WorldWideScience

Sample records for cable insulation scheme

  1. 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.

  2. Improvements to the electrical insulation resistance of high quality magnesia insulated cables

    International Nuclear Information System (INIS)

    Mauger, R.A.; Goodings, A.

    1984-03-01

    Mineral insulated signal cables for nuclear reactor instrumentation schemes have to meet stringent electrical insulation requirements at high temperatures. This report discusses the factors which influence the attainment of this objective and the way in which it has been reached under industrial manufacturing conditions. It emphasises the importance of moisture and gives details of the improvements achieved as a result of moisture reduction. (author)

  3. 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)

  4. Mineral insulated cables for post accident service

    International Nuclear Information System (INIS)

    McMillin, P.L.; Winkler, M.E.

    1986-01-01

    The regulatory requirement to measure the gamma radiation levels during accident conditions inside a reactor containment building is discussed. The development of a mineral-insulated cable and connector system to accurately transmit this measurement is described and a model of the response is developed

  5. Improved cable insulation for superconducting magnets

    International Nuclear Information System (INIS)

    Anerella, M.; Ghosh, A.K.; Kelly, E.; Schmalzle, J.; Willen, E.; Fraivillig, J.; Ochsner, J.; Parish, D.J.

    1993-01-01

    Several years ago, Brookhaven joined with DuPont in a cooperative effort to develop improved cable insulation for SSC superconducting dipole magnets. The effort was supported by the SSC Central Design Group and later the SSC Laboratory. It was undertaken because turn-to-turn and midplane shorts were routinely being experienced during the assembly of magnets with coils made of the existing Kapton/fiberglass (K/FG) system of Kapton film overwrapped with epoxy-impregnated fiberglass tape. Dissection of failed magnets showed that insulation disruption and punch-through was occurring near the inner edges of turns close to the magnet midplane. Coil pressures of greater than 17 kpsi were sufficient to disrupt the insulation at local high spots where the cable had been strongly compacted in the keystoning operation during cable manufacture. In the joint development program, numerous combinations of polyimide films manufactured by DuPont with varying configurations and properties (including thickness) were subjected to tests at Brookhaven. Early tests were bench trials using wrapped cable samples. The most promising candidates were used in coils and many of these promising candidates were used in coils and many of these assembled and tested as magnets in both the SSC and RHIC magnet programs currently underway. The Kapton CI (CI) system that has been adopted represents a suitable compromise of numerous competing factors. It exhibits improved performance in the critical parameter of compressive punch-through resistance as well as other advantages over the K/FG system

  6. Improved cable insulation for superconducting magnets

    International Nuclear Information System (INIS)

    Anerella, M.; Ghosh, A.K.; Kelly, E.; Schmalzle, J.; Willen, E.; Fraivillig, J.; Ochsner, J.; Parish, D.J.

    1993-01-01

    Several years ago, Brookhaven joined with DuPont in a cooperative effort to develop improved cable insulation for SSC superconducting dipole magnets. The effort was supported by the SSC Central Design Group and later the SSC Laboratory. It was undertaken because turn-to-turn and midplane shorts were routinely being experienced during the assembly of magnets with coils made of the existing Kapton/Fiberglass (K/FG) system of Kapton film overwrapped with epoxy-impregnated fiberglass tape. Dissection of failed magnets showed that insulation disruption and punch-through was occurring near the inner edges of turns close to the magnet midplane. Coil pressures of greater than 17 kpsi were sufficient to disrupt the insulation at local high spots where wires in neighboring turns crossed one another and where the cable had been strongly compacted in the keystoning operation during cable manufacture. In the joint development program, numerous combinations of polyimide films manufactured by DuPont with varying configurations and properties (including thickness) were subjected to tests at Brookhaven. Early tests were bench trials using wrapped cable samples. The most promising candidates were used in coils and many of these assembled and tested as magnets in both the SSC and RHIC magnet programs currently underway. The Kapton CI (CI) system that has been adopted represents a suitable compromise of numerous competing factors. It exhibits improved performance in the critical parameter of compressive punch-through resistance as well as other advantages over the K/FG system

  7. Crosslinking of wire and cable insulation using electron accelerators

    International Nuclear Information System (INIS)

    Feng Yongxiang; Ma Zueteh

    1992-01-01

    Radiation crosslinking of wire and cable insulation is a well-established technology that is widely used in industry. The advantages of radiation crosslinking over chemical crosslinking have helped maintain its steady growth. Since successful utilization of electron beam processing relies on the formulation of compounds used in insulation, the radiation crosslinking of various polymers is reviewed. The handling technology for crosslinking wire and cable insulation and the throughput capacity of electron beam processors are also discussed. More than 30% of the industrial electron accelerators in the world are used for the radiation crosslinking of wire and cable insulation. Prospects of increased use of electron accelerators for crosslinking of wire and cable insulation are very good. (orig.)

  8. Development mineral insulated cables for nuclear instrumentation of reactors

    International Nuclear Information System (INIS)

    Calvo, W.A.P.; Hess Junior, A.; Brito Maciel, R. de

    1990-01-01

    In-core and out-of-core neutron detectors for reactor and safety control systems are usually connected by means of mineral insulated cables. The electrical signal, either a pulse or a current, is transmitted along the cable at high temperature, pressure and radiation and should not be influenced by electromagnetic interfereces from the environment. In this paper it is presented the result of the analysis of the mechanical and electrical properties of several types of mineral insulated cables and also the design, manufacture, sealing, cable ends and their applications to nuclear detectors of various types. (author) [pt

  9. Similarity Analysis of Cable Insulations by Chemical Test

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Seog [Central Research Institute of Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of)

    2013-10-15

    As result of this experiment, it was found that FT-IR test for material composition, TGA test for aging trend are applicable for similarity analysis of cable materials. OIT is recommended as option if TGA doesn't show good trend. Qualification of new insulation by EQ report of old insulation should be based on higher activation energy of new insulation than that of old one in the consideration of conservatism. In old nuclear power plant, it is easy to find black cable which has no marking of cable information such as manufacturer, material name and voltage. If a type test is required for qualification of these cables, how could I select representative cable? How could I determine the similarity of these cables? If manufacturer has qualified a cable for nuclear power plant more than a decade ago and composition of cable material is changed with similar one, is it acceptable to use the old EQ report for recently manufactured cable? It is well known to use FT-IR method to determine the similarity of cable materials. Infrared ray is easy tool to compare compositions of each material. But, it is not proper to compare aging trend of these materials. Study for similarity analysis of cable insulation by chemical test is described herein. To study a similarity evaluation method for polymer materials, FT-IR, TGA and OIT tests were performed for two cable insulation(old and new) which were supplied from same manufacturer. FT-IR shows good result to compare material compositions while TGA and OIT show good result to compare aging character of materials.

  10. Similarity Analysis of Cable Insulations by Chemical Test

    International Nuclear Information System (INIS)

    Kim, Jong Seog

    2013-01-01

    As result of this experiment, it was found that FT-IR test for material composition, TGA test for aging trend are applicable for similarity analysis of cable materials. OIT is recommended as option if TGA doesn't show good trend. Qualification of new insulation by EQ report of old insulation should be based on higher activation energy of new insulation than that of old one in the consideration of conservatism. In old nuclear power plant, it is easy to find black cable which has no marking of cable information such as manufacturer, material name and voltage. If a type test is required for qualification of these cables, how could I select representative cable? How could I determine the similarity of these cables? If manufacturer has qualified a cable for nuclear power plant more than a decade ago and composition of cable material is changed with similar one, is it acceptable to use the old EQ report for recently manufactured cable? It is well known to use FT-IR method to determine the similarity of cable materials. Infrared ray is easy tool to compare compositions of each material. But, it is not proper to compare aging trend of these materials. Study for similarity analysis of cable insulation by chemical test is described herein. To study a similarity evaluation method for polymer materials, FT-IR, TGA and OIT tests were performed for two cable insulation(old and new) which were supplied from same manufacturer. FT-IR shows good result to compare material compositions while TGA and OIT show good result to compare aging character of materials

  11. Chemical oxidation of cable insulating oil contaminated soil

    NARCIS (Netherlands)

    Jinlan Xu,; Pancras, T.; Grotenhuis, J.T.C.

    2011-01-01

    Leaking cable insulating oil is a common source of soil contamination of high-voltage underground electricity cables in many European countries. In situ remediation of these contaminations is very difficult, due to the nature of the contamination and the high concentrations present. Chemical

  12. Polyethylene as a possible hvdc cable insulant

    Energy Technology Data Exchange (ETDEWEB)

    Hawley, W.G.; Body, R.S.; Mason, J.H.

    1966-10-01

    Many cable authorities have expressed the view that polyethylene would be attractive for this application. The dc conductivity of polyethylene is lower than that of impregnated paper, and varies less with temperature and stress. Polyethylene also has higher thermal conductivity and is resistant to moisture and electrochemical deterioration. Furthermore, processing polyethylene cables should ultimately involve lower capital and manufacturing costs. However, polyethylene has a lower limiting short circuit temperature unless it is cross linked.

  13. Insulation systems for superconducting transmission cables

    DEFF Research Database (Denmark)

    Tønnesen, Ole

    1996-01-01

    the electrical insulation is placed outside both the superconducting tube and the cryostat. The superconducting tube is cooled by liquid nitrogen which is pumped through the hollow part of the tube.2) The cryogenic dielectric design, where the electrical insulation is placed inside the cryostat and thus is kept...

  14. Corrosion of mineral insulated (MI) cables at MAPS-2

    International Nuclear Information System (INIS)

    Bora, J.S.; Babar, A.K.

    1989-01-01

    It has been experimentally verified that the cause of undesirable behaviour of mineral insulated (MI) cables at Madras Atomic Power Station Unit 2 (MAPS-2) is due to corrosion of termination. It is always possible to restore them to their normal condition by heating if degradation is due to absorption of moisture and by cutting and removing the affected portion in case of short or open failures. During extended shutdown, it is advisable to check other MI terminations and take appropriate corrective action in order to prevent failures in future. During installation MI Cables are to be heated before sealing and should never be heated after sealing. (author)

  15. Insulating materials for cables: state of the technology and future developments

    Energy Technology Data Exchange (ETDEWEB)

    Blechschmidt, H H [Hessische Elektrizitaets-A.G., Darmstadt (Germany, F.R.)

    1977-02-01

    This article gives a summary of old and new insulating materials for electrical cables. The electrical properties of some polymer insulating materials (PVC, polyethelene (PE), polymerised polyethelene (VPE), polypropylene) are compared in a table with the properties of paper insulation. The changeover from oiled paper to plastic insulation is almost complete for low voltage cables. Soft PVC is the dominant insulating material in this field. For medium voltage cables (10 kV and 20 kV supplies) and for high voltage cables (60 kV and 110 kV supplies) there is a trend to plastic PE/VPE, because these insulating materials have better electrical properties than PVC.

  16. Air insulated cables for medium and low voltage supplies of the EVU

    Energy Technology Data Exchange (ETDEWEB)

    Dienstel, S

    1977-02-01

    Air insulated cables and insulated overhead cables are electrical components, which, by the use of new insulating materials and technology, are particularly suitable for the introduction of systems for overhead power transmission plants. They combine the favorable properties of underground cables, such as compact construction and low inductance, with their high mechanical strength. The present report deals with the construction, accessories and technical properties of these cables. The constructional and operational aspects of such systems and their costs are also discussed.

  17. Time domain spectroscopy to monitor the condition of cable insulation

    International Nuclear Information System (INIS)

    Mopsik, F.I.; Martzloff, F.D.

    1989-01-01

    The use of Time Domain Spectroscopy, the measurement of dielectric constant and loss using time-domain response, the monitoring the aging of reactor cable insulation is examined. The method is presented, showing its sensitivity, accuracy and wide frequency range. The method's ability to acquire a great deal of information in a short time and its superiority to conventional single frequency data is shown. Different cable samples are examined before and after exposure to radiation and changes with exposure are clearly seen to occur. Also it is shown that a wide range of behavior can be found in different insulation systems. The requirements for performing valid measurements is presented. The need for controlled samples and correlation with other criteria for aging is discussed. 14 refs., 9 figs

  18. Optimization of electron beam crosslinking of wire and cable insulation

    International Nuclear Information System (INIS)

    Zimek, Zbigniew; Przybytniak, Grażyna; Nowicki, Andrzej

    2012-01-01

    The computer simulations based on Monte Carlo (MC) method and the ModeCEB software were carried out in connection with electron beam (EB) radiation set-up for crosslinking of electric wire and cable insulation. The theoretical predictions for absorbed dose distribution in irradiated electric insulation induced by scanned EB were compared to the experimental results of irradiation that was carried out in the experimental set-up based on ILU 6 electron accelerator with electron energy 0.5–2.0 MeV. The computer simulation of the dose distributions in two-sided irradiation system by a scanned electron beam in multilayer circular objects was performed for various process parameters, namely electric wire and cable geometry (thickness of insulation layers and copper wire diameter), type of polymer insulation, electron energy, energy spread and geometry of electron beam, electric wire and cable layout in irradiation zone. The geometry of electron beam distribution in the irradiation zone was measured using CTA and PVC foil dosimeters for available electron energy range. The temperature rise of the irradiated electric wire and irradiation homogeneity were evaluated for different experimental conditions to optimize technological process parameters. The results of computer simulation are consistent with the experimental data of dose distribution evaluated by gel-fraction measurements. Such conformity indicates that ModeCEB computer simulation is reliable and sufficient for optimization absorbed dose distribution in the multi-layer circular objects irradiated with scanned electron beams. - Highlights: ► We model wire and cables irradiation process by Monte Carlo simulations. ► We optimize irradiation configuration for various process parameters. ► Temperature rise and irradiation homogeneity were evaluated. ► Calculation (dose) and experimental (gel-fraction) results were compared. ► Computer simulation was found reliable and sufficient for process optimization.

  19. Optimization of electron beam crosslinking of wire and cable insulation

    International Nuclear Information System (INIS)

    Zimek, Z.; Przybytniak, G.; Nowicki, A.

    2011-01-01

    Complete text of publication follows. The computer simulations based on Monte Carlo method and the ModeCEB software program were carried out in connection with EB radiation set-up for crosslinking of electrical wire and cable insulation, located at the Center for Radiation Research and Technology of the Institute of Nuclear Chemistry and Technology. The theoretical predictions for absorbed dose distribution in irradiated electrical wire and cable insulation caused by scanned EB were compared to the experimental results of irradiation which were carried out in the experimental set-up based on ILU 6 electron accelerator, which is characterized by the following parameters: Electron energy 0.5-2.0 MeV; Average beam current 40-10 mA, pulse duration 400 μs; Width of scanning up to 80 cm; Scan frequency up to 50 Hz. The computer simulation of the dose distributions in two-sided irradiation system by a scanned electron beam in multilayer circular objects was performed for different process parameters; electrical wire and cable geometry (thickness of insulation layers and cupper wire diameter), type of polymer isolation, electron energy, energy spread, geometry of electron beam and electrical wire and cable distribution at irradiation zone. The geometry of electron beam distribution in irradiation zone was measured using TVA and PVC foil dosimeters for electron energy range available in ILU 6 accelerator. The temperature rise of irradiated electrical wire and irradiation homogeneity were evaluated for different experimental conditions to optimize process parameters. The obtained results of computer simulation were supported by experimental data of dose distribution based on gel-fraction measurements. Such agreement indicates that computer simulation ModeCEB is correct and sufficient for modelling of absorbed dose distribution in multi-layer circular objects irradiated with scanned electron beams. Acknowledgement: The R and D activities are supported by the European

  20. Nonlinear Dielectric Response of Water Treed XLPE Cable Insulation

    Energy Technology Data Exchange (ETDEWEB)

    Hvidsten, Sverre

    1999-07-01

    Condition assessment of XLPE power cables is becoming increasingly important for the utilities, due to a large number of old cables in service with high probability of failure caused by water tree degradation. The commercial available techniques are generally based upon measurements of the dielectric response, either by time (polarisation/depolarisation current or return voltage) or frequency domain measurements. Recently it has been found that a high number of water trees in XLPE insulated cables causes the dielectric response to increase more than linearly with increasing test voltage. This nonlinear feature of water tree degraded XLPE insulation has been suggested to be of a great importance, both for diagnostic purposes, and for fundamental understanding of the water tree phenomenon itself. The main purpose of this thesis have been to study the nonlinear feature of the dielectric response measured on watertreed XLPE insulation. This has been performed by dielectric response measurements in both time and frequency domain, numerical calculations of losses of simplified water tree models, and fmally water content and water permeation measurements on single water trees. The dielectric response measurements were performed on service aged cable samples and laboratory aged Rogowski type objects. The main reason for performing laboratory ageing was to facilitate diagnostic testing as a function of ageing time of samples containing mainly vented water trees. A new method, based upon inserting NaC1 particles at the interface between the upper semiconductive screen and the insulation, was found to successfully enhance initiation and growth of vented water trees. AC breakdown strength testing show that it is the vented water trees that reduce the breakdown level of both the laboratory aged test objects and service aged cable samples. Vented water treeing was found to cause the dielectric response to become nonlinear at a relatively low voltage level. However, the measured

  1. Compilation of radiation damage test data cable insulating materials

    CERN Document Server

    Schönbacher, H; CERN. Geneva

    1979-01-01

    This report summarizes radiation damage test data on commercially available organic cable insulation and jacket materials: ethylene- propylene rubber, Hypalon, neoprene rubber, polyethylene, polyurethane, polyvinylchloride, silicone rubber, etc. The materials have been irradiated in a nuclear reactor to integrated absorbed doses from 5*10/sup 5/ to 5*10/sup 6/ Gy. Mechanical properties, e.g. tensile strength, elongation at break, and hardness, have been tested on irradiated and non-irradiated samples. The results are presented in the form of tables and graphs, to show the effect of the absorbed dose on the measured properties. (13 refs).

  2. Built-in unit with short-circuit insulation for hermetic cable ducts

    International Nuclear Information System (INIS)

    Tschacher, B.; Gurr, W.; Kusserow, J.; Katzmarek, W.

    1984-01-01

    The invention concerns a built-in unit with short-circuit insulation for hermetic cable ducts, especially for containments of nuclear power reactors. The short-circuit insulation is achieved by an insulation plate made from radiation-resistant insulating materials of high mechanical strength

  3. Electric cable insulation pyrolysis and ignition resulting from potential hydrogen burn scenarios for nuclear containment buildings

    International Nuclear Information System (INIS)

    Berlad, A.L.; Jaung, R.; Pratt, W.T.

    1982-01-01

    Electric cable insulation in nuclear containment buildings may participate in pyrolysis and combustion processes engendered by hydrogen burn phenomena. This paper examines these pyrolysis/ignition processes of those polymeric materials present in the electric cable insulation and their possible relation to hydrogen burn scenarios

  4. Application of mineral insulated cable (MIC) in Tokamak fusion reactor

    International Nuclear Information System (INIS)

    Luo Tianyong; Jiang Jiaming; Cen Yishun

    2014-01-01

    To avoid the instability of plasma and achieve some experimental tasks in Tokamak fusion reactor, many in-vessel coils are designed such as the coils to mitigate the effect of Edge Localized Modes (ELMs coils) and the coils to provide vertical stabilization (VS coils). The in-vessel location presents special challenges in terms of nuclear radiation and temperature, and requires the use of mineral-insulated conductors. The in-vessel coils in ITER are designed to be Mineral-insulated Cable (MIC) with three-layer structures. The inner is hollow-core tube made by OFHC or CuCrZr, the middle is the insulation layer made by Mgo and the outer is the jacket by SS316L or Inconel 718. To control the effect of Edge Localized Modes and vertical instability of plasma, the MIC in-vessel coils shall be used in HL-2M. More details about the application of MIC in Tokamak fusion reactor will be shown in this report. (authors)

  5. THE EFFICACY OF THE CABLES OF 6–110 KW WITH XLPE INSULATION. Part 2

    Directory of Open Access Journals (Sweden)

    M. A. Korotkevich

    2017-01-01

    Full Text Available The assessment of the suitability of cables of 6–110 kW with XLPE insulation in comparison with cables of the same voltage but possessing paper-oil insulation has been fulfilled on the basis of the method of multi-objective optimization that makes it possible to account not only the quantitative characteristics (of reduced costs, but also qualitative ones. As an indicator of the reliability of the cable line the maximum mean time to failure (the value inversely proportional to the parameter of succession of failures, which is an order more for cable lines with XLPE insulation than for cable lines with paper insulation, is adopted. A comprehensive assessment of the convenience of installation of cable lines revealed that the installation of cable with XLPE insulation features a 1.2–1.6 times easier installation as compared to three-wire (voltage 10 kW and 1.4 times easier installation as compared to single-core oil-filled cables (voltage of 110 kW. The efficacy of the cables 6–110 kW with XLPE insulation is proved on the basis on the method of multi-objective optimization, that took into account as the costs for the construction and operation of cable lines and the reliability of its operation, ease of its installation and other quality indicators. If the goals taken into account are considered as equally important, the polyethylene-insulated cables for a voltage of 10–110 kW is more efficient as compared to three-wire (voltage 10 kW and solid (110 kW cables with paper insulation. Herewith, the cost of the cable with XLPE insulation may exceed the cost of cable with paper insulation up to two times. If the most important aim is to provide the minimum reduced costs for the construction and operation of the cable line, the use of cables with XLPE insulation for voltage of 10 kW is most advisable in individual cases.

  6. Study of the degradation of the insulation of HV cables with PVC insulation

    International Nuclear Information System (INIS)

    Quennehen, Pierre

    2014-01-01

    The observed decrease in the resistivity of the PVC insulation of some high voltage unipolar cables led to question their ability to perform their function. Provide answers concerning in particular the origin of the variation in resistivity and the impact on the dielectric strength were the objectives of this study. The characterizations were carried on cables withdrawn from service whose properties had changed during their use. Physico-chemical characterization (IR microscopy, UV spectroscopy, SEM - EDX and coulometry) showed that aging of the cable resulted from a mechanism of dehydro-chlorination. The presence of two modes of electric conduction in the material was observed: electronic conduction at a low temperature (≤ -10 C) and ionic conduction at room temperature and beyond. The presence of these two modes of conduction is consistent with the mechanism of dehydro-chlorination. In contrast to an Arrhenius law, artificial aging showed a threshold effect in the thermal activation of the mechanism at the origin of the resistivity drop. The dielectric strength of the cable has been confirmed by tests at voltages or temperatures well beyond the nominal values. Measurements of differential scanning calorimetry (DSC) showed occasional more or less pronounced over-heatings that correlate with the resistivity drops, and can therefore be considered as being at the origin of the observed evolutions. (author)

  7. Certificateless Key-Insulated Generalized Signcryption Scheme without Bilinear Pairings

    Directory of Open Access Journals (Sweden)

    Caixue Zhou

    2017-01-01

    Full Text Available Generalized signcryption (GSC can be applied as an encryption scheme, a signature scheme, or a signcryption scheme with only one algorithm and one key pair. A key-insulated mechanism can resolve the private key exposure problem. To ensure the security of cloud storage, we introduce the key-insulated mechanism into GSC and propose a concrete scheme without bilinear pairings in the certificateless cryptosystem setting. We provide a formal definition and a security model of certificateless key-insulated GSC. Then, we prove that our scheme is confidential under the computational Diffie-Hellman (CDH assumption and unforgeable under the elliptic curve discrete logarithm (EC-DL assumption. Our scheme also supports both random-access key update and secure key update. Finally, we evaluate the efficiency of our scheme and demonstrate that it is highly efficient. Thus, our scheme is more suitable for users who communicate with the cloud using mobile devices.

  8. Finite Element Modeling in 3D of the Impact of Superfluid Helium Filled Micro-channels on the Heat Transfer through LHC Type Cable Insulation

    CERN Document Server

    Bielert, E; ten Kate, H

    2012-01-01

    For a future luminosity upgrade of CERN’s Large Hadron Collider, a drastically improved heat removal in the inner triplet quadrupole magnets is required. One of the necessary improvements involves the cable insulation. A porous all-polyimide insulation scheme has been proposed recently. Essentially the insulation features a network of micro channels filled with superfluid helium that significantly increases the heat transfer through the insulation layer. A three dimensional Finite Element model required to simulate and study the enhanced heat transfer through the micro channels is presented here. The thermal coupling between heated cable and helium as well as the heat flux through the micro-channels are investigated. The model is validated by comparison of results with published measured data. Finally a sensitivity analysis is performed concerning the stability of the cables in magnet windings.

  9. Application of optical diagnosis to aged low-voltage cable insulation in nuclear plants

    International Nuclear Information System (INIS)

    Katagiri, Junichi; Takezawa, Yoshitaka; Shouji, Hiroshi

    2008-01-01

    We have developed a novel non-destructive optical diagnosis technique for low-voltage cable insulations used in nuclear power plants. The key features of this diagnosis are the use of two wavelengths to measure the change in reflective absorbance (ΔA R ), the use of polarized light to measure crystallinity and the use of element volatilizing to measure fluorescence. Chemical kinetics is used to predict the lifetimes of the cable insulations. When cable insulations darken and harden by time degradation, the ΔA R and depolarization parameters increase. This means that the cross-linking density in the cable insulations increases due to deterioration reactions. When the cross-linking density of insulation increases, its elasticity, corresponding to the material's life, increases. Similarly, as the crystallinity increases due to the change in the high-order structure of the insulating resin caused by irradiation, its elongation property decreases. The elongation property of insulation is one of the most important parameters that can be used to evaluate material lifetimes, because it relates to elasticity. The ΔA R correlated with the elongation property, and the correlation coefficient of an accelerated experiment using model pieces was over 0.9. Thus, we concluded that this optical diagnosis should be applied to evaluate the degradation of cable insulations used in nuclear power plants. (author)

  10. Effect of antioxidants on aging of nuclear plant cable insulation

    International Nuclear Information System (INIS)

    Reynolds, A.B.; Ray, J.W.; Wlodkowski, P.A.

    1991-01-01

    The effects of various antioxidants and antioxidant concentrations on the radiation and thermal stability of EPDM and XLPE polymers used for insulation of electric cable in nuclear power plants were measured. The objective was to determine if particular antioxidants could be identified as being especially effective for stabilization against radiation aging and combined thermal and radiation aging. Elongation to rupture was used as the measure of stability. Materials were irradiated to doses up to 2 MGy (200 Mrad) at a dose rate of 200 to 300 Gy/h in the Cobalt-60 Gamma Irradiation Facility at the University of Virginia. All of the antioxidants tested, which were known to provide excellent thermal stability, also provided good stability for radiation aging and combined thermal/radiation aging, although small differences between antioxidants were noted. No antioxidant or antioxidant combination was identified as being especially outstanding. Stabilization against radiation increased with increasing antioxidant concentration, but this trend was not observed for thermal aging. Damage from thermal and radiation aging was superposable. 9 refs., 16 figs., 12 tabs

  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. The insulation coordination and surge arrester design for HTS cable system in Icheon substation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hansang, E-mail: Hansang80@korea.ac.kr [School of Railway and Electrical Engineering, Kyungil University, Hayang-eup, Gyeongsan-si, Gyeongsangbuk-do 712-701 (Korea, Republic of); Yoon, Dong-Hee [Department of New and Renewable Energy, Kyungil University, Hayang-eup, Gyeongsan-si, Gyeongsangbuk-do 712-701 (Korea, Republic of); Lee, Seung-Ryul [Korea Electrotechnology Research Institute, Naeson-dong, Uiwang-si, Gyeonggi-do 437-080 (Korea, Republic of); Yang, Byeong-Mo [Korea Electric Power Research Institute, Munji-dong, Yuseong-gu, Daejeon 305-760 (Korea, Republic of); Jang, Gilsoo, E-mail: gjang@korea.ac.kr [School of Electrical Engineering, Korea University, Anam-dong 5-ga, Seongbuk-gu, Seoul 136-713 (Korea, Republic of)

    2013-01-15

    Highlights: ► It is necessary to study lightning response of the HTS cable. ► The analytic model has been developed for the HTS cable in the Icheon substation. ► Well-designed surge arrester has been verified through PSCAD/EMTDC simulations. -- Abstract: This paper proposes an insulation coordination and surge arrester design for HTS (High-Temperature Superconducting) cable system in Icheon substation in Korea. In the aspect of the economic analysis, since the HTS cable is very expensive, the insulation coordination to prevent the dielectric breakdown caused by the lightning surge should be considered carefully. Also, in the aspect of the power system reliability, since the HTS cable has much more capacity compared than conventional power cables and the ripple effect from the HTS cable failure may lead to the wide area blackout, an intensive study for insulation coordination from lightning surge is one of the most important considerations. In this paper, the insulation coordination for lightning surge is verified using HTS cable and power equipment models and the design of the proper surge arrester is proposed.

  13. 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.

  14. Evaluation of diagnostic technique for degradation of low-voltage electric cables with silicone rubber insulator

    International Nuclear Information System (INIS)

    Mikami, Masao

    2005-01-01

    As a part of countermeasures against ageing problems of nuclear power plants, it is requested to establish non-destructive diagnostic technique for their degradation of low voltage electric cables and assessment standard of their life. Having aimed at investigating the degradation of low-voltage electric cable with silicone rubber insulator, change of its surface hardness at elevated temperature were measured by indenter modules. Moreover, we also measured the elongation at break, which is regarded as general degradation index of electric cables, and the surface hardness with a micro hardness meter. Consequently, it is seen that the indenter modulus measurement is (1) capable to obtain general feature of the thermal degradation of silicone rubber insulator, (2) applicable to diagnose the degree of degradation of the electric cable by converting the result to elongation at break, (3) well correlated with the hardness measurement of the electric cable with the micro hardness meter. (author)

  15. Electrical Insulation of 500-m High-Tc Superconducting Power Cable

    International Nuclear Information System (INIS)

    Takahashi, T; Ichikawa, M; Suzuki, H; Okamoto, T; Akita, S; Mukoyama, S; Yagi, M; Maruyama, S; Kimura, A

    2006-01-01

    Electrical insulation is one of the essential technologies for the electric power apparatus. Determination of testing voltages and design method of the electrical insulation layer are inextricably linked each other, and are critical to developing and realizing a cold dielectric (CD) type high-Tc superconducting (HTS) power cable. The authors had proposed the electrical insulation design method with concepts of partial discharge-free designs for ac voltage condition. This paper discusses the testing voltages for a 77 kV 1000 A HTS power cable with a length of 500 m, and describes results of various voltage withstand test. As a result, it is concluded that the proposed electrical insulation design method is appropriate for the HTS power cable

  16. Influence of water trees on breakdown voltage of polymeric cables insulations

    Energy Technology Data Exchange (ETDEWEB)

    Stancu, Cristina [INCDIE ICPE CA, Bucharest (Romania); Notingher, Petru V.; Plopeanu, Mihai Gabriel [Politehnica University of Bucharest, Bucharest (Romania)

    2011-07-01

    In a previous paper was shown that water trees development modifies considerably the electric field repartition, which increases significantly in the vicinity of treed areas. In order to find the water trees influence on the breakdown voltage, in the present paper, an experimental study on model cables insulated with low density polyethylene is done. In insulation samples, water trees with various dimensions and densities were developed. For the reduction of the test duration, an electric field with a higher frequency (3-5 kHz) was used. For breakdown voltage measurement an automatic setup was realized. For each value of the ageing time the dimensions and densities of water trees and breakdown voltage were measured and the dependency of the breakdown voltage with these quantities were analysed. The results show a significant reduction of the breakdown voltage of treed cables insulations compared to un-treed ones. Key words: polyethylene, water treeing, electric field, breakdown, power cables.

  17. Heat transfer through the flat surface of Rutherford superconducting cable samples with novel pattern of electrical insulation immersed in He II

    Science.gov (United States)

    Strychalski, M.; Chorowski, M.; Polinski, J.

    2014-05-01

    Future accelerator magnets will be exposed to heat loads that exceed even by an order of magnitude presently observed heat fluxes transferred to superconducting magnet coils. To avoid the resistive transition of the superconducting cables, the efficiency of heat transfer between the magnet structure and the helium must be significantly increased. This can be achieved through the use of novel concepts of the cable’s electrical insulation wrapping, characterized by an enhanced permeability to helium while retaining sufficient electrical resistivity. This paper presents measurement results of the heat transfer through Rutherford NbTi cable samples immersed in a He II bath and subjected to the pressure loads simulating the counteracting of the Lorentz forces observed in powered magnets. The Rutherford cable samples that were tested used different electrical insulation wrapping schemes, including the scheme that is presently used and the proposed scheme for future LHC magnets. A new porous polyimide cable insulation with enhanced helium permeability was proposed in order to improve the evacuation of heat form the NbTi coil to He II bath. These tests were performed in a dedicated Claudet-type cryostat in pressurized He II at 1.9 K and 1 bar.

  18. Microscopic Void Detection for Predicting Remaining Life in Electric Cable Insulation

    International Nuclear Information System (INIS)

    Horvath, David A.; Avila, Steven M.

    2003-01-01

    A reliable method of testing for remaining life in electric cable insulation has continued to elude the nuclear industry as it seeks to extend the life and license of its nuclear stations. Until recently, a trendable, measurable electrical property has not been found, and unexpected cable failures continue to be reported. Most reliable approaches to date rely on monitoring mechanical properties, which are assumed to degrade faster than the insulation's electrical properties. This paper introduces a promising technique based on void characterization, which is dependent on an electrical property related to dielectric strength. A relationship between insulation void characteristics (size and density) and the onset of partial discharge is known to exist. A similar relationship can be shown between void characteristics and unacceptable leakage currents (another typical cable failure criterion). For low-voltage cables, it is believed void content can be correlated to mechanical property degradation.This paper will report on an approach for using void information, research results showing the existence of trendable void characteristics in commonly used electric insulation materials, and techniques for detecting the voids (both laboratory- and field-based techniques). Acoustical microscopy was found to be potentially more suitable than conventional ultrasound for nondestructive in situ detection and monitoring of void characteristics in jacketed multiconductor insulation while ignoring the jacket. Also, optical and scanning electron microscope techniques will play an essential role in establishing the database necessary for continued development and implementation of this promising technique

  19. Safety research of insulating materials of cable for nuclear power generating station

    Science.gov (United States)

    Lee, C. K.; Choi, J. H.; Kong, Y. K.; Chang, H. S.

    1988-01-01

    The polymers PE, EPR, PVC, Neoprene, CSP, CLPE, EP and other similar substances are frequently used as insulation and protective covering for cables used in nuclear power generating stations. In order to test these materials for flame retardation, environmental resistance, and cable specifications, they were given the cable normal test, flame test, chemical tests, and subjected to design analysis and loss of coolant accident tests. Material was collected on spark tests and actual experience standards were established through these contributions and technology was accumulated.

  20. Current redistribution in cables made of insulated, soldered, or oxidized strands

    International Nuclear Information System (INIS)

    Turck, B.

    1979-07-01

    Current redistributions are compared in cables made of insulated strands, soldered, or oxidized strands and insulated strands with periodic joints. After discussing the different current redistributions in the cases of a rapidly changing current and a dc current, several particular situations are investigated: what happens if a strand is broken, or if a local normal zone appears that does not affect all the strands equally, the detection of this normal zone, and the influence of short circuits between strands

  1. Suppression of discharge breakdown of polyethylene insulation during electron beam irradiation to power cable

    International Nuclear Information System (INIS)

    Sasaki, T.; Hosoi, F.; Kasai, N.; Hagiwara, M.

    1981-01-01

    In an attempt to apply the electron beam process to the crosslinking procedure for polyethylene insulation of high tension power cables, the suppression of discharge breakdown during irradiation has been investigated in the presence of crosslinking agents. Alkylamines of strong basicity and secondary or tertiary alcoholamines were found to be effective additives to suppress the discharge breakdown. The retardation of crosslinking by amines was minimized by reducing the amount of an amine and adding an alcohol instead. Polyethylene compounds contaning crosslinking agents, amines and alcohols which gave properties suitable for insulating a cable were obtained. The feasibility of these results are ascertained by irradiating cable specimens of a 22 kV class. (author)

  2. Cable Insulation Breakdowns in the Modulator with a Switch Mode High Voltage Power Supply

    CERN Document Server

    Cours, A

    2004-01-01

    The Advanced Photon Source modulators are PFN-type pulsers with 40 kV switch mode charging power supplies (PSs). The PS and the PFN are connected to each other by 18 feet of high-voltage (HV) cable. Another HV cable connects two separate parts of the PFN. The cables are standard 75 kV x-ray cables. All four cable connectors were designed by the PS manufacturer. Both cables were operating at the same voltage level (about 35 kV). The PS’s output connector has never failed during five years of operation. One of the other three connectors failed approximately five times more often than the others. In order to resolve the failure problem, a transient analysis was performed for all connectors. It was found that transient voltage in the connector that failed most often was subjected to more high-frequency, high-amplitude AC components than the other three connectors. It was thought that these components caused partial discharge in the connector insulation and led to the insulation breakdown. Modification o...

  3. Updated Aging Assessment Approach and Use with Electric Cable Insulation

    International Nuclear Information System (INIS)

    Horvath, David A.; Colaianni, R. Paul

    2003-01-01

    The service life of nuclear power plant equipment may include operation beyond the original design or qualified life. A technical basis is necessary to demonstrate that critical equipment is capable of continued safe operation for any life extension and renewed license term. Such a technical basis is also useful in addressing initial license term aging degradation, age-related failures, and maintenance issues. Early approaches for addressing aging effects developed for environmental qualification programs in the 1980s were incorporated into the Institute of Electrical and Electronic Engineers' (IEEE) IEEE Std. 1205-1993. However, subsequently, a number of events (including promulgation of the Maintenance Renewal Rule, the new License Renewal Rule, and initial plant owner submittals of License Renewal applications) have resulted in improved aging management approaches, which focus on addressing aging effects rather than attempting to identify and mitigate every possible aging mechanism.An example of a major issue facing nuclear power plants as they mature is the general health of the plant electrical cables. This issue came to the forefront as plants began preparing for license renewal, which requires an evaluation of cables to demonstrate that they will perform their function 20 yr beyond the original 40-yr license period. When the two lead plants started preparing for license renewal, there was no generally accepted approach to the bulk evaluation of plant cables, and there were many who thought it not possible to perform a complete plant cable evaluation. The approaches that emerged from the lead plant reviews demonstrated that an assessment of the general health of plant cables could be performed.IEEE's Nuclear Power Engineering Committee recognized the need to capture these improved approaches. A 2 1/2-yr effort of the IEEE Subcommittee-3 Working Group 3.4 culminating in IEEE Std. 1205-2000 is the consensus of representatives from the two lead license renewal

  4. Microwave heating of electric cable insulated wires before their impregnation with a hydrophobic material

    Energy Technology Data Exchange (ETDEWEB)

    Niculae, D; Mihailescu, A [Romanian Electricity Authority (Romania); Indreias, I; Martin, D [Institute of Atomic Physics, Bucharest (Romania); Margaritescu, A [ICPE Electrostatica, Bucharest, (Romania); Zlatonovici, D

    1998-12-31

    Underground insulated telecommunication cables must be impregnated with a hydrophobic material in order to prevent water penetration damage. To do so, the cable wire bundle must be heated to a temperature of 60 to 90 degrees C to ensure proper fluidity of the hydrophobic material that must fill the free spaces between the copper wires of the telephone cable. This paper described the microwave heating method of the wires before their impregnation. A cylindrical applicator was designed to perform a telephone bundle heating test. 800 W of microwave power were used on a telephone cable made up of 800 wires of 0.4 mm in diameter. A uniform heating was obtained throughout the section. Microwave heating was also found to be 53 per cent more energy efficient than hot air heating. 4 refs., 4 figs.

  5. Protection of insulated cables and lines in case of overload

    Energy Technology Data Exchange (ETDEWEB)

    Goltz, M

    1983-01-01

    After DIN 57100 Part 430/VDE 0100 part 430 for the protection of lines and cables was published in June 1981, the discussion flared up again whether this DIN/VDE-regulation is sufficient. Some papers have already been published on the right selection and arrangement of overload protection under normal operational conditions. The aim of this contribution is to explain abnormal operational conditions which are dealt with in DIN 57100 part 430/VDE 0100 part 430 in comments and the annex, and to supply some help for planning and projecting.

  6. Protection for low current superconducting coils wound with insulated strand cable

    International Nuclear Information System (INIS)

    Satti, J.

    1980-09-01

    The insulated strand cable concept for winding of low current superconducting coil leads to an ideal quench protection by induction coupling. A superconducting secondary loop was made within a cable of a 6.2 Henry dipole coil. When quenching occurred, current was induced in the secondary strand above the critical value. The normal strand quenched the whole cable due to good thermal contact. The secondary loop works as a heater turned on as the wire becomes normal throughout the coil. With a well spread quench, the energy dissipation density is decreased thus preventing local burnout. The mechanism is possible because of close coupling that is present in the insulated cable as in bifilar winding. For the coil tested a 12 strand cable was used, thus a favorable 11 to 1 turn ratio was obtained for the primary to secondary. The superconductor in the secondary had a lower resistance until the critical current was achieved. A theoretical explanation is described for a simplified circuit. Test on the dipole coil with four individual shells showed that the one shell protected with the induced coupling heater always had a more rapid reduction of current. The induced coupling heater tested and explained in this paper works automatically and does not rely on mechanical or electrical devices

  7. Tailored sPP/Silica Nanocomposite for Ecofriendly Insulation of Extruded HVDC Cable

    Directory of Open Access Journals (Sweden)

    Bin Dang

    2015-01-01

    Full Text Available Cross-linked polyethylene (XLPE is a thermosetting material that cannot be recycled at the end of its lifetime. This study investigated the potential of syndiotactic polypropylene (sPP/silica as an ecofriendly extruded insulation system for HVDC cables. We investigated the morphology, Fourier transform infrared, and thermal, thermomechanical, and electrical behaviors of sPP modified with 0.5–3% nanosilica. We found that the silica/sPP nanocomposite without cross-linking offered a suitable mechanical modulus at room temperature and sufficient intensity at high temperatures, and adding nanosilica modified by a silane coupling agent to the sPP resulted in significant DC resistivity and space charge improvement. The optimal nanosilica content in the sPP was determined by balancing the mechanical and thermomechanical characteristics and the DC resistivity. The sPP/silica nanocomposite reported here shows great potential as a candidate insulation material for future ecofriendly extruded HVDC cables.

  8. Research on material of high temperature cable and wire insulation by γ-rays

    International Nuclear Information System (INIS)

    Jia Shaojin; Zhang Zhicheng; Xu Xiangling; Ge Xuewu; Ye qiang; Wang Feng

    2000-01-01

    Radiation-crosslinking improves a number of essential properties of polymers, so the high -temperature-resistance of polyethylene (PE) was increased by irradiation. The national products of High -density-polyethylene (HDPE), crosslinking promoters, flame-retardant, antioxidants, Si rubber, and Ethylene-propylene-monomer (EPDM) were used as cable insulation. After -irradiation, thermal-endurance can get above 135, and high flame retardance was firmed, Oxygen index can get above 32 by crosslinking

  9. Microstructural characterization of XLPE electrical insulation in power cables: determination of void size distributions using TEM

    International Nuclear Information System (INIS)

    Markey, L; Stevens, G C

    2003-01-01

    In an effort to progress in our understanding of the ageing mechanisms of high voltage cables submitted to electrical and thermal stresses, we present a quantitative study of voids, the defects which are considered to be partly responsible for cable failure. We propose a method based on large data sets of transmission electron microscopy (TEM) observations of replicated samples allowing for the determination of void concentration distribution as a function of void size in the mesoscopic to microscopic range at any point in the cable insulation. A theory is also developed to calculate the effect of etching on the apparent size of the voids observed. We present the first results of this sort ever obtained on two industrial cables, one of which was aged in an AC field. Results clearly indicate that a much larger concentration of voids occur near the inner semiconductor compared to the bulk of the insulation, independently of ageing. An effect of ageing can also be seen near the inner semiconductor, resulting in an increase in the total void internal surface area and a slight shift of the concentration curve towards larger voids, with the peak moving from about 40 nm to about 50 nm

  10. Steady-state heat transfer in He II through porous superconducting cable insulation

    International Nuclear Information System (INIS)

    Baudouy, B.J.P.; Juster, F.P.; Meuris, C.; Vieillard, L.

    1996-01-01

    The LHC program includes the study of thermal behavior of the superconducting cables wound in the dipole magnet cooled by superfluid helium (He II). Insulation of these superconducting cables forms the major thermal shield hindering the He II cooling. This is particularly a problem in magnets which are subjected to thermal loads. To investigate He II heat transfer processes an experimental model has been realized which creates a one-dimensional heat transfer in such media. Insulation is generally realized by wrapping around the superconducting cable a combination of different kind of Kapton reg-sign tapes, fiber-glass impregnated by epoxy resin or Kevlar reg-sign fiber tapes. Steady-state heat transfer in He II through these multi-layer porous slabs has been analyzed. Experimental results for a range of heat flux show the existence of different thermal regimes related to He II. It is shown that the parameters of importance are a global geometrical factor which could be considered as an equivalent open-quotes permeabilityclose quotes related to He II heat transfer, the transfer function f(T) of He II and the thermal conductivity of the slab. The authors present and analyze results for different insulations as a function of the temperature

  11. Tracking of Nuclear Cable Insulation Polymer Structural Changes using the Gel Fraction and Uptake Factor Method

    Energy Technology Data Exchange (ETDEWEB)

    Correa, Miguel; Huang, Qian; Fifield, Leonard S.

    2018-04-11

    Cross-linked polyethylene (XLPE) cable insulation samples were exposed to heat and gamma radiation at a series of temperatures, dose rates, and exposure times to evaluate the effects of these variables on material degradation. The samples were tested using the solvent incubation method to collect gel fraction and uptake factor data in order to assess the crosslinking and chain scission occurring in polymer samples with aging. Consistent with previous reports, gel fraction values were observed to increase and uptake factor values to decrease with radiation and thermal exposure. The trends seen were also more prominent as exposure time increased, suggesting this to be a viable method of tracking structural changes in the XLPE-insulated cable material over extended periods. For the conditions explored, the cable insulation material evaluated did not indicate signs of anomalous aging such as inverse temperature effect in which radiation-induced aging is more severe at lower temperature. Ongoing aging under identical radiation conditions and at lower temperature will further inform conclusions regarding the importance of inverse temperature effects for this material under these conditions.

  12. Treeing phenomenon of thermoplastic polyethylene blends for recyclable cable insulation materials

    Science.gov (United States)

    Li, Lunzhi; Zhang, Kai; Zhong, Lisheng; Gao, Jinghui; Xu, Man; Chen, Guanghui; Fu, Mingli

    2017-02-01

    Owing to its good recyclability and low processing energy consumption, non-crosslinked polyethylene blends (e.g. LLDPE-HDPE blends) are considered as one of potential environmental-friendly substitutions for crosslinked polyethylene (XLPE) as cable insulation material. Although extensive work has been performed for measuring the basic dielectric properties, there is a lack of the investigations on the aging properties for such a material system, which hinders the evaluation of reliability and lifetime of the material for cable insulation. In this paper, we study the electric aging phenomenon of 0.7LLDPE-0.3HDPE blending material by investigating the treeing behavior, and its comparison with XLPE and LLDPE. Treeing tests show that the 0.7LLDPE-0.3HDPE blends have lower probability for treeing as well as smaller treeing dimensions. Further thermal analysis and microstructure study results suggest that the blends exhibit larger proportion of thick lamellae and higher crystallinity with homogeneously-distributed amorphous region, which is responsible for good anti-treeing performance. Our finding provides the evidence that the 0.7LLDPE-0.3HDPE blends exhibits better electric-aging-retardance properties than XLPE, which may result in a potential application for cable insulation.

  13. Treeing phenomenon of thermoplastic polyethylene blends for recyclable cable insulation materials

    Directory of Open Access Journals (Sweden)

    Lunzhi Li

    2017-02-01

    Full Text Available Owing to its good recyclability and low processing energy consumption, non-crosslinked polyethylene blends (e.g. LLDPE-HDPE blends are considered as one of potential environmental-friendly substitutions for crosslinked polyethylene (XLPE as cable insulation material. Although extensive work has been performed for measuring the basic dielectric properties, there is a lack of the investigations on the aging properties for such a material system, which hinders the evaluation of reliability and lifetime of the material for cable insulation. In this paper, we study the electric aging phenomenon of 0.7LLDPE-0.3HDPE blending material by investigating the treeing behavior, and its comparison with XLPE and LLDPE. Treeing tests show that the 0.7LLDPE-0.3HDPE blends have lower probability for treeing as well as smaller treeing dimensions. Further thermal analysis and microstructure study results suggest that the blends exhibit larger proportion of thick lamellae and higher crystallinity with homogeneously-distributed amorphous region, which is responsible for good anti-treeing performance. Our finding provides the evidence that the 0.7LLDPE-0.3HDPE blends exhibits better electric-aging-retardance properties than XLPE, which may result in a potential application for cable insulation.

  14. New piercing for insulated cables in underground networks; Novos conectores compactos perfurantes ('piercings') para cabos isoldados em redes subterraneas

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Fernando; Corral, Horacio [Tradis, SP (Brazil). E-mail: tradis@mandic.com.br

    1999-07-01

    This work presents a tap and transition connection in low voltage protected underground cables. This connection allows tapping for clients or branchings from a main energized cables. The compact connectors range various types of insulated cables protected and under grounded in a simple way. The work analysed the advantages of using two components polyurethane resins for the tapping protection and insulation restoring.

  15. Analysis of electrical tree propagation in XLPE power cable insulation

    International Nuclear Information System (INIS)

    Bao Minghui; Yin Xiaogen; He Junjia

    2011-01-01

    Electrical treeing is one of the major breakdown mechanisms for solid dielectrics subjected to high electrical stress. In this paper, the characteristics of electrical tree growth in XLPE samples have been investigated. XLPE samples are obtained from a commercial XLPE power cable, in which electrical trees have been grown from pin to plane in the frequency range of 4000-10,000 Hz, voltage range of 4-10 kV, and the distances between electrodes of 1 and 2 mm. Images of trees and their growing processes were taken by a CCD camera. The fractal dimensions of electric trees were obtained by using a simple box-counting technique. The results show that the tree growth rate and fractal dimension was bigger when the frequency or voltage was higher, or the distance between electrodes was smaller. Contrary to our expectation, it has been found that when the distance between electrodes changed from 1 to 2 mm, the required voltage of the similar electrical trees decreased only 1or 2 kV. In order to evaluate the difficulties of electrical tree propagation in different conditions, a simple energy threshold analysis method has been proposed. The threshold energy, which presents the minimum energy that a charge carrier in the well at the top of the tree should have to make the tree grow, has been computed considering the length of electrical tree, the fractal dimension, and the growth time. The computed results indicate that when one of the three parameters of voltage, frequency, and local electric field increase, the trends of energy threshold can be split into 3 regions.

  16. Effect of oxygen in the simulated LOCA environments of the degradation of cable insulating materials

    International Nuclear Information System (INIS)

    Kusuma, Y.; Okada, S.; Itoh, M.; Yagi, T.; Yoshikawa, M.; Yoshida, K.; Machi, S.; Tamura, N.; Kawakami, W.

    1990-01-01

    Five kinds of insulating and jacketing materials for the cables used in nuclear power plants were exposed to various LOCA environments of both simultaneous and sequential methods using SEAMATE-II. Experimental conditions of the simultaneous LOCA tests were done at different radiation dose rate, steam temperature and amount of air added to the LOCA environments. The sequential tests consist of two stages, that is, pre-irradiation and subsequent steam/spray exposure. Pre-irradiation conditions and subsequent steam/spray exposure conditions of the sequential LOCA tests are systematically changed in order to find appropriate conditions which can bring about the degradation of same degree to those obtained for various simultaneous LOCA simulations. Tensile properties, insulating resistance and water sorption of the insulating materials exposed to various LOCA environments are measured and discussed. (author). 11 refs, 19 figs, 3 tabs

  17. A Study of the Equality of Cable Insulations by comparing aging trend using an Oxidation Induction Time Measurement Test

    International Nuclear Information System (INIS)

    Park, Kyungheum; Bhang, Keugjin; Jeong, Sunchul

    2014-01-01

    Usually, the environmental qualification test is carried out by the cable manufacturer and the test report is presented while the cable manufacturer supplies the tested cables in nuclear power plant. If a cable manufacturer has environmentally qualified a cable for nuclear power plant more than a decade ago and the composition of the cable material is same, is it acceptable to use the old EQ report for recently manufactured cable? Even though the manufacturer insists the composition of the tested cable and recently manufactured cable's material are same, there can some questions or opposing opinions for two cables, tested cable and recently manufactured cable's equality. In this case, how can I determine the equality for the two cables? It is well known method to use FT-IR to determine the similarity of cable materials. FT-IR is easy tool to compare compositions of each material. But FT-IR method is not proper to compare aging trend of these materials. Oxidation induction time(OIT) testing is a technique that can be used to evaluate aging of organic materials and life assessment technique for cables used in nuclear power plants. In this paper, I studied the OIT technique to compare aging trend for the tested cable and recently manufactured cable to determine the equality for the two cables. To study a equality analysis for cable materials, OIT measurement tests were performed for two cable insulation(produced in 1995 and produced in 2013) which were supplied from same manufacturer. The two cables were irradiated up to 40 Mrad to simulate normal 40 years and thermally aged for 144 hours at 170 .deg. C equals to 40 years qualified life at 90 .deg. C. The OIT measurement were made in order to compare aging trends of the '95 cable and the '13 cable, the test were performed for three sequential steps; initial, after Normal Radiation and after Thermal Aging. The OIT measurement results at the temperature of 225 .deg. C showed very similar degradation

  18. Development of a method of partial discharge detection in extra-high voltage cross-linked polyethylene insulated cable lines

    International Nuclear Information System (INIS)

    Katsuta, G.; Toya, A.; Muraoka, K.; Endoh, T.; Sekii, Y.; Ikeda, C.

    1992-01-01

    This paper reports that deterioration in the insulation performance of extra-high voltage XLPE cables is believed to be attributable to the deterioration caused by partial discharges. In the authors study, after using an XLPE cable to investigate the behavior of partial discharges under various adverse conditions, we succeeded in developing a highly sensitive new method of measuring partial discharge in XLPE cable lines. Partial discharges in a 275 kV XLPE cable live line has been measured using this newly developed method. As a result, a detection sensitivity of 1 pC has been achieved

  19. Analysis of Insulating Material of XLPE Cables considering Innovative Patterns of Partial Discharges

    Directory of Open Access Journals (Sweden)

    Fernando Figueroa Godoy

    2017-01-01

    Full Text Available This paper aims to analyze the quality of insulation in high voltage underground cables XLPE using a prototype which classifies the following usual types of patterns of partial discharge (PD: (1 internal PD, (2 superficial PD, (3 corona discharge in air, and (4 corona discharge in oil, in addition to considering two new PD patterns: (1 false contact and (2 floating ground. The tests and measurements to obtain the patterns and study cases of partial discharges were performed at the Testing Laboratory Equipment and Materials (LEPEM of the Federal Electricity Commission of Mexico (CFE using a measuring equipment LDIC and norm IEC60270. To classify the six patterns of partial discharges mentioned above a Probabilistic Neural Network Bayesian Modified (PNNBM method having the feature of using a large amount of data will be used and it is not saturated. In addition, PNN converges, always finding a solution in a short period of time with low computational cost. The insulation of two high voltage cables with different characteristics was analyzed. The test results allow us to conclude which wire has better insulation.

  20. Comparison of time stepping schemes on the cable equation

    Directory of Open Access Journals (Sweden)

    Chuan Li

    2010-09-01

    Full Text Available Electrical propagation in excitable tissue, such as nerve fibers and heart muscle, is described by a parabolic PDE for the transmembrane voltage $V(x,t$, known as the cable equation, $$ frac{1}{r_a}frac{partial^2V}{partial x^2} = C_mfrac{partial V}{partial t} + I_{m ion}(V,t + I_{m stim}(t $$ where $r_a$ and $C_m$ are the axial resistance and membrane capacitance. The source term $I_{m ion}$ represents the total ionic current across the membrane, governed by the Hodgkin-Huxley or other more complicated ionic models. $I_{m stim}(t$ is an applied stimulus current.

  1. A new cable-in-conduit conductor magnet with insulated strands

    International Nuclear Information System (INIS)

    Yamaguchi, Satarou; Yamamoto, Junya; Motojima, Osamu.

    1995-09-01

    Many studies have used cable-in-conduit conductor (CICC) coils in trying to develop an AC superconducting magnet because of its enormous potential if AC losses were low and insulation voltage was high. The strands in the most recent CICC magnets are coated with chromium or another metal with high electrical resistance to order to induce current re-distribution among the strands and to avoid a quench caused by a current imbalance. Current re-distribution is highly complex and very difficult to analyze because the conditions of the strand surfaces and the contact areas vary greatly with the operation of the conductor. If, however, the cable currents were well-balanced, insulating the strands would be the best way to reduce AC losses. We propose a new CICC magnet structure featuring a current lead that balances the strand currents via its resistance. Having calculated current balances, we find that strand currents are well within the present parameters for nuclear fusion experiments and superconducting magnet energy storages. (author)

  2. Tailored sPP/Silica Nano composite for Eco friendly Insulation of Extruded HVDC Cable

    International Nuclear Information System (INIS)

    Dang, B.; He, J.; Hu, J.; Zhou, Y.

    2015-01-01

    Cross-linked polyethylene (XLPE) is a thermosetting material that cannot be recycled at the end of its lifetime. This study investigated the potential of syndiotactic polypropylene (sPP)/silica as an eco friendly extruded insulation system for HVDC cables. We investigated the morphology, Fourier transform infrared, and thermal, thermomechanical, and electrical behaviors of sPP modified with 0.5-3% nano silica. We found that the silica/sPP nano composite without cross-linking offered a suitable mechanical modulus at room temperature and sufficient intensity at high temperatures, and adding nano silica modified by a silane coupling agent to the sPP resulted in significant DC resistivity and space charge improvement. The optimal nano silica content in the sPP was determined by balancing the mechanical and thermomechanical characteristics and the DC resistivity. The sPP/silica nano composite reported here shows great potential as a candidate insulation material for future eco friendly extruded HVDC cables.

  3. Aging predictions in nuclear power plants: Crosslinked polyolefin and EPR cable insulation materials

    International Nuclear Information System (INIS)

    Gillen, K.T.; Clough, R.L.

    1991-06-01

    In two earlier reports, we derived a time-temperature-dose rate superposition methodology, which, when applicable, can be used to predict cable degradation versus dose rate, temperature and exposure time. This methodology results in long-term predictive capabilities at the low dose rates appropriate to ambient nuclear power plant aging environments. The methodology was successfully applied to numerous important cable materials used in nuclear applications and the extrapolated predictions were verified by comparisons with long-term (7 to 12 year) results for similar or identical materials aged in nuclear environments. In this report, we test the methodology on three crosslinked polyolefin (CLPO) and two ethylene propylene rubber (EPR) cable insulation materials. The methodology applies to one of the CLPO materials and one of the EPR materials, allowing predictions to be made for these materials under low dose-rate, low temperature conditions. For the other materials, it is determined that, at low temperatures, a decrease in temperature at a constant radiation dose rate leads to an increase in the degradation rate for the mechanical properties. Since these results contradict the fundamental assumption underlying time-temperature-dose rate superposition, this methodology cannot be applied to such data. As indicated in the earlier reports, such anomalous results might be expected when attempting to model data taken across the crystalline melting region of semicrystalline materials. Nonetheless, the existing experimental evidence suggests that these CLPO and EPR materials have substantial aging endurance for typical reactor conditions. 28 refs., 26 figs., 3 tabs

  4. Life estimation I and C cable insulation materials based on accelerated life testing accelerated life testing

    International Nuclear Information System (INIS)

    Santhosh, T.V.; Ramteke, P.K.; Shrestha, N.B.; Ahirwar, A.K.; Gopika, V.

    2016-01-01

    Accelerated Iife tests are becoming increasingly popular in today's industry due to the need for obtaining life data quickly and reliably. Life testing of products under higher stress levels without introducing additional failure modes can provide significant savings of both time and money. Correct analysis of data gathered via such accelerated life testing will yield parameters and other information for the product's life under use stress conditions. To be of practical use in assessing the operational behaviour of cables in NPPs, laboratory ageing aims to mimic the type of degradation observed under operational conditions. Conditions of testing therefore need to be carefully chosen to ensure that the degradation mechanism occurring in the accelerated tests are similar to those which occur in service. This paper presents the results of an investigation in which the elongation-at-break (EAB) measurements were carried on a typical control cable to predict the mean life at service conditions. A low voltage polyvinyl chloride (PVC) insulated and PVC sheathed control cable, used in NPP instrumentation and control (I and C) applications, was subjected thermal ageing at three elevated temperatures

  5. Research on FR-HDPE/EPDM for cable and wire insulation by γ rays

    International Nuclear Information System (INIS)

    Jia Shaojin; Zhang Zhicheng; Ge Xuewu; Du Zhiwen; Wang Zhenzhou

    2002-01-01

    By blending low-halogen flame-retarding agent with the basic resin and using γ irradiation FR-HDPE/EPDM for cable and wire insulation with 125 degree C heat resistance was prepared. The mechanical and electrical measurement showed that radiation crosslinking improves some essential properties of the material, such as the heat resistance, tensile strength et al. The dynamic flammability of the material was researched by cone calorimeter, it was found that radiation crosslinking decreases both release heat rate and effective heat of combustion while burning, besides, crosslinking increases oxygen index and the residues of combustion though the time to ignition of the irradiated material is somewhat decreased. The work was compared with the traditional method TG measurement

  6. Morphology and crystalline-phase-dependent electrical insulating properties in tailored polypropylene for HVDC cables

    Science.gov (United States)

    Zha, Jun-Wei; Yan, Hong-Da; Li, Wei-Kang; Dang, Zhi-Min

    2016-11-01

    Polypropylene (PP) has become one promising material to potentially replace the cross-link polyethylene used for high voltage direct current cables. Besides the isotactic polypropylene, the block polypropylene (b-PP) and random polypropylene (r-PP) can be synthesized through the copolymerization of ethylene and propylene molecules. In this letter, the effect of morphology and crystalline phases on the insulating electrical properties of PP was investigated. It was found that the introduction of polyethylene monomer resulted in the formation of β and γ phases in b-PP and r-PP. The results from the characteristic trap energy levels indicated that the β and γ phases could induce deep electron traps which enable to capture the carriers. And the space charge accumulation was obviously suppressed. Besides, the decreased electrical conductivity was observed in b-PP and r-PP. It is attributed to the existence of deep traps which can effectively reduce the carrier mobility and density in materials.

  7. Effects of thermal ageing and gamma radiations on ethylene-propylene based insulator of electric cables

    International Nuclear Information System (INIS)

    Baccaro, S.; D'Atanasio, P.

    1986-01-01

    This paper describes the effects of gamma radiation and thermal aging on cable insulator. The elastic properties degrade rapidly as the absorbed dose increases: the percent elongation at break attains nearly 100% value at 0.5 MGy absorbed dose. The gases evolved during the irradiation are mainly H 2 and CO 2 ; CO, CH 4 and C 2 H 6 are present in much lower concentrations. The damage undergone depends strongly on sequential radiation and thermal aging; the analysis of accelerated life test data by means of the Arrhenius model gave (1.23+-0.25) eV for the activation energy, about 1 eV higher than the values reported in the literature

  8. Long-term radiation effects on commercial cable-insulating materials irradiated at CERN

    International Nuclear Information System (INIS)

    Maier, P.; Stolarz, A.

    1983-01-01

    Long-term irradiation damage tests have been carried out on a variety of flexible cable-insulating materials offered to CERN by different European cable manufacturers. Tensile test specimens were exposed for a maximum of three years in high-level radiation areas of the Super Proton Synchrotron (SPS) and for comparison at high dose rates in a nuclear reactor. The degradation of mechanical properties after irradiation in air depends not only on the total absorbed dose, but also on the dose rate for most of these polymer compounds. These dose-rate effects vary between material types and for different compounds. The results presented here illustrate the difference in radiation damage between short-term and long-term irradiation conditions in a typical service application for the various materials tested. They also allow safety factors to be estimated for the extrapolation of the limiting exposure in service from accelerated material tests in the range of dose rates covered. A discussion of the available models of the dose-rate effects results in a conservative estimate for extrapolation to low dose rates from measured values at intermediate dose rates of the order of 0.1 Gy/s. Based on short-term irradiation tests only, the safety factors to be applied depend on the end-point criterion used, and may vary between 1 and 10 for the range of dose rates and materials considered here. (orig.)

  9. Accelerated thermal and radiation-oxidation combined degradation of electric cable insulation materials

    International Nuclear Information System (INIS)

    Yagi, Toshiaki; Seguchi, Tadao; Yoshida, Kenzo

    1986-03-01

    For the development of accelerated testing methodology to estimate the life time of electric cable, which is installed in radiation field such as a nuclear reactor containment vessel, radiation and thermal combined degradation of cable insulation and jacketing materials was studied. The materials were two types of formulated polyethylene, ethylene-propylene rubber, Hypalon, and Neoprene. With Co-60 γ-rays the materials were irradiated up to 0.5 MGy under vacuum and in oxygen under pressure, then exposed to thermal aging at elevated temperature in oxygen. The degradation was investigated by the tensile test, gelfraction, and swelling measurements. The thermal degradation rate for each sample increases with increase of oxygen concentration, i.e. oxygen pressure, during the aging, and tends to saturate above 0.2 MPa of oxygen pressure. Then, the effects of irradiation and the temperature on the thermal degradation rate were investigated at the oxygen pressure of 0.2 MPa in the temperature range from 110 deg C to 150 deg C. For all of samples irradiated in oxygen, the following thermal degradation rate was accelerated by several times comparing with unirradiated samples, while the rate of thermal degradation for the sample except Neoprene irradiated under vacuum was nearly equal to that of unirradiated one. By the analysis of thermal degradation rate against temperature using Arrhenius equation, it was found that the activation energy tends to decrease for the samples irradiated in oxidation condition. (author)

  10. Investigations of a mechanically failed cable insulation used in indoor conditions

    CERN Document Server

    Setnescu, R; Lungulescu, E M; Ilie, S; Marinescu, V; Mares, G; Setnescu, T

    2011-01-01

    This paper presents the investigation work on different polymeric materials used as insulation materials of conductors in a multicore instrumentation cable. Among differently colored materials, only the white one presented cracks after a few years of use. Isothermal and non-isothermal DSC measurements were performed on initial (non-used) and aged (in service used or laboratory aged) materials as well as on raw materials in order to characterize their stability and the ageing state after storage, use in service or laboratory ageing. As shown by the oxidation induction time values, a pronounced antioxidant loss occurred for all materials during storage or service; plus a strong effect of the ambient light on stability was observed for the white insulation material. Around 3\\% of filler, consisting mainly of TiO(2) particles (as revealed by SEM-XRF elemental analysis), was found in the white material. The higher degradability of the white material can be related to both the photocatalytic effect of the TiO(2) pa...

  11. Preparation and Dielectric Properties of SiC/LSR Nanocomposites for Insulation of High Voltage Direct Current Cable Accessories.

    Science.gov (United States)

    Shang, Nanqiang; Chen, Qingguo; Wei, Xinzhe

    2018-03-08

    The conductivity mismatch in the composite insulation of high voltage direct current (HVDC) cable accessories causes electric field distribution distortion and even insulation breakdown. Therefore, a liquid silicone rubber (LSR) filled with SiC nanoparticles is prepared for the insulation of cable accessories. The micro-morphology of the SiC/LSR nanocomposites is observed by scanning electron microscopy, and their trap parameters are characterized using thermal stimulated current (TSC) tests. Moreover, the dielectric properties of SiC/LSR nanocomposites with different SiC concentrations are tested. The results show that the 3 wt % SiC/LSR sample has the best nonlinear conductivity, more than one order of magnitude higher than that of pure LSR with improved temperature and nonlinear conductivity coefficients. The relative permittivity increased 0.2 and dielectric loss factor increased 0.003, while its breakdown strength decreased 5 kV/mm compared to those of pure LSR. Moreover, the TSC results indicate the introduction of SiC nanoparticles reduced the trap level and trap density. Furthermore, the SiC nanoparticles filling significantly increased the sensitivity of LSR to electric field stress and temperature changes, enhancing the conductivity and electric field distribution within the HVDC cable accessories, thus improving the reliability of the HVDC cable accessories.

  12. Construction of a line for radiation cross-linking of cable insulators at the Kablo Vrchlabi plant

    International Nuclear Information System (INIS)

    Kourim, P.; Zidek, L.; Kopecky, B.

    1983-01-01

    In order to introduce radiation curing into the technology of manufacturing conductors with silicone insulation the suitability was tested of the individual brands of silicone rubber used for cables. The criterion was the range of doses guaranteeing the required mechanical and rheological properties of the rubber. The ELV 1 accelerator was used for irradiation. A description is given of the design of the technological equipment of the line which was put into experimental operation. (J.P.)

  13. Effect of moisture on the electrical performance of transition-joints for medium voltage paper-insulated cables; Elektrische Beeintraechtigung durch Feuchtigkeit an oelgetraenkten Isolierpapieren. Mittelspannungsuebergangsmuffen

    Energy Technology Data Exchange (ETDEWEB)

    Cardinaels, Jos [Nexans Network Solution, Erembodegem (Belgium). Produktentwicklung; Baesch, Manfred [Nexans Power Accessories Germany, Dortmund (Germany). Produkt- und Qualitaetsmanagement

    2009-06-15

    Paper-insulated cables are constructed with an impervious metallic outer jacket in order to protect them against ingress of moisture. On 'modern' transition-joints to XLPE-insulated cables, this metal barrier is interrupted, hence, a risk of moisture penetration exists. This text presents measurements of water-vapour permeability of used materials and discusses the results of ageing tests. (orig.)

  14. Study of heat transfer in superconducting cable electrical insulation of accelerator magnet cooled by superfluid helium; Etude des transferts de chaleur dans les isolations electriques de cables supraconducteurs d'aimant d'accelerateur refroidi par helium superfluide

    Energy Technology Data Exchange (ETDEWEB)

    Baudouy, B

    1996-10-04

    Heat transfer studies of electrical cable insulation in superconducting winding are of major importance for stability studies in superconducting magnets. This work presents an experimental heat transfer study in superconducting cables of Large Hadron Collider dipoles cooled by superfluid helium and submitted to volume heat dissipation due to beam losses. For NbTi magnets cooled by superfluid helium the most severe heat barrier comes from the electrical insulation of the cables. Heat behaviour of a winding is approached through an experimental model in which insulation characteristics can be modified. Different tests on insulation patterns show that heat transfer is influenced by superfluid helium contained in insulation even for small volume of helium (2 % of cable volume). Electrical insulation can be considered as a composite material made of a solid matrix with a helium channels network which cannot be modelled easily. This network is characterised by another experimental apparatus which allows to study transverse and steady-state heat transfer through an elementary insulation pattern. Measurements in Landau regime ({delta}T{approx}10{sup -5} to 10{sup -3} K) and in Gorter-Mellink regime ({delta}T>10{sup -3} K) and using assumptions that helium thermal paths and conduction in the insulation are decoupled allow to determine an equivalent channel area (10{sup -6} m{sup 2}) and an equivalent channel diameter (25 {mu}). (author)

  15. Study of heat transfer in superconducting cable electrical insulation of accelerator magnet cooled by superfluid helium; Etude des transferts de chaleur dans les isolations electriques de cables supraconducteurs d'aimant d'accelerateur refroidi par helium superfluide

    Energy Technology Data Exchange (ETDEWEB)

    Baudouy, B

    1996-10-04

    Heat transfer studies of electrical cable insulation in superconducting winding are of major importance for stability studies in superconducting magnets. This work presents an experimental heat transfer study in superconducting cables of Large Hadron Collider dipoles cooled by superfluid helium and submitted to volume heat dissipation due to beam losses. For NbTi magnets cooled by superfluid helium the most severe heat barrier comes from the electrical insulation of the cables. Heat behaviour of a winding is approached through an experimental model in which insulation characteristics can be modified. Different tests on insulation patterns show that heat transfer is influenced by superfluid helium contained in insulation even for small volume of helium (2 % of cable volume). Electrical insulation can be considered as a composite material made of a solid matrix with a helium channels network which cannot be modelled easily. This network is characterised by another experimental apparatus which allows to study transverse and steady-state heat transfer through an elementary insulation pattern. Measurements in Landau regime ({delta}T{approx}10{sup -5} to 10{sup -3} K) and in Gorter-Mellink regime ({delta}T>10{sup -3} K) and using assumptions that helium thermal paths and conduction in the insulation are decoupled allow to determine an equivalent channel area (10{sup -6} m{sup 2}) and an equivalent channel diameter (25 {mu}). (author)

  16. Ceramic insulation for superconducting Nb{sub 3}Sn cables; Isolation ceramique pour cables supraconducteurs en Nb{sub 3}Sn

    Energy Technology Data Exchange (ETDEWEB)

    Puigsegur, A

    2005-01-15

    Nb{sub 3}Sn is the best superconductor candidate for the realization of high field magnets (>11 Tesla), its implementation remains delicate because of the great brittleness of material after the heat treatment necessary to the formation of Nb{sub 3}Sn compounds. The conventional insulation for Nb{sub 3}Sn requires to perform, after the heat treatment, a vacuum resin impregnation, which adds to the cost and raises failure risk. We have proposed an innovating ceramic insulation deposited directly on the unreacted conducting cable. After the heat treatment of the niobium tin, we obtain a coil having a mechanical cohesion, while maintaining a proper conductor positioning and a suitable electric insulation. After a rheological study, to characterize the impregnated suspension, we have shown that using this insulation in a coil manufacture process does not affect the electrical properties of the Nb{sub 3}Sn wires. A solenoid of small dimensions was tested with success in high external magnetic fields and has produced a magnetic field of 3.8 T under 740 A. (author)

  17. Joint efforts to harmonize sound insulation descriptors and classification schemes in Europe (COST TU0901)

    DEFF Research Database (Denmark)

    Rasmussen, Birgit

    2010-01-01

    Sound insulation descriptors, regulatory requirements and classification schemes in Europe represent a high degree of diversity. One implication is very little exchange of experience of housing design and construction details for different levels of sound insulation; another is trade barriers...... for building systems and products. Unfortunately, there is evidence for a development in the "wrong" direction. For example, sound classification schemes for dwellings exist in nine countries. There is no sign on increasing harmonization, rather the contrary, as more countries are preparing proposals with new......, new housing must meet the needs of the people and offer comfort. Also for existing housing, sound insulation aspects should be taken into account, when renovating housing; otherwise the renovation is not “sustainable”. A joint European Action, COST TU0901 "Integrating and Harmonizing Sound Insulation...

  18. Negative differential mobility for negative carriers as revealed by space charge measurements on crosslinked polyethylene insulated model cables

    International Nuclear Information System (INIS)

    Teyssedre, G.; Laurent, C.; Vu, T. T. N.

    2015-01-01

    Among features observed in polyethylene materials under relatively high field, space charge packets, consisting in a pulse of net charge that remains in the form of a pulse as it crosses the insulation, are repeatedly observed but without complete theory explaining their formation and propagation. Positive charge packets are more often reported, and the models based on negative differential mobility(NDM) for the transport of holes could account for some charge packets phenomenology. Conversely, NDM for electrons transport has never been reported so far. The present contribution reports space charge measurements by pulsed electroacoustic method on miniature cables that are model of HVDC cables. The measurements were realized at room temperature or with a temperature gradient of 10 °C through the insulation under DC fields on the order 30–60 kV/mm. Space charge results reveal systematic occurrence of a negative front of charges generated at the inner electrode that moves toward the outer electrode at the beginning of the polarization step. It is observed that the transit time of the front of negative charge increases, and therefore the mobility decreases, with the applied voltage. Further, the estimated mobility, in the range 10 −14 –10 −13  m 2  V −1  s −1 for the present results, increases when the temperature increases for the same condition of applied voltage. The features substantiate the hypothesis of negative differential mobility used for modelling space charge packets

  19. Negative differential mobility for negative carriers as revealed by space charge measurements on crosslinked polyethylene insulated model cables

    Science.gov (United States)

    Teyssedre, G.; Vu, T. T. N.; Laurent, C.

    2015-12-01

    Among features observed in polyethylene materials under relatively high field, space charge packets, consisting in a pulse of net charge that remains in the form of a pulse as it crosses the insulation, are repeatedly observed but without complete theory explaining their formation and propagation. Positive charge packets are more often reported, and the models based on negative differential mobility(NDM) for the transport of holes could account for some charge packets phenomenology. Conversely, NDM for electrons transport has never been reported so far. The present contribution reports space charge measurements by pulsed electroacoustic method on miniature cables that are model of HVDC cables. The measurements were realized at room temperature or with a temperature gradient of 10 °C through the insulation under DC fields on the order 30-60 kV/mm. Space charge results reveal systematic occurrence of a negative front of charges generated at the inner electrode that moves toward the outer electrode at the beginning of the polarization step. It is observed that the transit time of the front of negative charge increases, and therefore the mobility decreases, with the applied voltage. Further, the estimated mobility, in the range 10-14-10-13 m2 V-1 s-1 for the present results, increases when the temperature increases for the same condition of applied voltage. The features substantiate the hypothesis of negative differential mobility used for modelling space charge packets.

  20. Key-Insulated Undetachable Digital Signature Scheme and Solution for Secure Mobile Agents in Electronic Commerce

    Directory of Open Access Journals (Sweden)

    Yang Shi

    2016-01-01

    Full Text Available Considering the security of both the customers’ hosts and the eShops’ servers, we introduce the idea of a key-insulated undetachable digital signature, enabling mobile agents to generate undetachable digital signatures on remote hosts with the key-insulated property of the original signer’s signing key. From the theoretical perspective, we provide the formal definition and security notion of a key-insulated undetachable digital signature. From the practical perspective, we propose a concrete scheme to secure mobile agents in electronic commerce. The scheme is mainly focused on protecting the signing key from leakage and preventing the misuse of the signature algorithm on malicious servers. Agents do not carry the signing key when they generate digital signatures on behalf of the original signer, so the key is protected on remote servers. Furthermore, if a hacker gains the signing key of the original signer, the hacker is still unable to forge a signature for any time period other than the key being accessed. In addition, the encrypted function is combined with the original signer’s requirement to prevent the misuse of signing algorithm. The scheme is constructed on gap Diffie–Hellman groups with provable security, and the performance testing indicates that the scheme is efficient.

  1. Harmonization of sound insulation descriptors and classification schemes in Europe: COST Action TU0901

    DEFF Research Database (Denmark)

    Rasmussen, Birgit

    -in-Chief. Handbook of noise and vibration control, USA: Wiley and Son; 2007 [Ch. 114]. [4] COST Action TU0901 “Integrating and Harmonizing Sound Insulation Aspects in Sustainable Urban Housing Constructions”, 2009-2013, www.cost.eu/index.php?id=240&action_number=tu0901 (public information at COST website) or http...... insulation requirements seems unrealistic. However, by preparing a harmonized European classification scheme with a number of quality classes, member states could select a "harmonized" class fitting the national needs and conditions. A joint European Action, COST Action TU0901 "Integrating and Harmonizing...... on good workmanship. The paper will summarize the background, discuss the present situation in Europe and describe the joint efforts to reduce the diversity in Europe, thus supporting and initiating – where needed – improvement of sound insulation of new and existing dwellings in Europe to the benefit...

  2. Radiation resistance of cable insulation and jacket materials for nuclear power plants

    International Nuclear Information System (INIS)

    Morita, Minoru; Kon, Shuji; Nishikawa, Ichiro

    1978-01-01

    The cables for use in nuclear power plants are required to satisfy the specific environmental resistance and excellent flame resistance as stipulated in IEEE Std. 383. The materials to be used to cables intended for this specific purpose of use must therefore be strictly tested so as to evaluate their flame resistance in addition to compliance with various environmental requirements, such as heat resistance, water-vapor resistance, and radiation resistance. This paper describes general information on radiation resistance and deterioration of various high-molecular materials, suggests the direction of efforts to be made to improve their properties including flame resistance of various rubber and plastic materials for cables to be used in nuclear power plants, and indicates the performance characteristics of such materials. (author)

  3. 7 CFR 1755.890 - RUS specification for filled telephone cables with expanded insulation.

    Science.gov (United States)

    2010-01-01

    .... Catch and weigh any water that leaks from the end of the cable during the one hour period. If no water leaks from the sample, carefully remove the water from the closure. Then carefully remove the jacket... in ANSI/ICEA S-84-608-1988, paragraph 9.1 using a test temperature of 80 ±1 °C. (2) Water penetration...

  4. Design and test of low-capacitance, air-insulated, 80-kV, 0.5-sec source cables for MFTF sustaining-neutral-beam power supples

    International Nuclear Information System (INIS)

    Mayhall, D.J.; Wilson, J.H.; Caldwell, W.J.; Watson, T.F.; Jenkins, J.W. Jr.

    1981-01-01

    The design of air-insulated cables, which meet strict requirements, is described. Inductance, heat transfer, and electrostatic computer codes are used in design. Tests include electric circiut parameters, dc voltage holdoff, impulse voltage holdoff, heat rise at greater than peak duty, and shield mechanical strength

  5. Negative differential mobility for negative carriers as revealed by space charge measurements on crosslinked polyethylene insulated model cables

    Energy Technology Data Exchange (ETDEWEB)

    Teyssedre, G., E-mail: gilbert.teyssedre@laplace.univ-tlse.fr; Laurent, C. [Université de Toulouse, UPS, INPT, LAPLACE (Laboratoire Plasma et Conversion d' Energie), 118 route de Narbonne, F-31062 Toulouse cedex 9 (France); CNRS, LAPLACE, F-31062 Toulouse (France); Vu, T. T. N. [Université de Toulouse, UPS, INPT, LAPLACE (Laboratoire Plasma et Conversion d' Energie), 118 route de Narbonne, F-31062 Toulouse cedex 9 (France); Electric Power University, 235 Hoang Quoc Viet, 10000 Hanoi (Viet Nam)

    2015-12-21

    Among features observed in polyethylene materials under relatively high field, space charge packets, consisting in a pulse of net charge that remains in the form of a pulse as it crosses the insulation, are repeatedly observed but without complete theory explaining their formation and propagation. Positive charge packets are more often reported, and the models based on negative differential mobility(NDM) for the transport of holes could account for some charge packets phenomenology. Conversely, NDM for electrons transport has never been reported so far. The present contribution reports space charge measurements by pulsed electroacoustic method on miniature cables that are model of HVDC cables. The measurements were realized at room temperature or with a temperature gradient of 10 °C through the insulation under DC fields on the order 30–60 kV/mm. Space charge results reveal systematic occurrence of a negative front of charges generated at the inner electrode that moves toward the outer electrode at the beginning of the polarization step. It is observed that the transit time of the front of negative charge increases, and therefore the mobility decreases, with the applied voltage. Further, the estimated mobility, in the range 10{sup −14}–10{sup −13} m{sup 2} V{sup −1} s{sup −1} for the present results, increases when the temperature increases for the same condition of applied voltage. The features substantiate the hypothesis of negative differential mobility used for modelling space charge packets.

  6. Gaseous products and smoke generation on combustion of the insulation materials of nuclear cables

    International Nuclear Information System (INIS)

    Noguchi, Isamu; Takami, Hiroshi; Ueyama, Michio; Fujimura, Shun-ichi.

    1976-01-01

    Serious requirements have been introduced to the cables used for nuclear power plants on their flame retardation in the IEEE Standard 383-1974. The movements that the users prescribe the quantity of corrosive gas generated from cables are also observed. This report describes on the measured results of the gaseous products generated by burning polyethylene, polyvinyl-chloride (PVC) and their flame-resistant products, and a part of the covering materials of the cables for nuclear power plants (flame-resistant, crosslinking polyethylene, flame-resistant, low hydrochloric acid PVC, flame-resistant jute) in the infra-red rapid heating combustion test facility designed by the Furukawa Electric Co. Ltd. In addition, the report introduces the test method for the smoke generation evaluation of polymers and a part of the measured results. The gaseous products of combustion were collected and determined quantitatively by gas chromatographic method. Since smoke generation is affected greatly by the kinds, shape, atmosphere, temperature, ignition procedure and others of burnt matters, the establishment of the evaluation test method is difficult, and a number of methods have been proposed. As the measured results showed, it is clear that smoke generation increases with the increase of flame resistant reagent addition. The smoke generation of PVC was of course great in quantity because it contains considerable amount of chlorine for its molecular structure. Flame-resistant polyethylene generates smoke much more than polyethylene without flame-resisting treatment because of its flame resistivity, but less than that of PVC. (Wakatsuki, Y.)

  7. Ground Return Current Behaviour in High Voltage Alternating Current Insulated Cables

    Directory of Open Access Journals (Sweden)

    Roberto Benato

    2014-12-01

    Full Text Available The knowledge of ground return current in fault occurrence plays a key role in the dimensioning of the earthing grid of substations and of cable sealing end compounds, in the computation of rise of earth potential at substation sites and in electromagnetic interference (EMI on neighbouring parallel metallic conductors (pipes, handrails, etc.. Moreover, the ground return current evaluation is also important in steady-state regime since this stray current can be responsible for EMI and also for alternating current (AC corrosion. In fault situations and under some assumptions, the ground return current value at a substation site can be computed by means of k-factors. The paper shows that these simplified and approximated approaches have a lot of limitations and only multiconductor analysis can show the ground return current behaviour along the cable (not only the two end values both in steady-state regime and in short circuit occurrence (e.g., phase-to-ground and phase-to-phase-to-ground. Multiconductor cell analysis (MCA considers the cable system in its real asymmetry without simplified and approximated hypotheses. The sensitivity of ground return current on circuit parameters (cross-bonding box resistances, substation earthing resistances, soil resistivity is presented in the paper.

  8. Universal scheme to generate metal–insulator transition in disordered systems

    International Nuclear Information System (INIS)

    Guo, Ai-Min; Xiong, Shi-Jie; Xie, X C; Sun, Qing-feng

    2013-01-01

    We propose a scheme to generate metal–insulator transition in the random binary layer (RBL) model, which is constructed by randomly assigning two types of layers along the longitudinal direction. Based on a tight-binding Hamiltonian, the localization length is calculated for a variety of RBLs with different cross section geometries by using the transfer-matrix method. Both analytical and numerical results show that a band of extended states could appear in the quasi-one-dimensional RBLs and the systems behave as metals by properly tuning the model parameters, due to the existence of a completely ordered subband, leading to a metal–insulator transition in parameter space. Furthermore, the extended states are irrespective of the diagonal and off-diagonal disorder strengths. Our results can be generalized to two- and three-dimensional disordered systems with arbitrary layer structures, and may be realized in Bose–Einstein condensates. (paper)

  9. Primary heat transport pump trip by ground fault (deterioration of insulation in the cable quick disconnect)

    International Nuclear Information System (INIS)

    Chun, C.-Y.

    1991-01-01

    At 08:29 Sept. 1, 1988, Wolsong unit 1 was operating at 100% full power when a primary heat transport pump was suddenly tripped by breaker trip due to ground fault in the power distribution connector assembly. Soon after the pump trip, the reactor was shut down automatically on low heat transport flow. Operators tried to restart the pump twice but failed. A field operator reported to the shift supervisor that he found an electrical spark and smoke at the vicinity of the pump when the pump started to run. Inspection showed that a power distribution connector assembly for making fast and easy power connections to the PHT pump motor, 3312-PM2, was damaged severely by thermal shock. Particularly, broken parts of the insulating plug flew away across the boiler room and dropped to the floor. Direct causes of the failure were bad contact and deterioration of integrity along the creep paths between the insulating plug and the connector housing. The failed connector assembly had been used for more than 7 years. Its status had been checked infrequently during the in-service period. The standard torque value was not applied to the installation of connectors. Therefore, we concluded that long term inservice in combinations of application of improper torque value induced failure of insulation. This paper describes the scenarios, causes of the event and corrective actions to prevent recurrence of this event. (author)

  10. Primary heat transport pump trip by ground fault (deterioration of insulation in the cable quick disconnect)

    Energy Technology Data Exchange (ETDEWEB)

    Chun, C -Y [Wolsong Nuclear Power Plant, Korea Electric Power Corporation, Wolsong (Korea, Republic of)

    1991-04-01

    At 08:29 Sept. 1, 1988, Wolsong unit 1 was operating at 100% full power when a primary heat transport pump was suddenly tripped by breaker trip due to ground fault in the power distribution connector assembly. Soon after the pump trip, the reactor was shut down automatically on low heat transport flow. Operators tried to restart the pump twice but failed. A field operator reported to the shift supervisor that he found an electrical spark and smoke at the vicinity of the pump when the pump started to run. Inspection showed that a power distribution connector assembly for making fast and easy power connections to the PHT pump motor, 3312-PM2, was damaged severely by thermal shock. Particularly, broken parts of the insulating plug flew away across the boiler room and dropped to the floor. Direct causes of the failure were bad contact and deterioration of integrity along the creep paths between the insulating plug and the connector housing. The failed connector assembly had been used for more than 7 years. Its status had been checked infrequently during the in-service period. The standard torque value was not applied to the installation of connectors. Therefore, we concluded that long term inservice in combinations of application of improper torque value induced failure of insulation. This paper describes the scenarios, causes of the event and corrective actions to prevent recurrence of this event. (author)

  11. Measurement scheme of kicker impedances via beam-induced voltages of coaxial cables

    Energy Technology Data Exchange (ETDEWEB)

    Shobuda, Yoshihiro, E-mail: yoshihiro.shobuda@j-parc.jp [J-PARC Center, JAEA and KEK, 2-4 Shirakata Shirane, Tokaimura, Nakagun, Ibaraki 319-1195 (Japan); Irie, Yoshiro [KEK, High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Toyama, Takeshi; Kamiya, Junichiro [J-PARC Center, JAEA and KEK, 2-4 Shirakata Shirane, Tokaimura, Nakagun, Ibaraki 319-1195 (Japan); Watanabe, Masao [Ministry of Education, Culture, Sports, Science and Technology, 3-2-2 Kasumigaseki, Chiyoda, Tokyo 100-8959 (Japan)

    2013-06-11

    A new theory, which satisfies the causality condition, is developed to describe impedances of kicker magnets with coaxial cables. The theoretical results well describe measurement results, which are obtained by standard wire methods. On the other hand, when beams pass through the kicker, voltages are induced at the terminals of coaxial cables. In other words, by analyzing the voltages, the kicker impedance for the beams can be obtained. The observed impedances are consistent with the theoretical results. The theory describes the impedance for non-relativistic beams, as well. The theoretical, simulation and measurement results indicate that the horizontal kicker impedance is drastically reduced by the non-relativistic effect. -- Highlights: ► We develop an innovative method to measure kicker impedance including power cable. ► By analyzing voltages at the ends of coaxial cables, the impedance is derived. ► The horizontal impedance is reduced as the beam becomes non-relativistic.

  12. Estimation of the degradation state of insulated cables by measurement of performance indicators; Estimativa do estado de degradacao de cabos isolados por meio da medicao de indicadores de desempenho

    Energy Technology Data Exchange (ETDEWEB)

    Velasco, Loana [Universidade Federal de Uberlandia (UFU), MG (Brazil). Programa de Pos-Graduacao de Qualidade e Racionalizacao da Energia Eletrica; Freitas, Luiz Carlos de [Universidade Federal de Uberlandia (UFU), MG (Brazil). Fac. de Engenharia Eletrica; Oliveira, Jose Carlos de; Andrade, Darizon de [Universidade Federal de Uberlandia (UFU), MG (Brazil). Dept. de Engenharia Eletrica; Lima, Fernando de; Finazzi, Antonio [Universidade Federal de Mato Grosso (UFMT), Cuiaba, MT (Brazil). Dept. de Engenharia Eletrica

    2011-03-15

    This article presents the development of a prototype that enables the detection of leakage current and operating voltage and allows to employ methods to diagnose the operational state of insulated cables through performance indicators.

  13. Experimental and analytical study of the DC breakdown characteristics of polypropylene laminated paper with a butt gap condition considering the insulation design of superconducting cable

    Science.gov (United States)

    Seo, In-jin; Choi, Won; Seong, Jae-gyu; Lee, Bang-wook; Koo, Ja-yoon

    2014-08-01

    It has been reported that the insulation design under DC stress is considered as one of the critical factors in determining the performance of high-voltage direct current (HVDC) superconducting cable. Therefore, it is fundamentally necessary to investigate the DC breakdown characteristics of the composite insulation system consisting of liquid nitrogen (LN2)/polypropylene-laminated-paper (PPLP). In particular, the insulation characteristics under DC polarity reversal condition should be verified to understand the polarity effect of the DC voltage considering the unexpected incidents taking place at line-commutated-converters (LCC) under service at a DC power grid. In this study, to examine the variation of DC electric field strength, the step voltage and polarity reversal breakdown tests are performed under DC stress. Also, we investigate the electric field distributions in a butt gap of the LN2/PPLP condition considering the DC polarity reversal by using simulation software.

  14. Power cables with extruded insulation and their accessories for rated voltages from 1 kV (Um = 1,2 kV) up to 30 kV (Um = 36 kV) : Part 2: cables for rated voltages from 6 kV (Um = 7,2 kV) up to 30 kV (Um = 36 kV)

    CERN Document Server

    International Electrotechnical Commission. Geneva

    2005-01-01

    Power cables with extruded insulation and their accessories for rated voltages from 1 kV (Um = 1,2 kV) up to 30 kV (Um = 36 kV) : Part 2: cables for rated voltages from 6 kV (Um = 7,2 kV) up to 30 kV (Um = 36 kV)

  15. A new scheme for critical current measurements on straight superconducting cables in a large solenoid

    International Nuclear Information System (INIS)

    Rossi, L.; Volpini, G.

    1991-01-01

    The precision of I c measurement of straight superconducting cables in solenoids can be limited by the magnetic field inhomogeneity. A solution in order to improve the field homogeneity based on iron shims is presented here. A conceptual design for the experimental lay-out of a test station to be used in connection with the SOLEMI-I solenoid at the Milan INFN Section (LASA Laboratory) is given

  16. Damages of electrical insulation of cable products used at NPP`s and technique of their detection and operative control; Povrezhdeniya v ehlektricheskoj izolyatsii kabel`nykh izdulij, ehkspluatirue mykh na atomnykh ehlektrostantsiyakh i metody ikh obnaruzheniya i operativnogo kontro lya

    Energy Technology Data Exchange (ETDEWEB)

    Valeev, R S; Filatov, N I

    1994-12-31

    Analysis of possible damages in electrical insulation of cable products under their application at NPP`s is conducted. Basic methods for detecting such damages and rapid control of technical condition of cable products during the operation are considered.

  17. Development of Row of Vibration Insulators and its Mathematical Models on a Base of Common Multi-parameter Scheme of Element Axial Line

    Science.gov (United States)

    Ponomarev, Yury K.

    2018-01-01

    The mathematical model of deformation of a cable (rope) vibration insulator consisting of two identical clips connected by means of elastic elements of a complex axial line is developed in detail. The axial line of the element is symmetric relatively to the horizontal axis of the shape and is made up of five rectilinear sections of arbitrary length a, b, c, conjugated to four radius sections with parameters R1 and R2 with angular extent 90°. On the basis of linear representations of the theory of bending and torsion of mechanics of materials, applied mechanics and linear algebra, a mathematical model of loading of an element and a vibration insulator as a whole in the direction of the vertical Y axis has been developed. Generalized characteristics of the friction and elastic forces for an elastic element with a complete set of the listed sections are obtained. Further, with the help of nullification in the generalized model of the characteristics of certain parameters, special cases of friction and elastic forces are obtained without taking into account the nullified parameters. Simultaneously, on the basis of the 3D computer-aided design system, volumetric models of simplified structures were created, given in the work. It is shown that, with the help of a variation of the five parameters of the axial scheme of the element, in combination with the variation of the moment of inertia of the rope section and the number of elements entering the ensemble, the load characteristics and stiffness of the vibration insulators can be changed tens and hundreds of times. This opens up unlimited possibilities for the optimal design of vibration protection systems in terms of weight characteristics, in cost, in terms of vibration intensity, in overall dimensions in different directions, which is very important for aerospace and transport engineering.

  18. Line Differential Protection Scheme Modelling for Underground 420 kV Cable Systems

    DEFF Research Database (Denmark)

    Sztykiel, Michal; Bak, Claus Leth; Dollerup, Sebastian

    2011-01-01

    Based on the analysis of a specific relay model and an HVAC (High Voltage Alternating Current) cable system, a detailed approach to EMTDC/PSCAD modelling of protective relays is presented. Such approach allows to create complex and accurate relay models derived from the original algorithms. Relay...... models can be applied with various systems, allowing to obtain the most optimal configuration of the protective relaying. The present paper describes modelling methodology on the basis of Siemens SIPROTEC 4 7SD522/610. Relay model was verified experimentally with its real equivalent by both EMTP......-simulated and real world generated current signals connected to the relay....

  19. Line Differential Protection Scheme Modelling for Underground 420 kV Cable Systems

    DEFF Research Database (Denmark)

    Sztykiel, Michal; Bak, Claus Leth; Wiechowski, Wojciech

    2010-01-01

    Based on the analysis of a specific relay model and an HVAC (High Voltage Alternating Current) cable system, a new approach to EMTDC/PSCAD modelling of protective relays is presented. Such approach allows to create complex and accurate relay models derived from the original algorithms. Relay models...... can be applied with various systems, allowing to obtain the most optimal configuration of the protective relaying. The present paper describes modelling methodology on the basis of Siemens SIPROTEC 4 7SD522/610. Relay model was verified experimentally with its real equivalent by both EMTP......-simulated and real world generated current signals connected to the relay....

  20. Statistical analysis of aging trend of mechanical properties in ethylene propylene rubber-insulated safety-related cables sampled from containments (Denryoko Chuo Kenkyusho Hokoku, December 2013 issue)

    International Nuclear Information System (INIS)

    Fuse, Norikazu; Kanegami, Masaki; Misaka, Hideki; Homma, Hiroya; Okamoto, Tatsuki

    2013-01-01

    As for polymeric insulations used in nuclear power plant safety cables, it is known that the present prediction model sometimes estimates the service life conservatively. In order to sophisticate the model to reflect to the aging in containments, disconnections between the prediction and realities are needed to be clarified. In the present paper, statistical analysis has been carried out on various aging status of insulations removed from domestic containments. Aging in operational environment is found to be slower than the one expected from acceleration aging test results. Temperature dependence of estimated lifetime on Arrhenius plot also suggests that elementary chemical reaction dominant under the two aging conditions is different, which results in apparent difference in activation energies and pre-exponential factors. Following two kinds of issues are found necessary to be clarified for the model sophistication; temperature change in predominant degradation chemical processes, and the effect of low oxygen concentration environment in boiling water reactor type containment. (author)

  1. A continuous winding scheme for superconducting tokamak coils with cable-in-conduit conductor

    International Nuclear Information System (INIS)

    Kim, Sang-ho; Chung, Kie-hyung; Lee, Deok Kyo

    2001-01-01

    Superconducting magnet coils are essential for steady-state or long-pulse operation of tokamaks. In an advanced tokamak, the central solenoid (CS) coils are usually divided into several pairs of modules to provide for an extra plasma shaping capability in addition to those available from the shaping (poloidal field) coils. In the conventional pancake winding scheme of superconducting coils, each coil consists of separate superconducting 'double-pancake' coils connected together in series; however, such joints are not superconducting, which is one of the major disadvantages, especially in pulsed operations. A new type of winding was adopted for the ITER CS coil, which consists of cylindrical shell 'layers' joined in series. A disadvantage of this layer winding is its inability to yield modular coils that can provide certain degree of plasma shaping. Joints can be removed in a coil winding pack with the conventional pancake winding scheme, if the conductor is sufficiently long and the winding machine is properly equipped. The compactness, however, cannot be preserved with this scheme. The winding compactness is important since the radial build of the CS coils is one of the major parameters that determine the machine size. In this paper, we present a continuous winding scheme that requires no joints, allows coil fabrication at minimum dimension, and meets the flux swing requirement and other practical aspects

  2. 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.

  3. 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

  4. ELECTROMECHANICAL TRANSIENT PROCESSES DURING SUPPLY VOLTAGE CHANGING IN THE SYSTEM OF POLYMER INSULATION COVERING OF THE CURRENT-CARRYING CORE OF ULTRA HIGH VOLTAGE CABLES

    Directory of Open Access Journals (Sweden)

    V. M. Zolotaryov

    2018-04-01

    Full Text Available Aim. The article is devoted to the analysis of the electromechanical transient processes in a system of three frequency-controlled electric drives based on asynchronous motors that control current-carrying core motion, as well as to the study of the effect of such processes on the modes applying three-layer polymer insulation to the current-carrying core. Technique. The study was conducted based on the concepts of electromechanics, electromagnetic field theory, mathematical physics, mathematical modeling. Results. A mathematical model has been developed to analyze transients in an electromechanical system consisting of three frequency-controlled electric drives providing current-carrying core motion of ultra-high voltage cables in an inclined extrusion line. The coordination of the electromechanical parameters of the system drives has been carried out and the permissible changes in the supply voltage at the limiting mass while moving current-carrying core of ultra-high voltage cables with applied polymer insulation have been estimated. Scientific novelty. For the first time it is determined that with the limiting mass of the current-carrying core, the electromechanical system allows to stabilize the current-carrying core speed with the required accuracy at short-term decreases in the supply voltage by no more than 27 % of its amplitude value. It is also shown that this system is resistant to short-term increases in voltage by 32 % for 0.2 s. Practical significance. Using the developed model, it is possible to calculate the change in the configuration and speed of the slack current-carrying core when applying polymer insulation, depending on the specific mass of the current-carrying core per unit length, its tension at the bottom, the torque of the traction motor and the supply voltage to achieve stable operation of the system and accurate working of the set parameters.

  5. Radiation induced currents in mineral-insulated cables and in pick-up coils: model calculations and experimental verification in the BR1 reactor

    Science.gov (United States)

    Vermeeren, Ludo; Leysen, Willem; Brichard, Benoit

    2018-01-01

    Mineral-insulated (MI) cables and Low-Temperature Co-fired Ceramic (LTCC) magnetic pick-up coils are intended to be installed in various position in ITER. The severe ITER nuclear radiation field is expected to lead to induced currents that could perturb diagnostic measurements. In order to assess this problem and to find mitigation strategies models were developed for the calculation of neutron-and gamma-induced currents in MI cables and in LTCC coils. The models are based on calculations with the MCNPX code, combined with a dedicated model for the drift of electrons stopped in the insulator. The gamma induced currents can be easily calculated with a single coupled photon-electron MCNPX calculation. The prompt neutron induced currents requires only a single coupled neutron-photon-electron MCNPX run. The various delayed neutron contributions require a careful analysis of all possibly relevant neutron-induced reaction paths and a combination of different types of MCNPX calculations. The models were applied for a specific twin-core copper MI cable, for one quad-core copper cable and for silver conductor LTCC coils (one with silver ground plates in order to reduce the currents and one without such silver ground plates). Calculations were performed for irradiation conditions (neutron and gamma spectra and fluxes) in relevant positions in ITER and in the Y3 irradiation channel of the BR1 reactor at SCK•CEN, in which an irradiation test of these four test devices was carried out afterwards. We will present the basic elements of the models and show the results of all relevant partial currents (gamma and neutron induced, prompt and various delayed currents) in BR1-Y3 conditions. Experimental data will be shown and analysed in terms of the respective contributions. The tests were performed at reactor powers of 350 kW and 1 MW, leading to thermal neutron fluxes of 1E11 n/cm2s and 3E11 n/cm2s, respectively. The corresponding total radiation induced currents are ranging from

  6. Sound insulation and reverberation time for classrooms - Criteria in regulations and classification schemes in the Nordic countries

    DEFF Research Database (Denmark)

    Rasmussen, Birgit

    2016-01-01

    Acoustic regulations or guidelines for schools exist in all five Nordic countries. The acoustic criteria depend on room uses and deal with airborne and impact sound insulation, reverberation time, sound absorption, traffic noise, service equipment noise and other acoustic performance...... have become more extensive and stricter during the last two decades. The paper focuses on comparison of sound insulation and reverberation time criteria for classrooms in regulations and classification schemes in the Nordic countries. Limit values and changes over time will be discussed as well as how...... not identical. The national criteria for quality level C correspond to the national regulations or recommendations for new-build. The quality levels A and B are intended to define better acoustic performance than C, and D lower performance. Typically, acoustic regulations and classification criteria for schools...

  7. Semiannual report for the period April 1 to September 30, 1978 of work on: (1) superconducting power transmission system development; (2) cable insulation development. Power Transmission Project technical note No. 83

    Energy Technology Data Exchange (ETDEWEB)

    1978-11-07

    Progress in the development, fabrication and testing of superconductors for HVAC power transmission systems is reported. Information is included on the materials evaluation of superconducting alloys, production of tapes from these alloys, principally Nb/sub 3/Sn cable insulation requirements and development, and the cryogenic equipment used in this research program. (LCL)

  8. Research on vacuum insulation for cryocables

    International Nuclear Information System (INIS)

    Graneau, P.

    1974-01-01

    Vacuum insulation, as compared with solid insulation, simplifies the construction of both resistive or superconducting cryogenic cables. The common vacuum space in the cable can furnish thermal insulation between the environment and the cryogenic coolant, provide electrical insulation between conductors, and establish thermal isolation between go- and return-coolant streams. The differences between solid and vacuum high voltage insulation are discussed, and research on the design, materials selection, and testing of vacuum insulated cryogenic cables is described

  9. 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...

  10. Investigations of Electrical Trees in the Inner Layer of XLPE Cable Insulation Using Computer-aided Image Recording Monitoring

    OpenAIRE

    Xie, Ansheng; Zheng, Xiaoquan; Li, Shengtao; Chen, George

    2010-01-01

    Using a computer-aided image recording monitoring system, extensive measurements have been performed in the inner layer of 66 kV cross-linked polyethylene (XLPE)cables. It has been found that there are three kinds of electrical trees in the samples,the branch-like tree, the bush-like tree and the mixed tree that is a mixture of the above two kinds. When the applied voltage frequency is less than or equal to 250 Hz, only the mixed tree appears in XLPE samples, when the frequency is greater tha...

  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. Flammability of radiation cross-linked low density polyethylene as an insulating material for wire and cable

    International Nuclear Information System (INIS)

    Basfar, A.A.

    2002-01-01

    Various formulations of low-density polyethylene blended with ethylene vinyl acetate were prepared to improve the flame retardancy for wire and cable applications. The prepared formulations were cross-linked by γ-rays to 50, 100, 150 and 200 kGy in the presence of trimethylolpropane triacrylate (TMPTA). The effect of thermal aging on mechanical properties of these formulations were investigated. In addition, the influence of various combinations of aluminum trihydroxide and zinc borate as flame retardant fillers on the flammability was explored. Limiting oxygen index (LOI) and average extent of burning were used to characterize the flammability of investigated formulations. An improved flame retardancy of low density polyethylene was achieved by various combinations of flame ratardant fillers and cross-linking by gamma radiation

  13. Poly(4-vinylphenol gate insulator with cross-linking using a rapid low-power microwave induction heating scheme for organic thin-film-transistors

    Directory of Open Access Journals (Sweden)

    Ching-Lin Fan

    2016-03-01

    Full Text Available A Microwave-Induction Heating (MIH scheme is proposed for the poly(4-vinylphenol (PVP gate insulator cross-linking process to replace the traditional oven heating cross-linking process. The cross-linking time is significantly decreased from 1 h to 5 min by heating the metal below the PVP layer using microwave irradiation. The necessary microwave power was substantially reduced to about 50 W by decreasing the chamber pressure. The MIH scheme is a good candidate to replace traditional thermal heating for cross-linking of PVP as the gate insulator for organic thin-film-transistors.

  14. Poly(4-vinylphenol) gate insulator with cross-linking using a rapid low-power microwave induction heating scheme for organic thin-film-transistors

    Science.gov (United States)

    Fan, Ching-Lin; Shang, Ming-Chi; Hsia, Mao-Yuan; Wang, Shea-Jue; Huang, Bohr-Ran; Lee, Win-Der

    2016-03-01

    A Microwave-Induction Heating (MIH) scheme is proposed for the poly(4-vinylphenol) (PVP) gate insulator cross-linking process to replace the traditional oven heating cross-linking process. The cross-linking time is significantly decreased from 1 h to 5 min by heating the metal below the PVP layer using microwave irradiation. The necessary microwave power was substantially reduced to about 50 W by decreasing the chamber pressure. The MIH scheme is a good candidate to replace traditional thermal heating for cross-linking of PVP as the gate insulator for organic thin-film-transistors.

  15. Condition based maintenance of a 20 kV-PE/XLPE-insulated cable network using the IRC-Analysis; Zustandsorientierte Instandhaltung eines polymerisolierten 20-kV-Kabelnetzes mit der IRC-Analyse. Moderne Diagnostik reduziert Stoerungsrate

    Energy Technology Data Exchange (ETDEWEB)

    Hoff, G.; Kranz, H.G. [BUGH Wuppertal (Germany). Labs. fuer Hochspannungstechnik; Beigert, M.; Petzold, F. [Seba Dynatronic Mess- und Ortungstechnik GmbH, Baunach (Germany); Kneissl, C. [Bereich Konzeption und Messtechnik, Lech Elektrizitaetswerke AG, Augsburg (Germany)

    2001-10-22

    For a preventive maintenance of a polymer insulated cable network a destruction free estimation of the status of the buried PE/XLPE-cables is needed. This contribution presents a condition based maintenance concept which is based on the IRC-Analysis. With this concept a major German utility was able to reduce the amount of failures in a part of the 20kV-cable network. The general tendency of increasing faults was broken. (orig.) [German] Die praeventive Instandhaltung in polymerisolierten Kabelnetzen setzt eine zerstoerungsfreie Zustandbestimmung von gelegten PE/VPE-isolierten Kabeln voraus. Die-Verfasser beschreiben ein zustandsorientiertes Wartungskonzept auf Basis der IRC-Analyse, mit dem es gelungen ist, in einem Teil des 20-kV-Kabelnetzes eines Energieversorgers die in der Vergangenheit stetig steigende Stoerungsrate drastisch zu reduzieren. (orig.)

  16. Proposal for the award of a contract for the supply of polyimide film for cable and ground insulation of the LHC superconducting magnets

    CERN Document Server

    1999-01-01

    This document concerns the award of a contract for the supply of up to 79 tonnes of polyimide film, of three different types, for cable and ground insulation of the LHC superconducting magnets. A call for tenders (IT-2679/LHC/LHC) was sent on 21 September 1999 to two firms in Japan and one firm in the USA. By the closing date, CERN had received three tenders. The Finance Committee is invited to agree to the negotiation of a contract with the firm KANEKA (JP), the lowest bidder, for the supply of 79 tonnes of polyimide film of three different types for an amount of 5 425 541 USD (8 123 284 Swiss francs) for the polyimide film produced in the USA, not subject to revision, and 725 726 546 Japanese yen (10 109 020 Swiss francs) for the polyimide film produced in Japan, not subject to revision, with an option for the supply of up to 20% additional polyimide film of each type, for an amount of 1 085 108 USD (1 624 657 Swiss francs) and 145 145 309 Japanese yen (2 021 804 Swiss francs) respectively, not subject to r...

  17. Polyethylene Nanocomposites for the Next Generation of Ultralow-Transmission-Loss HVDC Cables: Insulation Containing Moisture-Resistant MgO Nanoparticles.

    Science.gov (United States)

    Pourrahimi, Amir Masoud; Pallon, Love K H; Liu, Dongming; Hoang, Tuan Anh; Gubanski, Stanislaw; Hedenqvist, Mikael S; Olsson, Richard T; Gedde, Ulf W

    2016-06-15

    The use of MgO nanoparticles in polyethylene for cable insulation has attracted considerable interest, although in humid media the surface regions of the nanoparticles undergo a conversion to a hydroxide phase. A facile method to obtain MgO nanoparticles with a large surface area and remarkable inertness to humidity is presented. The method involves (a) low temperature (400 °C) thermal decomposition of Mg(OH)2, (b) a silicone oxide coating to conceal the nanoparticles and prevent interparticle sintering upon exposure to high temperatures, and (c) heat treatment at 1000 °C. The formation of the hydroxide phase on these silicone oxide-coated MgO nanoparticles after extended exposure to humid air was assessed by thermogravimetry, infrared spectroscopy, and X-ray diffraction. The nanoparticles showed essentially no sign of any hydroxide phase compared to particles prepared by the conventional single-step thermal decomposition of Mg(OH)2. The moisture-resistant MgO nanoparticles showed improved dispersion and interfacial adhesion in the LDPE matrix with smaller nanosized particle clusters compared with conventionally prepared MgO. The addition of 1 wt % moisture-resistant MgO nanoparticles was sufficient to decrease the conductivity of polyethylene 30 times. The reduction in conductivity is discussed in terms of defect concentration on the surface of the moisture-resistant MgO nanoparticles at the polymer/nanoparticle interface.

  18. 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...

  19. 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

  20. Line Differential Protection Scheme Modelling for Underground 420 kV Cable Systems, EMTDC/PSCAD Relays Modelling

    DEFF Research Database (Denmark)

    Bak, Claus Leth; Sztykiel, Michal; Dollerup, Sebastian

    2011-01-01

    Based on the analysis of a specific relay model and an HVAC (High Voltage Alternating Current) cable system, a new approach to EMTDC/PSCAD modelling of protective relays is presented. Such approach allows creating complex and accurate relay models derived from the original algorithms. Relay models...... can be applied with various systems, allowing obtaining the most optimal configuration of the protective relaying. The present paper describes modelling methodology on the basis of Siemens SIPROTEC 4 7SD522/610. Relay model was verified experimentally with its real equivalent by both EMTP......-simulated and real world generated current signals connected to the relay....

  1. 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

  2. Semiannual report for the period October 1, 1979-March 31, 1980 of work on: (1) superconducting power transmission system development; (2) cable insulation development. Power Transmission Project Technical Note No. 106

    Energy Technology Data Exchange (ETDEWEB)

    1980-07-07

    Progress is reported in a program whose objective is to develop an underground superconducting power transmission system which is economical and technically attractive to the utility industry. The system would be capable of carrying very large blocks of electric power, and would supplant overhead lines in urban and suburban areas and regions of natural beauty. The program consisted initially of work in the laboratory to develop suitable materials, cryostats, and cable concepts. The materials work covers the development and testing of suitable superconductors and dielectric insulation. The laboratory work has now been extended to an outside test facility which represents an intermediate step between the laboratory scale and a full-scale system. The facility will allow cables several hundred feet long to be tested under realistic conditions. In addition, the refrigerator has been designed for optimum service for utility applications.

  3. 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

  4. Insulating and sheathing materials of electric and optical cables: common test methods part 4-1: methods specific to polyethylene and polypropylene compounds – resistance to environmental stress cracking – measurement of the melt flow index – carbon black and/or mineral filler content measurement in polyethylene by direct combustion – measurement of carbon black content by thermogravimetric analysis (TGA) – assessment of carbon black dispersion in polyethylene using a microscope

    CERN Document Server

    International Electrotechnical Commission. Geneva

    2004-01-01

    Specifies the test methods to be used for testing polymeric insulating and sheathing materials of electric cables for power distribution and telecommunications including cables used on ships. Gives the methods for measurements of the resistance to environmental stress cracking, for wrapping test after thermal ageing in air, for measurement of melt flow index and for measurement of carbon black and/or mineral filler content, which apply to PE and PP coumpounds, including cellular compounds and foam skin for insulation.

  5. 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

  6. 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.

  7. Cable aging management

    International Nuclear Information System (INIS)

    Anandkumaran, A.; Sedding, H.

    2012-01-01

    prerequisite for terminal electrical measurements. Instead, condition assessment of low voltage cables is based on chemical analysis of the materials that comprise the cable insulation and jacket. This contribution will discuss in detail the electrical, chemical and mechanical methods that have been employed in Canadian nuclear plants as well as the experience gained over the last 25 years. (author)

  8. 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

    A fire at a nuclear power plant (NPP) has the potential to damage structures, systems, and components important to safety, if not promptly detected and suppressed. At Browns Ferry Nuclear Power Plant on March 22, 1975, a fire in the reactor building damaged electrical power and control systems. Damage to instrumentation cables impeded the function of both normal and standby reactor coolant systems, and degraded the operators’ plant monitoring capability. This event resulted in additional NRC involvement with utilities to ensure that NPPs are properly protected from fire as intended by the NRC principle design criteria (i.e., general design criteria 3, Fire Protection). Current guidance and methods for both deterministic and performance based approaches typically make conservative (bounding) assumptions regarding the fire-induced failure modes of instrumentation cables and those failure modes effects on component and system response. Numerous fire testing programs have been conducted in the past to evaluate the failure modes and effects of electrical cables exposed to severe thermal conditions. However, that testing has primarily focused on control circuits with only a limited number of tests performed on instrumentation circuits. In 2001, the Nuclear Energy Institute (NEI) and the Electric Power Research Institute (EPRI) conducted a series of cable fire tests designed to address specific aspects of the cable failure and circuit fault issues of concern1. The NRC was invited to observe and participate in that program. The NRC sponsored Sandia National Laboratories to support this participation, whom among other things, added a 4-20 mA instrumentation circuit and instrumentation cabling to six of the tests. Although limited, one insight drawn from those instrumentation circuits tests was that the failure characteristics appeared to depend on the cable insulation material. The results showed that for thermoset insulated cables, the instrument reading tended to drift

  9. 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)

  10. 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

  11. 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

  12. Radiation techology in cable making industry

    International Nuclear Information System (INIS)

    Kourim, P.; Vokal, A.

    1985-01-01

    Electron accelerators are used in radiation cross-linking of elastomer and thermoplastic layers of cable insulation and sheathing. Another application is cross-linking of insulation bands and moulded products to achieve thermal contractibility. Ionizing radiation is used for curing insulation lacquers on winding leads. In Czechoslovakia, problems of radiation curing of silicone rubber have been studied since 1973. Instrumentation has been installed including accelerators. The feasibility has also been studied of radiation cross-linking of insulation and semiconductor cable cores of hose-type trailing cables. Polyethylene mixes have been designed and prepared which are suitable for radiation cross-linking aimed at increasing thermal resistance above 100 degC. (M.D.)

  13. 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)

  14. Behaviour at thermal ageing of power cable components through penetrations

    International Nuclear Information System (INIS)

    Puiu, D.; Gyongyosi, T.; Dinu, E.

    2009-01-01

    The materials for electric insulation and exterior jackets of the power cables are formulated organic compounds. The environmental service conditions will induce chemical and/or physical processes at molecular level of the material; these processes are the ageing mechanisms. The power cables passing through penetrations lead to an increase of the rate of thermal ageing mechanisms, resulting in irreversible degradation of mechanical and electric properties of the organic compounds and of the functional properties of the cable. The paper presents the results of the laboratory tests when the real environmental service conditions for penetration are simulated, the comparison with the results of the thermal computation of the power cables heating and the evaluation of the influence of temperature increase of the power cable components on the cable lifetime. For the particular case of a power cable with PVC insulation, we estimated a lifetime decrease about seven years as referred to lifetime of about 30 years for operation in air. (authors)

  15. Conventional cable testing methods: strengths, weaknesses and possibilities

    International Nuclear Information System (INIS)

    Reynolds, P.H.

    1988-01-01

    The paper reviews the major conventional methods that can be used to test power plant cables. It assesses their usefulness in diagnosing the condition of the insulation of the cable and then proposes some possible directions for innovation. The methods examined are dc insulation resistance measurement, ac signal injection for continuous monitoring and fault location, and the ac measurement of capacitance and loss angle. Specific subjects considered are the effects of temperature, cable construction and installation, and the validity of insulation resistance or loss angle measurement. The innovative proposals refer to the use of automation in the measurement and of computer-based Expert Systems for the evaluation of the results

  16. VPE single core medium voltage cables in EVU supply networks. [Polyethylene (VPE)

    Energy Technology Data Exchange (ETDEWEB)

    Reuter, E [Elektromark Kommunales Elektrizitaetswerk Mark A.G., Hagen (Germany, F.R.). Elektrotechnische Abt.

    1977-02-01

    This paper gives a brief outline of the different cable constructions and constructional parts of medium voltage cables (10 - 20 kV) in power supply networks. At medium voltage (particularly at 20 kV), single core cables are being used to an increasing extent, preferably for station supplies and for pole mounted cables. Polymerized polyethylene (VPE) is used as insulating material for this cable; according to present knowledge it is suitable for the insulation of power cables for all voltages up to 110 kV.

  17. Condition Monitoring of Cables Task 3 Report: Condition Monitoring Techniques for Electric Cables

    Energy Technology Data Exchange (ETDEWEB)

    Villaran, M.; Lofaro, R.; na

    2009-11-30

    For more than 20 years the NRC has sponsored research studying electric cable aging degradation, condition monitoring, and environmental qualification testing practices for electric cables used in nuclear power plants. This report summarizes several of the most effective and commonly used condition monitoring techniques available to detect damage and measure the extent of degradation in electric cable insulation. The technical basis for each technique is summarized, along with its application, trendability of test data, ease of performing the technique, advantages and limitations, and the usefulness of the test results to characterize and assess the condition of electric cables.

  18. Investigation of Rapid Low-Power Microwave-Induction Heating Scheme on the Cross-Linking Process of the Poly(4-vinylphenol) for the Gate Insulator of Pentacene-Based Thin-Film Transistors

    Science.gov (United States)

    Fan, Ching-Lin; Shang, Ming-Chi; Wang, Shea-Jue; Hsia, Mao-Yuan; Lee, Win-Der; Huang, Bohr-Ran

    2017-01-01

    In this study, a proposed Microwave-Induction Heating (MIH) scheme has been systematically studied to acquire suitable MIH parameters including chamber pressure, microwave power and heating time. The proposed MIH means that the thin indium tin oxide (ITO) metal below the Poly(4-vinylphenol) (PVP) film is heated rapidly by microwave irradiation and the heated ITO metal gate can heat the PVP gate insulator, resulting in PVP cross-linking. It is found that the attenuation of the microwave energy decreases with the decreasing chamber pressure. The optimal conditions are a power of 50 W, a heating time of 5 min, and a chamber pressure of 20 mTorr. When suitable MIH parameters were used, the effect of PVP cross-linking and the device performance were similar to those obtained using traditional oven heating, even though the cross-linking time was significantly decreased from 1 h to 5 min. Besides the gate leakage current, the interface trap state density (Nit) was also calculated to describe the interface status between the gate insulator and the active layer. The lowest interface trap state density can be found in the device with the PVP gate insulator cross-linked by using the optimal MIH condition. Therefore, it is believed that the MIH scheme is a good candidate to cross-link the PVP gate insulator for organic thin-film transistor applications as a result of its features of rapid heating (5 min) and low-power microwave-irradiation (50 W). PMID:28773101

  19. Investigation of Rapid Low-Power Microwave-Induction Heating Scheme on the Cross-Linking Process of the Poly(4-vinylphenol for the Gate Insulator of Pentacene-Based Thin-Film Transistors

    Directory of Open Access Journals (Sweden)

    Ching-Lin Fan

    2017-07-01

    Full Text Available In this study, a proposed Microwave-Induction Heating (MIH scheme has been systematically studied to acquire suitable MIH parameters including chamber pressure, microwave power and heating time. The proposed MIH means that the thin indium tin oxide (ITO metal below the Poly(4-vinylphenol (PVP film is heated rapidly by microwave irradiation and the heated ITO metal gate can heat the PVP gate insulator, resulting in PVP cross-linking. It is found that the attenuation of the microwave energy decreases with the decreasing chamber pressure. The optimal conditions are a power of 50 W, a heating time of 5 min, and a chamber pressure of 20 mTorr. When suitable MIH parameters were used, the effect of PVP cross-linking and the device performance were similar to those obtained using traditional oven heating, even though the cross-linking time was significantly decreased from 1 h to 5 min. Besides the gate leakage current, the interface trap state density (Nit was also calculated to describe the interface status between the gate insulator and the active layer. The lowest interface trap state density can be found in the device with the PVP gate insulator cross-linked by using the optimal MIH condition. Therefore, it is believed that the MIH scheme is a good candidate to cross-link the PVP gate insulator for organic thin-film transistor applications as a result of its features of rapid heating (5 min and low-power microwave-irradiation (50 W.

  20. Elements of a specification for superconducting cable and why they are important for magnet construction

    International Nuclear Information System (INIS)

    Greene, A.F.; Scanlan, R.M.

    1989-01-01

    The purpose of this paper is to point out several features of the specification for SSC superconducting cable and its insulation that are important for fabrication of dipole magnet coils. Among these are the dimensions of the cable and insulation and their relevance for obtaining coils with appropriate overall dimensions, Other important cable properties are related to the twist direction of wire used to fabricate it and the opposite twist (or lay) direction of the cable. For some coils it is easier to work with cable of a particular lay direction. In conjunction with the ease of coil winding comes the requirement in the specification for superconducting cable which restricts the cable surface condition. The ease of winding coils is governed by the ability to bend and twist the cable at the coil ends without having wires come out of place, possibly later leading to insulation damage and a turn-to-turn short. 5 refs., 11 figs., 1 tab

  1. 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.

  2. 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

  3. Fault Management of a Cold Dielectric HTS Power Transmission Cable

    International Nuclear Information System (INIS)

    Maguire, J; Allais, A; Yuan, J; Schmidt, F; Hamber, F; Welsh, Tom

    2006-01-01

    High temperature superconductor (HTS) power transmission cables offer significant advantages in power density over conventional copper-based cables. As with conventional cables, HTS cables must be safe and reliable when abnormal conditions, such as local and through faults, occur in the power grid. Due to the unique characteristics of HTS power cables, the fault management of an HTS cable is different from that of a conventional cable. Issues, such as nitrogen bubble formation within lapped dielectric material, need to be addressed. This paper reviews the efforts that have been performed to study the fault conditions of a cold dielectric HTS power cable. As a result of the efforts, a fault management scheme has been developed, which provides both local and through faults system protection. Details of the fault management scheme with examples are presented

  4. NRC Information Notice No. 92-01: Cable damage caused by inadequate cable installation procedures and controls

    International Nuclear Information System (INIS)

    Rossi, C.E.

    1993-01-01

    In June 1989, the Tennessee Valley Authority (TVA) removed the cables from a conduit in the reactor protection system of the Watts Bar Nuclear Plant, Unit 2, to inspect for damage. TVA selected this conduit in response to an employee's concern that a welding arc that struck the conduit in response to an employee's concern that a welding arc that struck the conduit during construction may have damaged cables in the conduit. When the cables were removed, TVA found significant damage in the insulation of some cables. This damage was not attributed to heat generated by the alleged welding arc. The damage was principally attributed to the pulling stresses exerted during the initial installation of the cables. Some of the cables had insulation removed down to the conductors. To assess the extent of cable damage and determine the scope of its investigation, TVA removed more cables from conduits that constituted the most difficult pulls (worst case) and found varying degrees of damage that it attributed to pulling stresses. To fill a conduit at Watts Bar, personnel used pull cords to pull more cables through the conduits over the top of existing cables. This practice is called ''pull-by.'' This practice can cause damage to the existing cables from the sawing action of the pull cords and the friction of cables as they are pulled over existing cables. TVA instituted programs to assess the adequacy of cable installation at all its nuclear facilities and take appropriate corrective actions. At Watts Bar, TVA replaced cables in conduits which exceeded a calculated threshold value of side wall bearing pressure (SWBP) and performed a high-potential (hi-pot) tests on a number of other cables in conduits with SWBP below the calculated threshold value

  5. ASSESSMENT OF CABLE AGING USING CONDITION MONITORING TECHNIQUES

    International Nuclear Information System (INIS)

    GROVE, E.; LOFARO, R.; SOO, P.; VILLARAN, M.; HSU, F.

    2000-01-01

    Electric cables in nuclear power plants suffer degradation during service as a result of the thermal and radiation environments in which they are installed. Instrumentation and control cables are one type of cable that provide an important role in reactor safety. Should the polymeric cable insulation material become embrittled and cracked during service, or during a loss-of-coolant-accident (LOCA) and when steam and high radiation conditions are anticipated, failure could occur and prevent the cables from fulfilling their intended safety function(s). A research program is being conducted at Brookhaven National Laboratory to evaluate condition monitoring (CM) techniques for estimating the amount of cable degradation experienced during in-plant service. The objectives of this program are to assess the ability of the cables to perform under a simulated LOCA without losing their ability to function effectively, and to identify CM techniques which may be used to determine the effective lifetime of cables. The cable insulation materials tested include ethylene propylene rubber (EPR) and cross-linked polyethylene (XLPE). Accelerated aging (thermal and radiation) to the equivalent of 40 years of service was performed, followed by exposure to simulated LOCA conditions. The effectiveness of chemical, electrical, and mechanical condition monitoring techniques are being evaluated. Results indicate that several of these methods can detect changes in material parameters with increasing age. However, each has its limitations, and a combination of methods may provide an effective means for trending cable degradation in order to assess the remaining life of cables

  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. 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.

  8. 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.

  9. Dielectric and Insulating Technology 2005 : Reviews & Forecasts

    Science.gov (United States)

    Okamoto, Tatsuki

    This article reports the state-of-art of TC-DEI ( Technical Committee of Dielectrics and Electrical Insulation of IEEJ) activites. The activiteis are basically based on the activites of 8-10 investigation committees under TC-DEI. Recent activites were categorized into three functions in this article and remarkable activity or trend for each category is mentioned as was done in the article of 2003. Thoese are activities on asset management (AI application and insulation diagnosis), activities on new insulating and functional materials (Nano composite) and activities on new insulation technology for power tansmission (high Tc superconducting cable insulation).

  10. Dielectric and Insulating Technology 2006 : Review & Forecast

    Science.gov (United States)

    Okamoto, Tatsuki

    This article reports the state-of-art of TC-DEI ( Technical Committee of Dielectrics and Electrical Insulation of IEEJ) activites. The activiteis are basically based on the activites of 8-10 investigation committees under TC-DEI. Recent activites were categorized into three functions in this article and remarkable activity or trend for each category is mentioned as was seen in the articles of 2005. Those are activities on asset management (AI application and insulation diagnosis), activities on new insulating and functional materials (Nano composite) and activities on new insulation technology for power tansmission (high Tc superconducting cable insulation).

  11. Sound Insulation between Dwellings

    DEFF Research Database (Denmark)

    Rasmussen, Birgit

    2011-01-01

    Regulatory sound insulation requirements for dwellings exist in more than 30 countries in Europe. In some countries, requirements have existed since the 1950s. Findings from comparative studies show that sound insulation descriptors and requirements represent a high degree of diversity...... and initiate – where needed – improvement of sound insulation of new and existing dwellings in Europe to the benefit of the inhabitants and the society. A European COST Action TU0901 "Integrating and Harmonizing Sound Insulation Aspects in Sustainable Urban Housing Constructions", has been established and runs...... 2009-2013. The main objectives of TU0901 are to prepare proposals for harmonized sound insulation descriptors and for a European sound classification scheme with a number of quality classes for dwellings. Findings from the studies provide input for the discussions in COST TU0901. Data collected from 24...

  12. Long-term test of the 22.9kV HTS power cable system in LS Cable Ltd

    International Nuclear Information System (INIS)

    Jang, Hyun Man; Lee, Chang Young; Kim, Choon Dong; Kim, Do Hyung; Park, In Son; Ji, Bong Ki; Kim, Dong Wook; Cho, Jeonwook

    2006-01-01

    Since 2001, LS cable Ltd. has been developing the design, manufacturing and evaluation technologies for high temperature superconducting (HTS) power cable system as a member of DAPAS (Dream for Advanced Power system by Applied Superconductivity technology) program in Korea. The 30 m HTS cable system that is rated at 22.9 kV and 1.2 kA giving a rated capacity of 50 MVA had been developed and tested. The cable was designed as a cold dielectric type employing Bi-2223 HTS tapes and polypropylene (PP) laminated paper as the conductor and electrical insulation, respectively. The cable is cooled with sub-cooled liquid nitrogen at temperature from 75 to 77 K. The manufacturing and the installation of the cable system were completed in 2004. Long-term performance test of the cable system has been conducted for six months to verify its electric and mechanical properties in 2005

  13. Modelling of long High Voltage AC Cables in the Transmission System

    DEFF Research Database (Denmark)

    Gudmundsdottir, Unnur Stella

    : conductor-insulation (with or without SC layers)-conductor-insulation(-conductor-insulation), whereas a transmission line single core XLPE cable will normally have the configuration: conductor-SC layerinsulation-SC layer-conductor-SC layer-conductor-insulation. Furthermore the existing cable models use......, EMTDC/PSCAD is provided. A typical HV AC underground power cable is formed by 4 main layers, namely; Conductor-Insulation-Screen-Insulation. In addition to these main layers, the cable also has semiconductive screens, swelling tapes and metal foil. For high frequency modelling in EMT-based software......-SC layer-solid hollow conductor) is implemented in the model. These improvements result in a more correct series impedance and hence a more correct damping of the simulations. Even though the series impedance is more correct, it does still not include the proximity effect and high frequency oscillations...

  14. High power cable with internal water cooling 400 kV

    Science.gov (United States)

    Rasquin, W.; Harjes, B.

    1982-08-01

    Due to the concentration of electricity production in large power plants, the need of higher power transmissions, and the protection of environment, developement of a 400 kV water cooled cable in the power range of 1 to 5 GVA was undertaken. The fabrication and testing of equipment, engineering of cable components, fabrication of a test cable, development of cable terminal laboratory, testing of test cable, field testing of test cable, fabrication of industrial cable laboratory, testing of industrial cable, field testing of industrial cable, and system analysis for optimization were prepared. The field testing was impossible to realize. However, it is proved that a cable consisting of an internal stainless steel water cooled tube, covered by stranded copper profiles, insulated with heavy high quality paper, and protected by an aluminum cover can be produced, withstand tests accordingly to IEC/VDE recommendations, and is able to fulfill all exploitation conditions.

  15. New, clean handling process introduced to improve cable quality

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, C G

    1990-05-01

    The clean room system introduced by Canada Wire and Cable Limited in its Toronto plant for its cable manufacturing operation is described. While clean room technology is common in the food processing industry, optical and aerospace manufacturing processes, this is the first time it has been applied to wire and cable extrusion in North America. The purpose of the clean compound handling system is to prevent particle contamination in the shielding and cable insulation materials, as part of an effort to prevent premature underground electric cable failures. Two rooms are dedicated to handling different types of insulation compound, two are dedicated to receiving semi-conducting shielding material, and the fifth room functions as an air lock for the two insulation rooms. The atmosphere is highly regulated with programmable logic control. The air supply filters capture 99.97% of all particles 0.3 microns or larger. The system also maintains air temperature, relative humidity and static pressure. The life variability of cross-linked polyethylene primary distribution cable is dependant on five factors: material purity, extra clean compound handling, cable design, manufacturing process, and installation and operation practices. The clean room system is expected to result in cable that is more resistant to water treeing failures. 2 figs.

  16. Sound cable crossing brings inexpensive electric power to Long Island

    International Nuclear Information System (INIS)

    Grzan, J.; Goyette, R.

    1992-01-01

    This paper reports that while many electric-utility customers in New York State benefit from inexpensive hydroelectric power from Canada and upstate New York, lack of sufficient transmission connections have prevented this electricity from reaching Long Island. However, a newly constructed underground/underwater link capable of carrying 700-MW now transmits low-cost electricity to the island, saving money for customers. The self-contained fluid-filled cable used for the underwater portion of the project is the largest underwater cable in the world. The use of high-pressure, fluid-filled pipe-type cable on the land portion represents the largest application of paper-polypropylene-paper (PPP) insulated cable in the United States. State-of-the-art technologies were implemented in the use of temperature monitoring and leak detection systems, SF 6 gas-insulated substation, and underwater cable laying and embedment techniques

  17. Ageing of instrumentation and control cables in NPPs

    International Nuclear Information System (INIS)

    Santhosh; Ghosh, A.K.; Fernandes, B.G.

    2011-01-01

    Cables are vital components of instrumentation and control (I and C) systems in nuclear power plants (NPPs). The polymer materials used for insulation and jacket materials for electric cables are susceptible to ageing and degradation mechanisms caused by exposure to many of the stressors encountered in NPP service conditions. Ageing of components in NPP is an important concern since the degradation caused by ageing can impact the performance of susceptible equipment. This is of particular concern for safety-related equipment since the failure due to ageing can compromise the continued safe operation of the plant. The state-of-the art for incorporating cable ageing effects into probabilistic safety assessment (PSA) is still evolving and in the reliability assessment of NPP systems, the ageing effect of electrical cable is generally not considered and also, there is no standard method exists for incorporating such ageing effects into the system reliability. Therefore, identification and quantification of ageing of electrical cables is very much essential for an accurate prediction of system reliability for PSA applications. The objective of this study is to develop a methodology to assess the susceptibility of polymeric cable insulation to various ageing mechanisms; and the state of the insulation at any chosen time in order to evaluate the remaining life-time of operating cables in NPPs. This paper presents the state-of-the-art tools and techniques for insulation condition assessment, insulation life prediction methodologies, equipment qualification guidelines, and ageing management programs relating to I and C cables in NPPs. An approach to calculate the insulation resistance subjecting to different stressors has also been presented in this paper. (author)

  18. 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....

  19. 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.

  20. 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)

  1. Estudio de la cargabilidad de cables de alta tensión de aislamiento sólido con las variaciones periódicas de la carga; Study of the current capacity of solid insulation high voltage cables with periodical changes of load

    Directory of Open Access Journals (Sweden)

    Juan F Zuñinga

    2011-02-01

    Full Text Available Se plantean los resultados obtenidos al introducir una corrección al método desarrollado en el CIPEL para elcálculo de la cargabilidad de cables soterrados considerando las variaciones periódicas de la curva de cargadiaria y la impedancia compleja del medio que rodea a la instalación a partir del empleo de funciones Bessel yHankel. La validación de la corrección propuesta se realizó mediante el cálculo, con y sin la corrección planteada,de la temperatura superficial de cables en servicio por el método de cálculo propuesto y su comparación conlos medidos en la superficie de dichos cables  This work presents the results obtaines after the introduction of a correction to the method developed in theCIPEL to calculate the current capacity of underground cables considering the periodical chnages of the loadchanges of the daily load curve and the complex impedance of the enviroment sorrounding the installation usingBessel and Hankel funtions.The validity of the proposed correction was carried out calculating the surfacetemperature of the cables in service by means of the calculating method  with and whithout the correction  andthe  comparison of these values with the temperature mesured on the surface of the cables

  2. Recent Progress in Electrical Insulation Techniques for HTS Power Apparatus

    Science.gov (United States)

    Hayakawa, Naoki; Kojima, Hiroki; Hanai, Masahiro; Okubo, Hitoshi

    This paper describes the electrical insulation techniques at cryogenic temperatures, i.e. Cryodielectrics, for HTS power apparatus, e.g. HTS power transmission cables, transformers, fault current limiters and SMES. Breakdown and partial discharge characteristics are discussed for different electrical insulation configurations of LN2, sub-cooled LN2, solid, vacuum and their composite insulation systems. Dynamic and static insulation performances with and without taking account of quench in HTS materials are also introduced.

  3. 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.

  4. Heat resistant/radiation resistant cable and incore structure test device for FBR type reactor

    International Nuclear Information System (INIS)

    Tanimoto, Hajime; Shiono, Takeo; Sato, Yoshimi; Ito, Kazumi; Sudo, Shigeaki; Saito, Shin-ichi; Mitsui, Hisayasu.

    1995-01-01

    A heat resistant/radiation resistant coaxial cable of the present invention comprises an insulation layer, an outer conductor and a protection cover in this order on an inner conductor, in which the insulation layer comprises thermoplastic polyimide. In the same manner, a heat resistant/radiation resistant power cable has an insulation layer comprising thermoplastic polyimide on a conductor, and is provided with a protection cover comprising braid of alamide fibers at the outer circumference of the insulation layer. An incore structure test device for an FBR type reactor comprises the heat resistant/radiation resistant coaxial cable and/or the power cable. The thermoplastic polyimide can be extrusion molded, and has excellent radiation resistant by the extrusion, as well as has high dielectric withstand voltage, good flexibility and electric characteristics at high temperature. The incore structure test device for the FBR type reactor of the present invention comprising such a cable has excellent reliability and durability. (T.M.)

  5. Gas insulated substations

    CERN Document Server

    2014-01-01

    This book provides an overview on the particular development steps of gas insulated high-voltage switchgear, and is based on the information given with the editor's tutorial. The theory is kept low only as much as it is needed to understand gas insulated technology, with the main focus of the book being on delivering practical application knowledge. It discusses some introductory and advanced aspects in the meaning of applications. The start of the book presents the theory of Gas Insulated Technology, and outlines reliability, design, safety, grounding and bonding, and factors for choosing GIS. The third chapter presents the technology, covering the following in detail: manufacturing, specification, instrument transformers, Gas Insulated Bus, and the assembly process. Next, the book goes into control and monitoring, which covers local control cabinet, bay controller, control schemes, and digital communication. Testing is explained in the middle of the book before installation and energization. Importantly, ...

  6. 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.

  7. Dielectric and Insulating Technology 2004 : Review & Forecast

    Science.gov (United States)

    Okamoto, Tatsuki

    This article reports the state-of-art of DEIS activites. DEIS activiteis are basically based on the activites of 8-10 investigation committees’ under DEIS committee. Recent DEIS activites are categlized into three functions in this article and remarkable activity or trend of each category is mentioned. Those are activities on insulation diagnosis (AI application and asset management), activities on new insulation technology for power tansmission (high Tc super conducting cable insulation and all solid sinulated substation), and activities on new insulating materials (Nanocomposite).

  8. Thin film conductors for self-equalizing cables

    Science.gov (United States)

    Owen, G.; Trutna, W. R.; Orsley, T. J.; Lucia, F.; Daly, C. B.

    2017-10-01

    Self-equalizing cables using hollow conductors with wall thickness less than the skin depth were proposed in 1929. However, they do not appear ever to have been widely used, although the idea has resurfaced and been refined from time to time. In the early 2000's, self-equalizing conductors consisting of solid magnetic steel cores coated with silver were developed by W.L. Gore, and used in their 2.5 Gb/s "Eye-Opener" cables, although higher speed versions never appeared. We have revived the original 1929 idea, proposing to use glass as a solid insulating core. This technology can potentially work at frequencies of many 10's of GHz. Possible uses include short range GHz links such as USB and Thunderbolt, and intra-rack interconnections in data centers. Our feasibility experiments have validated the principle. Copper coated glass fibers can, in principle, be manufactured, but in these tests, the conductors were capillaries internally coated with silver as these are easily obtainable, relatively inexpensive and serve to test the concept. The performance of these experimental twin lead cables corresponds to calculations, confirming the general principle. By calculation, we have compared the performance of cables made from copper-on-insulator conductors to that of similar cables made with solid copper conductors, and verified that copper-on-insulator cables have significantly less frequency dependent loss. We have also made and tested cables with copper on PEEK conductors as surrogates for copper on glass fiber.

  9. Sistema de prueba para la determinación de la capacitancia y permitividad relativa en cables de bajo voltaje del tipo TW y THW

    Directory of Open Access Journals (Sweden)

    Juan Almirall Mesa

    2011-02-01

    Full Text Available En los cables de baja tensión la comprobación de la calidad del material aislante de recubrimiento seefectúa a partir de la evaluación de parámetros eléctricos tales como: la resistencia de aislamiento y lacapacitancia del mismo. En el presente trabajo se expone el esquema de prueba, su calibración y elanálisis de la metodología de ensayo empleada, para medir la capacitancia de cables nacionales del tipoTW y THW. El esquema general de pruebas consta de dos partes fundamentales: el sistema de pruebapara la medición de los parámetros eléctricos y el sistema de control de temperatura y de nivel del líquidodonde se sumergen los cables para los ensayos, este último garantiza que los cambios de temperaturaen el mismo se mantengan en el rango establecido por las normas. La metodología tiene en cuenta ladeterminación del efecto que tienen las condiciones iniciales sobre los resultados finales.  The verification of the quality of the covering insulating material in low voltage cables is carried outbeginning whit the evaluation of electric parameters such as: insulating resistance and capacitance of thesame. In this work, the test scheme, its calibration and the analyses of the methodology of the employedtest, for measuring the national cables capacitance of the TW and THW type are exposed. The generalscheme of test consist in two fundamental parts: the test system for the measure of the electric parametersand the temperature and liquid level control system where the cables are immersed for the test, the lastsystem guarantee that the temperature changes in the same in the establish range by the standards aremaintained.The methodology taking into account the determination of the effect that has the startingconditions on the final results.

  10. NEPO cable system aging management programs

    International Nuclear Information System (INIS)

    Toman, G.

    2002-01-01

    Full text: Cable polymer aging and condition monitoring is being studied in detail under the Nuclear Energy Plant Optimization Program (NEPO) that is co-sponsored by the U.S. Department of Energy and EPRI. Significant advances in modeling of polymer aging and condition monitoring have occurred and continue to be developed. The activities include: Analysis of the linearity of the Arrhenius model to room temperature; Development of a wear-out technique for determining remaining life of cable polymers; Determination of the aging fragility point for composite EPR/CSPE insulation with respect to LOCA function; Development of visual/tactile training aids for cable assessment; Development of a totally new nuclear magnetic resonance condition monitoring technique; Assessment of existing techniques with regard to repeatability, accuracy and ease of use. Through use of highly precise oxygen consumption experiments, the linearity of the Arrhenius model is being evaluated. In these experiments, polymer is placed in vials with a known amount of oxygen and aged at much lower temperatures than is possible with standard accelerated aging techniques. aging results are possible at room temperature. The technique is being applied to commonly used insulation and jacket polymers. The wear-out technique allows highly non-linear aging behavior to be made linear. The wearout point of a polymer is determined through high-rate aging and use of a condition monitoring technique to establish the end point. Then, micro-samples of cable that have been naturally aged are subjected to high rate aging to the same end point. The ratio of the remaining high rate aging period to the total high rate aging time provides a linear indication of the remaining service time. Initial screening of nuclear plant cable systems can use visual/tactile techniques to identify cable that has aged significantly. Training aids have been developed by developing sets of specimens with accelerated aging ranging from none

  11. Bulk Electrical Cable Non-Destructive Examination Methods for Nuclear Power Plant Cable Aging Management Programs

    Energy Technology Data Exchange (ETDEWEB)

    Glass, Samuel W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jones, Anthony M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fifield, Leonard S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hartman, Trenton S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-09-01

    This Pacific Northwest National Laboratory milestone report describes progress to date on the investigation of nondestructive test methods focusing particularly on bulk electrical test methods that provide key indicators of cable aging and damage. The work includes a review of relevant literature as well as hands-on experimental verification of inspection capabilities. As nuclear power plants consider applying for second, or subsequent, license renewal to extend their operating period from 60 years to 80 years, it is important to understand how the materials installed in plant systems and components will age during that time and develop aging management programs to assure continued safe operation under normal and design basis events (DBE). Normal component and system tests typically confirm the cables can perform their normal operational function. The focus of the cable test program, however, is directed toward the more demanding challenge of assuring the cable function under accident or DBE. The industry has adopted 50% elongation at break (EAB) relative to the un-aged cable condition as the acceptability standard. All tests are benchmarked against the cable EAB test. EAB, however, is a destructive test so the test programs must apply an array of other nondestructive examination (NDE) tests to assure or infer the overall set of cable’s system integrity. Assessment of cable integrity is further complicated in many cases by vendor’s use of dissimilar material for jacket and insulation. Frequently the jacket will degrade more rapidly than the underlying insulation. Although this can serve as an early alert to cable damage, direct test of the cable insulation without violating the protective jacket becomes problematic. This report addresses the range of bulk electrical NDE cable tests that are or could be practically implemented in a field-test situation with a particular focus on frequency domain reflectometry (FDR). The FDR test method offers numerous advantages

  12. Electrically and Thermally Insulated Joint for Liquid Nitrogen Transfer

    DEFF Research Database (Denmark)

    Rasmussen, Carsten; Jensen, Kim Høj; Holbøll, Joachim T.

    1999-01-01

    A prototype of a superconducting cable is currently under construction. The cable conductor is cooled by liquid nitrogen in order to obtain superconductivity. The peripheral cooling circuit is kept at ground potential. This requires a joint which insulates both electrically and thermally...

  13. 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.

  14. The moisture proof connection of signal cables on test rig instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Joung, Chang Young; Ahn, Sung Ho; Hong, Jin Tae; Jeong, Hwang Young [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-10-15

    The rod inner pressure, centerline temperature, coolant temperature, and neutron flux resulting from the irradiation properties of nuclear fuel are an important factor for evaluating nuclear fuel properties in pile. In addition instrumentation and measurement techniques for nuclear fuel are necessary to measure the exact data. Special sensors such as a TC (thermocouple), LVDT (linear variable differential transformer) and SPND (self-powered neutron detector) are instrumented in and out of the fuel rod to measure the various irradiation characteristics of the nuclear fuel. These sensors are made up of the sensor itself and a signal cable. In the instrumentation, an MI (Mineral Insulated) cable used as the signal cable has such properties as high electrical insulation, heat resistance, and mechanical strength. However, it is difficult to handle and treat with care owing to the extremely hard composition, which is made up of weak signal wires and alumina powder in a stainless tube. The sealing of the end tip of the MI cable and extension cable is very important in terms of the insulation resistance to seal the insulator inside the MI cable tube from moisture. To maintain the insulation of sensors and signal cables, the insulation resistance must be checked in accordance with each process throughout the instrumentation and fabrication period. To safely mount the signal cables drawn from a fuel test rig on the terminal block of a junction panel, the MI and extension cables should be easy to connect. Therefore, it is necessary to develop instrumentation technologies of a moisture proof connection process for a fuel test rig. This paper will provide an overview of the work done with moisture proof connection procedures to connect the MI and extension cables to extend the MI cables jointed with the sensor.

  15. Organic dielectrics in high voltage cables

    Energy Technology Data Exchange (ETDEWEB)

    Vermeer, J

    1962-03-01

    It appears that the limit has been reached in the applicability of oil-impregnated paper as the dielectric for ehv cables, as with rising voltages the prevention of conductor losses becomes increasingly difficult, while the dielectric losses of the insulation, increasing as the square of the voltage, contribute to a greater extent to the temperature rise of the conductor. The power transmitting capacity of ehv cables reaches a maximum at 500 to 600 kV for these reasons. Apart from artificial cooling, a substantial improvement can be obtained only with the use of insulating materials with much lower dielectric losses; these can moreover be applied with a smaller wall thickness, but this means higher field strengths. Synthetic polymer materials meet these requirements but can be used successfully only in the form of lapped film tapes impregnated with suitable liquids. The electrical properties of these heterogeneous dielectrics, in particular, their impulse breakdown strengths are studied in detail.

  16. High temperature superconductor cable concepts for fusion magnets

    CERN Document Server

    AUTHOR|(CDS)2078397

    2013-01-01

    Three concepts of high temperature superconductor cables carrying kA currents (RACC, CORC and TSTC) are investigated, optimized and evaluated in the scope of their applicability as conductor in fusion magnets. The magnetic field and temperature dependence of the cables is measured; the thermal expansion and conductivity of structure, insulation and filling materials are investigated. High temperature superconductor winding packs for fusion magnets are calculated and compared with corresponding low temperature superconductor cases.

  17. Advanced refrigeration system for the Brookhaven superconducting cable project

    International Nuclear Information System (INIS)

    Jensen, J.E.

    1975-01-01

    A description is given of a basic supercritical refrigerator. The present status of the cable enclosure and the types of cooling schemes being considered are presented with some examples of laboratory results and computer analysis. (MOW)

  18. 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.

  19. 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....

  20. Interim report on assessment of cable aging for nuclear power plants

    International Nuclear Information System (INIS)

    2006-12-01

    Research on assessment of cable aging for nuclear power plants (NPPs) started in 2002 in order to obtain data of safety-related cables affected by thermal aging, simultaneous thermal and radiation aging, and Loss-of-Coolant Accident (LOCA) equivalent test, which could contribute to draft guideline on comprehensive assessment of cable aging for NPPs while taking into consideration the latest knowledge. For the cable aging test, cross-linked polyethylene, flame-retardant cross-linked polyethylene, ethylene propylene rubber, flame-retardant ethylene propylene rubber, silicone rubber and special heat-resistant polyvinyl chloride insulators were selected from the safety-related cables used in the nuclear power plants. Furthermore, 2 to 3 kinds of cables with insulators of different manufacturers were added making a total of 14 kinds of cable specimens for the test. Aging period was selected as a basic parameter while three temperature conditions for thermal aging specimen and combined nine conditions of three temperatures with three dose rates for simultaneous aging specimens. Degradation of cable aging was characterized by elongation at break of tensile test. LOCA test for 9 kinds of cables was also conducted using the simultaneous aging specimens. Furthermore, the investigation of applicability of non-destructive degradation diagnostic technologies for aged cables was conducted to confirm the validity of cable aging evaluation at actual operating plants. Interim report was issued in 2006 and based on cable aging test until 21,000 hrs maximum; 1) a significant difference might be observed at times in the aging progress depending on the insulator manufacturer even if the insulator type was identical, 2) activation energy values calculated from the thermal aging test data were smaller than those currently used and principles of calculation and application of the activation energy were developed for evaluation and 3) superposition of time dependent data was applicable to

  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. Aging, Loss-of-Coolant Accident (LOCA), and high potential testing of damaged cables

    International Nuclear Information System (INIS)

    Vigil, R.A.; Jacobus, M.J.

    1994-04-01

    Experiments were conducted to assess the effects of high potential testing of cables and to assess the survivability of aged and damaged cables under Loss-of-Coolant Accident (LOCA) conditions. High potential testing at 240 Vdc/mil on undamaged cables suggested that no damage was incurred on the selected virgin cables. During aging and LOCA testing, Okonite ethylene propylene rubber (EPR) cables with a bonded jacket experienced unexpected failures. The failures appear to be primarily related to the level of thermal aging and the presence of a bonded jacket that ages more rapidly than the insulation. For Brand Rex crosslinked polyolefin (XLPO) cables, the results suggest that 7 mils of insulation remaining should give the cables a high probability of surviving accident exposure following aging. The voltage necessary to detect when 7 mils of insulation remain on unaged Brand Rex cables is approximately 35 kVdc. This voltage level would almost certainly be unacceptable to a utility for use as a damage assessment tool. However, additional tests indicated that a 35 kvdc voltage application would not damage virgin Brand Rex cables when tested in water. Although two damaged Rockbestos silicone rubber cables also failed during the accident test, no correlation between failures and level of damage was apparent

  5. Results of Recent DOE Research on Development of Cable Condition Monitoring and Aging Management Technologies

    International Nuclear Information System (INIS)

    Campbell, C.J.; McConkey, J.B.; Hashemian, H.M.; Sexton, C.D.; Cummins, D.S.

    2012-01-01

    Analysis and Measurement Services (AMS) Corporation has been conducting two research projects focused on understanding cable aging and developing cable condition monitoring technologies for nuclear power plants. The goal of the first project is to correlate cable faults with testing techniques that can identify and locate the faults whether they are in the cable, conductor, or the insulation. This project involves laboratory experiments using low and medium voltage cable types typically installed in nuclear power plants. The second project is focused on development of an integrated cable condition monitoring system for nuclear facilities. This system integrates a number of cable testing and cable condition monitoring techniques, such as the time domain reflectometry (TDR), frequency domain reflectometry (FDR), inductance, capacitance, resistance (LCR), reverse TDR (RTDR), current-to-voltage (IV) for testing of nuclear instrumentation sensors, insulation resistance (IR) and other techniques. The purpose of the project is to combine all proven technologies into one system to detect and pinpoint problems in cable circuits as well as cable insulation, shield, or jacket material. (author)

  6. Acoustic insulator for combined well equipment of acoustic and radioactivity logging

    International Nuclear Information System (INIS)

    Arkad'ev, E.A.; Gorbachev, Yu.I.; Dseban', I.P.; Yagodov, G.I.

    1977-01-01

    The design of an acoustic insulator for cobined well equipment of acoustic and radioactivity logaing made on the basis of studying the velocity of elastic waves propagation and attenuation in cable structures of various marks is described. It is shown that the cable probe of electric loggign equipment which is recommended as an acoustic insulator for combined well equipment has the necessary sound-insulating properties

  7. Application study on the first cable-stayed bridge with CFRP cables in China

    Directory of Open Access Journals (Sweden)

    Kuihua Mei

    2015-08-01

    Full Text Available In order to push forward the development of CFRP cable-stayed bridge and accumulate experiences, the study on the application of the first cable-stayed bridge with CFRP cables in China was carried out. The design essentials of main components of the bridge were introduced and its integral performances, including static properties, dynamic properties and seismic response were analyzed using finite element method. A new bond-type anchorage was developed and the processes of fabricating and installing CFRP cables were elaborated. Based on the results of construction simulation, a tension scheme for bridge was propound. During constructing, the stresses and displacement of girder and pylon, as well as the forces and stresses of cables, were tested. The results indicate that all sections of the bridge could meet the requirements of the ultimate bearing capacity and normal service; the performance of the anchorage is good and the stresses in each cable system are similar; the tested values accord well with the calculated values. Further, creep deformation of the resin in anchorages under service load is not obvious. All these results demonstrate that the first application of CFRP cables in the cable-stayed bridge in China is successful.

  8. Thermal insulation

    International Nuclear Information System (INIS)

    Aspden, G.J.; Howard, R.S.

    1988-01-01

    The patent concerns high temperature thermal insulation of large vessels, such as the primary vessel of a liquid metal cooled nuclear reactor. The thermal insulation consists of multilayered thermal insulation modules, and each module comprises a number of metal sheet layers sandwiched between a back and front plate. The layers are linked together by straps and clips to control the thickness of the module. (U.K.)

  9. Cellulose Insulation

    Science.gov (United States)

    1980-01-01

    Fire retardant cellulose insulation is produced by shredding old newspapers and treating them with a combination of chemicals. Insulating material is blown into walls and attics to form a fiber layer which blocks the flow of air. All-Weather Insulation's founders asked NASA/UK-TAP to help. They wanted to know what chemicals added to newspaper would produce an insulating material capable of meeting federal specifications. TAP researched the query and furnished extensive information. The information contributed to successful development of the product and helped launch a small business enterprise which is now growing rapidly.

  10. Arc tracking energy balance for copper and aluminum aeronautic cables

    International Nuclear Information System (INIS)

    André, T; Valensi, F; Teulet, P; Cressault, Y; Zink, T; Caussé, R

    2017-01-01

    Arc tracking tests have been carried out between two voluntarily damaged aeronautic cables. Copper or aluminum conductors have been exposed to short circuits under alternating current. Various data have been recorded (arc voltage and current, radiated power and ablated mass), enabling to determine a power balance, in which every contribution is estimated. The total power is mainly transferred to the cables (between 50 and 65%, depending on the current and the cable type), and causes the melting and partial vaporization of the metallic core and insulating material, or is conducted or radiated. The other part is deposited into the arc column, being either radiated, convected or conducted. (paper)

  11. 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)

  12. Life-assessment technique for nuclear power plant cables

    International Nuclear Information System (INIS)

    Bartonicek, B.; Hnat, V.; Placek, V.

    1998-01-01

    The condition of polymer-based cable material can be best characterized by measuring elongation at break of its insulating materials. However, it is not often possible to take sufficiently large samples for measurement with the tensile testing machine. The problem has been conveniently solved by utilizing differential scanning calorimetry technique. From the tested cable, several microsamples are taken and the oxidation induction time (OIT) is determined. For each cable which is subject to the assessment of the lifetime, the correlation of OIT with elongation at break and the correlation of elongation at break with the cable service time has to be performed. A reliable assessment of the cable lifetime depends on accuracy of these correlations. Consequently, synergistic effects well known at this time - dose rate effects and effects resulting from the different sequence of applying radiation and elevated temperature must be taken into account

  13. Development of environmental-friendly wire and cable

    International Nuclear Information System (INIS)

    Ueno, Keiji

    1996-01-01

    The electron beam technology has been used in many industrial fields as a method of conventional polymer modification or optimum processability. The main industrial fields of radiation crosslinking are wire and cable, heat shrinkable tubings, plastic foams, precuring of tires, floppy disk curing, foods packaging films, and so on. The radiation crosslinking of wire and cable was started in 1961 in Japan and 15 wire and cable companies are now using electron beam accelerators for production or R and D. The dominant characteristics of crosslinking of insulation materials are application at high temperature, good oil and chemical resistibility and high mechanical properties. These radiation crosslinking wire and cable are applied widely in electronics equipments and automobiles. Recently, electronics manufacturers have indicated deep concern over the effects on the environment. Wire and cable also are required to be applicable for environmental preservation. (J.P.N.)

  14. 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.

  15. Crystal River 3 Cable Materials for Thermal and Gamma Radiation Aging

    Energy Technology Data Exchange (ETDEWEB)

    Fifield, Leonard S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Correa, Miguel [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zwoster, Andy [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2017-09-07

    The Expanded Materials Degradation Assessment Volume 5: Aging of Cables and Cable Systems (EMDA) summarizes the state of knowledge of materials, constructions, operating environments, and aging behavior of low voltage and medium cables in nuclear power plants (NPPs) and identifies potential knowledge gaps with regard to cable operation beyond 60 years. The greatest area of uncertainty relates to how well the accelerated aging used in the original equipment qualification (EQ) processes predicts the performance of cable materials in extended operation. General opinion and utility experience have indicated that actual operating environments of in-plant cables are not as severe, however, as the operating and design basis environments used in the qualification process. Better understanding of the long term aging behavior of cable insulation materials in service conditions and the analysis of actual cable operating environments are the objectives of ongoing research to support subsequent license renewal activities in particular and long term cable aging management in general. A key component of the effort to better understand cable material aging behavior is the availability of representative samples of cables that have been installed in operating light water reactors and have experienced long term service. Unique access to long term service cables, including relatively rich information on cable identity and history, occurred in 2016 through the assistance of the Electric Power Research Institute (EPRI). EPRI facilitated DOE receipt of harvested cables from the decommissioned Crystal River Unit 3 (CR3) pressurized water reactor representing six of the nine most common low voltage cable manufacturers (EPRI 103841R1): Rockbestos, Anaconda Wire and Cable Company (Anaconda), Boston Insulated Wire (BIW), Brand-Rex, Kerite and Okonite. Cable samples received had been installed in the operating plant for durations ranging from 10 years to 36 years. These cables provide the

  16. Reliability studies, construction and test of a pilot cable installation with supra-conductors

    International Nuclear Information System (INIS)

    Franke, H.; Allgemeine Elektricitaets-Gesellschaft AEG Telefunken Kabelwerke A.G., Moenchengladbach; Kabel- und Metallwerke Gutehoffnungshuette A.G., Hannover; Linde A.G., Hoellriegelskreuth

    1980-01-01

    The basic knowledge of electrical insulation, of current carrying capacity of superconductors, of contraction of papers and of thermal insulation was extended. Different kinds of cable-joints were developed. Voltage tests of a testline were made. The line stands the operating voltage, the terminations must be improved to stand the test voltage. The cooling system of a larger cable installation was studied. (orig.) [de

  17. Thermal insulation

    International Nuclear Information System (INIS)

    Pinsky, G.P.

    1977-01-01

    Thermal insulation for vessels and piping within the reactor containment area of nuclear power plants is disclosed. The thermal insulation of this invention can be readily removed and replaced from the vessels and piping for inservice inspection, can withstand repeated wettings and dryings, and can resist high temperatures for long periods of time. 4 claims, 3 figures

  18. Design and construction of the mineral insulated magnets

    International Nuclear Information System (INIS)

    Kurokawa, S.; Hirabayashi, H.; Taino, M.; Tsuchiya, K.; Yamamoto, A.

    1978-01-01

    The radiation resistant magnets with mineral insulated coils are designed and constructed. The electrical insulation of the cable is maintained by magnesium oxide in the form of a powder held around the copper hollow conductor by a copper shieth. By the direct water cooling through a hollow conductor the sometimes conflicting requirements of good insulation and high field are fulfilled. The magnets can with stand more than 10 12 rad of absorbed dose. (author)

  19. Status Report and Research Plan for Cables Harvested from Crystal River Unit 3 Nuclear Generating Plant

    Energy Technology Data Exchange (ETDEWEB)

    Fifield, Leonard S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-09-20

    Harvested cables from operating or decommissioned nuclear power plants present an important opportunity to validate models, understanding material aging behavior, and validate characterization techniques. Crystal River Unit 3 Nuclear Generating Plant is a pressurized water reactor that was licensed to operate from 1976 to 2013. Cable segments were harvested and made available to the Light Water Reactor Sustainability research program through the Electric Power Research Institute. Information on the locations and circuits within the reactor from whence the cable segments came, cable construction, sourcing and installation information, and photographs of the cable locations prior to harvesting were provided. The cable variations provided represent six of the ten most common cable insulations in the nuclear industry and experienced service usage for periods from 15 to 42 years. Subsequently, these cables constitute a valuable asset for research to understand aging behavior and measurement of nuclear cables. Received cables harvested from Crystal River Unit 3 Nuclear Generating Plant consist of low voltage, insulated conductor surrounded by jackets in lengths from 24 to 100 feet each. Cable materials will primarily be used to investigate aging under simultaneous thermal and gamma radiation exposure. Each cable insulation and jacket material will be characterized in its as-received condition, including determination of the temperatures associated with endothermic transitions in the material using differential scanning calorimetry and dynamic mechanical analysis. Temperatures for additional thermal exposure aging will be selected following the thermal analysis to avoid transitions in accelerated laboratory aging that do not occur in field conditions. Aging temperatures above thermal transitions may also be targeted to investigate the potential for artifacts in lifetime prediction from rapid accelerated aging. Total gamma doses and dose rates targeted for each material

  20. 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

  1. Literature review of environmental qualification of safety-related electric cables: Summary of past work. Volume 1

    International Nuclear Information System (INIS)

    Subudhi, M.

    1996-04-01

    This report summarizes the findings from a review of published documents dealing with research on the environmental qualification of safety-related electric cables used in nuclear power plants. Simulations of accelerated aging and accident conditions are important considerations in qualifying the cables. Significant research in these two areas has been performed in the US and abroad. The results from studies in France, Germany, and Japan are described in this report. In recent years, the development of methods to monitor the condition of cables has received special attention. Tests involving chemical and physical examination of cable's insulation and jacket materials, and electrical measurements of the insulation properties of cables are discussed. Although there have been significant advances in many areas, there is no single method which can provide the necessary information about the condition of a cable currently in service. However, it is possible that further research may identify a combination of several methods that can adequately characterize the cable's condition

  2. The numerical model of multi-layer insulation with a defined wrapping pattern immersed in superfluid helium

    Science.gov (United States)

    Malecha, Ziemowit; Lubryka, Eliza

    2017-11-01

    The numerical model of thin layers, characterized by a defined wrapping pattern can be a crucial element of many computational problems related to engineering and science. A motivating example is found in multilayer electrical insulation, which is an important component of superconducting magnets and other cryogenic installations. The wrapping pattern of the insulation can significantly affect heat transport and the performance of the considered instruments. The major objective of this study is to develop the numerical boundary conditions (BC) needed to model the wrapping pattern of thin insulation. An example of the practical application of the proposed BC includes the heat transfer of Rutherford NbTi cables immersed in super-fluid helium (He II) across thin layers of electrical insulation. The proposed BC and a mathematical model of heat transfer in He II are implemented in the open source CFD toolbox OpenFOAM. The implemented mathematical model and the BC are compared in the experiments. The study confirms that the thermal resistance of electrical insulation can be lowered by implementing the proper wrapping pattern. The proposed BC can be useful in the study of new patterns for wrapping schemes. The work has been supported by statutory funds from Polish Ministry for Science and Higher Education for the year of 2017.

  3. 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)

  4. 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.

  5. 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)

  6. 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.

  7. 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

  8. Assessment of NDE for key indicators of aging cables in nuclear power plants - Interim status

    Science.gov (United States)

    Glass, S. W.; Ramuhalli, P.; Fifield, L. S.; Prowant, M. S.; Dib, G.; Tedeschi, J. R.; Suter, J. D.; Jones, A. M.; Good, M. S.; Pardini, A. F.; Hartman, T. S.

    2016-02-01

    Degradation of the cable jacket, electrical insulation, and other cable components of installed cables within nuclear power plants (NPPs) is known to occur as a function of age, temperature, radiation, and other environmental factors. System tests verify cable function under normal loads; however, the concern is over cable performance under exceptional loads associated with design-basis events (DBEs). The cable's ability to perform safely over the initial 40-year planned and licensed life has generally been demonstrated and there have been very few age-related cable failures. With greater than 1000 km of power, control, instrumentation, and other cables typically found in an NPP, replacing all the cables would be a severe cost burden. Justification for life extension to 60 and 80 years requires a cable aging management program to justify cable performance under normal operation as well as accident conditions. Currently the gold standard for determining cable insulation degradation is the elongation-at-break (EAB). This, however, is an ex-situ measurement and requires removal of a sample for laboratory investigation. A reliable nondestructive examination (NDE) in-situ approach is desirable to objectively determine the suitability of the cable for service. A variety of tests are available to assess various aspects of electrical and mechanical cable performance, but none of these tests are suitable for all cable configurations nor does any single test confirm all features of interest. Nevertheless, the complete collection of test possibilities offers a powerful range of tools to assure the integrity of critical cables. Licensees and regulators have settled on a practical program to justify continued operation based on condition monitoring of a lead sample set of cables where test data is tracked in a database and the required test data are continually adjusted based on plant and fleet-wide experience. As part of the Light Water Reactor Sustainability program sponsored

  9. The degradation diagnosis of low voltage cables used at nuclear power plants

    International Nuclear Information System (INIS)

    Yamamoto, Toshio; Ashida, Tetsuya; Ikeda, Takeshi; Yasuhara, Takeshi; Takechi, Kei; Araki, Shogo

    2001-01-01

    Low voltage cables which have been used for the supply of electric power and the propagation of control signals in nuclear power plants must be sound for safe and stable operation. The long use of nuclear power plants has been reviewed, and the degradation diagnosis to estimate the soundness of low voltage cables has been emphasized. Mitsubishi Cable Industries has established a degradation diagnosis method of cables which convert the velocity of ultrasonic wave in the surface layer of the cable insulation or jacket into breaking elongation, and has developed a degradation diagnosis equipment of low voltage cables used at nuclear power plants in cooperation with Mitsubishi Heavy Industries. This equipment can be moved by an ultrasonic probe by sequential control and measure the ultrasonic velocity automatically. It is capable of a fast an sensitive diagnosis of the cables. We report the outline of this degradation diagnosis equipment and an example of the adaptability estimation at an actual nuclear power plant. (author)

  10. 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.

  11. 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

  12. Determining Remaining Useful Life of Aging Cables in Nuclear Power Plants – Interim Study FY13

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, Kevin L.; Fifield, Leonard S.; Westman, Matthew P.; Ramuhalli, Pradeep; Pardini, Allan F.; Tedeschi, Jonathan R.; Jones, Anthony M.

    2013-09-27

    The most important criterion for cable performance is its ability to withstand a design-basis accident. With nearly 1000 km of power, control, instrumentation, and other cables typically found in an NPP, it would be a significant undertaking to inspect all of the cables. Degradation of the cable jacket, electrical insulation, and other cable components is a key issue that is likely to affect the ability of the currently installed cables to operate safely and reliably for another 20 to 40 years beyond the initial operating life. The development of one or more nondestructive evaluation (NDE) techniques and supporting models that could assist in determining the remaining life expectancy of cables or their current degradation state would be of significant interest. The ability to nondestructively determine material and electrical properties of cable jackets and insulation without disturbing the cables or connections has been deemed essential. Currently, the only technique accepted by industry to measure cable elasticity (the gold standard for determining cable insulation degradation) is the indentation measurement. All other NDE techniques are used to find flaws in the cable and do not provide information to determine the current health or life expectancy. There is no single NDE technique that can satisfy all of the requirements needed for making a life-expectancy determination, but a wide range of methods have been evaluated for use in NPPs as part of a continuous evaluation program. The commonly used methods are indentation and visual inspection, but these are only suitable for easily accessible cables. Several NDE methodologies using electrical techniques are in use today for flaw detection but there are none that can predict the life of a cable. There are, however, several physical and chemical ptoperty changes in cable insulation as a result of thermal and radiation damage. In principle, these properties may be targets for advanced NDE methods to provide early

  13. Determining Remaining Useful Life of Aging Cables in Nuclear Power Plants - Interim Study FY13

    International Nuclear Information System (INIS)

    Simmons, Kevin L.; Fifield, Leonard S.; Westman, Matthew P.; Ramuhalli, Pradeep; Pardini, Allan F.; Tedeschi, Jonathan R.; Jones, Anthony M.

    2013-01-01

    The most important criterion for cable performance is its ability to withstand a design-basis accident. With nearly 1000 km of power, control, instrumentation, and other cables typically found in an NPP, it would be a significant undertaking to inspect all of the cables. Degradation of the cable jacket, electrical insulation, and other cable components is a key issue that is likely to affect the ability of the currently installed cables to operate safely and reliably for another 20 to 40 years beyond the initial operating life. The development of one or more nondestructive evaluation (NDE) techniques and supporting models that could assist in determining the remaining life expectancy of cables or their current degradation state would be of significant interest. The ability to nondestructively determine material and electrical properties of cable jackets and insulation without disturbing the cables or connections has been deemed essential. Currently, the only technique accepted by industry to measure cable elasticity (the gold standard for determining cable insulation degradation) is the indentation measurement. All other NDE techniques are used to find flaws in the cable and do not provide information to determine the current health or life expectancy. There is no single NDE technique that can satisfy all of the requirements needed for making a life-expectancy determination, but a wide range of methods have been evaluated for use in NPPs as part of a continuous evaluation program. The commonly used methods are indentation and visual inspection, but these are only suitable for easily accessible cables. Several NDE methodologies using electrical techniques are in use today for flaw detection but there are none that can predict the life of a cable. There are, however, several physical and chemical ptoperty changes in cable insulation as a result of thermal and radiation damage. In principle, these properties may be targets for advanced NDE methods to provide early

  14. 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.

  15. 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.)

  16. 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.

  17. 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.)

  18. Calculation and measurement of space charge in MV-size xxtruded cables systems under load conditions

    NARCIS (Netherlands)

    Morshuis, P.H.F.; Bodega, R.; Fabiani, D.; Montanari, G.C.; Dissado, L.A.; Smit, J.J.

    2007-01-01

    A load current in dc high voltage cables results in a temperature drop across the insulation and hence a radial distribution of the insulation conductivity is found. Direct consequence is an accumulation of space charge in the bulk of the nsulation, that may significantly affect its reliability.

  19. Long-term aging and loss-of-coolant accident (LOCA) testing of electrical cables

    International Nuclear Information System (INIS)

    Nelson, C.F.; Gauthier, G.; Carlin, F.

    1996-10-01

    Experiments were performed to assess the aging degradation and loss-of-coolant accident (LOCA) behavior of electrical cables subjected to long-term aging exposures. Four different cable types were tested in both the U.S. and France: (1) U.S. 2 conductor with ethylene propylene rubber (EPR) insulation and a Hypalon jacket. (2) U.S. 3 conductor with cross-linked polyethylene (XLPE) insulation and a Hypalon jacket. (3) French 3 conductor with EPR insulation and a Hypalon jacket. (4) French coaxial with polyethylene (PE) insulation and a PE jacket. The data represent up to 5 years of simultaneous aging where the cables were exposed to identical aging radiation doses at either 40 degrees C or 70 degrees C; however, the dose rate used for the aging irradiation was varied over a wide range (2-100 Gy/hr). Aging was followed by exposure to simulated French LOCA conditions. Several mechanical, electrical, and physical-chemical condition monitoring techniques were used to investigate the degradation behavior of the cables. All the cables, except for the French PE cable, performed acceptably during the aging and LOCA simulations. In general, cable degradation at a given dose was highest for the lowest dose rate, and the amount of degradation decreased as the dose rate was increased

  20. Thin film conductors for self-equalizing cables

    Directory of Open Access Journals (Sweden)

    G. Owen

    2017-10-01

    Full Text Available Self-equalizing cables using hollow conductors with wall thickness less than the skin depth were proposed in 1929. However, they do not appear ever to have been widely used, although the idea has resurfaced and been refined from time to time. In the early 2000’s, self-equalizing conductors consisting of solid magnetic steel cores coated with silver were developed by W.L. Gore, and used in their 2.5 Gb/s “Eye-Opener” cables, although higher speed versions never appeared. We have revived the original 1929 idea, proposing to use glass as a solid insulating core. This technology can potentially work at frequencies of many 10’s of GHz. Possible uses include short range GHz links such as USB and Thunderbolt, and intra-rack interconnections in data centers. Our feasibility experiments have validated the principle. Copper coated glass fibers can, in principle, be manufactured, but in these tests, the conductors were capillaries internally coated with silver as these are easily obtainable, relatively inexpensive and serve to test the concept. The performance of these experimental twin lead cables corresponds to calculations, confirming the general principle. By calculation, we have compared the performance of cables made from copper-on-insulator conductors to that of similar cables made with solid copper conductors, and verified that copper-on-insulator cables have significantly less frequency dependent loss. We have also made and tested cables with copper on PEEK conductors as surrogates for copper on glass fiber.

  1. 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.

  2. Development of a superconducting cable for transmission of high electric power

    International Nuclear Information System (INIS)

    Moisson, F.; Leroux, J.M.

    1971-01-01

    The opportunities opened by the use of cryoresistive and superconducting materials in underground transmission systems have led to a cryocable program. A first set of problems associated with the development of cryogenic cables deals with the cable system, i.e., design, safety, terminal equipment including leads, cryogenic equipment, refrigerators, and problems related to overload capability and reliability. A second set concerns the cable itself, i.e., scientific and technological problems associated with the conductor, the electrical insulation, and the thermal exchange between conductor and helium. Useful experience is gained on the design problems and on the technological problems involved in the construction of a cryoconducting cable. A 20-M aluminum cable cooled down to 25 0 K with pressurized helium flow was built and tested with 3500-A dc under 20 Kv; results are presented. On this model the following types of problems were solved. First, mechanical problems concerning cooling of the cable, thermal contraction of the pipes, electrical insulation and conductors, construction of an invariable cable constituted by elementary helically wound conductors were solved. Second, thermal problems of reduction of heat leaks, conception of thermal insulation, and segmentation of vacuum jackets were solved. Third, electrical problems of design of 300 0 to 25 0 K leads were solved; this problem of losses at both ends is, in proportion, more important for the short model than for long cable. Finally, refrigeration problems of helium and nitrogen flows, thermal shields and design of refrigerators (optimal capacity and spacing) were solved

  3. A New Contribution in Reducing Electric Field Distribution Within/Around Medium Voltage Underground Cable Terminations

    Directory of Open Access Journals (Sweden)

    S. S. Desouky

    2017-10-01

    Full Text Available Ιn medium voltage cables, the stress control layers play an important part in controlling the electric field distribution around the medium voltage underground cable terminations. Underground cable accessories, used in medium voltage cable systems, need a stress control tube in order to maintain and control the insulation level which is designed for long life times. The term “electrical stress control” refers to the cable termination analysis of optimizing the electrical stress in the area of insulation shield cutback to reduce the electrical field concentration at this point in order to reduce breakdown in the cable insulation. This paper presents the effect of some materials of different relative permittivities and geometrical regulation with the curved shape stress relief cones on the electric field distribution of cable termination. The optimization was done by comparing the results of eight materials used. Also, the effect of the change in the thickness of the stress control tube is presented. The modeling design is very important for engineers to find the optimal solution of terminator design of medium voltage cables. This paper also describes the evolution of stress control systems and their benefits. A developed program using Finite Element Method (FEM has calculated a numerical study to the stress control layering electric field distribution.

  4. Thermal insulation

    International Nuclear Information System (INIS)

    Durston, J.G.; Birch, W.; Facer, R.I.; Stuart, R.A.

    1977-01-01

    Reference is made to liquid metal cooled nuclear reactors. In the arrangement described the reactor vessel is clad with thermal insulation comprising a layer of insulating blocks spaced from the wall and from each other; each block is rigidly secured to the wall, and the interspaces are substantially closed against convectional flow of liquid by resilient closure members. A membrane covering is provided for the layer of blocks, with venting means to allow liquid from the reactor vessel to penetrate between the covering and the layer of blocks. The membrane covering may comprise a stainless steel sheet ribbed in orthogonal pattern to give flexibility for the accommodation of thermal strain. The insulating blocks may be comprised of stainless steel or cellular or porous material and may be hollow shells containing ceramic material or gas fillings. (U.K.)

  5. Ground Loop Impedance of Long EHV Cable Lines

    DEFF Research Database (Denmark)

    Ohno, Teruo; Bak, Claus Leth; Sørensen, Thomas K.

    2012-01-01

    The distance protection scheme without communication is often applied to the backup protection of EHV cable lines. For a reliable operation of a ground distance relay, the ground loop impedance of EHV cable lines needs to have a linear relationship to the distance from the relay location...... to the fault location. The discontinuity of the ground loop impedance at cross-bonding points may have an ill effect on the reliable operation of the ground distance relay. However, the cause and parameters of the discontinuity and its effects on the ground distance relay protection have not been discussed...... in literature. Through the calculation of the ground loop impedance for cable lines, it has been found that, for long EHV cable lines, the reliable operation of the ground distance relay is possible with a typical relay setting. Effects of parameters, such as substation grounding, cable layouts...

  6. Topological insulators

    CERN Document Server

    Franz, Marcel

    2013-01-01

    Topological Insulators, volume six in the Contemporary Concepts of Condensed Matter Series, describes the recent revolution in condensed matter physics that occurred in our understanding of crystalline solids. The book chronicles the work done worldwide that led to these discoveries and provides the reader with a comprehensive overview of the field. Starting in 2004, theorists began to explore the effect of topology on the physics of band insulators, a field previously considered well understood. However, the inclusion of topology brings key new elements into this old field. Whereas it was

  7. Frequency domain reflectometry modeling for nondestructive evaluation of nuclear power plant cables

    Science.gov (United States)

    Glass, S. W.; Fifield, L. S.; Jones, A. M.; Hartman, T. S.

    2018-04-01

    Cable insulation polymers are among the more susceptible materials to age-related degradation within a nuclear power plant. This is recognized by both regulators and utilities, so all plants have developed cable aging management programs to detect damage before critical component failure in compliance with regulatory guidelines. Although a wide range of tools are available to evaluate cables and cable systems, cable aging management programs vary in how condition monitoring and nondestructive examinations are conducted as utilities search for the most reliable and cost-effective ways to assess cable system condition. Frequency domain reflectometry (FDR) is emerging as one valuable tool to locate and assess damaged portions of a cable system with minimal cost and only requires access in most cases to one of the cable terminal ends. Since laboratory studies to evaluate the use of FDR for inspection of aged cables can be expensive and data interpretation may be confounded by multiple factors which influence results, a model-based approach is desired to parametrically investigate the effect of insulation material damage in a controlled manner. This work describes development of a physics-based FDR model which uses finite element simulations of cable segments in conjunction with cascaded circuit element simulations to efficiently study a cable system. One or more segments of the cable system model have altered physical or electrical properties which represent the degree of damage and the location of the damage in the system. This circuit model is then subjected to a simulated FDR examination. The modeling approach is verified using several experimental cases and by comparing it to a commercial simulator suitable for simulation of some cable configurations. The model is used to examine a broad range of parameters including defect length, defect profile, degree of degradation, number and location of defects, FDR bandwidth, and addition of impedance-matched extensions to

  8. Frequency Domain Reflectometry NDE for Aging Cables in Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Glass, Samuel W.; Jones, Anthony M.; Fifield, Leonard S.; Hartman, Trenton S.

    2017-02-16

    Cable insulation polymers are among the more susceptible materials to age-related degradation within a nuclear power plant. This is recognized by both regulators and utilities, so all plants have developed cable aging management programs to detect damage before critical component failure in compliance with regulatory guidelines. Although a wide range of tools are available to evaluate cables and cable systems, cable aging management programs vary in how condition monitoring and nondestructive examinations are conducted as utilities search for the most reliable and cost-effective ways to assess cable system condition. Frequency domain reflectometry (FDR) is emerging as one valuable tool to locate and assess damaged portions of a cable system with minimal cost and only requires access in most cases to one of the cable terminal ends. Since laboratory studies to evaluate the use of FDR for inspection of aged cables can be expensive and data interpretation may be confounded by multiple factors which influence results, a model-based approach is desired to parametrically investigate the effect of insulation material damage in a controlled manner. This work describes development of a physics-based FDR model which uses finite element simulations of cable segments in conjunction with cascaded circuit element simulations to efficiently study a cable system. One or more segments of the cable system model have altered physical or electrical properties which represent the degree of damage and the location of the damage in the system. This circuit model is then subjected to a simulated FDR examination. The modeling approach is verified using several experimental cases and by comparing it to a commercial simulator suitable for simulation of some cable configurations. The model is used to examine a broad range of parameters including defect length, defect profile, degree of degradation, number and location of defects, FDR bandwidth, and addition of impedance-matched extensions to

  9. 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.

  10. Design and testing of low capacitance, 80-kV source cables for MFTF sustaining neutral beam power supplies

    International Nuclear Information System (INIS)

    Mayhall, D.J.; Shimer, D.W.

    1979-01-01

    In this paper we summarize characteristics of several cable configurations and consider one design in detail, which consists of twelve, 250 MCM arc cables, ten 4/0 filament cables, and accel, gradient grid, control, and instrumentation cables within a circular split Al pipe. The pipe is air insulated from an outer 24-in. x 24-in. steel duct by utility pin insulators. Varying run lengths require adjustment of the arc inductance by variation of cross sectional cable position. Equilibrium heat transfer analysis indicates the pulse-off time for source conditioning must be somewhat greater than 60 s to keep conductor temperatures below 90 0 C. The results of a high voltage test of a model cable are presented

  11. Partial discharge tests and characterisation of the Advanced Photon Source linac modulator cables

    International Nuclear Information System (INIS)

    Cours, A.

    2007-01-01

    The advanced photon source (APS) linac modulators are PFN-type pulsers with switch-mode charging power supplies (PSs). The PS and the PFN are connected to each other by 15 feet of 100-kV x-ray cable, with the PFN end of the cable terminated with a connector that was confirmed partial-discharge (PD)-free up to 38 kV ac (53.5 kV peak). Another end of the cable is terminated with a connector that was designed by the PS manufacturer and cannot easily be replaced with another type of connector, since part of it is located inside the densely packed PS. PD tests of the cables with this type of connector show that the PD inception voltages (PDIVs) in different cables turn out to be located within a wide voltage range: 21 to 27 kV ac that corresponds to 29 to 38 kV peak. In order to evaluate the insulation condition of the modulator cables, detect insulation deterioration, and ensure failure-preventing equipment maintenance, over the last two years the PDIVs of all high-voltage (HV) cables in use in the modulators have been tested about every three and a half months. Before the tests, all cables were removed from the equipment, carefully cleaned, inspected, and regreased. The tests were performed using a 40-kV PD detector. The test results show that: 1 The PDIVs remain almost unchanged in all tested cables. 2 From test to test, the PDIV of any particular cable may slightly oscillate around some average value. This possibly depends on the connector regreasing technique. 3 There is no direct evidence of cable insulation deterioration during more than two years of operation under voltage higher than the PD inception level.

  12. 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)

  13. 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.)

  14. Insulated Wire Fed Floating Monopole Antenna for Coastal Monitoring

    Directory of Open Access Journals (Sweden)

    Z. M. Loni

    2018-04-01

    Full Text Available A thin, flexible, insulated wire submerged in seawater forms a coaxial cable which has attenuation at ultra-high frequency (UHF dependent on the operating frequency, the diameter of the insulating material and the diameter of the inner conductor. An extension of the insulated wire above the surface through a spherical float forms a monopole antenna. Attenuation through the wire depends on the conductivity and temperature of seawater. This paper reports the effect of electromagnetic (EM wave propagation at 433 MHz through insulated wires with different radii of the insulating material and inner conductor. The attenuation was calculated and measured in the range of 32-47 dB/m. The propagation from the monopole antenna to a fixed shore based receiver was measured to be approximately equal to 1 dB/m. The propagation measurements were compared with a shielded coaxial cable. Results show that the propagation range depends on the ratio of the insulation radius to conductor radius for insulated wire, however, a shielded coaxial cable showed no significant attenuation. The technique has applications in coastal wireless sensor networks where the water depth changes continually due to tide and wave motion.

  15. 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).

  16. 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)

  17. 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.

  18. 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...

  19. Ageing of cables and new approach for the study of polymer ageing

    International Nuclear Information System (INIS)

    Monchy-Leroy, C.; Therond, P.

    2011-01-01

    The study of nuclear cable ageing has become an important subject in particular within the framework of the lifetime extension of nuclear power plants. Until 2000, the approach developed by EDF was a purely empirical one, which establishes from a behavior law, the temporal evolution of a macroscopic property of the jacket or the insulation (generally elongation at break), according to the ageing conditions, such as the temperature and the dose rate. These simulations, coupled with analyses of cables taken on sites after several years of ageing, can demonstrate and justify the good behavior in time of the cables installed in the French nuclear power plants. However from an industrial point of view, this approach, as any empirical approach, is not sustainable and suffers numerous limitations. In particular, the results obtained are not transposable from one industrial formulation to another. That is why for some years, EDF has developed a more generic approach based on the understanding and the modeling of the ageing of polymers by thermo-oxidation and radio-oxidation. This new approach consists of identifying all the occurring reactions at the molecular scale during the polymer ageing. The numerical resolution of the system of differential equations stemming from the scheme of reactions, allows access to the spatial and temporal distributions of the oxidation products formed during the ageing. Today the studies are focused on elastomer matrices of type Polyethylene (PE) and co-polymers of type Ethylene-Propylene-Rubber (EPR) to which were added stabilizers and fillers. Later, the model will allow us to simulate the ageing of any industrial polymer. (authors)

  20. 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

  1. Remaining life prediction of I and C cables for reliability assessment of NPP systems

    International Nuclear Information System (INIS)

    Santhosh, T.V.; Ghosh, A.K.; Fernandes, B.G.

    2012-01-01

    Highlights: ► A framework for time dependent reliability prediction of I and C cables for use in PSA of NPP has been developed using stress–strength interference theory. ► The proposed methodology has been illustrated with the accelerated thermal aging data on a typical XLPE cable. ► The behavior of insulation resistance when the degradation process is linear or exponential has also been modeled. ► The reliability index or probability of failure obtained from this approach can be used in system reliability evaluation to account for cable aging for PSA of NPP. - Abstract: Instrumentation and control (I and C) cables are one of the most important components in nuclear power plants (NPPs) because they provide power to safety-related equipment and also to transmit signals to and from various controllers to perform safety operations. I and C cables in NPP are subjected to a variety of aging and degradation stressors that can produce immediate degradation or aging-related mechanisms causing the degradation of cable components over time. Although, there exits several life estimation techniques, currently there is no any standard methodology or an approach toward estimating the time dependent reliability of I and C cables that can be directly used in probabilistic safety assessment (PSA) applications. Hence, the objective of this study is to develop an approach to estimate and confirm the continued acceptable margin in cable insulation life over time subjected to aging. This paper presents a framework based on the structural reliability theory to quantify the life time of I and C cable subjecting to thermal aging. Since cross-linked polyethylene (XLPE) cables are extensively being used in Indian NPPs, the remaining life time evaluations have been carried out for a typical XLPE cable. However, the methodology can be extended to other cables such as polyvinyl chloride (PVC), ethylene propylene rubber (EPR), etc.

  2. 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

  3. An update on irradiation of wire and cable

    International Nuclear Information System (INIS)

    Hildreth, N.

    1981-01-01

    Radiation curing with electron accelerators is a growing high technology application in the wire and cable industry. They are used with voltages ranging from 500,000 up to 3,000,000 electron volts. Furthermore new machines are available up to 5.0 MeV. These industrial machines are high powered accelerators which operate continuously between 60 and 75 kilowatts with a few of the new machines operating up to 200 kilowatts. Radiation curing is used as a tool for developing new insulation systems based on low cost materials for applications which previously required the use of expensive fluorocarbon or silicone rubber type insulations. With the development of the larger, more efficient and reliable accelerators and the continuous trend toward developing new insulations designed to fully utilize the potential of radiation chemistry, the authors are confident that industry will continue to be provided with better, lower cost insulation systems

  4. 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

  5. Progress on qualification testing methodology study of electric cables

    International Nuclear Information System (INIS)

    Yoshida, K.; Seguchi, T.; Okada, S.; Ito, M.; Kusama, Y.; Yagi, T.; Yoshikawa, M.

    1983-01-01

    Many instrumental, control and power cables are installed in nuclear power plants, and these cables contain a large amount of organic polymers as insulating and jacketing materials. They are exposed to radiation at high dose rate, steam at high temperature and chemical (or water) spray simultaneously when a LOCA occurs. Under such conditions, the polymers tend to lose their original properties. For reactor safety, the cables should be functional even if they are subjected to a loss-of-coolant accident (LOCA) at the end of their intended service life. In Japan, cable manufacturers qualify their cables according to the proposed test standard issued from IEEJ in 1982, but the standard still has many unsolved problems or uncertainties which have been dealt with tentatively through the manufacturer-user's agreement. The objectives of this research are to study the methodologies for qualification testing of electric wires and cables, and to provide the improved technical bases for modification of the standard. Research activities are divided into the Accident (LOCA) Testing Methodology and the Accelerated Aging Methodology

  6. Trend analysis of cables failure events at nuclear power plants

    International Nuclear Information System (INIS)

    Fushimi, Yasuyuki

    2007-01-01

    In this study, 152 failure events related with cables at overseas nuclear power plants are selected from Nuclear Information Database, which is owned by The Institute of Nuclear Safety System, and these events are analyzed in view of occurrence, causal factor, and so on. And 15 failure events related with cables at domestic nuclear power plants are selected from Nuclear Information Archives, which is owned by JANTI, and these events are analyzed by the same manner. As a result of comparing both trends, it is revealed following; 1) A cable insulator failure rate is lower at domestic nuclear power plants than at foreign ones. It is thought that a deterioration diagnosis is performed broadly in Japan. 2) Many buried cables failure events have been occupied a significant portion of cables failure events during work activity at overseas plants, however none has been occurred at domestic plants. It is thought that sufficient survey is conducted before excavating activity in Japan. 3) A domestic age related cables failure rate in service is lower than the overseas one and domestic improper maintenance rate is higher than the overseas one. Maintenance worker' a skill improvement is expected in order to reduce improper maintenance. (author)

  7. 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.

  8. Analysis of effect of cable degradation on SPND IR calculation

    International Nuclear Information System (INIS)

    Tamboli, P.K.; Sharma, A.; Prasad, A.D.; Singh, Nita; Antony, J.; Kelkar, M.G.; Kaurav, Reetesh; Pramanik, M.

    2013-01-01

    Neutron flux is the most vital parameter in the nuclear reactor safety against Neutronic over power. The modern days Indian PHWRs with large core size are loosely coupled reactors and hence In-core Self Power Neutron Detectors (SPNDs) are most suitable for monitoring local neutron power for generating Regional Overpower Trip. However the SPNDs and its Mineral Insulation Cable are prone to IR loss due to use of ceramic insulation which are highly hygroscopic. The present paper covers the online analysis of IR f degraded cable as per the surveillance requirement of monitoring the IR to assess the healthiness of SPNDs which are part of SSC/SSE for Reactor Protection Systems. The paper also proposes an alternative method for monitoring IR for startup//low power range when SPND signals are yet to pick up and Reactor Control and Protection are based on out of core Ionization Chambers. (author)

  9. USING CONDITION MONITORING TO PREDICT REMAINING LIFE OF ELECTRIC CABLES

    International Nuclear Information System (INIS)

    LOFARO, R.; SOO, P.; VILLARAN, M.; GROVE, E.

    2001-01-01

    Electric cables are passive components used extensively throughout nuclear power stations to perform numerous safety and non-safety functions. It is known that the polymers commonly used to insulate the conductors on these cables can degrade with time; the rate of degradation being dependent on the severity of the conditions in which the cables operate. Cables do not receive routine maintenance and, since it can be very costly, they are not replaced on a regular basis. Therefore, to ensure their continued functional performance, it would be beneficial if condition monitoring techniques could be used to estimate the remaining useful life of these components. A great deal of research has been performed on various condition monitoring techniques for use on electric cables. In a research program sponsored by the U.S. Nuclear Regulatory Commission, several promising techniques were evaluated and found to provide trendable information on the condition of low-voltage electric cables. These techniques may be useful for predicting remaining life if well defined limiting values for the aging properties being measured can be determined. However, each technique has advantages and limitations that must be addressed in order to use it effectively, and the necessary limiting values are not always easy to obtain. This paper discusses how condition monitoring measurements can be used to predict the remaining useful life of electric cables. The attributes of an appropriate condition monitoring technique are presented, and the process to be used in estimating the remaining useful life of a cable is discussed along with the difficulties that must be addressed

  10. Tank Insulation

    Science.gov (United States)

    1979-01-01

    For NASA's Apollo program, McDonnell Douglas Astronautics Company, Huntington Beach, California, developed and built the S-IVB, uppermost stage of the three-stage Saturn V moonbooster. An important part of the development task was fabrication of a tank to contain liquid hydrogen fuel for the stage's rocket engine. The liquid hydrogen had to be contained at the supercold temperature of 423 degrees below zero Fahrenheit. The tank had to be perfectly insulated to keep engine or solar heat from reaching the fuel; if the hydrogen were permitted to warm up, it would have boiled off, or converted to gaseous form, reducing the amount of fuel available to the engine. McDonnell Douglas' answer was a supereffective insulation called 3D, which consisted of a one-inch thickness of polyurethane foam reinforced in three dimensions with fiberglass threads. Over a 13-year development and construction period, the company built 30 tanks and never experienced a failure. Now, after years of additional development, an advanced version of 3D is finding application as part of a containment system for transporting Liquefied Natural Gas (LNG) by ship.

  11. Cabling in the Skyrme–Faddeev model

    International Nuclear Information System (INIS)

    Jennings, Paul

    2015-01-01

    The Skyrme–Faddeev model is a three-dimensional nonlinear field theory that has topological soliton solutions, called hopfions, which are novel string-like solutions taking the form of knots and links. Solutions found thus far take the form of torus knots and links of these, however torus knots form only a small family of known knots. It is an open question whether any non-torus knot hopfions exist. In this paper we present a construction of knotted fields with the form of cable knots to which an energy minimization scheme can be applied. We find the first known hopfions which do not have the form of torus knots, but instead take the form of cable and hyperbolic knots. (paper)

  12. THE TECHNOLOGICAL AND EXPLOITATIVE FACTORS OF LOCAL INCREASE OF ELECTRIC FIELD STRENGTH IN THE POWER CABLE OF COAXIAL DESIGN

    Directory of Open Access Journals (Sweden)

    G. V. Bezprozvannych

    2016-12-01

    Full Text Available Introduction. Reliability of high voltage power cables in the process of long-term operation is largely due to the intensity of polymeric insulation aging. It is now established that the aging of polyethylene, which is the main material for the insulation of high voltage power cables, under the action of the electric field is determined primarily by the presence of structural heterogeneity arising both during cable production and during use. The cable is always there deviations from the ideal structure, which manifest in a deviation of diameters of conductors from nominal values; in the arrangement of the conductor and the insulation is not strictly coaxially and eccentrically; in elliptic (oval core and insulation; change in relative dielectric constant and thickness of insulation on cable length force the formation of low molecular weight products (including water in the flow at the manufacturing stage crosslinked polyethylene insulation and moisture during operation. Such defects are structural, technological and operational irregularities, which lead to a local change in the electric field. Purpose. Analysis of the influence of the eccentricity, elliptic and spherical inclusions in the electric field distribution in the power cable of a coaxial design with cross-linked polyethylene insulation, based on numerical simulation. Methodology. The bases of the numerical method of calculation of the electrical field strength are Fredholm integral equations of the first and second kind (method of secondary sources for an axially symmetric field. Analysis of the influence of irregularities, including water treeing, the shape of the sounding signal is made using the method of discrete resistive circuit inductance and capacitance of substitution with the initial conditions. Solving systems of linear algebraic equations nodal analysis performed by the sweep method. Results. The presence of the eccentricity and ellipticity in the construction of cable has

  13. 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

  14. 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.

  15. Selection and optimization of mooring cables on floating platform for special purposes

    Science.gov (United States)

    Ma, Guang-ying; Yao, Yun-long; Zhao, Chen-yao

    2017-08-01

    This paper studied a new type of assembled marine floating platform for special purposes. The selection and optimization of mooring cables on the floating platform are studied. By using ANSYS AQWA software, the hydrodynamic model of the platform was established to calculate the time history response of the platform motion under complex water environments, such as wind, wave, current and mooring. On this basis, motion response and cable tension were calculated with different cable mooring states under the designed environmental load. Finally, the best mooring scheme to meet the cable strength requirements was proposed, which can lower the motion amplitude of the platform effectively.

  16. A study on the condition monitoring for safety-related electric cables

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chul Hwan; Ahn, S. P.; Yeo, S. M.; Kang, Y. S.; Ahn, S. M.; Kim, I. S.; Kim, D. S.; Kang, J. S. [Sungkyunkwan Univ., Suwon (Korea, Republic of)

    2002-03-15

    In this report, we have studied compositions and characteristics of various types of insulation material for cables in Nuclear Power Plant. We arrange relationship with condition monitoring methods. Also, we propose new condition monitoring method using third harmonic frequency. We test the proposed method with CV cables. We also describe about feature of condition monitoring such as application, theory, characteristic, thereby other engineer can confirm to advantage and disadvantage for each method, and possibly choice adequate condition monitoring method for various types of cables.

  17. 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)

  18. Study of Transient Heat Transport Mechanisms in Superfluid Helium Cooled Rutherford-Cables

    CERN Document Server

    AUTHOR|(CDS)2100615

    The Large Hadron Collider leverages superconducting magnets to focus the particle beam or keep it in its circular track. These superconducting magnets are composed of NbTi-cables with a special insulation that allows superfluid helium to enter and cool the superconducting cable. Loss mechanisms, e.g. continuous random loss of particles escaping the collimation system heating up the magnets. Hence, a local temperature increase can occur and lead to a quench of the magnets when the superconductor warms up above the critical temperature. A detailed knowledge about the temperature increases in the superconducting cable (Rutherford type) ensures a secure operation of the LHC. A sample of the Rutherford cable has been instrumented with temperature sensors. Experiments with this sample have been performed within this study to investigate the cooling performance of the helium in the cable due to heat deposition. The experiment uses a superconducting coil, placed in a cryostat, to couple with the magnetic field loss m...

  19. AN EVALUATION OF CONDITION MONITORING TECHNIQUES FOR LOW-VOLTAGE ELECTRIC CABLES

    International Nuclear Information System (INIS)

    LOFARO, R.J.; GROVE, E.; SOO, P.

    2000-01-01

    Aging of systems and components in nuclear power plants is a well known occurrence that must be managed to ensure the continued safe operation of these plants. Much of the degradation due to aging is controlled through periodic maintenance and/or component replacement. However, there are components that do not receive periodic maintenance or monitoring once they are installed; electric cables are such a component. To provide a means of monitoring the condition of electric cables, research is ongoing to evaluate promising condition monitoring (CM) techniques that can be used in situ to monitor cable condition and predict remaining life. While several techniques are promising, each has limitations that must be considered in its application. This paper discusses the theory behind several of the promising cable CM techniques being studied, along with their effectiveness for monitoring aging degradation in typical cable insulation materials, such as cross-linked polyethylene and ethylene propylene rubber. Successes and limitations of each technique are also presented

  20. Qualification of cables to IEEE standards 323-1974 and 383-1974

    International Nuclear Information System (INIS)

    Hosticka, C.; Kingsbury, E.R.; Bruhin, A.C.

    1980-01-01

    Wire and Cable manufacturers generally qualify products for class IE application by envelope type testing to user specifications and environmental conditions recommended by IEEE Standards 323-1974 and 383-1974. The General Electric Wire and Cable Business Department recently completed two such qualification programs. Cable constructions tested were 600V control cables and 600 V, 2kV, and 15kV power cables insulated with flame resistant mineral filled crosslinked polyethylene. The 15kV samples included taped field splices. In the second test program, the steam pressure-temperature profile included a simulated main steam line break. Test specimens were wrapped on grounded mandrels and were electrically loaded throughout the simulated LOCA tests. After completion of environmental testing, samples were subjected to the IEEE 383 simulated post-LOCA test. 6 refs

  1. Qualification of cables to IEEE standards 323-1974 and 383-1974

    International Nuclear Information System (INIS)

    Hosticka, C.; Kingsbury, E.R.; Bruhin, A.C.

    1980-01-01

    Wire and Cable manufacturers generally qualify products for class IE application by envelope type testing to user specifications and environmental conditions recommended by IEEE Standards 323-1974 and 383-1974. The General Electric Wire and Cable Business Department recently completed two such qualification programs. Cable constructions tested were 600V control cables and 600 V, 2KV, and 15KV power cables insulated with flame resistant mineral filled crosslinked polyethylene. The 15KV samples included taped field splices. In the second test program, the steam pressure-temperature profile included a simulated main steam line break. Test specimens were wrapped on grounded mandrels and were electrically loaded throughout the simulated LOCA tests. After completion of environmental testing, samples were subjected to the IEEE 383 simulated post-LOCA test. 6 refs

  2. In search of extendable conditions for cable environmental qualification in nuclear power plants

    International Nuclear Information System (INIS)

    Alshaketheep, Tariq; Sekimura, Naoto; Itoi, Tatsuya; Murakami, Kenta

    2016-01-01

    The environmental qualification (EQ) for cable insulators in nuclear power plants (NPPs) has been developed on the basis of the design basis accident (DBA) to prevent reactor core damage. However, the latest safety principles require extending the design concept to prepare the utilized equipment for scenarios after core damage. Thus, we propose a modification to the EQ for cables connecting utilized equipment at design extension conditions. This paper surveys all electrical components for accident management in boiling water reactor-4 (BWR-4), and identifies their connecting cables' functional category as low-voltage power, instrumentation, and control cables. The EQ temperature profile of these cables during the incident phase was addressed for extension. This required postulating maximum temperature environments according to accident scenarios, knowledge of cable integrity degradation, and their current evaluation by the EQ. To evaluate whether these environments are suitable stressors, heat testing was conducted on flame-retardant ethylene propylene rubber (FR-EPR)-insulated cables. On the basis of those results, we suggest a maximum primary peak temperature of the EQ temperature profile of 250degC. We also suggest increasing the primary peak period of the EQ temperature profile to 48 h without experiment, on the basis of inherent excessive margin for mechanical integrity during the ageing phase. (author)

  3. Literature review of environmental qualification of safety-related electric cables: Summary of past work. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Subudhi, M. [Brookhaven National Lab., Upton, NY (United States)

    1996-04-01

    This report summarizes the findings from a review of published documents dealing with research on the environmental qualification of safety-related electric cables used in nuclear power plants. Simulations of accelerated aging and accident conditions are important considerations in qualifying the cables. Significant research in these two areas has been performed in the US and abroad. The results from studies in France, Germany, and Japan are described in this report. In recent years, the development of methods to monitor the condition of cables has received special attention. Tests involving chemical and physical examination of cable`s insulation and jacket materials, and electrical measurements of the insulation properties of cables are discussed. Although there have been significant advances in many areas, there is no single method which can provide the necessary information about the condition of a cable currently in service. However, it is possible that further research may identify a combination of several methods that can adequately characterize the cable`s condition.

  4. Helium II heat transfer in LHC magnets : polyimide cable insulation

    NARCIS (Netherlands)

    Winkler, Tiemo

    2017-01-01

    Today’s large particle accelerators like the LHC at CERN are using superconducting materials as a construction material for magnets. These magnets need to be cooled constantly to temperatures below the critical surface of the superconducting material. In the LHC this is achieved by using liquid

  5. Ageing of cable insulators made of polyethylene in nuclear environment

    International Nuclear Information System (INIS)

    Khelidj, N.

    2006-10-01

    This thesis deals with lifetime prediction for polyethylene in nuclear environment. It is mainly characterised by the search for a non empirical solution. We have tried to elaborate a model describing the polymer evolution (including the skin-core heterogeneity due to the kinetic control of oxidation by oxygen diffusion) at any temperature between ambient and the melting point of the polymer, and at any dose rate between 0 and 1 kGy.h-1, with lifetimes extending to several decades of years. The main difficulty was to take into account the dual character of initiation which results from the combination of polymer radiolysis and hydroperoxide thermal decomposition. The problem was resolved considering first the asymptotic regimes where one initiation process can be neglected relatively to the other one. The kinetic parameters specific to those regimes being identified, we have built a numerical model including all the processes. In the case of un-stabilised polyethylene, this model displays excellent predictive qualities, as well in lifetime, as in thickness distribution of oxidation products. The study of stabilised polyethylenes was then initiated with samples respectively stabilised by a hindered phenol, and a thio-diester. In the case of phenol, the study of consumption kinetics reveals the existence of complex mechanisms, especially the existence of a 'reservoir effect' linked to the presence of a separated phase of phenol in excess. A kinetic model has been proposed, but we still do not know how the results can be generalised to other phenolic stabilizers. (author)

  6. Trial manufacture of flame retardant and radiation resistant cables

    Energy Technology Data Exchange (ETDEWEB)

    Oshima, Yunosuke; Hagiwara, Miyuki (Japan Atomic Energy Research Inst., Takasaki, Gunma. Takasaki Radiation Chemistry Research Establishment); Oda, Eisuke

    1983-04-01

    High radiation resistance as well as incombustibility is required for the wires and cables used for nuclear facilities such as nuclear power stations. In order to give such performance to general purpose insulation materials such as ethylene-propylene copolymerized rubber, acenaphthylene bromide condensation product was developed anew. Moreover, by the use of this agent, the new flame retardant and radiation resistant cables were manufactured for trial, which are not different from ordinary plastic rubber cables in the handling such as flexibility, and withstand the radiation nearly up to 1000 Mrad. The requirement for the agent giving flame retardant and radiation resistant properties is explained. The synthesis of acenaphthylene bromide and its condensation product and the effect of giving flame retardant and radiation resistant properties are described. The test resultd of the prevention of spread of flame, the endurance in LOCA-simulating environment, and radiation resistance for the cables manufactured for trial are reported. It was confirmed that the cables of this type are suitable to the use in which the maintenance of mechanical properties after radiation exposure is required.

  7. Partial discharge testing of in-situ power cable accessories

    Energy Technology Data Exchange (ETDEWEB)

    Orban, H. E.

    2002-07-01

    An overview of commercially available diagnostic methods for in-situ power cable accessories is given and relevant field experiences with these diagnostics are described. The discussion includes both PILC and polymeric insulated cables. Two major types of degradation are most frequently involved in cable systems. One is an overall condition caused by chemical aging and /or water treeing. Diagnostics for this type of aging include dissipation factor (loss angle), harmonic analysis, return voltage, isothermal relaxation current, dielectric response, or dc leakage current. The second type of degradation is discrete or incremental; condition assessment utilizes dissipation factor measurements or partial discharge (PD) level measurements. The focus in this paper is on PD diagnostics, especially off-line methods such as the 60 Hz test, the combined AC and VLF diagnostic, and the oscillating wave test system test. Among on-line diagnostics, ultrasonic detection of partial discharge and measurement of partial discharge by installing direct, capacitive or inductive couplers near cable accessories, are described. Overall, partial discharge detection and location in cable accessories is considered inadequate, since interpretation of results is difficult due to the number of variables involved. 28 refs., 1 tab.

  8. Simultaneous Thermal and Gamma Radiation Aging of Electrical Cable Polymers

    Energy Technology Data Exchange (ETDEWEB)

    Fifield, Leonard S.

    2018-04-11

    The polymers used for insulation in nuclear power plant electrical cables are susceptible to aging during long term operation. Elevated temperature is the primary contributor to changes in polymer structure that result loss of mechanical and electrical properties, but gamma radiation is also a significant source of degradation for polymers used within relevant plant locations. Despite many years of polymer degradation research, the combined effects of simultaneous exposure to thermal and radiation stress are not well understood. As nuclear operators contemplate and prepare for extended operations beyond initial license periods, a predictive understanding of exposure-based cable material degradation is becoming an increasingly important input to safety, licensing, operations and economic decisions. We are focusing on carefully-controlled simultaneous thermal and gamma radiation accelerating aging and characterization of the most common nuclear cable polymers to understand the relative contributions of temperature, time, dose and dose rate to changes in cable polymer material structure and properties. Improved understanding of cable performance in long term operation will help support continued sustainable nuclear power generation.

  9. Development of cables for nuclear fuel processing facilities

    International Nuclear Information System (INIS)

    Kamimura, Seiji; Seki, Ikuo; Yamamoto, Yasuaki; Matsuyama, Shigeki; Endo, Shigeru; Yagi, Toshiaki; Kawakami, Waichiro.

    1988-01-01

    Accompanying the development of nuclear power stations, the expansion and repletion of the facilities for nuclear fuel cycle such as fuel reprocessing facilities and waste treatment facilities are requested. In these facilities, there is the environment which is exposed to very high level radiation, and in this case, the cables withstanding 10 MGy radiation dose are required. As the cables meeting such requirement, the new cables having excellent flexibility and radiation resistance were developed. In this paper, the points of material development and the characteristics of cables are reported. Considering the radiation resistance and others, ethylene propylene rubber was selected as the base polymer of the insulator, and polyethylene chlorosulfonate was selected as the sheath material. In order to give excellent radiation resistance, as the anti-rad, energy transfer type aromatic oil that absorbs and dissipates radiation energy and radical trap type anti-oxidant of amine group that catches and stabilizes the radicals generated in the polymer were added. The bromine group burning retarding agent having excellent radiation resistance was applied. In this way, the cables withstanding high radiation dose up to 10 MGy were able to be developed. (K.I.)

  10. 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.)

  11. 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.

  12. 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.

  13. 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...

  14. 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...

  15. Digital computers' cable replacement at the Hydro-Quebec Gentilly 2 nuclear power station

    International Nuclear Information System (INIS)

    Gour, N.; Rivest, J.-M.

    1992-01-01

    During the 1990 annual outage of Gentilly-2, inspection of the digital control computers revealed signs of degradation in about 20% of the cable connector assemblies. This raised concern of increased risk of signal failure by short circuit. The degradation of the insulation was traced to a material incompatibility problem originating during manufacture of the cables. Migration of the plasticizer contained in the PVC of the transparent sheaths surrounding many of the conductors resulted in chemical attack on the insulation. All the cable assemblies were replaced during 1991-1992. The new cable assemblies were manufactured using the Raychem process, which lacked the faulty material. Also, the opportunity was taken to modify the ground network while the computer systems were stripped of their main components. Although the work cost over C$900,000, nevertheless planning and execution were nearly flawless, and the project a complete success. Integrity of cable insulation should not be a concern for the rest of the plant's life. 5 refs

  16. Replacement of input/output cables of the digital control computers at Gentilly 2

    International Nuclear Information System (INIS)

    Melancon, P.; Lafreniere, P.

    1991-01-01

    During the 1990 annual outage at Gentilly 2 the Preventive Maintenance Program inspections on the digital control computers (DCCs) revealed an alarming degradation of cable insulation at several locations. It was found that approximately 20% of the cable connector assemblies inspected showed signs of degradation. These findings raised the concern of an increased risk of random short-circuit faults at the very heart of the station control system. Given the excellent reliability of the Gentilly 2 DCCs and their inherent design robustness, it was decided to proceed with the replacement of all of the complete cable connector assemblies within a reasonable time frame. It is planned to replace all assemblies of DCCX and DCCY during the 1991 annual outage. The degradation of the insulation was traced to a material incompatibility problem originating during cable manufacture. A migration of the plastifier contained in the PVC of the transparent sheaths, surrounding many of the cable conductors to terminal block connections, resulted in the chemical attack of the conductor insulation. This paper summarizes the problem identification and disposition process followed by Gentilly 2 Technical Unit personnel

  17. 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.

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

    International Nuclear Information System (INIS)

    Matsumoto, Tetsuo; Kimura, Hitoshi; Ishii, Nobuhisa

    1997-01-01

    Halogen-free flame-retardant cables were developed for PWR nuclear power stations. It was confirmed that the developed cables possess flame retardant property, corrosion resistance, low toxicity and low smoke generation, and withstand the normal operation in the environment in PWR containment vessels for 60 years and loss of coolant accident. In the advancement of LWR technology, it is important to improve the reliability of machinery and equipment, to extend the period of continuous operation, to optimize the operation cycle and to improve the maintenance of plants. By improving halogen-free flame-retardant material and applying it to the cables for nuclear power stations, it can contribute to the above purposes. The required characteristics of these cables are explained, and the targets of development are power cables, control cables, instrumentation cables and insulated wires which do not contain halogen. The basic material is polyolefin, in which flame retardant magnesium hydroxide and the agent for improving radiation resistance are mixed. The corrosive property and toxicity of gases, smoke generation and the prevention of spread of flame when the cables burn and the durability in environment were evaluated. (K.I.)

  19. Detail of photo 7903109 stack of superconducting cables in the modulus measuring device

    CERN Multimedia

    CERN PhotoLab

    1979-01-01

    The picture shows an assembly of insulated superconducting cables of the type used in the Po dipole magnet inserted in the elastic modulus measuring device (photos 7903547X and 7903169) in order to measures its mechanical properties under azimuthal compression. See also 7903547X, 7903169, 8307552X.

  20. 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,

  1. 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.

  2. The effect of particulate debris on the insulation integrity of SSC coils during molding and collaring

    International Nuclear Information System (INIS)

    Nehrlich, E.; Markley, F.; Rogers, D.

    1991-03-01

    In order to simulate the effect of accidentally introduced debris on SSC coil insulation integrity, models consisting of two pieces of insulated SSC cable have been loaded in an hydraulic press after introducing foreign particles between the layers. The tests were originally suggested by R. Palmer of the SSC Laboratory. A high voltage (2 Kv) was continually applied between the two cables and the load gradually increased until an electrical short occurred. The high voltage was used as an easy method of detecting insulation punctures and to continue the general type of testing begun at Brookhaven by J. Skaritka, now at the SSC Laboratory, and continued at Fermilab by F. Markley and presented at last year's session of the Conference. A range of particles of different size, shape, and hardness were used, and both conducting and insulating particles were included. Fine wires were also used. When the data are normalized using the control (no particles added), data for each cable batch used, there is a slight correlation between pressure at breakdown and particle size for cables insulated with Kapton only. Adjustment must be made for soft particles that tend to deform and for particles with aspect ratios greater than one. Additional measurements have also been made where the opoxy-fiberglass layer was added to the Kapton insulation overwrap. These show a correlation between conductivity and breakdown pressure. 1 ref., 7 figs

  3. Ionizing radiation effects on ISS ePTFE jacketed cable assembly

    Science.gov (United States)

    Koontz, S. L.; Golden, J. L.; Lorenz, M. J.; Pedley, M. D.

    2003-09-01

    Polytetrafluoroethylene (PTFE), which is susceptible to embrittlement by ionizing radiation, is used as a primary material in the Mobile Transporter's (MT) Trailing Umbilical System (TUS) cable on the International Space Station (ISS). The TUS cable provides power and data service between the ISS truss and the MT. The TUS cable is normally stowed in an uptake reel and is fed out to follow the MT as it moves along rails on the ISS truss structure. For reliable electrical and mechanical performance, TUS cable polymeric materials must be capable of >3.5% elongation without cracking or breaking. The MT TUS cable operating temperature on ISS is expected to range between -100°C and +130°C. The on-orbit functional life requirement for the MT TUS cable is 10 years. Analysis and testing were performed to verify that the MT TUS cable would be able to meet full-life mechanical and electrical performance requirements, despite progressive embrittlement by the natural ionizing radiation environment. Energetic radiation belt electrons (trapped electrons) are the principal contributor to TUS cable radiation dose. TUS cable specimens were irradiated, in vacuum, with both energetic electrons and gamma rays. Electron beam energy was chosen to minimize charging effects on the non-conductive ePTFE (expanded PTFE) targets. Tensile testing was then performed, over the expected range of operating temperatures, as a function of radiation dose. When compared to the expected in-flight radiation dose/depth profile, atomic oxygen (AO) erosion of the radiation damaged TUS cable jacket surfaces is more rapid than the development of radiation induced embrittlement of the same surfaces. Additionally, the layered construction of the jacket prevents crack growth propagation, leaving the inner layer material compliant with the design elongation requirements. As a result, the TUS cable insulation design was verified to meet performance life requirements.

  4. Electric field analysis of extra high voltage (EHV) underground cables using finite element method

    DEFF Research Database (Denmark)

    Kumar, Mantosh; Bhaskar, Mahajan Sagar; Padmanaban, Sanjeevikumar

    2017-01-01

    used for the insulator due electrical, thermal or environmental stress. Most of these problems are related to the electric field stress on the insulation of the underground cables. The objective of the electric field analysis by using different numerical techniques is to find electric field stress...... electric field stress and other parameters of EHV underground cables with given boundary conditions using 2-D electric field analysis software package (IES-ELECTRO module) which is based on the finite element method (FEM).......Transmission and Distribution of electric power through underground cables is a viable alternative to overhead lines, particularly in residential or highly populated areas. The electrical stresses are consequences of regular voltages and over voltages and the thermal stresses are related to heat...

  5. Sound insulation requirements in the Nordic countries

    DEFF Research Database (Denmark)

    Rasmussen, Birgit

    All Nordic countries have sound insulation requirements for housing and sound classification schemes originating from a common INSTA‐proposal in the mid 90’s, but unfortunately being increasingly diversified since then. The present situation impedes development and create barriers for trade and e...

  6. 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

  7. Studying radiolytic ageing of nuclear power plant electric cables with FTIR spectroscopy.

    Science.gov (United States)

    Levet, A; Colombani, J; Duponchel, L

    2017-09-01

    Due to the willingness to extend the nuclear power plants length of life, it is of prime importance to understand long term ageing effect on all constitutive materials. For this purpose gamma-irradiation effects on insulation of instrumentation and control cables are studied. Mid-infrared spectroscopy and principal components analysis (PCA) were used to highlight molecular modifications induced by gamma-irradiation under oxidizing conditions. In order to be closer to real world conditions, a low dose rate of 11Gyh -1 was used to irradiate insulations in full cable or alone with a dose up to 58 kGy. Spectral differences according to irradiation dose were extracted using PCA. It was then possible to observe different behaviors of the insulation constitutive compounds i.e. ethylene vinyl acetate (EVA), ethylene propylene diene monomer (EPDM) and aluminium trihydrate (ATH). Irradiation of insulations led to the oxidation of their constitutive polymers and a modification of filler-polymer ratio. Moreover all these modifications were observed for insulations alone or in full cable indicating that oxygen easily diffuses into the material. Spectral contributions were discussed considering different degradation mechanisms. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. 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.)

  9. 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…

  10. 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.

  11. Effect of D.C. testing water tree deteriorated cable and a preliminary evaluation of V.L.F. as alternate

    International Nuclear Information System (INIS)

    Eager, G.S. Jr.; Fryszczyn, B.; Katz, C.; ElBadaly, H.A.; Jean, A.R.

    1992-01-01

    This paper reports that according to the experience of some power utilities, the application of industry recommended high voltage d.c. field tests on 5-35 kV extruded dielectric cables, containing water trees, sometimes causes further deterioration of the insulation. Tests conducted on laboratory aged 15 kV ethylene propylene rubber (EP) and 15 and 28 kV crosslinked polyethylene (XLPE) insulated cables indicate that d.c. proof tests in accordance with AEIC specifications an IEEE test guides without flashover do not appear to cause further deterioration. Depending on the degree of cable aging and the level of test voltage, when flashovers take place, damage may be inflicted to XLPE cables. No damage was observed on aged EP cable, at the same test levels. Because of the aforementioned power utility experience, some users have requested an alternate field proof test. Tests conducted on new XLPE and EP cables indicate that damage to the insulation structure can be detected using VLF (0.1 Hz) voltage at approximately one-third the d.c. voltage level. Field tests conducted on severely tree deteriorated 15 kV polyethylene (PE) cable using AEIC recommended d.c. voltage level of about five times operating voltage level caused cable failure; VLF voltage levels up to two times operating voltage did not. VLF voltage appears to be a suitable alternate to d.c. voltage for field proof testing

  12. 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.

  13. 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...

  14. 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.

  15. 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

  16. High Voltage Hybrid Electric Propulsion - Multilayered Functional Insulation System (MFIS) NASA-GRC

    Science.gov (United States)

    Lizcano, M.

    2017-01-01

    High power transmission cables pose a key challenge in future Hybrid Electric Propulsion Aircraft. The challenge arises in developing safe transmission lines that can withstand the unique environment found in aircraft while providing megawatts of power. High voltage AC, variable frequency cables do not currently exist and present particular electrical insulation challenges since electrical arcing and high heating are more prevalent at higher voltages and frequencies. Identifying and developing materials that maintain their dielectric properties at high voltage and frequencies is crucial.

  17. A novel extrusion head for the renovation of cable sheaths - numeric simulation speeds conceptual work; Une tete d'extrusion novatrice pour revetir des cables. La simulation numerique pour accelerer sa conception

    Energy Technology Data Exchange (ETDEWEB)

    Ata-Caesar, D.; Gendre, F.; Schillaci, J.

    2005-07-01

    This article describes a new method of applying layers of insulation to power cables. The disadvantages of traditional methods of extrusion of cable insulation are looked at, that often are a source of impurities that can possibly degrade the physical and chemical qualities of the end product. The article discusses how the new method was developed in co-operation with a specialised University of Applied Science. Also, the savings in time and money that can be made during the optimisation of a prototype are discussed. The numeric simulation methods used are examined and the commercialisation of the product is looked at.

  18. Design of a 30 m long 1 kA 10 kV YBCO cable

    Energy Technology Data Exchange (ETDEWEB)

    Rostila, L [Institute of Electromagnetics, Tampere University of Technology, PO Box 692, FIN-33101 Tampere (Finland); Lehtonen, J [Institute of Electromagnetics, Tampere University of Technology, PO Box 692, FIN-33101 Tampere (Finland); Masti, M [Institute of Electromagnetics, Tampere University of Technology, PO Box 692, FIN-33101 Tampere (Finland); Lallouet, N [Nexas France, rue Mozart 4-10, 92587 Clichy (France); Saugrain, J-M [Nexas France, rue Mozart 4-10, 92587 Clichy (France); Allais, A [Nexans Deutschland Industries GmbH and Co. KG, Kabelkamp 20, D-30179 Hannover (Germany); Schippl, K [Nexans Deutschland Industries GmbH and Co. KG, Kabelkamp 20, D-30179 Hannover (Germany); Schmidt, F [Nexans Deutschland Industries GmbH and Co. KG, Kabelkamp 20, D-30179 Hannover (Germany); Balog, G [Nexans Norway, PO Box 6450, Etterstad, N-0605, Oslo, Norway (Norway); Marot, G [Air Liquide DTA, 2 rue de Clemenciere BP15, 38360 Sassenage (France); Ravex, A [Air Liquide DTA, 2 rue de Clemenciere BP15, 38360 Sassenage (France); Usoskin, A [European High Temperature Superconductors Gmbh and Co. KG, Windausweg 2, 37037 Goettingen (Germany); Goemoery, F [Institute of Electrical Engineering, Slovak Academy of Sciences, Dubravska cesta 9, 84104 Bratislava (Slovakia); Klincok, B [Institute of Electrical Engineering, Slovak Academy of Sciences, Dubravska cesta 9, 84104 Bratislava (Slovakia); Souc, J [Institute of Electrical Engineering, Slovak Academy of Sciences, Dubravska cesta 9, 84104 Bratislava (Slovakia); Freyhardt, H C [Institute of Materialphysic, University of Goettingen, Friedrich-Hund-Platz 1, D-37077 Goettingen (Germany)

    2006-04-15

    In this paper a 30 m long one-phase coaxial YBCO cable with 1 kA transport current and 10 kV operating voltage was designed for the Super3C project to check the feasibility of YBCO tapes for low-loss cables. The final design incorporates cryogenic, mechanical and electromagnetic aspects. The electromagnetic losses during normal operation must be minimized. The cryogenic design must also take into account the generation of heat during short circuit conditions. Mechanical restrictions set the minimum gaps between the coated conductor tapes and the minimum lay angles in order to make the cabling feasible and to enable handling of the cable. The design of the electric insulation should be according to the international standard as far as applicable. The final design has to take into account all of the above restrictions.

  19. Design of a 30 m long 1 kA 10 kV YBCO cable

    International Nuclear Information System (INIS)

    Rostila, L; Lehtonen, J; Masti, M; Lallouet, N; Saugrain, J-M; Allais, A; Schippl, K; Schmidt, F; Balog, G; Marot, G; Ravex, A; Usoskin, A; Goemoery, F; Klincok, B; Souc, J; Freyhardt, H C

    2006-01-01

    In this paper a 30 m long one-phase coaxial YBCO cable with 1 kA transport current and 10 kV operating voltage was designed for the Super3C project to check the feasibility of YBCO tapes for low-loss cables. The final design incorporates cryogenic, mechanical and electromagnetic aspects. The electromagnetic losses during normal operation must be minimized. The cryogenic design must also take into account the generation of heat during short circuit conditions. Mechanical restrictions set the minimum gaps between the coated conductor tapes and the minimum lay angles in order to make the cabling feasible and to enable handling of the cable. The design of the electric insulation should be according to the international standard as far as applicable. The final design has to take into account all of the above restrictions

  20. Influence of LOCA simulating conditions on the variation of electrical characteristics of insulating materials

    International Nuclear Information System (INIS)

    Okada, Sohei; Yoshikawa, Masato; Ito, Masayuki; Kusama, Yasuo; Yagi, Toshiaki

    1982-01-01

    The authors have examined the variation of insulation resistance when the sheets of insulating materials and cables were exposed to various LOCA simulating environment. This report describes the summarized results obtained so far for ethylene propylene rubber (EPR) which is important as an insulating material of cables. The samples used were an EPR sheet of standard compound ratio, 2 kinds of EPR sheets of practical compound ratio, 6 types of PH cables (fire-retardant, EPR insulated, chlorosulphonated polyethylene sheathed cable) produced for trial as reactor use, and 6 kinds of EPR sheets of the same composition as the cable core. To discuss the difference of insulation resistance change, the logarithmic mean of the ratio of 1 min values to initial insulation resistance rho/rhosub(o) was used. PWR LOCA-simulating environment was used, while the thermal aging in the air at 121 deg C for 7 days and 50 Mrad irradiation in the air at room temperature were given as the predeterioration. The effect of LOCA-simulation period in the simultaneous method without air, in which steam and radiation were given in parallel, the difference in the experimental results of cables and sheets, the effect of air, the comparison of the simultaneous method with the sequential method in which LOCA-simulating steam was applied after the irradiation in the air and the reverse sequential method (dielectric property measurements) are described. Under the existence of air, the sequential method seems to be a good simulation condition for the simultaneous method, though many experiments are required further. (Wakatsuki, Y.)

  1. Influence of LOCA simulating conditions on the variation of electrical characteristics of insulating materials

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Sohei; Yoshikawa, Masato; Ito, Masayuki; Kusama, Yasuo; Yagi, Toshiaki

    1982-12-01

    The authors have examined the variation of insulation resistance when the sheets of insulating materials and cables were exposed to various LOCA simulating environment. This report describes the summarized results obtained so far for ethylene propylene rubber (EPR) which is important as an insulating material of cables. The samples used were an EPR sheet of standard compound ratio, 2 kinds of EPR sheets of practical compound ratio, 6 types of PH cables (fire-retardant, EPR insulated, chlorosulphonated polyethylene sheathed cable) produced for trial as reactor use, and 6 kinds of EPR sheets of the same composition as the cable core. To discuss the difference of insulation resistance change, the logarithmic mean of the ratio of 1 min values to initial insulation resistance rho/rhosub(o) was used. PWR LOCA-simulating environment was used, while the thermal aging in the air at 121 deg C for 7 days and 50 Mrad irradiation in the air at room temperature were given as the predeterioration. The effect of LOCA-simulation period in the simultaneous method without air, in which steam and radiation were given in parallel, the difference in the experimental results of cables and sheets, the effect of air, the comparison of the simultaneous method with the sequential method in which LOCA-simulating steam was applied after the irradiation in the air and the reverse sequential method (dielectric property measurements) are described. Under the existence of air, the sequential method seems to be a good simulation condition for the simultaneous method, though many experiments are required further.

  2. Effects evaluation of artificial aging by temperature and gamma radiation on cables for Laguna Verde nuclear power plant (LVNPP)

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez C, R. M.; Bonifacio M, J.; Garcia H, E. E.; Loperena Z, J. A. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Garcia M, C., E-mail: raulmario.vazquez@inin.gob.m [CFE, Central Nuclear Laguna Verde, Km. 42.5 Carretera Cardel-Nautla, Veracruz (Mexico)

    2010-10-15

    A set of tests has been carried out at the Equipment Qualification Laboratory at National Institute of Nuclear Research to perform accelerated aging up to 60 years under temperature and gamma radiation environment for electrical cables. The results obtained from such tests are the base line data for comparison to with the current cable conditions at the plant. This work is intended for establishing the cable aging management program for the Laguna Verde nuclear power plant (LVNPP). For such purpose, the Institute has prepared methodologies and procedures to apply condition monitoring techniques in accelerated aging tests on samples of new cables drawn from the LVNPP warehouse. The condition indicators of the material selected for condition monitoring and the aging management process of cables were: Elongation at Break (EAB) and Oxidation Induction Time (OIT). A cable aging management program includes activities for cable selection, determination of condition indicators of the cable materials (EAB, OIT, Ind enter), accelerated aging of cable samples at the laboratory, analysis of maintenance history, operational experience of the plant and analysis of the environmental and service conditions (temperature and gamma radiation), as well as the establishment of a condition monitoring plan for cables in the plant. Two cable model samples were thermally aged and gamma irradiated with doses corresponding to differential operational periods. EAB and OIT values of cable insulating material (ethylene propylene and cross linked polyethylene) were obtained. It was found that the EAB and OIT data correlation is very closed, and it could be applied to infer values that are not possible to measure directly at the plant and be used for cable aging evaluation and remaining life time determination. (Author)

  3. Evaluation of the indenter modulus (IM) method in the international round robin test about the cable condition monitoring

    International Nuclear Information System (INIS)

    Kajimura, Yuusaku

    2016-01-01

    In order to ensure the reliability and safety of nuclear power plants, the diagnosis of cable aging is important. The Institute of Nuclear Safety System (INSS) has been developing the indenter modulus (IM) method for more than a dozen years. Its usefulness was demonstrated in the research project 'Assessment of cable aging for nuclear power plant' by the Japan Nuclear Energy Safety Organization in 2009. Furthermore, INSS participated in the IAEA Coordinated Research Project in 2013 to 2015, measuring and acquiring data of insulation materials of cables and cable jackets with insulation which had been never measured before by INSS. The main results are as follows. (1) The IM method is useful for new materials (for example, crosslinked polyolefins) which had never been measured before by INSS. (2) The IM method is also applicable to evaluation of cable jackets with insulation made of such materials as chlorosulfonated polyethylene. Therefore, the IM method is evaluated to be useful and applicable for most cable materials except those which have a high IM value initially and which have a small change in IM value during aging. (author)

  4. Economically optimal thermal insulation

    Energy Technology Data Exchange (ETDEWEB)

    Berber, J.

    1978-10-01

    Exemplary calculations to show that exact adherence to the demands of the thermal insulation ordinance does not lead to an optimal solution with regard to economics. This is independent of the mode of financing. Optimal thermal insulation exceeds the values given in the thermal insulation ordinance.

  5. Problems of increasing specific characteristics of pulse capacitors and cables

    International Nuclear Information System (INIS)

    Kuchinskij, G.S.; Monastyrskij, A.E.; Shilin, O.V.

    1984-01-01

    Requirements for high specific energy are practically related to all types of pulse capacitors of energy storage. At present the specific energy for most types of home and foreign pulse capacitors is about 0.1 MJ/m 3 at operating electric field intensity 70-100 kV/mm. It is shown that the basic means for increasing the specific energy and working intensity is the application of new polymeric film materials. Application of paper-film and film insulation permits to develop the specific types of capacitors designed for a limited service life in an aperiodic discharge mode with lower reliabiliy and the specific energy upto 0.5 MJ/m 3 . Characteristics of separate types of pulse capacitors and cables are given, and reliability criterion is considered. Measures of increasing reliability and service life for pulse capacitors and cables, used as tokamak power supplies are enumerated

  6. Utilization of two-way multicore cables and comparison of various electrode configurations in electrical prospecting; Denki tansa ni okeru sohokogata tashin cable no riyo to kakushu dekyoku haichi no hikaku

    Energy Technology Data Exchange (ETDEWEB)

    Takakura, S [Geological Survey of Japan, Tsukuba (Japan); Matsushima, J [The University of Tokyo, Tokyo (Japan). Faculty of Engineering

    1996-10-01

    For more precise electrical prospecting, the new multicore cable was developed to allow high-density measurement by conventional equipment. Since conventional multicore cables are inferior in cost, length and weight, the new cable is composed of an n-conductor cable, two n-conductor male connectors and n lead wires. For connection of the multi-conductor cable and lead wires, cable sheath is peeled at n points at specific intervals. Sheath of the k-th conductor is peeled at k-th point from the terminal, and restored for insulation after connection of the conductor and lead wire. The male connectors are attached to the both ends of the multi-conductor cable. Since this two-way type cable can be used at every end, the measuring equipment can measure at one divisional point after another of a long measuring line while shifting the equipment from one point to another. All measurements are perfected only with two short cables. Resistivities were successfully measured along the long measuring line of 480m long with 97 electrodes arranged at intervals of 5m. Various electrode configurations were also compared. 1 ref., 4 figs., 2 tabs.

  7. Change of electric parameters of power cables for nuclear installations under separated and combined effect of radiation and humidity; Izmenenie ehlektricheskikh parametrov silovykh kabelej dlya yadernykh ustano vok pri razdel`nom i sovmestnom vozdejstvii izlucheniya i povyshennoj vlazhnosti

    Energy Technology Data Exchange (ETDEWEB)

    Filatov, N I

    1994-12-31

    Results of an experimental investigation into the changes of insulation resistance, capacitance and tangent of force cable dielectric loss angle under separate and combined action of gamma radiation and increased humidity of the environment are presented.

  8. 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.)

  9. Review of candidate methods for detecting incipient defects due to aging of installed cables in nuclear power plants

    International Nuclear Information System (INIS)

    Martzloff, F.D.

    1988-01-01

    Several types of test methods have been proposed for detecting incipient defects due to aging in cable insulation systems, none offering certainty of detecting all possible types of defects. Some methods apply direct detection of a defect in the cable; other methods detect changes in electrical or non-electrical parameters from which inference can be drawn on the integrity of the cable. The paper summarizes the first year of a program conducted at the National Bureau of Standards to assess the potential of success for in situ detection of incipient defects by the most promising of these methods

  10. Insulating and sheathing materials of electric and optical cables - Common test methods - Part 5-1: Methods specific to filling compounds - Drop-point - Separation of oil - Lower temperature brittleness - Total acid number - Absence of corrosive components - Permittivity at 23 °C - DC resistivity at 23 °C and 100 °C

    CERN Document Server

    International Electrotechnical Commission. Geneva

    2004-01-01

    Specifies the test methods for filling compounds of electric cables used with telecommunication equipment. Gives the methods for drop-point, separation of oil, lower temperature brittleness, total acid number, absence of corrosive components, permittivity at 23 °C, d.c. resistivity at 23°C and 100°C.

  11. Thermal insulating panel

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, J.T.

    1985-09-11

    A panel of thermal insulation material has at least one main portion which comprises a dry particulate insulation material compressed within a porous envelope so that it is rigid or substantially rigid and at least one auxiliary portion which is secured to and extends along at least one of the edges of the main portions. The auxiliary portions comprise a substantially uncompressed dry particulate insulation material contained within an envelope. The insulation material of the auxiliary portion may be the same as or may be different from the insulation material of the main portion. The envelope of the auxiliary portion may be made of a porous or a non-porous material. (author).

  12. CABLE MECHANISMS USED FOR ACTUATING CAR ELEVATORS WITH 2 AND 4 POLES

    Directory of Open Access Journals (Sweden)

    Dan MESARICI

    2015-05-01

    Full Text Available This paper presents the kinematic scheme and the operating mode of the cable mechanism used for car elevators with 2 and 4 poles. In order to increase the efficiency of the 4- pole elevator, we suggest using a new hoists type cable mechanism, which can multiply the piston travel inside the actuating cylinder twice at the platform level, when lifting and lowering.

  13. Dynamic space charge behaviour in polymeric DC cables

    DEFF Research Database (Denmark)

    Rasmussen, Claus Nygaard; Holbøll, Joachim; Henriksen, Mogens

    2002-01-01

    The use of extruded insulation for DC cables involves a risk of local electric field enhancement, caused by a space charge build-up within the dielectric. In this work, the theory of charge generation and transport in polymers is applied in a numerical computer model in order to predict...... the formation and transport of space charges in a polymeric dielectric. The model incorporates the processes of field assisted electron-hole pair generation from impurity atoms, trapping and charge injection at the electrodes. Its aim has been to study the field- and temperature dependent dynamic behaviour...

  14. Advanced Twisted Pair Cables for Distributed Local Area Networks in Intelligent Structure Systems

    Science.gov (United States)

    Semenov, Andrey

    2018-03-01

    The possibility of a significant increase in the length of cable communication channels of local area networks of automation and engineering support systems of buildings in the case of their implementation on balanced twisted pair cables is shown. Assuming a direct connection scheme and an effective speed of 100 Mbit/s, analytical relationships are obtained for the calculation of the maximum communication distance. The necessity of using in the linear part of such systems of twisted pair cables with U/UTP structure and interference parameters at the level of category 5e is grounded.

  15. Effect of dose rate on irreversible changes of electric parameters of power cables for nuclear power plants; Vliyanie moshchnosti dozy na neobratimye izmeneniya ehlektricheskikh paramet rov silovykh kabelej dlya yadernykh ehnergetricheskikh ustanovok

    Energy Technology Data Exchange (ETDEWEB)

    Filatov, N I

    1994-12-31

    Results of an experimental investigation into an irreversible change of insulation resistance, capacitance and tangent of force cable dielectric loss angle under effect of continuous gamma radiation within the certain dose range are presented. In cables with polyethylene insulation dependence of the critical dose on the dose rate in the range investigated is in the for of the function degrees with a degree index of approximately 0.7.

  16. Complete Fiber/Copper Cable Solution for Long-Term Temperature and Pressure Measurement in Supercritical Reservoirs and EGS Wells

    Energy Technology Data Exchange (ETDEWEB)

    Pastouret, Alan [Draka Cableteq USA, Inc., North Dighton, MA (United States); Gooijer, Frans [Draka Cableteq USA, Inc., North Dighton, MA (United States); Overton, Bob [Draka Cableteq USA, Inc., North Dighton, MA (United States); Jonker, Jan [Draka Cableteq USA, Inc., North Dighton, MA (United States); Curley, Jim [Draka Cableteq USA, Inc., North Dighton, MA (United States); Constantine, Walter [Draka Cableteq USA, Inc., North Dighton, MA (United States); Waterman, Kendall Miller [Draka Cableteq USA, Inc., North Dighton, MA (United States)

    2015-11-13

    High Temperature insulated wire and optical fiber cable is a key enabling technology for the Geothermal Technologies Program (GTP). Without insulated electrical wires and optical fiber, downhole temperature and pressure sensors, flow meters and gauges cannot communicate with the surface. Unfortunately, there are currently no insulated electrical wire or fiber cable constructions capable of surviving for extended periods of deployment in a geothermal well (240-325°C) or supercritical (374°C) reservoir. This has severely hindered engineered reservoir creation, management and utilization, as hot zones and cool water intrusions cannot be understood over time. The lack of a insulated electrical wire and fiber cable solution is a fundamental limitation to the viability of this energy source. The High Temperature Downhole Tools target specification is development of tools and sensors for logging and monitoring wellbore conditions at depths of up to 10,000 meters and temperatures up to 374oC. It well recognized in the industry that no current electronic or fiber cable can be successfully deployed in a well and function successfully for more a few days at temperatures over 240oC. The goal of this project was to raise this performance level significantly. Prysmian Group’s objective in this project was to develop a complete, multi-purpose cable solution for long-term deployment in geothermal wells/reservoirs that can be used with the widest variety of sensors. In particular, the overall project objective was to produce a manufacturable cable design that can perform without serious degradation: • At temperatures up to 374°C; • At pressures up to 220 bar; • In a hydrogen-rich environment; and • For the life of the well (> 5 years). This cable incorporates: • Specialty optical fibers, with specific glass chemistry and high temperature and pressure protective coatings for data communication and distributed temperature and pressure sensing, and • High

  17. 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.

  18. 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...

  19. 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...

  20. 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...

  1. The thermal relay design to improve power system security for the HTS cables in Icheon substation

    International Nuclear Information System (INIS)

    Lee, Hansang; Yang, Byeong-Mo; Jang, Gilsoo

    2013-01-01

    Highlights: •It is important to study thermal characteristics of the HTS cable. •The thermal relay in the Icheon substation has been developed. •Well-designed thermal relay has been verified through PSCAD/EMTDC simulations. -- Abstract: This paper proposes a model for thermal protection relay for the high temperature superconducting (HTS) cables and thermal protection scheme in Icheon substation in Korea. The thermal protection is one of the most important factors to guarantee the reliability of the HTS cable as well as power system security. The superconductivity of the HTS cables, which can be guaranteed by the liquid nitrogen near 70 K, can be threatened by the large fault current. To avoid the overheating in HTS cable and to secure the power system operation with the HTS cable, the thermal protection relay should be considered. To find the optimal thermal-protection scheme, the model for the superconducting power system has been achieved in Icheon substation and the thermal protection scheme has been verified through PSCAD/EMTDC simulation

  2. The thermal relay design to improve power system security for the HTS cables in Icheon substation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hansang, E-mail: hslee80@kiu.ac.kr [School of Railway and Electrical Engineering, Kyungil University, Hayang-eup, Gyeongsan-si, Gyeongsangbuk-do 712-701 (Korea, Republic of); Yang, Byeong-Mo [Korea Electric Power Research Institute, Munji-dong, Yuseong-gu, Daejeon 305-760 (Korea, Republic of); Jang, Gilsoo, E-mail: gjang@korea.ac.kr [School of Electrical Engineering, Korea University, Anam-dong 5-ga, Seongbuk-gu, Seoul 136-713 (Korea, Republic of)

    2013-11-15

    Highlights: •It is important to study thermal characteristics of the HTS cable. •The thermal relay in the Icheon substation has been developed. •Well-designed thermal relay has been verified through PSCAD/EMTDC simulations. -- Abstract: This paper proposes a model for thermal protection relay for the high temperature superconducting (HTS) cables and thermal protection scheme in Icheon substation in Korea. The thermal protection is one of the most important factors to guarantee the reliability of the HTS cable as well as power system security. The superconductivity of the HTS cables, which can be guaranteed by the liquid nitrogen near 70 K, can be threatened by the large fault current. To avoid the overheating in HTS cable and to secure the power system operation with the HTS cable, the thermal protection relay should be considered. To find the optimal thermal-protection scheme, the model for the superconducting power system has been achieved in Icheon substation and the thermal protection scheme has been verified through PSCAD/EMTDC simulation.

  3. 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)

  4. Analysis of the electrodynamics of subcable current distribution in the superconducting POLO coil cable

    International Nuclear Information System (INIS)

    Sihler, C.; Heller, R.; Maurer, W.; Ulbricht, A.; Wuechner, F.

    1995-10-01

    Unexpected ramp rate limitations (RRL) found in superconducting magnets during the development of magnet systems can be attributed to a current imbalance amongst the cabled strands which leads to a lower than expected quench current. In superconducting magnets the current distribution in the cable during ramping depends mainly on the electromagnetic properties of the system. A detailed analysis of principle causes for RRL phenomena was performed with a model for one half of the POLO coil considering the complete inductance matrix of the cable and the fact that all turns are mutually coupled. The main results of these calculations are that unequal contact resistances can not be responsible for RRL phenomena in coils with parameters comparable to those of the POLO coil and that already minor geometrical disturbances in the cable structure can lead to major and lasting imbalances in the current distribution of cables with insulated and non-insulated strands. During the POLO experiment the half-coil model was employed to get a better understanding of the measured compensated subcable voltages during quench. The good agreement of the calculated and measured results demonstrates the validity of the model for RRL analyses. (orig.)

  5. Analytical studies on hotspot temperature of cable-in-conduit conductors

    International Nuclear Information System (INIS)

    Yoshida, Kiyoshi; Takigami, Hiroyoshi; Kubo, Hiroatsu

    2001-01-01

    This paper describes an analytical study to review the hotspot temperature design criteria of the cable-in-conduit conductors for the ITER magnet system. The ITER magnet system uses three kinds of cable-in-conduit conductors for the Toroidal Field (TF) coils, the Central Solenoid (CS) and the Poloidal Field (PF) coils. The amount of copper in the superconducting cable has been defined by using the classical hotspot temperature design criteria that is based on the adiabatic condition. In the current design, ITER superconducting cables include a large amount of pure copper strands to satisfy the classical criteria. However, temperature and stress in the conduit and insulations after quench can be simulated with the quench simulation program and stress analysis program using the latest analysis tools. This analysis shows that the strand temperature is dominated by the conduction along strands and the heat capacity of other conductor materials and coolant. The hotspot temperature depends strongly on the delay time for quench detection. This analysis provides an estimation of delay times for quench detection. The thermal and stress analysis can provide the maximum allowable temperature after quench by determination of a failure or a functional disorder condition of the jacket material and turn insulation. In conclusion, it is found that the current density of the cable space can be increased, by reducing the extra copper strand, thereby, allowing a reduction of the coil radial build. (author)

  6. Development of flame retardant, radiation resistant insulating materials

    Energy Technology Data Exchange (ETDEWEB)

    Hagiwara, M.

    1984-01-01

    On the cables used for nuclear power stations, in particular those ranked as IE class, flame retardation test, simulated LOCA environment test, radiation resistance test and so on are imposed. The results of the evaluation of performance by these tests largely depend on the insulating materials mainly made of polymers. Ethylene propylene copolymer rubber has been widely used as cable insulator because of its electrical characteristics, workability, economy and relatively good radiation resistance, but it is combustible, therefore, in the practical use, it is necessary to make it fire resistant. The author et al. have advanced the research on the molecular design of new fire retarding materials, and successfully developed acenaphthylene bromide condensate, which is not only fire resistant but also effective for improving radiation resistance. The condition of flame retardant, radiation resistant auxiliary agents is explained, and there are additive type and reaction type in fire retarding materials. The synthesis of acenaphthylene bromide condensate and its effect of giving flame retardant and radiation resistant properties are reported. The characteristics of the cables insulated with the flame retardant ethylene propylene rubber containing acenaphthylene bromide condensate were tested, and the results are shown. (Kako, I.).

  7. 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....

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Harmonizing power cables and power lines. Harmonisierung der Starkstromkabel und -leitungen

    Energy Technology Data Exchange (ETDEWEB)

    Heinhold, L [Siemens A.G., Erlangen (Germany, F.R.); Retzlaff, E; Warner, A [Verband Deutscher Elektrotechniker (VDE) e.V., Frankfurt am Main (Germany, F.R.)

    1976-01-01

    The article gives a summarizing view of the present level of harmonization in the field of power cables and lines. Special attention is paid to problems referring to using harmonized designs for flexible lines and using lines for solid layout with PVC and rubber insulation in the German standards DIN 57281/VDE 0281 and DIN 57282/VDE 0282 and problems of taking the types used until today out of use. A general view of the power lines fully harmonized is given and a harmonization-labelling (common labelling) for cables and lines is described.

  13. Design of a termination for a high temperature superconduction power cable

    DEFF Research Database (Denmark)

    Rasmussen, Carsten; Kühle (fratrådt), Anders Van Der Aa; Tønnesen, Ole

    1999-01-01

    ). This assembly is electrically insulated with an extruded polymer dielectric kept at room temperature. Cooling is provided by a flow of liquid nitrogen inside the former. The purpose of the termination is to connect the superconducting cable conductor at cryogenic temperature to the existing power grid at room...... temperatures, the transfer of liquid nitrogen over a high voltage drop and that of providing a well defined atmosphere inside the termination and around the cable conductor. Designs based on calculations and experiments will be presented. The solutions are optimized with respect to a low heat in-leak....

  14. Panels of microporous insulation

    Energy Technology Data Exchange (ETDEWEB)

    McWilliams, J.A.; Morgan, D.E.; Jackson, J.D.J.

    1990-08-07

    Microporous thermal insulation materials have a lattice structure in which the average interstitial dimension is less than the mean free path of the molecules of air or other gas in which the material is arranged. This results in a heat flow which is less than that attributable to the molecular heat diffusion of the gas. According to this invention, a method is provided for manufacturing panels of microporous thermal insulation, in particular such panels in which the insulation material is bonded to a substrate. The method comprises the steps of applying a film of polyvinyl acetate emulsion to a non-porous substrate, and compacting powdery microporous thermal insulation material against the film so as to cause the consolidated insulation material to bond to the substrate and form a panel. The polyvinyl acetate may be applied by brushing or spraying, and is preferably allowed to dry prior to compacting the insulation material. 1 fig.

  15. Wall insulation system

    Energy Technology Data Exchange (ETDEWEB)

    Kostek, P.T.

    1987-08-11

    In a channel specially designed to fasten semi-rigid mineral fibre insulation to masonry walls, it is known to be constructed from 20 gauge galvanized steel or other suitable material. The channel is designed to have pre-punched holes along its length for fastening of the channel to the drywall screw. The unique feature of the channel is the teeth running along its length which are pressed into the surface of the butted together sections of the insulation providing a strong grip between the two adjacent pieces of insulation. Of prime importance to the success of this system is the recent technological advancements of the mineral fibre itself which allow the teeth of the channel to engage the insulation fully and hold without mechanical support, rather than be repelled or pushed back by the inherent nature of the insulation material. After the insulation is secured to the masonry wall by concrete nail fastening systems, the drywall is screwed to the channel.

  16. Cabling design of booster and storage ring construction progress of TPS

    International Nuclear Information System (INIS)

    Wong, Y.-S.; Liu, K.-B.; Liu, C.-Y.; Wang, B.-S.

    2017-01-01

    The 2012 Taiwan Photon Source (TPS) cable construction project started after 10 months to complete the cable laying and installation of power supply. The circumference of the booster ring (BR) is 496.8 m, whereas that of the storage ring (SR) is 518.4 m. Beam current is set to 500 mA at 3.3 GeV. The paper on grounding systems discusses the design of the ground wire (< 0.2 Ω) with low impedance, power supply of the accelerator and cabling tray. The flow and size of the ground current are carefully evaluated to avoid grounded current from flowing everywhere, which causes interference problems. In the design of the TPS, special shielding will be established to isolate the effects of electromagnetic interference on the magnet and ground current. Booster ring dipoles are connected by a series of 54-magnet bending dipole; the cable size of its stranded wire measures 250 mm"2, with a total length of 5000 m. Booster ring and storage ring quadrupoles have 150 magnets; the cable size of their stranded wire is 250 mm"2, with a total length of 17000 m. Storage ring dipole consists of 48 magnets; the cable size of its stranded wire is 325 mm"2, with a total length of 6000 m. This study discusses the power supply cabling design of the storage ring and booster ring construction progress of TPS. The sections of this paper are divided into discussions of the construction of the control and instrument area, cabling layout of booster ring and storage ring, as well as the installation and commission machine. This study also discusses the use of a high-impedance meter to determine the effect of cabling insulation and TPS power supply machine on energy transfer to ensure the use of safe and correct magnet.

  17. 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

  18. Colour schemes

    DEFF Research Database (Denmark)

    van Leeuwen, Theo

    2013-01-01

    This chapter presents a framework for analysing colour schemes based on a parametric approach that includes not only hue, value and saturation, but also purity, transparency, luminosity, luminescence, lustre, modulation and differentiation.......This chapter presents a framework for analysing colour schemes based on a parametric approach that includes not only hue, value and saturation, but also purity, transparency, luminosity, luminescence, lustre, modulation and differentiation....

  19. Sound classification of dwellings - Comparison of schemes in Europe

    DEFF Research Database (Denmark)

    Rasmussen, Birgit

    2009-01-01

    National sound classification schemes for dwellings exist in nine countries in Europe, and proposals are under preparation in more countries. The schemes specify class criteria concerning several acoustic aspects, the main criteria being about airborne and impact sound insulation between dwellings......, facade sound insulation and installation noise. The quality classes reflect dierent levels of acoustical comfort. The paper presents and compares the sound classification schemes in Europe. The schemes have been implemented and revised gradually since the 1990es. However, due to lack of coordination...

  20. A 40 kA NbTi cable in conduit conductor for the large poloidal field coils of net

    International Nuclear Information System (INIS)

    Torossian, A.; Bessette, D.; Turck, B.; Kazimierzak, B.

    1990-01-01

    The main feature of this cable in conduit design is to separate the manufacture of the full length of the steel conduit (400 m) and of the cable in order to minimize the industrial risk and consequently the cost. A circular cross section for that cable seems to be the most suitable for that purpose: - axisymmetric cabling with full transposition of strands, - cable behaviour independent of the field orientation, - less deformation of subcables, - cross section remains circular when the cable is under tension and makes the slippage of the cable in the conduit easier, - butt welding of 8 m long tubes forming the conduit becomes simpler. The square external shape allows to minimize the amount of insulating material and consequently improves the overall current density of the coil. This conductor is aimed to large poloidal field coils for NET which do not require high field and in that case NbTi seems to be the best choice with regard to reliability and cost but Nb 3 Sn could be used as well. Stainless steel ribbons are inserted between subcables in order to reduce losses induced by the rapid field changes and also to improve the mechanical behaviour of the cable

  1. Integrated cable vibration control system using wireless sensors

    Science.gov (United States)

    Jeong, Seunghoo; Cho, Soojin; Sim, Sung-Han

    2017-04-01

    As the number of long-span bridges is increasing worldwide, maintaining their structural integrity and safety become an important issue. Because the stay cable is a critical member in most long-span bridges and vulnerable to wind-induced vibrations, vibration mitigation has been of interest both in academia and practice. While active and semi-active control schemes are known to be quite effective in vibration reduction compared to the passive control, requirements for equipment including data acquisition, control devices, and power supply prevent a widespread adoption in real-world applications. This study develops an integrated system for vibration control of stay-cables using wireless sensors implementing a semi-active control. Arduino, a low-cost single board system, is employed with a MEMS digital accelerometer and a Zigbee wireless communication module to build the wireless sensor. The magneto-rheological (MR) damper is selected as a damping device, controlled by an optimal control algorithm implemented on the Arduino sensing system. The developed integrated system is tested in a laboratory environment using a cable to demonstrate the effectiveness of the proposed system on vibration reduction. The proposed system is shown to reduce the vibration of stay-cables with low operating power effectively.

  2. 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.

  3. Translucent insulating building envelope

    DEFF Research Database (Denmark)

    Rahbek, Jens Eg

    1997-01-01

    A new type of translucent insulating material has been tested. This material is made of Celulose-Acetat and have a honey-comb structure. The material has a high solar transmittance and is highly insulating. The material is relatively cheap to produce. Danish Title: Translucent isolerende klimaskærm....

  4. 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.

  5. Trajectory generation to suppress oscillations in under-constrained cable-driven parallel robots

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Sung Wook; Bak, Jeong Hyeon; Yoon, Jong Hyun; Park, Jong Hyeon [Dept. of Mechanical Engineering, Hanyang University, Seoul (Korea, Republic of); Park, Jong Oh [School of Mechanical Engineering, Chonnam National University, Gwangju (Korea, Republic of)

    2016-12-15

    Cable-driven parallel robots (CDPRs) have many advantages over conventional link-based robot manipulators in terms of acceleration due to their low inertia. This paper concerns about under-constrained CDPRs, which have a less number of cables than six, often used favorably due to their simpler structures. Since a smaller number of cables than 6 are employed, however, their payloads have extra degrees of motion freedom and exhibit swaying motions or oscillation. In this paper, a scheme to suppress unwanted oscillatory motions of the payload of a 4-cable-driven CDPR based on a Zero-vibration (ZV) input-shaping scheme is proposed. In this method, a motion in the 3-dimensional space is projected onto the independent motions on two vertical planes perpendicular to each other. On each of the vertical plane, the natural frequency of the CDPR is computed based on a 2-cable-driven planar CDPR model. The precise dynamic model of a planar CDPR is obtained in order to find the natural frequency, which depends on the payload position. The advantage of the proposed scheme is that it is possible to generate an oscillation-free trajectory based on a ZV input-shaping scheme despite the complexity in the dynamics of the CDPR and the difficulty in computing the natural frequencies of the CDPR, which is required in any ZV input-shaping scheme. To verify the effectiveness of the proposed method, a series of computer simulations and experiments were conducted for 3- dimensional motions with a 4-cable-driven CDPR. Their results showed that the motions of the CDPR with the proposed method exhibited a significant reduction in oscillations of the payload. However, when the payload moves near the edges of its workspace, the improvement in oscillation reduction diminished as expected due to the errors in model projection.

  6. Concepts for evaluation of sound insulation of dwellings

    DEFF Research Database (Denmark)

    Rasmussen, Birgit; Rindel, Jens Holger

    2005-01-01

    Legal sound insulation requirements have existed more than 50 years in some countries, and single-number quantities for evaluation of sound insulation have existed nearly as long time. However, the concepts have changed considerably over time from simple arithmetic averaging of frequency bands......¬ments and classification schemes revealed significant differences of concepts. The paper summarizes the history of concepts, the disadvantages of the present chaos and the benefits of consensus concerning concepts for airborne and impact sound insulation between dwellings and airborne sound insulation of facades...... with a trend towards light-weight constructions are contradictory and challenging. This calls for exchange of data and experience, implying a need for harmonized concepts, including use of spectrum adaptation terms. The paper will provide input for future discussions in EAA TC-RBA WG4: "Sound insulation...

  7. 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.

  8. 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

  9. Superheated-steam test of ethylene propylene rubber cables using a simultaneous aging and accident environment

    International Nuclear Information System (INIS)

    Bennett, P.R.; St Clair, S.D.; Gilmore, T.W.

    1986-06-01

    The superheated-steam test exposed different ethylene propylene rubber (EPR) cables and insulation specimens to simultaneous aging and a 21-day simultaneous accident environment. In addition, some insulation specimens were exposed to five different aging conditions prior to the 21-day simultaneous accident simulation. The purpose of this superheated-steam test (a follow-on to the saturated-steam tests (NUREG/CR-3538)) was to: (1) examine electrical degradation of different configurations of EPR cables; (2) investigate differences between using superheated-steam or saturated-steam at the start of an accident simulation; (3) determine whether the aging technique used in the saturated-steam test induced artificial degradation; and (4) identify the constituents in EPR that affect moisture absorption

  10. Automation of extrusion of porous cable products based on a digital controller

    Science.gov (United States)

    Chostkovskii, B. K.; Mitroshin, V. N.

    2017-07-01

    This paper presents a new approach to designing an automated system for monitoring and controlling the process of applying porous insulation material on a conductive cable core, which is based on using structurally and parametrically optimized digital controllers of an arbitrary order instead of calculating typical PID controllers using known methods. The digital controller is clocked by signals from the clock length sensor of a measuring wheel, instead of a timer signal, and this provides the robust properties of the system with respect to the changing insulation speed. Digital controller parameters are tuned to provide the operating parameters of the manufactured cable using a simulation model of stochastic extrusion and are minimized by moving a regular simplex in the parameter space of the tuned controller.

  11. A highly precise frequency-based method for estimating the tension of an inclined cable with unknown boundary conditions

    Science.gov (United States)

    Ma, Lin

    2017-11-01

    This paper develops a method for precisely determining the tension of an inclined cable with unknown boundary conditions. First, the nonlinear motion equation of an inclined cable is derived, and a numerical model of the motion of the cable is proposed using the finite difference method. The proposed numerical model includes the sag-extensibility, flexural stiffness, inclination angle and rotational stiffness at two ends of the cable. Second, the influence of the dynamic parameters of the cable on its frequencies is discussed in detail, and a method for precisely determining the tension of an inclined cable is proposed based on the derivatives of the eigenvalues of the matrices. Finally, a multiparameter identification method is developed that can simultaneously identify multiple parameters, including the rotational stiffness at two ends. This scheme is applicable to inclined cables with varying sag, varying flexural stiffness and unknown boundary conditions. Numerical examples indicate that the method provides good precision. Because the parameters of cables other than tension (e.g., the flexural stiffness and rotational stiffness at the ends) are not accurately known in practical engineering, the multiparameter identification method could further improve the accuracy of cable tension measurements.

  12. 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.

  13. 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.

  14. 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.

  15. Magnetization Losses of Roebel Cable Samples with 2G YBCO Coated Conductor Strands

    CERN Document Server

    Yang, Y.; Falorio, I.; Young, E.A.; Kario, A.; Goldacker, W.; Dhallé, M. M. J.; van Nugteren, J.; Kirby, G.; Bottura, L.; Ballarino, A.

    2016-01-01

    Roebel cable with 2G YBCO strands is one of the promising HTS solutions of fully transposed high current conductors for high field accelerator magnets. Following the considerable research effort on the manufacturing of Roebel cables in recent years, sample conductors are now available in useful lengths with reproducible performances to allow detailed characterizations beyond the standard critical current measurements. The ac loss and strands coupling are of significant interest for the field quality of the accelerator magnets. We report a set of systematic ac loss measurements on two different Roebel cable samples prepared for the EuCARD2 collaboration. The measurements were performed over a wide range of temperature between 5 K and 90 K and the results were analyzed in the context of strands architecture and coupling. The results show that the transposed bundles are partially decoupled and the strands in transposition sections behave as an isolated single tape if the strands are insulated.

  16. Design of HTS tri-axial cable in steady-state operation

    International Nuclear Information System (INIS)

    Hu, N.; Toda, M.; Ozcivan, A.N.; Yagai, T.; Tsuda, M.; Hamajima, T.

    2010-01-01

    By the advantage of more compact structure, small leakage field, and low heat loss, tri-axial cable become to be mainstream design in recently HTS practical project. However, the imbalance current problem was also reported by some practice experiments. Since the HTS tri-axial cable is composed of three concentric phases, an unsymmetrical inductance and capacitance distribution which is determined by twist pitches and radii, gives an inherent imbalance in three-phase currents distribution. In our previous research, we proposed a two sections structure design to overcome this limitation. Inductance has been balanced by twist pitch adjusting. In that case, the imbalance ratio of current only can be caused by capacitance distribution which is depending on voltage and line length. In this paper, we evaluate the thickness of insulation, the unsymmetrical capacitance distribution and cable fabrication error. Then we investigate the imbalance ratio due to the capacitance as functions of voltage and length by using Electromagnetic Transients Program (EMTP).

  17. Tradable schemes

    NARCIS (Netherlands)

    J.K. Hoogland (Jiri); C.D.D. Neumann

    2000-01-01

    textabstractIn this article we present a new approach to the numerical valuation of derivative securities. The method is based on our previous work where we formulated the theory of pricing in terms of tradables. The basic idea is to fit a finite difference scheme to exact solutions of the pricing

  18. 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.

  19. Heat insulation support device

    International Nuclear Information System (INIS)

    Takahashi, Hiroyuki; Koda, Tomokazu; Motojima, Osamu; Yamamoto, Junya.

    1994-01-01

    The device of the present invention comprises a plurality of heat insulation legs disposed in a circumferential direction. Each of the heat insulative support legs has a hollow shape, and comprises an outer column and an inner column as support structures having a heat insulative property (heat insulative structure), and a thermal anchor which absorbs compulsory displacement by a thin flat plate (displacement absorber). The outer column, the thermal anchor and the inner column are connected by a support so as to offset the positional change of objects to be supported due to shrinkage when they are shrunk. In addition, the portion between the superconductive coils as the objects to be supported and the inner column is connected by the support. The superconductive thermonuclear device is entirely contained in a heat insulative vacuum vessel, and the heat insulative support legs are disposed on a lower lid of the heat insulative vacuum vessel. With such a constitution, they are strengthened against lateral load and buckling, thereby enabling to reduce the amount of heat intrusion while keeping the compulsory displacement easy to be absorbed. (I.N.)

  20. Benchmark Analysis for Condition Monitoring Test Techniques of Aged Low Voltage Cables in Nuclear Power Plants. Final Results of a Coordinated Research Project

    International Nuclear Information System (INIS)

    2017-10-01

    This publication provides information and guidelines on how to monitor the performance of insulation and jacket materials of existing cables and establish a programme of cable degradation monitoring and ageing management for operating reactors and the next generation of nuclear facilities. This research was done through a coordinated research project (CRP) with participants from 17 Member States. This group of experts compiled the current knowledge in a report together with areas of future research and development to cover aging mechanisms and means to identify and manage the consequences of aging. They established a benchmarking programme using cable samples aged under thermal and/or radiation conditions, and tested before and after ageing by various methods and organizations. In particular, 12 types of cable insulation or jacket material were tested, each using 14 different condition monitoring techniques. Condition monitoring techniques yield usable and traceable results. Techniques such as elongation at break, indenter modulus, oxidation induction time and oxidation induction temperature were found to work reasonably well for degradation trending of all materials. However, other condition monitoring techniques, such as insulation resistance, were only partially successful on some cables and other methods like ultrasonic or Tan δ were either unsuccessful or failed to provide reliable information to qualify the method for degradation trending or ageing assessment of cables. The electrical in situ tests did not show great promise for cable degradation trending or ageing assessment, although these methods are known to be very effective for finding and locating faults in cable insulation material. In particular, electrical methods such as insulation resistance and reflectometry techniques are known to be rather effective for locating insulation damage, hot spots or other faults in essentially all cable types. The advantage of electrical methods is that they can be

  1. 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.

  2. 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…

  3. 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.

  4. External electromagnetic transient sources: analysis of its effect in underground power cables; Fuentes transitorias electromagneticas externas: analisis de su efecto en los cables de potencia subterraneos

    Energy Technology Data Exchange (ETDEWEB)

    Escamilla Paz, Antonio

    2009-07-01

    In most of the electrical power systems that operate at present, the subterranean cables are only a complement. The cost of these cables is generally higher than the one of the aerial power lines, thus its use is restricted only to those areas where the construction of the aerial power lines is not feasible. It is estimated that for voltages lower than 110 kV this cost is up to seven times greater than the one of an aerial power line and for voltages higher than 380 kV it can be up to twenty times greater. Nevertheless, important reasons exist to construct a subterranean cable system such as: a) the fast growth of the urban centers and the industrial zones, which brings about restrictions of the rights of way for the construction of aerial power lines, b) the crossing of large water bodies, c) the congestion of aerial power lines near the generating substations or power plants, d) the crossing of air lines and e) the laws and the regulations, to mention some of them. The importance of the underground transmission systems of high and extra high voltage will be increased in the medium and the long term, therefore, it is considered that the effects of the external phenomena in these systems, like the inductions produced by the electromagnetic transient sources, will be more severe. In this research work the atmospheric discharges are defined as the external electromagnetic transient sources. The large dimension cables such as the power cables, behave as large collectors of the interferences produced by the atmospheric discharges, which can bring about damages in the components of a system. In order to avoid the damages and to increase the reliability of the subterranean cable systems it is necessary to use protective devices and appropriate insulation levels, mainly. If the phenomenon and the behavior of the system are properly represented, it is possible to more accurately determine the characteristics that the equipment must have to resist the over voltages and the

  5. Vacuum foil insulation system

    International Nuclear Information System (INIS)

    Hanson, J.P.; Sabolcik, R.E.; Svedberg, R.C.

    1976-01-01

    In a multifoil thermal insulation package having a plurality of concentric cylindrical cups, means are provided for reducing heat loss from the penetration region which extends through the cups. At least one cup includes an integral skirt extending from one end of the cup to intersection with the penetration means. Assembly of the insulation package with the skirted cup is facilitated by splitting the cup to allow it to be opened up and fitted around the other cups during assembly. The insulation is for an implantable nuclear powered artificial heart

  6. Degradation diagnosing method for low voltage electric wire and cable in nuclear facility

    International Nuclear Information System (INIS)

    Kamimura, Seiji; Seki, Ikuo; Yagyu, Hideki; Onishi, Takao; Kusama, Yasuo.

    1991-01-01

    A considerable skill is required for a visual inspection method which has been used most widely for determining the degradation of low voltage electric wires and cables used mostly in facilities such as nuclear power plants. It is extremely difficult to determine the degradation accurately and appropriately even for skilled inspectors because of individual difference. Then, a small amount of organic insulation materials is taken as a sample from insulators or sheath materials actually disposed. The pyrolytic temperature of the sample is measured by thermal gravimetric analysis to determine the extent of the degradation of the electric wire and cable based on the relationship between the degradation and the elongation. Since there is a close relationship between the temperature at which the measured weight of the sample is reduced by 5% and the degradation behavior of the mechanical property, analysis can be conducted effectively by an extremely small amount of the sample. Since the insulation degradation of relatively low voltage electric wires and cables can be determined in a non-destructive manner at high accuracy, the lifetime can be forecasted. (N.H.)

  7. 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

  8. 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.)

  9. 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…

  10. Design of load-to-failure tests of high-voltage insulation breaks for ITER's cryogenic network

    CERN Document Server

    Langeslag, S A E; Aviles Santillana, I; Sgobba, S; Foussat, A

    2015-01-01

    The development of new generation superconducting magnets for fusion research, such as the ITER experiment, is largely based on coils wound with so-called cable-in-conduit conductors. The concept of the cable-in-conduit conductor is based on a direct cooling principle, by supercritical helium, flowing through the central region of the conductor, in close contact with the superconducting strands. Consequently, a direct connection exists between the electrically grounded helium coolant supply line and the highly energised magnet windings. Various insulated regions, constructed out of high-voltage insulation breaks, are put in place to isolate sectors with different electrical potential. In addition to high voltages and significant internal helium pressure, the insulation breaks will experience various mechanical forces resulting from differential thermal contraction phenomena and electro-magnetic loads. Special test equipment was designed, prepared and employed to assess the mechanical reliability of the insul...

  11. Cooper Pairs in Insulators?

    International Nuclear Information System (INIS)

    Valles, James

    2008-01-01

    Nearly 50 years elapsed between the discovery of superconductivity and the emergence of the microscopic theory describing this zero resistance state. The explanation required a novel phase of matter in which conduction electrons joined in weakly bound pairs and condensed with other pairs into a single quantum state. Surprisingly, this Cooper pair formation has also been invoked to account for recently uncovered high-resistance or insulating phases of matter. To address this possibility, we have used nanotechnology to create an insulating system that we can probe directly for Cooper pairs. I will present the evidence that Cooper pairs exist and dominate the electrical transport in these insulators and I will discuss how these findings provide new insight into superconductor to insulator quantum phase transitions.

  12. Heat-shrinkable splicing materials for Class 1E wire and cable systems in nuclear power generating stations

    International Nuclear Information System (INIS)

    Handa, Katsue; Maruyama, Masahiro; Kanno, Mikio; Ohya, Shingo; Nagakawa, Seiji; Sugimori, Mikihiro

    1987-01-01

    This report describes the shapes of heat-shrinkable splicing materials (cable sleeve and breakout, and round end cap) made of polyolefine resin, their application to cable splicing, and the properties of the materials as well as of the splice using them. Particularly, the report features introduction of their properties as determined by tests under the same conditions as used in Japan in qualifying tests on wires and cables for nuclear power generating stations. The heat-shrinkable splicing materials proved to be equal in properties to flame-retardant cables for nuclear power plants when tested for oxygen index and subjected to a vertical flame test on ''insulated wire'' and a vertical tray flame test on the cable splice. It was also confirmed that Class 1E cable using these splicing materials could stand the most rigorous environmental test in Japan. Therefore they can be used for splicing Class 1E wires and cables and the splice formed with them can be regarded as Class 1E specified in IEEE Std. 383. (author)

  13. Thermal Conductance and High-Frequency Properties of Cryogenic Normal or Superconducting Semi-rigid Coaxial Cables in the Temperature Range of 1-8 K

    Science.gov (United States)

    Kushino, A.; Kasai, S.; Ukibe, M.; Ohkubo, M.

    2018-04-01

    In this study, the characteristics of thin semi-rigid cables composed of different conductors and with outer diameters ranging from 0.86 to 1.19 mm were investigated at low temperatures. The thermal conductance was measured between approximately 1 and 8 K, and the frequency dependence of the attenuation in the cables was obtained at 3 K. The electrical conductors used in the cables were alloys: beryllium copper, brass, stainless steel (SUS304), phosphor bronze, cupronickel (CuNi), and niobium-titanium (NbTi). The thermal conductance of a commercial miniature coaxial cable with braided wires forming the outer electrical conductor was also examined for reference. The measured thermal conductance was compared to published data and that generated from material libraries and databases. Among the measured cables using normal metals, the semi-rigid cable composed of SUS304 conductors and a polytetrafluoroethylene insulator showed the lowest thermal conductance. The transmission performance of the semi-rigid cables using SUS304 or CuNi was improved by plating the central conductors with a silver coating of approximately 3 μm thickness, and their thermal conductance with the plating increased by approximately one order of magnitude. The superconducting NbTi semi-rigid cable exhibited the lowest thermal conductance of all the cables considered in the present study along with very small attenuation up to above 5 GHz.

  14. Wrapped Multilayer Insulation

    Science.gov (United States)

    Dye, Scott A.

    2015-01-01

    New NASA vehicles, such as Earth Departure Stage (EDS), Orion, landers, and orbiting fuel depots, need improved cryogenic propellant transfer and storage for long-duration missions. Current cryogen feed line multilayer insulation (MLI) performance is 10 times worse per area than tank MLI insulation. During each launch, cryogenic piping loses approximately 150,000 gallons (equivalent to $300,000) in boil-off during transfer, chill down, and ground hold. Quest Product Development Corp., teaming with Ball Aerospace, developed an innovative advanced insulation system, Wrapped MLI (wMLI), to provide improved thermal insulation for cryogenic feed lines. wMLI is high-performance multilayer insulation designed for cryogenic piping. It uses Quest's innovative discrete-spacer technology to control layer spacing/ density and reduce heat leak. The Phase I project successfully designed, built, and tested a wMLI prototype with a measured heat leak 3.6X lower than spiral-wrapped conventional MLI widely used for piping insulation. A wMLI prototype had a heat leak of 7.3 W/m2, or 27 percent of the heat leak of conventional MLI (26.7 W/m2). The Phase II project is further developing wMLI technology with custom, molded polymer spacers and advancing the product toward commercialization via a rigorous testing program, including developing advanced vacuuminsulated pipe for ground support equipment.

  15. 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

  16. Survey of thermal insulation systems

    International Nuclear Information System (INIS)

    Kinoshita, Izumi

    1983-01-01

    Better thermal insulations have been developed to meet the growing demands of industry, and studies on thermal insulation at both high temperature and low temperature have been widely performed. The purpose of this survey is to summarize data on the performances and characteristics of thermal insulation materials and thermal insulation structures (for instance, gas cooled reactors, space vehicles and LNG storage tanks), and to discuss ravious problems regarding the design of thermal insulation structures of pool-type LMFBRs. (author)

  17. A comparison between national scheme for the acoustic classification of dwellings in Europe and in the U.S

    DEFF Research Database (Denmark)

    Berardi, Umberto; Rasmussen, Birgit

    2015-01-01

    , focusing on sound insulation performance, national schemes for sound classification of dwellings have been developed in several European countries. These schemes define acoustic classes according to different levels of sound insulation. Due to the lack of coordination among countries, a significant...... scheme may facilitate exchanging experiences about constructions fulfilling different classes, reducing trade barriers, and finally increasing the sound insulation of dwellings....... diversity in terms of descriptors, number of classes, and class intervals occurred between national schemes. However, a proposal ”acoustic classification scheme for dwellings” has been developed recently in the European COST Action TU0901 with 32 member countries. This proposal has been accepted as an ISO...

  18. Physical processes in high field insulating liquid conduction

    Science.gov (United States)

    Mazarakis, Michael; Kiefer, Mark; Leckbee, Joshua; Anderson, Delmar; Wilkins, Frank; Obregon, Robert

    2017-10-01

    In the power grid transmission where a large amount of energy is transmitted to long distances, High Voltage DC (HVDC) transmission of up to 1MV becomes more attractive since is more efficient than the counterpart AC. However, two of the most difficult problems to solve are the cable connections to the high voltage power sources and their insulation from the ground. The insulating systems are usually composed of transformer oil and solid insulators. The oil behavior under HVDC is similar to that of a weak electrolyte. Its behavior under HVDC is dominated more by conductivity than dielectric constant. Space charge effects in the oil bulk near high voltage electrodes and impeded plastic insulators affect the voltage oil hold-off. We have constructed an experimental facility where we study the oil and plastic insulator behavior in an actual HVDC System. Experimental results will be presented and compared with the present understanding of the physics governing the oil behavior under very high electrical stresses. Sandia National Laboratories managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. D.O.E., NNSA under contract DE-NA-0003525.

  19. 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).

  20. BC Hydro's integrated approach on replacing underground feeder cables

    Energy Technology Data Exchange (ETDEWEB)

    Tarampi, D. [BC Hydro, Burnaby, BC (Canada)

    2008-07-01

    BC Hydro's integrated approach on replacing underground feeder cables was discussed. The feeder cables were all in ducts encased in concrete and splices were identified in concrete manholes. The feeder cables averaged 35 to 40 failures per year, with a large majority of failures occurring in manholes or near terminations. The age of the cables was not known. A graphical representation of a condition assessment was presented with reference to an electrical test, metallurgical test, hardness test, and dye penetrating test. Prioritization steps were also listed, including a condition index and replacement threshold. Steps in prioritizing the condition index included determining the insulation index based on electrical test results; determining the manhole condition based on metallurgical test results; determining the customer importance factor and feeder load factor; and calculating the overall condition index based on the indices. A process flowchart was also illustrated. A replacement strategy was then discussed and a cost comparison of two options was described. Option 1 was to replace only the unjacketed cables while option two involved selective replacement. tabs., figs.

  1. Numerical simulation of fractional Cable equation of spiny neuronal dendrites

    Directory of Open Access Journals (Sweden)

    N.H. Sweilam

    2014-03-01

    Full Text Available In this article, numerical study for the fractional Cable equation which is fundamental equations for modeling neuronal dynamics is introduced by using weighted average of finite difference methods. The stability analysis of the proposed methods is given by a recently proposed procedure similar to the standard John von Neumann stability analysis. A simple and an accurate stability criterion valid for different discretization schemes of the fractional derivative and arbitrary weight factor is introduced and checked numerically. Numerical results, figures, and comparisons have been presented to confirm the theoretical results and efficiency of the proposed method.

  2. 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.

  3. Design and development of 500 m long HTS cable system in the KEPCO power grid, Korea

    Science.gov (United States)

    Sohn, S. H.; Lim, J. H.; Yang, B. M.; Lee, S. K.; Jang, H. M.; Kim, Y. H.; Yang, H. S.; Kim, D. L.; Kim, H. R.; Yim, S. W.; Won, Y. J.; Hwang, S. D.

    2010-11-01

    In Korea, two long-term field demonstrations for high temperature superconducting (HTS) cable have been carried out for several years; Korea Electric Power Corporation (KEPCO) and LS Cable Ltd. (LSC) independently. Encouraged at the result of the projects performed in parallel, a new project targeting the real grid operation was launched in the fourth quarter of 2008 with the Korean government's financial support. KEPCO and LSC are jointly collaborating in the selection of substation, determination of cable specification, design of cryogenic system, and the scheme of protection coordination. A three phase 500 m long HTS cable at a distribution level voltage of 22.9 kV is to be built at 154/22.9 kV Icheon substation located in near Seoul. A hybrid cryogenic system reflecting the contingency plan is being designed including cryocoolers. The HTS cable system will be installed in the second quarter of 2010, being commissioned by the fall of 2010. This paper describes the objectives of the project and design issues of the cable and cryogenic system in detail.

  4. Tension layer winding of cable-in-conduit conductor

    International Nuclear Information System (INIS)

    Devernoe, A.; Ciancetta, G.; King, M.; Parizh, M.; Painter, T.; Miller, J.

    1996-01-01

    A 710 mm i.d. by 440 mm long, 6 layer Cable-in-Conduit (CIC) coil was precision tension layer wound with Incoloy 908 jacketed conductor to model winding technology that will be used for the Nb 3 Sn outsert coils of the 45 Tesla Hybrid Magnet Project at the US National High Magnetic Field Laboratory. This paper reports on the set up of a new winding facility with unique capabilities for insulating and winding long length CIC conductor and on special procedures which were developed to wind and support layer to layer transitions and to safely form conductor into and out of the winding. Analytical methods used to predict conduit keystoning, springback and back tensioning requirements before winding are reported in comparison to results obtained during winding and actual winding build-up dimensions on a layer by layer basis in comparison to design requirements

  5. 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.

  6. Reusable Surface Insulation

    Science.gov (United States)

    1997-01-01

    Advanced Flexible Reusable Surface Insulation, developed by Ames Research Center, protects the Space Shuttle from the searing heat that engulfs it on reentry into the Earth's atmosphere. Initially integrated into the Space Shuttle by Rockwell International, production was transferred to Hi-Temp Insulation Inc. in 1974. Over the years, Hi-Temp has created many new technologies to meet the requirements of the Space Shuttle program. This expertise is also used commercially, including insulation blankets to cover aircrafts parts, fire barrier material to protect aircraft engine cowlings and aircraft rescue fire fighter suits. A Fire Protection Division has also been established, offering the first suit designed exclusively by and for aircraft rescue fire fighters. Hi-Temp is a supplier to the Los Angeles City Fire Department as well as other major U.S. civil and military fire departments.

  7. Insulators for fusion applications

    International Nuclear Information System (INIS)

    1987-04-01

    Design studies for fusion devices and reactors have become more detailed in recent years and with this has come a better understanding of requirements and operating conditions for insulators in these machines. Ceramic and organic insulators are widely used for many components of fusion devices and reactors namely: radio frequency (RF) energy injection systems (BeO, Al 2 O 3 , Mg Al 2 O 4 , Si 3 N 4 ); electrical insulation for the torus structure (SiC, Al 2 O 3 , MgO, Mg Al 2 O 4 , Si 4 Al 2 O 2 N 6 , Si 3 N 4 , Y 2 O 3 ); lightly-shielded magnetic coils (MgO, MgAl 2 O 4 ); the toroidal field coil (epoxies, polyimides), neutron shield (B 4 C, TiH 2 ); high efficiency electrical generation; as well as the generation of very high temperatures for high efficiency hydrogen production processes (ZrO 2 and Al 2 O 3 - mat, graphite and carbon - felt). Timely development of insulators for fusion applications is clearly necessary. Those materials to be used in fusion machines should show high resistance to radiation damage and maintain their structural integrity. Now the need is urgent for a variety of radiation resistant materials, but much effort in these areas is required for insulators to be considered seriously by the design community. This document contains 14 papers from an IAEA meeting. It was the objective of this meeting to identify existing problems in analysing various situations of applications and requirements of electrical insulators and ceramics in fusion and to recommend strategies and different stages of implementation. This meeting was endorsed by the International Fusion Research Council

  8. 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

  9. 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.

  10. Sound classification of dwellings – A diversity of national schemes in Europe

    DEFF Research Database (Denmark)

    Rasmussen, Birgit

    2011-01-01

    Sound classification schemes for dwellings exist in ten countries in Europe, typically prepared and published as national standards. The schemes define quality classes intended to reflect different levels of acoustical comfort. The main criteria concern airborne and impact sound insulation between...... dwellings, facade sound insulation and installation noise. This paper presents the sound classification schemes in Europe and compares the class criteria for sound insulation between dwellings. The schemes have been implemented and revised gradually since the early 1990s. However, due to lack...... constructions fulfilling different classes. The current variety of descriptors and classes also causes trade barriers. Thus, there is a need to harmonize characteristics of the schemes, and a European COST Action TU0901 "Integrating and Harmonizing Sound Insulation Aspects in Sustainable Urban Housing...

  11. 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...

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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)

  17. 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...

  18. 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.

  19. 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.

  20. Characterization of dielectric properties of nanocellulose from wood and algae for electrical insulator applications.

    Science.gov (United States)

    Le Bras, David; Strømme, Maria; Mihranyan, Albert

    2015-05-07

    Cellulose is one of the oldest electrically insulating materials used in oil-filled high-power transformers and cables. However, reports on the dielectric properties of nanocellulose for electrical insulator applications are scarce. The aim of this study was to characterize the dielectric properties of two nanocellulose types from wood, viz., nanofibrillated cellulose (NFC), and algae, viz., Cladophora cellulose, for electrical insulator applications. The cellulose materials were characterized with X-ray diffraction, nitrogen gas and moisture sorption isotherms, helium pycnometry, mechanical testing, and dielectric spectroscopy at various relative humidities. The algae nanocellulose sample was more crystalline and had a lower moisture sorption capacity at low and moderate relative humidities, compared to NFC. On the other hand, it was much more porous, which resulted in lower strength and higher dielectric loss than for NFC. It is concluded that the solid-state properties of nanocellulose may have a substantial impact on the dielectric properties of electrical insulator applications.

  1. 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. ...

  2. 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...

  3. Insulation Reformulation Development

    Science.gov (United States)

    Chapman, Cynthia; Bray, Mark

    2015-01-01

    The current Space Launch System (SLS) internal solid rocket motor insulation, polybenzimidazole acrylonitrile butadiene rubber (PBI-NBR), is a new insulation that replaced asbestos-based insulations found in Space Shuttle heritage solid rocket boosters. PBI-NBR has some outstanding characteristics such as an excellent thermal erosion resistance, low thermal conductivity, and low density. PBI-NBR also has some significant challenges associated with its use: Air entrainment/entrapment during manufacture and lay-up/cure and low mechanical properties such as tensile strength, modulus, and fracture toughness. This technology development attempted to overcome these challenges by testing various reformulated versions of booster insulation. The results suggest the SLS program should continue to investigate material alternatives for potential block upgrades or use an entirely new, more advanced booster. The experimental design was composed of a logic path that performs iterative formulation and testing in order to maximize the effort. A lab mixing baseline was developed and documented for the Rubber Laboratory in Bldg. 4602/Room 1178.

  4. Beyond insulation and isolation

    DEFF Research Database (Denmark)

    Højlund, Marie Koldkjær

    2016-01-01

    are insulation and isolation strategies to reduce measurable and perceptual noise levels. However, these strategies do not actively support the need to feel like an integral part of the shared hospital environment, which is a key element in creating healing environments, according to the paradigm of Evidence-Based...

  5. Self-Healing Wire Insulation

    Science.gov (United States)

    Parrish, Clyde F. (Inventor)

    2012-01-01

    A self-healing system for an insulation material initiates a self-repair process by rupturing a plurality of microcapsules disposed on the insulation material. When the plurality of microcapsules are ruptured, reactants within the plurality of microcapsules react to form a replacement polymer in a break of the insulation material. This self-healing system has the ability to repair multiple breaks in a length of insulation material without exhausting the repair properties of the material.

  6. Additive operator-difference schemes splitting schemes

    CERN Document Server

    Vabishchevich, Petr N

    2013-01-01

    Applied mathematical modeling isconcerned with solving unsteady problems. This bookshows how toconstruct additive difference schemes to solve approximately unsteady multi-dimensional problems for PDEs. Two classes of schemes are highlighted: methods of splitting with respect to spatial variables (alternating direction methods) and schemes of splitting into physical processes. Also regionally additive schemes (domain decomposition methods)and unconditionally stable additive schemes of multi-component splitting are considered for evolutionary equations of first and second order as well as for sy

  7. Integrated Multilayer Insulation

    Science.gov (United States)

    Dye, Scott

    2009-01-01

    Integrated multilayer insulation (IMLI) is being developed as an improved alternative to conventional multilayer insulation (MLI), which is more than 50 years old. A typical conventional MLI blanket comprises between 10 and 120 metallized polymer films separated by polyester nets. MLI is the best thermal- insulation material for use in a vacuum, and is the insulation material of choice for spacecraft and cryogenic systems. However, conventional MLI has several disadvantages: It is difficult or impossible to maintain the desired value of gap distance between the film layers (and consequently, it is difficult or impossible to ensure consistent performance), and fabrication and installation are labor-intensive and difficult. The development of IMLI is intended to overcome these disadvantages to some extent and to offer some additional advantages over conventional MLI. The main difference between IMLI and conventional MLI lies in the method of maintaining the gaps between the film layers. In IMLI, the film layers are separated by what its developers call a micro-molded discrete matrix, which can be loosely characterized as consisting of arrays of highly engineered, small, lightweight, polymer (typically, thermoplastic) frames attached to, and placed between, the film layers. The term "micro-molded" refers to both the smallness of the frames and the fact that they are fabricated in a process that forms precise small features, described below, that are essential to attainment of the desired properties. The term "discrete" refers to the nature of the matrix as consisting of separate frames, in contradistinction to a unitary frame spanning entire volume of an insulation blanket.

  8. SCAP: the Nea project on stress corrosion cracking and cable ageing

    International Nuclear Information System (INIS)

    Yamamoto, A.; Huerta, A.; Gott, K.; Koshy, T.

    2007-01-01

    Two subjects - stress corrosion cracking (SCC) and degradation of cable insulation - were selected as the focus of the SCC and Cable Ageing Project (SCAP) due to their relevance for plant ageing assessments and their implication on inspection practices. Fourteen NEA member countries agreed to contribute to the project. The main SCAP objectives are to: establish a complete database with regard to major ageing phenomena for SCC and degradation of cable insulation through collective efforts by OECD/NEA members; establish a knowledge base in these areas by compiling and evaluating the collected data and information systematically; perform an assessment of the data and identify the basis for commendable practices which would help regulators and operators to enhance ageing management. The aim of the knowledge base is to provide a state-of-the-art description of the degradation mechanisms, the main influencing factors, the most susceptible materials and locations, and common strategies available for mitigation and repair. The SCAP project is currently in the development phase, defining and refining the database performance requirements, data format and coding guidelines. The project is scheduled to last four years. It is anticipated that the database definition and the collection of data from member countries will take approximately two years. The subsequent assessment and the commendable practices report are expected to take one year each

  9. Surface Layer Fluorination-Modulated Space Charge Behaviors in HVDC Cable Accessory

    Directory of Open Access Journals (Sweden)

    Jin Li

    2018-05-01

    Full Text Available Space charges tend to accumulate on the surface and at the interface of ethylene–propylene–diene terpolymer (EPDM, serving as high voltage direct current (HVDC cable accessory insulation, which likely induces electrical field distortion and dielectric breakdown. Direct fluorination is an effective method to modify the surface characteristics of the EPDM without altering the bulk properties too much. In this paper, the surface morphology, hydrophobic properties, relative permittivity, and DC conductivity of the EPDM before and after fluorination treatment were tested. Furthermore, the surface and interface charge behaviors in the HVDC cable accessory were investigated by the pulsed electroacoustic (PEA method, and explained from the point of view of trap distribution. The results show that fluorination helps the EPDM polymer obtain lower surface energy and relative permittivity, which is beneficial to the interface match in composite insulation systems. The lowest degree of space charge accumulation occurs in EPDM with 30 min of fluorination. After analyzing the results of the 3D potentials and the density of states (DOS behaviors in EPDM before and after fluorination, it can be found that fluorination treatment introduces shallower electron traps, and the special electrostatic potential after fluorination can significantly suppress the space charge accumulation at the interface in the HVDC cable accessory.

  10. 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...

  11. International proposal for an acoustic classification scheme for dwellings

    DEFF Research Database (Denmark)

    Rasmussen, Birgit

    2014-01-01

    Acoustic classification schemes specify different quality levels for acoustic conditions. Regulations and classification schemes for dwellings typically include criteria for airborne and impact sound insulation, façade sound insulation and service equipment noise. However, although important...... classes, implying also trade barriers. Thus, a harmonized classification scheme would be useful, and the European COST Action TU0901 "Integrating and Harmonizing Sound Insulation Aspects in Sustainable Urban Housing Constructions", running 2009-2013 with members from 32 countries, including three overseas...... for quality of life, information about acoustic conditions is rarely available, neither for new or existing housing. Regulatory acoustic requirements will, if enforced, ensure a corresponding quality for new dwellings, but satisfactory conditions for occupants are not guaranteed. Consequently, several...

  12. Effect that radiation exerts to insulation breakdown of heat resistant polymer materials

    International Nuclear Information System (INIS)

    Fujita, Shigetaka; Baba, Makoto; Noto, Fumitoshi; Ruike, Mitsuo.

    1990-01-01

    Artificial satellites are always exposed to cosmic rays which contain the radiations which do not reach the ground, therefore, the radiation resistance of the polymer insulators for cables and others used in such environment becomes a problem. Also the polymer insulator materials used for nuclear facilities require excellent radiation resistance. It is important to examine the effect that radiation exerts to electric insulation characteristics from the viewpoint of material development. In this paper, the insulation breakdown characteristics of heat resistant polymer films and the mini-cables made for trial of heat resistant polymer materials in the case without irradiation and in the case of gamma ray irradiation, and the results of the structural analysis are reported. The specimens tested, the experimental method and the results are described. The insulation breakdown strength of PFA and FEP films lowered from 0.15-0.2 MGy, but that of PEEK film did not change up to 5 MGy. It was found that fluorine group resins were apt to deteriorate by oxidation as dose increased. (K.I.)

  13. Development of Integrated Assessment System for Underground Power Cable Performance: A Case Study

    Science.gov (United States)

    Turan, Faiz Mohd; Johan, Kartina; Soliha Sahimi, Nur; Nor, Nik Hisyamudin Muhd

    2017-08-01

    The basic operation of any electrical machines that is catered to serve needs of civilization involves electrical power which is the main source to trigger the internal mechanism in the machines then transfer the power to other form of energy such as mechanical, light, sound and etc. The supplies of electrical does not happen just by providing the source itself, it has load carrying agent which in many cases, user would refer to it as cable. Specifically, it is the power cable which its ampacity depends significantly on the operation temperature and load stress on it. Apart from having to focus on providing improvement on improving efficiency on the source itself, power cable plays and important role because without it, current ranging from low to high could not be transmitted and hence a failure of the power system generally. Studies have conducted to discuss whether which factor contributes relatively more to the causes of power cable failure or breakdown. Such factors can be narrowed down to the three major causes which are over temperature, over voltage and stress caused by over current. Over current is one of the factor which is depends on the usage of the power system itself. The higher the usage of the power system, higher the chances of over current to take place. This will then produce load stress on the cable which eventually destroy the insulator of the cable and slowly reach the core of the cable. It is believed that an assessment method should be implemented in order to predict the performance and failure rate of the power cable and use this prediction as reference rather than just letting power failure to happen anytime unpredictable which cause huge inconvenience to users and industries. Not only do a method should be implemented, it should be as easy to be used and understood by large range of users and integrated by a graphical user interface to be used. Therefore, this research will further narrow down on the approaches to do so and the location

  14. Study on condition monitoring techniques for low voltage electrical cables in nuclear power plants

    International Nuclear Information System (INIS)

    Hirao, Hideo; Sakai, Takeshi; Kajimura, Yuusaku

    2017-01-01

    Low voltage electrical cables installed in nuclear power plants are required to maintain its function in a design basis accident environment and they are qualified to that environment. The cables degrade also in normal operating conditions due to ageing and they must maintain integrity until the end of their qualified life. Demands for the condition monitoring technique for low voltage electrical cables have therefore been increasing as nuclear power plants operate longer. A single perfect method for this purpose is not available yet, but the possibility to use two different types of methods which can complement with each other has been examined. The combination of Fourier Transform Infrared Spectroscopy (FT-IR) and Indenter Modulus (IM) method was found highly effective. FT-IR is a method that determines chemical properties (changes in molecular bindings) of cables by using infrared rays, while IM is a method that determines mechanical properties (changes in hardness) of cables by indenters. Both methods are non-destructive and can be applied in-situ to the same material. Reliability of the evaluation can be assured by applying two different types of measurement principles that complement with each other. In this study, various cable samples with different kinds of insulation material (cross-linked polyethylene, ethylene propylene rubber, silicone rubber etc.) were aged with a special accelerated ageing technique which applies simultaneous thermal and radiation ageing to simulate ageing phenomena in a more realistic manner, and the degree of ageing was evaluated with FT-IR and IM. The evaluation result shows good correlation with ageing time and other ageing properties for most material types and the effectiveness of these methods were demonstrated. (author)

  15. Non-destructive qualification tests for ITER cryogenic axial insulating breaks

    International Nuclear Information System (INIS)

    Kosek, Jacek; Lopez, Roberto; Tommasini, Davide; Rodriguez-Mateos, Felix

    2014-01-01

    In the ITER superconducting magnets the dielectric separation between the CICC (Cable-In-Conduit Conductors) and the helium supply pipes is made through the so-called insulating breaks (IB). These devices shall provide the required dielectric insulation at a 30 kV level under different types of stresses and constraints: thermal, mechanical, dielectric and ionizing radiations. As part of the R and D program, the ITER Organization launched contracts with industrial companies aimed at the qualification of the manufacturing techniques. After reviewing the main functional aspects, this paper describes and discusses the protocol established for non-destructive qualification tests of the prototypes

  16. Non-destructive qualification tests for ITER cryogenic axial insulating breaks

    Energy Technology Data Exchange (ETDEWEB)

    Kosek, Jacek [Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland and CERN, Geneva 23,CH-1211 (Switzerland); Lopez, Roberto; Tommasini, Davide [CERN, Geneva 23,CH-1211 (Switzerland); Rodriguez-Mateos, Felix [CERN, Geneva 23,CH-1211, Switzerland and ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul lez Durance (France)

    2014-01-29

    In the ITER superconducting magnets the dielectric separation between the CICC (Cable-In-Conduit Conductors) and the helium supply pipes is made through the so-called insulating breaks (IB). These devices shall provide the required dielectric insulation at a 30 kV level under different types of stresses and constraints: thermal, mechanical, dielectric and ionizing radiations. As part of the R and D program, the ITER Organization launched contracts with industrial companies aimed at the qualification of the manufacturing techniques. After reviewing the main functional aspects, this paper describes and discusses the protocol established for non-destructive qualification tests of the prototypes.

  17. Assessment of a magnet system combining the advantages of cable-in-conduit forced-flow and pool-boiling magnets

    International Nuclear Information System (INIS)

    Slack, D.; Hassenzahl, W.; Felker, B.; Chaplin, M.

    1993-01-01

    This paper presents an idea for a magnet system that could be used to advantage in tokamaks and other fusion engineering devices. Higher performance designs, specifically newer tokamaks such as those for the international Tokamak Engineering Reactor (ITER) and Tokamak Physics Experiment (TPX) use Cable in Conduit Conductor (CICC) forced flow coils to advantage to meet field and current density requirements. Pool boiling magnets lack structural integrity to resist high magnetic forces since helium cooling areas must surround each conductor. A second problem is that any leak can threaten the voltage standoff integrity of the magnet system. This is because a leak can result in low-pressure helium gas becoming trapped by limited conductance in the magnet bundle and low-pressure helium has poor dielectric strength. The system proposed here is basically a CICC system, with it's inherent advantages, but bathed in higher pressure supercritical helium to eliminate the leak and voltage break-down problems. Schemes to simplify helium coolant plumbing with the proposed system are discussed. A brief historical review of related magnet systems is included. The advantages and disadvantages of using higher pressure, supercritical helium in combination with solid electrical insulation in a CICC system are discussed. Related electrical data from some previous works are compiled and discussed

  18. Metal-insulator transitions

    Science.gov (United States)

    Imada, Masatoshi; Fujimori, Atsushi; Tokura, Yoshinori

    1998-10-01

    Metal-insulator transitions are accompanied by huge resistivity changes, even over tens of orders of magnitude, and are widely observed in condensed-matter systems. This article presents the observations and current understanding of the metal-insulator transition with a pedagogical introduction to the subject. Especially important are the transitions driven by correlation effects associated with the electron-electron interaction. The insulating phase caused by the correlation effects is categorized as the Mott Insulator. Near the transition point the metallic state shows fluctuations and orderings in the spin, charge, and orbital degrees of freedom. The properties of these metals are frequently quite different from those of ordinary metals, as measured by transport, optical, and magnetic probes. The review first describes theoretical approaches to the unusual metallic states and to the metal-insulator transition. The Fermi-liquid theory treats the correlations that can be adiabatically connected with the noninteracting picture. Strong-coupling models that do not require Fermi-liquid behavior have also been developed. Much work has also been done on the scaling theory of the transition. A central issue for this review is the evaluation of these approaches in simple theoretical systems such as the Hubbard model and t-J models. Another key issue is strong competition among various orderings as in the interplay of spin and orbital fluctuations. Experimentally, the unusual properties of the metallic state near the insulating transition have been most extensively studied in d-electron systems. In particular, there is revived interest in transition-metal oxides, motivated by the epoch-making findings of high-temperature superconductivity in cuprates and colossal magnetoresistance in manganites. The article reviews the rich phenomena of anomalous metallicity, taking as examples Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Ru compounds. The diverse phenomena include strong spin and

  19. 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)

  20. 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.…

  1. 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…

  2. 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…

  3. 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,…

  4. 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…

  5. 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…

  6. 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

  7. 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.

  8. 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.

  9. 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.

  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. 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

  12. Classification of PD sources in HV cables using neural networks and the LN-FDTD method

    Energy Technology Data Exchange (ETDEWEB)

    Barros, W.H.; Oliveira, R.M.; Sobrinho, C.L.; Leite, R.C. [Univ. Federal do Para, Para (Brazil). Dept. of Computational and Electrical Engineering

    2008-07-01

    Partial discharges can be generated by the presence of several defects, and are often the cause of failures in electrical equipment insulators. In this study, a local non-orthogonal finite difference time-domain method (LN-FDTD) was used to simulate the sources of partial discharges in a high voltage coaxial cable model. The artificial neural network (ANN) technique used a Marquandt-Levenberg training algorithm to detect and classify cable PD sources. A set of harmonics obtained from the difference between the registered signals in the time domain was used as part of the training procedure. A failure was inserted on an electrical cable in each simulation in order to obtain the correlated data. Input signals were injected using a voltage pulse represented by a Gaussian function. A total of 90 simulations were conducted to generate 360 data groups in order to consider 6 different types of failures. Results of the study showed that the method can be used to detect and classify partial discharges in cables. 12 refs., 21 figs.

  13. Compound deterioration properties of non-halogen flame-resisting cables

    International Nuclear Information System (INIS)

    Yamamoto, Yasuaki; Yagyu, Hideki; Onishi, Takao; Kamiharako, Shinji

    1984-01-01

    Conventional flame-resisting cables release harmful gas such as hydrogen chloride and smoke on burning. To improve this disadvantage, the cables for nuclear power plants using new non-halogen flame-resisting insulating material have been developed. In this experiment, the non-halogen flame-resisting cables were subjected to the environmental test with varying test conditions. The test conditions included the order of exposure (heat treatment, γ-ray irradiation and steam exposure) and dose rate. After the environmental test, the mechanical and electrical properties of the samples were measured. In all test conditions, the samples did not crack in bending, and withstood the bending and withstand-voltage in-water test. The tensile strength and a.c. breakdown voltage did not change, and were stable. The elongation decreased greatly, but maintained the value of about 100 %, and the volumetric resistivity decreased by only one figure. It was confirmed that these cables were able to withstand various environmental tests. (Yoshitake, I.)

  14. Effect of air on speed of insulating material deterioration under simulated LOCA environment. [Gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kusama, Yasuo; Yagi, Toshiaki; Ito, Masayuki; Okada, Sohei; Yoshikawa, Masato (Japan Atomic Energy Research Inst., Takasaki, Gunma. Takasaki Radiation Chemistry Research Establishment)

    1982-12-01

    To examine the quality approval testing method for the electric cables used for nuclear reactors, various covering insulating materials employed for the cables have been investigated from all angles. The factors which are considered to affect the deterioration of cable materials in a simulated LOCA (loss of coolant accident) environmental test are numerous. This paper reports on the result of investigation on the effect of air on the rate of deterioration of various organic materials usually used as the insulating and covering materials for the cables. Five kinds of polymer sheets (1 mm thick) used for reactor cables were employed as samples. The samples of both standard compounding ratio and the compounding ratio for practical reactor use were tested. As the deterioration prior to LOCA simulation, the thermal deterioration corresponding to 40 years aging (at 121 deg C for 7 days) was given, and subsequently, 50 Mrad gamma -irradiation at 1 Mrad/h was performed in the air. After that, the samples were subject to LOCA simulated environment. Since the results were different according to the kinds of samples, those are described separately for Hypalon, ethylene propylene rubber, cross-linked polyethylene, chloroprene and silicone rubber. The existence of air under LOCA environment accelerated the deterioration of insulation materials except silicone rubber, though its influence differed to the polymers. These materials swelled in the presence of air, and the degree of swelling increased with the temperature, having the close relation to oxidation deterioration. Polyethylene was more susceptible to the effect of air, and silicone rubber was rather stable. The samples of fire-retardant compounding ratio more swelled by water absorption than those of standard compounding ratio.

  15. Heat insulating plates

    Energy Technology Data Exchange (ETDEWEB)

    Allan, J.A.F.

    1976-10-28

    Micro-porous insulation plates are dealt with, for example, how they are used in the insulation of heat storage devices. Since one side of such plates is exposed to a temperature of over 700/sup 0/C, a shrinkage of the glass texture of the covering can occur, which can exceed the shrinkage of the inner micro-porous material, so that cracks and splits in the high temperature side of the covering can come about. The task of the invention is to design the plate in such a way as to prevent this from happening. For this purpose the plate is provided, according to invention specifications, with flutes, waves, ribs, waffle or grid patterns and the covering is set into the recesses originating from this.

  16. Green insulation: hemp fibers

    Energy Technology Data Exchange (ETDEWEB)

    Anon,

    2011-09-15

    Indian hemp (Cannabis indica) is known for its psychotropic values and it is banned in most countries. However, industrial hemp (Cannabis sativa) is known for its tough fibers. Several manufactures in Europe including, small niche players, have been marketing hemp insulation products for several years. Hemp is a low environmental impact material. Neither herbicide nor pesticide is used during the growth of hemp. The fibers are extracted in a waste-free and chemical-free mechanical process. Hemp can consume CO2 during its growth. In addition, hemp fiber can be disposed of harmlessly by composting or incineration at the end of its life. Hemp fibers are processed and treated only minimally to resist rot and fungal activity. There is little health risk when producing and installing the insulation, thanks to the absence of toxic additive. Its thermal resistance is comparable to mineral wool. But the development and marketing of hemp fibers may be restricted in North America.

  17. Super-insulation

    International Nuclear Information System (INIS)

    Gerold, J.

    1985-01-01

    The invention concerns super-insulation, which also acts as spacing between two pressurized surfaces, where the crossing bars in at least two layers are provided, with interposed foil. The super-insulation is designed so that it can take compression forces and limits thermal radiation and thermal conduction sufficiently, where the total density of heat flow is usually limited to a few watts per m 2 . The solution to the problem is characterized by the fact that the bars per layer are parallel and from layer to layer they are at an angle to each other and the crossover positions of the bars of different layers are at fixed places and so form contact columns. The basic idea is that bars crossing over each other to support compression forces are used so that contact columns are formed, which are compressed to a certain extent by the load. (orig./PW) [de

  18. Compact vacuum insulation embodiments

    Science.gov (United States)

    Benson, D.K.; Potter, T.F.

    1992-04-28

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially point' or line' contacts with the metal wall sheets. In the case of monolithic spacers that form line' contacts, two such spacers with the line contacts running perpendicular to each other form effectively point' contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included. 26 figs.

  19. Compact vacuum insulation

    Science.gov (United States)

    Benson, D.K.; Potter, T.F.

    1993-01-05

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially point'' or line'' contacts with the metal wall sheets. In the case of monolithic spacers that form line'' contacts, two such spacers with the line contacts running perpendicular to each other form effectively point'' contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

  20. Insulating materials for optoelectronics

    International Nuclear Information System (INIS)

    Agullo-Lopez, F.

    1990-01-01

    Optoelectronics is an interdisciplinary field. Basic functions of an optoelectronic system include the generator of the optical signal, its transmission and handling and, finally, its detection, storage and display. A large variety of semiconductor and insulating materials are used or are being considered to perform those functions. The authors focus on insulating materials, mostly oxides. For signal generation, tunable solid state lasers, either vibronic or those based oon colour centres are briefly described, and their main operating parameters summarized. Reference is made to some developments on fiber and waveguide lasers. Relevant physical features of the silica fibres used for low-loss, long-band, optical transmission are reviewed, as well as present efforts to further reduce attenuation in the mid-infrared range. Particular attention is paid to photorefractive materials (LiNbO 3 , BGO, BSO, etc.), which are being investigated

  1. Super insulating aerogel glazing

    DEFF Research Database (Denmark)

    Schultz, Jørgen Munthe; Jensen, Karsten Ingerslev; Kristiansen, Finn Harken

    2004-01-01

    form the weakest part of the thermal envelope with respect to heat loss coefficient, but on the other hand also play an important role for passive solar energy utilisation. For window orientations other than south, the net energy balance will be close to or below zero. However, the properties......Monolithic silica aerogel offers the possibility of combining super insulation and high solar energy transmittance, which has been the background for a previous and a current EU project on research and development of monolithic silica aerogel as transparent insulation in windows. Generally, windows...... of aerogel glazing will allow for a positive net energy gain even for north facing vertical windows in a Danish climate during the heating season. This means that high quality daylight can be obtained even with additional energy gain. On behalf of the partners of the two EU projects, results related...

  2. Insulated pipe clamp design

    International Nuclear Information System (INIS)

    Anderson, M.J.; Hyde, L.L.; Wagner, S.E.; Severud, L.K.

    1980-01-01

    Thin wall large diameter piping for breeder reactor plants can be subjected to significant thermal shocks during reactor scrams and other upset events. On the Fast Flux Test Facility, the addition of thick clamps directly on the piping was undesired because the differential metal temperatures between the pipe wall and the clamp could have significantly reduced the pipe thermal fatigue life cycle capabilities. Accordingly, an insulated pipe clamp design concept was developed. The design considerations and methods along with the development tests are presented. Special considerations to guard against adverse cracking of the insulation material, to maintain the clamp-pipe stiffness desired during a seismic event, to minimize clamp restraint on the pipe during normal pipe heatup, and to resist clamp rotation or spinning on the pipe are emphasized

  3. Effect of radiation resistance additives for insulation materials

    International Nuclear Information System (INIS)

    Yamamoto, Yasuaki; Yagyu, Hideki; Seguchi, Tadao.

    1988-01-01

    For the electric wires and cables used in radiation environment such as nuclear power stations and fuel reprocessing facilities, the properties of excellent radiation resistance are required. For these insulators and sheath materials, ethylene propylene rubber, polyethylene and other polymers have been used, but it cannot be said that they always have good radiation resistance. However, it has been well known that radiation resistance can be improved with small amount of additives, and heat resistance and burning retarding property as well as radiation resistance are given to the insulators of wires and cables for nuclear facilities by mixing various additives. In this research, the measuring method for quantitatively determining the effect of Anti-rad (radiation resistant additive) was examined. Through the measurement of gel fraction, radical formation and decomposed gas generation, the effect of Anti-rad protecting polymers from radiation deterioration was examined from the viewpoint of chemical reaction. The experimental method and the results are reported. The radiation energy for cutting C-H coupling is polymers is dispersed by Anti-rad, and the probability of cutting is lowered. Anti-rad catches and extinguishes radicals that start oxidation reaction. (K.I.)

  4. Insulated pipe clamp design

    International Nuclear Information System (INIS)

    Anderson, M.J.; Hyde, L.L.; Wagner, S.E.; Severud, L.K.

    1980-01-01

    Thin wall large diameter piping for breeder reactor plants can be subjected to significant thermal shocks during reactor scrams and other upset events. On the Fast Flux Test Facility, the addition of thick clamps directly on the piping was undesired because the differential metal temperatures between the pipe wall and the clamp could have significantly reduced the pipe thermal fatigue life cycle capabilities. Accordingly, an insulated pipe clamp design concept was developed. 5 refs

  5. Pourable Foam Insulation

    Science.gov (United States)

    Harvey, James A.; Butler, John M.; Chartoff, Richard P.

    1989-01-01

    Report describes search for polyisocyanurate/polyurethane foam insulation with superior characteristics. Discusses chemistry of current formulations. Tests of formulations, of individual ingredients and or alternative new formulations described. Search revealed commercially available formulations exhibiting increased thermal stability at temperatures up to 600 degree C, pours readily before curing, presents good appearance after curing, and remains securely bonded to aluminum at cryogenic temperatures. Total of 42 different formulations investigated, 10 found to meet requirements.

  6. Outages of electric power supply resulting from cable failures Boston Edison Company system

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-07-01

    Factual data are provided regarding 5 electric power supply interruptions that occurred in the Boston Metropolitan area during April to June, 1979. Common to all of these outages was the failure of an underground cable as the initiating event, followed by multiple equipment failures. There was significant variation in the voltage ratings and types of cables which failed. The investigation was unable to delineate a single specific Boston Edison design operating or maintenance practice that could be cited as the cause of the outages. After reviewing the investigative report the following actions were recommended: the development and implementation of a plan to eliminate the direct current cable network; develop a network outage restoration plan; regroup primary feeder cables wherever possible to minimize the number of circuits in manholes, and to separate feeders to high load density areas; develop a program to detect incipient cable faults; evaluate the separation of the north and south sections of Back Bay network into separate networks; and, as a minimum, install the necessary facilities to make it possible to re-energize one section without interfering with the other; and re-evaluate the cathodic protection scheme where necessary. (LCL)

  7. Lightning simulation of a combined overhead line/cable connected GIS

    DEFF Research Database (Denmark)

    Kessel, Jakob; Atlason, Vioir; Bak, Claus Leth

    2008-01-01

    performance, compared to a system consisting solely of AIS connected thorugh overhead lines. The main purpose is to investigate whether overvoltage protection is necessary at the GIS busbar. Here, the price for a GIS SA is significantly more expensive than the price for an AIS SA. The analysis is conducted......The paper concerns different investigations of lightning simulation of a combined 170 kV overhead line/cable connected GIS. This is interesting due to the increasing amount of underground cables and GIS in the Danish transmission system. This creates a different system with respect to lightning...... by implementing a simulation model in PSCAD/EMTDC. Simulations are conducted for both SF and BFO where the overvoltage at the transformer are evaluated as this component has the lowest insulation strength. The overvoltages are evaluated for different front imes of the lightning surge, different soil resistivities...

  8. Submerged Medium Voltage Cable Systems at Nuclear Power Plants. A Review of Research Efforts Relevant to Aging Mechanisms and Condition Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Jason [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bernstein, Robert [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); White, II, Gregory Von [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Glover, Steven F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Neely, Jason C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Pena, Gary [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Williamson, Kenneth Martin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Zutavern, Fred J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gelbard, Fred [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-03-01

    In a submerged environment, power cables may experience accelerated insulation degradation due to water - related aging mechanisms . Direct contact with water or moisture intrusion in the cable insulation s ystem has been identified in the literature as a significant aging stressor that can affect performance and lifetime of electric cables . Progressive reduction of the dielectric strength is commonly a result of water treeing which involves the development of permanent hydrophilic structures in the insulation coinciding with the absorption of water into the cable . Water treeing is a phenomenon in which dendritic microvoids are formed in electric cable insulation due to electrochemic al reactions , electromechanical forces , and diffusion of contaminants over time . These reactions are caused by the combined effect s of water presence and high electrical stress es in the material . Water tree growth follow s a tree - like branching pattern , i ncreasing in volume and length over time . Although these cables can be "dried out," water tree degradation , specifically the growth of hydrophilic regions, is believed to be permanent and typically worsens over time. Based on established research , water treeing or water induced damage can occur in a variety of electric cables including XLPE, TR - XLPE and other insulating materials, such as EPR and butyl rubber . Once water trees or water induced damage form, the dielectric strength of an insulation materia l will decrease gradually with time as the water trees grow in length, which could eventually result in failure of the insulating material . Under wet conditions or i n submerged environments , several environmental and operational parameters can influence w ater tree initiation and affect water tree growth . These parameters include voltage cycling, field frequency, temperature, ion concentration and chemistry, type of insula tion material , and the characteristics of its defects. In this effort, a review of academic

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Reduction of heat insulation upon soaking of the insulation layer

    Science.gov (United States)

    Achtliger, J.

    1983-09-01

    Improved thermal protection of hollow masonry by introduction of a core insulation between the inner and outer shell is discussed. The thermal conductivity of insulation materials was determined in dry state and after soaking by water with different volume-related moisture contents. The interpolated thermal conductivity values from three measured values at 10 C average temperature are presented as a function of the pertinent moisture content. Fills of expanded polystyrene, perlite and granulated mineral fibers, insulating boards made of mineral fibers and in situ cellular plastics produced from urea-formaldehyde resin were investigated. Test results show a confirmation of thermal conductivity values for insulating materials in hollow masonry.

  15. 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

  16. Electrical insulating liquid: A review

    Directory of Open Access Journals (Sweden)

    Deba Kumar Mahanta

    2017-08-01

    Full Text Available Insulating liquid plays an important role for the life span of the transformer. Petroleum-based mineral oil has become dominant insulating liquid of transformer for more than a century for its excellent dielectric and cooling properties. However, the usage of petroleum-based mineral oil, derived from a nonrenewable energy source, has affected the environment for its nonbiodegradability property. Therefore, researchers direct their attention to renewable and biodegradable alternatives. Palm fatty acid ester, coconut oil, sunflower oil, etc. are considered as alternatives to replace mineral oil as transformer insulation liquid. This paper gives an extensive review of different liquid insulating materials used in a transformer. Characterization of different liquids as an insulating material has been discussed. An attempt has been made to classify different insulating liquids-based on different properties.

  17. 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...

  18. 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

  19. 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

  20. 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 ...

  1. 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...

  2. Design and construction of a high temperature superconducting power cable cryostat for use in railway system applications

    International Nuclear Information System (INIS)

    Tomita, M; Muralidhar, M; Suzuki, K; Fukumoto, Y; Ishihara, A; Akasaka, T; Kobayashi, Y

    2013-01-01

    The primary objective of the current effort was to design and test a cryostat using a prototype five-meter long high temperature Bi 2 Sr 2 Ca 2 Cu 3 O y (Bi-2223) superconducting dc power cable for railway systems. To satisfy the safety regulations of the Govt of Japan a mill sheet covered by super-insulation was used inside the walls of the cryostat. The thicknesses of various walls in the cryostat were obtained from a numerical analysis. A non-destructive inspection was utilized to find leaks under vacuum or pressure. The cryostat target temperature range was around 50 K, which is well below liquid nitrogen temperature, the operating temperature of the superconducting cable. The qualification testing was carried out from 77 down to 66 K. When using only the inner sheet wire, the maximum current at 77.3 K was 10 kA. The critical current (I c ) value increased with decreasing temperature and reached 11.79 kA at 73.7 K. This is the largest dc current reported in a Bi 2 Sr 2 Ca 2 Cu 3 O y or YBa 2 Cu 3 O y (Y-123) superconducting prototype cable so far. These results verify that the developed DC superconducting cable is reliable and fulfils all the requirements necessary for successful use in various power applications including railway systems. The key issues for the design of a reliable cryogenic system for superconducting power cables for railway systems are discussed. (paper)

  3. Wire in the Cable-Driven System of Surgical Robot

    Science.gov (United States)

    Wang, X. F.; Lv, N.; Mu, H. Z.; Xue, L. J.

    2017-07-01

    During the evolution of the surgical robot, cable plays an important role. It translates motion and force precisely from surgeon’s hand to the tool’s tips. In the paper, the vertical wires, the composition of cable, are mathematically modeled from a geometric point of view. The cable structure and tension are analyzed according to the characteristics of wire screw twist. The structural equations of the wires in different positions are derived for both non-bent cable and bent cable, respectively. The bending moment formula of bent cable is also obtained. This will help researchers find suitable cable and design more matched pulley.

  4. DC Model Cable under Polarity Inversion and Thermal Gradient: Build-Up of Design-Related Space Charge

    Directory of Open Access Journals (Sweden)

    Nugroho Adi

    2017-07-01

    Full Text Available In the field of energy transport, High-Voltage DC (HVDC technologies are booming at present due to the more flexible power converter solutions along with needs to bring electrical energy from distributed production areas to consumption sites and to strengthen large-scale energy networks. These developments go with challenges in qualifying insulating materials embedded in those systems and in the design of insulations relying on stress distribution. Our purpose in this communication is to illustrate how far the field distribution in DC insulation systems can be anticipated based on conductivity data gathered as a function of temperature and electric field. Transient currents and conductivity estimates as a function of temperature and field were recorded on miniaturized HVDC power cables with construction of 1.5 mm thick crosslinked polyethylene (XLPE insulation. Outputs of the conductivity model are compared to measured field distributions using space charge measurements techniques. It is shown that some features of the field distribution on model cables put under thermal gradient can be anticipated based on conductivity data. However, space charge build-up can induce substantial electric field strengthening when materials are not well controlled.

  5. On the Minimum Cable Tensions for the Cable-Based Parallel Robots

    Directory of Open Access Journals (Sweden)

    Peng Liu

    2014-01-01

    Full Text Available This paper investigates the minimum cable tension distributions in the workspace for cable-based parallel robots to find out more information on the stability. First, the kinematic model of a cable-based parallel robot is derived based on the wrench matrix. Then, a noniterative polynomial-based optimization algorithm with the proper optimal objective function is presented based on the convex optimization theory, in which the minimum cable tension at any pose is determined. Additionally, three performance indices are proposed to show the distributions of the minimum cable tensions in a specified region of the workspace. An important thing is that the three performance indices can be used to evaluate the stability of the cable-based parallel robots. Furthermore, a new workspace, the Specified Minimum Cable Tension Workspace (SMCTW, is introduced, within which all the minimum tensions exceed a specified value, therefore meeting the specified stability requirement. Finally, a camera robot parallel driven by four cables for aerial panoramic photographing is selected to illustrate the distributions of the minimum cable tensions in the workspace and the relationship between the three performance indices and the stability.

  6. Parametrically excited oscillation of stay cable and its control in cable-stayed bridges.

    Science.gov (United States)

    Sun, Bing-nan; Wang, Zhi-gang; Ko, J M; Ni, Y Q

    2003-01-01

    This paper presents a nonlinear dynamic model for simulation and analysis of a kind of parametrically excited vibration of stay cable caused by support motion in cable-stayed bridges. The sag, inclination angle of the stay cable are considered in the model, based on which, the oscillation mechanism and dynamic response characteristics of this kind of vibration are analyzed through numerical calculation. It is noted that parametrically excited oscillation of a stay cable with certain sag, inclination angle and initial static tension force may occur in cable-stayed bridges due to deck vibration under the condition that the natural frequency of a cable approaches to about half of the first model frequency of the bridge deck system. A new vibration control system installed on the cable anchorage is proposed as a possible damping system to suppress the cable parametric oscillation. The numerical calculation results showed that with the use of this damping system, the cable oscillation due to the vibration of the deck and/or towers will be considerably reduced.

  7. 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....

  8. 47 CFR 32.2422 - Underground cable.

    Science.gov (United States)

    2010-10-01

    ... FOR TELECOMMUNICATIONS COMPANIES Instructions for Balance Sheet Accounts § 32.2422 Underground cable... manholes and ducts in connection with construction work and the cost of permits and privileges for the...

  9. 47 CFR 32.2423 - Buried cable.

    Science.gov (United States)

    2010-10-01

    ... FOR TELECOMMUNICATIONS COMPANIES Instructions for Balance Sheet Accounts § 32.2423 Buried cable. (a... of cleaning manholes and ducts in connection with construction work and the cost of permits and...

  10. Chinese Market for Fibres and Cables

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    This article presents a summary of Chinese market of optical fibres and cables based on the development of the optical communications industry. Analysis shows that the market will keep growing for sometime in the future.

  11. Innovating Technological Process for Expanding the Service Life of Underground Power Cables

    Directory of Open Access Journals (Sweden)

    Tabacaru V.

    2016-08-01

    Full Text Available As a public power distribution operator on low voltage (023/0.4 kV, medium voltage (6 and 20 kV, and high voltage (110 kV in the territory of Galati County, SDEE Galati serves approximately 240,000 consumers (captive and eligible, domestic and non-domestic For this purpose, in the field of medium voltage underground distribution lines, SDEE Galati manages and operates a volume of approx. 500 km UDL/6kV circuit and approximately 630 km UDL/20 kV circuit. Many of these cables which are still in operation, were manufactured with materials and on the technological level of the ’60s,’70s and ‘80s decades and have reached the end of their service life. Evidence does and incident statistics from these networks in which, every year, one of the "tips" is the medium voltage cables damaged "technical wear" normal operating conditions. The current paper will present the main features of an innovating technological process called SPR (Sustained Pressure Rejuvenation, designed for on-site refurbishing of underground power cable insulation medium and high voltage. The process offers a viable alternative that has proven, over the 25 years of application initially on the American content and now on the worldwide, substantially more cost effective than replacing cables. The paper does not propose detailed presentation of the technological process, but to inform the family of energetics NPS about the existence and the benefits of applying this new technological process to the old cable medium and high voltage.

  12. Magnetically insulated H- diodes

    International Nuclear Information System (INIS)

    Fisher, A.; Bystritskii, V.; Garate, E.; Prohaska, R.; Rostoker, N.

    1993-01-01

    At the Univ. of California, Irvine, the authors have been studying the production of intense H - beams using pulse power techniques for the past 7 years. Previously, current densities of H - ions for various diode designs at UCI have been a few A/cm 2 . Recently, they have developed diodes similar to the coaxial design of the Lebedev Physical Institute, Moscow, USSR, where current densities of up to 200 A/cm 2 were reported using nuclear activation of a carbon target. In experiments at UCI employing the coaxial diode, current densities of up to 35 A/cm 2 from a passive polyethylene cathode loaded with TiH 2 have been measured using a pinhole camera and CR-39 track recording plastic. The authors have also been working on a self-insulating, annular diode which can generate a directed beam of H - ions. In the annular diode experiments a plasma opening switch was used to provide a prepulse and a current path which self-insulated the diode. These experiments were done on the machine APEX, a 1 MV, 50 ns, 7 Ω pulseline with a unipolar negative prepulse of ∼ 100 kV and 400 ns duration. Currently, the authors are modifying the pulseline to include an external LC circuit which can generate a bipolar, 150 kV, 1 μs duration prepulse (similar prepulse characteristic as in the Lebedev Institute experiments cited above)

  13. Cable system transients theory, modeling and simulation

    CERN Document Server

    Ametani, Akihiro; Nagaoka, Naoto

    2015-01-01

    A systematic and comprehensive introduction to electromagnetic transient in cable systems, written by the internationally renowned pioneer in this field Presents a systematic and comprehensive introduction to electromagnetic transient in cable systems Written by the internationally renowned pioneer in the field Thorough coverage of the state of the art on the topic, presented in a well-organized, logical style, from fundamentals and practical applications A companion website is available

  14. Torsion instability of Dynamic Cables during Installation

    OpenAIRE

    Opgård, Marie Finstad

    2017-01-01

    The oil and gas industry today is a heavily regulated segment, and current standard hasestablished restrictions which yields a very limited weather window for offshore cable installations. This is due to experience with cable failure in harsh weather. A limiting factor in current practice is the design criterion for the minimum allowable radius of curvature in the touchdown point. In addition, current practice does not allow for occurrence of compression in the touch down zone...

  15. Ecology: Electrical Cable Bacteria Save Marine Life

    DEFF Research Database (Denmark)

    Nielsen, Lars Peter

    2016-01-01

    Animals at the bottom of the sea survive oxygen depletion surprisingly often, and a new study identifies cable bacteria in the sediment as the saviors. The bacterial electrical activity creates an iron 'carpet', trapping toxic hydrogen sulfide.......Animals at the bottom of the sea survive oxygen depletion surprisingly often, and a new study identifies cable bacteria in the sediment as the saviors. The bacterial electrical activity creates an iron 'carpet', trapping toxic hydrogen sulfide....

  16. A Cable-Shaped Lithium Sulfur Battery.

    Science.gov (United States)

    Fang, Xin; Weng, Wei; Ren, Jing; Peng, Huisheng

    2016-01-20

    A carbon nanostructured hybrid fiber is developed by integrating mesoporous carbon and graphene oxide into aligned carbon nanotubes. This hybrid fiber is used as a 1D cathode to fabricate a new cable-shaped lithium-sulfur battery. The fiber cathode exhibits a decent specific capacity and lifespan, which makes the cable-shaped lithium-sulfur battery rank far ahead of other fiber-shaped batteries. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. MVAC Submarine cable, impedance measurements and analysis

    DEFF Research Database (Denmark)

    Arentsen, Martin Trolle; Expethit, Adrian; Pedersen, Morten Virklund

    2017-01-01

    influence the losses. Secondly, cable parameters such as component impedances, positive-, zero-sequence impedances and losses are measured for varying currents and frequencies. Zero sequence is measured for two setups, one with armour grounded, and with armour open to match CIGREs formula assumption......-sequence impedance is found between the measurements and the CIGRÉ formulas. It is concluded that the formulas are not accurate for the specific cable under test....

  18. The analysis of cable forces based on natural frequency

    Science.gov (United States)

    Suangga, Made; Hidayat, Irpan; Juliastuti; Bontan, Darwin Julius

    2017-12-01

    A cable is a flexible structural member that is effective at resisting tensile forces. Cables are used in a variety of structures that employ their unique characteristics to create efficient design tension members. The condition of the cable forces in the cable supported structure is an important indication of judging whether the structure is in good condition. Several methods have been developed to measure on site cable forces. Vibration technique using correlation between natural frequency and cable forces is a simple method to determine in situ cable forces, however the method need accurate information on the boundary condition, cable mass, and cable length. The natural frequency of the cable is determined using FFT (Fast Fourier Transform) Technique to the acceleration record of the cable. Based on the natural frequency obtained, the cable forces then can be determine by analytical or by finite element program. This research is focus on the vibration techniques to determine the cable forces, to understand the physical parameter effect of the cable and also modelling techniques to the natural frequency and cable forces.

  19. Novel powering schemes for pixel and tracking detectors

    CERN Document Server

    Feld, Lutz Werner

    2013-01-01

    Future pixel and tracking systems like the ones foreseen in the upgrade programs of the LHC experiments are very demanding on the power supply systems. An increased amount of power has to be supplied to the front-end electronics at a reduced voltage, through existing cable plants. Novel powering schemes are needed to avoid excessive cable losses. The two schemes under consideration, serial powering and DC-DC conversion, are reviewed. Particular emphasis is put on system integration aspects. As an example, the new CMS pixel system, which will be powered via DC-DC conversion, is presented in more detail. This allows to discuss challenges and solutions for a concrete application while the conclusions should be relevant for other applications as well.

  20. Structural behavior of cable superconductors

    International Nuclear Information System (INIS)

    Becker, H.; Marston, P.

    1983-01-01

    The structural properties of cable superconductor coils, for particle accelerators such as the Tevatron and the CBA (Colliding Beam Accelerator), depend upon direction of loading. For compression perpendicular to the ''flat faces'' of the conductor, the coils exhibit nonlinear, inelastic and time dependent behavior. The same is true for ''inplane'' compression loading perpendicular to the conductor edges. In the lengthwise direction, the coils display tension and compression stress-strain curves typical of structural metals. The loading of primary concern is compression perpendicular to the conductor faces since deformations in that direction can have a major influence on magnetic field quality. However, the coil behavior under that condition is uncertain because of the nonlinear stress strain curve complicated by creep and relaxation at the stress levels induced by preloading and Lorentz forces. Furthermore, the stiffness of the loading fixture appears to influence the data as shown by results from tests run under different conditions at Berkeley, Brookhaven and MIT. The paper displays test data on stress-strain curves for all three loading directions. Results are presented for RT, 77 K and 4 K behavior. Data of various investigators are compared. The applicability of a relatively simple power law between stress and strain is depicted

  1. Environmental assessment of submarine power cables

    Energy Technology Data Exchange (ETDEWEB)

    Isus, Daniel; Martinez, Juan D. [Grupo General Cable Sistemas, S.A., 08560-Manlleu, Barcelona (Spain); Arteche, Amaya; Del Rio, Carmen; Madina, Virginia [Tecnalia Research and Innovation, 20009 San Sebastian (Spain)

    2011-03-15

    Extensive analyses conducted by the European Community revealed that offshore wind energy have relatively benign effects on the marine environment by comparison to other forms of electric power generation [1]. However, the materials employed in offshore wind power farms suffer major changes to be confined to the marine environment at extreme conditions: saline medium, hydrostatic pressure... which can produce an important corrosion effect. This phenomenon can affect on the one hand, to the material from the structural viewpoint and on the other hand, to the marine environment. In this sense, to better understand the environmental impacts of generating electricity from offshore wind energy, this study evaluated the life cycle assessment for some new designs of submarine power cables developed by General Cable. To achieve this goal, three approaches have been carried out: leaching tests, eco-toxicity tests and Life Cycle Assessment (LCA) methodologies. All of them are aimed to obtaining quantitative data for environmental assessment of selected submarine cables. LCA is a method used to assess environmental aspects and potential impacts of a product or activity. LCA does not include financial and social factors, which means that the results of an LCA cannot exclusively form the basis for assessment of a product's sustainability. Leaching tests results allowed to conclude that pH of seawater did not significantly changed by the presence of submarine three-core cables. Although, it was slightly higher in case of broken cable, pH values were nearly equals. Concerning to the heavy metals which could migrate to the aquatic medium, there were significant differences in both scenarios. The leaching of zinc is the major environmental concern during undersea operation of undamaged cables whereas the fully sectioned three-core cable produced the migration of significant quantities of copper and iron apart from the zinc migrated from the galvanized steel. Thus, the tar

  2. Environmental assessment of submarine power cables

    International Nuclear Information System (INIS)

    Isus, Daniel; Martinez, Juan D.; Arteche, Amaya; Del Rio, Carmen; Madina, Virginia

    2011-03-01

    Extensive analyses conducted by the European Community revealed that offshore wind energy have relatively benign effects on the marine environment by comparison to other forms of electric power generation [1]. However, the materials employed in offshore wind power farms suffer major changes to be confined to the marine environment at extreme conditions: saline medium, hydrostatic pressure... which can produce an important corrosion effect. This phenomenon can affect on the one hand, to the material from the structural viewpoint and on the other hand, to the marine environment. In this sense, to better understand the environmental impacts of generating electricity from offshore wind energy, this study evaluated the life cycle assessment for some new designs of submarine power cables developed by General Cable. To achieve this goal, three approaches have been carried out: leaching tests, eco-toxicity tests and Life Cycle Assessment (LCA) methodologies. All of them are aimed to obtaining quantitative data for environmental assessment of selected submarine cables. LCA is a method used to assess environmental aspects and potential impacts of a product or activity. LCA does not include financial and social factors, which means that the results of an LCA cannot exclusively form the basis for assessment of a product's sustainability. Leaching tests results allowed to conclude that pH of seawater did not significantly changed by the presence of submarine three-core cables. Although, it was slightly higher in case of broken cable, pH values were nearly equals. Concerning to the heavy metals which could migrate to the aquatic medium, there were significant differences in both scenarios. The leaching of zinc is the major environmental concern during undersea operation of undamaged cables whereas the fully sectioned three-core cable produced the migration of significant quantities of copper and iron apart from the zinc migrated from the galvanized steel. Thus, the tar

  3. Insulation structure of thermonuclear device

    International Nuclear Information System (INIS)

    Suzuki, Takayuki; Usami, Saburo; Tsukamoto, Hideo; Kikuchi, Mitsuru

    1998-01-01

    The present invention provides an insulating structure of a thermonuclear device, in which insulation materials between toroidal coils are not broken even if superconductive toroidal coils are used. Namely, a tokamak type thermonuclear device of an insulating structure type comprises superconductive toroidal coils for confining plasmas arranged in a circular shape directing the center each at a predetermined angle, and the toroidal coils are insulated from each other. The insulation materials are formed by using a biaxially oriented fiber reinforced plastics. The contact surface of the toroidal coils and the insulating materials are arranged so that they are contact at a woven surface of the fiber reinforced plastics. Either or both of the contact surfaces of the fiber reinforced plastics and the toroidal coils are coated with a high molecular compound having a low friction coefficient. With such a constitution, since the interlayer shearing strength of the biaxially oriented fiber reinforced plastics is about 1/10 of the compression strength, the shearing stress exerted on the insulation material is reduced. Since a static friction coefficient on the contact surface is reduced to provide a structure causing slipping, shearing stress does not exceeds a predetermined limit. As a result, breakage of the insulation materials between the toroidal coils can be prevented. (I.S.)

  4. Plastic Materials for Insulating Applications.

    Science.gov (United States)

    Wang, S. F.; Grossman, S. J.

    1987-01-01

    Discusses the production and use of polymer materials as thermal insulators. Lists several materials that provide varying degrees of insulation. Describes the production of polymer foam and focuses on the major applications of polystyrene foam, polyurethane foam, and polyisocyanurate foam. (TW)

  5. Magnetically self-insulated transformers

    International Nuclear Information System (INIS)

    Novac, B.M.; Smith, I.R.; Brown, J.

    2002-01-01

    Magnetic insulation is the only practicable form of insulation for much equipment used in ultrahigh pulsed-power work, including transmission lines and plasma opening switches. It has not however so far been successfully exploited in the transformers that are necessarily involved, and the first proposed design that appeared more than 30 years ago raised apparently insuperable problems. The two novel arrangements for a magnetically insulated transformer described in this paper overcome the problems faced by the earlier designs and also offer considerable scope for development in a number of important areas. Theoretical justification is given for their insulating properties, and this is confirmed by proof-of-principle results obtained from a small-scale experimental prototype in which magnetic insulation was demonstrated at up to 100 kV. (author)

  6. Development of signal processing electronics for self powered neutron detector signal with built-in on-line insulation monitoring [Paper No.:E3

    International Nuclear Information System (INIS)

    Das, Amitabha; Chaganty, S.P.

    1993-01-01

    Self powered neutron detectors (SPNDs) are employed to monitor in-core neutron flux in nuclear reactors for control, safety and mapping of in-core neutron flux. The d.c. current produced by SPND is converted into a proportional d.c. voltage, which in turn is used for various purposes stated above. This paper describes various features of the SPND amplifier developed in the Electronics Division of Bhabha Atomic Research Centre (BARC). It also outlines the principle of working of on-line monitoring of insulation resistance (IR) of the detector and associated mineral insulated (MI) and soft cables. The amplifier generates an alarm in case of the IR of the detector and the cable assembly falls below an accepted value or the cable is not connected to the amplifier and relieves the operator from periodic and manual checking of each of the individual detectors and ensures the validity of the signal for further processing. (author). 3 figs

  7. The Role of Interfaces in Polyethylene/Metal-Oxide Nanocomposites for Ultrahigh-Voltage Insulating Materials.

    Science.gov (United States)

    Pourrahimi, Amir Masoud; Olsson, Richard T; Hedenqvist, Mikael S

    2018-01-01

    Recent progress in the development of polyethylene/metal-oxide nanocomposites for extruded high-voltage direct-current (HVDC) cables with ultrahigh electric insulation properties is presented. This is a promising technology with the potential of raising the upper voltage limit in today's underground/submarine cables, based on pristine polyethylene, to levels where the loss of energy during electric power transmission becomes low enough to ensure intercontinental electric power transmission. The development of HVDC insulating materials together with the impact of the interface between the particles and the polymer on the nanocomposites electric properties are shown. Important parameters from the atomic to the microlevel, such as interfacial chemistry, interfacial area, and degree of particle dispersion/aggregation, are discussed. This work is placed in perspective with important work by others, and suggested mechanisms for improved insulation using nanoparticles, such as increased charge trap density, adsorption of impurities/ions, and induced particle dipole moments are considered. The effects of the nanoparticles and of their interfacial structures on the mechanical properties and the implications of cavitation on the electric properties are also discussed. Although the main interest in improving the properties of insulating polymers has been on the use of nanoparticles, leading to nanodielectrics, it is pointed out here that larger microscopic hierarchical metal-oxide particles with high surface porosity also impart good insulation properties. The impact of the type of particle and its inherent properties (purity and conductivity) on the nanocomposite dielectric and insulating properties are also discussed based on data obtained by a newly developed technique to directly observe the charge distribution on a nanometer scale in the nanocomposite. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Concepts for evaluation of sound insulation of dwellings - from chaos to consensus?

    DEFF Research Database (Denmark)

    Rasmussen, Birgit; Rindel, Jens Holger

    2005-01-01

    Legal sound insulation requirements have existed more than 50 years in some countries, and single-number quantities for evaluation of sound insulation have existed nearly as long time. However, the concepts have changed considerably over time from simple arithmetic averaging of frequency bands......¬ments and classification schemes revealed significant differences of concepts. The paper summarizes the history of concepts, the disadvantages of the present chaos and the benefits of consensus concerning concepts for airborne and impact sound insulation between dwellings and airborne sound insulation of facades...... with a trend towards light-weight constructions are contradictory and challenging. This calls for exchange of data and experience, implying a need for harmonized concepts, including use of spectrum adaptation terms. The paper will provide input for future discussions in EAA TC-RBA WG4: "Sound insulation...

  9. The experiment study of the thermal insulation of the roof-slab of the main vessel of a LMFBR

    International Nuclear Information System (INIS)

    Wang Zhifeng; Wang Zhou; Yang Xianyong

    1995-01-01

    The effects of composition of insulation, i.e., reflective multi-plate thermal insulator, protecting the roof-slab of the vessel of the LMFBR on the heat transfer performance has been studied experimentally for CEFR. A economical form of the thermal insulation is suggested for CEFR. In addition, the scheme without reflective thermal insulator which has only a forced convection cooling system has been studied experimentally and a formula to calculate the average Nusselt number of the flow channel, which is valuable for CEFR design, has been raised

  10. Excitons in insulators

    International Nuclear Information System (INIS)

    Grasser, R.; Scharmann, A.

    1983-01-01

    This chapter investigates absorption, reflectivity, and intrinsic luminescence spectra of free and/or self-trapped (localized) excitons in alkali halides and rare gas solids. Introduces the concepts underlying the Wannier-Mott and Frenkel exciton models, two extreme pictures of an exciton in crystalline materials. Discusses the theoretical and experimental background; excitons in alkali halides; and excitons in rare gas solids. Shows that the intrinsic optical behavior of wide gap insulators in the range of the fundamental absorption edge is controlled by modified Wannier-Mott excitons. Finds that while that alkali halides only show free and relaxed molecular-like exciton emission, in rare gas crystals luminescence due to free, single and double centered localized excitons is observed. Indicates that the simultaneous existence of free and self-trapped excitons in these solid requires an energy barrier for self-trapping

  11. Ship nuclear power device of cable aging management

    International Nuclear Information System (INIS)

    Wei Hua; Chen Miao; Chen Tao

    2012-01-01

    Cable for marine nuclear power plant continuous delivery of electrical energy. Cable is mostly in the high temperature and strong radiation and harsh working environment, and can not be replaced in the lifetime This should be the cable aging management methods through research, maintenance and repair program to provide a scientific basis. Cable aging management approach for a number of different levels of cable management at different levels, relying on computers and other modern tools, the use of information management database software maintenance of the cable through the science of aging control. Cable Aging Management including the scope of cable aging management, classification management basis and used for different levels of management supervision and implementation of means testing approach. Application of the ship that has the operational management science, both planned maintenance to improve the science, but also improves the efficiency of aging management. This management method can be extended to nuclear power plants of cable aging management. (authors)

  12. Cable condition monitoring in a pressurized water reactor environment

    International Nuclear Information System (INIS)

    Al-Hussaini, T.J.

    1988-01-01

    Oconee Nuclear Station is the first nuclear plant designed, engineered and constructed by Duke Power Company. Even though the accelerated aging method was available to determine the life expectancy of the cable used in the reactor building, no natural aging data was available at that time. In order to be able to verify the condition of the reactor building cable over the life of the plant, an on-going cable monitoring plan was instituted. Various types of cable were selected to be monitored, and they were installed in cable life evaluation circuits in the reactor building. At five year intervals over the life of the plant, cable samples would be removed from these cable life evaluation circuits and tested to determine the effects of the reactor building environment on the integrity of the cable. A review of the cable life evaluation circuits and the results of the evaluation program to date is presented

  13. Characterization of fiber optic cables under large tensile loads

    International Nuclear Information System (INIS)

    Ogle, J.W.; Looney, L.D.; Peterson, R.T.

    1984-01-01

    Fiber optic cables designed for the Nevada Test Site (NTS) have to withstand an unusually harsh environment. Cables have been manufactured under a 6 year old DOE specification that has been slightly modified as the cable requirements are better understood. In order to better understand the cable properties a unique capability has been established at the NTS. Instrumentation has been developed to characterize the transmission properties of 1 km of fiber optic cable placed under a controlled tensile load up to 1500 lbs. The properties measured are cable tension, cable elongation, induced attenuation, attenuation vs. location, fiber strain, bandwidth, and ambient temperature. Preforming these measurements on cables from the two qualified NTS fiber optic cable manufacturers, Siecor and Andrew Corp., led to a new set of specifications

  14. 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.)

  15. Applying Diagnostics to Enhance Cable System Reliability (Cable Diagnostic Focused Initiative, Phase II)

    Energy Technology Data Exchange (ETDEWEB)

    Hartlein, Rick [Georgia Tech Research Corporation (GTRC), Atlanta, GA (United States). National Electric Energy Testing, Research and Applications Center (NEETRAC); Hampton, Nigel [Georgia Tech Research Corporation (GTRC), Atlanta, GA (United States). National Electric Energy Testing, Research and Applications Center (NEETRAC); Perkel, Josh [Georgia Tech Research Corporation (GTRC), Atlanta, GA (United States). National Electric Energy Testing, Research and Applications Center (NEETRAC); Hernandez, JC [Univ. de Los Andes, Merida (Venezuela); Elledge, Stacy [Georgia Tech Research Corporation (GTRC), Atlanta, GA (United States). National Electric Energy Testing, Research and Applications Center (NEETRAC); del Valle, Yamille [Georgia Tech Research Corporation (GTRC), Atlanta, GA (United States). National Electric Energy Testing, Research and Applications Center (NEETRAC); Grimaldo, Jose [Georgia Inst. of Technology, Atlanta, GA (United States). School of Electrical and Computer Engineering; Deku, Kodzo [Georgia Inst. of Technology, Atlanta, GA (United States). George W. Woodruff School of Mechanical Engineering

    2016-02-01

    The Cable Diagnostic Focused Initiative (CDFI) played a significant and powerful role in clarifying the concerns and understanding the benefits of performing diagnostic tests on underground power cable systems. This project focused on the medium and high voltage cable systems used in utility transmission and distribution (T&D) systems. While many of the analysis techniques and interpretations are applicable to diagnostics and cable systems outside of T&D, areas such as generating stations (nuclear, coal, wind, etc.) and other industrial environments were not the focus. Many large utilities in North America now deploy diagnostics or have changed their diagnostic testing approach as a result of this project. Previous to the CDFI, different diagnostic technology providers individually promoted their approach as the “the best” or “the only” means of detecting cable system defects.

  16. Controlling the Optical and Magnetic Properties of Nanostructured Cuprous Oxide Synthesized from Waste Electric Cables

    Science.gov (United States)

    Abdelbasir, S. M.; El-Sheikh, S. M.; Rashad, M. M.; Rayan, D. A.

    2018-03-01

    Cuprous oxide Cu2O nanopowders were purposefully synthesised from waste electric cables (WECs) via a simple precipitation route at room temperature using lactose as a reducing agent. In this regard, dimethyl sulfoxide (DMSO) was first applied as an organic solvent for the dissolution of the cable insulating materials. Several parameters were investigated during dissolution of WECs such as dissolution temperature, time and solid/liquid ratio to determine the dissolution percentage of the insulating materials in DMSO. The morphology and the optical properties of the formed Cu2O particles were investigated using X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), Fourier-transform infrared spectroscopy and UV-visible-near IR spectrophotometer. XRD data confirmed the presence of single crystalline phase of Cu2O nanoparticles. FE-SEM and TEM images revealed spherical, cubic and octahedral shapes with the various particle sizes ranged from 16 to 57 nm depending on the synthesis conditions. A possible mechanism explaining the Cu2O nanostructures formation was proposed. The band gap energies of the Cu2O nanostructures were estimated and the values were located between 1.5 and 2.08 eV. Photoluminescence spectroscopy analysis clearly showed a noticeably blue-shifted emission for the synthesized samples compared to spectrum of the bulk. Eventually, magnetic properties of the synthesized nanoparticles have been measured by vibrating sample magnetometer and the attained results implied that the synthesized particles are weakly ferromagnetic in nature at normal temperature.

  17. FY 2000 research and development of fundamental technologies for AC superconducting power devices. R and D of fundamental technologies for superconducting power cables and faults current limiters, R and D of superconducting magnets for power applications, and study on the total systems and related subjects; 2000 nendo koryu chodendo denryoku kiki kiban gijutsu kenkyu kaihatsu seika hokokusho. Chodendo soden cable kiban gijutsu no kenkyu kaihatsu, chodendo genryuki kiban gijutsu no kenkyu kaihatsu, denryokuyo chodendo magnet no kenkyu kaihatsu, total system nado no kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    The project for research and development of fundamental technologies for AC superconducting power devices has been started, and the FY 2000 results are reported. The R and D of fundamental technologies for superconducting power cables include grasping the mechanical characteristics associated with integration necessary for fabrication of large current capacity and long cables; development of barrier cable materials by various methods; and development of short insulated tubes as cooling technology for long superconducting cables, and grasping its thermal/mechanical characteristics. The R and D of faults current limiters include introduction of the unit for superconducting film fabrication, determination of the structures and layouts for large currents, and improvement of performance of each device for high voltages. R and D of superconducting magnets for power applications include grasping the fundamental characteristics of insulation at cryogenic temperature, completion of the insulation designs for high voltage/current lead bushing, and development of prototype sub-cooled nitrogen cooling unit for cooling each AC power device. Study on the total systems and related subjects include analysis for stabilization of the group model systems, to confirm improved voltage stability when the superconducting cable is in service. (NEDO)

  18. Improving regulatory practices through the OECD-NEA Stress Corrosion Cracking and Cable Ageing Project (SCAP)

    International Nuclear Information System (INIS)

    Yamamoto, A.; Huerta, A.; Sekimura, N.; Gott, K.; Koshy, T.

    2012-01-01

    For regulatory authorities, it is important to verify the adequacy of ageing management methods applied by the licensees, based on reliable technical evidence. In order to achieve that goal, 14 NEA member countries joined the SCAP (Project) in 2006 to share knowledge and three more countries joined during the course of the project. The project focused on two important safety issues, the stress corrosion cracking (SCC) and the degradation of cable insulation, due to their relevance for plant ageing assessments and their implication on inspection practices. The commendable practices identified in the project are intended to strengthen technical approaches to optimize ageing management in the areas of SCC and cable ageing. The SCAP SCC and Cable data- and knowledge bases provided extensive information to benefit all stakeholders in designing, constructing, operating and regulating Nuclear Power Plants and also provide commendable practices applicable to new reactors. The paper presents the product of SCAP work resulting from 4 years of technical interactions and shared knowledge from all participants from June 2006 to June 2010. (author)

  19. Cavitation as a Precursor to Breakdown of Mass-Impregnated HVDC Cables

    Energy Technology Data Exchange (ETDEWEB)

    Evenset, Gunnar

    1999-09-01

    Thermal cycling has proven to be a critical test for mass-impregnated HVDC cables. The dielectric strength of the insulation is significantly reduced during the first part of the cooling. This decrease of the dielectric strength limits the development of mass-impregnated cables for higher operating voltages and higher power transfer capacities. The decrease of the dielectric strength during cooling has been assumed to be caused by formation of cavities in the mass because the thermal contraction of the mass is larger than that of the paper. Cavities have previously been observed in thermally cycled cables, but their actual formation and growth have not been studied. The fact that breakdown usually occurs a few hours into the cooling period indicates that the dynamics of the growth is important. This work studies the dynamic phenomena occurring in mass-impregnated cables during thermal cycling. In experiments on a system of mass and insulating paper, cavities were observed near the paper surface, probably caused by heterogeneous nucleation. Knowing the tensile stress at cavity formation is important because it controls the size of the cavities and the distance between independently formed cavities in a cable insulation. A test cell was designed to investigate cavitation in models of lapped insulation. The formation, growth and collapse of the cavities could be visually observed while the insulation was electrically stressed and partial discharges were measured. The first cavity generally formed in one of the butt gaps and grew both along the butt gap and into the mass layers between the papers towards adjacent butt gaps. When the cavity between the papers grew into an adjacent butt gap, the gas/vapour filled channel connecting the butt gaps was closed. In this way, one cavity grew into several butt gaps. The extent of cavities between the papers was observed to depend on the interfacial pressure. Considerable less tension is required to suck the menisci of a cavity

  20. Young's moduli of cables for high field superconductive dipole magnet

    International Nuclear Information System (INIS)

    Yamada, Shunji; Shintomi, Takakazu.

    1983-01-01

    Superconductive dipole magnets for big accelerators are subjected to enormous electro-magnetic force, when they are operated with high field such as 10 Tesla. They should be constructed by means of superconductive cables, which have high Young's modulus, to obtain good performance. To develop such cables we measured the Young's moduli of cables for practical use of accelerator magnets. They are monolithic and compacted strand cables. We measured also Young's moduli of monolithic copper and brass cables for comparison. The obtained data showed the Young's moduli of 35 and 15 GPa for the monolithic and compacted strand cables, respectively. (author)