Power Company d/b/a Dominion Virginia Power and Old Dominion Electric Cooperative (jointly referred to as...

  19. Automatic integrated testing bench for tubes in translation

    International Nuclear Information System (INIS)

    All the nondestructive tests required for receiving the cladding tubes intended for fast nuclear reactor are integrated on this bench: quality control by eddy currents and ultra-sounds, thickness and (inner and outer) diameter measurement. The linear displacement of the tube allows very high rates to be attained

  20. Multifrequency eddy current testing of helical tubes of steam generators

    International Nuclear Information System (INIS)

    In the event of a water-sodium reaction in a steam-generator of a fast breeder reactor, it is necessary to test the tubes close to the leak to evaluate the damage. In SUPERPHENIX, the tubes are about 100m long and are coiled on a dead body. This report describes the equipment and the technic to test such tubes with multifrequency eddy current technics

  1. Titanium condenser tubes

    International Nuclear Information System (INIS)

    The corrosion resistance of titanium in sea water is extremely excellent, but titanium tubes are expensive, and the copper alloy tubes resistant in polluted sea water were developed, therefore they were not used practically. In 1970, ammonia attack was found on the copper alloy tubes in the air-cooled portion of condensers, and titanium tubes have been used as the countermeasure. As the result of the use, the galvanic attack an copper alloy tube plates with titanium tubes as cathode and the hydrogen absorption at titanium tube ends owing to excess electrolytic protection were observed, but the corrosion resistance of titanium tubes was perfect. These problems can be controlled by the application of proper electrolytic protection. The condensers with all titanium tubes adopted recently in USA are intended to realize perfectly no-leak condensers as the countermeasure to the corrosion in steam generators of PWR plants. Regarding large condensers of nowadays, three problems are pointed out, namely the vibration of condenser tubes, the method of joining tubes and tube plates, and the tubes of no coolant leak. These three problems in case of titanium tubes were studied, and the problem of the fouling of tubes was also examined. The intervals of supporting plates for titanium tubes should be narrowed. The joining of titanium tubes and titanium tube plates by welding is feasible and promising. The cleaning with sponge balls is effective to control fouling. (Kako, I.)

  2. Financial Flexibility in North Carolina Schools.

    Science.gov (United States)

    Suarez, Tanya M.; Polen, Deborah A.

    This paper explores educational financial flexibility with a focus on the specific issues surrounding local flexibility in North Carolina school districts. Strategies that states have used to increase local financial flexibility include waivers, reduction of budget categories, block grants, and school-based budgeting. The North Carolina system of…

  3. Colon Cancer Screening in North Carolina.

    Science.gov (United States)

    Harvin, Glenn

    2016-01-01

    Colorectal cancer (CRC) is the 2nd leading cause of cancer death both in North Carolina and in the United States. The goal of CRC screening is early detection and prevention. This commentary reviews the evidence for screening, discusses current screening options, and explores which options are best suited for use in North Carolina. PMID:27154885

  4. North Carolina School Nurse Leadership Institute

    Science.gov (United States)

    Guttu, Martha

    2007-01-01

    Recognizing that school nurse leaders are essential to the development of school nurses, the North Carolina School Nurse Leadership Institute was developed to enable school nurse leaders to update and advance their leadership skills. The Institute was a collaborative endeavor between the North Carolina Department of Health and Human Services,…

  5. Development of Zirconium alloys (for pressure tubes)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Suk; Kwon, Sang Chul; Choo, Ki Nam; Jung, Chung Hwan; Yim, Kyong Soo; Kim, Sung Soo; Baek, Jong Hyuk; Jeong, Yong Hwan; Kim, Kyong Ho; Cho, Hae Dong [Korea Atomic Energy Research Inst., Daeduk (Korea, Republic of); Hwang, S. K.; Kim, M. H. [Inha Univ., Incheon (Korea, Republic of); Kwon, S. I [Korea Univ., Seoul (Korea, Republic of); Kim, I. S. [Korea Advanced Inst. of Science and Technology, Taejon (Korea, Republic of)

    1997-09-01

    The objective of this research is to set up the basic technologies for the evaluation of pressure tube integrity and to develop improved zirconium alloys to prevent pressure tube failures due to DHC and hydride blister caused by excessive creep-down of pressure tubes. The experimental procedure and facilities for characterization of pressure tubes were developed. The basic research related to a better understanding of the in-reactor performances of pressure tubes leads to noticeable findings for the first time : the microstructural effect on corrosion and hydrogen pick-up behavior of Zr-2.5Nb pressure tubes, texture effect on strength and DHC resistance and enhanced recrystallization by Fe in zirconium alloys and etc. Analytical methodology for the assessment of pressure tubes with surface flaws was set up. A joint research is being under way with AECL to determine the fracture toughness of O-8 at the EOL (End of Life) that had been quadruple melted and was taken out of the Wolsung Unit-1 after 10 year operation. In addition, pressure tube with texture controlled is being made along with VNINM in Russia as a joint project between KAERI and Russia. Finally, we succeeded in developing 4 different kinds of zirconium alloys with better corrosion resistance, low hydrogen pickup fraction and higher creep strength. (author). 121 refs., 65 tabs., 260 figs

  6. Scanning tunneling microscope assembly, reactor, and system

    Science.gov (United States)

    Tao, Feng; Salmeron, Miquel; Somorjai, Gabor A

    2014-11-18

    An embodiment of a scanning tunneling microscope (STM) reactor includes a pressure vessel, an STM assembly, and three spring coupling objects. The pressure vessel includes a sealable port, an interior, and an exterior. An embodiment of an STM system includes a vacuum chamber, an STM reactor, and three springs. The three springs couple the STM reactor to the vacuum chamber and are operable to suspend the scanning tunneling microscope reactor within the interior of the vacuum chamber during operation of the STM reactor. An embodiment of an STM assembly includes a coarse displacement arrangement, a piezoelectric fine displacement scanning tube coupled to the coarse displacement arrangement, and a receiver. The piezoelectric fine displacement scanning tube is coupled to the coarse displacement arrangement. The receiver is coupled to the piezoelectric scanning tube and is operable to receive a tip holder, and the tip holder is operable to receive a tip.

  7. 75 FR 9006 - Virginia Disaster #VA-00028

    Science.gov (United States)

    2010-02-26

    ... Commonwealth of Virginia (FEMA-1874-DR), dated 02/16/2010. Incident: Severe Winter Storm and Snowstorm... Park City, Montgomery, Nelson, Norton City, Orange, Page, Prince William, Rockbridge, Russell,...

  8. A Guide for Virginia's Forest Landowners

    OpenAIRE

    Munsell, John F; Gagnon, Jennifer L.

    2011-01-01

    Provides Virginia's forest landowners with strategies for making profitable investments through sustainable forest management. It describes the seven-criteria Montreal Process and lists sources of information and assistance.

  9. Physics launches first Virginia Tech signature experience

    OpenAIRE

    Doss, Catherine

    2010-01-01

    When Professor Nahum Arav joined the Department of Physics in the College of Science in January 2008, he says he had a dream: to introduce Virginia Tech students to the beauty and wonders of the universe.

  10. Virginia ESI: MGT (Management Area Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains boundaries for management areas, national parks, state and local parks, and wildlife refuges in Virginia. Vector polygons in this data set...

  11. Virginia ESI: HYDRO (Hydrography Lines and Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector lines and polygons representing coastal hydrography used in the creation of the Environmental Sensitivity Index (ESI) for Virginia....

  12. Virginia Woolfi tunnid kummitavad edasi / Andres Laasik

    Index Scriptorium Estoniae

    Laasik, Andres, 1960-2016

    2003-01-01

    Virginia Woolfi teosest "Mrs. Dalloway" ajendatud Michael Cunninghami romaanil "Tunnid" põhinev mängufilm "Tunnid" ("The Hours") : režissöör Stephen Daldry : kesksetes rollides Meryl Streep, Nicole Kidman, Julianne Moore : Suurbritannia 2002

  13. Virginia Tech partnership wins NASPA award

    OpenAIRE

    Harris, Sally L.

    2005-01-01

    A program fostered and nurtured by Landrum Cross, Virginia Tech's vice president for Student Affairs, has won the Global Partnership Program award in NASPA International Education Knowledge Community's 3rd Annual Best Practices in International Education and Learning Awards.

  14. Recently Deceased: The First Amendment in Virginia.

    Science.gov (United States)

    Meyers, Terry L.

    2002-01-01

    Describes how a Virginia law forbidding state employees to access sexually explicit material on state-owned computers without written permission from their agency's head has "plagued" one professor, requiring numerous incidents of permission-seeking regarding Victorian poetry. (EV)

  15. 2011 FEMA Lidar: Southern Virginia Cities

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Dewberry collected LiDAR for ~3,341 square miles in various Virginia Counties, a part of Worcester County, and Hooper's Island. The acquisition was performed by...

  16. 2012 FEMA Lidar: Southern Virginia Counties

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Dewberry collected LiDAR for ~3,341 square miles in various Virginia Counties, a part of Worcester County, and Hoopers Island. The acquisition was performed by...

  17. ORTHOIMAGERY, CITY OF POQUOSON, VIRGINIA, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — These files contain Digital Orthophoto files for the State of Virginia developed from imagery acquired in spring 2007. In the spring of 2006, the Commonwealth of...

  18. Failure analysis of retired steam generator tubings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hong Pyo; Kim, J. S.; Hwang, S. S. and others

    2005-04-15

    Degradation of steam generator leads to forced outage and extension of outage, which causes increase in repair cost, cost of purchasing replacement power and radiation exposure of workers. Steam generator tube rupture incident occurred in Uljin 4 in 2002, which made public sensitive to nuclear power plant. To keep nuclear energy as a main energy source, integrity of steam generator should be demonstrated. Quantitative relationship between ECT(eddy current test) signal and crack size is needed in assesment of integrity of steam generator in pressurized water reactor. However, it is not fully established for application in industry. Retired steam generator of Kori 1 has many kinds of crack such as circumferential and axial primary water stress corrosion crack and outer diameter stress corrosion crack(ODSCC). So, it can be used in qualifying and improving ECT technology and in condition monitoring assesment for crack detected in ISI(in service inspection). In addition, examination of pulled tube of Kori 1 retired steam generator will give information about effectiveness of non welded sleeving technology which was employed to repair defect tubes and remedial action which was applied to mitigate ODSCC. In this project, hardware such as semi hot lab. for pulled tube examination and modification transportation cask for pulled tube and software such as procedure of transportation of radioactive steam generator tube and non-destructive and destructive examination of pulled tube were established. Non-destructive and destructive examination of pulled tubes from Kori 1 retired steam generator were performed in semi hot lab. Remedial actions applied to Kori 1 retired steam generator, PWSCC trend and bulk water chemistry and crevice chemistry in Kori 1 were evaluated. Electrochemical decontamination technology for pulled tube was developed to reduce radiation exposure and enhance effectiveness of pulled tube examination. Multiparameter algorithm developed at ANL, USA was

  19. Reactor operation environmental information document

    Energy Technology Data Exchange (ETDEWEB)

    Wike, L.D.; Specht, W.L.; Mackey, H.E.; Paller, M.H.; Wilde, E.W.; Dicks, A.S.

    1989-12-01

    The Savannah River Site (SRS) is a large United States Department of Energy installation on the upper Atlantic Coastal Plain of South Carolina. The SRS contains diverse habitats, flora, and fauna. Habitats include upland terrestrial areas, varied wetlands including Carolina Bays, the Savannah River swamp system, and impoundment related and riparian wetlands, and the aquatic habitats of several stream systems, two large cooling reservoirs, and the Savannah River. These diverse habitats support a large variety of plants and animals including many commercially or recreational valuable species and several rare, threatened or endangered species. This volume describes the major habitats and their biota found on the SRS, and discuss the impacts of continued operation of the K, L, and P production reactors.

  20. Computation and measurement of calandria tube sag in PHWR

    International Nuclear Information System (INIS)

    Calandria tubes and liquid injection shutdown system (LISS) tubes in a pressurized heavy water reactor (PHWR) is known to sag due to irradiation creep and growth during plant operation. When the sag of calandria tube becomes bigger, the calandria tube possibly comes in contact with LISS tube crossing beneath and calandria tube. The contact subsequently may cause the damage on the calandria tube resulting in unpredicted outage of the plant. It is therefore necessary to check the gap between the two tubes in order to periodically confirm no contact by using a proper measure during the plant life. An ultrasonic gap measuring probe assembly which can be inserted into two viewing ports of the calandria was developed in Korea and utilized to measure the sags of both tubes in the PHWR. It was found that the centerlines of calandria tubes and liquid injection shutdown system tubes can be precisely detected by ultrasonic wave. The gaps between two tubes were easily obtained from the relative distance of the measured centerline elevations of the tubes. Based on the irradiation creep equation and the measurement data, a computer program to calculate the sags was also developed. With the computer program, the sag at the end of plant life was predicted. (author)

  1. Structural and lithologic relationships in the Raleigh metamorphic belt near Lake Gaston, Virginia and North Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Sacks, P.E.; Horton, J.W. Jr. (Geological Survey, Reston, VA (United States))

    1993-03-01

    Preliminary results of mapping along the NC-VA State line eastward from the Buggs Is. granite about 35 km to the Hollister fault zone yield new information about structural and lithologic relationships in the Raleigh metamorphic belt. The layered rocks are predominantly two-mica schist and sillimanite-mica schist interlayered with lesser amounts of muscovite-biotite-quartz-plagioclase paragneiss and hornblende-biotite gneiss. The overall rock assemblage here differs from those along strike near Goochland, VA, and near Raleigh, NC, and is reminiscent of an accretionary complex. Bodies of foliated to massive two-mica granite are abundant and commonly contain garnet. One body, the Wise pluton, contains a N--NW-striking, steeply dipping foliation, but the intrusive contact of the granite with the metamorphic rocks is discordant. The most prominent regional foliation, parallel to transposed compositional layering, is axial planar to relict, reclined, isoclinal outcrop-scale folds. This foliation is folded at both outcrop and map scale by open folds plunging NW and SW. Some foliated, two-mica granite sheets are warped by the open folds; other bodies of similar granite cut across these folds. Sillimanite needles are locally aligned with the hinges of some of the open folds, an indication that sillimanite-muscovite-grade metamorphism was associated with this folding event. The two-mica granites resemble other late Paleozoic granites in the region. If these granites prove to be late Paleozoic (Alleghanian), then the deformation and metamorphism that produced sillimanite along the hingelines also must be Alleghanian. Relatively younger, NW- and SE-plunging crenulations and chevron folds are associated with a crenulation cleavage that dips steeply NE or SW. Sillimanite needles are folded by these crenulations. Crenulation cleavage and related folds may have developed in response to transpression of these rocks between the dextral Lake Gordon and Hollister mylonite zones.

  2. 2008 NOAA Integrated Ocean and Coastal Mapping (IOCM) LiDAR: North Carolina and Virginia

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data were collected by the National Oceanic Atmospheric Administration National Geodetic Survey Remote Sensing Division using an OPTECH ALTM system. The data...

  3. Agricultural and residential pesticides in wipe samples from farmworker family residences in North Carolina and Virginia.

    OpenAIRE

    Quandt, Sara A.; Arcury, Thomas A.; Rao, Pamela; Snively, Beverly M.; Camann, David E.; Doran, Alicia M; Yau, Alice Y; Hoppin, Jane A; Jackson, David S

    2004-01-01

    Children of farmworkers can be exposed to pesticides through multiple pathways, including agricultural take-home and drift as well as residential applications. Because farmworker families often live in poor-quality housing, the exposure from residential pesticide use may be substantial. We measured eight locally reported agricultural pesticides and 13 pesticides commonly found in U.S. houses in residences of 41 farmworker families with at least one child < 7 years of age in western North Caro...

  4. Coastal Virginia to Coastal North Carolina RGB Aerial Photography: Integrated Ocean and Coastal Mapping Product

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Integrated Ocean and Coastal Mapping Product (IOCM). The images were acquired from a nominal altitude of 7,500 feet above ground level (AGL), using an Applanix...

  5. Plant life management strategies for pressurized heavy water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Suk; Kwon, Sang Chul; Choo, Ki Nam; Ahn, Sang Bok; Kuk, Il Hyun [Korea Atomic Energy Research Institute, Taejon (Korea)

    1998-06-01

    This technical report reviewed aging mechanism of the major components of CANDU 6 reactor such as pressure tubes, calandria tube, end fitting, fuel channel spacer and calandria. Furthermore, the surveillance methodology was described for monitoring and inspection of these core components. Based on the in-reactor performances data such as delayed hydride cracking, leak-before-break, enhanced deformation-creep and growth, the life management of pressure tubes was illustrated in this report. (author). 19 refs., 11 figs., 2 tabs.

  6. N Reactor

    Data.gov (United States)

    Federal Laboratory Consortium — The last of Hanfordqaodmasdkwaspemas7ajkqlsmdqpakldnzsdflss nine plutonium production reactors to be built was the N Reactor.This reactor was called a dual purpose...

  7. 76 FR 54189 - Television Broadcasting Services; Hampton-Norfolk, Virginia; Norfolk, Virginia-Elizabeth City, NC

    Science.gov (United States)

    2011-08-31

    ... COMMISSION 47 CFR Part 73 Television Broadcasting Services; Hampton-Norfolk, Virginia; Norfolk, Virginia... Association (``HRETA''), the licensee of noncommercial educational television station WHRO-TV, channel *16... license. There is presently a freeze on the filing of television allotment rulemaking petitions, but...

  8. The Russell gold deposit, Carolina Slate Belt, North Carolina

    Science.gov (United States)

    Klein, T.L.; Cunningham, C.G.; Logan, M.A.V.; Seal, R.R.

    2007-01-01

    Gold deposits have been mined in the Carolina slate belt from the early 1800s to recent times, with most of the production from large mines in South Carolina. The Russell mine, one of the larger producers in North Carolina, is located in the central Uwharrie Mountains, and produced over 470 kg of gold. Ore grades averaged about 3.4 grams per tonne (g/ t), with higher-grade zones reported. The Russell deposit is interpreted to be a sediment-hosted, gold-rich, base-metal poor, volcanogenic massive sulfide deposit in which gold was remobilized, in part, during Ordovician metamorphism. The ore was deposited syngenetically with laminated siltstones of the late Proterozoic Tillery Formation that have been metamorphosed to a lower greenschist facies. The Tillery Formation regionally overlies subaerial to shallow marine rhyolitic volcanic and volcaniclastic rocks of the Uwharrie Formation and underlies the marine volcanic and sedimentary rocks of the Cid Formation. Recent mapping has shown that a rhyolitic dome near the Russell mine was extruded during the deposition of the lower part of the Tillery Formation, at about the same time as ore deposition. Relict mafic, rock fragments present in the ore zones suggest contemporaneous bimodal (rhyolite-basalt) volcanism. The maximum formation age of the Russell deposit is younger than 558 Ma, which is similar to that of the larger, well known Brewer, Haile, and Ridgeway deposits of South Carolina. Gold was mined from at least six zones that are parallel to the regional metamorphic foliation. These strongly deformed zones consist of northeast-trending folds, high-angle reverse faults, and asymmetric doubly plunging folds overturned to the southeast. The dominant structure at the mine is an asymmetric doubly plunging anticline with the axis trending N 45?? E, probably related to late Ordovician (456 ?? 2 Ma) regional metamorphism and deformation. Two stages of pyrite growth are recognized. Stage 1, primary, spongy pyrite, is

  9. 76 FR 11522 - South Carolina Electric and Gas Company (SCE&G) and the South Carolina Public Service Authority...

    Science.gov (United States)

    2011-03-02

    ... COMMISSION South Carolina Electric and Gas Company (SCE&G) and the South Carolina Public Service Authority... Carolina Electric and Gas Company (SCE&G) acting as itself and agent for the South Carolina Public Service... not have access to ADAMS, or who encounter problems in accessing the documents located in...

  10. Innovation in pressure tube life assessment

    International Nuclear Information System (INIS)

    The hydrogen equivalent concentration and the rate of hydrogen ingress (in particular, deuterium) in pressure tubes are important parameters that must be assessed to determine the fitness-for-service of CANDU reactors. This paper presents the latest refinement in a process referred to as 'Pressure Tube Sampling', which is the only fully qualified and proven method that allows accurate determination of both the hydrogen equivalent concentration and the rate deuterium ingress without performing an expensive fuel channel removal. Pressure Tube Sampling has evolved over the past fifteen years during which over 2,300 samples have been obtained from CANDU reactors around the globe. In-reactor sampling is the standard method for determining the hydrogen equivalent concentrations and deuterium ingress rates in CANDU reactors. Over the past fifteen years, continual improvements in the Pressure Tube Sampling process have resulted in: the capability to obtain circumferential and axial samples, reduced 'on-face' time, reduced cost, reduced dose to workers, and improved analysis accuracy. Most recently, the new Multi-Head Sampling Tool (MHST) has been developed that continues this trend by using one tool to sample at all four axial pressure tube locations in a single visit to the fuel channel, thereby further improving efficiency. In 2001 October, the MHST was successfully deployed at Wolsong 1 by AECL for Korea Hydro and Nuclear Power. The tool was delivered using their Advanced Delivery Machine (ADM) and a total of sixteen samples were obtained from four channels. A significant saving in time was achieved with a rate of one channel (four samples) being sampled every 2 1/2 hours. For a typical 10-channel campaign, this could equate to a 2 to 3 days time/saving, which is significant in terms of outage schedule, cost, and worker dose. This paper provides a description of some of the latest innovations, with specific details on site application, performance, and end results

  11. Oscillatory flow chemical reactors

    Directory of Open Access Journals (Sweden)

    Slavnić Danijela S.

    2014-01-01

    Full Text Available Global market competition, increase in energy and other production costs, demands for high quality products and reduction of waste are forcing pharmaceutical, fine chemicals and biochemical industries, to search for radical solutions. One of the most effective ways to improve the overall production (cost reduction and better control of reactions is a transition from batch to continuous processes. However, the reactions of interests for the mentioned industry sectors are often slow, thus continuous tubular reactors would be impractically long for flow regimes which provide sufficient heat and mass transfer and narrow residence time distribution. The oscillatory flow reactors (OFR are newer type of tube reactors which can offer solution by providing continuous operation with approximately plug flow pattern, low shear stress rates and enhanced mass and heat transfer. These benefits are the result of very good mixing in OFR achieved by vortex generation. OFR consists of cylindrical tube containing equally spaced orifice baffles. Fluid oscillations are superimposed on a net (laminar flow. Eddies are generated when oscillating fluid collides with baffles and passes through orifices. Generation and propagation of vortices create uniform mixing in each reactor cavity (between baffles, providing an overall flow pattern which is close to plug flow. Oscillations can be created by direct action of a piston or a diaphragm on fluid (or alternatively on baffles. This article provides an overview of oscillatory flow reactor technology, its operating principles and basic design and scale - up characteristics. Further, the article reviews the key research findings in heat and mass transfer, shear stress, residence time distribution in OFR, presenting their advantages over the conventional reactors. Finally, relevant process intensification examples from pharmaceutical, polymer and biofuels industries are presented.

  12. [Workshop for coordinating South Carolina`s pre-college systemic initiatives in science and mathematics

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-31

    On December 19, 1991, South Carolina`s Governor, established the Governor`s Mathematics and Sciences Advisory Board (MSAB) to articulate a vision and develop a statewide plan for improving science and mathematics education in South Carolina. The MSAB recognized that systemic change must occur if the achievement levels of students in South Carolina are to improve in a dramatic way. The MSAB holds two fundamental beliefs about systemic change: (1) All the elements of the science and mathematics education system must be working in harmony towards the same vision; and (2) Each element of the system must be held against high standards and progress must be assessed regularly against these standards.

  13. Airborne radioactivity survey of parts of Atlantic Ocean beach, Virginia to Florida

    Science.gov (United States)

    Moxham, R.M.; Johnson, R.W.

    1953-01-01

    The accompanying maps show the results of an airborne radioactivity survey along the Atlantic Ocean beach from Cape Henry, Virginia to Cape Fear, North Carolina and from Savannah Bach Georgia to Miami Beach, Florida. The survey was made March 23-24, 1953, as part of a cooperative program with the U.S. Atomic Energy Commission. The survey was made with scintillation detection equipment mounted in a Douglas DC-3 aircraft and consisted of one flight line, at a 500-foot altitude, parallel to the beach. The vertical projection of the flight line coincided approximately with the landward limit of the modern beach. The width of the zone on the ground from which anomalous radiation is measured at the normal 500 foot flight altitude varies with the areal extent radioactivity of the source. For strong sources of radioactivity the width of the zone would be as much as 1,400 feet. The location of the flight lines is shown on the index map below. No abnormal radioactivity was detected along the northern flight line between Cape Henry, Virginia and Cape Fear, North Carolina. Along the southern flight line fourteen areas of abnormal radioactivity were detected between Savannah Beach, Georgia and Anastasia Island, Florida as shown on the map on the left. The abnormal radioactivity is apparently due to radioactive minerals associated with "black sand" deposits with occur locally along the beach in this region. The present technique of airborne radioactivity measurement does not permit distinguishing between activity sue to thorium and that due to uranium. An anomaly, therefore, may represent radioactivity due entirely to one or to a combination of these elements. It is not possible to determine the extent or radioactive content of the materials responsible for the abnormal radioactivity. The information given on the accompanying map indicates only those localities of greater-than-average radioactivity and, therefore suggest areas in which uranium and thorium deposits are more

  14. Virginia Tech forms new partnership to develop better wheat varieties

    OpenAIRE

    Greiner, Lori A.

    2010-01-01

    Virginia Tech and Monsanto announced today a mutually beneficial public-private collaborative agreement that will allow both parties to improve their wheat breeding programs and generate improved wheat varieties for growers in Virginia.

  15. Duke, Nolen to serve on Virginia Tech Board of Visitors

    OpenAIRE

    Hincker, Lawrence

    2005-01-01

    Governor Mark R. Warner recently announced appointments to several university boards of visitors, as well as the State Council of Higher Education for Virginia and the Board of Trustees for the Southern Virginia Higher Education Center.

  16. 2011 South Carolina DNR Lidar: York County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Towill Inc. collected LiDAR for over 3,500 square miles in York, Pickens, Anderson, and Oconee Counties in South Carolina. This metadata covers the LiDAR produced...

  17. 2012 South Carolina DNR Lidar: Calhoun County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Towill Inc. collected LiDAR for over 3,300 square miles in Calhoun, Aiken, Barnwell, Edgefield, McCormick, and Abbeville counties in South Carolina. This metadata...

  18. 2014 Horry County, South Carolina Lidar

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is comprised of lidar point cloud data. This project required lidar data to be acquired over Horry County, South Carolina. The total area of the Horry...

  19. 2012 South Carolina DNR Lidar: Abbeville County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Towill Inc. collected LiDAR for over 3,300 square miles in Calhoun, Aiken, Barnwell, Edgefield, McCormick, and Abbeville counties in South Carolina. This metadata...

  20. 2012 South Carolina DNR Lidar: Edgefield County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Towill Inc. collected LiDAR for over 3,300 square miles in Calhoun, Aiken, Barnwell, Edgefield, McCormick, and Abbeville counties in South Carolina. This metadata...

  1. 2008 South Carolina Lidar: Chester County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The project area is composed of 16 counties in the State of South Carolina - Cherokee, Union, Laurens, Greenwood, Newberry, Chester, Fairfield, Lancaster,...

  2. 2008 South Carolina Lidar: Marion County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The project area is composed of 16 counties in the State of South Carolina - Cherokee, Union, Laurens, Greenwood, Newberry, Chester, Fairfield, Lancaster,...

  3. 2008 South Carolina Lidar: Newberry County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The project area is composed of 16 counties in the State of South Carolina - Cherokee, Union, Laurens, Greenwood, Newberry, Chester, Fairfield, Lancaster,...

  4. 2008 South Carolina Lidar: Clarendon County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The project area is composed of 16 counties in the State of South Carolina - Cherokee, Union, Laurens, Greenwood, Newberry, Chester, Fairfield, Lancaster,...

  5. Chloritoid-sillimanite assemblage from North Carolina.

    Science.gov (United States)

    Milton, D.J.

    1986-01-01

    The occurrence of sillimanite and Fe-rich chloritoid in apparent equilibrium in a quartzite near Charlotte, North Carolina, is reported. The implications for the kyanite-andalusite-sillimanite triple point are discussed.-J.A.Z.

  6. 2012 South Carolina DNR Lidar: Aiken County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Towill Inc. collected LiDAR for over 3,300 square miles in Calhoun, Aiken, Barnwell, Edgefield, McCormick, and Abbeville counties in South Carolina. This metadata...

  7. 2008 South Carolina Lidar: Chesterfield County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The project area is composed of 16 counties in the State of South Carolina - Cherokee, Union, Laurens, Greenwood, Newberry, Chester, Fairfield, Lancaster,...

  8. 2008 South Carolina Lidar: Williamsburg County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The project area is composed of 16 counties in the State of South Carolina - Cherokee, Union, Laurens, Greenwood, Newberry, Chester, Fairfield, Lancaster,...

  9. 2008 South Carolina Lidar: Marlboro County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The project area is composed of 16 counties in the State of South Carolina - Cherokee, Union, Laurens, Greenwood, Newberry, Chester, Fairfield, Lancaster,...

  10. 2008 South Carolina Lidar: Greenwood County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The project area is composed of 16 counties in the State of South Carolina - Cherokee, Union, Laurens, Greenwood, Newberry, Chester, Fairfield, Lancaster,...

  11. 2008 South Carolina Lidar: Darlington County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The project area is composed of 16 counties in the State of South Carolina - Cherokee, Union, Laurens, Greenwood, Newberry, Chester, Fairfield, Lancaster,...

  12. 2008 South Carolina Lidar: Lancaster County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The project area is composed of 16 counties in the State of South Carolina - Cherokee, Union, Laurens, Greenwood, Newberry, Chester, Fairfield, Lancaster,...

  13. 2008 South Carolina Lidar: Orangeburg County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The project area is composed of 16 counties in the State of South Carolina - Cherokee, Union, Laurens, Greenwood, Newberry, Chester, Fairfield, Lancaster,...

  14. 2008 South Carolina Lidar: Laurens County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The project area is composed of 16 counties in the State of South Carolina - Cherokee, Union, Laurens, Greenwood, Newberry, Chester, Fairfield, Lancaster,...

  15. 2008 South Carolina Lidar: Union County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The project area is composed of 16 counties in the State of South Carolina - Cherokee, Union, Laurens, Greenwood, Newberry, Chester, Fairfield, Lancaster,...

  16. 2008 South Carolina Lidar: Cherokee County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The project area is composed of 16 counties in the State of South Carolina - Cherokee, Union, Laurens, Greenwood, Newberry, Chester, Fairfield, Lancaster,...

  17. 2008 South Carolina Lidar: Dillon County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The project area is composed of 16 counties in the State of South Carolina - Cherokee, Union, Laurens, Greenwood, Newberry, Chester, Fairfield, Lancaster,...

  18. 2008 South Carolina Lidar: Fairfield County

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The project area is composed of 16 counties in the State of South Carolina - Cherokee, Union, Laurens, Greenwood, Newberry, Chester, Fairfield, Lancaster,...

  19. A Survey of Perceptions of the Virginia Tech Tragedy

    Science.gov (United States)

    Fallahi, Carolyn R.; Austad, Carol Shaw; Fallon, Marianne; Leishman, Lisa

    2009-01-01

    The recent shootings at the Virginia Polytechnic Institute (Virginia Tech) shocked the nation and brought violence on college campuses to the forefront of the nation's attention. We surveyed college students and faculty/staff three weeks after the incident about their perceptions of the Virginia Tech shooting, subsequent media exposure, and school…

  20. NASA Consortium awards funding to Virginia Tech's geospatial program

    OpenAIRE

    Davis, Lynn

    2004-01-01

    NASA has selected a partnership between the Virginia Space Grant Consortium (VSGC) and Virginia Tech to receive a $100,000 grant for geospatial education and work force development. The grant, awarded through the NASA Space Grant College and Fellowship program, allows the partners to continue the already successful Virginia Geospatial Extension Program that was established in July 2003.

  1. William Knocke receives 2008 Virginia Outstanding Civil Engineer Award

    OpenAIRE

    Daniilidi, Christina

    2008-01-01

    William R. Knocke, W.C. English Professor and head of the Charles E. Via, Jr. Department of Civil and Environmental Engineering at Virginia Tech, was awarded the 2008 Virginia Outstanding Civil Engineer Award at the Virginia Section of the American Society of Civil Engineers' (ASCE) banquet, held recently in Williamsburg, Va.

  2. 27 CFR 9.135 - Virginia's Eastern Shore.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Virginia's Eastern Shore... Virginia's Eastern Shore. (a) Name. The name of the viticultural area described in this section is “Virginia's Eastern Shore.” (b) Approved maps. The appropriate maps for determining the boundaries of...

  3. New scholarship provides opportunities for Virginia Community College graduates

    OpenAIRE

    Lazenby, Jenna

    2006-01-01

    The Office of University Scholarships and Financial Aid has launched the new"Virginia Tech-Virginia Community College System Lifeline Scholarship Program." Native Virginia Community College System (VCCS) students who complete their associates' degree are now eligible for one of six"Lifeline Scholarships," a new academic merit award given to graduates with the highest grade point average (GPA).

  4. West Virginia Interpretive Guide Training: A Collaborative Effort

    Science.gov (United States)

    Balcarczyk, Kelly; McKenney, Kathryn; Smaldone, Dave; Arborgast, Doug

    2013-01-01

    West Virginia University's Extension Service partnered with the Recreation, Parks, and Tourism Resources Program to improve guide performance in West Virginia's tourism industry. The result of this partnership is a West Virginia Interpretive Guide Training program aimed at providing low-cost, widely available training to guides…

  5. 75 FR 39560 - West Virginia; Major Disaster and Related Determinations

    Science.gov (United States)

    2010-07-09

    ... SECURITY Federal Emergency Management Agency West Virginia; Major Disaster and Related Determinations... Presidential declaration of a major disaster for the State of West Virginia (FEMA-1918-DR), dated June 24, 2010... follows: I have determined that the damage in certain areas of the State of West Virginia resulting...

  6. 77 FR 76061 - West Virginia; Major Disaster and Related Determinations

    Science.gov (United States)

    2012-12-26

    ... SECURITY Federal Emergency Management Agency West Virginia; Major Disaster and Related Determinations... Presidential declaration of a major disaster for the State of West Virginia (FEMA-4093-DR), dated November 27... West Virginia resulting from Hurricane Sandy during the period of October 29 to November 8, 2012, is...

  7. 75 FR 11902 - West Virginia; Major Disaster and Related Determinations

    Science.gov (United States)

    2010-03-12

    ... SECURITY Federal Emergency Management Agency West Virginia; Major Disaster and Related Determinations... Presidential declaration of a major disaster for the State of West Virginia (FEMA-1881-DR), dated March 2, 2010... follows: I have determined that the damage in certain areas of the State of West Virginia resulting from...

  8. Anders appointed director of Virginia Tech Hampton Roads Center

    OpenAIRE

    Felker, Susan B.

    2007-01-01

    Long-time Virginia Tech employee Charlotte L. Anders is the new director of the Virginia Tech Hampton Roads Center in Virginia Beach, Va., one of the university's five Commonwealth Campus Centers that offer graduate, continuing and professional education, and other lifelong learning programs.

  9. Tracheostomy tube - speaking

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000465.htm Tracheostomy tube - speaking To use the sharing features on ... are even speaking devices that can help you. Tracheostomy Tubes and Speaking Air passing through vocal cords ( ...

  10. Neural Tube Defects

    Science.gov (United States)

    Neural tube defects are birth defects of the brain, spine, or spinal cord. They happen in the ... that she is pregnant. The two most common neural tube defects are spina bifida and anencephaly. In ...

  11. Virginia big-eared bats (Corynorhinus townsendii virginianus) roosting in abandoned coal mines in West Virginia

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, J.B.; Edwards, J.W.; Wood, P.B. [West Virginia University, Morgantown, WV (US). Wildlife & Fisheries Resources Programme

    2005-07-01

    We surveyed bats at 36 abandoned coal mines during summer 2002 and 47 mines during fall 2002 at New River Gorge National River and Gauley River National Recreation Area, WV. During summer, we captured three federally endangered Virginia big-eared bats at two mine entrances, and 25 were captured at 12 mine entrances during fall. These represent the first documented captures of this species at coal mines in West Virginia. Future survey efforts conducted throughout the range of the Virginia big-eared bat should include abandoned coal mines.

  12. Reactivity control rod for controlling reactor power distribution

    International Nuclear Information System (INIS)

    Since a cladding tube is situated at the outer side, it undergoes neutron irradiation in a reactor core and also undergoes compression force due to high pressure of reactor coolants to cause a creep phenomenon, and the diameter is reduced as it is used. Then, neutron absorbing rods as reactivity control rods for controlling the power distribution are constituted with a cladding tube, a spacer tube disposed at the central portion of the cladding tube and a borosilicate glass tube disposed between the cladding tube and the spacer tube. The gap between the borosilicate glass tube and the spacer tube is gradually changed so that the inner diameter of the borosilicate glass is increased as it comes closer to the lower end plug. The time of contact between the cladding tube and the spacer tube in the inside is delayed by the constitution of the borosilicate glass tube disposed in the cladding tube of the neutron absorbing rod as the reactivity control rod thereby capable of extending the integral working life time with no rupture of the cladding tube. (N.H.)

  13. Mechanistic modeling of thermal-mechanical deformation of CANDU pressure tube under localized high temperature condition

    International Nuclear Information System (INIS)

    Thermal strain deformation is a pressure tube failure mechanism. The main objective of this paper is to develop mechanistic models to evaluate local thermal-mechanical deformation of a pressure tube in CANDU reactor and to investigate fuel channel integrity under localized contact between fuel elements and pressure tube. The consequence of concern is potential creep strain failure of a pressure tube and calandria tube. The initial focus will be on the case where a fuel rod contacts the pressure tube at full power with highly cooling condition

  14. Using XSLT's SQL Extension with Encyclopedia Virginia

    Directory of Open Access Journals (Sweden)

    Matthew Gibson

    2012-02-01

    Full Text Available This paper explores how to integrate data across a hybrid relational database and XML-based management system. It examines specifically how XSLT's SQL extension can be used to communicate information between SQL tables and TEI-conformant XML documents to make data-centric content more manageable and flexible and thereby leverage the strengths of both systems. In what follows, one will learn about some of the methods, benefits, and shortcomings of XSLT's SQL extension in the context of Encyclopedia Virginia, an open access publication of the Virginia Foundation for the Humanities that utilizes a suite of digital humanities and digital library XML vocabularies such as TEI and METS.

  15. Present status of JRR-3 neutron guide tubes

    International Nuclear Information System (INIS)

    JRR-3 reactor is a research reactor of 20 MW, and its main use is neutron beam experiments. Aiming at effective and efficient utilization, neutron guide tubes were introduced in 1990. Neutron guide tubes consist of 2 tubes for hot neutrons and 3 tubes for cold neutrons, and they are laid up to the beam hall adjacent to the reactor building. This allows the installation of about 20 experimental devices, and a wide variety of researches are carried out using these devices. To achieve higher performance of these neutron guide tubes, the updating to supermirror with high neutron transport efficiency is under way. As for the hot neutron guide tubes, hot neutron intensity has become approximately 6 times until now, which realized a large extent of efficiency. On the other hand, the soundness of the equipment has become a major issue after the Great East Japan Earthquake. This paper reports the confirmation of the soundness of neutron guide tubes, contents of restoration work, and current situation after the restoration work. (A.O.)

  16. Reactor Physics

    Energy Technology Data Exchange (ETDEWEB)

    Ait Abderrahim, A

    2001-04-01

    The Reactor Physics and MYRRHA Department of SCK-CEN offers expertise in various areas of reactor physics, in particular in neutronics calculations, reactor dosimetry, reactor operation, reactor safety and control and non-destructive analysis of reactor fuel. This expertise is applied in the Department's own research projects in the VENUS critical facility, in the BR1 reactor and in the MYRRHA project (this project aims at designing a prototype Accelerator Driven System). Available expertise is also used in programmes external to the Department such as the reactor pressure steel vessel programme, the BR2 reactor dosimetry, and the preparation and interpretation of irradiation experiments by means of neutron and gamma calculations. The activities of the Fuzzy Logic and Intelligent Technologies in Nuclear Science programme cover several domains outside the department. Progress and achievements in these topical areas in 2000 are summarised.

  17. 21 CFR 868.5800 - Tracheostomy tube and tube cuff.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tracheostomy tube and tube cuff. 868.5800 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5800 Tracheostomy tube and tube cuff. (a) Identification. A tracheostomy tube and tube cuff is a device intended to be placed into...

  18. Reactor safeguards

    CERN Document Server

    Russell, Charles R

    2013-01-01

    Reactor Safeguards provides information for all who are interested in the subject of reactor safeguards. Much of the material is descriptive although some sections are written for the engineer or physicist directly concerned with hazards analysis or site selection problems. The book opens with an introductory chapter on radiation hazards, the construction of nuclear reactors, safety issues, and the operation of nuclear reactors. This is followed by separate chapters that discuss radioactive materials, reactor kinetics, control and safety systems, containment, safety features for water reactor

  19. Reactor operation

    CERN Document Server

    Shaw, J

    2013-01-01

    Reactor Operation covers the theoretical aspects and design information of nuclear reactors. This book is composed of nine chapters that also consider their control, calibration, and experimentation.The opening chapters present the general problems of reactor operation and the principles of reactor control and operation. The succeeding chapters deal with the instrumentation, start-up, pre-commissioning, and physical experiments of nuclear reactors. The remaining chapters are devoted to the control rod calibrations and temperature coefficient measurements in the reactor. These chapters also exp

  20. Stages of Concern in the Implementation of the Virginia Credentialing Initiative in Rural Southwestern Virginia

    OpenAIRE

    Stacy, Christopher B.

    2012-01-01

    The purpose of this study was to describe the needs and concerns regarding the Virginia Credentialing Initiative (VCI) of career and technical education (CTE) stakeholders in rural southwestern Virginia. These stakeholders included central office CTE administrators, high school principals, guidance counselors, and high school CTE teachers. The Stages of Concern Questionnaire (George, Hall, & Stiegelbauer, 2008) was sent to 355 participants with 260 responding for a return rate of 73...

  1. Circumferential cracking of steam generator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Karwoski, K.J.

    1997-04-01

    On April 28, 1995, the U.S. Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 95-03, {open_quote}Circumferential Cracking of Steam Generator Tubes.{close_quote} GL 95-03 was issued to obtain information needed to verify licensee compliance with existing regulatory requirements regarding the integrity of steam generator tubes in domestic pressurized-water reactors (PWRs). This report briefly describes the design and function of domestic steam generators and summarizes the staff`s assessment of the responses to GL 95-03. The report concludes with several observations related to steam generator operating experience. This report is intended to be representative of significant operating experience pertaining to circumferential cracking of steam generator tubes from April 1995 through December 1996. Operating experience prior to April 1995 is discussed throughout the report, as necessary, for completeness.

  2. International banker to speak at Virginia Tech

    OpenAIRE

    Ho, Sookhan

    2004-01-01

    International banker David Bieri will give a talk, "Why Central Banks Manage Reserves," on Monday, April 5, 11 a.m. in 1045 Pamplin Hall on the Virginia Tech campus. His talk is part of the "International Business and Culture" guest lecture series sponsored by the Pamplin College of Business. The talk is free and open to the public.

  3. Virginia power thermal-hydraulic methods

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, R.C.; Harrell, J.R.; Basehore, K.L.

    1987-01-01

    Virginia Power Company operates two nuclear units at Surry and another pair at North Anna, with rated thermal powers of 2441 and 2893 MW, respectively. In support of the operation of these units, the nuclear safety analysis group is required to perform departure from nucleate boiling ratio (DNBR) calculations. In order to perform DNBR in-house analyses, Virginia Power acquired the COBRA IIIc/MIT thermal-hydraulic (T/H) code in the mid-1970s. The COBRA code is used primarily to evaluate reload core designs. Additional applications include peaking factor evaluation and may include transient reanalysis. More recently, in an effort gain DNBR margin by taking credit for excessive conservatism in the methodology for treating key uncertainties, Virginia Power submitted a topical report that described a proposed statistical combination of those uncertainties. In an alternate approach to gain DNBR margin, Virginia Power submitted a topical report that describes the qualification of the proprietary WRB-1 DNBR correlation in COBRA. These reports have been combined in a recent North Anna submittal. The margin gain was used to support reanalysis of key DNBR events with more conservative assumptions, thus reducing the likelihood of future reload violations. Upon NRC approval, this submittal will greatly streamline the reload verification process, while providing core design flexibility and relaxing operational restrictions for North Anna.

  4. Virginia Tech offers forest products selling course

    OpenAIRE

    Davis, Lynn

    2005-01-01

    Virginia Tech's Center for Forest Products Marketing and Managing recognizes that many professionals in the industry don't have the training they need to begin a successful career in marketing forest products. Selling Forest Products is a program designed to address that need, especially today, in light of fierce global competition.

  5. The Virginia Tech Open Access Subvention Fund

    OpenAIRE

    McMillan, Gail

    2013-01-01

    Let your journal articles be openly accessible. Don't hide your research behind a pay-wall that only the well-endowed researchers can access. Learn about the cooperative venture between the Library, the Provost, and the Office of Research that will fund open access scholarship. University Libraries, Virginia Tech, Open Access Week

  6. Virginia Tech Center for Autism Research

    OpenAIRE

    Virginia Tech Center for Autism Research

    2012-01-01

    These slides serve as a welcome for the Autism Research Conference held at Virginia Tech on August 15 2012. The slides describe symptoms and prevalence of autism spectrum disorders, list goals for the proposed Center for Autism Research, and list the speakers and agenda for the conference.

  7. 77 FR 74908 - Virginia Disaster #VA-00051

    Science.gov (United States)

    2012-12-18

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Virginia Disaster VA-00051 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY... INFORMATION CONTACT: A. Escobar, Office of Disaster Assistance, U.S. Small Business Administration, 409...

  8. Computer Anxiety Levels of Virginia Extension Personnel.

    Science.gov (United States)

    Martin, Brenda L.; Stewart, Daisy L.; Hillison, John

    2001-01-01

    Survey responses from 402 Virginia extension personnel showed that secretaries and younger staff had the lowest computer anxiety, technicians and older staff the highest. Time spent using computers, age, and years of employment were somewhat associated with anxiety. Training recommendations were made. (SK)

  9. 76 FR 67637 - West Virginia Regulatory Program

    Science.gov (United States)

    2011-11-02

    ... non- Federal and non-Indian lands within its borders by demonstrating that its program includes, among... Virginia program in the January 21, 1981, Federal Register (46 FR 5915). You can also find later actions... The State is proposing to add the language ``either in the application or in an electronic...

  10. 76 FR 37996 - West Virginia Regulatory Program

    Science.gov (United States)

    2011-06-29

    ... surface coal mining and reclamation operations on non- Federal and non-Indian lands within its borders by... of approval of the West Virginia program in the January 21, 1981, Federal Register (46 FR 5915). You... actual language of State regulatory programs and program amendments because each program is drafted...

  11. On Virginia Woolf’s Literary Experimentation

    Institute of Scientific and Technical Information of China (English)

    毕琳娜

    2013-01-01

    The paper takes the content of Virginia Woolf’s diary and novel as materials to analyze three of her most important theories which are“subjective vision”,“moment of being”and“character as center”to explain her literary experimentation which aims to find a new form for a new novel in an era of modernist literature.

  12. The Right to Marry: "Loving v. Virginia."

    Science.gov (United States)

    Wallenstein, Peter

    1995-01-01

    Discusses the background, legal issues, and significance of the Supreme Court decision, "Loving v. Virginia" (1967). Outlines the history of laws against interracial marriage throughout U.S. history. Asserts that interpretation of the Fourteenth Amendment, applying federal civil rights to the states, was a key factor in the case. (CFR)

  13. Business Plan: The Virginia Space Flight Center

    Science.gov (United States)

    Reed, Billie M.

    1997-01-01

    The Virginia Commercial Space Flight Authority (VCSFA) was established on July 1, 1995 and codified at Sections 9-266.1 et seq., Code of Virginia. It is governed by an eleven person Board of Directors representing industry, state and local government and academia. VCSFA has designated the Center for Commercial Space Infrastructure as its Executive Directorate and Operating Agent. This Business Plan has been developed to provide information to prospective customers, prospective investors, state and federal government agencies, the VCSFA Board and other interested parties regarding development and operation of the Virginia Space Flight Center (VSFC) at Wallops Island. The VSFC is an initiative sponsored by VCSFA to achieve its stated objectives in the areas of economic development and education. Further, development of the VSFC is in keeping with the state's economic goals set forth in Opportunity Virginia, the strategic plan for jobs and prosperity, which are to: (1) Strengthen the rapidly growing aerospace industry in space based services including launch services, remote sensing, satellite manufacturing and telecommunications; and (2) Capitalize on intellectual and technical resources throughout the state and become a leader in the development of advanced technology businesses.

  14. Central Virginia Community College 1999 Fact Book.

    Science.gov (United States)

    Hicks, Geoffrey

    The Fact Book is an annual publication of the Office of Research, Assessment and Planning at Central Virginia Community College (CVCC). It includes data and trends from 1994-1998 and is divided into six parts: (1) "The College" includes information on the College Board, institutional history, facilities, mission and goals, revenues and…

  15. Virginia Tech's Undergraduate Admissions Director Resigns

    OpenAIRE

    Cox, Clara B.

    2003-01-01

    Karen E. Torgersen, director of undergraduate admissions at Virginia Tech since 1997, has submitted her resignation from the university effective Dec. 31 to become associate executive director of U21pedagogica Limited (Pedagogica), a new international educational enterprise in Charlottesville, Va.

  16. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... YouTube Videos > NEI YouTube Videos: Amblyopia NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration Amblyopia ... of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia NEI on Twitter NEI on YouTube NEI ...

  17. NEI You Tube Videos: Amblyopia

    Science.gov (United States)

    ... NEI YouTube Videos > NEI YouTube Videos: Amblyopia NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration ... Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia NEI on Twitter NEI on YouTube ...

  18. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... NEI YouTube Videos > NEI YouTube Videos: Amblyopia NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration ... Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia NEI on Twitter NEI on YouTube ...

  19. Post-hurricane Joaquin Coastal Oblique Aerial Photographs Collected from the South Carolina/North Carolina Border to Montauk Point, New York, October 7–9, 2015

    Science.gov (United States)

    Morgan, Karen L.M.

    2016-06-27

    The U.S. Geological Survey (USGS), as part of the National Assessment of Coastal Change Hazards project, conducts baseline and storm-response photography missions to document and understand the changes in vulnerability of the Nation's coasts to extreme storms (Morgan, 2009). On October 7–9, 2015, the USGS conducted an oblique aerial photographic survey of the coast from the South Carolina/North Carolina border to Montauk Point, New York (fig. 1), aboard a Cessna 182 (aircraft) at an altitude of 500 feet (ft) and approximately 1,200 ft offshore fig. 2. This mission was conducted to collect post-Hurricane Joaquin data for assessing incremental changes in the beach and nearshore area since the last surveys, mission flown in September 2014 (Virginia to New York: Morgan, 2015), November 2012 (northern North Carolina: Morgan and others, 2014) and May 2008 (southern North Carolina: unpublished report), and the data can be used to assess of future coastal change.The photographs in this report are Joint Photographic Experts Group (JPEG) images. ExifTool was used to add the following to the header of each photo: time of collection, Global Positioning System (GPS) latitude, GPS longitude, keywords, credit, artist (photographer), caption, copyright, and contact information. The photograph locations are an estimate of the position of the aircraft at the time the photograph was taken and do not indicate the location of any feature in the images (see the Navigation Data page). These photographs document the state of the barrier islands and other coastal features at the time of the survey. Pages containing thumbnail images of the photographs, referred to as contact sheets, were created in 5-minute segments of flight time. These segments can be found on the Photos and Maps page. Photographs can be opened directly with any JPEG-compatible image viewer by clicking on a thumbnail on the contact sheet.In addition to the photographs, a Google Earth Keyhole Markup Language (KML) file

  20. Nuclear reactor container

    International Nuclear Information System (INIS)

    A gas containing vessel has a water pool which is in communication with a dry well containing a reactor pressure vessel by way of a communication pipe is disposed. A capacity of a gas phase portion of the gas containing chamber, a capacity of the dry well, a water depth of a bent tube communicating the dry well with a pressure suppression pool of a pressure suppression chamber and a water depth of the communication pipe are determined so as to satisfy specific conditions. Since the water depth of the communication pipe is less than the water depth of the bent tube, incondensible gases and steams in the dry well flow into the water pool of the gas containing chamber at the initial stage of loss of coolant accident. Subsequently, steams in the dry well flow into the pressure suppression pool of the pressure suppression chamber by way of the bent tube. Accordingly, since the incondensible gases in the dry well do not flow into the pressure suppression chamber, pool swelling phenomenon in the pressure suppression chamber is not caused even if the water depth of the bent tube which leads to the pressure suppression chamber is great. Further, pressure increase due to transfer of the incondensible gases is decreased. (I.N.)

  1. DIGITAL FLOOD INSURANCE RATE MAP DATABASE, Franklin County, NORTH CAROLINA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — This Flood Insurance Study was produced through a cooperative partnership between the State of North Carolina and FEMA. The North Carolina Floodplain Mapping...

  2. North Carolina Statewide Lidar DEM 2014 Phase 1

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Geographic Extent: North Carolina Area of Interest for Sandy, covering approximately 9,396 square miles. Dataset Description: The North Carolina - Sandy LiDAR...

  3. 2014 NCFMP Lidar: Statewide North Carolina (Phase 1)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Geographic Extent: North Carolina Area of Interest for Sandy, covering approximately 9,396 square miles. Dataset Description: The North Carolina - Sandy LiDAR...

  4. DIGITAL FLOOD INSURANCE RATE MAP DATABASE, LENOIR COUNTY, NORTH CAROLINA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — This Flood Insurance Study was produced through a cooperative partnership between the State of North Carolina and FEMA. The North Carolina Floodplain Mapping...

  5. DIGITAL FLOOD INSURANCE RATE MAP DATABASE, GREENE COUNTY, NORTH CAROLINA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — This Flood Insurance Study was produced through a cooperative partnership between the State of North Carolina and FEMA. The North Carolina Floodplain Mapping...

  6. DIGITAL FLOOD INSURANCE RATE MAP DATABASE, HALIFAX COUNTY, NORTH CAROLINA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — This Flood Insurance Study was produced through a cooperative partnership between the State of North Carolina and FEMA. The North Carolina Floodplain Mapping...

  7. DIGITAL FLOOD INSURANCE RATE MAP DATABASE, EDGECOMBE COUNTY, NORTH CAROLINA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — This Flood Insurance Study was produced through a cooperative partnership between the State of North Carolina and FEMA. The North Carolina Floodplain Mapping...

  8. DIGITAL FLOOD INSURANCE RATE MAP DATABASE, WILSON COUNTY, NORTH CAROLINA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — This Flood Insurance Study was produced through a cooperative partnership between the State of North Carolina and FEMA. The North Carolina Floodplain Mapping...

  9. DIGITAL FLOOD INSURANCE RATE MAP DATABASE, Scotland County, North Carolina

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — This Flood Insurance Study was produced through a cooperative partnership between the State of North Carolina and FEMA. The North Carolina Floodplain Mapping...

  10. Tube Discovered During Decommissioning of Pond, Dounreay, United Kingdom

    International Nuclear Information System (INIS)

    An underwater survey was conducted as part of preparations to decommission the pond adjacent to the Dounreay Materials Test Reactor (MTR). Investigation of a higher than expected radiation reading identified a hollow metal tube on the floor of the pond. The tube measured approximately 45 cm in length and 4.5 cm in diameter. It posed no risk to the workers in its position because it was beneath 4 m of water

  11. Measurement in nuclear reactors

    International Nuclear Information System (INIS)

    A nuclear reactor construction has a flux detector comprising a bundle of fibre optics each having a bead incorporating a substance which scintillates on being struck by neutrons or gamma radiations. The other ends of the fibre optics terminate at an image intensifier. The optical fibres may be of glass made from a mixture of silica, alkaline earth metal oxide, cerous oxide and alkali metal oxide. The beads may be incorporated in a disc forming a detector head, which is in a protective guide tube, through which an inert gas may be passed. (author)

  12. Research reactors

    International Nuclear Information System (INIS)

    This article proposes an overview of research reactors, i.e. nuclear reactors of less than 100 MW. Generally, these reactors are used as neutron generators for basic research in matter sciences and for technological research as a support to power reactors. The author proposes an overview of the general design of research reactors in terms of core size, of number of fissions, of neutron flow, of neutron space distribution. He outlines that this design is a compromise between a compact enough core, a sufficient experiment volume, and high enough power densities without affecting neutron performance or its experimental use. The author evokes the safety framework (same regulations as for power reactors, more constraining measures after Fukushima, international bodies). He presents the main characteristics and operation of the two families which represent almost all research reactors; firstly, heavy water reactors (photos, drawings and figures illustrate different examples); and secondly light water moderated and cooled reactors with a distinction between open core pool reactors like Melusine and Triton, pool reactors with containment, experimental fast breeder reactors (Rapsodie, the Russian BOR 60, the Chinese CEFR). The author describes the main uses of research reactors: basic research, applied and technological research, safety tests, production of radio-isotopes for medicine and industry, analysis of elements present under the form of traces at very low concentrations, non destructive testing, doping of silicon mono-crystalline ingots. The author then discusses the relationship between research reactors and non proliferation, and finally evokes perspectives (decrease of the number of research reactors in the world, the Jules Horowitz project)

  13. Reactor physics and reactor computations

    International Nuclear Information System (INIS)

    Mathematical methods and computer calculations for nuclear and thermonuclear reactor kinetics, reactor physics, neutron transport theory, core lattice parameters, waste treatment by transmutation, breeding, nuclear and thermonuclear fuels are the main interests of the conference

  14. Newspaper Advertising Trends and Teacher Supply in the Carolinas.

    Science.gov (United States)

    Dewalt, Mark W.; Graham, Patricia L.

    This year-long research project documented critical issues of supply and demand for teachers in the Carolinas. Researchers focused on the number of public and private school education positions advertised in the four major newspapers serving South Carolina and the Charlotte metropolitan region of North Carolina. They documented advertising trends…

  15. Safety issues at the defense production reactors

    International Nuclear Information System (INIS)

    The United States produces plutonium and tritium for use in nuclear weapons at the defense production reactors endash the N Reactor in Washington and the Savannah River reactors in South Carolina. This report reaches general conclusions about the management of those reactors and highlights a number of safety and technical issues that should be resolved. The report provides an assessment of the safety management, safety review, and safety methodology employed by the Department of Energy and the private contractors who operate the reactors for the federal government. The report is necessarily based on a limited review of the defense production reactors. It does not address whether any of the reactors are ''safe,'' because such an analysis would involve a determination of acceptable risk endash a matter of obvious importance, but one that was beyond the purview of the committee. It also does not address whether the safety of the production reactors is comparable to that of commercial nuclear power stations, because even this narrower question extended beyond the charge to the committee and would have involved detailed analyses that the committee could not undertake

  16. Lunar Lava Tube Sensing

    Science.gov (United States)

    York, Cheryl Lynn; Walden, Bryce; Billings, Thomas L.; Reeder, P. Douglas

    1992-01-01

    Large (greater than 300 m diameter) lava tube caverns appear to exist on the Moon and could provide substantial safety and cost benefits for lunar bases. Over 40 m of basalt and regolith constitute the lava tube roof and would protect both construction and operations. Constant temperatures of -20 C reduce thermal stress on structures and machines. Base designs need not incorporate heavy shielding, so lightweight materials can be used and construction can be expedited. Identification and characterization of lava tube caverns can be incorporated into current precursor lunar mission plans. Some searches can even be done from Earth. Specific recommendations for lunar lava tube search and exploration are (1) an Earth-based radar interferometer, (2) an Earth-penetrating radar (EPR) orbiter, (3) kinetic penetrators for lunar lava tube confirmation, (4) a 'Moon Bat' hovering rocket vehicle, and (5) the use of other proposed landers and orbiters to help find lunar lava tubes.

  17. Virginia Forest Landowners Events Calendar, Vol. 1, No. 3, Summer 1997

    OpenAIRE

    1997-01-01

    A quarterly calendar listing events that promote Virginia forest stewardship through sustainable forestry, wildlife management, timber marketing, outdoor recreation, and soil and water conservation. Calendar sponsors include: Virginia Forestry Association (VFA); VFA Sustainable Forestry Task Force Virginia Department of Forestry; Virginia Forestry Educational Foundation; VA Tech College of Forestry & Wildlife Resources; Virginia Cooperative Extension

  18. Demonstration for the Applicability of the EPRI ETSS on the SG Tube Wear Defects Formed at the Tube Support Structure

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Ki Seok; Cheon, Keun Young; Nam, Min Woo [Korea Hydro and Nuclear Power Co. Ltd, Daejeon (Korea, Republic of); Min, Kyong Mahn [Universal Monitoring and Inspection Inc., Daejeon (Korea, Republic of)

    2013-10-15

    In this paper, the authorized EPRI ETSS 27906.2 applied to the detection of tapered wear volumetric indications and depth sizing within the free span area, loose part not present was reviewed and applied to the site SG tubes for getting the actual value of the wear depth and providing structural integrity interpretation based on engineering evaluation. The experiment to demonstrate the applicability of EPRI ETSS was performed by the employment of the newly prepared STD tube and resulted in ensuring the effectiveness and equivalency of the EPRI ETSS as well. The authorized EPRI ETSS 27906.2 for getting the actual value of the wear depth and providing structural integrity interpretation based on engineering evaluation was reviewed and applied to the site SG tubes. The testing results were reviewed with the influences of SG tube material and the support structure. The impact of the tube materials was insignificant and that of the tube support structure showed somewhat conservative results. The testing resulted in successful demonstration of applicability of the EPRI ETSS on the SG tube wear defects at the tube support. One of the major flaw mechanisms detected in the currently operating domestic OPR-1000 pressurized water reactors(PWR's) steam generator(SG) tubes is wear defect. In general, wear defect has been constantly detected in the upper tube bundle imposed to the flow induced vibration interaction between tube and its support structure, and the quantity of the affected tubes has also shown the tendency to increase as plant operation life is added. In order to take appropriate measures and maintain the structural integrity for the SG tubes, wear defect is currently categorized as active damage mechanism and the tubes containing 40% or greater wear depth of the nominal tube wall thickness shall be plugged per SGMP(SG Management Program) Recently, a fairly large amplitude of wear defects on the Batwing(BW), one of the upper tube support structures in the SG

  19. Digital elevations and extents of regional hydrogeologic units in the Northern Atlantic Coastal Plain aquifer system from Long Island, New York, to North Carolina

    Science.gov (United States)

    Pope, Jason P.; Andreasen, David C.; Mcfarland, E. Randolph; Watt, Martha K.

    2016-08-31

    Digital geospatial datasets of the extents and top elevations of the regional hydrogeologic units of the Northern Atlantic Coastal Plain aquifer system from Long Island, New York, to northeastern North Carolina were developed to provide an updated hydrogeologic framework to support analysis of groundwater resources. The 19 regional hydrogeologic units were delineated by elevation grids and extent polygons for 20 layers: the land and bathymetric surface at the top of the unconfined surficial aquifer, the upper surfaces of 9 confined aquifers and 9 confining units, and the bedrock surface that defines the base of all Northern Atlantic Coastal Plain sediments. The delineation of the regional hydrogeologic units relied on the interpretive work from source reports for New York, New Jersey, Delaware and Maryland, Virginia, and North Carolina rather than from re-analysis of fundamental hydrogeologic data. This model of regional hydrogeologic unit geometries represents interpolation, extrapolation, and generalization of the earlier interpretive work. Regional units were constructed from available digital data layers from the source studies in order to extend units consistently across political boundaries and approximate units in offshore areas.Though many of the Northern Atlantic Coastal Plain hydrogeologic units may extend eastward as far as the edge of the Atlantic Continental Shelf, the modeled boundaries of all regional hydrogeologic units in this study were clipped to an area approximately defined by the furthest offshore extent of fresh to brackish water in any part of the aquifer system, as indicated by chloride concentrations of 10,000 milligrams per liter. Elevations and extents of units that do not exist onshore in Long Island, New York, were not included north of New Jersey. Hydrogeologic units in North Carolina were included primarily to provide continuity across the Virginia-North Carolina State boundary, which was important for defining the southern edge of

  20. Tubing weld cracking test

    International Nuclear Information System (INIS)

    A tubing weld cracking (TWC) test was developed for applications involving advanced austenitic alloys (such as modified 800H and 310HCbN). Compared to the Finger hot cracking test, the TWC test shows an enhanced ability to evaluate the crack sensitivity of tubing materials. The TWC test can evaluate the cracking tendency of base as well as filter materials. Thus, it is a useful tool for tubing suppliers, filler metal producers and fabricators