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Sample records for scale cable fire

  1. Full-scale fire experiments on vertical horizontal cable trays

    International Nuclear Information System (INIS)

    Mangs, J.; Keski-Rahkonen, O.

    1997-10-01

    Two full-scale fire experiments on PVC cables used in nuclear power plants were carried out, one with cables in vertical position and one with cables in horizontal position. The vertical cable bundle, 3 m high, 300 mm wide and 30 mm thick, was attached to a steel cable ladder. The vertical bundle experiment was carried out in nearly free space with three walls near the cable ladder guiding air flow in order to stabilise flames. The horizontal cable experiment was carried out in a small room with five cable bundles attached to steel cable ladders. Three of the 2 m long cable bundles were located in an array, equally spaced above each other near one long side of the room and two correspondingly near the opposite long side. The vertical cable bundle was ignited with a small propane gas burner beneath the lower edge of the bundle. The horizontal cable bundles were ignited with a small propane burner beneath the lowest bundle in an array of three bundles. Rate of heat release by means of oxygen consumption calorimetry, mass change, CO 2 , CO and smoke production rate and gas, wall and cable surface temperatures were measured as a function of time, as well as time to sprinkler operation and failure of test voltage in cables. Additionally, the minimum rate of heat release needed to ignite the bundle was determined. This paper concentrates on describing and recording the experimental set-up and the data obtained. (orig.)

  2. Fire spread simulation of a full scale cable tunnel

    International Nuclear Information System (INIS)

    Huhtanen, R.

    1999-11-01

    A fire simulation of a full scale tunnel was performed by using the commercial code EFFLUENT as the simulation platform. Estimation was made for fire spread on the stacked cable trays, possibility of fire spread to the cable trays on the opposite wall of the tunnel, detection time of smoke detectors in the smouldering phase and response of sprinkler heads in the flaming phase. According to the simulation, the rise of temperature in the smouldering phase is minimal, only of the order 1 deg C. The estimates of optical density of smoke show that normal smoke detectors should give an alarm within 2-4 minutes from the beginning of the smouldering phase, depending on the distance to the detector (in this case it was assumed that the thermal source connected to the smoke source was 50 W). The flow conditions at smoke detectors may be challenging, because the velocity magnitude is rather low at this phase. At 4 minutes the maximum velocity at the detectors is 0.12 m/s. During the flaming phase (beginning from 11 minutes) fire spreads on the stacked cable trays in an expected way, although the ignition criterion seems to perform poorly when ignition of new objects is considered. The Upper cable trays are forced to ignite by boundary condition definitions according to the experience found from ti full scale experiment and an earlier simulation. After 30 minutes the hot layer in the room becomes so hot that it speeds up the fire spread and the rate of heat release of burning objects. Further, the hot layer ignites the cable trays on the opposite wall of the tunnel after 45 minutes. It is estimated that the sprinkler heads would be activated at 20-22 minutes near the fire source and at 24-28 minutes little further from the fire source when fast sprinkler heads are used. The slow heads are activated between 26-32 minutes. (orig.)

  3. Report on full-scale horizontal cable tray fire tests, FY 1988

    International Nuclear Information System (INIS)

    Riches, W.M.

    1988-09-01

    In recent years, there has been much discussion throughout industry and various governmental and fire protection agencies relative to the flammability and fire propagation characteristics of electrical cables in open cable trays. It has been acknowledged that under actual fire conditions, in the presence of other combustibles, electrical cable insulation can contribute to combustible fire loading and toxicity of smoke generation. Considerable research has been conducted on vertical cable tray fire propagation, mostly under small scale laboratory conditions. In July 1987, the Fermi National Accelerator Laboratory initiated a program of full scale, horizontal cable tray fire tests, in the absence of other building combustible loading, to determine the flammability and rate of horizontal fire propagation in cable tray configurations and cable mixes typical of those existing in underground tunnel enclosures and support buildings at the Laboratory. The series of tests addressed the effects of ventilation rates and cable tray fill, fire fighting techniques, and effectiveness and value of automatic sprinklers, smoke detection and cable coating fire barriers in detecting, controlling or extinguishing a cable tray fire. This report includes a description of the series of fire tests completed in June 1988, as well as conclusions reached from the test results

  4. Full-scale horizontal cable-tray tests: Fire-propagation characteristics

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    At the Fermi National Accelerator Center (Fermilab), as at any high-energy physics laboratory, the experimental program depends on complex arrays of equipment that require years to assemble and place in service. These equipment arrays are typically located in enclosed tunnels or experimental halls and could be destroyed by rapidly propagating, uncontrolled fire. Cable trays, both vertical and horizontal, are an integral and ubiquitous component of these installations. Concurrently, throughout industry and within the professional fire-fighting community, there has been concern over the flammability and fire propagation characteristics of electrical cables in open cable trays. While some information was available concerning fire propagation in vertical cable trays, little was known about fires in horizontal cable trays. In view of the potential for loss of equipment and facilities, not to mention the programmatic impact of a fire, Fermilab initiated a program of full-scale, horizontal cable-tray fire tests to determine the flammability and rate of horizontal fire propagation in cable-tray configurations and cable mixed typical of those existing in underground tunnel enclosures and support buildings as Fermilab. This series of tests addressed the effects of ventilation rates and cable-tray fill, fire-fighting techniques, and the effectiveness and value of automatic sprinklers, smoke detection, and cable-coating fire barriers in detecting, controlling, or extinguishing a cable-tray fire. Detailed descriptions of each fire test, including sketches of cable-tray configuration and contents, instrumentation, ventilation rates, Fermilab Fire Department personnel observations, photographs, and graphs of thermocouple readings are available in a report of these tests prepared by the Fermilab Safety Section

  5. Cable tray fire tests

    International Nuclear Information System (INIS)

    Klamerus, L.J.

    1978-01-01

    Funds were authorized by the Nuclear Regulatory Commission to provide data needed for confirmation of the suitability of current design standards and regulatory guides for fire protection and control in water reactor power plants. The activities of this program through August 1978 are summarized. A survey of industry to determine current design practices and a screening test to select two cable constructions which were used in small scale and full scale testing are described. Both small and full scale tests to assess the adequacy of fire retardant coatings and full scale tests on fire shields to determine their effectiveness are outlined

  6. Cable fire tests in France

    International Nuclear Information System (INIS)

    Kaercher, M.

    2000-01-01

    Modifications are being carried out in all French nuclear power plants to improve fire safety. These modifications are based on a three level defense in depth concept: fire preventing, fire containing and fire controlling. Fire containing requires many modifications such as protection of cable races and assessment of fire propagation which both need R and D development. On one hand, cable wraps made with mineral wool were tested in all configurations including effect of aging, overheating and fire and qualified for the use as protection from common failure modes. On the other hand, cables races in scale one were subject to gas burner or solvent pool fire to simulate ignition and fire propagation between trays and flash over situations. These tests have been performed under several typical lay out conditions. The results of the tests can be used as input data in computer modelling for validation of fire protection measures. (orig.) [de

  7. Fully predictive simulation of real-scale cable tray fire based on small-scale laboratory experiments

    Energy Technology Data Exchange (ETDEWEB)

    Beji, Tarek; Merci, Bart [Ghent Univ. (Belgium). Dept. of Flow, Heat and Combustion Mechanics; Bonte, Frederick [Bel V, Brussels (Belgium)

    2015-12-15

    This paper presents a computational fluid dynamics (CFD)-based modelling strategy for real-scale cable tray fires. The challenge was to perform fully predictive simulations (that could be called 'blind' simulations) using solely information from laboratory-scale experiments, in addition to the geometrical arrangement of the cables. The results of the latter experiments were used (1) to construct the fuel molecule and the chemical reaction for combustion, and (2) to estimate the overall pyrolysis and burning behaviour. More particularly, the strategy regarding the second point consists of adopting a surface-based pyrolysis model. Since the burning behaviour of each cable could not be tracked individually (due to computational constraints), 'groups' of cables were modelled with an overall cable surface area equal to the actual value. The results obtained for one large-scale test (a stack of five horizontal trays) are quite encouraging, especially for the peak Heat Release Rate (HRR) that was predicted with a relative deviation of 3 %. The time to reach the peak is however overestimated by 4.7 min (i.e. 94 %). Also, the fire duration is overestimated by 5 min (i.e. 24 %). These discrepancies are mainly attributed to differences in the HRRPUA (heat release rate per unit area) profiles between the small-scale and large-scale. The latter was calculated by estimating the burning area of cables using video fire analysis (VFA).

  8. Performing of recent real scale cable fire experiments and presentation of the results in the frame of the international collaborative fire modeling project ICFMP. Final report

    International Nuclear Information System (INIS)

    Hosser, Dietmar; Riese, Olaf; Klingenberg, Mark

    2005-01-01

    As a part of the Fire Risk Research Program, the German iBMB (Institut fuer Baustoffe, Massivbau und Brandschutz) of Braunschweig University of Technology and GRS (Gesellschaft fuer Anlagenund Reaktorsicherheit mbH) are participating in an International Collaborative Fire Modeling Project (ICFMP) to assess and validate fire computer codes for nuclear power plant applications. This assessment is being conducted through benchmarking and validation exercises. The tests are simulating cable fires scenarios in a single compartment. The goal of the actual cable fire series is to investigate the effects of a natural fire to vertically routed cables (worst case) with different cable insulation material (PVC and FRNC). Another important aspect of cable fire is the risk of function failure. Therefore in the test series the short circuit and the conduction loss of cables are measured. This report includes a first description of the experimental results for test 1 - test 4 of the International Collaborative Fire Model Project conducted in December 2003 at the iBMB in Germany. The experimental data are reported on the International Collaborative Fire Model Project - Platform. The measured data shall be the basis for fire simulations. The tests show that the FRNC cables have significantly better characteristics in case of fire. No substantial flame spread takes place even in case of preheating. PVC cables could be ignited with a burner output of 50 kW, in contrary, the FRNC cables could be ignited at burner output of 150 kW. The preheating has a complex effect on the fire behavior of the cables. It may occur that gases are pyrolysed which are not ignited during the phase of preheating. These gases are transported from the cable surrounding and may leave the fire room. Short circuits occur first in case ''conductor to conductor'' and later in case ''conductor to tray''. The time periods until short circuits occur are strongly dependent on the preheating of the cables. In case of

  9. Behaviour of electrical cables under fire conditions

    International Nuclear Information System (INIS)

    Bertrand, R.; Chaussard, M.; Gonzalez, R.; Lacoue, J.; Mattei, J.M.; Such, J.M.

    2002-01-01

    A Fire Probabilistic Safety Assessment - called the Fire PSA - is being carried out by the French Institute of Radiological Protection and Nuclear Safety (IPSN) to be used in the framework of the safety assessment of operating 900 MWe PWRs. The aim of this study is to evaluate the core damage conditional probability which could result from a fire. A fire can induce unavailability of safety equipment, notably damaging electrical cables introducing a significant risk contributor. The purpose of this paper is to present the electrical cable fire tests carried out by IPSN to identify the failure modes and to determine the cable damage criteria. The impact of each kind of cable failure mode and the methodology used to estimate the conditional probability of a failure mode when cable damage occurred is also discussed. (orig.) [de

  10. Analytical model for cable tray fires

    International Nuclear Information System (INIS)

    Clarke, R.K.

    1975-09-01

    A model for cable tray fires based on buoyant plume theory is presented. Using the model in conjunction with empirical data on size of natural fires and burning rate of cellulosic materials, estimates are made of the heat flux as a function of vertical and horizontal distance from a tray fire. Both local fires and fires extending along a significant length of tray are considered. For the particular set of fire parameters assumed in the calculations, the current tray separation criteria of five feet vertical and three feet horizontal are found to be marginal for local fires and too small to prevent fire spread for extended tray fires. 8 references. (auth)

  11. Prevention of cable fires in nuclear power plants

    International Nuclear Information System (INIS)

    Murota, George; Yajima, Kazuo

    1979-01-01

    Nuclear power generation is indispensable to secure required electric power, therefore double or triple safety measures are necessary to prevent serious accidents absolutely. As for the countermeasures to cable fires, interest grew rapidly with the fire in Browns Ferry Power Station in USA in 1975 as the turning point, because multi-strand grouped cables caused to promote the spread of fire. In Japan, also the fire prevention measures for wires and cables were more strengthened, and the measures for preventing the spread of cable fires with the agent preventing the spread of fires have occupied the important position. When multi-strand cables are ignited by some cause, the fire spreads with very large combustion force along wirings to other rooms and installations, and electric systems are broken down. The harmful corrosive gas generated from the burning coating materials of cables diffuses very quickly. In nuclear power stations, the cables which are very hard to burn are adopted, fire prevention sections are established positively, the fire-resisting capability of fire prevention barriers is reviewed, and fire-resisting and smoke-preventing treatments are applied to the parts where cables penetrate walls, floors or ceilings. The paint and the sealing material which prevent the spread of fires are introduced. (Kako, I.)

  12. Cable fire risk of a nuclear power plant

    International Nuclear Information System (INIS)

    Aulamo, H.

    1998-02-01

    The aim of the study is to carry out a comprehensive review of cable fire risk issues of nuclear power plants (NPP) taking into account latest fire and risk assessment research results. A special emphasis is put on considering the fire risk analysis of cable rooms in the framework of TVO Olkiluoto NPP probabilistic safety assessment. The assumptions made in the analysis are assessed. The literature study section considers significant fire events at nuclear power plants, the most severe of which have nearly led to a reactor core damage (Browns Ferry, Greifswald, Armenia, Belojarsk, Narora). Cable fire research results are also examined

  13. Cable fire risk of a nuclear power plant; Ydinvoimalaitoksen kaapelipaloriski

    Energy Technology Data Exchange (ETDEWEB)

    Aulamo, H.

    1998-02-01

    The aim of the study is to carry out a comprehensive review of cable fire risk issues of nuclear power plants (NPP) taking into account latest fire and risk assessment research results. A special emphasis is put on considering the fire risk analysis of cable rooms in the framework of TVO Olkiluoto NPP probabilistic safety assessment. The assumptions made in the analysis are assessed. The literature study section considers significant fire events at nuclear power plants, the most severe of which have nearly led to a reactor core damage (Browns Ferry, Greifswald, Armenia, Belojarsk, Narora). Cable fire research results are also examined. 62 refs.

  14. Design guide for fire protection of grouped electrical cables

    International Nuclear Information System (INIS)

    Dungan, K.W.

    1991-05-01

    This paper develops design guidance for fire protection of grouped electrical cables using previous research and the concept of design objectives based on damage limits. A quantitative approach is taken to establishing performance-oriented design objectives and addressing fires exposing cables as well as cable fires. A one-page Design Calculation Checklist is developed and examples are shown. In addition, testing was done for placement of linear thermal detection on cable trays and recommendations are given. 32 refs., 10 figs., 8 tabs

  15. Behaviour of French electrical cables under fire conditions

    Energy Technology Data Exchange (ETDEWEB)

    Bertrand, R.; Chaussard, M.; Gonzalez, R.; Lacoue, J.; Mattei, J.M.; Such, J.M

    2001-12-01

    A fire Probabilistic Safety Assessment - called fire PSA - is being carried out by the French Institute of Nuclear Safety and Protection (IPSN) to be used in the framework of the safety assessment of operating 900 MWe PWRs. The aim of this study is to evaluate the core damage conditional probability which could result from a fire. A fire can induce unavailability of safety equipment notably damaging electrical cables that are a significant risk contributor. The purpose of this communication is to present the electrical cable fire tests carried out by IPSN to identify the failure modes and to determine the cable damage criteria. Moreover, are indicated the impact of each kind of cable failure mode and the methodology used to estimate the conditional probability of a failure mode when cable damage occurred. (authors)

  16. Fire safety requirements for electrical cables towards nuclear reactor safety

    International Nuclear Information System (INIS)

    Raju, M.R.

    2002-01-01

    Full text: Electrical power supply forms a very important part of any nuclear reactor. Power supplies have been categorized in to class I, II, III and IV from reliability point. The safety related equipment are provided with highly reliable power supply to achieve the safety of very high order. Vast network of cables in a nuclear reactor are grouped and segregated to ensure availability of power to at least one group under all anticipated occurrences. Since fire can result in failures leading to unavailability of power caused by common cause, both passive and active fire protection methods are adopted in addition to fire detection system. The paper describes the requirement for passive fire protection to electrical cables viz. fire barrier and fire breaks. The paper gives an account of the tests required to standardize the products. Fire safety implementation for cables in research reactors is described

  17. Response of Nuclear Power Plant Instrumentation Cables Exposed to Fire Conditions.

    Energy Technology Data Exchange (ETDEWEB)

    Muna, Alice Baca [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); LaFleur, Chris Bensdotter [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Brooks, Dusty Marie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-09-01

    This report presents the results of instrumentation cable tests sponsored by the US Nuclear Regulatory Commission (NRC) Office of Nuclear Regulatory Research and performed at Sandia National Laboratories (SNL). The goal of the tests was to assess thermal and electrical response behavior under fire-exposure conditions for instrumentation cables and circuits. The test objective was to assess how severe radiant heating conditions surrounding an instrumentation cable affect current or voltage signals in an instrumentation circuit. A total of thirty-nine small-scale tests were conducted. Ten different instrumentation cables were tested, ranging from one conductor to eight-twisted pairs. Because the focus of the tests was thermoset (TS) cables, only two of the ten cables had thermoplastic (TP) insulation and jacket material and the remaining eight cables were one of three different TS insulation and jacket material. Two instrumentation cables from previous cable fire testing were included, one TS and one TP. Three test circuits were used to simulate instrumentation circuits present in nuclear power plants: a 4–20 mA current loop, a 10–50 mA current loop and a 1–5 VDC voltage loop. A regression analysis was conducted to determine key variables affecting signal leakage time.

  18. Fire protection of nuclear power plant cable ducts

    International Nuclear Information System (INIS)

    Kandrac, J.; Lukac, L.

    1987-01-01

    Fire protection of cable ducts in the Bohunice and Dukovany V-2 nuclear power plants is of a fourtier type. The first level consists in preventive measures incorporated in the power plant design and layout. The second level consists in early detection and a quick repressive action provided by an electric fire alarm system and a stationary spray system, respectively. Fire partitions and glands represent the third level while special spray, paint and lining materials represent the fourth level of the protection. Briefly discussed are the results of an analysis of the stationary spray system and the effects reducing the efficiency of a fire-fighting action using this system. The analysis showed the need of putting off cable duct fires using mobile facilities in case the stationary spray system cannot cope any longer. (Z.M.). 3 figs., 2 refs

  19. Cable Hot Shorts and Circuit Analysis in Fire Risk Assessment

    International Nuclear Information System (INIS)

    LaChance, Jeffrey; Nowlen, Steven P.; Wyant, Frank

    1999-01-01

    Under existing methods of probabilistic risk assessment (PRA), the analysis of fire-induced circuit faults has typically been conducted on a simplistic basis. In particular, those hot-short methodologies that have been applied remain controversial in regards to the scope of the assessments, the underlying methods, and the assumptions employed. To address weaknesses in fire PRA methodologies, the USNRC has initiated a fire risk analysis research program that includes a task for improving the tools for performing circuit analysis. The objective of this task is to obtain a better understanding of the mechanisms linking fire-induced cable damage to potentially risk-significant failure modes of power, control, and instrumentation cables. This paper discusses the current status of the circuit analysis task

  20. An enhanced fire hazard assessment model and validation experiments for vertical cable trays

    International Nuclear Information System (INIS)

    Li, Lu; Huang, Xianjia; Bi, Kun; Liu, Xiaoshuang

    2016-01-01

    Highlights: • An enhanced model was developed for vertical cable fire hazard assessment in NPP. • The validated experiments on vertical cable tray fires were conducted. • The capability of the model for cable tray with different cable spacing were tested. - Abstract: The model, referred to as FLASH-CAT (Flame Spread over Horizontal Cable Trays), was developed to estimate the heat release rate for vertical cable tray fire. The focus of this work is to investigate the application of an enhanced model to the single vertical cable tray fires with different cable spacing. The experiments on vertical cable tray fires with three typical cable spacing were conducted. The histories of mass loss rate and flame length were recorded during the cable fire. From the experimental results, it is found that the space between cable lines intensifies the cable combustion and accelerates the flame spread. The predictions by the enhanced model show good agreements with the experimental data. At the same time, it is shown that the enhanced model is capable of predicting the different behaviors of cable fires with different cable spacing by adjusting the flame spread speed only.

  1. An enhanced fire hazard assessment model and validation experiments for vertical cable trays

    Energy Technology Data Exchange (ETDEWEB)

    Li, Lu [Sate Key Laboratory of Fire Science, University of Science and Technology of China, Hefei 230027 (China); Huang, Xianjia, E-mail: huangxianjia@gziit.ac.cn [Joint Laboratory of Fire Safety in Nuclear Power Plants, Institute of Industry Technology Guangzhou & Chinese Academy of Sciences, Guangzhou 511458 (China); Bi, Kun; Liu, Xiaoshuang [China Nuclear Power Design Co., Ltd., Shenzhen 518045 (China)

    2016-05-15

    Highlights: • An enhanced model was developed for vertical cable fire hazard assessment in NPP. • The validated experiments on vertical cable tray fires were conducted. • The capability of the model for cable tray with different cable spacing were tested. - Abstract: The model, referred to as FLASH-CAT (Flame Spread over Horizontal Cable Trays), was developed to estimate the heat release rate for vertical cable tray fire. The focus of this work is to investigate the application of an enhanced model to the single vertical cable tray fires with different cable spacing. The experiments on vertical cable tray fires with three typical cable spacing were conducted. The histories of mass loss rate and flame length were recorded during the cable fire. From the experimental results, it is found that the space between cable lines intensifies the cable combustion and accelerates the flame spread. The predictions by the enhanced model show good agreements with the experimental data. At the same time, it is shown that the enhanced model is capable of predicting the different behaviors of cable fires with different cable spacing by adjusting the flame spread speed only.

  2. Assessment of the burning behavior of protected and unprotected cables and cable trays in nuclear installations using small- and large-scale experiments

    Energy Technology Data Exchange (ETDEWEB)

    Siemon, Matthias; Riese, Olaf; Zehfuss, Jochen [Technische Univ. Braunschweig (Germany). Inst. fuer Baustoffe, Massivbau und Brandschutz (iBMB)

    2015-12-15

    Electric installations and cables are a main fire risk source in industrial buildings and power plants. In general, cables and cable systems are associated with flash-over phenomena due to pyrolysis of fuel gases induced by the heat of an adjacent fire, fire spread along cable trays affecting additional areas besides the fire origin, being an ignition source due to malfunction. If burning, cables can emit large amounts of smoke and toxic products affecting occupants as well as the long-term functionality of structure and installations. Paying attention to these risks has led to the development of fire retardant non-corrosive (non-halogenated) cables which are qualified to reduce the individual or all of the risks mentioned. For existing installations in industrial buildings and power plants with halogenated cables, different protection measures are available and widely applied retroactively. Important protective measures are intumescent or ablative coatings, cable casings and bindings. For qualification of the effects of the protection measures, small-scale tests investigating a single cable specimen as well as large-scale cable tray test setups have been developed and carried out in the last 20 years at iBMB. In this paper, these test results are analysed regarding their effects on the heat release, ignition time and fire spread over cable trays. Furthermore, national and international research projects have investigated the burning behaviour of different cable types, tray installations, tray loading and spacing and ventilation conditions. As a conclusion, the main outcomes of past researches are summarized. Influence factors (e.g. pre-heating due to high power utilization, influence of cable aging) which have not been accounted for in detail are emphasized. The modelling of unprotected cables has been internationally studied in recent years. For future applications, the question of applicability of recently developed sub-models on the fire behaviour of protected

  3. Development of new radiation resistant, fire-retardant cables

    International Nuclear Information System (INIS)

    Hagiwara, Ko; Morita, Yosuke; Udagawa, Takashi; Fujimura, Shun-ichi; Oda, Eisuke.

    1982-01-01

    For the cables for nuclear facilities, radiation resistance and fire-retardation are severely required. The authors took note of the fact that even in the existing cables for nuclear power plants, their mechanical properties are greatly degraded by the exposure to large dose (for example, 200 Mrad in PWR testing conditions), and attempted the improvement. They employed a new additive, bromated acenaphthylene condensate (con-BACN), which effectively gives radiation resistance and also is a good flame retarder, to be compounded to an insulation material, and examined the characteristics. In this paper, the features of con-BACN and the investigation of fire-retardant EPDM composition are described. As an initial composition, a small amount of zinc white, sulphur, stearic acid, noclac 224 (Ouchi-Shinko Chemicals, Co.), and antimony trioxide, 100 parts of tale and 45 parts of con-BACN were added to 100 parts of EPDM (propylene content 34 %, Japan Synthetic Rubber Co.). As the antiaging agent, it was decided to use phenol series No. 3 as a result of test. The fire-retardant EP rubber-composed cable was produced for trial, its insulation being fabricated, using a Furukawa's pressurized salt bath continuous vulcanizer. The tests of γ-irradiation, simulated LOCA and combustion were carried out, and the test results are reported. It was indicated that the cable resisted against high dose several times as much as 200 Mrad, and was suitable for the applications, in which the mechanical properties such as bending are required to be maintained after radiation exposure. It was also found that con-BACN was safe, and its properties of decomposition, concentration and acute toxicity were all very low. (Wakatsuki, Y.)

  4. Improvement of flame resistance of non-flame retardant cables by applying fire protection measures

    International Nuclear Information System (INIS)

    Takemura, Yujiro; Segoshi, Yoshinori; Jinno, Susumu; Mii, Kazuki

    2017-01-01

    The new regulatory requirements, which were put in force after the Fukushima Daiichi accident, impose the use of flame retardant cables on the plant components having safety functions for the purpose of fire protection. However, some Japanese nuclear power plants built in the early days use non-flame retardant cables that do not pass the demonstration test to check for the flame resistance. To cope with the new regulatory requirements, a fire protection measure for non-flame retardant cables was introduced to assure flame resistance of non-flame retardant cables equivalent to or higher than that of flame retardant cables. To illustrate the fire protection measure, both non-flame retardant cables and its cable tray are covered with fire protection sheet fabricated from incombustible material to form an assembly. Considering the demonstration test results, it can be concluded that flame resistance performance of non-flame retardant cables equivalent to or higher than that of flame retardant cables can be assured by forming the assembly even if an external fire outside the assembly and internal cable fire inside the assembly are assumed. This paper introduces the design of the assembly consisting of a bundle of cables and a cable tray and summarizes the results of demonstration tests. (author)

  5. Fire safety requirements for electric cables and lines in deep coal mines

    Energy Technology Data Exchange (ETDEWEB)

    Herms, C D

    1982-01-07

    In the case of a mine fire, an additional hazard from combustible cable material is likely to arise only in those few areas of the mine where special circumstances might help the fire to spread along the cables. It is more important to preserve the functional integrity of cables in the outbye roads which are affected by fire gases then at the actual seat of the fire. Mine cables with better fire-resistant properties should be made from materials which do not propagate fires, do not release burning drops, develop the lowest possible fume density and/or will permanently resist gas temperatures of 200 to 300/sup 0/C. Fire test specifications should be defined for such special cables, based on corresponding draft VDE directives. In proposing these measures the proviso is made then improvement in safety can be clearly demonstrated.

  6. Ceramic fiber blanket wrap for fire protection of cable trays and conduits

    International Nuclear Information System (INIS)

    Chaille, C.E.; Reiman, R.J.

    1980-01-01

    In some areas of nuclear power plants, cables of redundant electrical systems, which are necessary for the safe shutdown of the reactor, are in close proximity. If a fire should occur in one of these areas, both electrical systems could be destroyed before the fire is extinguished and control of the reactor may be lost. A ceramic fiber blanket was evaluated as a fire protective wrap around cable trays and conduits. 2 refs

  7. The correspondence concerning fire protection regulation for operating reactors (separation flame test of unpurified cables)

    International Nuclear Information System (INIS)

    Hasegawa, Takayasu; Miyakoshi, Hirohisa; Goto, Masami

    2013-01-01

    Nuclear power plants are taking fire protection measures taking into account past findings about the effects of fire by the demonstration test in order to maintain the safety of nuclear power plant in the event of a fire. The objective of the demonstration test described in this paper is to obtain advanced knowledge about over current fire of unqualified cable to be applied to fire protection measures. (author)

  8. Development of scaling rules for Rutherford type superconducting cables

    International Nuclear Information System (INIS)

    Royet, J.M.; Scanlan, R.M.

    1991-01-01

    During the R and D phase of the Superconducting Supercollider (SSC) program, LBL was responsible for establishing the parameters for cables used in SSC dipole and quadrupole magnets. In addition, LBL has collaborated with Fermi National Accelerator Laboratory on the design and fabrication of a new cable for use in the Low Beta Quadrupoles. As a result of the development work on these and other cables, we have arrived a set of scaling rules which provide guidelines for choosing the parameters for a wide range of superconducting cables. These parameters include strand size, strand number, keystone angle, percent compaction, cable pitch and compacted cable dimensions. In addition, we have defined the tolerance ranges for the key cable manufacturing parameters such as mandrel size and shape, strand tension, and Turkshead temperature control. In this paper, the authors present the results on cables ranging from 8 strands to 36 strands of 0.65mm wire and from 8 strands to 30 strands of 0.8mm wire. The authors use these results to demonstrate the application of the scaling rules for Rutherford-type cable

  9. Development of scaling rules for Rutherford type superconducting cables

    International Nuclear Information System (INIS)

    Royet, J.M.; Scanlan, R.M.

    1990-09-01

    During the R ampersand D phase of the Superconducting Supercollider (SSC) program, LBL was responsible for establishing the parameters for cables used in SSC dipole and quadrupole magnets. In addition, the design and fabrication of a new cable for use in the Low Beta Quadrupoles. As a result of the development work on these and other cables, we have arrived a set of scaling rules which provide guidelines for choosing the parameters for a wide range of superconducting cables. These parameters include strand size, strand number, keystone angle, percent compaction, cable pitch and compacted cable dimensions. In addition, we have defined the tolerance ranges for the key cable manufacturing parameters such as mandrel size and shape, stand tension, and Turkshead temperature control. In this paper, we present the results on cables ranging from 8 strands to 36 strands of 0.65mm wire and from 8 strands to 30 strands of 0.8mm wire. We use these results to demonstrate the application of the scaling rules for Rutherford-type cable

  10. Large scale fire experiments in the HDR containment as a basis for fire code development

    International Nuclear Information System (INIS)

    Hosser, D.; Dobbernack, R.

    1993-01-01

    Between 1984 and 1991 7 different series of large scale fire experiments and related numerical and theoretical investigations have been performed in the containment of a high pressure reactor in Germany (known as HDR plant). The experimental part included: gas burner tests for checking the containment behaviour; naturally ventilated fires with wood cribs; naturally and forced ventilated oil pool fires; naturally and forced ventilated cable fires. Many results of the oil pool and cable fires can directly be applied to predict the impact of real fires at different locations in a containment on mechanical or structural components as well as on plant personnel. But the main advantage of the measurements and observations was to serve as a basis for fire code development and validation. Different types of fire codes have been used to predict in advance or evaluate afterwards the test results: zone models for single room and multiple room configurations; system codes for multiple room configurations; field models for complex single room configurations. Finally, there exist codes of varying degree of specialization which have proven their power and sufficient exactness to predict fire effects as a basis for optimum fire protection design. (author)

  11. Large-scale pool fires

    Directory of Open Access Journals (Sweden)

    Steinhaus Thomas

    2007-01-01

    Full Text Available A review of research into the burning behavior of large pool fires and fuel spill fires is presented. The features which distinguish such fires from smaller pool fires are mainly associated with the fire dynamics at low source Froude numbers and the radiative interaction with the fire source. In hydrocarbon fires, higher soot levels at increased diameters result in radiation blockage effects around the perimeter of large fire plumes; this yields lower emissive powers and a drastic reduction in the radiative loss fraction; whilst there are simplifying factors with these phenomena, arising from the fact that soot yield can saturate, there are other complications deriving from the intermittency of the behavior, with luminous regions of efficient combustion appearing randomly in the outer surface of the fire according the turbulent fluctuations in the fire plume. Knowledge of the fluid flow instabilities, which lead to the formation of large eddies, is also key to understanding the behavior of large-scale fires. Here modeling tools can be effectively exploited in order to investigate the fluid flow phenomena, including RANS- and LES-based computational fluid dynamics codes. The latter are well-suited to representation of the turbulent motions, but a number of challenges remain with their practical application. Massively-parallel computational resources are likely to be necessary in order to be able to adequately address the complex coupled phenomena to the level of detail that is necessary.

  12. Evaluation of the Cable Types for Safety Requirements during Fire Conditions in Nuclear Facility

    International Nuclear Information System (INIS)

    Al-kattan, W.A.

    2015-01-01

    In Nuclear Power Plants (NPPs), the fire in cables causes many dangerous events in electrical or mechanical operations causing a nuclear reactor melt down. Main Control Room (MCR) in nuclear power plants have therefore, special concern in the fire protection systems. The Nuclear International Atomic Energy Agency (IAEA) has promoted the use of risk-informed and performance based methods for fire protection. These methods affirm the relevant needs to develop realistic methods to quantify the risk of fire to NPPs safety. The recent electrical cable testing has been carried out to provide empirical data on the failure modes and likelihood of fire-induced damage. In this thesis, will use fire modeling to develop fire probabilistic safety assessment to estimate the likelihood of fire induced cable damage given a specified fire profile. The objective of this work is to provide a comprehensive evaluation of the most recent fire-induced circuit failure due to different cables type that used inside the NPPs by simulation using fire modeling. One of this work scope is to suggest a suitable cable insulation material especially in case of the thermal failure thresholds, for developing the electrical cable thermal fragility distributions and evaluate parameters that influence fire-induced circuit failure modes. The main control room is implementing using the CFAST (fire simulation package). The simulation results represent the full development fire temperature and heat flux as well as the output gases. The results can be used as the basic parameters of the cables comparison and then evaluation.The importance of these results are not only for evaluating the cables but one can efficiently use them to improve the whole NPPs safety levels. The gases results of the fire simulation inside the room are oxygen, carbon monoxide, carbon dioxide, and hydrogen chloride. These gases are being used lot achieving the healthy protection of NPPs. Finally, one can measure the healthy environment

  13. Process to realize a tight and fire-proof cable penetration, ensuring a biological protection and associated cable penetration

    International Nuclear Information System (INIS)

    Beckers, G.

    1986-01-01

    According to the present invention, the cables pass through a wall by means of an opening. A casting panel is realized for plugging each opening face, and a viscous, rapid-setting and fire-proof cement is injected to form continuous external caps. One spare tube allows the inside part to communicate with the outside of the opening; a liquid resin mixture containing at least a material of high atomic weight is injected through this tube between the two casting panels. The resin harden by polymerization in-situ. The invention applies, more particularly, to cable penetrations in nuclear reactors [fr

  14. Modeling of Electrical Cable Failure in a Dynamic Assessment of Fire Risk

    Science.gov (United States)

    Bucknor, Matthew D.

    Fires at a nuclear power plant are a safety concern because of their potential to defeat the redundant safety features that provide a high level of assurance of the ability to safely shutdown the plant. One of the added complexities of providing protection against fires is the need to determine the likelihood of electrical cable failure which can lead to the loss of the ability to control or spurious actuation of equipment that is required for safe shutdown. A number of plants are now transitioning from their deterministic fire protection programs to a risk-informed, performance based fire protection program according to the requirements of National Fire Protection Association (NFPA) 805. Within a risk-informed framework, credit can be taken for the analysis of fire progression within a fire zone that was not permissible within the deterministic framework of a 10 CFR 50.48 Appendix R safe shutdown analysis. To perform the analyses required for the transition, plants need to be able to demonstrate with some level of assurance that cables related to safe shutdown equipment will not be compromised during postulated fire scenarios. This research contains the development of new cable failure models that have the potential to more accurately predict electrical cable failure in common cable bundle configurations. Methods to determine the thermal properties of the new models from empirical data are presented along with comparisons between the new models and existing techniques used in the nuclear industry today. A Dynamic Event Tree (DET) methodology is also presented which allows for the proper treatment of uncertainties associated with fire brigade intervention and its effects on cable failure analysis. Finally a shielding analysis is performed to determine the effects on the temperature response of a cable bundle that is shielded from a fire source by an intervening object such as another cable tray. The results from the analyses demonstrate that models of similar

  15. Dynamically Scaled Model Experiment of a Mooring Cable

    Directory of Open Access Journals (Sweden)

    Lars Bergdahl

    2016-01-01

    Full Text Available The dynamic response of mooring cables for marine structures is scale-dependent, and perfect dynamic similitude between full-scale prototypes and small-scale physical model tests is difficult to achieve. The best possible scaling is here sought by means of a specific set of dimensionless parameters, and the model accuracy is also evaluated by two alternative sets of dimensionless parameters. A special feature of the presented experiment is that a chain was scaled to have correct propagation celerity for longitudinal elastic waves, thus providing perfect geometrical and dynamic scaling in vacuum, which is unique. The scaling error due to incorrect Reynolds number seemed to be of minor importance. The 33 m experimental chain could then be considered a scaled 76 mm stud chain with the length 1240 m, i.e., at the length scale of 1:37.6. Due to the correct elastic scale, the physical model was able to reproduce the effect of snatch loads giving rise to tensional shock waves propagating along the cable. The results from the experiment were used to validate the newly developed cable-dynamics code, MooDy, which utilises a discontinuous Galerkin FEM formulation. The validation of MooDy proved to be successful for the presented experiments. The experimental data is made available here for validation of other numerical codes by publishing digitised time series of two of the experiments.

  16. Characterization of the cable fire in Block 1 of the Greifswald nuclear power plant

    International Nuclear Information System (INIS)

    Albrecht, L.; Gelfort, E.

    1996-01-01

    In December 1975 a cable fire was initiated in a stand-by power distribution by a short circuit and an incorrectly fitted diode. Unpredictably and accidentally, some control and power cables were destroyed during the fire. This caused the failure of safety-relevant components. Decay heat removal was achieved initially by natural convection in the primary loop, and finally by an emergency feed pump in the secondary loop, for which a preovisional power cable had been successfully installed after approximately 8.5 hours. This serious accident was caused by human failure and lack of experience, by the insufficiency of the redundancies as provided in the plant design, by the lack of spatial separation of safety systems, and by insufficient quality control. (orig.) [de

  17. Optimal Selection of AC Cables for Large Scale Offshore Wind Farms

    DEFF Research Database (Denmark)

    Hou, Peng; Hu, Weihao; Chen, Zhe

    2014-01-01

    The investment of large scale offshore wind farms is high in which the electrical system has a significant contribution to the total cost. As one of the key components, the cost of the connection cables affects the initial investment a lot. The development of cable manufacturing provides a vast...... and systematical way for the optimal selection of cables in large scale offshore wind farms....

  18. Development of highly fire-retardant irradiated polyolefin cables

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, Keiji; Inui, Toshifumi; Uda, Ikujiro (Sumitomo Electric Industries Ltd., Osaka (Japan))

    1982-12-01

    In recent years, motors, automobiles, heaters, etc., have been made into light weight and compact form in view of labour-saving and energy-saving. For this purpose, the wires for the electrical appliances used for these equipment are required to reduce insulation thickness and to improve heat resistance. On the other hand, the requirement for fire-retardant property has become severer than before from the viewpoint of safety. As an insulation for the wires which meets such requirement, the polyolefin cross-linked by irradiation was investigated, and the heat-resistant, highly fire-retardant, polyolefin-insulated wires have been developed, which have passed vertical combustion test (VW-1) and have the insulation thickness of 0.4 mm (voltage rating 300V) and UL standard 125 deg C and 150 deg C grades. Fire-retardant polyolefin resin is normally obtained by adding halogen series flame retarders. The selection of flame retarders requires the investigation on high thermal stability, high flame retardation, no impedance to cross-linking, and good dispersion into polymers. The evaluation of heat resistance performed on two points, thermal aging and thermal deformation. The use of oxidation inhibitors is indispensable to improve the anti-thermal aging capability, but it is important to balance the requirements well by combining oxidation inhibitors, considering thermal deformation, colouring and discolouration. By comparative test with silicone rubber, cross-linked polyethylene and cross-linked PVC-insulated wires, the characteristics of highly fire-retardant wires, insulated with polyethylene cross-linked by irradiation, are described about the fire retardation, thermal deformation, thermal aging resistance, electrical characteristics and oil resistance.

  19. Development of CFD fire models for deterministic analyses of the cable issues in the nuclear power plant

    International Nuclear Information System (INIS)

    Lin, C.-H.; Ferng, Y.-M.; Pei, B.-S.

    2009-01-01

    Additional fire barriers of electrical cables are required for the nuclear power plants (NPPs) in Taiwan due to the separation requirements of Appendix R to 10 CFR Part 50. The risk-informed fire analysis (RIFA) may provide a viable method to resolve these fire barrier issues. However, it is necessary to perform the fire scenario analyses so that RIFA can quantitatively determine the risk related to the fire barrier wrap. The CFD fire models are then proposed in this paper to help the RIFA in resolving these issues. Three typical fire scenarios are selected to assess the present CFD models. Compared with the experimental data and other model's simulations, the present calculated results show reasonable agreements, rendering that present CFD fire models can provide the quantitative information for RIFA analyses to release the cable wrap requirements for NPPs

  20. Fire structures pine serotiny at different scales.

    Science.gov (United States)

    Hernández-Serrano, Ana; Verdú, Miguel; González-Martínez, Santiago C; Pausas, Juli G

    2013-12-01

    Serotiny (delayed seed release with the consequent accumulation of a canopy seedbank) confers fitness benefits in environments with crown-fire regimes. Thus, we predicted that serotiny level should be higher in populations recurrently subjected to crown-fires than in populations where crown-fires are rare. In addition, under a high frequency of fires, space and resources are recurrently available, permitting recruitment around each mother to follow the seed rain shadow. Thus, we also predicted spatial aggregation of serotiny within populations. We compared serotiny, considering both the proportion and the age of serotinous cones, in populations living in contrasting fire regimes for two iconic Mediterranean pine species (Pinus halepensis, P. pinaster). We framed our results by quantitatively comparing the strength of the fire-serotiny relationship with previous studies worldwide. For the two species, populations living under high crown-fire recurrence regimes had a higher serotiny level than those populations where the recurrence of crown-fires was low. For P. halepensis (the species with higher serotiny), populations in high fire recurrence regimes had higher fine-scale spatial aggregation of serotiny than those inhabiting low fire recurrence systems. The strength of the observed fire-serotiny relationship in P. halepensis is among the highest in published literature. Fire regime shapes serotiny level among populations, and in populations with high serotiny, recurrent fires maintain a significant spatial structure for this trait. Consequently, fire has long-term evolutionary implications at different scales, emphasizing its prominent role in shaping the ecology of pines.

  1. Development of new radiation resistant, fire-retardant cables. [Gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Hagiwara, Ko; Morita, Yosuke; Udagawa, Takashi (Japan Atomic Energy Research Inst., Takasaki, Gunma. Takasaki Radiation Chemistry Research Establishment); Fujimura, Shun-ichi; Oda, Eisuke

    1982-12-01

    For the cables for nuclear facilities, radiation resistance and fire-retardation are severely required. The authors took note of the fact that even in the existing cables for nuclear power plants, their mechanical properties are greatly degraded by the exposure to large dose (for example, 200 Mrad in PWR testing conditions), and attempted the improvement. They employed a new additive, bromated acenaphthylene condensate (con-BACN), which effectively gives radiation resistance and also is a good flame retarder, to be compounded to an insulation material, and examined the characteristics. In this paper, the features of con-BACN and the investigation of fire-retardant EPDM composition are described. As an initial composition, a small amount of zinc white, sulphur, stearic acid, noclac 224 (Ouchi-Shinko Chemicals, Co.), and antimony trioxide, 100 parts of tale and 45 parts of con-BACN were added to 100 parts of EPDM (propylene content 34 %, Japan Synthetic Rubber Co.). As the antiaging agent, it was decided to use phenol series No. 3 as a result of test. The fire-retardant EP rubber-composed cable was produced for trial, its insulation being fabricated, using a Furukawa's pressurized salt bath continuous vulcanizer. The tests of ..gamma..-irradiation, simulated LOCA and combustion were carried out, and the test results are reported. It was indicated that the cable resisted against high dose several times as much as 200 Mrad, and was suitable for the applications, in which the mechanical properties such as bending are required to be maintained after radiation exposure. It was also found that con-BACN was safe, and its properties of decomposition, concentration and acute toxicity were all very low.

  2. Determination of cable parameters in skeletal muscle fibres during repetitive firing of action potentials

    Science.gov (United States)

    Riisager, Anders; Duehmke, Rudy; Nielsen, Ole Bækgaard; Huang, Christopher L; Pedersen, Thomas Holm

    2014-01-01

    Recent studies in rat muscle fibres show that repetitive firing of action potentials causes changes in fibre resting membrane conductance (Gm) that reflect regulation of ClC-1 Cl− and KATP K+ ion channels. Methodologically, these findings were obtained by inserting two microelectrodes at close proximity in the same fibres enabling measurements of fibre input resistance (Rin) in between action potential trains. Since the fibre length constant (λ) could not be determined, however, the calculation of Gm relied on the assumptions that the specific cytosolic resistivity (Ri) and muscle fibre volume remained constant during the repeated action potential firing. Here we present a three-microelectrode technique that enables determinations of multiple cable parameters in action potential-firing fibres including Rin and λ as well as waveform and conduction velocities of fully propagating action potentials. It is shown that in both rat and mouse extensor digitorum longus (EDL) fibres, action potential firing leads to substantial changes in both muscle fibre volume and Ri. The analysis also showed, however, that regardless of these changes, rat and mouse EDL fibres both exhibited initial decreases in Gm that were eventually followed by a ∼3-fold, fully reversible increase in Gm after the firing of 1450–1800 action potentials. Using this three-electrode method we further show that the latter rise in Gm was closely associated with excitation failures and loss of action potential signal above −20 mV. PMID:25128573

  3. Large Scale Experiments on Spacecraft Fire Safety

    DEFF Research Database (Denmark)

    Urban, David L.; Ruff, Gary A.; Minster, Olivier

    2012-01-01

    -based microgravity facilities or has been limited to very small fuel samples. Still, the work conducted to date has shown that fire behaviour in low-gravity is very different from that in normal-gravity, with differences observed for flammability limits, ignition delay, flame spread behaviour, flame colour and flame......Full scale fire testing complemented by computer modelling has provided significant knowhow about the risk, prevention and suppression of fire in terrestrial systems (cars, ships, planes, buildings, mines, and tunnels). In comparison, no such testing has been carried out for manned spacecraft due...... to the complexity, cost and risk associ-ated with operating a long duration fire safety experiment of a relevant size in microgravity. Therefore, there is currently a gap in knowledge of fire behaviour in spacecraft. The entire body of low-gravity fire research has either been conducted in short duration ground...

  4. HTS cables open the window for large-scale renewables

    International Nuclear Information System (INIS)

    Geschiere, A; Willen, D; Piga, E; Barendregt, P

    2008-01-01

    In a realistic approach to future energy consumption, the effects of sustainable power sources and the effects of growing welfare with increased use of electricity need to be considered. These factors lead to an increased transfer of electric energy over the networks. A dominant part of the energy need will come from expanded large-scale renewable sources. To use them efficiently over Europe, large energy transits between different countries are required. Bottlenecks in the existing infrastructure will be avoided by strengthening the network. For environmental reasons more infrastructure will be built underground. Nuon is studying the HTS technology as a component to solve these challenges. This technology offers a tremendously large power transport capacity as well as the possibility to reduce short circuit currents, making integration of renewables easier. Furthermore, power transport will be possible at lower voltage levels, giving the opportunity to upgrade the existing network while re-using it. This will result in large cost savings while reaching the future energy challenges. In a 6 km backbone structure in Amsterdam Nuon wants to install a 50 kV HTS Triax cable for a significant increase of the transport capacity, while developing its capabilities. Nevertheless several barriers have to be overcome

  5. Large Scale Experiments on Spacecraft Fire Safety

    Science.gov (United States)

    Urban, David; Ruff, Gary A.; Minster, Olivier; Fernandez-Pello, A. Carlos; Tien, James S.; Torero, Jose L.; Legros, Guillaume; Eigenbrod, Christian; Smirnov, Nickolay; Fujita, Osamu; hide

    2012-01-01

    Full scale fire testing complemented by computer modelling has provided significant knowhow about the risk, prevention and suppression of fire in terrestrial systems (cars, ships, planes, buildings, mines, and tunnels). In comparison, no such testing has been carried out for manned spacecraft due to the complexity, cost and risk associated with operating a long duration fire safety experiment of a relevant size in microgravity. Therefore, there is currently a gap in knowledge of fire behaviour in spacecraft. The entire body of low-gravity fire research has either been conducted in short duration ground-based microgravity facilities or has been limited to very small fuel samples. Still, the work conducted to date has shown that fire behaviour in low-gravity is very different from that in normal gravity, with differences observed for flammability limits, ignition delay, flame spread behaviour, flame colour and flame structure. As a result, the prediction of the behaviour of fires in reduced gravity is at present not validated. To address this gap in knowledge, a collaborative international project, Spacecraft Fire Safety, has been established with its cornerstone being the development of an experiment (Fire Safety 1) to be conducted on an ISS resupply vehicle, such as the Automated Transfer Vehicle (ATV) or Orbital Cygnus after it leaves the ISS and before it enters the atmosphere. A computer modelling effort will complement the experimental effort. Although the experiment will need to meet rigorous safety requirements to ensure the carrier vehicle does not sustain damage, the absence of a crew removes the need for strict containment of combustion products. This will facilitate the possibility of examining fire behaviour on a scale that is relevant to spacecraft fire safety and will provide unique data for fire model validation. This unprecedented opportunity will expand the understanding of the fundamentals of fire behaviour in spacecraft. The experiment is being

  6. Fires in large scale ventilation systems

    International Nuclear Information System (INIS)

    Gregory, W.S.; Martin, R.A.; White, B.W.; Nichols, B.D.; Smith, P.R.; Leslie, I.H.; Fenton, D.L.; Gunaji, M.V.; Blythe, J.P.

    1991-01-01

    This paper summarizes the experience gained simulating fires in large scale ventilation systems patterned after ventilation systems found in nuclear fuel cycle facilities. The series of experiments discussed included: (1) combustion aerosol loading of 0.61x0.61 m HEPA filters with the combustion products of two organic fuels, polystyrene and polymethylemethacrylate; (2) gas dynamic and heat transport through a large scale ventilation system consisting of a 0.61x0.61 m duct 90 m in length, with dampers, HEPA filters, blowers, etc.; (3) gas dynamic and simultaneous transport of heat and solid particulate (consisting of glass beads with a mean aerodynamic diameter of 10μ) through the large scale ventilation system; and (4) the transport of heat and soot, generated by kerosene pool fires, through the large scale ventilation system. The FIRAC computer code, designed to predict fire-induced transients in nuclear fuel cycle facility ventilation systems, was used to predict the results of experiments (2) through (4). In general, the results of the predictions were satisfactory. The code predictions for the gas dynamics, heat transport, and particulate transport and deposition were within 10% of the experimentally measured values. However, the code was less successful in predicting the amount of soot generation from kerosene pool fires, probably due to the fire module of the code being a one-dimensional zone model. The experiments revealed a complicated three-dimensional combustion pattern within the fire room of the ventilation system. Further refinement of the fire module within FIRAC is needed. (orig.)

  7. Instrumentation Cables Test Plan

    Energy Technology Data Exchange (ETDEWEB)

    Muna, Alice Baca [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); LaFleur, Chris Bensdotter [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-10-01

    and fluctuate, while the thermoplastic insulated cables, the instrument reading fell off-scale rapidly. From an operational point of view, the latter failure characteristics would likely be identified as a failure from the effects of fire, while the former may result in inaccurate readings.

  8. Large-Scale Spacecraft Fire Safety Tests

    Science.gov (United States)

    Urban, David; Ruff, Gary A.; Ferkul, Paul V.; Olson, Sandra; Fernandez-Pello, A. Carlos; T'ien, James S.; Torero, Jose L.; Cowlard, Adam J.; Rouvreau, Sebastien; Minster, Olivier; hide

    2014-01-01

    An international collaborative program is underway to address open issues in spacecraft fire safety. Because of limited access to long-term low-gravity conditions and the small volume generally allotted for these experiments, there have been relatively few experiments that directly study spacecraft fire safety under low-gravity conditions. Furthermore, none of these experiments have studied sample sizes and environment conditions typical of those expected in a spacecraft fire. The major constraint has been the size of the sample, with prior experiments limited to samples of the order of 10 cm in length and width or smaller. This lack of experimental data forces spacecraft designers to base their designs and safety precautions on 1-g understanding of flame spread, fire detection, and suppression. However, low-gravity combustion research has demonstrated substantial differences in flame behavior in low-gravity. This, combined with the differences caused by the confined spacecraft environment, necessitates practical scale spacecraft fire safety research to mitigate risks for future space missions. To address this issue, a large-scale spacecraft fire experiment is under development by NASA and an international team of investigators. This poster presents the objectives, status, and concept of this collaborative international project (Saffire). The project plan is to conduct fire safety experiments on three sequential flights of an unmanned ISS re-supply spacecraft (the Orbital Cygnus vehicle) after they have completed their delivery of cargo to the ISS and have begun their return journeys to earth. On two flights (Saffire-1 and Saffire-3), the experiment will consist of a flame spread test involving a meter-scale sample ignited in the pressurized volume of the spacecraft and allowed to burn to completion while measurements are made. On one of the flights (Saffire-2), 9 smaller (5 x 30 cm) samples will be tested to evaluate NASAs material flammability screening tests

  9. Circuit bridging of digital equipment caused by smoke from a cable fire

    International Nuclear Information System (INIS)

    Tanaka, T.J.; Anderson, D.J.

    1997-01-01

    Advanced reactor systems are likely to use protection systems with digital electronics that ideally should be resistant to environmental hazards, including smoke from possible cable fires. Previous smoke tests have shown that digital safety systems can fail even at relatively low levels of smoke density and that short-term failures are likely to be caused by circuit bridging. Experiments were performed to examine these failures, with a focus on component packaging and protection schemes. Circuit bridging, which causes increased leakage currents and arcs, was gauged by measuring leakage currents among the leads of component packages. The resistance among circuit leads typically varies over a wide range, depending on the nature of the circuitry between the pins, bias conditions, circuit board material, etc. Resistance between leads can be as low as 20 kΩ and still be good, depending on the component. For these tests, the authors chose a printed circuit board and components that normally have an interlead resistance above 10 12 Ω, but if the circuit is exposed to smoke, circuit bridging causes the resistance to fall below 10 3 Ω. Plated-through-hole (PTH) and surface-mounted (SMT) packages were exposed to a series of different smoke environments using a mixture of environmentally qualified cables for fuel. Conformal coatings and enclosures were tested as circuit protection methods. High fuel levels, high humidity, and high flaming burns were the conditions most likely to cause circuit bridging. The inexpensive conformal coating that was tested - an acrylic spray - reduced leakage currents, but enclosure in a chassis with a fan did not. PTH packages were more resistant to smoke-induced circuit bridging than SMT packages. Active components failed most often in tests where the leakage currents were high, but failure did not always accompany high leakage currents

  10. Small Scale Hydrocarbon Fire Test Concept

    Directory of Open Access Journals (Sweden)

    Joachim Søreng Bjørge

    2017-11-01

    Full Text Available In the oil and gas industry, hydrocarbon process equipment was previously often thermally insulated by applying insulation directly to the metal surface. Fire protective insulation was applied outside the thermal insulation. In some cases, severe corrosion attacks were observed due to ingress of humidity and condensation at cold surfaces. Introducing a 25 mm air gap to prevent wet thermal insulation and metal wall contact is expected to solve the corrosion issues. This improved insulation methodology does, however, require more space that may not be available when refurbishing older process plants. Relocating structural elements would introduce much hot work, which should be minimized in live plants. It is also costly. The aim of the present study is therefore to develop a test concept for testing fire resistance of equipment protected with only air-gap and thermal insulation, i.e., without the fire-protective insulation. The present work demonstrates a conceptual methodology for small scale fire testing of mockups resembling a section of a distillation column. The mockups were exposed to a small-scale propane flame in a test configuration where the flow rate and the flame zone were optimized to give heat flux levels in the range 250–350 kW/m2. Results are presented for a mockup resembling a 16 mm thick distillation column steel wall. It is demonstrated that the modern distance insulation in combination with the heat capacity of the column wall indicates 30+ minutes fire resistance. The results show that this methodology has great potentials for low cost fire testing of other configurations, and it may serve as a set-up for product development.

  11. AC losses in superconductors: a multi-scale approach for the design of high current cables

    International Nuclear Information System (INIS)

    Escamez, Guillaume

    2016-01-01

    The work reported in this PhD deals with AC losses in superconducting material for large scale applications such as cables or magnets. Numerical models involving FEM or integral methods have been developed to solve the time transient electromagnetic distributions of field and current densities with the peculiarity of the superconducting constitutive E-J equation. Two main conductors have been investigated. First, REBCO superconductors for applications operating at 77 K are studied and a new architecture of conductor (round wires) for 3 kA cables. Secondly, for very high current cables, 3-D simulations on MgB_2 wires are built and solved using FEM modeling. The following chapter introduced new development used for the calculation of AC losses in DC cables with ripples. The thesis ends with the use of the developed numerical model on a practical example in the european BEST-PATHS project: a 10 kA MgB_2 demonstrator [fr

  12. Evaluation of the influence of a postulated lubrication oil fire on safety related cables in the top shield platform of PFBR RCB by using FDS Code

    International Nuclear Information System (INIS)

    Mangarjuna Rao, P.; Jayasuriya, C.; Nashine, B.K.; Chellapandi, P.; Velusamy, K.

    2010-01-01

    Top deck of Prototype Fast Breeder Reactor (PFBR) primary system houses redundant safety related systems like Control and Safety Rod Drive Mechanisms (CSRDM), Diverse Safety Rod Drive Mechanism (DSRDM), subassembly outlet sodium temperature measurement system and central canal plug. These systems protrude out from the reactor through the Control Plug (CP), which is supported on the Top Shield (TS) of PFBR. Control and instrumentation signal cables and power cables of these safety related systems that are coming out from the CP are routed through Top Shield Platform (TSP, which is concentric with Reactor Vault (RV) at EL 34.1 m above the TS) to the peripheral local instrumentation control centers via the cable junction boxes supported on TS. Influence approach fire hazard analysis (FHA) has been carried out to evaluate the condition of redundant safety related cables under the scenario of a postulated oil fire in the TSP using Fire Dynamics Simulator code (FDS, Version 5). FDS is a computational fluid dynamics (CFD) based fire analysis code and it is developed by National Institute of Standards and Technology (NIST), USA. In this paper the details of the model developed and the results of the analysis carried out are discussed. In TSP, a postulated oil fire scenario with complete inventory of a primary sodium pump (PSP) lubrication oil leak (200 lt) has been considered at 30 m elevation on the TS. Computational model with the geometry of TSP and with other important structural components on TS like PSPs, intermediate heat exchangers (IHXs), large rotating plug (LRP), small rotating plug (SRP), CP and etc. has been developed along with a fire of 1800 kW/m 2 heat release rate in the vicinity of the PSP1. Numerical simulation has been carried out to evaluate this oil fire influence on the typical safety related cables routed at 34 m elevation. It has been found that the surface temperature of the cables that are routed directly above the fire only crosses the ignition

  13. External heating of electrical cables and auto-ignition investigation

    Energy Technology Data Exchange (ETDEWEB)

    Courty, L., E-mail: leo.courty@univ-orleans.fr [Univ. Orleans, PRISME EA 4229, 63 Avenue de Lattre de Tassigny, 18020 Bourges (France); Garo, J.P. [Institut P’, UPR 3346 CNRS, ENSMA, Univ. Poitiers, 1 Av. Clément Ader, Téléport 2, BP 40109, 86961 Futuroscope Chasseneuil (France)

    2017-01-05

    Highlights: • Electrical cables pyrolysis and flammability have been studied. • Two different experimental setups were used to study cables mass loss and flammability. • A 1-D thermal model for cables mass loss and temperature is proposed. • Spontaneous and piloted ignitions have been investigated. - Abstract: Electric cables are now extensively used for both residential and industrial applications. During more than twenty years, multi-scale approaches have been developed to study fire behavior of such cables that represents a serious challenge. Cables are rather complicated materials because they consist of an insulated part and jacket of polymeric materials. These polymeric materials can have various chemical structures, thicknesses and additives and generally have a char-forming tendency when exposed to heat source. In this work, two test methods are used for the characterization of cable pyrolysis and flammability. The first one permits the investigation of cable pyrolysis. A description of the cable mass loss is obtained, coupling an Arrhenius expression with a 1D thermal model of cables heating. Numerical results are successfully compared with experimental data obtained for two types of cable commonly used in French nuclear power plants. The second one is devoted to ignition investigations (spontaneous or piloted) of these cables. All these basic observations, measurements and modelling efforts are of major interest for a more comprehensive fire resistance evaluation of electric cables.

  14. External heating of electrical cables and auto-ignition investigation

    International Nuclear Information System (INIS)

    Courty, L.; Garo, J.P.

    2017-01-01

    Highlights: • Electrical cables pyrolysis and flammability have been studied. • Two different experimental setups were used to study cables mass loss and flammability. • A 1-D thermal model for cables mass loss and temperature is proposed. • Spontaneous and piloted ignitions have been investigated. - Abstract: Electric cables are now extensively used for both residential and industrial applications. During more than twenty years, multi-scale approaches have been developed to study fire behavior of such cables that represents a serious challenge. Cables are rather complicated materials because they consist of an insulated part and jacket of polymeric materials. These polymeric materials can have various chemical structures, thicknesses and additives and generally have a char-forming tendency when exposed to heat source. In this work, two test methods are used for the characterization of cable pyrolysis and flammability. The first one permits the investigation of cable pyrolysis. A description of the cable mass loss is obtained, coupling an Arrhenius expression with a 1D thermal model of cables heating. Numerical results are successfully compared with experimental data obtained for two types of cable commonly used in French nuclear power plants. The second one is devoted to ignition investigations (spontaneous or piloted) of these cables. All these basic observations, measurements and modelling efforts are of major interest for a more comprehensive fire resistance evaluation of electric cables.

  15. Temporal scaling behavior of forest and urban fires

    Science.gov (United States)

    Wang, J.; Song, W.; Zheng, H.; Telesca, L.

    2009-04-01

    It has been found that many natural systems are characterized by scaling behavior. In such systems natural factors dominate the event dynamics. Forest fires in different countries have been found to exhibit frequency-size power law over many orders of magnitude and with similar value of parameters. But in countries with high population density such as China and Japan, more than 95% of the forest fire disasters are caused by human activities. Furthermore, with the development of society, the wildland-urban interface (WUI) area is becoming more and more populated, and the forest fire is much connected with urban fire. Therefore exploring the scaling behavior of fires dominated by human-related factors is very challenging. The present paper explores the temporal scaling behavior of forest fires and urban fires in Japan with mathematical methods. Two factors, Allan factor (AF) and Fano factor (FF) are used to investigate time-scaling of fire systems. It is found that the FF for both forest fires and urban fires increases linearly in log-log scales, and this indicates that it behaves as a power-law for all the investigated timescales. From the AF plot a 7 days cycle is found, which indicates a weekly cycle. This may be caused by human activities which has a weekly periodicity because on weekends people usually have more outdoor activities, which may cause more hidden trouble of fire disasters. Our findings point out that although the human factors are the main cause, both the forest fires and urban fires exhibit time-scaling behavior. At the same time, the scaling exponents for urban fires are larger than forest fires, signifying a more intense clustering. The reason may be that fires are affected not only by weather condition, but also by human activities, which play a more important role for urban fires than forest fires and have a power law distribution and scaling behavior. Then some work is done to the relative humidity. Similar distribution law characterizes the

  16. Wildland Fire Behaviour Case Studies and Fuel Models for Landscape-Scale Fire Modeling

    Directory of Open Access Journals (Sweden)

    Paul-Antoine Santoni

    2011-01-01

    Full Text Available This work presents the extension of a physical model for the spreading of surface fire at landscape scale. In previous work, the model was validated at laboratory scale for fire spreading across litters. The model was then modified to consider the structure of actual vegetation and was included in the wildland fire calculation system Forefire that allows converting the two-dimensional model of fire spread to three dimensions, taking into account spatial information. Two wildland fire behavior case studies were elaborated and used as a basis to test the simulator. Both fires were reconstructed, paying attention to the vegetation mapping, fire history, and meteorological data. The local calibration of the simulator required the development of appropriate fuel models for shrubland vegetation (maquis for use with the model of fire spread. This study showed the capabilities of the simulator during the typical drought season characterizing the Mediterranean climate when most wildfires occur.

  17. Deterministic analysis of mid scale outdoor fire

    International Nuclear Information System (INIS)

    Vidmar, P.; Petelin, S.

    2003-01-01

    The idea behind the article is how to define fire behaviour. The work is based on an analytical study of fire origin, its development and spread. Mathematical fire model called FDS (Fire Dynamic Simulator) is used in the presented work. A CFD (Computational Fluid Dynamic) model using LES (Large Eddie Simulation) is used to calculate fire development and spread of combustion products in the environment. The fire source is located in the vicinity of the hazardous plant, power, chemical etc. The article presents the brief background of the FDS computer program and the initial and boundary conditions used in the mathematical model. Results discuss output data and check the validity of results. The work also presents some corrections of the physical model used, which influence the quality of results. The obtained results were discussed and compared with the Fire Safety Analysis report included in the Probabilistic Safety Assessment of Krsko nuclear power plant. (author)

  18. A Scale for Rating Fire-Prevention Contactors

    Science.gov (United States)

    M.L. Doolittle

    1979-01-01

    A scale is constructed to help fire-prevention program administrators determine if an individual contactor is effective at influencing people. The 24 items in the scale indicate the qualities that an effective contactor should have.

  19. Synoptic-scale fire weather conditions in Alaska

    Science.gov (United States)

    Hayasaka, Hiroshi; Tanaka, Hiroshi L.; Bieniek, Peter A.

    2016-09-01

    Recent concurrent widespread fires in Alaska are evaluated to assess their associated synoptic-scale weather conditions. Several periods of high fire activity from 2003 to 2015 were identified using Moderate Resolution Imaging Spectroradiometer (MODIS) hotspot data by considering the number of daily hotspots and their continuity. Fire weather conditions during the top six periods of high fire activity in the fire years of 2004, 2005, 2009, and 2015 were analyzed using upper level (500 hPa) and near surface level (1000 hPa) atmospheric reanalysis data. The top four fire-periods occurred under similar unique high-pressure fire weather conditions related to Rossby wave breaking (RWB). Following the ignition of wildfires, fire weather conditions related to RWB events typically result in two hotspot peaks occurring before and after high-pressure systems move from south to north across Alaska. A ridge in the Gulf of Alaska resulted in southwesterly wind during the first hotspot peak. After the high-pressure system moved north under RWB conditions, the Beaufort Sea High developed and resulted in relatively strong easterly wind in Interior Alaska and a second (largest) hotspot peak during each fire period. Low-pressure-related fire weather conditions occurring under cyclogenesis in the Arctic also resulted in high fire activity under southwesterly wind with a single large hot-spot peak.

  20. Fire safety

    International Nuclear Information System (INIS)

    Keski-Rahkonen, O.; Bjoerkman, J.; Hostikka, S.; Mangs, J.; Huhtanen, R.; Palmen, H.; Salminen, A.; Turtola, A.

    1998-01-01

    According to experience and probabilistic risk assessments, fires present a significant hazard in a nuclear power plant. Fires may be initial events for accidents or affect safety systems planned to prevent accidents and to mitigate their consequences. The project consists of theoretical work, experiments and simulations aiming to increase the fire safety at nuclear power plants. The project has four target areas: (1) to produce validated models for numerical simulation programmes, (2) to produce new information on the behavior of equipment in case of fire, (3) to study applicability of new active fire protecting systems in nuclear power plants, and (4) to obtain quantitative knowledge of ignitions induced by important electric devices in nuclear power plants. These topics have been solved mainly experimentally, but modelling at different level is used to interpret experimental data, and to allow easy generalisation and engineering use of the obtained data. Numerical fire simulation has concentrated in comparison of CFD modelling of room fires, and fire spreading on cables on experimental data. So far the success has been good to fair. A simple analytical and numerical model has been developed for fire effluents spreading beyond the room of origin in mechanically strongly ventilated compartments. For behaviour of equipment in fire several full scale and scaled down calorimetric experiments were carried out on electronic cabinets, as well as on horizontal and vertical cable trays. These were carried out to supply material for CFD numerical simulation code validation. Several analytical models were developed and validated against obtained experimental results to allow quick calculations for PSA estimates as well as inter- and extrapolations to slightly different objects. Response times of different commercial fire detectors were determined for different types of smoke, especially emanating from smoldering and flaming cables to facilitate selection of proper detector

  1. The Phoenix series large scale LNG pool fire experiments.

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, Richard B.; Jensen, Richard Pearson; Demosthenous, Byron; Luketa, Anay Josephine; Ricks, Allen Joseph; Hightower, Marion Michael; Blanchat, Thomas K.; Helmick, Paul H.; Tieszen, Sheldon Robert; Deola, Regina Anne; Mercier, Jeffrey Alan; Suo-Anttila, Jill Marie; Miller, Timothy J.

    2010-12-01

    The increasing demand for natural gas could increase the number and frequency of Liquefied Natural Gas (LNG) tanker deliveries to ports across the United States. Because of the increasing number of shipments and the number of possible new facilities, concerns about the potential safety of the public and property from an accidental, and even more importantly intentional spills, have increased. While improvements have been made over the past decade in assessing hazards from LNG spills, the existing experimental data is much smaller in size and scale than many postulated large accidental and intentional spills. Since the physics and hazards from a fire change with fire size, there are concerns about the adequacy of current hazard prediction techniques for large LNG spills and fires. To address these concerns, Congress funded the Department of Energy (DOE) in 2008 to conduct a series of laboratory and large-scale LNG pool fire experiments at Sandia National Laboratories (Sandia) in Albuquerque, New Mexico. This report presents the test data and results of both sets of fire experiments. A series of five reduced-scale (gas burner) tests (yielding 27 sets of data) were conducted in 2007 and 2008 at Sandia's Thermal Test Complex (TTC) to assess flame height to fire diameter ratios as a function of nondimensional heat release rates for extrapolation to large-scale LNG fires. The large-scale LNG pool fire experiments were conducted in a 120 m diameter pond specially designed and constructed in Sandia's Area III large-scale test complex. Two fire tests of LNG spills of 21 and 81 m in diameter were conducted in 2009 to improve the understanding of flame height, smoke production, and burn rate and therefore the physics and hazards of large LNG spills and fires.

  2. Development of the Database of Cables of Almaraz NPP as the fire deterministic analysis support; Elaboracion de la base de datos de cables de C.N. Almaraz como soporte de los analisis deterministas de incendios

    Energy Technology Data Exchange (ETDEWEB)

    Villar Sanchez, T.; Fernandez Ramos, P.; Garcia Romero, A.; Fuente Prieto, I.

    2013-07-01

    Within the process of transition to the NFPA-805, it requires a deterministic analysis of fire, for which it is necessary, on the one hand, the identification and location of the cables and equipment necessary and important for achieve and maintain safe, and stop on the other hand, the analysis of the different types of spurious multiple, based on the methodology described in the NEI 00-01 Rev. 2. the base Almaraz NPP cables data it collects this information and is a fundamental tool to analyze the capacity of the plant to achieve the stop safe in case of fire, which allows you to find possible vulnerabilities and take appropriate measures to improve the security of it.

  3. Scaling up the microwave firing of ceramics

    International Nuclear Information System (INIS)

    Wroe, F.C.R.

    1993-01-01

    EA Technology, through a comprehensive R ampersand D program, is developing new microwave furnace technology focused on the ceramics processing industries. Using a combination of computer modelling, experimentation and feasibility studies, EA Technology has developed processes and procedures for firing large ceramic components. The aim of this work is to describe the investigation of the firing of ceramic products such as bricks, pottery, refractories, and industrial ceramics, using advanced processing techniques to produce and maintain uniformity of temperature throughout the components and kiln environment. This has achieved the goal of producing uniform microstructures and low thermal stress by careful control of the firing cycle. This paper illustrates the feasibility of microwave-assisted firing and shows it to be economically viable in terms of energy costs and process control. 6 refs., 1 fig

  4. Use of Distributed Temperature Sensing Technology to Characterize Fire Behavior

    Directory of Open Access Journals (Sweden)

    Douglas Cram

    2016-10-01

    Full Text Available We evaluated the potential of a fiber optic cable connected to distributed temperature sensing (DTS technology to withstand wildland fire conditions and quantify fire behavior parameters. We used a custom-made ‘fire cable’ consisting of three optical fibers coated with three different materials—acrylate, copper and polyimide. The 150-m cable was deployed in grasslands and burned in three prescribed fires. The DTS system recorded fire cable output every three seconds and integrated temperatures every 50.6 cm. Results indicated the fire cable was physically capable of withstanding repeated rugged use. Fiber coating materials withstood temperatures up to 422 °C. Changes in fiber attenuation following fire were near zero (−0.81 to 0.12 dB/km indicating essentially no change in light gain or loss as a function of distance or fire intensity over the length of the fire cable. Results indicated fire cable and DTS technology have potential to quantify fire environment parameters such as heat duration and rate of spread but additional experimentation and analysis are required to determine efficacy and response times. This study adds understanding of DTS and fire cable technology as a potential new method for characterizing fire behavior parameters at greater temporal and spatial scales.

  5. Development of Large-Scale Spacecraft Fire Safety Experiments

    DEFF Research Database (Denmark)

    Ruff, Gary A.; Urban, David L.; Fernandez-Pello, A. Carlos

    2013-01-01

    exploration missions outside of low-earth orbit and accordingly, more complex in terms of operations, logistics, and safety. This will increase the challenge of ensuring a fire-safe environment for the crew throughout the mission. Based on our fundamental uncertainty of the behavior of fires in low...... of the spacecraft fire safety risk. The activity of this project is supported by an international topical team of fire experts from other space agencies who conduct research that is integrated into the overall experiment design. The large-scale space flight experiment will be conducted in an Orbital Sciences...

  6. Hot Firing of a Full Scale Copper Tubular Combustion Chamber

    National Research Council Canada - National Science Library

    Cooley, C

    2002-01-01

    This paper describes the chamber design and hot firing test results for a full-scale copper tubular combustion chamber that has future application in a high-thrust, upper-stage expander cycle engine...

  7. Study of special spacer with damping device for suppressing wake galloping in tandem cables of cable-stayed bridges and its application to full scale bridge; Nendanseitai wo riyoshita heiretsu cable yo gensui kinotsuki spacer to sono jikkyo cable eno tekiyo ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Yoneda, M.; Setouchi, H.; Yoshioka, A. [Kawada Industries Inc., Tokyo (Japan); Shimoda, I.; Kawahara, S. [Oiles Corp., Tokyo (Japan)

    1996-12-20

    Cable vibration called wake galloping occurs in a cable-stayed bridge, in which cables are arranged tandem, and suppression of the vibration is an extremely important discussion item. This paper describes a complex eigen value analysis performed on tandem cables having lengths of 200 m and 100 m. The analysis revealed that damping characteristics added by a spacer system with a damping device (a type to install a visco-elastic body at about middle of the tandem cables via a jig) depend largely on torsional rigidity of the cables; and the characteristics may vary with difference in intervals between cable centers and that in cable diameters. A visco-elastic damping material of an asphalt system and a spacer with a damping device used as a spring material were fabricated and applied to a full scale bridge to identify quantitatively the damping addition characteristics of this system. Furthermore, the results of tests on the full scale bridge were compared with the result of the complex eigen value analysis, from which findings useful for actual works were obtained. 18 refs., 17 figs., 6 tabs.

  8. External heating of electrical cables and auto-ignition investigation.

    Science.gov (United States)

    Courty, L; Garo, J P

    2017-01-05

    Electric cables are now extensively used for both residential and industrial applications. During more than twenty years, multi-scale approaches have been developed to study fire behavior of such cables that represents a serious challenge. Cables are rather complicated materials because they consist of an insulated part and jacket of polymeric materials. These polymeric materials can have various chemical structures, thicknesses and additives and generally have a char-forming tendency when exposed to heat source. In this work, two test methods are used for the characterization of cable pyrolysis and flammability. The first one permits the investigation of cable pyrolysis. A description of the cable mass loss is obtained, coupling an Arrhenius expression with a 1D thermal model of cables heating. Numerical results are successfully compared with experimental data obtained for two types of cable commonly used in French nuclear power plants. The second one is devoted to ignition investigations (spontaneous or piloted) of these cables. All these basic observations, measurements and modelling efforts are of major interest for a more comprehensive fire resistance evaluation of electric cables. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Small Scale Hydrocarbon Fire Test Concept

    OpenAIRE

    Joachim Søreng Bjørge; Maria-Monika Metallinou; Arjen Kraaijeveld; Torgrim Log

    2017-01-01

    In the oil and gas industry, hydrocarbon process equipment was previously often thermally insulated by applying insulation directly to the metal surface. Fire protective insulation was applied outside the thermal insulation. In some cases, severe corrosion attacks were observed due to ingress of humidity and condensation at cold surfaces. Introducing a 25 mm air gap to prevent wet thermal insulation and metal wall contact is expected to solve the corrosion issues. This improved insulation met...

  10. Scaling of the burning efficiency for multicomponent fuel pool fires

    DEFF Research Database (Denmark)

    van Gelderen, Laurens; Farahani, Hamed Farmahini; Rangwala, Ali S.

    In order to improve the validity of small scale crude oil burning experiments, which seem to underestimate the burning efficiency obtained in larger scales, the gasification mechanism of crude oil was studied. Gasification models obtained from literature were used to make a set of predictions for...... an external heat source to simulate the larger fire size are currently in process....

  11. Identification of aeroelastic forces and static drag coefficients of a twin cable bridge stay from full-scale ambient vibration measurements

    DEFF Research Database (Denmark)

    Acampora, Antonio; Georgakis, Christos T.; Macdonald, J.H.G.

    2014-01-01

    Despite much research in recent years, large amplitude vibrations of inclined cables continue to be of concern for cable-stayed bridges. Various excitation mechanisms have been suggested, including rain-wind excitation, dry inclined cable galloping, high reduced velocity vortex shedding...... and excitation from the deck and/or towers. Although there have been many observations of large cable vibrations on bridges, there are relatively few cases of direct full-scale cable vibration and wind measurements, and most research has been based on wind tunnel tests and theoretical modelling.This paper...... presents results from full-scale measurements on the special arrangement of twin cables adopted for the Øresund Bridge. The monitoring system records wind and weather conditions, as well as accelerations of certain cables and a few locations on the deck and tower. Using the Eigenvalue Realization Algorithm...

  12. Identification of aeroelastic forces on bridge cables from full-scale measurements

    DEFF Research Database (Denmark)

    Acampora, Antonio; Macdonald, J.H.G.; Georgakis, Christos

    2011-01-01

    Despite much research in recent years, large amplitude vibrations of inclined cables continue to be of concern for cable-stayed bridges. Various mechanisms have been suggested for their excitation, including rain-wind excitation, dry inclined cable galloping, high reduced velocity vortex shedding...... Bridge. The system records wind conditions and weather conditions, as well as accelerations of certain cables and a few locations on the deck and tower. Using state-of-the-art methods of output-only system identification, the vibration modes of the cables have been identified. From these modes...

  13. Systems for animal exposure in full-scale fire tests

    Science.gov (United States)

    Hilado, C. J.; Cumming, H. J.; Kourtides, D. A.; Parker, J. A.

    1977-01-01

    Two systems for exposing animals in full-scale fire tests are described. Both systems involve the simultaneous exposure of two animal species, mice and rats, in modular units; determination of mortality, morbidity, and behavioral response; and analysis of the blood for carboxyhemoglobin. The systems described represent two of many possible options for obtaining bioassay data from full-scale fire tests. In situations where the temperatures to which the test animals are exposed can not be controlled, analytical techniques may be more appropriate than bioassay techniques.

  14. Full-scale measurements and system identification on Sutong cable-stayed bridge during Typhoon Fung-Wong.

    Science.gov (United States)

    Wang, Hao; Tao, Tianyou; Guo, Tong; Li, Jian; Li, Aiqun

    2014-01-01

    The structural health monitoring system (SHMS) provides an effective tool to conduct full-scale measurements on existing bridges for essential research on bridge wind engineering. In July 2008, Typhoon Fung-Wong lashed China and hit Sutong cable-stayed bridge (SCB) in China. During typhoon period, full-scale measurements were conducted to record the wind data and the structural vibration responses were collected by the SHMS installed on SCB. Based on the statistical method and the spectral analysis technique, the measured data are analyzed to obtain the typical parameters and characteristics. Furthermore, this paper analyzed the measured structural vibration responses and indicated the vibration characteristics of the stay cable and the deck, the relationship between structural vibrations and wind speed, the comparison of upstream and downstream cable vibrations, the effectiveness of cable dampers, and so forth. Considering the significance of damping ratio in vibration mitigation, the modal damping ratios of the SCB are identified based on the Hilbert-Huang transform (HHT) combined with the random decrement technique (RDT). The analysis results can be used to validate the current dynamic characteristic analysis methods, buffeting calculation methods, and wind tunnel test results of the long-span cable-stayed bridges.

  15. Full-Scale Measurements and System Identification on Sutong Cable-Stayed Bridge during Typhoon Fung-Wong

    Directory of Open Access Journals (Sweden)

    Hao Wang

    2014-01-01

    Full Text Available The structural health monitoring system (SHMS provides an effective tool to conduct full-scale measurements on existing bridges for essential research on bridge wind engineering. In July 2008, Typhoon Fung-Wong lashed China and hit Sutong cable-stayed bridge (SCB in China. During typhoon period, full-scale measurements were conducted to record the wind data and the structural vibration responses were collected by the SHMS installed on SCB. Based on the statistical method and the spectral analysis technique, the measured data are analyzed to obtain the typical parameters and characteristics. Furthermore, this paper analyzed the measured structural vibration responses and indicated the vibration characteristics of the stay cable and the deck, the relationship between structural vibrations and wind speed, the comparison of upstream and downstream cable vibrations, the effectiveness of cable dampers, and so forth. Considering the significance of damping ratio in vibration mitigation, the modal damping ratios of the SCB are identified based on the Hilbert-Huang transform (HHT combined with the random decrement technique (RDT. The analysis results can be used to validate the current dynamic characteristic analysis methods, buffeting calculation methods, and wind tunnel test results of the long-span cable-stayed bridges.

  16. Experimental evaluation of a self-powered smart damping system in reducing vibrations of a full-scale stay cable

    International Nuclear Information System (INIS)

    Kim, In-Ho; Jung, Hyung-Jo; Koo, Jeong-Hoi

    2010-01-01

    This paper investigates the effectiveness of a self-powered smart damping system consisting of a magnetorheological (MR) damper and an electromagnetic induction (EMI) device in reducing cable vibrations. The proposed smart damping system incorporates an EMI device, which is capable of converting vibration energy into useful electrical energy. Thus, the incorporated EMI device can be used as an alternative power source for the MR damper, making it a self-powering system. The primary goal of this experimental study is to evaluate the performance of the proposed smart damping system using a full-scale, 44.7 m long, high-tension cable. To this end, an EMI part and an MR damper were designed and manufactured. Using a cable test setup in a laboratory setting, a series of tests were performed to evaluate the effectiveness of the self-powered smart damping system in reducing free vibration responses of the cable. The performances of the proposed smart damping system are compared with those of an equivalent passive system. Moreover, the damping characteristics of the smart damping system and the passive system are compared. The experimental results show that the self-powered smart damping system outperforms the passive control cases in reducing the vibrations of the cable. The results also show that the EMI can operate the smart damping system as a sole power source, demonstrating the feasibility of the self-powering capability of the system

  17. Full Scale Test on a 100km, 150kV AC Cable

    DEFF Research Database (Denmark)

    Faria da Silva, Filipe Farria; Wiechowski, W.; Bak, Claus Leth

    2010-01-01

    phenomena is conducted. The cases analysed in this paper are: Zero-missing phenomenon, Ferranti effect, energisation transient, effect of the cable's connection in the busbar voltage and cable disconnection. For all the phenomena described in the paper measurement data are presented and it is verified......This paper presents some of the results obtained from the electrical measurements on a 99.7 km, 150 kV three-phase AC cable, connecting 215 MW offshore wind farm Horns Rev 2, located in Denmark west coast, to Denmark's 400 kV transmission network. The measurements were performed at nominal voltage...... if the obtained results are in accordance with the theory and also with simulations performed in PSCAD/EMTDC. With the exception of the cable disconnection, for all the remaining cases introduced in this paper the measurements confirmed the theoretical expectations. Depending on the cable disconnection sequence...

  18. Flame spread and smoke temperature of full-scale fire test of car fire

    Directory of Open Access Journals (Sweden)

    Dayan Li

    2017-09-01

    Full Text Available Full-scale experiments using two 4-door sedan passenger cars, placed side by side in the reverse direction, were carried out to establish the burning behavior and describe the spread of fire to adjacent car. The temperature was measured by thermocouples. Radiant heat flux was measured with heat flux gauge placed at a distance of 5 m, at the right side of the car. Four cameras were placed inside the car and in the fire test room recording burning behavior during the test. Engine compartment was ignited by a sponge dipped with little gasoline. During the experiment, the ignition was initiated in the engine compartment of car I and approximately 20 min were enough time for fire to spread into the second car. Fully-developed burning of two cars occurred at 29 min. It was observed that the flame spread through car roof faster than through the bottom of car compartment. The fire followed a slow rate spread from engine compartment to car cab. The temperature inside the car peaked at the point of 900 °C. The peak smoke temperatures at every location were measured at the range of 89–285 °C. The smoke production at the time of 11 min to 15 min 50 s of fire was 1.76 m3/s, which was obtained through indirect calculation method.

  19. Test results of full-scale high temperature superconductors cable models destined for a 36 kV, 2 kA(rms) utility demonstration

    DEFF Research Database (Denmark)

    Daumling, M.; Rasmussen, C.N.; Hansen, F.

    2001-01-01

    Power cable systems using high temperature superconductors (HTS) are nearing technical feasibility. This presentation summarises the advancements and status of a project aimed at demonstrating a 36 kV, 2 kA(rms) AC cable system by installing a 30 m long full-scale functional model in a power...

  20. A Practical Guide to Assessing Adult Firesetters' Fire-Specific Treatment Needs Using the Four Factor Fire Scales.

    Science.gov (United States)

    Ó Ciardha, Caoilte; Tyler, Nichola; Gannon, Theresa A

    2015-01-01

    Practitioners working with offenders who have set fires have access to very few measures examining fire-specific treatment needs (e.g., fire interest, fire attitudes). In this article we examine the new Four Factor Fire Scales (Ó Ciardha et al., 2015), which may be used by practitioners to examine fire-specific treatment needs for offenders who have set deliberate fires. We present a standardized scoring procedure when using these scales, as well as an associated scoring template for practitioner use. Norm data are based on male and female firesetters (n = 378) and nonfiresetters (n = 187) recruited from 19 prison establishments (including six female establishments, one young offender institution) and 12 secure mixed-gender mental health settings. We present a full overview of all data we have collected to date relating to the Four Factor Fire Scales across prison, mental health, and young offending participants. For each population, we present mean scores as well as associated cutoff scores and reliable change indices to aid practitioners in their interpretation of scores. The Four Factor Fire Scales provide professionals working in the area with a robust template for administering, scoring, and interpreting the fire-specific factors currently identified as playing a role in deliberate firesetting behavior. Strengths and limitations of the measure are discussed.

  1. Characterization and multi-scales modeling of the thermomechanical behaviour of a superconducting composite cable

    International Nuclear Information System (INIS)

    Gourdin, C.; Reytier, M.; Vedrine, P.

    2000-06-01

    The prediction of the superconducting cable mechanical properties (NbTi and Nb 3 Sn) becomes a great stake for the STCM applications. During the design phase of our magnets, the electromagnetic forces become considerable. Therefore, the control and the accuracy of the structural calculations need well known mechanical properties for each component. But, superconducting cables present, in compression, a non linear mechanical behaviour with a significant hysteresis, which will have to be taken into account in a near future. That is why a study is started in order to understand and to formulate this particular mechanical behaviour. In this paper, the NbTi and Nb 3 Sn cable structure is first presented as well as their manufacturing process. Then, a description of the experimental procedure used to realize the compression tests is made. Finally, the main results obtained at room temperature and also in liquid helium at 4.2 K are discussed. (author)

  2. submitter Design and Manufacturing of a 45 kA at 10 T REBCO-CORC Cable-in-Conduit Conductor for Large-Scale Magnets

    CERN Document Server

    Mulder, Tim; Mentink, Matthias; Silva, Helder; van der Laan, Danko; Dhalle, Marc; ten Kate, Herman

    2016-01-01

    The European Organization for Nuclear Research (CERN) is developing high-current ReBCO-CORC strand-based cables for use in future large-scale detector magnets. A six-around-one, forced flow gas-cooled ReBCO-CORC cable-in-conduit conductor (CICC) is envisioned for application in magnets operating in the 20-40 K temperature range. A CICC, rated for 45 kA at 4.2 K and 10 T, is designed and in production. The CICC comprises a cable of six CORC strands helically wound around a tube. The cable has an expected current density of 105 $A/mm^2$ at 10 T/4.2 K, which corresponds to an overall current density of 53 $A/mm^2$. A cable current density of 110 $A/mm^2$ can be reached when increasing the temperature to 20 K and operating in a magnetic field of 5 T.

  3. Comparison of the burning behaviour of electric cables with intumescent coating in different test methods

    International Nuclear Information System (INIS)

    Will, J.; Hosser, D.

    2000-01-01

    Cables used for electric power and control systems represent a significant potential hazard, particularly in buildings with highly complex wiring. To reduce the risk of ignition and of flame spread and to limit the fire effects, protective intumescent coatings or cables with fire retardant insulation materials have been implemented in safety related areas and locations, particularly of nuclear power plants. Since 1994, extensive experimental research has been performed by iBMB of the Branschweig University of Technology on the burning behaviour of unprotected as well as coated PVC cables. The main goal of this investigations was to develop a qualification method and licensing procedure for cable systems with protective coatings based on realistic fire conditions, which is accepted by the building authorities for application in buildings in general and, in particular, in nuclear power plants. For comparative results of tests with intumescent coatings in different scales - according to the standard IEC 332-3 (large scale), German standard DIN 4102-1 (intermediate scale) and ISO 5660 (small scale) - will be introduced. The setup of the different test procedures and the corresponding phases of natural fires will be discussed. It will be shown that cables with protective coatings are appropriate for fire scenarios up to a developed room fire while only resistance to a local ignition source could be guaranteed by testing according to international or national valid standard. The necessity of testing cables with insulation material, which should guarantee a fire retardant behaviour, by these different methods should be reasonable, because depending on the results of future tests, a more distinguished qualification and application of cables might be possible. (orig.) [de

  4. Post-fire bedload sediment delivery across spatial scales in the interior western United States

    Science.gov (United States)

    Joseph W. Wagenbrenner; Peter R. Robichaud

    2014-01-01

    Post-fire sediment yields can be up to three orders of magnitude greater than sediment yields in unburned forests. Much of the research on post-fire erosion rates has been at small scales (100m2 or less), and post-fire sediment delivery rates across spatial scales have not been quantified in detail. We developed relationships for post-fire bedload sediment delivery...

  5. Properties of large-scale methane/hydrogen jet fires

    Energy Technology Data Exchange (ETDEWEB)

    Studer, E. [CEA Saclay, DEN, LTMF Heat Transfer and Fluid Mech Lab, 91 - Gif-sur-Yvette (France); Jamois, D.; Leroy, G.; Hebrard, J. [INERIS, F-60150 Verneuil En Halatte (France); Jallais, S. [Air Liquide, F-78350 Jouy En Josas (France); Blanchetiere, V. [GDF SUEZ, 93 - La Plaine St Denis (France)

    2009-12-15

    A future economy based on reduction of carbon-based fuels for power generation and transportation may consider hydrogen as possible energy carrier Extensive and widespread use of hydrogen might require a pipeline network. The alternatives might be the use of the existing natural gas network or to design a dedicated network. Whatever the solution, mixing hydrogen with natural gas will modify the consequences of accidents, substantially The French National Research Agency (ANR) funded project called HYDROMEL focuses on these critical questions Within this project large-scale jet fires have been studied experimentally and numerically The main characteristics of these flames including visible length, radiation fluxes and blowout have been assessed. (authors)

  6. Pool fires in a large scale ventilation system

    International Nuclear Information System (INIS)

    Smith, P.R.; Leslie, I.H.; Gregory, W.S.; White, B.

    1991-01-01

    A series of pool fire experiments was carried out in the Large Scale Flow Facility of the Mechanical Engineering Department at New Mexico State University. The various experiments burned alcohol, hydraulic cutting oil, kerosene, and a mixture of kerosene and tributylphosphate. Gas temperature and wall temperature measurements as a function of time were made throughout the 23.3m 3 burn compartment and the ducts of the ventilation system. The mass of the smoke particulate deposited upon the ventilation system 0.61m x 0.61m high efficiency particulate air filter for the hydraulic oil, kerosene, and kerosene-tributylphosphate mixture fires was measured using an in situ null balance. Significant increases in filter resistance were observed for all three fuels for burning time periods ranging from 10 to 30 minutes. This was found to be highly dependent upon initial ventilation system flow rate, fuel type, and flow configuration. The experimental results were compared to simulated results predicted by the Los Alamos National Laboratory FIRAC computer code. In general, the experimental and the computer results were in reasonable agreement, despite the fact that the fire compartment for the experiments was an insulated steel tank with 0.32 cm walls, while the compartment model FIRIN of FIRAC assumes 0.31 m thick concrete walls. This difference in configuration apparently caused FIRAC to consistently underpredict the measured temperatures in the fire compartment. The predicted deposition of soot proved to be insensitive to ventilation system flow rate, but the measured values showed flow rate dependence. However, predicted soot deposition was of the same order of magnitude as measured soot deposition

  7. Cables - a question of custom-design

    International Nuclear Information System (INIS)

    Doig, Tom

    1994-01-01

    Electrical equipment such as cabling can often be the limiting factor as far as machine operations in radioactive environments are concerned. Electronic and electrical equipment will degrade if exposed to ionising radiation, affecting equipment reliability, or causing complete failure. However, several companies provide custom-designed products directed specifically at the nuclear industry. One such company is Habia Cable which has built up its business in submarine cables, internal engine cables, and cables for high fire risk situations. It began supplying custom-designed cables to the nuclear industry in 1986, and has since then supplied cables throughout Europe from its plant in Sweden. (Author)

  8. Response of fire detectors to different smokes

    International Nuclear Information System (INIS)

    Bjoerkman, J.; Keski-Rahkonen, O.

    1997-01-01

    The purpose of this work is to characterize the behavior of fire alarm systems based on smoke detectors on smoldering fires especially cable fires in nuclear power plants (NPP). Full-scale fire experiments were carried out in a laboratory designed according to the standard EN54-9. The laboratory was instrumented with additional equipment such as thermocouples and flow meters which are not used in standard fire sensitivity tests. This allows the results to be used as experimental data for validation tasks of numerical fire simulation computerized fluid dynamics (CFD)-codes. The ultimate goal of the research is to model theoretically smoldering and flaming cable fires, their smoke production, transfer of smoke to detectors, as well as the response of detectors and fire alarm systems to potential fires. This would allow the use of numerical fire simulation to predict fire hazards in different fire scenarios found important in PSA (probability safety assessment) of NPPs. This report concentrates on explaining full-scale fire experiments in the smoke sensitivity laboratory and experimental results from fire tests of detectors. Validation tasks with CFD-codes will be first carried out 'blind' without any idea about corresponding experimental results. Accordingly, the experimental results cannot be published in this report. (orig.)

  9. Full-Scale Measurement and Prediction of the Dynamics of High-Speed Helicopter Tow Cables

    Science.gov (United States)

    2014-02-14

    which corresponds to a strain of about 1 jxs. Vandiver et al. (2006) used Bragg gratings to record bending strains due to strumming of a flexible ...The vibration models will be based on MIT’s VIVA software (Triantafyllou et al., 1999). VIVA predicts the vibrations of flexible cylinders...including marine cables and offshore risers ) by assuming a harmonic response consisting of complex modes whose amplitude and phase vary along the cylinder

  10. Broad-Scale Environmental Conditions Responsible for Post-Fire Vegetation Dynamics

    OpenAIRE

    Casady, Grant M.; Marsh, Stuart E.

    2010-01-01

    Ecosystem response to disturbance is influenced by environmental conditions at a number of scales. Changes in climate have altered fire regimes across the western United States, and have also likely altered spatio-temporal patterns of post-fire vegetation regeneration. Fire occurrence data and a vegetation index (NDVI) derived from the NOAA Advanced Very High Resolution Radiometer (AVHRR) were used to monitor post-fire vegetation from 1989 to 2007. We first investigated differences in post-fi...

  11. Broad-Scale Environmental Conditions Responsible for Post-Fire Vegetation Dynamics

    Directory of Open Access Journals (Sweden)

    Stuart E. Marsh

    2010-11-01

    Full Text Available Ecosystem response to disturbance is influenced by environmental conditions at a number of scales. Changes in climate have altered fire regimes across the western United States, and have also likely altered spatio-temporal patterns of post-fire vegetation regeneration. Fire occurrence data and a vegetation index (NDVI derived from the NOAA Advanced Very High Resolution Radiometer (AVHRR were used to monitor post-fire vegetation from 1989 to 2007. We first investigated differences in post-fire rates of vegetation regeneration between ecoregions. We then related precipitation, temperature, and elevation records at four temporal scales to rates of post-fire vegetation regeneration to ascertain the influence of climate on post-fire vegetation dynamics. We found that broad-scale climate factors are an important influence on post-fire vegetation regeneration. Most notably, higher rates of post-fire regeneration occurred with warmer minimum temperatures. Increases in precipitation also resulted in higher rates of post-fire vegetation growth. While explanatory power was slight, multiple statistical approaches provided evidence for real ecological drivers of post-fire regeneration that should be investigated further at finer scales. The sensitivity of post-disturbance vegetation dynamics to climatic drivers has important ramifications for the management of ecosystems under changing climatic conditions. Shifts in temperature and precipitation regimes are likely to result in changes in post-disturbance dynamics, which could represent important feedbacks into the global climate system.

  12. Research and management issues in large-scale fire modeling

    Science.gov (United States)

    David L. Peterson; Daniel L. Schmoldt

    2000-01-01

    In 1996, a team of North American fire scientists and resource managers convened to assess the effects of fire disturbance on ecosystems and to develop scientific recommendations for future fire research and management activities. These recommendations - elicited with the Analytic Hierarchy Process - include numerically ranked scientific and managerial questions and...

  13. Modeling regional-scale wildland fire emissions with the wildland fire emissions information system

    Science.gov (United States)

    Nancy H.F. French; Donald McKenzie; Tyler Erickson; Benjamin Koziol; Michael Billmire; K. Endsley; Naomi K.Y. Scheinerman; Liza Jenkins; Mary E. Miller; Roger Ottmar; Susan Prichard

    2014-01-01

    As carbon modeling tools become more comprehensive, spatial data are needed to improve quantitative maps of carbon emissions from fire. The Wildland Fire Emissions Information System (WFEIS) provides mapped estimates of carbon emissions from historical forest fires in the United States through a web browser. WFEIS improves access to data and provides a consistent...

  14. Regional scales of fire danger rating in the forest: improved technique

    Directory of Open Access Journals (Sweden)

    A. V. Volokitina

    2017-04-01

    Full Text Available Wildland fires distribute unevenly in time and over area under the influence of weather and other factors. It is unfeasible to air patrol the whole forest area daily during a fire season as well as to keep all fire suppression forces constantly alert. Daily work and preparedness of forest fire protection services is regulated by the level of fire danger according to weather conditions (Nesterov’s index. PV-1 index, fire hazard class (Melekhov’s scale, regional scales (earlier called local scales. Unfortunately, there is still no unified comparable technique of making regional scales. As a result, it is difficult to maneuver forest fire protection resources, since the techniques currently used are not approved and not tested for their performance. They give fire danger rating incomparable even for neighboring regions. The paper analyzes the state-of-the-art in Russia and abroad. It is stated the irony is that with factors of fire danger measured quantitatively, the fire danger itself as a function has no quantitative expression. Thus, selection of an absolute criteria is of high importance for improvement of daily fire danger rating. On the example of the Chunsky forest ranger station (Krasnoyarsk Krai, an improved technique is suggested of making comparable local scales of forest fire danger rating based on an absolute criterion of fire danger rating – a probable density of active fires per million ha. A method and an algorithm are described of automatized local scales of fire danger that should facilitate effective creation of similar scales for any forest ranger station or aviation regional office using a database on forest fires and weather conditions. The information system of distant monitoring by Federal Forestry Agency of Russia is analyzed for its application in making local scales. To supplement the existing weather station net it is suggested that automatic compact weather stations or, if the latter is not possible, simple

  15. The Design of a Fire Source in Scale-Model Experiments with Smoke Ventilation

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm; Brohus, Henrik; la Cour-Harbo, H.

    2004-01-01

    The paper describes the design of a fire and a smoke source for scale-model experiments with smoke ventilation. It is only possible to work with scale-model experiments where the Reynolds number is reduced compared to full scale, and it is demonstrated that special attention to the fire source...... (heat and smoke source) may improve the possibility of obtaining Reynolds number independent solutions with a fully developed flow. The paper shows scale-model experiments for the Ofenegg tunnel case. Design of a fire source for experiments with smoke ventilation in a large room and smoke movement...

  16. COPPER CABLE RECYCLING TECHNOLOGY

    International Nuclear Information System (INIS)

    Chelsea Hubbard

    2001-01-01

    The United States Department of Energy (DOE) continually seeks safer and more cost-effective technologies for use in deactivation and decommissioning (D and D) of nuclear facilities. The Deactivation and Decommissioning Focus Area (DDFA) of the DOE's Office of Science and Technology (OST) sponsors large-scale demonstration and deployment projects (LSDDPs). At these LSDDPs, developers and vendors of improved or innovative technologies showcase products that are potentially beneficial to the DOE's projects and to others in the D and D community. Benefits sought include decreased health and safety risks to personnel and the environment, increased productivity, and decreased costs of operation. The Idaho National Engineering and Environmental Laboratory (INEEL) generated a list of statements defining specific needs and problems where improved technology could be incorporated into ongoing D and D tasks. One such need is to reduce the volume of waste copper wire and cable generated by D and D. Deactivation and decommissioning activities of nuclear facilities generates hundreds of tons of contaminated copper cable, which are sent to radioactive waste disposal sites. The Copper Cable Recycling Technology separates the clean copper from contaminated insulation and dust materials in these cables. The recovered copper can then be reclaimed and, more importantly, landfill disposal volumes can be reduced. The existing baseline technology for disposing radioactively contaminated cables is to package the cables in wooden storage boxes and dispose of the cables in radioactive waste disposal sites. The Copper Cable Recycling Technology is applicable to facility decommissioning projects at many Department of Energy (DOE) nuclear facilities and commercial nuclear power plants undergoing decommissioning activities. The INEEL Copper Cable Recycling Technology Demonstration investigated the effectiveness and efficiency to recycle 13.5 tons of copper cable. To determine the effectiveness

  17. Sensitivity to spatial and temporal scale and fire regime inputs in deriving fire regime condition class

    Science.gov (United States)

    Linda Tedrow; Wendel J. Hann

    2015-01-01

    The Fire Regime Condition Class (FRCC) is a composite departure measure that compares current vegetation structure and fire regime to historical reference conditions. FRCC is computed as the average of: 1) Vegetation departure (VDEP) and 2) Regime (frequency and severity) departure (RDEP). In addition to the FRCC rating, the Vegetation Condition Class (VCC) and Regime...

  18. Fractional cable equation models for anomalous electrodiffusion in nerve cells: infinite domain solutions.

    Science.gov (United States)

    Langlands, T A M; Henry, B I; Wearne, S L

    2009-12-01

    We introduce fractional Nernst-Planck equations and derive fractional cable equations as macroscopic models for electrodiffusion of ions in nerve cells when molecular diffusion is anomalous subdiffusion due to binding, crowding or trapping. The anomalous subdiffusion is modelled by replacing diffusion constants with time dependent operators parameterized by fractional order exponents. Solutions are obtained as functions of the scaling parameters for infinite cables and semi-infinite cables with instantaneous current injections. Voltage attenuation along dendrites in response to alpha function synaptic inputs is computed. Action potential firing rates are also derived based on simple integrate and fire versions of the models. Our results show that electrotonic properties and firing rates of nerve cells are altered by anomalous subdiffusion in these models. We have suggested electrophysiological experiments to calibrate and validate the models.

  19. FIRE

    International Nuclear Information System (INIS)

    Brtis, J.S.; Hausheer, T.G.

    1990-01-01

    FIRE, a microcomputer based program to assist engineers in reviewing and documenting the fire protection impact of design changes has been developed. Acting as an electronic consultant, FIRE is designed to work with an experienced nuclear system engineer, who may not have any detailed fire protection expertise. FIRE helps the engineer to decide if a modification might adversely affect the fire protection design of the station. Since its first development, FIRE has been customized to reflect the fire protection philosophy of the Commonwealth Edison Company. That program is in early production use. This paper discusses the FIRE program in light of its being a useful application of expert system technologies in the power industry

  20. Predicting the effect of fire on large-scale vegetation patterns in North America.

    Science.gov (United States)

    Donald McKenzie; David L. Peterson; Ernesto. Alvarado

    1996-01-01

    Changes in fire regimes are expected across North America in response to anticipated global climatic changes. Potential changes in large-scale vegetation patterns are predicted as a result of altered fire frequencies. A new vegetation classification was developed by condensing Kuchler potential natural vegetation types into aggregated types that are relatively...

  1. Combustion Aerosols from Full-Scale Suspension-Firing of Wood Pellets

    DEFF Research Database (Denmark)

    Damø, Anne Juul; Wu, Hao; Frandsen, Flemming

    2012-01-01

    The objectives of the present work were to investigate the aerosol formation mechanisms during full-scale suspension firing of wood, and, to evaluate the effect of coal fly ash addition on the formation of aerosols under different ash load conditions. Tests with suspension firing of 100 % wood...

  2. Fluid dynamics structures in a fire environment observed in laboratory-scale experiments

    Science.gov (United States)

    J. Lozano; W. Tachajapong; D.R. Weise; S. Mahalingam; M. Princevac

    2010-01-01

    Particle Image Velocimetry (PIV) measurements were performed in laboratory-scale experimental fires spreading across horizontal fuel beds composed of aspen (Populus tremuloides Michx) excelsior. The continuous flame, intermittent flame, and thermal plume regions of a fire were investigated. Utilizing a PIV system, instantaneous velocity fields for...

  3. The optimization of aircraft seat cushion fire-blocking layers. Full Scale: Test description and results

    Science.gov (United States)

    Schutter, K. J.; Duskin, F. E.

    1982-01-01

    Full-scale burn tests were conducted on thirteen different seat cushion configurations in a cabin fire simulator. The fire source used was a quartz lamp radiant energy panel with a propane pilot flame. During each test, data were recorded for cushion temperatures, radiant heat flux, rate of weight loss of test specimens, and cabin temperatures. When compared to existing passenger aircraft seat cushions, the test specimens incorporating a fire barrier and those fabricated from advance materials, using improved construction methods, exhibited significantly greater fire resistance.

  4. Catchment-scale Validation of a Physically-based, Post-fire Runoff and Erosion Model

    Science.gov (United States)

    Quinn, D.; Brooks, E. S.; Robichaud, P. R.; Dobre, M.; Brown, R. E.; Wagenbrenner, J.

    2017-12-01

    The cascading consequences of fire-induced ecological changes have profound impacts on both natural and managed forest ecosystems. Forest managers tasked with implementing post-fire mitigation strategies need robust tools to evaluate the effectiveness of their decisions, particularly those affecting hydrological recovery. Various hillslope-scale interfaces of the physically-based Water Erosion Prediction Project (WEPP) model have been successfully validated for this purpose using fire-effected plot experiments, however these interfaces are explicitly designed to simulate single hillslopes. Spatially-distributed, catchment-scale WEPP interfaces have been developed over the past decade, however none have been validated for post-fire simulations, posing a barrier to adoption for forest managers. In this validation study, we compare WEPP simulations with pre- and post-fire hydrological records for three forested catchments (W. Willow, N. Thomas, and S. Thomas) that burned in the 2011 Wallow Fire in Northeastern Arizona, USA. Simulations were conducted using two approaches; the first using automatically created inputs from an online, spatial, post-fire WEPP interface, and the second using manually created inputs which incorporate the spatial variability of fire effects observed in the field. Both approaches were compared to five years of observed post-fire sediment and flow data to assess goodness of fit.

  5. Termites Are Resistant to the Effects of Fire at Multiple Spatial Scales.

    Directory of Open Access Journals (Sweden)

    Sarah C Avitabile

    Full Text Available Termites play an important ecological role in many ecosystems, particularly in nutrient-poor arid and semi-arid environments. We examined the distribution and occurrence of termites in the fire-prone, semi-arid mallee region of south-eastern Australia. In addition to periodic large wildfires, land managers use fire as a tool to achieve both asset protection and ecological outcomes in this region. Twelve taxa of termites were detected by using systematic searches and grids of cellulose baits at 560 sites, clustered in 28 landscapes selected to represent different fire mosaic patterns. There was no evidence of a significant relationship between the occurrence of termite species and time-since-fire at the site scale. Rather, the occurrence of species was related to habitat features such as the density of mallee trees and large logs (>10 cm diameter. Species richness was greater in chenopod mallee vegetation on heavier soils in swales, rather than Triodia mallee vegetation of the sandy dune slopes. At the landscape scale, there was little evidence that the frequency of occurrence of termite species was related to fire, and no evidence that habitat heterogeneity generated by fire influenced termite species richness. The most influential factor at the landscape scale was the environmental gradient represented by average annual rainfall. Although termites may be associated with flammable habitat components (e.g. dead wood, they appear to be buffered from the effects of fire by behavioural traits, including nesting underground, and the continued availability of dead wood after fire. There is no evidence to support the hypothesis that a fine-scale, diverse mosaic of post-fire age-classes will enhance the diversity of termites. Rather, termites appear to be resistant to the effects of fire at multiple spatial scales.

  6. Numerical modeling of water spray suppression of conveyor belt fires in a large-scale tunnel.

    Science.gov (United States)

    Yuan, Liming; Smith, Alex C

    2015-05-01

    Conveyor belt fires in an underground mine pose a serious life threat to miners. Water sprinkler systems are usually used to extinguish underground conveyor belt fires, but because of the complex interaction between conveyor belt fires and mine ventilation airflow, more effective engineering designs are needed for the installation of water sprinkler systems. A computational fluid dynamics (CFD) model was developed to simulate the interaction between the ventilation airflow, the belt flame spread, and the water spray system in a mine entry. The CFD model was calibrated using test results from a large-scale conveyor belt fire suppression experiment. Simulations were conducted using the calibrated CFD model to investigate the effects of sprinkler location, water flow rate, and sprinkler activation temperature on the suppression of conveyor belt fires. The sprinkler location and the activation temperature were found to have a major effect on the suppression of the belt fire, while the water flow rate had a minor effect.

  7. Numerical modeling of water spray suppression of conveyor belt fires in a large-scale tunnel

    Science.gov (United States)

    Yuan, Liming; Smith, Alex C.

    2015-01-01

    Conveyor belt fires in an underground mine pose a serious life threat to miners. Water sprinkler systems are usually used to extinguish underground conveyor belt fires, but because of the complex interaction between conveyor belt fires and mine ventilation airflow, more effective engineering designs are needed for the installation of water sprinkler systems. A computational fluid dynamics (CFD) model was developed to simulate the interaction between the ventilation airflow, the belt flame spread, and the water spray system in a mine entry. The CFD model was calibrated using test results from a large-scale conveyor belt fire suppression experiment. Simulations were conducted using the calibrated CFD model to investigate the effects of sprinkler location, water flow rate, and sprinkler activation temperature on the suppression of conveyor belt fires. The sprinkler location and the activation temperature were found to have a major effect on the suppression of the belt fire, while the water flow rate had a minor effect. PMID:26190905

  8. thermal analysis of a small scale solid waste-fired steam boiler

    African Journals Online (AJOL)

    user

    Thermal analysis of a small scale solid waste-fired steam generator is presented in this paper. The analysis was based on the chosen design specifications which are operating steam ... include: wind, bio-energy, geothermal, solar thermal,.

  9. Co-firing of Coal with Biomass and Waste in Full-scale Suspension-fired Boilers

    DEFF Research Database (Denmark)

    Dam-Johansen, Kim; Jappe Frandsen, Flemming; Jensen, Peter Arendt

    2013-01-01

    and boiler manufacturers to optimize design and operation and minimize cost and environmental impact using alternative fuels in suspension fired boilers. Our contribution has been made via a combination of full-scale measuring campaigns, pilot-scale studies, lab-scale measurements and modeling tools....... The research conducted has addressed many issues important for co-firing, i.e. fuel processing, ash induced boiler deposit formation and corrosion, boiler chamber fuel conversion and emission formation, influence on flue gas cleaning equipment and the utilization of residual products. This paper provides...... research has provided results with implications for operation of milling and burner equipment, appropriate fuel mixing strategies, minimization of ash deposit formation and corrosion, minimization of NO formation, appropriate operation of SCR catalyst equipment and utilization of residual products...

  10. A method for mapping fire hazard and risk across multiple scales and its application in fire management

    Science.gov (United States)

    Robert E. Keane; Stacy A. Drury; Eva C. Karau; Paul F. Hessburg; Keith M. Reynolds

    2010-01-01

    This paper presents modeling methods for mapping fire hazard and fire risk using a research model called FIREHARM (FIRE Hazard and Risk Model) that computes common measures of fire behavior, fire danger, and fire effects to spatially portray fire hazard over space. FIREHARM can compute a measure of risk associated with the distribution of these measures over time using...

  11. Modeling fire susceptibility to delineate wildland-urban interface for municipal-scale fire risk management.

    Science.gov (United States)

    Whitman, Ellen; Rapaport, Eric; Sherren, Kate

    2013-12-01

    The wildland-urban interface (WUI) is the region where development meets and intermingles with wildlands. The WUI has an elevated fire risk due to the proximity of development and residents to wildlands with natural wildfire regimes. Existing methods of delineating WUI are typically applied over a large region, use proxies for risk, and do not consider site-specific fire hazard drivers. While these models are appropriate for federal and provincial risk management, municipal managers require models intended for smaller regions. The model developed here uses the Burn-P3 fire behavior model to model WUI from local fire susceptibility (FS) in two study communities. Forest fuel code (FFC) maps for the study communities were modified using remote sensing data to produce detailed forest edges, including ladder fuels, update data currency, and add buildings and roads. The modified FFC maps used in Burn-P3 produced bimodal FS distributions for each community. The WUI in these communities was delineated as areas within community bounds where FS was greater than or equal to -1 SD from the mean FS value ([Formula: see text]), which fell in the trough of the bimodal distribution. The WUI so delineated conformed to the definition of WUI. This model extends WUI modeling for broader risk management initiatives for municipal management of risk, as it (a) considers site-specific drivers of fire behavior; (b) models risk, represented by WUI, specific to a community; and, (c) does not use proxies for risk.

  12. Contribution of regional-scale fire events to ozone and PM2.5 ...

    Science.gov (United States)

    Two specific fires from 2011 are tracked for local to regional scale contribution to ozone (O3) and fine particulate matter (PM2.5) using a freely available regulatory modeling system that includes the BlueSky wildland fire emissions tool, Spare Matrix Operator Kernel Emissions (SMOKE) model, Weather and Research Forecasting (WRF) meteorological model, and Community Multiscale Air Quality (CMAQ) photochemical grid model. The modeling system was applied to track the contribution from a wildfire (Wallow) and prescribed fire (Flint Hills) using both source sensitivity and source apportionment approaches. The model estimated fire contribution to primary and secondary pollutants are comparable using source sensitivity (brute-force zero out) and source apportionment (Integrated Source Apportionment Method) approaches. Model estimated O3 enhancement relative to CO is similar to values reported in literature indicating the modeling system captures the range of O3 inhibition possible near fires and O3 production both near the fire and downwind. O3 and peroxyacetyl nitrate (PAN) are formed in the fire plume and transported downwind along with highly reactive VOC species such as formaldehyde and acetaldehyde that are both emitted by the fire and rapidly produced in the fire plume by VOC oxidation reactions. PAN and aldehydes contribute to continued downwind O3 production. The transport and thermal decomposition of PAN to nitrogen oxides (NOX) enables O3 production in areas

  13. Length of a Hanging Cable

    Directory of Open Access Journals (Sweden)

    Eric Costello

    2011-01-01

    Full Text Available The shape of a cable hanging under its own weight and uniform horizontal tension between two power poles is a catenary. The catenary is a curve which has an equation defined by a hyperbolic cosine function and a scaling factor. The scaling factor for power cables hanging under their own weight is equal to the horizontal tension on the cable divided by the weight of the cable. Both of these values are unknown for this problem. Newton's method was used to approximate the scaling factor and the arc length function to determine the length of the cable. A script was written using the Python programming language in order to quickly perform several iterations of Newton's method to get a good approximation for the scaling factor.

  14. Exposure doses received from a large scale fire in the restricted area

    International Nuclear Information System (INIS)

    Kawakami, Hiroto; Yamada, Norikazu; Shimomura, Masanori; Ichiki, Takahiko; Kajimoto, Mitsuhiro; Kasahara, Fumio; Tanemura, Munenori; Tsuchino, Susumu; Okubo, Atsushi

    2012-02-01

    At the request of the Local Nuclear Emergency Response Headquarters established in Fukushima Prefecture, Japan Nuclear Energy Safety Organization (JNES) has estimated exposure doses of a fireman and the public during a large scale fire in the restricted area. Data on the contamination of the area were compiled and contaminants deposited on combustible materials in forests were investigated. Estimated doses during a fire vary widely due to the uncertainties and variations in assessment methods, location of the fire (radioactivity in the area, amounts of combustible substance and so on), the scale of the fire (the area of fire spreading), weather conditions (wind direction, wind speed, turbulence type and so on), and the distances of the fireman and the public from the fire. In this reports, effects of these factors were integrated as fire-effect indexes. One can easily obtain exposure doses by multiplying these indexes to the results in each of the assessing conditions. In the severer conditions such as 20 hs of fire spreading area, a contaminant concentration of 6 MBq/m"2 in the area, external dose of a fireman working in the highest air contaminated zone in the vicinity of the fire for 1 hour is estimated to be 50 μSv. If he does not wear a front mask, the internal committed dose is estimated to be 430 μSv. Sum of these doses can rise up to 480 μSv. External and internal doses of the public at the severest location in the distance of 2 km from the fire for 1 hour is estimated to be 5 μSv and 45 μSv respectively, and the sum of these doses is 50 μSv. In the stable conditions where a plume of fire can reach to a longer distance without dispersion, external and internal doses of the public at the 20 km distance from the fire for 1 hour are estimated to be 0.5 μSv and 4.5 μSv respectively, and the sum of them is less than 5 μSv. Though the total exposure dose will not exceed 1 mSv even if the fire lingers for some days, monitoring of radiation is important in

  15. Perspective methods of fire and explosion protection of 'Ukrytie' object

    International Nuclear Information System (INIS)

    Zakhmatov, V.D.; Potikha, V.M.; Shkarabura, N.G.

    1999-01-01

    There are 5 atomic power stations in Ukraine-Chernobyl, Zaporozhe, Rivne, Khmelnytsk, Yuzhnoukrainsk. Fire statistics on them: 1993 - 5 fires, 1994 - 2, 1995 - 2, 1996 - 3, 1997-98 no fires. The most valuable unique experience, accumulated in Ukraine, -is extinguishing of different fires, arising in the radioactive zone. There were the following kinds of fires: burning roof of the 4-th bloc; forest fires; fires in cable tunnels; spilled oil in wrecked constructions and buildings. Professional impulse fire-extinguisher is one of the most perspective developments. These fire-extinguishers have high power, range and scale of action. They are universal: able to solve different tasks in extinguishing, to decontaminate, for group and individual light and heat protection, for preventing explosions of dust and gas of up to 50 m 3 volume and in the open space

  16. Cables for nuclear power generating stations, (6)

    International Nuclear Information System (INIS)

    Kakuta, Tsunemi; Asakawa, Naoki; Yamamoto, Tomotaka; Watanabe, Mikio; Shingo, Yoshioki.

    1981-01-01

    New inorganic material insulated flexible triaxial cables have been developed for the purpose of applying around the primary circuit of fast breeder reactor (FBR). These cables were tested at high temperature and high #betta#-ray radiation environment, and they showed good electrical properties. Other noted results were that they showed good fire proof and flame resistant properties. (author)

  17. OTEC riser cable model and prototype testing

    Science.gov (United States)

    Kurt, J. P.; Schultz, J. A.; Roblee, L. H. S.

    1981-12-01

    Two different OTEC riser cables have been developed to span the distance between a floating OTEC power plant and the ocean floor. The major design concerns for a riser cable in the dynamic OTEC environment are fatigue, corrosion, and electrical/mechanical aging of the cable components. The basic properties of the cable materials were studied through tests on model cables and on samples of cable materials. Full-scale prototype cables were manufactured and were tested to measure their electrical and mechanical properties and performance. The full-scale testing was culminated by the electrical/mechanical fatigue test, which exposes full-scale cables to simultaneous tension, bending and electrical loads, all in a natural seawater environment.

  18. Large-Scale Spacecraft Fire Safety Experiments in ISS Resupply Vehicles

    Science.gov (United States)

    Ruff, Gary A.; Urban, David

    2013-01-01

    Our understanding of the fire safety risk in manned spacecraft has been limited by the small scale of the testing we have been able to conduct in low-gravity. Fire growth and spread cannot be expected to scale linearly with sample size so we cannot make accurate predictions of the behavior of realistic scale fires in spacecraft based on the limited low-g testing to date. As a result, spacecraft fire safety protocols are necessarily very conservative and costly. Future crewed missions are expected to be longer in duration than previous exploration missions outside of low-earth orbit and accordingly, more complex in terms of operations, logistics, and safety. This will increase the challenge of ensuring a fire-safe environment for the crew throughout the mission. Based on our fundamental uncertainty of the behavior of fires in low-gravity, the need for realistic scale testing at reduced gravity has been demonstrated. To address this concern, a spacecraft fire safety research project is underway to reduce the uncertainty and risk in the design of spacecraft fire safety systems by testing at nearly full scale in low-gravity. This project is supported by the NASA Advanced Exploration Systems Program Office in the Human Exploration and Operations Mission Directorate. The activity of this project is supported by an international topical team of fire experts from other space agencies to maximize the utility of the data and to ensure the widest possible scrutiny of the concept. The large-scale space flight experiment will be conducted on three missions; each in an Orbital Sciences Corporation Cygnus vehicle after it has deberthed from the ISS. Although the experiment will need to meet rigorous safety requirements to ensure the carrier vehicle does not sustain damage, the absence of a crew allows the fire products to be released into the cabin. The tests will be fully automated with the data downlinked at the conclusion of the test before the Cygnus vehicle reenters the

  19. Large scale network management. Condition indicators for network stations, high voltage power conductions and cables

    International Nuclear Information System (INIS)

    Eggen, Arnt Ove; Rolfseng, Lars; Langdal, Bjoern Inge

    2006-02-01

    In the Strategic Institute Programme (SIP) 'Electricity Business enters e-business (eBee)' SINTEF Energy research has developed competency that can help the energy business employ ICT systems and computer technology in an improved way. Large scale network management is now a reality, and it is characterized by large entities with increasing demands on efficiency and quality. These are goals that can only be reached by using ICT systems and computer technology in a more clever way than what is the case today. At the same time it is important that knowledge held by experienced co-workers is consulted when formal rules for evaluations and decisions in ICT systems are developed. In this project an analytical concept for evaluation of networks based information in different ICT systems has been developed. The method estimating the indicators to describe different conditions in a network is general, and indicators can be made to fit different levels of decision and network levels, for example network station, transformer circuit, distribution network and regional network. Moreover, the indicators can contain information about technical aspects, economy and HSE. An indicator consists of an indicator name, an indicator value, and an indicator colour based on a traffic-light analogy to indicate a condition or a quality for the indicator. Values on one or more indicators give an impression of important conditions in the network, and make up the basis for knowing where more detailed evaluations have to be conducted before a final decision on for example maintenance or renewal is made. A prototype has been developed for testing the new method. The prototype has been developed in Excel, and especially designed for analysing transformer circuits in a distribution network. However, the method is a general one, and well suited for implementation in a commercial computer system (ml)

  20. Chapter 4. Predicting post-fire erosion and sedimentation risk on a landscape scale

    Science.gov (United States)

    MacDonald, L.H.; Sampson, R.; Brady, D.; Juarros, L.; Martin, Deborah

    2000-01-01

    Historic fire suppression efforts have increased the likelihood of large wildfires in much of the western U.S. Post-fire soil erosion and sedimentation risks are important concerns to resource managers. In this paper we develop and apply procedures to predict post-fire erosion and sedimentation risks on a pixel-, catchment-, and landscape-scale in central and western Colorado.Our model for predicting post-fire surface erosion risk is conceptually similar to the Revised Universal Soil Loss Equation (RUSLE). One key addition is the incorporation of a hydrophobicity risk index (HY-RISK) based on vegetation type, predicted fire severity, and soil texture. Post-fire surface erosion risk was assessed for each 90-m pixel by combining HYRISK, slope, soil erodibility, and a factor representing the likely increase in soil wetness due to removal of the vegetation. Sedimentation risk was a simple function of stream gradient. Composite surface erosion and sedimentation risk indices were calculated and compared across the 72 catchments in the study area.When evaluated on a catchment scale, two-thirds of the catchments had relatively little post-fire erosion risk. Steeper catchments with higher fuel loadings typically had the highest post-fire surface erosion risk. These were generally located along the major north-south mountain chains and, to a lesser extent, in west-central Colorado. Sedimentation risks were usually highest in the eastern part of the study area where a higher proportion of streams had lower gradients. While data to validate the predicted erosion and sedimentation risks are lacking, the results appear reasonable and are consistent with our limited field observations. The models and analytic procedures can be readily adapted to other locations and should provide useful tools for planning and management at both the catchment and landscape scale.

  1. Optical Measurement of Cable and String Vibration

    Directory of Open Access Journals (Sweden)

    Y. Achkire

    1998-01-01

    Full Text Available This paper describes a non contacting measurement technique for the transverse vibration of small cables and strings using an analog position sensing detector. On the one hand, the sensor is used to monitor the cable vibrations of a small scale mock-up of a cable structure in order to validate the nonlinear cable dynamics model. On the other hand, the optical sensor is used to evaluate the performance of an active tendon control algorithm with guaranteed stability properties. It is demonstrated experimentally, that a force feedback control law based on a collocated force sensor measuring the tension in the cable is feasible and provides active damping in the cable.

  2. Co-firing of coal with biomass and waste in full-scale suspension-fired boilers

    Energy Technology Data Exchange (ETDEWEB)

    Dam-Johansen, Kim; Frandsen, Flemming J.; Jensen, Peter A.; Jensen, Anker D. [Technical Univ. of Denmark, Lyngby (Denmark). Dept. of chemical and Biochemical Engineering

    2013-07-01

    The energy policy in Denmark has for many years focused on lowering the net CO{sub 2} emission from heat and power production by replacing fossil fuels by renewable resources. This has been done by developing dedicated grate-fired boilers for biomass and waste fuels but also by developing coal-based suspension-fired boilers to accept still higher fractions of biomass or waste material as fuels. This last development has been challenging of many reasons, including pre-treatment of fuels, and solving potential emission and operational problems during the simultaneous development of supercritical steam cycles with steam temperatures close to 600 C, providing power efficiencies close to 50% (Hein KRG, Sustainable energy supply and environment protection - strategies, resources and technologies. In: Gupta R, Wall T, Hupa M, Wigley F, Tillman D, Frandsen FJ (eds) Proceedings of international conference on impact of fuel quality on power production and the environment, Banff Conference Centre, Banff, Alberta, Canada, 29 Sept-4 Oct, 2008). For 25 years the CHEC (Combustion and Harmful Emission Control) Research Centre at DTU Chemical Engineering, has attained a leading role in research, supporting power producing industry, plant owners and boiler manufacturers to optimize design and operation and minimize cost and environmental impact using alternative fuels in suspension fired boilers. Our contribution has been made via a combination of full-scale measuring campaigns, pilot-scale studies, lab-scale measurements and modeling tools. The research conducted has addressed many issues important for co-firing, i.e. fuel processing, ash induced boiler deposit formation and corrosion, boiler chamber fuel conversion and emission formation, influence on flue gas cleaning equipment and the utilization of residual products. This chapter provides an overview of research activities, aiming at increasing biomass shares during co-firing in suspension, conducted in close collaboration with

  3. Cable handling

    International Nuclear Information System (INIS)

    1980-01-01

    In computerized axial tomography scanning, problems arise in exchanging electrical signals between fixed and rotating assemblies. A novel method of overcoming this problem is described in detail for both signal and high voltage cables. Apparatus using a sequence of drums and pulleys is used to maintain the interconnecting cables in a neat arrangement and free from mechanical strain. The apparatus is simple and relatively easy and inexpensive to assemble and maintain. (UK)

  4. Detecting Local Drivers of Fire Cycle Heterogeneity in Boreal Forests: A Scale Issue

    Directory of Open Access Journals (Sweden)

    Annie Claude Bélisle

    2016-07-01

    Full Text Available Severe crown fires are determining disturbances for the composition and structure of boreal forests in North America. Fire cycle (FC associations with continental climate gradients are well known, but smaller scale controls remain poorly documented. Using a time since fire map (time scale of 300 years, the study aims to assess the relative contributions of local and regional controls on FC and to describe the relationship between FC heterogeneity and vegetation patterns. The study area, located in boreal eastern North America, was partitioned into watersheds according to five scales going from local (3 km2 to landscape (2800 km2 scales. Using survival analysis, we observed that dry surficial deposits and hydrography density better predict FC when measured at the local scale, while terrain complexity and slope position perform better when measured at the middle and landscape scales. The most parsimonious model was selected according to the Akaike information criterion to predict FC throughout the study area. We detected two FC zones, one short (159 years and one long (303 years, with specific age structures and tree compositions. We argue that the local heterogeneity of the fire regime contributes to ecosystem diversity and must be considered in ecosystem management.

  5. The effect of urban growth on landscape-scale restoration for a fire-dependent songbird

    Science.gov (United States)

    Pickens, Bradley A.; Marcus, Jeffrey F.; Carpenter, John P.; Anderson, Scott; Taillie, Paul J.; Collazo, Jaime A.

    2017-01-01

    A landscape-scale perspective on restoration ecology has been advocated, but few studies have informed restoration with landscape metrics or addressed broad-scale threats. Threats such as urban growth may affect restoration effectiveness in a landscape context. Here, we studied longleaf pine savanna in the rapidly urbanizing southeastern United States where a habitat-specialist bird, Bachman's sparrow (Peucaea aestivalis), is closely associated with savanna vegetation structure and frequent fire. Our objectives were to construct a species distribution model for Bachman's sparrow, determine the relationship between fire and urbanization, quantify the urban growth effect (2010–2090), identify potential restoration areas, and determine the interaction between restoration potential and urban growth by 2050. Number of patches, patch size, and isolation metrics were used to evaluate scenarios. The species distribution model was 88% accurate and emphasized multiscale canopy cover characteristics, fire, and percent habitat. Fires were less common urban areas, and this fire suppression effect exacerbated urban growth effects. For restoration scenarios, canopy cover reduction by 30% resulted in nearly double the amount of habitat compared to the prescribed fire scenario; canopy cover reduction resulted in larger patch sizes and less patch isolation compared to current conditions. The effect of urban growth on restoration scenarios was unequal. Seventy-four percent of restoration areas from the prescribed fire scenario overlapped with projected urban growth, whereas the canopy cover reduction scenario only overlapped by 9%. We emphasize the benefits of simultaneously considering the effects of urban growth and landscape-scale restoration potential to promote a landscape with greater patch sizes and less isolation.

  6. Restoration of a Mediterranean forest after a fire: bioremediation and rhizoremediation field-scale trial.

    Science.gov (United States)

    Pizarro-Tobías, Paloma; Fernández, Matilde; Niqui, José Luis; Solano, Jennifer; Duque, Estrella; Ramos, Juan-Luis; Roca, Amalia

    2015-01-01

    Forest fires pose a serious threat to countries in the Mediterranean basin, often razing large areas of land each year. After fires, soils are more likely to erode and resilience is inhibited in part by the toxic aromatic hydrocarbons produced during the combustion of cellulose and lignins. In this study, we explored the use of bioremediation and rhizoremediation techniques for soil restoration in a field-scale trial in a protected Mediterranean ecosystem after a controlled fire. Our bioremediation strategy combined the use of Pseudomonas putida strains, indigenous culturable microbes and annual grasses. After 8 months of monitoring soil quality parameters, including the removal of monoaromatic and polycyclic aromatic hydrocarbons as well as vegetation cover, we found that the site had returned to pre-fire status. Microbial population analysis revealed that fires induced changes in the indigenous microbiota and that rhizoremediation favours the recovery of soil microbiota in time. The results obtained in this study indicate that the rhizoremediation strategy could be presented as a viable and cost-effective alternative for the treatment of ecosystems affected by fires. © 2014 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  7. Landscape-scale patterns of fire and drought on the high plains, USA

    Science.gov (United States)

    Paulette Ford; Charles Jackson; Matthew Reeves; Benjamin Bird; Dave Turner

    2015-01-01

    We examine 31 years (1982-2012) of temperature, precipitation and natural wildfire occurrence data for Federal and Tribal lands to determine landscape-scale patterns of drought and fire on the southern and central High Plains of the western United States. The High Plains states of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas and...

  8. The Influence of Large-Scale Circulation on Fire Outbreaks in the Amazon Region

    Science.gov (United States)

    Pires, L. B. M.; Romao, M.; Freitas, A. C. V.

    2017-12-01

    The combination of alterations in land use cover and severe droughts may dramatically increase fire outbreaks. Tropical convection in the Amazon Basin is regulated mainly by large-scale atmospheric systems such as the Walker circulation. Many of the documented drought episodes in the Amazon occurred during intense El Niño events such as those recorded in 1926, 1983, 1997-1998, and 2010. However, not all El Niño events are related to drought in the Amazon. Recent studies have also pointed out the importance of the tropical Atlantic Ocean in the modulation of the Amazonian climate, as observed during the drought episodes in 2005 and 2010. This work investigates the fire outbreak tendency in the Amazon region, and the influence of large-scale circulation on these events. Data from the Fire Program of the Center for Weather Forecasting and Climate Studies (CPTEC/INPE) show a substantial increase in the number of fire outbreaks in the last few years, especially during 2016. However, in the 2017 year a sharp drop in fire outbreaks reaching levels similar to the years prior to 2016 is being noted, already showing a reduction of 54% in relation to the preceding 2016 year. The 2015-2016 period was marked by one of the strongest El Niño in history. This was reflected in the increase of the number of fire outbreaks due to the increase of the drought and temperature elevation period. On the other hand, the 2017 year is being characterized by a condition of neutrality in relation to the El Niño-Southern Oscillation (ENSO) phenomena, and have overall presented positive sea surface temperature (SST) anomalies in the tropical Atlantic. Variations of these systems and their relation to fire outbreaks is demonstrated.

  9. Measuring wildland fire leadership: the crewmember perceived leadership scale

    Science.gov (United States)

    Alexis L. Waldron; David P. Schary; Bradley J. Cardinal

    2015-01-01

    The aims of this research were to develop and test a scale used to measure leadership in wildland firefighting using two samples of USA wildland firefighters. The first collection of data occurred in the spring and early summer and consisted of an online survey. The second set of data was collected towards late summer and early fall (autumn). The second set of...

  10. Landscape-scale effects of fire severity on mixed-conifer and red fir forest structure in Yosemite National Park

    Science.gov (United States)

    Kane, Van R.; Lutz, James A.; Roberts, Susan L.; Smith, Douglas F.; McGaughey, Robert J.; Povak, Nicholas A.; Brooks, Matthew L.

    2013-01-01

    While fire shapes the structure of forests and acts as a keystone process, the details of how fire modifies forest structure have been difficult to evaluate because of the complexity of interactions between fires and forests. We studied this relationship across 69.2 km2 of Yosemite National Park, USA, that was subject to 32 fires ⩾40 ha between 1984 and 2010. Forests types included ponderosa pine (Pinus ponderosa), white fir-sugar pine (Abies concolor/Pinus lambertiana), and red fir (Abies magnifica). We estimated and stratified burned area by fire severity using the Landsat-derived Relativized differenced Normalized Burn Ratio (RdNBR). Airborne LiDAR data, acquired in July 2010, measured the vertical and horizontal structure of canopy material and landscape patterning of canopy patches and gaps. Increasing fire severity changed structure at the scale of fire severity patches, the arrangement of canopy patches and gaps within fire severity patches, and vertically within tree clumps. Each forest type showed an individual trajectory of structural change with increasing fire severity. As a result, the relationship between estimates of fire severity such as RdNBR and actual changes appears to vary among forest types. We found three arrangements of canopy patches and gaps associated with different fire severities: canopy-gap arrangements in which gaps were enclosed in otherwise continuous canopy (typically unburned and low fire severities); patch-gap arrangements in which tree clumps and gaps alternated and neither dominated (typically moderate fire severity); and open-patch arrangements in which trees were scattered across open areas (typically high fire severity). Compared to stands outside fire perimeters, increasing fire severity generally resulted first in loss of canopy cover in lower height strata and increased number and size of gaps, then in loss of canopy cover in higher height strata, and eventually the transition to open areas with few or no trees. However

  11. Intermediate-scale Fire Performance of Composite Panels under Varying Loads

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Alexander [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jernigan, Dann A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Dodd, Amanda B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-04-01

    New aircraft are being designed with increasing quantities of composite materials used in their construction. Different from the more traditional metals, composites have a higher propensity to burn. This presents a challenge to transportation safety analyses, as the aircraft structure now represents an additional fuel source involved in the fire scenario. Most of the historical fire testing of composite materials is aime d at studying kinetics, flammability or yield strength under fire conditions. Most of this testing is small - scale. Heterogeneous reactions are often length - scale dependent, and this is thought to be particularly true for composites which exhibit signific ant microscopic dynamics that can affect macro - scale behavior. We have designed a series of tests to evaluate composite materials under various structural loading conditions with a consistent thermal condition. We have measured mass - loss , heat flux, and temperature throughout the experiments. Several types of panels have been tested, including simple composite panels, and sandwich panels. The main objective of the testing was to understand the importance of the structural loading on a composite to its b ehavior in response to fire - like conditions. During flaming combustion at early times, there are some features of the panel decomposition that are unique to the type of loading imposed on the panels. At load levels tested, fiber reaction rates at later t imes appear to be independent of the initial structural loading.

  12. Cable Stability

    Energy Technology Data Exchange (ETDEWEB)

    Bottura, L [European Organization for Nuclear Research, Geneva (Switzerland)

    2014-07-01

    Superconductor stability is at the core of the design of any successful cable and magnet application. This chapter reviews the initial understanding of the stability mechanism, and reviews matters of importance for stability such as the nature and magnitude of the perturbation spectrum and the cooling mechanisms. Various stability strategies are studied, providing criteria that depend on the desired design and operating conditions.

  13. Some relevant parameters for assessing fire hazards of combustible mine materials using laboratory scale experiments.

    Science.gov (United States)

    Litton, Charles D; Perera, Inoka E; Harteis, Samuel P; Teacoach, Kara A; DeRosa, Maria I; Thomas, Richard A; Smith, Alex C

    2018-04-15

    When combustible materials ignite and burn, the potential for fire growth and flame spread represents an obvious hazard, but during these processes of ignition and flaming, other life hazards present themselves and should be included to ensure an effective overall analysis of the relevant fire hazards. In particular, the gases and smoke produced both during the smoldering stages of fires leading to ignition and during the advanced flaming stages of a developing fire serve to contaminate the surrounding atmosphere, potentially producing elevated levels of toxicity and high levels of smoke obscuration that render the environment untenable. In underground mines, these hazards may be exacerbated by the existing forced ventilation that can carry the gases and smoke to locations far-removed from the fire location. Clearly, materials that require high temperatures (above 1400 K) and that exhibit low mass loss during thermal decomposition, or that require high heat fluxes or heat transfer rates to ignite represent less of a hazard than materials that decompose at low temperatures or ignite at low levels of heat flux. In order to define and quantify some possible parameters that can be used to assess these hazards, small-scale laboratory experiments were conducted in a number of configurations to measure: 1) the toxic gases and smoke produced both during non-flaming and flaming combustion; 2) mass loss rates as a function of temperature to determine ease of thermal decomposition; and 3) mass loss rates and times to ignition as a function of incident heat flux. This paper describes the experiments that were conducted, their results, and the development of a set of parameters that could possibly be used to assess the overall fire hazard of combustible materials using small scale laboratory experiments.

  14. Understanding of bridge cable vibrations and the associate flow-field through the full-scale monitoring of vibrations and Wind

    DEFF Research Database (Denmark)

    Acampora, Antonio

    This dissertation investigates the conditions that promote rain-wind-induced vibrations of inclined cable on cable-stayed bridges. Rain-wind-induced vibrations are known as the most common type of cable vibrations and capable of severe vibrations. The recent increase in the number of cable stayed...... bridges continuously becoming longer and lighter have resulted in a high number of observations of cable vibrations. A theoretical background for the tool used in this work is presented in terms of cables vibrations mechanisms, aerodynamic damping and system identification techniques. A detailed...... literature review of reported observations of rain-wind-induced cable vibrations of fullscale bridges is shown. The database of observed events on bridges collects information about the conditions that likely develop the phenomenon, together with the means used to suppress or reduce the occurrence of cable...

  15. Measurement of inter- and intra-annual variability of landscape fire activity at a continental scale: The Australian case

    Science.gov (United States)

    Grant J. Williamson; Lynda D. Prior; Matt Jolly; Mark A. Cochrane; Brett P. Murphy; David M. J. S. Bowman

    2016-01-01

    Climate dynamics at diurnal, seasonal and inter-annual scales shape global fire activity, although difficulties of assembling reliable fire and meteorological data with sufficient spatio-temporal resolution have frustrated quantification of this variability. Using Australia as a case study, we combine data from 4760 meteorological stations with 12 years of satellite-...

  16. Experimental study on the influence of different thermal insulation materials on the fire dynamics in a reduced-scale enclosure

    DEFF Research Database (Denmark)

    Leisted, Rolff Ripke; Sørensen, Martin X.; Jomaas, Grunde

    2017-01-01

    Four scaled (1:5) fire experiments with two identically classified types of commercially available sandwich panels incorporating either stone wool (SW) or poly-isocyanurate (PIR) foam as cores were conducted using a modified version of the ISO 13784-1 (Reaction to fire tests for sandwich panel...

  17. Implications of the Baltimore Rail Tunnel Fire for Full-Scale Testing of Shipping Casks

    International Nuclear Information System (INIS)

    Halstead, R. J.; Dilger, F.

    2003-01-01

    The U.S. Nuclear Regulatory Commission (NRC) does not currently require full-scale physical testing of shipping casks as part of its certification process. Stakeholders have long urged NRC to require full-scale testing as part of certification. NRC is currently preparing a full-scale casktesting proposal as part of the Package Performance Study (PPS) that grew out of the NRC reexamination of the Modal Study. The State of Nevada and Clark County remain committed to the position that demonstration testing would not be an acceptable substitute for a combination of full-scale testing, scale-model tests, and computer simulation of each new cask design prior to certification. Based on previous analyses of cask testing issues, and on preliminary findings regarding the July 2001 Baltimore rail tunnel fire, the authors recommend that NRC prioritize extra-regulatory thermal testing of a large rail cask and the GA-4 truck cask under the PPS. The specific fire conditions and other aspects of the full-scale extra-regulatory tests recommended for the PPS are yet to be determined. NRC, in consultation with stakeholders, must consider past real-world accidents and computer simulations to establish temperature failure thresholds for cask containment and fuel cladding. The cost of extra-regulatory thermal testing is yet to be determined. The minimum cost for regulatory thermal testing of a legal-weight truck cask would likely be $3.3-3.8 million

  18. Simulating smoke transport from wildland fires with a regional-scale air quality model: sensitivity to spatiotemporal allocation of fire emissions.

    Science.gov (United States)

    Garcia-Menendez, Fernando; Hu, Yongtao; Odman, Mehmet T

    2014-09-15

    Air quality forecasts generated with chemical transport models can provide valuable information about the potential impacts of fires on pollutant levels. However, significant uncertainties are associated with fire-related emission estimates as well as their distribution on gridded modeling domains. In this study, we explore the sensitivity of fine particulate matter concentrations predicted by a regional-scale air quality model to the spatial and temporal allocation of fire emissions. The assessment was completed by simulating a fire-related smoke episode in which air quality throughout the Atlanta metropolitan area was affected on February 28, 2007. Sensitivity analyses were carried out to evaluate the significance of emission distribution among the model's vertical layers, along the horizontal plane, and into hourly inputs. Predicted PM2.5 concentrations were highly sensitive to emission injection altitude relative to planetary boundary layer height. Simulations were also responsive to the horizontal allocation of fire emissions and their distribution into single or multiple grid cells. Additionally, modeled concentrations were greatly sensitive to the temporal distribution of fire-related emissions. The analyses demonstrate that, in addition to adequate estimates of emitted mass, successfully modeling the impacts of fires on air quality depends on an accurate spatiotemporal allocation of emissions. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Power plant cable condition monitoring and testing at Georgia Power

    International Nuclear Information System (INIS)

    Champion, T.C.

    1988-01-01

    Georgia Power's Research Center has been heavily involved in the evaluation of electrical insulating materials and cables since its inception more than 17 years ago. For the past ten years that expertise has been applied to cables used in generation plants. This paper discusses the results of two test programs. The first is a quality control inspection on 169 samples of new power generation cables. The second is a material degradation evaluation on four short cable samples removed from a coal fired plant during an equipment upgrade. The new material evaluation was performed to identify the cause of a high failure rate upon initial hi-pot testing of newly installed cables. The material degradation evaluation was performed to evaluate the need for replacement of existing cables during an equipment upgrade. Results of the evaluations have led to development of a detailed proposal for a program to evaluate cable degradation and remaining life for cables used in power generation facilities

  20. Static and dynamic controls on fire activity at moderate spatial and temporal scales in the Alaskan boreal forest

    Science.gov (United States)

    Barrett, Kirsten; Loboda, Tatiana; McGuire, A. David; Genet, Hélène; Hoy, Elizabeth; Kasischke, Eric

    2016-01-01

    Wildfire, a dominant disturbance in boreal forests, is highly variable in occurrence and behavior at multiple spatiotemporal scales. New data sets provide more detailed spatial and temporal observations of active fires and the post-burn environment in Alaska. In this study, we employ some of these new data to analyze variations in fire activity by developing three explanatory models to examine the occurrence of (1) seasonal periods of elevated fire activity using the number of MODIS active fire detections data set (MCD14DL) within an 11-day moving window, (2) unburned patches within a burned area using the Monitoring Trends in Burn Severity fire severity product, and (3) short-to-moderate interval (fires using areas of burned area overlap in the Alaska Large Fire Database. Explanatory variables for these three models included dynamic variables that can change over the course of the fire season, such as weather and burn date, as well as static variables that remain constant over a fire season, such as topography, drainage, vegetation cover, and fire history. We found that seasonal periods of high fire activity are associated with both seasonal timing and aggregated weather conditions, as well as the landscape composition of areas that are burning. Important static inputs to the model of seasonal fire activity indicate that when fire weather conditions are suitable, areas that typically resist fire (e.g., deciduous stands) may become more vulnerable to burning and therefore less effective as fire breaks. The occurrence of short-to-moderate interval fires appears to be primarily driven by weather conditions, as these were the only relevant explanatory variables in the model. The unique importance of weather in explaining short-to-moderate interval fires implies that fire return intervals (FRIs) will be sensitive to projected climate changes in the region. Unburned patches occur most often in younger stands, which may be related to a greater deciduous fraction of

  1. Development of radiation resistant PEEK insulation cable

    International Nuclear Information System (INIS)

    Mio, Keigo; Ogiwara, Norio; Hikichi, Yusuke; Furukori, Hisayoshi; Arai, Hideyuki; Nishizawa, Daiji; Nishidono, Toshiro

    2009-04-01

    Material characterization and development has been carried out for cable insulation suitable for use in the J-PARC 3-GeV RCS radiation environment. In spite of its high cost, PEEK (polyether-ether-ketone) has emerged as the leading candidate satisfying requirements of being non-halogen based, highly incombustible and with radiation resistant at least 10 MGy, along with the usual mechanical characteristics such as good elongation at break, which are needed in a cable insulation. Gamma-ray irradiation tests have been done in order to study radiation resistance of PEEK cable. Further, mechanical, electrical and fire retardant characteristics of a complete cable such as would be used at the J-PARC RCS were investigated. As a result, PEEK cables were shown to be not degraded by radiation up to at least 10 MGy, and thus could be expected to operate stably under the 3-GeV RCS radiation environment. (author)

  2. Quantifying differences between computational results and measurements in the case of a large-scale well-confined fire scenario

    International Nuclear Information System (INIS)

    Audouin, L.; Chandra, L.; Consalvi, J.-L.; Gay, L.; Gorza, E.; Hohm, V.; Hostikka, S.; Ito, T.; Klein-Hessling, W.; Lallemand, C.; Magnusson, T.; Noterman, N.; Park, J.S.; Peco, J.; Rigollet, L.; Suard, S.; Van-Hees, P.

    2011-01-01

    Research Highlights: → We performed a numerical benchmark in the framework of an OECD experimental program of a pool fire in a well-confined compartment. → The benchmark involves 17 participants using 8 fire models, 3 CFD and 5 zone models. → We investigated the capabilities of validation metrics for a real large-scale fire. → Six quantities were compared during the whole fire duration. → It is important to consider more than one metric for the validation process. - Abstract: The objective of this work was to quantify comparisons between several computational results and measurements performed during a pool fire scenario in a well-confined compartment. This collaborative work was initiated under the framework of the OECD fire research program and involves the most frequently used fire models in the fire community, including field and zone models. The experimental scenario was conducted at the French Institut de Radioprotection et de Surete Nucleaire (IRSN) and deals with a full-scale liquid pool fire in a confined and mechanically ventilated compartment representative for nuclear plants. The practical use of different metric operators and their ability to report the capabilities of fire models are presented. The quantitative comparisons between measurements and numerical results obtained from 'open' calculations concern six important quantities from a safety viewpoint: gas temperature, oxygen concentration, wall temperature, total heat flux, compartment pressure and ventilation flow rate during the whole fire duration. The results indicate that it is important to use more than one metric for the validation process in order to get information on the uncertainties associated with different aspects of fire safety.

  3. Improvement of a high current DC power supply system for testing the large scaled superconducting cables and magnets

    International Nuclear Information System (INIS)

    Yamada, Shuichi; Chikaraishi, Hirotaka; Tanahashi, Shugo

    1993-11-01

    A dc 75 kA power supply system was constructed to test the superconducting (SC) R and D cables and magnets for the Large Helical Device. It consists of three 25 kA unit banks. A unit bank has two double-star-rectifier connections with the inter-phase reactors. A digital feedback control method is applied to the automatic current regulation (ACR) in each unit bank. For shortening the dead time of the feedback process, a new algorithm of a digital phase controller for the ACR is investigated. A Bode diagram of the feedback process is directly measured. It is confirmed that the dead time of the feedback process is reduced to one sixth, and that the feedback gain of PID compensation is improved by a factor of two from the original method. (author)

  4. Post-fire hydrologic response in Central Portugal. A four years study at microplot scale.

    Science.gov (United States)

    Vieira, Diana; Malvar, Maruxa; Martins, Martinho; Machado, Ana; Nunes, João; Keizer, Jacob

    2014-05-01

    Wildfires are a natural phenomenon in regions with a Mediterranean-type climate. However, their present-day widespread occurrence in southern Europe is unprecedented and strongly reflects human activity such as ignition, land-use changes, land abandonment and introduction of highly flammable plantations. Besides wildfires, post-fire management practices such as plowing, terracing, clearcutting and logging should also be considered, since their occurrence is getting increasingly common. And, in a long-term period these practices seem to be executed intercalated with repeated fire occurrences in the same site, sharing the impacts together with fire in an escalated degradational effect. In this sense, the work presented here concerns four years of runoff and erosion data at microplot scale after the wildfire, comparing different land management practices that occurred before the fire. Preliminary results indicate that in four years of monitoring, runoff is constantly higher in plowed sites than in the unplowed ones, with the exception of the first year. Regarding soil losses the plowed plots present always higher sediment rates than the unplowed ones. The comparison between two unplowed sites with different land uses, indicate higher runoff and erosion risk for pine comparatively to the eucalypt ones, however the reduced soil depth in the first can have an important role in these differences. Following these facts, the aim of the present work is to answer the following research questions: i) Do these four years of observations fit with the window of disturbance model presented by Prosser and Williams (1998). or the alternative version by Wittenberg and Inbar (2009)?; ii) Does pre-fire disturbances (wildfire, land use changes and land management practices) still have repercussions after wildfire?; In what sense does four years of intensive monitoring provides that one year couldn't provide?

  5. Decadal time-scale monitoring of forest fires in Similipal Biosphere Reserve, India using remote sensing and GIS.

    Science.gov (United States)

    Saranya, K R L; Reddy, C Sudhakar; Rao, P V V Prasada; Jha, C S

    2014-05-01

    Analyzing the spatial extent and distribution of forest fires is essential for sustainable forest resource management. There is no comprehensive data existing on forest fires on a regular basis in Biosphere Reserves of India. The present work have been carried out to locate and estimate the spatial extent of forest burnt areas using Resourcesat-1 data and fire frequency covering decadal fire events (2004-2013) in Similipal Biosphere Reserve. The anomalous quantity of forest burnt area was recorded during 2009 as 1,014.7 km(2). There was inconsistency in the fire susceptibility across the different vegetation types. The spatial analysis of burnt area shows that an area of 34.2 % of dry deciduous forests, followed by tree savannah, shrub savannah, and grasslands affected by fires in 2013. The analysis based on decadal time scale satellite data reveals that an area of 2,175.9 km(2) (59.6 % of total vegetation cover) has been affected by varied rate of frequency of forest fires. Fire density pattern indicates low count of burnt area patches in 2013 estimated at 1,017 and high count at 1,916 in 2004. An estimate of fire risk area over a decade identifies 12.2 km(2) is experiencing an annual fire damage. Summing the fire frequency data across the grids (each 1 km(2)) indicates 1,211 (26 %) grids are having very high disturbance regimes due to repeated fires in all the 10 years, followed by 711 grids in 9 years and 418 in 8 years and 382 in 7 years. The spatial database offers excellent opportunities to understand the ecological impact of fires on biodiversity and is helpful in formulating conservation action plans.

  6. Performance ceramic red mass containing mill scale of rolling in different firing temperatures

    International Nuclear Information System (INIS)

    Meller, J.G.; Arnt, A.B.C; Rocha, M.R.

    2014-01-01

    This study aimed to evaluate the performance of the properties of samples of red clay with addition of mill scale steel. This residue consists of oxides of iron has the function replace pigments used in ceramic materials. The mechanical strength of the sintered material can be associated with reactions that occur during sintering, leading to the formation of compounds provided with good mechanical characteristics, particle size of the components and the structure of the dough piece after the compactation. After chemical and microstructural characterization diffraction and fluorescence X-rays, this residue was added in the proportion of 1.45% of a commercial ceramic mass. The formulations were subjected to different temperatures and performance of the formulations was evaluated for physical characteristics: loss on ignition, linear firing shrinkage, water absorption, flexural strength by 3 and intensity of tone. The loss on ignition and linear firing shrinkage tests relate to the sintering temperature with the performance of the tested formulations. (author)

  7. Landscape management of fire and grazing regimes alters the fine-scale habitat utilisation by feral cats.

    Science.gov (United States)

    McGregor, Hugh W; Legge, Sarah; Jones, Menna E; Johnson, Christopher N

    2014-01-01

    Intensification of fires and grazing by large herbivores has caused population declines in small vertebrates in many ecosystems worldwide. Impacts are rarely direct, and usually appear driven via indirect pathways, such as changes to predator-prey dynamics. Fire events and grazing may improve habitat and/or hunting success for the predators of small mammals, however, such impacts have not been documented. To test for such an interaction, we investigated fine-scale habitat selection by feral cats in relation to fire, grazing and small-mammal abundance. Our study was conducted in north-western Australia, where small mammal populations are sensitive to changes in fire and grazing management. We deployed GPS collars on 32 cats in landscapes with contrasting fire and grazing treatments. Fine-scale habitat selection was determined using discrete choice modelling of cat movements. We found that cats selected areas with open grass cover, including heavily-grazed areas. They strongly selected for areas recently burnt by intense fires, but only in habitats that typically support high abundance of small mammals. Intense fires and grazing by introduced herbivores created conditions that are favoured by cats, probably because their hunting success is improved. This mechanism could explain why, in northern Australia, impacts of feral cats on small mammals might have increased. Our results suggest the impact of feral cats could be reduced in most ecosystems by maximising grass cover, minimising the incidence of intense fires, and reducing grazing by large herbivores.

  8. Landscape management of fire and grazing regimes alters the fine-scale habitat utilisation by feral cats.

    Directory of Open Access Journals (Sweden)

    Hugh W McGregor

    Full Text Available Intensification of fires and grazing by large herbivores has caused population declines in small vertebrates in many ecosystems worldwide. Impacts are rarely direct, and usually appear driven via indirect pathways, such as changes to predator-prey dynamics. Fire events and grazing may improve habitat and/or hunting success for the predators of small mammals, however, such impacts have not been documented. To test for such an interaction, we investigated fine-scale habitat selection by feral cats in relation to fire, grazing and small-mammal abundance. Our study was conducted in north-western Australia, where small mammal populations are sensitive to changes in fire and grazing management. We deployed GPS collars on 32 cats in landscapes with contrasting fire and grazing treatments. Fine-scale habitat selection was determined using discrete choice modelling of cat movements. We found that cats selected areas with open grass cover, including heavily-grazed areas. They strongly selected for areas recently burnt by intense fires, but only in habitats that typically support high abundance of small mammals. Intense fires and grazing by introduced herbivores created conditions that are favoured by cats, probably because their hunting success is improved. This mechanism could explain why, in northern Australia, impacts of feral cats on small mammals might have increased. Our results suggest the impact of feral cats could be reduced in most ecosystems by maximising grass cover, minimising the incidence of intense fires, and reducing grazing by large herbivores.

  9. Re-evaluation of the 1995 Hanford Large Scale Drum Fire Test Results

    International Nuclear Information System (INIS)

    Yang, J M

    2007-01-01

    A large-scale drum performance test was conducted at the Hanford Site in June 1995, in which over one hundred (100) 55-gal drums in each of two storage configurations were subjected to severe fuel pool fires. The two storage configurations in the test were pallet storage and rack storage. The description and results of the large-scale drum test at the Hanford Site were reported in WHC-SD-WM-TRP-246, ''Solid Waste Drum Array Fire Performance,'' Rev. 0, 1995. This was one of the main references used to develop the analytical methodology to predict drum failures in WHC-SD-SQA-ANAL-501, 'Fire Protection Guide for Waste Drum Storage Array,'' September 1996. Three drum failure modes were observed from the test reported in WHC-SD-WM-TRP-246. They consisted of seal failure, lid warping, and catastrophic lid ejection. There was no discernible failure criterion that distinguished one failure mode from another. Hence, all three failure modes were treated equally for the purpose of determining the number of failed drums. General observations from the results of the test are as follows: (lg b ullet) Trash expulsion was negligible. (lg b ullet) Flame impingement was identified as the main cause for failure. (lg b ullet) The range of drum temperatures at failure was 600 C to 800 C. This is above the yield strength temperature for steel, approximately 540 C (1,000 F). (lg b ullet) The critical heat flux required for failure is above 45 kW/m 2 . (lg b ullet) Fire propagation from one drum to the next was not observed. The statistical evaluation of the test results using, for example, the student's t-distribution, will demonstrate that the failure criteria for TRU waste drums currently employed at nuclear facilities are very conservative relative to the large-scale test results. Hence, the safety analysis utilizing the general criteria described in the five bullets above will lead to a technically robust and defensible product that bounds the potential consequences from postulated

  10. Methodology for fire PSA during design process

    International Nuclear Information System (INIS)

    Kollasko, Heiko; Blombach, Joerg

    2009-01-01

    Fire PSA is an essential part of a full scope level 1 PSA. Cable fires play an important role in fire PSA. Usually, cable routing is therefore modeled in detail. During the design of new nuclear power plants the information on cable routing is not yet available. However, for the use of probabilistic safety insights during the design and for licensing purposes a fire PSA may be requested. Therefore a methodology has been developed which makes use of the strictly divisional separation of redundancies in the design of modern nuclear power plants: cable routing is not needed within one division but replaced by the conservative assumption that all equipment fails due to a fire in the concerned division; critical fire areas are defined where components belonging to different divisions may be affected by a fire. For the determination of fire frequencies a component based approach is proposed. The resulting core damage frequencies due to fire are conservative. (orig.)

  11. Fire safety assessment for the fire areas of the nuclear power plant using fire model CFAST

    International Nuclear Information System (INIS)

    Lee, Yoon Hwan; Yang, Joon Eon; Kim, Jong Hoon

    2005-03-01

    Now the deterministic analysis results for the cable integrity is not given in case of performing the fire PSA. So it is necessary to develop the assessment methodology for the fire growth and propagation. This document is intended to analyze the peak temperature of the upper gas layer using the fire modeling code, CFAST, to evaluate the integrity of the cable located on the dominant pump rooms, and to assess the CCDP(Conditional Core Damage Probability) using the results of the cable integrity. According to the analysis results, the cable integrity of the pump rooms is maintained and CCDP is reduced about two times than the old one. Accordingly, the fire safety assessment for the dominant fire areas using the fire modeling code will capable to reduce the uncertainty and to develop a more realistic model

  12. Development of non-halogen cables for nuclear power stations

    Energy Technology Data Exchange (ETDEWEB)

    Yagyu, Hideki; Yamamoto, Yasuaki; Onishi, Takao (Hitachi Cable, Ltd., Tokyo (Japan))

    1983-12-01

    The non-halogen fire-resistant cables for nuclear power stations which never generate halogen gas, have been developed. The cables comprise the insulator of EP rubber and the sheath of polyolefine containing non-halogen inorganic fire-retardant. The results of the environmental test and fire-resistance test are described. In the environmental test, the cables were subjected to the heating, gamma-irradiation and steam exposure successively, according to IEEE specification 323,383, and subsequently the change in the appearance, tensile strength and electrical performance of the cables was measured. In the fire-resistance test, the vertical tray fire test according to the IEEE specification 383 was adopted, and other tests including the vertical fire test on insulator cores, oxygen index, the generation of corrosive gas, copper mirror corrosion test, gas toxicity test and optical smoke density test were carried out. It became clear that the cables did not generate halogen gas on burning, and brought about reduced toxicity, corrosion and smoke, and that the safety against fire is greatly improved by using the cables.

  13. Development of non-halogen cables for nuclear power stations

    International Nuclear Information System (INIS)

    Yagyu, Hideki; Yamamoto, Yasuaki; Onishi, Takao

    1983-01-01

    The non-halogen fire-resistant cables for nuclear power stations which never generate halogen gas, have been developed. The cables comprise the insulator of EP rubber and the sheath of polyolefine containing non-halogen inorganic fire-retardant. The results of the environmental test and fire-resistance test are described. In the environmental test, the cables were subjected to the heating, gamma-irradiation and steam exposure successively, according to IEEE specification 323,383, and subsequently the change in the appearance, tensile strength and electrical performance of the cables was measured. In the fire-resistance test, the vertical tray fire test according to the IEEE specification 383 was adopted, and other tests including the vertical fire test on insulator cores, oxygen index, the generation of corrosive gas, copper mirror corrosion test, gas toxicity test and optical smoke density test were carried out. It became clear that the cables did not generate halogen gas on burning, and brought about reduced toxicity, corrosion and smoke, and that the safety against fire is greatly improved by using the cables. (Yoshitake, I.)

  14. CABLES MUSCULARES

    Directory of Open Access Journals (Sweden)

    Alejandro Gómez

    Full Text Available Los cables musculares o fibras de nitinol presentan una excelente alternativa a los actuadores convencionales, con una fuerza de actuación muy alta, equivalente a la de los actuadores hidráulicos, proporcionalmente a su peso, además de su acción silenciosa. Este material, inventado en 1963, aún no es muy conocido y de ahí que se haya realizado una recopilación de sus propiedades. Entre ellas, la temperatura de transición es la más importante, por ser la que activa la aleación. Muchos sistemas se han creado para alcanzar adecuadamente la temperatura de transición, y también se continúa en la investigación de métodos que ayuden a lograr un control preciso del movimiento de la aleación con memoria de forma (SMA.

  15. Economic evaluation of externally fired gas turbine cycles for small-scale biomass cogeneration

    Energy Technology Data Exchange (ETDEWEB)

    Anheden, Marie [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Chemical Engineering and Technology

    2001-01-01

    In this conceptual study, externally fired gas turbine (EFGT) cycles in combination with a biomass-fueled, atmospheric circulating fluidized bed (CFB) furnace are investigated for small scale heat and power production ({approx} 8 MW fuel input). Three cycle configurations are considered: closed cycle, with nitrogen, helium, and a helium/carbon dioxide mixture as working fluids; open cycle operating in parallel to the CFB system; and open cycle with a series connection to the CFB system. Intercooling, postcooling, and recuperation are employed with the goal of maximizing efficiency. Aside from a thermodynamic performance analysis, the study includes an economic analysis of both the closed and open externally fired gas turbine configurations, and comparisons are made with existing and emerging alternatives for small-scale biomass cogeneration. Simulation results show that thermodynamic performance varies slightly between the different configurations and working fluids, with electrical efficiencies of 31-38% (LHV) and total efficiency of 85-106% (LHV). The economic evaluation shows that the turbomachinery and the CFB furnace dominate the total plant cost, with each contributing about 1/3 of the total installed equipment cost. The specific capital cost for installation in Sweden in 1998 currency is calculated as 26-31 kSEK/kW{sub e} which is equivalent to 3 200-3 900 USD/kW{sub e} or 2 700-3 300 EUR/kW{sub e} .The cost of electricity, COE, is estimated to 590-670 SEK/MWh{sub e} (equivalent to 73-84 USD/MWh{sub e} or 62-71 EUR/MWh{sub e}) for 4 000 full load hours per year in a cogeneration application. Comparing the economic results for the externally fired gas turbine cycles in a slightly larger scale (40-50 MW{sub f}) to the economics of conventional biomass fired steam turbine cycles shows that the cost of electricity for the two plant configurations are roughly the same with a COE of 300-350 SEK/MWh{sub e}. It is believed that the economic performance of the EFGT

  16. Development of halogen-free cables for nuclear power plants

    International Nuclear Information System (INIS)

    Yamamoto, Mitsuo; Ito, Kazumi; Yaji, Takeo; Yoshida, Shin; Sakurai, Takako; Matsushita, Shigetoshi.

    1990-01-01

    On the occasion where serious fire accidents were experienced in the past, the need for making flame-retardant wire and cable incombustible took place and has since been generalizing. Various sorts of flame-retardant cables have already been developed and been actually used. From the viewpoint of avoiding the interference with the evacuation and fire-fighting activity in case of fire or the secondary accidents such as corrosion of the distributing panel, etc., the demand for non-halogen flame-retardant cable has rapidly been increasing in recent years in some fields of general industries, because this specific cable would generate the least amount of toxic smoke or corrosive gas even when it should burn. Similar demand has been increasing also for the cable used for nuclear power plants. In this field, earnest desire has been made for the development of non-halogen flame-retardant cable having specific environmental resistance specially required at nuclear power plants in addition to the properties and capacities required in general industries. The authors have continued examinations on the anti-environmental properties of the materials for cable such as long heat resistance, radiation resistance, steam resistance and succeeded in completing various sorts of non-halogen flame-retardant cable for nuclear power plants. In this report, we will introduce various features of the cable we have developed this time as well as the long-term reliability of non-halogen flame-retardant materials. (author)

  17. Universal Cable Brackets

    Science.gov (United States)

    Vanvalkenburgh, C.

    1985-01-01

    Concept allows routing easily changed. No custom hardware required in concept. Instead, standard brackets cut to length and installed at selected locations along cable route. If cable route is changed, brackets simply moved to new locations. Concept for "universal" cable brackets make it easy to route electrical cable around and through virtually any structure.

  18. Cable line engineering

    International Nuclear Information System (INIS)

    Jang, Hak Sin; Kim, Sin Yeong

    1998-02-01

    This book is about cable line engineering. It is comprised of nine chapters, which deals with summary of cable communication such as way, process of cable communication and optical communication, Line constant of transmission on primary constant, reflection and crosstalk, communication cable line of types like flat cable, coaxial cable and loaded cable, Install of communication line with types and facility of aerial line, construction method of communication line facility, Measurement of communication line, Carrier communication of summary, PCM communication with Introduction, regeneration relay system sampling and quantization and Electric communication service and general information network with mobile communication technique and satellite communication system.

  19. Water, land, fire, and forest: Multi-scale determinants of rainforests in the Australian monsoon tropics.

    Science.gov (United States)

    Ondei, Stefania; Prior, Lynda D; Williamson, Grant J; Vigilante, Tom; Bowman, David M J S

    2017-03-01

    The small rainforest fragments found in savanna landscapes are powerful, yet often overlooked, model systems to understand the controls of these contrasting ecosystems. We analyzed the relative effect of climatic variables on rainforest density at a subcontinental level, and employed high-resolution, regional-level analyses to assess the importance of landscape settings and fire activity in determining rainforest density in a frequently burnt Australian savanna landscape. Estimates of rainforest density (ha/km 2 ) across the Northern Territory and Western Australia, derived from preexisting maps, were used to calculate the correlations between rainforest density and climatic variables. A detailed map of the northern Kimberley (Western Australia) rainforests was generated and analyzed to determine the importance of geology and topography in controlling rainforests, and to contrast rainforest density on frequently burnt mainland and nearby islands. In the northwestern Australian, tropics rainforest density was positively correlated with rainfall and moisture index, and negatively correlated with potential evapotranspiration. At a regional scale, rainforests showed preference for complex topographic positions and more fertile geology. Compared with mainland areas, islands had significantly lower fire activity, with no differences between terrain types. They also displayed substantially higher rainforest density, even on level terrain where geomorphological processes do not concentrate nutrients or water. Our multi-scale approach corroborates previous studies that suggest moist climate, infrequent fires, and geology are important stabilizing factors that allow rainforest fragments to persist in savanna landscapes. These factors need to be incorporated in models to predict the future extent of savannas and rainforests under climate change.

  20. Improvement of fire fighting means for NPPs

    International Nuclear Information System (INIS)

    Viktorov, V.V.

    1993-01-01

    The problems dealing with testing of flame dampers for NPP ventilation systems are considered. The characteristics of the Darmatt fire-resistant material developed for protection of cable lines and equipment against fire effects are given

  1. Mid-term and scaling effects of forest residue mulching on post-fire runoff and soil erosion.

    Science.gov (United States)

    Prats, Sergio Alegre; Wagenbrenner, Joseph W; Martins, Martinho António Santos; Malvar, Maruxa Cortizo; Keizer, Jan Jacob

    2016-12-15

    Mulching is an effective post-fire soil erosion mitigation treatment. Experiments with forest residue mulch have demonstrated that it increased ground cover to 70% and reduced runoff and soil loss at small spatial scales and for short post-fire periods. However, no studies have systematically assessed the joint effects of scale, time since burning, and mulching on runoff, soil loss, and organic matter loss. The objective of this study was to evaluate the effects of scale and forest residue mulch using 0.25m 2 micro-plots and 100m 2 slope-scale plots in a burnt eucalypt plantation in central Portugal. We assessed the underlying processes involved in the post-fire hydrologic and erosive responses, particularly the effects of soil moisture and soil water repellency. Runoff amount in the micro-plots was more than ten-fold the runoff in the larger slope-scale plots in the first year and decreased to eight-fold in the third post-fire year. Soil losses in the micro-plots were initially about twice the values in the slope-scale plots and this ratio increased over time. The mulch greatly reduced the cumulative soil loss measured in the untreated slope-scale plots (616gm -2 ) by 91% during the five post-fire years. The implications are that applying forest residue mulch immediately after a wildfire can reduce soil losses at spatial scales of interest to land managers throughout the expected post-fire window of disturbance, and that mulching resulted in a substantial relative gain in soil organic matter. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Physical degradation assessment of generator station cables

    International Nuclear Information System (INIS)

    Stonkus, D.J.

    1988-01-01

    Preliminary studies of fossil-fired and nuclear generator station cables indicate that the low voltage PVC insulated cables are in relatively good condition. The insulation is flexible and in the case of nuclear cables can withstand a design basis event after nearly 15 years of service. Cables insulated with styrene butadiene rubber have been found embrittled and cables insulated with SBR should be closely inspected in any plant assurance program. Thermal analysis using oxidative induction technique shows promise to indicate cable insulation degradation. Long term reliability assurance and plant life extension studies are being actively pursued at Ontario Hydro. A major study is currently underway to extend the life of the oldest operating fossil-fuel station, the 8-unit, 2400 MW Lakeview TGS in operation since the 1960s. Plant life assurance programs have been initiated at the 2000 MW Lambton TGS in operation since 1969, and for the oldest operating nuclear plant, Pickering NGS A in operation since the early 1970s. As cables are considered one of the critical components in a generator station due to the extreme difficulty and cost of cable replacement, test programs have been initiated to evaluate the physical degradation of the cables and relate the results to electrical diagnostic tests and to chemical changes. The decommissioning of two small nuclear stations, the 20 MW Nuclear Power Demonstration (NPD) and the 200 MW Douglas Point NGS, which were placed in service in 1962 and 1967 respectively, will provide an opportunity to perform destructive electrical and physical evaluation on field aged cables

  3. Multiplatform inversion of the 2013 Rim Fire smoke emissions using regional-scale modeling: important nocturnal fire activity, air quality, and climate impacts

    Science.gov (United States)

    Saide, P. E.; Peterson, D. A.; da Silva, A. M., Jr.; Ziemba, L. D.; Anderson, B.; Diskin, G. S.; Sachse, G. W.; Hair, J. W.; Butler, C. F.; Fenn, M. A.; Jimenez, J. L.; Campuzano Jost, P.; Dibb, J. E.; Yokelson, R. J.; Toon, B.; Carmichael, G. R.

    2014-12-01

    Large wildfire events are increasingly recognized for their adverse effects on air quality and visibility, thus providing motivation for improving smoke emission estimates. The Rim Fire, one of the largest events in California's history, produced a large smoke plume that was sampled by the Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) DC-8 aircraft with a full suite of in-situ and remote sensing measurements on 26-27 August 2013. We developed an inversion methodology which uses the WRF-Chem modeling system to constrain hourly fire emissions, using as initial estimates the NASA Quick Fire Emissions Dataset (QFED). This method differs from the commonly performed top-down estimates that constrain daily (or longer time scale) emissions. The inversion method is able to simultaneously improve the model fit to various SEAC4RS airborne measurements (e.g., organic aerosol, carbon monoxide (CO), aerosol extinction), ground based measurements (e.g., AERONET aerosol optical depth (AOD), CO), and satellite data (MODIS AOD) by modifying fire emissions and utilizing the information content of all these measurements. Preliminary results show that constrained emissions for a 6 day period following the largest fire growth are a factor 2-4 higher than the initial top-down estimates. Moreover, there is a tendency to increase nocturnal emissions by factors sometimes larger than 20, indicating that vigorous fire activity continued during the night. This deviation from a typical diurnal cycle is confirmed using geostationary satellite data. The constrained emissions also have a larger day-to-day variability than the initial emissions and correlate better to daily area burned estimates as observed by airborne infrared measurements (NIROPS). Experiments with the assimilation system show that performing the inversion using only satellite AOD data produces much smaller correction factors than when using all available data

  4. Increased fire frequency promotes stronger spatial genetic structure and natural selection at regional and local scales in Pinus halepensis Mill.

    Science.gov (United States)

    Budde, Katharina B; González-Martínez, Santiago C; Navascués, Miguel; Burgarella, Concetta; Mosca, Elena; Lorenzo, Zaida; Zabal-Aguirre, Mario; Vendramin, Giovanni G; Verdú, Miguel; Pausas, Juli G; Heuertz, Myriam

    2017-04-01

    The recurrence of wildfires is predicted to increase due to global climate change, resulting in severe impacts on biodiversity and ecosystem functioning. Recurrent fires can drive plant adaptation and reduce genetic diversity; however, the underlying population genetic processes have not been studied in detail. In this study, the neutral and adaptive evolutionary effects of contrasting fire regimes were examined in the keystone tree species Pinus halepensis Mill. (Aleppo pine), a fire-adapted conifer. The genetic diversity, demographic history and spatial genetic structure were assessed at local (within-population) and regional scales for populations exposed to different crown fire frequencies. Eight natural P. halepensis stands were sampled in the east of the Iberian Peninsula, five of them in a region exposed to frequent crown fires (HiFi) and three of them in an adjacent region with a low frequency of crown fires (LoFi). Samples were genotyped at nine neutral simple sequence repeats (SSRs) and at 251 single nucleotide polymorphisms (SNPs) from coding regions, some of them potentially important for fire adaptation. Fire regime had no effects on genetic diversity or demographic history. Three high-differentiation outlier SNPs were identified between HiFi and LoFi stands, suggesting fire-related selection at the regional scale. At the local scale, fine-scale spatial genetic structure (SGS) was overall weak as expected for a wind-pollinated and wind-dispersed tree species. HiFi stands displayed a stronger SGS than LoFi stands at SNPs, which probably reflected the simultaneous post-fire recruitment of co-dispersed related seeds. SNPs with exceptionally strong SGS, a proxy for microenvironmental selection, were only reliably identified under the HiFi regime. An increasing fire frequency as predicted due to global change can promote increased SGS with stronger family structures and alter natural selection in P. halepensis and in plants with similar life history traits

  5. How do you like them cables?

    CERN Multimedia

    Sergei Malyukov

    Cabling work is not for clautrophobic people! Cables are like the blood vessels and nervous system of ATLAS. With the help of all these cables, we can power ATLAS, control the detector and read out the data. Like the human blood vessels, they penetrate inside the ATLAS volume, reaching each of its elements. The ATLAS developers started to think about design of services, cables and pipes at the very first stages of the project. The cabling project has been developing most intensively during the last five years, passing through the projection and CAD design phases, then the installation of cable trays and finally the cables. The cable installation itself took two and a half years and was done by teams of technicians from several institutes from Russia, the Czech Republic and Poland. Here are some numbers to illustrate the scale of the ATLAS cabling system. More than 25000 optical fiber channels are used for reading the information from the sub-detectors and delivering the timing signals. The total numbe...

  6. Power cables now and in the future

    Energy Technology Data Exchange (ETDEWEB)

    Wanser, G

    1976-01-01

    A survey is presented of the problems to be faced with the underground supply of electric power to large, urban areas and of the contributions that improvements in power cable technology will make to solving these problems. It is concluded that the increase in population densities and the rising demand for energy on the part of individual consumers bring up problems for electricity supply and thus have a direct influence on development trends in cable engineering. During the last few years the increasing capacities required in power transmission have led to the use of higher voltages and to the application of special methods of cooling for the oil-filled cable. When the technical and economic possibilities with present-day cable techniques have been exhausted, we must anticipate the introduction of new types of cable, i.e., gas-insulated cables and superconducting cables. The problems involved in power distribution are being solved successfully by resorting to larger conductor cross-sectional areas and by raising the voltage levels. The advantages of plastic cables are also being utilized on a wide scale. The requirement that there be freedom from partial discharges in plastic cables operating at medium and higher voltages is becoming increasingly more widely adopted as a new quality criterion in cable engineering. New materials from the polymer range are permitting the introduction of fittings which are easier to install and which reduce costs. Cable engineering has already, to a considerable extent, adapted itself to face future problems. Even so, there are still a large number of problems in cable engineering requiring research, development and operation.

  7. Modeling Fire Occurrence at the City Scale: A Comparison between Geographically Weighted Regression and Global Linear Regression.

    Science.gov (United States)

    Song, Chao; Kwan, Mei-Po; Zhu, Jiping

    2017-04-08

    An increasing number of fires are occurring with the rapid development of cities, resulting in increased risk for human beings and the environment. This study compares geographically weighted regression-based models, including geographically weighted regression (GWR) and geographically and temporally weighted regression (GTWR), which integrates spatial and temporal effects and global linear regression models (LM) for modeling fire risk at the city scale. The results show that the road density and the spatial distribution of enterprises have the strongest influences on fire risk, which implies that we should focus on areas where roads and enterprises are densely clustered. In addition, locations with a large number of enterprises have fewer fire ignition records, probably because of strict management and prevention measures. A changing number of significant variables across space indicate that heterogeneity mainly exists in the northern and eastern rural and suburban areas of Hefei city, where human-related facilities or road construction are only clustered in the city sub-centers. GTWR can capture small changes in the spatiotemporal heterogeneity of the variables while GWR and LM cannot. An approach that integrates space and time enables us to better understand the dynamic changes in fire risk. Thus governments can use the results to manage fire safety at the city scale.

  8. Novel approach for extinguishing large-scale coal fires using gas-liquid foams in open pit mines.

    Science.gov (United States)

    Lu, Xinxiao; Wang, Deming; Qin, Botao; Tian, Fuchao; Shi, Guangyi; Dong, Shuaijun

    2015-12-01

    Coal fires are a serious threat to the workers' security and safe production in open pit mines. The coal fire source is hidden and innumerable, and the large-area cavity is prevalent in the coal seam after the coal burned, causing the conventional extinguishment technology difficult to work. Foams are considered as an efficient means of fire extinguishment in these large-scale workplaces. A noble foam preparation method is introduced, and an original design of cavitation jet device is proposed to add foaming agent stably. The jet cavitation occurs when the water flow rate and pressure ratio reach specified values. Through self-building foaming system, the high performance foams are produced and then infused into the blast drilling holes at a large flow. Without complicated operation, this system is found to be very suitable for extinguishing large-scale coal fires. Field application shows that foam generation adopting the proposed key technology makes a good fire extinguishment effect. The temperature reduction using foams is 6-7 times higher than water, and CO concentration is reduced from 9.43 to 0.092‰ in the drilling hole. The coal fires are controlled successfully in open pit mines, ensuring the normal production as well as the security of personnel and equipment.

  9. Superconducting ac cable

    Science.gov (United States)

    Schmidt, F.

    1980-11-01

    The components of a superconducting 110 kV ac cable for power ratings or = 2000 MVA were developed. The cable design is of the semiflexible type, with a rigid cryogenic envelope containing a flexible hollow coaxial cable core. The cable core consists of spirally wound Nb-A1 composite wires electrically insulated by high pressure polyethylene tape wrappings. A 35 m long single phase test cable with full load terminals rated at 110 kV and 10 kA was constructed and successfully tested. The results obtained prove the technical feasibility and capability of this cable design.

  10. Superconducting ac cable

    International Nuclear Information System (INIS)

    Schmidt, F.

    1980-01-01

    The components of a superconducting 110 kV ac cable for power ratings >= 2000 MVA have been developed. The cable design especially considered was of the semiflexible type, with a rigid cryogenic envelope and flexible hollow coaxial cable cores pulled into the former. The cable core consists of spirally wound Nb-Al composite wires and a HDPE-tape wrapped electrical insulation. A 35 m long single phase test cable with full load terminations for 110 kV and 10 kA was constructed and successfully tested. The results obtained prove the technical feasibility and capability of our cable design. (orig.) [de

  11. A PSO Driven Intelligent Model Updating and Parameter Identification Scheme for Cable-Damper System

    Directory of Open Access Journals (Sweden)

    Danhui Dan

    2015-01-01

    Full Text Available The precise measurement of the cable force is very important for monitoring and evaluating the operation status of cable structures such as cable-stayed bridges. The cable system should be installed with lateral dampers to reduce the vibration, which affects the precise measurement of the cable force and other cable parameters. This paper suggests a cable model updating calculation scheme driven by the particle swarm optimization (PSO algorithm. By establishing a finite element model considering the static geometric nonlinearity and stress-stiffening effect firstly, an automatically finite element method model updating powered by PSO algorithm is proposed, with the aims to identify the cable force and relevant parameters of cable-damper system precisely. Both numerical case studies and full-scale cable tests indicated that, after two rounds of updating process, the algorithm can accurately identify the cable force, moment of inertia, and damping coefficient of the cable-damper system.

  12. Continuous operation of NPP Kori Unit 1 - Fireproof paint for cables

    International Nuclear Information System (INIS)

    Wendt, Dipl-Ing. Ruediger; Kim, Duill; Sik, Cho Hong

    2008-01-01

    Fireproof cable coating materials have been used in European NPP, especially in Germany, Russia, Ukraine, Czech Republic, Lithuania, Switzerland. Wide experiences were made during operation while applying these systems. In NPP Kori, Unit 1, a fire proof cable coating project was realised for the first time in a NPP of KHNP. The scope of services of the cable trays to coat amounts to 15,587m 2 . In different fire compartments and rooms the cables should be coated partially respectively completely with the fire proof cable coating system. The extent of cable surfaces to coat was stipulated by KHNP on the basis of an analysis made by KHNP. The project was tendered on the basis of a technical specification of KHNP. The specification is mainly predicted on Korean and US standards. The most important criteria for the fire proof cable coating is resumed as follows: The fireproof cable coating has to assure the fire protection of the cables for a period defined and for operational conditions defined in such a manner that the general conditions for the operation of the cable installation will not be affected

  13. The effect of urban growth on landscape-scale restoration for a fire-dependent songbird.

    Science.gov (United States)

    Pickens, Bradley A; Marcus, Jeffrey F; Carpenter, John P; Anderson, Scott; Taillie, Paul J; Collazo, Jaime A

    2017-04-15

    A landscape-scale perspective on restoration ecology has been advocated, but few studies have informed restoration with landscape metrics or addressed broad-scale threats. Threats such as urban growth may affect restoration effectiveness in a landscape context. Here, we studied longleaf pine savanna in the rapidly urbanizing southeastern United States where a habitat-specialist bird, Bachman's sparrow (Peucaea aestivalis), is closely associated with savanna vegetation structure and frequent fire. Our objectives were to construct a species distribution model for Bachman's sparrow, determine the relationship between fire and urbanization, quantify the urban growth effect (2010-2090), identify potential restoration areas, and determine the interaction between restoration potential and urban growth by 2050. Number of patches, patch size, and isolation metrics were used to evaluate scenarios. The species distribution model was 88% accurate and emphasized multiscale canopy cover characteristics, fire, and percent habitat. Fires were less common urban areas, and this fire suppression effect exacerbated urban growth effects. For restoration scenarios, canopy cover reduction by 30% resulted in nearly double the amount of habitat compared to the prescribed fire scenario; canopy cover reduction resulted in larger patch sizes and less patch isolation compared to current conditions. The effect of urban growth on restoration scenarios was unequal. Seventy-four percent of restoration areas from the prescribed fire scenario overlapped with projected urban growth, whereas the canopy cover reduction scenario only overlapped by 9%. We emphasize the benefits of simultaneously considering the effects of urban growth and landscape-scale restoration potential to promote a landscape with greater patch sizes and less isolation. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  14. Numerical Field Model Simulation of Full Scale Fire Tests in a Closed Spherical/Cylindrical Vessel.

    Science.gov (United States)

    1987-12-01

    the behavior of an actual fire on board a ship. The computer model will be verified by the experimental data obtained in Fire-l. It is important to... behavior in simulations where convection is important. The upwind differencing scheme takes into account the unsymmetrical phenomenon of convection by using...TANK CELL ON THE NORTH SIDE) FOR A * * PARTICULAR FIRE CELL * * COSUMS (I,J) = THE ARRAY TO STORE THE SIMILIAR VALUE FOR THE FIRE * * CELL TO THE SOUTH

  15. Energy cable engineering. Energiekabeltechnik

    Energy Technology Data Exchange (ETDEWEB)

    Luecking, H W

    1981-01-01

    This textbook intends to explain cable elements and common cable constructions according to VDE, and in a second part, to review the theoretical fundamentals and their consequences with a view to the construction of cables for higher voltages and powers. It will give the student a picture of the variety of problems and solutions which make cable engineering so interesting and show the practising engineer how to derive a theoretical system from their extensive everyday experience.

  16. Cable Supported Bridges

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    Cable supported bridges in the form of suspension bridges and cable-stayed bridges are distinguished by their ability to overcome large spans.The book concentrates on the synthesis of cable supported bridges, covering both design and construction aspects. The analytical part covers simple methods...... to quantify the different structural configurations and allows a preliminary optimization of the main structure.Included are the most recent advances in structural design, corrosion protection of cables, aerodynamic safety, and erection procedures....

  17. Preliminary report on fire protection research program (July 6, 1977 test)

    International Nuclear Information System (INIS)

    Klamerus, L.J.

    1977-10-01

    This preliminary report describes a fire test performed at Sandia Laboratories on an array of cable trays filled with fire retardant (IEEE 383 qualified) electrical cable. The cable trays were arranged in an open-space horizontal configuration with the separation distances of Regulatory Guide 1.75 between those trays representing redundant safety divisions. Propane burners were used to produce a fully developed cable fire in one tray which then was allowed to interact with other trays. From this test it appears that it is possible for a fire to propagate across the vertical separation distance between safety divisions, if a fully developed cable fire is the initiating event

  18. Large-Scale Controls and Characteristics of Fire Activity in Central Chile, 2001-2015

    Science.gov (United States)

    McWethy, D. B.; Pauchard, A.; García, R.; Holz, A.; González, M.; Veblen, T. T.; Stahl, J.

    2016-12-01

    In recent decades, fire activity has increased in many ecosystems worldwide, even where fuel conditions and natural ignitions historically limited fire activity, and this increase begs questions of whether climate change, land-use change, and/or altered vegetation are responsible. Increased frequency of large fires in these settings has been attributed to drier-than-average summers and longer fire seasons as well as fuel accumulation related to ENSO events, raising concerns about the trajectory of post-fire vegetation dynamics and future fire regimes. In temperate and Mediterranean forests of central Chile, recent large fires associated with altered ecosystems, climate variability and land-use change highlight the risk and hazard of increasing fire activity yet the causes and consequences are poorly understood. To better understand characteristics of recent fire activity, key drivers of fire occurrence and the spatial probability of wildfire we examined the relationship between fire activity derived from MODIS satellite imagery and biophysical, land-cover and land-use variables. The probability of fire occurrence and annual area burned was best predicted by seasonal precipitation, annual temperature and land cover type. The likelihood of fire occurrence was greatest in Matorral shrublands, agricultural lands (including pasture lands) and Pinus and Eucalyptus plantations, highlighting the importance of vegetation type and fuel flammability as a critical control on fire activity. Our results suggest that land-use change responsible for the widespread presence of highly flammable vegetation and projections for continued warming and drying will likely combine to promote the occurrence of large fires in central Chile in the future.

  19. A new proposed approach for future large-scale de-carbonization coal-fired power plants

    International Nuclear Information System (INIS)

    Xu, Gang; Liang, Feifei; Wu, Ying; Yang, Yongping; Zhang, Kai; Liu, Wenyi

    2015-01-01

    The post-combustion CO 2 capture technology provides a feasible and promising method for large-scale CO 2 capture in coal-fired power plants. However, the large-scale CO 2 capture in conventionally designed coal-fired power plants is confronted with various problems, such as the selection of the steam extraction point and steam parameter mismatch. To resolve these problems, an improved design idea for the future coal-fired power plant with large-scale de-carbonization is proposed. A main characteristic of the proposed design is the adoption of a back-pressure steam turbine, which extracts the suitable steam for CO 2 capture and ensures the stability of the integrated system. A new let-down steam turbine generator is introduced to retrieve the surplus energy from the exhaust steam of the back-pressure steam turbine when CO 2 capture is cut off. Results show that the net plant efficiency of the improved design is 2.56% points higher than that of the conventional one when CO 2 capture ratio reaches 80%. Meanwhile, the net plant efficiency of the improved design maintains the same level to that of the conventional design when CO 2 capture is cut off. Finally, the match between the extracted steam and the heat demand of the reboiler is significantly increased, which solves the steam parameter mismatch problem. The techno-economic analysis indicates that the proposed design is a cost-effective approach for the large-scale CO 2 capture in coal-fired power plants. - Highlights: • Problems caused by CO 2 capture in the power plant are deeply analyzed. • An improved design idea for coal-fired power plants with CO 2 capture is proposed. • Thermodynamic, exergy and techno-economic analyses are quantitatively conducted. • Energy-saving effects are found in the proposed coal-fired power plant design idea

  20. Experimental and modeling studies of fire in compartments at Electricite de France, Research and Development Division

    International Nuclear Information System (INIS)

    Gautier, B.

    1997-12-01

    Since 1985, The Research and Development Division at Electricite de France has been in charge, through the development of the software MAGIC, to simulate the fire propagation in Nuclear Plants. The research program has included, since its beginning, an experimental activity dedicated to the combustion of fluids and electrical cables. This paper gives an overview of the works in progress and presents the latest results obtained, in particular in cable combustion. In this field, a three scale approach has been carried on, based on micro-thermo-gravimetry, calorimetry and real scale experiments. (author)

  1. Cable Television: Franchising Considerations.

    Science.gov (United States)

    Baer, Walter S.; And Others

    This volume is a comprehensive reference guide to cable television technology and issues of planning, franchising, and regulating a cable system. It is intended for local government officials and citizens concerned with the development of cable television systems in their communities, as well as for college and university classes in…

  2. Colleges and Cable Franchising.

    Science.gov (United States)

    Glenn, Neal D.

    After noting issues of audience appeal and financial and philosophical support for educational broadcasting, this paper urges community colleges to play an active role in the process of cable franchising. The paper first describes a cable franchise as a contract between a government unit and the cable television (CATV) company which specifies what…

  3. Cable strengthened arches

    NARCIS (Netherlands)

    Kamerling, M.W.

    2013-01-01

    The structural efficiency of arches, subjected to several variable loads, can be increased by strengthening these arches with cables. For these structures it can be necessary, especially in case the permanent load is small, to post-tension the cables to avoid any compression acting on the cables. A

  4. Quantifying the multi-scale response of avifauna to prescribed fire experiments in the southwest United States

    Science.gov (United States)

    Brett G. Dickson; Barry R. Noon; Curtis H. Flather; Stephanie Jentsch; William M. Block

    2009-01-01

    Landscape-scale disturbance events, including ecological restoration and fuel reduction activities, can modify habitat and affect relationships between species and their environment. To reduce the risk of uncharacteristic stand-replacing fires in the southwestern United States, land managers are implementing restoration and fuels treatments (e.g., mechanical thinning,...

  5. An Experimental Study on Burning Characteristics of n-Heptane/Ethanol Mixture Pool Fires in a Reduced Scaled Tunnel

    Science.gov (United States)

    Yozgatligil, Ahmet; Shafee, Sina

    2016-11-01

    Fire accidents in recent decades have drawn attention to safety issues associated with the design, construction and maintenance of tunnels. A reduced scale tunnel model constructed based on Froude scaling technique is used in the current work. Mixtures of n-heptane and ethanol are burned with ethanol volumetric fraction up to 30 percent and the longitudinal ventilation velocity varying from 0.5 to 2.5 m/s. The burning rates of the pool fires are measured using a precision load cell. The heat release rates of the fires are calculated according to oxygen calorimetry method and the temperature distributions inside the tunnel are also measured. Results of the experiments show that the ventilation velocity variation has a significant effect on the pool fire burning rate, smoke temperature and the critical ventilation velocity. With increased oxygen depletion in case of increased ethanol content of blended pool fires, the quasi-steady heat release rate values tend to increase as well as the ceiling temperatures while the combustion duration decreases.

  6. Fire activity as a function of fire–weather seasonal severity and antecedent climate across spatial scales in southern Europe and Pacific western USA

    Science.gov (United States)

    Urbieta, Itziar R.; Zavala, Gonzalo; Bedia, Joaquin; Gutierrez, Jose M.; San Miguel-Ayanz, Jesus; Camia, Andrea; Keeley, Jon E.; Moreno, Jose M.

    2015-01-01

    Climate has a strong influence on fire activity, varying across time and space. We analyzed the relationships between fire–weather conditions during the main fire season and antecedent water-balance conditions and fires in two Mediterranean-type regions with contrasted management histories: five southern countries of the European Union (EUMED)(all fires); the Pacific western coast of the USA (California and Oregon, PWUSA)(national forest fires). Total number of fires (≥1 ha), number of large fires (≥100 ha) and area burned were related to mean seasonal fire weather index (FWI), number of days over the 90th percentile of the FWI, and to the standardized precipitation-evapotranspiration index (SPEI) from the preceding 3 (spring) or 8 (autumn through spring) months. Calculations were made at three spatial aggregations in each area, and models related first-difference (year-to-year change) of fires and FWI/climate variables to minimize autocorrelation. An increase in mean seasonal FWI resulted in increases in the three fire variables across spatial scales in both regions. SPEI contributed little to explain fires, with few exceptions. Negative water-balance (dry) conditions from autumn through spring (SPEI8) were generally more important than positive conditions (moist) in spring (SPEI3), both of which contributed positively to fires. The R2 of the models generally improved with increasing area of aggregation. For total number of fires and area burned, the R2 of the models tended to decrease with increasing mean seasonal FWI. Thus, fires were more susceptible to change with climate variability in areas with less amenable conditions for fires (lower FWI) than in areas with higher mean FWI values. The relationships were similar in both regions, albeit weaker in PWUSA, probably due to the wider latitudinal gradient covered in PWUSA than in EUMED. The large variance explained by some of the models indicates that large-scale seasonal forecast could help anticipating

  7. Decadal-scale relationship between measurements of aerosols, land-use change, and fire over Southeast Asia

    Science.gov (United States)

    Blake Cohen, Jason; Lecoeur, Eve; Loong Ng, Daniel Hui

    2017-01-01

    A simultaneous analysis of 13 years of remotely sensed data of land cover, fires, precipitation, and aerosols from the MODIS, TRMM, and MISR satellites and the AERONET network over Southeast Asia is performed, leading to a set of robust relationships between land-use change and fire being found on inter-annual and intra-annual scales over Southeast Asia, reflecting the heavy amounts of anthropogenic influence over land-use change and fires in this region of the world. First, we find that fires occur annually, but with a considerable amount of variance in their onset, duration, and intensity from year to year, and from two separate regions within Southeast Asia. Second, we show that a simple regression model of the land-cover, fire, and precipitation data can be used to recreate a robust representation of the timing and magnitude of measured aerosol optical depth (AOD) from multiple measurements sources of this region using either 8-day (better for onset and duration) or monthly (better for magnitude) measurements, but not daily measurements. We find that the reconstructed AOD matches the timing and intensity from AERONET measurements to within 70 to 90 % and the timing and intensity of MISR measurements to within 50 to 95 %. This is a unique finding in this part of the world since cloud-covered regions are large, yet the model is still robustly capable, including over regions where no fires are observed and hence no emissions would be expected to contribute to AOD. Third, we determine that while Southeast Asia is a source region of such intense smoke emissions, portions of it are also impacted by smoke transported from other regions. There are regions in northern Southeast Asia which have two annual AOD peaks, one during the local fire season and the other, smaller peak corresponding to a combination of some local smoke sources as well as transport of aerosols from fires in southern Southeast Asia and possibly even from anthropogenic sources in South Asia. Overall

  8. DC Cable for Railway

    Science.gov (United States)

    Tomita, Masaru

    The development of a superconducting cable for railways has commenced, assuming that a DC transmission cable will be used for electric trains. The cable has been fabricated based on the results of current testing of a superconducting wire, and various evaluation tests have been performed to determine the characteristics of the cable. A superconducting transmission cable having zero electrical resistance and suitable for railway use is expected to enhance regeneration efficiency, reduce power losses, achieve load leveling and integration of sub-stations, and reduce rail potential.

  9. Numerical modeling of laboratory-scale surface-to-crown fire transition

    Science.gov (United States)

    Castle, Drew Clayton

    Understanding the conditions leading to the transition of fire spread from a surface fuel to an elevated (crown) fuel is critical to effective fire risk assessment and management. Surface fires that successfully transition to crown fires can be very difficult to suppress, potentially leading to damages in the natural and built environments. This is relevant to chaparral shrub lands which are common throughout parts of the Southwest U.S. and represent a significant part of the wildland urban interface. The ability of the Wildland-Urban Interface Fire Dynamic Simulator (WFDS) to model surface-to-crown fire transition was evaluated through comparison to laboratory experiments. The WFDS model is being developed by the U.S. Forest Service (USFS) and the National Institute of Standards and Technology. The experiments were conducted at the USFS Forest Fire Laboratory in Riverside, California. The experiments measured the ignition of chamise (Adenostoma fasciculatum) crown fuel held above a surface fire spreading through excelsior fuel. Cases with different crown fuel bulk densities, crown fuel base heights, and imposed wind speeds were considered. Cold-flow simulations yielded wind speed profiles that closely matched the experimental measurements. Next, fire simulations with only the surface fuel were conducted to verify the rate of spread while factors such as substrate properties were varied. Finally, simulations with both a surface fuel and a crown fuel were completed. Examination of specific surface fire characteristics (rate of spread, flame angle, etc.) and the corresponding experimental surface fire behavior provided a basis for comparison of the factors most responsible for transition from a surface fire to the raised fuel ignition. The rate of spread was determined by tracking the flame in the Smokeview animations using a tool developed for tracking an actual flame in a video. WFDS simulations produced results in both surface fire spread and raised fuel bed

  10. Large-scale straw supplies to existing coal-fired power stations

    International Nuclear Information System (INIS)

    Gylling, M.; Parsby, M.; Thellesen, H.Z.; Keller, P.

    1992-08-01

    It is considered that large-scale supply of straw to power stations and decentral cogeneration plants could open up new economical systems and methods of organization of straw supply in Denmark. This thesis is elucidated and involved constraints are pointed out. The aim is to describe to what extent large-scale straw supply is interesting with regard to monetary savings and available resources. Analyses of models, systems and techniques described in a foregoing project are carried out. It is reckoned that the annual total amount of surplus straw in Denmark is 3.6 million tons. At present, use of straw which is not agricultural is limited to district heating plants with an annual consumption of 2-12 thousand tons. A prerequisite for a significant increase in the use of straw is an annual consumption by power and cogeneration plants of more than 100.000 tons. All aspects of straw management are examined in detail, also in relation to two actual Danish coal-fired plants. The reliability of straw supply is considered. It is concluded that very significant resources of straw are available in Denmark but there remain a number of constraints. Price competitiveness must be considered in relation to other fuels. It is suggested that the use of corn harvests, with whole stems attached (handled as large bales or in the same way as sliced straw alone) as fuel, would result in significant monetary savings in transport and storage especially. An equal status for whole-harvested corn with other forms of biomass fuels, with following changes in taxes and subsidies could possibly reduce constraints on large scale straw fuel supply. (AB) (13 refs.)

  11. Cable aging tests

    International Nuclear Information System (INIS)

    Hubbard, G.

    1993-01-01

    This paper describes the results from aging, condition monitoring, and loss-of-coolant accident (LOCA) testing of class 1E electrical cables, per NUREG/CR-5772. This test was designed to test the performance of cables which had been aged with simultaneous radiation and thermal exposure. The tested cables included crosslinked polyolefin cables, ethylene propylene rubber cables, and miscellaneous cable types. Cables were exposed to 20, 40, and 60 years equivalent aging, and then exposed to LOCA tests at the end of their qualified life to determine the minimum insulation thickness needed for survival of the test. Failures were found in a large number of the tested cables. As a result the NRC has sent information notices to the industry regarding potential insulation problems. The results have raised the question of whether the artificial aging methods provide adequate testing methods. As a result of this testing the NRC is reviewing the artificial aging procedures, the adequacy of environmental qualification requirements for cable safety, and reexamining data from condition monitoring of installed cables

  12. Improvement of fire protection measures for nuclear power plants

    International Nuclear Information System (INIS)

    2012-01-01

    Improvements of fire protection measures for nuclear power plants were performed as following items: Development of fire hazard analysis method. Application of developed Fire Dynamic tool to actual plants, With regard to fire tests for the fire data acquisition, cable fire test and oil fire test were performed. Implementation of fire hazard analysis code and simulation were performed as following items: Fire analysis codes FDS, SYLVIA, CFAST were implemented in order to analyze the fire progression phenomena, Trial simulation of fire hazard as Metal-Clad Switch Gear Fire of ONAGAWA NPP in Tohoku earthquake (HEAF accident). (author)

  13. Emissions of volatile organic compounds and particulate matter from small-scale peat fires

    Science.gov (United States)

    Air pollution emitted from peat fires can negatively impact regional air quality, visibility, climate, and human health. Peat fires can smolder over long periods of time and, therefore, can release significantly greater amounts of carbon into the atmosphere per unit area compared...

  14. Sizewell 'B' cable installation

    International Nuclear Information System (INIS)

    Gemmell, D.R.

    1992-01-01

    N G Bailey and Co. Ltd., UK were awarded the contract for the procurement, manufacture, works testing, works finishing, supply, delivery, off-loading, storage, installation, site finishing, preservation, setting to work and site testing of the following; the main cable installation throughout the Station including the addition of the Radioactive Waste Building, earthing and lightning protection installation, cable supporting steelwork and carriers and glanding and termination of cables. The cabling installation comprises power distribution, control and instrumentation cabling including all the associated cabling accessories, terminal boxes and similar components. The way that the contract was set-up, awarded and is now being carried out is described. Planning and industrial relations have been key features of the contract. (Author)

  15. Toxic Combustion Product Yields as a Function of Equivalence Ratio and Flame Retardants in Under-Ventilated Fires: Bench-Large-Scale Comparisons

    Directory of Open Access Journals (Sweden)

    David A. Purser

    2016-09-01

    Full Text Available In large-scale compartment fires; combustion product yields vary with combustion conditions mainly in relation to the fuel:air equivalence ratio (Φ and the effects of gas-phase flame retardants. Yields of products of inefficient combustion; including the major toxic products CO; HCN and organic irritants; increase considerably as combustion changes from well-ventilated (Φ < 1 to under-ventilated (Φ = 1–3. It is therefore essential that bench-scale toxicity tests reproduce this behaviour across the Φ range. Yield data from repeat compartment fire tests for any specific fuel show some variation on either side of a best-fit curve for CO yield as a function of Φ. In order to quantify the extent to which data from the steady state tube furnace (SSTF [1]; ISO TS19700 [2] represents compartment fire yields; the range and average deviations of SSTF data for CO yields from the compartment fire best-fit curve were compared to those for direct compartment fire measurements for six different polymeric fuels with textile and non-textile applications and for generic post-flashover fire CO yield data. The average yields; range and standard deviations of the SSTF data around the best-fit compartment fire curves were found to be close to those for the compartment fire data. It is concluded that SSTF data are as good a predictor of compartment fire yields as are repeat compartment fire test data.

  16. Cable support arrangements

    International Nuclear Information System (INIS)

    Pendleton, E.; Murray, A.

    1983-01-01

    A cable support arrangement extending from a refuelling level floor of a nuclear reactor to the inner shield of a double rotatable shield comprises a linearly extensible cable support and disciplining boom, reaching from the floor to the main shield, and a circumferentially extensible cable support and disciplining means running from the end of the boom to a fixed end on the inner shield. (author)

  17. High voltage dc cables

    Energy Technology Data Exchange (ETDEWEB)

    Bjustrom, B

    1965-12-01

    How stress distribution in dc cables varies with temperature and stress level, influence of polarity reversals and space charges, and different types of overvoltage to which dc cable may be subjected are discussed. Design problems, especially as related to corrosion protection and to mechanical stress caused by wire armoring during manufacturing and laying, accessories and work done on test methods, and the possibility of designing 400 to 600 kV dc cables for transmitting 2000 to 4000 MW are described.

  18. Electrical power cable engineering

    CERN Document Server

    Thue, William A

    2011-01-01

    Fully updated, Electrical Power Cable Engineering, Third Edition again concentrates on the remarkably complex design, application, and preparation methods required to terminate and splice cables. This latest addition to the CRC Press Power Engineering series covers cutting-edge methods for design, manufacture, installation, operation, and maintenance of reliable power cable systems. It is based largely on feedback from experienced university lecturers who have taught courses on these very concepts.The book emphasizes methods to optimize vital design and installation of power cables used in the

  19. Development of low-smoke, flame-retarding cables

    International Nuclear Information System (INIS)

    Kato, H.; Kanemitsuya, K.; Furukawa, K.; Mio, K.

    1983-01-01

    A great deal of attention has been given to the potential fire hazard of combustion gases from organic materials. Although cable industries have developed flame-retarding organic materials for the insulation and jacketing of wires and cables, there was insufficient prevention of toxic gas formation during combustion. To cope with these problems associated with conventional PVC cables, the authors have directed to develop low-smoke, flame-retarding plasticized PVC formulations retaining the original mechanical, electrical and aging properties. A series of basic investigations on smoke suppression followed by an evaluation on practical cables could indicate some effective means to end these problems. This paper describes the results and discussion on smoke suppressing study of plasticized PVC as well as behavior and characteristics of the low-smoke, flame-retarding PVC wires and cables using these materials. (author)

  20. Pilot-Scale Demonstration of ALTA for NOx Control in Pulverized Coal-Fired Boilers

    Energy Technology Data Exchange (ETDEWEB)

    Andrew Fry; Devin Davis; Marc Cremer; Bradley Adams

    2008-04-30

    This report describes computational fluid dynamics (CFD) modeling and pilot-scale testing conducted to demonstrate the ability of the Advanced Layered Technology Approach (ALTA) to reduce NO{sub x} emissions in a pulverized coal (PC) boiler. Testing specifically focused on characterizing NO{sub x} behavior with deep burner staging combined with Rich Reagent Injection (RRI). Tests were performed in a 4 MBtu/hr pilot-scale furnace at the University of Utah. Reaction Engineering International (REI) led the project team which included the University of Utah and Combustion Components Associates (CCA). Deep burner staging and RRI, combined with selective non-catalytic reduction (SNCR), make up the Advanced Layered Technology Approach (ALTA) for NO{sub x} reduction. The application of ALTA in a PC environment requires homogenization and rapid reaction of post-burner combustion gases and has not been successfully demonstrated in the past. Operation of the existing low-NO{sub x} burner and design and operation of an application specific ALTA burner was guided by CFD modeling conducted by REI. Parametric pilot-scale testing proved the chemistry of RRI in a PC environment with a NOx reduction of 79% at long residence times and high baseline NOx rate. At representative particle residence times, typical operation of the dual-register low-NO{sub x} burner provided an environment that was unsuitable for NO{sub x} reduction by RRI, showing no NOx reduction. With RRI, the ALTA burner was able to produce NO{sub x} emissions 20% lower than the low-NO{sub x} burner, 76 ppmv vs. 94 ppmv, at a burner stoichiometric ratio (BSR) of 0.7 and a normalized stoichiometric ratio (NSR) of 2.0. CFD modeling was used to investigate the application of RRI for NO{sub x} control on a 180 MW{sub e} wall-fired, PC boiler. A NO{sub x} reduction of 37% from baseline (normal operation) was predicted using ALTA burners with RRI to produce a NO{sub x} emission rate of 0.185 lb/MBtu at the horizontal nose of

  1. How can prescribed burning and harvesting restore shortleaf pine-oak woodland at the landscape scale in central United States? Modeling joint effects of harvest and fire regimes

    Science.gov (United States)

    Wenchi Jin; Hong S. He; Stephen R. Shifley; Wen J. Wang; John M. Kabrick; Brian K. Davidson

    2018-01-01

    Historical fire regimes in the central United States maintained open-canopy shortleaf pine-oak woodlands on xeric sites. Following large-scale harvest and fire suppression, those woodlands grew denser with more continuous canopy cover, and they gained mesic species at the expense of shortleaf pine. There is high interest in restoring shortleaf pine-oak woodlands; most...

  2. Ventilation system in fire modelization

    International Nuclear Information System (INIS)

    Cordero Garcia, S.

    2012-01-01

    There is a model of fire in an enclosure formed by two rooms. In one of them, it will cause the fire and check how the system of ventilation in different configurations responds. In addition, the behavior of selected targets, which will be a configuration of cables similar to those found in nuclear power stations will be analyzed.

  3. Cable Diagnostic Focused Initiative

    Energy Technology Data Exchange (ETDEWEB)

    Hartlein, R.A.; Hampton, R.N.

    2010-12-30

    This report summarizes an extensive effort made to understand how to effectively use the various diagnostic technologies to establish the condition of medium voltage underground cable circuits. These circuits make up an extensive portion of the electric delivery infrastructure in the United States. Much of this infrastructure is old and experiencing unacceptable failure rates. By deploying efficient diagnostic testing programs, electric utilities can replace or repair circuits that are about to fail, providing an optimal approach to improving electric system reliability. This is an intrinsically complex topic. Underground cable systems are not homogeneous. Cable circuits often contain multiple branches with different cable designs and a range of insulation materials. In addition, each insulation material ages differently as a function of time, temperature and operating environment. To complicate matters further, there are a wide variety of diagnostic technologies available for assessing the condition of cable circuits with a diversity of claims about the effectiveness of each approach. As a result, the benefits of deploying cable diagnostic testing programs have been difficult to establish, leading many utilities to avoid the their use altogether. This project was designed to help address these issues. The information provided is the result of a collaborative effort between Georgia Tech NEETRAC staff, Georgia Tech academic faculty, electric utility industry participants, as well as cable system diagnostic testing service providers and test equipment providers. Report topics include: •How cable systems age and fail, •The various technologies available for detecting potential failure sites, •The advantages and disadvantages of different diagnostic technologies, •Different approaches for utilities to employ cable system diagnostics. The primary deliverables of this project are this report, a Cable Diagnostic Handbook (a subset of this report) and an online

  4. Advanced numerical modelling of a fire. Final report

    International Nuclear Information System (INIS)

    Heikkilae, L.; Keski-Rahkonen, O.

    1996-03-01

    Experience and probabilistic risk assessments show that fires present a major hazard in a nuclear power plant (NPP). The PALOME project (1988-92) improved the quality of numerical simulation of fires to make it a useful tool for fire safety analysis. Some of the most advanced zone model fire simulation codes were acquired. The performance of the codes was studied through literature and personal interviews in earlier studies and BRI2 code from the Japanese Building Research Institute was selected for further use. In PALOME 2 project this work was continued. Information obtained from large-scale fire tests at the German HDR facility allowed reliable prediction of the rate of heat release and was used for code validation. BRI2 code was validated particularly by participation in the CEC standard problem 'Prediction of effects caused by a cable fire experiment within the HDR-facility'. Participation in the development of a new field model code SOFIE specifically for fire applications as British-Swedish-Finnish cooperation was one of the goals of the project. SOFIE code was implemented at VTT and the first results of validation simulations were obtained. Well instrumented fire tests on electronic cabinets were carried out to determine source terms for simulation of room fires and to estimate fire spread to adjacent cabinets. The particular aim of this study was to measure the rate of heat release from a fire in an electronic cabinet. From the three tests, differing mainly in the amount of the fire load, data was obtained for source terms in numerical modelling of fires in rooms containing electronic cabinets. On the basis of these tests also a simple natural ventilation model was derived. (19 refs.)

  5. Climatic and socio-economic fire drivers in the Mediterranean basin at a century scale: Analysis and modelling based on historical fire statistics and dynamic global vegetation models (DGVMs)

    Science.gov (United States)

    Mouillot, F.; Koutsias, N.; Conedera, M.; Pezzatti, B.; Madoui, A.; Belhadj Kheder, C.

    2017-12-01

    Wildfire is the main disturbance affecting Mediterranean ecosystems, with implications on biogeochemical cycles, biosphere/atmosphere interactions, air quality, biodiversity, and socio-ecosystems sustainability. The fire/climate relationship is time-scale dependent and may additionally vary according to concurrent changes climatic, environmental (e.g. land use), and fire management processes (e.g. fire prevention and control strategies). To date, however, most studies focus on a decadal scale only, being fire statistics ore remote sensing data usually available for a few decades only. Long-term fire data may allow for a better caption of the slow-varying human and climate constrains and for testing the consistency of the fire/climate relationship on the mid-time to better apprehend global change effects on fire risks. Dynamic Global Vegetation Models (DGVMs) associated with process-based fire models have been recently developed to capture both the direct role of climate on fire hazard and the indirect role of changes in vegetation and human population, to simulate biosphere/atmosphere interactions including fire emissions. Their ability to accurately reproduce observed fire patterns is still under investigation regarding seasonality, extreme events or temporal trend to identify potential misrepresentations of processes. We used a unique long-term fire reconstruction (from 1880 to 2016) of yearly burned area along a North/South and East/West environmental gradient across the Mediterranean Basin (southern Switzerland, Greece, Algeria, Tunisia) to capture the climatic and socio economic drivers of extreme fire years by linking yearly burned area with selected climate indices derived from historical climate databases and socio-economic variables. We additionally compared the actual historical reconstructed fire history with the yearly burned area simulated by a panel of DGVMS (FIREMIP initiative) driven by daily CRU climate data at 0.5° resolution across the

  6. Influence of Icing on Bridge Cable Aerodynamics

    DEFF Research Database (Denmark)

    Koss, Holger; Frej Henningsen, Jesper; Olsen, Idar

    2013-01-01

    In recent years the relevance of ice accretion for wind-induced vibration of structural bridge cables has been recognised and became a subject of research in bridge engineering. Full-scale monitoring and observation indicate that light precipitation at moderate low temperatures between zero and -5......°C may lead to large amplitude vibrations of bridge cables under wind action. For the prediction of aerodynamic instability quasi-steady models have been developed estimating the cable response magnitude based on structural properties and aerodynamic force coefficients for drag, lift and torsion...... forces of different bridge cables types. The experiments were conducted in a wind tunnel facility capable amongst others to simulate incloud icing conditions....

  7. Development and Testing of Industrial Scale Coal Fired Combustion System, Phase 3

    Energy Technology Data Exchange (ETDEWEB)

    Bert Zauderer

    1998-09-30

    Coal Tech Corp's mission is to develop, license & sell innovative, lowest cost, solid fuel fired power systems & total emission control processes using proprietary and patented technology for domestic and international markets. The present project 'DEVELOPMENT & TESTING OF INDUSTRIAL SCALE, COAL FIRED COMBUSTION SYSTEM, PHASE 3' on DOE Contract DE-AC22-91PC91162 was a key element in achieving this objective. The project consisted of five tasks that were divided into three phases. The first phase, 'Optimization of First Generation 20 MMBtu/hr Air-Cooled Slagging Coal Tech Combustor', consisted of three tasks, which are detailed in Appendix 'A' of this report. They were implemented in 1992 and 1993 at the first generation, 20 MMBtu/hour, combustor-boiler test site in Williamsport, PA. It consisted of substantial combustor modifications and coal-fired tests designed to improve the combustor's wall cooling, slag and ash management, automating of its operation, and correcting severe deficiencies in the coal feeding to the combustor. The need for these changes was indicated during the prior 900-hour test effort on this combustor that was conducted as part of the DOE Clean Coal Program. A combination of combustor changes, auxiliary equipment changes, sophisticated multi-dimensional combustion analysis, computer controlled automation, and series of single and double day shift tests totaling about 300 hours, either resolved these operational issues or indicated that further corrective changes were needed in the combustor design. The key result from both analyses and tests was that the combustor must be substantially lengthened to maximize combustion efficiency and sharply increase slag retention in the combustor. A measure of the success of these modifications was realized in the third phase of this project, consisting of task 5 entitled: 'Site Demonstration with the Second Generation 20 MMBtu/hr Air-Cooled Slagging Coal Tech

  8. Impact of a long term fire retardant (Fire Trol 931) on the leaching of Na, Al, Fe, Mn, Cu and Si from a Mediterranean forest soil: a short-term, lab-scale study.

    Science.gov (United States)

    Koufopoulou, Sofia; Michalopoulos, Charalampos; Tzamtzis, Nikolaos; Pappa, Athina

    2014-06-01

    Long term fire retardant (LTR) application for forest fire prevention purposes as well as wildland fires can result in chemical leaching from forest soils. Large quantities of sodium (Na), aluminium (Al), iron (Fe), manganese (Mn), copper (Cu) and silicon (Si) in leachates, mainly due to ammonium (one of the major LTR components) soil deposition, could affect the groundwater quality. The leaching of Na, Al, Fe, Mn, Cu and Si due to nitrogen based LTR application (Fire Trol 931) was studied at laboratory scale. The concentrations of Na(+), Al(3+), Fe(3+)/Fe(2+), Mn(2+), Cu(2+) and Si(4+) were measured in the resulting leachates from pots with forest soil and pine trees alone and in combination with fire. The leaching of Na, Fe and Si from treated pots was significantly greater than that from control pots. The leaching of Al, Mn and Cu was extremely low.

  9. Automated Cable Preparation for Robotized Stator Cable Winding

    Directory of Open Access Journals (Sweden)

    Erik Hultman

    2017-04-01

    Full Text Available A method for robotized cable winding of the Uppsala University Wave Energy Converter generator stator has previously been presented and validated. The purpose of this study is to present and validate further developments to the method: automated stand-alone equipment for the preparation of the winding cables. The cable preparation consists of three parts: feeding the cable from a drum, forming the cable end and cutting the cable. Forming and cutting the cable was previously done manually and only small cable drums could be handled. Therefore the robot cell needed to be stopped frequently. The new equipment was tested in an experimental robot stator cable winding setup. Through the experiments, the equipment was validated to be able to perform fully automated and robust cable preparation. Suggestions are also given on how to further develop the equipment with regards to performance, robustness and quality. Hence, this work represents another important step towards demonstrating completely automated robotized stator cable winding.

  10. PIV measurements of the turbulence integral length scale on cold combustion flow field of tangential firing boiler

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Wen-fei; Xie, Jing-xing; Gong, Zhi-jun; Li, Bao-wei [Inner Mongolia Univ. of Science and Technology, Baotou (China). Inner Mongolia Key Lab. for Utilization of Bayan Obo Multi-Metallic Resources: Elected State Key Lab.

    2013-07-01

    The process of the pulverized coal combustion in tangential firing boiler has prominent significance on improving boiler operation efficiency and reducing NO{sub X} emission. This paper aims at researching complex turbulent vortex coherent structure formed by the four corners jets in the burner zone, a cold experimental model of tangential firing boiler has been built. And by employing spatial correlation analysis method and PIV (Particle Image Velocimetry) technique, the law of Vortex scale distribution on the three typical horizontal layers of the model based on the turbulent Integral Length Scale (ILS) has been researched. According to the correlation analysis of ILS and the temporal average velocity, it can be seen that the turbulent vortex scale distribution in the burner zone of the model is affected by both jet velocity and the position of wind layers, and is not linear with the variation of jet velocity. The vortex scale distribution of the upper primary air is significantly different from the others. Therefore, studying the ILS of turbulent vortex integral scale is instructive to high efficiency cleaning combustion of pulverized coal in theory.

  11. Problems with conductors and dielectrics for cryogenic cables

    Energy Technology Data Exchange (ETDEWEB)

    Bogner, G; Penczynski, P [Siemens A.G., Erlangen (F.R. Germany). Abt. Reaktortechnik

    1976-06-01

    The most important problems which need to be solved if superconducting power cables are to be used on a large scale are connected with the superconducting cable materials and the dielectrics used for insulation. Research work on superconducting materials for ac and dc cables is briefly reviewed together with stabilization problems for these materials. Three types of insulation are considered - vacuum, subcooled or supercritical helium, and foil wound insulation. The merits and problems encountered in each case are discussed.

  12. Metallographic autopsies of full-scale ITER prototype cable-in-conduit conductors after full testing in SULTAN: 1. The mechanical role of copper strands in a CICC

    International Nuclear Information System (INIS)

    Sanabria, Carlos; Lee, Peter J; Starch, William; Blum, Timothy; Larbalestier, David C; Devred, Arnaud; Jewell, Matthew C; Pong, Ian; Martovetsky, Nicolai

    2015-01-01

    Cables made with Nb 3 Sn-based superconductor strands will provide the 13 T maximum peak magnetic field of the ITER central solenoid (CS) coils and they must survive up to 60 000 electromagnetic cycles. Accordingly, prototype designs of CS cable-in-conduit-conductors (CICC) were electromagnetically tested over multiple magnetic field cycles and warm-up-cool-down scenarios in the SULTAN facility at CRPP. We report here a post-mortem metallographic analysis of two CS CICC prototypes which exhibited some rate of irreversible performance degradation during cycling. The standard ITER CS CICC cable design uses a combination of superconducting and Cu strands, and because the Lorentz force on the strand is proportional to the transport current in the strand, removing the copper strands (while increasing the Cu:SC ratio of the superconducting strands) was proposed as one way of reducing the strand load. In this study we compare the two alternative CICCs, with and without Cu strands, keeping in mind that the degradation after the SULTAN test was lower for the CICC without Cu strands. The post-mortem metallographic evaluation revealed that the overall strand transverse movement was 20% lower in the CICC without Cu strands and that the tensile filament fractures found were less, both indications of an overall reduction in high tensile strain regions. It was interesting to see that the Cu strands in the mixed cable design (with higher degradation) helped reduce the contact stresses on the high pressure side of the CICC, but in either case, the strain reduction mechanisms were not enough to suppress cyclic degradation. Advantages and disadvantages of each conductor design are discussed here aimed to understand the sources of the degradation. (paper)

  13. Cable aging management

    International Nuclear Information System (INIS)

    Anandkumaran, A.; Sedding, H.

    2012-01-01

    Worldwide, due to the age of the majority of nuclear generating stations significant attention is being paid to the condition of the major components, e.g., reactor, steam generator, turbine generator, transformer, etc., with respect to relicensing and life extension. However, there is recognition that cable systems are critical to the safe, reliable and economic operation of nuclear power plants. Consequently, there is great interest in ageing management of low and medium voltage cables in the nuclear environment. Successful implementation of such programs requires an understanding of how the materials associated with cables and their accessories behave under normal operating and accident conditions. However, there is also a great need to determine the actual condition of the materials and systems in order to make rational decisions on whether or not to replace cables to ensure long term assurance of reliable operation. This proposed contribution describes an approach to cable ageing management of low and medium voltage cables based on measurements of material and electrical properties obtained in the laboratory and in the field. The effectiveness of various chemical, mechanical and electrical test methods are discussed in the context of, • Cable configuration, i.e., low or medium voltage, shielded or unshielded • Material type, i.e., PVC, XLPE, EPR, etc., • Ageing stress, i.e., electrical, thermal, radiation, thermal plus radiation, etc. These factors are key to identifying the most appropriate test method (or methods) to enable understanding of the current condition of the cable. While electrical test methods, e.g., ac withstand testing, partial discharge and various dielectric loss measurement techniques have been found effective for medium voltage cables, they are of very limited use on low voltage cables that constitute the majority of cables in nuclear power plants. This limited effectiveness is due to the lack of a well defined ground plane that is a

  14. A Landscape-Scale, Applied Fire Management Experiment Promotes Recovery of a Population of the Threatened Gouldian Finch, Erythrura gouldiae, in Australia's Tropical Savannas.

    Directory of Open Access Journals (Sweden)

    Sarah Legge

    Full Text Available Fire is an integral part of savanna ecology and changes in fire patterns are linked to biodiversity loss in savannas worldwide. In Australia, changed fire regimes are implicated in the contemporary declines of small mammals, riparian species, obligate-seeding plants and grass seed-eating birds. Translating this knowledge into management to recover threatened species has proved elusive. We report here on a landscape-scale experiment carried out by the Australian Wildlife Conservancy (AWC on Mornington Wildlife Sanctuary in northwest Australia. The experiment was designed to understand the response of a key savanna bird guild to fire, and to use that information to manage fire with the aim of recovering a threatened species population. We compared condition indices among three seed-eating bird species--one endangered (Gouldian finch and two non-threatened (long-tailed finch and double-barred finch--from two large areas (> 2,830 km2 with initial contrasting fire regimes ('extreme': frequent, extensive, intense fire; versus 'benign': less frequent, smaller, lower intensity fires. Populations of all three species living with the extreme fire regime had condition indices that differed from their counterparts living with the benign fire regime, including higher haematocrit levels in some seasons (suggesting higher levels of activity required to find food, different seasonal haematocrit profiles, higher fat scores in the early wet season (suggesting greater food uncertainty, and then lower muscle scores later in the wet season (suggesting prolonged food deprivation. Gouldian finches also showed seasonally increasing stress hormone concentrations with the extreme fire regime. Cumulatively, these patterns indicated greater nutritional stress over many months for seed-eating birds exposed to extreme fire regimes. We tested these relationships by monitoring finch condition over the following years, as AWC implemented fire management to produce the 'benign

  15. A Landscape-Scale, Applied Fire Management Experiment Promotes Recovery of a Population of the Threatened Gouldian Finch, Erythrura gouldiae, in Australia's Tropical Savannas.

    Science.gov (United States)

    Legge, Sarah; Garnett, Stephen; Maute, Kim; Heathcote, Joanne; Murphy, Steve; Woinarski, John C Z; Astheimer, Lee

    2015-01-01

    Fire is an integral part of savanna ecology and changes in fire patterns are linked to biodiversity loss in savannas worldwide. In Australia, changed fire regimes are implicated in the contemporary declines of small mammals, riparian species, obligate-seeding plants and grass seed-eating birds. Translating this knowledge into management to recover threatened species has proved elusive. We report here on a landscape-scale experiment carried out by the Australian Wildlife Conservancy (AWC) on Mornington Wildlife Sanctuary in northwest Australia. The experiment was designed to understand the response of a key savanna bird guild to fire, and to use that information to manage fire with the aim of recovering a threatened species population. We compared condition indices among three seed-eating bird species--one endangered (Gouldian finch) and two non-threatened (long-tailed finch and double-barred finch)--from two large areas (> 2,830 km2) with initial contrasting fire regimes ('extreme': frequent, extensive, intense fire; versus 'benign': less frequent, smaller, lower intensity fires). Populations of all three species living with the extreme fire regime had condition indices that differed from their counterparts living with the benign fire regime, including higher haematocrit levels in some seasons (suggesting higher levels of activity required to find food), different seasonal haematocrit profiles, higher fat scores in the early wet season (suggesting greater food uncertainty), and then lower muscle scores later in the wet season (suggesting prolonged food deprivation). Gouldian finches also showed seasonally increasing stress hormone concentrations with the extreme fire regime. Cumulatively, these patterns indicated greater nutritional stress over many months for seed-eating birds exposed to extreme fire regimes. We tested these relationships by monitoring finch condition over the following years, as AWC implemented fire management to produce the 'benign' fire regime

  16. Fire-protection research for energy technology: Fy 80 year end report

    Science.gov (United States)

    Hasegawa, H. K.; Alvares, N. J.; Lipska, A. E.; Ford, H.; Priante, S.; Beason, D. G.

    1981-05-01

    This continuing research program was initiated in order to advance fire protection strategies for Fusion Energy Experiments (FEE). The program expanded to encompass other forms of energy research. Accomplishments for fiscal year 1980 were: finalization of the fault-free analysis of the Shiva fire management system; development of a second-generation, fire-growth analysis using an alternate model and new LLNL combustion dynamics data; improvements of techniques for chemical smoke aerosol analysis; development and test of a simple method to assess the corrosive potential of smoke aerosols; development of an initial aerosol dilution system; completion of primary small-scale tests for measurements of the dynamics of cable fires; finalization of primary survey format for non-LLNL energy technology facilities; and studies of fire dynamics and aerosol production from electrical insulation and computer tape cassettes.

  17. Fire-protection research for energy technology: FY 80 year-end report

    International Nuclear Information System (INIS)

    Hasegawa, H.K.; Alvares, N.J.; Lipska, A.E.; Ford, H.; Priante, S.; Beason, D.G.

    1981-01-01

    This continuing research program was initiated in 1977 in order to advance fire protection strategies for Fusion Energy Experiments (FEE). The program has since been expanded to encompass other forms of energy research. Accomplishments for fiscal year 1980 were: finalization of the fault-tree analysis of the Shiva fire management system; development of a second-generation, fire-growth analysis using an alternate moel and new LLNL combustion dynamics data; improvements of techniques for chemical smoke aerosol analysis; development and test of a simple method to assess the corrosive potential of smoke aerosols; development of an initial aerosol dilution system; completion of primary small-scale tests for measurements of the dynamics of cable fires; finalization of primary survey format for non-LLNL energy technology facilities; and studies of fire dynamics and aerosol production from electrical insulation and computer tape cassettes

  18. Fire Resistance of Large-Scale Cross-Laminated Timber Panels

    Science.gov (United States)

    Henek, Vladan; Venkrbec, Václav; Novotný, Miloslav

    2017-12-01

    Wooden structures are increasingly being used in the construction of residential buildings. A common and often published reason to avoid wooden structures is their insufficient fire resistance, which reduces bearing capacity. For this reason, composite sandwich structures began to be designed to eliminate this drawback, as well as others. Recently, however, the trend is for a return to the original, wood-only variant and a search is underway for new technical means of improving the properties of such structures. Many timber structure technologies are known, but structures made from cross-laminated timber (CLT) panels have been used very often in recent years. CLT panels, also known as X-LAM, are currently gaining popularity in Europe. In the case of CLT panels composed of several layers of boards, they can be said to offer a certain advantage in that after the surface layer of a board has burnt and the subsurface layer has dried, oxygen is not drawn to the unburned wood for further combustion and thus the burning process ceases. CLT panels do not need to be specially modified or coated with fire resistant materials, although they are usually lined with gypsum-fibre fire resistant boards due to guidelines set out in the relevant standards. This paper presents a new method for the assessment of load-bearing perimeter walls fabricated from CLT panels without the use of an inner fire-retardant lining to ensure fire resistance at the level required by European standards (i.e. those harmonized for the Czech construction industry). The calculations were verified through laboratory tests which show that better parameters can be achieved during the classification of structures from the fire resistance point of view. The aim of the article is to utilize the results of assessment and testing by an accredited laboratory in order to demonstrate the possibilities of using CLT panels for the construction of multistorey as well as multi-purpose buildings in the Czech Republic.

  19. Continental-scale simulation of burn probabilities, flame lengths, and fire size distribution for the United States

    Science.gov (United States)

    Mark A. Finney; Charles W. McHugh; Isaac Grenfell; Karin L. Riley

    2010-01-01

    Components of a quantitative risk assessment were produced by simulation of burn probabilities and fire behavior variation for 134 fire planning units (FPUs) across the continental U.S. The system uses fire growth simulation of ignitions modeled from relationships between large fire occurrence and the fire danger index Energy Release Component (ERC). Simulations of 10,...

  20. Monitoring and assessment of soil erosion at micro-scale and macro-scale in forests affected by fire damage in northern Iran.

    Science.gov (United States)

    Akbarzadeh, Ali; Ghorbani-Dashtaki, Shoja; Naderi-Khorasgani, Mehdi; Kerry, Ruth; Taghizadeh-Mehrjardi, Ruhollah

    2016-12-01

    Understanding the occurrence of erosion processes at large scales is very difficult without studying them at small scales. In this study, soil erosion parameters were investigated at micro-scale and macro-scale in forests in northern Iran. Surface erosion and some vegetation attributes were measured at the watershed scale in 30 parcels of land which were separated into 15 fire-affected (burned) forests and 15 original (unburned) forests adjacent to the burned sites. The soil erodibility factor and splash erosion were also determined at the micro-plot scale within each burned and unburned site. Furthermore, soil sampling and infiltration studies were carried out at 80 other sites, as well as the 30 burned and unburned sites, (a total of 110 points) to create a map of the soil erodibility factor at the regional scale. Maps of topography, rainfall, and cover-management were also determined for the study area. The maps of erosion risk and erosion risk potential were finally prepared for the study area using the Revised Universal Soil Loss Equation (RUSLE) procedure. Results indicated that destruction of the protective cover of forested areas by fire had significant effects on splash erosion and the soil erodibility factor at the micro-plot scale and also on surface erosion, erosion risk, and erosion risk potential at the watershed scale. Moreover, the results showed that correlation coefficients between different variables at the micro-plot and watershed scales were positive and significant. Finally, assessment and monitoring of the erosion maps at the regional scale showed that the central and western parts of the study area were more susceptible to erosion compared with the western regions due to more intense crop-management, greater soil erodibility, and more rainfall. The relationships between erosion parameters and the most important vegetation attributes were also used to provide models with equations that were specific to the study region. The results of this

  1. Fire damage data analysis as related to current testing practices for nuclear power applications

    International Nuclear Information System (INIS)

    Klevan, J.; MacDougall, E.A.; Hall, R.E.

    1978-01-01

    A review of reports of specific fires which have occurred in nuclear power plants in the United States is presented. A limited comparison of cable and similar fires with results of the IEEE 383 fire test used to evaluate cable insulation is also presented

  2. Proposed superscreened cables and connectors

    International Nuclear Information System (INIS)

    Fowler, E.P.

    1975-11-01

    The paper summarises the present availability of superscreened cables and proposes the specification of a family of cables to meet the foreseeable needs of the nuclear power industry. The cable numbering system is described, special tests outlined and important details given for the chosen cables. Appropriate connectors are also discussed and listed with an outline of their required screening performance. (author)

  3. PROTOTYPE SCALE TESTING OF LIMB TECHNOLOGY FOR A PULVERIZED-COAL-FIRED BOILER

    Science.gov (United States)

    The report summarizes results of an evaluation of furnace sorbent injection (FSI) to control sulfur dioxide (SO2) emissions from coal-fired utility boilers. (NOTE: FSI of calcium-based sorbents has shown promise as a moderate SO2 removal technology.) The Electric Power Research I...

  4. Variance in population firing rate as a measure of slow time-scale correlation

    Directory of Open Access Journals (Sweden)

    Adam C. Snyder

    2013-12-01

    Full Text Available Correlated variability in the spiking responses of pairs of neurons, also known as spike count correlation, is a key indicator of functional connectivity and a critical factor in population coding. Underscoring the importance of correlation as a measure for cognitive neuroscience research is the observation that spike count correlations are not fixed, but are rather modulated by perceptual and cognitive context. Yet while this context fluctuates from moment to moment, correlation must be calculated over multiple trials. This property undermines its utility as a dependent measure for investigations of cognitive processes which fluctuate on a trial-to-trial basis, such as selective attention. A measure of functional connectivity that can be assayed on a moment-to-moment basis is needed to investigate the single-trial dynamics of populations of spiking neurons. Here, we introduce the measure of population variance in normalized firing rate for this goal. We show using mathematical analysis, computer simulations and in vivo data how population variance in normalized firing rate is inversely related to the latent correlation in the population, and how this measure can be used to reliably classify trials from different typical correlation conditions, even when firing rate is held constant. We discuss the potential advantages for using population variance in normalized firing rate as a dependent measure for both basic and applied neuroscience research.

  5. GREENHOUSE GAS EMISSIONS CONTROL BY OXYGEN FIRING IN CIRCULATING FLUIDIZED BED BOILERS: PHASE II--PILOT SCALE TESTING AND UPDATED PERFORMANCE AND ECONOMICS FOR OXYGEN FIRED CFB WITH CO2 CAPTURE

    Energy Technology Data Exchange (ETDEWEB)

    Nsakala ya Nsakala; Gregory N. Liljedahl; David G. Turek

    2004-10-27

    Because fossil fuel fired power plants are among the largest and most concentrated producers of CO{sub 2} emissions, recovery and sequestration of CO{sub 2} from the flue gas of such plants has been identified as one of the primary means for reducing anthropogenic CO{sub 2} emissions. In this Phase II study, ALSTOM Power Inc. (ALSTOM) has investigated one promising near-term coal fired power plant configuration designed to capture CO{sub 2} from effluent gas streams for sequestration. Burning fossil fuels in mixtures of oxygen and recirculated flue gas (made principally of CO{sub 2}) essentially eliminates the presence of atmospheric nitrogen in the flue gas. The resulting flue gas is comprised primarily of CO{sub 2}, along with some moisture, nitrogen, oxygen, and trace gases like SO{sub 2} and NO{sub x}. Oxygen firing in utility scale Pulverized Coal (PC) fired boilers has been shown to be a more economical method for CO{sub 2} capture than amine scrubbing (Bozzuto, et al., 2001). Additionally, oxygen firing in Circulating Fluid Bed Boilers (CFB's) can be more economical than in PC or Stoker firing, because recirculated gas flow can be reduced significantly. Oxygen-fired PC and Stoker units require large quantities of recirculated flue gas to maintain acceptable furnace temperatures. Oxygen-fired CFB units, on the other hand, can accomplish this by additional cooling of recirculated solids. The reduced recirculated gas flow with CFB plants results in significant Boiler Island cost savings resulting from reduced component The overall objective of the Phase II workscope, which is the subject of this report, is to generate a refined technical and economic evaluation of the Oxygen fired CFB case (Case-2 from Phase I) utilizing the information learned from pilot-scale testing of this concept. The objective of the pilot-scale testing was to generate detailed technical data needed to establish advanced CFB design requirements and performance when firing coals and

  6. Material Selection for Cable Gland to Improved Reliability of the High-hazard Industries

    Science.gov (United States)

    Vashchuk, S. P.; Slobodyan, S. M.; Deeva, V. S.; Vashchuk, D. S.

    2018-01-01

    The sealed cable glands (SCG) are available to ensure safest connection sheathed single wire for the hazard production facility (nuclear power plant and others) the same as pilot cable, control cables, radio-frequency cables et al. In this paper, we investigate the specifics of the material selection of SCG with the express aim of hazardous man-made facility. We discuss the safe working conditions for cable glands. The research indicates the sintering powdered metals cables provide the reliability growth due to their properties. A number of studies have demonstrated the verification of material selection. On the face of it, we make findings indicating that double glazed sealed units could enhance reliability. We had evaluated sample reliability under fire conditions, seismic load, and pressure containment failure. We used the samples mineral insulated thermocouple cable.

  7. Using fine-scale fuel measurements to assess wildland fuels, potential fire behavior and hazard mitigation treatments in the southeastern USA

    International Nuclear Information System (INIS)

    Ottmar, Roger D.; Blake, John I.; Crolly, William T.

    2012-01-01

    The inherent spatial and temporal heterogeneity of fuelbeds in forests of the southeastern United States may require fine scale fuel measurements for providing reliable fire hazard and fuel treatment effectiveness estimates. In a series of five papers, an intensive, fine scale fuel inventory from the Savanna River Site in the southeastern United States is used for building fuelbeds and mapping fire behavior potential, evaluating fuel treatment options for effectiveness, and providing a comparative analysis of landscape modeled fire behavior using three different data sources including the Fuel Characteristic Classification System, LANDFIRE, and the Southern Wildfire Risk Assessment. The research demonstrates that fine scale fuel measurements associated with fuel inventories repeated over time can be used to assess broad scale wildland fire potential and hazard mitigation treatment effectiveness in the southeastern USA and similar fire prone regions. Additional investigations will be needed to modify and improve these processes and capture the true potential of these fine scale data sets for fire and fuel management planning.

  8. Improvement of fire protection measures for nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-08-15

    Improvements of fire protection measures for nuclear power plants were performed as following items: Development of fire hazard analysis method. Application of developed Fire Dynamic Tool to actual plants (FDT{sup S}), With regard to fire tests for the fire data acquisition, cable fire test and High Energy Arcing Faults (HEAF) fire test were performed. Implementation of fire hazard analysis code and simulation were performed as following items: Fire analysis codes FDS, SYLVIA, and CFAST were implemented in order to analyze the fire progression phenomena. Trial simulation of HEAF accident of Onagawa NPP in Tohoku earthquake. (author)

  9. Design, processing, and properties of Bi 2212\\/Ag Rutherford cables

    CERN Document Server

    Collings, E W; Scanlan, R M; Dietderich, D R; Motowidlo, L R; Sokolowski, R S; Aoki, Y; Hasegawa, T

    1999-01-01

    In a program intended to explore the use of high temperature superconducting (HTSC) cables in high field synchrotron dipole magnets model Bi:2212/Ag Rutherford cables were designed bearing in mind the needs for mechanical integrity, relatively high tensile strength, and low coupling losses. To satisfy these needs a core-type cable design was selected and a readily available heat-resistant core material acquired. Cables were wound for critical current- and AC loss measurement. Both winding-induced (mechanical) and core-induced (chemical) critical current degradation was examined. Interstrand coupling loss was measured calorimetrically on model cable samples with bare- and oxide-coated cores. From the results it was predicted that the losses of full-scale Bi:2212/Ag-wound LHC-type Rutherford cables would fall close to the acceptability range for the windings of high-field accelerator dipoles. (10 refs).

  10. EOSLT Consortium Biomass Co-firing. WP 4. Biomass co-firing in oxy-fuel combustion. Part 1. Lab- Scale Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Fryda, L.E. [ECN Biomass, Coal and Environmental Research, Petten (Netherlands)

    2011-07-15

    In the frame of WP4 of the EOS LT Co-firing program, the ash formation and deposition of selected coal/biomass blends under oxyfuel and air conditions were studied experimentally in the ECN lab scale coal combustor (LCS). The fuels used were Russian coal, South African coal and Greek Lignite, either combusted separately or in blends with cocoa and olive residue. The first trial period included tests with the Russian and South African coals and their blends with cocoa, the second trial period included Lignite with olive residue tests and a final period firing only Lignite and Russian coal, mainly to check and verify the observed results. During the testing, also enriched air combustion was applied, in order to establish conclusions whether a systematic trend on ash formation and deposition exists, ranging from conventional air, to enriched air (improving post combustion applications) until oxyfuel conditions. A horizontal deposition probe equipped with thermocouples and heat transfer sensors for on line data acquisition, and a cascade impactor (staged filter) to obtain size distributed ash samples including the submicron range at the reactor exit were used. The deposition ratio and the deposition propensity measured for the various experimental conditions were higher in all oxyfuel cases. No significant variations in the ash formation mechanisms and the ash composition were established. Finally the data obtained from the tests performed under air and oxy-fuel conditions were utilised for chemical equilibrium calculations in order to facilitate the interpretation of the measured data; the results indicate that temperature dependence and fuels/blends ash composition are the major factors affecting gaseous compound and ash composition rather than the combustion environment, which seems to affect neither the ash and fine ash (submicron) formation, nor the ash composition. The ash deposition mechanisms were studied in more detail in Part II of this report.

  11. Specifications, tests, and installation of wires and cables for the Diablo Canyon Nuclear Power Project

    International Nuclear Information System (INIS)

    Dan, F.J.

    1977-01-01

    The process of selecting wires and cables for the Diablo Canyon Nuclear Power Project is described. The criteria for the fire and environmental tests, the basis for the specifications, and the reasons for the final choice and acceptance are outlined. A short section is dedicated to the installation of cables in raceways with reference to separation and color coding. Also covered are the selection and testing of fire stops and the selection of seismic supports

  12. Costly cables; Lange Leitung

    Energy Technology Data Exchange (ETDEWEB)

    Hautmann, Daniel

    2012-08-15

    Connection of offshore wind turbines to the onshore power supply grid requires costly cables for HV DC power transmission. The technology is mature enough to enable low-loss power transmission, but construction times may last several years.

  13. Cable Aerodynamic Control

    DEFF Research Database (Denmark)

    Kleissl, Kenneth

    to a categorization of the different control technics together with an identification of two key mechanisms for reduction of the design drag force. During this project extensive experimental work examining the aerodynamics of the currently used cable surface modifications together with new innovative proposals have...... been conducted. The two current prevailing systems consisting of helically filleted cables and cables with a pattern-indented surface were directly compared under the same conditions and both applications were found with attractive properties. The pattern-indented surface maintained a low supercritical...... of reducing the intensity of the axial flow and disrupting the near wake flow structures. Similar studies during wet conditions with artificial simulation of light rain in the wind tunnel showed that the plain cable suffered from severe rain-wind induced vibrations. But despite the presence of both upper...

  14. Fatigue of cable anchorage of large cable stayed bridge; Daikibo shachokyo cable teichaku kozo no hiro

    Energy Technology Data Exchange (ETDEWEB)

    Endo, T.; Matsumoto, T. [Honshu-Shikoku Bridge Authority, Tokyo (Japan); Tsukahara, H. [Yokogawa Bridge Corp., Tokyo (Japan); Miki, C. [Tokyo Institute of Technology, Tokyo (Japan)

    1995-10-21

    Design considerations such as design schemes, the assemblage and welding of steel plates, and safety for fatigue of welded connections have to be taken for the cable anchorages of the steel cable stayed bridges. In this study, two full scale models, which have different shape of box anchorages welded to the web of the main girder, were made to investigate fatigue characteristics as well as assemblage of plate and gelding details. Finite element analyses for both test models and actual bridges here carried out to compare stress distribution. It was confirmed that the assemblage and welding of both types of box anchorage were attainable kith required quality and accuracy. According to the fatigue test, fatigue cracks originated from the weldings of the bearing plate to which the load from cable socket applied directly were caused by out-of-plane bending of the bearing plate. It was proved that the slight modifications of the details around the bearing plate resulted in sufficient fatigue strength in both types of anchorage. 1 ref., 23 figs., 2 tabs.

  15. Full-scale Milling Tests of Wood Pellets for Combustion in a Suspension-Fired Power Plant Boiler

    DEFF Research Database (Denmark)

    Masche, Marvin; Puig Arnavat, Maria; Wadenbäck, Johan

    The size reduction of pelletized wood is crucial in suspension-fired power plants, and hence its milling characteristics are of interest to optimize the milling and combustion process. The objective of the study was to compare the size and shape of pellets disintegrated in hot water with that from......), and analyzing the comminuted particle shape and particle size distribution (PSD). Large-scale pellet comminution produced finer and wider PSDs than pellet disintegration in hot water, but only slightly altered the particle shape. The mill pressure loss, absorbed mill power, and hence SGEC depended on the pellet...

  16. Estimating evapotranspiration change due to forest treatment and fire at the basin scale in the Sierra Nevada, California

    Science.gov (United States)

    Roche, J. W.; Goulden, M.; Bales, R. C.

    2017-12-01

    Increased forest evapotranspiration (ET) coupled with snowpack decreases in a warming climate is likely to decrease runoff and increase forest drought stress. Field experiments and modeling suggest that forest thinning can reduce ET and thus increase potential runoff relative to untreated areas. We investigated the potential magnitude and duration of ET decreases resulting from forest-thinning treatments and fire using a robust empirical relation between Landsat-derived mean-annual normalized difference vegetation index (NDVI) and annual ET measured at flux towers. Among forest treatments, the minimum observed NDVI change required to produce a significant departure from control plots with NDVI of about 0.70 was -0.07 units, corresponding to a basal-area reduction of 3.1 m2 ha-1, and equivalent to an estimated ET reduction of -102 mm yr-1. Intensive thinning in highly productive forests that approached pre-fire-exclusion densities reduced basal area by 40-50%, generating estimated ET reductions of 152-216 mm yr-1 over five years following treatment. Between 1990 and 2008, fires in the American River basin generated more than twice the ET reduction per unit area than those in the Kings River basin, corresponding to greater water and energy limitations in the latter and greater fire severity in the former. A rough extrapolation of these results to the entire American River watershed, much of which would have burned naturally during this 19-year period, could result in ET reductions that approach 10% of full natural flows for drought years and 5% averaged over all years. This work demonstrates the potential utility to estimate forest ET change at the patch scale, which in turn may allow managers to estimate thinning benefits in areas lacking detailed hydrologic measurements.

  17. Safety study of fire protection for nuclear fuel cycle facility

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-08-15

    Based on the investigation of fire protection standards for domestic and foreign nuclear facilities, the fire protection guideline for nuclear fuel cycle facility has been completed. In 2012, trial operation is started by private company using the guideline. In addition, the acquisition of fire evaluation data for a components (electric cable) targeted for spread of fire and the evaluation model of fire source were continued for the fire hazard analysis (FHA). (author)

  18. Safety study of fire protection for nuclear fuel cycle facility

    International Nuclear Information System (INIS)

    2013-01-01

    Based on the investigation of fire protection standards for domestic and foreign nuclear facilities, the fire protection guideline for nuclear fuel cycle facility has been completed. In 2012, trial operation is started by private company using the guideline. In addition, the acquisition of fire evaluation data for a components (electric cable) targeted for spread of fire and the evaluation model of fire source were continued for the fire hazard analysis (FHA). (author)

  19. Magnet cable manufacturing

    International Nuclear Information System (INIS)

    Royet, J.

    1985-07-01

    The superconducting magnets used in the construction of particle accelerators are mostly built from flat, multistrand cables with rectangular or keystoned cross sections. The superconducting strands are mostly circular but a design of a cable made of preflattened wires was proposed a few years ago under the name of Berkeley flat; such cable shows some interesting characteristics. Another design consists of a few smaller precabled wires (e.g. 6 around 1). This configuration allows smaller filaments and a better transposition of the current elements. The Superconducting Super Collider project involves the largest amount of superconducting cable ever envisaged for a single machine. Furthermore, the design calls for exceptional accuracy and improved characteristics of the cable. A part of the SSC research and development program is focused on these important questions. In this paper we emphasize the difference between the conventional cabling and wires with superconducting. A new concept for the tooling will be introduced as well as the necessary characteristics of a specialized cabler. 5 figs

  20. Lab-scale co-firing of virgin and torrefied bamboo species Guadua angustifolia Kunth as a fuel substitute in coal fired power plants

    International Nuclear Information System (INIS)

    Fryda, Lydia; Daza, Claudia; Pels, Jan; Janssen, Arno; Zwart, Robin

    2014-01-01

    Bamboo is a potential sustainable biomass source for renewable heat and power production as it presents common fuel characteristics with other biomass feedstocks regarding heating value and chemical composition. This paper presents an evaluation of the combustion behaviour of the bamboo species Guadua angustifolia Kunth, virgin as well as torrefied, in blends with coal or pure, comparing with other biomass feedstocks such as wood and herbaceous biomass. The bamboo pre-treatment and the combustion experiments were carried out at dedicated installations at ECN, including a laboratory scale batch torrefaction reactor and a combustion simulation test facility. The results on combustion and co-firing reveal that in terms of fouling, the untreated bamboo shows behaviour closer to herbaceous biomass rather than to wood, with specific fouling factors of wood, bamboo and herbaceous biomass of 0.91·10 −3 , 2.9·10 −3 , 3.1·10 −3  K·m 2 ·W −1 ·g −1 respectively. Dry torrefaction improves its physical properties by increasing the density and grindability without improving significantly its fouling behaviour while the fouling behaviour of wet torrefied bamboo is similar to woody biomass; the specific fouling factors of dry torrefied and wet torrefied bamboo are 2.4·10 −3 and 0.89·10 −3  K·m 2 ·W −1 ·g −1 respectively. The fouling behaviour of biomass and coal blends lies between the fuels of the blend. Alternative bamboo species were evaluated using the alkali index A i based on their fuel composition. It appears that the fouling behaviour of alternative species is better than for G. angustifolia, therefore these should be further analysed. - Highlights: • Bamboo species Guadua angustifolia is a promising feedstock for power generation. • Dry and wet torrefaction of selected samples were carried out at ECN. • Virgin (untreated) and pretreated samples were fired pure or in coal blends. • Pretreated bamboo is suitable for large scale power

  1. Advanced circulating fluidised bed technology (CFB) for large-scale solid biomass fuel firing power plants

    Energy Technology Data Exchange (ETDEWEB)

    Jaentti, Timo; Zabetta, Edgardo Coda; Nuortimo, Kalle [Foster Wheeler Energia Oy, Varkaus (Finland)

    2013-04-01

    Worldwide the nations are taking initiatives to counteract global warming by reducing their greenhouse gas emissions. Efforts to increase boiler efficiency and the use of biomass and other solid renewable fuels are well in line with these objectives. Circulating fluidised bed boilers (CFB) are ideal for efficient power generation, capable to fire a broad variety of solid biomass fuels from small CHP plants to large utility power plants. Relevant boiler references in commercial operation are made for Finland and Poland.

  2. Biomass assessment and small scale biomass fired electricity generation in the Green Triangle, Australia

    International Nuclear Information System (INIS)

    Rodriguez, Luis C.; May, Barrie; Herr, Alexander; O'Connell, Deborah

    2011-01-01

    Coal fired electricity is a major factor in Australia's greenhouse gas emissions (GHG) emissions. The country has adopted a mandatory renewable energy target (MRET) to ensure that 20% of electricity comes from renewable sources by 2020. In order to support the MRET, a market scheme of tradable Renewable Energy Certificates (RECs) has been implemented since 2001. Generators using biomass from eligible sources are able to contribute to GHG emission reduction through the substitution of coal for electricity production and are eligible to create and trade RECs. This paper quantifies the potential biomass resources available for energy generation from forestry and agriculture in the Green Triangle, one of the most promising Australian Regions for biomass production. We analyse the cost of electricity generation using direct firing of biomass, and estimate the required REC prices to make it competitive with coal fired electricity generation. Major findings suggest that more than 2.6 million tonnes of biomass are produced every year within 200 km of the regional hub of Mount Gambier and biomass fired electricity is viable using feedstock with a plant gate cost of 46 Australian Dollars (AUD) per tonne under the current REC price of 34 AUD per MWh. These findings are then discussed in the context of regional energy security and existing targets and incentives for renewable energies. -- Highlights: → We assessed the biomass production in the Green Triangle. → 2.6 million tonnes of biomass per year are produced within 200 km from Mt Gambier. → Renewable Energy Certificates makes bioenergy competitive with coal electricity. → At a REC price of 34 AUD, biomass of up to 46 AUD/tonne might be used for bionergy

  3. The fire course and consequences to be drawn from the fire in the Browns Ferry nuclear power station

    International Nuclear Information System (INIS)

    Hoffmeister, N.

    1977-01-01

    After a short description of the fire course and the fire fighting measures during the cable fire at Browns Ferry nuclear power station, the effects on the safety system are given in chronological order, and consequences are drawn for a general fire protection programme for nuclear power plants. In this context, the licensing guideline of the NRC for fire protection in nuclear power plants is mentioned, which took particular account of the consequences to be drawn from the Browns Ferry fire. (ORU) [de

  4. Modeling of phosphorus fluxes produced by wild fires at watershed scales.

    Science.gov (United States)

    Matyjasik, M.; Hernandez, M.; Shaw, N.; Baker, M.; Fowles, M. T.; Cisney, T. A.; Jex, A. P.; Moisen, G.

    2017-12-01

    River runoff is one of the controlling processes in the terrestrial phosphorus cycle. Phosphorus is often a limiting factor in fresh water. One of the factors that has not been studied and modeled in detail is phosporus flux produced from forest wild fires. Phosphate released by weathering is quickly absorbed in soils. Forest wild fires expose barren soils to intensive erosion, thus releasing relatively large fluxes of phosphorus. Measurements from three control burn sites were used to correlate erosion with phosphorus fluxes. These results were used to model phosphorus fluxes from burned watersheds during a five year long period after fires occurred. Erosion in our model is simulated using a combination of two models: the WEPP (USDA Water Erosion Prediction Project) and the GeoWEPP (GIS-based Water Erosion Prediction Project). Erosion produced from forest disturbances is predicted for any watershed using hydrologic, soil, and meteorological data unique to the individual watersheds or individual slopes. The erosion results are modified for different textural soil classes and slope angles to model fluxes of phosphorus. The results of these models are calibrated using measured concentrations of phosphorus for three watersheds located in the Interior Western United States. The results will help the United States Forest Service manage phosporus fluxes in national forests.

  5. Alkali chloride induced corrosion of superheaters under biomass firing conditions: Improved insights from laboratory scale studies

    DEFF Research Database (Denmark)

    Okoro, Sunday Chukwudi; Montgomery, Melanie; Jappe Frandsen, Flemming

    2015-01-01

    One of the major operational challenges experienced by power plants firing biomass is the high corrosion rate of superheaters. This limits the outlet steam temperature of the superheaters and consequently, the efficiency of the power plants. The high corrosion rates have been attributed to the fo......One of the major operational challenges experienced by power plants firing biomass is the high corrosion rate of superheaters. This limits the outlet steam temperature of the superheaters and consequently, the efficiency of the power plants. The high corrosion rates have been attributed......, [1–3]). However, complete understanding of the corrosion mechanism under biomass-firing conditions has not yet been achieved. This is attributed partly to the complex nature of the corrosion process since there are many species produced from fuel combustion which can interact with one another...... and the steel surface. Many studies have focused on specific parameters such as, deposit composition (KCl, K2SO4, K2CO3, etc.) or gas species such as HCl, SO2, H2O [4–6], however, more research is necessary to understand the interaction of deposits and gas mixtures with each other and metallic superheater...

  6. Electro magnetic compatibility of cabling and wiring in buildings and installations

    NARCIS (Netherlands)

    Steenstra, H.T.

    2008-01-01

    The thesis deals with the behaviour, with respect to EMC (Electro Magnetic Compatibility), of cabling and wiring in buildings and installations. Measurement and calculation methods are developed and applied to cabling in a large scale installation as well as to individual cables. Besides, the

  7. Offshore Wind Farm Cable Connection Configuration Optimization using Dynamic Minimum Spanning Tree Algorithm

    DEFF Research Database (Denmark)

    Hou, Peng; Hu, Weihao; Chen, Zhe

    2015-01-01

    Anew approach, Dynamic Minimal Spanning Tree (DMST) algorithm, whichisbased on the MST algorithm isproposed in this paper to optimizethe cable connectionlayout for large scale offshore wind farm collection system. The current carrying capacity of the cable is considered as the main constraint....... It is amore economicalway for cable connection configurationdesignof offshore wind farm collection system....

  8. Vulnerability and Resilience of Temperate Forest Landscapes to Broad-Scale Deforestation in Response to Changing Fire Regimes and Altered Post-Fire Vegetation Dynamics

    Science.gov (United States)

    Tepley, A. J.; Veblen, T. T.; Perry, G.; Anderson-Teixeira, K. J.

    2015-12-01

    In the face of on-going climatic warming and land-use change, there is growing concern that temperate forest landscapes could be near a tipping point where relatively small changes to the fire regime or altered post-fire vegetation dynamics could lead to extensive conversion to shrublands or savannas. To evaluate vulnerability and resilience to such conversion, we develop a simple model based on three factors we hypothesize to be key in predicting temperate forest responses to changing fire regimes: (1) the hazard rate (i.e., the probability of burning in the next year given the time since the last fire) in closed-canopy forests, (2) the hazard rate for recently-burned, open-canopy vegetation, and (3) the time to redevelop canopy closure following fire. We generate a response surface representing the proportions of the landscape potentially supporting closed-canopy forest and non-forest vegetation under nearly all combinations of these three factors. We then place real landscapes on this response surface to assess the type and magnitude of changes to the fire regime that would drive extensive forest loss. We show that the deforestation of much of New Zealand that followed initial human colonization and the introduction of a new ignition source ca. 750 years ago was essentially inevitable due to the slow rate of forest recovery after fire and the high flammability of post-fire vegetation. In North America's Pacific Northwest, by contrast, a predominantly forested landscape persisted despite two periods of widespread burning in the recent past due in large part to faster post-fire forest recovery and less pronounced differences in flammability between forests and the post-fire vegetation. We also assess the factors that could drive extensive deforestation in other regions to identify where management could reduce this potential and to guide field and modeling work to better understand the responses and ecological feedbacks to changing fire regimes.

  9. Full-scale demonstration. Fire testing of a system for penetration sealing based on foamed silicone elastomer: Studsvik 77-05-26

    International Nuclear Information System (INIS)

    Brown, A.

    1978-06-01

    Testing of a system for making fire retardant penetration seals based on foamed-in-place silicone elastomer is described. The report covers - Concept of fire retardant penetration seals and the Chemtrol system, Design FC 225 - Account of materials used to prepare seals and method of application - Test assembly and full-scale facility at Studsvik - Classification of seals used in demonstration - Diagrams of seals and photographs taken after demonstration

  10. Full-scale demonstration. Fire testing of a system for penetration sealing based on foamed silicone elastomer: Studsvik 77-05-26

    International Nuclear Information System (INIS)

    Brown, A.

    1978-06-01

    Testing of a system for making fire retardant penetration seals based on foamed-in-place silicone elastomer is described. The report covers - Concept of fire retardant penetration seals and the Chemtrol system, Design FC 225 - Account of materials used to prepare seals and method of application - Test assembly and full-scale facility at Studsvik - Classification of seals used in demonstration - Diagrams of seals and photographs taken after demonstration (author)

  11. Breed locally, disperse globally: Fine-scale genetic structure despite landscape-scale panmixia in a fire-specialist

    Science.gov (United States)

    Jennifer C. Pierson; Fred W. Allendorf; Pierre Drapeau; Michael K. Schwartz

    2013-01-01

    An exciting advance in the understanding of metapopulation dynamics has been the investigation of how populations respond to ephemeral patches that go 'extinct' during the lifetime of an individual. Previous research has shown that this scenario leads to genetic homogenization across large spatial scales. However, little is known about fine-scale genetic...

  12. Using fine-scale fuel measurements to assess wildland fuels, potential fire behavior and hazard mitigation treatments in the southeastern USA

    Science.gov (United States)

    Roger D. Ottmar; John I. Blake; William T. Crolly

    2012-01-01

    The inherent spatial and temporal heterogeneity of fuel beds in forests of the southeastern United States may require fine scale fuel measurements for providing reliable fire hazard and fuel treatment effectiveness estimates. In a series of five papers, an intensive, fine scale fuel inventory from the Savanna River Site in the southeastern United States is used for...

  13. AC loss in superconducting tapes and cables

    NARCIS (Netherlands)

    Oomen, M.P.

    2000-01-01

    The present study discusses the AC loss in high-temperature superconductors. Superconducting materials with a relatively high critical temperature were discovered in 1986. They are presently developed for use in large-scale power-engineering devices such as power-transmission cables, transformers

  14. Characteristics of SUS-MI cables and it's application to wiring in nuclear power facilities

    International Nuclear Information System (INIS)

    Okuno, Michio; Sato, Toshio; Handa, Katsue; Ohya, Shingo; Ioroi, Masaya

    1984-01-01

    SUS-MI cables are the inorganic insulation cables using austenitic stainless steel SUS 321 as the sheath, oxygen-free copper as the conductor and high purity magnesium oxide as the insulatingmaterial. Because of the excellent characteristics of the composing materials, the properties withstanding radiation, fire and heat, and sodium of the cables are superior. In the nuclear power facilities being developed such as fast breeder reactors and nuclear fusion reactors, there is the environment the cables with organic materials as the components cannot meet. As the cables to be applied to such places, the SUS-MI cables are most suitable. In this report, the electric properties and the mechanical strength of the cables and the examples of practical use are described. The highest temperature of using the SUS-MI cables is 800 deg C. The form and the composing materials of the SUS-MI cables, the characteristics and the cable laying are reported. Ceramic connectors and heat-resistant wall penetration parts were developed. The characteristics of the cables for the preheaters of fast breeder reactors are compared. (Kako, I.)

  15. Logistics, Costs, and GHG Impacts of Utility-Scale Co-Firing with 20% Biomass

    Energy Technology Data Exchange (ETDEWEB)

    Nichol, Corrie Ian [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2013-06-01

    This study analyzes the possibility that biopower in the U.S. is a cost-competitive option to significantly reduce greenhouse gas emissions. In 2009, net greenhouse gas (GHG) emitted in the United States was equivalent to 5,618 million metric tons CO2, up 5.6% from 1990 (EPA 2011). Coal-fired power generation accounted for 1,748 million metric tons of this total. Intuitively, life-cycle CO2 emissions in the power sector could be reduced by substituting renewable biomass for coal. If just 20% of the coal combusted in 2009 had been replaced with biomass, CO2 emissions would have been reduced by 350 million metric tons, or about 6% of net annual GHG emission. This would have required approximately 225 million tons of dry biomass. Such an ambitious fuel substitution would require development of a biomass feedstock production and supply system tantamount to coal. This material would need to meet stringent specifications to ensure reliable conveyance to boiler burners, efficient combustion, and no adverse impact on heat transfer surfaces and flue gas cleanup operations. Therefore, this report addresses the potential cost/benefit tradeoffs of co-firing 20% specification-qualified biomass (on an energy content basis) in large U.S. coal-fired power plants. The dependence and sensitivity of feedstock cost on source of material, location, supply distance, and demand pressure was established. Subsequently, the dependence of levelized cost of electricity (LCOE) on feedstock costs, power plant feed system retrofit, and impact on boiler performance was determined. Overall life-cycle assessment (LCA) of greenhouse gas emissions saving were next evaluated and compared to wind and solar energy to benchmark the leading alternatives for meeting renewable portfolio standards (or RPS).

  16. Cable laying methods in a multi-cable elevator system

    Energy Technology Data Exchange (ETDEWEB)

    Dvornikov, V.I.; Makhinyan, V.V.

    1984-01-01

    Based on the solution of differential equations describing the stress and deformation state of cables during rolling on the drum, a conclusion is made concerning a rational method for hanging cables with a free-spinning end.

  17. Development and test of small-scale batch-fired straw boilers in Denmark

    International Nuclear Information System (INIS)

    Kristensen, E.F.; Kristensen, J.K.

    2004-01-01

    In Denmark, government subsidies for the testing and installation of biomass-fired boilers were available for the period from 1995 until 2002. Each boiler type had to pass an official approval test to achieve subsidy. The combustion abilities of the boiler were optimized prior to the test. The main aim of this subsidy was to encourage the development of energy-efficient and environmentally friendly boilers. The scheme was therefore organized in such a way that the greatest subsidies were awarded for boilers with high efficiency and low emissions. This goal has in effect been achieved for batch-fired straw boilers, where the typical efficiency has been increased from about 75% in 1995 to about 87% in 2002. Similarly, the carbon monoxide emissions have been reduced from 5000 ppm (reference value 10% O 2 ) in 1995 to less than 1000 ppm in 2002. These improvements are mainly due to better insulation inside the combustion chamber, more efficient techniques for supplying air to the combustion process, improved cooling of the flue gas, and optimization of the electronic control unit for the air supply

  18. Simulations of microphysical, radiative, and dynamical processes in a continental-scale forest fire smoke plume

    Science.gov (United States)

    Westphal, Douglas L.; Toon, Owen B.

    1991-01-01

    The impact of a large forest fire smoke plume on atmospheric processes is studied through a numerical model of meteorology, aerosols, and radiative transfer. The simulated smoke optical depths at 0.63-micron wavelength are in agreement with analyses of satellite data and show values as high as 1.8. The smoke has an albedo of 35 percent, or more than double the clear-sky value, and cools the surface by as much as 5 K. An imaginary refractive index, n sub im, of 0.01 yields results which closely match the observed cooling, single scattering albedo, and the Angstrom wavelength exponent. An n exp im of 0.1, typical of smoke from urban fires, produces 9 K cooling. Coagulation causes the geometric mean radius by number to increase from the initial value of 0.08 micron to a final value of 0.15 micron, while the specific extinction and absorption increase by 40 and 25 percent, respectively.

  19. Vibration isolation of cable tray hangers

    International Nuclear Information System (INIS)

    Pearce, B.K.; Dixon, M.W.; Jackson, J.E.

    1984-01-01

    Analytical and experimental investigations have been performed to partially evaluate the feasibility of using much more flexible support systems than those presently used to support electrical and control cables in nuclear power plants. This approach, which entails introducing a flexible element between the support and the component being supported, could apply to many types of support systems, such as for piping, HVAC or even bridges. However, this paper addresses the specific case of cable tray hangers only. It was found that, for appropriate stiffness and damping characteristics, this concept could be used effectively to isolate cable trays from hanger motion caused by seismic excitation and to significantly reduce hanger loads while maintaining reasonable displacements. This was found to be true for all variations in system parameters investigated. Thus, the flexible hanger concept appears to offer much potential. However, additional study including full-scale testing and more detailed analysis must be completed before the concept can be validated for plant use

  20. Spacecraft Fire Safety Demonstration

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of the Spacecraft Fire Safety Demonstration project is to develop and conduct large-scale fire safety experiments on an International Space Station...

  1. Shape accuracy optimization for cable-rib tension deployable antenna structure with tensioned cables

    Science.gov (United States)

    Liu, Ruiwei; Guo, Hongwei; Liu, Rongqiang; Wang, Hongxiang; Tang, Dewei; Song, Xiaoke

    2017-11-01

    Shape accuracy is of substantial importance in deployable structures as the demand for large-scale deployable structures in various fields, especially in aerospace engineering, increases. The main purpose of this paper is to present a shape accuracy optimization method to find the optimal pretensions for the desired shape of cable-rib tension deployable antenna structure with tensioned cables. First, an analysis model of the deployable structure is established by using finite element method. In this model, geometrical nonlinearity is considered for the cable element and beam element. Flexible deformations of the deployable structure under the action of cable network and tensioned cables are subsequently analyzed separately. Moreover, the influence of pretension of tensioned cables on natural frequencies is studied. Based on the results, a genetic algorithm is used to find a set of reasonable pretension and thus minimize structural deformation under the first natural frequency constraint. Finally, numerical simulations are presented to analyze the deployable structure under two kinds of constraints. Results show that the shape accuracy and natural frequencies of deployable structure can be effectively improved by pretension optimization.

  2. The effect of regional-scale soil-moisture deficits on mesoscale atmospheric dynamics that influence fire severity

    Energy Technology Data Exchange (ETDEWEB)

    Fast, J.D.

    1994-09-30

    This study employs a three-dimensional, nonhydrostatic mesoscale model to evaluate the effects of horizontally heterogeneous soil moisture and vegetation type on the atmosphere during two periods in which wildland fires occurred. Numerical sensitivity simulations demonstrate that evapotranspiration significantly affects the boundary-layer structure embedded in the synoptic-scale circulations. In regions with sufficiently moist soils, evapotranspiration increases the humidity and modifies the diurnally varying temperature near the surface. Occasionally, changes in the humidity and temperature fields can also be seen a significant distance downwind of the moist soil regions. The perturbations in the temperature fields ultimately affect the wind speed and direction over or at the boundaries of the moist-soil regions, but only at certain times during the simulation period. The higher humidity also increases the cloudiness and changes the precipitation amounts, indicating that soil moisture and vegetation may play an important role in modifying the spatial distribution and intensity of precipitation. A lower atmospheric stability index, that is an indicator of the potential for wildland fire, is also calculated from the model results. This index is also sensitive to the horizontal distribution of soil moisture and vegetation, especially in regions with relatively moist soils. While only two periods are examined in this study, the impact of surface inhomogeneities in soil moisture and vegetation type on the atmosphere is expected to be highly dependent on the particular synoptic conditions and upon the distribution of soil moisture.

  3. PILOT-AND FULL-SCALE DEMONSTRATION OF ADVANCED MERCURY CONTROL TECHNOLOGIES FOR LIGNITE-FIRED POWER PLANTS

    Energy Technology Data Exchange (ETDEWEB)

    Steven A. Benson; Charlene R. Crocker; Kevin C. Galbreath; Jay R. Gunderson; Michael J. Holmes; Jason D. Laumb; Jill M. Mackenzie; Michelle R. Olderbak; John H. Pavlish; Li Yan; Ye Zhuang

    2005-02-01

    The overall objective of the project was to develop advanced innovative mercury control technologies to reduce mercury emissions by 50%-90% in flue gases typically found in North Dakota lignite-fired power plants at costs from one-half to three-quarters of current estimated costs. Power plants firing North Dakota lignite produce flue gases that contain >85% elemental mercury, which is difficult to collect. The specific objectives were focused on determining the feasibility of the following technologies: Hg oxidation for increased Hg capture in dry scrubbers, incorporation of additives and technologies that enhance Hg sorbent effectiveness in electrostatic precipitators (ESPs) and baghouses, the use of amended silicates in lignite-derived flue gases for Hg capture, and the use of Hg adsorbents within a baghouse. The approach to developing Hg control technologies for North Dakota lignites involved examining the feasibility of the following technologies: Hg capture upstream of an ESP using sorbent enhancement, Hg oxidation and control using dry scrubbers, enhanced oxidation at a full-scale power plant using tire-derived fuel and oxidizing catalysts, and testing of Hg control technologies in the Advanced Hybrid{trademark} filter.

  4. Development of no halogen incombustible cables for atomic energy

    International Nuclear Information System (INIS)

    Ishii, Nobumasa; Kimura, Hitoshi; Fujimura, Shun-ichi

    1990-01-01

    In upgrading light water reactor technology, it is important to improve the reliability of machinery and equipment, to make regular inspection efficient, to extend the period of continuous operation, to optimize operation cycle and to improve the maintainability of plant facilities. For the cables for nuclear power stations, high incombustibility is required, and at present halogen system incombustible materials are used. Recently the development of no halogen incombustible cables has been advanced, with which the generation of corrosive gas and smoke at the time of fires is slight. In this study, the application of such no halogen incombustible cables to nuclear power stations and the improvement of reliability of the cables were investigated. The cables to be developed are those for electric power, control and instrumentation in BWR plants and insulated electric wires. The required characteristics are incombustibility, no generation of smoke and corrosive gas at the time of fires, radiation resistance and steam resistance in LOCA. The selection of base polymers, metal hydrates and radiation protectors, the evaluation of radiation resistance and steam resistance, the examination of the corrosive and poisonous properties of generated gas and smoke generation and so on are reported. The development was successful. (K.I.)

  5. High Temperature Superconducting Underground Cable

    International Nuclear Information System (INIS)

    Farrell, Roger A.

    2010-01-01

    The purpose of this Project was to design, build, install and demonstrate the technical feasibility of an underground high temperature superconducting (HTS) power cable installed between two utility substations. In the first phase two HTS cables, 320 m and 30 m in length, were constructed using 1st generation BSCCO wire. The two 34.5 kV, 800 Arms, 48 MVA sections were connected together using a superconducting joint in an underground vault. In the second phase the 30 m BSCCO cable was replaced by one constructed with 2nd generation YBCO wire. 2nd generation wire is needed for commercialization because of inherent cost and performance benefits. Primary objectives of the Project were to build and operate an HTS cable system which demonstrates significant progress towards commercial progress and addresses real world utility concerns such as installation, maintenance, reliability and compatibility with the existing grid. Four key technical areas addressed were the HTS cable and terminations (where the cable connects to the grid), cryogenic refrigeration system, underground cable-to-cable joint (needed for replacement of cable sections) and cost-effective 2nd generation HTS wire. This was the worlds first installation and operation of an HTS cable underground, between two utility substations as well as the first to demonstrate a cable-to-cable joint, remote monitoring system and 2nd generation HTS.

  6. The Danish Superconducting Cable Project

    DEFF Research Database (Denmark)

    Tønnesen, Ole

    1997-01-01

    The design and construction of a superconducting cable is described. The cable has a room temperature dielectric design with the cryostat placed inside the electrical insulation.BSCCO 2223 superconducting tapes wound in helix form around a former are used as the cable conductor. Results from...

  7. Selection of fire-created snags at two spatial scales by cavity-nesting birds

    Science.gov (United States)

    Victoria A. Saab; Ree Brannon; Jonathan Dudley; Larry Donohoo; Dave Vanderzanden; Vicky Johnson; Henry Lachowski

    2002-01-01

    We examined the use of snag stands by seven species of cavity-nesting birds from 1994-1998. Selection of snags was studied in logged and unlogged burned forests at two spatial scales: microhabitat (local vegetation characteristics) and landscape (composition and patterning of surrounding vegetation types). We modeled nest occurrence at the landscape scale by using...

  8. Contribution of regional-scale fire events to ozone and PM2.5 air quality estimated by photochemical modeling approaches

    Science.gov (United States)

    Baker, K. R.; Woody, M. C.; Tonnesen, G. S.; Hutzell, W.; Pye, H. O. T.; Beaver, M. R.; Pouliot, G.; Pierce, T.

    2016-09-01

    Two specific fires from 2011 are tracked for local to regional scale contribution to ozone (O3) and fine particulate matter (PM2.5) using a freely available regulatory modeling system that includes the BlueSky wildland fire emissions tool, Spare Matrix Operator Kernel Emissions (SMOKE) model, Weather and Research Forecasting (WRF) meteorological model, and Community Multiscale Air Quality (CMAQ) photochemical grid model. The modeling system was applied to track the contribution from a wildfire (Wallow) and prescribed fire (Flint Hills) using both source sensitivity and source apportionment approaches. The model estimated fire contribution to primary and secondary pollutants are comparable using source sensitivity (brute-force zero out) and source apportionment (Integrated Source Apportionment Method) approaches. Model estimated O3 enhancement relative to CO is similar to values reported in literature indicating the modeling system captures the range of O3 inhibition possible near fires and O3 production both near the fire and downwind. O3 and peroxyacetyl nitrate (PAN) are formed in the fire plume and transported downwind along with highly reactive VOC species such as formaldehyde and acetaldehyde that are both emitted by the fire and rapidly produced in the fire plume by VOC oxidation reactions. PAN and aldehydes contribute to continued downwind O3 production. The transport and thermal decomposition of PAN to nitrogen oxides (NOX) enables O3 production in areas limited by NOX availability and the photolysis of aldehydes to produce free radicals (HOX) causes increased O3 production in NOX rich areas. The modeling system tends to overestimate hourly surface O3 at routine rural monitors in close proximity to the fires when the model predicts elevated fire impacts on O3 and Hazard Mapping System (HMS) data indicates possible fire impact. A sensitivity simulation in which solar radiation and photolysis rates were more aggressively attenuated by aerosol in the plume

  9. Copper Cable Recycling Technology. Innovative Technology Summary Report

    International Nuclear Information System (INIS)

    2001-01-01

    The United States Department of Energy (DOE) continually seeks safer and more cost-effective technologies for use in deactivation and decommissioning (D and D) of nuclear facilities. The Deactivation and Decommissioning Focus Area (DDFA) of the DOE's Office of Science and Technology (OST) sponsors large-scale demonstration and deployment projects (LSDDPs). At these LSDDPs, developers and vendors of improved or innovative technologies showcase products that are potentially beneficial to the DOE's projects and to others in the D and D community. Benefits sought include decreased health and safety risks to personnel and the environment, increased productivity, and decreased costs of operation. The Idaho National Engineering and Environmental Laboratory (INEEL) generated a list of statements defining specific needs and problems where improved technology could be incorporated into ongoing D and D tasks. One such need is to reduce the volume of waste copper wire and cable generated by D and D. Deactivation and decommissioning activities of nuclear facilities generates hundreds of tons of contaminated copper cable, which are sent to radioactive waste disposal sites. The Copper Cable Recycling Technology separates the clean copper from contaminated insulation and dust materials in these cables. The recovered copper can then be reclaimed and, more importantly, landfill disposal volumes can be reduced. The existing baseline technology for disposing radioactively contaminated cables is to package the cables in wooden storage boxes and dispose of the cables in radioactive waste disposal sites. The Copper Cable Recycling Technology is applicable to facility decommissioning projects at many Department of Energy (DOE) nuclear facilities and commercial nuclear power plants undergoing decommissioning activities. The INEEL Copper Cable Recycling Technology Demonstration investigated the effectiveness and efficiency to recycle 13.5 tons of copper cable. To determine the effectiveness

  10. Cable indenter aging monitor

    International Nuclear Information System (INIS)

    Shook, T.A.; Gardner, J.B.

    1988-07-01

    This project was undertaken to develop a hand-held, nondestructive test device to assess the aged condition of electrical cable by in situ measurement of mechanical properties of polymeric jackets and insulations. The device is an indenter similar to those used to make hardness measurements. Comparison of measurements made on installed cables with previous measurements serving as baseline aging/mechanical property data will determine the state of aging of the field cables. Such a device will be valuable in nuclear and fossil plant life extension programs. Preliminary laboratory tests on cables covered with ethylene propylene rubber (EPR) and chlorosulfated polyethylene (CSPE) point to the measurement of the rate of force increase resulting from constant rate deformation as having the best correlation with progressive thermal aging. This first phase of the work has demonstrated the technical feasibility of the method. A second phase will include the generation of additional groundwork data and the design of the portable indenter for in situ plant measurements

  11. Smoke flow temperature beneath tunnel ceiling for train fire at subway station: Reduced-scale experiments and correlations

    International Nuclear Information System (INIS)

    Meng, Na; Wang, Qiang; Liu, Zhaoxia; Li, Xiao; Yang, He

    2017-01-01

    Highlights: • Reduced-scale experiments on train fire at subway station. • Smoke flow temperature beneath tunnel ceiling measured and correlated. • Effect of platform-tunnel conjunction door type on smoke temperature is clarified. - Abstract: This paper is to investigate the smoke flow temperature beneath tunnel ceiling for a train on fire stopping besides a subway station. Experiments were carried out in a reduced-scale (1:10) subway station model to study the maximum smoke temperature and the longitudinal temperature distribution beneath the tunnel ceiling by considering platform-tunnel conjunction doors of two types: the full-seal platform screen door (PSD) and the full-height safety door. For the maximum temperature beneath the tunnel ceiling, it is found to be well correlated non-dimensionally with heat release rate by a 3.65 and a 2.92 power law function for the full-seal platform screen door and the full-height safety door, respectively. For the longitudinal temperature distribution along the tunnel ceiling, it can be well correlated by an exponential function for both types of platform-tunnel conjunction doors. Concerning the effect of the door type, the maximum temperature is lower and the longitudinal temperature decays faster for full-height safety door than that for full-seal PSD. This is due to that with the full-height safety door, the effective width of the tunnel ceiling is widened, which results in more heat losses from the smoke flow to the ceiling.

  12. New trends in design and fabrication of signal and power cables to increase nuclear safety

    International Nuclear Information System (INIS)

    Salmen, Florin; Florescu, Gheorghe; Ionescu, Aurel

    2007-01-01

    Based on NPP operating experiences in the past, it was found that the inadequate management of aging degradation caused shortening of the lifetime of equipment, which in turn, hindered plant life extension. Aging degradation of plant structures and components should be properly managed to ensure the designated safety function of plant systems during design life and extended life. From a safety perspective, aging management means maintaining the aging degradation level in major equipment and structures below the allowable limit and holding the capacity to sustain abnormal operating condition. Cable aging was not considered as a significant factor in relation to the nuclear power plant maintenance due to its long life which is almost the same as the plant design life. Attempts to extend the lifetime of NPP has become one of the major concern in the nuclear industry world wide. Consequently, life evaluation and lifetime management of cables to survive over 40 years has become major topic of discussion. In connection to this, accelerated aging must be studied in detail in order to simulate the natural aging in NPP. Test results for evaluating aging degradation after accelerated aging of polyethylene jacket will be described herein.There are hundred types of cables in NPPs. These cables can be classified as medium/low voltage cable, low power cable, instrument and control cable, panel connect line cable, special cable, security line cable, phone line cable and ground cable. Insulation and jacket material in electrical cables are fabricated of polymer materials combined with a number of additives and filler to provide the required mechanical, electrical and fire retardant proprieties. The most commonly used insulation materials are XLPE/EPR/EPDM and PVC. PVC has been widely used as an insulation material, particularly in old plants, but it is less used in modern plants. Neoprene/CSPE/PVC are commonly used material for nuclear cable jacket. The old types of cables

  13. Test results for cables used in nuclear power plants by a new environmental testing method

    Energy Technology Data Exchange (ETDEWEB)

    Handa, Katsue; Fujimura, Shun-ichi; Hayashi, Toshiyasu; Takano, Keiji; Oya, Shingo

    1982-12-01

    In the nuclear power plants using PWRs or BWRs in Japan, environmental tests are provided, in which simulated LOCA conditions are considered so as to conform with Japanese conditions, and many cables which passed these tests are presently employed. Lately, the new environmental testing, in which a credible accident called MSLB (main steam line breakage) is taken into account, is investigated in PWR nuclear power plants, besides LOCA. This paper reports on the results of evaluating some PWR cables for this new environmental testing conditions. The several cables tested were selected out of PH cables (fire-retardant, ethylene propylene rubber insulated, chlorosulfonated polyethylene sheathed cables) as the cables for safety protecting circuits and to be used in containment vessels where the cables are to be exposed to severe environmental test conditions of 2 x 10/sup 8/ Rad ..gamma..-irradiation and simulated LOCA. All these cables have been accepted after the vertical tray burning test provided in the IEEE Standard 383. The new testing was carried out by sequentially applying thermal deterioration, ..gamma..-irradiation, and the exposure to steam (twice 300 s exposures to 190 deg C superheated steam). After completing each step, tensile strength, elongation, insulation resistance and breakdown voltage were measured, respectively. Every cable tested showed satisfactory breakdown voltage after the exposure to steam, thus it was decided to be acceptable. In future, it is required to investigate the influence of the rate of temperature rise on the cable to be tested in MSLB simulation.

  14. Test results for cables used in nuclear power plants by a new environmental testing method

    International Nuclear Information System (INIS)

    Handa, Katsue; Fujimura, Shun-ichi; Hayashi, Toshiyasu; Takano, Keiji; Oya, Shingo

    1982-01-01

    In the nuclear power plants using PWRs or BWRs in Japan, environmental tests are provided, in which simulated LOCA conditions are considered so as to conform with Japanese conditions, and many cables which passed these tests are presently employed. Lately, the new environmental testing, in which a credible accident called MSLB (main steam line breakage) is taken into account, is investigated in PWR nuclear power plants, besides LOCA. This paper reports on the results of evaluating some PWR cables for this new environmental testing conditions. The several cables tested were selected out of PH cables (fire-retardant, ethylene propylene rubber insulated, chlorosulfonated polyethylene sheathed cables) as the cables for safety protecting circuits and to be used in containment vessels where the cables are to be exposed to severe environmental test conditions of 2 x 10 8 Rad γ-irradiation and simulated LOCA. All these cables have been accepted after the vertical tray burning test provided in the IEEE Standard 383. The new testing was carried out by sequentially applying thermal deterioration, γ-irradiation, and the exposure to steam (twice 300 s exposures to 190 deg C superheated steam). After completing each step, tensile strength, elongation, insulation resistance and breakdown voltage were measured, respectively. Every cable tested showed satisfactory breakdown voltage after the exposure to steam, thus it was decided to be acceptable. In future, it is required to investigate the influence of the rate of temperature rise on the cable to be tested in MSLB simulation. (Wakatsuki, Y.)

  15. Reducing Actuator Requirements in Continuum Robots Through Optimized Cable Routing.

    Science.gov (United States)

    Case, Jennifer C; White, Edward L; SunSpiral, Vytas; Kramer-Bottiglio, Rebecca

    2018-02-01

    Continuum manipulators offer many advantages compared to their rigid-linked counterparts, such as increased degrees of freedom and workspace volume. Inspired by biological systems, such as elephant trunks and octopus tentacles, many continuum manipulators are made of multiple segments that allow large-scale deformations to be distributed throughout the body. Most continuum manipulators currently control each segment individually. For example, a planar cable-driven system is typically controlled by a pair of cables for each segment, which implies two actuators per segment. In this article, we demonstrate how highly coupled crossing cable configurations can reduce both actuator count and actuator torque requirements in a planar continuum manipulator, while maintaining workspace reachability and manipulability. We achieve highly coupled actuation by allowing cables to cross through the manipulator to create new cable configurations. We further derive an analytical model to predict the underactuated manipulator workspace and experimentally verify the model accuracy with a physical system. We use this model to compare crossing cable configurations to the traditional cable configuration using workspace performance metrics. Our work here focuses on a simplified planar robot, both in simulation and in hardware, with the goal of extending this to spiraling-cable configurations on full 3D continuum robots in future work.

  16. IPSN's experimental programmes on fires

    International Nuclear Information System (INIS)

    1999-01-01

    Every year fires occur in nuclear installations as they do in any industrial facility. They feed on cables, electrical equipment cabinets, oils, solvents..., they might lead to the degradation of the safety standard of the installation or they might threaten the confinement of radioactive materials. In this document IPSN presents its experimental programmes and its facilities in Saclay and Cadarache designed to study the triggering and the propagation of fires and flames in closed and ventilated premises. (A.C.)

  17. LARGE-SCALE MECURY CONTROL TECHNOLOGY TESTING FOR LIGNITE-FIRED UTILITIES-OXIDATION SYSTEMS FOR WET FGD

    Energy Technology Data Exchange (ETDEWEB)

    Michael J. Holmes; Steven A. Benson; Jeffrey S. Thompson

    2004-03-01

    The Energy & Environmental Research Center (EERC) is conducting a consortium-based effort directed toward resolving the mercury (Hg) control issues facing the lignite industry. Specifically, the EERC team--the EERC, EPRI, URS, ADA-ES, Babcock & Wilcox, the North Dakota Industrial Commission, SaskPower, and the Mercury Task Force, which includes Basin Electric Power Cooperative, Otter Tail Power Company, Great River Energy, Texas Utilities (TXU), Montana-Dakota Utilities Co., Minnkota Power Cooperative, BNI Coal Ltd., Dakota Westmoreland Corporation, and the North American Coal Company--has undertaken a project to significantly and cost-effectively oxidize elemental mercury in lignite combustion gases, followed by capture in a wet scrubber. This approach will be applicable to virtually every lignite utility in the United States and Canada and potentially impact subbituminous utilities. The oxidation process is proven at the pilot-scale and in short-term full-scale tests. Additional optimization is continuing on oxidation technologies, and this project focuses on longer-term full-scale testing. The lignite industry has been proactive in advancing the understanding of and identifying control options for Hg in lignite combustion flue gases. Approximately 1 year ago, the EERC and EPRI began a series of Hg-related discussions with the Mercury Task Force as well as utilities firing Texas and Saskatchewan lignites. This project is one of three being undertaken by the consortium to perform large-scale Hg control technology testing to address the specific needs and challenges to be met in controlling Hg from lignite-fired power plants. This project involves Hg oxidation upstream of a system equipped with an electrostatic precipitator (ESP) followed by wet flue gas desulfurization (FGD). The team involved in conducting the technical aspects of the project includes the EERC, Babcock & Wilcox, URS, and ADA-ES. The host sites include Minnkota Power Cooperative Milton R. Young

  18. Modal resonant dynamics of cables with a flexible support: A modulated diffraction problem

    Science.gov (United States)

    Guo, Tieding; Kang, Houjun; Wang, Lianhua; Liu, Qijian; Zhao, Yueyu

    2018-06-01

    Modal resonant dynamics of cables with a flexible support is defined as a modulated (wave) diffraction problem, and investigated by asymptotic expansions of the cable-support coupled system. The support-cable mass ratio, which is usually very large, turns out to be the key parameter for characterizing cable-support dynamic interactions. By treating the mass ratio's inverse as a small perturbation parameter and scaling the cable tension properly, both cable's modal resonant dynamics and the flexible support dynamics are asymptotically reduced by using multiple scale expansions, leading finally to a reduced cable-support coupled model (i.e., on a slow time scale). After numerical validations of the reduced coupled model, cable-support coupled responses and the flexible support induced coupling effects on the cable, are both fully investigated, based upon the reduced model. More explicitly, the dynamic effects on the cable's nonlinear frequency and force responses, caused by the support-cable mass ratio, the resonant detuning parameter and the support damping, are carefully evaluated.

  19. Post Fire Safe Shutdown Analysis Using a Fault Tree Logic Model

    International Nuclear Information System (INIS)

    Yim, Hyun Tae; Park, Jun Hyun

    2005-01-01

    Every nuclear power plant should have its own fire hazard analysis including the fire safe shutdown analysis. A safe shutdown (SSD) analysis is performed to demonstrate the capability of the plant to safely shut down for a fire in any given area. The basic assumption is that there will be fire damage to all cables and equipment located within a common fire area. When evaluating the SSD capabilities of the plant, based on a review of the systems, equipment and cables within each fire area, it should be determined which shutdown paths are either unaffected or least impacted by a postulated fire within the fire area. Instead of seeking a success path for safe shutdown given all cables and equipment damaged by a fire, there can be an alternative approach to determine the SSD capability: fault tree analysis. This paper introduces the methodology for fire SSD analysis using a fault tree logic model

  20. CCDP evaluation of the fire areas of KSNP using CFAST

    International Nuclear Information System (INIS)

    Lee, Yoon Hwan; Yang, Joon Eon; Kim, Jong Hoon

    2005-01-01

    During the past decade, the nuclear power industry has been moving away from prescriptive rules and practices toward risk-informed and performance-based engineering analysis to support the decision making for plant fire protection programs. For example, the National Fire Protection Association (NFPA) prepared NFPA 805, Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants 2001 Edition. One crucial element in supporting the risk-informed fire protection is availability of simple and reliable methods and tools for evaluating the likelihood and consequences of fire scenarios. These tools directly benefit risk-informed and performance-based fire protection and application of risk information to resolve fire protection issues. Now the deterministic analysis results for the cable integrity is not given in case of performing the fire PSA. So it is necessary to apply the results for the fire modeling to the fire PSA model to develop the more realistic model. This document is intended to analyze the peak temperature of the upper gas layer using the fire modeling code, CFAST , to evaluate the integrity of the cable located on the dominant pump rooms, and to assess the CCDP(Conditional Core Damage Probability) using the results of the cable integrity. Accordingly, the fire safety assessment for the dominant fire areas using the fire modeling code will be capable of evaluating the consequences of the fire scenario, of reducing the the uncertainty, and to develop a more realistic model

  1. A summary of the Fire Testing Program at the German HDR Test Facility

    International Nuclear Information System (INIS)

    Nowlen, S.P.

    1995-11-01

    This report provides an overview of the fire safety experiments performed under the sponsorship of the German government in the containment building of the decommissioned pilot nuclear power plant known as HDR. This structure is a highly complex, multi-compartment, multi-level building which has been used as the test bed for a wide range of nuclear power plant operation safety experiments. These experiments have included numerous fire tests. Test fire fuel sources have included gas burners, wood cribs, oil pools, nozzle release oil fires, and cable in cable trays. A wide range of ventilation conditions including full natural ventilation, full forced ventilation, and combined natural and forced ventilation have been evaluated. During most of the tests, the fire products mixed freely with the full containment volume. Macro-scale building circulation patterns which were very sensitive to such factors as ventilation configuration were observed and characterized. Testing also included the evaluation of selective area pressurization schemes as a means of smoke control for emergency access and evacuation stairwells

  2. Jointly optimizing selection of fuel treatments and siting of forest biomass-based energy production facilities for landscape-scale fire hazard reduction.

    Science.gov (United States)

    Peter J. Daugherty; Jeremy S. Fried

    2007-01-01

    Landscape-scale fuel treatments for forest fire hazard reduction potentially produce large quantities of material suitable for biomass energy production. The analytic framework FIA BioSum addresses this situation by developing detailed data on forest conditions and production under alternative fuel treatment prescriptions, and computes haul costs to alternative sites...

  3. Dry sorbent injection of trona to control acid gases from a pilot-scale coal-fired combustion facility

    Directory of Open Access Journals (Sweden)

    Tiffany L. B. Yelverton

    2016-01-01

    Full Text Available  Gaseous and particulate emissions from the combustion of coal have been associated with adverse effects on human and environmental health, and have for that reason been subject to regulation by federal and state governments. Recent regulations by the United States Environmental Protection Agency have further restricted the emissions of acid gases from electricity generating facilities and other industrial facilities, and upcoming deadlines are forcing industry to consider both pre- and post-combustion controls to maintain compliance. As a result of these recent regulations, dry sorbent injection of trona to remove acid gas emissions (e.g. HCl, SO2, and NOx from coal combustion, specifically 90% removal of HCl, was the focus of the current investigation. Along with the measurement of HCl, SO2, and NOx, measurements of particulate matter (PM, elemental (EC, and organic carbon (OC were also accomplished on a pilot-scale coal-fired combustion facility. Gaseous and particulate emissions from a coal-fired combustor burning bituminous coal and using dry sorbent injection were the focus of the current study. From this investigation it was shown that high levels of trona were needed to achieve the goal of 90% HCl removal, but with this increased level of trona injection the ESP and BH were still able to achieve greater than 95% fine PM control. In addition to emissions reported, measurement of acid gases by standard EPA methods were compared to those of an infrared multi-component gas analyzer. This comparison revealed good correlation for emissions of HCl and SO2, but poor correlation in the measurement of NOx emissions.

  4. Development of Inspection Robots for Bridge Cables

    Directory of Open Access Journals (Sweden)

    Hae-Bum Yun

    2013-01-01

    Full Text Available This paper presents the bridge cable inspection robot developed in Korea. Two types of the cable inspection robots were developed for cable-suspension bridges and cable-stayed bridge. The design of the robot system and performance of the NDT techniques associated with the cable inspection robot are discussed. A review on recent advances in emerging robot-based inspection technologies for bridge cables and current bridge cable inspection methods is also presented.

  5. Development of inspection robots for bridge cables.

    Science.gov (United States)

    Yun, Hae-Bum; Kim, Se-Hoon; Wu, Liuliu; Lee, Jong-Jae

    2013-01-01

    This paper presents the bridge cable inspection robot developed in Korea. Two types of the cable inspection robots were developed for cable-suspension bridges and cable-stayed bridge. The design of the robot system and performance of the NDT techniques associated with the cable inspection robot are discussed. A review on recent advances in emerging robot-based inspection technologies for bridge cables and current bridge cable inspection methods is also presented.

  6. Recent development of the Cu/Nb-Ti superconducting cables for SSC in Hitachi Cable, Ltd

    International Nuclear Information System (INIS)

    Sakai, S.; Iwaki, G.; Sawada, Y.; Moriai, H.; Ishigami, Y.

    1989-01-01

    In these few years, Cu/Nb-Ti superconducting cables for the dipole magnets of SSC projects have been developed in the industrial scale in Hitachi Cable, Ltd. The features of these developed conductors are as follows. (1) The diameter of Nb-Ti filaments is very small, 4-6 μm. (2) The critical current density (J c ) is very high, 2,850-3,050 A/mm 2 at 5 T on wires, 2750-2950 A/mm 2 at 5 T on cables in industrial scale. The champion J c of wires is 3,460 A/mm 2 at 5 T in the laboratory scale. (3) The RRR Residual Resistivity Ratio values of developed cables is very high, approximately 200, due to the newly developed high purity Oxygen Free Copper (OFC). (4) The conductors have been wound to the 1 m length dipole magnet in Hitachi Ltd., and it has generated 6.7 T in the central magnetic field at 6,595 A. The Cu/Cu-Mn/Nb-Ti composite wires which avoid the possibility of electrical coupling of the filaments have been produced in laboratory scale. The RRR of the copper stabilizer and J c properties have not degraded because of no metallurgical reactions between Cu and Mn, Nb-Ti and Mn. 7 refs., 9 figs., 4 tabs

  7. Experimental Investigation of Aerodynamic Instability of Iced Bridge Cable Sections

    DEFF Research Database (Denmark)

    Koss, Holger; Lund, Mia Schou Møller

    2013-01-01

    The accretion of ice on structural bridge cables changes the aerodynamic conditions of the surface and influences hence the acting wind load process. Full-scale monitoring indicates that light precipitation at moderate low temperatures between zero and -5°C may lead to large amplitude vibrations...... of bridge cables under wind action. This paper describes the experimental simulation of ice accretion on a real bridge cable sheet HDPE tube segment (diameter 160mm) and its effect on the aerodynamic load. Furthermore, aerodynamic instability will be estimated with quasi-steady theory using the determined...

  8. Wildland fire emissions, carbon, and climate: Seeing the forest and the trees - A cross-scale assessment of wildfire and carbon dynamics in fire-prone, forested ecosystems

    Science.gov (United States)

    Rachel A. Loehman; Elizabeth Reinhardt; Karin L. Riley

    2014-01-01

    Wildfires are an important component of the terrestrial carbon cycle and one of the main pathways for movement of carbon from the land surface to the atmosphere. Fires have received much attention in recent years as potential catalysts for shifting landscapes from carbon sinks to carbon sources. Unless structural or functional ecosystem shifts occur, net carbon balance...

  9. Simulating spatial and temporally related fire weather

    Science.gov (United States)

    Isaac C. Grenfell; Mark Finney; Matt Jolly

    2010-01-01

    Use of fire behavior models has assumed an increasingly important role for managers of wildfire incidents to make strategic decisions. For fire risk assessments and danger rating at very large spatial scales, these models depend on fire weather variables or fire danger indices. Here, we describe a method to simulate fire weather at a national scale that captures the...

  10. Towards Experimental Operational Fire Weather Prediction at Subseasonal to Seasonal Scales for Alaska Using the NMME Hindcasts and Realtime Forecasts.

    Science.gov (United States)

    Sampath, A.; Bhatt, U. S.; Bieniek, P.; York, A.; Peng, P.; Brettschneider, B.; Thoman, R.; Jandt, R.; Ziel, R.; Branson, G.; Strader, M. H.; Alden, M. S.

    2017-12-01

    The summer 2004 and 2015 wildfires in Alaska were the two largest fire seasons on record since 1950 where approximately the land area of Massachusetts burned. The record fire year of 2004 resulted in 6.5 million acres burned while the 2015 wildfire season resulted in 5.2 million acres burned. In addition to the logistical cost of fighting fires and the loss of infrastructure, wildfires also lead to dangerous air quality in Alaska. Fires in Alaska result from lightning strikes coupled with persistent (extreme) dry warm conditions in remote areas with limited fire management and the seasonal climate/weather determine the extent of the fire season in Alaska. Advanced weather/climate outlooks for allocating staff and resources from days to a season are particularly needed by fire managers. However, there are no operational seasonal products currently for the Alaska region. Probabilistic forecasts of the expected seasonal climate/weather would aid tremendously in the planning process. Earlier insight of both lightening and fuel conditions would assist fire managers in planning resource allocation for the upcoming season. For fuel conditions, the state-of-the-art NMME (1982-2017) climate predictions were used to compute the Canadian Forest Fire Weather Index System (CFFWIS). The CFFWIS is used by fire managers to forecast forest fires in Alaska. NMME forecast (March and May) based Buildup Index (BUI) values were underestimated compared to BUI based on reanalysis and station data, demonstrating the necessity for bias correction. Post processing of NMME data will include bias correction using the quantile mapping technique. This study will provide guidance as to the what are the best available products for anticipating the fire season.

  11. Cable networks, services, and management

    CERN Document Server

    2015-01-01

    Cable Networks, Services, and Management is the first book to cover cable networks, services, and their management, in-depth, for network operators, engineers, researchers, and students. Thirteen experts in various fields have contributed their knowledge of network architectures and services, Operations, Administration, Maintenance, Provisioning, Troubleshooting (OAMPT) for residential and business services, cloud, Software Defined Networks (SDN), as well as virtualization concepts and their applications as part of the future directions of cable networks. The book begins by introducing architecture and services for Data Over Cable Service Interface Specification (DOCSIS) 3.0/ 3.1, Converged Cable Access Platform (CCAP), Content Distribution Networks (CDN, IP TV, and Packet Cable and Wi-Fi for Residential Services. Topics that are discussed in proceeding chapters include: operational systems and management architectures, service orders, provisioning, fault manageme t, performance management, billing systems a...

  12. 14 CFR 23.689 - Cable systems.

    Science.gov (United States)

    2010-01-01

    ... in cable tension throughout the range of travel under operating conditions and temperature variations... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Cable systems. 23.689 Section 23.689... Systems § 23.689 Cable systems. (a) Each cable, cable fitting, turnbuckle, splice, and pulley used must...

  13. The design and management of cables and supporting steelwork systems for Sizewell 'B'

    International Nuclear Information System (INIS)

    Kerry, L.P.

    1992-01-01

    Sizewell B Power Station has over 33,000 cables connecting in excess of 20,000 items of equipment. Over 120 cable types are used. Many cables supply power to, or monitor, safety category 1 equipment essential to the safe operation of the Reactor and supporting systems. Cables must be designed to survive the postulated hazards of Reactor systems fault, earthquake, fire and radiation exposure. The cable network is the nerve system of the station; its role is to distribute electrical power and control indication, metering and protection signals to the various items of plant and equipment under normal and emergency operating conditions. To perform these functions satisfactorily a new range of cable insulations had to be developed and supporting steelwork designed to withstand the effect of an earthquake. The 63 month Sizewell B construction programme means record cable laying and completion rates have to be achieved needing careful and detailed planning from design to installation. As with electrical equipment, cables are designated either essential (to Reactor safety operation) or non-essential. This paper describes the required safety design criteria, how these are achieved and the design approaches to seismically qualified supporting steelwork. Also described are the cable design, scheduling, routing and planning processes which lead to the required installation and commissioning activities being completed in a controlled and timely manner. (Author)

  14. Dynamic testing of cable structures

    Directory of Open Access Journals (Sweden)

    Caetano Elsa

    2015-01-01

    Full Text Available The paper discusses the role of dynamic testing in the study of cable structures. In this context, the identification of cable force based on vibration measurements is discussed. Vibration and damping assessment are then introduced as the focus of dynamic monitoring systems, and particular aspects of the structural behaviour under environmental loads are analysed. Diverse application results are presented to support the discussion centred on cable-stayed bridges, roof structures, a guyed mast and a transmission line.

  15. 14 CFR 23.1359 - Electrical system fire protection.

    Science.gov (United States)

    2010-01-01

    ... procedures must be fire-resistant. (c) Insulation on electrical wire and electrical cable must be self... this part, or other approved equivalent methods. The average burn length must not exceed 3 inches (76...

  16. Longest cable-stayed bridge TATARA; Longest shachokyo Tatara Ohashi

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, K. [Hiroshima University, Hiroshima (Japan). Faculty of Engineering

    1998-06-15

    The world`s longest cable-stayed bridge Tatara having a central span of 890 m had the both ends closed in August 1997, linking Namakuchi Island and Omishima Island. Final finishing work is continuing for opening of the West Seto Expressway in the spring of 1999. A cable-stayed bridge supports the bridge girders by perpendicular components of tensile force of cables stayed obliquely. On the other hand, there is a concern that the girders may have axial compression force generated due to horizontal components of the force from the cable tensile force, which can cause buckling of the girders. Therefore, in order to suspend the girders efficiently by increasing the perpendicular components of the cable force, and moreover to suppress the axial compression force on the girders, it is more advantageous to make bridge towers high, hence the towers of this bridge are highest among the bridges on the Shimanami Ocean Road. This bridge whose long girders are stayed with 21-stage multi cables presented a problem in designing the buckling in steel girders near the towers due to the horizontal components of the force generated by the bridge. Discussions were given, therefore, by using load withstanding force experiments using a whole bridge model of 1/50 scale, buckling experiments on full-size reinforcing plate models, and load withstanding force analysis using a tower model. A number of other technical discussions were repeated, by which the world`s longest cable-stayed bridge was completed. 9 figs., 1 tab.

  17. Electromagnetic transients in power cables

    CERN Document Server

    da Silva, Filipe Faria

    2013-01-01

    From the more basic concepts to the most advanced ones where long and laborious simulation models are required, Electromagnetic Transients in Power Cables provides a thorough insight into the study of electromagnetic transients and underground power cables. Explanations and demonstrations of different electromagnetic transient phenomena are provided, from simple lumped-parameter circuits to complex cable-based high voltage networks, as well as instructions on how to model the cables.Supported throughout by illustrations, circuit diagrams and simulation results, each chapter contains exercises,

  18. Superconducting flat tape cable magnet

    Science.gov (United States)

    Takayasu, Makoto

    2015-08-11

    A method for winding a coil magnet with the stacked tape cables, and a coil so wound. The winding process is controlled and various shape coils can be wound by twisting about the longitudinal axis of the cable and bending following the easy bend direction during winding, so that sharp local bending can be obtained by adjusting the twist pitch. Stack-tape cable is twisted while being wound, instead of being twisted in a straight configuration and then wound. In certain embodiments, the straight length should be half of the cable twist-pitch or a multiple of it.

  19. Study of the fire behavior of high-energy lithium-ion batteries with full-scale burning test

    Science.gov (United States)

    Ping, Ping; Wang, QingSong; Huang, PeiFeng; Li, Ke; Sun, JinHua; Kong, DePeng; Chen, ChunHua

    2015-07-01

    A full-scale burning test is conducted to evaluate the safety of large-size and high-energy 50 Ah lithium-iron phosphate/graphite battery pack, which is composed of five 10 Ah single cells. The complex fire hazards associated with the combustion process of the battery are presented. The battery combustion behavior can be summarized into the following stages: battery expansion, jet flame, stable combustion, a second cycle of a jet flame followed by stable combustion, a third cycle of a jet flame followed by stable combustion, abatement and extinguishment. The multiple jets of flame indicate serious consequences for the battery and pose a challenge for battery safety. The battery ignites when the battery temperature reaches approximately 175-180 °C. This critical temperature is related to an internal short circuit of the battery, which results from the melting of the separator. The maximum temperature of the flame can reach 1500 °C. The heat release rate (HRR) varies based on the oxygen generated by the battery and the Joule effect of the internal short circuit. The HRR and heat of combustion can reach 49.4 kW and 18,195.1 kJ, respectively. The state of charge of the battery has a significant effect on the maximum HRR, the overall heat generation and the mass loss of the battery.

  20. Pilot-scale multistage membrane process for the separation of CO2 from LNG-fired flue gas

    KAUST Repository

    Choi, Seung Hak

    2013-06-01

    In this study, a multistage pilot-scale membrane plant was constructed and operated for the separation of CO2 from Liquefied Natural Gas (LNG)-fired boiler flue gas of 1000 Nm3/day. The target purity and recovery of CO2 were 99 vol.% and 90%, respectively. For this purpose, asymmetric polyethersulfone (PES) hollow fibers membranes has been developed in our previous work and has evaluated the effects of operating pressure and feed concentration of CO2 on separation performance. The operating and permeation data obtained were also analyzed in relation with the numerical simulation data using countercurrent flow model. Based on these results, in this study, four-staged membrane process including dehumidification process has been designed, installed, and operated to demonstrate the feasibility of multistage membrane systems for removing CO2 from flue gases. The operation results using this plant were compared to the numerical simulation results on multistage membrane process. The experimental results matched well with the numerical simulation data. The concentration and the recovery of CO2 in the permeate stream of final stage were ranged from 95-99 vol.% and 70-95%, respectively, depending on the operating conditions. This study demonstrated the applicability of the membrane-based pilot plant for CO2 recovery from flue gas. © 2013 Elsevier B.V. All rights reserved.

  1. Development of flame retardant and anti-pollution (AP) electric cable

    International Nuclear Information System (INIS)

    Fujimura, Shunichi; Ishitani, Hayao; Sakamoto, Kazuhide; Ohtani, Kenichi; Udoh, Sinichi; Hisatsune, Toyokazu; Igarashi, Yasuhiro; Ohya, Shingo; Handa, Katsue

    1985-01-01

    Varies means are in use to prevent the spread of cable fire. But little attention has been paid to the generation of smoke, corrosive gas, and toxic gas from burning cables. In Europe control on gas-producing cables is widespread, and Japan is beginning to be influenced by it. The authors report their development of what is called ''anti-pollution flame-retardant cable'' which produces no metal-corroding and highly toxic halogenides and only very little smoke. The AP cable can be designed in varied constructions according to the applications for which it is used. It is therefore usable for power transmission, communications, ships, vehicles, nuclear power facilities, etc. (author)

  2. Development of halogen-free flame-retardant cable for nuclear power plant

    International Nuclear Information System (INIS)

    Ishii, Nobuhisa; Morii, Akira; Fujimura, Shunichi

    1991-01-01

    Conventional flame-retardant cables release a large amount of corrosive and toxic gases and also smoke during combustion on fire. Cables covered with halogen-free flame-retardant material, containing no halogen in it, have been developed to reduce generation of such gases and smoke, and already used in telecommunication plant, subway and shipboard applications. In the case of nuclear power plant application, cable covering materials should also have radiation resistance and other properties including long-term physical stability. We have developed halogen-free flame-retardant cables for nuclear power plant with sufficient flame retardancy, radiation resistance, and environmental resistance including steam-exposure resistance, all of which are in accordance with Japanese specifications for nuclear cables, and with characteristics as low corrosiveness, low toxicity, and low smoke evolution. (author)

  3. The development of landscape-scale ecological units and their application to the greater Huachuca Mountains fire planning process

    Science.gov (United States)

    Larry E. Laing; David Gori; James T. Jones

    2005-01-01

    The multi-partner Greater Huachuca Mountains fire planning effort involves over 500,000 acres of public and private lands. This large area supports distinct landscapes that have evolved with fire. Utilizing GIS as a tool, the United States Forest Service (USFS), General Ecosystem Survey (GES), and Natural Resources Conservation Service (NRCS) State Soil Geographic...

  4. Prove of structural fire design in nuclear power plants

    International Nuclear Information System (INIS)

    Schneider, U.; Hosser, D.; Max, U.

    1986-01-01

    Based on the application of comprehensive heat balance calculations the whole parameters like geometry, fire load, ventilation conditions etc. of a German PWR were covered. A practical design procedure based on diagrams was developed whereby separate diagrams for oil and cable fires were presented. A probabilistic safety concept was employed as to account for the specific variations of fire parameters as fire load and area, ventilation condition, rate of burning. With respect to the frequency of fire occurrences and the impact of fire fighting measures on the spread of fires latest statistical data of a special BMI investigation were used. (orig./HP) [de

  5. Development of superior radiation resistant materials and cables. 2

    Energy Technology Data Exchange (ETDEWEB)

    Ikehara, Junichiro; Kanemitsuya, Kazuhiko; Ohara, Hideo; Araki, Syogo; Hamachi, Katsuhiko [Mitsubishi Cable Industries Ltd., Tokyo (Japan)

    1996-01-01

    Many nuclear power plants have been constructed in Japan and electric power generation is now highly dependent on this technology. Therefore, the needs for facilities that will enrich and reprocess nuclear fuel from nuclear power stations will be high. As there are areas with high levels of radiation, the cables which can be used in these environments are needed. We have developed a superior radiation-resistant cable which uses halogen flame-retardant materials. This radiation-resistant cable consists of Ethylene-propylene rubber (EPDM) insulation and Chlorosulfonated polyethylene (CSM) sheath can be safely used in areas with high levels of radiation. We developed this product to aid in disaster prevention. Non-halogen, flame-retardant EPDM is used for the insulation, and low-halogen, flame-retardant CSM and new non-halogen, flame-retardant materials are used for the sheath. These cables have superior flame-retardant properties and generate little smoke on corrosive gas. This products can hence reduce the danger of a secondary disaster in a fire. We expect that these cables will find application in areas with high levels of radiation. (author).

  6. Development of superior radiation resistant materials and cables. 2

    International Nuclear Information System (INIS)

    Ikehara, Junichiro; Kanemitsuya, Kazuhiko; Ohara, Hideo; Araki, Syogo; Hamachi, Katsuhiko

    1996-01-01

    Many nuclear power plants have been constructed in Japan and electric power generation is now highly dependent on this technology. Therefore, the needs for facilities that will enrich and reprocess nuclear fuel from nuclear power stations will be high. As there are areas with high levels of radiation, the cables which can be used in these environments are needed. We have developed a superior radiation-resistant cable which uses halogen flame-retardant materials. This radiation-resistant cable consists of Ethylene-propylene rubber (EPDM) insulation and Chlorosulfonated polyethylene (CSM) sheath can be safely used in areas with high levels of radiation. We developed this product to aid in disaster prevention. Non-halogen, flame-retardant EPDM is used for the insulation, and low-halogen, flame-retardant CSM and new non-halogen, flame-retardant materials are used for the sheath. These cables have superior flame-retardant properties and generate little smoke on corrosive gas. This products can hence reduce the danger of a secondary disaster in a fire. We expect that these cables will find application in areas with high levels of radiation. (author)

  7. Fire characteristics charts for fire behavior and U.S. fire danger rating

    Science.gov (United States)

    Faith Ann Heinsch; Pat Andrews

    2010-01-01

    The fire characteristics chart is a graphical method of presenting U.S. National Fire Danger Rating indices or primary surface or crown fire behavior characteristics. A desktop computer application has been developed to produce fire characteristics charts in a format suitable for inclusion in reports and presentations. Many options include change of scales, colors,...

  8. Community participation in fire management planning: The Trinity county fire safe council's fire plan

    Science.gov (United States)

    Yvonne Everett

    2008-01-01

    In 1999, Trinity County CA, initiated a participatory fire management planning effort. Since that time, the Trinity County Fire Safe Council has completed critical portions of a fire safe plan and has begun to implement projects defined in the plan. Completion of a GIS based, landscape scale fuels reduction element in the plan defined by volunteer fire fighters, agency...

  9. Tunnel fire dynamics

    CERN Document Server

    Ingason, Haukur; Lönnermark, Anders

    2015-01-01

    This book covers a wide range of issues in fire safety engineering in tunnels, describes the phenomena related to tunnel fire dynamics, presents state-of-the-art research, and gives detailed solutions to these major issues. Examples for calculations are provided. The aim is to significantly improve the understanding of fire safety engineering in tunnels. Chapters on fuel and ventilation control, combustion products, gas temperatures, heat fluxes, smoke stratification, visibility, tenability, design fire curves, heat release, fire suppression and detection, CFD modeling, and scaling techniques all equip readers to create their own fire safety plans for tunnels. This book should be purchased by any engineer or public official with responsibility for tunnels. It would also be of interest to many fire protection engineers as an application of evolving technical principles of fire safety.

  10. Predicting the effectiveness of different mulching techniques in reducing post-fire runoff and erosion at plot scale with the RUSLE, MMF and PESERA models.

    Science.gov (United States)

    Vieira, D C S; Serpa, D; Nunes, J P C; Prats, S A; Neves, R; Keizer, J J

    2018-08-01

    Wildfires have become a recurrent threat for many Mediterranean forest ecosystems. The characteristics of the Mediterranean climate, with its warm and dry summers and mild and wet winters, make this a region prone to wildfire occurrence as well as to post-fire soil erosion. This threat is expected to be aggravated in the future due to climate change and land management practices and planning. The wide recognition of wildfires as a driver for runoff and erosion in burnt forest areas has created a strong demand for model-based tools for predicting the post-fire hydrological and erosion response and, in particular, for predicting the effectiveness of post-fire management operations to mitigate these responses. In this study, the effectiveness of two post-fire treatments (hydromulch and natural pine needle mulch) in reducing post-fire runoff and soil erosion was evaluated against control conditions (i.e. untreated conditions), at different spatial scales. The main objective of this study was to use field data to evaluate the ability of different erosion models: (i) empirical (RUSLE), (ii) semi-empirical (MMF), and (iii) physically-based (PESERA), to predict the hydrological and erosive response as well as the effectiveness of different mulching techniques in fire-affected areas. The results of this study showed that all three models were reasonably able to reproduce the hydrological and erosive processes occurring in burned forest areas. In addition, it was demonstrated that the models can be calibrated at a small spatial scale (0.5 m 2 ) but provide accurate results at greater spatial scales (10 m 2 ). From this work, the RUSLE model seems to be ideal for fast and simple applications (i.e. prioritization of areas-at-risk) mainly due to its simplicity and reduced data requirements. On the other hand, the more complex MMF and PESERA models would be valuable as a base of a possible tool for assessing the risk of water contamination in fire-affected water bodies and

  11. Experimental characterization of shape memory alloy actuator cables

    Science.gov (United States)

    Biggs, Daniel B.; Shaw, John A.

    2016-04-01

    Wire rope (or cables) are a fundamental structural element in many engineering applications. Recently, there has been growing interest in stranding NiTi wires into cables to scale up the adaptive properties of NiTi tension elements and to make use of the desirable properties of wire rope. Exploratory experiments were performed to study the actuation behavior of two NiTi shape memory alloy cables and straight monofilament wire of the same material. The specimens were held under various dead loads ranging from 50 MPa to 400 MPa and thermally cycled 25 times from 140°C to 5°C at a rate of 12°C/min. Performance metrics of actuation stroke, residual strain, and work output were measured and compared between specimen types. The 7x7 cable exhibited similar actuation to the single straight wire, but with slightly longer stroke and marginally more shakedown, while maintaining equivalent specific work output. This leads to the conclusion that the 7x7 cable effectively scaled up the adaptive properties the straight wire. Under loads below 150 MPa, the 1x27 cable had up to double the actuation stroke and work output, but exhibited larger shakedown and poorer performance when loaded higher.

  12. Cable deterioration analysis method

    International Nuclear Information System (INIS)

    Sugiyama, Masahiko; Nitta, Makoto.

    1997-01-01

    At first, a hardness of a minute region and an elongation at break are measured relative to a plurality of reference samples having deterioration which is different stepwise, to obtain a relation between the hardness of the minute region and the elongation at break. They are obtained as information of correlation showing the degree of deterioration of cables. Then, samples are collected. The samples are collected from a PVC sheath. In this case, the samples to be used for the measurement are extremely small piece having the size of one side of about several hundred μm. Then, the hardness of the minute region of the samples is measured. The measured hardness of the minute region is corresponded to the previously obtained information of the correlation for deteriorations to judge the state of deterioration for the collected samples. With such procedures, the state of deterioration for electric wires and cables to be used in nuclear facilities such as power plants can easily be diagnosed substantially non destructively. (I.N.)

  13. Cable Television in Sedalia, Missouri.

    Science.gov (United States)

    Lamkin, Kathryn Janel

    A field study was conducted of the status of cable television in Sedalia, Missouri. Based on interviews of city council members and staff members of Cablevision, the Sedalia cable franchise holder, the following issues were investigated: (1) subscription rates; (2) franchise negotiations; (3) quality of existing services; and (4) possible…

  14. The optimum spanning catenary cable

    Science.gov (United States)

    Wang, C. Y.

    2015-03-01

    A heavy cable spans two points in space. There exists an optimum cable length such that the maximum tension is minimized. If the two end points are at the same level, the optimum length is 1.258 times the distance between the ends. The optimum lengths for end points of different heights are also found.

  15. Fire danger and fire behavior modeling systems in Australia, Europe, and North America

    Science.gov (United States)

    Francis M. Fujioka; A. Malcolm Gill; Domingos X. Viegas; B. Mike Wotton

    2009-01-01

    Wildland fire occurrence and behavior are complex phenomena involving essentially fuel (vegetation), topography, and weather. Fire managers around the world use a variety of systems to track and predict fire danger and fire behavior, at spatial scales that span from local to global extents, and temporal scales ranging from minutes to seasons. The fire management...

  16. Photonic-powered cable assembly

    Science.gov (United States)

    Sanderson, Stephen N.; Appel, Titus James; Wrye, IV, Walter C.

    2013-01-22

    A photonic-cable assembly includes a power source cable connector ("PSCC") coupled to a power receive cable connector ("PRCC") via a fiber cable. The PSCC electrically connects to a first electronic device and houses a photonic power source and an optical data transmitter. The fiber cable includes an optical transmit data path coupled to the optical data transmitter, an optical power path coupled to the photonic power source, and an optical feedback path coupled to provide feedback control to the photonic power source. The PRCC electrically connects to a second electronic device and houses an optical data receiver coupled to the optical transmit data path, a feedback controller coupled to the optical feedback path to control the photonic power source, and a photonic power converter coupled to the optical power path to convert photonic energy received over the optical power path to electrical energy to power components of the PRCC.

  17. Cable Bacteria in Freshwater Sediments

    DEFF Research Database (Denmark)

    Risgaard-Petersen, Nils; Kristiansen, Michael; Frederiksen, Rasmus

    2015-01-01

    In marine sediments cathodic oxygen reduction at the sediment surface can be coupled to anodic sulfide oxidation in deeper anoxic layers through electrical currents mediated by filamentous, multicellular bacteria of the Desulfobulbaceae family, the so-called cable bacteria. Until now, cable...... bacteria have only been reported from marine environments. In this study, we demonstrate that cable bacteria also occur in freshwater sediments. In a first step, homogenized sediment collected from the freshwater stream Giber Å, Denmark, was incubated in the laboratory. After 2 weeks, pH signatures...... marine cable bacteria, with the genus Desulfobulbus as the closest cultured lineage. The results of the present study indicate that electric currents mediated by cable bacteria could be important for the biogeochemistry in many more environments than anticipated thus far and suggest a common evolutionary...

  18. Electro magnetic compatibility of cabling and wiring in buildings and installations

    OpenAIRE

    Steenstra, H.T.

    2008-01-01

    The thesis deals with the behaviour, with respect to EMC (Electro Magnetic Compatibility), of cabling and wiring in buildings and installations. Measurement and calculation methods are developed and applied to cabling in a large scale installation as well as to individual cables. Besides, the location and interconnection of conductors, especially concrete reinforcement, in a building is investigated. Finally a procedure is developed that is used to deal with EMC issues in a large installation...

  19. Advanced Simulation Tool for Improved Damage Assessment 2) Water-Mist Suppression of Large Scale Compartment Fires

    National Research Council Canada - National Science Library

    Prasad, Kuldeep

    2000-01-01

    .... In the first report, we adopted a domain decomposition approach, based on the multiblock Chimera technique, to simulate fires in single uncluttered compartments and predicted spread of smoke in multi...

  20. Ash transformation and deposit build-up during biomass suspension and grate firing: Full-scale experimental studies

    DEFF Research Database (Denmark)

    Shafique Bashir, Muhammad; Jensen, Peter Arendt; Frandsen, Flemming

    2012-01-01

    An attractive option for reducing the net CO2 emissions is to substitute coal with biomass in large power plant boilers. However, the presence of chlorine (Cl) and alkali metals (K, Na) in biomassmay induce large operational problems due to ash deposit formation on the superheater tubes. The aim...... of this study was to investigate ash transformation and deposition behavior in two biomass-fired boilers, firing wheat straw and/or wood. The influence of strawfiring technology (grate and suspension) on the ash transformation, deposit formation rate and deposit characteristics has been investigated. Bulk...... elemental analysis of fly ashes revealed that fly ash from suspension firing of straw has high contents of Si, K and Ca, while fly ash from straw firing on grate was rich in the volatile elements K, Cl and S. Investigations of deposit formation ratesweremade in the superheater and convective pass regions...

  1. Fire Perimeters

    Data.gov (United States)

    California Natural Resource Agency — The Fire Perimeters data consists of CDF fires 300 acres and greater in size and USFS fires 10 acres and greater throughout California from 1950 to 2003. Some fires...

  2. Fire History

    Data.gov (United States)

    California Natural Resource Agency — The Fire Perimeters data consists of CDF fires 300 acres and greater in size and USFS fires 10 acres and greater throughout California from 1950 to 2002. Some fires...

  3. The fire at Browns Ferry station

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    A cable fire broke out at Browns Ferry-1 and -2 power station when sealing material which had been used as a make-shift seal for a cable duct caught fire in the course of a leakage test with an open light. Both blocks of the power station were scrammed manually so that nobody was injured and no activity was released. On the basis of the information supplied by NRC and TVA (the operator), the IRS has attemped a tentative evaluation of the incident. The results are presented in a summarized version. Note: a detailed description of the incident as published by the operator is available at ZAED. (orig./AK) [de

  4. Beyond annual budgets: carbon flux at different temporal scales in fire-prone Siberian Scots pine forests

    International Nuclear Information System (INIS)

    Wirth, C.; Czimczik, C.I.; Schulze, E.D.

    2002-01-01

    Along four chronosequences of fire-prone Siberian Scots pine forests we compared net primary production (NPP) and two different mass-based estimates of net ecosystem productivity (NEP C and NEP S ). NEP C quantifies changes in carbon pools along the chronosequences, whereas NEP S estimates the short-term stand-level carbon balance in intervals between fires. The chronosequences differed in the mean return interval of surface fires (unburned or moderately burned, 40 yr; heavily burned, 25 yr) and site quality (lichen versus Vaccinium type). Of the Vaccinium type (higher site quality) only a moderately burned chronosequence was studied. NEP C was derived from the rate of changes of two major carbon pools along the chronosequence time axes: (1) decomposition of old coarse woody debris (CWD) left from the previous generation after stand-replacing fire, and (2) accumulation of new carbon in biomass, CWD and soil organic layer by the regenerating stand. Young stands of all chronosequences were losing carbon at rates of -4 to -19 mol C/m 2 /yr (-48 to -228 g C/m 2 /yr). Depending on initial CWD pools and site-specific accumulation rates the stands became net carbon sinks after 12 yr (Vaccinium type) to 24 yr (lichen type) following the stand-replacing fire and offset initial carbon losses after 27 and 70 yr, respectively. Highest NEP C was reached in the unburned chronosequence (10.8 mol C/m 2 /yr or 130 g C/m 2 /yr). Maximum NEP C in the burned chronosequences ranged from 1.8 to 5.1 mol C/m 2 /yr (22 to 61 g C/m 2 /yr) depending on site quality and fire regime. Around a stand age of 200 yr NEP C was 1.6 ± 0.6 mol C/m 2 /yr (19 ± 7 g C/m 2 /yr) across all chronosequences. NEP S represents the current stand-level carbon accumulation in intervals between recurring surface fires and can be viewed as a mass-based analogue of net ecosystem exchange measured with flux towers. It was estimated based on measurements of current woody NPP, modelled decomposition of measured CWD

  5. Optimization of investment economic in PCI using the methodology of benefits design in analysis of the spread of fires with FDS (Fire Dynamics Simulator) in areas of nuclear fire

    International Nuclear Information System (INIS)

    Salellas, J.

    2015-01-01

    Fire simulation analysis allows knowing the evolution and spread fire in areas of interest within a NPP such as control room, cable room and multi zone comportment among others. fires are a main concern regarding safety analysis of NPP. IDOM has the capability to carry out fire simulations, taken in to account smoke control, fire spread, toxicity levels, ventilation and all physical phenomena. As a result, appropriate fire protection measures can be assessed in each scenario. CFD tools applied to fire simulations can determine with higher resolution all damages caused during the fire. Furthermore, such tools can reduce costs due to a lower impact of design modifications. (Author)

  6. Experimental study of the heat of combustion of electrical cables: Pitcairn/calorimetre test bench

    International Nuclear Information System (INIS)

    Gautier, B.; Bosseboeuf, G.

    1995-11-01

    The R and D has been developing for about ten years, through the MAGIC software, a modeling program on the propagation of fire in power plants. The potential fuels in a power plant are mainly limited to the oils existing in engines and control systems, and electric cables. Those cables present a complex combustion due to their fire-resistant design. In order to study that combustion, two test benches, the PITCAIRN oven and the CALORIMETRE EDF/CNRS have been linked. This report presents briefly the experimental installation, then it comments on the first experimental data obtained with two types of samples, a PVC and an EPR-Hypalon cable. The tested cables are selected from those commonly used in French Nuclear Power Plants. They present complex components (fire-retarding chemical agents, mechanical reinforcement). The data show that the behavior of those cables cannot be reduced to a mass loss rate associated to a constant Heat of Combustion. The Heat of Combustion of the PVC cable tested varies little at the beginning of the pyrolysis from 5 kJ.g -1 to 10 kJ.g -1 , then increases quickly up to 30 kJ.g -1 . In the same way, the EPR-Hypalon cable shows a continuous and slow increase of the Heat of Combustion from 1 kJ.g -1 to 20 kJ.g -1 during the pyrolysis, then rises quickly up to 40 kJ.g -1 at the end. Those data corroborate the thesis of the dilution of flammable species by fire-retarding agents, which lower the Heat of combustion but seems to disappear at the end of the pyrolysis. (authors). 7 refs., 6 figs

  7. 10BASE5 Ethernet Cable & Vampire Tap

    CERN Document Server

    1983-01-01

    10BASE5 Thick Ethernet Cable, 10Mbit/sec. In the 1980s and early 1990's, Ethernet became more popular and provided a much faster data transmission rate. This cable is one of the first ethernet cables from 1983, a thick, bulky affair. Computers were attached via "Vampire Taps" which were connectors screwed straight through the shielding of the cable.

  8. 14 CFR 27.1365 - Electric cables.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Electric cables. 27.1365 Section 27.1365... STANDARDS: NORMAL CATEGORY ROTORCRAFT Equipment Electrical Systems and Equipment § 27.1365 Electric cables. (a) Each electric connecting cable must be of adequate capacity. (b) Each cable that would overheat...

  9. 30 CFR 18.45 - Cable reels.

    Science.gov (United States)

    2010-07-01

    ... and locomotives shall maintain positive tension on the portable cable during reeling and unreeling. Such tension shall only be high enough to prevent a machine from running over its own cable(s). (e... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Cable reels. 18.45 Section 18.45 Mineral...

  10. 14 CFR 25.689 - Cable systems.

    Science.gov (United States)

    2010-01-01

    ... cable system must be designed so that there will be no hazardous change in cable tension throughout the... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Cable systems. 25.689 Section 25.689... STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Control Systems § 25.689 Cable systems. (a...

  11. Background information to the installers guide for small scale mains connected PV

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    This report contains background information used by BRE, EA Technology, Halcrows and Sundog when compiling guidance for the UK's New and Renewable Energy Programme on the installation of small-scale photovoltaics (PV) in buildings. The report considers: relevant standards; general safety issues; fire and safety issues, including the fire resistance of PV modules; PV module ratings such as maximum voltage and maximum current; DC cabling; the DC disconnect; the DC junction box; fault analysis; general and AC side earthing; DC earthing; lightning and surge suppression; inverters; AC modules; AC systems; getting connection; mounting options; and installation issues.

  12. Emerging Subsea Networks: SMART Cable Systems for Science and Society

    Science.gov (United States)

    Howe, B. M.; Butler, R.; Joint Task Force, U.

    2016-02-01

    The subsea telecommunications cable industry is approaching a prospective new era: deploying SMART subsea cable systems (SMART = Science Monitoring And Reliable Telecommunication). The current global, commercial cable infrastructure consists of 1 Gm of cable, being refreshed now and expanding in the future. The SMART concept is to add a small external sensor package along the cable system at its optical repeaters to transmit important real-time environmental data via a dedicated wavelength or overhead channel in the transmission system, avoiding any impact on the commercial traffic. These small, reliable, existing sensors would precisely measure temperature, pressure and three-axis acceleration across the world's ocean floor over an extended period of time, being deployed using standard cable-laying procedures on new or refurbished cables, but not requiring maintenance through the 2-3 decade life of the cable systems. The game-changing factor is the urgent international need for ocean environmental data related to mitigating climate and sea-level change and improving tsunami and slope failure hazard warnings. Societal costs incurred by these are reaching billions of dollars and hundreds of thousands of deaths. Pressures for new and urgent public policies are evident from the 5th IPCC Assessment, USA-China agreement on limiting greenhouse gas emissions, clear evidence for rapid global warming, 21st Session of the Conference of the Parties to the UNFCCC (December 2015, Paris), and the scale of the costs of inaction. To support revised public policies and actions, decision-makers, industry leaders, and the public are seeking key scientific data, which will necessitate new sources of funding. Hence, the emergence of new SMART cable systems offered by the subsea telecommunications industry will provide new market opportunities, engage additional non-traditional users, and make profound societal contributions. The Joint Task Force (JTF) on SMART Subsea Cable Systems

  13. Co-emergence of multi-scale cortical activities of irregular firing, oscillations and avalanches achieves cost-efficient information capacity.

    Directory of Open Access Journals (Sweden)

    Dong-Ping Yang

    2017-02-01

    Full Text Available The brain is highly energy consuming, therefore is under strong selective pressure to achieve cost-efficiency in both cortical connectivities and activities. However, cost-efficiency as a design principle for cortical activities has been rarely studied. Especially it is not clear how cost-efficiency is related to ubiquitously observed multi-scale properties: irregular firing, oscillations and neuronal avalanches. Here we demonstrate that these prominent properties can be simultaneously observed in a generic, biologically plausible neural circuit model that captures excitation-inhibition balance and realistic dynamics of synaptic conductance. Their co-emergence achieves minimal energy cost as well as maximal energy efficiency on information capacity, when neuronal firing are coordinated and shaped by moderate synchrony to reduce otherwise redundant spikes, and the dynamical clusterings are maintained in the form of neuronal avalanches. Such cost-efficient neural dynamics can be employed as a foundation for further efficient information processing under energy constraint.

  14. Co-firing Bosnian coals with woody biomass: Experimental studies on a laboratory-scale furnace and 110 MWe power unit

    Directory of Open Access Journals (Sweden)

    Smajevic Izet

    2012-01-01

    Full Text Available This paper presents the findings of research into cofiring two Bosnian cola types, brown coal and lignite, with woody biomass, in this case spruce sawdust. The aim of the research was to find the optimal blend of coal and sawdust that may be substituted for 100% coal in large coal-fired power stations in Bosnia and Herzegovina. Two groups of experimental tests were performed in this study: laboratory testing of co-firing and trial runs on a large-scale plant based on the laboratory research results. A laboratory experiment was carried out in an electrically heated and entrained pulverized-fuel flow furnace. Coal-sawdust blends of 93:7% by weight and 80:20% by weight were tested. Co-firing trials were conducted over a range of the following process variables: process temperature, excess air ratio and air distribution. Neither of the two coal-sawdust blends used produced any significant ash-related problems provided the blend volume was 7% by weight sawdust and the process temperature did not exceed 1250ºC. It was observed that in addition to the nitrogen content in the co-fired blend, the volatile content and particle size distribution of the mixture also influenced the level of NOx emissions. The brown coal-sawdust blend generated a further reduction of SO2 due to the higher sulphur capture rate than for coal alone. Based on and following the laboratory research findings, a trial run was carried out in a large-scale utility - the Kakanj power station, Unit 5 (110 MWe, using two mixtures; one in which 5%/wt and one in which 7%/wt of brown coal was replaced with sawdust. Compared to a reference firing process with 100% coal, these co-firing trials produced a more intensive redistribution of the alkaline components in the slag in the melting chamber, with a consequential beneficial effect on the deposition of ash on the superheater surfaces of the boiler. The outcome of the tests confirms the feasibility of using 7%wt of sawdust in combination

  15. A taxonomic framework for cable bacteria and proposal of the candidate genera Electrothrix and Electronema

    DEFF Research Database (Denmark)

    Trojan, Daniela; Schreiber, Lars; Bjerg, Jesper Tataru

    2016-01-01

    Cable bacteria are long, multicellular filaments that can conduct electric currents over centimeter-scale distances. All cable bacteria identified to date belong to the deltaproteobacterial family Desulfobulbaceae and have not been isolated in pure culture yet. Their taxonomic delineation and exa...

  16. Motility of electric cable bacteria

    DEFF Research Database (Denmark)

    Bjerg, Jesper Tataru; Damgaard, Lars Riis; Holm, Simon Agner

    2016-01-01

    Cable bacteria are filamentous bacteria that electrically couple sulfide oxidation and oxygen reduction at centimeter distances, and observations in sediment environments have suggested that they are motile. By time-lapse microscopy, we found that cable bacteria used gliding motility on surfaces...... with a highly variable speed of 0.50.3 ms1 (meanstandard deviation) and time between reversals of 155108 s. They frequently moved forward in loops, and formation of twisted loops revealed helical rotation of the filaments. Cable bacteria responded to chemical gradients in their environment, and around the oxic......-anoxic interface, they curled and piled up, with straight parts connecting back to the source of sulfide. Thus, it appears that motility serves the cable bacteria in establishing and keeping optimal connections between their distant electron donor and acceptors in a dynamic sediment environment....

  17. Cable SGEMP Code Validation Study

    Energy Technology Data Exchange (ETDEWEB)

    Ballard, William Parker [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Center for CA Weapons Systems Engineering

    2013-05-01

    This report compared data taken on the Modular Bremsstrahlung Simulator using copper jacketed (cujac) cables with calculations using the RHSD-RA Cable SGEMP analysis tool. The tool relies on CEPXS/ONBFP to perform radiation transport in a series of 1D slices through the cable, and then uses a Green function technique to evaluate the expected current drive on the center conductor. The data were obtained in 2003 as part of a Cabana verification and validation experiment using 1-D geometries, but were not evaluated until now. The agreement between data and model is not adequate unless gaps between the dielectric and outer conductor (ground) are assumed, and these gaps are large compared with what is believed to be in the actual cable.

  18. Air flow around suspended cables

    Directory of Open Access Journals (Sweden)

    Gołębiowska Irena

    2017-01-01

    Full Text Available The impact of wind on construction structures is essential issue in design and operation. In particular, the wind can cause the dengerous vibrations of slender structures with low rigidity, eg. vibrations of cables of suspension and cable-stayed bridges or high voltage transmision lines, thus understanding of wind flow around such constructions is significant. In the paper the results of the analysis of wind flow around the cables for different Reynolds number is presented. The analysed flow meets the Navier-Stokes and continuity equations. The circle and elipse section of the cable is analysed. The discusion of vorticity, drag and lift coefficients and cases due to different angle of wind flow action is presented. The boundary layer and its infuence on total flow is analysed.

  19. Nuclear instrumentation cable end seal

    International Nuclear Information System (INIS)

    Cannon, C.P.; Brown, D.P.

    1979-01-01

    An improved coaxial end seal for hermetically sealed nuclear instrumentation cable exhibiting an improved breakdown pulse noise characteristic under high voltage, high temperature conditions is described. A tubular insulator body has metallized interior and exterior surface portions which are braze sealed to a center conductor and an outer conductive sheath. The end surface of the insulator body which is directed toward the coaxial cable to which it is sealed has a recessed surface portion within which the braze seal material terminates

  20. Radiation effects on power cables for nuclear power plants

    International Nuclear Information System (INIS)

    Arora, R.; Munshi, P.; Badshah, M.G.Q.

    1988-01-01

    A large number of power and control cables, insulated with organic/polymeric materials, are installed quite near the reactor in nuclear power plants. The reliability of electrical equipment, receiving power through these cables, is critically important for the design and safety of the power stations. The radiation intensity inside the containment varies significantly from one location to another. The extent of material degradation is associated with the local radiation intensity. The cables used in the nuclear environment require several unique properties, the most obvious of these being radiation resistance, fire resistance, and the ability to withstand the loss-of-coolant accident in a nuclear power plant as specified in Institute of Electrical and Electronics Engineers (IEEE) Standard 383. In this study, four specific electrical power cable samples insulated with polyethylene, polyvinyl chloride, ethylene propylene rubber, and silicone rubber were chosen to investigate the effect of radiation in reactor environments on the electrical properties of the samples. Voltage breakdown tests and dielectric loss factor (tan δ) and conductor resistance measurements were carried out on each sample before and after irradiating them to near lifetime doses at ambient temperatures in atmospheric conditions

  1. The dispersion of radioactive aerosols in fires

    International Nuclear Information System (INIS)

    Buijs, K.; Chavane de Dalmassy, B.; Pickering, S.

    1989-01-01

    Experimental results are reported on the resuspension, due to fire, of radioactive nuclear fuel particles from a variety of substrates. Experiments were carried out both on large and small scale. In small-scale fires uranium-plutonium oxide particles were used and in the large-scale fires cerium-europium oxide particles were used. The mechanisms of particle resuspension were investigated in separate series of experiments. It was found that in small-scale fires up to 20% of the particle inventory can be resuspended and in large-scale fires up to 75%. In both cases most of the resuspended material deposits within the fire chamber and a maximum of 2% is carried into the ventilation duct at the outlet of the fire chamber. The predominant resuspension mechanisms are bubble bursting in small-scale fires and turbulence in large-scale fires. (orig.)

  2. Static and Dynamic Characteristics of a Long-Span Cable-Stayed Bridge with CFRP Cables

    Directory of Open Access Journals (Sweden)

    Xu Xie

    2014-06-01

    Full Text Available In this study, the scope of CFRP cables in cable-stayed bridges is studied by establishing a numerical model of a 1400-m span of the same. The mechanical properties and characteristics of CFRP stay cables and of a cable-stayed bridge with CFRP cables are here subjected to comprehensive analysis. The anomalies in the damping properties of free vibration, nonlinear parametric vibration and wind fluctuating vibration between steel cables and CFRP cables are determined. The structural stiffness, wind resistance and traffic vibration of the cable-stayed bridge with CFRP cables are also analyzed. It was found that the static performances of a cable-stayed bridge with CFRP cables and steel cables are basically the same. The natural frequencies of CFRP cables do not coincide with the major natural frequencies of the cable-stayed bridge, so the likelihood of CFRP cable-bridge coupling vibration is minuscule. For CFRP cables, the response amplitudes of both parametric vibration and wind fluctuating vibration are smaller than those of steel cables. It can be concluded from the research that the use of CFRP cables does not change the dynamic characteristics of the vehicle-bridge coupling vibration. Therefore, they can be used in long-span cable-stayed bridges with an excellent mechanical performance.

  3. Static and Dynamic Characteristics of a Long-Span Cable-Stayed Bridge with CFRP Cables.

    Science.gov (United States)

    Xie, Xu; Li, Xiaozhang; Shen, Yonggang

    2014-06-23

    In this study, the scope of CFRP cables in cable-stayed bridges is studied by establishing a numerical model of a 1400-m span of the same. The mechanical properties and characteristics of CFRP stay cables and of a cable-stayed bridge with CFRP cables are here subjected to comprehensive analysis. The anomalies in the damping properties of free vibration, nonlinear parametric vibration and wind fluctuating vibration between steel cables and CFRP cables are determined. The structural stiffness, wind resistance and traffic vibration of the cable-stayed bridge with CFRP cables are also analyzed. It was found that the static performances of a cable-stayed bridge with CFRP cables and steel cables are basically the same. The natural frequencies of CFRP cables do not coincide with the major natural frequencies of the cable-stayed bridge, so the likelihood of CFRP cable-bridge coupling vibration is minuscule. For CFRP cables, the response amplitudes of both parametric vibration and wind fluctuating vibration are smaller than those of steel cables. It can be concluded from the research that the use of CFRP cables does not change the dynamic characteristics of the vehicle-bridge coupling vibration. Therefore, they can be used in long-span cable-stayed bridges with an excellent mechanical performance.

  4. Fire PRA requantification studies. Final report

    International Nuclear Information System (INIS)

    Parkinson, W.

    1993-03-01

    This report describes the requantification of two existing fire probabilistic risk assessments (PRAs) using a fire PRA method and data that are being developed by the Electric Power Research Institute (EPRI). The two existing studies are the Seabrook Station Probabilistic Safety Assessment that was made in 1983 and the 1989 NUREG-1150 analysis of the Peach Bottom Plant. Except for the fire methods and data, the original assumptions were used. The results from the requantification show that there were excessive conservatisms in the original studies. The principal reason for a hundredfold reduction in the Peach Bottom core- damage frequency is the determination that no electrical cabinet fire in a switchgear room would damage both offsite power feeds. Past studies often overestimated the heat release from electrical cabinet fires. EPRI's electrical cabinet heat release rates are based on tests that were conducted for Sandia's fire research program. The rates are supported by the experience in the EPRI Fire Events Database for U.S. nuclear plants. Test data and fire event experience also removed excessive conservatisms in the Peach Bottom control and cable spreading rooms, and the Seabrook primary component cooling pump, turbine building relay and cable spreading rooms. The EPRI fire PRA method and data will show that there are excessive conservatisms in studies that were made for many plants and can benefit them accordingly

  5. Combustion performance of pyrolysis oil/ethanol blends in a residential-scale oil-fired boiler

    Science.gov (United States)

    A 40 kWth oil-fired commercial boiler was fueled with blends of biomass pyrolysis oil (py-oil) and ethanol to determine the feasibility of using these blends as a replacement for fuel oil in home heating applications. An optimal set of test parameters was determined for the combustion of these blend...

  6. Optimization of investment economic in PCI using the methodology of benefits design in analysis of the spread of fires with FDS (Fire Dynamics Simulator) in areas of nuclear fire; Optimizacion de la inversion economica en PCI mediante la metodologia de diseo prestaional en el analisis de la propagacion de incendios con FDS (Fire Dynnamics Simulator) en areas de fuego de centrales nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Salellas, J.

    2015-07-01

    Fire simulation analysis allows knowing the evolution and spread fire in areas of interest within a NPP such as control room, cable room and multi zone comportment among others. fires are a main concern regarding safety analysis of NPP. IDOM has the capability to carry out fire simulations, taken in to account smoke control, fire spread, toxicity levels, ventilation and all physical phenomena. As a result, appropriate fire protection measures can be assessed in each scenario. CFD tools applied to fire simulations can determine with higher resolution all damages caused during the fire. Furthermore, such tools can reduce costs due to a lower impact of design modifications. (Author)

  7. Investigation of the sensitivity of MIS-sensor to thermal decomposition products of cables insulation

    Science.gov (United States)

    Filipchuk, D. V.; Litvinov, A. V.; Etrekova, M. O.; Nozdrya, D. A.

    2017-12-01

    Sensitivity of the MIS-sensor to products of thermal decomposition of insulation and jacket of the most common types of cables is investigated. It is shown that hydrogen is evolved under heating the insulation to temperatures not exceeding 250 °C. Registration of the evolved hydrogen by the MIS-sensor can be used for detection of fires at an early stage.

  8. Comparison of Available Technologies for Fire Spots Detection via Linear Heat Detector

    Directory of Open Access Journals (Sweden)

    Miksa František

    2016-12-01

    Full Text Available It is very demanding to detect fire spots under difficult conditions with high occurrence of interfering external factors such as large distances, airflow difficultly, high dustiness, high humidity, etc. Spot fire sensors do not meet the requirements due to the aforementioned conditions as well as large distances. Therefore, the detection of a fire spot via linear heat sensing cables is utilized.

  9. Fire safety engineering

    International Nuclear Information System (INIS)

    Smith, D.N.

    1989-01-01

    The periodic occurrence of large-scale, potentially disastrous industrial accidents involving fire in hazardous environments such as oilwell blowouts, petrochemical explosions and nuclear installations highlights the need for an integrated approach to fire safety engineering. Risk reduction 'by design' and rapid response are of equal importance in the saving of life and property in such situations. This volume of papers covers the subject thoroughly, touching on such topics as hazard analysis, safety design and testing, fire detection and control, and includes studies of fire hazard in the context of environment protection. (author)

  10. Combustion behaviour and deposition characteristics of Cynara Cardunculus/Greek lignite co-firing under various thermal shares in a thermal pilot-scale facility

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, Aaron; Maier, Joerg; Scheffknecht, Guenter [Stuttgart Univ. (Germany). Inst. of Combustion and Power Plant Technology; Pawlak-Kruczek, Halina [Wroclaw Univ. of Technology (Poland). Inst. of Heat Engineering and Fluid Mechanics; Karampinis, Emmanouil; Grammelis, Panagiotis; Kakaras, Emmanuel [Centre for Research and Technology Hellas, Ptolemais (Greece). Chemical Process and Energy Resources Inst.; National Technical Univ. of Athens (Greece). Lab. of Steam Boilers and Thermal Plants

    2013-06-01

    The combustion of herbaceous biomass in industrial boilers, either as co-firing fuel or in dedicated combustion units, possess significant operating challenges due to increased risks for corrosion and slagging/fouling. The present work aims at investigating the combustion behaviour of Cynara Cardunculus (cardoon) in a range of thermal shares (0 to 100 %) with a Greek lignite. Combustion tests were performed in a 0.5 MW thermal input pulverised fuel pilot-scale test facility. Deposits were characterised in terms of morphological and ash fusion behaviour, and slagging/fouling tendencies were determined. (orig.)

  11. Uncertainty analysis of moderate- versus coarse-scale satellite fire products for quantifying agricultural burning: Implications for Air Quality in European Russia, Belarus, and Lithuania

    Science.gov (United States)

    McCarty, J. L.; Krylov, A.; Prishchepov, A. V.; Banach, D. M.; Potapov, P.; Tyukavina, A.; Rukhovitch, D.; Koroleva, P.; Turubanova, S.; Romanenkov, V.

    2015-12-01

    Cropland and pasture burning are common agricultural management practices that negatively impact air quality at a local and regional scale, including contributing to short-lived climate pollutants (SLCPs). This research focuses on both cropland and pasture burning in European Russia, Lithuania, and Belarus. Burned area and fire detections were derived from 500 m and 1 km Moderate Resolution Imaging Spectroradiometer (MODIS), 30 m Landsat 7 Enhanced Thematic Mapper Plus (ETM+), and Landsat 8 Operational Land Imager (OLI) data. Carbon, particulate matter, volatile organic carbon (VOCs), and harmful air pollutants (HAPs) emissions were then calculated using MODIS and Landsat-based estimates of fire and land-cover and land-use. Agricultural burning in Belarus, Lithuania, and European Russia showed a strong and consistent seasonal geographic pattern from 2002 to 2012, with the majority of fire detections occurring in March - June and smaller peak in July and August. Over this 11-year period, there was a decrease in both cropland and pasture burning throughout this region. For Smolensk Oblast, a Russian administrative region with comparable agro-environmental conditions to Belarus and Lithuania, a detailed analysis of Landsat-based burned area estimations for croplands and pastures and field data collected in summer 2014 showed that the agricultural burning area can be up to 10 times higher than the 1 km MODIS active fire estimates. In general, European Russia is the main source of agricultural burning emissions compared to Lithuania and Belarus. On average, all cropland burning in European Russia as detected by the MCD45A1 MODIS Burned Area Product emitted 17.66 Gg of PM10 while annual burning of pasture in Smolensk Oblast, Russia as detected by Landsat burn scars emitted 494.85 Gg of PM10, a 96% difference. This highlights that quantifying the contribution of pasture burning and burned area versus cropland burning in agricultural regions is important for accurately

  12. Medium scale fire tests of propane tanks to study the boiling liquid expanding vapour explosion (BLEVE) and transient two-phase jet release

    Energy Technology Data Exchange (ETDEWEB)

    Ye Zhifei

    1994-07-01

    A series of medium scale fire tests were conducted to study boiling liquid expanding vapour explosions (BLEVE) and transient jet releases resulting from thermally induced propane tank ruptures. The tests were conducted using commercial propane contained in automotive propane tanks with a capacity of ca 400 liters. The tanks were brought to failure using a combination of torch and pool fire impingement. Instrumentation was included to measure internal pressure, liquid, vapour and wall temperature distribution, tank and lading mass, external blast overpressure, and fireball thermal radiation. Video and still cameras were used to record the fireball and jet fire shapes and dimensions. Two different kinds of BLEVE failure were observed. For very weak tanks the BLEVE was a single step process where the rupture propagated rapidly along the length of the tank. The duration of these events was measured in milliseconds and it is suggested that the process is driven by the vapour space energy. The other type of BLEVE was a two step process where a crack would start in a weakened area, arrest in a stronger part of the tank, and then start again to end in catastrophic failure. Initial failure and jet type release results in violent boiling and pressure recovery in the tank, leading to restart of the crack and catastrophic failure. Time duration is measured in seconds, and is driven by energy stored in the liquid. A computer model was developed to simulate the transient jet release resulting from finite tank failures, and can predict transient mass flow, tank pressure decay, visible flame length and jet fire thermal radiation. 253 refs., 132 figs., 29 tabs.

  13. Probabilistic Fatigue Life Prediction of Bridge Cables Based on Multiscaling and Mesoscopic Fracture Mechanics

    Directory of Open Access Journals (Sweden)

    Zhongxiang Liu

    2016-04-01

    Full Text Available Fatigue fracture of bridge stay-cables is usually a multiscale process as the crack grows from micro-scale to macro-scale. Such a process, however, is highly uncertain. In order to make a rational prediction of the residual life of bridge cables, a probabilistic fatigue approach is proposed, based on a comprehensive vehicle load model, finite element analysis and multiscaling and mesoscopic fracture mechanics. Uncertainties in both material properties and external loads are considered. The proposed method is demonstrated through the fatigue life prediction of cables of the Runyang Cable-Stayed Bridge in China, and it is found that cables along the bridge spans may have significantly different fatigue lives, and due to the variability, some of them may have shorter lives than those as expected from the design.

  14. Seismic Fragility Assessment of an Isolated Multipylon Cable-Stayed Bridge Using Shaking Table Tests

    Directory of Open Access Journals (Sweden)

    Yutao Pang

    2017-01-01

    Full Text Available In recent decades, cable-stayed bridges have been widely built around the world due to the appealing aesthetics and efficient and fast mode of construction. Numerous studies have concluded that the cable-stayed bridges are sensitive to earthquakes because they possess low damping characteristics and high flexibility. Moreover, cable-stayed bridges need to warrant operability especially in the moderate-to-severe earthquakes. The provisions implemented in the seismic codes allow obtaining adequate seismic performance for the cable-stayed bridge components; nevertheless, they do not provide definite yet reliable rules to protect the bridge. To date, very few experimental tests have been carried out on the seismic fragility analysis of cable-stayed bridges which is the basis of performance-based analyses. The present paper is aimed at proposing a method to derive the seismic fragility curves of multipylon cable-stayed bridge through shake table tests. Toward this aim, a 1/20 scale three-dimensional model of a 22.5 m cable-stayed bridge in China is constructed and tested dynamically by using the shaking table facility of Tongji University. The cable-stayed bridge contains three pylons and one side pier. The outcomes of the comprehensive shaking table tests carried out on cable-stayed bridge have been utilized to derive fragility curves based on a systemic approach.

  15. The RHIC transfer line cable database

    International Nuclear Information System (INIS)

    Scholl, E.H.; Satogata, T.

    1995-01-01

    A cable database was created to facilitate and document installation of cables and wiring in the RHIC project, as well as to provide a data source to track possible wiring and signal problems. The eight tables of this relational database, currently implemented in Sybase, contain information ranging from cable routing to attenuation of individual wires. This database was created in a hierarchical scheme under the assumption that cables contain wires -- each instance of a cable has one to many wires associated with it. This scheme allows entry of information pertinent to individual wires while only requiring single entries for each cable. Relationships to other RHIC databases are also discussed

  16. Applications of Living Fire PRA models to Fire Protection Significance Determination Process in Taiwan

    International Nuclear Information System (INIS)

    De-Cheng, Chen; Chung-Kung, Lo; Tsu-Jen, Lin; Ching-Hui, Wu; Lin, James C.

    2004-01-01

    The living fire probabilistic risk assessment (PRA) models for all three operating nuclear power plants (NPPs) in Taiwan had been established in December 2000. In that study, a scenario-based PRA approach was adopted to systematically evaluate the fire and smoke hazards and associated risks. Using these fire PRA models developed, a risk-informed application project had also been completed in December 2002 for the evaluation of cable-tray fire-barrier wrapping exemption. This paper presents a new application of the fire PRA models to fire protection issues using the fire protection significance determination process (FP SDP). The fire protection issues studied may involve the selection of appropriate compensatory measures during the period when an automatic fire detection or suppression system in a safety-related fire zone becomes inoperable. The compensatory measure can either be a 24-hour fire watch or an hourly fire patrol. The living fire PRA models were used to estimate the increase in risk associated with the fire protection issue in terms of changes in core damage frequency (CDF) and large early release frequency (LERF). In compliance with SDP at-power and the acceptance guidelines specified in RG 1.174, the fire protection issues in question can be grouped into four categories; red, yellow, white and green, in accordance with the guidelines developed for FD SDP. A 24-hour fire watch is suggested only required for the yellow condition, while an hourly fire patrol may be adopted for the white condition. More limiting requirement is suggested for the red condition, but no special consideration is needed for the green condition. For the calculation of risk measures, risk impacts from any additional fire scenarios that may have been introduced, as well as more severe initiating events and fire damages that may accompany the fire protection issue should be considered carefully. Examples are presented in this paper to illustrate the evaluation process. (authors)

  17. How The Australian National University's emergency management and continuity plans responded to a large-scale fire.

    Science.gov (United States)

    Meehan, Bart

    2008-01-01

    On 18th January, 2003, one of the worst bushfires in the history of Australia hit the capital city, Canberra. By the time it was under control, four people were dead and more than 500 homes were destroyed. The fire also destroyed the Mount Stromlo campus of the Australian National University, the location of the Research School of Astronomy and Astrophysics. In response to the fires, the University initiated its emergency management strategy and business continuity plans. These allowed the School to recommence limited operations within two weeks of the disaster. This paper details a case study of the impact of the fire (in part using personal recollections of staff and students), and the emergency response implemented by the University. It describes the development of the University's emergency management strategy, with its emphasis on the key elements of clear chain of command and flexibility in developing an incident-specific response. The paper also provides an assessment of how the plan worked during an actual incident and some of the lessons learned, including the importance of the early response, managing the impact on people, media management, insurance and communications.

  18. Fire protection in the nuclear power plant

    International Nuclear Information System (INIS)

    Takuma, Masao

    1977-01-01

    According to the publication by US NRC, 32 fires have occurred in the nuclear power stations in operation, but most of them were small fire, and did not affect the safety of the nuclear power stations. The largest fire was that which occurred in the Browns Ferry Nuclear Power Station of TVA, USA, in March, 1976. It did not jeopardize the safety of the reactor facilities, and the leak of radioactive substance did not occur at all. But the investigation was made extensively by the joint committee of both houses, the government and others, and the deficiency in the countermeasures to fire was found, and it was clarified that some revision would by required on the standard applied heretofore. It was the valuable experience for improving further the safety of nuclear power stations. The fire occurred by the ignition of the polyurethane for sealing cable penetrations due to candle flame for testing. About 1600 cables were burned. When fire breaks out in a nuclear power station, it is necessary to stop and cool the reactor without fail, and to prevent the leak of radioactive substances definitely. In case of the fire in Browns Ferry, these requirements were fulfilled satisfactorily. The countermeasures on the basis of the experience in Browns Ferry and the design of the counterplan to fire in nuclear power stations are explained. (Kako, I.)

  19. Static and Dynamic Mechanical Properties of Long-Span Cable-Stayed Bridges Using CFRP Cables

    Directory of Open Access Journals (Sweden)

    Mei Kuihua

    2017-01-01

    Full Text Available The elastic modulus and deadweight of carbon fiber-reinforced polymer (CFRP cables are different from those of steel cables. Thus, the static and dynamic behaviors of cable-stayed bridges using CFRP cables are different from those of cable-stayed bridges using steel cables. The static and dynamic performances of the two kinds of bridges with a span of 1000 m were studied using the numerical method. The effects of geometric nonlinear factors on static performance of the two kinds of cable-stayed bridges were analyzed. The live load effects and temperature effects of the two cable-stayed bridges were also analyzed. The influences of design parameters, including different structural systems, the numbers of auxiliary piers, and the space arrangement types of cable, on the dynamic performance of the cable-stayed bridge using CFRP cables were also studied. Results demonstrate that sag effect of the CFRP cable is much smaller than that of steel cable. The temperature effects of CFRP cable-stayed bridge are less than those of steel cable-stayed bridge. The vertical bending natural vibration frequency of the CFRP cable-stayed bridge is generally lower than that of steel cable-stayed bridge, whereas the torsional natural vibration frequency of the former is higher than that of the latter.

  20. Fire and EMS Districts, These layers show the geographic area of each Fire and EMS responder contained in the County of Polk, Wisconsin., Published in 2006, 1:2400 (1in=200ft) scale, Polk County Government.

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — Fire and EMS Districts dataset current as of 2006. These layers show the geographic area of each Fire and EMS responder contained in the County of Polk, Wisconsin..

  1. Characterisation of solid recovered fuels for direct co-firing in large-scale PF power plants

    Energy Technology Data Exchange (ETDEWEB)

    Dunnu, Gregory

    2013-04-01

    Solid Recovered Fuels are solid fuels prepared from high calorific fractions of non-hazardous waste materials intended to be co-fired in coal power plants and industrial furnaces (CEN/TC 343). They are composed of a variety of materials of which some, although recyclable in theory, may be in a form that makes their recycling an unsound option. The SRF with a typical size range of 3 mm through 25 mm are to be directly co-fired in an existing pulverised coal power plant. In comparison to pulverised coal, the particle size distribution of the SRF is of several magnitudes higher, resulting in a different burnout behaviour. Size reduction of the SRF to a fraction similar to coal is not economically feasible. The aim here is, therefore, the direct co-firing of the solid recovered fuels in the boilers without any further size reduction. This approach, however, bears the risk of incomplete combustion if the injection points of the solid recovered fuels are not optimally selected. Accordingly, the prediction of the burner levels, at which the solid recovered fuels should be injected and whether or not a complete combustion will be achieved under full load condition, is the primary objective of this dissertation. In this research work, laboratory experiments have been conducted to forecast the success of co-firing the SRF in a commercial pulverised coal power plant. It involves the analyses of the fuel and its intermediate chars generated at conditions comparable to boiler conditions to determine some characteristic parameters, namely the burnout time, the aerodynamic lift velocity, the drag coefficient and the apparent densities. The data gathered from the laboratory experiments are transferred to boiler conditions to determine the particle trajectories and the maximum distance likely to travel before they are completely converted in the boiler. Different scenarios are examined and based on the results the best boiler injection points are predicted. Furthermore, an on

  2. Advanced superconducting power cable for MV urban power supply

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Frank [Nexans Deutschland GmbH, Hannover (Germany); Merschel, Frank [RWE Deutschland AG, Essen (Germany); Noe, Mathias [Karlsruhe Institute of Technology, Karlsruhe (Germany)

    2015-07-01

    In recent years the technology of superconducting power cable systems has progressed such that the technical hurdles preparing for commercial applications have been mastered. Several field tests of large scale prototypes for the applications of superconducting cables as well as superconducting fault current limiters have been successfully accomplished and the technology of such systems is ready for commercialization. The presentation will give a detailed overview of the German AmpaCity project. An overview will be given on the development, manufacturing and installation of the 10 kV, 40 MVA HTS system consisting of a fault current limiter and of a 1 km cable in the city of Essen. Since it is the first time that a one kilometer HTS cable system is installed together with an HTS fault current limiter in a real grid application between two substations within a city center area, AmpaCity serves as a lighthouse project. In addition it is worldwide the longest installed HTS cable system so far. It is expected that relatively large technical advances will be made in the future of the comparatively new HTS technology, which in turn will bring associated cost reductions. For this reason, the AmpaCity pilot project in the downtown area of Essen in Germany will be an important step on the way to achieving more widespread application of HTS technology.

  3. Laplace Synthesis Validation through Measurements on Underground Transmission Cables

    Directory of Open Access Journals (Sweden)

    Uribe-Campos Felipe Alejandro

    2014-10-01

    Full Text Available Underground cable electrical parameters ZY as well as their modal propagation characteristics are highly frequency dependent which in certain cases turns its analysis difficult. To perform electromagnetic transient studies of cables the calculation of electrical parameters is essential to obtain the waves propagation solution through the multiconductor system. At the same time this requires to solve the inverse Laplace transform on a numerical form. Although the analytic Laplace transform has an indisputable accuracy, the application of its numerical version up-to-date has not been completely accepted. A complete methodology is developed in this work to guide analyst engineers or graduate students in the calculation of electromagnetic transients of underground cable systems. Finally, to help the validation of the numerical inverse Laplace transform a scaled prototype experiment is performed in the laboratory in which a transient step-response at the remote end of an energized conductor is measured.

  4. Umbilical Cable Recovery Load Analysis

    Institute of Scientific and Technical Information of China (English)

    YAN Shu-wang; JIA Zhao-lin; FENG Xiao-wei; LI Shi-tao

    2013-01-01

    Umbilical cable is a kind of integrated subsea cable widely used in the exploration and exploitation of oil and gas field.The severe ocean environment makes great challenges to umbilical maintenance and repair work.Damaged umbilical is usually recovered for the regular operation of the offshore production system.Analysis on cables in essence is a two-point boundary problem.The tension load at the mudline must be known first,and then the recovery load and recovery angle on the vessel can be solved by use of catenary equation.The recovery analysis also involves umbilicalsoil interaction and becomes more complicated.Calculation methods for recovery load of the exposed and buried umbilical are established and the relationship between the position of touch down point and the recovery load as well as the recovery angle and recovery load are analyzed.The analysis results provide a theoretical reference for offshore on-deck operation.

  5. Multi-compartment Fire Modeling for Switchgear Room using CFAST

    International Nuclear Information System (INIS)

    Han, Kiyoon; Kang, Dae Il; Lim, Ho Gon

    2015-01-01

    In this study, multi-compartment fire modeling for fire propagation scenario from SWGR A to SWGR B is performed using CFAST. New fire PSA method (NUREG/CR-6850) requires that the severity factor is to be calculated by fire modeling. If fire modeling is not performed, the severity factor should be estimated as one conservatively. Also, the possibility of the damages of components and cables located at adjacent compartments should be considered. Detailed fire modeling of multi-compartment fires refers to the evaluation of fire-generated conditions in one compartment that spread to adjacent ones. In general, the severity factor for multi-compartment fire scenario is smaller than that of single compartment scenario. Preliminary quantification of Hanul Unit 3 fire PSA was performed without fire modeling. As a result of quantification, multi-compartment scenario, fire propagation scenario from switchgear room (SWGR) A to SWGR B, is one of significant contributor to the CDF. In this study, fire modeling of multi-compartment was performed by Consolidated Fire Growth and Smoke Transport (CFAST) to identify the possibility of fire propagation. As a result of fire simulation, it is identified that fire propagation has little influences

  6. Multi-compartment Fire Modeling for Switchgear Room using CFAST

    Energy Technology Data Exchange (ETDEWEB)

    Han, Kiyoon; Kang, Dae Il; Lim, Ho Gon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    In this study, multi-compartment fire modeling for fire propagation scenario from SWGR A to SWGR B is performed using CFAST. New fire PSA method (NUREG/CR-6850) requires that the severity factor is to be calculated by fire modeling. If fire modeling is not performed, the severity factor should be estimated as one conservatively. Also, the possibility of the damages of components and cables located at adjacent compartments should be considered. Detailed fire modeling of multi-compartment fires refers to the evaluation of fire-generated conditions in one compartment that spread to adjacent ones. In general, the severity factor for multi-compartment fire scenario is smaller than that of single compartment scenario. Preliminary quantification of Hanul Unit 3 fire PSA was performed without fire modeling. As a result of quantification, multi-compartment scenario, fire propagation scenario from switchgear room (SWGR) A to SWGR B, is one of significant contributor to the CDF. In this study, fire modeling of multi-compartment was performed by Consolidated Fire Growth and Smoke Transport (CFAST) to identify the possibility of fire propagation. As a result of fire simulation, it is identified that fire propagation has little influences.

  7. Fire fighting precautions at Bohunice Atomic Power Plants

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    Some shortcomings are discussed of the project design of fire protection at the V-1 and V-2 nuclear power plants. The basic shortcoming of the system is insufficient division of the units for fire protection. Fire fighting measures are described for cable areas, switch houses and outside transformers, primary and secondary circuits and auxiliary units. Measures are presented for increasing fire safety in Jaslovske Bohunice proceedi.ng from experience gained with a fire which had occurred at a nuclear power plant in Armenia. (E.S.)

  8. Measurement of the temperature distribution inside the power cable using distributed temperature system

    Science.gov (United States)

    Jaros, Jakub; Liner, Andrej; Papes, Martin; Vasinek, Vladimir; Mach, Veleslav; Hruby, David; Kajnar, Tomas; Perecar, Frantisek

    2015-01-01

    Nowadays, the power cables are manufactured to fulfill the following condition - the highest allowable temperature of the cable during normal operation and the maximum allowable temperature at short circuit conditions cannot exceed the condition of the maximum allowable internal temperature. The distribution of the electric current through the conductor leads to the increase of the amplitude of electrons in the crystal lattice of the cables material. The consequence of this phenomenon is the increase of friction and the increase of collisions between particles inside the material, which causes the temperature increase of the carrying elements. The temperature increase is unwanted phenomena, because it is causing losses. In extreme cases, the long-term overload leads to the cable damaging or fire. This paper deals with the temperature distribution measurement inside the power cables using distributed temperature system. With cooperation with Kabex company, the tube containing optical fibers was installed into the center of power cables. These fibers, except telecommunications purposes, can be also used as sensors in measurements carrying out with distributed temperature system. These systems use the optical fiber as a sensor and allow the continual measurement of the temperature along the whole cable in real time with spatial resolution 1 m. DTS systems are successfully deployed in temperature measurement applications in industry areas yet. These areas include construction, drainage, hot water etc. Their advantages are low cost, resistance to electromagnetic radiation and the possibility of real time monitoring at the distance of 8 km. The location of the optical fiber in the center of the power cable allows the measurement of internal distribution of the temperature during overloading the cable. This measurement method can be also used for prediction of short-circuit and its exact location.

  9. Evidence of fuels management and fire weather influencing fire severity in an extreme fire event.

    Science.gov (United States)

    Lydersen, Jamie M; Collins, Brandon M; Brooks, Matthew L; Matchett, John R; Shive, Kristen L; Povak, Nicholas A; Kane, Van R; Smith, Douglas F

    2017-10-01

    Following changes in vegetation structure and pattern, along with a changing climate, large wildfire incidence has increased in forests throughout the western United States. Given this increase, there is great interest in whether fuels treatments and previous wildfire can alter fire severity patterns in large wildfires. We assessed the relative influence of previous fuels treatments (including wildfire), fire weather, vegetation, and water balance on fire-severity in the Rim Fire of 2013. We did this at three different spatial scales to investigate whether the influences on fire severity changed across scales. Both fuels treatments and previous low to moderate-severity wildfire reduced the prevalence of high-severity fire. In general, areas without recent fuels treatments and areas that previously burned at high severity tended to have a greater proportion of high-severity fire in the Rim Fire. Areas treated with prescribed fire, especially when combined with thinning, had the lowest proportions of high severity. The proportion of the landscape burned at high severity was most strongly influenced by fire weather and proportional area previously treated for fuels or burned by low to moderate severity wildfire. The proportion treated needed to effectively reduce the amount of high severity fire varied by spatial scale of analysis, with smaller spatial scales requiring a greater proportion treated to see an effect on fire severity. When moderate and high-severity fire encountered a previously treated area, fire severity was significantly reduced in the treated area relative to the adjacent untreated area. Our results show that fuels treatments and low to moderate-severity wildfire can reduce fire severity in a subsequent wildfire, even when burning under fire growth conditions. These results serve as further evidence that both fuels treatments and lower severity wildfire can increase forest resilience. © 2017 by the Ecological Society of America.

  10. Online Cable Tester and Rerouter

    Science.gov (United States)

    Lewis, Mark; Medelius, Pedro

    2012-01-01

    Hardware and algorithms have been developed to transfer electrical power and data connectivity safely, efficiently, and automatically from an identified damaged/defective wire in a cable to an alternate wire path. The combination of online cable testing capabilities, along with intelligent signal rerouting algorithms, allows the user to overcome the inherent difficulty of maintaining system integrity and configuration control, while autonomously rerouting signals and functions without introducing new failure modes. The incorporation of this capability will increase the reliability of systems by ensuring system availability during operations.

  11. Data Base On Cables And Connectors

    Science.gov (United States)

    Bowen, Arlen R.; Oliver, John D.

    1995-01-01

    Report describes Connector Adapter Cable Information Data Base (CONNAID) computer program, managing data base containing necessary information concerning electrical connectors, breakout boxes, adapter cables, backshells, and pertinent torque specifications for engineering project.

  12. The Cooney Ridge Fire Experiment: An early operation to relate pre-, active, and post-fire field and remotely sensed measurements

    Science.gov (United States)

    Andrew T. Hudak; Patrick H. Freeborn; Sarah A. Lewis; Sharon M. Hood; Helen Y. Smith; Colin C. Hardy; Robert J. Kremens; Bret W. Butler; Casey Teske; Robert G. Tissell; Lloyd P. Queen; Bryce L. Nordgren; Benjamin C. Bright; Penelope Morgan; Philip J. Riggan; Lee Macholz; Leigh B. Lentile; James P. Riddering; Edward E. Mathews

    2018-01-01

    The Cooney Ridge Fire Experiment conducted by fire scientists in 2003 was a burnout operation supported by a fire suppression crew on the active Cooney Ridge wildfire incident. The fire experiment included measurements of pre-fire fuels, active fire behavior, and immediate post-fire effects. Heat flux measurements collected at multiple scales with multiple ground and...

  13. 30 CFR 7.407 - Test for flame resistance of electric cables and cable splices.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Test for flame resistance of electric cables... Electric Cables, Signaling Cables, and Cable Splice Kits § 7.407 Test for flame resistance of electric... material and 21/2 inches of conductor insulation. The type, amperage, voltage rating, and construction of...

  14. Impacts of an extreme cyclone event on landscape-scale savanna fire, productivity and greenhouse gas emissions

    International Nuclear Information System (INIS)

    Hutley, L B; Maier, S W; Evans, B J; Beringer, J; Cook, G D; Razon, E

    2013-01-01

    North Australian tropical savanna accounts for 12% of the world’s total savanna land cover. Accordingly, understanding processes that govern carbon, water and energy exchange within this biome is critical to global carbon and water budgeting. Climate and disturbances drive ecosystem carbon dynamics. Savanna ecosystems of the coastal and sub-coastal of north Australia experience a unique combination of climatic extremes and are in a state of near constant disturbance from fire events (1 in 3 years), storms resulting in windthrow (1 in 5–10 years) and mega-cyclones (1 in 500–1000 years). Critically, these disturbances occur over large areas creating a spatial and temporal mosaic of carbon sources and sinks. We quantify the impact on gross primary productivity (GPP) and fire occurrence from a tropical mega-cyclone, tropical Cyclone Monica (TC Monica), which affected 10 400 km 2 of savanna across north Australia, resulting in the mortality and severe structural damage to ∼140 million trees. We estimate a net carbon equivalent emission of 43 Tg of CO 2 -e using the moderate resolution imaging spectroradiometer (MODIS) GPP (MOD17A2) to quantify spatial and temporal patterns pre- and post-TC Monica. GPP was suppressed for four years after the event, equivalent to a loss of GPP of 0.5 Tg C over this period. On-ground fuel loads were estimated to potentially release 51.2 Mt CO 2 -e, equivalent to ∼10% of Australia’s accountable greenhouse gas emissions. We present a simple carbon balance to examine the relative importance of frequency versus impact for a number of key disturbance processes such as fire, termite consumption and intense but infrequent mega-cyclones. Our estimates suggested that fire and termite consumption had a larger impact on Net Biome Productivity than infrequent mega-cyclones. We demonstrate the importance of understanding how climate variability and disturbance impacts savanna dynamics in the context of the increasing interest in

  15. Trenchless Replacement of Buried Cable Lines

    Directory of Open Access Journals (Sweden)

    Hans-Joachim Bayer

    2007-01-01

    Full Text Available An enormous amount of underground electricity and telecommunication cables have been worn over the time with technical defects or need capacity increases. Thus, new lines need to be installed. In urban areas, even in smaller communities and in natural reserves, open trenching is difficult and often not permitted.In response, new patented methods of trenchless cable replacement using the HDD equipment have been developed by the TT Group. The new technology is called “Wash-over-cable-replacement” and applies specially designed drill heads, cutting around the old cable string in various configurations (completely closed, U-shape or S-shape embracing, depending to the coating type of the old cable. This special cable replacement drill head separates the cable from the surrounding adhesive soil or the sand bedding by creating a very small annular space around the cable thus enabling the pulling or dragging out of the old cable section between the start and the exit pit. After the old cable has been loosened from the surrounding soil by means of the wash over process and pulled out, the new cable can be smoothly pulled into the void using the drill rods and embedding the new cable in a rich bed of Bentonite.The wash-over drill heads are slim and have inner and outer nozzles for Bentonite and bits to handle roots, pebbles, gravel and the like. These drill heads perform very quickly (up to 3 meters per minute to effectively wash over existing cables without damaging the cable coating and prepare the ground for a fast new laying of a new cable in the existing line. Network owners also benefit from the fact that new geodetic or topographic surveys and documentations of the new cable are not necessary. Only the documents, remarks, technical codes and existing geodetic data need to be updated.The paper will outline the technological background and include several practical job examples.

  16. Active optical cable for intrasatellite communications

    Science.gov (United States)

    Blasco, J.; Cano, D.; Navasquillo, O.; Esteban, M. A.

    2017-11-01

    DAS Photonics and Airbus Defence and Space (Spain) have been working for more than six years in the concept of an Active Optical Cable (AOC) for copper cable substitution. The main advantages that AOC offers are significant mass and size saving, better flexibility and routing of the cable and immunity to EMI.

  17. Cable Television Report and Suggested Ordinance.

    Science.gov (United States)

    League of California Cities, Sacramento.

    Guidelines and suggested ordinances for cable television regulation by local governments are comprehensively discussed in this report. The emphasis is placed on franchising the cable operator. Seventeen legal aspects of franchising are reviewed, and an exemplary ordinance is presented. In addition, current statistics about cable franchising in…

  18. Remote Acquisition Amplifier For 50-Ohm Cable

    Science.gov (United States)

    Amador, Jose J.

    1995-01-01

    Buffer-amplifier unit designed to drive 50-Ohm cables up to 100 ft. (30 m) long, compensating for attenuation in cables and enabling remote operation of oscilloscopes. Variable resistor provides for adjustment of gain of amplifier, such that overall gain from input terminals of amplifier to output end of cable set to unity.

  19. Designing fire safe interiors.

    Science.gov (United States)

    Belles, D W

    1992-01-01

    Any product that causes a fire to grow large is deficient in fire safety performance. A large fire in any building represents a serious hazard. Multiple-death fires almost always are linked to fires that grow quickly to a large size. Interior finishes have large, continuous surfaces over which fire can spread. They are regulated to slow initial fire growth, and must be qualified for use on the basis of fire tests. To obtain meaningful results, specimens must be representative of actual installation. Variables--such as the substrate, the adhesive, and product thickness and density--can affect product performance. The tunnel test may not adequately evaluate some products, such as foam plastics or textile wall coverings, thermoplastic materials, or materials of minimal mass. Where questions exist, products should be evaluated on a full-scale basis. Curtains and draperies are examples of products that ignite easily and spread flames readily. The present method for testing curtains and draperies evaluates one fabric at a time. Although a fabric tested alone may perform well, fabrics that meet test standards individually sometimes perform poorly when tested in combination. Contents and furnishings constitute the major fuels in many fires. Contents may involve paper products and other lightweight materials that are easily ignited and capable of fast fire growth. Similarly, a small source may ignite many items of furniture that are capable of sustained fire growth. Upholstered furniture can reach peak burning rates in less than 5 minutes. Furnishings have been associated with many multiple-death fires.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Probabilistic fire risk assessment for Koeberg Nuclear Power Station Unit 1

    International Nuclear Information System (INIS)

    Grobbelaar, J.F.; Foster, N.A.S.; Luesse, L.J.

    1995-01-01

    A probabilistic fire risk assessment was done for Koeberg Nuclear Power Station Unit 1. Areas where fires are likely to start were identified. Equipment important to safety, as well as their power and/or control cable routes were identified in each fire confinement sector. Fire confinement sectors where internal initiating events could be caused by fire were identified. Detection failure and suppression failure fault trees and event trees were constructed. The core damage frequency associated with each fire confinement sector was calculated, and important fire confinement sectors were identified. (author)

  1. Analysis of High Frequency Resonance in DFIG-based Offshore Wind Farm via Long Transmission Cable

    DEFF Research Database (Denmark)

    Song, Yipeng; Ebrahimzadeh, Esmaeil; Blaabjerg, Frede

    2018-01-01

    During the past two decades, the Doubly Fed Induction Generator (DFIG) based wind farm has been under rapid growth, and the increasing wind power penetration has been seen. Practically, these wind farms are connected to the three-phase AC grid through long transmission cable which can be modelled...... as several II units. The impedance of this cable cannot be neglected and requires careful investigation due to its long distance. As a result, the impedance interaction between the DFIG based wind farm and the long cable is inevitable, and may produce High Frequency Resonance (HFR) in the wind farm....... This paper discusses the HFR of the large scale DFIG based wind farm connected to the long cable. Several influencing factors, including 1) the length of the cable, 2) the output active power and 3) the rotor speed, are investigated. Simulation validations using MATLAB / Simulink have been conducted...

  2. Vibration based monitoring of stay cable force using wireless piezoelectric based strain sensor nodes

    International Nuclear Information System (INIS)

    Nguyen, Khac Duy; Kim, Jeong Tae

    2012-01-01

    This study presents a method to monitor cable force using wireless sensor nodes and piezoelectric sensors. The following approaches are carried out to achieve the objective. Firstly, the principle of piezoelectric materials (e.g., PZT) as strain sensors is reviewed. A cable force estimation method using dynamic features of cables measured by piezoelectric materials is presented. Secondly, the design of an automated cable force monitoring system using the data acquisition sensor node Imote2/SHM DAQ is described. The sensor node is originally developed by University of Illinois at Urbana champaign and is adopted in this study to monitor strain induced voltage from PZT sensors. The advantages of the system are cheap, and eligible for wireless communication and automated operation. Finally, the feasibility of the proposed monitoring system is evaluated on a lab scaled cable

  3. A full 3D time-dependent electromagnetic model for Roebel cables

    DEFF Research Database (Denmark)

    Rodriguez Zermeno, Victor Manuel; Grilli, Francesco; Sirois, Frederic

    2013-01-01

    High temperature superconductor Roebel cables are well known for their large current capacity and low AC losses. For this reason they have become attractive candidates for many power applications. The continuous transposition of their strands reduces the coupling losses while ensuring better...... is unavoidably a large scale computational problem. In this work, we present a full 3D model of a Roebel cable with 14 strands. The model is based on the H-formulation, widely used for 2D problems. In order to keep the 3D features of the cable (in particular the magnetization currents near the transpositions......), no simplifications are made other than the reduction of the modelled length according to the periodicity of the cable structure. The 3D model is used to study the dependence of AC losses on the amplitude of the AC applied magnetic field or transport current. Beyond the importance of simulating the Roebel cable...

  4. Experimental study of the heat of combustion of electrical cables: Pitcairn/calorimetre test bench; Etude experimentale sur la combustion de cables electriques: le banc d`essais Pitcairn/calorimetre

    Energy Technology Data Exchange (ETDEWEB)

    Gautier, B.; Bosseboeuf, G.

    1995-11-01

    The R and D has been developing for about ten years, through the MAGIC software, a modeling program on the propagation of fire in power plants. The potential fuels in a power plant are mainly limited to the oils existing in engines and control systems, and electric cables. Those cables present a complex combustion due to their fire-resistant design. In order to study that combustion, two test benches, the PITCAIRN oven and the CALORIMETRE EDF/CNRS have been linked. This report presents briefly the experimental installation, then it comments on the first experimental data obtained with two types of samples, a PVC and an EPR-Hypalon cable. The tested cables are selected from those commonly used in French Nuclear Power Plants. They present complex components (fire-retarding chemical agents, mechanical reinforcement). The data show that the behavior of those cables cannot be reduced to a mass loss rate associated to a constant Heat of Combustion. The Heat of Combustion of the PVC cable tested varies little at the beginning of the pyrolysis from 5 kJ.g{sup -1} to 10 kJ.g{sup -1}, then increases quickly up to 30 kJ.g{sup -1}. In the same way, the EPR-Hypalon cable shows a continuous and slow increase of the Heat of Combustion from 1 kJ.g{sup -1} to 20 kJ.g{sup -1} during the pyrolysis, then rises quickly up to 40 kJ.g{sup -1} at the end. Those data corroborate the thesis of the dilution of flammable species by fire-retarding agents, which lower the Heat of combustion but seems to disappear at the end of the pyrolysis. (authors). 7 refs., 6 figs.

  5. 300 Area signal cable study

    International Nuclear Information System (INIS)

    Whattam, J.W.

    1994-01-01

    This report was prepared to discuss the alternatives available for removing the 300 Area overhead signal cable system. This system, installed in 1969, has been used for various monitoring and communication signaling needs throughout the 300 Area. Over the years this cabling system has deteriorated, has been continually reconfigured, and has been poorly documented to the point of nonreliability. The first step was to look at the systems utilizing the overhead signal cable that are still required for operation. Of the ten systems that once operated via the signal cable, only five are still required; the civil defense evacuation alarms, the public address (PA) system, the criticality alarms, the Pacific Northwest Laboratory Facilities Management Control System (FMCS), and the 384 annunciator panel. Of these five, the criticality alarms and the FMCS have been dealt with under other proposals. Therefore, this study focused on the alternatives available for the remaining three systems (evacuation alarms, PA system, and 384 panel) plus the accountability aid phones. Once the systems to be discussed were determined, then three alternatives for providing the signaling pathway were examined for each system: (1) re-wire using underground communication ducts, (2) use the Integrated Voice/Data Telecommunications System (IVDTS) already installed and operated by US West, and (3) use radio control. Each alternative was developed with an estimated cost, advantages, and disadvantages. Finally, a recommendation was provided for the best alternative for each system

  6. Arrangement for guiding transport cables

    International Nuclear Information System (INIS)

    1981-01-01

    This patent relates especially to x-ray equipment such as that used for computerized tomography, and in particular to an arrangement for guiding and supporting a plurality of power transmission cables and cooling hoses in a flexible manner. (U.K.)

  7. Selecting a Cable System Operator.

    Science.gov (United States)

    Cable Television Information Center, Washington, DC.

    Intended to assist franchising authorities with the process of selecting a cable television system operator from franchise applicants, this document provides a framework for analysis of individual applications. Section 1 deals with various methods which can be used to select an operator. The next section covers the application form, the vehicle a…

  8. Experimental-theoretical approach to carbon monoxide density calculation at the incipient stage of the fire indoors

    Science.gov (United States)

    Puzach, S. V.; Suleykin, E. V.; Akperov, R. G.; Nguyen, T. D.

    2017-11-01

    A new experimental-theoretical approach to the toxic gases concentrations assessment in case of fire indoors is offered. The analytical formulas for calculation of CO average volume density are received. These formulas do not contain the geometrical sizes of the room and surfaces dimensions of combustible materials and, therefore, are valid under conditions of as a small-scale fire as a large-scale fire. A small-scale experimental installation for modeling fire thermal and gas dynamics in the closed or open thermodynamic system has been designed. The results of the experiments on determining dependencies of CO average volume density from average volume temperature and oxygen average volume density as well as dependencies of specific coefficients of CO emission and specific mass rates of the combustible material gasification from the time of tests during the burning of wood, transformer oil and PVC cables shield are presented. The results of numerical experiments on CO density calculation in small and large scale rooms using the proposed analytical solutions, integral, zone and field models for calculation of fire thermal and gas dynamics are presented. The comparison with the experimental data obtained by the authors and given in the literature has been performed. It is shown that CO density calculation in the full-scale room at the incipient stage of the fire can be carried out taking into account only the experimental dependences of CO from temperature or O2 density, that have been obtained from small-scale experiments. Therefore the solution of the equation of carbon monoxide mass conservation law is not necessary.

  9. Estimation of Scale Deposition in the Water Walls of an Operating Indian Coal Fired Boiler: Predictive Modeling Approach Using Artificial Neural Networks

    Science.gov (United States)

    Kumari, Amrita; Das, Suchandan Kumar; Srivastava, Prem Kumar

    2016-04-01

    Application of computational intelligence for predicting industrial processes has been in extensive use in various industrial sectors including power sector industry. An ANN model using multi-layer perceptron philosophy has been proposed in this paper to predict the deposition behaviors of oxide scale on waterwall tubes of a coal fired boiler. The input parameters comprises of boiler water chemistry and associated operating parameters, such as, pH, alkalinity, total dissolved solids, specific conductivity, iron and dissolved oxygen concentration of the feed water and local heat flux on boiler tube. An efficient gradient based network optimization algorithm has been employed to minimize neural predictions errors. Effects of heat flux, iron content, pH and the concentrations of total dissolved solids in feed water and other operating variables on the scale deposition behavior have been studied. It has been observed that heat flux, iron content and pH of the feed water have a relatively prime influence on the rate of oxide scale deposition in water walls of an Indian boiler. Reasonably good agreement between ANN model predictions and the measured values of oxide scale deposition rate has been observed which is corroborated by the regression fit between these values.

  10. Numerical Simulation of Electro-Mechanical Impedance Response in Cable-Anchor Connection Interface

    International Nuclear Information System (INIS)

    Nguyen, Khac Duy; Kim, Jeong Tae

    2011-01-01

    In this study, a finite element(FE) analysis on electro-mechanical impedance response of cable-anchor connection interface under various anchor force is presented. In order to achieve the objective, the following approaches are implemented. Firstly, an interface washer coupled with piezoelectric(PZT) material is designed for monitoring cable-force loss. The interface washer is a small aluminum plate on which a PZT patch is surface-bonded. Cable-force loss could be monitored by installing the interface washer between the anchor plate and the anchorage of cable-anchor connection and examining the changes of impedance of the interface washer. Secondly, a FE model for cable-anchor connection is established to examine the effect of cable-force on impedance response of interface washer. Also, the effects of geometrical and material properties of the interface washer on impedance responses under various cable-forces are investigated. Finally, validation of the FE analysis is experimentally evaluated by a lab-scale cable-anchor connection

  11. Sodium fire protection

    International Nuclear Information System (INIS)

    Raju, C.; Kale, R.D.

    1979-01-01

    Results of experiments carried out with sodium fires to develop extinguishment techniques are presented. Characteristics, ignition temperature, heat evolution and other aspects of sodium fires are described. Out of the powders tested for extinguishment of 10 Kg sodium fires, sodium bi-carbonate based dry chemical powder has been found to be the best extinguisher followed by large sized vermiculite and then calcium carbonate powders distributed by spray nozzles. Powders, however, do not extinguish large fires effectively due to sodium-concrete reaction. To control large scale fires in a LMFBR, collection trays with protective cover have been found to cause oxygen starvation better than flooding with inert gas. This system has an added advantage in that there is no damage to the sodium facilities as has been in the case of powders which often contain chlorine compounds and cause stress corrosion cracking. (M.G.B.)

  12. Large scale carbon dioxide production from coal-fired power stations for enhanced oil recovery: a new economic feasibility study

    International Nuclear Information System (INIS)

    Tontiwachwuthikul, P.; Chan, C. W.; Kritpiphat, W.; Demontigny, D.; Skoropad, D.; Gelowitz, D.; Aroonwilas, A.; Mourits, F.; Wilson, M.; Ward, L.

    1998-01-01

    The concept of capturing carbon dioxide from fossil-fuelled electric power generating plants and utilizing it as a flooding agent in enhanced oil recovery (EOR) processes, was explored. In this context, this paper describes how cogeneration concepts, together with process optimization strategies, help to reduce the carbon dioxide production cost by utilizing low-pressure steam and waste heat from various sections of the power generation process. Based on these optimization strategies, the recovery cost of carbon dioxide from coal-fired power stations is estimated to be in the range of $ 0.50 to $ 2.00/mscf. Assuming an average cost of $ 1.25/mscf, the production cost of incremental oil would be about $ 18.00. This means that even with today's modest oil prices, there is room for profit to be made operating a carbon dioxide flood with flue gas extracted carbon dioxide

  13. Large scale carbon dioxide production from coal-fired power stations for enhanced oil recovery : a new economic feasibility study

    International Nuclear Information System (INIS)

    Tontiwachwuthikul, P.; Chan, C.W.; Kritpiphat, W.; DeMontigny, D.; Skoropad, D.; Gelowitz, D.; Aroonwilas, A.; Mourits, F.; Wilson, M.; Ward, L.

    1998-01-01

    A study was conducted to investigate the economics of capturing carbon dioxide from coal-fired power plants to be subsequently used as a flooding agent for enhanced oil recovery (EOR) technologies. It was shown that the production of CO 2 for EOR projects can be technically and economically feasible, particularly when the concepts of cogeneration and optimization are used to reduce steam and electricity expenditures. This is done by using low-pressure steam and waste heat from various sections of the power generation process. It was shown that recovery costs could range between $0.50 to $2.00 per mscf. This translates to a recovered oil price of in the range of $17.39 to $19.95 per bbl., suggesting that even at today's low oil prices there is room for CO 2 flooding with flue gas extracted CO 2 . Practical implications for Saskatchewan were examined. 15 refs., 4 tabs., 7 figs

  14. Full Scale Deposition Trials at 150 MWe PF-boiler Co-firing COal and Straw: Summary of Results

    DEFF Research Database (Denmark)

    Andersen, Karin Hedebo; Frandsen, Flemming; Hansen, Peter Farkas Binderup

    1999-01-01

    A conventional PF-fired boiler at the Danish energy company I/S Midtkraft has been converted to coal-straw co-combustion and a two-year demonstration programme was initiated in January 1996 addressing several aspects of coal-straw co-combustion. Deposition trials were performed as part...... during co-combustion with straw. In addition, where Fe dominated upstream deposits are found in the hottest positions during pure coal combustion, Ca, and to some degree Si, are playing the major role during co-combustion. The addition of straw to the fuel is also seen to lead to a change in the texture...... of the upstream deposits, from an ordered dendritic structure of the larger particles with small particles in between during pure coal combustion, to a more random deposition of the larger particles among the small during co-combustion. No deposition of chlorine species was observed in the SEM-EDX analysis...

  15. Large-Scale Mercury Control Technology Testing for Lignite-Fired Utilities - Oxidation Systems for Wet FGD

    Energy Technology Data Exchange (ETDEWEB)

    Steven A. Benson; Michael J. Holmes; Donald P. McCollor; Jill M. Mackenzie; Charlene R. Crocker; Lingbu Kong; Kevin C. Galbreath

    2007-03-31

    Mercury (Hg) control technologies were evaluated at Minnkota Power Cooperative's Milton R. Young (MRY) Station Unit 2, a 450-MW lignite-fired cyclone unit near Center, North Dakota, and TXU Energy's Monticello Steam Electric Station (MoSES) Unit 3, a 793-MW lignite--Powder River Basin (PRB) subbituminous coal-fired unit near Mt. Pleasant, Texas. A cold-side electrostatic precipitator (ESP) and wet flue gas desulfurization (FGD) scrubber are used at MRY and MoSES for controlling particulate and sulfur dioxide (SO{sub 2}) emissions, respectively. Several approaches for significantly and cost-effectively oxidizing elemental mercury (Hg{sup 0}) in lignite combustion flue gases, followed by capture in an ESP and/or FGD scrubber were evaluated. The project team involved in performing the technical aspects of the project included Babcock & Wilcox, the Energy & Environmental Research Center (EERC), the Electric Power Research Institute, and URS Corporation. Calcium bromide (CaBr{sub 2}), calcium chloride (CaCl{sub 2}), magnesium chloride (MgCl{sub 2}), and a proprietary sorbent enhancement additive (SEA), hereafter referred to as SEA2, were added to the lignite feeds to enhance Hg capture in the ESP and/or wet FGD. In addition, powdered activated carbon (PAC) was injected upstream of the ESP at MRY Unit 2. The work involved establishing Hg concentrations and removal rates across existing ESP and FGD units, determining costs associated with a given Hg removal efficiency, quantifying the balance-of-plant impacts of the control technologies, and facilitating technology commercialization. The primary project goal was to achieve ESP-FGD Hg removal efficiencies of {ge}55% at MRY and MoSES for about a month.

  16. Offshore Cable Installation - Lillgrund. Lillgrund Pilot Project

    Energy Technology Data Exchange (ETDEWEB)

    Unosson, Oscar [Vattenfall Vindkraft AB, Stockholm (Sweden)

    2009-01-15

    This report describes the installation method and the experiences gained during the installation of the submarine cables for the offshore wind farm at Lillgrund. The wind farm consists of 48 wind turbines and is expected to produce 0.33 TWh annually. Different aspects of the installation, such as techniques, co-operation between the installation teams, weather conditions and regulatory and environmental issues are described in this report. In addition, recommendations and guidelines are provided, which hopefully can be utilised in future offshore wind projects. The trenches, in which the submarine cables were laid, were excavated weeks before the cable laying. This installation technique proved to be successful for the laying of the inter array cables. The export cable, however, was laid into position with difficulty. The main reason why the laying of the export cable proved more challenging was due to practical difficulties connected with the barge entrusted with the cable laying, Nautilus Maxi. The barge ran aground a number of times and it had difficulties with the thrusters, which made it impossible to manoeuvre. When laying the inter array cables, the method specification was closely followed, and the laying of the cables was executed successfully. The knowledge and experience gained from the offshore cable installation in Lillgrund is essential when writing technical specifications for new wind plant projects. It is recommended to avoid offshore cable installation work in winter seasons. That will lower the chances of dealing with bad weather and, in turn, will reduce the risks

  17. Fire protection

    International Nuclear Information System (INIS)

    Janetzky, E.

    1980-01-01

    Safety and fire prevention measurements have to be treated like the activities developing, planning, construction and erection. Therefore it is necessary that these measurements have to be integrated into the activities mentioned above at an early stage in order to guarantee their effectiveness. With regard to fire accidents the statistics of the insurance companies concerned show that the damage caused increased in the last years mainly due to high concentration of material. Organization of fire prevention and fire fighting, reasons of fire break out, characteristics and behaviour of fire, smoke and fire detection, smoke and heat venting, fire extinguishers (portable and stationary), construction material in presence of fire, respiratory protection etc. will be discussed. (orig./RW)

  18. Metallographic autopsies of full-scale ITER prototype cable-in-conduit conductors after full cyclic testing in SULTAN: II. Significant reduction of strand movement and strand damage in short twist pitch CICCs

    International Nuclear Information System (INIS)

    Sanabria, Carlos; Lee, Peter J; Starch, William; Larbalestier, David C; Devred, Arnaud

    2015-01-01

    Prototype cable-in-conduit-conductors (CICCs) destined for use in the toroidal field and central solenoid coils of the ITER experimental fusion reactor underwent severe cyclic loading in the SULTAN facility. Their autopsies revealed significant and permanent transverse strand migration due to the large Lorentz forces of the SULTAN test. The movement resulted in a 3%–7% void fraction increase on the low pressure (LP) side of the longer twist pitch CICCs. However, short twist pitch conductors exhibited less than 1% void fraction increase in the LP side, as well as a complete absence of the Nb 3 Sn filament fractures observed in the longer twist pitch conductors. We report here a detailed strand-to-cable analysis of short and longer ‘baseline’ twist pitch CICCs. It was found that the use of internal tin (IT) strands in the longer ‘baseline’ twist pitch CICCs can be beneficial possibly because of their superior stiffness—which better resist strand movement—while the use of bronze process strands showed more movement and poorer cyclic test performance. This was not the case for the short twist pitch CICC. Such conductor design seems to work well with both strand types. But it was found that despite the absence of filament fractures, the short twist pitch CICC made from the IT strands studied here developed severe strand distortion during cabling which resulted in diffusion barrier breaks and Sn contamination of the Cu stabilizer during the heat treatment. Conversely, the short twist pitch CICC made from bronze process strands preserved diffusion barrier integrity. (paper)

  19. Slipstream pilot-scale demonstration of a novel amine-based post-combustion technology for carbon dioxide capture from coal-fired power plant flue gas

    Energy Technology Data Exchange (ETDEWEB)

    Krishnamurthy, Krish R. [Linde LLC, Murray Hill, NJ (United States)

    2017-02-03

    Post-combustion CO2 capture (PCC) technology offers flexibility to treat the flue gas from both existing and new coal-fired power plants and can be applied to treat all or a portion of the flue gas. Solvent-based technologies are today the leading option for PCC from commercial coal-fired power plants as they have been applied in large-scale in other applications. Linde and BASF have been working together to develop and further improve a PCC process incorporating BASF’s novel aqueous amine-based solvent technology. This technology offers significant benefits compared to other solvent-based processes as it aims to reduce the regeneration energy requirements using novel solvents that are very stable under the coal-fired power plant feed gas conditions. BASF has developed the desired solvent based on the evaluation of a large number of candidates. In addition, long-term small pilot-scale testing of the BASF solvent has been performed on a lignite-fired flue gas. In coordination with BASF, Linde has evaluated a number of options for capital cost reduction in large engineered systems for solvent-based PCC technology. This report provides a summary of the work performed and results from a project supported by the US DOE (DE-FE0007453) for the pilot-scale demonstration of a Linde-BASF PCC technology using coal-fired power plant flue gas at a 1-1.5 MWe scale in Wilsonville, AL at the National Carbon Capture Center (NCCC). Following a project kick-off meeting in November 2011 and the conclusion of pilot plant design and engineering in February 2013, mechanical completion of the pilot plant was achieved in July 2014, and final commissioning activities were completed to enable start-up of operations in January 2015. Parametric tests were performed from January to December 2015 to determine optimal test conditions and evaluate process performance over a variety of operation parameters. A long-duration 1500-hour continuous test campaign was performed from May to

  20. Optimisation of Offshore Wind Farm Cable Connection Layout Considering Levelised Production Cost Using Dynamic Minimum Spanning Tree Algorithm

    DEFF Research Database (Denmark)

    Hou, Peng; Hu, Weihao; Chen, Cong

    2016-01-01

    The approach in this paper hads been developed to optimize the cable connection layout of large scale offshore wind farms. The objective is to minimize the Levelised Production Cost (LPC) og an offshore wind farm by optimizing the cable connection configuration. Based on the minimum spanning tree...... (MST) algorithm, an improved algorithm, the Dynamic Minimum Spanning Tree (DMST) algorithm is proposed. The current carrying capacity of the cable is considered to be the main constraint and the cable sectional area is changed dynamically. An irregular shaped wind farm is chosen as the studie case...

  1. Post-fire restoration in Alpine environment: from the microsite to the landscape. Multi-scale approach for the definition of mitigation strategies

    OpenAIRE

    marcolin, enrico

    2013-01-01

    Forest fires in the Alps are increasing both in frequency and size, especially on southern slopes where environmental conditions are more suitable for fire ignition and spread. Post-fire restoration activities are often applied without considering the large heterogeneity and variability of ecological constraints. Fire severity, species composition and site characteristics heavily affect vegetation recovery dynamics. The main objectives of this study were to test the hypothesis that post-fi...

  2. Literature study regarding fire protection in nuclear power plants. Part I: Fire rated separations

    International Nuclear Information System (INIS)

    Isaksson, S.

    1995-06-01

    This literature study has been made on behalf of the Swedish Nuclear Power Inspectorate. The aim is to describe different aspects of fire protection in nuclear power plants. Conventional building codes can not give guidance on where to make fire rated separations in order to separate redundant trains of safety systems. The separation must originate in functional demands from the authorities on what functions are essential during and after a fire, and under what circumstances these functions shall be retained, i.e. the number of independent faults and initiating events. As a basic demand it is suggested to rate the strength of separations according to conventional building code, based on fire load. The whole separating construction shall have the same fire rating, including the ventilation system. Deviations from the basic demand can de done in case it can be proven that it is possible to compensate some or all of the fire rating with other measures. There is a general lack of statistical information regarding the reliability of fire separating constructions such as walls, fire doors, penetration seals and fire dampers. The amount of cables penetrating a seal is in many cases much higher in real installations than what has been tested for type approval. It would therefore be valuable to perform a furnace test with a more representative amount of cables passing through a penetration seal. Tests have shown that the 20 foot horizontal separation distance stipulated by NRC is not a guarantee against fire damage. Spatial separations based on general requirements shall not be allowed, but considered from case to case based on actual circumstances. For fire protection by isolation or coatings, it is of great importance to choose the method of protection carefully, to be compatible with the material it shall be applied on, and the environment and types of fire that may occur. 48 refs, 2 figs, 5 tabs

  3. Tubing and cable cutting tool

    Science.gov (United States)

    Mcsmith, D. D.; Richardson, J. I. (Inventor)

    1984-01-01

    A hand held hydraulic cutting tool was developed which is particularly useful in deactivating ejection seats in military aircraft rescue operations. The tool consists primarily of a hydraulic system composed of a fluid reservoir, a pumping piston, and an actuator piston. Mechanical cutting jaws are attached to the actuator piston rod. The hydraulic system is controlled by a pump handle. As the pump handle is operated the actuator piston rod is forced outward and thus the cutting jaws are forced together. The frame of the device is a flexible metal tubing which permits easy positioning of the tool cutting jaws in remote and normally inaccessible locations. Bifurcated cutting edges ensure removal of a section of the tubing or cable to thereby reduce the possibility of accidental reactivation of the tubing or cable being severed.

  4. Electromagnetic Transients in Power Cables

    DEFF Research Database (Denmark)

    Silva, Filipe Faria Da; Bak, Claus Leth

    . The chapter ends by proposing a systematic method that can be used when doing the insulation co-ordination study for a line, as well as the modelling requirements, both modelling depth and modelling detail of the equipment, for the study of the different types of transients followed by a step-by-step generic...... typically used for the screens of cables (both-ends bonding and cross-boding) and also presents methods that can be used to estimate the maximum current of a cable for different types of soils, i.e. thermal calculations. The end of the chapter introduces the shunt reactor, which is an important element...... detail of the equipment, for the study of the different types of transients followed by a step-by-step generic example....

  5. Potential of remote multiplexing systems in reducing cabling cost and complexity in nuclear power stations

    International Nuclear Information System (INIS)

    Stirling, A.J.; L'Archeveque, J.V.R.

    1977-03-01

    Control and instrumentation cabling accounts for nearly 1% of the capital cost of a CANDU generating station. This study of cabling requirements, methods and costs for nuclear reactors, shows that efficient design and scale economies make CANDU wiring costs (per field point) among the lowest for comparable applications. Although attractive in other reactors, commercially available remote multiplexing systems are not, as yet, cost effective for general use in CANDU stations. The report, with its comprehensive tabulation of remote multiplexing equipment, and analysis of cabling procedures describes an approach for re-evaluating the tradeoff between remote multiplexing and conventional wiring as conditions change. (author)

  6. Deposit formation in a full-scale pulverized wood-fired power plant with and without coal fly ash addition

    DEFF Research Database (Denmark)

    Wu, Hao; Shafique Bashir, Muhammad; Jensen, Peter Arendt

    2013-01-01

    Ash transformation and deposition in a pulverized wood-fired power plant boiler of 800 MWth were studied with and without the addition of coal fly ash. The transient ash deposition behavior was investigated by using an advanced deposit probe system at two different boiler locations with flue gas...... at the low-temperature location showed a slow initial build-up and a stable mass of deposits after approximately 1-5 h. The deposits collected during pulverized wood combustion contained a considerable amount of K2SO4, KCl, and KOH/K2CO3. With the addition of coal fly ash (~4 times of the mass flow of wood...... ash) to the boiler, these alkali species were effectively removed both in the fly ash and in the deposits, and a more frequent shedding of the deposits was observed. The results imply that coal fly ash can be an effective additive to reduce ash deposition and corrosion problems in a pulverized wood...

  7. Fire Stations

    Data.gov (United States)

    Department of Homeland Security — Fire Stations in the United States Any location where fire fighters are stationed or based out of, or where equipment that such personnel use in carrying out their...

  8. Climatic and weather factors affecting fire occurrence and behavior

    Science.gov (United States)

    Randall P. Benson; John O. Roads; David R. Weise

    2009-01-01

    Weather and climate have a profound influence on wildland fire ignition potential, fire behavior, and fire severity. Local weather and climate are affected by large-scale patterns of winds over the hemispheres that predispose wildland fuels to fire. The characteristics of wildland fuels, especially the moisture content, ultimately determine fire behavior and the impact...

  9. Holocene fire dynamics in Fennoscandia

    Science.gov (United States)

    Clear, Jennifer; Seppa, Heikki; Kuosmanen, Niina; Molinari, Chiara; Lehsten, Veiko; Allen, Katherine; Bradshaw, Richard

    2015-04-01

    Prescribed burning is advocated in Fennoscandia to promote regeneration and to encourage biodiversity. This method of forest management is based on the perception that fire was much more frequent in the recent past and over a century of active fire suppression has created a boreal forest ecosystem almost free of natural fire. The absence of fire is thought to have contributed to the widespread dominance of Picea abies (Norway spruce) with the successive spruce dominated forest further reducing fire ignition potential. However, humans have altered the natural fire dynamics of Fennoscandia since the early- to mid-Holocene and disentangling the anthropogenic driven fire dynamics from the natural fire dynamics is challenging. Through palaeoecology and sedimentary charcoal deposits we are able to explore the Holocene spatial and temporal variability and changing drivers of fire and vegetation dynamics in Fennoscandia. At the local-scale, two forest hollow environments (history are compared to identify unique and mutual changes in disturbance history. Pollen derived quantitative reconstruction of vegetation at both the local- and regional-scale identifies local-scale disturbance dynamics and large-scale ecosystem response. Spatio-temporal heterogeneity and variability in biomass burning is explored throughout Fennoscandia and Denmark to identify the changing drives of fire dynamics throughout the Holocene. Palaeo-vegetation reconstructions are compared to process-based, climate driven dynamic vegetation model output to test the significance of fire frequency as a driver of vegetation composition and dynamics. Early-Holocene fire regimes in Fennoscandia are driven by natural climate variations and fuel availability. The establishment and spread of Norway spruce is driven by an increase in continentality of climate, but local natural and anthropogenic ecosystem disturbance may have aided this spread. The expansion of spruce led to a step-wise reduction in regional biomass

  10. Ecological fire use for ecological fire management: Managing large wildfires by design

    Science.gov (United States)

    Timothy Ingalsbee

    2015-01-01

    Past fire exclusion policies and fire suppression actions have led to a historic "fire deficit" on public wildlands. These sociocultural actions have led to unprecedented environmental changes that have created conditions conducive to more frequent large-scale wildfires. Politicians, the newsmedia, and agency officials portray large wildland fires as...

  11. Sodium fires in nuclear facilities

    International Nuclear Information System (INIS)

    Menzenhauer, P.

    1974-01-01

    The work deals with the behaviour of liquid sodium when it comes into contact with air, especially in the course of fires in technical plants. The most important fire procedures are constructed as realistically as possible, that is to say that the fires were not only carried out on a laboratory scale but with quantities of up to 200 kg sodium at temperatures of up to 800 0 C. The following was investigated: 1) the course of the fire in rooms, 2) restriction of the fire, 3) removal of the burnt remains, 4) protection measures. The fire was varied in its most important physical appearance such as surface fire, spurt fire and fire on isolated pipe lines. The fires were checked by precautionary, contructive measures - it was not necessary to place persons at the site of the fire - and by active measures such as for example by covering with extinguishing powder. All important test phases were captured in film and slides series. Visible material is thus available for the operation team of sodium plants and fire brigades who might possibly be called upon. (orig./LH) [de

  12. Adsorber fires

    International Nuclear Information System (INIS)

    Holmes, W.

    1987-01-01

    The following conclusions are offered with respect to activated charcoal filter systems in nuclear power plants: (1) The use of activated charcoal in nuclear facilities presents a potential for deep-seated fires. (2) The defense-in-depth approach to nuclear fire safety requires that if an ignition should occur, fires must be detected quickly and subsequently suppressed. (3) Deep-seated fires in charcoal beds are difficult to extinguish. (4) Automatic water sprays can be used to extinguish fires rapidly and reliably when properly introduced into the burning medium. The second part of the conclusions offered are more like challenges: (1) The problem associated with inadvertent actuations of fire protection systems is not a major one, and it can be reduced further by proper design review, installation, testing, and maintenance. Eliminating automatic fire extinguishing systems for the protection of charcoal adsorbers is not justified. (2) Removal of automatic fire protection systems due to fear of inadvertent fire protection system operation is a case of treating the effect rather than the cause. On the other hand, properly maintaining automatic fire protection systems will preserve the risk of fire loss at acceptable levels while at the same time reducing the risk of damage presented by inadvertent operation of fire protection systems

  13. Comparison study of cable geometries and superconducting tape layouts for high-temperature superconductor cables

    Science.gov (United States)

    Ta, Wurui; Shao, Tianchong; Gao, Yuanwen

    2018-04-01

    High-temperature superconductor (HTS) rare-earth-barium-copper-oxide (REBCO) tapes are very promising for use in high-current cables. The cable geometry and the layout of the superconducting tapes are directly related to the performance of the HTS cable. In this paper, we use numerical methods to perform a comparison study of multiple-stage twisted stacked-tape cable (TSTC) conductors to find better cable structures that can both improve the critical current and minimize the alternating current (AC) losses of the cable. The sub-cable geometry is designed to have a stair-step shape. Three superconducting tape layouts are chosen and their transport performance and AC losses are evaluated. The magnetic field and current density profiles of the cables are obtained. The results show that arrangement of the superconducting tapes from the interior towards the exterior of the cable based on their critical current values in descending order can enhance the cable's transport capacity while significantly reducing the AC losses. These results imply that cable transport capacity improvements can be achieved by arranging the superconducting tapes in a manner consistent with the electromagnetic field distribution. Through comparison of the critical currents and AC losses of four types of HTS cables, we determine the best structural choice among these cables.

  14. US Fire Administration Fire Statistics

    Data.gov (United States)

    Department of Homeland Security — The U.S. Fire Administration collects data from a variety of sources to provide information and analyses on the status and scope of the fire problem in the United...

  15. NASA Goddard Earth Sciences Graduate Student Program. [FIRE CIRRUS-II examination of coupling between an upper tropospheric cloud system and synoptic-scale dynamics

    Science.gov (United States)

    Ackerman, Thomas P.

    1994-01-01

    The evolution of synoptic-scale dynamics associated with a middle and upper tropospheric cloud event that occurred on 26 November 1991 is examined. The case under consideration occurred during the FIRE CIRRUS-II Intensive Field Observing Period held in Coffeyville, KS during Nov. and Dec., 1991. Using data from the wind profiler demonstration network and a temporally and spatially augmented radiosonde array, emphasis is given to explaining the evolution of the kinematically-derived ageostrophic vertical circulations and correlating the circulation with the forcing of an extensively sampled cloud field. This is facilitated by decomposing the horizontal divergence into its component parts through a natural coordinate representation of the flow. Ageostrophic vertical circulations are inferred and compared to the circulation forcing arising from geostrophic confluence and shearing deformation derived from the Sawyer-Eliassen Equation. It is found that a thermodynamically indirect vertical circulation existed in association with a jet streak exit region. The circulation was displaced to the cyclonic side of the jet axis due to the orientation of the jet exit between a deepening diffluent trough and building ridge. The cloud line formed in the ascending branch of the vertical circulation with the most concentrated cloud development occurring in conjunction with the maximum large-scale vertical motion. The relationship between the large scale dynamics and the parameterization of middle and upper tropospheric clouds in large-scale models is discussed and an example of ice water contents derived from a parameterization forced by the diagnosed vertical motions and observed water vapor contents is presented.

  16. An industrial cabling machine for the SSC

    International Nuclear Information System (INIS)

    Royet, J.; Armer, R.; Hannaford, R.; Scanlan, R.

    1989-02-01

    The SSC project will need the manufacturing of some 25,000 kilometers of keystoned flat cable. The technical specifications of the various cables to be produced are the result of five years of research and development work at LBL. An experimental cable machine was built and run in the laboratory; many improvements were implemented and tested. Semi-industrial production of the various cables was performed, and the resulting cables were used and tested in the one-meter model magnets and 17.5 meter dipole prototypes. From these experiments an industrial cabler specification was generated and used for an international RFQ. The winner of the contract is Dour Metal, a Belgium company that built the first industrial prototype which is now in a production line at New England Electric Wire Company. In this paper we describe the main characteristics of the machine and give the first industrial production results of superconducting keystoned cable for the SSC project. 4 refs

  17. Initial tension loss in cerclage cables.

    Science.gov (United States)

    Ménard, Jérémie; Émard, Maxime; Canet, Fanny; Brailovski, Vladimir; Petit, Yvan; Laflamme, George Y

    2013-10-01

    Cerclage cables, frequently used in the management of fractures and osteotomies, are associated with a high failure rate and significant loosening during surgery. This study compared the capacity to maintain tension of different types of orthopaedic cable systems. Multifilament Cobalt-Chrome (CoCr) cables with four different crimp/clamp devices (DePuy, Stryker, Zimmer and Smith&Nephew) and one non-metallic Nylon (Ny) cable from Kinamed were instrumented with a load cell to measure tension during insertion. Significant tension loss was observed with crimping for all cables (Ptensioner led to an additional unexpected tension loss (CoCr-DePuy: 18%, CoCr-Stryker: 29%, CoCr-Smith&Nephew: 33%, Ny: 46%, and CoCr-Zimmer: 52%). The simple CoCr (DePuy) cable system outperformed the more sophisticated locking devices due to its significantly better ability to prevent tension loss. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Large Pilot Scale Testing of Linde/BASF Post-Combustion CO2 Capture Technology at the Abbott Coal-Fired Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    O' Brien, Kevin C. [University of Illinois, Champaign, IL (United States)

    2017-08-18

    The work summarized in this report is the first step towards a project that will re-train and create jobs for personnel in the coal industry and continue regional economic development to benefit regions impacted by previous downturns. The larger project is aimed at capturing ~300 tons/day (272 metric tonnes/day) CO2 at a 90% capture rate from existing coal- fired boilers at the Abbott Power Plant on the campus of University of Illinois (UI). It will employ the Linde-BASF novel amine-based advanced CO2 capture technology, which has already shown the potential to be cost-effective, energy efficient and compact at the 0.5-1.5 MWe pilot scales. The overall objective of the project is to design and install a scaled-up system of nominal 15 MWe size, integrate it with the Abbott Power Plant flue gas, steam and other utility systems, and demonstrate the viability of continuous operation under realistic conditions with high efficiency and capacity. The project will also begin to build a workforce that understands how to operate and maintain the capture plants by including students from regional community colleges and universities in the operation and evaluation of the capture system. This project will also lay the groundwork for follow-on projects that pilot utilization of the captured CO2 from coal-fired power plants. The net impact will be to demonstrate a replicable means to (1) use a standardized procedure to evaluate power plants for their ability to be retrofitted with a pilot capture unit; (2) design and construct reliable capture systems based on the Linde-BASF technology; (3) operate and maintain these systems; (4) implement training programs with local community colleges and universities to establish a workforce to operate and maintain the systems; and (5) prepare to evaluate at the large pilot scale level various methods to utilize the resulting captured CO2. Towards the larger project goal, the UI-led team, together

  19. Micro-scale grain-size analysis and magnetic properties of coal-fired power plant fly ash and its relevance for environmental magnetic pollution studies

    Energy Technology Data Exchange (ETDEWEB)

    Blaha, U.; Sapkota, B.; Appel, E.; Stanjek, H.; Rosler, W. [University of Tubingen, Tubingen (Germany). Inst. of Geoscience

    2008-11-15

    Two fly ash samples from a black coal-fired power plant (Bexbach, Germany) were investigated for their magnetic properties, particle structure, grain-size distribution and chemical composition. Grain-size distribution was determined on bulk samples and on magnetic extracts. Magnetic susceptibility of different grain-size fractions was analyzed with respect to the according amount of fractions, high- and low-temperature dependence of magnetic susceptibility and thermal demagnetization of IRM identified magnetite and hematite as magnetic phases. Magnetic spherules were quantitatively extracted from bulk fly ash samples and examined using SEM/EDX analysis. Particle morphology and grain-size analysis on the magnetically extracted material were studied. Individual spherule types were identified and internal structures of selected polished particles were investigated by SEM and EDX analyses. Main element contents of the internal structures which consist of 'magnetite' crystals and 'glassy' matrix were systematically determined and statistically assessed. The chemical data of the micro-scale structures in the magnetic spherules were compared with XRF data from bulk material, revealing the relative element distribution in composed magnetic spherules. Comparison of the bulk sample grain-size (0.5-300 {mu}m) and grain-size spectra from magnetic extracts (1-186.5 {mu}m) shows that strongly magnetic particles mainly occur in the fine fractions of < 63 {mu}m. This study comprises a comprehensive characterization of coal-fired power plant fly ash, using magnetic, chemical, and microscopic methods. The results can serve as reference data for a variety of environmental magnetic studies.

  20. 47 CFR 76.802 - Disposition of cable home wiring.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Disposition of cable home wiring. 76.802... MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Cable Inside Wiring § 76.802 Disposition of cable home wiring. (a)(1) Upon voluntary termination of cable service by a subscriber in a single unit installation, a...

  1. Low Friction Cryostat for HTS Power Cable of Dutch Project

    NARCIS (Netherlands)

    Chevtchenko, O.; Zuijderduin, R.; Smit, J.; Willen, D.; Lentge, H.; Thidemann, C.; Traeholt, C.

    2012-01-01

    Particulars of 6 km long HTS AC power cable for Amsterdam project are: a cable has to fit in an annulus of 160 mm, with only two cooling stations at the cable ends [1]. Application of existing solutions for HTS cables would result in excessively high coolant pressure drop in the cable, possibly

  2. Field application of a cable NDT system for cable-stayed bridge using MFL sensors integrated

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ju Won; Choi, Jun Sung; Park, Seung Hee [Sungkyunkwan University, Seoul (Korea, Republic of); Lee, Eun Chan [Korea Maintance Co., Ltd., Seoul (Korea, Republic of)

    2014-02-15

    In this study, an automated cable non-destructive testing(NDT) system was developed to monitor the steel cables that are a core component of cable-stayed bridges. The magnetic flux leakage(MFL) method, which is suitable for ferromagnetic continuum structures and has been verified in previous studies, was applied to the cable inspection. A multi-channel MFL sensor head was fabricated using hall sensors and permanent magnets. A wheel-based cable climbing robot was fabricated to improve the accessibility to the cables, and operating software was developed to monitor the MFL-based NDT research and control the climbing robot. Remote data transmission and robot control were realized by applying wireless LAN communication. Finally, the developed element techniques were integrated into an MFL-based cable NDT system, and the field applicability of this system was verified through a field test at Seohae Bridge, which is a typical cable-stayed bridge currently in operation.

  3. Field application of a cable NDT system for cable-stayed bridge using MFL sensors integrated

    International Nuclear Information System (INIS)

    Kim, Ju Won; Choi, Jun Sung; Park, Seung Hee; Lee, Eun Chan

    2014-01-01

    In this study, an automated cable non-destructive testing(NDT) system was developed to monitor the steel cables that are a core component of cable-stayed bridges. The magnetic flux leakage(MFL) method, which is suitable for ferromagnetic continuum structures and has been verified in previous studies, was applied to the cable inspection. A multi-channel MFL sensor head was fabricated using hall sensors and permanent magnets. A wheel-based cable climbing robot was fabricated to improve the accessibility to the cables, and operating software was developed to monitor the MFL-based NDT research and control the climbing robot. Remote data transmission and robot control were realized by applying wireless LAN communication. Finally, the developed element techniques were integrated into an MFL-based cable NDT system, and the field applicability of this system was verified through a field test at Seohae Bridge, which is a typical cable-stayed bridge currently in operation.

  4. High-voltage polymeric insulated cables

    Energy Technology Data Exchange (ETDEWEB)

    Ross, A

    1987-01-01

    Reviews developments in high-voltage (here defined as 25 kV, 66 kV and 132 kV) polymeric insulated cables in the UK over the period 1979-1986, with particular reference to the experience of the Eastern Electricity Board. Outlines the background to the adoption of XPLE-insulated solid cable, and the design, testing, terminations, jointing and costs of 25 kV, 66 kV and 132 kV cables.

  5. Device for guiding various diameter size cable

    Energy Technology Data Exchange (ETDEWEB)

    Litvinov, I.M.; Klauzer, L.P.; Yeganov, L.I.; Zaripov, A.M.

    1982-01-30

    A design is submitted for a device to guide cable of various diameters. This device consists of a profiled multiple-pass roller, and clamps for uniting cut cable. This design is simplified by allowing both the rollers and their supports to rotate on the roller axis thus facilitating interaction with the clamps. The working surface of the supports is evolute while the outside surfaces have screw-channels for transfering the cable from one roller pass to the other.

  6. Forest fires

    International Nuclear Information System (INIS)

    Fuller, M.

    1991-01-01

    This book examines the many complex and sensitive issues relating to wildland fires. Beginning with an overview of the fires of 1980s, the book discusses the implications of continued drought and considers the behavior of wildland fires, from ignition and spread to spotting and firestorms. Topics include the effects of weather, forest fuels, fire ecology, and the effects of fire on plants and animals. In addition, the book examines firefighting methods and equipment, including new minimum impact techniques and compressed air foam; prescribed burning; and steps that can be taken to protect individuals and human structures. A history of forest fire policies in the U.S. and a discussion of solutions to fire problems around the world completes the coverage. With one percent of the earth's surface burning every year in the last decade, this is a penetrating book on a subject of undeniable importance

  7. Dynamic Behaviour of Different Types of Cable-Stayed Bridges Due to Earthquake Loads

    Directory of Open Access Journals (Sweden)

    Alireza Mirza Goltabar Roshan

    2016-12-01

    Full Text Available Construction of large-scale structures has been considered as one of the human's main achievements.  With their suitable view and high economical aspects, High-strength steel cables have been developed for analysis and erection of cable-stayed bridges in light of high speed development in computer technology. This type of bridges, while providing different behavior due to cable flexibility, has been recognized as one of the most practical choices for mid to large span bridges. This paper studies the non-linear dynamic behavior of cable bridges and the effect of some parameters (such as cable arrangement and shape of pylon on them. For this purpose, CSI Bridge software with the direct integration method of dynamic analysis has been used and the behavior of structure under different earthquake components has been analyzed for various conditions of cable arrangements and pylon shapes. Results indicate that the most suitable behavior would be for cable bridges with H-shape pylons arranged in series and also with A-shape pylons in radial arrangement.

  8. Forest fires in Pennsylvania.

    Science.gov (United States)

    Donald A. Haines; William A. Main; Eugene F. McNamara

    1978-01-01

    Describes factors that contribute to forest fires in Pennsylvania. Includes an analysis of basic statistics; distribution of fires during normal, drought, and wet years; fire cause, fire activity by day-of-week; multiple-fire day; and fire climatology.

  9. Vincennes University: Pioneer in Cable TV

    Science.gov (United States)

    Beckes, Isaac K.

    1972-01-01

    The development of cable educational television at Vincennes University (Indiana) is discussed in terms of the financing, securing of franchises, educational goals and plans for future expansion. (RN)

  10. Capacitor discharge process for welding braided cable

    Science.gov (United States)

    Wilson, Rick D.

    1995-01-01

    A capacitor discharge process for welding a braided cable formed from a plurality of individual cable strands to a solid metallic electrically conductive member comprises the steps of: (a) preparing the electrically conductive member for welding by bevelling one of its end portions while leaving an ignition projection extending outwardly from the apex of the bevel; (b) clamping the electrically conductive member in a cathode fixture; (c) connecting the electrically conductive member clamped in the cathode fixture to a capacitor bank capable of being charged to a preselected voltage value; (d) preparing the braided cable for welding by wrapping one of its end portions with a metallic sheet to form a retaining ring operable to maintain the individual strands of the braided cable in fixed position within the retaining ring; (e) clamping the braided cable and the retaining ring as a unit in an anode fixture so that the wrapped end portion of the braided cable faces the ignition projection of the electrically conductive member; and (f) moving the cathode fixture towards the anode fixture until the ignition projection of the electrically conductive member contacts the end portion of the braided cable thereby allowing the capacitor bank to discharge through the electrically conductive member and through the braided cable and causing the electrically conductive member to be welded to the braided cable via capacitor discharge action.

  11. Analytical and numerical construction of equivalent cables.

    Science.gov (United States)

    Lindsay, K A; Rosenberg, J R; Tucker, G

    2003-08-01

    The mathematical complexity experienced when applying cable theory to arbitrarily branched dendrites has lead to the development of a simple representation of any branched dendrite called the equivalent cable. The equivalent cable is an unbranched model of a dendrite and a one-to-one mapping of potentials and currents on the branched model to those on the unbranched model, and vice versa. The piecewise uniform cable, with a symmetrised tri-diagonal system matrix, is shown to represent the canonical form for an equivalent cable. Through a novel application of the Laplace transform it is demonstrated that an arbitrary branched model of a dendrite can be transformed to the canonical form of an equivalent cable. The characteristic properties of the equivalent cable are extracted from the matrix for the transformed branched model. The one-to-one mapping follows automatically from the construction of the equivalent cable. The equivalent cable is used to provide a new procedure for characterising the location of synaptic contacts on spinal interneurons.

  12. Fire intensity impacts on post-fire temperate coniferous forest net primary productivity

    Science.gov (United States)

    Sparks, Aaron M.; Kolden, Crystal A.; Smith, Alistair M. S.; Boschetti, Luigi; Johnson, Daniel M.; Cochrane, Mark A.

    2018-02-01

    Fire is a dynamic ecological process in forests and impacts the carbon (C) cycle through direct combustion emissions, tree mortality, and by impairing the ability of surviving trees to sequester carbon. While studies on young trees have demonstrated that fire intensity is a determinant of post-fire net primary productivity, wildland fires on landscape to regional scales have largely been assumed to either cause tree mortality, or conversely, cause no physiological impact, ignoring the impacted but surviving trees. Our objective was to understand how fire intensity affects post-fire net primary productivity in conifer-dominated forested ecosystems on the spatial scale of large wildland fires. We examined the relationships between fire radiative power (FRP), its temporal integral (fire radiative energy - FRE), and net primary productivity (NPP) using 16 years of data from the MOderate Resolution Imaging Spectrometer (MODIS) for 15 large fires in western United States coniferous forests. The greatest NPP post-fire loss occurred 1 year post-fire and ranged from -67 to -312 g C m-2 yr-1 (-13 to -54 %) across all fires. Forests dominated by fire-resistant species (species that typically survive low-intensity fires) experienced the lowest relative NPP reductions compared to forests with less resistant species. Post-fire NPP in forests that were dominated by fire-susceptible species were not as sensitive to FRP or FRE, indicating that NPP in these forests may be reduced to similar levels regardless of fire intensity. Conversely, post-fire NPP in forests dominated by fire-resistant and mixed species decreased with increasing FRP or FRE. In some cases, this dose-response relationship persisted for more than a decade post-fire, highlighting a legacy effect of fire intensity on post-fire C dynamics in these forests.

  13. Material problems related to large scale firing of biomass. Steam oxidation of TP 347H FG and X20

    Energy Technology Data Exchange (ETDEWEB)

    Noergaard Hansson, A.

    2009-07-01

    TP 347 H and X20 is often used as construction material in biomass-fired boilers. The corrosion rate of the alloys is affected by the metal temperature. In this project, the oxidation behaviour of TP 347H FG and X20 is studied by field-testing, laboratory exposures, and thermodynamic/kinetic modelling. The long term oxidation behaviour of TP 347H FG at ultra supercritical steam conditions was assessed by exposing the steel in 4 test superheater loops in a coal-fired power plant. The steel was exposed for 7720, 22985, 29588, and 57554 h at metal temperatures between 499 and 650 deg. C. In the laboratory furnace, the oxidation behaviour of TP 347H FG, TP 347H CG, and X20 was studied in water vapour containing environments (8 or 46%) in the temperature range 500-700 deg. C. Air, Ar and Ar+7% H{sub 2} were used as carrier gas. The microstructure of the oxide layer and the subjacent alloy was investigated with X-ray diffraction (XRD), reflective light microscopy (RLM), scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS), and transmission electron microscopy (TEM) equipped with electron diffraction (ED) and EDS. Double-layered oxides developed during steam oxidation of TP 347H FG both during field-testing and during laboratory exposures. TEM investigation suggested that the interior of the alloy grain was oxidised internally, forming particles of metallic Ni/Fe and Fe-Cr spinel. A FeCr{sub 2}O{sub 4} layer developed along the former alloy grain boundaries. Cr{sub 2}O{sub 3} developed in between this layer and the alloy during field-testing, and its formation was promoted by higher temperature. The morphology of the inner layer for the samples oxidised below and above approx. 585 deg. C looked very different in SEM (field-testing). It is suggested that more Cr is incorporated into the oxide layer at higher temperature, gradually transforming the morphology of the inner oxide layer. The alloy beneath the oxide layer was depleted in Cr

  14. 30 CFR 77.601 - Trailing cables or portable cables; temporary splices.

    Science.gov (United States)

    2010-07-01

    ... LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Trailing Cables § 77.601 Trailing cables or portable cables; temporary... or splices that heat or spark under load shall not be used. ...

  15. Switching Restrikes in HVAC Cable Lines and Hybrid HVAC Cable/OHL Lines

    DEFF Research Database (Denmark)

    da Silva, Filipe Miguel Faria; Bak, Claus Leth; Balle Holst, Per

    2011-01-01

    The disconnection of HV underground cables may, if unsuccessful, originate a restrike in the circuit breaker, leading to high overvoltages, and potentially damaging the cable and near equipment. Due to the cable high capacitance and low resistance the voltage damping is slow, resulting, half a cy...

  16. Probabilistic assessment of fire hazard: a contribution of power industry to the development of fire protection engineering

    International Nuclear Information System (INIS)

    Kandrac, J.; Skvarka, P.

    1990-01-01

    Draft methodology was developed for assessment of fire hazard in nuclear power plants. Named DIMEHORP, the methodology is based on fire hazard analyses and on the analyses of the possible ways of fire propagation and of the power plant systems. The former includes determining the spaces of the power plant in which a fire can arise. Fire propagation analysis deals with the probability that within a given section the fire will propagate and cause damage to the equipment before it is localized. The mathematical model used is based on probability theory in conjunction with expert estimates. The methodology was applied to the assessment of the effect of fire in the cable rooms of the Dukovany nuclear power plant on the safety and reliability of its operation. (Z.M.). 3 tabs., 6 refs

  17. Development and characteristics of halogen-free flame-retardant cables for nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Kanemitsuya, K.; Furukawa, K.; Tachibana, T.; Ohara, H.; Ebiike, Y.; Hamachi, K.; Makino, M. (Mitsubishi Cable Industries Ltd., Tokyo (Japan))

    1992-10-01

    Halogen-free flame-retardant (HF-FR) cables for use in nuclear power plants, especially in pressurized water type (PWR) plants, have been developed to advancing the safety and reliability of nuclear power plants. HF-FR cables generate no corrosive gases and minimal amount of toxic gases and smoke during fires, and are accordingly quite safe in comparison with the conventional cables which can cause the secondary calamity by eliminating a large amount of hydrogen halide gas and smoke. HF-FR ethylene-propylene rubber (EPR) and crosslinked polyolefin (XLPO) are used as insulating materials, and HF-FR ethylene-vinyl acetate (EVA) elastomer and polyolefin (PO) are used as jacketing materials. The results of a series of experiments on several types of HF-FR cables have revealed that these cables fully satisfy every requirement, including reliability under LOCA (Loss of Coolant Accidents) simulated conditions, long-term (40y) reliability under thermal and [gamma]-ray exposure, and flame resistivity under vertical tray test (IEEE Std. 383). (author).

  18. Bench-scale Development of an Advanced Solid Sorbent-based CO2 Capture Process for Coal-fired Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Thomas [Research Triangle Institute (RTI), Research Triangle Park, NC (United States); Kataria, Atish [Research Triangle Institute (RTI), Research Triangle Park, NC (United States); Soukri, Mustapha [Research Triangle Institute (RTI), Research Triangle Park, NC (United States); Farmer, Justin [Research Triangle Institute (RTI), Research Triangle Park, NC (United States); Mobley, Paul [Research Triangle Institute (RTI), Research Triangle Park, NC (United States); Tanthana, Jak [Research Triangle Institute (RTI), Research Triangle Park, NC (United States); Wang, Dongxiang [Research Triangle Institute (RTI), Research Triangle Park, NC (United States); Wang, Xiaoxing [Research Triangle Institute (RTI), Research Triangle Park, NC (United States); Song, Chunshan [Research Triangle Institute (RTI), Research Triangle Park, NC (United States)

    2015-12-31

    It is increasingly clear that CO2 capture and sequestration (CCS) must play a critical role in curbing worldwide CO2 emissions to the atmosphere. Development of these technologies to cost-effectively remove CO2 from coal-fired power plants is very important to mitigating the impact these power plants have within the world’s power generation portfolio. Currently, conventional CO2 capture technologies, such as aqueous-monoethanolamine based solvent systems, are prohibitively expensive and if implemented could result in a 75 to 100% increase in the cost of electricity for consumers worldwide. Solid sorbent CO2 capture processes – such as RTI’s Advanced Solid Sorbent CO2, Capture Process – are promising alternatives to conventional, liquid solvents. Supported amine sorbents – of the nature RTI has developed – are particularly attractive due to their high CO2 loadings, low heat capacities, reduced corrosivity/volatility and the potential to reduce the regeneration energy needed to carry out CO2 capture. Previous work in this area has failed to adequately address various technology challenges such as sorbent stability and regenerability, sorbent scale-up, improved physical strength and attrition-resistance, proper heat management and temperature control, proper solids handling and circulation control, as well as the proper coupling of process engineering advancements that are tailored for a promising sorbent technology. The remaining challenges for these sorbent processes have provided the framework for the project team’s research and development and target for advancing the technology beyond lab- and bench-scale testing. Under a cooperative agreement with the US Department of Energy, and part of NETL’s CO2 Capture Program, RTI has led an effort to address and mitigate the challenges associated with solid sorbent CO2 capture. The overall objective

  19. 46 CFR 28.820 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Fire pumps, fire mains, fire hydrants, and fire hoses... REQUIREMENTS FOR COMMERCIAL FISHING INDUSTRY VESSELS Aleutian Trade Act Vessels § 28.820 Fire pumps, fire mains, fire hydrants, and fire hoses. (a) Each vessel must be equipped with a self-priming, power driven fire...

  20. Wildland fire limits subsequent fire occurrence

    Science.gov (United States)

    Sean A. Parks; Carol Miller; Lisa M. Holsinger; Scott Baggett; Benjamin J. Bird

    2016-01-01

    Several aspects of wildland fire are moderated by site- and landscape-level vegetation changes caused by previous fire, thereby creating a dynamic where one fire exerts a regulatory control on subsequent fire. For example, wildland fire has been shown to regulate the size and severity of subsequent fire. However, wildland fire has the potential to influence...

  1. Processes for the evaluation of a potential of scaling behaviour of power plant coals and guarantee of a plant protective fire management; Verfahren zur Beurteilung des Ansatzbildungspotenzials von Kraftwerkskohlen und Gewaehrleistung einer anlagenschonenden Feuerfuehrung

    Energy Technology Data Exchange (ETDEWEB)

    Altmann, Ulrich-Steffen; Grusla, Steffen; Mueller, Frank [Hochschule Zittau/Goerlitz (DE). Inst. fuer Prozesstechnik, Prozessautomatisierung und Messtechnik (IPM); Marschner, Carsten [Vattenfall Europe Generation AG und Co. KG, Peitz (Germany). Kraftwerk Jaenschwalde; Bischoff, Helmut [Vattenfall Europe PowerConsult GmbH, Vetschau (Germany); Sturm, Andreas [CombTech GmbH, Zittau (Germany)

    2008-07-01

    An environmental friendly, economic and resource-protective energetic use of power station coals requires comprehensive information on the operational behaviour of future fuels as well as a suitable process control and process diagnosis. Under this aspect, the authors of the contribution under consideration report on procedures for the evaluation of potentials of the scaling behaviour of power station coals and for the guarantee of a plant preventing fire control. The following main points of work are regarded as urgent: (a) Further development of the empirical firing control for the statement of a realistic optimization potential of the management and support of the operator by recommendations for action; (b) Completion of a controller (project FireControl) for the computer-aided trimming of the distributor; (c) Development of technologies in line with standard usage for fuel evaluation, supply of a power station specific data base for the behaviour of feed coals.

  2. Understanding losses in three core armoured submarine cables

    DEFF Research Database (Denmark)

    Silva, Filipe Miguel Faria da; Ebdrup, Thomas; Bak, Claus Leth

    2016-01-01

    . For practical an economical reasons the preferred choice of cable for both the array and the transmission cables are three-core armoured submarine cables. Therefore, it has becoming increasingly important to be able to calculate the ampacity of such cables accurately. At present time, the ampacity of three......-core armoured submarine cables is calculated according to IEC 60287-1-1 [1]. Various measurements conducted both by cable manufacturers and transmission system operators (TSO) have shown that using the cable rating method stated in IEC 60287-1-1 underestimates the cable ampacity [2]-[6]. Furthermore......, measurements conducted within the cable industry have shown that an armoured three core cable has higher losses than equal unarmoured three core cables. It is also suggested that the inaccuracy in the IEC armour’s loss factor (λ2) is the main responsible for the conservatism in the IEC cable rating method...

  3. How fire history, fire suppression practices and climate change affect wildfire regimes in Mediterranean landscapes.

    Directory of Open Access Journals (Sweden)

    Lluís Brotons

    Full Text Available Available data show that future changes in global change drivers may lead to an increasing impact of fires on terrestrial ecosystems worldwide. Yet, fire regime changes in highly humanised fire-prone regions are difficult to predict because fire effects may be heavily mediated by human activities We investigated the role of fire suppression strategies in synergy with climate change on the resulting fire regimes in Catalonia (north-eastern Spain. We used a spatially-explicit fire-succession model at the landscape level to test whether the use of different firefighting opportunities related to observed reductions in fire spread rates and effective fire sizes, and hence changes in the fire regime. We calibrated this model with data from a period with weak firefighting and later assess the potential for suppression strategies to modify fire regimes expected under different levels of climate change. When comparing simulations with observed fire statistics from an eleven-year period with firefighting strategies in place, our results showed that, at least in two of the three sub-regions analysed, the observed fire regime could not be reproduced unless taking into account the effects of fire suppression. Fire regime descriptors were highly dependent on climate change scenarios, with a general trend, under baseline scenarios without fire suppression, to large-scale increases in area burnt. Fire suppression strategies had a strong capacity to compensate for climate change effects. However, strong active fire suppression was necessary to accomplish such compensation, while more opportunistic fire suppression strategies derived from recent fire history only had a variable, but generally weak, potential for compensation of enhanced fire impacts under climate change. The concept of fire regime in the Mediterranean is probably better interpreted as a highly dynamic process in which the main determinants of fire are rapidly modified by changes in landscape

  4. How fire history, fire suppression practices and climate change affect wildfire regimes in Mediterranean landscapes.

    Science.gov (United States)

    Brotons, Lluís; Aquilué, Núria; de Cáceres, Miquel; Fortin, Marie-Josée; Fall, Andrew

    2013-01-01

    Available data show that future changes in global change drivers may lead to an increasing impact of fires on terrestrial ecosystems worldwide. Yet, fire regime changes in highly humanised fire-prone regions are difficult to predict because fire effects may be heavily mediated by human activities We investigated the role of fire suppression strategies in synergy with climate change on the resulting fire regimes in Catalonia (north-eastern Spain). We used a spatially-explicit fire-succession model at the landscape level to test whether the use of different firefighting opportunities related to observed reductions in fire spread rates and effective fire sizes, and hence changes in the fire regime. We calibrated this model with data from a period with weak firefighting and later assess the potential for suppression strategies to modify fire regimes expected under different levels of climate change. When comparing simulations with observed fire statistics from an eleven-year period with firefighting strategies in place, our results showed that, at least in two of the three sub-regions analysed, the observed fire regime could not be reproduced unless taking into account the effects of fire suppression. Fire regime descriptors were highly dependent on climate change scenarios, with a general trend, under baseline scenarios without fire suppression, to large-scale increases in area burnt. Fire suppression strategies had a strong capacity to compensate for climate change effects. However, strong active fire suppression was necessary to accomplish such compensation, while more opportunistic fire suppression strategies derived from recent fire history only had a variable, but generally weak, potential for compensation of enhanced fire impacts under climate change. The concept of fire regime in the Mediterranean is probably better interpreted as a highly dynamic process in which the main determinants of fire are rapidly modified by changes in landscape, climate and

  5. How Fire History, Fire Suppression Practices and Climate Change Affect Wildfire Regimes in Mediterranean Landscapes

    Science.gov (United States)

    Brotons, Lluís; Aquilué, Núria; de Cáceres, Miquel; Fortin, Marie-Josée; Fall, Andrew

    2013-01-01

    Available data show that future changes in global change drivers may lead to an increasing impact of fires on terrestrial ecosystems worldwide. Yet, fire regime changes in highly humanised fire-prone regions are difficult to predict because fire effects may be heavily mediated by human activities We investigated the role of fire suppression strategies in synergy with climate change on the resulting fire regimes in Catalonia (north-eastern Spain). We used a spatially-explicit fire-succession model at the landscape level to test whether the use of different firefighting opportunities related to observed reductions in fire spread rates and effective fire sizes, and hence changes in the fire regime. We calibrated this model with data from a period with weak firefighting and later assess the potential for suppression strategies to modify fire regimes expected under different levels of climate change. When comparing simulations with observed fire statistics from an eleven-year period with firefighting strategies in place, our results showed that, at least in two of the three sub-regions analysed, the observed fire regime could not be reproduced unless taking into account the effects of fire suppression. Fire regime descriptors were highly dependent on climate change scenarios, with a general trend, under baseline scenarios without fire suppression, to large-scale increases in area burnt. Fire suppression strategies had a strong capacity to compensate for climate change effects. However, strong active fire suppression was necessary to accomplish such compensation, while more opportunistic fire suppression strategies derived from recent fire history only had a variable, but generally weak, potential for compensation of enhanced fire impacts under climate change. The concept of fire regime in the Mediterranean is probably better interpreted as a highly dynamic process in which the main determinants of fire are rapidly modified by changes in landscape, climate and

  6. Collective firing regularity of a scale-free Hodgkin–Huxley neuronal network in response to a subthreshold signal

    Energy Technology Data Exchange (ETDEWEB)

    Yilmaz, Ergin, E-mail: erginyilmaz@yahoo.com [Department of Biomedical Engineering, Engineering Faculty, Bülent Ecevit University, 67100 Zonguldak (Turkey); Ozer, Mahmut [Department of Electrical and Electronics Engineering, Engineering Faculty, Bülent Ecevit University, 67100 Zonguldak (Turkey)

    2013-08-01

    We consider a scale-free network of stochastic HH neurons driven by a subthreshold periodic stimulus and investigate how the collective spiking regularity or the collective temporal coherence changes with the stimulus frequency, the intrinsic noise (or the cell size), the network average degree and the coupling strength. We show that the best temporal coherence is obtained for a certain level of the intrinsic noise when the frequencies of the external stimulus and the subthreshold oscillations of the network elements match. We also find that the collective regularity exhibits a resonance-like behavior depending on both the coupling strength and the network average degree at the optimal values of the stimulus frequency and the cell size, indicating that the best temporal coherence also requires an optimal coupling strength and an optimal average degree of the connectivity.

  7. Land cover mapping, fire regeneration, and scaling studies in the Canadian boreal forest with 1 km AVHRR and Landsat TM data

    Science.gov (United States)

    Steyaert, L.T.; Hall, F.G.; Loveland, Thomas R.

    1997-01-01

    A multitemporal 1 km advanced very high resolution radiometer (AVHRR) land cover analysis approach was used as the basis for regional land cover mapping, fire disturbance-regeneration, and multiresolution land cover scaling studies in the boreal forest ecosystem of central Canada. The land cover classification was developed by using regional field observations from ground and low-level aircraft transits to analyze spectral-temporal clusters that were derived from an unsupervised cluster analysis of monthly normalized difference vegetation index (NDVI) image composites (April-September 1992). Quantitative areal proportions of the major boreal forest components were determined for a 821 km ?? 619 km region, ranging from the southern grasslands-boreal forest ecotone to the northern boreal transitional forest. The boreal wetlands (mostly lowland black spruce, tamarack, mosses, fens, and bogs) occupied approximately 33% of the region, while lakes accounted for another 13%. Upland mixed coniferous-deciduous forests represented 23% of the ecosystem. A SW-NE productivity gradient across the region is manifested by three levels of tree stand density for both the boreal wetland conifer and the mixed forest classes, which are generally aligned with isopleths of regional growing degree days. Approximately 30% of the region was directly affected by fire disturbance within the preceding 30-35 years, especially in the Canadian Shield Zone where large fire-regeneration patterns contribute to the heterogeneous boreal landscape. Intercomparisons with land cover classifications derived from 30-m Landsat Thematic Mapper (TM) data provided important insights into the relative accuracy of the 1 km AVHRR land cover classification. Primarily due to the multitemporal NDVI image compositing process, the 1 km AVHRR land cover classes have an effective spatial resolution in the 3-4 km range; therefore fens, bogs, small water bodies, and small patches of dry jack pine cannot be resolved within

  8. Fire and EMS Districts, Fire District boundaries within Sedgwick County. Cover is programmatically derived from taxing unit districts. Used for Public Safety map rolls. Primary attribute is fire district name. Published to scfiredia.shp., Published in 2008, 1:1200 (1in=100ft) scale, Sedgwick County Government.

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — Fire and EMS Districts dataset current as of 2008. Fire District boundaries within Sedgwick County. Cover is programmatically derived from taxing unit districts....

  9. A two-step combination of top-down and bottom-up fire emission estimates at regional and global scales: strengths and main uncertainties

    Science.gov (United States)

    Sofiev, Mikhail; Soares, Joana; Kouznetsov, Rostislav; Vira, Julius; Prank, Marje

    2016-04-01

    Top-down emission estimation via inverse dispersion modelling is used for various problems, where bottom-up approaches are difficult or highly uncertain. One of such areas is the estimation of emission from wild-land fires. In combination with dispersion modelling, satellite and/or in-situ observations can, in principle, be used to efficiently constrain the emission values. This is the main strength of the approach: the a-priori values of the emission factors (based on laboratory studies) are refined for real-life situations using the inverse-modelling technique. However, the approach also has major uncertainties, which are illustrated here with a few examples of the Integrated System for wild-land Fires (IS4FIRES). IS4FIRES generates the smoke emission and injection profile from MODIS and SEVIRI active-fire radiative energy observations. The emission calculation includes two steps: (i) initial top-down calibration of emission factors via inverse dispersion problem solution that is made once using training dataset from the past, (ii) application of the obtained emission coefficients to individual-fire radiative energy observations, thus leading to bottom-up emission compilation. For such a procedure, the major classes of uncertainties include: (i) imperfect information on fires, (ii) simplifications in the fire description, (iii) inaccuracies in the smoke observations and modelling, (iv) inaccuracies of the inverse problem solution. Using examples of the fire seasons 2010 in Russia, 2012 in Eurasia, 2007 in Australia, etc, it is pointed out that the top-down system calibration performed for a limited number of comparatively moderate cases (often the best-observed ones) may lead to errors in application to extreme events. For instance, the total emission of 2010 Russian fires is likely to be over-estimated by up to 50% if the calibration is based on the season 2006 and fire description is simplified. Longer calibration period and more sophisticated parameterization

  10. Vibration mitigation of a bridge cable using a nonlinear energy sink: design and experiment

    Directory of Open Access Journals (Sweden)

    Weiss Mathieu

    2015-01-01

    Full Text Available This work deals with the design and experiment of a cubic nonlinear energy sink (NES for horizontal vibration mitigation of a bridge cable. Modal analysis of horizontal linear modes of the cable is experimentally performed using accelerometers and displacement sensors. A theoretical simplified 2-dof model of the coupled cable-NES system is used to analytically design the NES by mean of multi-time scale systems behaviours and detection its invariant manifold, equilibrium and singular points which stand for periodic and strongly modulated regimes, respectively. Numerical integration is used to confirm the efficiency of the designed NES for the system under step release excitation. Then, the prototype system is built using geometrical cubic nonlinearity as the potential of the NES. Efficiency of the prototype system for mitigation of horizontal vibrations of the cable under for step release and forced excitations is experimentally demonstrated.

  11. Impedance-Based Cable Force Monitoring in Tendon-Anchorage Using Portable PZT-Interface Technique

    Directory of Open Access Journals (Sweden)

    Thanh-Canh Huynh

    2014-01-01

    Full Text Available In this paper, a portable PZT interface for tension force monitoring in the cable-anchorage subsystem is developed. Firstly, the theoretical background of the impedance-based method is presented. A few damage evaluation approaches are outlined to quantify the variation of impedance signatures. Secondly, a portable PZT interface is designed to monitor impedance signatures from the cable-anchorage subsystem. One degree-of-freedom analytical model of the PZT interface is established to explain how to represent the loss of cable force from the change in the electromechanical impedance of the PZT interface as well as reducing the sensitive frequency band by implementing the interface device. Finally, the applicability of the proposed PZT-interface technique is experimentally evaluated for cable force-loss monitoring in a lab-scaled test structure.

  12. Flexural behaviour of partially bonded carbon fibre reinforced polymers strengthened concrete beams: Application to fire protection systems design

    International Nuclear Information System (INIS)

    Firmo, J.P.; Arruda, M.R.T.; Correia, J.R.; Tiago, C.

    2015-01-01

    Highlights: • The mechanical behaviour of partially bonded CFRP strengthened beams was modelled. • Two dimensional non-linear finite element models were developed. • Partially bonded beams can present similar flexural strength to fully bonded ones. • Relations between the bonded length and the strength reduction were proposed. • The proposed relations were used for the design of fire protection systems. - Abstract: Recent fire resistance tests on reinforced concrete (RC) beams strengthened with carbon fibre reinforced polymers (CFRP) laminates showed that it is possible to attain considerable fire endurance provided that thermal insulation is applied at the anchorage zones of the strengthening system. With such protection, although the CFRP laminate prematurely debonds in the central part of the beam, it transforms into a cable fixed at the extremities until one of the anchorage zones loses its bond strength. The main objective of this paper is to propose a simplified methodology for the design of fire protection systems for CFRP strengthened-RC beams, which is based on applying thicker insulation at the anchorage zones (promoting the above mentioned “cable behaviour”) and a thinner one at the current zone (avoiding tensile rupture of the carbon fibres). As a first step towards the validation of this methodology, finite element (FE) models were developed to simulate the flexural behaviour at ambient temperature of full-scale RC beams strengthened with CFRP laminates according to the externally bonded reinforcement (EBR) and near surface mounted (NSM) techniques, in both cases fully or partially bonded (the latter simulating the cable). The FE models were calibrated with results of 4-point bending tests on small-scale beams and then extended for different beam geometries, with spans (L) varying from 2 m to 5 m, in which the influence of the CFRP bonded length (l b ) and the loading type (point or uniformly distributed) on the strength reduction was

  13. Assessment of sodium conductor distribution cable

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-06-01

    The study assesses the barriers and incentives for using sodium conductor distribution cable. The assessment considers environmental, safety, energy conservation, electrical performance and economic factors. Along with all of these factors considered in the assessment, the sodium distribution cable system is compared to the present day alternative - an aluminum conductor system. (TFD)

  14. Cable Television: Citizen Participation After the Franchise.

    Science.gov (United States)

    Price, Monroe E.; Botein, Michael

    The Federal Communications Commission (FCC) has incorporated several allowances in its regulations pertaining to cable television. Some of these enable citizen groups and communities to intervene in the cable franchise after the final issuance in order to correct deficiencies in the franchising process and the administration of the franchise.…

  15. Cable Technology: A Challenge for Adult Educators.

    Science.gov (United States)

    Palchinsky, Jo

    The penetration of cable television throughout American communities makes it a potentially significant tool for improving the quality and accessibility of adult education. As cities begin to include in the cable franchise allotment monies for access by community members, adult educators need to become actively involved during the development of a…

  16. The Selling of Cable Television 1972.

    Science.gov (United States)

    National Cable Television Association, Inc., Washington, DC.

    The 1972 Cable Television Marketing Workshop reviewed in depth a wide variety of marketing and public relations techniques as they pertain to cable television. The workshop was attended by representatives of commercial television systems throughout the United States; it was intended to disseminate the sales and marketing experience of those…

  17. An ACLU Guide to Cable Television.

    Science.gov (United States)

    Powledge, Fred

    Proceeding from the hypothesis that cable television (CATV) is one of the most significant developments in modern America, this booklet examines the medium itself and then devotes special attention to the capacity of CATV to serve the First Amendment interest in diversity of expression. The opening section deals with the size and growth of cable,…

  18. Cable Television: The Process of Franchising.

    Science.gov (United States)

    Johnson, Leland L.; Botein, Michael

    In an effort to insure that cable television franchising procedures at the local level are based on a competitive and well-conceived selection process, this report discusses some of the most important steps of the franchising process. Not only does it show how the community should assess its needs and appraise the merits of the cable operator, but…

  19. Cable Television and Educational Access: A Reconsideration.

    Science.gov (United States)

    Thornton, Lee R.; Greene, James C.

    1986-01-01

    Considers the possible impact of recent federal legislation on educational utilization of cable television. Stresses the importance of educators understanding the law's provisions and acting to initiate relationships with cable companies. Reviews public educational or governmental access provisions. Presents strategies for promoting reciprocity…

  20. Intermodal resonance of vibrating suspended cables

    NARCIS (Netherlands)

    Rienstra, S.W.

    2010-01-01

    The weakly nonlinear free vibrations of a single suspended cable, or a coupled system of suspended cables, may be classified as gravity modes (no tension variations to leading order) and elasto-gravity modes (tension and vertical displacement equally important). It was found earlier [12] that the

  1. A new multiconstraint method for determining the optimal cable stresses in cable-stayed bridges.

    Science.gov (United States)

    Asgari, B; Osman, S A; Adnan, A

    2014-01-01

    Cable-stayed bridges are one of the most popular types of long-span bridges. The structural behaviour of cable-stayed bridges is sensitive to the load distribution between the girder, pylons, and cables. The determination of pretensioning cable stresses is critical in the cable-stayed bridge design procedure. By finding the optimum stresses in cables, the load and moment distribution of the bridge can be improved. In recent years, different research works have studied iterative and modern methods to find optimum stresses of cables. However, most of the proposed methods have limitations in optimising the structural performance of cable-stayed bridges. This paper presents a multiconstraint optimisation method to specify the optimum cable forces in cable-stayed bridges. The proposed optimisation method produces less bending moments and stresses in the bridge members and requires shorter simulation time than other proposed methods. The results of comparative study show that the proposed method is more successful in restricting the deck and pylon displacements and providing uniform deck moment distribution than unit load method (ULM). The final design of cable-stayed bridges can be optimised considerably through proposed multiconstraint optimisation method.

  2. Nonlinear Analysis of Cable Vibration of a Multispan Cable-Stayed Bridge under Transverse Excitation

    Directory of Open Access Journals (Sweden)

    Kun Lin

    2014-01-01

    Full Text Available The nonlinear vibrations of cable in a multispan cable-stayed bridge subjected to transverse excitation are investigated. The MECS (multielements cable system model, where multielements per cable stay are used, is built up and used to analyze the model properties of the multispan cable-stayed bridges. Then, a simplified two-degrees-of-freedom (2-DOFs model, where the tower or the deck is reduced to a beam, is proposed to analyze the nonlinear dynamic behaviors of the beam and cable. The results of MECS model analysis show that the main tower in the multispan cable-stayed bridge is prone to the transverse vibration, and the local vibration of cables only has a little impact on the frequency values of the global modes. The results of simplified model analysis show that the energy can be transformed between the modes of the beam and cable when the nature frequencies of them are very close. On the other hand, with the transverse excitation changing, the cable can exhibit richer quasi-periodic or chaotic motions due to the nonlinear terms caused by the coupled mode between the beam and cable.

  3. A New Multiconstraint Method for Determining the Optimal Cable Stresses in Cable-Stayed Bridges

    Directory of Open Access Journals (Sweden)

    B. Asgari

    2014-01-01

    Full Text Available Cable-stayed bridges are one of the most popular types of long-span bridges. The structural behaviour of cable-stayed bridges is sensitive to the load distribution between the girder, pylons, and cables. The determination of pretensioning cable stresses is critical in the cable-stayed bridge design procedure. By finding the optimum stresses in cables, the load and moment distribution of the bridge can be improved. In recent years, different research works have studied iterative and modern methods to find optimum stresses of cables. However, most of the proposed methods have limitations in optimising the structural performance of cable-stayed bridges. This paper presents a multiconstraint optimisation method to specify the optimum cable forces in cable-stayed bridges. The proposed optimisation method produces less bending moments and stresses in the bridge members and requires shorter simulation time than other proposed methods. The results of comparative study show that the proposed method is more successful in restricting the deck and pylon displacements and providing uniform deck moment distribution than unit load method (ULM. The final design of cable-stayed bridges can be optimised considerably through proposed multiconstraint optimisation method.

  4. Nuclear power plant cable materials :

    Energy Technology Data Exchange (ETDEWEB)

    Celina, Mathias C.; Gillen, Kenneth T; Lindgren, Eric Richard

    2013-05-01

    A selective literature review was conducted to assess whether currently available accelerated aging and original qualification data could be used to establish operational margins for the continued use of cable insulation and jacketing materials in nuclear power plant environments. The materials are subject to chemical and physical degradation under extended radiationthermal- oxidative conditions. Of particular interest were the circumstances under which existing aging data could be used to predict whether aged materials should pass loss of coolant accident (LOCA) performance requirements. Original LOCA qualification testing usually involved accelerated aging simulations of the 40-year expected ambient aging conditions followed by a LOCA simulation. The accelerated aging simulations were conducted under rapid accelerated aging conditions that did not account for many of the known limitations in accelerated polymer aging and therefore did not correctly simulate actual aging conditions. These highly accelerated aging conditions resulted in insulation materials with mostly inert aging processes as well as jacket materials where oxidative damage dropped quickly away from the air-exposed outside jacket surface. Therefore, for most LOCA performance predictions, testing appears to have relied upon heterogeneous aging behavior with oxidation often limited to the exterior of the cable cross-section a situation which is not comparable with the nearly homogenous oxidative aging that will occur over decades under low dose rate and low temperature plant conditions. The historical aging conditions are therefore insufficient to determine with reasonable confidence the remaining operational margins for these materials. This does not necessarily imply that the existing 40-year-old materials would fail if LOCA conditions occurred, but rather that unambiguous statements about the current aging state and anticipated LOCA performance cannot be provided based on

  5. Review of the IAEA fire symposium

    International Nuclear Information System (INIS)

    Fischer, J.

    1991-01-01

    The IAEA Symposium on Fire Protection and Fire Fighting in Nuclear Installations covered a large scope in the field in order to provide the opportunity for screening all aspects of present technology, research and development, standardization, licensing and fire fighting practices. Although application to any nuclear facility was within its scope, the majority of presentations concerned nuclear power plants. The approach to fire protection is the classical one in all plant designs: reduction of fire loads, appropriate zoning, manual and automatic extinguishment. However, methods of analysis and consequence prediction are changing. Computerized fire modelling is becoming a powerful tool in this area; probabilistic analytical methods are being improved, though they are not yet used widely for fire hazards. Differences in opinion were revealed in the definition of barrier resistance, the prediction of cable insulation behaviour and the optimal design of extinguishing systems. Greater international co-operation, especially in these areas, may be a good way of optimizing results with limited resources. Discussion contributions showed interest in exchange of experience in more specialized topics and encouraged the IAEA to increase its activity in the area of fire protection. (orig.)

  6. Application of Pulse Spark Discharges for Scale Prevention and Continuous Filtration Methods in Coal-Fired Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Young; Fridman, Alexander

    2012-06-30

    The overall objective of the present work was to develop a new scale-prevention technology by continuously precipitating and removing dissolved mineral ions (such as calcium and magnesium) in cooling water while the COC could be doubled from the present standard value of 3.5. The hypothesis of the present study was that if we could successfully precipitate and remove the excess calcium ions in cooling water, we could prevent condenser-tube fouling and at the same time double the COC. The approach in the study was to utilize pulse spark discharges directly in water to precipitate dissolved mineral ions in recirculating cooling water into relatively large suspended particles, which could be removed by a self-cleaning filter. The present study began with a basic scientific research to better understand the mechanism of pulse spark discharges in water and conducted a series of validation experiments using hard water in a laboratory cooling tower. Task 1 of the present work was to demonstrate if the spark discharge could precipitate the mineral ions in water. Task 2 was to demonstrate if the selfcleaning filter could continuously remove these precipitated calcium particles such that the blowdown could be eliminated or significantly reduced. Task 3 was to demonstrate if the scale could be prevented or minimized at condenser tubes with a COC of 8 or (almost) zero blowdown. In Task 1, we successfully completed the validation study that confirmed the precipitation of dissolved calcium ions in cooling water with the supporting data of calcium hardness over time as measured by a calcium ion probe. In Task 2, we confirmed through experimental tests that the self-cleaning filter could continuously remove precipitated calcium particles in a simulated laboratory cooling tower such that the blowdown could be eliminated or significantly reduced. In addition, chemical water analysis data were obtained which were used to confirm the COC calculation. In Task 3, we conducted a series

  7. Fiber optic fire detection technology

    International Nuclear Information System (INIS)

    Hering, D.W.

    1990-01-01

    Electrostatic application of paint was, and still is, the most technically feasible method of reducing VOC (volatile organic compounds) emissions, while reducing the cost to apply the coatings. Prior to the use of electrostatics, only two sides of the traditional fire triangle were normally present in the booth, fuel (solvent), and oxygen (air). Now the third leg (the ignition source) was present at virtually all times during the production operation in the form of the electrostatic charge and the resulting energy in the system. The introduction of fiber optics into the field of fire detection was for specific application to the electrostatic painting industry, but specifically, robots used in the application of electrostatic painting in the automotive industry. The use of fiber optics in this hazard provided detection for locations that have been previously prohibited or inaccessible with the traditional fire detection systems. The fiber optic technology that has been adapted to the field of fire detection operates on the principle of transmission of photons through a light guide (optic fiber). When the light guide is subjected to heat, the cladding on the light guide melts away from the core and allows the light (photons) to escape. The controller, which contains the emitter and receiver is set-up to distinguish between partial loss of light and a total loss of light. Glass optical fibers carrying light offer distinct advantages over wires or coaxial cables carrying electricity as a transmission media. The uses of fiber optic detection will be expanded in the near future into such areas as aircraft, cable trays and long conveyor runs because fiber optics can carry more information and deliver it with greater clarity over longer distances with total immunity to all kinds of electrical interference

  8. Coal fires in Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Whitehouse, Alfred E.; Mulyana, Asep A.S. [Office of Surface Mining/Ministry of Energy and Mineral Resources Coal Fire Project, Ministry of Energy and Mineral Resources, Agency for Training and Education, Jl. Gatot Subroto, Kav. 49, Jakarta 12950 (Indonesia)

    2004-07-12

    Indonesia's fire and haze problem is increasingly being ascribed to large-scale forest conversion and land clearing activities making way for pulpwood, rubber and oil palm plantations. Fire is the cheapest tool available to small holders and plantation owners to reduce vegetation cover and prepare and fertilize extremely poor soils. Fires that escaped from agricultural burns have ravaged East Kalimantan forests on the island of Borneo during extreme drought periods in 1982-1983, 1987, 1991, 1994 and 1997-1998. Estimates based on satellite data and ground observations are that more than five million hectares were burned in East Kalimantan during the 1997/1998 dry season. Not only were the economic losses and ecological damage from these surface fires enormous, they ignited coal seams exposed at the ground surface along their outcrops.Coal fires now threaten Indonesia's shrinking ecological resources in Kutai National Park and Sungai Wain Nature Reserve. Sungai Wain has one of the last areas of unburned primary rainforest in the Balikpapan-Samarinda area with an extremely rich biodiversity. Although fires in 1997/1998 damaged nearly 50% of this Reserve and ignited 76 coal fires, it remains the most valuable water catchment area in the region and it has been used as a reintroduction site for the endangered orangutan. The Office of Surface Mining provided Indonesia with the capability to take quick action on coal fires that presented threats to public health and safety, infrastructure or the environment. The US Department of State's Southeast Asia Environmental Protection Initiative through the US Agency for International Development funded the project. Technical assistance and training transferred skills in coal fire management through the Ministry of Energy and Mineral Resource's Training Agency to the regional offices; giving the regions the long-term capability to manage coal fires. Funding was also included to extinguish coal fires as

  9. Laboratory-scale evaluation of various sampling and analytical methods for determining mercury emissions from coal-fired power plants

    Energy Technology Data Exchange (ETDEWEB)

    Agbede, R.O.; Bochan, A.J.; Clements, J.L. [Advanced Technology Systems, Inc., Monroeville, PA (United States)] [and others

    1995-11-01

    Comparative bench-scale mercury sampling method tests were performed at the Advanced Technology Systems, Inc. (ATS) laboratories for EPA Method 101A, EPA Method 29 and the Ontario Hydro Method. Both blank and impinger spiking experiments were performed. The experimental results show that the ambient level of mercury in the ATS laboratory is at or below the detection limit (10 ng Hg) as measured by a cold vapor atomic absorption spectrophotometer (CVAAS) which was used to analyze the mercury samples. From the mercury spike studies, the following observations and findings were made. (a) The recovery of mercury spikes using EPA Method 101A was 104%. (b) The Ontario Hydro Method retains about 90% of mercury spikes in the first absorbing solution but has a total spike retention of 106%. As a result, the test data shows possible migration of spiked mercury from the first impinger solution (KCI) to the permanganate impingers. (c) For the EPA Method 29 solutions, when only the peroxide impingers were spiked, mercury recoveries were 65.6% for the peroxide impingers, 0.1% for the knockout impinger and 32.8% for the permanganate impingers with an average total mercury recovery of 98.4%. At press time, data was still being obtained for both the peroxide and permanganate impinger solution spikes. This and other data will be available at the presentation.

  10. Parallel monostrand stay cable bending fatigue

    DEFF Research Database (Denmark)

    Winkler, Jan Pawel

    This dissertation investigates the bending fatigue response of high-strength steel monostrands and multistrand stay cables to cyclic transverse deformations. Increasing bridge stock numbers and a push for longer cable-supported span lengths have led to an increased number of reported incidents...... of damage and replacement of bridge stay cables due to wind and traffic-induced fatigue. The understanding of fatigue mechanisms in most steel structures is well established. However, in the case of cables composed of steel strands, many important aspects related with bending fatigue remain to be clarified...... associated with variable loading, and different testing procedures. As most of the contemporary stay cables are comprised of a number of individual highstrength steel monostrands, the research study started with an extensive experimental work on the fatigue response of a single monostrand to cyclic flexural...

  11. Modified cable equation incorporating transverse polarization of neuronal membranes for accurate coupling of electric fields.

    Science.gov (United States)

    Wang, Boshuo; Aberra, Aman S; Grill, Warren M; Peterchev, Angel V

    2018-04-01

    We present a theory and computational methods to incorporate transverse polarization of neuronal membranes into the cable equation to account for the secondary electric field generated by the membrane in response to transverse electric fields. The effect of transverse polarization on nonlinear neuronal activation thresholds is quantified and discussed in the context of previous studies using linear membrane models. The response of neuronal membranes to applied electric fields is derived under two time scales and a unified solution of transverse polarization is given for spherical and cylindrical cell geometries. The solution is incorporated into the cable equation re-derived using an asymptotic model that separates the longitudinal and transverse dimensions. Two numerical methods are proposed to implement the modified cable equation. Several common neural stimulation scenarios are tested using two nonlinear membrane models to compare thresholds of the conventional and modified cable equations. The implementations of the modified cable equation incorporating transverse polarization are validated against previous results in the literature. The test cases show that transverse polarization has limited effect on activation thresholds. The transverse field only affects thresholds of unmyelinated axons for short pulses and in low-gradient field distributions, whereas myelinated axons are mostly unaffected. The modified cable equation captures the membrane's behavior on different time scales and models more accurately the coupling between electric fields and neurons. It addresses the limitations of the conventional cable equation and allows sound theoretical interpretations. The implementation provides simple methods that are compatible with current simulation approaches to study the effect of transverse polarization on nonlinear membranes. The minimal influence by transverse polarization on axonal activation thresholds for the nonlinear membrane models indicates that

  12. Controls on carbon consumption during Alaskan wildland fires

    Science.gov (United States)

    Eric S. Kasischke; Elizabeth E. Hoy

    2012-01-01

    A method was developed to estimate carbon consumed during wildland fires in interior Alaska based on medium-spatial scale data (60 m cell size) generated on a daily basis. Carbon consumption estimates were developed for 41 fire events in the large fire year of 2004 and 34 fire events from the small fire years of 2006-2008. Total carbon consumed during the large fire...

  13. Fire risk analysis, fire simulation, fire spreading and impact of smoke and heat on instrumentation electronics - State-of-the-Art Report

    International Nuclear Information System (INIS)

    Roewekamp, M.; Bertrand, R.; Bonneval, F.; Hamblen, D.; Siu, N.; Aulamo, H.; Martila, J.; Sandberg, J.; Virolainen, R.

    2000-01-01

    Numerous fire PSAs (probabilistic safety assessments) have shown that fire can be a major contributor to nuclear power plant risk. However, there are considerable uncertainties in the results of these assessments, due to significant gaps in current abilities to perform realistic assessments. These gaps involve multiple aspects of fire PSA, including the estimation of the probability of important fire scenarios, the modeling of fire growth and suppression, the prediction of fire-induced damage to equipment (including the effects of smoke), and the treatment of plant and operator responses to the fire. In response to recommendations of /VIR 93/, CSNI/PWG5 established a Task Group to review the present status and maturity of current methods used in fire risk assessments for operating nuclear power plants. The Task Group issued a questionnaire in May 1997 to all nuclear power generating OECD countries. The prime focus of the questionnaire (see Appendix A) was on a number of important issues in fire PSA: Fire PSA methodology and applications; Fire simulation codes; Ignition and damageability data; Modeling of fire spread on cables or other equipment; Modeling of smoke production and spread; Impact of smoke and heat on instrumentation, electronics, or other electrical equipment; Impact of actual cable fires on safety systems. The questionnaire requested specific information on these topics (e.g., computer codes used in fire PSAs, the physical parameters used to model ignition). Responses to the questionnaire were provided by Finland, France, Germany, Hungary, Japan, Spain, Switzerland, United Kingdom, and the USA. This report summarizes the questionnaire responses and thereby: a) provides a perspective on the current fire PSA state of the art (SOAR) with respect to the issues listed above, and b) provides numerous references for more detailed information regarding these issues. The main responsibility for writing different chapters of this report was divided between some

  14. Wind-induced cable vibrations and countermeasures of cables of PC cable-stayed bridge. PC syachokyo keburu no kaze ni yoru shindo to sono taisaku

    Energy Technology Data Exchange (ETDEWEB)

    Yoneda, M. (Kawada Industries Inc., Tokyo (Japan))

    1994-05-01

    In recent years, long span of cable-stayed bridges is remarkable. The wind-induced cable vibration called as line vibration and wake galloping was given as an important problem not only in the steel cable-stayed bridges but also in the PC cable-stayed bridges. The technical engineers in design of the cable-stayed bridges have many times to confront the problems on the vibration control of cables, it is considered that sufficient understand of the wind-induced vibration and countermeasures for cables of the PC cable-stayed bridges is necessary. Many reports on the countermeasure examples and trend of vibration control centred on cables of the cable-stayed bridges have been published. In this paper, the wind-induced vibration of cables in the cable-stayed bridges was reviewed, the examples of countermeasures of vibration control on cables in the PC cable-stayed bridges was mainly introduced. The remaining tasks and future prospects on vibration control of the PC cable-stayed bridges were described. 14 refs., 13 figs., 4 tabs.

  15. A Cable-tunnel Inspecting Robot for Dangerous Environment

    Directory of Open Access Journals (Sweden)

    Fu Zhuang

    2008-11-01

    Full Text Available This paper presents a kind of mobile robot used for inspecting the cable tunnel online in the dangerous environment. Usually, the calble tunnel is full of poisonous gases after fire, such as CO,CH4, CO2 and so on. Then, the mobile robot is able to tell us whether the tunnel environment is safe or not. In this paper the architecture of the robot is designed at first to meet the motion requirement in the tunnel. These characteristics distinguish the mobile robot from others like compact structure,small size,little weight and easily being carried. Next, the moving mechanism and its kinematics are described. And thus, the operating procedure and experiments are introuduced to validate its reliablity.

  16. A cable-tunnel inspecting robot for dangerous environment

    Directory of Open Access Journals (Sweden)

    Fu Zhuang

    2008-09-01

    Full Text Available This paper presents a kind of mobile robot used for inspecting the cable tunnel online in the dangerous environment. Usually, the calble tunnel is full of poisonous gases after fire, such as CO, CH4, CO2 and so on. Then, the mobile robot is able to tell us whether the tunnel environment is safe or not. In this paper the architecture of the robot is designed at first to meet the motion requirement in the tunnel. These characteristics distinguish the mobile robot from others like compact structure, small size, little weight and easily being carried. Next, the moving mechanism and its kinematics are described. And thus, the operating procedure and experiments are introuduced to validate its reliablity.

  17. Synchronization of two coupled turbulent fires

    Science.gov (United States)

    Takagi, Kazushi; Gotoda, Hiroshi; Miyano, Takaya; Murayama, Shogo; Tokuda, Isao T.

    2018-04-01

    We numerically study the scale-free nature of a buoyancy-induced turbulent fire and synchronization of two coupled turbulent fires. A scale-free structure is detected in weighted networks between vortices, while its lifetime obeys a clear power law, indicating intermittent appearances, disappearances, and reappearances of the scale-free property. A significant decrease in the distance between the two fire sources gives rise to a synchronized state in the near field dominated by the unstable motion of large-scale of transverse vortex rings. The synchronized state vanishes in the far field forming well-developed turbulent plumes, regardless of the distance between the two fire sources.

  18. Scales

    Science.gov (United States)

    Scales are a visible peeling or flaking of outer skin layers. These layers are called the stratum ... Scales may be caused by dry skin, certain inflammatory skin conditions, or infections. Examples of disorders that ...

  19. On fire

    DEFF Research Database (Denmark)

    Hansen, Helle Rabøl

    The title of this paper: “On fire”, refers to two (maybe three) aspects: firstly as a metaphor of having engagement in a community of practice according to Lave & Wenger (1991), and secondly it refers to the concrete element “fire” in the work of the fire fighters – and thirdly fire as a signifier...

  20. Fire Power

    Science.gov (United States)

    Denker, Deb; West, Lee

    2009-01-01

    For education administrators, campus fires are not only a distressing loss, but also a stark reminder that a campus faces risks that require special vigilance. In many ways, campuses resemble small communities, with areas for living, working and relaxing. A residence hall fire may raise the specter of careless youth, often with the complication of…

  1. Some insights from fire risk analysis of US nuclear power plants

    International Nuclear Information System (INIS)

    Kazarians, M.; Lambright, J.A.; Frank, M.V.

    1998-01-01

    Fire risk analysis has been conducted for a significant portion of the nuclear power plants in the U.S. using either Probabilistic Risk Assessments (PRAs) or FIVE or a combination of the two methodologies. Practically all fire risk studies have used step-wise, screening approach. To establish the contents of a compartment, the cable routing information collected for Appendix R compliance have been used in practically all risk studies. In several cases, the analysts have gone beyond the Appendix R and have obtained the routing of additional cables. For fire impact analysis typically an existing PRA model is used. For fire frequencies, typically, a generic data base is used. Fire scenarios are identified in varying levels of detail. The most common approach, in the early stages of screening, is based on the assumption that given a fire, the entire contents of the compartment are lost. Less conservative scenarios are introduced at later stages of the analysis which may include fire propagation patterns, fires localized to an item. and suppression of the fire before critical damage. For fire propagation and damage analysis, a large number of studies have used FIVE and many have used COMPBRN. For detection and suppression analysis, the generic suppression system unavailabilities given in FIVE have been used. The total core damage frequencies typically range between 1x10 -6 to 1x10 -4 per year. Control rooms and cable spreading rooms are the two most common areas found to be significant contributors to fire risk. Other areas are mainly from the Auxiliary Building (in the case of PWRs) and Reactor Building (in the case of BWRs). Only in one case, the main contributor to fire is the turbine building, which included several safety related equipment and cables. (author)

  2. Advanced methods for a probabilistic safety analysis of fires. Development of advanced methods for performing as far as possible realistic plant specific fire risk analysis (fire PSA)

    International Nuclear Information System (INIS)

    Hofer, E.; Roewekamp, M.; Tuerschmann, M.

    2003-07-01

    In the frame of the research project RS 1112 'Development of Methods for a Recent Probabilistic Safety Analysis, Particularly Level 2' funded by the German Federal Ministry of Economics and Technology (BMWi), advanced methods, in particular for performing as far as possible realistic plant specific fire risk analyses (fire PSA), should be developed. The present Technical Report gives an overview on the methodologies developed in this context for assessing the fire hazard. In the context of developing advanced methodologies for fire PSA, a probabilistic dynamics analysis with a fire simulation code including an uncertainty and sensitivity study has been performed for an exemplary scenario of a cable fire induced by an electric cabinet inside the containment of a modern Konvoi type German nuclear power plant taking into consideration the effects of fire detection and fire extinguishing means. With the present study, it was possible for the first time to determine the probabilities of specified fire effects from a class of fire events by means of probabilistic dynamics supplemented by uncertainty and sensitivity analyses. The analysis applies a deterministic dynamics model, consisting of a dynamic fire simulation code and a model of countermeasures, considering effects of the stochastics (so-called aleatory uncertainties) as well as uncertainties in the state of knowledge (so-called epistemic uncertainties). By this means, probability assessments including uncertainties are provided to be used within the PSA. (orig.) [de

  3. Model of large pool fires

    Energy Technology Data Exchange (ETDEWEB)

    Fay, J.A. [Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)]. E-mail: jfay@mit.edu

    2006-08-21

    A two zone entrainment model of pool fires is proposed to depict the fluid flow and flame properties of the fire. Consisting of combustion and plume zones, it provides a consistent scheme for developing non-dimensional scaling parameters for correlating and extrapolating pool fire visible flame length, flame tilt, surface emissive power, and fuel evaporation rate. The model is extended to include grey gas thermal radiation from soot particles in the flame zone, accounting for emission and absorption in both optically thin and thick regions. A model of convective heat transfer from the combustion zone to the liquid fuel pool, and from a water substrate to cryogenic fuel pools spreading on water, provides evaporation rates for both adiabatic and non-adiabatic fires. The model is tested against field measurements of large scale pool fires, principally of LNG, and is generally in agreement with experimental values of all variables.

  4. Model of large pool fires

    International Nuclear Information System (INIS)

    Fay, J.A.

    2006-01-01

    A two zone entrainment model of pool fires is proposed to depict the fluid flow and flame properties of the fire. Consisting of combustion and plume zones, it provides a consistent scheme for developing non-dimensional scaling parameters for correlating and extrapolating pool fire visible flame length, flame tilt, surface emissive power, and fuel evaporation rate. The model is extended to include grey gas thermal radiation from soot particles in the flame zone, accounting for emission and absorption in both optically thin and thick regions. A model of convective heat transfer from the combustion zone to the liquid fuel pool, and from a water substrate to cryogenic fuel pools spreading on water, provides evaporation rates for both adiabatic and non-adiabatic fires. The model is tested against field measurements of large scale pool fires, principally of LNG, and is generally in agreement with experimental values of all variables

  5. 46 CFR 28.315 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Fire pumps, fire mains, fire hydrants, and fire hoses... After September 15, 1991, and That Operate With More Than 16 Individuals on Board § 28.315 Fire pumps, fire mains, fire hydrants, and fire hoses. (a) Each vessel 36 feet (11.8 meters) or more in length must...

  6. Forest-fire models

    Science.gov (United States)

    Haiganoush Preisler; Alan Ager

    2013-01-01

    For applied mathematicians forest fire models refer mainly to a non-linear dynamic system often used to simulate spread of fire. For forest managers forest fire models may pertain to any of the three phases of fire management: prefire planning (fire risk models), fire suppression (fire behavior models), and postfire evaluation (fire effects and economic models). In...

  7. Simulation of the cabling process for Rutherford cables: An advanced finite element model

    Science.gov (United States)

    Cabanes, J.; Garlasche, M.; Bordini, B.; Dallocchio, A.

    2016-12-01

    In all existing large particle accelerators (Tevatron, HERA, RHIC, LHC) the main superconducting magnets are based on Rutherford cables, which are characterized by having: strands fully transposed with respect to the magnetic field, a significant compaction that assures a large engineering critical current density and a geometry that allows efficient winding of the coils. The Nb3Sn magnets developed in the framework of the HL-LHC project for improving the luminosity of the Large Hadron Collider (LHC) are also based on Rutherford cables. Due to the characteristics of Nb3Sn wires, the cabling process has become a crucial step in the magnet manufacturing. During cabling the wires experience large plastic deformations that strongly modify the geometrical dimensions of the sub-elements constituting the superconducting strand. These deformations are particularly severe on the cable edges and can result in a significant reduction of the cable critical current as well as of the Residual Resistivity Ratio (RRR) of the stabilizing copper. In order to understand the main parameters that rule the cabling process and their impact on the cable performance, CERN has developed a 3D Finite Element (FE) model based on the LS-Dyna® software that simulates the whole cabling process. In the paper the model is presented together with a comparison between experimental and numerical results for a copper cable produced at CERN.

  8. Non-cable vehicle guidance

    Energy Technology Data Exchange (ETDEWEB)

    Daugela, G.C.; Willott, A.M.; Chopiuk, R.G.; Thornton, S.E.

    1988-06-01

    The purpose is to determine the most promising driverless mine vehicle guidance systems that are not dependent on buried cables, and to plan their development. The project is presented in two phases: a preliminary study and literature review to determine whether suitable technologies exist to justify further work; and an in-depth assessment and selection of technologies for vehicle guidance. A large number of guidance elements are involved in a completely automated vehicle. The technologies that hold the best potential for development of guidance systems for mine vehicles are ultrasonics, radar, lasers, dead reckoning, and guidance algorithms. The best approach to adaptation of these technologies is on a step by step basis. Guidance modules that are complete in themselves and are designed to be integrated with other modules can provide short term benefits. Two modules are selected for development: the dragline operations monitor and automated machine control for optimized mining (AMCOM). 99 refs., 20 figs., 40 tabs.

  9. Experimental study of thermal field deriving from an underground electrical power cable buried in non-homogeneous soils

    International Nuclear Information System (INIS)

    Lieto Vollaro, Roberto de; Fontana, Lucia; Vallati, Andrea

    2014-01-01

    The electrical cables ampacity mainly depends on the cable system operation temperature. To achieve a better cable utilization and reduce the conservativeness typically employed in buried cable design, an accurate evaluation of the heat dissipation through the cables and the surrounding soil is important. In the traditional method adopted by the International Electrotechnical Commission (IEC) and the Institute of Electrical and Electronics Engineers (IEEE) for the computation of the thermal resistance between an existing underground cable system and the external environment, it is still assumed that the soil is homogeneous and has uniform thermal conductivity. Numerical studies have been conducted to predict the temperature distribution around the cable for various configurations and thermal properties of the soil. The paper presents an experimental study conducted on a scale model to investigate the heat transfer of a buried cable, with different geometrical configurations and thermal properties of the soil, and to validate a simplified model proposed by the authors in 2012 for the calculation of the thermal resistance between the underground pipe or electrical cable and the ground surface, in cases where the filling of the trench is filled with layers of materials with different thermal properties. Results show that experimental data are in good agreement with the numerical ones. -- Highlights: • Heat transfer of a buried cable has been experimentally studied on a scale model. • Different configurations and thermal properties of the soil have been tested. • Authors previously proposed a simplified model and obtained numerical results. • Experimental results and numerical ones previously obtained were in accordance

  10. Introduction of Integrity Evaluation Criteria Developing during and after fire for Nuclear Power Plant Buildings

    International Nuclear Information System (INIS)

    Lee, Jin Woo

    2016-01-01

    The first project for nuclear power plant built in Korea to taking account the engineering based approach was started on October 2015 including the whole process such as fire hazard analysis, standard fire modeling, cable tray fire with multi spurious operation, structural fire integrity evaluation, and large area fire induced air craft crash. This paper covers the brief developing scheme and roadmap focusing on structural fire evaluation criteria. The meaningful first step for developing the structural fire integrity in nuclear power plant building is started with the series of fire related sub sections mentioned in earlier section. The recognition and sufficient effort of fire research leads to set up the safe and reliable design of nuclear power plant

  11. Introduction of Integrity Evaluation Criteria Developing during and after fire for Nuclear Power Plant Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jin Woo [KEPCo, Gimcheon (Korea, Republic of)

    2016-05-15

    The first project for nuclear power plant built in Korea to taking account the engineering based approach was started on October 2015 including the whole process such as fire hazard analysis, standard fire modeling, cable tray fire with multi spurious operation, structural fire integrity evaluation, and large area fire induced air craft crash. This paper covers the brief developing scheme and roadmap focusing on structural fire evaluation criteria. The meaningful first step for developing the structural fire integrity in nuclear power plant building is started with the series of fire related sub sections mentioned in earlier section. The recognition and sufficient effort of fire research leads to set up the safe and reliable design of nuclear power plant.

  12. Self-healing cable for extreme environments

    Science.gov (United States)

    Huston, Dryver R. (Inventor); Tolmie, Bernard R. (Inventor)

    2009-01-01

    Self-healing cable apparatus and methods disclosed. The self-healing cable has a central core surrounded by an adaptive cover that can extend over the entire length of the self-healing cable or just one or more portions of the self-healing cable. The adaptive cover includes an axially and/or radially compressible-expandable (C/E) foam layer that maintains its properties over a wide range of environmental conditions. A tape layer surrounds the C/E layer and is applied so that it surrounds and axially and/or radially compresses the C/E layer. When the self-healing cable is subjected to a damaging force that causes a breach in the outer jacket and the tape layer, the corresponding localized axially and/or radially compressed portion of the C/E foam layer expands into the breach to form a corresponding localized self-healed region. The self-healing cable is manufacturable with present-day commercial self-healing cable manufacturing tools.

  13. Neutron detector with gamma compensated cable

    International Nuclear Information System (INIS)

    Warren, H.D.

    1975-01-01

    An illustrative embodiment of the invention describes a technique for essentially eliminating the radiation induced background currents that are generated in the cable that connects an ''in-core'' neutron detector to an electrical terminal that is outside of the reactor's radiation field. This undesirable radiation-induced cable current is suppressed through an appropriate selection of conductor and cable sheath materials and sizes that generally satisfy the equation: Z/sub l/sup n/d/sub l/ = Z/sub s/sup m/d/sub s/ where Z is the atomic number of the material; d is a characteristic of the size of the cable component; m and/n have values between 1 and 5 to express the electron emissivity of the cable component from photoelectric and Compton effects; l represents the conductor; and s represents the sheath. Thus, the radiation-generated electrons emitted from the conductor and the oppositely-directed electrons emitted from the inner surface of the cable sheath are mutually cancelled if this equation is satisfied. A typical cable that does meet this criterion at low temperatures has a centrally disposed Zircaloy-2 inner conductor of 0.011 inch diameter, an annular insulation of magnesium oxide powder compacted to 100 percent density, and an Inconel sheath with an outside diameter of 0.062 inch and 0.011 inch wall thickness. (auth)

  14. A nautical study of towed marine seismic streamer cable configurations

    Energy Technology Data Exchange (ETDEWEB)

    Pedersen, Egil

    1996-12-31

    This study concerns marine seismic surveying and especially the towed in-sea hardware which is dominated by recording cables (streamers) that are extremely long compared to their diameter, neutrally buoyant and depth controlled. The present work aims to examine the operations from a nautical viewpoint, and the final objective is to propose improvements to the overall efficiency of marine seismic operations. Full-scale data were gathered from seismic vessels in order to identify which physical parameters affect the dynamic motion of the towing vessel and its in-sea hardware. Experimental test programmes have been carried out, and data bases with the hydrodynamic characteristics of the test equipment have been established at speeds comparable to those used in seismic operations. A basic analysis tool to provide dynamic simulations of a seismic streamer cable has been developed by tailoring the computer program system Riflex, and the validation and accuracy of this modified Riflex system are evaluated by performing uncertainty analyses of measurements and computations. Unexpected, low-frequency depth motions in towed seismic streamer cables occasionally take place when seismic data are being acquired. The phenomenon is analysed and discussed. 99 refs., 116 figs., 5 tabs.

  15. A nautical study of towed marine seismic streamer cable configurations

    Energy Technology Data Exchange (ETDEWEB)

    Pedersen, Egil

    1997-12-31

    This study concerns marine seismic surveying and especially the towed in-sea hardware which is dominated by recording cables (streamers) that are extremely long compared to their diameter, neutrally buoyant and depth controlled. The present work aims to examine the operations from a nautical viewpoint, and the final objective is to propose improvements to the overall efficiency of marine seismic operations. Full-scale data were gathered from seismic vessels in order to identify which physical parameters affect the dynamic motion of the towing vessel and its in-sea hardware. Experimental test programmes have been carried out, and data bases with the hydrodynamic characteristics of the test equipment have been established at speeds comparable to those used in seismic operations. A basic analysis tool to provide dynamic simulations of a seismic streamer cable has been developed by tailoring the computer program system Riflex, and the validation and accuracy of this modified Riflex system are evaluated by performing uncertainty analyses of measurements and computations. Unexpected, low-frequency depth motions in towed seismic streamer cables occasionally take place when seismic data are being acquired. The phenomenon is analysed and discussed. 99 refs., 116 figs., 5 tabs.

  16. 46 CFR 111.60-5 - Cable installation.

    Science.gov (United States)

    2010-10-01

    ... REQUIREMENTS Wiring Materials and Methods § 111.60-5 Cable installation. (a) Each cable installation must meet... 46 Shipping 4 2010-10-01 2010-10-01 false Cable installation. 111.60-5 Section 111.60-5 Shipping... incorporated by reference; see 46 CFR 110.10-1), including clause 8. (b) Each cable installation made in...

  17. TMI cable tracer operation and maintenance manual for assembly 417910

    International Nuclear Information System (INIS)

    Sumstine, R.L.

    1983-11-01

    This manual provides technical information and instructions to operate and maintain the cable tracer designed for the Three Mile Island (TMI) Unit 2 Reactor Building. The TMI cable tracer was developed to allow TMI personnel to trace cables in cable trays that may be tested or sectioned for destructive examination

  18. Electrical cabling system associated at a nuclear reactor

    International Nuclear Information System (INIS)

    Dejeux, P.; Desfontaines, G.

    1988-01-01

    This cabling system for an electrical device in a nuclear reactor comprises at least a first cable issued of the device, a second cable comprising a first portion, a second portion and a third portion joining the second by a multiple quick fitting connector capable to connect at least ten second portions at ten other third portions of the second cable [fr

  19. Choice Of Computer Networking Cables And Their Effect On Data ...

    African Journals Online (AJOL)

    Computer networking is the order of the day in this Information and Communication Technology (ICT) age. Although a network can be through a wireless device most local connections are done using cables. There are three main computer-networking cables namely coaxial cable, unshielded twisted pair cable and the optic ...

  20. Non-linear stochastic response of a shallow cable

    DEFF Research Database (Denmark)

    Larsen, Jesper Winther; Nielsen, Søren R.K.

    2004-01-01

    The paper considers the stochastic response of geometrical non-linear shallow cables. Large rain-wind induced cable oscillations with non-linear interactions have been observed in many large cable stayed bridges during the last decades. The response of the cable is investigated for a reduced two...